Index: vendor/zstd/dist/circle.yml =================================================================== --- vendor/zstd/dist/circle.yml (revision 339613) +++ vendor/zstd/dist/circle.yml (nonexistent) @@ -1,63 +0,0 @@ -dependencies: - override: - - sudo dpkg --add-architecture i386 - - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test; sudo apt-get -y -qq update - - sudo apt-get -y install gcc-powerpc-linux-gnu gcc-arm-linux-gnueabi libc6-dev-armel-cross gcc-aarch64-linux-gnu libc6-dev-arm64-cross - -test: - override: - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then cc -v; CFLAGS="-O0 -Werror" make all && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make gnu90build && make clean; fi - : - parallel: true - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make c99build && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make gnu99build && make clean; fi - : - parallel: true - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make c11build && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make ppc64build && make clean; fi - : - parallel: true - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make aarch64build && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make ppcbuild && make clean; fi - : - parallel: true - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make -j regressiontest && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make armbuild && make clean; fi - : - parallel: true - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make shortest && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make -C tests test-legacy test-longmatch test-symbols && make clean; fi - : - parallel: true - - ? | - if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make cxxtest && make clean; fi && - if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make -C lib libzstd-nomt && make clean; fi - : - parallel: true - - post: - - echo Circle CI tests finished - - # Longer tests - #- make -C tests test-zstd-nolegacy && make clean - #- pyenv global 3.4.4; make -C tests versionsTest && make clean - #- make zlibwrapper && make clean - #- gcc -v; make -C tests test32 MOREFLAGS="-I/usr/include/x86_64-linux-gnu" && make clean - #- make uasan && make clean - #- make asan32 && make clean - #- make -C tests test32 CC=clang MOREFLAGS="-g -fsanitize=address -I/usr/include/x86_64-linux-gnu" - # Valgrind tests - #- CFLAGS="-O1 -g" make -C zlibWrapper valgrindTest && make clean - #- make -C tests valgrindTest && make clean - # ARM, AArch64, PowerPC, PowerPC64 tests - #- make ppctest && make clean - #- make ppc64test && make clean - #- make armtest && make clean - #- make aarch64test && make clean Index: vendor/zstd/dist/.gitattributes =================================================================== --- vendor/zstd/dist/.gitattributes (revision 339613) +++ vendor/zstd/dist/.gitattributes (revision 339614) @@ -1,24 +1,21 @@ # Set the default behavior * text eol=lf # Explicitly declare source files *.c text eol=lf *.h text eol=lf # Denote files that should not be modified. *.odt binary *.png binary # Visual Studio *.sln text eol=crlf *.vcxproj* text eol=crlf *.vcproj* text eol=crlf *.suo binary *.rc text eol=crlf # Windows *.bat text eol=crlf *.cmd text eol=crlf - -# .travis.yml merging -.travis.yml merge=ours Index: vendor/zstd/dist/CODE_OF_CONDUCT.md =================================================================== --- vendor/zstd/dist/CODE_OF_CONDUCT.md (nonexistent) +++ vendor/zstd/dist/CODE_OF_CONDUCT.md (revision 339614) @@ -0,0 +1,5 @@ +# Code of Conduct + +Facebook has adopted a Code of Conduct that we expect project participants to adhere to. +Please read the [full text](https://code.fb.com/codeofconduct/) +so that you can understand what actions will and will not be tolerated. Index: vendor/zstd/dist/Makefile =================================================================== --- vendor/zstd/dist/Makefile (revision 339613) +++ vendor/zstd/dist/Makefile (revision 339614) @@ -1,362 +1,390 @@ # ################################################################ # Copyright (c) 2015-present, Yann Collet, Facebook, Inc. # All rights reserved. # # This source code is licensed under both the BSD-style license (found in the # LICENSE file in the root directory of this source tree) and the GPLv2 (found # in the COPYING file in the root directory of this source tree). # ################################################################ PRGDIR = programs ZSTDDIR = lib BUILDIR = build ZWRAPDIR = zlibWrapper TESTDIR = tests FUZZDIR = $(TESTDIR)/fuzz # Define nul output VOID = /dev/null ifneq (,$(filter Windows%,$(OS))) EXT =.exe else EXT = endif +## default: Build lib-release and zstd-release .PHONY: default default: lib-release zstd-release .PHONY: all -all: | allmost examples manual contrib +all: allmost examples manual contrib .PHONY: allmost -allmost: allzstd - $(MAKE) -C $(ZWRAPDIR) all +allmost: allzstd zlibwrapper -#skip zwrapper, can't build that on alternate architectures without the proper zlib installed +# skip zwrapper, can't build that on alternate architectures without the proper zlib installed .PHONY: allzstd -allzstd: - $(MAKE) -C $(ZSTDDIR) all +allzstd: lib $(MAKE) -C $(PRGDIR) all $(MAKE) -C $(TESTDIR) all .PHONY: all32 all32: $(MAKE) -C $(PRGDIR) zstd32 $(MAKE) -C $(TESTDIR) all32 -.PHONY: lib -lib: +.PHONY: lib lib-release libzstd.a +lib lib-release : @$(MAKE) -C $(ZSTDDIR) $@ -.PHONY: lib-release -lib-release: - @$(MAKE) -C $(ZSTDDIR) - -.PHONY: zstd -zstd: +.PHONY: zstd zstd-release +zstd zstd-release: @$(MAKE) -C $(PRGDIR) $@ cp $(PRGDIR)/zstd$(EXT) . -.PHONY: zstd-release -zstd-release: - @$(MAKE) -C $(PRGDIR) - cp $(PRGDIR)/zstd$(EXT) . - .PHONY: zstdmt zstdmt: @$(MAKE) -C $(PRGDIR) $@ cp $(PRGDIR)/zstd$(EXT) ./zstdmt$(EXT) .PHONY: zlibwrapper -zlibwrapper: - $(MAKE) -C $(ZWRAPDIR) test +zlibwrapper: lib + $(MAKE) -C $(ZWRAPDIR) all +## test: run long-duration tests .PHONY: test +test: MOREFLAGS += -g -DDEBUGLEVEL=1 -Werror test: - $(MAKE) -C $(PRGDIR) allVariants MOREFLAGS+="-g -DZSTD_DEBUG=1" + MOREFLAGS="$(MOREFLAGS)" $(MAKE) -j -C $(PRGDIR) allVariants $(MAKE) -C $(TESTDIR) $@ +## shortest: same as `make check` .PHONY: shortest shortest: $(MAKE) -C $(TESTDIR) $@ +## check: run basic tests for `zstd` cli .PHONY: check check: shortest +## examples: build all examples in `/examples` directory .PHONY: examples -examples: +examples: lib CPPFLAGS=-I../lib LDFLAGS=-L../lib $(MAKE) -C examples/ all +## manual: generate API documentation in html format .PHONY: manual manual: $(MAKE) -C contrib/gen_html $@ +## man: generate man page +.PHONY: man +man: + $(MAKE) -C programs $@ + +## contrib: build all supported projects in `/contrib` directory .PHONY: contrib contrib: lib $(MAKE) -C contrib/pzstd all $(MAKE) -C contrib/seekable_format/examples all $(MAKE) -C contrib/adaptive-compression all + $(MAKE) -C contrib/largeNbDicts all .PHONY: cleanTabs cleanTabs: cd contrib; ./cleanTabs .PHONY: clean clean: @$(MAKE) -C $(ZSTDDIR) $@ > $(VOID) @$(MAKE) -C $(PRGDIR) $@ > $(VOID) @$(MAKE) -C $(TESTDIR) $@ > $(VOID) @$(MAKE) -C $(ZWRAPDIR) $@ > $(VOID) @$(MAKE) -C examples/ $@ > $(VOID) @$(MAKE) -C contrib/gen_html $@ > $(VOID) @$(MAKE) -C contrib/pzstd $@ > $(VOID) @$(MAKE) -C contrib/seekable_format/examples $@ > $(VOID) @$(MAKE) -C contrib/adaptive-compression $@ > $(VOID) + @$(MAKE) -C contrib/largeNbDicts $@ > $(VOID) @$(RM) zstd$(EXT) zstdmt$(EXT) tmp* @$(RM) -r lz4 @echo Cleaning completed #------------------------------------------------------------------------------ -# make install is validated only for Linux, OSX, Hurd and some BSD targets +# make install is validated only for Linux, macOS, Hurd and some BSD targets #------------------------------------------------------------------------------ -ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU FreeBSD DragonFly NetBSD MSYS_NT)) +ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD DragonFly NetBSD MSYS_NT Haiku)) HOST_OS = POSIX -CMAKE_PARAMS = -DZSTD_BUILD_CONTRIB:BOOL=ON -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON -DZSTD_ZLIB_SUPPORT:BOOL=ON -DZSTD_LZMA_SUPPORT:BOOL=ON +CMAKE_PARAMS = -DZSTD_BUILD_CONTRIB:BOOL=ON -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON -DZSTD_ZLIB_SUPPORT:BOOL=ON -DZSTD_LZMA_SUPPORT:BOOL=ON -DCMAKE_BUILD_TYPE=Release +EGREP = egrep --color=never + +# Print a two column output of targets and their description. To add a target description, put a +# comment in the Makefile with the format "## : ". For example: +# +## list: Print all targets and their descriptions (if provided) .PHONY: list list: - @$(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | egrep -v -e '^[^[:alnum:]]' -e '^$@$$' | xargs + @TARGETS=$$($(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null \ + | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' \ + | $(EGREP) -v -e '^[^[:alnum:]]' | sort); \ + { \ + printf "Target Name\tDescription\n"; \ + printf "%0.s-" {1..16}; printf "\t"; printf "%0.s-" {1..40}; printf "\n"; \ + for target in $$TARGETS; do \ + line=$$($(EGREP) "^##[[:space:]]+$$target:" $(lastword $(MAKEFILE_LIST))); \ + description=$$(echo $$line | awk '{i=index($$0,":"); print substr($$0,i+1)}' | xargs); \ + printf "$$target\t$$description\n"; \ + done \ + } | column -t -s $$'\t' .PHONY: install clangtest armtest usan asan uasan install: @$(MAKE) -C $(ZSTDDIR) $@ @$(MAKE) -C $(PRGDIR) $@ .PHONY: uninstall uninstall: @$(MAKE) -C $(ZSTDDIR) $@ @$(MAKE) -C $(PRGDIR) $@ .PHONY: travis-install travis-install: $(MAKE) install PREFIX=~/install_test_dir .PHONY: gcc5build gcc5build: clean gcc-5 -v CC=gcc-5 $(MAKE) all MOREFLAGS="-Werror" .PHONY: gcc6build gcc6build: clean gcc-6 -v CC=gcc-6 $(MAKE) all MOREFLAGS="-Werror" .PHONY: gcc7build gcc7build: clean gcc-7 -v CC=gcc-7 $(MAKE) all MOREFLAGS="-Werror" .PHONY: clangbuild clangbuild: clean clang -v CXX=clang++ CC=clang $(MAKE) all MOREFLAGS="-Werror -Wconversion -Wno-sign-conversion -Wdocumentation" m32build: clean gcc -v $(MAKE) all32 armbuild: clean CC=arm-linux-gnueabi-gcc CFLAGS="-Werror" $(MAKE) allzstd aarch64build: clean CC=aarch64-linux-gnu-gcc CFLAGS="-Werror" $(MAKE) allzstd ppcbuild: clean CC=powerpc-linux-gnu-gcc CFLAGS="-m32 -Wno-attributes -Werror" $(MAKE) allzstd ppc64build: clean CC=powerpc-linux-gnu-gcc CFLAGS="-m64 -Werror" $(MAKE) allzstd armfuzz: clean CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest aarch64fuzz: clean + ld -v CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest ppcfuzz: clean CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest ppc64fuzz: clean CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest .PHONY: cxxtest cxxtest: CXXFLAGS += -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror cxxtest: clean $(MAKE) -C $(PRGDIR) all CC="$(CXX) -Wno-deprecated" CFLAGS="$(CXXFLAGS)" # adding -Wno-deprecated to avoid clang++ warning on dealing with C files directly gcc5test: clean gcc-5 -v $(MAKE) all CC=gcc-5 MOREFLAGS="-Werror" gcc6test: clean gcc-6 -v $(MAKE) all CC=gcc-6 MOREFLAGS="-Werror" clangtest: clean clang -v - $(MAKE) all CXX=clang-++ CC=clang MOREFLAGS="-Werror -Wconversion -Wno-sign-conversion -Wdocumentation" + $(MAKE) all CXX=clang++ CC=clang MOREFLAGS="-Werror -Wconversion -Wno-sign-conversion -Wdocumentation" armtest: clean $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static ZSTDRTTEST= MOREFLAGS="-Werror -static" FUZZER_FLAGS=--no-big-tests aarch64test: $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static ZSTDRTTEST= MOREFLAGS="-Werror -static" FUZZER_FLAGS=--no-big-tests ppctest: clean $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc-static ZSTDRTTEST= MOREFLAGS="-Werror -Wno-attributes -static" FUZZER_FLAGS=--no-big-tests ppc64test: clean $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static ZSTDRTTEST= MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests arm-ppc-compilation: $(MAKE) -C $(PRGDIR) clean zstd CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static ZSTDRTTEST= MOREFLAGS="-Werror -static" $(MAKE) -C $(PRGDIR) clean zstd CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static ZSTDRTTEST= MOREFLAGS="-Werror -static" $(MAKE) -C $(PRGDIR) clean zstd CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc-static ZSTDRTTEST= MOREFLAGS="-Werror -Wno-attributes -static" $(MAKE) -C $(PRGDIR) clean zstd CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static ZSTDRTTEST= MOREFLAGS="-m64 -static" regressiontest: $(MAKE) -C $(FUZZDIR) regressiontest uasanregressiontest: $(MAKE) -C $(FUZZDIR) regressiontest CC=clang CXX=clang++ CFLAGS="-O3 -fsanitize=address,undefined" CXXFLAGS="-O3 -fsanitize=address,undefined" msanregressiontest: $(MAKE) -C $(FUZZDIR) regressiontest CC=clang CXX=clang++ CFLAGS="-O3 -fsanitize=memory" CXXFLAGS="-O3 -fsanitize=memory" # run UBsan with -fsanitize-recover=signed-integer-overflow # due to a bug in UBsan when doing pointer subtraction # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63303 usan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=undefined -Werror" asan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fsanitize=address -Werror" asan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=address -Werror" $(MAKE) -C $(TESTDIR) $* msan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fsanitize=memory -fno-omit-frame-pointer -Werror" HAVE_LZMA=0 # datagen.c fails this test for no obvious reason msan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=memory -fno-omit-frame-pointer -Werror" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) HAVE_LZMA=0 $* asan32: clean $(MAKE) -C $(TESTDIR) test32 CC=clang MOREFLAGS="-g -fsanitize=address" uasan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=address,undefined -Werror" uasan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=address,undefined -Werror" $(MAKE) -C $(TESTDIR) $* tsan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=thread -Werror" $(MAKE) -C $(TESTDIR) $* FUZZER_FLAGS=--no-big-tests apt-install: sudo apt-get -yq --no-install-suggests --no-install-recommends --force-yes install $(APT_PACKAGES) apt-add-repo: sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test sudo apt-get update -y -qq ppcinstall: APT_PACKAGES="qemu-system-ppc qemu-user-static gcc-powerpc-linux-gnu" $(MAKE) apt-install arminstall: APT_PACKAGES="qemu-system-arm qemu-user-static gcc-arm-linux-gnueabi libc6-dev-armel-cross gcc-aarch64-linux-gnu libc6-dev-arm64-cross" $(MAKE) apt-install valgrindinstall: APT_PACKAGES="valgrind" $(MAKE) apt-install libc6install: APT_PACKAGES="libc6-dev-i386 gcc-multilib" $(MAKE) apt-install gcc6install: apt-add-repo APT_PACKAGES="libc6-dev-i386 gcc-multilib gcc-6 gcc-6-multilib" $(MAKE) apt-install gcc7install: apt-add-repo APT_PACKAGES="libc6-dev-i386 gcc-multilib gcc-7 gcc-7-multilib" $(MAKE) apt-install +gcc8install: apt-add-repo + APT_PACKAGES="libc6-dev-i386 gcc-multilib gcc-8 gcc-8-multilib" $(MAKE) apt-install + gpp6install: apt-add-repo APT_PACKAGES="libc6-dev-i386 g++-multilib gcc-6 g++-6 g++-6-multilib" $(MAKE) apt-install clang38install: APT_PACKAGES="clang-3.8" $(MAKE) apt-install # Ubuntu 14.04 ships a too-old lz4 lz4install: [ -e lz4 ] || git clone https://github.com/lz4/lz4 && sudo $(MAKE) -C lz4 install endif ifneq (,$(filter MSYS%,$(shell uname))) HOST_OS = MSYS CMAKE_PARAMS = -G"MSYS Makefiles" -DZSTD_MULTITHREAD_SUPPORT:BOOL=OFF -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON endif #------------------------------------------------------------------------ # target specific tests #------------------------------------------------------------------------ ifneq (,$(filter $(HOST_OS),MSYS POSIX)) cmakebuild: cmake --version $(RM) -r $(BUILDIR)/cmake/build mkdir $(BUILDIR)/cmake/build cd $(BUILDIR)/cmake/build ; cmake -DCMAKE_INSTALL_PREFIX:PATH=~/install_test_dir $(CMAKE_PARAMS) .. ; $(MAKE) install ; $(MAKE) uninstall c90build: clean $(CC) -v - CFLAGS="-std=c90" $(MAKE) allmost # will fail, due to missing support for `long long` + CFLAGS="-std=c90 -Werror" $(MAKE) allmost # will fail, due to missing support for `long long` gnu90build: clean $(CC) -v - CFLAGS="-std=gnu90" $(MAKE) allmost + CFLAGS="-std=gnu90 -Werror" $(MAKE) allmost c99build: clean $(CC) -v - CFLAGS="-std=c99" $(MAKE) allmost + CFLAGS="-std=c99 -Werror" $(MAKE) allmost gnu99build: clean $(CC) -v - CFLAGS="-std=gnu99" $(MAKE) allmost + CFLAGS="-std=gnu99 -Werror" $(MAKE) allmost c11build: clean $(CC) -v - CFLAGS="-std=c11" $(MAKE) allmost + CFLAGS="-std=c11 -Werror" $(MAKE) allmost bmix64build: clean $(CC) -v CFLAGS="-O3 -mbmi -Werror" $(MAKE) -C $(TESTDIR) test bmix32build: clean $(CC) -v CFLAGS="-O3 -mbmi -mx32 -Werror" $(MAKE) -C $(TESTDIR) test bmi32build: clean $(CC) -v CFLAGS="-O3 -mbmi -m32 -Werror" $(MAKE) -C $(TESTDIR) test -staticAnalyze: clean +# static analyzer test uses clang's scan-build +# does not analyze zlibWrapper, due to detected issues in zlib source code +staticAnalyze: SCANBUILD ?= scan-build +staticAnalyze: $(CC) -v - CPPFLAGS=-g scan-build --status-bugs -v $(MAKE) all + CC=$(CC) CPPFLAGS=-g $(SCANBUILD) --status-bugs -v $(MAKE) allzstd examples contrib endif Index: vendor/zstd/dist/NEWS =================================================================== --- vendor/zstd/dist/NEWS (revision 339613) +++ vendor/zstd/dist/NEWS (revision 339614) @@ -1,366 +1,402 @@ +v1.3.7 +perf: slightly better decompression speed on clang (depending on hardware target) +fix : performance of dictionary compression for small input < 4 KB at levels 9 and 10 +build: no longer build backtrace by default in release mode; restrict further automatic mode +build: control backtrace support through build macro BACKTRACE +misc: added man pages for zstdless and zstdgrep, by @samrussell + +v1.3.6 +perf: much faster dictionary builder, by @jenniferliu +perf: faster dictionary compression on small data when using multiple contexts, by @felixhandte +perf: faster dictionary decompression when using a very large number of dictionaries simultaneously +cli : fix : does no longer overwrite destination when source does not exist (#1082) +cli : new command --adapt, for automatic compression level adaptation +api : fix : block api can be streamed with > 4 GB, reported by @catid +api : reduced ZSTD_DDict size by 2 KB +api : minimum negative compression level is defined, and can be queried using ZSTD_minCLevel(). +build: support Haiku target, by @korli +build: Read Legacy format is limited to v0.5+ by default. Can be changed at compile time with macro ZSTD_LEGACY_SUPPORT. +doc : zstd_compression_format.md updated to match wording in IETF RFC 8478 +misc: tests/paramgrill, a parameter optimizer, by @GeorgeLu97 + +v1.3.5 +perf: much faster dictionary compression, by @felixhandte +perf: small quality improvement for dictionary generation, by @terrelln +perf: slightly improved high compression levels (notably level 19) +mem : automatic memory release for long duration contexts +cli : fix : overlapLog can be manually set +cli : fix : decoding invalid lz4 frames +api : fix : performance degradation for dictionary compression when using advanced API, by @terrelln +api : change : clarify ZSTD_CCtx_reset() vs ZSTD_CCtx_resetParameters(), by @terrelln +build: select custom libzstd scope through control macros, by @GeorgeLu97 +build: OpenBSD patch, by @bket +build: make and make all are compatible with -j +doc : clarify zstd_compression_format.md, updated for IETF RFC process +misc: pzstd compatible with reproducible compilation, by @lamby + v1.3.4 perf: faster speed (especially decoding speed) on recent cpus (haswell+) perf: much better performance associating --long with multi-threading, by @terrelln perf: better compression at levels 13-15 cli : asynchronous compression by default, for faster experience (use --single-thread for former behavior) cli : smoother status report in multi-threading mode cli : added command --fast=#, for faster compression modes cli : fix crash when not overwriting existing files, by Pádraig Brady (@pixelb) api : `nbThreads` becomes `nbWorkers` : 1 triggers asynchronous mode api : compression levels can be negative, for even more speed api : ZSTD_getFrameProgression() : get precise progress status of ZSTDMT anytime api : ZSTDMT can accept new compression parameters during compression api : implemented all advanced dictionary decompression prototypes build: improved meson recipe, by Shawn Landden (@shawnl) build: VS2017 scripts, by @HaydnTrigg misc: all /contrib projects fixed misc: added /contrib/docker script by @gyscos v1.3.3 perf: faster zstd_opt strategy (levels 16-19) fix : bug #944 : multithreading with shared ditionary and large data, reported by @gsliepen cli : fix : content size written in header by default cli : fix : improved LZ4 format support, by @felixhandte cli : new : hidden command `-S`, to benchmark multiple files while generating one result per file api : fix : support large skippable frames, by @terrelln api : fix : streaming interface was adding a useless 3-bytes null block to small frames api : change : when setting `pledgedSrcSize`, use `ZSTD_CONTENTSIZE_UNKNOWN` macro value to mean "unknown" build: fix : compilation under rhel6 and centos6, reported by @pixelb build: added `check` target v1.3.2 new : long range mode, using --long command, by Stella Lau (@stellamplau) new : ability to generate and decode magicless frames (#591) changed : maximum nb of threads reduced to 200, to avoid address space exhaustion in 32-bits mode fix : multi-threading compression works with custom allocators fix : ZSTD_sizeof_CStream() was over-evaluating memory usage fix : a rare compression bug when compression generates very large distances and bunch of other conditions (only possible at --ultra -22) fix : 32-bits build can now decode large offsets (levels 21+) cli : added LZ4 frame support by default, by Felix Handte (@felixhandte) cli : improved --list output cli : new : can split input file for dictionary training, using command -B# cli : new : clean operation artefact on Ctrl-C interruption cli : fix : do not change /dev/null permissions when using command -t with root access, reported by @mike155 (#851) cli : fix : write file size in header in multiple-files mode api : added macro ZSTD_COMPRESSBOUND() for static allocation api : experimental : new advanced decompression API api : fix : sizeof_CCtx() used to over-estimate build: fix : no-multithread variant compiles without pool.c dependency, reported by Mitchell Blank Jr (@mitchblank) (#819) build: better compatibility with reproducible builds, by Bernhard M. Wiedemann (@bmwiedemann) (#818) example : added streaming_memory_usage license : changed /examples license to BSD + GPLv2 license : fix a few header files to reflect new license (#825) v1.3.1 New license : BSD + GPLv2 perf: substantially decreased memory usage in Multi-threading mode, thanks to reports by Tino Reichardt (@mcmilk) perf: Multi-threading supports up to 256 threads. Cap at 256 when more are requested (#760) cli : improved and fixed --list command, by @ib (#772) cli : command -vV to list supported formats, by @ib (#771) build : fixed binary variants, reported by @svenha (#788) build : fix Visual compilation for non x86/x64 targets, reported by Greg Slazinski (@GregSlazinski) (#718) API exp : breaking change : ZSTD_getframeHeader() provides more information API exp : breaking change : pinned down values of error codes doc : fixed huffman example, by Ulrich Kunitz (@ulikunitz) new : contrib/adaptive-compression, I/O driven compression strength, by Paul Cruz (@paulcruz74) new : contrib/long_distance_matching, statistics by Stella Lau (@stellamplau) updated : contrib/linux-kernel, by Nick Terrell (@terrelln) v1.3.0 cli : new : `--list` command, by Paul Cruz cli : changed : xz/lzma support enabled by default cli : changed : `-t *` continue processing list after a decompression error API : added : ZSTD_versionString() API : promoted to stable status : ZSTD_getFrameContentSize(), by Sean Purcell API exp : new advanced API : ZSTD_compress_generic(), ZSTD_CCtx_setParameter() API exp : new : API for static or external allocation : ZSTD_initStatic?Ctx() API exp : added : ZSTD_decompressBegin_usingDDict(), requested by Guy Riddle (#700) API exp : clarified memory estimation / measurement functions. API exp : changed : strongest strategy renamed ZSTD_btultra, fastest strategy ZSTD_fast set to 1 tools : decodecorpus can generate random dictionary-compressed samples, by Paul Cruz new : contrib/seekable_format, demo and API, by Sean Purcell changed : contrib/linux-kernel, updated version and license, by Nick Terrell v1.2.0 cli : changed : Multithreading enabled by default (use target zstd-nomt or HAVE_THREAD=0 to disable) cli : new : command -T0 means "detect and use nb of cores", by Sean Purcell cli : new : zstdmt symlink hardwired to `zstd -T0` cli : new : command --threads=# (#671) cli : changed : cover dictionary builder by default, for improved quality, by Nick Terrell cli : new : commands --train-cover and --train-legacy, to select dictionary algorithm and parameters cli : experimental targets `zstd4` and `xzstd4`, with support for lz4 format, by Sean Purcell cli : fix : does not output compressed data on console cli : fix : ignore symbolic links unless --force specified, API : breaking change : ZSTD_createCDict_advanced(), only use compressionParameters as argument API : added : prototypes ZSTD_*_usingCDict_advanced(), for direct control over frameParameters. API : improved: ZSTDMT_compressCCtx() reduced memory usage API : fix : ZSTDMT_compressCCtx() now provides srcSize in header (#634) API : fix : src size stored in frame header is controlled at end of frame API : fix : enforced consistent rules for pledgedSrcSize==0 (#641) API : fix : error code "GENERIC" replaced by "dstSizeTooSmall" when appropriate build: improved cmake script, by @Majlen build: enabled Multi-threading support for *BSD, by Baptiste Daroussin tools: updated Paramgrill. Command -O# provides best parameters for sample and speed target. new : contrib/linux-kernel version, by Nick Terrell v1.1.4 cli : new : can compress in *.gz format, using --format=gzip command, by Przemyslaw Skibinski cli : new : advanced benchmark command --priority=rt cli : fix : write on sparse-enabled file systems in 32-bits mode, by @ds77 cli : fix : --rm remains silent when input is stdin cli : experimental : xzstd, with support for xz/lzma decoding, by Przemyslaw Skibinski speed : improved decompression speed in streaming mode for single shot scenarios (+5%) memory: DDict (decompression dictionary) memory usage down from 150 KB to 20 KB arch: 32-bits variant able to generate and decode very long matches (>32 MB), by Sean Purcell API : new : ZSTD_findFrameCompressedSize(), ZSTD_getFrameContentSize(), ZSTD_findDecompressedSize() API : changed : dropped support of legacy versions <= v0.3 (can be changed by modifying ZSTD_LEGACY_SUPPORT value) build : new: meson build system in contrib/meson, by Dima Krasner build : improved cmake script, by @Majlen build : added -Wformat-security flag, as recommended by Padraig Brady doc : new : educational decoder, by Sean Purcell v1.1.3 cli : zstd can decompress .gz files (can be disabled with `make zstd-nogz` or `make HAVE_ZLIB=0`) cli : new : experimental target `make zstdmt`, with multi-threading support cli : new : improved dictionary builder "cover" (experimental), by Nick Terrell, based on prior work by Giuseppe Ottaviano. cli : new : advanced commands for detailed parameters, by Przemyslaw Skibinski cli : fix zstdless on Mac OS-X, by Andrew Janke cli : fix #232 "compress non-files" dictBuilder : improved dictionary generation quality, thanks to Nick Terrell API : new : lib/compress/ZSTDMT_compress.h multithreading API (experimental) API : new : ZSTD_create?Dict_byReference(), requested by Bartosz Taudul API : new : ZDICT_finalizeDictionary() API : fix : ZSTD_initCStream_usingCDict() properly writes dictID into frame header, by Gregory Szorc (#511) API : fix : all symbols properly exposed in libzstd, by Nick Terrell build : support for Solaris target, by Przemyslaw Skibinski doc : clarified specification, by Sean Purcell v1.1.2 API : streaming : decompression : changed : automatic implicit reset when chain-decoding new frames without init API : experimental : added : dictID retrieval functions, and ZSTD_initCStream_srcSize() API : zbuff : changed : prototypes now generate deprecation warnings lib : improved : faster decompression speed at ultra compression settings and 32-bits mode lib : changed : only public ZSTD_ symbols are now exposed lib : changed : reduced usage of stack memory lib : fixed : several corner case bugs, by Nick Terrell cli : new : gzstd, experimental version able to decode .gz files, by Przemyslaw Skibinski cli : new : preserve file attributes cli : new : added zstdless and zstdgrep tools cli : fixed : status displays total amount decoded, even for file consisting of multiple frames (like pzstd) cli : fixed : zstdcat zlib_wrapper : added support for gz* functions, by Przemyslaw Skibinski install : better compatibility with FreeBSD, by Dimitry Andric source tree : changed : zbuff source files moved to lib/deprecated v1.1.1 New : command -M#, --memory=, --memlimit=, --memlimit-decompress= to limit allowed memory consumption New : doc/zstd_manual.html, by Przemyslaw Skibinski Improved : slightly better compression ratio at --ultra levels (>= 20) Improved : better memory usage when using streaming compression API, thanks to @Rogier-5 report Added : API : ZSTD_initCStream_usingCDict(), ZSTD_initDStream_usingDDict() (experimental section) Added : example/multiple_streaming_compression.c Changed : zstd_errors.h is now installed within /include (and replaces errors_public.h) Updated man page Fixed : zstd-small, zstd-compress and zstd-decompress compilation targets v1.1.0 New : contrib/pzstd, parallel version of zstd, by Nick Terrell added : NetBSD install target (#338) Improved : speed for batches of small files Improved : speed of zlib wrapper, by Przemyslaw Skibinski Changed : libzstd on Windows supports legacy formats, by Christophe Chevalier Fixed : CLI -d output to stdout by default when input is stdin (#322) Fixed : CLI correctly detects console on Mac OS-X Fixed : CLI supports recursive mode `-r` on Mac OS-X Fixed : Legacy decoders use unified error codes, reported by benrg (#341), fixed by Przemyslaw Skibinski Fixed : compatibility with OpenBSD, reported by Juan Francisco Cantero Hurtado (#319) Fixed : compatibility with Hurd, by Przemyslaw Skibinski (#365) Fixed : zstd-pgo, reported by octoploid (#329) v1.0.0 Change Licensing, all project is now BSD, Copyright Facebook Small decompression speed improvement API : Streaming API supports legacy format API : ZDICT_getDictID(), ZSTD_sizeof_{CCtx, DCtx, CStream, DStream}(), ZSTD_setDStreamParamter() CLI supports legacy formats v0.4+ Fixed : compression fails on certain huge files, reported by Jesse McGrew Enhanced documentation, by Przemyslaw Skibinski v0.8.1 New streaming API Changed : --ultra now enables levels beyond 19 Changed : -i# now selects benchmark time in second Fixed : ZSTD_compress* can now compress > 4 GB in a single pass, reported by Nick Terrell Fixed : speed regression on specific patterns (#272) Fixed : support for Z_SYNC_FLUSH, by Dmitry Krot (#291) Fixed : ICC compilation, by Przemyslaw Skibinski v0.8.0 Improved : better speed on clang and gcc -O2, thanks to Eric Biggers New : Build on FreeBSD and DragonFly, thanks to JrMarino Changed : modified API : ZSTD_compressEnd() Fixed : legacy mode with ZSTD_HEAPMODE=0, by Christopher Bergqvist Fixed : premature end of frame when zero-sized raw block, reported by Eric Biggers Fixed : large dictionaries (> 384 KB), reported by Ilona Papava Fixed : checksum correctly checked in single-pass mode Fixed : combined --test amd --rm, reported by Andreas M. Nilsson Modified : minor compression level adaptations Updated : compression format specification to v0.2.0 changed : zstd.h moved to /lib directory v0.7.5 Transition version, supporting decoding of v0.8.x v0.7.4 Added : homebrew for Mac, by Daniel Cade Added : more examples Fixed : segfault when using small dictionaries, reported by Felix Handte Modified : default compression level for CLI is now 3 Updated : specification, to v0.1.1 v0.7.3 New : compression format specification New : `--` separator, stating that all following arguments are file names. Suggested by Chip Turner. New : `ZSTD_getDecompressedSize()` New : OpenBSD target, by Juan Francisco Cantero Hurtado New : `examples` directory fixed : dictBuilder using HC levels, reported by Bartosz Taudul fixed : legacy support from ZSTD_decompress_usingDDict(), reported by Felix Handte fixed : multi-blocks decoding with intermediate uncompressed blocks, reported by Greg Slazinski modified : removed "mem.h" and "error_public.h" dependencies from "zstd.h" (experimental section) modified : legacy functions no longer need magic number v0.7.2 fixed : ZSTD_decompressBlock() using multiple consecutive blocks. Reported by Greg Slazinski. fixed : potential segfault on very large files (many gigabytes). Reported by Chip Turner. fixed : CLI displays system error message when destination file cannot be created (#231). Reported by Chip Turner. v0.7.1 fixed : ZBUFF_compressEnd() called multiple times with too small `dst` buffer, reported by Christophe Chevalier fixed : dictBuilder fails if first sample is too small, reported by Руслан Ковалёв fixed : corruption issue, reported by cj modified : checksum enabled by default in command line mode v0.7.0 New : Support for directory compression, using `-r`, thanks to Przemyslaw Skibinski New : Command `--rm`, to remove source file after successful de/compression New : Visual build scripts, by Christophe Chevalier New : Support for Sparse File-systems (do not use space for zero-filled sectors) New : Frame checksum support New : Support pass-through mode (when using `-df`) API : more efficient Dictionary API : `ZSTD_compress_usingCDict()`, `ZSTD_decompress_usingDDict()` API : create dictionary files from custom content, by Giuseppe Ottaviano API : support for custom malloc/free functions New : controllable Dictionary ID New : Support for skippable frames v0.6.1 New : zlib wrapper API, thanks to Przemyslaw Skibinski New : Ability to compile compressor / decompressor separately Changed : new lib directory structure Fixed : Legacy codec v0.5 compatible with dictionary decompression Fixed : Decoder corruption error (#173) Fixed : null-string roundtrip (#176) New : benchmark mode can select directory as input Experimental : midipix support, VMS support v0.6.0 Stronger high compression modes, thanks to Przemyslaw Skibinski API : ZSTD_getFrameParams() provides size of decompressed content New : highest compression modes require `--ultra` command to fully unleash their capacity Fixed : zstd cli return error code > 0 and removes dst file artifact when decompression fails, thanks to Chip Turner v0.5.1 New : Optimal parsing => Very high compression modes, thanks to Przemyslaw Skibinski Changed : Dictionary builder integrated into libzstd and zstd cli Changed (!) : zstd cli now uses "multiple input files" as default mode. See `zstd -h`. Fix : high compression modes for big-endian platforms New : zstd cli : `-t` | `--test` command v0.5.0 New : dictionary builder utility Changed : streaming & dictionary API Improved : better compression of small data v0.4.7 Improved : small compression speed improvement in HC mode Changed : `zstd_decompress.c` has ZSTD_LEGACY_SUPPORT to 0 by default fix : bt search bug v0.4.6 fix : fast compression mode on Windows New : cmake configuration file, thanks to Artyom Dymchenko Improved : high compression mode on repetitive data New : block-level API New : ZSTD_duplicateCCtx() v0.4.5 new : -m/--multiple : compress/decompress multiple files v0.4.4 Fixed : high compression modes for Windows 32 bits new : external dictionary API extended to buffered mode and accessible through command line new : windows DLL project, thanks to Christophe Chevalier v0.4.3 : new : external dictionary API new : zstd-frugal v0.4.2 : Generic minor improvements for small blocks Fixed : big-endian compatibility, by Peter Harris (#85) v0.4.1 Fixed : ZSTD_LEGACY_SUPPORT=0 build mode (reported by Luben) removed `zstd.c` v0.4.0 Command line utility compatible with high compression levels Removed zstdhc => merged into zstd Added : ZBUFF API (see zstd_buffered.h) Rolling buffer support v0.3.6 small blocks params v0.3.5 minor generic compression improvements v0.3.4 Faster fast cLevels v0.3.3 Small compression ratio improvement v0.3.2 Fixed Visual Studio v0.3.1 : Small compression ratio improvement v0.3 HC mode : compression levels 2-26 v0.2.2 Fix : Visual Studio 2013 & 2015 release compilation, by Christophe Chevalier v0.2.1 Fix : Read errors, advanced fuzzer tests, by Hanno Böck v0.2.0 **Breaking format change** Faster decompression speed Can still decode v0.1 format v0.1.3 fix uninitialization warning, reported by Evan Nemerson v0.1.2 frame concatenation support v0.1.1 fix compression bug detects write-flush errors v0.1.0 first release Index: vendor/zstd/dist/README.md =================================================================== --- vendor/zstd/dist/README.md (revision 339613) +++ vendor/zstd/dist/README.md (revision 339614) @@ -1,151 +1,153 @@

Zstandard

__Zstandard__, or `zstd` as short version, is a fast lossless compression algorithm, targeting real-time compression scenarios at zlib-level and better compression ratios. It's backed by a very fast entropy stage, provided by [Huff0 and FSE library](https://github.com/Cyan4973/FiniteStateEntropy). -The project is provided as an open-source BSD-licensed **C** library, +The project is provided as an open-source dual [BSD](LICENSE) and [GPLv2](COPYING) licensed **C** library, and a command line utility producing and decoding `.zst`, `.gz`, `.xz` and `.lz4` files. Should your project require another programming language, a list of known ports and bindings is provided on [Zstandard homepage](http://www.zstd.net/#other-languages). Development branch status : [![Build Status][travisDevBadge]][travisLink] [![Build status][AppveyorDevBadge]][AppveyorLink] [![Build status][CircleDevBadge]][CircleLink] [travisDevBadge]: https://travis-ci.org/facebook/zstd.svg?branch=dev "Continuous Integration test suite" [travisLink]: https://travis-ci.org/facebook/zstd [AppveyorDevBadge]: https://ci.appveyor.com/api/projects/status/xt38wbdxjk5mrbem/branch/dev?svg=true "Windows test suite" [AppveyorLink]: https://ci.appveyor.com/project/YannCollet/zstd-p0yf0 [CircleDevBadge]: https://circleci.com/gh/facebook/zstd/tree/dev.svg?style=shield "Short test suite" [CircleLink]: https://circleci.com/gh/facebook/zstd ### Benchmarks For reference, several fast compression algorithms were tested and compared on a server running Linux Debian (`Linux version 4.14.0-3-amd64`), with a Core i7-6700K CPU @ 4.0GHz, using [lzbench], an open-source in-memory benchmark by @inikep compiled with [gcc] 7.3.0, on the [Silesia compression corpus]. [lzbench]: https://github.com/inikep/lzbench [Silesia compression corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia [gcc]: https://gcc.gnu.org/ | Compressor name | Ratio | Compression| Decompress.| | --------------- | ------| -----------| ---------- | | **zstd 1.3.4 -1** | 2.877 | 470 MB/s | 1380 MB/s | | zlib 1.2.11 -1 | 2.743 | 110 MB/s | 400 MB/s | | brotli 1.0.2 -0 | 2.701 | 410 MB/s | 430 MB/s | | quicklz 1.5.0 -1 | 2.238 | 550 MB/s | 710 MB/s | | lzo1x 2.09 -1 | 2.108 | 650 MB/s | 830 MB/s | | lz4 1.8.1 | 2.101 | 750 MB/s | 3700 MB/s | | snappy 1.1.4 | 2.091 | 530 MB/s | 1800 MB/s | | lzf 3.6 -1 | 2.077 | 400 MB/s | 860 MB/s | [zlib]:http://www.zlib.net/ [LZ4]: http://www.lz4.org/ Zstd can also offer stronger compression ratios at the cost of compression speed. Speed vs Compression trade-off is configurable by small increments. Decompression speed is preserved and remains roughly the same at all settings, a property shared by most LZ compression algorithms, such as [zlib] or lzma. The following tests were run on a server running Linux Debian (`Linux version 4.14.0-3-amd64`) with a Core i7-6700K CPU @ 4.0GHz, using [lzbench], an open-source in-memory benchmark by @inikep compiled with [gcc] 7.3.0, on the [Silesia compression corpus]. Compression Speed vs Ratio | Decompression Speed ---------------------------|-------------------- ![Compression Speed vs Ratio](doc/images/CSpeed2.png "Compression Speed vs Ratio") | ![Decompression Speed](doc/images/DSpeed3.png "Decompression Speed") A few other algorithms can produce higher compression ratios at slower speeds, falling outside of the graph. For a larger picture including slow modes, [click on this link](doc/images/DCspeed5.png). ### The case for Small Data compression Previous charts provide results applicable to typical file and stream scenarios (several MB). Small data comes with different perspectives. The smaller the amount of data to compress, the more difficult it is to compress. This problem is common to all compression algorithms, and reason is, compression algorithms learn from past data how to compress future data. But at the beginning of a new data set, there is no "past" to build upon. To solve this situation, Zstd offers a __training mode__, which can be used to tune the algorithm for a selected type of data. Training Zstandard is achieved by providing it with a few samples (one file per sample). The result of this training is stored in a file called "dictionary", which must be loaded before compression and decompression. Using this dictionary, the compression ratio achievable on small data improves dramatically. The following example uses the `github-users` [sample set](https://github.com/facebook/zstd/releases/tag/v1.1.3), created from [github public API](https://developer.github.com/v3/users/#get-all-users). It consists of roughly 10K records weighing about 1KB each. Compression Ratio | Compression Speed | Decompression Speed ------------------|-------------------|-------------------- ![Compression Ratio](doc/images/dict-cr.png "Compression Ratio") | ![Compression Speed](doc/images/dict-cs.png "Compression Speed") | ![Decompression Speed](doc/images/dict-ds.png "Decompression Speed") These compression gains are achieved while simultaneously providing _faster_ compression and decompression speeds. Training works if there is some correlation in a family of small data samples. The more data-specific a dictionary is, the more efficient it is (there is no _universal dictionary_). Hence, deploying one dictionary per type of data will provide the greatest benefits. Dictionary gains are mostly effective in the first few KB. Then, the compression algorithm will gradually use previously decoded content to better compress the rest of the file. #### Dictionary compression How To: 1) Create the dictionary `zstd --train FullPathToTrainingSet/* -o dictionaryName` 2) Compress with dictionary `zstd -D dictionaryName FILE` 3) Decompress with dictionary `zstd -D dictionaryName --decompress FILE.zst` ### Build instructions #### Makefile If your system is compatible with standard `make` (or `gmake`), invoking `make` in root directory will generate `zstd` cli in root directory. Other available options include: - `make install` : create and install zstd cli, library and man pages - `make check` : create and run `zstd`, tests its behavior on local platform #### cmake A `cmake` project generator is provided within `build/cmake`. It can generate Makefiles or other build scripts to create `zstd` binary, and `libzstd` dynamic and static libraries. + +By default, `CMAKE_BUILD_TYPE` is set to `Release`. #### Meson A Meson project is provided within `contrib/meson`. #### Visual Studio (Windows) Going into `build` directory, you will find additional possibilities: - Projects for Visual Studio 2005, 2008 and 2010. + VS2010 project is compatible with VS2012, VS2013, VS2015 and VS2017. - Automated build scripts for Visual compiler by [@KrzysFR](https://github.com/KrzysFR), in `build/VS_scripts`, which will build `zstd` cli and `libzstd` library without any need to open Visual Studio solution. ### Status Zstandard is currently deployed within Facebook. It is used continuously to compress large amounts of data in multiple formats and use cases. Zstandard is considered safe for production environments. ### License Zstandard is dual-licensed under [BSD](LICENSE) and [GPLv2](COPYING). ### Contributing The "dev" branch is the one where all contributions are merged before reaching "master". If you plan to propose a patch, please commit into the "dev" branch, or its own feature branch. Direct commit to "master" are not permitted. For more information, please read [CONTRIBUTING](CONTRIBUTING.md). Index: vendor/zstd/dist/TESTING.md =================================================================== --- vendor/zstd/dist/TESTING.md (revision 339613) +++ vendor/zstd/dist/TESTING.md (revision 339614) @@ -1,44 +1,44 @@ Testing ======= Zstandard CI testing is split up into three sections: short, medium, and long tests. Short Tests ----------- Short tests run on CircleCI for new commits on every branch and pull request. They consist of the following tests: - Compilation on all supported targets (x86, x86_64, ARM, AArch64, PowerPC, and PowerPC64) - Compilation on various versions of gcc, clang, and g++ - `tests/playTests.sh` on x86_64, without the tests on long data (CLI tests) - Small tests (`tests/legacy.c`, `tests/longmatch.c`, `tests/symbols.c`) on x64_64 Medium Tests ------------ Medium tests run on every commit and pull request to `dev` branch, on TravisCI. They consist of the following tests: - The following tests run with UBsan and Asan on x86_64 and x86, as well as with Msan on x86_64 - `tests/playTests.sh --test-long-data` - Fuzzer tests: `tests/fuzzer.c`, `tests/zstreamtest.c`, and `tests/decodecorpus.c` - `tests/zstreamtest.c` under Tsan (streaming mode, including multithreaded mode) - Valgrind Test (`make -C tests valgrindTest`) (testing CLI and fuzzer under valgrind) - Fuzzer tests (see above) on ARM, AArch64, PowerPC, and PowerPC64 Long Tests ---------- Long tests run on all commits to `master` branch, and once a day on the current version of `dev` branch, on TravisCI. They consist of the following tests: - Entire test suite (including fuzzers and some other specialized tests) on: - x86_64 and x86 with UBsan and Asan - x86_64 with Msan - ARM, AArch64, PowerPC, and PowerPC64 - Streaming mode fuzzer with Tsan (for the `zstdmt` testing) - ZlibWrapper tests, including under valgrind - Versions test (ensuring `zstd` can decode files from all previous versions) - `pzstd` with asan and tsan, as well as in 32-bits mode - Testing `zstd` with legacy mode off - Testing `zbuff` (old streaming API) -- Entire test suite and make install on OS X +- Entire test suite and make install on macOS Index: vendor/zstd/dist/appveyor.yml =================================================================== --- vendor/zstd/dist/appveyor.yml (revision 339613) +++ vendor/zstd/dist/appveyor.yml (revision 339614) @@ -1,249 +1,249 @@ - version: 1.0.{build} branches: only: - master environment: matrix: - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x64" SCRIPT: "make allzstd MOREFLAGS=-static && make -C tests test-symbols fullbench-lib" ARTIFACT: "true" BUILD: "true" - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x86" SCRIPT: "make allzstd MOREFLAGS=-static" ARTIFACT: "true" BUILD: "true" - COMPILER: "clang" HOST: "mingw" PLATFORM: "x64" SCRIPT: "MOREFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make allzstd" BUILD: "true" - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x64" SCRIPT: "" TEST: "cmake" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Release" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Release" install: - ECHO Installing %COMPILER% %PLATFORM% %CONFIGURATION% - SET PATH_ORIGINAL=%PATH% - if [%HOST%]==[mingw] ( SET "PATH_MINGW32=C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin" && SET "PATH_MINGW64=C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin" && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin\make.exe && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin\make.exe ) - IF [%HOST%]==[visual] IF [%PLATFORM%]==[x64] ( SET ADDITIONALPARAM=/p:LibraryPath="C:\Program Files\Microsoft SDKs\Windows\v7.1\lib\x64;c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\amd64;C:\Program Files (x86)\Microsoft Visual Studio 10.0\;C:\Program Files (x86)\Microsoft Visual Studio 10.0\lib\amd64;" ) build_script: - if [%HOST%]==[mingw] ( ( if [%PLATFORM%]==[x64] ( SET "PATH=%PATH_MINGW64%;%PATH_ORIGINAL%" ) else if [%PLATFORM%]==[x86] ( SET "PATH=%PATH_MINGW32%;%PATH_ORIGINAL%" ) ) ) - if [%HOST%]==[mingw] if [%BUILD%]==[true] ( make -v && sh -c "%COMPILER% -v" && ECHO Building zlib to static link && SET "CC=%COMPILER%" && sh -c "cd .. && git clone --depth 1 --branch v1.2.11 https://github.com/madler/zlib" && sh -c "cd ../zlib && make -f win32/Makefile.gcc libz.a" ECHO Building zstd && SET "CPPFLAGS=-I../../zlib" && SET "LDFLAGS=../../zlib/libz.a" && sh -c "%SCRIPT%" && ( if [%COMPILER%]==[gcc] if [%ARTIFACT%]==[true] ECHO Creating artifacts && ECHO %cd% && lib\dll\example\build_package.bat && make -C programs DEBUGFLAGS= clean zstd && cd programs\ && 7z a -tzip -mx9 zstd-win-binary-%PLATFORM%.zip zstd.exe && appveyor PushArtifact zstd-win-binary-%PLATFORM%.zip && cp zstd.exe ..\bin\zstd.exe && git clone --depth 1 --branch master https://github.com/facebook/zstd && cd zstd && git archive --format=tar master -o zstd-src.tar && ..\zstd -19 zstd-src.tar && appveyor PushArtifact zstd-src.tar.zst && certUtil -hashfile zstd-src.tar.zst SHA256 > zstd-src.tar.zst.sha256.sig && appveyor PushArtifact zstd-src.tar.zst.sha256.sig && cd ..\..\bin\ && 7z a -tzip -mx9 zstd-win-release-%PLATFORM%.zip * && appveyor PushArtifact zstd-win-release-%PLATFORM%.zip ) ) - if [%HOST%]==[visual] ( ECHO *** && ECHO *** Building Visual Studio 2008 %PLATFORM%\%CONFIGURATION% in %APPVEYOR_BUILD_FOLDER% && ECHO *** && msbuild "build\VS2008\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v90 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2008\bin\%PLATFORM%\%CONFIGURATION%\*.exe && MD5sum build/VS2008/bin/%PLATFORM%/%CONFIGURATION%/*.exe && COPY build\VS2008\bin\%PLATFORM%\%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2008_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2010 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" %ADDITIONALPARAM% /m /verbosity:minimal /property:PlatformToolset=v100 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" %ADDITIONALPARAM% /m /verbosity:minimal /property:PlatformToolset=v100 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2010_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2012 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v110 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v110 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2012_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2013 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v120 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v120 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2013_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2015 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2015_%PLATFORM%_%CONFIGURATION%.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe tests\ ) test_script: - ECHO Testing %COMPILER% %PLATFORM% %CONFIGURATION% - SET "CC=gcc" - SET "CXX=g++" - if [%TEST%]==[cmake] ( mkdir build\cmake\build && cd build\cmake\build && cmake -G "Visual Studio 14 2015 Win64" .. && cd ..\..\.. && make clean ) - SET "FUZZERTEST=-T30s" - if [%HOST%]==[visual] if [%CONFIGURATION%]==[Release] ( CD tests && SET ZSTD=./zstd.exe && sh -e playTests.sh --test-large-data && fullbench.exe -i1 && fullbench.exe -i1 -P0 && fuzzer_VS2008_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2010_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2012_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2013_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2015_%PLATFORM%_Release.exe %FUZZERTEST% ) - version: 1.0.{build} environment: matrix: - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x64" - SCRIPT: "make allzstd" + SCRIPT: "CPPFLAGS=-DDEBUGLEVEL=2 CFLAGS=-Werror make -j allzstd DEBUGLEVEL=2" - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x86" - SCRIPT: "make allzstd" + SCRIPT: "CFLAGS=-Werror make -j allzstd" - COMPILER: "clang" HOST: "mingw" PLATFORM: "x64" - SCRIPT: "MOREFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make allzstd" + SCRIPT: "CFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make -j allzstd" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Release" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Release" install: - ECHO Installing %COMPILER% %PLATFORM% %CONFIGURATION% - SET PATH_ORIGINAL=%PATH% - if [%HOST%]==[mingw] ( SET "PATH_MINGW32=C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin" && SET "PATH_MINGW64=C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin" && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin\make.exe && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin\make.exe ) - IF [%HOST%]==[visual] IF [%PLATFORM%]==[x64] ( SET ADDITIONALPARAM=/p:LibraryPath="C:\Program Files\Microsoft SDKs\Windows\v7.1\lib\x64;c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\amd64;C:\Program Files (x86)\Microsoft Visual Studio 10.0\;C:\Program Files (x86)\Microsoft Visual Studio 10.0\lib\amd64;" ) build_script: - ECHO Building %COMPILER% %PLATFORM% %CONFIGURATION% - if [%HOST%]==[mingw] ( ( if [%PLATFORM%]==[x64] ( SET "PATH=%PATH_MINGW64%;%PATH_ORIGINAL%" ) else if [%PLATFORM%]==[x86] ( SET "PATH=%PATH_MINGW32%;%PATH_ORIGINAL%" ) ) && make -v && sh -c "%COMPILER% -v" && set "CC=%COMPILER%" && sh -c "%SCRIPT%" ) - if [%HOST%]==[visual] ( ECHO *** && ECHO *** Building Visual Studio 2015 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2015_%PLATFORM%_%CONFIGURATION%.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe tests\ ) Index: vendor/zstd/dist/contrib/adaptive-compression/Makefile =================================================================== --- vendor/zstd/dist/contrib/adaptive-compression/Makefile (revision 339613) +++ vendor/zstd/dist/contrib/adaptive-compression/Makefile (revision 339614) @@ -1,76 +1,76 @@ ZSTDDIR = ../../lib PRGDIR = ../../programs ZSTDCOMMON_FILES := $(ZSTDDIR)/common/*.c ZSTDCOMP_FILES := $(ZSTDDIR)/compress/*.c ZSTDDECOMP_FILES := $(ZSTDDIR)/decompress/*.c ZSTD_FILES := $(ZSTDDECOMP_FILES) $(ZSTDCOMMON_FILES) $(ZSTDCOMP_FILES) MULTITHREAD_LDFLAGS = -pthread DEBUGFLAGS= -g -DZSTD_DEBUG=1 CPPFLAGS += -I$(ZSTDDIR) -I$(ZSTDDIR)/common -I$(ZSTDDIR)/compress \ -I$(ZSTDDIR)/dictBuilder -I$(ZSTDDIR)/deprecated -I$(PRGDIR) CFLAGS ?= -O3 CFLAGS += -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \ -Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement \ -Wstrict-prototypes -Wundef -Wformat-security \ -Wvla -Wformat=2 -Winit-self -Wfloat-equal -Wwrite-strings \ -Wredundant-decls CFLAGS += $(DEBUGFLAGS) CFLAGS += $(MOREFLAGS) FLAGS = $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $(MULTITHREAD_LDFLAGS) all: adapt datagen adapt: $(ZSTD_FILES) adapt.c $(CC) $(FLAGS) $^ -o $@ adapt-debug: $(ZSTD_FILES) adapt.c $(CC) $(FLAGS) -DDEBUG_MODE=2 $^ -o adapt datagen : $(PRGDIR)/datagen.c datagencli.c $(CC) $(FLAGS) $^ -o $@ test-adapt-correctness: datagen adapt @./test-correctness.sh @echo "test correctness complete" test-adapt-performance: datagen adapt @./test-performance.sh @echo "test performance complete" clean: @$(RM) -f adapt datagen @$(RM) -rf *.dSYM @$(RM) -f tmp* @$(RM) -f tests/*.zst @$(RM) -f tests/tmp* @echo "finished cleaning" #----------------------------------------------------------------------------- -# make install is validated only for Linux, OSX, BSD, Hurd and Solaris targets +# make install is validated only for Linux, macOS, BSD, Hurd and Solaris targets #----------------------------------------------------------------------------- ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD NetBSD DragonFly SunOS)) ifneq (,$(filter $(shell uname),SunOS)) INSTALL ?= ginstall else INSTALL ?= install endif PREFIX ?= /usr/local DESTDIR ?= BINDIR ?= $(PREFIX)/bin INSTALL_PROGRAM ?= $(INSTALL) -m 755 install: adapt @echo Installing binaries @$(INSTALL) -d -m 755 $(DESTDIR)$(BINDIR)/ @$(INSTALL_PROGRAM) adapt $(DESTDIR)$(BINDIR)/zstd-adaptive @echo zstd-adaptive installation completed uninstall: @$(RM) $(DESTDIR)$(BINDIR)/zstd-adaptive @echo zstd-adaptive programs successfully uninstalled endif Index: vendor/zstd/dist/contrib/gen_html/Makefile =================================================================== --- vendor/zstd/dist/contrib/gen_html/Makefile (revision 339613) +++ vendor/zstd/dist/contrib/gen_html/Makefile (revision 339614) @@ -1,51 +1,51 @@ # ################################################################ # Copyright (c) 2016-present, Facebook, Inc. # All rights reserved. # # This source code is licensed under both the BSD-style license (found in the # LICENSE file in the root directory of this source tree) and the GPLv2 (found # in the COPYING file in the root directory of this source tree). # ################################################################ CXXFLAGS ?= -O3 CXXFLAGS += -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow -Wstrict-aliasing=1 -Wswitch-enum -Wno-comment CXXFLAGS += $(MOREFLAGS) -FLAGS = $(CPPFLAGS) $(CXXFLAGS) $(CXXFLAGS) $(LDFLAGS) +FLAGS = $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) ZSTDAPI = ../../lib/zstd.h ZSTDMANUAL = ../../doc/zstd_manual.html LIBVER_MAJOR_SCRIPT:=`sed -n '/define ZSTD_VERSION_MAJOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < $(ZSTDAPI)` LIBVER_MINOR_SCRIPT:=`sed -n '/define ZSTD_VERSION_MINOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < $(ZSTDAPI)` LIBVER_PATCH_SCRIPT:=`sed -n '/define ZSTD_VERSION_RELEASE/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < $(ZSTDAPI)` LIBVER_SCRIPT:= $(LIBVER_MAJOR_SCRIPT).$(LIBVER_MINOR_SCRIPT).$(LIBVER_PATCH_SCRIPT) LIBVER := $(shell echo $(LIBVER_SCRIPT)) # Define *.exe as extension for Windows systems ifneq (,$(filter Windows%,$(OS))) EXT =.exe else EXT = endif .PHONY: default default: gen_html .PHONY: all all: manual gen_html: gen_html.cpp $(CXX) $(FLAGS) $^ -o $@$(EXT) $(ZSTDMANUAL): gen_html $(ZSTDAPI) echo "Update zstd manual in /doc" ./gen_html $(LIBVER) $(ZSTDAPI) $(ZSTDMANUAL) .PHONY: manual manual: gen_html $(ZSTDMANUAL) .PHONY: clean clean: @$(RM) gen_html$(EXT) @echo Cleaning completed Index: vendor/zstd/dist/contrib/meson/meson.build =================================================================== --- vendor/zstd/dist/contrib/meson/meson.build (revision 339613) +++ vendor/zstd/dist/contrib/meson/meson.build (revision 339614) @@ -1,142 +1,144 @@ project('zstd', 'c', license: 'BSD') libm = meson.get_compiler('c').find_library('m', required: true) lib_dir = join_paths('..', '..', 'lib') common_dir = join_paths(lib_dir, 'common') compress_dir = join_paths(lib_dir, 'compress') decompress_dir = join_paths(lib_dir, 'decompress') dictbuilder_dir = join_paths(lib_dir, 'dictBuilder') deprecated_dir = join_paths(lib_dir, 'deprecated') libzstd_srcs = [ join_paths(common_dir, 'entropy_common.c'), join_paths(common_dir, 'fse_decompress.c'), join_paths(common_dir, 'threading.c'), join_paths(common_dir, 'pool.c'), join_paths(common_dir, 'zstd_common.c'), join_paths(common_dir, 'error_private.c'), join_paths(common_dir, 'xxhash.c'), join_paths(compress_dir, 'fse_compress.c'), + join_paths(compress_dir, 'hist.c'), join_paths(compress_dir, 'huf_compress.c'), join_paths(compress_dir, 'zstd_compress.c'), join_paths(compress_dir, 'zstd_fast.c'), join_paths(compress_dir, 'zstd_double_fast.c'), join_paths(compress_dir, 'zstd_lazy.c'), join_paths(compress_dir, 'zstd_opt.c'), join_paths(compress_dir, 'zstd_ldm.c'), join_paths(compress_dir, 'zstdmt_compress.c'), join_paths(decompress_dir, 'huf_decompress.c'), join_paths(decompress_dir, 'zstd_decompress.c'), join_paths(dictbuilder_dir, 'cover.c'), join_paths(dictbuilder_dir, 'divsufsort.c'), join_paths(dictbuilder_dir, 'zdict.c'), join_paths(deprecated_dir, 'zbuff_common.c'), join_paths(deprecated_dir, 'zbuff_compress.c'), join_paths(deprecated_dir, 'zbuff_decompress.c') ] libzstd_includes = [include_directories(common_dir, dictbuilder_dir, compress_dir, lib_dir)] legacy = get_option('legacy_support') if legacy == '0' legacy = 'false' endif if legacy != 'false' if legacy == 'true' legacy = '1' endif #See ZSTD_LEGACY_SUPPORT of programs/README.md message('Enabling legacy support back to version 0.' + legacy) legacy_int = legacy.to_int() if legacy_int > 7 legacy_int = 7 endif libzstd_cflags = ['-DZSTD_LEGACY_SUPPORT=' + legacy] legacy_dir = join_paths(lib_dir, 'legacy') libzstd_includes += [include_directories(legacy_dir)] if legacy_int <= 1 libzstd_srcs += join_paths(legacy_dir, 'zstd_v01.c') endif if legacy_int <= 2 libzstd_srcs += join_paths(legacy_dir, 'zstd_v02.c') endif if legacy_int <= 3 libzstd_srcs += join_paths(legacy_dir, 'zstd_v03.c') endif if legacy_int <= 4 libzstd_srcs += join_paths(legacy_dir, 'zstd_v04.c') endif if legacy_int <= 5 libzstd_srcs += join_paths(legacy_dir, 'zstd_v05.c') endif if legacy_int <= 6 libzstd_srcs += join_paths(legacy_dir, 'zstd_v06.c') endif if legacy_int <= 7 libzstd_srcs += join_paths(legacy_dir, 'zstd_v07.c') endif else libzstd_cflags = [] endif if get_option('multithread') message('Enabling multi-threading support') add_global_arguments('-DZSTD_MULTITHREAD', language: 'c') libzstd_deps = [dependency('threads')] else libzstd_deps = [] endif libzstd = library('zstd', libzstd_srcs, include_directories: libzstd_includes, c_args: libzstd_cflags, dependencies: libzstd_deps, install: true, soversion: '1', ) programs_dir = join_paths('..', '..', 'programs') zstd = executable('zstd', join_paths(programs_dir, 'bench.c'), join_paths(programs_dir, 'datagen.c'), join_paths(programs_dir, 'dibio.c'), join_paths(programs_dir, 'fileio.c'), join_paths(programs_dir, 'zstdcli.c'), include_directories: libzstd_includes, c_args: ['-DZSTD_NODICT', '-DZSTD_NOBENCH'], link_with: libzstd, install: true) tests_dir = join_paths('..', '..', 'tests') datagen_c = join_paths(programs_dir, 'datagen.c') test_includes = libzstd_includes + [include_directories(programs_dir)] fullbench = executable('fullbench', datagen_c, join_paths(tests_dir, 'fullbench.c'), include_directories: test_includes, link_with: libzstd) test('fullbench', fullbench) fuzzer = executable('fuzzer', datagen_c, join_paths(tests_dir, 'fuzzer.c'), include_directories: test_includes, link_with: libzstd) test('fuzzer', fuzzer) if target_machine.system() != 'windows' paramgrill = executable('paramgrill', datagen_c, join_paths(tests_dir, 'paramgrill.c'), + join_paths(programs_dir, 'bench.c'), include_directories: test_includes, link_with: libzstd, dependencies: libm) test('paramgrill', paramgrill) datagen = executable('datagen', datagen_c, join_paths(tests_dir, 'datagencli.c'), include_directories: test_includes, link_with: libzstd) endif Index: vendor/zstd/dist/contrib/pzstd/Makefile =================================================================== --- vendor/zstd/dist/contrib/pzstd/Makefile (revision 339613) +++ vendor/zstd/dist/contrib/pzstd/Makefile (revision 339614) @@ -1,269 +1,269 @@ # ################################################################ # Copyright (c) 2016-present, Facebook, Inc. # All rights reserved. # # This source code is licensed under both the BSD-style license (found in the # LICENSE file in the root directory of this source tree) and the GPLv2 (found # in the COPYING file in the root directory of this source tree). # ################################################################ # Standard variables for installation DESTDIR ?= PREFIX ?= /usr/local BINDIR := $(DESTDIR)$(PREFIX)/bin ZSTDDIR = ../../lib PROGDIR = ../../programs # External program to use to run tests, e.g. qemu or valgrind TESTPROG ?= # Flags to pass to the tests TESTFLAGS ?= # We use gcc/clang to generate the header dependencies of files DEPFLAGS = -MMD -MP -MF $*.Td POSTCOMPILE = mv -f $*.Td $*.d # CFLAGS, CXXFLAGS, CPPFLAGS, and LDFLAGS are for the users to override CFLAGS ?= -O3 -Wall -Wextra CXXFLAGS ?= -O3 -Wall -Wextra -pedantic CPPFLAGS ?= LDFLAGS ?= # Include flags PZSTD_INC = -I$(ZSTDDIR) -I$(ZSTDDIR)/common -I$(PROGDIR) -I. GTEST_INC = -isystem googletest/googletest/include PZSTD_CPPFLAGS = $(PZSTD_INC) PZSTD_CCXXFLAGS = PZSTD_CFLAGS = $(PZSTD_CCXXFLAGS) PZSTD_CXXFLAGS = $(PZSTD_CCXXFLAGS) -std=c++11 PZSTD_LDFLAGS = EXTRA_FLAGS = ALL_CFLAGS = $(EXTRA_FLAGS) $(CPPFLAGS) $(PZSTD_CPPFLAGS) $(CFLAGS) $(PZSTD_CFLAGS) ALL_CXXFLAGS = $(EXTRA_FLAGS) $(CPPFLAGS) $(PZSTD_CPPFLAGS) $(CXXFLAGS) $(PZSTD_CXXFLAGS) -ALL_LDFLAGS = $(EXTRA_FLAGS) $(LDFLAGS) $(PZSTD_LDFLAGS) +ALL_LDFLAGS = $(EXTRA_FLAGS) $(CXXFLAGS) $(LDFLAGS) $(PZSTD_LDFLAGS) # gtest libraries need to go before "-lpthread" because they depend on it. GTEST_LIB = -L googletest/build/googlemock/gtest LIBS = # Compilation commands -LD_COMMAND = $(CXX) $^ $(ALL_LDFLAGS) $(LIBS) -lpthread -o $@ +LD_COMMAND = $(CXX) $^ $(ALL_LDFLAGS) $(LIBS) -pthread -o $@ CC_COMMAND = $(CC) $(DEPFLAGS) $(ALL_CFLAGS) -c $< -o $@ CXX_COMMAND = $(CXX) $(DEPFLAGS) $(ALL_CXXFLAGS) -c $< -o $@ # Get a list of all zstd files so we rebuild the static library when we need to ZSTDCOMMON_FILES := $(wildcard $(ZSTDDIR)/common/*.c) \ $(wildcard $(ZSTDDIR)/common/*.h) ZSTDCOMP_FILES := $(wildcard $(ZSTDDIR)/compress/*.c) \ $(wildcard $(ZSTDDIR)/compress/*.h) ZSTDDECOMP_FILES := $(wildcard $(ZSTDDIR)/decompress/*.c) \ $(wildcard $(ZSTDDIR)/decompress/*.h) ZSTDPROG_FILES := $(wildcard $(PROGDIR)/*.c) \ $(wildcard $(PROGDIR)/*.h) ZSTD_FILES := $(wildcard $(ZSTDDIR)/*.h) \ $(ZSTDDECOMP_FILES) $(ZSTDCOMMON_FILES) $(ZSTDCOMP_FILES) \ $(ZSTDPROG_FILES) # List all the pzstd source files so we can determine their dependencies PZSTD_SRCS := $(wildcard *.cpp) PZSTD_TESTS := $(wildcard test/*.cpp) UTILS_TESTS := $(wildcard utils/test/*.cpp) ALL_SRCS := $(PZSTD_SRCS) $(PZSTD_TESTS) $(UTILS_TESTS) # Define *.exe as extension for Windows systems ifneq (,$(filter Windows%,$(OS))) EXT =.exe else EXT = endif # Standard targets .PHONY: default default: all .PHONY: test-pzstd test-pzstd: TESTFLAGS=--gtest_filter=-*ExtremelyLarge* test-pzstd: clean googletest pzstd tests check .PHONY: test-pzstd32 test-pzstd32: clean googletest32 all32 check .PHONY: test-pzstd-tsan test-pzstd-tsan: LDFLAGS=-fuse-ld=gold test-pzstd-tsan: TESTFLAGS=--gtest_filter=-*ExtremelyLarge* test-pzstd-tsan: clean googletest tsan check .PHONY: test-pzstd-asan test-pzstd-asan: LDFLAGS=-fuse-ld=gold test-pzstd-asan: TESTFLAGS=--gtest_filter=-*ExtremelyLarge* test-pzstd-asan: clean asan check .PHONY: check check: $(TESTPROG) ./utils/test/BufferTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./utils/test/RangeTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./utils/test/ResourcePoolTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./utils/test/ScopeGuardTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./utils/test/ThreadPoolTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./utils/test/WorkQueueTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./test/OptionsTest$(EXT) $(TESTFLAGS) $(TESTPROG) ./test/PzstdTest$(EXT) $(TESTFLAGS) .PHONY: install install: PZSTD_CPPFLAGS += -DNDEBUG install: pzstd$(EXT) install -d -m 755 $(BINDIR)/ install -m 755 pzstd$(EXT) $(BINDIR)/pzstd$(EXT) .PHONY: uninstall uninstall: $(RM) $(BINDIR)/pzstd$(EXT) # Targets for many different builds .PHONY: all all: PZSTD_CPPFLAGS += -DNDEBUG all: pzstd$(EXT) .PHONY: debug debug: EXTRA_FLAGS += -g debug: pzstd$(EXT) tests roundtrip .PHONY: tsan tsan: PZSTD_CCXXFLAGS += -fsanitize=thread -fPIC tsan: PZSTD_LDFLAGS += -fsanitize=thread tsan: debug .PHONY: asan asan: EXTRA_FLAGS += -fsanitize=address asan: debug .PHONY: ubsan ubsan: EXTRA_FLAGS += -fsanitize=undefined ubsan: debug .PHONY: all32 all32: EXTRA_FLAGS += -m32 all32: all tests roundtrip .PHONY: debug32 debug32: EXTRA_FLAGS += -m32 debug32: debug .PHONY: asan32 asan32: EXTRA_FLAGS += -m32 asan32: asan .PHONY: tsan32 tsan32: EXTRA_FLAGS += -m32 tsan32: tsan .PHONY: ubsan32 ubsan32: EXTRA_FLAGS += -m32 ubsan32: ubsan # Run long round trip tests .PHONY: roundtripcheck roundtripcheck: roundtrip check $(TESTPROG) ./test/RoundTripTest$(EXT) $(TESTFLAGS) # Build the main binary pzstd$(EXT): main.o Options.o Pzstd.o SkippableFrame.o $(ZSTDDIR)/libzstd.a $(LD_COMMAND) # Target that depends on all the tests .PHONY: tests tests: EXTRA_FLAGS += -Wno-deprecated-declarations tests: $(patsubst %,%$(EXT),$(basename $(PZSTD_TESTS) $(UTILS_TESTS))) # Build the round trip tests .PHONY: roundtrip roundtrip: EXTRA_FLAGS += -Wno-deprecated-declarations roundtrip: test/RoundTripTest$(EXT) # Use the static library that zstd builds for simplicity and # so we get the compiler options correct $(ZSTDDIR)/libzstd.a: $(ZSTD_FILES) CFLAGS="$(ALL_CFLAGS)" LDFLAGS="$(ALL_LDFLAGS)" $(MAKE) -C $(ZSTDDIR) libzstd.a # Rules to build the tests test/RoundTripTest$(EXT): test/RoundTripTest.o $(PROGDIR)/datagen.o Options.o \ Pzstd.o SkippableFrame.o $(ZSTDDIR)/libzstd.a $(LD_COMMAND) test/%Test$(EXT): PZSTD_LDFLAGS += $(GTEST_LIB) test/%Test$(EXT): LIBS += -lgtest -lgtest_main test/%Test$(EXT): test/%Test.o $(PROGDIR)/datagen.o Options.o Pzstd.o \ SkippableFrame.o $(ZSTDDIR)/libzstd.a $(LD_COMMAND) utils/test/%Test$(EXT): PZSTD_LDFLAGS += $(GTEST_LIB) utils/test/%Test$(EXT): LIBS += -lgtest -lgtest_main utils/test/%Test$(EXT): utils/test/%Test.o $(LD_COMMAND) GTEST_CMAKEFLAGS = # Install googletest .PHONY: googletest googletest: PZSTD_CCXXFLAGS += -fPIC googletest: @$(RM) -rf googletest @git clone https://github.com/google/googletest @mkdir -p googletest/build @cd googletest/build && cmake $(GTEST_CMAKEFLAGS) -DCMAKE_CXX_FLAGS="$(ALL_CXXFLAGS)" .. && $(MAKE) .PHONY: googletest32 googletest32: PZSTD_CCXXFLAGS += -m32 googletest32: googletest .PHONY: googletest-mingw64 googletest-mingw64: GTEST_CMAKEFLAGS += -G "MSYS Makefiles" googletest-mingw64: googletest .PHONY: clean clean: $(RM) -f *.o pzstd$(EXT) *.Td *.d $(RM) -f test/*.o test/*Test$(EXT) test/*.Td test/*.d $(RM) -f utils/test/*.o utils/test/*Test$(EXT) utils/test/*.Td utils/test/*.d $(RM) -f $(PROGDIR)/*.o $(PROGDIR)/*.Td $(PROGDIR)/*.d $(MAKE) -C $(ZSTDDIR) clean @echo Cleaning completed # Cancel implicit rules %.o: %.c %.o: %.cpp # Object file rules %.o: %.c $(CC_COMMAND) $(POSTCOMPILE) $(PROGDIR)/%.o: $(PROGDIR)/%.c $(CC_COMMAND) $(POSTCOMPILE) %.o: %.cpp $(CXX_COMMAND) $(POSTCOMPILE) test/%.o: PZSTD_CPPFLAGS += $(GTEST_INC) test/%.o: test/%.cpp $(CXX_COMMAND) $(POSTCOMPILE) utils/test/%.o: PZSTD_CPPFLAGS += $(GTEST_INC) utils/test/%.o: utils/test/%.cpp $(CXX_COMMAND) $(POSTCOMPILE) # Dependency file stuff .PRECIOUS: %.d test/%.d utils/test/%.d # Include rules that specify header file dependencies -include $(patsubst %,%.d,$(basename $(ALL_SRCS))) Index: vendor/zstd/dist/contrib/pzstd/Options.cpp =================================================================== --- vendor/zstd/dist/contrib/pzstd/Options.cpp (revision 339613) +++ vendor/zstd/dist/contrib/pzstd/Options.cpp (revision 339614) @@ -1,439 +1,428 @@ /* * Copyright (c) 2016-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ #include "Options.h" #include "util.h" #include "utils/ScopeGuard.h" #include #include #include #include #include #include #include -#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) || \ - defined(__CYGWIN__) -#include /* _isatty */ -#define IS_CONSOLE(stdStream) _isatty(_fileno(stdStream)) -#elif defined(_POSIX_C_SOURCE) || defined(_XOPEN_SOURCE) || defined(_POSIX_SOURCE) || (defined(__APPLE__) && defined(__MACH__)) || \ - defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) /* https://sourceforge.net/p/predef/wiki/OperatingSystems/ */ -#include /* isatty */ -#define IS_CONSOLE(stdStream) isatty(fileno(stdStream)) -#else -#define IS_CONSOLE(stdStream) 0 -#endif namespace pzstd { namespace { unsigned defaultNumThreads() { #ifdef PZSTD_NUM_THREADS return PZSTD_NUM_THREADS; #else return std::thread::hardware_concurrency(); #endif } unsigned parseUnsigned(const char **arg) { unsigned result = 0; while (**arg >= '0' && **arg <= '9') { result *= 10; result += **arg - '0'; ++(*arg); } return result; } const char *getArgument(const char *options, const char **argv, int &i, int argc) { if (options[1] != 0) { return options + 1; } ++i; if (i == argc) { std::fprintf(stderr, "Option -%c requires an argument, but none provided\n", *options); return nullptr; } return argv[i]; } const std::string kZstdExtension = ".zst"; constexpr char kStdIn[] = "-"; constexpr char kStdOut[] = "-"; constexpr unsigned kDefaultCompressionLevel = 3; constexpr unsigned kMaxNonUltraCompressionLevel = 19; #ifdef _WIN32 const char nullOutput[] = "nul"; #else const char nullOutput[] = "/dev/null"; #endif void notSupported(const char *option) { std::fprintf(stderr, "Operation not supported: %s\n", option); } void usage() { std::fprintf(stderr, "Usage:\n"); std::fprintf(stderr, " pzstd [args] [FILE(s)]\n"); std::fprintf(stderr, "Parallel ZSTD options:\n"); - std::fprintf(stderr, " -p, --processes # : number of threads to use for (de)compression (default:%d)\n", defaultNumThreads()); + std::fprintf(stderr, " -p, --processes # : number of threads to use for (de)compression (default:)\n"); std::fprintf(stderr, "ZSTD options:\n"); std::fprintf(stderr, " -# : # compression level (1-%d, default:%d)\n", kMaxNonUltraCompressionLevel, kDefaultCompressionLevel); std::fprintf(stderr, " -d, --decompress : decompression\n"); std::fprintf(stderr, " -o file : result stored into `file` (only if 1 input file)\n"); std::fprintf(stderr, " -f, --force : overwrite output without prompting, (de)compress links\n"); std::fprintf(stderr, " --rm : remove source file(s) after successful (de)compression\n"); std::fprintf(stderr, " -k, --keep : preserve source file(s) (default)\n"); std::fprintf(stderr, " -h, --help : display help and exit\n"); std::fprintf(stderr, " -V, --version : display version number and exit\n"); std::fprintf(stderr, " -v, --verbose : verbose mode; specify multiple times to increase log level (default:2)\n"); std::fprintf(stderr, " -q, --quiet : suppress warnings; specify twice to suppress errors too\n"); std::fprintf(stderr, " -c, --stdout : force write to standard output, even if it is the console\n"); #ifdef UTIL_HAS_CREATEFILELIST std::fprintf(stderr, " -r : operate recursively on directories\n"); #endif std::fprintf(stderr, " --ultra : enable levels beyond %i, up to %i (requires more memory)\n", kMaxNonUltraCompressionLevel, ZSTD_maxCLevel()); std::fprintf(stderr, " -C, --check : integrity check (default)\n"); std::fprintf(stderr, " --no-check : no integrity check\n"); std::fprintf(stderr, " -t, --test : test compressed file integrity\n"); std::fprintf(stderr, " -- : all arguments after \"--\" are treated as files\n"); } } // anonymous namespace Options::Options() : numThreads(defaultNumThreads()), maxWindowLog(23), compressionLevel(kDefaultCompressionLevel), decompress(false), overwrite(false), keepSource(true), writeMode(WriteMode::Auto), checksum(true), verbosity(2) {} Options::Status Options::parse(int argc, const char **argv) { bool test = false; bool recursive = false; bool ultra = false; bool forceStdout = false; bool followLinks = false; // Local copy of input files, which are pointers into argv. std::vector localInputFiles; for (int i = 1; i < argc; ++i) { const char *arg = argv[i]; // Protect against empty arguments if (arg[0] == 0) { continue; } // Everything after "--" is an input file if (!std::strcmp(arg, "--")) { ++i; std::copy(argv + i, argv + argc, std::back_inserter(localInputFiles)); break; } // Long arguments that don't have a short option { bool isLongOption = true; if (!std::strcmp(arg, "--rm")) { keepSource = false; } else if (!std::strcmp(arg, "--ultra")) { ultra = true; maxWindowLog = 0; } else if (!std::strcmp(arg, "--no-check")) { checksum = false; } else if (!std::strcmp(arg, "--sparse")) { writeMode = WriteMode::Sparse; notSupported("Sparse mode"); return Status::Failure; } else if (!std::strcmp(arg, "--no-sparse")) { writeMode = WriteMode::Regular; notSupported("Sparse mode"); return Status::Failure; } else if (!std::strcmp(arg, "--dictID")) { notSupported(arg); return Status::Failure; } else if (!std::strcmp(arg, "--no-dictID")) { notSupported(arg); return Status::Failure; } else { isLongOption = false; } if (isLongOption) { continue; } } // Arguments with a short option simply set their short option. const char *options = nullptr; if (!std::strcmp(arg, "--processes")) { options = "p"; } else if (!std::strcmp(arg, "--version")) { options = "V"; } else if (!std::strcmp(arg, "--help")) { options = "h"; } else if (!std::strcmp(arg, "--decompress")) { options = "d"; } else if (!std::strcmp(arg, "--force")) { options = "f"; } else if (!std::strcmp(arg, "--stdout")) { options = "c"; } else if (!std::strcmp(arg, "--keep")) { options = "k"; } else if (!std::strcmp(arg, "--verbose")) { options = "v"; } else if (!std::strcmp(arg, "--quiet")) { options = "q"; } else if (!std::strcmp(arg, "--check")) { options = "C"; } else if (!std::strcmp(arg, "--test")) { options = "t"; } else if (arg[0] == '-' && arg[1] != 0) { options = arg + 1; } else { localInputFiles.emplace_back(arg); continue; } assert(options != nullptr); bool finished = false; while (!finished && *options != 0) { // Parse the compression level if (*options >= '0' && *options <= '9') { compressionLevel = parseUnsigned(&options); continue; } switch (*options) { case 'h': case 'H': usage(); return Status::Message; case 'V': std::fprintf(stderr, "PZSTD version: %s.\n", ZSTD_VERSION_STRING); return Status::Message; case 'p': { finished = true; const char *optionArgument = getArgument(options, argv, i, argc); if (optionArgument == nullptr) { return Status::Failure; } if (*optionArgument < '0' || *optionArgument > '9') { std::fprintf(stderr, "Option -p expects a number, but %s provided\n", optionArgument); return Status::Failure; } numThreads = parseUnsigned(&optionArgument); if (*optionArgument != 0) { std::fprintf(stderr, "Option -p expects a number, but %u%s provided\n", numThreads, optionArgument); return Status::Failure; } break; } case 'o': { finished = true; const char *optionArgument = getArgument(options, argv, i, argc); if (optionArgument == nullptr) { return Status::Failure; } outputFile = optionArgument; break; } case 'C': checksum = true; break; case 'k': keepSource = true; break; case 'd': decompress = true; break; case 'f': overwrite = true; forceStdout = true; followLinks = true; break; case 't': test = true; decompress = true; break; #ifdef UTIL_HAS_CREATEFILELIST case 'r': recursive = true; break; #endif case 'c': outputFile = kStdOut; forceStdout = true; break; case 'v': ++verbosity; break; case 'q': --verbosity; // Ignore them for now break; // Unsupported options from Zstd case 'D': case 's': notSupported("Zstd dictionaries."); return Status::Failure; case 'b': case 'e': case 'i': case 'B': notSupported("Zstd benchmarking options."); return Status::Failure; default: std::fprintf(stderr, "Invalid argument: %s\n", arg); return Status::Failure; } if (!finished) { ++options; } } // while (*options != 0); } // for (int i = 1; i < argc; ++i); // Set options for test mode if (test) { outputFile = nullOutput; keepSource = true; } // Input file defaults to standard input if not provided. if (localInputFiles.empty()) { localInputFiles.emplace_back(kStdIn); } // Check validity of input files if (localInputFiles.size() > 1) { const auto it = std::find(localInputFiles.begin(), localInputFiles.end(), std::string{kStdIn}); if (it != localInputFiles.end()) { std::fprintf( stderr, "Cannot specify standard input when handling multiple files\n"); return Status::Failure; } } if (localInputFiles.size() > 1 || recursive) { if (!outputFile.empty() && outputFile != nullOutput) { std::fprintf( stderr, "Cannot specify an output file when handling multiple inputs\n"); return Status::Failure; } } g_utilDisplayLevel = verbosity; // Remove local input files that are symbolic links if (!followLinks) { std::remove_if(localInputFiles.begin(), localInputFiles.end(), [&](const char *path) { bool isLink = UTIL_isLink(path); if (isLink && verbosity >= 2) { std::fprintf( stderr, "Warning : %s is symbolic link, ignoring\n", path); } return isLink; }); } // Translate input files/directories into files to (de)compress if (recursive) { char *scratchBuffer = nullptr; unsigned numFiles = 0; const char **files = UTIL_createFileList(localInputFiles.data(), localInputFiles.size(), &scratchBuffer, &numFiles, followLinks); if (files == nullptr) { std::fprintf(stderr, "Error traversing directories\n"); return Status::Failure; } auto guard = makeScopeGuard([&] { UTIL_freeFileList(files, scratchBuffer); }); if (numFiles == 0) { std::fprintf(stderr, "No files found\n"); return Status::Failure; } inputFiles.resize(numFiles); std::copy(files, files + numFiles, inputFiles.begin()); } else { inputFiles.resize(localInputFiles.size()); std::copy(localInputFiles.begin(), localInputFiles.end(), inputFiles.begin()); } localInputFiles.clear(); assert(!inputFiles.empty()); // If reading from standard input, default to standard output if (inputFiles[0] == kStdIn && outputFile.empty()) { assert(inputFiles.size() == 1); outputFile = "-"; } if (inputFiles[0] == kStdIn && IS_CONSOLE(stdin)) { assert(inputFiles.size() == 1); std::fprintf(stderr, "Cannot read input from interactive console\n"); return Status::Failure; } if (outputFile == "-" && IS_CONSOLE(stdout) && !(forceStdout && decompress)) { std::fprintf(stderr, "Will not write to console stdout unless -c or -f is " "specified and decompressing\n"); return Status::Failure; } // Check compression level { unsigned maxCLevel = ultra ? ZSTD_maxCLevel() : kMaxNonUltraCompressionLevel; if (compressionLevel > maxCLevel || compressionLevel == 0) { std::fprintf(stderr, "Invalid compression level %u.\n", compressionLevel); return Status::Failure; } } // Check that numThreads is set if (numThreads == 0) { std::fprintf(stderr, "Invalid arguments: # of threads not specified " "and unable to determine hardware concurrency.\n"); return Status::Failure; } // Modify verbosity // If we are piping input and output, turn off interaction if (inputFiles[0] == kStdIn && outputFile == kStdOut && verbosity == 2) { verbosity = 1; } // If we are in multi-file mode, turn off interaction if (inputFiles.size() > 1 && verbosity == 2) { verbosity = 1; } return Status::Success; } std::string Options::getOutputFile(const std::string &inputFile) const { if (!outputFile.empty()) { return outputFile; } // Attempt to add/remove zstd extension from the input file if (decompress) { int stemSize = inputFile.size() - kZstdExtension.size(); if (stemSize > 0 && inputFile.substr(stemSize) == kZstdExtension) { return inputFile.substr(0, stemSize); } else { return ""; } } else { return inputFile + kZstdExtension; } } } Index: vendor/zstd/dist/contrib/pzstd/Pzstd.cpp =================================================================== --- vendor/zstd/dist/contrib/pzstd/Pzstd.cpp (revision 339613) +++ vendor/zstd/dist/contrib/pzstd/Pzstd.cpp (revision 339614) @@ -1,618 +1,611 @@ /* * Copyright (c) 2016-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ +#include "platform.h" /* Large Files support, SET_BINARY_MODE */ #include "Pzstd.h" #include "SkippableFrame.h" #include "utils/FileSystem.h" #include "utils/Range.h" #include "utils/ScopeGuard.h" #include "utils/ThreadPool.h" #include "utils/WorkQueue.h" #include #include #include #include #include #include -#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) -# include /* _O_BINARY */ -# include /* _setmode, _isatty */ -# define SET_BINARY_MODE(file) { if (_setmode(_fileno(file), _O_BINARY) == -1) perror("Cannot set _O_BINARY"); } -#else -# include /* isatty */ -# define SET_BINARY_MODE(file) -#endif namespace pzstd { namespace { #ifdef _WIN32 const std::string nullOutput = "nul"; #else const std::string nullOutput = "/dev/null"; #endif } using std::size_t; static std::uintmax_t fileSizeOrZero(const std::string &file) { if (file == "-") { return 0; } std::error_code ec; auto size = file_size(file, ec); if (ec) { size = 0; } return size; } static std::uint64_t handleOneInput(const Options &options, const std::string &inputFile, FILE* inputFd, const std::string &outputFile, FILE* outputFd, SharedState& state) { auto inputSize = fileSizeOrZero(inputFile); // WorkQueue outlives ThreadPool so in the case of error we are certain // we don't accidently try to call push() on it after it is destroyed WorkQueue> outs{options.numThreads + 1}; std::uint64_t bytesRead; std::uint64_t bytesWritten; { // Initialize the (de)compression thread pool with numThreads ThreadPool executor(options.numThreads); // Run the reader thread on an extra thread ThreadPool readExecutor(1); if (!options.decompress) { // Add a job that reads the input and starts all the compression jobs readExecutor.add( [&state, &outs, &executor, inputFd, inputSize, &options, &bytesRead] { bytesRead = asyncCompressChunks( state, outs, executor, inputFd, inputSize, options.numThreads, options.determineParameters()); }); // Start writing bytesWritten = writeFile(state, outs, outputFd, options.decompress); } else { // Add a job that reads the input and starts all the decompression jobs readExecutor.add([&state, &outs, &executor, inputFd, &bytesRead] { bytesRead = asyncDecompressFrames(state, outs, executor, inputFd); }); // Start writing bytesWritten = writeFile(state, outs, outputFd, options.decompress); } } if (!state.errorHolder.hasError()) { std::string inputFileName = inputFile == "-" ? "stdin" : inputFile; std::string outputFileName = outputFile == "-" ? "stdout" : outputFile; if (!options.decompress) { double ratio = static_cast(bytesWritten) / static_cast(bytesRead + !bytesRead); state.log(INFO, "%-20s :%6.2f%% (%6" PRIu64 " => %6" PRIu64 " bytes, %s)\n", inputFileName.c_str(), ratio * 100, bytesRead, bytesWritten, outputFileName.c_str()); } else { state.log(INFO, "%-20s: %" PRIu64 " bytes \n", inputFileName.c_str(),bytesWritten); } } return bytesWritten; } static FILE *openInputFile(const std::string &inputFile, ErrorHolder &errorHolder) { if (inputFile == "-") { SET_BINARY_MODE(stdin); return stdin; } // Check if input file is a directory { std::error_code ec; if (is_directory(inputFile, ec)) { errorHolder.setError("Output file is a directory -- ignored"); return nullptr; } } auto inputFd = std::fopen(inputFile.c_str(), "rb"); if (!errorHolder.check(inputFd != nullptr, "Failed to open input file")) { return nullptr; } return inputFd; } static FILE *openOutputFile(const Options &options, const std::string &outputFile, SharedState& state) { if (outputFile == "-") { SET_BINARY_MODE(stdout); return stdout; } // Check if the output file exists and then open it if (!options.overwrite && outputFile != nullOutput) { auto outputFd = std::fopen(outputFile.c_str(), "rb"); if (outputFd != nullptr) { std::fclose(outputFd); if (!state.log.logsAt(INFO)) { state.errorHolder.setError("Output file exists"); return nullptr; } state.log( INFO, "pzstd: %s already exists; do you wish to overwrite (y/n) ? ", outputFile.c_str()); int c = getchar(); if (c != 'y' && c != 'Y') { state.errorHolder.setError("Not overwritten"); return nullptr; } } } auto outputFd = std::fopen(outputFile.c_str(), "wb"); if (!state.errorHolder.check( outputFd != nullptr, "Failed to open output file")) { return nullptr; } return outputFd; } int pzstdMain(const Options &options) { int returnCode = 0; SharedState state(options); for (const auto& input : options.inputFiles) { // Setup the shared state auto printErrorGuard = makeScopeGuard([&] { if (state.errorHolder.hasError()) { returnCode = 1; state.log(ERROR, "pzstd: %s: %s.\n", input.c_str(), state.errorHolder.getError().c_str()); } }); // Open the input file auto inputFd = openInputFile(input, state.errorHolder); if (inputFd == nullptr) { continue; } auto closeInputGuard = makeScopeGuard([&] { std::fclose(inputFd); }); // Open the output file auto outputFile = options.getOutputFile(input); if (!state.errorHolder.check(outputFile != "", "Input file does not have extension .zst")) { continue; } auto outputFd = openOutputFile(options, outputFile, state); if (outputFd == nullptr) { continue; } auto closeOutputGuard = makeScopeGuard([&] { std::fclose(outputFd); }); // (de)compress the file handleOneInput(options, input, inputFd, outputFile, outputFd, state); if (state.errorHolder.hasError()) { continue; } // Delete the input file if necessary if (!options.keepSource) { // Be sure that we are done and have written everything before we delete if (!state.errorHolder.check(std::fclose(inputFd) == 0, "Failed to close input file")) { continue; } closeInputGuard.dismiss(); if (!state.errorHolder.check(std::fclose(outputFd) == 0, "Failed to close output file")) { continue; } closeOutputGuard.dismiss(); if (std::remove(input.c_str()) != 0) { state.errorHolder.setError("Failed to remove input file"); continue; } } } // Returns 1 if any of the files failed to (de)compress. return returnCode; } /// Construct a `ZSTD_inBuffer` that points to the data in `buffer`. static ZSTD_inBuffer makeZstdInBuffer(const Buffer& buffer) { return ZSTD_inBuffer{buffer.data(), buffer.size(), 0}; } /** * Advance `buffer` and `inBuffer` by the amount of data read, as indicated by * `inBuffer.pos`. */ void advance(Buffer& buffer, ZSTD_inBuffer& inBuffer) { auto pos = inBuffer.pos; inBuffer.src = static_cast(inBuffer.src) + pos; inBuffer.size -= pos; inBuffer.pos = 0; return buffer.advance(pos); } /// Construct a `ZSTD_outBuffer` that points to the data in `buffer`. static ZSTD_outBuffer makeZstdOutBuffer(Buffer& buffer) { return ZSTD_outBuffer{buffer.data(), buffer.size(), 0}; } /** * Split `buffer` and advance `outBuffer` by the amount of data written, as * indicated by `outBuffer.pos`. */ Buffer split(Buffer& buffer, ZSTD_outBuffer& outBuffer) { auto pos = outBuffer.pos; outBuffer.dst = static_cast(outBuffer.dst) + pos; outBuffer.size -= pos; outBuffer.pos = 0; return buffer.splitAt(pos); } /** * Stream chunks of input from `in`, compress it, and stream it out to `out`. * * @param state The shared state * @param in Queue that we `pop()` input buffers from * @param out Queue that we `push()` compressed output buffers to * @param maxInputSize An upper bound on the size of the input */ static void compress( SharedState& state, std::shared_ptr in, std::shared_ptr out, size_t maxInputSize) { auto& errorHolder = state.errorHolder; auto guard = makeScopeGuard([&] { out->finish(); }); // Initialize the CCtx auto ctx = state.cStreamPool->get(); if (!errorHolder.check(ctx != nullptr, "Failed to allocate ZSTD_CStream")) { return; } { auto err = ZSTD_resetCStream(ctx.get(), 0); if (!errorHolder.check(!ZSTD_isError(err), ZSTD_getErrorName(err))) { return; } } // Allocate space for the result auto outBuffer = Buffer(ZSTD_compressBound(maxInputSize)); auto zstdOutBuffer = makeZstdOutBuffer(outBuffer); { Buffer inBuffer; // Read a buffer in from the input queue while (in->pop(inBuffer) && !errorHolder.hasError()) { auto zstdInBuffer = makeZstdInBuffer(inBuffer); // Compress the whole buffer and send it to the output queue while (!inBuffer.empty() && !errorHolder.hasError()) { if (!errorHolder.check( !outBuffer.empty(), "ZSTD_compressBound() was too small")) { return; } // Compress auto err = ZSTD_compressStream(ctx.get(), &zstdOutBuffer, &zstdInBuffer); if (!errorHolder.check(!ZSTD_isError(err), ZSTD_getErrorName(err))) { return; } // Split the compressed data off outBuffer and pass to the output queue out->push(split(outBuffer, zstdOutBuffer)); // Forget about the data we already compressed advance(inBuffer, zstdInBuffer); } } } // Write the epilog size_t bytesLeft; do { if (!errorHolder.check( !outBuffer.empty(), "ZSTD_compressBound() was too small")) { return; } bytesLeft = ZSTD_endStream(ctx.get(), &zstdOutBuffer); if (!errorHolder.check( !ZSTD_isError(bytesLeft), ZSTD_getErrorName(bytesLeft))) { return; } out->push(split(outBuffer, zstdOutBuffer)); } while (bytesLeft != 0 && !errorHolder.hasError()); } /** * Calculates how large each independently compressed frame should be. * * @param size The size of the source if known, 0 otherwise * @param numThreads The number of threads available to run compression jobs on * @param params The zstd parameters to be used for compression */ static size_t calculateStep( std::uintmax_t size, size_t numThreads, const ZSTD_parameters ¶ms) { (void)size; (void)numThreads; return size_t{1} << (params.cParams.windowLog + 2); } namespace { enum class FileStatus { Continue, Done, Error }; /// Determines the status of the file descriptor `fd`. FileStatus fileStatus(FILE* fd) { if (std::feof(fd)) { return FileStatus::Done; } else if (std::ferror(fd)) { return FileStatus::Error; } return FileStatus::Continue; } } // anonymous namespace /** * Reads `size` data in chunks of `chunkSize` and puts it into `queue`. * Will read less if an error or EOF occurs. * Returns the status of the file after all of the reads have occurred. */ static FileStatus readData(BufferWorkQueue& queue, size_t chunkSize, size_t size, FILE* fd, std::uint64_t *totalBytesRead) { Buffer buffer(size); while (!buffer.empty()) { auto bytesRead = std::fread(buffer.data(), 1, std::min(chunkSize, buffer.size()), fd); *totalBytesRead += bytesRead; queue.push(buffer.splitAt(bytesRead)); auto status = fileStatus(fd); if (status != FileStatus::Continue) { return status; } } return FileStatus::Continue; } std::uint64_t asyncCompressChunks( SharedState& state, WorkQueue>& chunks, ThreadPool& executor, FILE* fd, std::uintmax_t size, size_t numThreads, ZSTD_parameters params) { auto chunksGuard = makeScopeGuard([&] { chunks.finish(); }); std::uint64_t bytesRead = 0; // Break the input up into chunks of size `step` and compress each chunk // independently. size_t step = calculateStep(size, numThreads, params); state.log(DEBUG, "Chosen frame size: %zu\n", step); auto status = FileStatus::Continue; while (status == FileStatus::Continue && !state.errorHolder.hasError()) { // Make a new input queue that we will put the chunk's input data into. auto in = std::make_shared(); auto inGuard = makeScopeGuard([&] { in->finish(); }); // Make a new output queue that compress will put the compressed data into. auto out = std::make_shared(); // Start compression in the thread pool executor.add([&state, in, out, step] { return compress( state, std::move(in), std::move(out), step); }); // Pass the output queue to the writer thread. chunks.push(std::move(out)); state.log(VERBOSE, "%s\n", "Starting a new frame"); // Fill the input queue for the compression job we just started status = readData(*in, ZSTD_CStreamInSize(), step, fd, &bytesRead); } state.errorHolder.check(status != FileStatus::Error, "Error reading input"); return bytesRead; } /** * Decompress a frame, whose data is streamed into `in`, and stream the output * to `out`. * * @param state The shared state * @param in Queue that we `pop()` input buffers from. It contains * exactly one compressed frame. * @param out Queue that we `push()` decompressed output buffers to */ static void decompress( SharedState& state, std::shared_ptr in, std::shared_ptr out) { auto& errorHolder = state.errorHolder; auto guard = makeScopeGuard([&] { out->finish(); }); // Initialize the DCtx auto ctx = state.dStreamPool->get(); if (!errorHolder.check(ctx != nullptr, "Failed to allocate ZSTD_DStream")) { return; } { auto err = ZSTD_resetDStream(ctx.get()); if (!errorHolder.check(!ZSTD_isError(err), ZSTD_getErrorName(err))) { return; } } const size_t outSize = ZSTD_DStreamOutSize(); Buffer inBuffer; size_t returnCode = 0; // Read a buffer in from the input queue while (in->pop(inBuffer) && !errorHolder.hasError()) { auto zstdInBuffer = makeZstdInBuffer(inBuffer); // Decompress the whole buffer and send it to the output queue while (!inBuffer.empty() && !errorHolder.hasError()) { // Allocate a buffer with at least outSize bytes. Buffer outBuffer(outSize); auto zstdOutBuffer = makeZstdOutBuffer(outBuffer); // Decompress returnCode = ZSTD_decompressStream(ctx.get(), &zstdOutBuffer, &zstdInBuffer); if (!errorHolder.check( !ZSTD_isError(returnCode), ZSTD_getErrorName(returnCode))) { return; } // Pass the buffer with the decompressed data to the output queue out->push(split(outBuffer, zstdOutBuffer)); // Advance past the input we already read advance(inBuffer, zstdInBuffer); if (returnCode == 0) { // The frame is over, prepare to (maybe) start a new frame ZSTD_initDStream(ctx.get()); } } } if (!errorHolder.check(returnCode <= 1, "Incomplete block")) { return; } // We've given ZSTD_decompressStream all of our data, but there may still // be data to read. while (returnCode == 1) { // Allocate a buffer with at least outSize bytes. Buffer outBuffer(outSize); auto zstdOutBuffer = makeZstdOutBuffer(outBuffer); // Pass in no input. ZSTD_inBuffer zstdInBuffer{nullptr, 0, 0}; // Decompress returnCode = ZSTD_decompressStream(ctx.get(), &zstdOutBuffer, &zstdInBuffer); if (!errorHolder.check( !ZSTD_isError(returnCode), ZSTD_getErrorName(returnCode))) { return; } // Pass the buffer with the decompressed data to the output queue out->push(split(outBuffer, zstdOutBuffer)); } } std::uint64_t asyncDecompressFrames( SharedState& state, WorkQueue>& frames, ThreadPool& executor, FILE* fd) { auto framesGuard = makeScopeGuard([&] { frames.finish(); }); std::uint64_t totalBytesRead = 0; // Split the source up into its component frames. // If we find our recognized skippable frame we know the next frames size // which means that we can decompress each standard frame in independently. // Otherwise, we will decompress using only one decompression task. const size_t chunkSize = ZSTD_DStreamInSize(); auto status = FileStatus::Continue; while (status == FileStatus::Continue && !state.errorHolder.hasError()) { // Make a new input queue that we will put the frames's bytes into. auto in = std::make_shared(); auto inGuard = makeScopeGuard([&] { in->finish(); }); // Make a output queue that decompress will put the decompressed data into auto out = std::make_shared(); size_t frameSize; { // Calculate the size of the next frame. // frameSize is 0 if the frame info can't be decoded. Buffer buffer(SkippableFrame::kSize); auto bytesRead = std::fread(buffer.data(), 1, buffer.size(), fd); totalBytesRead += bytesRead; status = fileStatus(fd); if (bytesRead == 0 && status != FileStatus::Continue) { break; } buffer.subtract(buffer.size() - bytesRead); frameSize = SkippableFrame::tryRead(buffer.range()); in->push(std::move(buffer)); } if (frameSize == 0) { // We hit a non SkippableFrame, so this will be the last job. // Make sure that we don't use too much memory in->setMaxSize(64); out->setMaxSize(64); } // Start decompression in the thread pool executor.add([&state, in, out] { return decompress(state, std::move(in), std::move(out)); }); // Pass the output queue to the writer thread frames.push(std::move(out)); if (frameSize == 0) { // We hit a non SkippableFrame ==> not compressed by pzstd or corrupted // Pass the rest of the source to this decompression task state.log(VERBOSE, "%s\n", "Input not in pzstd format, falling back to serial decompression"); while (status == FileStatus::Continue && !state.errorHolder.hasError()) { status = readData(*in, chunkSize, chunkSize, fd, &totalBytesRead); } break; } state.log(VERBOSE, "Decompressing a frame of size %zu", frameSize); // Fill the input queue for the decompression job we just started status = readData(*in, chunkSize, frameSize, fd, &totalBytesRead); } state.errorHolder.check(status != FileStatus::Error, "Error reading input"); return totalBytesRead; } /// Write `data` to `fd`, returns true iff success. static bool writeData(ByteRange data, FILE* fd) { while (!data.empty()) { data.advance(std::fwrite(data.begin(), 1, data.size(), fd)); if (std::ferror(fd)) { return false; } } return true; } std::uint64_t writeFile( SharedState& state, WorkQueue>& outs, FILE* outputFd, bool decompress) { auto& errorHolder = state.errorHolder; auto lineClearGuard = makeScopeGuard([&state] { state.log.clear(INFO); }); std::uint64_t bytesWritten = 0; std::shared_ptr out; // Grab the output queue for each decompression job (in order). while (outs.pop(out)) { if (errorHolder.hasError()) { continue; } if (!decompress) { // If we are compressing and want to write skippable frames we can't // start writing before compression is done because we need to know the // compressed size. // Wait for the compressed size to be available and write skippable frame SkippableFrame frame(out->size()); if (!writeData(frame.data(), outputFd)) { errorHolder.setError("Failed to write output"); return bytesWritten; } bytesWritten += frame.kSize; } // For each chunk of the frame: Pop it from the queue and write it Buffer buffer; while (out->pop(buffer) && !errorHolder.hasError()) { if (!writeData(buffer.range(), outputFd)) { errorHolder.setError("Failed to write output"); return bytesWritten; } bytesWritten += buffer.size(); state.log.update(INFO, "Written: %u MB ", static_cast(bytesWritten >> 20)); } } return bytesWritten; } } Index: vendor/zstd/dist/contrib/seekable_format/examples/Makefile =================================================================== --- vendor/zstd/dist/contrib/seekable_format/examples/Makefile (revision 339613) +++ vendor/zstd/dist/contrib/seekable_format/examples/Makefile (revision 339614) @@ -1,42 +1,48 @@ # ################################################################ # Copyright (c) 2017-present, Facebook, Inc. # All rights reserved. # # This source code is licensed under both the BSD-style license (found in the # LICENSE file in the root directory of this source tree) and the GPLv2 (found # in the COPYING file in the root directory of this source tree). # ################################################################ # This Makefile presumes libzstd is built, using `make` in / or /lib/ -LDFLAGS += ../../../lib/libzstd.a +ZSTDLIB_PATH = ../../../lib +ZSTDLIB_NAME = libzstd.a +ZSTDLIB = $(ZSTDLIB_PATH)/$(ZSTDLIB_NAME) + CPPFLAGS += -I../ -I../../../lib -I../../../lib/common CFLAGS ?= -O3 CFLAGS += -g -SEEKABLE_OBJS = ../zstdseek_compress.c ../zstdseek_decompress.c +SEEKABLE_OBJS = ../zstdseek_compress.c ../zstdseek_decompress.c $(ZSTDLIB) .PHONY: default all clean test default: all all: seekable_compression seekable_decompression parallel_processing + +$(ZSTDLIB): + make -C $(ZSTDLIB_PATH) $(ZSTDLIB_NAME) seekable_compression : seekable_compression.c $(SEEKABLE_OBJS) $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ seekable_decompression : seekable_decompression.c $(SEEKABLE_OBJS) $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ parallel_processing : parallel_processing.c $(SEEKABLE_OBJS) $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ -pthread parallel_compression : parallel_compression.c $(SEEKABLE_OBJS) $(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@ -pthread clean: @rm -f core *.o tmp* result* *.zst \ seekable_compression seekable_decompression \ parallel_processing parallel_compression @echo Cleaning completed Index: vendor/zstd/dist/contrib/seekable_format/examples/seekable_compression.c =================================================================== --- vendor/zstd/dist/contrib/seekable_format/examples/seekable_compression.c (revision 339613) +++ vendor/zstd/dist/contrib/seekable_format/examples/seekable_compression.c (revision 339614) @@ -1,132 +1,133 @@ /* * Copyright (c) 2017-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ #include // malloc, free, exit, atoi #include // fprintf, perror, feof, fopen, etc. #include // strlen, memset, strcat #define ZSTD_STATIC_LINKING_ONLY #include // presumes zstd library is installed #include "zstd_seekable.h" static void* malloc_orDie(size_t size) { void* const buff = malloc(size); if (buff) return buff; /* error */ perror("malloc:"); exit(1); } static FILE* fopen_orDie(const char *filename, const char *instruction) { FILE* const inFile = fopen(filename, instruction); if (inFile) return inFile; /* error */ perror(filename); exit(3); } static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file) { size_t const readSize = fread(buffer, 1, sizeToRead, file); if (readSize == sizeToRead) return readSize; /* good */ if (feof(file)) return readSize; /* good, reached end of file */ /* error */ perror("fread"); exit(4); } static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file) { size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file); if (writtenSize == sizeToWrite) return sizeToWrite; /* good */ /* error */ perror("fwrite"); exit(5); } static size_t fclose_orDie(FILE* file) { if (!fclose(file)) return 0; /* error */ perror("fclose"); exit(6); } static void compressFile_orDie(const char* fname, const char* outName, int cLevel, unsigned frameSize) { FILE* const fin = fopen_orDie(fname, "rb"); FILE* const fout = fopen_orDie(outName, "wb"); size_t const buffInSize = ZSTD_CStreamInSize(); /* can always read one full block */ void* const buffIn = malloc_orDie(buffInSize); size_t const buffOutSize = ZSTD_CStreamOutSize(); /* can always flush a full block */ void* const buffOut = malloc_orDie(buffOutSize); ZSTD_seekable_CStream* const cstream = ZSTD_seekable_createCStream(); if (cstream==NULL) { fprintf(stderr, "ZSTD_seekable_createCStream() error \n"); exit(10); } size_t const initResult = ZSTD_seekable_initCStream(cstream, cLevel, 1, frameSize); if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_initCStream() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); } size_t read, toRead = buffInSize; while( (read = fread_orDie(buffIn, toRead, fin)) ) { ZSTD_inBuffer input = { buffIn, read, 0 }; while (input.pos < input.size) { ZSTD_outBuffer output = { buffOut, buffOutSize, 0 }; toRead = ZSTD_seekable_compressStream(cstream, &output , &input); /* toRead is guaranteed to be <= ZSTD_CStreamInSize() */ if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_seekable_compressStream() error : %s \n", ZSTD_getErrorName(toRead)); exit(12); } if (toRead > buffInSize) toRead = buffInSize; /* Safely handle case when `buffInSize` is manually changed to a value < ZSTD_CStreamInSize()*/ fwrite_orDie(buffOut, output.pos, fout); } } while (1) { ZSTD_outBuffer output = { buffOut, buffOutSize, 0 }; size_t const remainingToFlush = ZSTD_seekable_endStream(cstream, &output); /* close stream */ if (ZSTD_isError(remainingToFlush)) { fprintf(stderr, "ZSTD_seekable_endStream() error : %s \n", ZSTD_getErrorName(remainingToFlush)); exit(13); } fwrite_orDie(buffOut, output.pos, fout); if (!remainingToFlush) break; } ZSTD_seekable_freeCStream(cstream); fclose_orDie(fout); fclose_orDie(fin); free(buffIn); free(buffOut); } -static const char* createOutFilename_orDie(const char* filename) +static char* createOutFilename_orDie(const char* filename) { size_t const inL = strlen(filename); size_t const outL = inL + 5; void* outSpace = malloc_orDie(outL); memset(outSpace, 0, outL); strcat(outSpace, filename); strcat(outSpace, ".zst"); - return (const char*)outSpace; + return (char*)outSpace; } int main(int argc, const char** argv) { const char* const exeName = argv[0]; if (argc!=3) { printf("wrong arguments\n"); printf("usage:\n"); printf("%s FILE FRAME_SIZE\n", exeName); return 1; } { const char* const inFileName = argv[1]; unsigned const frameSize = (unsigned)atoi(argv[2]); - const char* const outFileName = createOutFilename_orDie(inFileName); + char* const outFileName = createOutFilename_orDie(inFileName); compressFile_orDie(inFileName, outFileName, 5, frameSize); + free(outFileName); } return 0; } Index: vendor/zstd/dist/contrib/seekable_format/examples/seekable_decompression.c =================================================================== --- vendor/zstd/dist/contrib/seekable_format/examples/seekable_decompression.c (revision 339613) +++ vendor/zstd/dist/contrib/seekable_format/examples/seekable_decompression.c (revision 339614) @@ -1,138 +1,138 @@ /* * Copyright (c) 2017-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ #include // malloc, exit #include // fprintf, perror, feof #include // strerror #include // errno #define ZSTD_STATIC_LINKING_ONLY #include // presumes zstd library is installed #include #include "zstd_seekable.h" #define MIN(a, b) ((a) < (b) ? (a) : (b)) static void* malloc_orDie(size_t size) { void* const buff = malloc(size); if (buff) return buff; /* error */ perror("malloc"); exit(1); } static void* realloc_orDie(void* ptr, size_t size) { ptr = realloc(ptr, size); if (ptr) return ptr; /* error */ perror("realloc"); exit(1); } static FILE* fopen_orDie(const char *filename, const char *instruction) { FILE* const inFile = fopen(filename, instruction); if (inFile) return inFile; /* error */ perror(filename); exit(3); } static size_t fread_orDie(void* buffer, size_t sizeToRead, FILE* file) { size_t const readSize = fread(buffer, 1, sizeToRead, file); if (readSize == sizeToRead) return readSize; /* good */ if (feof(file)) return readSize; /* good, reached end of file */ /* error */ perror("fread"); exit(4); } static size_t fwrite_orDie(const void* buffer, size_t sizeToWrite, FILE* file) { size_t const writtenSize = fwrite(buffer, 1, sizeToWrite, file); if (writtenSize == sizeToWrite) return sizeToWrite; /* good */ /* error */ perror("fwrite"); exit(5); } static size_t fclose_orDie(FILE* file) { if (!fclose(file)) return 0; /* error */ perror("fclose"); exit(6); } static void fseek_orDie(FILE* file, long int offset, int origin) { if (!fseek(file, offset, origin)) { if (!fflush(file)) return; } /* error */ perror("fseek"); exit(7); } -static void decompressFile_orDie(const char* fname, unsigned startOffset, unsigned endOffset) +static void decompressFile_orDie(const char* fname, off_t startOffset, off_t endOffset) { FILE* const fin = fopen_orDie(fname, "rb"); FILE* const fout = stdout; size_t const buffOutSize = ZSTD_DStreamOutSize(); /* Guarantee to successfully flush at least one complete compressed block in all circumstances. */ void* const buffOut = malloc_orDie(buffOutSize); ZSTD_seekable* const seekable = ZSTD_seekable_create(); if (seekable==NULL) { fprintf(stderr, "ZSTD_seekable_create() error \n"); exit(10); } size_t const initResult = ZSTD_seekable_initFile(seekable, fin); if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_seekable_init() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); } while (startOffset < endOffset) { size_t const result = ZSTD_seekable_decompress(seekable, buffOut, MIN(endOffset - startOffset, buffOutSize), startOffset); if (ZSTD_isError(result)) { fprintf(stderr, "ZSTD_seekable_decompress() error : %s \n", ZSTD_getErrorName(result)); exit(12); } fwrite_orDie(buffOut, result, fout); startOffset += result; } ZSTD_seekable_free(seekable); fclose_orDie(fin); fclose_orDie(fout); free(buffOut); } int main(int argc, const char** argv) { const char* const exeName = argv[0]; if (argc!=4) { fprintf(stderr, "wrong arguments\n"); fprintf(stderr, "usage:\n"); fprintf(stderr, "%s FILE START END\n", exeName); return 1; } { const char* const inFilename = argv[1]; - unsigned const startOffset = (unsigned) atoi(argv[2]); - unsigned const endOffset = (unsigned) atoi(argv[3]); + off_t const startOffset = atoll(argv[2]); + off_t const endOffset = atoll(argv[3]); decompressFile_orDie(inFilename, startOffset, endOffset); } return 0; } Index: vendor/zstd/dist/contrib/seekable_format/zstd_seekable.h =================================================================== --- vendor/zstd/dist/contrib/seekable_format/zstd_seekable.h (revision 339613) +++ vendor/zstd/dist/contrib/seekable_format/zstd_seekable.h (revision 339614) @@ -1,184 +1,186 @@ #ifndef SEEKABLE_H #define SEEKABLE_H #if defined (__cplusplus) extern "C" { #endif #include +#include "zstd.h" /* ZSTDLIB_API */ -static const unsigned ZSTD_seekTableFooterSize = 9; + +#define ZSTD_seekTableFooterSize 9 #define ZSTD_SEEKABLE_MAGICNUMBER 0x8F92EAB1 #define ZSTD_SEEKABLE_MAXFRAMES 0x8000000U /* Limit the maximum size to avoid any potential issues storing the compressed size */ #define ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE 0x80000000U /*-**************************************************************************** * Seekable Format * * The seekable format splits the compressed data into a series of "frames", * each compressed individually so that decompression of a section in the * middle of an archive only requires zstd to decompress at most a frame's * worth of extra data, instead of the entire archive. ******************************************************************************/ typedef struct ZSTD_seekable_CStream_s ZSTD_seekable_CStream; typedef struct ZSTD_seekable_s ZSTD_seekable; /*-**************************************************************************** * Seekable compression - HowTo * A ZSTD_seekable_CStream object is required to tracking streaming operation. * Use ZSTD_seekable_createCStream() and ZSTD_seekable_freeCStream() to create/ * release resources. * * Streaming objects are reusable to avoid allocation and deallocation, * to start a new compression operation call ZSTD_seekable_initCStream() on the * compressor. * * Data streamed to the seekable compressor will automatically be split into * frames of size `maxFrameSize` (provided in ZSTD_seekable_initCStream()), * or if none is provided, will be cut off whenever ZSTD_seekable_endFrame() is * called or when the default maximum frame size (2GB) is reached. * * Use ZSTD_seekable_initCStream() to initialize a ZSTD_seekable_CStream object * for a new compression operation. * `maxFrameSize` indicates the size at which to automatically start a new * seekable frame. `maxFrameSize == 0` implies the default maximum size. * `checksumFlag` indicates whether or not the seek table should include frame * checksums on the uncompressed data for verification. * @return : a size hint for input to provide for compression, or an error code * checkable with ZSTD_isError() * * Use ZSTD_seekable_compressStream() repetitively to consume input stream. * The function will automatically update both `pos` fields. * Note that it may not consume the entire input, in which case `pos < size`, * and it's up to the caller to present again remaining data. * @return : a size hint, preferred nb of bytes to use as input for next * function call or an error code, which can be tested using * ZSTD_isError(). * Note 1 : it's just a hint, to help latency a little, any other * value will work fine. * * At any time, call ZSTD_seekable_endFrame() to end the current frame and * start a new one. * * ZSTD_seekable_endStream() will end the current frame, and then write the seek * table so that decompressors can efficiently find compressed frames. * ZSTD_seekable_endStream() may return a number > 0 if it was unable to flush * all the necessary data to `output`. In this case, it should be called again * until all remaining data is flushed out and 0 is returned. ******************************************************************************/ /*===== Seekable compressor management =====*/ ZSTDLIB_API ZSTD_seekable_CStream* ZSTD_seekable_createCStream(void); ZSTDLIB_API size_t ZSTD_seekable_freeCStream(ZSTD_seekable_CStream* zcs); /*===== Seekable compression functions =====*/ ZSTDLIB_API size_t ZSTD_seekable_initCStream(ZSTD_seekable_CStream* zcs, int compressionLevel, int checksumFlag, unsigned maxFrameSize); ZSTDLIB_API size_t ZSTD_seekable_compressStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input); ZSTDLIB_API size_t ZSTD_seekable_endFrame(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output); ZSTDLIB_API size_t ZSTD_seekable_endStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output); /*= Raw seek table API * These functions allow for the seek table to be constructed directly. * This table can then be appended to a file of concatenated frames. * This allows the frames to be compressed independently, even in parallel, * and compiled together afterward into a seekable archive. * * Use ZSTD_seekable_createFrameLog() to allocate and initialize a tracking * structure. * * Call ZSTD_seekable_logFrame() once for each frame in the archive. * checksum is optional, and will not be used if checksumFlag was 0 when the * frame log was created. If present, it should be the least significant 32 * bits of the XXH64 hash of the uncompressed data. * * Call ZSTD_seekable_writeSeekTable to serialize the data into a seek table. * If the entire table was written, the return value will be 0. Otherwise, * it will be equal to the number of bytes left to write. */ typedef struct ZSTD_frameLog_s ZSTD_frameLog; ZSTDLIB_API ZSTD_frameLog* ZSTD_seekable_createFrameLog(int checksumFlag); ZSTDLIB_API size_t ZSTD_seekable_freeFrameLog(ZSTD_frameLog* fl); ZSTDLIB_API size_t ZSTD_seekable_logFrame(ZSTD_frameLog* fl, unsigned compressedSize, unsigned decompressedSize, unsigned checksum); ZSTDLIB_API size_t ZSTD_seekable_writeSeekTable(ZSTD_frameLog* fl, ZSTD_outBuffer* output); /*-**************************************************************************** * Seekable decompression - HowTo * A ZSTD_seekable object is required to tracking the seekTable. * * Call ZSTD_seekable_init* to initialize a ZSTD_seekable object with the * the seek table provided in the input. * There are three modes for ZSTD_seekable_init: * - ZSTD_seekable_initBuff() : An in-memory API. The data contained in * `src` should be the entire seekable file, including the seek table. * `src` should be kept alive and unmodified until the ZSTD_seekable object * is freed or reset. * - ZSTD_seekable_initFile() : A simplified file API using stdio. fread and * fseek will be used to access the required data for building the seek * table and doing decompression operations. `src` should not be closed * or modified until the ZSTD_seekable object is freed or reset. * - ZSTD_seekable_initAdvanced() : A general API allowing the client to * provide its own read and seek callbacks. * + ZSTD_seekable_read() : read exactly `n` bytes into `buffer`. * Premature EOF should be treated as an error. * + ZSTD_seekable_seek() : seek the read head to `offset` from `origin`, * where origin is either SEEK_SET (beginning of * file), or SEEK_END (end of file). * Both functions should return a non-negative value in case of success, and a * negative value in case of failure. If implementing using this API and * stdio, be careful with files larger than 4GB and fseek. All of these * functions return an error code checkable with ZSTD_isError(). * * Call ZSTD_seekable_decompress to decompress `dstSize` bytes at decompressed * offset `offset`. ZSTD_seekable_decompress may have to decompress the entire * prefix of the frame before the desired data if it has not already processed * this section. If ZSTD_seekable_decompress is called multiple times for a * consecutive range of data, it will efficiently retain the decompressor object * and avoid redecompressing frame prefixes. The return value is the number of * bytes decompressed, or an error code checkable with ZSTD_isError(). * * The seek table access functions can be used to obtain the data contained * in the seek table. If frameIndex is larger than the value returned by * ZSTD_seekable_getNumFrames(), they will return error codes checkable with * ZSTD_isError(). Note that since the offset access functions return * unsigned long long instead of size_t, in this case they will instead return * the value ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE. ******************************************************************************/ /*===== Seekable decompressor management =====*/ ZSTDLIB_API ZSTD_seekable* ZSTD_seekable_create(void); ZSTDLIB_API size_t ZSTD_seekable_free(ZSTD_seekable* zs); /*===== Seekable decompression functions =====*/ ZSTDLIB_API size_t ZSTD_seekable_initBuff(ZSTD_seekable* zs, const void* src, size_t srcSize); ZSTDLIB_API size_t ZSTD_seekable_initFile(ZSTD_seekable* zs, FILE* src); ZSTDLIB_API size_t ZSTD_seekable_decompress(ZSTD_seekable* zs, void* dst, size_t dstSize, unsigned long long offset); ZSTDLIB_API size_t ZSTD_seekable_decompressFrame(ZSTD_seekable* zs, void* dst, size_t dstSize, unsigned frameIndex); #define ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE (0ULL-2) /*===== Seek Table access functions =====*/ ZSTDLIB_API unsigned ZSTD_seekable_getNumFrames(ZSTD_seekable* const zs); ZSTDLIB_API unsigned long long ZSTD_seekable_getFrameCompressedOffset(ZSTD_seekable* const zs, unsigned frameIndex); ZSTDLIB_API unsigned long long ZSTD_seekable_getFrameDecompressedOffset(ZSTD_seekable* const zs, unsigned frameIndex); ZSTDLIB_API size_t ZSTD_seekable_getFrameCompressedSize(ZSTD_seekable* const zs, unsigned frameIndex); ZSTDLIB_API size_t ZSTD_seekable_getFrameDecompressedSize(ZSTD_seekable* const zs, unsigned frameIndex); ZSTDLIB_API unsigned ZSTD_seekable_offsetToFrameIndex(ZSTD_seekable* const zs, unsigned long long offset); /*===== Seekable advanced I/O API =====*/ typedef int(ZSTD_seekable_read)(void* opaque, void* buffer, size_t n); typedef int(ZSTD_seekable_seek)(void* opaque, long long offset, int origin); typedef struct { void* opaque; ZSTD_seekable_read* read; ZSTD_seekable_seek* seek; } ZSTD_seekable_customFile; ZSTDLIB_API size_t ZSTD_seekable_initAdvanced(ZSTD_seekable* zs, ZSTD_seekable_customFile src); #if defined (__cplusplus) } #endif #endif Index: vendor/zstd/dist/contrib/seekable_format/zstdseek_decompress.c =================================================================== --- vendor/zstd/dist/contrib/seekable_format/zstdseek_decompress.c (revision 339613) +++ vendor/zstd/dist/contrib/seekable_format/zstdseek_decompress.c (revision 339614) @@ -1,462 +1,464 @@ /* * Copyright (c) 2017-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. */ /* ********************************************************* * Turn on Large Files support (>4GB) for 32-bit Linux/Unix ***********************************************************/ #if !defined(__64BIT__) || defined(__MINGW32__) /* No point defining Large file for 64 bit but MinGW-w64 requires it */ # if !defined(_FILE_OFFSET_BITS) # define _FILE_OFFSET_BITS 64 /* turn off_t into a 64-bit type for ftello, fseeko */ # endif # if !defined(_LARGEFILE_SOURCE) /* obsolete macro, replaced with _FILE_OFFSET_BITS */ # define _LARGEFILE_SOURCE 1 /* Large File Support extension (LFS) - fseeko, ftello */ # endif # if defined(_AIX) || defined(__hpux) # define _LARGE_FILES /* Large file support on 32-bits AIX and HP-UX */ # endif #endif /* ************************************************************ -* Avoid fseek()'s 2GiB barrier with MSVC, MacOS, *BSD, MinGW +* Avoid fseek()'s 2GiB barrier with MSVC, macOS, *BSD, MinGW ***************************************************************/ #if defined(_MSC_VER) && _MSC_VER >= 1400 # define LONG_SEEK _fseeki64 #elif !defined(__64BIT__) && (PLATFORM_POSIX_VERSION >= 200112L) /* No point defining Large file for 64 bit */ # define LONG_SEEK fseeko #elif defined(__MINGW32__) && !defined(__STRICT_ANSI__) && !defined(__NO_MINGW_LFS) && defined(__MSVCRT__) # define LONG_SEEK fseeko64 #elif defined(_WIN32) && !defined(__DJGPP__) # include static int LONG_SEEK(FILE* file, __int64 offset, int origin) { LARGE_INTEGER off; DWORD method; off.QuadPart = offset; if (origin == SEEK_END) method = FILE_END; else if (origin == SEEK_CUR) method = FILE_CURRENT; else method = FILE_BEGIN; if (SetFilePointerEx((HANDLE) _get_osfhandle(_fileno(file)), off, NULL, method)) return 0; else return -1; } #else # define LONG_SEEK fseek #endif #include /* malloc, free */ #include /* FILE* */ +#include #define XXH_STATIC_LINKING_ONLY #define XXH_NAMESPACE ZSTD_ #include "xxhash.h" #define ZSTD_STATIC_LINKING_ONLY #include "zstd.h" #include "zstd_errors.h" #include "mem.h" #include "zstd_seekable.h" #undef ERROR #define ERROR(name) ((size_t)-ZSTD_error_##name) #define CHECK_IO(f) { int const errcod = (f); if (errcod < 0) return ERROR(seekableIO); } #undef MIN #undef MAX #define MIN(a, b) ((a) < (b) ? (a) : (b)) #define MAX(a, b) ((a) > (b) ? (a) : (b)) /* Special-case callbacks for FILE* and in-memory modes, so that we can treat * them the same way as the advanced API */ static int ZSTD_seekable_read_FILE(void* opaque, void* buffer, size_t n) { size_t const result = fread(buffer, 1, n, (FILE*)opaque); if (result != n) { return -1; } return 0; } -static int ZSTD_seekable_seek_FILE(void* opaque, S64 offset, int origin) +static int ZSTD_seekable_seek_FILE(void* opaque, long long offset, int origin) { int const ret = LONG_SEEK((FILE*)opaque, offset, origin); if (ret) return ret; return fflush((FILE*)opaque); } typedef struct { const void *ptr; size_t size; size_t pos; } buffWrapper_t; static int ZSTD_seekable_read_buff(void* opaque, void* buffer, size_t n) { buffWrapper_t* buff = (buffWrapper_t*) opaque; if (buff->size + n > buff->pos) return -1; memcpy(buffer, (const BYTE*)buff->ptr + buff->pos, n); buff->pos += n; return 0; } -static int ZSTD_seekable_seek_buff(void* opaque, S64 offset, int origin) +static int ZSTD_seekable_seek_buff(void* opaque, long long offset, int origin) { - buffWrapper_t* buff = (buffWrapper_t*) opaque; + buffWrapper_t* const buff = (buffWrapper_t*) opaque; unsigned long long newOffset; switch (origin) { case SEEK_SET: newOffset = offset; break; case SEEK_CUR: newOffset = (unsigned long long)buff->pos + offset; break; case SEEK_END: newOffset = (unsigned long long)buff->size - offset; break; + default: + assert(0); /* not possible */ } if (newOffset > buff->size) { return -1; } buff->pos = newOffset; return 0; } typedef struct { U64 cOffset; U64 dOffset; U32 checksum; } seekEntry_t; typedef struct { seekEntry_t* entries; size_t tableLen; int checksumFlag; } seekTable_t; #define SEEKABLE_BUFF_SIZE ZSTD_BLOCKSIZE_MAX struct ZSTD_seekable_s { ZSTD_DStream* dstream; seekTable_t seekTable; ZSTD_seekable_customFile src; U64 decompressedOffset; U32 curFrame; BYTE inBuff[SEEKABLE_BUFF_SIZE]; /* need to do our own input buffering */ BYTE outBuff[SEEKABLE_BUFF_SIZE]; /* so we can efficiently decompress the starts of chunks before we get to the desired section */ ZSTD_inBuffer in; /* maintain continuity across ZSTD_seekable_decompress operations */ buffWrapper_t buffWrapper; /* for `src.opaque` in in-memory mode */ XXH64_state_t xxhState; }; ZSTD_seekable* ZSTD_seekable_create(void) { ZSTD_seekable* zs = malloc(sizeof(ZSTD_seekable)); if (zs == NULL) return NULL; /* also initializes stage to zsds_init */ memset(zs, 0, sizeof(*zs)); zs->dstream = ZSTD_createDStream(); if (zs->dstream == NULL) { free(zs); return NULL; } return zs; } size_t ZSTD_seekable_free(ZSTD_seekable* zs) { if (zs == NULL) return 0; /* support free on null */ ZSTD_freeDStream(zs->dstream); free(zs->seekTable.entries); free(zs); return 0; } /** ZSTD_seekable_offsetToFrameIndex() : * Performs a binary search to find the last frame with a decompressed offset * <= pos * @return : the frame's index */ -U32 ZSTD_seekable_offsetToFrameIndex(ZSTD_seekable* const zs, U64 pos) +U32 ZSTD_seekable_offsetToFrameIndex(ZSTD_seekable* const zs, unsigned long long pos) { U32 lo = 0; U32 hi = zs->seekTable.tableLen; if (pos >= zs->seekTable.entries[zs->seekTable.tableLen].dOffset) { return zs->seekTable.tableLen; } while (lo + 1 < hi) { U32 const mid = lo + ((hi - lo) >> 1); if (zs->seekTable.entries[mid].dOffset <= pos) { lo = mid; } else { hi = mid; } } return lo; } U32 ZSTD_seekable_getNumFrames(ZSTD_seekable* const zs) { return zs->seekTable.tableLen; } -U64 ZSTD_seekable_getFrameCompressedOffset(ZSTD_seekable* const zs, U32 frameIndex) +unsigned long long ZSTD_seekable_getFrameCompressedOffset(ZSTD_seekable* const zs, U32 frameIndex) { if (frameIndex >= zs->seekTable.tableLen) return ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE; return zs->seekTable.entries[frameIndex].cOffset; } -U64 ZSTD_seekable_getFrameDecompressedOffset(ZSTD_seekable* const zs, U32 frameIndex) +unsigned long long ZSTD_seekable_getFrameDecompressedOffset(ZSTD_seekable* const zs, U32 frameIndex) { if (frameIndex >= zs->seekTable.tableLen) return ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE; return zs->seekTable.entries[frameIndex].dOffset; } size_t ZSTD_seekable_getFrameCompressedSize(ZSTD_seekable* const zs, U32 frameIndex) { if (frameIndex >= zs->seekTable.tableLen) return ERROR(frameIndex_tooLarge); return zs->seekTable.entries[frameIndex + 1].cOffset - zs->seekTable.entries[frameIndex].cOffset; } size_t ZSTD_seekable_getFrameDecompressedSize(ZSTD_seekable* const zs, U32 frameIndex) { if (frameIndex > zs->seekTable.tableLen) return ERROR(frameIndex_tooLarge); return zs->seekTable.entries[frameIndex + 1].dOffset - zs->seekTable.entries[frameIndex].dOffset; } static size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable* zs) { int checksumFlag; ZSTD_seekable_customFile src = zs->src; /* read the footer, fixed size */ CHECK_IO(src.seek(src.opaque, -(int)ZSTD_seekTableFooterSize, SEEK_END)); CHECK_IO(src.read(src.opaque, zs->inBuff, ZSTD_seekTableFooterSize)); if (MEM_readLE32(zs->inBuff + 5) != ZSTD_SEEKABLE_MAGICNUMBER) { return ERROR(prefix_unknown); } { BYTE const sfd = zs->inBuff[4]; checksumFlag = sfd >> 7; /* check reserved bits */ if ((checksumFlag >> 2) & 0x1f) { return ERROR(corruption_detected); } } { U32 const numFrames = MEM_readLE32(zs->inBuff); U32 const sizePerEntry = 8 + (checksumFlag?4:0); U32 const tableSize = sizePerEntry * numFrames; U32 const frameSize = tableSize + ZSTD_seekTableFooterSize + ZSTD_skippableHeaderSize; U32 remaining = frameSize - ZSTD_seekTableFooterSize; /* don't need to re-read footer */ { U32 const toRead = MIN(remaining, SEEKABLE_BUFF_SIZE); CHECK_IO(src.seek(src.opaque, -(S64)frameSize, SEEK_END)); CHECK_IO(src.read(src.opaque, zs->inBuff, toRead)); remaining -= toRead; } if (MEM_readLE32(zs->inBuff) != (ZSTD_MAGIC_SKIPPABLE_START | 0xE)) { return ERROR(prefix_unknown); } if (MEM_readLE32(zs->inBuff+4) + ZSTD_skippableHeaderSize != frameSize) { return ERROR(prefix_unknown); } { /* Allocate an extra entry at the end so that we can do size * computations on the last element without special case */ seekEntry_t* entries = (seekEntry_t*)malloc(sizeof(seekEntry_t) * (numFrames + 1)); - const BYTE* tableBase = zs->inBuff + ZSTD_skippableHeaderSize; U32 idx = 0; U32 pos = 8; U64 cOffset = 0; U64 dOffset = 0; if (!entries) { free(entries); return ERROR(memory_allocation); } /* compute cumulative positions */ for (; idx < numFrames; idx++) { if (pos + sizePerEntry > SEEKABLE_BUFF_SIZE) { - U32 const toRead = MIN(remaining, SEEKABLE_BUFF_SIZE); U32 const offset = SEEKABLE_BUFF_SIZE - pos; + U32 const toRead = MIN(remaining, SEEKABLE_BUFF_SIZE - offset); memmove(zs->inBuff, zs->inBuff + pos, offset); /* move any data we haven't read yet */ CHECK_IO(src.read(src.opaque, zs->inBuff+offset, toRead)); remaining -= toRead; pos = 0; } entries[idx].cOffset = cOffset; entries[idx].dOffset = dOffset; cOffset += MEM_readLE32(zs->inBuff + pos); pos += 4; dOffset += MEM_readLE32(zs->inBuff + pos); pos += 4; if (checksumFlag) { entries[idx].checksum = MEM_readLE32(zs->inBuff + pos); pos += 4; } } entries[numFrames].cOffset = cOffset; entries[numFrames].dOffset = dOffset; zs->seekTable.entries = entries; zs->seekTable.tableLen = numFrames; zs->seekTable.checksumFlag = checksumFlag; return 0; } } } size_t ZSTD_seekable_initBuff(ZSTD_seekable* zs, const void* src, size_t srcSize) { zs->buffWrapper = (buffWrapper_t){src, srcSize, 0}; { ZSTD_seekable_customFile srcFile = {&zs->buffWrapper, &ZSTD_seekable_read_buff, &ZSTD_seekable_seek_buff}; return ZSTD_seekable_initAdvanced(zs, srcFile); } } size_t ZSTD_seekable_initFile(ZSTD_seekable* zs, FILE* src) { ZSTD_seekable_customFile srcFile = {src, &ZSTD_seekable_read_FILE, &ZSTD_seekable_seek_FILE}; return ZSTD_seekable_initAdvanced(zs, srcFile); } size_t ZSTD_seekable_initAdvanced(ZSTD_seekable* zs, ZSTD_seekable_customFile src) { zs->src = src; { const size_t seekTableInit = ZSTD_seekable_loadSeekTable(zs); if (ZSTD_isError(seekTableInit)) return seekTableInit; } zs->decompressedOffset = (U64)-1; zs->curFrame = (U32)-1; { const size_t dstreamInit = ZSTD_initDStream(zs->dstream); if (ZSTD_isError(dstreamInit)) return dstreamInit; } return 0; } -size_t ZSTD_seekable_decompress(ZSTD_seekable* zs, void* dst, size_t len, U64 offset) +size_t ZSTD_seekable_decompress(ZSTD_seekable* zs, void* dst, size_t len, unsigned long long offset) { U32 targetFrame = ZSTD_seekable_offsetToFrameIndex(zs, offset); do { /* check if we can continue from a previous decompress job */ if (targetFrame != zs->curFrame || offset != zs->decompressedOffset) { zs->decompressedOffset = zs->seekTable.entries[targetFrame].dOffset; zs->curFrame = targetFrame; CHECK_IO(zs->src.seek(zs->src.opaque, zs->seekTable.entries[targetFrame].cOffset, SEEK_SET)); zs->in = (ZSTD_inBuffer){zs->inBuff, 0, 0}; XXH64_reset(&zs->xxhState, 0); ZSTD_resetDStream(zs->dstream); } while (zs->decompressedOffset < offset + len) { size_t toRead; ZSTD_outBuffer outTmp; size_t prevOutPos; if (zs->decompressedOffset < offset) { /* dummy decompressions until we get to the target offset */ outTmp = (ZSTD_outBuffer){zs->outBuff, MIN(SEEKABLE_BUFF_SIZE, offset - zs->decompressedOffset), 0}; } else { outTmp = (ZSTD_outBuffer){dst, len, zs->decompressedOffset - offset}; } prevOutPos = outTmp.pos; toRead = ZSTD_decompressStream(zs->dstream, &outTmp, &zs->in); if (ZSTD_isError(toRead)) { return toRead; } if (zs->seekTable.checksumFlag) { XXH64_update(&zs->xxhState, (BYTE*)outTmp.dst + prevOutPos, outTmp.pos - prevOutPos); } zs->decompressedOffset += outTmp.pos - prevOutPos; if (toRead == 0) { /* frame complete */ /* verify checksum */ if (zs->seekTable.checksumFlag && (XXH64_digest(&zs->xxhState) & 0xFFFFFFFFU) != zs->seekTable.entries[targetFrame].checksum) { return ERROR(corruption_detected); } if (zs->decompressedOffset < offset + len) { /* go back to the start and force a reset of the stream */ targetFrame = ZSTD_seekable_offsetToFrameIndex(zs, zs->decompressedOffset); } break; } /* read in more data if we're done with this buffer */ if (zs->in.pos == zs->in.size) { toRead = MIN(toRead, SEEKABLE_BUFF_SIZE); CHECK_IO(zs->src.read(zs->src.opaque, zs->inBuff, toRead)); zs->in.size = toRead; zs->in.pos = 0; } } } while (zs->decompressedOffset != offset + len); return len; } size_t ZSTD_seekable_decompressFrame(ZSTD_seekable* zs, void* dst, size_t dstSize, U32 frameIndex) { if (frameIndex >= zs->seekTable.tableLen) { return ERROR(frameIndex_tooLarge); } { size_t const decompressedSize = zs->seekTable.entries[frameIndex + 1].dOffset - zs->seekTable.entries[frameIndex].dOffset; if (dstSize < decompressedSize) { return ERROR(dstSize_tooSmall); } return ZSTD_seekable_decompress( zs, dst, decompressedSize, zs->seekTable.entries[frameIndex].dOffset); } } Index: vendor/zstd/dist/doc/images/linux-git-mt-compress.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/linux-git-mt-compress.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/linux-4.7-12-mt-compress.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/linux-4.7-12-mt-compress.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/linux-git-compress.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/linux-git-compress.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/ldmCspeed.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/ldmCspeed.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/ldmDspeed.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/ldmDspeed.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/linux-4.7-12-compress.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/linux-4.7-12-compress.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/linux-4.7-12-decompress.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/linux-4.7-12-decompress.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/linux-git-decompress.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/linux-git-decompress.png ___________________________________________________________________ Deleted: svn:mime-type ## -1 +0,0 ## -image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/cdict_v136.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/cdict_v136.png ___________________________________________________________________ Added: svn:mime-type ## -0,0 +1 ## +image/png \ No newline at end of property Index: vendor/zstd/dist/doc/images/zstd_cdict_v1_3_5.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Property changes on: vendor/zstd/dist/doc/images/zstd_cdict_v1_3_5.png ___________________________________________________________________ Added: svn:mime-type ## -0,0 +1 ## +image/png \ No newline at end of property Index: vendor/zstd/dist/doc/zstd_compression_format.md =================================================================== --- vendor/zstd/dist/doc/zstd_compression_format.md (revision 339613) +++ vendor/zstd/dist/doc/zstd_compression_format.md (revision 339614) @@ -1,1535 +1,1645 @@ Zstandard Compression Format ============================ ### Notices Copyright (c) 2016-present Yann Collet, Facebook, Inc. Permission is granted to copy and distribute this document for any purpose and without charge, including translations into other languages and incorporation into compilations, provided that the copyright notice and this notice are preserved, and that any substantive changes or deletions from the original are clearly marked. Distribution of this document is unlimited. ### Version -0.2.6 (19/08/17) +0.3.0 (25/09/18) Introduction ------------ The purpose of this document is to define a lossless compressed data format, that is independent of CPU type, operating system, file system and character set, suitable for file compression, pipe and streaming compression, using the [Zstandard algorithm](http://www.zstandard.org). +The text of the specification assumes a basic background in programming +at the level of bits and other primitive data representations. The data can be produced or consumed, even for an arbitrarily long sequentially presented input data stream, using only an a priori bounded amount of intermediate storage, and hence can be used in data communications. The format uses the Zstandard compression method, and optional [xxHash-64 checksum method](http://www.xxhash.org), for detection of data corruption. The data format defined by this specification does not attempt to allow random access to compressed data. -This specification is intended for use by implementers of software -to compress data into Zstandard format and/or decompress data from Zstandard format. -The text of the specification assumes a basic background in programming -at the level of bits and other primitive data representations. - Unless otherwise indicated below, a compliant compressor must produce data sets that conform to the specifications presented here. It doesn’t need to support all options though. A compliant decompressor must be able to decompress at least one working set of parameters that conforms to the specifications presented here. It may also ignore informative fields, such as checksum. Whenever it does not support a parameter defined in the compressed stream, it must produce a non-ambiguous error code and associated error message explaining which parameter is unsupported. +This specification is intended for use by implementers of software +to compress data into Zstandard format and/or decompress data from Zstandard format. +The Zstandard format is supported by an open source reference implementation, +written in portable C, and available at : https://github.com/facebook/zstd . + + ### Overall conventions In this document: - square brackets i.e. `[` and `]` are used to indicate optional fields or parameters. - the naming convention for identifiers is `Mixed_Case_With_Underscores` ### Definitions Content compressed by Zstandard is transformed into a Zstandard __frame__. Multiple frames can be appended into a single file or stream. A frame is completely independent, has a defined beginning and end, and a set of parameters which tells the decoder how to decompress it. A frame encapsulates one or multiple __blocks__. -Each block can be compressed or not, +Each block contains arbitrary content, which is described by its header, and has a guaranteed maximum content size, which depends on frame parameters. Unlike frames, each block depends on previous blocks for proper decoding. However, each block can be decompressed without waiting for its successor, allowing streaming operations. Overview --------- - [Frames](#frames) - [Zstandard frames](#zstandard-frames) - [Blocks](#blocks) - [Literals Section](#literals-section) - [Sequences Section](#sequences-section) - [Sequence Execution](#sequence-execution) - [Skippable frames](#skippable-frames) - [Entropy Encoding](#entropy-encoding) - [FSE](#fse) - [Huffman Coding](#huffman-coding) - [Dictionary Format](#dictionary-format) Frames ------ Zstandard compressed data is made of one or more __frames__. -Each frame is independent and can be decompressed indepedently of other frames. +Each frame is independent and can be decompressed independently of other frames. The decompressed content of multiple concatenated frames is the concatenation of each frame decompressed content. There are two frame formats defined by Zstandard: Zstandard frames and Skippable frames. Zstandard frames contain compressed data, while -skippable frames contain no data and can be used for metadata. +skippable frames contain custom user metadata. ## Zstandard frames The structure of a single Zstandard frame is following: | `Magic_Number` | `Frame_Header` |`Data_Block`| [More data blocks] | [`Content_Checksum`] | |:--------------:|:--------------:|:----------:| ------------------ |:--------------------:| | 4 bytes | 2-14 bytes | n bytes | | 0-4 bytes | __`Magic_Number`__ 4 Bytes, __little-endian__ format. Value : 0xFD2FB528 +Note: This value was selected to be less probable to find at the beginning of some random file. +It avoids trivial patterns (0x00, 0xFF, repeated bytes, increasing bytes, etc.), +contains byte values outside of ASCII range, +and doesn't map into UTF8 space. +It reduces the chances that a text file represent this value by accident. __`Frame_Header`__ 2 to 14 Bytes, detailed in [`Frame_Header`](#frame_header). __`Data_Block`__ Detailed in [`Blocks`](#blocks). That’s where compressed data is stored. __`Content_Checksum`__ An optional 32-bit checksum, only present if `Content_Checksum_flag` is set. The content checksum is the result of [xxh64() hash function](http://www.xxhash.org) digesting the original (decoded) data as input, and a seed of zero. The low 4 bytes of the checksum are stored in __little-endian__ format. ### `Frame_Header` The `Frame_Header` has a variable size, with a minimum of 2 bytes, and up to 14 bytes depending on optional parameters. The structure of `Frame_Header` is following: | `Frame_Header_Descriptor` | [`Window_Descriptor`] | [`Dictionary_ID`] | [`Frame_Content_Size`] | | ------------------------- | --------------------- | ----------------- | ---------------------- | | 1 byte | 0-1 byte | 0-4 bytes | 0-8 bytes | #### `Frame_Header_Descriptor` The first header's byte is called the `Frame_Header_Descriptor`. It describes which other fields are present. Decoding this byte is enough to tell the size of `Frame_Header`. | Bit number | Field name | | ---------- | ---------- | | 7-6 | `Frame_Content_Size_flag` | | 5 | `Single_Segment_flag` | | 4 | `Unused_bit` | | 3 | `Reserved_bit` | | 2 | `Content_Checksum_flag` | | 1-0 | `Dictionary_ID_flag` | In this table, bit 7 is the highest bit, while bit 0 is the lowest one. __`Frame_Content_Size_flag`__ This is a 2-bits flag (`= Frame_Header_Descriptor >> 6`), specifying if `Frame_Content_Size` (the decompressed data size) is provided within the header. `Flag_Value` provides `FCS_Field_Size`, which is the number of bytes used by `Frame_Content_Size` according to the following table: | `Flag_Value` | 0 | 1 | 2 | 3 | | -------------- | ------ | --- | --- | --- | |`FCS_Field_Size`| 0 or 1 | 2 | 4 | 8 | When `Flag_Value` is `0`, `FCS_Field_Size` depends on `Single_Segment_flag` : -if `Single_Segment_flag` is set, `Field_Size` is 1. -Otherwise, `Field_Size` is 0 : `Frame_Content_Size` is not provided. +if `Single_Segment_flag` is set, `FCS_Field_Size` is 1. +Otherwise, `FCS_Field_Size` is 0 : `Frame_Content_Size` is not provided. __`Single_Segment_flag`__ If this flag is set, data must be regenerated within a single continuous memory segment. In this case, `Window_Descriptor` byte is skipped, but `Frame_Content_Size` is necessarily present. As a consequence, the decoder must allocate a memory segment of size equal or larger than `Frame_Content_Size`. In order to preserve the decoder from unreasonable memory requirements, a decoder is allowed to reject a compressed frame which requests a memory size beyond decoder's authorized range. For broader compatibility, decoders are recommended to support memory sizes of at least 8 MB. This is only a recommendation, each decoder is free to support higher or lower limits, depending on local limitations. __`Unused_bit`__ -The value of this bit should be set to zero. -A decoder compliant with this specification version shall not interpret it. -It might be used in a future version, -to signal a property which is not mandatory to properly decode the frame. +A decoder compliant with this specification version shall not interpret this bit. +It might be used in any future version, +to signal a property which is transparent to properly decode the frame. +An encoder compliant with this specification version must set this bit to zero. __`Reserved_bit`__ This bit is reserved for some future feature. Its value _must be zero_. A decoder compliant with this specification version must ensure it is not set. This bit may be used in a future revision, to signal a feature that must be interpreted to decode the frame correctly. __`Content_Checksum_flag`__ If this flag is set, a 32-bits `Content_Checksum` will be present at frame's end. See `Content_Checksum` paragraph. __`Dictionary_ID_flag`__ This is a 2-bits flag (`= FHD & 3`), telling if a dictionary ID is provided within the header. -It also specifies the size of this field as `Field_Size`. +It also specifies the size of this field as `DID_Field_Size`. -|`Flag_Value`| 0 | 1 | 2 | 3 | -| ---------- | --- | --- | --- | --- | -|`Field_Size`| 0 | 1 | 2 | 4 | +|`Flag_Value` | 0 | 1 | 2 | 3 | +| -------------- | --- | --- | --- | --- | +|`DID_Field_Size`| 0 | 1 | 2 | 4 | #### `Window_Descriptor` Provides guarantees on minimum memory buffer required to decompress a frame. This information is important for decoders to allocate enough memory. The `Window_Descriptor` byte is optional. When `Single_Segment_flag` is set, `Window_Descriptor` is not present. In this case, `Window_Size` is `Frame_Content_Size`, which can be any value from 0 to 2^64-1 bytes (16 ExaBytes). | Bit numbers | 7-3 | 2-0 | | ----------- | ---------- | ---------- | | Field name | `Exponent` | `Mantissa` | The minimum memory buffer size is called `Window_Size`. It is described by the following formulas : ``` windowLog = 10 + Exponent; windowBase = 1 << windowLog; windowAdd = (windowBase / 8) * Mantissa; Window_Size = windowBase + windowAdd; ``` The minimum `Window_Size` is 1 KB. The maximum `Window_Size` is `(1<<41) + 7*(1<<38)` bytes, which is 3.75 TB. +In general, larger `Window_Size` tend to improve compression ratio, +but at the cost of memory usage. + To properly decode compressed data, a decoder will need to allocate a buffer of at least `Window_Size` bytes. In order to preserve decoder from unreasonable memory requirements, a decoder is allowed to reject a compressed frame which requests a memory size beyond decoder's authorized range. For improved interoperability, -decoders are recommended to be compatible with `Window_Size <= 8 MB`, -and encoders are recommended to not request more than 8 MB. +it's recommended for decoders to support `Window_Size` of up to 8 MB, +and it's recommended for encoders to not generate frame requiring `Window_Size` larger than 8 MB. It's merely a recommendation though, decoders are free to support larger or lower limits, depending on local limitations. #### `Dictionary_ID` This is a variable size field, which contains the ID of the dictionary required to properly decode the frame. `Dictionary_ID` field is optional. When it's not present, -it's up to the decoder to make sure it uses the correct dictionary. +it's up to the decoder to know which dictionary to use. -Field size depends on `Dictionary_ID_flag`. +`Dictionary_ID` field size is provided by `DID_Field_Size`. +`DID_Field_Size` is directly derived from value of `Dictionary_ID_flag`. 1 byte can represent an ID 0-255. 2 bytes can represent an ID 0-65535. 4 bytes can represent an ID 0-4294967295. Format is __little-endian__. It's allowed to represent a small ID (for example `13`) with a large 4-bytes dictionary ID, even if it is less efficient. _Reserved ranges :_ -If the frame is going to be distributed in a private environment, -any dictionary ID can be used. -However, for public distribution of compressed frames using a dictionary, -the following ranges are reserved and shall not be used : +Within private environments, any `Dictionary_ID` can be used. + +However, for frames and dictionaries distributed in public space, +`Dictionary_ID` must be attributed carefully. +Rules for public environment are not yet decided, +but the following ranges are reserved for some future registrar : - low range : `<= 32767` - high range : `>= (1 << 31)` +Outside of these ranges, any value of `Dictionary_ID` +which is both `>= 32768` and `< (1<<31)` can be used freely, +even in public environment. + + + #### `Frame_Content_Size` This is the original (uncompressed) size. This information is optional. `Frame_Content_Size` uses a variable number of bytes, provided by `FCS_Field_Size`. `FCS_Field_Size` is provided by the value of `Frame_Content_Size_flag`. `FCS_Field_Size` can be equal to 0 (not present), 1, 2, 4 or 8 bytes. | `FCS_Field_Size` | Range | | ---------------- | ---------- | | 0 | unknown | | 1 | 0 - 255 | | 2 | 256 - 65791| | 4 | 0 - 2^32-1 | | 8 | 0 - 2^64-1 | `Frame_Content_Size` format is __little-endian__. When `FCS_Field_Size` is 1, 4 or 8 bytes, the value is read directly. When `FCS_Field_Size` is 2, _the offset of 256 is added_. It's allowed to represent a small size (for example `18`) using any compatible variant. Blocks ------- After `Magic_Number` and `Frame_Header`, there are some number of blocks. Each frame must have at least one block, but there is no upper limit on the number of blocks per frame. The structure of a block is as follows: | `Block_Header` | `Block_Content` | |:--------------:|:---------------:| | 3 bytes | n bytes | `Block_Header` uses 3 bytes, written using __little-endian__ convention. It contains 3 fields : | `Last_Block` | `Block_Type` | `Block_Size` | |:------------:|:------------:|:------------:| | bit 0 | bits 1-2 | bits 3-23 | __`Last_Block`__ The lowest bit signals if this block is the last one. The frame will end after this last block. It may be followed by an optional `Content_Checksum` (see [Zstandard Frames](#zstandard-frames)). __`Block_Type`__ The next 2 bits represent the `Block_Type`. There are 4 block types : | Value | 0 | 1 | 2 | 3 | | ------------ | ----------- | ----------- | ------------------ | --------- | | `Block_Type` | `Raw_Block` | `RLE_Block` | `Compressed_Block` | `Reserved`| - `Raw_Block` - this is an uncompressed block. `Block_Content` contains `Block_Size` bytes. - `RLE_Block` - this is a single byte, repeated `Block_Size` times. `Block_Content` consists of a single byte. On the decompression side, this byte must be repeated `Block_Size` times. - `Compressed_Block` - this is a [Zstandard compressed block](#compressed-blocks), explained later on. `Block_Size` is the length of `Block_Content`, the compressed data. The decompressed size is not known, but its maximum possible value is guaranteed (see below) - `Reserved` - this is not a block. This value cannot be used with current version of this specification. + If such a value is present, it is considered corrupted data. __`Block_Size`__ The upper 21 bits of `Block_Header` represent the `Block_Size`. +`Block_Size` is the size of the block excluding the header. +A block can contain any number of bytes (even zero), up to +`Block_Maximum_Decompressed_Size`, which is the smallest of: +- Window_Size +- 128 KB -Block sizes must respect a few rules : -- For `Compressed_Block`, `Block_Size` is always strictly less than decompressed size. -- Block decompressed size is always <= `Window_Size` -- Block decompressed size is always <= 128 KB. +A `Compressed_Block` has the extra restriction that `Block_Size` is always +strictly less than the decompressed size. +If this condition cannot be respected, +the block must be sent uncompressed instead (`Raw_Block`). -A block can contain any number of bytes (even empty), -up to `Block_Maximum_Decompressed_Size`, which is the smallest of : -- `Window_Size` -- 128 KB - Compressed Blocks ----------------- To decompress a compressed block, the compressed size must be provided from `Block_Size` field within `Block_Header`. A compressed block consists of 2 sections : - [Literals Section](#literals-section) - [Sequences Section](#sequences-section) The results of the two sections are then combined to produce the decompressed data in [Sequence Execution](#sequence-execution) #### Prerequisites To decode a compressed block, the following elements are necessary : - Previous decoded data, up to a distance of `Window_Size`, - or all previously decoded data when `Single_Segment_flag` is set. + or beginning of the Frame, whichever is smaller. - List of "recent offsets" from previous `Compressed_Block`. -- Decoding tables of previous `Compressed_Block` for each symbol type - (literals, literals lengths, match lengths, offsets). +- The previous Huffman tree, required by `Treeless_Literals_Block` type +- Previous FSE decoding tables, required by `Repeat_Mode` + for each symbol type (literals lengths, match lengths, offsets) +Note that decoding tables aren't always from the previous `Compressed_Block`. + +- Every decoding table can come from a dictionary. +- The Huffman tree comes from the previous `Compressed_Literals_Block`. + Literals Section ---------------- All literals are regrouped in the first part of the block. They can be decoded first, and then copied during [Sequence Execution], or they can be decoded on the flow during [Sequence Execution]. Literals can be stored uncompressed or compressed using Huffman prefix codes. When compressed, an optional tree description can be present, followed by 1 or 4 streams. -| `Literals_Section_Header` | [`Huffman_Tree_Description`] | Stream1 | [Stream2] | [Stream3] | [Stream4] | -| ------------------------- | ---------------------------- | ------- | --------- | --------- | --------- | +| `Literals_Section_Header` | [`Huffman_Tree_Description`] | [jumpTable] | Stream1 | [Stream2] | [Stream3] | [Stream4] | +| ------------------------- | ---------------------------- | ----------- | ------- | --------- | --------- | --------- | -#### `Literals_Section_Header` +### `Literals_Section_Header` Header is in charge of describing how literals are packed. It's a byte-aligned variable-size bitfield, ranging from 1 to 5 bytes, using __little-endian__ convention. | `Literals_Block_Type` | `Size_Format` | `Regenerated_Size` | [`Compressed_Size`] | | --------------------- | ------------- | ------------------ | ------------------- | | 2 bits | 1 - 2 bits | 5 - 20 bits | 0 - 18 bits | In this representation, bits on the left are the lowest bits. __`Literals_Block_Type`__ This field uses 2 lowest bits of first byte, describing 4 different block types : | `Literals_Block_Type` | Value | | --------------------------- | ----- | | `Raw_Literals_Block` | 0 | | `RLE_Literals_Block` | 1 | | `Compressed_Literals_Block` | 2 | | `Treeless_Literals_Block` | 3 | - `Raw_Literals_Block` - Literals are stored uncompressed. - `RLE_Literals_Block` - Literals consist of a single byte value repeated `Regenerated_Size` times. - `Compressed_Literals_Block` - This is a standard Huffman-compressed block, starting with a Huffman tree description. See details below. - `Treeless_Literals_Block` - This is a Huffman-compressed block, using Huffman tree _from previous Huffman-compressed literals block_. `Huffman_Tree_Description` will be skipped. Note: If this mode is triggered without any previous Huffman-table in the frame (or [dictionary](#dictionary-format)), this should be treated as data corruption. __`Size_Format`__ `Size_Format` is divided into 2 families : - For `Raw_Literals_Block` and `RLE_Literals_Block`, it's only necessary to decode `Regenerated_Size`. There is no `Compressed_Size` field. - For `Compressed_Block` and `Treeless_Literals_Block`, it's required to decode both `Compressed_Size` and `Regenerated_Size` (the decompressed size). It's also necessary to decode the number of streams (1 or 4). For values spanning several bytes, convention is __little-endian__. __`Size_Format` for `Raw_Literals_Block` and `RLE_Literals_Block`__ : -- Value ?0 : `Size_Format` uses 1 bit. +`Size_Format` uses 1 _or_ 2 bits. +Its value is : `Size_Format = (Literals_Section_Header[0]>>2) & 3` + +- `Size_Format` == 00 or 10 : `Size_Format` uses 1 bit. `Regenerated_Size` uses 5 bits (0-31). - `Literals_Section_Header` has 1 byte. - `Regenerated_Size = Header[0]>>3` -- Value 01 : `Size_Format` uses 2 bits. + `Literals_Section_Header` uses 1 byte. + `Regenerated_Size = Literals_Section_Header[0]>>3` +- `Size_Format` == 01 : `Size_Format` uses 2 bits. `Regenerated_Size` uses 12 bits (0-4095). - `Literals_Section_Header` has 2 bytes. - `Regenerated_Size = (Header[0]>>4) + (Header[1]<<4)` -- Value 11 : `Size_Format` uses 2 bits. + `Literals_Section_Header` uses 2 bytes. + `Regenerated_Size = (Literals_Section_Header[0]>>4) + (Literals_Section_Header[1]<<4)` +- `Size_Format` == 11 : `Size_Format` uses 2 bits. `Regenerated_Size` uses 20 bits (0-1048575). - `Literals_Section_Header` has 3 bytes. - `Regenerated_Size = (Header[0]>>4) + (Header[1]<<4) + (Header[2]<<12)` + `Literals_Section_Header` uses 3 bytes. + `Regenerated_Size = (Literals_Section_Header[0]>>4) + (Literals_Section_Header[1]<<4) + (Literals_Section_Header[2]<<12)` Only Stream1 is present for these cases. Note : it's allowed to represent a short value (for example `13`) using a long format, even if it's less efficient. __`Size_Format` for `Compressed_Literals_Block` and `Treeless_Literals_Block`__ : -- Value 00 : _A single stream_. +`Size_Format` always uses 2 bits. + +- `Size_Format` == 00 : _A single stream_. Both `Regenerated_Size` and `Compressed_Size` use 10 bits (0-1023). - `Literals_Section_Header` has 3 bytes. -- Value 01 : 4 streams. + `Literals_Section_Header` uses 3 bytes. +- `Size_Format` == 01 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 10 bits (0-1023). - `Literals_Section_Header` has 3 bytes. -- Value 10 : 4 streams. + `Literals_Section_Header` uses 3 bytes. +- `Size_Format` == 10 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 14 bits (0-16383). - `Literals_Section_Header` has 4 bytes. -- Value 11 : 4 streams. + `Literals_Section_Header` uses 4 bytes. +- `Size_Format` == 11 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 18 bits (0-262143). - `Literals_Section_Header` has 5 bytes. + `Literals_Section_Header` uses 5 bytes. Both `Compressed_Size` and `Regenerated_Size` fields follow __little-endian__ convention. Note: `Compressed_Size` __includes__ the size of the Huffman Tree description _when_ it is present. -### Raw Literals Block +#### Raw Literals Block The data in Stream1 is `Regenerated_Size` bytes long, it contains the raw literals data to be used during [Sequence Execution]. -### RLE Literals Block +#### RLE Literals Block Stream1 consists of a single byte which should be repeated `Regenerated_Size` times to generate the decoded literals. -### Compressed Literals Block and Treeless Literals Block +#### Compressed Literals Block and Treeless Literals Block Both of these modes contain Huffman encoded data. -`Treeless_Literals_Block` does not have a `Huffman_Tree_Description`. -#### `Huffman_Tree_Description` +For `Treeless_Literals_Block`, +the Huffman table comes from previously compressed literals block, +or from a dictionary. + + +### `Huffman_Tree_Description` This section is only present when `Literals_Block_Type` type is `Compressed_Literals_Block` (`2`). The format of the Huffman tree description can be found at [Huffman Tree description](#huffman-tree-description). The size of `Huffman_Tree_Description` is determined during decoding process, it must be used to determine where streams begin. `Total_Streams_Size = Compressed_Size - Huffman_Tree_Description_Size`. -For `Treeless_Literals_Block`, -the Huffman table comes from previously compressed literals block. -Huffman compressed data consists of either 1 or 4 Huffman-coded streams. +### Jump Table +The Jump Table is only present when there are 4 Huffman-coded streams. +Reminder : Huffman compressed data consists of either 1 or 4 Huffman-coded streams. + If only one stream is present, it is a single bitstream occupying the entire remaining portion of the literals block, encoded as described within [Huffman-Coded Streams](#huffman-coded-streams). -If there are four streams, the literals section header only provides enough -information to know the decompressed and compressed sizes of all four streams _combined_. -The decompressed size of each stream is equal to `(Regenerated_Size+3)/4`, +If there are four streams, `Literals_Section_Header` only provided +enough information to know the decompressed and compressed sizes +of all four streams _combined_. +The decompressed size of _each_ stream is equal to `(Regenerated_Size+3)/4`, except for the last stream which may be up to 3 bytes smaller, to reach a total decompressed size as specified in `Regenerated_Size`. -The compressed size of each stream is provided explicitly: -the first 6 bytes of the compressed data consist of three 2-byte __little-endian__ fields, +The compressed size of each stream is provided explicitly in the Jump Table. +Jump Table is 6 bytes long, and consist of three 2-byte __little-endian__ fields, describing the compressed sizes of the first three streams. `Stream4_Size` is computed from total `Total_Streams_Size` minus sizes of other streams. `Stream4_Size = Total_Streams_Size - 6 - Stream1_Size - Stream2_Size - Stream3_Size`. -Note: remember that `Total_Streams_Size` can be smaller than `Compressed_Size` in header, -because `Compressed_Size` also contains `Huffman_Tree_Description_Size` when it is present. +Note: if `Stream1_Size + Stream2_Size + Stream3_Size > Total_Streams_Size`, +data is considered corrupted. Each of these 4 bitstreams is then decoded independently as a Huffman-Coded stream, as described at [Huffman-Coded Streams](#huffman-coded-streams) Sequences Section ----------------- A compressed block is a succession of _sequences_ . A sequence is a literal copy command, followed by a match copy command. A literal copy command specifies a length. It is the number of bytes to be copied (or extracted) from the Literals Section. A match copy command specifies an offset and a length. When all _sequences_ are decoded, -if there are literals left in the _literal section_, +if there are literals left in the _literals section_, these bytes are added at the end of the block. -This is described in more detail in [Sequence Execution](#sequence-execution) +This is described in more detail in [Sequence Execution](#sequence-execution). The `Sequences_Section` regroup all symbols required to decode commands. There are 3 symbol types : literals lengths, offsets and match lengths. They are encoded together, interleaved, in a single _bitstream_. The `Sequences_Section` starts by a header, followed by optional probability tables for each symbol type, followed by the bitstream. | `Sequences_Section_Header` | [`Literals_Length_Table`] | [`Offset_Table`] | [`Match_Length_Table`] | bitStream | | -------------------------- | ------------------------- | ---------------- | ---------------------- | --------- | To decode the `Sequences_Section`, it's required to know its size. -This size is deduced from `Block_Size - Literals_Section_Size`. +Its size is deduced from the size of `Literals_Section`: +`Sequences_Section_Size = Block_Size - Literals_Section_Size`. #### `Sequences_Section_Header` Consists of 2 items: - `Number_of_Sequences` - Symbol compression modes __`Number_of_Sequences`__ This is a variable size field using between 1 and 3 bytes. Let's call its first byte `byte0`. - `if (byte0 == 0)` : there are no sequences. The sequence section stops there. Decompressed content is defined entirely as Literals Section content. + The FSE tables used in `Repeat_Mode` aren't updated. - `if (byte0 < 128)` : `Number_of_Sequences = byte0` . Uses 1 byte. - `if (byte0 < 255)` : `Number_of_Sequences = ((byte0-128) << 8) + byte1` . Uses 2 bytes. - `if (byte0 == 255)`: `Number_of_Sequences = byte1 + (byte2<<8) + 0x7F00` . Uses 3 bytes. __Symbol compression modes__ This is a single byte, defining the compression mode of each symbol type. |Bit number| 7-6 | 5-4 | 3-2 | 1-0 | | -------- | ----------------------- | -------------- | -------------------- | ---------- | |Field name| `Literals_Lengths_Mode` | `Offsets_Mode` | `Match_Lengths_Mode` | `Reserved` | The last field, `Reserved`, must be all-zeroes. `Literals_Lengths_Mode`, `Offsets_Mode` and `Match_Lengths_Mode` define the `Compression_Mode` of literals lengths, offsets, and match lengths symbols respectively. They follow the same enumeration : | Value | 0 | 1 | 2 | 3 | | ------------------ | ----------------- | ---------- | --------------------- | ------------- | | `Compression_Mode` | `Predefined_Mode` | `RLE_Mode` | `FSE_Compressed_Mode` | `Repeat_Mode` | - `Predefined_Mode` : A predefined FSE distribution table is used, defined in [default distributions](#default-distributions). No distribution table will be present. -- `RLE_Mode` : The table description consists of a single byte. - This code will be repeated for all sequences. -- `Repeat_Mode` : The table used in the previous compressed block will be used again. - No distribution table will be present. - Note: this includes RLE mode, so if `Repeat_Mode` follows `RLE_Mode`, the same symbol will be repeated. - If this mode is used without any previous sequence table in the frame - (or [dictionary](#dictionary-format)) to repeat, this should be treated as corruption. +- `RLE_Mode` : The table description consists of a single byte, which contains the symbol's value. + This symbol will be used for all sequences. - `FSE_Compressed_Mode` : standard FSE compression. A distribution table will be present. The format of this distribution table is described in [FSE Table Description](#fse-table-description). Note that the maximum allowed accuracy log for literals length and match length tables is 9, and the maximum accuracy log for the offsets table is 8. + `FSE_Compressed_Mode` must not be used when only one symbol is present, + `RLE_Mode` should be used instead (although any other mode will work). +- `Repeat_Mode` : The table used in the previous `Compressed_Block` with `Number_of_Sequences > 0` will be used again, + or if this is the first block, table in the dictionary will be used. + Note that this includes `RLE_mode`, so if `Repeat_Mode` follows `RLE_Mode`, the same symbol will be repeated. + It also includes `Predefined_Mode`, in which case `Repeat_Mode` will have same outcome as `Predefined_Mode`. + No distribution table will be present. + If this mode is used without any previous sequence table in the frame + (nor [dictionary](#dictionary-format)) to repeat, this should be treated as corruption. #### The codes for literals lengths, match lengths, and offsets. Each symbol is a _code_ in its own context, which specifies `Baseline` and `Number_of_Bits` to add. _Codes_ are FSE compressed, and interleaved with raw additional bits in the same bitstream. ##### Literals length codes Literals length codes are values ranging from `0` to `35` included. They define lengths from 0 to 131071 bytes. The literals length is equal to the decoded `Baseline` plus the result of reading `Number_of_Bits` bits from the bitstream, as a __little-endian__ value. | `Literals_Length_Code` | 0-15 | | ---------------------- | ---------------------- | | length | `Literals_Length_Code` | | `Number_of_Bits` | 0 | | `Literals_Length_Code` | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | | ---------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 16 | 18 | 20 | 22 | 24 | 28 | 32 | 40 | | `Number_of_Bits` | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 | | `Literals_Length_Code` | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | | ---------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 48 | 64 | 128 | 256 | 512 | 1024 | 2048 | 4096 | | `Number_of_Bits` | 4 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | | `Literals_Length_Code` | 32 | 33 | 34 | 35 | | ---------------------- | ---- | ---- | ---- | ---- | | `Baseline` | 8192 |16384 |32768 |65536 | | `Number_of_Bits` | 13 | 14 | 15 | 16 | ##### Match length codes Match length codes are values ranging from `0` to `52` included. They define lengths from 3 to 131074 bytes. The match length is equal to the decoded `Baseline` plus the result of reading `Number_of_Bits` bits from the bitstream, as a __little-endian__ value. | `Match_Length_Code` | 0-31 | | ------------------- | ----------------------- | | value | `Match_Length_Code` + 3 | | `Number_of_Bits` | 0 | | `Match_Length_Code` | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | | ------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 35 | 37 | 39 | 41 | 43 | 47 | 51 | 59 | | `Number_of_Bits` | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 | | `Match_Length_Code` | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | | ------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 67 | 83 | 99 | 131 | 259 | 515 | 1027 | 2051 | | `Number_of_Bits` | 4 | 4 | 5 | 7 | 8 | 9 | 10 | 11 | | `Match_Length_Code` | 48 | 49 | 50 | 51 | 52 | | ------------------- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 4099 | 8195 |16387 |32771 |65539 | | `Number_of_Bits` | 12 | 13 | 14 | 15 | 16 | ##### Offset codes Offset codes are values ranging from `0` to `N`. A decoder is free to limit its maximum `N` supported. Recommendation is to support at least up to `22`. For information, at the time of this writing. -the reference decoder supports a maximum `N` value of `28` in 64-bits mode. +the reference decoder supports a maximum `N` value of `31`. An offset code is also the number of additional bits to read in __little-endian__ fashion, and can be translated into an `Offset_Value` using the following formulas : ``` Offset_Value = (1 << offsetCode) + readNBits(offsetCode); if (Offset_Value > 3) offset = Offset_Value - 3; ``` -It means that maximum `Offset_Value` is `(2^(N+1))-1` and it supports back-reference distance up to `(2^(N+1))-4` +It means that maximum `Offset_Value` is `(2^(N+1))-1` +supporting back-reference distances up to `(2^(N+1))-4`, but is limited by [maximum back-reference distance](#window_descriptor). `Offset_Value` from 1 to 3 are special : they define "repeat codes". This is described in more detail in [Repeat Offsets](#repeat-offsets). #### Decoding Sequences FSE bitstreams are read in reverse direction than written. In zstd, the compressor writes bits forward into a block and the decompressor must read the bitstream _backwards_. To find the start of the bitstream it is therefore necessary to know the offset of the last byte of the block which can be found by counting `Block_Size` bytes after the block header. After writing the last bit containing information, the compressor writes a single `1`-bit and then fills the byte with 0-7 `0` bits of padding. The last byte of the compressed bitstream cannot be `0` for that reason. When decompressing, the last byte containing the padding is the first byte to read. The decompressor needs to skip 0-7 initial `0`-bits and the first `1`-bit it occurs. Afterwards, the useful part of the bitstream begins. FSE decoding requires a 'state' to be carried from symbol to symbol. For more explanation on FSE decoding, see the [FSE section](#fse). For sequence decoding, a separate state keeps track of each literal lengths, offsets, and match lengths symbols. Some FSE primitives are also used. For more details on the operation of these primitives, see the [FSE section](#fse). ##### Starting states The bitstream starts with initial FSE state values, each using the required number of bits in their respective _accuracy_, decoded previously from their normalized distribution. It starts by `Literals_Length_State`, followed by `Offset_State`, and finally `Match_Length_State`. Reminder : always keep in mind that all values are read _backward_, so the 'start' of the bitstream is at the highest position in memory, immediately before the last `1`-bit for padding. After decoding the starting states, a single sequence is decoded `Number_Of_Sequences` times. These sequences are decoded in order from first to last. Since the compressor writes the bitstream in the forward direction, this means the compressor must encode the sequences starting with the last one and ending with the first. ##### Decoding a sequence For each of the symbol types, the FSE state can be used to determine the appropriate code. -The code then defines the baseline and number of bits to read for each type. +The code then defines the `Baseline` and `Number_of_Bits` to read for each type. See the [description of the codes] for how to determine these values. [description of the codes]: #the-codes-for-literals-lengths-match-lengths-and-offsets Decoding starts by reading the `Number_of_Bits` required to decode `Offset`. It then does the same for `Match_Length`, and then for `Literals_Length`. This sequence is then used for [sequence execution](#sequence-execution). If it is not the last sequence in the block, the next operation is to update states. Using the rules pre-calculated in the decoding tables, `Literals_Length_State` is updated, followed by `Match_Length_State`, and then `Offset_State`. See the [FSE section](#fse) for details on how to update states from the bitstream. This operation will be repeated `Number_of_Sequences` times. At the end, the bitstream shall be entirely consumed, otherwise the bitstream is considered corrupted. #### Default Distributions If `Predefined_Mode` is selected for a symbol type, its FSE decoding table is generated from a predefined distribution table defined here. For details on how to convert this distribution into a decoding table, see the [FSE section]. [FSE section]: #from-normalized-distribution-to-decoding-tables ##### Literals Length The decoding table uses an accuracy log of 6 bits (64 states). ``` short literalsLength_defaultDistribution[36] = { 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1, -1,-1,-1,-1 }; ``` ##### Match Length The decoding table uses an accuracy log of 6 bits (64 states). ``` short matchLengths_defaultDistribution[53] = { 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1, -1,-1,-1,-1,-1 }; ``` ##### Offset Codes The decoding table uses an accuracy log of 5 bits (32 states), and supports a maximum `N` value of 28, allowing offset values up to 536,870,908 . If any sequence in the compressed block requires a larger offset than this, it's not possible to use the default distribution to represent it. ``` short offsetCodes_defaultDistribution[29] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1,-1,-1 }; ``` Sequence Execution ------------------ Once literals and sequences have been decoded, they are combined to produce the decoded content of a block. Each sequence consists of a tuple of (`literals_length`, `offset_value`, `match_length`), decoded as described in the [Sequences Section](#sequences-section). -To execute a sequence, first copy `literals_length` bytes from the literals section -to the output. +To execute a sequence, first copy `literals_length` bytes +from the decoded literals to the output. Then `match_length` bytes are copied from previous decoded data. The offset to copy from is determined by `offset_value`: if `offset_value > 3`, then the offset is `offset_value - 3`. If `offset_value` is from 1-3, the offset is a special repeat offset value. See the [repeat offset](#repeat-offsets) section for how the offset is determined in this case. The offset is defined as from the current position, so an offset of 6 and a match length of 3 means that 3 bytes should be copied from 6 bytes back. Note that all offsets leading to previously decoded data must be smaller than `Window_Size` defined in `Frame_Header_Descriptor`. #### Repeat offsets As seen in [Sequence Execution](#sequence-execution), the first 3 values define a repeated offset and we will call them `Repeated_Offset1`, `Repeated_Offset2`, and `Repeated_Offset3`. They are sorted in recency order, with `Repeated_Offset1` meaning "most recent one". If `offset_value == 1`, then the offset used is `Repeated_Offset1`, etc. There is an exception though, when current sequence's `literals_length = 0`. In this case, repeated offsets are shifted by one, so an `offset_value` of 1 means `Repeated_Offset2`, an `offset_value` of 2 means `Repeated_Offset3`, and an `offset_value` of 3 means `Repeated_Offset1 - 1_byte`. -For the first block, the starting offset history is populated with the following values : 1, 4 and 8 (in order). +For the first block, the starting offset history is populated with following values : +`Repeated_Offset1`=1, `Repeated_Offset2`=4, `Repeated_Offset3`=8, +unless a dictionary is used, in which case they come from the dictionary. Then each block gets its starting offset history from the ending values of the most recent `Compressed_Block`. Note that blocks which are not `Compressed_Block` are skipped, they do not contribute to offset history. [Offset Codes]: #offset-codes ###### Offset updates rules The newest offset takes the lead in offset history, shifting others back (up to its previous place if it was already present). This means that when `Repeated_Offset1` (most recent) is used, history is unmodified. When `Repeated_Offset2` is used, it's swapped with `Repeated_Offset1`. If any other offset is used, it becomes `Repeated_Offset1` and the rest are shift back by one. Skippable Frames ---------------- | `Magic_Number` | `Frame_Size` | `User_Data` | |:--------------:|:------------:|:-----------:| | 4 bytes | 4 bytes | n bytes | -Skippable frames allow the insertion of user-defined data +Skippable frames allow the insertion of user-defined metadata into a flow of concatenated frames. -Its design is pretty straightforward, -with the sole objective to allow the decoder to quickly skip -over user-defined data and continue decoding. Skippable frames defined in this specification are compatible with [LZ4] ones. [LZ4]:http://www.lz4.org +From a compliant decoder perspective, skippable frames need just be skipped, +and their content ignored, resuming decoding after the skippable frame. + +It can be noted that a skippable frame +can be used to watermark a stream of concatenated frames +embedding any kind of tracking information (even just an UUID). +Users wary of such possibility should scan the stream of concatenated frames +in an attempt to detect such frame for analysis or removal. + __`Magic_Number`__ 4 Bytes, __little-endian__ format. Value : 0x184D2A5?, which means any value from 0x184D2A50 to 0x184D2A5F. All 16 values are valid to identify a skippable frame. +This specification doesn't detail any specific tagging for skippable frames. __`Frame_Size`__ This is the size, in bytes, of the following `User_Data` (without including the magic number nor the size field itself). This field is represented using 4 Bytes, __little-endian__ format, unsigned 32-bits. This means `User_Data` can’t be bigger than (2^32-1) bytes. __`User_Data`__ The `User_Data` can be anything. Data will just be skipped by the decoder. + Entropy Encoding ---------------- Two types of entropy encoding are used by the Zstandard format: FSE, and Huffman coding. +Huffman is used to compress literals, +while FSE is used for all other symbols +(`Literals_Length_Code`, `Match_Length_Code`, offset codes) +and to compress Huffman headers. + FSE --- FSE, short for Finite State Entropy, is an entropy codec based on [ANS]. FSE encoding/decoding involves a state that is carried over between symbols, so decoding must be done in the opposite direction as encoding. Therefore, all FSE bitstreams are read from end to beginning. +Note that the order of the bits in the stream is not reversed, +we just read the elements in the reverse order they are written. For additional details on FSE, see [Finite State Entropy]. [Finite State Entropy]:https://github.com/Cyan4973/FiniteStateEntropy/ FSE decoding involves a decoding table which has a power of 2 size, and contain three elements: `Symbol`, `Num_Bits`, and `Baseline`. The `log2` of the table size is its `Accuracy_Log`. -The FSE state represents an index in this table. +An FSE state value represents an index in this table. To obtain the initial state value, consume `Accuracy_Log` bits from the stream as a __little-endian__ value. The next symbol in the stream is the `Symbol` indicated in the table for that state. To obtain the next state value, the decoder should consume `Num_Bits` bits from the stream as a __little-endian__ value and add it to `Baseline`. [ANS]: https://en.wikipedia.org/wiki/Asymmetric_Numeral_Systems ### FSE Table Description To decode FSE streams, it is necessary to construct the decoding table. The Zstandard format encodes FSE table descriptions as follows: An FSE distribution table describes the probabilities of all symbols from `0` to the last present one (included) on a normalized scale of `1 << Accuracy_Log` . +Note that there must be two or more symbols with nonzero probability. It's a bitstream which is read forward, in __little-endian__ fashion. -It's not necessary to know its exact size, -since it will be discovered and reported by the decoding process. +It's not necessary to know bitstream exact size, +it will be discovered and reported by the decoding process. The bitstream starts by reporting on which scale it operates. +Let's `low4Bits` designate the lowest 4 bits of the first byte : `Accuracy_Log = low4bits + 5`. Then follows each symbol value, from `0` to last present one. The number of bits used by each field is variable. It depends on : - Remaining probabilities + 1 : __example__ : Presuming an `Accuracy_Log` of 8, and presuming 100 probabilities points have already been distributed, - the decoder may read any value from `0` to `255 - 100 + 1 == 156` (inclusive). - Therefore, it must read `log2sup(156) == 8` bits. + the decoder may read any value from `0` to `256 - 100 + 1 == 157` (inclusive). + Therefore, it must read `log2sup(157) == 8` bits. - Value decoded : small values use 1 less bit : __example__ : - Presuming values from 0 to 156 (inclusive) are possible, - 255-156 = 99 values are remaining in an 8-bits field. + Presuming values from 0 to 157 (inclusive) are possible, + 255-157 = 98 values are remaining in an 8-bits field. They are used this way : - first 99 values (hence from 0 to 98) use only 7 bits, - values from 99 to 156 use 8 bits. + first 98 values (hence from 0 to 97) use only 7 bits, + values from 98 to 157 use 8 bits. This is achieved through this scheme : | Value read | Value decoded | Number of bits used | | ---------- | ------------- | ------------------- | - | 0 - 98 | 0 - 98 | 7 | - | 99 - 127 | 99 - 127 | 8 | - | 128 - 226 | 0 - 98 | 7 | - | 227 - 255 | 128 - 156 | 8 | + | 0 - 97 | 0 - 97 | 7 | + | 98 - 127 | 98 - 127 | 8 | + | 128 - 225 | 0 - 97 | 7 | + | 226 - 255 | 128 - 157 | 8 | Symbols probabilities are read one by one, in order. Probability is obtained from Value decoded by following formula : `Proba = value - 1` It means value `0` becomes negative probability `-1`. `-1` is a special probability, which means "less than 1". Its effect on distribution table is described in the [next section]. For the purpose of calculating total allocated probability points, it counts as one. [next section]:#from-normalized-distribution-to-decoding-tables When a symbol has a __probability__ of `zero`, it is followed by a 2-bits repeat flag. This repeat flag tells how many probabilities of zeroes follow the current one. It provides a number ranging from 0 to 3. If it is a 3, another 2-bits repeat flag follows, and so on. When last symbol reaches cumulated total of `1 << Accuracy_Log`, decoding is complete. If the last symbol makes cumulated total go above `1 << Accuracy_Log`, distribution is considered corrupted. Then the decoder can tell how many bytes were used in this process, and how many symbols are present. The bitstream consumes a round number of bytes. Any remaining bit within the last byte is just unused. -##### From normalized distribution to decoding tables +#### From normalized distribution to decoding tables The distribution of normalized probabilities is enough to create a unique decoding table. It follows the following build rule : The table has a size of `Table_Size = 1 << Accuracy_Log`. Each cell describes the symbol decoded, and instructions to get the next state. Symbols are scanned in their natural order for "less than 1" probabilities. Symbols with this probability are being attributed a single cell, -starting from the end of the table. +starting from the end of the table and retreating. These symbols define a full state reset, reading `Accuracy_Log` bits. -All remaining symbols are sorted in their natural order. +All remaining symbols are allocated in their natural order. Starting from symbol `0` and table position `0`, -each symbol gets attributed as many cells as its probability. +each symbol gets allocated as many cells as its probability. Cell allocation is spreaded, not linear : each successor position follow this rule : ``` position += (tableSize>>1) + (tableSize>>3) + 3; position &= tableSize-1; ``` A position is skipped if already occupied by a "less than 1" probability symbol. `position` does not reset between symbols, it simply iterates through each position in the table, switching to the next symbol when enough states have been allocated to the current one. The result is a list of state values. Each state will decode the current symbol. To get the `Number_of_Bits` and `Baseline` required for next state, it's first necessary to sort all states in their natural order. The lower states will need 1 more bit than higher ones. +The process is repeated for each symbol. __Example__ : Presuming a symbol has a probability of 5. It receives 5 state values. States are sorted in natural order. Next power of 2 is 8. Space of probabilities is divided into 8 equal parts. Presuming the `Accuracy_Log` is 7, it defines 128 states. Divided by 8, each share is 16 large. In order to reach 8, 8-5=3 lowest states will count "double", -taking shares twice larger, +doubling the number of shares (32 in width), requiring one more bit in the process. -Numbering starts from higher states using less bits. +Baseline is assigned starting from the higher states using fewer bits, +and proceeding naturally, then resuming at the first state, +each takes its allocated width from Baseline. | state order | 0 | 1 | 2 | 3 | 4 | | ---------------- | ----- | ----- | ------ | ---- | ----- | | width | 32 | 32 | 32 | 16 | 16 | | `Number_of_Bits` | 5 | 5 | 5 | 4 | 4 | | range number | 2 | 4 | 6 | 0 | 1 | | `Baseline` | 32 | 64 | 96 | 0 | 16 | | range | 32-63 | 64-95 | 96-127 | 0-15 | 16-31 | The next state is determined from current state by reading the required `Number_of_Bits`, and adding the specified `Baseline`. See [Appendix A] for the results of this process applied to the default distributions. [Appendix A]: #appendix-a---decoding-tables-for-predefined-codes + Huffman Coding -------------- Zstandard Huffman-coded streams are read backwards, similar to the FSE bitstreams. Therefore, to find the start of the bitstream, it is therefore to know the offset of the last byte of the Huffman-coded stream. After writing the last bit containing information, the compressor writes a single `1`-bit and then fills the byte with 0-7 `0` bits of padding. The last byte of the compressed bitstream cannot be `0` for that reason. When decompressing, the last byte containing the padding is the first byte to read. The decompressor needs to skip 0-7 initial `0`-bits and the first `1`-bit it occurs. Afterwards, the useful part of the bitstream begins. The bitstream contains Huffman-coded symbols in __little-endian__ order, with the codes defined by the method below. ### Huffman Tree Description + Prefix coding represents symbols from an a priori known alphabet by bit sequences (codewords), one codeword for each symbol, in a manner such that different symbols may be represented by bit sequences of different lengths, but a parser can always parse an encoded string unambiguously symbol-by-symbol. Given an alphabet with known symbol frequencies, the Huffman algorithm allows the construction of an optimal prefix code using the fewest bits of any possible prefix codes for that alphabet. Prefix code must not exceed a maximum code length. More bits improve accuracy but cost more header size, and require more memory or more complex decoding operations. This specification limits maximum code length to 11 bits. +#### Representation -##### Representation - All literal values from zero (included) to last present one (excluded) are represented by `Weight` with values from `0` to `Max_Number_of_Bits`. Transformation from `Weight` to `Number_of_Bits` follows this formula : ``` Number_of_Bits = Weight ? (Max_Number_of_Bits + 1 - Weight) : 0 ``` The last symbol's `Weight` is deduced from previously decoded ones, by completing to the nearest power of 2. This power of 2 gives `Max_Number_of_Bits`, the depth of the current tree. +`Max_Number_of_Bits` must be <= 11, +otherwise the representation is considered corrupted. __Example__ : Let's presume the following Huffman tree must be described : -| literal | 0 | 1 | 2 | 3 | 4 | 5 | +| literal value | 0 | 1 | 2 | 3 | 4 | 5 | | ---------------- | --- | --- | --- | --- | --- | --- | | `Number_of_Bits` | 1 | 2 | 3 | 0 | 4 | 4 | -The tree depth is 4, since its smallest element uses 4 bits. -Value `5` will not be listed as it can be determined from the values for 0-4, +The tree depth is 4, since its longest elements uses 4 bits +(longest elements are the one with smallest frequency). +Value `5` will not be listed, as it can be determined from values for 0-4, nor will values above `5` as they are all 0. Values from `0` to `4` will be listed using `Weight` instead of `Number_of_Bits`. Weight formula is : ``` Weight = Number_of_Bits ? (Max_Number_of_Bits + 1 - Number_of_Bits) : 0 ``` It gives the following series of weights : -| literal | 0 | 1 | 2 | 3 | 4 | -| -------- | --- | --- | --- | --- | --- | -| `Weight` | 4 | 3 | 2 | 0 | 1 | +| literal value | 0 | 1 | 2 | 3 | 4 | +| ------------- | --- | --- | --- | --- | --- | +| `Weight` | 4 | 3 | 2 | 0 | 1 | The decoder will do the inverse operation : -having collected weights of literals from `0` to `4`, -it knows the last literal, `5`, is present with a non-zero weight. -The weight of `5` can be determined by advancing to the next power of 2. +having collected weights of literal symbols from `0` to `4`, +it knows the last literal, `5`, is present with a non-zero `Weight`. +The `Weight` of `5` can be determined by advancing to the next power of 2. The sum of `2^(Weight-1)` (excluding 0's) is : `8 + 4 + 2 + 0 + 1 = 15`. -Nearest power of 2 is 16. -Therefore, `Max_Number_of_Bits = 4` and `Weight[5] = 1`. +Nearest larger power of 2 value is 16. +Therefore, `Max_Number_of_Bits = 4` and `Weight[5] = 16-15 = 1`. -##### Huffman Tree header +#### Huffman Tree header This is a single byte value (0-255), -which describes how to decode the list of weights. +which describes how the series of weights is encoded. -- if `headerByte` >= 128 : this is a direct representation, - where each `Weight` is written directly as a 4 bits field (0-15). - They are encoded forward, 2 weights to a byte with the first weight taking - the top four bits and the second taking the bottom four (e.g. the following - operations could be used to read the weights: - `Weight[0] = (Byte[0] >> 4), Weight[1] = (Byte[0] & 0xf)`, etc.). - The full representation occupies `((Number_of_Symbols+1)/2)` bytes, - meaning it uses a last full byte even if `Number_of_Symbols` is odd. - `Number_of_Symbols = headerByte - 127`. - Note that maximum `Number_of_Symbols` is 255-127 = 128. - A larger series must necessarily use FSE compression. - - if `headerByte` < 128 : - the series of weights is compressed by FSE. + the series of weights is compressed using FSE (see below). The length of the FSE-compressed series is equal to `headerByte` (0-127). -##### Finite State Entropy (FSE) compression of Huffman weights +- if `headerByte` >= 128 : + + the series of weights uses a direct representation, + where each `Weight` is encoded directly as a 4 bits field (0-15). + + They are encoded forward, 2 weights to a byte, + first weight taking the top four bits and second one taking the bottom four. + * e.g. the following operations could be used to read the weights: + `Weight[0] = (Byte[0] >> 4), Weight[1] = (Byte[0] & 0xf)`, etc. + + The full representation occupies `Ceiling(Number_of_Weights/2)` bytes, + meaning it uses only full bytes even if `Number_of_Weights` is odd. + + `Number_of_Weights = headerByte - 127`. + * Note that maximum `Number_of_Weights` is 255-127 = 128, + therefore, only up to 128 `Weight` can be encoded using direct representation. + * Since the last non-zero `Weight` is _not_ encoded, + this scheme is compatible with alphabet sizes of up to 129 symbols, + hence including literal symbol 128. + * If any literal symbol > 128 has a non-zero `Weight`, + direct representation is not possible. + In such case, it's necessary to use FSE compression. + +#### Finite State Entropy (FSE) compression of Huffman weights + In this case, the series of Huffman weights is compressed using FSE compression. It's a single bitstream with 2 interleaved states, sharing a single distribution table. To decode an FSE bitstream, it is necessary to know its compressed size. Compressed size is provided by `headerByte`. It's also necessary to know its _maximum possible_ decompressed size, which is `255`, since literal values span from `0` to `255`, -and last symbol's weight is not represented. +and last symbol's `Weight` is not represented. An FSE bitstream starts by a header, describing probabilities distribution. It will create a Decoding Table. -For a list of Huffman weights, the maximum accuracy log is 7 bits. +For a list of Huffman weights, the maximum accuracy log is 6 bits. For more description see the [FSE header description](#fse-table-description) The Huffman header compression uses 2 states, which share the same FSE distribution table. The first state (`State1`) encodes the even indexed symbols, -and the second (`State2`) encodes the odd indexes. +and the second (`State2`) encodes the odd indexed symbols. `State1` is initialized first, and then `State2`, and they take turns decoding a single symbol and updating their state. For more details on these FSE operations, see the [FSE section](#fse). The number of symbols to decode is determined by tracking bitStream overflow condition: If updating state after decoding a symbol would require more bits than remain in the stream, it is assumed that extra bits are 0. Then, -the symbols for each of the final states are decoded and the process is complete. +symbols for each of the final states are decoded and the process is complete. -##### Conversion from weights to Huffman prefix codes +#### Conversion from weights to Huffman prefix codes All present symbols shall now have a `Weight` value. -It is possible to transform weights into Number_of_Bits, using this formula: +It is possible to transform weights into `Number_of_Bits`, using this formula: ``` -Number_of_Bits = Number_of_Bits ? Max_Number_of_Bits + 1 - Weight : 0 +Number_of_Bits = (Weight>0) ? Max_Number_of_Bits + 1 - Weight : 0 ``` -Symbols are sorted by `Weight`. Within same `Weight`, symbols keep natural order. +Symbols are sorted by `Weight`. +Within same `Weight`, symbols keep natural sequential order. Symbols with a `Weight` of zero are removed. -Then, starting from lowest weight, prefix codes are distributed in order. +Then, starting from lowest `Weight`, prefix codes are distributed in sequential order. __Example__ : Let's presume the following list of weights has been decoded : | Literal | 0 | 1 | 2 | 3 | 4 | 5 | | -------- | --- | --- | --- | --- | --- | --- | | `Weight` | 4 | 3 | 2 | 0 | 1 | 1 | -Sorted by weight and then natural order, +Sorted by weight and then natural sequential order, it gives the following distribution : | Literal | 3 | 4 | 5 | 2 | 1 | 0 | | ---------------- | --- | --- | --- | --- | --- | ---- | | `Weight` | 0 | 1 | 1 | 2 | 3 | 4 | | `Number_of_Bits` | 0 | 4 | 4 | 3 | 2 | 1 | | prefix codes | N/A | 0000| 0001| 001 | 01 | 1 | ### Huffman-coded Streams + Given a Huffman decoding table, it's possible to decode a Huffman-coded stream. Each bitstream must be read _backward_, that is starting from the end down to the beginning. Therefore it's necessary to know the size of each bitstream. -It's also necessary to know exactly which _bit_ is the latest. +It's also necessary to know exactly which _bit_ is the last one. This is detected by a final bit flag : the highest bit of latest byte is a final-bit-flag. Consequently, a last byte of `0` is not possible. And the final-bit-flag itself is not part of the useful bitstream. Hence, the last byte contains between 0 and 7 useful bits. Starting from the end, it's possible to read the bitstream in a __little-endian__ fashion, keeping track of already used bits. Since the bitstream is encoded in reverse order, starting from the end read symbols in forward order. For example, if the literal sequence "0145" was encoded using above prefix code, it would be encoded (in reverse order) as: |Symbol | 5 | 4 | 1 | 0 | Padding | |--------|------|------|----|---|---------| |Encoding|`0000`|`0001`|`01`|`1`| `00001` | Resulting in following 2-bytes bitstream : ``` 00010000 00001101 ``` Here is an alternative representation with the symbol codes separated by underscore: ``` 0001_0000 00001_1_01 ``` Reading highest `Max_Number_of_Bits` bits, it's possible to compare extracted value to decoding table, determining the symbol to decode and number of bits to discard. The process continues up to reading the required number of symbols per stream. If a bitstream is not entirely and exactly consumed, hence reaching exactly its beginning position with _all_ bits consumed, the decoding process is considered faulty. Dictionary Format ----------------- Zstandard is compatible with "raw content" dictionaries, free of any format restriction, except that they must be at least 8 bytes. These dictionaries function as if they were just the `Content` part of a formatted dictionary. But dictionaries created by `zstd --train` follow a format, described here. __Pre-requisites__ : a dictionary has a size, defined either by a buffer limit, or a file size. | `Magic_Number` | `Dictionary_ID` | `Entropy_Tables` | `Content` | | -------------- | --------------- | ---------------- | --------- | __`Magic_Number`__ : 4 bytes ID, value 0xEC30A437, __little-endian__ format __`Dictionary_ID`__ : 4 bytes, stored in __little-endian__ format. `Dictionary_ID` can be any value, except 0 (which means no `Dictionary_ID`). It's used by decoders to check if they use the correct dictionary. _Reserved ranges :_ If the frame is going to be distributed in a private environment, any `Dictionary_ID` can be used. However, for public distribution of compressed frames, the following ranges are reserved and shall not be used : - low range : <= 32767 - high range : >= (2^31) -__`Entropy_Tables`__ : following the same format as the tables in compressed blocks. +__`Entropy_Tables`__ : follow the same format as tables in [compressed blocks]. See the relevant [FSE](#fse-table-description) and [Huffman](#huffman-tree-description) sections for how to decode these tables. They are stored in following order : Huffman tables for literals, FSE table for offsets, FSE table for match lengths, and FSE table for literals lengths. These tables populate the Repeat Stats literals mode and Repeat distribution mode for sequence decoding. It's finally followed by 3 offset values, populating recent offsets (instead of using `{1,4,8}`), stored in order, 4-bytes __little-endian__ each, for a total of 12 bytes. Each recent offset must have a value < dictionary size. __`Content`__ : The rest of the dictionary is its content. The content act as a "past" in front of data to compress or decompress, so it can be referenced in sequence commands. As long as the amount of data decoded from this frame is less than or equal to `Window_Size`, sequence commands may specify offsets longer than the total length of decoded output so far to reference back to the - dictionary. After the total output has surpassed `Window_Size` however, + dictionary, even parts of the dictionary with offsets larger than `Window_Size`. + After the total output has surpassed `Window_Size` however, this is no longer allowed and the dictionary is no longer accessible. [compressed blocks]: #the-format-of-compressed_block +If a dictionary is provided by an external source, +it should be loaded with great care, its content considered untrusted. + + Appendix A - Decoding tables for predefined codes ------------------------------------------------- This appendix contains FSE decoding tables for the predefined literal length, match length, and offset codes. The tables have been constructed using the algorithm as given above in chapter "from normalized distribution to decoding tables". The tables here can be used as examples to crosscheck that an implementation build its decoding tables correctly. #### Literal Length Code: | State | Symbol | Number_Of_Bits | Base | | ----- | ------ | -------------- | ---- | | 0 | 0 | 4 | 0 | | 1 | 0 | 4 | 16 | | 2 | 1 | 5 | 32 | | 3 | 3 | 5 | 0 | | 4 | 4 | 5 | 0 | | 5 | 6 | 5 | 0 | | 6 | 7 | 5 | 0 | | 7 | 9 | 5 | 0 | | 8 | 10 | 5 | 0 | | 9 | 12 | 5 | 0 | | 10 | 14 | 6 | 0 | | 11 | 16 | 5 | 0 | | 12 | 18 | 5 | 0 | | 13 | 19 | 5 | 0 | | 14 | 21 | 5 | 0 | | 15 | 22 | 5 | 0 | | 16 | 24 | 5 | 0 | | 17 | 25 | 5 | 32 | | 18 | 26 | 5 | 0 | | 19 | 27 | 6 | 0 | | 20 | 29 | 6 | 0 | | 21 | 31 | 6 | 0 | | 22 | 0 | 4 | 32 | | 23 | 1 | 4 | 0 | | 24 | 2 | 5 | 0 | | 25 | 4 | 5 | 32 | | 26 | 5 | 5 | 0 | | 27 | 7 | 5 | 32 | | 28 | 8 | 5 | 0 | | 29 | 10 | 5 | 32 | | 30 | 11 | 5 | 0 | | 31 | 13 | 6 | 0 | | 32 | 16 | 5 | 32 | | 33 | 17 | 5 | 0 | | 34 | 19 | 5 | 32 | | 35 | 20 | 5 | 0 | | 36 | 22 | 5 | 32 | | 37 | 23 | 5 | 0 | | 38 | 25 | 4 | 0 | | 39 | 25 | 4 | 16 | | 40 | 26 | 5 | 32 | | 41 | 28 | 6 | 0 | | 42 | 30 | 6 | 0 | | 43 | 0 | 4 | 48 | | 44 | 1 | 4 | 16 | | 45 | 2 | 5 | 32 | | 46 | 3 | 5 | 32 | | 47 | 5 | 5 | 32 | | 48 | 6 | 5 | 32 | | 49 | 8 | 5 | 32 | | 50 | 9 | 5 | 32 | | 51 | 11 | 5 | 32 | | 52 | 12 | 5 | 32 | | 53 | 15 | 6 | 0 | | 54 | 17 | 5 | 32 | | 55 | 18 | 5 | 32 | | 56 | 20 | 5 | 32 | | 57 | 21 | 5 | 32 | | 58 | 23 | 5 | 32 | | 59 | 24 | 5 | 32 | | 60 | 35 | 6 | 0 | | 61 | 34 | 6 | 0 | | 62 | 33 | 6 | 0 | | 63 | 32 | 6 | 0 | #### Match Length Code: | State | Symbol | Number_Of_Bits | Base | | ----- | ------ | -------------- | ---- | | 0 | 0 | 6 | 0 | | 1 | 1 | 4 | 0 | | 2 | 2 | 5 | 32 | | 3 | 3 | 5 | 0 | | 4 | 5 | 5 | 0 | | 5 | 6 | 5 | 0 | | 6 | 8 | 5 | 0 | | 7 | 10 | 6 | 0 | | 8 | 13 | 6 | 0 | | 9 | 16 | 6 | 0 | | 10 | 19 | 6 | 0 | | 11 | 22 | 6 | 0 | | 12 | 25 | 6 | 0 | | 13 | 28 | 6 | 0 | | 14 | 31 | 6 | 0 | | 15 | 33 | 6 | 0 | | 16 | 35 | 6 | 0 | | 17 | 37 | 6 | 0 | | 18 | 39 | 6 | 0 | | 19 | 41 | 6 | 0 | | 20 | 43 | 6 | 0 | | 21 | 45 | 6 | 0 | | 22 | 1 | 4 | 16 | | 23 | 2 | 4 | 0 | | 24 | 3 | 5 | 32 | | 25 | 4 | 5 | 0 | | 26 | 6 | 5 | 32 | | 27 | 7 | 5 | 0 | | 28 | 9 | 6 | 0 | | 29 | 12 | 6 | 0 | | 30 | 15 | 6 | 0 | | 31 | 18 | 6 | 0 | | 32 | 21 | 6 | 0 | | 33 | 24 | 6 | 0 | | 34 | 27 | 6 | 0 | | 35 | 30 | 6 | 0 | | 36 | 32 | 6 | 0 | | 37 | 34 | 6 | 0 | | 38 | 36 | 6 | 0 | | 39 | 38 | 6 | 0 | | 40 | 40 | 6 | 0 | | 41 | 42 | 6 | 0 | | 42 | 44 | 6 | 0 | | 43 | 1 | 4 | 32 | | 44 | 1 | 4 | 48 | | 45 | 2 | 4 | 16 | | 46 | 4 | 5 | 32 | | 47 | 5 | 5 | 32 | | 48 | 7 | 5 | 32 | | 49 | 8 | 5 | 32 | | 50 | 11 | 6 | 0 | | 51 | 14 | 6 | 0 | | 52 | 17 | 6 | 0 | | 53 | 20 | 6 | 0 | | 54 | 23 | 6 | 0 | | 55 | 26 | 6 | 0 | | 56 | 29 | 6 | 0 | | 57 | 52 | 6 | 0 | | 58 | 51 | 6 | 0 | | 59 | 50 | 6 | 0 | | 60 | 49 | 6 | 0 | | 61 | 48 | 6 | 0 | | 62 | 47 | 6 | 0 | | 63 | 46 | 6 | 0 | #### Offset Code: | State | Symbol | Number_Of_Bits | Base | | ----- | ------ | -------------- | ---- | | 0 | 0 | 5 | 0 | | 1 | 6 | 4 | 0 | | 2 | 9 | 5 | 0 | | 3 | 15 | 5 | 0 | | 4 | 21 | 5 | 0 | | 5 | 3 | 5 | 0 | | 6 | 7 | 4 | 0 | | 7 | 12 | 5 | 0 | | 8 | 18 | 5 | 0 | | 9 | 23 | 5 | 0 | | 10 | 5 | 5 | 0 | | 11 | 8 | 4 | 0 | | 12 | 14 | 5 | 0 | | 13 | 20 | 5 | 0 | | 14 | 2 | 5 | 0 | | 15 | 7 | 4 | 16 | | 16 | 11 | 5 | 0 | | 17 | 17 | 5 | 0 | | 18 | 22 | 5 | 0 | | 19 | 4 | 5 | 0 | | 20 | 8 | 4 | 16 | | 21 | 13 | 5 | 0 | | 22 | 19 | 5 | 0 | | 23 | 1 | 5 | 0 | | 24 | 6 | 4 | 16 | | 25 | 10 | 5 | 0 | | 26 | 16 | 5 | 0 | | 27 | 28 | 5 | 0 | | 28 | 27 | 5 | 0 | | 29 | 26 | 5 | 0 | | 30 | 25 | 5 | 0 | | 31 | 24 | 5 | 0 | + + +Appendix B - Resources for implementers +------------------------------------------------- + +An open source reference implementation is available on : +https://github.com/facebook/zstd + +The project contains a frame generator, called [decodeCorpus], +which can be used by any 3rd-party implementation +to verify that a tested decoder is compliant with the specification. + +[decodeCorpus]: https://github.com/facebook/zstd/tree/v1.3.4/tests#decodecorpus---tool-to-generate-zstandard-frames-for-decoder-testing + +`decodeCorpus` generates random valid frames. +A compliant decoder should be able to decode them all, +or at least provide a meaningful error code explaining for which reason it cannot +(memory limit restrictions for example). + + Version changes --------------- +- 0.3.0 : minor edits to match RFC8478 +- 0.2.9 : clarifications for huffman weights direct representation, by Ulrich Kunitz +- 0.2.8 : clarifications for IETF RFC discuss +- 0.2.7 : clarifications from IETF RFC review, by Vijay Gurbani and Nick Terrell - 0.2.6 : fixed an error in huffman example, by Ulrich Kunitz - 0.2.5 : minor typos and clarifications - 0.2.4 : section restructuring, by Sean Purcell - 0.2.3 : clarified several details, by Sean Purcell - 0.2.2 : added predefined codes, by Johannes Rudolph - 0.2.1 : clarify field names, by Przemyslaw Skibinski - 0.2.0 : numerous format adjustments for zstd v0.8+ - 0.1.2 : limit Huffman tree depth to 11 bits - 0.1.1 : reserved dictID ranges - 0.1.0 : initial release Index: vendor/zstd/dist/doc/zstd_manual.html =================================================================== --- vendor/zstd/dist/doc/zstd_manual.html (revision 339613) +++ vendor/zstd/dist/doc/zstd_manual.html (revision 339614) @@ -1,1171 +1,1293 @@ -zstd 1.3.4 Manual +zstd 1.3.7 Manual -

zstd 1.3.4 Manual

+

zstd 1.3.7 Manual

Contents

  1. Introduction
  2. Version
    3. -
  3. Simple API
    4. -
  4. Explicit context
    5. -
  5. Simple dictionary API
    6. -
  6. Bulk processing dictionary API
    7. -
  7. Streaming
    8. -
  8. Streaming compression - HowTo
    9. -
  9. Streaming decompression - HowTo
    10. -
  10. START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
    11. -
  11. Advanced types
    12. +
  12. Default constant
    13. +
  13. Simple API
    14. +
  14. Explicit context
    15. +
  15. Simple dictionary API
    16. +
  16. Bulk processing dictionary API
    17. +
  17. Streaming
    18. +
  18. Streaming compression - HowTo
    19. +
  19. Streaming decompression - HowTo
    20. +
  20. ADVANCED AND EXPERIMENTAL FUNCTIONS
  21. Frame size functions
  22. Memory management
  23. Advanced compression functions
  24. Advanced decompression functions
  25. Advanced streaming functions
  26. Buffer-less and synchronous inner streaming functions
  27. Buffer-less streaming compression (synchronous mode)
  28. Buffer-less streaming decompression (synchronous mode)
  29. New advanced API (experimental)
  30. Block level API

Introduction

-  zstd, short for Zstandard, is a fast lossless compression algorithm,
-  targeting real-time compression scenarios at zlib-level and better compression ratios.
-  The zstd compression library provides in-memory compression and decompression functions.
-  The library supports compression levels from 1 up to ZSTD_maxCLevel() which is currently 22.
-  Levels >= 20, labeled `--ultra`, should be used with caution, as they require more memory.
+  zstd, short for Zstandard, is a fast lossless compression algorithm, targeting
+  real-time compression scenarios at zlib-level and better compression ratios.
+  The zstd compression library provides in-memory compression and decompression
+  functions.
+
+  The library supports regular compression levels from 1 up to ZSTD_maxCLevel(),
+  which is currently 22. Levels >= 20, labeled `--ultra`, should be used with
+  caution, as they require more memory. The library also offers negative
+  compression levels, which extend the range of speed vs. ratio preferences.
+  The lower the level, the faster the speed (at the cost of compression).
+
   Compression can be done in:
     - a single step (described as Simple API)
     - a single step, reusing a context (described as Explicit context)
     - unbounded multiple steps (described as Streaming compression)
-  The compression ratio achievable on small data can be highly improved using a dictionary in:
+
+  The compression ratio achievable on small data can be highly improved using
+  a dictionary. Dictionary compression can be performed in:
     - a single step (described as Simple dictionary API)
-    - a single step, reusing a dictionary (described as Bulk-processing dictionary API)
+    - a single step, reusing a dictionary (described as Bulk-processing
+      dictionary API)
 
-  Advanced experimental functions can be accessed using #define ZSTD_STATIC_LINKING_ONLY before including zstd.h.
-  Advanced experimental APIs shall never be used with a dynamic library.
-  They are not "stable", their definition may change in the future. Only static linking is allowed.
+  Advanced experimental functions can be accessed using
+  `#define ZSTD_STATIC_LINKING_ONLY` before including zstd.h.
+
+  Advanced experimental APIs should never be used with a dynamically-linked
+  library. They are not "stable"; their definitions or signatures may change in
+  the future. Only static linking is allowed.

Version


 
 
unsigned ZSTD_versionNumber(void);   /**< useful to check dll version */
 


-
Simple API

+
Default constant

 
+
Simple API

+
 
size_t ZSTD_compress( void* dst, size_t dstCapacity,
                 const void* src, size_t srcSize,
                       int compressionLevel);
 
  Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
   Hint : compression runs faster if `dstCapacity` >=  `ZSTD_compressBound(srcSize)`.
   @return : compressed size written into `dst` (<= `dstCapacity),
             or an error code if it fails (which can be tested using ZSTD_isError()). 
 


 
 
size_t ZSTD_decompress( void* dst, size_t dstCapacity,
                   const void* src, size_t compressedSize);
 
  `compressedSize` : must be the _exact_ size of some number of compressed and/or skippable frames.
   `dstCapacity` is an upper bound of originalSize to regenerate.
   If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data.
   @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
             or an errorCode if it fails (which can be tested using ZSTD_isError()). 
 


 
 
#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
 #define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
 unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
 
  `src` should point to the start of a ZSTD encoded frame.
   `srcSize` must be at least as large as the frame header.
             hint : any size >= `ZSTD_frameHeaderSize_max` is large enough.
-  @return : - decompressed size of the frame in `src`, if known
+  @return : - decompressed size of `src` frame content, if known
             - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
             - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
    note 1 : a 0 return value means the frame is valid but "empty".
    note 2 : decompressed size is an optional field, it may not be present, typically in streaming mode.
             When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
             In which case, it's necessary to use streaming mode to decompress data.
             Optionally, application can rely on some implicit limit,
             as ZSTD_decompress() only needs an upper bound of decompressed size.
             (For example, data could be necessarily cut into blocks <= 16 KB).
-   note 3 : decompressed size is always present when compression is done with ZSTD_compress()
+   note 3 : decompressed size is always present when compression is completed using single-pass functions,
+            such as ZSTD_compress(), ZSTD_compressCCtx() ZSTD_compress_usingDict() or ZSTD_compress_usingCDict().
    note 4 : decompressed size can be very large (64-bits value),
             potentially larger than what local system can handle as a single memory segment.
             In which case, it's necessary to use streaming mode to decompress data.
    note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
             Always ensure return value fits within application's authorized limits.
             Each application can set its own limits.
    note 6 : This function replaces ZSTD_getDecompressedSize() 
 


 
 
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
 
  NOTE: This function is now obsolete, in favor of ZSTD_getFrameContentSize().
   Both functions work the same way, but ZSTD_getDecompressedSize() blends
   "empty", "unknown" and "error" results to the same return value (0),
   while ZSTD_getFrameContentSize() gives them separate return values.
- `src` is the start of a zstd compressed frame.
- @return : content size to be decompressed, as a 64-bits value _if known and not empty_, 0 otherwise. 
+ @return : decompressed size of `src` frame content _if known and not empty_, 0 otherwise. 
 


 
 
Helper functions
#define ZSTD_COMPRESSBOUND(srcSize)   ((srcSize) + ((srcSize)>>8) + (((srcSize) < (128<<10)) ? (((128<<10) - (srcSize)) >> 11) /* margin, from 64 to 0 */ : 0))  /* this formula ensures that bound(A) + bound(B) <= bound(A+B) as long as A and B >= 128 KB */
 size_t      ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case single-pass scenario */
 unsigned    ZSTD_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
 const char* ZSTD_getErrorName(size_t code);     /*!< provides readable string from an error code */
 int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
 


-
Explicit context

+
Explicit context

 
 
Compression context
  When compressing many times,
   it is recommended to allocate a context just once, and re-use it for each successive compression operation.
   This will make workload friendlier for system's memory.
   Use one context per thread for parallel execution in multi-threaded environments. 
 
typedef struct ZSTD_CCtx_s ZSTD_CCtx;
 ZSTD_CCtx* ZSTD_createCCtx(void);
 size_t     ZSTD_freeCCtx(ZSTD_CCtx* cctx);
 


 
size_t ZSTD_compressCCtx(ZSTD_CCtx* ctx,
                          void* dst, size_t dstCapacity,
                    const void* src, size_t srcSize,
                          int compressionLevel);
 
  Same as ZSTD_compress(), requires an allocated ZSTD_CCtx (see ZSTD_createCCtx()). 
 


 
 
Decompression context
  When decompressing many times,
   it is recommended to allocate a context only once,
   and re-use it for each successive compression operation.
   This will make workload friendlier for system's memory.
   Use one context per thread for parallel execution. 
 
typedef struct ZSTD_DCtx_s ZSTD_DCtx;
 ZSTD_DCtx* ZSTD_createDCtx(void);
 size_t     ZSTD_freeDCtx(ZSTD_DCtx* dctx);
 


 
size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize);
 
  Same as ZSTD_decompress(), requires an allocated ZSTD_DCtx (see ZSTD_createDCtx()) 
 


 
-
Simple dictionary API

+
Simple dictionary API

 
 
size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const void* dict,size_t dictSize,
                                int compressionLevel);
 
  Compression using a predefined Dictionary (see dictBuilder/zdict.h).
   Note : This function loads the dictionary, resulting in significant startup delay.
   Note : When `dict == NULL || dictSize < 8` no dictionary is used. 
 


 
 
size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
                                  void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize,
                            const void* dict,size_t dictSize);
 
  Decompression using a predefined Dictionary (see dictBuilder/zdict.h).
   Dictionary must be identical to the one used during compression.
   Note : This function loads the dictionary, resulting in significant startup delay.
   Note : When `dict == NULL || dictSize < 8` no dictionary is used. 
 


 
-
Bulk processing dictionary API

+
Bulk processing dictionary API

 
 
ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
                              int compressionLevel);
 
  When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
   ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
   ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
-  `dictBuffer` can be released after ZSTD_CDict creation, since its content is copied within CDict 
+  `dictBuffer` can be released after ZSTD_CDict creation, since its content is copied within CDict
+  Note : A ZSTD_CDict can be created with an empty dictionary, but it is inefficient for small data. 
 


 
 
size_t      ZSTD_freeCDict(ZSTD_CDict* CDict);
 
  Function frees memory allocated by ZSTD_createCDict(). 
 


 
 
size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize,
                           const ZSTD_CDict* cdict);
 
  Compression using a digested Dictionary.
   Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
   Note that compression level is decided during dictionary creation.
-  Frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) 
+  Frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no)
+  Note : ZSTD_compress_usingCDict() can be used with a ZSTD_CDict created from an empty dictionary.
+         But it is inefficient for small data, and it is recommended to use ZSTD_compressCCtx(). 
 


 
 
ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);
 
  Create a digested dictionary, ready to start decompression operation without startup delay.
   dictBuffer can be released after DDict creation, as its content is copied inside DDict 
 


 
 
size_t      ZSTD_freeDDict(ZSTD_DDict* ddict);
 
  Function frees memory allocated with ZSTD_createDDict() 
 


 
 
size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
                                   void* dst, size_t dstCapacity,
                             const void* src, size_t srcSize,
                             const ZSTD_DDict* ddict);
 
  Decompression using a digested Dictionary.
   Faster startup than ZSTD_decompress_usingDict(), recommended when same dictionary is used multiple times. 
 


 
-
Streaming

+
Streaming

 
 
typedef struct ZSTD_inBuffer_s {
   const void* src;    /**< start of input buffer */
   size_t size;        /**< size of input buffer */
   size_t pos;         /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
 } ZSTD_inBuffer;
 


 
typedef struct ZSTD_outBuffer_s {
   void*  dst;         /**< start of output buffer */
   size_t size;        /**< size of output buffer */
   size_t pos;         /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
 } ZSTD_outBuffer;
 


-
Streaming compression - HowTo
+
Streaming compression - HowTo
   A ZSTD_CStream object is required to track streaming operation.
   Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources.
   ZSTD_CStream objects can be reused multiple times on consecutive compression operations.
   It is recommended to re-use ZSTD_CStream in situations where many streaming operations will be achieved consecutively,
   since it will play nicer with system's memory, by re-using already allocated memory.
   Use one separate ZSTD_CStream per thread for parallel execution.
 
-  Start a new compression by initializing ZSTD_CStream.
+  Start a new compression by initializing ZSTD_CStream context.
   Use ZSTD_initCStream() to start a new compression operation.
-  Use ZSTD_initCStream_usingDict() or ZSTD_initCStream_usingCDict() for a compression which requires a dictionary (experimental section)
+  Use variants ZSTD_initCStream_usingDict() or ZSTD_initCStream_usingCDict() for streaming with dictionary (experimental section)
 
-  Use ZSTD_compressStream() repetitively to consume input stream.
-  The function will automatically update both `pos` fields.
-  Note that it may not consume the entire input, in which case `pos < size`,
-  and it's up to the caller to present again remaining data.
+  Use ZSTD_compressStream() as many times as necessary to consume input stream.
+  The function will automatically update both `pos` fields within `input` and `output`.
+  Note that the function may not consume the entire input,
+  for example, because the output buffer is already full,
+  in which case `input.pos < input.size`.
+  The caller must check if input has been entirely consumed.
+  If not, the caller must make some room to receive more compressed data,
+  typically by emptying output buffer, or allocating a new output buffer,
+  and then present again remaining input data.
   @return : a size hint, preferred nb of bytes to use as input for next function call
             or an error code, which can be tested using ZSTD_isError().
             Note 1 : it's just a hint, to help latency a little, any other value will work fine.
             Note 2 : size hint is guaranteed to be <= ZSTD_CStreamInSize()
 
-  At any moment, it's possible to flush whatever data remains within internal buffer, using ZSTD_flushStream().
-  `output->pos` will be updated.
-  Note that some content might still be left within internal buffer if `output->size` is too small.
-  @return : nb of bytes still present within internal buffer (0 if it's empty)
+  At any moment, it's possible to flush whatever data might remain stuck within internal buffer,
+  using ZSTD_flushStream(). `output->pos` will be updated.
+  Note that, if `output->size` is too small, a single invocation of ZSTD_flushStream() might not be enough (return code > 0).
+  In which case, make some room to receive more compressed data, and call again ZSTD_flushStream().
+  @return : 0 if internal buffers are entirely flushed,
+            >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
             or an error code, which can be tested using ZSTD_isError().
 
   ZSTD_endStream() instructs to finish a frame.
   It will perform a flush and write frame epilogue.
   The epilogue is required for decoders to consider a frame completed.
-  ZSTD_endStream() may not be able to flush full data if `output->size` is too small.
-  In which case, call again ZSTD_endStream() to complete the flush.
+  flush() operation is the same, and follows same rules as ZSTD_flushStream().
   @return : 0 if frame fully completed and fully flushed,
-             or >0 if some data is still present within internal buffer
-                  (value is minimum size estimation for remaining data to flush, but it could be more)
+            >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
             or an error code, which can be tested using ZSTD_isError().
 
  
 

 
 
typedef ZSTD_CCtx ZSTD_CStream;  /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
 


 
ZSTD_CStream management functions
ZSTD_CStream* ZSTD_createCStream(void);
 size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
 


 
Streaming compression functions
size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
 size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
 size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
 size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
 


 
size_t ZSTD_CStreamInSize(void);    /**< recommended size for input buffer */
 


 
size_t ZSTD_CStreamOutSize(void);   /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */
 


-
Streaming decompression - HowTo
+
Streaming decompression - HowTo
   A ZSTD_DStream object is required to track streaming operations.
   Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources.
   ZSTD_DStream objects can be re-used multiple times.
 
   Use ZSTD_initDStream() to start a new decompression operation,
    or ZSTD_initDStream_usingDict() if decompression requires a dictionary.
    @return : recommended first input size
 
   Use ZSTD_decompressStream() repetitively to consume your input.
   The function will update both `pos` fields.
   If `input.pos < input.size`, some input has not been consumed.
   It's up to the caller to present again remaining data.
+  The function tries to flush all data decoded immediately, repecting buffer sizes.
   If `output.pos < output.size`, decoder has flushed everything it could.
-  @return : 0 when a frame is completely decoded and fully flushed,
-            an error code, which can be tested using ZSTD_isError(),
-            any other value > 0, which means there is still some decoding to do to complete current frame.
-            The return value is a suggested next input size (a hint to improve latency) that will never load more than the current frame.
+  But if `output.pos == output.size`, there is no such guarantee,
+  it's likely that some decoded data was not flushed and still remains within internal buffers.
+  In which case, call ZSTD_decompressStream() again to flush whatever remains in the buffer.
+  When no additional input is provided, amount of data flushed is necessarily <= ZSTD_BLOCKSIZE_MAX.
+ @return : 0 when a frame is completely decoded and fully flushed,
+        or an error code, which can be tested using ZSTD_isError(),
+        or any other value > 0, which means there is still some decoding or flushing to do to complete current frame :
+                                the return value is a suggested next input size (a hint for better latency)
+                                that will never load more than the current frame.
  
 

 
 
typedef ZSTD_DCtx ZSTD_DStream;  /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
 


 
ZSTD_DStream management functions
ZSTD_DStream* ZSTD_createDStream(void);
 size_t ZSTD_freeDStream(ZSTD_DStream* zds);
 


 
Streaming decompression functions
size_t ZSTD_initDStream(ZSTD_DStream* zds);
 size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
 


 
size_t ZSTD_DStreamInSize(void);    /*!< recommended size for input buffer */
 


 
size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
 


-
START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
 The definitions in this section are considered experimental.
+
ADVANCED AND EXPERIMENTAL FUNCTIONS
+ The definitions in this section are considered experimental.
  They should never be used with a dynamic library, as prototypes may change in the future.
  They are provided for advanced scenarios.
  Use them only in association with static linking.
  
 

 
-
Advanced types

-
+
int ZSTD_minCLevel(void);  /*!< minimum negative compression level allowed */
+


 
typedef enum { ZSTD_fast=1, ZSTD_dfast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2,
                ZSTD_btlazy2, ZSTD_btopt, ZSTD_btultra } ZSTD_strategy;   /* from faster to stronger */
 


 
typedef struct {
     unsigned windowLog;      /**< largest match distance : larger == more compression, more memory needed during decompression */
     unsigned chainLog;       /**< fully searched segment : larger == more compression, slower, more memory (useless for fast) */
     unsigned hashLog;        /**< dispatch table : larger == faster, more memory */
     unsigned searchLog;      /**< nb of searches : larger == more compression, slower */
     unsigned searchLength;   /**< match length searched : larger == faster decompression, sometimes less compression */
     unsigned targetLength;   /**< acceptable match size for optimal parser (only) : larger == more compression, slower */
     ZSTD_strategy strategy;
 } ZSTD_compressionParameters;
 


 
typedef struct {
     unsigned contentSizeFlag; /**< 1: content size will be in frame header (when known) */
     unsigned checksumFlag;    /**< 1: generate a 32-bits checksum at end of frame, for error detection */
     unsigned noDictIDFlag;    /**< 1: no dictID will be saved into frame header (if dictionary compression) */
 } ZSTD_frameParameters;
 


 
typedef struct {
     ZSTD_compressionParameters cParams;
     ZSTD_frameParameters fParams;
 } ZSTD_parameters;
 


 
typedef enum {
     ZSTD_dct_auto=0,      /* dictionary is "full" when starting with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */
     ZSTD_dct_rawContent,  /* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */
     ZSTD_dct_fullDict     /* refuses to load a dictionary if it does not respect Zstandard's specification */
 } ZSTD_dictContentType_e;
 


 
typedef enum {
     ZSTD_dlm_byCopy = 0, /**< Copy dictionary content internally */
     ZSTD_dlm_byRef,      /**< Reference dictionary content -- the dictionary buffer must outlive its users. */
 } ZSTD_dictLoadMethod_e;
 


 
Frame size functions

 
 
size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
 
  `src` should point to the start of a ZSTD encoded frame or skippable frame
   `srcSize` must be >= first frame size
   @return : the compressed size of the first frame starting at `src`,
             suitable to pass to `ZSTD_decompress` or similar,
             or an error code if input is invalid 
 


 
 
unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);
 
  `src` should point the start of a series of ZSTD encoded and/or skippable frames
   `srcSize` must be the _exact_ size of this series
        (i.e. there should be a frame boundary exactly at `srcSize` bytes after `src`)
   @return : - decompressed size of all data in all successive frames
             - if the decompressed size cannot be determined: ZSTD_CONTENTSIZE_UNKNOWN
             - if an error occurred: ZSTD_CONTENTSIZE_ERROR
 
    note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
             When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
             In which case, it's necessary to use streaming mode to decompress data.
    note 2 : decompressed size is always present when compression is done with ZSTD_compress()
    note 3 : decompressed size can be very large (64-bits value),
             potentially larger than what local system can handle as a single memory segment.
             In which case, it's necessary to use streaming mode to decompress data.
    note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
             Always ensure result fits within application's authorized limits.
             Each application can set its own limits.
    note 5 : ZSTD_findDecompressedSize handles multiple frames, and so it must traverse the input to
             read each contained frame header.  This is fast as most of the data is skipped,
             however it does mean that all frame data must be present and valid. 
 


 
 
size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
-
   `src` should point to the start of a ZSTD frame
-   `srcSize` must be >= ZSTD_frameHeaderSize_prefix.
-   @return : size of the Frame Header 
+
  srcSize must be >= ZSTD_frameHeaderSize_prefix.
+ @return : size of the Frame Header,
+           or an error code (if srcSize is too small) 
 


 
 
Memory management

 
 
size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
 size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
 size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
 size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
 size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
 
  These functions give the current memory usage of selected object.
   Object memory usage can evolve when re-used. 
 


 
 
size_t ZSTD_estimateCCtxSize(int compressionLevel);
 size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
 size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params);
 size_t ZSTD_estimateDCtxSize(void);
 
  These functions make it possible to estimate memory usage
   of a future {D,C}Ctx, before its creation.
   ZSTD_estimateCCtxSize() will provide a budget large enough for any compression level up to selected one.
   It will also consider src size to be arbitrarily "large", which is worst case.
   If srcSize is known to always be small, ZSTD_estimateCCtxSize_usingCParams() can provide a tighter estimation.
   ZSTD_estimateCCtxSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
   ZSTD_estimateCCtxSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParam_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_p_nbWorkers is >= 1.
   Note : CCtx size estimation is only correct for single-threaded compression. 
 


 
 
size_t ZSTD_estimateCStreamSize(int compressionLevel);
 size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams);
 size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params);
 size_t ZSTD_estimateDStreamSize(size_t windowSize);
 size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize);
 
  ZSTD_estimateCStreamSize() will provide a budget large enough for any compression level up to selected one.
   It will also consider src size to be arbitrarily "large", which is worst case.
   If srcSize is known to always be small, ZSTD_estimateCStreamSize_usingCParams() can provide a tighter estimation.
   ZSTD_estimateCStreamSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
   ZSTD_estimateCStreamSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParam_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_p_nbWorkers is >= 1.
   Note : CStream size estimation is only correct for single-threaded compression.
   ZSTD_DStream memory budget depends on window Size.
   This information can be passed manually, using ZSTD_estimateDStreamSize,
   or deducted from a valid frame Header, using ZSTD_estimateDStreamSize_fromFrame();
   Note : if streaming is init with function ZSTD_init?Stream_usingDict(),
          an internal ?Dict will be created, which additional size is not estimated here.
          In this case, get total size by adding ZSTD_estimate?DictSize 
 


 
 
size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel);
 size_t ZSTD_estimateCDictSize_advanced(size_t dictSize, ZSTD_compressionParameters cParams, ZSTD_dictLoadMethod_e dictLoadMethod);
 size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod);
 
  ZSTD_estimateCDictSize() will bet that src size is relatively "small", and content is copied, like ZSTD_createCDict().
   ZSTD_estimateCDictSize_advanced() makes it possible to control compression parameters precisely, like ZSTD_createCDict_advanced().
   Note : dictionaries created by reference (`ZSTD_dlm_byRef`) are logically smaller.
  
 


 
 
ZSTD_CCtx*    ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize);
 ZSTD_CStream* ZSTD_initStaticCStream(void* workspace, size_t workspaceSize);    /**< same as ZSTD_initStaticCCtx() */
 
  Initialize an object using a pre-allocated fixed-size buffer.
   workspace: The memory area to emplace the object into.
              Provided pointer *must be 8-bytes aligned*.
              Buffer must outlive object.
   workspaceSize: Use ZSTD_estimate*Size() to determine
                  how large workspace must be to support target scenario.
  @return : pointer to object (same address as workspace, just different type),
            or NULL if error (size too small, incorrect alignment, etc.)
   Note : zstd will never resize nor malloc() when using a static buffer.
          If the object requires more memory than available,
          zstd will just error out (typically ZSTD_error_memory_allocation).
   Note 2 : there is no corresponding "free" function.
            Since workspace is allocated externally, it must be freed externally too.
   Note 3 : cParams : use ZSTD_getCParams() to convert a compression level
            into its associated cParams.
   Limitation 1 : currently not compatible with internal dictionary creation, triggered by
                  ZSTD_CCtx_loadDictionary(), ZSTD_initCStream_usingDict() or ZSTD_initDStream_usingDict().
   Limitation 2 : static cctx currently not compatible with multi-threading.
   Limitation 3 : static dctx is incompatible with legacy support.
  
 


 
 
ZSTD_DStream* ZSTD_initStaticDStream(void* workspace, size_t workspaceSize);    /**< same as ZSTD_initStaticDCtx() */
 


 
typedef void* (*ZSTD_allocFunction) (void* opaque, size_t size);
 typedef void  (*ZSTD_freeFunction) (void* opaque, void* address);
 typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; void* opaque; } ZSTD_customMem;
 static ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL };  /**< this constant defers to stdlib's functions */
 
  These prototypes make it possible to pass your own allocation/free functions.
   ZSTD_customMem is provided at creation time, using ZSTD_create*_advanced() variants listed below.
   All allocation/free operations will be completed using these custom variants instead of regular  ones.
  
 


 
 
Advanced compression functions

 
 
ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
 
  Create a digested dictionary for compression
   Dictionary content is simply referenced, and therefore stays in dictBuffer.
   It is important that dictBuffer outlives CDict, it must remain read accessible throughout the lifetime of CDict 
 


 
 
ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
 
   @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
    `estimatedSrcSize` value is optional, select 0 if not known 
 


 
 
ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
 
   same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
    All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 
 


 
 
size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
 
   Ensure param values remain within authorized range 
 


 
 
ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
 
  optimize params for a given `srcSize` and `dictSize`.
   both values are optional, select `0` if unknown. 
 


 
 
size_t ZSTD_compress_advanced (ZSTD_CCtx* cctx,
                       void* dst, size_t dstCapacity,
                 const void* src, size_t srcSize,
                 const void* dict,size_t dictSize,
                       ZSTD_parameters params);
 
   Same as ZSTD_compress_usingDict(), with fine-tune control over each compression parameter 
 


 
 
size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
                       void* dst, size_t dstCapacity,
                 const void* src, size_t srcSize,
                 const ZSTD_CDict* cdict, ZSTD_frameParameters fParams);
 
   Same as ZSTD_compress_usingCDict(), with fine-tune control over frame parameters 
 


 
 
Advanced decompression functions

 
 
unsigned ZSTD_isFrame(const void* buffer, size_t size);
 
  Tells if the content of `buffer` starts with a valid Frame Identifier.
   Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
   Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
   Note 3 : Skippable Frame Identifiers are considered valid. 
 


 
 
ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize);
 
  Create a digested dictionary, ready to start decompression operation without startup delay.
   Dictionary content is referenced, and therefore stays in dictBuffer.
   It is important that dictBuffer outlives DDict,
   it must remain read accessible throughout the lifetime of DDict 
 


 
 
unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
 
  Provides the dictID stored within dictionary.
   if @return == 0, the dictionary is not conformant with Zstandard specification.
   It can still be loaded, but as a content-only dictionary. 
 


 
 
unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
 
  Provides the dictID of the dictionary loaded into `ddict`.
   If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
   Non-conformant dictionaries can still be loaded, but as content-only dictionaries. 
 


 
 
unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
 
  Provides the dictID required to decompressed the frame stored within `src`.
   If @return == 0, the dictID could not be decoded.
   This could for one of the following reasons :
   - The frame does not require a dictionary to be decoded (most common case).
   - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
     Note : this use case also happens when using a non-conformant dictionary.
   - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
   - This is not a Zstandard frame.
   When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. 
 


 
 
Advanced streaming functions

 
 
Advanced Streaming compression functions
size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize);   /**< pledgedSrcSize must be correct. If it is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs, "0" also disables frame content size field. It may be enabled in the future. */
 size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); /**< creates of an internal CDict (incompatible with static CCtx), except if dict == NULL or dictSize < 8, in which case no dict is used. Note: dict is loaded with ZSTD_dm_auto (treated as a full zstd dictionary if it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.*/
 size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
                                              ZSTD_parameters params, unsigned long long pledgedSrcSize);  /**< pledgedSrcSize must be correct. If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN. dict is loaded with ZSTD_dm_auto and ZSTD_dlm_byCopy. */
 size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);  /**< note : cdict will just be referenced, and must outlive compression session */
 size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* cdict, ZSTD_frameParameters fParams, unsigned long long pledgedSrcSize);  /**< same as ZSTD_initCStream_usingCDict(), with control over frame parameters. pledgedSrcSize must be correct. If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN. */
 


 
size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize);
 
  start a new compression job, using same parameters from previous job.
-  This is typically useful to skip dictionary loading stage, since it will re-use it in-place..
+  This is typically useful to skip dictionary loading stage, since it will re-use it in-place.
   Note that zcs must be init at least once before using ZSTD_resetCStream().
   If pledgedSrcSize is not known at reset time, use macro ZSTD_CONTENTSIZE_UNKNOWN.
   If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end.
   For the time being, pledgedSrcSize==0 is interpreted as "srcSize unknown" for compatibility with older programs,
   but it will change to mean "empty" in future version, so use macro ZSTD_CONTENTSIZE_UNKNOWN instead.
- @return : 0, or an error code (which can be tested using ZSTD_isError()) 
+ @return : 0, or an error code (which can be tested using ZSTD_isError())
+ 
 


 
 
typedef struct {
-    unsigned long long ingested;
-    unsigned long long consumed;
-    unsigned long long produced;
+    unsigned long long ingested;   /* nb input bytes read and buffered */
+    unsigned long long consumed;   /* nb input bytes actually compressed */
+    unsigned long long produced;   /* nb of compressed bytes generated and buffered */
+    unsigned long long flushed;    /* nb of compressed bytes flushed : not provided; can be tracked from caller side */
+    unsigned currentJobID;         /* MT only : latest started job nb */
+    unsigned nbActiveWorkers;      /* MT only : nb of workers actively compressing at probe time */
 } ZSTD_frameProgression;
 


+
size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx);
+
  Tell how many bytes are ready to be flushed immediately.
+  Useful for multithreading scenarios (nbWorkers >= 1).
+  Probe the oldest active job, defined as oldest job not yet entirely flushed,
+  and check its output buffer.
+ @return : amount of data stored in oldest job and ready to be flushed immediately.
+  if @return == 0, it means either :
+  + there is no active job (could be checked with ZSTD_frameProgression()), or
+  + oldest job is still actively compressing data,
+    but everything it has produced has also been flushed so far,
+    therefore flushing speed is currently limited by production speed of oldest job
+    irrespective of the speed of concurrent newer jobs.
+ 
+


+
 
Advanced Streaming decompression functions
typedef enum { DStream_p_maxWindowSize } ZSTD_DStreamParameter_e;
 size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);   /* obsolete : this API will be removed in a future version */
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); /**< note: no dictionary will be used if dict == NULL or dictSize < 8 */
 size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);  /**< note : ddict is referenced, it must outlive decompression session */
 size_t ZSTD_resetDStream(ZSTD_DStream* zds);  /**< re-use decompression parameters from previous init; saves dictionary loading */
 


 
Buffer-less and synchronous inner streaming functions
   This is an advanced API, giving full control over buffer management, for users which need direct control over memory.
   But it's also a complex one, with several restrictions, documented below.
   Prefer normal streaming API for an easier experience.
  
 

 
 
Buffer-less streaming compression (synchronous mode)
   A ZSTD_CCtx object is required to track streaming operations.
   Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource.
   ZSTD_CCtx object can be re-used multiple times within successive compression operations.
 
   Start by initializing a context.
   Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression,
   or ZSTD_compressBegin_advanced(), for finer parameter control.
   It's also possible to duplicate a reference context which has already been initialized, using ZSTD_copyCCtx()
 
   Then, consume your input using ZSTD_compressContinue().
   There are some important considerations to keep in mind when using this advanced function :
   - ZSTD_compressContinue() has no internal buffer. It uses externally provided buffers only.
   - Interface is synchronous : input is consumed entirely and produces 1+ compressed blocks.
   - Caller must ensure there is enough space in `dst` to store compressed data under worst case scenario.
     Worst case evaluation is provided by ZSTD_compressBound().
     ZSTD_compressContinue() doesn't guarantee recover after a failed compression.
   - ZSTD_compressContinue() presumes prior input ***is still accessible and unmodified*** (up to maximum distance size, see WindowLog).
     It remembers all previous contiguous blocks, plus one separated memory segment (which can itself consists of multiple contiguous blocks)
   - ZSTD_compressContinue() detects that prior input has been overwritten when `src` buffer overlaps.
     In which case, it will "discard" the relevant memory section from its history.
 
   Finish a frame with ZSTD_compressEnd(), which will write the last block(s) and optional checksum.
   It's possible to use srcSize==0, in which case, it will write a final empty block to end the frame.
   Without last block mark, frames are considered unfinished (hence corrupted) by compliant decoders.
 
   `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress again.
 

 
 
Buffer-less streaming compression functions
size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
 size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
 size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize : If srcSize is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN */
 size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); /**< note: fails if cdict==NULL */
 size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict, ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize);   /* compression parameters are already set within cdict. pledgedSrcSize must be correct. If srcSize is not known, use macro ZSTD_CONTENTSIZE_UNKNOWN */
 size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**<  note: if pledgedSrcSize is not known, use ZSTD_CONTENTSIZE_UNKNOWN */
 


 
Buffer-less streaming decompression (synchronous mode)
   A ZSTD_DCtx object is required to track streaming operations.
   Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
   A ZSTD_DCtx object can be re-used multiple times.
 
   First typical operation is to retrieve frame parameters, using ZSTD_getFrameHeader().
   Frame header is extracted from the beginning of compressed frame, so providing only the frame's beginning is enough.
   Data fragment must be large enough to ensure successful decoding.
  `ZSTD_frameHeaderSize_max` bytes is guaranteed to always be large enough.
   @result : 0 : successful decoding, the `ZSTD_frameHeader` structure is correctly filled.
            >0 : `srcSize` is too small, please provide at least @result bytes on next attempt.
            errorCode, which can be tested using ZSTD_isError().
 
   It fills a ZSTD_frameHeader structure with important information to correctly decode the frame,
   such as the dictionary ID, content size, or maximum back-reference distance (`windowSize`).
   Note that these values could be wrong, either because of data corruption, or because a 3rd party deliberately spoofs false information.
   As a consequence, check that values remain within valid application range.
   For example, do not allocate memory blindly, check that `windowSize` is within expectation.
   Each application can set its own limits, depending on local restrictions.
   For extended interoperability, it is recommended to support `windowSize` of at least 8 MB.
 
   ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize` bytes.
   ZSTD_decompressContinue() is very sensitive to contiguity,
   if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
   or that previous contiguous segment is large enough to properly handle maximum back-reference distance.
   There are multiple ways to guarantee this condition.
 
   The most memory efficient way is to use a round buffer of sufficient size.
   Sufficient size is determined by invoking ZSTD_decodingBufferSize_min(),
   which can @return an error code if required value is too large for current system (in 32-bits mode).
   In a round buffer methodology, ZSTD_decompressContinue() decompresses each block next to previous one,
   up to the moment there is not enough room left in the buffer to guarantee decoding another full block,
   which maximum size is provided in `ZSTD_frameHeader` structure, field `blockSizeMax`.
   At which point, decoding can resume from the beginning of the buffer.
   Note that already decoded data stored in the buffer should be flushed before being overwritten.
 
   There are alternatives possible, for example using two or more buffers of size `windowSize` each, though they consume more memory.
 
   Finally, if you control the compression process, you can also ignore all buffer size rules,
   as long as the encoder and decoder progress in "lock-step",
   aka use exactly the same buffer sizes, break contiguity at the same place, etc.
 
   Once buffers are setup, start decompression, with ZSTD_decompressBegin().
   If decompression requires a dictionary, use ZSTD_decompressBegin_usingDict() or ZSTD_decompressBegin_usingDDict().
 
   Then use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
   ZSTD_nextSrcSizeToDecompress() tells how many bytes to provide as 'srcSize' to ZSTD_decompressContinue().
   ZSTD_decompressContinue() requires this _exact_ amount of bytes, or it will fail.
 
  @result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
   It can be zero : it just means ZSTD_decompressContinue() has decoded some metadata item.
   It can also be an error code, which can be tested with ZSTD_isError().
 
   A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
   Context can then be reset to start a new decompression.
 
   Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
   This information is not required to properly decode a frame.
 
   == Special case : skippable frames 
 
   Skippable frames allow integration of user-defined data into a flow of concatenated frames.
   Skippable frames will be ignored (skipped) by decompressor.
   The format of skippable frames is as follows :
   a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
   b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
   c) Frame Content - any content (User Data) of length equal to Frame Size
   For skippable frames ZSTD_getFrameHeader() returns zfhPtr->frameType==ZSTD_skippableFrame.
   For skippable frames ZSTD_decompressContinue() always returns 0 : it only skips the content.
 

 
 
Buffer-less streaming decompression functions
typedef enum { ZSTD_frame, ZSTD_skippableFrame } ZSTD_frameType_e;
 typedef struct {
     unsigned long long frameContentSize; /* if == ZSTD_CONTENTSIZE_UNKNOWN, it means this field is not available. 0 means "empty" */
     unsigned long long windowSize;       /* can be very large, up to <= frameContentSize */
     unsigned blockSizeMax;
     ZSTD_frameType_e frameType;          /* if == ZSTD_skippableFrame, frameContentSize is the size of skippable content */
     unsigned headerSize;
     unsigned dictID;
     unsigned checksumFlag;
 } ZSTD_frameHeader;
+/** ZSTD_getFrameHeader() :
+ *  decode Frame Header, or requires larger `srcSize`.
+ * @return : 0, `zfhPtr` is correctly filled,
+ *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
+ *           or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize);   /**< doesn't consume input */
 size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize);  /**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */
 


 
typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
 


 
New advanced API (experimental)

 
 
typedef enum {
     /* Opened question : should we have a format ZSTD_f_auto ?
      * Today, it would mean exactly the same as ZSTD_f_zstd1.
      * But, in the future, should several formats become supported,
      * on the compression side, it would mean "default format".
      * On the decompression side, it would mean "automatic format detection",
      * so that ZSTD_f_zstd1 would mean "accept *only* zstd frames".
      * Since meaning is a little different, another option could be to define different enums for compression and decompression.
      * This question could be kept for later, when there are actually multiple formats to support,
      * but there is also the question of pinning enum values, and pinning value `0` is especially important */
     ZSTD_f_zstd1 = 0,        /* zstd frame format, specified in zstd_compression_format.md (default) */
     ZSTD_f_zstd1_magicless,  /* Variant of zstd frame format, without initial 4-bytes magic number.
                               * Useful to save 4 bytes per generated frame.
                               * Decoder cannot recognise automatically this format, requiring instructions. */
 } ZSTD_format_e;
 


 
typedef enum {
     /* compression format */
     ZSTD_p_format = 10,      /* See ZSTD_format_e enum definition.
                               * Cast selected format as unsigned for ZSTD_CCtx_setParameter() compatibility. */
 
     /* compression parameters */
     ZSTD_p_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
                               * Default level is ZSTD_CLEVEL_DEFAULT==3.
-                              * Special: value 0 means "do not change cLevel".
+                              * Special: value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT.
                               * Note 1 : it's possible to pass a negative compression level by casting it to unsigned type.
                               * Note 2 : setting a level sets all default values of other compression parameters.
                               * Note 3 : setting compressionLevel automatically updates ZSTD_p_compressLiterals. */
     ZSTD_p_windowLog,        /* Maximum allowed back-reference distance, expressed as power of 2.
                               * Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
                               * Special: value 0 means "use default windowLog".
                               * Note: Using a window size greater than ZSTD_MAXWINDOWSIZE_DEFAULT (default: 2^27)
                               *       requires explicitly allowing such window size during decompression stage. */
-    ZSTD_p_hashLog,          /* Size of the probe table, as a power of 2.
+    ZSTD_p_hashLog,          /* Size of the initial probe table, as a power of 2.
                               * Resulting table size is (1 << (hashLog+2)).
                               * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
                               * Larger tables improve compression ratio of strategies <= dFast,
                               * and improve speed of strategies > dFast.
                               * Special: value 0 means "use default hashLog". */
-    ZSTD_p_chainLog,         /* Size of the full-search table, as a power of 2.
+    ZSTD_p_chainLog,         /* Size of the multi-probe search table, as a power of 2.
                               * Resulting table size is (1 << (chainLog+2)).
+                              * Must be clamped between ZSTD_CHAINLOG_MIN and ZSTD_CHAINLOG_MAX.
                               * Larger tables result in better and slower compression.
                               * This parameter is useless when using "fast" strategy.
+                              * Note it's still useful when using "dfast" strategy,
+                              * in which case it defines a secondary probe table.
                               * Special: value 0 means "use default chainLog". */
     ZSTD_p_searchLog,        /* Number of search attempts, as a power of 2.
                               * More attempts result in better and slower compression.
                               * This parameter is useless when using "fast" and "dFast" strategies.
                               * Special: value 0 means "use default searchLog". */
     ZSTD_p_minMatch,         /* Minimum size of searched matches (note : repCode matches can be smaller).
                               * Larger values make faster compression and decompression, but decrease ratio.
                               * Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
                               * Note that currently, for all strategies < btopt, effective minimum is 4.
                               *                    , for all strategies > fast, effective maximum is 6.
                               * Special: value 0 means "use default minMatchLength". */
     ZSTD_p_targetLength,     /* Impact of this field depends on strategy.
                               * For strategies btopt & btultra:
                               *     Length of Match considered "good enough" to stop search.
                               *     Larger values make compression stronger, and slower.
                               * For strategy fast:
                               *     Distance between match sampling.
                               *     Larger values make compression faster, and weaker.
                               * Special: value 0 means "use default targetLength". */
     ZSTD_p_compressionStrategy, /* See ZSTD_strategy enum definition.
                               * Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
                               * The higher the value of selected strategy, the more complex it is,
                               * resulting in stronger and slower compression.
                               * Special: value 0 means "use default strategy". */
 
     ZSTD_p_enableLongDistanceMatching=160, /* Enable long distance matching.
                                          * This parameter is designed to improve compression ratio
                                          * for large inputs, by finding large matches at long distance.
                                          * It increases memory usage and window size.
                                          * Note: enabling this parameter increases ZSTD_p_windowLog to 128 MB
                                          * except when expressly set to a different value. */
     ZSTD_p_ldmHashLog,       /* Size of the table for long distance matching, as a power of 2.
                               * Larger values increase memory usage and compression ratio,
                               * but decrease compression speed.
                               * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
                               * default: windowlog - 7.
                               * Special: value 0 means "automatically determine hashlog". */
     ZSTD_p_ldmMinMatch,      /* Minimum match size for long distance matcher.
                               * Larger/too small values usually decrease compression ratio.
                               * Must be clamped between ZSTD_LDM_MINMATCH_MIN and ZSTD_LDM_MINMATCH_MAX.
                               * Special: value 0 means "use default value" (default: 64). */
     ZSTD_p_ldmBucketSizeLog, /* Log size of each bucket in the LDM hash table for collision resolution.
                               * Larger values improve collision resolution but decrease compression speed.
                               * The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX .
                               * Special: value 0 means "use default value" (default: 3). */
     ZSTD_p_ldmHashEveryLog,  /* Frequency of inserting/looking up entries in the LDM hash table.
                               * Must be clamped between 0 and (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN).
                               * Default is MAX(0, (windowLog - ldmHashLog)), optimizing hash table usage.
                               * Larger values improve compression speed.
                               * Deviating far from default value will likely result in a compression ratio decrease.
                               * Special: value 0 means "automatically determine hashEveryLog". */
 
     /* frame parameters */
     ZSTD_p_contentSizeFlag=200, /* Content size will be written into frame header _whenever known_ (default:1)
                               * Content size must be known at the beginning of compression,
                               * it is provided using ZSTD_CCtx_setPledgedSrcSize() */
     ZSTD_p_checksumFlag,     /* A 32-bits checksum of content is written at end of frame (default:0) */
     ZSTD_p_dictIDFlag,       /* When applicable, dictionary's ID is written into frame header (default:1) */
 
     /* multi-threading parameters */
     /* These parameters are only useful if multi-threading is enabled (ZSTD_MULTITHREAD).
      * They return an error otherwise. */
     ZSTD_p_nbWorkers=400,    /* Select how many threads will be spawned to compress in parallel.
                               * When nbWorkers >= 1, triggers asynchronous mode :
                               * ZSTD_compress_generic() consumes some input, flush some output if possible, and immediately gives back control to caller,
                               * while compression work is performed in parallel, within worker threads.
                               * (note : a strong exception to this rule is when first invocation sets ZSTD_e_end : it becomes a blocking call).
                               * More workers improve speed, but also increase memory usage.
                               * Default value is `0`, aka "single-threaded mode" : no worker is spawned, compression is performed inside Caller's thread, all invocations are blocking */
     ZSTD_p_jobSize,          /* Size of a compression job. This value is enforced only in non-blocking mode.
                               * Each compression job is completed in parallel, so this value indirectly controls the nb of active threads.
                               * 0 means default, which is dynamically determined based on compression parameters.
                               * Job size must be a minimum of overlapSize, or 1 MB, whichever is largest.
                               * The minimum size is automatically and transparently enforced */
     ZSTD_p_overlapSizeLog,   /* Size of previous input reloaded at the beginning of each job.
                               * 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
 
     /* =================================================================== */
     /* experimental parameters - no stability guaranteed                   */
     /* =================================================================== */
 
-    ZSTD_p_compressLiterals=1000, /* control huffman compression of literals (enabled) by default.
-                              * disabling it improves speed and decreases compression ratio by a large amount.
-                              * note : this setting is automatically updated when changing compression level.
-                              *        positive compression levels set ZSTD_p_compressLiterals to 1.
-                              *        negative compression levels set ZSTD_p_compressLiterals to 0. */
-
     ZSTD_p_forceMaxWindow=1100, /* Force back-reference distances to remain < windowSize,
                               * even when referencing into Dictionary content (default:0) */
+    ZSTD_p_forceAttachDict,  /* ZSTD supports usage of a CDict in-place
+                              * (avoiding having to copy the compression tables
+                              * from the CDict into the working context). Using
+                              * a CDict in this way saves an initial setup step,
+                              * but comes at the cost of more work per byte of
+                              * input. ZSTD has a simple internal heuristic that
+                              * guesses which strategy will be faster. You can
+                              * use this flag to override that guess.
+                              *
+                              * Note that the by-reference, in-place strategy is
+                              * only used when reusing a compression context
+                              * with compatible compression parameters. (If
+                              * incompatible / uninitialized, the working
+                              * context needs to be cleared anyways, which is
+                              * about as expensive as overwriting it with the
+                              * dictionary context, so there's no savings in
+                              * using the CDict by-ref.)
+                              *
+                              * Values greater than 0 force attaching the dict.
+                              * Values less than 0 force copying the dict.
+                              * 0 selects the default heuristic-guided behavior.
+                              */
 
 } ZSTD_cParameter;
 


 
size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
 
  Set one compression parameter, selected by enum ZSTD_cParameter.
-  Setting a parameter is generally only possible during frame initialization (before starting compression),
-  except for a few exceptions which can be updated during compression: compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
-  Note : when `value` is an enum, cast it to unsigned for proper type checking.
-  @result : informational value (typically, value being set clamped correctly),
+  Setting a parameter is generally only possible during frame initialization (before starting compression).
+  Exception : when using multi-threading mode (nbThreads >= 1),
+              following parameters can be updated _during_ compression (within same frame):
+              => compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
+              new parameters will be active on next job, or after a flush().
+  Note : when `value` type is not unsigned (int, or enum), cast it to unsigned for proper type checking.
+  @result : informational value (typically, value being set, correctly clamped),
             or an error code (which can be tested with ZSTD_isError()). 
 


 
+
size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned* value);
+
 Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
+ @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ 
+


+
 
size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
 
  Total input data size to be compressed as a single frame.
   This value will be controlled at the end, and result in error if not respected.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Note 1 : 0 means zero, empty.
            In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
            ZSTD_CONTENTSIZE_UNKNOWN is default value for any new compression job.
   Note 2 : If all data is provided and consumed in a single round,
            this value is overriden by srcSize instead. 
 


 
 
size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
 size_t ZSTD_CCtx_loadDictionary_byReference(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
 size_t ZSTD_CCtx_loadDictionary_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
 
  Create an internal CDict from `dict` buffer.
   Decompression will have to use same dictionary.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special: Adding a NULL (or 0-size) dictionary invalidates previous dictionary,
            meaning "return to no-dictionary mode".
   Note 1 : Dictionary will be used for all future compression jobs.
            To return to "no-dictionary" situation, load a NULL dictionary
   Note 2 : Loading a dictionary involves building tables, which are dependent on compression parameters.
            For this reason, compression parameters cannot be changed anymore after loading a dictionary.
            It's also a CPU consuming operation, with non-negligible impact on latency.
   Note 3 :`dict` content will be copied internally.
            Use ZSTD_CCtx_loadDictionary_byReference() to reference dictionary content instead.
            In such a case, dictionary buffer must outlive its users.
   Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
            to precisely select how dictionary content must be interpreted. 
 


 
 
size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
 
  Reference a prepared dictionary, to be used for all next compression jobs.
   Note that compression parameters are enforced from within CDict,
   and supercede any compression parameter previously set within CCtx.
   The dictionary will remain valid for future compression jobs using same CCtx.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special : adding a NULL CDict means "return to no-dictionary mode".
   Note 1 : Currently, only one dictionary can be managed.
            Adding a new dictionary effectively "discards" any previous one.
   Note 2 : CDict is just referenced, its lifetime must outlive CCtx. 
 


 
-
size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize);
-size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
+
size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx,
+                           const void* prefix, size_t prefixSize);
+size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx,
+                           const void* prefix, size_t prefixSize,
+                           ZSTD_dictContentType_e dictContentType);
 
  Reference a prefix (single-usage dictionary) for next compression job.
-  Decompression need same prefix to properly regenerate data.
-  Prefix is **only used once**. Tables are discarded at end of compression job.
-  Subsequent compression jobs will be done without prefix (if none is explicitly referenced).
-  If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict instead.
+  Decompression will need same prefix to properly regenerate data.
+  Compressing with a prefix is similar in outcome as performing a diff and compressing it,
+  but performs much faster, especially during decompression (compression speed is tunable with compression level).
+  Note that prefix is **only used once**. Tables are discarded at end of compression job (ZSTD_e_end).
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
-  Note 1 : Prefix buffer is referenced. It must outlive compression job.
-  Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
+  Note 1 : Prefix buffer is referenced. It **must** outlive compression job.
+           Its contain must remain unmodified up to end of compression (ZSTD_e_end).
+  Note 2 : If the intention is to diff some large src data blob with some prior version of itself,
+           ensure that the window size is large enough to contain the entire source.
+           See ZSTD_p_windowLog.
+  Note 3 : Referencing a prefix involves building tables, which are dependent on compression parameters.
            It's a CPU consuming operation, with non-negligible impact on latency.
-  Note 3 : By default, the prefix is treated as raw content (ZSTD_dm_rawContent).
+           If there is a need to use same prefix multiple times, consider loadDictionary instead.
+  Note 4 : By default, the prefix is treated as raw content (ZSTD_dm_rawContent).
            Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode. 
 


 
 
void ZSTD_CCtx_reset(ZSTD_CCtx* cctx);
 
  Return a CCtx to clean state.
   Useful after an error, or to interrupt an ongoing compression job and start a new one.
   Any internal data not yet flushed is cancelled.
+  The parameters and dictionary are kept unchanged, to reset them use ZSTD_CCtx_resetParameters().
+ 
+


+
+
size_t ZSTD_CCtx_resetParameters(ZSTD_CCtx* cctx);
+
  All parameters are back to default values (compression level is ZSTD_CLEVEL_DEFAULT).
   Dictionary (if any) is dropped.
-  All parameters are back to default values.
-  It's possible to modify compression parameters after a reset.
+  Resetting parameters is only possible during frame initialization (before starting compression).
+  To reset the context use ZSTD_CCtx_reset().
+  @return 0 or an error code (which can be checked with ZSTD_isError()).
  
 


 
 
typedef enum {
-    ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal conditions */
-    ZSTD_e_flush,      /* flush any data provided so far - frame will continue, future data can still reference previous data for better compression */
-    ZSTD_e_end         /* flush any remaining data and close current frame. Any additional data starts a new frame. */
+    ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal compression ratio */
+    ZSTD_e_flush,      /* flush any data provided so far,
+                        * it creates (at least) one new block, that can be decoded immediately on reception;
+                        * frame will continue: any future data can still reference previously compressed data, improving compression. */
+    ZSTD_e_end         /* flush any remaining data and close current frame.
+                        * any additional data starts a new frame.
+                        * each frame is independent (does not reference any content from previous frame). */
 } ZSTD_EndDirective;
 


 
size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
                               ZSTD_outBuffer* output,
                               ZSTD_inBuffer* input,
                               ZSTD_EndDirective endOp);
 
  Behave about the same as ZSTD_compressStream. To note :
   - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_setParameter()
   - Compression parameters cannot be changed once compression is started.
   - outpot->pos must be <= dstCapacity, input->pos must be <= srcSize
   - outpot->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
   - In single-thread mode (default), function is blocking : it completed its job before returning to caller.
   - In multi-thread mode, function is non-blocking : it just acquires a copy of input, and distribute job to internal worker threads,
                                                      and then immediately returns, just indicating that there is some data remaining to be flushed.
                                                      The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
   - Exception : in multi-threading mode, if the first call requests a ZSTD_e_end directive, it is blocking : it will complete compression before giving back control to caller.
   - @return provides a minimum amount of data remaining to be flushed from internal buffers
             or an error code, which can be tested using ZSTD_isError().
             if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
             This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
             For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
   - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
             only ZSTD_e_end or ZSTD_e_flush operations are allowed.
             Before starting a new compression job, or changing compression parameters,
             it is required to fully flush internal buffers.
  
 


 
 
size_t ZSTD_compress_generic_simpleArgs (
                 ZSTD_CCtx* cctx,
                 void* dst, size_t dstCapacity, size_t* dstPos,
           const void* src, size_t srcSize, size_t* srcPos,
                 ZSTD_EndDirective endOp);
 
  Same as ZSTD_compress_generic(),
   but using only integral types as arguments.
   Argument list is larger than ZSTD_{in,out}Buffer,
   but can be helpful for binders from dynamic languages
   which have troubles handling structures containing memory pointers.
  
 


 
 
ZSTD_CCtx_params* ZSTD_createCCtxParams(void);
 size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params);
 
  Quick howto :
   - ZSTD_createCCtxParams() : Create a ZSTD_CCtx_params structure
   - ZSTD_CCtxParam_setParameter() : Push parameters one by one into
                                     an existing ZSTD_CCtx_params structure.
                                     This is similar to
                                     ZSTD_CCtx_setParameter().
   - ZSTD_CCtx_setParametersUsingCCtxParams() : Apply parameters to
                                     an existing CCtx.
                                     These parameters will be applied to
                                     all subsequent compression jobs.
   - ZSTD_compress_generic() : Do compression using the CCtx.
   - ZSTD_freeCCtxParams() : Free the memory.
 
   This can be used with ZSTD_estimateCCtxSize_advanced_usingCCtxParams()
   for static allocation for single-threaded compression.
  
 


 
 
size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params);
 
  Reset params to default values.
  
 


 
 
size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel);
 
  Initializes the compression parameters of cctxParams according to
   compression level. All other parameters are reset to their default values.
  
 


 
 
size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);
 
  Initializes the compression and frame parameters of cctxParams according to
   params. All other parameters are reset to their default values.
  
 


 
 
size_t ZSTD_CCtxParam_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, unsigned value);
 
  Similar to ZSTD_CCtx_setParameter.
   Set one compression parameter, selected by enum ZSTD_cParameter.
   Parameters must be applied to a ZSTD_CCtx using ZSTD_CCtx_setParametersUsingCCtxParams().
   Note : when `value` is an enum, cast it to unsigned for proper type checking.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
  
 


 
+
size_t ZSTD_CCtxParam_getParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, unsigned* value);
+
 Similar to ZSTD_CCtx_getParameter.
+ Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
+ @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ 
+


+
 
size_t ZSTD_CCtx_setParametersUsingCCtxParams(
         ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params);
 
  Apply a set of ZSTD_CCtx_params to the compression context.
   This can be done even after compression is started,
     if nbWorkers==0, this will have no impact until a new compression is started.
     if nbWorkers>=1, new parameters will be picked up at next job,
        with a few restrictions (windowLog, pledgedSrcSize, nbWorkers, jobSize, and overlapLog are not updated).
  
 


 
-
Advanced parameters for decompression API


+
Advanced decompression API
/* ==================================== */
+


 
size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
 size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
 size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
 
  Create an internal DDict from dict buffer,
   to be used to decompress next frames.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special : Adding a NULL (or 0-size) dictionary invalidates any previous dictionary,
             meaning "return to no-dictionary mode".
   Note 1 : `dict` content will be copied internally.
             Use ZSTD_DCtx_loadDictionary_byReference()
             to reference dictionary content instead.
             In which case, the dictionary buffer must outlive its users.
   Note 2 : Loading a dictionary involves building tables,
            which has a non-negligible impact on CPU usage and latency.
   Note 3 : Use ZSTD_DCtx_loadDictionary_advanced() to select
            how dictionary content will be interpreted and loaded.
  
 


 
 
size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
 
  Reference a prepared dictionary, to be used to decompress next frames.
   The dictionary remains active for decompression of future frames using same DCtx.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Note 1 : Currently, only one dictionary can be managed.
            Referencing a new dictionary effectively "discards" any previous one.
   Special : adding a NULL DDict means "return to no-dictionary mode".
   Note 2 : DDict is just referenced, its lifetime must outlive its usage from DCtx.
  
 


 
-
size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize);
-size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
+
size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx,
+                        const void* prefix, size_t prefixSize);
+size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx,
+                        const void* prefix, size_t prefixSize,
+                        ZSTD_dictContentType_e dictContentType);
 
  Reference a prefix (single-usage dictionary) for next compression job.
-  Prefix is **only used once**. It must be explicitly referenced before each frame.
-  If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_DDict instead.
+  This is the reverse operation of ZSTD_CCtx_refPrefix(),
+  and must use the same prefix as the one used during compression.
+  Prefix is **only used once**. Reference is discarded at end of frame.
+  End of frame is reached when ZSTD_DCtx_decompress_generic() returns 0.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Note 1 : Adding any prefix (including NULL) invalidates any previously set prefix or dictionary
-  Note 2 : Prefix buffer is referenced. It must outlive compression job.
+  Note 2 : Prefix buffer is referenced. It **must** outlive decompression job.
+           Prefix buffer must remain unmodified up to the end of frame,
+           reached when ZSTD_DCtx_decompress_generic() returns 0.
   Note 3 : By default, the prefix is treated as raw content (ZSTD_dm_rawContent).
            Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode.
   Note 4 : Referencing a raw content prefix has almost no cpu nor memory cost.
+           A fulldict prefix is more costly though.
  
 


 
 
size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize);
 
  Refuses allocating internal buffers for frames requiring a window size larger than provided limit.
   This is useful to prevent a decoder context from reserving too much memory for itself (potential attack scenario).
   This parameter is only useful in streaming mode, since no internal buffer is allocated in direct mode.
   By default, a decompression context accepts all window sizes <= (1 << ZSTD_WINDOWLOG_MAX)
  @return : 0, or an error code (which can be tested using ZSTD_isError()).
  
 


 
 
size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format);
 
  Instruct the decoder context about what kind of data to decode next.
   This instruction is mandatory to decode data without a fully-formed header,
   such ZSTD_f_zstd1_magicless for example.
  @return : 0, or an error code (which can be tested using ZSTD_isError()).
  
+


+
+
size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr,
+            const void* src, size_t srcSize, ZSTD_format_e format);
+
  same as ZSTD_getFrameHeader(),
+  with added capability to select a format (like ZSTD_f_zstd1_magicless) 
 


 
 
size_t ZSTD_decompress_generic(ZSTD_DCtx* dctx,
                                ZSTD_outBuffer* output,
                                ZSTD_inBuffer* input);
 
  Behave the same as ZSTD_decompressStream.
   Decompression parameters cannot be changed once decompression is started.
  @return : an error code, which can be tested using ZSTD_isError()
            if >0, a hint, nb of expected input bytes for next invocation.
            `0` means : a frame has just been fully decoded and flushed.
  
 


 
 
size_t ZSTD_decompress_generic_simpleArgs (
                 ZSTD_DCtx* dctx,
                 void* dst, size_t dstCapacity, size_t* dstPos,
           const void* src, size_t srcSize, size_t* srcPos);
 
  Same as ZSTD_decompress_generic(),
   but using only integral types as arguments.
   Argument list is larger than ZSTD_{in,out}Buffer,
   but can be helpful for binders from dynamic languages
   which have troubles handling structures containing memory pointers.
  
 


 
 
void ZSTD_DCtx_reset(ZSTD_DCtx* dctx);
 
  Return a DCtx to clean state.
   If a decompression was ongoing, any internal data not yet flushed is cancelled.
   All parameters are back to default values, including sticky ones.
   Dictionary (if any) is dropped.
   Parameters can be modified again after a reset.
  
 


 
 
Block level API

 
 
    Frame metadata cost is typically ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes).
     User will have to take in charge required information to regenerate data, such as compressed and content sizes.
 
     A few rules to respect :
     - Compressing and decompressing require a context structure
       + Use ZSTD_createCCtx() and ZSTD_createDCtx()
     - It is necessary to init context before starting
       + compression : any ZSTD_compressBegin*() variant, including with dictionary
       + decompression : any ZSTD_decompressBegin*() variant, including with dictionary
       + copyCCtx() and copyDCtx() can be used too
     - Block size is limited, it must be <= ZSTD_getBlockSize() <= ZSTD_BLOCKSIZE_MAX == 128 KB
       + If input is larger than a block size, it's necessary to split input data into multiple blocks
       + For inputs larger than a single block size, consider using the regular ZSTD_compress() instead.
         Frame metadata is not that costly, and quickly becomes negligible as source size grows larger.
     - When a block is considered not compressible enough, ZSTD_compressBlock() result will be zero.
       In which case, nothing is produced into `dst`.
       + User must test for such outcome and deal directly with uncompressed data
       + ZSTD_decompressBlock() doesn't accept uncompressed data as input !!!
       + In case of multiple successive blocks, should some of them be uncompressed,
         decoder must be informed of their existence in order to follow proper history.
         Use ZSTD_insertBlock() for such a case.
 


 
 
Raw zstd block functions
size_t ZSTD_getBlockSize   (const ZSTD_CCtx* cctx);
 size_t ZSTD_compressBlock  (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_insertBlock    (ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize);  /**< insert uncompressed block into `dctx` history. Useful for multi-blocks decompression. */
 


 
 
Index: vendor/zstd/dist/lib/BUCK
===================================================================
--- vendor/zstd/dist/lib/BUCK	(revision 339613)
+++ vendor/zstd/dist/lib/BUCK	(revision 339614)
@@ -1,220 +1,221 @@
 cxx_library(
     name='zstd',
     header_namespace='',
     visibility=['PUBLIC'],
     deps=[
         ':common',
         ':compress',
         ':decompress',
         ':deprecated',
     ],
 )
 
 cxx_library(
     name='compress',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('compress', 'zstd*.h'),
     ]),
     srcs=glob(['compress/zstd*.c']),
     deps=[':common'],
 )
 
 cxx_library(
     name='decompress',
     header_namespace='',
     visibility=['PUBLIC'],
     headers=subdir_glob([
         ('decompress', '*_impl.h'),
     ]),
     srcs=glob(['decompress/zstd*.c']),
     deps=[
         ':common',
         ':legacy',
     ],
 )
 
 cxx_library(
     name='deprecated',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('decprecated', '*.h'),
     ]),
     srcs=glob(['deprecated/*.c']),
     deps=[':common'],
 )
 
 cxx_library(
     name='legacy',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('legacy', '*.h'),
     ]),
     srcs=glob(['legacy/*.c']),
     deps=[':common'],
     exported_preprocessor_flags=[
         '-DZSTD_LEGACY_SUPPORT=4',
     ],
 )
 
 cxx_library(
     name='zdict',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('dictBuilder', 'zdict.h'),
     ]),
     headers=subdir_glob([
         ('dictBuilder', 'divsufsort.h'),
+        ('dictBuilder', 'cover.h'),
     ]),
     srcs=glob(['dictBuilder/*.c']),
     deps=[':common'],
 )
 
 cxx_library(
     name='compiler',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'compiler.h'),
     ]),
 )
 
 cxx_library(
     name='cpu',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'cpu.h'),
     ]),
 )
 
 cxx_library(
     name='bitstream',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'bitstream.h'),
     ]),
 )
 
 cxx_library(
     name='entropy',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'fse.h'),
         ('common', 'huf.h'),
     ]),
     srcs=[
         'common/entropy_common.c',
         'common/fse_decompress.c',
         'compress/fse_compress.c',
         'compress/huf_compress.c',
         'decompress/huf_decompress.c',
     ],
     deps=[
         ':bitstream',
         ':compiler',
         ':errors',
         ':mem',
     ],
 )
 
 cxx_library(
     name='errors',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'error_private.h'),
         ('common', 'zstd_errors.h'),
     ]),
     srcs=['common/error_private.c'],
 )
 
 cxx_library(
     name='mem',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'mem.h'),
     ]),
 )
 
 cxx_library(
     name='pool',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'pool.h'),
     ]),
     srcs=['common/pool.c'],
     deps=[
         ':threading',
         ':zstd_common',
     ],
 )
 
 cxx_library(
     name='threading',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'threading.h'),
     ]),
     srcs=['common/threading.c'],
     exported_preprocessor_flags=[
         '-DZSTD_MULTITHREAD',
     ],
     exported_linker_flags=[
         '-pthread',
     ],
 )
 
 cxx_library(
     name='xxhash',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('common', 'xxhash.h'),
     ]),
     srcs=['common/xxhash.c'],
     exported_preprocessor_flags=[
         '-DXXH_NAMESPACE=ZSTD_',
     ],
 )
 
 cxx_library(
     name='zstd_common',
     header_namespace='',
     visibility=['PUBLIC'],
     exported_headers=subdir_glob([
         ('', 'zstd.h'),
         ('common', 'zstd_internal.h'),
     ]),
     srcs=['common/zstd_common.c'],
     deps=[
         ':compiler',
         ':errors',
         ':mem',
     ],
 )
 
 cxx_library(
     name='common',
     deps=[
         ':bitstream',
         ':compiler',
         ':cpu',
         ':entropy',
         ':errors',
         ':mem',
         ':pool',
         ':threading',
         ':xxhash',
         ':zstd_common',
     ]
 )
Index: vendor/zstd/dist/lib/Makefile
===================================================================
--- vendor/zstd/dist/lib/Makefile	(revision 339613)
+++ vendor/zstd/dist/lib/Makefile	(revision 339614)
@@ -1,189 +1,247 @@
 # ################################################################
 # Copyright (c) 2015-present, Yann Collet, Facebook, Inc.
 # All rights reserved.
 #
 # This source code is licensed under both the BSD-style license (found in the
 # LICENSE file in the root directory of this source tree) and the GPLv2 (found
 # in the COPYING file in the root directory of this source tree).
 # ################################################################
 
 # Version numbers
 LIBVER_MAJOR_SCRIPT:=`sed -n '/define ZSTD_VERSION_MAJOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < ./zstd.h`
 LIBVER_MINOR_SCRIPT:=`sed -n '/define ZSTD_VERSION_MINOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < ./zstd.h`
 LIBVER_PATCH_SCRIPT:=`sed -n '/define ZSTD_VERSION_RELEASE/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < ./zstd.h`
 LIBVER_SCRIPT:= $(LIBVER_MAJOR_SCRIPT).$(LIBVER_MINOR_SCRIPT).$(LIBVER_PATCH_SCRIPT)
 LIBVER_MAJOR := $(shell echo $(LIBVER_MAJOR_SCRIPT))
 LIBVER_MINOR := $(shell echo $(LIBVER_MINOR_SCRIPT))
 LIBVER_PATCH := $(shell echo $(LIBVER_PATCH_SCRIPT))
 LIBVER := $(shell echo $(LIBVER_SCRIPT))
 VERSION?= $(LIBVER)
 
 CPPFLAGS+= -I. -I./common -DXXH_NAMESPACE=ZSTD_
+ifeq ($(OS),Windows_NT)   # MinGW assumed
+CPPFLAGS   += -D__USE_MINGW_ANSI_STDIO   # compatibility with %zu formatting
+endif
 CFLAGS  ?= -O3
-DEBUGFLAGS = -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
+DEBUGFLAGS= -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
             -Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement \
             -Wstrict-prototypes -Wundef -Wpointer-arith -Wformat-security \
             -Wvla -Wformat=2 -Winit-self -Wfloat-equal -Wwrite-strings \
-            -Wredundant-decls
+            -Wredundant-decls -Wmissing-prototypes
 CFLAGS  += $(DEBUGFLAGS) $(MOREFLAGS)
 FLAGS    = $(CPPFLAGS) $(CFLAGS)
 
+GREP = grep --color=never
 
-ZSTD_FILES := $(sort $(wildcard common/*.c compress/*.c decompress/*.c dictBuilder/*.c deprecated/*.c))
+ZSTDCOMMON_FILES := $(sort $(wildcard common/*.c))
+ZSTDCOMP_FILES := $(sort $(wildcard compress/*.c))
+ZSTDDECOMP_FILES := $(sort $(wildcard decompress/*.c))
+ZDICT_FILES := $(sort $(wildcard dictBuilder/*.c))
+ZDEPR_FILES := $(sort $(wildcard deprecated/*.c))
+ZSTD_FILES := $(ZSTDCOMMON_FILES)
 
-ZSTD_LEGACY_SUPPORT ?= 4
+ZSTD_LEGACY_SUPPORT ?= 5
+ZSTD_LIB_COMPRESSION ?= 1
+ZSTD_LIB_DECOMPRESSION ?= 1
+ZSTD_LIB_DICTBUILDER ?= 1
+ZSTD_LIB_DEPRECATED ?= 1
 
+ifeq ($(ZSTD_LIB_COMPRESSION), 0)
+	ZSTD_LIB_DICTBUILDER = 0
+	ZSTD_LIB_DEPRECATED = 0
+endif
+
+ifeq ($(ZSTD_LIB_DECOMPRESSION), 0)
+	ZSTD_LEGACY_SUPPORT = 0
+	ZSTD_LIB_DEPRECATED = 0
+endif
+
+ifneq ($(ZSTD_LIB_COMPRESSION), 0)
+	ZSTD_FILES += $(ZSTDCOMP_FILES)
+endif
+
+ifneq ($(ZSTD_LIB_DECOMPRESSION), 0)
+	ZSTD_FILES += $(ZSTDDECOMP_FILES)
+endif
+
+ifneq ($(ZSTD_LIB_DEPRECATED), 0)
+	ZSTD_FILES += $(ZDEPR_FILES)
+endif
+
+ifneq ($(ZSTD_LIB_DICTBUILDER), 0)
+	ZSTD_FILES += $(ZDICT_FILES)
+endif
+
 ifneq ($(ZSTD_LEGACY_SUPPORT), 0)
 ifeq ($(shell test $(ZSTD_LEGACY_SUPPORT) -lt 8; echo $$?), 0)
-	ZSTD_FILES += $(shell ls legacy/*.c | grep 'v0[$(ZSTD_LEGACY_SUPPORT)-7]')
+	ZSTD_FILES += $(shell ls legacy/*.c | $(GREP) 'v0[$(ZSTD_LEGACY_SUPPORT)-7]')
 endif
 	CPPFLAGS += -I./legacy
 endif
 CPPFLAGS  += -DZSTD_LEGACY_SUPPORT=$(ZSTD_LEGACY_SUPPORT)
 
 ZSTD_OBJ   := $(patsubst %.c,%.o,$(ZSTD_FILES))
 
-# OS X linker doesn't support -soname, and use different extension
+# macOS linker doesn't support -soname, and use different extension
 # see : https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/DynamicLibraryDesignGuidelines.html
 ifeq ($(shell uname), Darwin)
 	SHARED_EXT = dylib
 	SHARED_EXT_MAJOR = $(LIBVER_MAJOR).$(SHARED_EXT)
 	SHARED_EXT_VER = $(LIBVER).$(SHARED_EXT)
 	SONAME_FLAGS = -install_name $(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR) -compatibility_version $(LIBVER_MAJOR) -current_version $(LIBVER)
 else
 	SONAME_FLAGS = -Wl,-soname=libzstd.$(SHARED_EXT).$(LIBVER_MAJOR)
 	SHARED_EXT = so
 	SHARED_EXT_MAJOR = $(SHARED_EXT).$(LIBVER_MAJOR)
 	SHARED_EXT_VER = $(SHARED_EXT).$(LIBVER)
 endif
 
-LIBZSTD = libzstd.$(SHARED_EXT_VER)
 
-
 .PHONY: default all clean install uninstall
 
 default: lib-release
 
 all: lib
 
 libzstd.a: ARFLAGS = rcs
 libzstd.a: $(ZSTD_OBJ)
 	@echo compiling static library
 	@$(AR) $(ARFLAGS) $@ $^
 
 libzstd.a-mt: CPPFLAGS += -DZSTD_MULTITHREAD
 libzstd.a-mt: libzstd.a
 
-$(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
+ifneq (,$(filter Windows%,$(OS)))
+
+LIBZSTD = dll\libzstd.dll
 $(LIBZSTD): $(ZSTD_FILES)
 	@echo compiling dynamic library $(LIBVER)
-ifneq (,$(filter Windows%,$(OS)))
-	@$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -shared $^ -o dll\libzstd.dll
-	dlltool -D dll\libzstd.dll -d dll\libzstd.def -l dll\libzstd.lib
+	@$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -shared $^ -o $@
+	dlltool -D $@ -d dll\libzstd.def -l dll\libzstd.lib
+
 else
+
+LIBZSTD = libzstd.$(SHARED_EXT_VER)
+$(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
+$(LIBZSTD): $(ZSTD_FILES)
+	@echo compiling dynamic library $(LIBVER)
 	@$(CC) $(FLAGS) $^ $(LDFLAGS) $(SONAME_FLAGS) -o $@
 	@echo creating versioned links
 	@ln -sf $@ libzstd.$(SHARED_EXT_MAJOR)
 	@ln -sf $@ libzstd.$(SHARED_EXT)
+
 endif
 
+
 libzstd : $(LIBZSTD)
 
 libzstd-mt : CPPFLAGS += -DZSTD_MULTITHREAD
 libzstd-mt : libzstd
 
 lib: libzstd.a libzstd
 
 lib-mt: CPPFLAGS += -DZSTD_MULTITHREAD
 lib-mt: lib
 
 lib-release lib-release-mt: DEBUGFLAGS :=
 lib-release: lib
 lib-release-mt: lib-mt
 
 # Special case : building library in single-thread mode _and_ without zstdmt_compress.c
 ZSTDMT_FILES = compress/zstdmt_compress.c
 ZSTD_NOMT_FILES = $(filter-out $(ZSTDMT_FILES),$(ZSTD_FILES))
 libzstd-nomt: LDFLAGS += -shared -fPIC -fvisibility=hidden
 libzstd-nomt: $(ZSTD_NOMT_FILES)
 	@echo compiling single-thread dynamic library $(LIBVER)
 	@echo files : $(ZSTD_NOMT_FILES)
 	@$(CC) $(FLAGS) $^ $(LDFLAGS) $(SONAME_FLAGS) -o $@
 
 clean:
-	@$(RM) -r *.dSYM   # Mac OS-X specific
+	@$(RM) -r *.dSYM   # macOS-specific
 	@$(RM) core *.o *.a *.gcda *.$(SHARED_EXT) *.$(SHARED_EXT).* libzstd.pc
 	@$(RM) dll/libzstd.dll dll/libzstd.lib libzstd-nomt*
 	@$(RM) common/*.o compress/*.o decompress/*.o dictBuilder/*.o legacy/*.o deprecated/*.o
 	@echo Cleaning library completed
 
 #-----------------------------------------------------------------------------
-# make install is validated only for Linux, OSX, BSD, Hurd and Solaris targets
+# make install is validated only for Linux, macOS, BSD, Hurd and Solaris targets
 #-----------------------------------------------------------------------------
-ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD NetBSD DragonFly SunOS))
+ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD NetBSD DragonFly SunOS Haiku))
 
 DESTDIR     ?=
 # directory variables : GNU conventions prefer lowercase
 # see https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
 # support both lower and uppercase (BSD), use uppercase in script
 prefix      ?= /usr/local
 PREFIX      ?= $(prefix)
 exec_prefix ?= $(PREFIX)
 libdir      ?= $(exec_prefix)/lib
 LIBDIR      ?= $(libdir)
 includedir  ?= $(PREFIX)/include
 INCLUDEDIR  ?= $(includedir)
 
-ifneq (,$(filter $(shell uname),OpenBSD FreeBSD NetBSD DragonFly))
+ifneq (,$(filter $(shell uname),FreeBSD NetBSD DragonFly))
 PKGCONFIGDIR ?= $(PREFIX)/libdata/pkgconfig
 else
 PKGCONFIGDIR ?= $(LIBDIR)/pkgconfig
 endif
 
 ifneq (,$(filter $(shell uname),SunOS))
 INSTALL ?= ginstall
 else
 INSTALL ?= install
 endif
 
 INSTALL_PROGRAM ?= $(INSTALL)
 INSTALL_DATA    ?= $(INSTALL) -m 644
 
 
 libzstd.pc:
 libzstd.pc: libzstd.pc.in
 	@echo creating pkgconfig
 	@sed -e 's|@PREFIX@|$(PREFIX)|' \
              -e 's|@LIBDIR@|$(LIBDIR)|' \
              -e 's|@INCLUDEDIR@|$(INCLUDEDIR)|' \
              -e 's|@VERSION@|$(VERSION)|' \
              $< >$@
 
-install: libzstd.a libzstd libzstd.pc
-	@$(INSTALL) -d -m 755 $(DESTDIR)$(PKGCONFIGDIR)/ $(DESTDIR)$(INCLUDEDIR)/
+install: install-pc install-static install-shared install-includes
+	@echo zstd static and shared library installed
+
+install-pc: libzstd.pc
+	@$(INSTALL) -d -m 755 $(DESTDIR)$(PKGCONFIGDIR)/
 	@$(INSTALL_DATA) libzstd.pc $(DESTDIR)$(PKGCONFIGDIR)/
-	@echo Installing libraries
+
+install-static: libzstd.a
+	@echo Installing static library
+	@$(INSTALL) -d -m 755 $(DESTDIR)$(LIBDIR)/
 	@$(INSTALL_DATA) libzstd.a $(DESTDIR)$(LIBDIR)
+
+install-shared: libzstd
+	@echo Installing shared library
+	@$(INSTALL) -d -m 755 $(DESTDIR)$(LIBDIR)/
 	@$(INSTALL_PROGRAM) $(LIBZSTD) $(DESTDIR)$(LIBDIR)
 	@ln -sf $(LIBZSTD) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR)
 	@ln -sf $(LIBZSTD) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT)
+
+install-includes:
 	@echo Installing includes
+	@$(INSTALL) -d -m 755 $(DESTDIR)$(INCLUDEDIR)/
 	@$(INSTALL_DATA) zstd.h $(DESTDIR)$(INCLUDEDIR)
 	@$(INSTALL_DATA) common/zstd_errors.h $(DESTDIR)$(INCLUDEDIR)
 	@$(INSTALL_DATA) deprecated/zbuff.h $(DESTDIR)$(INCLUDEDIR)     # prototypes generate deprecation warnings
 	@$(INSTALL_DATA) dictBuilder/zdict.h $(DESTDIR)$(INCLUDEDIR)
-	@echo zstd static and shared library installed
 
 uninstall:
 	@$(RM) $(DESTDIR)$(LIBDIR)/libzstd.a
 	@$(RM) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT)
 	@$(RM) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR)
 	@$(RM) $(DESTDIR)$(LIBDIR)/$(LIBZSTD)
 	@$(RM) $(DESTDIR)$(PKGCONFIGDIR)/libzstd.pc
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zstd.h
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zstd_errors.h
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zbuff.h   # Deprecated streaming functions
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zdict.h
 	@echo zstd libraries successfully uninstalled
 
 endif
Index: vendor/zstd/dist/lib/README.md
===================================================================
--- vendor/zstd/dist/lib/README.md	(revision 339613)
+++ vendor/zstd/dist/lib/README.md	(revision 339614)
@@ -1,115 +1,120 @@
 Zstandard library files
 ================================
 
 The __lib__ directory is split into several sub-directories,
 in order to make it easier to select or exclude features.
 
 
 #### Building
 
 `Makefile` script is provided, supporting all standard [Makefile conventions](https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html#Makefile-Conventions),
 including commands variables, staged install, directory variables and standard targets.
 - `make` : generates both static and dynamic libraries
 - `make install` : install libraries in default system directories
 
 `libzstd` default scope includes compression, decompression, dictionary building,
-and decoding support for legacy formats >= v0.4.0.
+and decoding support for legacy formats >= v0.5.0.
 
 
 #### API
 
 Zstandard's stable API is exposed within [lib/zstd.h](zstd.h).
 
 
 #### Advanced API
 
 Optional advanced features are exposed via :
 
 - `lib/common/zstd_errors.h` : translates `size_t` function results
                               into an `ZSTD_ErrorCode`, for accurate error handling.
 - `ZSTD_STATIC_LINKING_ONLY` : if this macro is defined _before_ including `zstd.h`,
                           it unlocks access to advanced experimental API,
                           exposed in second part of `zstd.h`.
                           These APIs are not "stable", their definition may change in the future.
                           As a consequence, it shall ___never be used with dynamic library___ !
                           Only static linking is allowed.
 
 
 #### Modular build
 
 It's possible to compile only a limited set of features.
 
 - Directory `lib/common` is always required, for all variants.
 - Compression source code lies in `lib/compress`
 - Decompression source code lies in `lib/decompress`
 - It's possible to include only `compress` or only `decompress`, they don't depend on each other.
 - `lib/dictBuilder` : makes it possible to generate dictionaries from a set of samples.
         The API is exposed in `lib/dictBuilder/zdict.h`.
         This module depends on both `lib/common` and `lib/compress` .
 - `lib/legacy` : source code to decompress legacy zstd formats, starting from `v0.1.0`.
         This module depends on `lib/common` and `lib/decompress`.
-        To enable this feature, it's required to define `ZSTD_LEGACY_SUPPORT` during compilation.
-        Typically, with `gcc`, add argument `-DZSTD_LEGACY_SUPPORT=1`.
-        Using higher number limits versions supported.
+        To enable this feature, define `ZSTD_LEGACY_SUPPORT` during compilation.
+        Specifying a number limits versions supported to that version onward.
         For example, `ZSTD_LEGACY_SUPPORT=2` means : "support legacy formats >= v0.2.0".
         `ZSTD_LEGACY_SUPPORT=3` means : "support legacy formats >= v0.3.0", and so on.
-        Starting v0.8.0, all versions of `zstd` produce frames compliant with specification.
-        As a consequence, `ZSTD_LEGACY_SUPPORT=8` (or more) doesn't trigger legacy support.
-        Also, `ZSTD_LEGACY_SUPPORT=0` means "do __not__ support legacy formats".
+        Currently, the default library setting is `ZST_LEGACY_SUPPORT=5`.
+        It can be changed at build by any other value.
+        Note that any number >= 8 translates into "do __not__ support legacy formats",
+        since all versions of `zstd` >= v0.8 are compatible with v1+ specification.
+        `ZSTD_LEGACY_SUPPORT=0` also means "do __not__ support legacy formats".
         Once enabled, this capability is transparently triggered within decompression functions.
         It's also possible to invoke directly legacy API, as exposed in `lib/legacy/zstd_legacy.h`.
         Each version also provides an additional dedicated set of advanced API.
         For example, advanced API for version `v0.4` is exposed in `lib/legacy/zstd_v04.h` .
         Note : `lib/legacy` only supports _decoding_ legacy formats.
+- Similarly, you can define `ZSTD_LIB_COMPRESSION, ZSTD_LIB_DECOMPRESSION`, `ZSTD_LIB_DICTBUILDER`,
+        and `ZSTD_LIB_DEPRECATED` as 0 to forgo compilation of the corresponding features. This will
+        also disable compilation of all dependencies (eg. `ZSTD_LIB_COMPRESSION=0` will also disable
+        dictBuilder).
 
 
 #### Multithreading support
 
 Multithreading is disabled by default when building with `make`.
 Enabling multithreading requires 2 conditions :
 - set macro `ZSTD_MULTITHREAD`
 - on POSIX systems : compile with pthread (`-pthread` compilation flag for `gcc`)
 
 Both conditions are automatically triggered by invoking `make lib-mt` target.
 Note that, when linking a POSIX program with a multithreaded version of `libzstd`,
 it's necessary to trigger `-pthread` flag during link stage.
 
 Multithreading capabilities are exposed
 via [advanced API `ZSTD_compress_generic()` defined in `lib/zstd.h`](https://github.com/facebook/zstd/blob/dev/lib/zstd.h#L919).
 This API is still considered experimental,
 but is expected to become "stable" at some point in the future.
 
 
 #### Windows : using MinGW+MSYS to create DLL
 
 DLL can be created using MinGW+MSYS with the `make libzstd` command.
 This command creates `dll\libzstd.dll` and the import library `dll\libzstd.lib`.
 The import library is only required with Visual C++.
 The header file `zstd.h` and the dynamic library `dll\libzstd.dll` are required to
 compile a project using gcc/MinGW.
 The dynamic library has to be added to linking options.
 It means that if a project that uses ZSTD consists of a single `test-dll.c`
 file it should be linked with `dll\libzstd.dll`. For example:
 ```
     gcc $(CFLAGS) -Iinclude/ test-dll.c -o test-dll dll\libzstd.dll
 ```
 The compiled executable will require ZSTD DLL which is available at `dll\libzstd.dll`.
 
 
 #### Deprecated API
 
 Obsolete API on their way out are stored in directory `lib/deprecated`.
 At this stage, it contains older streaming prototypes, in `lib/deprecated/zbuff.h`.
 These prototypes will be removed in some future version.
 Consider migrating code towards supported streaming API exposed in `zstd.h`.
 
 
 #### Miscellaneous
 
 The other files are not source code. There are :
 
  - `LICENSE` : contains the BSD license text
  - `Makefile` : `make` script to build and install zstd library (static and dynamic)
  - `BUCK` : support for `buck` build system (https://buckbuild.com/)
  - `libzstd.pc.in` : for `pkg-config` (used in `make install`)
  - `README.md` : this file
Index: vendor/zstd/dist/lib/common/bitstream.h
===================================================================
--- vendor/zstd/dist/lib/common/bitstream.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/bitstream.h	(revision 339614)
@@ -1,471 +1,455 @@
 /* ******************************************************************
    bitstream
    Part of FSE library
-   header file (to include)
-   Copyright (C) 2013-2017, Yann Collet.
+   Copyright (C) 2013-present, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 ****************************************************************** */
 #ifndef BITSTREAM_H_MODULE
 #define BITSTREAM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /*
 *  This API consists of small unitary functions, which must be inlined for best performance.
 *  Since link-time-optimization is not available for all compilers,
 *  these functions are defined into a .h to be included.
 */
 
 /*-****************************************
 *  Dependencies
 ******************************************/
 #include "mem.h"            /* unaligned access routines */
+#include "debug.h"          /* assert(), DEBUGLOG(), RAWLOG() */
 #include "error_private.h"  /* error codes and messages */
 
 
-/*-*************************************
-*  Debug
-***************************************/
-#if defined(BIT_DEBUG) && (BIT_DEBUG>=1)
-#  include 
-#else
-#  ifndef assert
-#    define assert(condition) ((void)0)
-#  endif
-#endif
-
-
 /*=========================================
 *  Target specific
 =========================================*/
 #if defined(__BMI__) && defined(__GNUC__)
 #  include    /* support for bextr (experimental) */
 #endif
 
 #define STREAM_ACCUMULATOR_MIN_32  25
 #define STREAM_ACCUMULATOR_MIN_64  57
 #define STREAM_ACCUMULATOR_MIN    ((U32)(MEM_32bits() ? STREAM_ACCUMULATOR_MIN_32 : STREAM_ACCUMULATOR_MIN_64))
 
 
 /*-******************************************
 *  bitStream encoding API (write forward)
 ********************************************/
 /* bitStream can mix input from multiple sources.
  * A critical property of these streams is that they encode and decode in **reverse** direction.
  * So the first bit sequence you add will be the last to be read, like a LIFO stack.
  */
-typedef struct
-{
+typedef struct {
     size_t bitContainer;
     unsigned bitPos;
     char*  startPtr;
     char*  ptr;
     char*  endPtr;
 } BIT_CStream_t;
 
 MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC, void* dstBuffer, size_t dstCapacity);
 MEM_STATIC void   BIT_addBits(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
 MEM_STATIC void   BIT_flushBits(BIT_CStream_t* bitC);
 MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC);
 
 /* Start with initCStream, providing the size of buffer to write into.
 *  bitStream will never write outside of this buffer.
 *  `dstCapacity` must be >= sizeof(bitD->bitContainer), otherwise @return will be an error code.
 *
 *  bits are first added to a local register.
 *  Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
 *  Writing data into memory is an explicit operation, performed by the flushBits function.
 *  Hence keep track how many bits are potentially stored into local register to avoid register overflow.
 *  After a flushBits, a maximum of 7 bits might still be stored into local register.
 *
 *  Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
 *
 *  Last operation is to close the bitStream.
 *  The function returns the final size of CStream in bytes.
 *  If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
 */
 
 
 /*-********************************************
 *  bitStream decoding API (read backward)
 **********************************************/
-typedef struct
-{
+typedef struct {
     size_t   bitContainer;
     unsigned bitsConsumed;
     const char* ptr;
     const char* start;
     const char* limitPtr;
 } BIT_DStream_t;
 
 typedef enum { BIT_DStream_unfinished = 0,
                BIT_DStream_endOfBuffer = 1,
                BIT_DStream_completed = 2,
                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
 
 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
 
 
 /* Start by invoking BIT_initDStream().
 *  A chunk of the bitStream is then stored into a local register.
 *  Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
 *  You can then retrieve bitFields stored into the local register, **in reverse order**.
 *  Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
 *  A reload guarantee a minimum of ((8*sizeof(bitD->bitContainer))-7) bits when its result is BIT_DStream_unfinished.
 *  Otherwise, it can be less than that, so proceed accordingly.
 *  Checking if DStream has reached its end can be performed with BIT_endOfDStream().
 */
 
 
 /*-****************************************
 *  unsafe API
 ******************************************/
 MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
 /* faster, but works only if value is "clean", meaning all high bits above nbBits are 0 */
 
 MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC);
 /* unsafe version; does not check buffer overflow */
 
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
 /* faster, but works only if nbBits >= 1 */
 
 
 
 /*-**************************************************************
 *  Internal functions
 ****************************************************************/
 MEM_STATIC unsigned BIT_highbit32 (U32 val)
 {
     assert(val != 0);
     {
 #   if defined(_MSC_VER)   /* Visual */
         unsigned long r=0;
         _BitScanReverse ( &r, val );
         return (unsigned) r;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
         return 31 - __builtin_clz (val);
 #   else   /* Software version */
         static const unsigned DeBruijnClz[32] = { 0,  9,  1, 10, 13, 21,  2, 29,
                                                  11, 14, 16, 18, 22, 25,  3, 30,
                                                   8, 12, 20, 28, 15, 17, 24,  7,
                                                  19, 27, 23,  6, 26,  5,  4, 31 };
         U32 v = val;
         v |= v >> 1;
         v |= v >> 2;
         v |= v >> 4;
         v |= v >> 8;
         v |= v >> 16;
         return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
 #   endif
     }
 }
 
 /*=====    Local Constants   =====*/
 static const unsigned BIT_mask[] = {
     0,          1,         3,         7,         0xF,       0x1F,
     0x3F,       0x7F,      0xFF,      0x1FF,     0x3FF,     0x7FF,
     0xFFF,      0x1FFF,    0x3FFF,    0x7FFF,    0xFFFF,    0x1FFFF,
     0x3FFFF,    0x7FFFF,   0xFFFFF,   0x1FFFFF,  0x3FFFFF,  0x7FFFFF,
     0xFFFFFF,   0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF, 0xFFFFFFF, 0x1FFFFFFF,
     0x3FFFFFFF, 0x7FFFFFFF}; /* up to 31 bits */
 #define BIT_MASK_SIZE (sizeof(BIT_mask) / sizeof(BIT_mask[0]))
 
 /*-**************************************************************
 *  bitStream encoding
 ****************************************************************/
 /*! BIT_initCStream() :
  *  `dstCapacity` must be > sizeof(size_t)
  *  @return : 0 if success,
  *            otherwise an error code (can be tested using ERR_isError()) */
 MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC,
                                   void* startPtr, size_t dstCapacity)
 {
     bitC->bitContainer = 0;
     bitC->bitPos = 0;
     bitC->startPtr = (char*)startPtr;
     bitC->ptr = bitC->startPtr;
     bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->bitContainer);
     if (dstCapacity <= sizeof(bitC->bitContainer)) return ERROR(dstSize_tooSmall);
     return 0;
 }
 
 /*! BIT_addBits() :
  *  can add up to 31 bits into `bitC`.
  *  Note : does not check for register overflow ! */
 MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
                             size_t value, unsigned nbBits)
 {
     MEM_STATIC_ASSERT(BIT_MASK_SIZE == 32);
     assert(nbBits < BIT_MASK_SIZE);
     assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
     bitC->bitContainer |= (value & BIT_mask[nbBits]) << bitC->bitPos;
     bitC->bitPos += nbBits;
 }
 
 /*! BIT_addBitsFast() :
- *  works only if `value` is _clean_, meaning all high bits above nbBits are 0 */
+ *  works only if `value` is _clean_,
+ *  meaning all high bits above nbBits are 0 */
 MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC,
                                 size_t value, unsigned nbBits)
 {
     assert((value>>nbBits) == 0);
     assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
     bitC->bitContainer |= value << bitC->bitPos;
     bitC->bitPos += nbBits;
 }
 
 /*! BIT_flushBitsFast() :
  *  assumption : bitContainer has not overflowed
  *  unsafe version; does not check buffer overflow */
 MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC)
 {
     size_t const nbBytes = bitC->bitPos >> 3;
     assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
     MEM_writeLEST(bitC->ptr, bitC->bitContainer);
     bitC->ptr += nbBytes;
     assert(bitC->ptr <= bitC->endPtr);
     bitC->bitPos &= 7;
     bitC->bitContainer >>= nbBytes*8;
 }
 
 /*! BIT_flushBits() :
  *  assumption : bitContainer has not overflowed
  *  safe version; check for buffer overflow, and prevents it.
  *  note : does not signal buffer overflow.
  *  overflow will be revealed later on using BIT_closeCStream() */
 MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
 {
     size_t const nbBytes = bitC->bitPos >> 3;
     assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
     MEM_writeLEST(bitC->ptr, bitC->bitContainer);
     bitC->ptr += nbBytes;
     if (bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr;
     bitC->bitPos &= 7;
     bitC->bitContainer >>= nbBytes*8;
 }
 
 /*! BIT_closeCStream() :
  *  @return : size of CStream, in bytes,
  *            or 0 if it could not fit into dstBuffer */
 MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
 {
     BIT_addBitsFast(bitC, 1, 1);   /* endMark */
     BIT_flushBits(bitC);
     if (bitC->ptr >= bitC->endPtr) return 0; /* overflow detected */
     return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
 }
 
 
 /*-********************************************************
 *  bitStream decoding
 **********************************************************/
 /*! BIT_initDStream() :
  *  Initialize a BIT_DStream_t.
  * `bitD` : a pointer to an already allocated BIT_DStream_t structure.
  * `srcSize` must be the *exact* size of the bitStream, in bytes.
  * @return : size of stream (== srcSize), or an errorCode if a problem is detected
  */
 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
 {
     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
 
     bitD->start = (const char*)srcBuffer;
     bitD->limitPtr = bitD->start + sizeof(bitD->bitContainer);
 
     if (srcSize >=  sizeof(bitD->bitContainer)) {  /* normal case */
         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(bitD->bitContainer);
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
           bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;  /* ensures bitsConsumed is always set */
           if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
     } else {
         bitD->ptr   = bitD->start;
         bitD->bitContainer = *(const BYTE*)(bitD->start);
         switch(srcSize)
         {
         case 7: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);
                 /* fall-through */
 
         case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
                 /* fall-through */
 
         case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
                 /* fall-through */
 
         case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24;
                 /* fall-through */
 
         case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16;
                 /* fall-through */
 
         case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) <<  8;
                 /* fall-through */
 
         default: break;
         }
         {   BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
             bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
             if (lastByte == 0) return ERROR(corruption_detected);  /* endMark not present */
         }
         bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize)*8;
     }
 
     return srcSize;
 }
 
 MEM_STATIC size_t BIT_getUpperBits(size_t bitContainer, U32 const start)
 {
     return bitContainer >> start;
 }
 
 MEM_STATIC size_t BIT_getMiddleBits(size_t bitContainer, U32 const start, U32 const nbBits)
 {
-#if defined(__BMI__) && defined(__GNUC__) && __GNUC__*1000+__GNUC_MINOR__ >= 4008  /* experimental */
-#  if defined(__x86_64__)
-    if (sizeof(bitContainer)==8)
-        return _bextr_u64(bitContainer, start, nbBits);
-    else
-#  endif
-        return _bextr_u32(bitContainer, start, nbBits);
-#else
+    U32 const regMask = sizeof(bitContainer)*8 - 1;
+    /* if start > regMask, bitstream is corrupted, and result is undefined */
     assert(nbBits < BIT_MASK_SIZE);
-    return (bitContainer >> start) & BIT_mask[nbBits];
-#endif
+    return (bitContainer >> (start & regMask)) & BIT_mask[nbBits];
 }
 
 MEM_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
 {
     assert(nbBits < BIT_MASK_SIZE);
     return bitContainer & BIT_mask[nbBits];
 }
 
 /*! BIT_lookBits() :
  *  Provides next n bits from local register.
  *  local register is not modified.
  *  On 32-bits, maxNbBits==24.
  *  On 64-bits, maxNbBits==56.
  * @return : value extracted */
 MEM_STATIC size_t BIT_lookBits(const BIT_DStream_t* bitD, U32 nbBits)
 {
-#if defined(__BMI__) && defined(__GNUC__)   /* experimental; fails if bitD->bitsConsumed + nbBits > sizeof(bitD->bitContainer)*8 */
+    /* arbitrate between double-shift and shift+mask */
+#if 1
+    /* if bitD->bitsConsumed + nbBits > sizeof(bitD->bitContainer)*8,
+     * bitstream is likely corrupted, and result is undefined */
     return BIT_getMiddleBits(bitD->bitContainer, (sizeof(bitD->bitContainer)*8) - bitD->bitsConsumed - nbBits, nbBits);
 #else
+    /* this code path is slower on my os-x laptop */
     U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
     return ((bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> 1) >> ((regMask-nbBits) & regMask);
 #endif
 }
 
 /*! BIT_lookBitsFast() :
  *  unsafe version; only works if nbBits >= 1 */
 MEM_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t* bitD, U32 nbBits)
 {
     U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
     assert(nbBits >= 1);
     return (bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> (((regMask+1)-nbBits) & regMask);
 }
 
 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     bitD->bitsConsumed += nbBits;
 }
 
 /*! BIT_readBits() :
  *  Read (consume) next n bits from local register and update.
  *  Pay attention to not read more than nbBits contained into local register.
  * @return : extracted value. */
 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     size_t const value = BIT_lookBits(bitD, nbBits);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 /*! BIT_readBitsFast() :
  *  unsafe version; only works only if nbBits >= 1 */
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
 {
     size_t const value = BIT_lookBitsFast(bitD, nbBits);
     assert(nbBits >= 1);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 /*! BIT_reloadDStream() :
  *  Refill `bitD` from buffer previously set in BIT_initDStream() .
  *  This function is safe, it guarantees it will not read beyond src buffer.
  * @return : status of `BIT_DStream_t` internal register.
  *           when status == BIT_DStream_unfinished, internal register is filled with at least 25 or 57 bits */
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
 {
     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* overflow detected, like end of stream */
         return BIT_DStream_overflow;
 
     if (bitD->ptr >= bitD->limitPtr) {
         bitD->ptr -= bitD->bitsConsumed >> 3;
         bitD->bitsConsumed &= 7;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         return BIT_DStream_unfinished;
     }
     if (bitD->ptr == bitD->start) {
         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
         return BIT_DStream_completed;
     }
     /* start < ptr < limitPtr */
     {   U32 nbBytes = bitD->bitsConsumed >> 3;
         BIT_DStream_status result = BIT_DStream_unfinished;
         if (bitD->ptr - nbBytes < bitD->start) {
             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
             result = BIT_DStream_endOfBuffer;
         }
         bitD->ptr -= nbBytes;
         bitD->bitsConsumed -= nbBytes*8;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD->bitContainer), otherwise bitD->ptr == bitD->start */
         return result;
     }
 }
 
 /*! BIT_endOfDStream() :
  * @return : 1 if DStream has _exactly_ reached its end (all bits consumed).
  */
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
 {
     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* BITSTREAM_H_MODULE */
Index: vendor/zstd/dist/lib/common/compiler.h
===================================================================
--- vendor/zstd/dist/lib/common/compiler.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/compiler.h	(revision 339614)
@@ -1,111 +1,133 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_COMPILER_H
 #define ZSTD_COMPILER_H
 
 /*-*******************************************************
 *  Compiler specifics
 *********************************************************/
 /* force inlining */
 #if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #  define INLINE_KEYWORD inline
 #else
 #  define INLINE_KEYWORD
 #endif
 
 #if defined(__GNUC__)
 #  define FORCE_INLINE_ATTR __attribute__((always_inline))
 #elif defined(_MSC_VER)
 #  define FORCE_INLINE_ATTR __forceinline
 #else
 #  define FORCE_INLINE_ATTR
 #endif
 
 /**
  * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant
  * parameters. They must be inlined for the compiler to elimininate the constant
  * branches.
  */
 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
 /**
  * HINT_INLINE is used to help the compiler generate better code. It is *not*
  * used for "templates", so it can be tweaked based on the compilers
  * performance.
  *
  * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the
  * always_inline attribute.
  *
  * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline
  * attribute.
  */
 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5
 #  define HINT_INLINE static INLINE_KEYWORD
 #else
 #  define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR
 #endif
 
 /* force no inlining */
 #ifdef _MSC_VER
 #  define FORCE_NOINLINE static __declspec(noinline)
 #else
 #  ifdef __GNUC__
 #    define FORCE_NOINLINE static __attribute__((__noinline__))
 #  else
 #    define FORCE_NOINLINE static
 #  endif
 #endif
 
 /* target attribute */
 #ifndef __has_attribute
   #define __has_attribute(x) 0  /* Compatibility with non-clang compilers. */
 #endif
 #if defined(__GNUC__)
 #  define TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
 #else
 #  define TARGET_ATTRIBUTE(target)
 #endif
 
 /* Enable runtime BMI2 dispatch based on the CPU.
  * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default.
  */
 #ifndef DYNAMIC_BMI2
-  #if (defined(__clang__) && __has_attribute(__target__)) \
+  #if ((defined(__clang__) && __has_attribute(__target__)) \
       || (defined(__GNUC__) \
-          && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) \
+          && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \
       && (defined(__x86_64__) || defined(_M_X86)) \
       && !defined(__BMI2__)
   #  define DYNAMIC_BMI2 1
   #else
   #  define DYNAMIC_BMI2 0
   #endif
 #endif
 
-/* prefetch */
-#if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))  /* _mm_prefetch() is not defined outside of x86/x64 */
-#  include    /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
-#  define PREFETCH(ptr)   _mm_prefetch((const char*)ptr, _MM_HINT_T0)
-#elif defined(__GNUC__)
-#  define PREFETCH(ptr)   __builtin_prefetch(ptr, 0, 0)
+/* prefetch
+ * can be disabled, by declaring NO_PREFETCH macro
+ * All prefetch invocations use a single default locality 2,
+ * generating instruction prefetcht1,
+ * which, according to Intel, means "load data into L2 cache".
+ * This is a good enough "middle ground" for the time being,
+ * though in theory, it would be better to specialize locality depending on data being prefetched.
+ * Tests could not determine any sensible difference based on locality value. */
+#if defined(NO_PREFETCH)
+#  define PREFETCH(ptr)     (void)(ptr)  /* disabled */
 #else
-#  define PREFETCH(ptr)   /* disabled */
-#endif
+#  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))  /* _mm_prefetch() is not defined outside of x86/x64 */
+#    include    /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
+#    define PREFETCH(ptr)   _mm_prefetch((const char*)(ptr), _MM_HINT_T1)
+#  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
+#    define PREFETCH(ptr)   __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */)
+#  else
+#    define PREFETCH(ptr)   (void)(ptr)  /* disabled */
+#  endif
+#endif  /* NO_PREFETCH */
+
+#define CACHELINE_SIZE 64
+
+#define PREFETCH_AREA(p, s)  {            \
+    const char* const _ptr = (const char*)(p);  \
+    size_t const _size = (size_t)(s);     \
+    size_t _pos;                          \
+    for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) {  \
+        PREFETCH(_ptr + _pos);            \
+    }                                     \
+}
 
 /* disable warnings */
 #ifdef _MSC_VER    /* Visual Studio */
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
 #endif
 
 #endif /* ZSTD_COMPILER_H */
Index: vendor/zstd/dist/lib/common/cpu.h
===================================================================
--- vendor/zstd/dist/lib/common/cpu.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/cpu.h	(revision 339614)
@@ -1,216 +1,215 @@
 /*
  * Copyright (c) 2018-present, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_COMMON_CPU_H
 #define ZSTD_COMMON_CPU_H
 
 /**
  * Implementation taken from folly/CpuId.h
  * https://github.com/facebook/folly/blob/master/folly/CpuId.h
  */
 
 #include 
 
 #include "mem.h"
 
 #ifdef _MSC_VER
 #include 
 #endif
 
 typedef struct {
     U32 f1c;
     U32 f1d;
     U32 f7b;
     U32 f7c;
 } ZSTD_cpuid_t;
 
 MEM_STATIC ZSTD_cpuid_t ZSTD_cpuid(void) {
     U32 f1c = 0;
     U32 f1d = 0;
     U32 f7b = 0;
     U32 f7c = 0;
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86))
     int reg[4];
     __cpuid((int*)reg, 0);
     {
         int const n = reg[0];
         if (n >= 1) {
             __cpuid((int*)reg, 1);
             f1c = (U32)reg[2];
             f1d = (U32)reg[3];
         }
         if (n >= 7) {
             __cpuidex((int*)reg, 7, 0);
             f7b = (U32)reg[1];
             f7c = (U32)reg[2];
         }
     }
 #elif defined(__i386__) && defined(__PIC__) && !defined(__clang__) && defined(__GNUC__)
     /* The following block like the normal cpuid branch below, but gcc
      * reserves ebx for use of its pic register so we must specially
      * handle the save and restore to avoid clobbering the register
      */
     U32 n;
     __asm__(
         "pushl %%ebx\n\t"
         "cpuid\n\t"
         "popl %%ebx\n\t"
         : "=a"(n)
         : "a"(0)
         : "ecx", "edx");
     if (n >= 1) {
       U32 f1a;
       __asm__(
           "pushl %%ebx\n\t"
           "cpuid\n\t"
           "popl %%ebx\n\t"
           : "=a"(f1a), "=c"(f1c), "=d"(f1d)
-          : "a"(1)
-          :);
+          : "a"(1));
     }
     if (n >= 7) {
       __asm__(
           "pushl %%ebx\n\t"
           "cpuid\n\t"
           "movl %%ebx, %%eax\n\r"
           "popl %%ebx"
           : "=a"(f7b), "=c"(f7c)
           : "a"(7), "c"(0)
           : "edx");
     }
 #elif defined(__x86_64__) || defined(_M_X64) || defined(__i386__)
     U32 n;
     __asm__("cpuid" : "=a"(n) : "a"(0) : "ebx", "ecx", "edx");
     if (n >= 1) {
       U32 f1a;
       __asm__("cpuid" : "=a"(f1a), "=c"(f1c), "=d"(f1d) : "a"(1) : "ebx");
     }
     if (n >= 7) {
       U32 f7a;
       __asm__("cpuid"
               : "=a"(f7a), "=b"(f7b), "=c"(f7c)
               : "a"(7), "c"(0)
               : "edx");
     }
 #endif
     {
         ZSTD_cpuid_t cpuid;
         cpuid.f1c = f1c;
         cpuid.f1d = f1d;
         cpuid.f7b = f7b;
         cpuid.f7c = f7c;
         return cpuid;
     }
 }
 
 #define X(name, r, bit)                                                        \
   MEM_STATIC int ZSTD_cpuid_##name(ZSTD_cpuid_t const cpuid) {                 \
     return ((cpuid.r) & (1U << bit)) != 0;                                     \
   }
 
 /* cpuid(1): Processor Info and Feature Bits. */
 #define C(name, bit) X(name, f1c, bit)
   C(sse3, 0)
   C(pclmuldq, 1)
   C(dtes64, 2)
   C(monitor, 3)
   C(dscpl, 4)
   C(vmx, 5)
   C(smx, 6)
   C(eist, 7)
   C(tm2, 8)
   C(ssse3, 9)
   C(cnxtid, 10)
   C(fma, 12)
   C(cx16, 13)
   C(xtpr, 14)
   C(pdcm, 15)
   C(pcid, 17)
   C(dca, 18)
   C(sse41, 19)
   C(sse42, 20)
   C(x2apic, 21)
   C(movbe, 22)
   C(popcnt, 23)
   C(tscdeadline, 24)
   C(aes, 25)
   C(xsave, 26)
   C(osxsave, 27)
   C(avx, 28)
   C(f16c, 29)
   C(rdrand, 30)
 #undef C
 #define D(name, bit) X(name, f1d, bit)
   D(fpu, 0)
   D(vme, 1)
   D(de, 2)
   D(pse, 3)
   D(tsc, 4)
   D(msr, 5)
   D(pae, 6)
   D(mce, 7)
   D(cx8, 8)
   D(apic, 9)
   D(sep, 11)
   D(mtrr, 12)
   D(pge, 13)
   D(mca, 14)
   D(cmov, 15)
   D(pat, 16)
   D(pse36, 17)
   D(psn, 18)
   D(clfsh, 19)
   D(ds, 21)
   D(acpi, 22)
   D(mmx, 23)
   D(fxsr, 24)
   D(sse, 25)
   D(sse2, 26)
   D(ss, 27)
   D(htt, 28)
   D(tm, 29)
   D(pbe, 31)
 #undef D
 
 /* cpuid(7): Extended Features. */
 #define B(name, bit) X(name, f7b, bit)
   B(bmi1, 3)
   B(hle, 4)
   B(avx2, 5)
   B(smep, 7)
   B(bmi2, 8)
   B(erms, 9)
   B(invpcid, 10)
   B(rtm, 11)
   B(mpx, 14)
   B(avx512f, 16)
   B(avx512dq, 17)
   B(rdseed, 18)
   B(adx, 19)
   B(smap, 20)
   B(avx512ifma, 21)
   B(pcommit, 22)
   B(clflushopt, 23)
   B(clwb, 24)
   B(avx512pf, 26)
   B(avx512er, 27)
   B(avx512cd, 28)
   B(sha, 29)
   B(avx512bw, 30)
   B(avx512vl, 31)
 #undef B
 #define C(name, bit) X(name, f7c, bit)
   C(prefetchwt1, 0)
   C(avx512vbmi, 1)
 #undef C
 
 #undef X
 
 #endif /* ZSTD_COMMON_CPU_H */
Index: vendor/zstd/dist/lib/common/debug.c
===================================================================
--- vendor/zstd/dist/lib/common/debug.c	(nonexistent)
+++ vendor/zstd/dist/lib/common/debug.c	(revision 339614)
@@ -0,0 +1,44 @@
+/* ******************************************************************
+   debug
+   Part of FSE library
+   Copyright (C) 2013-present, Yann Collet.
+
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+   You can contact the author at :
+   - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
+****************************************************************** */
+
+
+/*
+ * This module only hosts one global variable
+ * which can be used to dynamically influence the verbosity of traces,
+ * such as DEBUGLOG and RAWLOG
+ */
+
+#include "debug.h"
+
+int g_debuglevel = DEBUGLEVEL;

Property changes on: vendor/zstd/dist/lib/common/debug.c
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
Index: vendor/zstd/dist/lib/common/debug.h
===================================================================
--- vendor/zstd/dist/lib/common/debug.h	(nonexistent)
+++ vendor/zstd/dist/lib/common/debug.h	(revision 339614)
@@ -0,0 +1,123 @@
+/* ******************************************************************
+   debug
+   Part of FSE library
+   Copyright (C) 2013-present, Yann Collet.
+
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+   You can contact the author at :
+   - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
+****************************************************************** */
+
+
+/*
+ * The purpose of this header is to enable debug functions.
+ * They regroup assert(), DEBUGLOG() and RAWLOG() for run-time,
+ * and DEBUG_STATIC_ASSERT() for compile-time.
+ *
+ * By default, DEBUGLEVEL==0, which means run-time debug is disabled.
+ *
+ * Level 1 enables assert() only.
+ * Starting level 2, traces can be generated and pushed to stderr.
+ * The higher the level, the more verbose the traces.
+ *
+ * It's possible to dynamically adjust level using variable g_debug_level,
+ * which is only declared if DEBUGLEVEL>=2,
+ * and is a global variable, not multi-thread protected (use with care)
+ */
+
+#ifndef DEBUG_H_12987983217
+#define DEBUG_H_12987983217
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+
+/* static assert is triggered at compile time, leaving no runtime artefact,
+ * but can only work with compile-time constants.
+ * This variant can only be used inside a function. */
+#define DEBUG_STATIC_ASSERT(c) (void)sizeof(char[(c) ? 1 : -1])
+
+
+/* DEBUGLEVEL is expected to be defined externally,
+ * typically through compiler command line.
+ * Value must be a number. */
+#ifndef DEBUGLEVEL
+#  define DEBUGLEVEL 0
+#endif
+
+/* recommended values for DEBUGLEVEL :
+ * 0 : no debug, all run-time functions disabled
+ * 1 : no display, enables assert() only
+ * 2 : reserved, for currently active debug path
+ * 3 : events once per object lifetime (CCtx, CDict, etc.)
+ * 4 : events once per frame
+ * 5 : events once per block
+ * 6 : events once per sequence (verbose)
+ * 7+: events at every position (*very* verbose)
+ *
+ * It's generally inconvenient to output traces > 5.
+ * In which case, it's possible to selectively enable higher verbosity levels
+ * by modifying g_debug_level.
+ */
+
+#if (DEBUGLEVEL>=1)
+#  include 
+#else
+#  ifndef assert   /* assert may be already defined, due to prior #include  */
+#    define assert(condition) ((void)0)   /* disable assert (default) */
+#  endif
+#endif
+
+#if (DEBUGLEVEL>=2)
+#  include 
+extern int g_debuglevel; /* here, this variable is only declared,
+                           it actually lives in debug.c,
+                           and is shared by the whole process.
+                           It's typically used to enable very verbose levels
+                           on selective conditions (such as position in src) */
+
+#  define RAWLOG(l, ...) {                                      \
+                if (l<=g_debuglevel) {                          \
+                    fprintf(stderr, __VA_ARGS__);               \
+            }   }
+#  define DEBUGLOG(l, ...) {                                    \
+                if (l<=g_debuglevel) {                          \
+                    fprintf(stderr, __FILE__ ": " __VA_ARGS__); \
+                    fprintf(stderr, " \n");                     \
+            }   }
+#else
+#  define RAWLOG(l, ...)      {}    /* disabled */
+#  define DEBUGLOG(l, ...)    {}    /* disabled */
+#endif
+
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* DEBUG_H_12987983217 */

Property changes on: vendor/zstd/dist/lib/common/debug.h
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
Index: vendor/zstd/dist/lib/common/entropy_common.c
===================================================================
--- vendor/zstd/dist/lib/common/entropy_common.c	(revision 339613)
+++ vendor/zstd/dist/lib/common/entropy_common.c	(revision 339614)
@@ -1,221 +1,236 @@
 /*
    Common functions of New Generation Entropy library
    Copyright (C) 2016, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 *************************************************************************** */
 
 /* *************************************
 *  Dependencies
 ***************************************/
 #include "mem.h"
 #include "error_private.h"       /* ERR_*, ERROR */
 #define FSE_STATIC_LINKING_ONLY  /* FSE_MIN_TABLELOG */
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY  /* HUF_TABLELOG_ABSOLUTEMAX */
 #include "huf.h"
 
 
 /*===   Version   ===*/
 unsigned FSE_versionNumber(void) { return FSE_VERSION_NUMBER; }
 
 
 /*===   Error Management   ===*/
 unsigned FSE_isError(size_t code) { return ERR_isError(code); }
 const char* FSE_getErrorName(size_t code) { return ERR_getErrorName(code); }
 
 unsigned HUF_isError(size_t code) { return ERR_isError(code); }
 const char* HUF_getErrorName(size_t code) { return ERR_getErrorName(code); }
 
 
 /*-**************************************************************
 *  FSE NCount encoding-decoding
 ****************************************************************/
 size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
                  const void* headerBuffer, size_t hbSize)
 {
     const BYTE* const istart = (const BYTE*) headerBuffer;
     const BYTE* const iend = istart + hbSize;
     const BYTE* ip = istart;
     int nbBits;
     int remaining;
     int threshold;
     U32 bitStream;
     int bitCount;
     unsigned charnum = 0;
     int previous0 = 0;
 
-    if (hbSize < 4) return ERROR(srcSize_wrong);
+    if (hbSize < 4) {
+        /* This function only works when hbSize >= 4 */
+        char buffer[4];
+        memset(buffer, 0, sizeof(buffer));
+        memcpy(buffer, headerBuffer, hbSize);
+        {   size_t const countSize = FSE_readNCount(normalizedCounter, maxSVPtr, tableLogPtr,
+                                                    buffer, sizeof(buffer));
+            if (FSE_isError(countSize)) return countSize;
+            if (countSize > hbSize) return ERROR(corruption_detected);
+            return countSize;
+    }   }
+    assert(hbSize >= 4);
+
+    /* init */
+    memset(normalizedCounter, 0, (*maxSVPtr+1) * sizeof(normalizedCounter[0]));   /* all symbols not present in NCount have a frequency of 0 */
     bitStream = MEM_readLE32(ip);
     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
     bitStream >>= 4;
     bitCount = 4;
     *tableLogPtr = nbBits;
     remaining = (1<1) & (charnum<=*maxSVPtr)) {
         if (previous0) {
             unsigned n0 = charnum;
             while ((bitStream & 0xFFFF) == 0xFFFF) {
                 n0 += 24;
                 if (ip < iend-5) {
                     ip += 2;
                     bitStream = MEM_readLE32(ip) >> bitCount;
                 } else {
                     bitStream >>= 16;
                     bitCount   += 16;
             }   }
             while ((bitStream & 3) == 3) {
                 n0 += 3;
                 bitStream >>= 2;
                 bitCount += 2;
             }
             n0 += bitStream & 3;
             bitCount += 2;
             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
             while (charnum < n0) normalizedCounter[charnum++] = 0;
             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
+                assert((bitCount >> 3) <= 3); /* For first condition to work */
                 ip += bitCount>>3;
                 bitCount &= 7;
                 bitStream = MEM_readLE32(ip) >> bitCount;
             } else {
                 bitStream >>= 2;
         }   }
         {   int const max = (2*threshold-1) - remaining;
             int count;
 
             if ((bitStream & (threshold-1)) < (U32)max) {
                 count = bitStream & (threshold-1);
                 bitCount += nbBits-1;
             } else {
                 count = bitStream & (2*threshold-1);
                 if (count >= threshold) count -= max;
                 bitCount += nbBits;
             }
 
             count--;   /* extra accuracy */
             remaining -= count < 0 ? -count : count;   /* -1 means +1 */
             normalizedCounter[charnum++] = (short)count;
             previous0 = !count;
             while (remaining < threshold) {
                 nbBits--;
                 threshold >>= 1;
             }
 
             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
                 ip += bitCount>>3;
                 bitCount &= 7;
             } else {
                 bitCount -= (int)(8 * (iend - 4 - ip));
                 ip = iend - 4;
             }
             bitStream = MEM_readLE32(ip) >> (bitCount & 31);
     }   }   /* while ((remaining>1) & (charnum<=*maxSVPtr)) */
     if (remaining != 1) return ERROR(corruption_detected);
     if (bitCount > 32) return ERROR(corruption_detected);
     *maxSVPtr = charnum-1;
 
     ip += (bitCount+7)>>3;
     return ip-istart;
 }
 
 
 /*! HUF_readStats() :
     Read compact Huffman tree, saved by HUF_writeCTable().
     `huffWeight` is destination buffer.
     `rankStats` is assumed to be a table of at least HUF_TABLELOG_MAX U32.
     @return : size read from `src` , or an error Code .
     Note : Needed by HUF_readCTable() and HUF_readDTableX?() .
 */
 size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                      U32* nbSymbolsPtr, U32* tableLogPtr,
                      const void* src, size_t srcSize)
 {
     U32 weightTotal;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize;
     size_t oSize;
 
     if (!srcSize) return ERROR(srcSize_wrong);
     iSize = ip[0];
     /* memset(huffWeight, 0, hwSize);   *//* is not necessary, even though some analyzer complain ... */
 
     if (iSize >= 128) {  /* special header */
         oSize = iSize - 127;
         iSize = ((oSize+1)/2);
         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
         if (oSize >= hwSize) return ERROR(corruption_detected);
         ip += 1;
         {   U32 n;
             for (n=0; n> 4;
                 huffWeight[n+1] = ip[n/2] & 15;
     }   }   }
     else  {   /* header compressed with FSE (normal case) */
         FSE_DTable fseWorkspace[FSE_DTABLE_SIZE_U32(6)];  /* 6 is max possible tableLog for HUF header (maybe even 5, to be tested) */
         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
         oSize = FSE_decompress_wksp(huffWeight, hwSize-1, ip+1, iSize, fseWorkspace, 6);   /* max (hwSize-1) values decoded, as last one is implied */
         if (FSE_isError(oSize)) return oSize;
     }
 
     /* collect weight stats */
     memset(rankStats, 0, (HUF_TABLELOG_MAX + 1) * sizeof(U32));
     weightTotal = 0;
     {   U32 n; for (n=0; n= HUF_TABLELOG_MAX) return ERROR(corruption_detected);
             rankStats[huffWeight[n]]++;
             weightTotal += (1 << huffWeight[n]) >> 1;
     }   }
     if (weightTotal == 0) return ERROR(corruption_detected);
 
     /* get last non-null symbol weight (implied, total must be 2^n) */
     {   U32 const tableLog = BIT_highbit32(weightTotal) + 1;
         if (tableLog > HUF_TABLELOG_MAX) return ERROR(corruption_detected);
         *tableLogPtr = tableLog;
         /* determine last weight */
         {   U32 const total = 1 << tableLog;
             U32 const rest = total - weightTotal;
             U32 const verif = 1 << BIT_highbit32(rest);
             U32 const lastWeight = BIT_highbit32(rest) + 1;
             if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
             huffWeight[oSize] = (BYTE)lastWeight;
             rankStats[lastWeight]++;
     }   }
 
     /* check tree construction validity */
     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
 
     /* results */
     *nbSymbolsPtr = (U32)(oSize+1);
     return iSize+1;
 }
Index: vendor/zstd/dist/lib/common/fse.h
===================================================================
--- vendor/zstd/dist/lib/common/fse.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/fse.h	(revision 339614)
@@ -1,704 +1,708 @@
 /* ******************************************************************
    FSE : Finite State Entropy codec
    Public Prototypes declaration
    Copyright (C) 2013-2016, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 ****************************************************************** */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #ifndef FSE_H
 #define FSE_H
 
 
 /*-*****************************************
 *  Dependencies
 ******************************************/
 #include     /* size_t, ptrdiff_t */
 
 
 /*-*****************************************
 *  FSE_PUBLIC_API : control library symbols visibility
 ******************************************/
 #if defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1) && defined(__GNUC__) && (__GNUC__ >= 4)
 #  define FSE_PUBLIC_API __attribute__ ((visibility ("default")))
 #elif defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1)   /* Visual expected */
 #  define FSE_PUBLIC_API __declspec(dllexport)
 #elif defined(FSE_DLL_IMPORT) && (FSE_DLL_IMPORT==1)
 #  define FSE_PUBLIC_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
 #else
 #  define FSE_PUBLIC_API
 #endif
 
 /*------   Version   ------*/
 #define FSE_VERSION_MAJOR    0
 #define FSE_VERSION_MINOR    9
 #define FSE_VERSION_RELEASE  0
 
 #define FSE_LIB_VERSION FSE_VERSION_MAJOR.FSE_VERSION_MINOR.FSE_VERSION_RELEASE
 #define FSE_QUOTE(str) #str
 #define FSE_EXPAND_AND_QUOTE(str) FSE_QUOTE(str)
 #define FSE_VERSION_STRING FSE_EXPAND_AND_QUOTE(FSE_LIB_VERSION)
 
 #define FSE_VERSION_NUMBER  (FSE_VERSION_MAJOR *100*100 + FSE_VERSION_MINOR *100 + FSE_VERSION_RELEASE)
 FSE_PUBLIC_API unsigned FSE_versionNumber(void);   /**< library version number; to be used when checking dll version */
 
+
 /*-****************************************
 *  FSE simple functions
 ******************************************/
 /*! FSE_compress() :
     Compress content of buffer 'src', of size 'srcSize', into destination buffer 'dst'.
     'dst' buffer must be already allocated. Compression runs faster is dstCapacity >= FSE_compressBound(srcSize).
     @return : size of compressed data (<= dstCapacity).
     Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
                      if return == 1, srcData is a single byte symbol * srcSize times. Use RLE compression instead.
                      if FSE_isError(return), compression failed (more details using FSE_getErrorName())
 */
 FSE_PUBLIC_API size_t FSE_compress(void* dst, size_t dstCapacity,
                              const void* src, size_t srcSize);
 
 /*! FSE_decompress():
     Decompress FSE data from buffer 'cSrc', of size 'cSrcSize',
     into already allocated destination buffer 'dst', of size 'dstCapacity'.
     @return : size of regenerated data (<= maxDstSize),
               or an error code, which can be tested using FSE_isError() .
 
     ** Important ** : FSE_decompress() does not decompress non-compressible nor RLE data !!!
     Why ? : making this distinction requires a header.
     Header management is intentionally delegated to the user layer, which can better manage special cases.
 */
 FSE_PUBLIC_API size_t FSE_decompress(void* dst,  size_t dstCapacity,
                                const void* cSrc, size_t cSrcSize);
 
 
 /*-*****************************************
 *  Tool functions
 ******************************************/
 FSE_PUBLIC_API size_t FSE_compressBound(size_t size);       /* maximum compressed size */
 
 /* Error Management */
 FSE_PUBLIC_API unsigned    FSE_isError(size_t code);        /* tells if a return value is an error code */
 FSE_PUBLIC_API const char* FSE_getErrorName(size_t code);   /* provides error code string (useful for debugging) */
 
 
 /*-*****************************************
 *  FSE advanced functions
 ******************************************/
 /*! FSE_compress2() :
     Same as FSE_compress(), but allows the selection of 'maxSymbolValue' and 'tableLog'
     Both parameters can be defined as '0' to mean : use default value
     @return : size of compressed data
     Special values : if return == 0, srcData is not compressible => Nothing is stored within cSrc !!!
                      if return == 1, srcData is a single byte symbol * srcSize times. Use RLE compression.
                      if FSE_isError(return), it's an error code.
 */
 FSE_PUBLIC_API size_t FSE_compress2 (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
 
 
 /*-*****************************************
 *  FSE detailed API
 ******************************************/
 /*!
 FSE_compress() does the following:
-1. count symbol occurrence from source[] into table count[]
+1. count symbol occurrence from source[] into table count[] (see hist.h)
 2. normalize counters so that sum(count[]) == Power_of_2 (2^tableLog)
 3. save normalized counters to memory buffer using writeNCount()
 4. build encoding table 'CTable' from normalized counters
 5. encode the data stream using encoding table 'CTable'
 
 FSE_decompress() does the following:
 1. read normalized counters with readNCount()
 2. build decoding table 'DTable' from normalized counters
 3. decode the data stream using decoding table 'DTable'
 
 The following API allows targeting specific sub-functions for advanced tasks.
 For example, it's possible to compress several blocks using the same 'CTable',
 or to save and provide normalized distribution using external method.
 */
 
 /* *** COMPRESSION *** */
 
-/*! FSE_count():
-    Provides the precise count of each byte within a table 'count'.
-    'count' is a table of unsigned int, of minimum size (*maxSymbolValuePtr+1).
-    *maxSymbolValuePtr will be updated if detected smaller than initial value.
-    @return : the count of the most frequent symbol (which is not identified).
-              if return == srcSize, there is only one symbol.
-              Can also return an error code, which can be tested with FSE_isError(). */
-FSE_PUBLIC_API size_t FSE_count(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
-
 /*! FSE_optimalTableLog():
     dynamically downsize 'tableLog' when conditions are met.
     It saves CPU time, by using smaller tables, while preserving or even improving compression ratio.
     @return : recommended tableLog (necessarily <= 'maxTableLog') */
 FSE_PUBLIC_API unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);
 
 /*! FSE_normalizeCount():
     normalize counts so that sum(count[]) == Power_of_2 (2^tableLog)
     'normalizedCounter' is a table of short, of minimum size (maxSymbolValue+1).
     @return : tableLog,
               or an errorCode, which can be tested using FSE_isError() */
-FSE_PUBLIC_API size_t FSE_normalizeCount(short* normalizedCounter, unsigned tableLog, const unsigned* count, size_t srcSize, unsigned maxSymbolValue);
+FSE_PUBLIC_API size_t FSE_normalizeCount(short* normalizedCounter, unsigned tableLog,
+                    const unsigned* count, size_t srcSize, unsigned maxSymbolValue);
 
 /*! FSE_NCountWriteBound():
     Provides the maximum possible size of an FSE normalized table, given 'maxSymbolValue' and 'tableLog'.
     Typically useful for allocation purpose. */
 FSE_PUBLIC_API size_t FSE_NCountWriteBound(unsigned maxSymbolValue, unsigned tableLog);
 
 /*! FSE_writeNCount():
     Compactly save 'normalizedCounter' into 'buffer'.
     @return : size of the compressed table,
               or an errorCode, which can be tested using FSE_isError(). */
-FSE_PUBLIC_API size_t FSE_writeNCount (void* buffer, size_t bufferSize, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
+FSE_PUBLIC_API size_t FSE_writeNCount (void* buffer, size_t bufferSize,
+                                 const short* normalizedCounter,
+                                 unsigned maxSymbolValue, unsigned tableLog);
 
-
 /*! Constructor and Destructor of FSE_CTable.
     Note that FSE_CTable size depends on 'tableLog' and 'maxSymbolValue' */
 typedef unsigned FSE_CTable;   /* don't allocate that. It's only meant to be more restrictive than void* */
 FSE_PUBLIC_API FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog);
 FSE_PUBLIC_API void        FSE_freeCTable (FSE_CTable* ct);
 
 /*! FSE_buildCTable():
     Builds `ct`, which must be already allocated, using FSE_createCTable().
     @return : 0, or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_buildCTable(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
 
 /*! FSE_compress_usingCTable():
     Compress `src` using `ct` into `dst` which must be already allocated.
     @return : size of compressed data (<= `dstCapacity`),
               or 0 if compressed data could not fit into `dst`,
               or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_compress_usingCTable (void* dst, size_t dstCapacity, const void* src, size_t srcSize, const FSE_CTable* ct);
 
 /*!
 Tutorial :
 ----------
 The first step is to count all symbols. FSE_count() does this job very fast.
 Result will be saved into 'count', a table of unsigned int, which must be already allocated, and have 'maxSymbolValuePtr[0]+1' cells.
 'src' is a table of bytes of size 'srcSize'. All values within 'src' MUST be <= maxSymbolValuePtr[0]
 maxSymbolValuePtr[0] will be updated, with its real value (necessarily <= original value)
 FSE_count() will return the number of occurrence of the most frequent symbol.
 This can be used to know if there is a single symbol within 'src', and to quickly evaluate its compressibility.
 If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).
 
 The next step is to normalize the frequencies.
 FSE_normalizeCount() will ensure that sum of frequencies is == 2 ^'tableLog'.
 It also guarantees a minimum of 1 to any Symbol with frequency >= 1.
 You can use 'tableLog'==0 to mean "use default tableLog value".
 If you are unsure of which tableLog value to use, you can ask FSE_optimalTableLog(),
 which will provide the optimal valid tableLog given sourceSize, maxSymbolValue, and a user-defined maximum (0 means "default").
 
 The result of FSE_normalizeCount() will be saved into a table,
 called 'normalizedCounter', which is a table of signed short.
 'normalizedCounter' must be already allocated, and have at least 'maxSymbolValue+1' cells.
 The return value is tableLog if everything proceeded as expected.
 It is 0 if there is a single symbol within distribution.
 If there is an error (ex: invalid tableLog value), the function will return an ErrorCode (which can be tested using FSE_isError()).
 
 'normalizedCounter' can be saved in a compact manner to a memory area using FSE_writeNCount().
 'buffer' must be already allocated.
 For guaranteed success, buffer size must be at least FSE_headerBound().
 The result of the function is the number of bytes written into 'buffer'.
 If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError(); ex : buffer size too small).
 
 'normalizedCounter' can then be used to create the compression table 'CTable'.
 The space required by 'CTable' must be already allocated, using FSE_createCTable().
 You can then use FSE_buildCTable() to fill 'CTable'.
 If there is an error, both functions will return an ErrorCode (which can be tested using FSE_isError()).
 
 'CTable' can then be used to compress 'src', with FSE_compress_usingCTable().
 Similar to FSE_count(), the convention is that 'src' is assumed to be a table of char of size 'srcSize'
 The function returns the size of compressed data (without header), necessarily <= `dstCapacity`.
 If it returns '0', compressed data could not fit into 'dst'.
 If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).
 */
 
 
 /* *** DECOMPRESSION *** */
 
 /*! FSE_readNCount():
     Read compactly saved 'normalizedCounter' from 'rBuffer'.
     @return : size read from 'rBuffer',
               or an errorCode, which can be tested using FSE_isError().
               maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
-FSE_PUBLIC_API size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSymbolValuePtr, unsigned* tableLogPtr, const void* rBuffer, size_t rBuffSize);
+FSE_PUBLIC_API size_t FSE_readNCount (short* normalizedCounter,
+                           unsigned* maxSymbolValuePtr, unsigned* tableLogPtr,
+                           const void* rBuffer, size_t rBuffSize);
 
 /*! Constructor and Destructor of FSE_DTable.
     Note that its size depends on 'tableLog' */
 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
 FSE_PUBLIC_API FSE_DTable* FSE_createDTable(unsigned tableLog);
 FSE_PUBLIC_API void        FSE_freeDTable(FSE_DTable* dt);
 
 /*! FSE_buildDTable():
     Builds 'dt', which must be already allocated, using FSE_createDTable().
     return : 0, or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_buildDTable (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
 
 /*! FSE_decompress_usingDTable():
     Decompress compressed source `cSrc` of size `cSrcSize` using `dt`
     into `dst` which must be already allocated.
     @return : size of regenerated data (necessarily <= `dstCapacity`),
               or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_decompress_usingDTable(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, const FSE_DTable* dt);
 
 /*!
 Tutorial :
 ----------
 (Note : these functions only decompress FSE-compressed blocks.
  If block is uncompressed, use memcpy() instead
  If block is a single repeated byte, use memset() instead )
 
 The first step is to obtain the normalized frequencies of symbols.
 This can be performed by FSE_readNCount() if it was saved using FSE_writeNCount().
 'normalizedCounter' must be already allocated, and have at least 'maxSymbolValuePtr[0]+1' cells of signed short.
 In practice, that means it's necessary to know 'maxSymbolValue' beforehand,
 or size the table to handle worst case situations (typically 256).
 FSE_readNCount() will provide 'tableLog' and 'maxSymbolValue'.
 The result of FSE_readNCount() is the number of bytes read from 'rBuffer'.
 Note that 'rBufferSize' must be at least 4 bytes, even if useful information is less than that.
 If there is an error, the function will return an error code, which can be tested using FSE_isError().
 
 The next step is to build the decompression tables 'FSE_DTable' from 'normalizedCounter'.
 This is performed by the function FSE_buildDTable().
 The space required by 'FSE_DTable' must be already allocated using FSE_createDTable().
 If there is an error, the function will return an error code, which can be tested using FSE_isError().
 
 `FSE_DTable` can then be used to decompress `cSrc`, with FSE_decompress_usingDTable().
 `cSrcSize` must be strictly correct, otherwise decompression will fail.
 FSE_decompress_usingDTable() result will tell how many bytes were regenerated (<=`dstCapacity`).
 If there is an error, the function will return an error code, which can be tested using FSE_isError(). (ex: dst buffer too small)
 */
 
 #endif  /* FSE_H */
 
 #if defined(FSE_STATIC_LINKING_ONLY) && !defined(FSE_H_FSE_STATIC_LINKING_ONLY)
 #define FSE_H_FSE_STATIC_LINKING_ONLY
 
 /* *** Dependency *** */
 #include "bitstream.h"
 
 
 /* *****************************************
 *  Static allocation
 *******************************************/
 /* FSE buffer bounds */
 #define FSE_NCOUNTBOUND 512
 #define FSE_BLOCKBOUND(size) (size + (size>>7))
 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* It is possible to statically allocate FSE CTable/DTable as a table of FSE_CTable/FSE_DTable using below macros */
 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<= `1024` unsigned
- */
-size_t FSE_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
-                 const void* source, size_t sourceSize, unsigned* workSpace);
+ *  FSE advanced API
+ ***************************************** */
 
-/** FSE_countFast() :
- *  same as FSE_count(), but blindly trusts that all byte values within src are <= *maxSymbolValuePtr
- */
-size_t FSE_countFast(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
-
-/* FSE_countFast_wksp() :
- * Same as FSE_countFast(), but using an externally provided scratch buffer.
- * `workSpace` must be a table of minimum `1024` unsigned
- */
-size_t FSE_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned* workSpace);
-
-/*! FSE_count_simple() :
- * Same as FSE_countFast(), but does not use any additional memory (not even on stack).
- * This function is unsafe, and will segfault if any value within `src` is `> *maxSymbolValuePtr` (presuming it's also the size of `count`).
-*/
-size_t FSE_count_simple(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
-
-
-
 unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus);
 /**< same as FSE_optimalTableLog(), which used `minus==2` */
 
 /* FSE_compress_wksp() :
  * Same as FSE_compress2(), but using an externally allocated scratch buffer (`workSpace`).
  * FSE_WKSP_SIZE_U32() provides the minimum size required for `workSpace` as a table of FSE_CTable.
  */
 #define FSE_WKSP_SIZE_U32(maxTableLog, maxSymbolValue)   ( FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue) + ((maxTableLog > 12) ? (1 << (maxTableLog - 2)) : 1024) )
 size_t FSE_compress_wksp (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize);
 
 size_t FSE_buildCTable_raw (FSE_CTable* ct, unsigned nbBits);
 /**< build a fake FSE_CTable, designed for a flat distribution, where each symbol uses nbBits */
 
 size_t FSE_buildCTable_rle (FSE_CTable* ct, unsigned char symbolValue);
 /**< build a fake FSE_CTable, designed to compress always the same symbolValue */
 
 /* FSE_buildCTable_wksp() :
  * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`).
  * `wkspSize` must be >= `(1<= BIT_DStream_completed
 
 When it's done, verify decompression is fully completed, by checking both DStream and the relevant states.
 Checking if DStream has reached its end is performed by :
     BIT_endOfDStream(&DStream);
 Check also the states. There might be some symbols left there, if some high probability ones (>50%) are possible.
     FSE_endOfDState(&DState);
 */
 
 
 /* *****************************************
 *  FSE unsafe API
 *******************************************/
 static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
 
 
 /* *****************************************
 *  Implementation of inlined functions
 *******************************************/
 typedef struct {
     int deltaFindState;
     U32 deltaNbBits;
 } FSE_symbolCompressionTransform; /* total 8 bytes */
 
 MEM_STATIC void FSE_initCState(FSE_CState_t* statePtr, const FSE_CTable* ct)
 {
     const void* ptr = ct;
     const U16* u16ptr = (const U16*) ptr;
     const U32 tableLog = MEM_read16(ptr);
     statePtr->value = (ptrdiff_t)1<stateTable = u16ptr+2;
     statePtr->symbolTT = ((const U32*)ct + 1 + (tableLog ? (1<<(tableLog-1)) : 1));
     statePtr->stateLog = tableLog;
 }
 
 
 /*! FSE_initCState2() :
 *   Same as FSE_initCState(), but the first symbol to include (which will be the last to be read)
 *   uses the smallest state value possible, saving the cost of this symbol */
 MEM_STATIC void FSE_initCState2(FSE_CState_t* statePtr, const FSE_CTable* ct, U32 symbol)
 {
     FSE_initCState(statePtr, ct);
     {   const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
         const U16* stateTable = (const U16*)(statePtr->stateTable);
         U32 nbBitsOut  = (U32)((symbolTT.deltaNbBits + (1<<15)) >> 16);
         statePtr->value = (nbBitsOut << 16) - symbolTT.deltaNbBits;
         statePtr->value = stateTable[(statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
     }
 }
 
 MEM_STATIC void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* statePtr, U32 symbol)
 {
     FSE_symbolCompressionTransform const symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
     const U16* const stateTable = (const U16*)(statePtr->stateTable);
     U32 const nbBitsOut  = (U32)((statePtr->value + symbolTT.deltaNbBits) >> 16);
     BIT_addBits(bitC, statePtr->value, nbBitsOut);
     statePtr->value = stateTable[ (statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
 }
 
 MEM_STATIC void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* statePtr)
 {
     BIT_addBits(bitC, statePtr->value, statePtr->stateLog);
     BIT_flushBits(bitC);
+}
+
+
+/* FSE_getMaxNbBits() :
+ * Approximate maximum cost of a symbol, in bits.
+ * Fractional get rounded up (i.e : a symbol with a normalized frequency of 3 gives the same result as a frequency of 2)
+ * note 1 : assume symbolValue is valid (<= maxSymbolValue)
+ * note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
+MEM_STATIC U32 FSE_getMaxNbBits(const void* symbolTTPtr, U32 symbolValue)
+{
+    const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
+    return (symbolTT[symbolValue].deltaNbBits + ((1<<16)-1)) >> 16;
+}
+
+/* FSE_bitCost() :
+ * Approximate symbol cost, as fractional value, using fixed-point format (accuracyLog fractional bits)
+ * note 1 : assume symbolValue is valid (<= maxSymbolValue)
+ * note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
+MEM_STATIC U32 FSE_bitCost(const void* symbolTTPtr, U32 tableLog, U32 symbolValue, U32 accuracyLog)
+{
+    const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
+    U32 const minNbBits = symbolTT[symbolValue].deltaNbBits >> 16;
+    U32 const threshold = (minNbBits+1) << 16;
+    assert(tableLog < 16);
+    assert(accuracyLog < 31-tableLog);  /* ensure enough room for renormalization double shift */
+    {   U32 const tableSize = 1 << tableLog;
+        U32 const deltaFromThreshold = threshold - (symbolTT[symbolValue].deltaNbBits + tableSize);
+        U32 const normalizedDeltaFromThreshold = (deltaFromThreshold << accuracyLog) >> tableLog;   /* linear interpolation (very approximate) */
+        U32 const bitMultiplier = 1 << accuracyLog;
+        assert(symbolTT[symbolValue].deltaNbBits + tableSize <= threshold);
+        assert(normalizedDeltaFromThreshold <= bitMultiplier);
+        return (minNbBits+1)*bitMultiplier - normalizedDeltaFromThreshold;
+    }
 }
 
 
 /* ======    Decompression    ====== */
 
 typedef struct {
     U16 tableLog;
     U16 fastMode;
 } FSE_DTableHeader;   /* sizeof U32 */
 
 typedef struct
 {
     unsigned short newState;
     unsigned char  symbol;
     unsigned char  nbBits;
 } FSE_decode_t;   /* size == U32 */
 
 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
 {
     const void* ptr = dt;
     const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
     DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
     BIT_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 MEM_STATIC BYTE FSE_peekSymbol(const FSE_DState_t* DStatePtr)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     return DInfo.symbol;
 }
 
 MEM_STATIC void FSE_updateState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     size_t const lowBits = BIT_readBits(bitD, nbBits);
     DStatePtr->state = DInfo.newState + lowBits;
 }
 
 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     BYTE const symbol = DInfo.symbol;
     size_t const lowBits = BIT_readBits(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 /*! FSE_decodeSymbolFast() :
     unsafe, only works if no symbol has a probability > 50% */
 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     BYTE const symbol = DInfo.symbol;
     size_t const lowBits = BIT_readBitsFast(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
 {
     return DStatePtr->state == 0;
 }
 
 
 
 #ifndef FSE_COMMONDEFS_ONLY
 
 /* **************************************************************
 *  Tuning parameters
 ****************************************************************/
 /*!MEMORY_USAGE :
 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect
 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
 #ifndef FSE_MAX_MEMORY_USAGE
 #  define FSE_MAX_MEMORY_USAGE 14
 #endif
 #ifndef FSE_DEFAULT_MEMORY_USAGE
 #  define FSE_DEFAULT_MEMORY_USAGE 13
 #endif
 
 /*!FSE_MAX_SYMBOL_VALUE :
 *  Maximum symbol value authorized.
 *  Required for proper stack allocation */
 #ifndef FSE_MAX_SYMBOL_VALUE
 #  define FSE_MAX_SYMBOL_VALUE 255
 #endif
 
 /* **************************************************************
 *  template functions type & suffix
 ****************************************************************/
 #define FSE_FUNCTION_TYPE BYTE
 #define FSE_FUNCTION_EXTENSION
 #define FSE_DECODE_TYPE FSE_decode_t
 
 
 #endif   /* !FSE_COMMONDEFS_ONLY */
 
 
 /* ***************************************************************
 *  Constants
 *****************************************************************/
 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
 #define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX
 #  error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
 #endif
 
 #define FSE_TABLESTEP(tableSize) ((tableSize>>1) + (tableSize>>3) + 3)
 
 
 #endif /* FSE_STATIC_LINKING_ONLY */
 
 
 #if defined (__cplusplus)
 }
 #endif
Index: vendor/zstd/dist/lib/common/fse_decompress.c
===================================================================
--- vendor/zstd/dist/lib/common/fse_decompress.c	(revision 339613)
+++ vendor/zstd/dist/lib/common/fse_decompress.c	(revision 339614)
@@ -1,309 +1,309 @@
 /* ******************************************************************
    FSE : Finite State Entropy decoder
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 
 /* **************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include "bitstream.h"
 #include "compiler.h"
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #include "error_private.h"
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_isError ERR_isError
-#define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
+#define FSE_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)   /* use only *after* variable declarations */
 
 /* check and forward error code */
 #define CHECK_F(f) { size_t const e = f; if (FSE_isError(e)) return e; }
 
 
 /* **************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 /* Function templates */
 FSE_DTable* FSE_createDTable (unsigned tableLog)
 {
     if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX;
     return (FSE_DTable*)malloc( FSE_DTABLE_SIZE_U32(tableLog) * sizeof (U32) );
 }
 
 void FSE_freeDTable (FSE_DTable* dt)
 {
     free(dt);
 }
 
 size_t FSE_buildDTable(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     void* const tdPtr = dt+1;   /* because *dt is unsigned, 32-bits aligned on 32-bits */
     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*) (tdPtr);
     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
 
     U32 const maxSV1 = maxSymbolValue + 1;
     U32 const tableSize = 1 << tableLog;
     U32 highThreshold = tableSize-1;
 
     /* Sanity Checks */
     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
 
     /* Init, lay down lowprob symbols */
     {   FSE_DTableHeader DTableH;
         DTableH.tableLog = (U16)tableLog;
         DTableH.fastMode = 1;
         {   S16 const largeLimit= (S16)(1 << (tableLog-1));
             U32 s;
             for (s=0; s= largeLimit) DTableH.fastMode=0;
                     symbolNext[s] = normalizedCounter[s];
         }   }   }
         memcpy(dt, &DTableH, sizeof(DTableH));
     }
 
     /* Spread symbols */
     {   U32 const tableMask = tableSize-1;
         U32 const step = FSE_TABLESTEP(tableSize);
         U32 s, position = 0;
         for (s=0; s highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }   }
         if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
     }
 
     /* Build Decoding table */
     {   U32 u;
         for (u=0; utableLog = 0;
     DTableH->fastMode = 0;
 
     cell->newState = 0;
     cell->symbol = symbolValue;
     cell->nbBits = 0;
 
     return 0;
 }
 
 
 size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     void* dPtr = dt + 1;
     FSE_decode_t* const dinfo = (FSE_decode_t*)dPtr;
     const unsigned tableSize = 1 << nbBits;
     const unsigned tableMask = tableSize - 1;
     const unsigned maxSV1 = tableMask+1;
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
 
     /* Build Decoding Table */
     DTableH->tableLog = (U16)nbBits;
     DTableH->fastMode = 1;
     for (s=0; s sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[1] = FSE_GETSYMBOL(&state2);
 
         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
 
         op[2] = FSE_GETSYMBOL(&state1);
 
         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[3] = FSE_GETSYMBOL(&state2);
     }
 
     /* tail */
     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
     while (1) {
         if (op>(omax-2)) return ERROR(dstSize_tooSmall);
         *op++ = FSE_GETSYMBOL(&state1);
         if (BIT_reloadDStream(&bitD)==BIT_DStream_overflow) {
             *op++ = FSE_GETSYMBOL(&state2);
             break;
         }
 
         if (op>(omax-2)) return ERROR(dstSize_tooSmall);
         *op++ = FSE_GETSYMBOL(&state2);
         if (BIT_reloadDStream(&bitD)==BIT_DStream_overflow) {
             *op++ = FSE_GETSYMBOL(&state1);
             break;
     }   }
 
     return op-ostart;
 }
 
 
 size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
                             const void* cSrc, size_t cSrcSize,
                             const FSE_DTable* dt)
 {
     const void* ptr = dt;
     const FSE_DTableHeader* DTableH = (const FSE_DTableHeader*)ptr;
     const U32 fastMode = DTableH->fastMode;
 
     /* select fast mode (static) */
     if (fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
 }
 
 
 size_t FSE_decompress_wksp(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, FSE_DTable* workSpace, unsigned maxLog)
 {
     const BYTE* const istart = (const BYTE*)cSrc;
     const BYTE* ip = istart;
     short counting[FSE_MAX_SYMBOL_VALUE+1];
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
 
     /* normal FSE decoding mode */
     size_t const NCountLength = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
     if (FSE_isError(NCountLength)) return NCountLength;
     //if (NCountLength >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size; supposed to be already checked in NCountLength, only remaining case : NCountLength==cSrcSize */
     if (tableLog > maxLog) return ERROR(tableLog_tooLarge);
     ip += NCountLength;
     cSrcSize -= NCountLength;
 
     CHECK_F( FSE_buildDTable (workSpace, counting, maxSymbolValue, tableLog) );
 
     return FSE_decompress_usingDTable (dst, dstCapacity, ip, cSrcSize, workSpace);   /* always return, even if it is an error code */
 }
 
 
 typedef FSE_DTable DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
 
 size_t FSE_decompress(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize)
 {
     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
     return FSE_decompress_wksp(dst, dstCapacity, cSrc, cSrcSize, dt, FSE_MAX_TABLELOG);
 }
 
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
Index: vendor/zstd/dist/lib/common/huf.h
===================================================================
--- vendor/zstd/dist/lib/common/huf.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/huf.h	(revision 339614)
@@ -1,327 +1,334 @@
 /* ******************************************************************
-   Huffman coder, part of New Generation Entropy library
-   header file
-   Copyright (C) 2013-2016, Yann Collet.
+   huff0 huffman codec,
+   part of Finite State Entropy library
+   Copyright (C) 2013-present, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 ****************************************************************** */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #ifndef HUF_H_298734234
 #define HUF_H_298734234
 
 /* *** Dependencies *** */
 #include     /* size_t */
 
 
 /* *** library symbols visibility *** */
 /* Note : when linking with -fvisibility=hidden on gcc, or by default on Visual,
  *        HUF symbols remain "private" (internal symbols for library only).
  *        Set macro FSE_DLL_EXPORT to 1 if you want HUF symbols visible on DLL interface */
 #if defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1) && defined(__GNUC__) && (__GNUC__ >= 4)
 #  define HUF_PUBLIC_API __attribute__ ((visibility ("default")))
 #elif defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1)   /* Visual expected */
 #  define HUF_PUBLIC_API __declspec(dllexport)
 #elif defined(FSE_DLL_IMPORT) && (FSE_DLL_IMPORT==1)
 #  define HUF_PUBLIC_API __declspec(dllimport)  /* not required, just to generate faster code (saves a function pointer load from IAT and an indirect jump) */
 #else
 #  define HUF_PUBLIC_API
 #endif
 
 
 /* ========================== */
 /* ***  simple functions  *** */
 /* ========================== */
 
 /** HUF_compress() :
  *  Compress content from buffer 'src', of size 'srcSize', into buffer 'dst'.
  * 'dst' buffer must be already allocated.
  *  Compression runs faster if `dstCapacity` >= HUF_compressBound(srcSize).
  * `srcSize` must be <= `HUF_BLOCKSIZE_MAX` == 128 KB.
  * @return : size of compressed data (<= `dstCapacity`).
  *  Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
  *                   if HUF_isError(return), compression failed (more details using HUF_getErrorName())
  */
 HUF_PUBLIC_API size_t HUF_compress(void* dst, size_t dstCapacity,
                              const void* src, size_t srcSize);
 
 /** HUF_decompress() :
  *  Decompress HUF data from buffer 'cSrc', of size 'cSrcSize',
  *  into already allocated buffer 'dst', of minimum size 'dstSize'.
  * `originalSize` : **must** be the ***exact*** size of original (uncompressed) data.
  *  Note : in contrast with FSE, HUF_decompress can regenerate
  *         RLE (cSrcSize==1) and uncompressed (cSrcSize==dstSize) data,
  *         because it knows size to regenerate (originalSize).
  * @return : size of regenerated data (== originalSize),
  *           or an error code, which can be tested using HUF_isError()
  */
 HUF_PUBLIC_API size_t HUF_decompress(void* dst,  size_t originalSize,
                                const void* cSrc, size_t cSrcSize);
 
 
 /* ***   Tool functions *** */
 #define HUF_BLOCKSIZE_MAX (128 * 1024)                  /**< maximum input size for a single block compressed with HUF_compress */
 HUF_PUBLIC_API size_t HUF_compressBound(size_t size);   /**< maximum compressed size (worst case) */
 
 /* Error Management */
 HUF_PUBLIC_API unsigned    HUF_isError(size_t code);       /**< tells if a return value is an error code */
 HUF_PUBLIC_API const char* HUF_getErrorName(size_t code);  /**< provides error code string (useful for debugging) */
 
 
 /* ***   Advanced function   *** */
 
 /** HUF_compress2() :
  *  Same as HUF_compress(), but offers control over `maxSymbolValue` and `tableLog`.
  * `maxSymbolValue` must be <= HUF_SYMBOLVALUE_MAX .
  * `tableLog` must be `<= HUF_TABLELOG_MAX` . */
 HUF_PUBLIC_API size_t HUF_compress2 (void* dst, size_t dstCapacity,
                                const void* src, size_t srcSize,
                                unsigned maxSymbolValue, unsigned tableLog);
 
 /** HUF_compress4X_wksp() :
  *  Same as HUF_compress2(), but uses externally allocated `workSpace`.
  * `workspace` must have minimum alignment of 4, and be at least as large as HUF_WORKSPACE_SIZE */
 #define HUF_WORKSPACE_SIZE (6 << 10)
 #define HUF_WORKSPACE_SIZE_U32 (HUF_WORKSPACE_SIZE / sizeof(U32))
 HUF_PUBLIC_API size_t HUF_compress4X_wksp (void* dst, size_t dstCapacity,
                                      const void* src, size_t srcSize,
                                      unsigned maxSymbolValue, unsigned tableLog,
                                      void* workSpace, size_t wkspSize);
 
 #endif   /* HUF_H_298734234 */
 
 /* ******************************************************************
  *  WARNING !!
  *  The following section contains advanced and experimental definitions
  *  which shall never be used in the context of a dynamic library,
  *  because they are not guaranteed to remain stable in the future.
  *  Only consider them in association with static linking.
  * *****************************************************************/
 #if defined(HUF_STATIC_LINKING_ONLY) && !defined(HUF_H_HUF_STATIC_LINKING_ONLY)
 #define HUF_H_HUF_STATIC_LINKING_ONLY
 
 /* *** Dependencies *** */
 #include "mem.h"   /* U32 */
 
 
 /* *** Constants *** */
 #define HUF_TABLELOG_MAX      12      /* max runtime value of tableLog (due to static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
 #define HUF_TABLELOG_DEFAULT  11      /* default tableLog value when none specified */
 #define HUF_SYMBOLVALUE_MAX  255
 
 #define HUF_TABLELOG_ABSOLUTEMAX  15  /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
 #if (HUF_TABLELOG_MAX > HUF_TABLELOG_ABSOLUTEMAX)
 #  error "HUF_TABLELOG_MAX is too large !"
 #endif
 
 
 /* ****************************************
 *  Static allocation
 ******************************************/
 /* HUF buffer bounds */
 #define HUF_CTABLEBOUND 129
 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true when incompressible is pre-filtered with fast heuristic */
 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* static allocation of HUF's Compression Table */
 #define HUF_CTABLE_SIZE_U32(maxSymbolValue)   ((maxSymbolValue)+1)   /* Use tables of U32, for proper alignment */
 #define HUF_CTABLE_SIZE(maxSymbolValue)       (HUF_CTABLE_SIZE_U32(maxSymbolValue) * sizeof(U32))
 #define HUF_CREATE_STATIC_CTABLE(name, maxSymbolValue) \
     U32 name##hb[HUF_CTABLE_SIZE_U32(maxSymbolValue)]; \
     void* name##hv = &(name##hb); \
     HUF_CElt* name = (HUF_CElt*)(name##hv)   /* no final ; */
 
 /* static allocation of HUF's DTable */
 typedef U32 HUF_DTable;
 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<(maxTableLog)))
-#define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
+#define HUF_CREATE_STATIC_DTABLEX1(DTable, maxTableLog) \
         HUF_DTable DTable[HUF_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1) * 0x01000001) }
-#define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
+#define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
         HUF_DTable DTable[HUF_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog) * 0x01000001) }
 
 
 /* ****************************************
 *  Advanced decompression functions
 ******************************************/
-size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
-size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
+size_t HUF_decompress4X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
+size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
 
 size_t HUF_decompress4X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< decodes RLE and uncompressed */
 size_t HUF_decompress4X_hufOnly(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize); /**< considers RLE and uncompressed as errors */
 size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize); /**< considers RLE and uncompressed as errors */
-size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
-size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< single-symbol decoder */
-size_t HUF_decompress4X4_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
-size_t HUF_decompress4X4_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< double-symbols decoder */
+size_t HUF_decompress4X1_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
+size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< single-symbol decoder */
+size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
+size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< double-symbols decoder */
 
 
 /* ****************************************
  *  HUF detailed API
  * ****************************************/
 
 /*! HUF_compress() does the following:
  *  1. count symbol occurrence from source[] into table count[] using FSE_count() (exposed within "fse.h")
  *  2. (optional) refine tableLog using HUF_optimalTableLog()
  *  3. build Huffman table from count using HUF_buildCTable()
  *  4. save Huffman table to memory buffer using HUF_writeCTable()
  *  5. encode the data stream using HUF_compress4X_usingCTable()
  *
  *  The following API allows targeting specific sub-functions for advanced tasks.
  *  For example, it's possible to compress several blocks using the same 'CTable',
  *  or to save and regenerate 'CTable' using external methods.
  */
 unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);
 typedef struct HUF_CElt_s HUF_CElt;   /* incomplete type */
 size_t HUF_buildCTable (HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue, unsigned maxNbBits);   /* @return : maxNbBits; CTable and count can overlap. In which case, CTable will overwrite count content */
 size_t HUF_writeCTable (void* dst, size_t maxDstSize, const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog);
 size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
 
 typedef enum {
    HUF_repeat_none,  /**< Cannot use the previous table */
    HUF_repeat_check, /**< Can use the previous table but it must be checked. Note : The previous table must have been constructed by HUF_compress{1, 4}X_repeat */
-   HUF_repeat_valid  /**< Can use the previous table and it is asumed to be valid */
+   HUF_repeat_valid  /**< Can use the previous table and it is assumed to be valid */
  } HUF_repeat;
 /** HUF_compress4X_repeat() :
  *  Same as HUF_compress4X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
  *  If it uses hufTable it does not modify hufTable or repeat.
  *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
  *  If preferRepeat then the old table will always be used if valid. */
 size_t HUF_compress4X_repeat(void* dst, size_t dstSize,
                        const void* src, size_t srcSize,
                        unsigned maxSymbolValue, unsigned tableLog,
                        void* workSpace, size_t wkspSize,    /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
                        HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2);
 
 /** HUF_buildCTable_wksp() :
  *  Same as HUF_buildCTable(), but using externally allocated scratch buffer.
  * `workSpace` must be aligned on 4-bytes boundaries, and its size must be >= HUF_CTABLE_WORKSPACE_SIZE.
  */
 #define HUF_CTABLE_WORKSPACE_SIZE_U32 (2*HUF_SYMBOLVALUE_MAX +1 +1)
 #define HUF_CTABLE_WORKSPACE_SIZE (HUF_CTABLE_WORKSPACE_SIZE_U32 * sizeof(unsigned))
-size_t HUF_buildCTable_wksp (HUF_CElt* tree, const U32* count, U32 maxSymbolValue, U32 maxNbBits, void* workSpace, size_t wkspSize);
+size_t HUF_buildCTable_wksp (HUF_CElt* tree,
+                       const U32* count, U32 maxSymbolValue, U32 maxNbBits,
+                             void* workSpace, size_t wkspSize);
 
 /*! HUF_readStats() :
  *  Read compact Huffman tree, saved by HUF_writeCTable().
  * `huffWeight` is destination buffer.
  * @return : size read from `src` , or an error Code .
  *  Note : Needed by HUF_readCTable() and HUF_readDTableXn() . */
 size_t HUF_readStats(BYTE* huffWeight, size_t hwSize,
                      U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr,
                      const void* src, size_t srcSize);
 
 /** HUF_readCTable() :
  *  Loading a CTable saved with HUF_writeCTable() */
 size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
 
+/** HUF_getNbBits() :
+ *  Read nbBits from CTable symbolTable, for symbol `symbolValue` presumed <= HUF_SYMBOLVALUE_MAX
+ *  Note 1 : is not inlined, as HUF_CElt definition is private
+ *  Note 2 : const void* used, so that it can provide a statically allocated table as argument (which uses type U32) */
+U32 HUF_getNbBits(const void* symbolTable, U32 symbolValue);
 
 /*
  * HUF_decompress() does the following:
- * 1. select the decompression algorithm (X2, X4) based on pre-computed heuristics
+ * 1. select the decompression algorithm (X1, X2) based on pre-computed heuristics
  * 2. build Huffman table from save, using HUF_readDTableX?()
  * 3. decode 1 or 4 segments in parallel using HUF_decompress?X?_usingDTable()
  */
 
 /** HUF_selectDecoder() :
  *  Tells which decoder is likely to decode faster,
  *  based on a set of pre-computed metrics.
- * @return : 0==HUF_decompress4X2, 1==HUF_decompress4X4 .
+ * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
  *  Assumption : 0 < dstSize <= 128 KB */
 U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize);
 
 /**
  *  The minimum workspace size for the `workSpace` used in
- *  HUF_readDTableX2_wksp() and HUF_readDTableX4_wksp().
+ *  HUF_readDTableX1_wksp() and HUF_readDTableX2_wksp().
  *
  *  The space used depends on HUF_TABLELOG_MAX, ranging from ~1500 bytes when
  *  HUF_TABLE_LOG_MAX=12 to ~1850 bytes when HUF_TABLE_LOG_MAX=15.
  *  Buffer overflow errors may potentially occur if code modifications result in
  *  a required workspace size greater than that specified in the following
  *  macro.
  */
 #define HUF_DECOMPRESS_WORKSPACE_SIZE (2 << 10)
 #define HUF_DECOMPRESS_WORKSPACE_SIZE_U32 (HUF_DECOMPRESS_WORKSPACE_SIZE / sizeof(U32))
 
+size_t HUF_readDTableX1 (HUF_DTable* DTable, const void* src, size_t srcSize);
+size_t HUF_readDTableX1_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
 size_t HUF_readDTableX2 (HUF_DTable* DTable, const void* src, size_t srcSize);
 size_t HUF_readDTableX2_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
-size_t HUF_readDTableX4 (HUF_DTable* DTable, const void* src, size_t srcSize);
-size_t HUF_readDTableX4_wksp (HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize);
 
 size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
+size_t HUF_decompress4X1_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
 size_t HUF_decompress4X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
-size_t HUF_decompress4X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
 
 
 /* ====================== */
 /* single stream variants */
 /* ====================== */
 
 size_t HUF_compress1X (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
 size_t HUF_compress1X_wksp (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize);  /**< `workSpace` must be a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */
 size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable);
 /** HUF_compress1X_repeat() :
  *  Same as HUF_compress1X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
  *  If it uses hufTable it does not modify hufTable or repeat.
  *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
  *  If preferRepeat then the old table will always be used if valid. */
 size_t HUF_compress1X_repeat(void* dst, size_t dstSize,
                        const void* src, size_t srcSize,
                        unsigned maxSymbolValue, unsigned tableLog,
                        void* workSpace, size_t wkspSize,   /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
                        HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2);
 
-size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
-size_t HUF_decompress1X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbol decoder */
+size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* single-symbol decoder */
+size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /* double-symbol decoder */
 
 size_t HUF_decompress1X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
 size_t HUF_decompress1X_DCtx_wksp (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);
-size_t HUF_decompress1X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
-size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< single-symbol decoder */
-size_t HUF_decompress1X4_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
-size_t HUF_decompress1X4_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< double-symbols decoder */
+size_t HUF_decompress1X1_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< single-symbol decoder */
+size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< single-symbol decoder */
+size_t HUF_decompress1X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< double-symbols decoder */
+size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize);   /**< double-symbols decoder */
 
 size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);   /**< automatic selection of sing or double symbol decoder, based on DTable */
+size_t HUF_decompress1X1_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
 size_t HUF_decompress1X2_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
-size_t HUF_decompress1X4_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable);
 
 /* BMI2 variants.
  * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0.
  */
 size_t HUF_decompress1X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2);
-size_t HUF_decompress1X2_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2);
+size_t HUF_decompress1X1_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2);
 size_t HUF_decompress4X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2);
 size_t HUF_decompress4X_hufOnly_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2);
 
 #endif /* HUF_STATIC_LINKING_ONLY */
 
 #if defined (__cplusplus)
 }
 #endif
Index: vendor/zstd/dist/lib/common/mem.h
===================================================================
--- vendor/zstd/dist/lib/common/mem.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/mem.h	(revision 339614)
@@ -1,362 +1,380 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef MEM_H_MODULE
 #define MEM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /*-****************************************
 *  Dependencies
 ******************************************/
 #include      /* size_t, ptrdiff_t */
 #include      /* memcpy */
 
 
 /*-****************************************
 *  Compiler specifics
 ******************************************/
 #if defined(_MSC_VER)   /* Visual Studio */
 #   include   /* _byteswap_ulong */
 #   include   /* _byteswap_* */
 #endif
 #if defined(__GNUC__)
 #  define MEM_STATIC static __inline __attribute__((unused))
 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 #  define MEM_STATIC static inline
 #elif defined(_MSC_VER)
 #  define MEM_STATIC static __inline
 #else
 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
 #endif
 
+#ifndef __has_builtin
+#  define __has_builtin(x) 0  /* compat. with non-clang compilers */
+#endif
+
 /* code only tested on 32 and 64 bits systems */
 #define MEM_STATIC_ASSERT(c)   { enum { MEM_static_assert = 1/(int)(!!(c)) }; }
 MEM_STATIC void MEM_check(void) { MEM_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); }
 
 
 /*-**************************************************************
 *  Basic Types
 *****************************************************************/
 #if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
 # include 
   typedef   uint8_t BYTE;
   typedef  uint16_t U16;
   typedef   int16_t S16;
   typedef  uint32_t U32;
   typedef   int32_t S32;
   typedef  uint64_t U64;
   typedef   int64_t S64;
 #else
+# include 
+#if CHAR_BIT != 8
+#  error "this implementation requires char to be exactly 8-bit type"
+#endif
   typedef unsigned char      BYTE;
+#if USHRT_MAX != 65535
+#  error "this implementation requires short to be exactly 16-bit type"
+#endif
   typedef unsigned short      U16;
   typedef   signed short      S16;
+#if UINT_MAX != 4294967295
+#  error "this implementation requires int to be exactly 32-bit type"
+#endif
   typedef unsigned int        U32;
   typedef   signed int        S32;
+/* note : there are no limits defined for long long type in C90.
+ * limits exist in C99, however, in such case,  is preferred */
   typedef unsigned long long  U64;
   typedef   signed long long  S64;
 #endif
 
 
 /*-**************************************************************
 *  Memory I/O
 *****************************************************************/
 /* MEM_FORCE_MEMORY_ACCESS :
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
  *            It can generate buggy code on targets depending on alignment.
  *            In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6)
  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define MEM_FORCE_MEMORY_ACCESS 2
 #  elif defined(__INTEL_COMPILER) || defined(__GNUC__)
 #    define MEM_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }
 
 MEM_STATIC unsigned MEM_isLittleEndian(void)
 {
     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
     return one.c[0];
 }
 
 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
 
 /* violates C standard, by lying on structure alignment.
 Only use if no other choice to achieve best performance on target platform */
 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
 MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; }
 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; }
 
 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 #if defined(_MSC_VER) || (defined(__INTEL_COMPILER) && defined(WIN32))
     __pragma( pack(push, 1) )
     typedef struct { U16 v; } unalign16;
     typedef struct { U32 v; } unalign32;
     typedef struct { U64 v; } unalign64;
     typedef struct { size_t v; } unalignArch;
     __pragma( pack(pop) )
 #else
     typedef struct { U16 v; } __attribute__((packed)) unalign16;
     typedef struct { U32 v; } __attribute__((packed)) unalign32;
     typedef struct { U64 v; } __attribute__((packed)) unalign64;
     typedef struct { size_t v; } __attribute__((packed)) unalignArch;
 #endif
 
 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign16*)ptr)->v; }
 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign32*)ptr)->v; }
 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign64*)ptr)->v; }
 MEM_STATIC size_t MEM_readST(const void* ptr) { return ((const unalignArch*)ptr)->v; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign16*)memPtr)->v = value; }
 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign32*)memPtr)->v = value; }
 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign64*)memPtr)->v = value; }
 
 #else
 
 /* default method, safe and standard.
    can sometimes prove slower */
 
 MEM_STATIC U16 MEM_read16(const void* memPtr)
 {
     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U32 MEM_read32(const void* memPtr)
 {
     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U64 MEM_read64(const void* memPtr)
 {
     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC size_t MEM_readST(const void* memPtr)
 {
     size_t val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 MEM_STATIC void MEM_write32(void* memPtr, U32 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 MEM_STATIC void MEM_write64(void* memPtr, U64 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 #endif /* MEM_FORCE_MEMORY_ACCESS */
 
 MEM_STATIC U32 MEM_swap32(U32 in)
 {
 #if defined(_MSC_VER)     /* Visual Studio */
     return _byteswap_ulong(in);
-#elif defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)
+#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
+  || (defined(__clang__) && __has_builtin(__builtin_bswap32))
     return __builtin_bswap32(in);
 #else
     return  ((in << 24) & 0xff000000 ) |
             ((in <<  8) & 0x00ff0000 ) |
             ((in >>  8) & 0x0000ff00 ) |
             ((in >> 24) & 0x000000ff );
 #endif
 }
 
 MEM_STATIC U64 MEM_swap64(U64 in)
 {
 #if defined(_MSC_VER)     /* Visual Studio */
     return _byteswap_uint64(in);
-#elif defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)
+#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
+  || (defined(__clang__) && __has_builtin(__builtin_bswap64))
     return __builtin_bswap64(in);
 #else
     return  ((in << 56) & 0xff00000000000000ULL) |
             ((in << 40) & 0x00ff000000000000ULL) |
             ((in << 24) & 0x0000ff0000000000ULL) |
             ((in << 8)  & 0x000000ff00000000ULL) |
             ((in >> 8)  & 0x00000000ff000000ULL) |
             ((in >> 24) & 0x0000000000ff0000ULL) |
             ((in >> 40) & 0x000000000000ff00ULL) |
             ((in >> 56) & 0x00000000000000ffULL);
 #endif
 }
 
 MEM_STATIC size_t MEM_swapST(size_t in)
 {
     if (MEM_32bits())
         return (size_t)MEM_swap32((U32)in);
     else
         return (size_t)MEM_swap64((U64)in);
 }
 
 /*=== Little endian r/w ===*/
 
 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read16(memPtr);
     else {
         const BYTE* p = (const BYTE*)memPtr;
         return (U16)(p[0] + (p[1]<<8));
     }
 }
 
 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
 {
     if (MEM_isLittleEndian()) {
         MEM_write16(memPtr, val);
     } else {
         BYTE* p = (BYTE*)memPtr;
         p[0] = (BYTE)val;
         p[1] = (BYTE)(val>>8);
     }
 }
 
 MEM_STATIC U32 MEM_readLE24(const void* memPtr)
 {
     return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
 }
 
 MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val)
 {
     MEM_writeLE16(memPtr, (U16)val);
     ((BYTE*)memPtr)[2] = (BYTE)(val>>16);
 }
 
 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read32(memPtr);
     else
         return MEM_swap32(MEM_read32(memPtr));
 }
 
 MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32)
 {
     if (MEM_isLittleEndian())
         MEM_write32(memPtr, val32);
     else
         MEM_write32(memPtr, MEM_swap32(val32));
 }
 
 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read64(memPtr);
     else
         return MEM_swap64(MEM_read64(memPtr));
 }
 
 MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64)
 {
     if (MEM_isLittleEndian())
         MEM_write64(memPtr, val64);
     else
         MEM_write64(memPtr, MEM_swap64(val64));
 }
 
 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
 {
     if (MEM_32bits())
         return (size_t)MEM_readLE32(memPtr);
     else
         return (size_t)MEM_readLE64(memPtr);
 }
 
 MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val)
 {
     if (MEM_32bits())
         MEM_writeLE32(memPtr, (U32)val);
     else
         MEM_writeLE64(memPtr, (U64)val);
 }
 
 /*=== Big endian r/w ===*/
 
 MEM_STATIC U32 MEM_readBE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_swap32(MEM_read32(memPtr));
     else
         return MEM_read32(memPtr);
 }
 
 MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32)
 {
     if (MEM_isLittleEndian())
         MEM_write32(memPtr, MEM_swap32(val32));
     else
         MEM_write32(memPtr, val32);
 }
 
 MEM_STATIC U64 MEM_readBE64(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_swap64(MEM_read64(memPtr));
     else
         return MEM_read64(memPtr);
 }
 
 MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64)
 {
     if (MEM_isLittleEndian())
         MEM_write64(memPtr, MEM_swap64(val64));
     else
         MEM_write64(memPtr, val64);
 }
 
 MEM_STATIC size_t MEM_readBEST(const void* memPtr)
 {
     if (MEM_32bits())
         return (size_t)MEM_readBE32(memPtr);
     else
         return (size_t)MEM_readBE64(memPtr);
 }
 
 MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val)
 {
     if (MEM_32bits())
         MEM_writeBE32(memPtr, (U32)val);
     else
         MEM_writeBE64(memPtr, (U64)val);
 }
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* MEM_H_MODULE */
Index: vendor/zstd/dist/lib/common/pool.c
===================================================================
--- vendor/zstd/dist/lib/common/pool.c	(revision 339613)
+++ vendor/zstd/dist/lib/common/pool.c	(revision 339614)
@@ -1,283 +1,340 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /* ======   Dependencies   ======= */
-#include   /* size_t */
-#include "pool.h"
+#include     /* size_t */
+#include "debug.h"     /* assert */
 #include "zstd_internal.h"  /* ZSTD_malloc, ZSTD_free */
+#include "pool.h"
 
 /* ======   Compiler specifics   ====== */
 #if defined(_MSC_VER)
 #  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
 #endif
 
 
 #ifdef ZSTD_MULTITHREAD
 
 #include "threading.h"   /* pthread adaptation */
 
 /* A job is a function and an opaque argument */
 typedef struct POOL_job_s {
     POOL_function function;
     void *opaque;
 } POOL_job;
 
 struct POOL_ctx_s {
     ZSTD_customMem customMem;
     /* Keep track of the threads */
-    ZSTD_pthread_t *threads;
-    size_t numThreads;
+    ZSTD_pthread_t* threads;
+    size_t threadCapacity;
+    size_t threadLimit;
 
     /* The queue is a circular buffer */
     POOL_job *queue;
     size_t queueHead;
     size_t queueTail;
     size_t queueSize;
 
     /* The number of threads working on jobs */
     size_t numThreadsBusy;
     /* Indicates if the queue is empty */
     int queueEmpty;
 
     /* The mutex protects the queue */
     ZSTD_pthread_mutex_t queueMutex;
     /* Condition variable for pushers to wait on when the queue is full */
     ZSTD_pthread_cond_t queuePushCond;
     /* Condition variables for poppers to wait on when the queue is empty */
     ZSTD_pthread_cond_t queuePopCond;
     /* Indicates if the queue is shutting down */
     int shutdown;
 };
 
 /* POOL_thread() :
-   Work thread for the thread pool.
-   Waits for jobs and executes them.
-   @returns : NULL on failure else non-null.
-*/
+ * Work thread for the thread pool.
+ * Waits for jobs and executes them.
+ * @returns : NULL on failure else non-null.
+ */
 static void* POOL_thread(void* opaque) {
     POOL_ctx* const ctx = (POOL_ctx*)opaque;
     if (!ctx) { return NULL; }
     for (;;) {
         /* Lock the mutex and wait for a non-empty queue or until shutdown */
         ZSTD_pthread_mutex_lock(&ctx->queueMutex);
 
-        while (ctx->queueEmpty && !ctx->shutdown) {
+        while ( ctx->queueEmpty
+            || (ctx->numThreadsBusy >= ctx->threadLimit) ) {
+            if (ctx->shutdown) {
+                /* even if !queueEmpty, (possible if numThreadsBusy >= threadLimit),
+                 * a few threads will be shutdown while !queueEmpty,
+                 * but enough threads will remain active to finish the queue */
+                ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
+                return opaque;
+            }
             ZSTD_pthread_cond_wait(&ctx->queuePopCond, &ctx->queueMutex);
         }
-        /* empty => shutting down: so stop */
-        if (ctx->queueEmpty) {
-            ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
-            return opaque;
-        }
         /* Pop a job off the queue */
         {   POOL_job const job = ctx->queue[ctx->queueHead];
             ctx->queueHead = (ctx->queueHead + 1) % ctx->queueSize;
             ctx->numThreadsBusy++;
             ctx->queueEmpty = ctx->queueHead == ctx->queueTail;
             /* Unlock the mutex, signal a pusher, and run the job */
             ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
             ZSTD_pthread_cond_signal(&ctx->queuePushCond);
 
             job.function(job.opaque);
 
             /* If the intended queue size was 0, signal after finishing job */
+            ZSTD_pthread_mutex_lock(&ctx->queueMutex);
+            ctx->numThreadsBusy--;
             if (ctx->queueSize == 1) {
-                ZSTD_pthread_mutex_lock(&ctx->queueMutex);
-                ctx->numThreadsBusy--;
-                ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
                 ZSTD_pthread_cond_signal(&ctx->queuePushCond);
-        }   }
+            }
+            ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
+        }
     }  /* for (;;) */
-    /* Unreachable */
+    assert(0);  /* Unreachable */
 }
 
 POOL_ctx* POOL_create(size_t numThreads, size_t queueSize) {
     return POOL_create_advanced(numThreads, queueSize, ZSTD_defaultCMem);
 }
 
-POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize, ZSTD_customMem customMem) {
+POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize,
+                               ZSTD_customMem customMem) {
     POOL_ctx* ctx;
-    /* Check the parameters */
+    /* Check parameters */
     if (!numThreads) { return NULL; }
     /* Allocate the context and zero initialize */
     ctx = (POOL_ctx*)ZSTD_calloc(sizeof(POOL_ctx), customMem);
     if (!ctx) { return NULL; }
     /* Initialize the job queue.
-     * It needs one extra space since one space is wasted to differentiate empty
-     * and full queues.
+     * It needs one extra space since one space is wasted to differentiate
+     * empty and full queues.
      */
     ctx->queueSize = queueSize + 1;
     ctx->queue = (POOL_job*)ZSTD_malloc(ctx->queueSize * sizeof(POOL_job), customMem);
     ctx->queueHead = 0;
     ctx->queueTail = 0;
     ctx->numThreadsBusy = 0;
     ctx->queueEmpty = 1;
     (void)ZSTD_pthread_mutex_init(&ctx->queueMutex, NULL);
     (void)ZSTD_pthread_cond_init(&ctx->queuePushCond, NULL);
     (void)ZSTD_pthread_cond_init(&ctx->queuePopCond, NULL);
     ctx->shutdown = 0;
     /* Allocate space for the thread handles */
     ctx->threads = (ZSTD_pthread_t*)ZSTD_malloc(numThreads * sizeof(ZSTD_pthread_t), customMem);
-    ctx->numThreads = 0;
+    ctx->threadCapacity = 0;
     ctx->customMem = customMem;
     /* Check for errors */
     if (!ctx->threads || !ctx->queue) { POOL_free(ctx); return NULL; }
     /* Initialize the threads */
     {   size_t i;
         for (i = 0; i < numThreads; ++i) {
             if (ZSTD_pthread_create(&ctx->threads[i], NULL, &POOL_thread, ctx)) {
-                ctx->numThreads = i;
+                ctx->threadCapacity = i;
                 POOL_free(ctx);
                 return NULL;
         }   }
-        ctx->numThreads = numThreads;
+        ctx->threadCapacity = numThreads;
+        ctx->threadLimit = numThreads;
     }
     return ctx;
 }
 
 /*! POOL_join() :
     Shutdown the queue, wake any sleeping threads, and join all of the threads.
 */
 static void POOL_join(POOL_ctx* ctx) {
     /* Shut down the queue */
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     ctx->shutdown = 1;
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
     /* Wake up sleeping threads */
     ZSTD_pthread_cond_broadcast(&ctx->queuePushCond);
     ZSTD_pthread_cond_broadcast(&ctx->queuePopCond);
     /* Join all of the threads */
     {   size_t i;
-        for (i = 0; i < ctx->numThreads; ++i) {
-            ZSTD_pthread_join(ctx->threads[i], NULL);
+        for (i = 0; i < ctx->threadCapacity; ++i) {
+            ZSTD_pthread_join(ctx->threads[i], NULL);  /* note : could fail */
     }   }
 }
 
 void POOL_free(POOL_ctx *ctx) {
     if (!ctx) { return; }
     POOL_join(ctx);
     ZSTD_pthread_mutex_destroy(&ctx->queueMutex);
     ZSTD_pthread_cond_destroy(&ctx->queuePushCond);
     ZSTD_pthread_cond_destroy(&ctx->queuePopCond);
     ZSTD_free(ctx->queue, ctx->customMem);
     ZSTD_free(ctx->threads, ctx->customMem);
     ZSTD_free(ctx, ctx->customMem);
 }
 
+
+
 size_t POOL_sizeof(POOL_ctx *ctx) {
     if (ctx==NULL) return 0;  /* supports sizeof NULL */
     return sizeof(*ctx)
         + ctx->queueSize * sizeof(POOL_job)
-        + ctx->numThreads * sizeof(ZSTD_pthread_t);
+        + ctx->threadCapacity * sizeof(ZSTD_pthread_t);
 }
 
+
+/* @return : 0 on success, 1 on error */
+static int POOL_resize_internal(POOL_ctx* ctx, size_t numThreads)
+{
+    if (numThreads <= ctx->threadCapacity) {
+        if (!numThreads) return 1;
+        ctx->threadLimit = numThreads;
+        return 0;
+    }
+    /* numThreads > threadCapacity */
+    {   ZSTD_pthread_t* const threadPool = (ZSTD_pthread_t*)ZSTD_malloc(numThreads * sizeof(ZSTD_pthread_t), ctx->customMem);
+        if (!threadPool) return 1;
+        /* replace existing thread pool */
+        memcpy(threadPool, ctx->threads, ctx->threadCapacity * sizeof(*threadPool));
+        ZSTD_free(ctx->threads, ctx->customMem);
+        ctx->threads = threadPool;
+        /* Initialize additional threads */
+        {   size_t threadId;
+            for (threadId = ctx->threadCapacity; threadId < numThreads; ++threadId) {
+                if (ZSTD_pthread_create(&threadPool[threadId], NULL, &POOL_thread, ctx)) {
+                    ctx->threadCapacity = threadId;
+                    return 1;
+            }   }
+    }   }
+    /* successfully expanded */
+    ctx->threadCapacity = numThreads;
+    ctx->threadLimit = numThreads;
+    return 0;
+}
+
+/* @return : 0 on success, 1 on error */
+int POOL_resize(POOL_ctx* ctx, size_t numThreads)
+{
+    int result;
+    if (ctx==NULL) return 1;
+    ZSTD_pthread_mutex_lock(&ctx->queueMutex);
+    result = POOL_resize_internal(ctx, numThreads);
+    ZSTD_pthread_cond_broadcast(&ctx->queuePopCond);
+    ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
+    return result;
+}
+
 /**
  * Returns 1 if the queue is full and 0 otherwise.
  *
- * If the queueSize is 1 (the pool was created with an intended queueSize of 0),
- * then a queue is empty if there is a thread free and no job is waiting.
+ * When queueSize is 1 (pool was created with an intended queueSize of 0),
+ * then a queue is empty if there is a thread free _and_ no job is waiting.
  */
 static int isQueueFull(POOL_ctx const* ctx) {
     if (ctx->queueSize > 1) {
         return ctx->queueHead == ((ctx->queueTail + 1) % ctx->queueSize);
     } else {
-        return ctx->numThreadsBusy == ctx->numThreads ||
+        return (ctx->numThreadsBusy == ctx->threadLimit) ||
                !ctx->queueEmpty;
     }
 }
 
 
 static void POOL_add_internal(POOL_ctx* ctx, POOL_function function, void *opaque)
 {
     POOL_job const job = {function, opaque};
     assert(ctx != NULL);
     if (ctx->shutdown) return;
 
     ctx->queueEmpty = 0;
     ctx->queue[ctx->queueTail] = job;
     ctx->queueTail = (ctx->queueTail + 1) % ctx->queueSize;
     ZSTD_pthread_cond_signal(&ctx->queuePopCond);
 }
 
 void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque)
 {
     assert(ctx != NULL);
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     /* Wait until there is space in the queue for the new job */
     while (isQueueFull(ctx) && (!ctx->shutdown)) {
         ZSTD_pthread_cond_wait(&ctx->queuePushCond, &ctx->queueMutex);
     }
     POOL_add_internal(ctx, function, opaque);
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
 }
 
 
 int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque)
 {
     assert(ctx != NULL);
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     if (isQueueFull(ctx)) {
         ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
         return 0;
     }
     POOL_add_internal(ctx, function, opaque);
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
     return 1;
 }
 
 
 #else  /* ZSTD_MULTITHREAD  not defined */
 
 /* ========================== */
 /* No multi-threading support */
 /* ========================== */
 
 
 /* We don't need any data, but if it is empty, malloc() might return NULL. */
 struct POOL_ctx_s {
     int dummy;
 };
 static POOL_ctx g_ctx;
 
 POOL_ctx* POOL_create(size_t numThreads, size_t queueSize) {
     return POOL_create_advanced(numThreads, queueSize, ZSTD_defaultCMem);
 }
 
 POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize, ZSTD_customMem customMem) {
     (void)numThreads;
     (void)queueSize;
     (void)customMem;
     return &g_ctx;
 }
 
 void POOL_free(POOL_ctx* ctx) {
     assert(!ctx || ctx == &g_ctx);
     (void)ctx;
+}
+
+int POOL_resize(POOL_ctx* ctx, size_t numThreads) {
+    (void)ctx; (void)numThreads;
+    return 0;
 }
 
 void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque) {
     (void)ctx;
     function(opaque);
 }
 
 int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque) {
     (void)ctx;
     function(opaque);
     return 1;
 }
 
 size_t POOL_sizeof(POOL_ctx* ctx) {
     if (ctx==NULL) return 0;  /* supports sizeof NULL */
     assert(ctx == &g_ctx);
     return sizeof(*ctx);
 }
 
 #endif  /* ZSTD_MULTITHREAD */
Index: vendor/zstd/dist/lib/common/pool.h
===================================================================
--- vendor/zstd/dist/lib/common/pool.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/pool.h	(revision 339614)
@@ -1,74 +1,84 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef POOL_H
 #define POOL_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 #include    /* size_t */
 #define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_customMem */
 #include "zstd.h"
 
 typedef struct POOL_ctx_s POOL_ctx;
 
 /*! POOL_create() :
  *  Create a thread pool with at most `numThreads` threads.
  * `numThreads` must be at least 1.
  *  The maximum number of queued jobs before blocking is `queueSize`.
  * @return : POOL_ctx pointer on success, else NULL.
 */
 POOL_ctx* POOL_create(size_t numThreads, size_t queueSize);
 
-POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize, ZSTD_customMem customMem);
+POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize,
+                               ZSTD_customMem customMem);
 
 /*! POOL_free() :
-    Free a thread pool returned by POOL_create().
-*/
+ *  Free a thread pool returned by POOL_create().
+ */
 void POOL_free(POOL_ctx* ctx);
 
+/*! POOL_resize() :
+ *  Expands or shrinks pool's number of threads.
+ *  This is more efficient than releasing + creating a new context,
+ *  since it tries to preserve and re-use existing threads.
+ * `numThreads` must be at least 1.
+ * @return : 0 when resize was successful,
+ *           !0 (typically 1) if there is an error.
+ *    note : only numThreads can be resized, queueSize remains unchanged.
+ */
+int POOL_resize(POOL_ctx* ctx, size_t numThreads);
+
 /*! POOL_sizeof() :
-    return memory usage of pool returned by POOL_create().
-*/
+ * @return threadpool memory usage
+ *  note : compatible with NULL (returns 0 in this case)
+ */
 size_t POOL_sizeof(POOL_ctx* ctx);
 
 /*! POOL_function :
-    The function type that can be added to a thread pool.
-*/
+ *  The function type that can be added to a thread pool.
+ */
 typedef void (*POOL_function)(void*);
-/*! POOL_add_function :
-    The function type for a generic thread pool add function.
-*/
-typedef void (*POOL_add_function)(void*, POOL_function, void*);
 
 /*! POOL_add() :
-    Add the job `function(opaque)` to the thread pool. `ctx` must be valid.
-    Possibly blocks until there is room in the queue.
-    Note : The function may be executed asynchronously, so `opaque` must live until the function has been completed.
-*/
+ *  Add the job `function(opaque)` to the thread pool. `ctx` must be valid.
+ *  Possibly blocks until there is room in the queue.
+ *  Note : The function may be executed asynchronously,
+ *         therefore, `opaque` must live until function has been completed.
+ */
 void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque);
 
 
 /*! POOL_tryAdd() :
-    Add the job `function(opaque)` to the thread pool if a worker is available.
-    return immediately otherwise.
-   @return : 1 if successful, 0 if not.
-*/
+ *  Add the job `function(opaque)` to thread pool _if_ a worker is available.
+ *  Returns immediately even if not (does not block).
+ * @return : 1 if successful, 0 if not.
+ */
 int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque);
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif
Index: vendor/zstd/dist/lib/common/xxhash.c
===================================================================
--- vendor/zstd/dist/lib/common/xxhash.c	(revision 339613)
+++ vendor/zstd/dist/lib/common/xxhash.c	(revision 339614)
@@ -1,875 +1,876 @@
 /*
 *  xxHash - Fast Hash algorithm
 *  Copyright (C) 2012-2016, Yann Collet
 *
 *  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *  * Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following disclaimer
 *  in the documentation and/or other materials provided with the
 *  distribution.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You can contact the author at :
 *  - xxHash homepage: http://www.xxhash.com
 *  - xxHash source repository : https://github.com/Cyan4973/xxHash
 */
 
 
 /* *************************************
 *  Tuning parameters
 ***************************************/
 /*!XXH_FORCE_MEMORY_ACCESS :
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
  *            It can generate buggy code on targets which do not support unaligned memory accesses.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See http://stackoverflow.com/a/32095106/646947 for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define XXH_FORCE_MEMORY_ACCESS 2
 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
 #    define XXH_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 /*!XXH_ACCEPT_NULL_INPUT_POINTER :
  * If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer.
  * When this option is enabled, xxHash output for null input pointers will be the same as a null-length input.
  * By default, this option is disabled. To enable it, uncomment below define :
  */
 /* #define XXH_ACCEPT_NULL_INPUT_POINTER 1 */
 
 /*!XXH_FORCE_NATIVE_FORMAT :
  * By default, xxHash library provides endian-independant Hash values, based on little-endian convention.
  * Results are therefore identical for little-endian and big-endian CPU.
  * This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.
  * Should endian-independance be of no importance for your application, you may set the #define below to 1,
  * to improve speed for Big-endian CPU.
  * This option has no impact on Little_Endian CPU.
  */
 #ifndef XXH_FORCE_NATIVE_FORMAT   /* can be defined externally */
 #  define XXH_FORCE_NATIVE_FORMAT 0
 #endif
 
 /*!XXH_FORCE_ALIGN_CHECK :
  * This is a minor performance trick, only useful with lots of very small keys.
  * It means : check for aligned/unaligned input.
  * The check costs one initial branch per hash; set to 0 when the input data
  * is guaranteed to be aligned.
  */
 #ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
 #  if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
 #    define XXH_FORCE_ALIGN_CHECK 0
 #  else
 #    define XXH_FORCE_ALIGN_CHECK 1
 #  endif
 #endif
 
 
 /* *************************************
 *  Includes & Memory related functions
 ***************************************/
 /* Modify the local functions below should you wish to use some other memory routines */
 /* for malloc(), free() */
 #include 
+#include      /* size_t */
 static void* XXH_malloc(size_t s) { return malloc(s); }
 static void  XXH_free  (void* p)  { free(p); }
 /* for memcpy() */
 #include 
 static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
 
 #ifndef XXH_STATIC_LINKING_ONLY
 #  define XXH_STATIC_LINKING_ONLY
 #endif
 #include "xxhash.h"
 
 
 /* *************************************
 *  Compiler Specific Options
 ***************************************/
 #if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #  define INLINE_KEYWORD inline
 #else
 #  define INLINE_KEYWORD
 #endif
 
 #if defined(__GNUC__)
 #  define FORCE_INLINE_ATTR __attribute__((always_inline))
 #elif defined(_MSC_VER)
 #  define FORCE_INLINE_ATTR __forceinline
 #else
 #  define FORCE_INLINE_ATTR
 #endif
 
 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
 
 
 #ifdef _MSC_VER
 #  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
 #endif
 
 
 /* *************************************
 *  Basic Types
 ***************************************/
 #ifndef MEM_MODULE
 # define MEM_MODULE
 # if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
 #   include 
     typedef uint8_t  BYTE;
     typedef uint16_t U16;
     typedef uint32_t U32;
     typedef  int32_t S32;
     typedef uint64_t U64;
 #  else
     typedef unsigned char      BYTE;
     typedef unsigned short     U16;
     typedef unsigned int       U32;
     typedef   signed int       S32;
     typedef unsigned long long U64;   /* if your compiler doesn't support unsigned long long, replace by another 64-bit type here. Note that xxhash.h will also need to be updated. */
 #  endif
 #endif
 
 
 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
 
 /* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
 static U32 XXH_read32(const void* memPtr) { return *(const U32*) memPtr; }
 static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign;
 
 static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 static U64 XXH_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
 
 #else
 
 /* portable and safe solution. Generally efficient.
  * see : http://stackoverflow.com/a/32095106/646947
  */
 
 static U32 XXH_read32(const void* memPtr)
 {
     U32 val;
     memcpy(&val, memPtr, sizeof(val));
     return val;
 }
 
 static U64 XXH_read64(const void* memPtr)
 {
     U64 val;
     memcpy(&val, memPtr, sizeof(val));
     return val;
 }
 
 #endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
 
 
 /* ****************************************
 *  Compiler-specific Functions and Macros
 ******************************************/
 #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
 
 /* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */
 #if defined(_MSC_VER)
 #  define XXH_rotl32(x,r) _rotl(x,r)
 #  define XXH_rotl64(x,r) _rotl64(x,r)
 #else
 #  define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
 #  define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))
 #endif
 
 #if defined(_MSC_VER)     /* Visual Studio */
 #  define XXH_swap32 _byteswap_ulong
 #  define XXH_swap64 _byteswap_uint64
 #elif GCC_VERSION >= 403
 #  define XXH_swap32 __builtin_bswap32
 #  define XXH_swap64 __builtin_bswap64
 #else
 static U32 XXH_swap32 (U32 x)
 {
     return  ((x << 24) & 0xff000000 ) |
             ((x <<  8) & 0x00ff0000 ) |
             ((x >>  8) & 0x0000ff00 ) |
             ((x >> 24) & 0x000000ff );
 }
 static U64 XXH_swap64 (U64 x)
 {
     return  ((x << 56) & 0xff00000000000000ULL) |
             ((x << 40) & 0x00ff000000000000ULL) |
             ((x << 24) & 0x0000ff0000000000ULL) |
             ((x << 8)  & 0x000000ff00000000ULL) |
             ((x >> 8)  & 0x00000000ff000000ULL) |
             ((x >> 24) & 0x0000000000ff0000ULL) |
             ((x >> 40) & 0x000000000000ff00ULL) |
             ((x >> 56) & 0x00000000000000ffULL);
 }
 #endif
 
 
 /* *************************************
 *  Architecture Macros
 ***************************************/
 typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
 
 /* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */
 #ifndef XXH_CPU_LITTLE_ENDIAN
     static const int g_one = 1;
 #   define XXH_CPU_LITTLE_ENDIAN   (*(const char*)(&g_one))
 #endif
 
 
 /* ***************************
 *  Memory reads
 *****************************/
 typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
 
 FORCE_INLINE_TEMPLATE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
 {
     if (align==XXH_unaligned)
         return endian==XXH_littleEndian ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
     else
         return endian==XXH_littleEndian ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);
 }
 
 FORCE_INLINE_TEMPLATE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
 {
     return XXH_readLE32_align(ptr, endian, XXH_unaligned);
 }
 
 static U32 XXH_readBE32(const void* ptr)
 {
     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
 }
 
 FORCE_INLINE_TEMPLATE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
 {
     if (align==XXH_unaligned)
         return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
     else
         return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
 }
 
 FORCE_INLINE_TEMPLATE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
 {
     return XXH_readLE64_align(ptr, endian, XXH_unaligned);
 }
 
 static U64 XXH_readBE64(const void* ptr)
 {
     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
 }
 
 
 /* *************************************
 *  Macros
 ***************************************/
 #define XXH_STATIC_ASSERT(c)   { enum { XXH_static_assert = 1/(int)(!!(c)) }; }    /* use only *after* variable declarations */
 
 
 /* *************************************
 *  Constants
 ***************************************/
 static const U32 PRIME32_1 = 2654435761U;
 static const U32 PRIME32_2 = 2246822519U;
 static const U32 PRIME32_3 = 3266489917U;
 static const U32 PRIME32_4 =  668265263U;
 static const U32 PRIME32_5 =  374761393U;
 
 static const U64 PRIME64_1 = 11400714785074694791ULL;
 static const U64 PRIME64_2 = 14029467366897019727ULL;
 static const U64 PRIME64_3 =  1609587929392839161ULL;
 static const U64 PRIME64_4 =  9650029242287828579ULL;
 static const U64 PRIME64_5 =  2870177450012600261ULL;
 
 XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
 
 
 /* **************************
 *  Utils
 ****************************/
 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dstState, const XXH32_state_t* restrict srcState)
 {
     memcpy(dstState, srcState, sizeof(*dstState));
 }
 
 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dstState, const XXH64_state_t* restrict srcState)
 {
     memcpy(dstState, srcState, sizeof(*dstState));
 }
 
 
 /* ***************************
 *  Simple Hash Functions
 *****************************/
 
 static U32 XXH32_round(U32 seed, U32 input)
 {
     seed += input * PRIME32_2;
     seed  = XXH_rotl32(seed, 13);
     seed *= PRIME32_1;
     return seed;
 }
 
 FORCE_INLINE_TEMPLATE U32 XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_endianess endian, XXH_alignment align)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* bEnd = p + len;
     U32 h32;
 #define XXH_get32bits(p) XXH_readLE32_align(p, endian, align)
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (p==NULL) {
         len=0;
         bEnd=p=(const BYTE*)(size_t)16;
     }
 #endif
 
     if (len>=16) {
         const BYTE* const limit = bEnd - 16;
         U32 v1 = seed + PRIME32_1 + PRIME32_2;
         U32 v2 = seed + PRIME32_2;
         U32 v3 = seed + 0;
         U32 v4 = seed - PRIME32_1;
 
         do {
             v1 = XXH32_round(v1, XXH_get32bits(p)); p+=4;
             v2 = XXH32_round(v2, XXH_get32bits(p)); p+=4;
             v3 = XXH32_round(v3, XXH_get32bits(p)); p+=4;
             v4 = XXH32_round(v4, XXH_get32bits(p)); p+=4;
         } while (p<=limit);
 
         h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
     } else {
         h32  = seed + PRIME32_5;
     }
 
     h32 += (U32) len;
 
     while (p+4<=bEnd) {
         h32 += XXH_get32bits(p) * PRIME32_3;
         h32  = XXH_rotl32(h32, 17) * PRIME32_4 ;
         p+=4;
     }
 
     while (p> 15;
     h32 *= PRIME32_2;
     h32 ^= h32 >> 13;
     h32 *= PRIME32_3;
     h32 ^= h32 >> 16;
 
     return h32;
 }
 
 
 XXH_PUBLIC_API unsigned int XXH32 (const void* input, size_t len, unsigned int seed)
 {
 #if 0
     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
     XXH32_CREATESTATE_STATIC(state);
     XXH32_reset(state, seed);
     XXH32_update(state, input, len);
     return XXH32_digest(state);
 #else
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if (XXH_FORCE_ALIGN_CHECK) {
         if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
             if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
                 return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
             else
                 return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
     }   }
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
     else
         return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
 #endif
 }
 
 
 static U64 XXH64_round(U64 acc, U64 input)
 {
     acc += input * PRIME64_2;
     acc  = XXH_rotl64(acc, 31);
     acc *= PRIME64_1;
     return acc;
 }
 
 static U64 XXH64_mergeRound(U64 acc, U64 val)
 {
     val  = XXH64_round(0, val);
     acc ^= val;
     acc  = acc * PRIME64_1 + PRIME64_4;
     return acc;
 }
 
 FORCE_INLINE_TEMPLATE U64 XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_endianess endian, XXH_alignment align)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* const bEnd = p + len;
     U64 h64;
 #define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (p==NULL) {
         len=0;
         bEnd=p=(const BYTE*)(size_t)32;
     }
 #endif
 
     if (len>=32) {
         const BYTE* const limit = bEnd - 32;
         U64 v1 = seed + PRIME64_1 + PRIME64_2;
         U64 v2 = seed + PRIME64_2;
         U64 v3 = seed + 0;
         U64 v4 = seed - PRIME64_1;
 
         do {
             v1 = XXH64_round(v1, XXH_get64bits(p)); p+=8;
             v2 = XXH64_round(v2, XXH_get64bits(p)); p+=8;
             v3 = XXH64_round(v3, XXH_get64bits(p)); p+=8;
             v4 = XXH64_round(v4, XXH_get64bits(p)); p+=8;
         } while (p<=limit);
 
         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
         h64 = XXH64_mergeRound(h64, v1);
         h64 = XXH64_mergeRound(h64, v2);
         h64 = XXH64_mergeRound(h64, v3);
         h64 = XXH64_mergeRound(h64, v4);
 
     } else {
         h64  = seed + PRIME64_5;
     }
 
     h64 += (U64) len;
 
     while (p+8<=bEnd) {
         U64 const k1 = XXH64_round(0, XXH_get64bits(p));
         h64 ^= k1;
         h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;
         p+=8;
     }
 
     if (p+4<=bEnd) {
         h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1;
         h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
         p+=4;
     }
 
     while (p> 33;
     h64 *= PRIME64_2;
     h64 ^= h64 >> 29;
     h64 *= PRIME64_3;
     h64 ^= h64 >> 32;
 
     return h64;
 }
 
 
 XXH_PUBLIC_API unsigned long long XXH64 (const void* input, size_t len, unsigned long long seed)
 {
 #if 0
     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
     XXH64_CREATESTATE_STATIC(state);
     XXH64_reset(state, seed);
     XXH64_update(state, input, len);
     return XXH64_digest(state);
 #else
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if (XXH_FORCE_ALIGN_CHECK) {
         if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
             if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
                 return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
             else
                 return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
     }   }
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
     else
         return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
 #endif
 }
 
 
 /* **************************************************
 *  Advanced Hash Functions
 ****************************************************/
 
 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
 {
     return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
 }
 XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
 {
     XXH_free(statePtr);
     return XXH_OK;
 }
 
 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
 {
     return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
 }
 XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
 {
     XXH_free(statePtr);
     return XXH_OK;
 }
 
 
 /*** Hash feed ***/
 
 XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, unsigned int seed)
 {
     XXH32_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
     memset(&state, 0, sizeof(state)-4);   /* do not write into reserved, for future removal */
     state.v1 = seed + PRIME32_1 + PRIME32_2;
     state.v2 = seed + PRIME32_2;
     state.v3 = seed + 0;
     state.v4 = seed - PRIME32_1;
     memcpy(statePtr, &state, sizeof(state));
     return XXH_OK;
 }
 
 
 XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed)
 {
     XXH64_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
     memset(&state, 0, sizeof(state)-8);   /* do not write into reserved, for future removal */
     state.v1 = seed + PRIME64_1 + PRIME64_2;
     state.v2 = seed + PRIME64_2;
     state.v3 = seed + 0;
     state.v4 = seed - PRIME64_1;
     memcpy(statePtr, &state, sizeof(state));
     return XXH_OK;
 }
 
 
 FORCE_INLINE_TEMPLATE XXH_errorcode XXH32_update_endian (XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* const bEnd = p + len;
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (input==NULL) return XXH_ERROR;
 #endif
 
     state->total_len_32 += (unsigned)len;
     state->large_len |= (len>=16) | (state->total_len_32>=16);
 
     if (state->memsize + len < 16)  {   /* fill in tmp buffer */
         XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, len);
         state->memsize += (unsigned)len;
         return XXH_OK;
     }
 
     if (state->memsize) {   /* some data left from previous update */
         XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, 16-state->memsize);
         {   const U32* p32 = state->mem32;
             state->v1 = XXH32_round(state->v1, XXH_readLE32(p32, endian)); p32++;
             state->v2 = XXH32_round(state->v2, XXH_readLE32(p32, endian)); p32++;
             state->v3 = XXH32_round(state->v3, XXH_readLE32(p32, endian)); p32++;
             state->v4 = XXH32_round(state->v4, XXH_readLE32(p32, endian)); p32++;
         }
         p += 16-state->memsize;
         state->memsize = 0;
     }
 
     if (p <= bEnd-16) {
         const BYTE* const limit = bEnd - 16;
         U32 v1 = state->v1;
         U32 v2 = state->v2;
         U32 v3 = state->v3;
         U32 v4 = state->v4;
 
         do {
             v1 = XXH32_round(v1, XXH_readLE32(p, endian)); p+=4;
             v2 = XXH32_round(v2, XXH_readLE32(p, endian)); p+=4;
             v3 = XXH32_round(v3, XXH_readLE32(p, endian)); p+=4;
             v4 = XXH32_round(v4, XXH_readLE32(p, endian)); p+=4;
         } while (p<=limit);
 
         state->v1 = v1;
         state->v2 = v2;
         state->v3 = v3;
         state->v4 = v4;
     }
 
     if (p < bEnd) {
         XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
         state->memsize = (unsigned)(bEnd-p);
     }
 
     return XXH_OK;
 }
 
 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* state_in, const void* input, size_t len)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH32_update_endian(state_in, input, len, XXH_littleEndian);
     else
         return XXH32_update_endian(state_in, input, len, XXH_bigEndian);
 }
 
 
 
 FORCE_INLINE_TEMPLATE U32 XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
 {
     const BYTE * p = (const BYTE*)state->mem32;
     const BYTE* const bEnd = (const BYTE*)(state->mem32) + state->memsize;
     U32 h32;
 
     if (state->large_len) {
         h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18);
     } else {
         h32 = state->v3 /* == seed */ + PRIME32_5;
     }
 
     h32 += state->total_len_32;
 
     while (p+4<=bEnd) {
         h32 += XXH_readLE32(p, endian) * PRIME32_3;
         h32  = XXH_rotl32(h32, 17) * PRIME32_4;
         p+=4;
     }
 
     while (p> 15;
     h32 *= PRIME32_2;
     h32 ^= h32 >> 13;
     h32 *= PRIME32_3;
     h32 ^= h32 >> 16;
 
     return h32;
 }
 
 
 XXH_PUBLIC_API unsigned int XXH32_digest (const XXH32_state_t* state_in)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH32_digest_endian(state_in, XXH_littleEndian);
     else
         return XXH32_digest_endian(state_in, XXH_bigEndian);
 }
 
 
 
 /* **** XXH64 **** */
 
 FORCE_INLINE_TEMPLATE XXH_errorcode XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* const bEnd = p + len;
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (input==NULL) return XXH_ERROR;
 #endif
 
     state->total_len += len;
 
     if (state->memsize + len < 32) {  /* fill in tmp buffer */
         XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
         state->memsize += (U32)len;
         return XXH_OK;
     }
 
     if (state->memsize) {   /* tmp buffer is full */
         XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, 32-state->memsize);
         state->v1 = XXH64_round(state->v1, XXH_readLE64(state->mem64+0, endian));
         state->v2 = XXH64_round(state->v2, XXH_readLE64(state->mem64+1, endian));
         state->v3 = XXH64_round(state->v3, XXH_readLE64(state->mem64+2, endian));
         state->v4 = XXH64_round(state->v4, XXH_readLE64(state->mem64+3, endian));
         p += 32-state->memsize;
         state->memsize = 0;
     }
 
     if (p+32 <= bEnd) {
         const BYTE* const limit = bEnd - 32;
         U64 v1 = state->v1;
         U64 v2 = state->v2;
         U64 v3 = state->v3;
         U64 v4 = state->v4;
 
         do {
             v1 = XXH64_round(v1, XXH_readLE64(p, endian)); p+=8;
             v2 = XXH64_round(v2, XXH_readLE64(p, endian)); p+=8;
             v3 = XXH64_round(v3, XXH_readLE64(p, endian)); p+=8;
             v4 = XXH64_round(v4, XXH_readLE64(p, endian)); p+=8;
         } while (p<=limit);
 
         state->v1 = v1;
         state->v2 = v2;
         state->v3 = v3;
         state->v4 = v4;
     }
 
     if (p < bEnd) {
         XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
         state->memsize = (unsigned)(bEnd-p);
     }
 
     return XXH_OK;
 }
 
 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* state_in, const void* input, size_t len)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH64_update_endian(state_in, input, len, XXH_littleEndian);
     else
         return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
 }
 
 
 
 FORCE_INLINE_TEMPLATE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
 {
     const BYTE * p = (const BYTE*)state->mem64;
     const BYTE* const bEnd = (const BYTE*)state->mem64 + state->memsize;
     U64 h64;
 
     if (state->total_len >= 32) {
         U64 const v1 = state->v1;
         U64 const v2 = state->v2;
         U64 const v3 = state->v3;
         U64 const v4 = state->v4;
 
         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
         h64 = XXH64_mergeRound(h64, v1);
         h64 = XXH64_mergeRound(h64, v2);
         h64 = XXH64_mergeRound(h64, v3);
         h64 = XXH64_mergeRound(h64, v4);
     } else {
         h64  = state->v3 + PRIME64_5;
     }
 
     h64 += (U64) state->total_len;
 
     while (p+8<=bEnd) {
         U64 const k1 = XXH64_round(0, XXH_readLE64(p, endian));
         h64 ^= k1;
         h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;
         p+=8;
     }
 
     if (p+4<=bEnd) {
         h64 ^= (U64)(XXH_readLE32(p, endian)) * PRIME64_1;
         h64  = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
         p+=4;
     }
 
     while (p> 33;
     h64 *= PRIME64_2;
     h64 ^= h64 >> 29;
     h64 *= PRIME64_3;
     h64 ^= h64 >> 32;
 
     return h64;
 }
 
 
 XXH_PUBLIC_API unsigned long long XXH64_digest (const XXH64_state_t* state_in)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH64_digest_endian(state_in, XXH_littleEndian);
     else
         return XXH64_digest_endian(state_in, XXH_bigEndian);
 }
 
 
 /* **************************
 *  Canonical representation
 ****************************/
 
 /*! Default XXH result types are basic unsigned 32 and 64 bits.
 *   The canonical representation follows human-readable write convention, aka big-endian (large digits first).
 *   These functions allow transformation of hash result into and from its canonical format.
 *   This way, hash values can be written into a file or buffer, and remain comparable across different systems and programs.
 */
 
 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
 {
     XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
     memcpy(dst, &hash, sizeof(*dst));
 }
 
 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
 {
     XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
     memcpy(dst, &hash, sizeof(*dst));
 }
 
 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
 {
     return XXH_readBE32(src);
 }
 
 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
 {
     return XXH_readBE64(src);
 }
Index: vendor/zstd/dist/lib/common/zstd_common.c
===================================================================
--- vendor/zstd/dist/lib/common/zstd_common.c	(revision 339613)
+++ vendor/zstd/dist/lib/common/zstd_common.c	(revision 339614)
@@ -1,86 +1,81 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include       /* malloc, calloc, free */
 #include       /* memset */
 #include "error_private.h"
 #include "zstd_internal.h"
 
 
 /*-****************************************
 *  Version
 ******************************************/
 unsigned ZSTD_versionNumber(void) { return ZSTD_VERSION_NUMBER; }
 
 const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }
 
 
 /*-****************************************
 *  ZSTD Error Management
 ******************************************/
 /*! ZSTD_isError() :
  *  tells if a return value is an error code */
 unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }
 
 /*! ZSTD_getErrorName() :
  *  provides error code string from function result (useful for debugging) */
 const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }
 
 /*! ZSTD_getError() :
  *  convert a `size_t` function result into a proper ZSTD_errorCode enum */
 ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
 
 /*! ZSTD_getErrorString() :
  *  provides error code string from enum */
 const char* ZSTD_getErrorString(ZSTD_ErrorCode code) { return ERR_getErrorString(code); }
 
-/*! g_debuglog_enable :
- *  turn on/off debug traces (global switch) */
-#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG >= 2)
-int g_debuglog_enable = 1;
-#endif
 
 
 /*=**************************************************************
 *  Custom allocator
 ****************************************************************/
 void* ZSTD_malloc(size_t size, ZSTD_customMem customMem)
 {
     if (customMem.customAlloc)
         return customMem.customAlloc(customMem.opaque, size);
     return malloc(size);
 }
 
 void* ZSTD_calloc(size_t size, ZSTD_customMem customMem)
 {
     if (customMem.customAlloc) {
         /* calloc implemented as malloc+memset;
          * not as efficient as calloc, but next best guess for custom malloc */
         void* const ptr = customMem.customAlloc(customMem.opaque, size);
         memset(ptr, 0, size);
         return ptr;
     }
     return calloc(1, size);
 }
 
 void ZSTD_free(void* ptr, ZSTD_customMem customMem)
 {
     if (ptr!=NULL) {
         if (customMem.customFree)
             customMem.customFree(customMem.opaque, ptr);
         else
             free(ptr);
     }
 }
Index: vendor/zstd/dist/lib/common/zstd_internal.h
===================================================================
--- vendor/zstd/dist/lib/common/zstd_internal.h	(revision 339613)
+++ vendor/zstd/dist/lib/common/zstd_internal.h	(revision 339614)
@@ -1,290 +1,257 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_CCOMMON_H_MODULE
 #define ZSTD_CCOMMON_H_MODULE
 
 /* this module contains definitions which must be identical
  * across compression, decompression and dictBuilder.
  * It also contains a few functions useful to at least 2 of them
  * and which benefit from being inlined */
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include "compiler.h"
 #include "mem.h"
+#include "debug.h"                 /* assert, DEBUGLOG, RAWLOG, g_debuglevel */
 #include "error_private.h"
 #define ZSTD_STATIC_LINKING_ONLY
 #include "zstd.h"
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #ifndef XXH_STATIC_LINKING_ONLY
 #  define XXH_STATIC_LINKING_ONLY  /* XXH64_state_t */
 #endif
 #include "xxhash.h"                /* XXH_reset, update, digest */
 
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+/* ---- static assert (debug) --- */
+#define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
 
-/*-*************************************
-*  Debug
-***************************************/
-#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=1)
-#  include 
-#else
-#  ifndef assert
-#    define assert(condition) ((void)0)
-#  endif
-#endif
 
-#define ZSTD_STATIC_ASSERT(c) { enum { ZSTD_static_assert = 1/(int)(!!(c)) }; }
-
-#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=2)
-#  include 
-extern int g_debuglog_enable;
-/* recommended values for ZSTD_DEBUG display levels :
- * 1 : no display, enables assert() only
- * 2 : reserved for currently active debug path
- * 3 : events once per object lifetime (CCtx, CDict, etc.)
- * 4 : events once per frame
- * 5 : events once per block
- * 6 : events once per sequence (*very* verbose) */
-#  define RAWLOG(l, ...) {                                      \
-                if ((g_debuglog_enable) & (l<=ZSTD_DEBUG)) {    \
-                    fprintf(stderr, __VA_ARGS__);               \
-            }   }
-#  define DEBUGLOG(l, ...) {                                    \
-                if ((g_debuglog_enable) & (l<=ZSTD_DEBUG)) {    \
-                    fprintf(stderr, __FILE__ ": " __VA_ARGS__); \
-                    fprintf(stderr, " \n");                     \
-            }   }
-#else
-#  define RAWLOG(l, ...)      {}    /* disabled */
-#  define DEBUGLOG(l, ...)    {}    /* disabled */
-#endif
-
-
 /*-*************************************
 *  shared macros
 ***************************************/
 #undef MIN
 #undef MAX
 #define MIN(a,b) ((a)<(b) ? (a) : (b))
 #define MAX(a,b) ((a)>(b) ? (a) : (b))
 #define CHECK_F(f) { size_t const errcod = f; if (ERR_isError(errcod)) return errcod; }  /* check and Forward error code */
 #define CHECK_E(f, e) { size_t const errcod = f; if (ERR_isError(errcod)) return ERROR(e); }  /* check and send Error code */
 
 
 /*-*************************************
 *  Common constants
 ***************************************/
 #define ZSTD_OPT_NUM    (1<<12)
 
 #define ZSTD_REP_NUM      3                 /* number of repcodes */
 #define ZSTD_REP_MOVE     (ZSTD_REP_NUM-1)
 static const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };
 
 #define KB *(1 <<10)
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
 #define BIT7 128
 #define BIT6  64
 #define BIT5  32
 #define BIT4  16
 #define BIT1   2
 #define BIT0   1
 
 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
 #define ZSTD_WINDOWLOG_DEFAULTMAX 27 /* Default maximum allowed window log */
 static const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };
 static const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };
 
-#define ZSTD_FRAMEIDSIZE 4
-static const size_t ZSTD_frameIdSize = ZSTD_FRAMEIDSIZE;  /* magic number size */
+#define ZSTD_FRAMEIDSIZE 4   /* magic number size */
 
 #define ZSTD_BLOCKHEADERSIZE 3   /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
 static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
 typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;
 
 #define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */
 #define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */)   /* for a non-null block */
 
 #define HufLog 12
 typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;
 
 #define LONGNBSEQ 0x7F00
 
 #define MINMATCH 3
 
 #define Litbits  8
 #define MaxLit ((1<= 3)   /* GCC Intrinsic */
         return 31 - __builtin_clz(val);
 #   else   /* Software version */
         static const U32 DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
         U32 v = val;
         v |= v >> 1;
         v |= v >> 2;
         v |= v >> 4;
         v |= v >> 8;
         v |= v >> 16;
         return DeBruijnClz[(v * 0x07C4ACDDU) >> 27];
 #   endif
     }
 }
 
 
 /* ZSTD_invalidateRepCodes() :
  * ensures next compression will not use repcodes from previous block.
  * Note : only works with regular variant;
  *        do not use with extDict variant ! */
 void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx);   /* zstdmt, adaptive_compression (shouldn't get this definition from here) */
 
 
 typedef struct {
     blockType_e blockType;
     U32 lastBlock;
     U32 origSize;
 } blockProperties_t;
 
 /*! ZSTD_getcBlockSize() :
  *  Provides the size of compressed block from block header `src` */
 /* Used by: decompress, fullbench (does not get its definition from here) */
 size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
                           blockProperties_t* bpPtr);
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif   /* ZSTD_CCOMMON_H_MODULE */
Index: vendor/zstd/dist/lib/compress/fse_compress.c
===================================================================
--- vendor/zstd/dist/lib/compress/fse_compress.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/fse_compress.c	(revision 339614)
@@ -1,849 +1,721 @@
 /* ******************************************************************
    FSE : Finite State Entropy encoder
-   Copyright (C) 2013-2015, Yann Collet.
+   Copyright (C) 2013-present, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 /* **************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
-#include       /* printf (debug) */
-#include "bitstream.h"
 #include "compiler.h"
+#include "mem.h"        /* U32, U16, etc. */
+#include "debug.h"      /* assert, DEBUGLOG */
+#include "hist.h"       /* HIST_count_wksp */
+#include "bitstream.h"
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #include "error_private.h"
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_isError ERR_isError
-#define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /* **************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 /* Function templates */
 
 /* FSE_buildCTable_wksp() :
  * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`).
  * wkspSize should be sized to handle worst case situation, which is `1<>1 : 1) ;
     FSE_symbolCompressionTransform* const symbolTT = (FSE_symbolCompressionTransform*) (FSCT);
     U32 const step = FSE_TABLESTEP(tableSize);
     U32 cumul[FSE_MAX_SYMBOL_VALUE+2];
 
     FSE_FUNCTION_TYPE* const tableSymbol = (FSE_FUNCTION_TYPE*)workSpace;
     U32 highThreshold = tableSize-1;
 
     /* CTable header */
     if (((size_t)1 << tableLog) * sizeof(FSE_FUNCTION_TYPE) > wkspSize) return ERROR(tableLog_tooLarge);
     tableU16[-2] = (U16) tableLog;
     tableU16[-1] = (U16) maxSymbolValue;
+    assert(tableLog < 16);   /* required for threshold strategy to work */
 
     /* For explanations on how to distribute symbol values over the table :
-    *  http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */
+     * http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */
 
+     #ifdef __clang_analyzer__
+     memset(tableSymbol, 0, sizeof(*tableSymbol) * tableSize);   /* useless initialization, just to keep scan-build happy */
+     #endif
+
     /* symbol start positions */
     {   U32 u;
         cumul[0] = 0;
         for (u=1; u<=maxSymbolValue+1; u++) {
             if (normalizedCounter[u-1]==-1) {  /* Low proba symbol */
                 cumul[u] = cumul[u-1] + 1;
                 tableSymbol[highThreshold--] = (FSE_FUNCTION_TYPE)(u-1);
             } else {
                 cumul[u] = cumul[u-1] + normalizedCounter[u-1];
         }   }
         cumul[maxSymbolValue+1] = tableSize+1;
     }
 
     /* Spread symbols */
     {   U32 position = 0;
         U32 symbol;
         for (symbol=0; symbol<=maxSymbolValue; symbol++) {
             int nbOccurences;
-            for (nbOccurences=0; nbOccurences highThreshold) position = (position + step) & tableMask;   /* Low proba area */
+                while (position > highThreshold)
+                    position = (position + step) & tableMask;   /* Low proba area */
         }   }
 
-        if (position!=0) return ERROR(GENERIC);   /* Must have gone through all positions */
+        assert(position==0);  /* Must have initialized all positions */
     }
 
     /* Build table */
     {   U32 u; for (u=0; u> 3) + 3;
     return maxSymbolValue ? maxHeaderSize : FSE_NCOUNTBOUND;  /* maxSymbolValue==0 ? use default */
 }
 
-static size_t FSE_writeNCount_generic (void* header, size_t headerBufferSize,
-                                       const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog,
-                                       unsigned writeIsSafe)
+static size_t
+FSE_writeNCount_generic (void* header, size_t headerBufferSize,
+                   const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog,
+                         unsigned writeIsSafe)
 {
     BYTE* const ostart = (BYTE*) header;
     BYTE* out = ostart;
     BYTE* const oend = ostart + headerBufferSize;
     int nbBits;
     const int tableSize = 1 << tableLog;
     int remaining;
     int threshold;
-    U32 bitStream;
-    int bitCount;
-    unsigned charnum = 0;
-    int previous0 = 0;
+    U32 bitStream = 0;
+    int bitCount = 0;
+    unsigned symbol = 0;
+    unsigned const alphabetSize = maxSymbolValue + 1;
+    int previousIs0 = 0;
 
-    bitStream = 0;
-    bitCount  = 0;
     /* Table Size */
     bitStream += (tableLog-FSE_MIN_TABLELOG) << bitCount;
     bitCount  += 4;
 
     /* Init */
     remaining = tableSize+1;   /* +1 for extra accuracy */
     threshold = tableSize;
     nbBits = tableLog+1;
 
-    while (remaining>1) {  /* stops at 1 */
-        if (previous0) {
-            unsigned start = charnum;
-            while (!normalizedCounter[charnum]) charnum++;
-            while (charnum >= start+24) {
+    while ((symbol < alphabetSize) && (remaining>1)) {  /* stops at 1 */
+        if (previousIs0) {
+            unsigned start = symbol;
+            while ((symbol < alphabetSize) && !normalizedCounter[symbol]) symbol++;
+            if (symbol == alphabetSize) break;   /* incorrect distribution */
+            while (symbol >= start+24) {
                 start+=24;
                 bitStream += 0xFFFFU << bitCount;
-                if ((!writeIsSafe) && (out > oend-2)) return ERROR(dstSize_tooSmall);   /* Buffer overflow */
+                if ((!writeIsSafe) && (out > oend-2))
+                    return ERROR(dstSize_tooSmall);   /* Buffer overflow */
                 out[0] = (BYTE) bitStream;
                 out[1] = (BYTE)(bitStream>>8);
                 out+=2;
                 bitStream>>=16;
             }
-            while (charnum >= start+3) {
+            while (symbol >= start+3) {
                 start+=3;
                 bitStream += 3 << bitCount;
                 bitCount += 2;
             }
-            bitStream += (charnum-start) << bitCount;
+            bitStream += (symbol-start) << bitCount;
             bitCount += 2;
             if (bitCount>16) {
-                if ((!writeIsSafe) && (out > oend - 2)) return ERROR(dstSize_tooSmall);   /* Buffer overflow */
+                if ((!writeIsSafe) && (out > oend - 2))
+                    return ERROR(dstSize_tooSmall);   /* Buffer overflow */
                 out[0] = (BYTE)bitStream;
                 out[1] = (BYTE)(bitStream>>8);
                 out += 2;
                 bitStream >>= 16;
                 bitCount -= 16;
         }   }
-        {   int count = normalizedCounter[charnum++];
-            int const max = (2*threshold-1)-remaining;
+        {   int count = normalizedCounter[symbol++];
+            int const max = (2*threshold-1) - remaining;
             remaining -= count < 0 ? -count : count;
             count++;   /* +1 for extra accuracy */
-            if (count>=threshold) count += max;   /* [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ */
+            if (count>=threshold)
+                count += max;   /* [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ */
             bitStream += count << bitCount;
             bitCount  += nbBits;
             bitCount  -= (count>=1; }
         }
         if (bitCount>16) {
-            if ((!writeIsSafe) && (out > oend - 2)) return ERROR(dstSize_tooSmall);   /* Buffer overflow */
+            if ((!writeIsSafe) && (out > oend - 2))
+                return ERROR(dstSize_tooSmall);   /* Buffer overflow */
             out[0] = (BYTE)bitStream;
             out[1] = (BYTE)(bitStream>>8);
             out += 2;
             bitStream >>= 16;
             bitCount -= 16;
     }   }
 
+    if (remaining != 1)
+        return ERROR(GENERIC);  /* incorrect normalized distribution */
+    assert(symbol <= alphabetSize);
+
     /* flush remaining bitStream */
-    if ((!writeIsSafe) && (out > oend - 2)) return ERROR(dstSize_tooSmall);   /* Buffer overflow */
+    if ((!writeIsSafe) && (out > oend - 2))
+        return ERROR(dstSize_tooSmall);   /* Buffer overflow */
     out[0] = (BYTE)bitStream;
     out[1] = (BYTE)(bitStream>>8);
     out+= (bitCount+7) /8;
 
-    if (charnum > maxSymbolValue + 1) return ERROR(GENERIC);
-
     return (out-ostart);
 }
 
 
-size_t FSE_writeNCount (void* buffer, size_t bufferSize, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
+size_t FSE_writeNCount (void* buffer, size_t bufferSize,
+                  const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);   /* Unsupported */
     if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC);   /* Unsupported */
 
     if (bufferSize < FSE_NCountWriteBound(maxSymbolValue, tableLog))
         return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 0);
 
-    return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 1);
+    return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 1 /* write in buffer is safe */);
 }
 
 
-
 /*-**************************************************************
-*  Counting histogram
-****************************************************************/
-/*! FSE_count_simple
-    This function counts byte values within `src`, and store the histogram into table `count`.
-    It doesn't use any additional memory.
-    But this function is unsafe : it doesn't check that all values within `src` can fit into `count`.
-    For this reason, prefer using a table `count` with 256 elements.
-    @return : count of most numerous element.
-*/
-size_t FSE_count_simple(unsigned* count, unsigned* maxSymbolValuePtr,
-                        const void* src, size_t srcSize)
-{
-    const BYTE* ip = (const BYTE*)src;
-    const BYTE* const end = ip + srcSize;
-    unsigned maxSymbolValue = *maxSymbolValuePtr;
-    unsigned max=0;
-
-    memset(count, 0, (maxSymbolValue+1)*sizeof(*count));
-    if (srcSize==0) { *maxSymbolValuePtr = 0; return 0; }
-
-    while (ip max) max = count[s]; }
-
-    return (size_t)max;
-}
-
-
-/* FSE_count_parallel_wksp() :
- * Same as FSE_count_parallel(), but using an externally provided scratch buffer.
- * `workSpace` size must be a minimum of `1024 * sizeof(unsigned)`.
- * @return : largest histogram frequency, or an error code (notably when histogram would be larger than *maxSymbolValuePtr). */
-static size_t FSE_count_parallel_wksp(
-                                unsigned* count, unsigned* maxSymbolValuePtr,
-                                const void* source, size_t sourceSize,
-                                unsigned checkMax, unsigned* const workSpace)
-{
-    const BYTE* ip = (const BYTE*)source;
-    const BYTE* const iend = ip+sourceSize;
-    unsigned maxSymbolValue = *maxSymbolValuePtr;
-    unsigned max=0;
-    U32* const Counting1 = workSpace;
-    U32* const Counting2 = Counting1 + 256;
-    U32* const Counting3 = Counting2 + 256;
-    U32* const Counting4 = Counting3 + 256;
-
-    memset(workSpace, 0, 4*256*sizeof(unsigned));
-
-    /* safety checks */
-    if (!sourceSize) {
-        memset(count, 0, maxSymbolValue + 1);
-        *maxSymbolValuePtr = 0;
-        return 0;
-    }
-    if (!maxSymbolValue) maxSymbolValue = 255;            /* 0 == default */
-
-    /* by stripes of 16 bytes */
-    {   U32 cached = MEM_read32(ip); ip += 4;
-        while (ip < iend-15) {
-            U32 c = cached; cached = MEM_read32(ip); ip += 4;
-            Counting1[(BYTE) c     ]++;
-            Counting2[(BYTE)(c>>8) ]++;
-            Counting3[(BYTE)(c>>16)]++;
-            Counting4[       c>>24 ]++;
-            c = cached; cached = MEM_read32(ip); ip += 4;
-            Counting1[(BYTE) c     ]++;
-            Counting2[(BYTE)(c>>8) ]++;
-            Counting3[(BYTE)(c>>16)]++;
-            Counting4[       c>>24 ]++;
-            c = cached; cached = MEM_read32(ip); ip += 4;
-            Counting1[(BYTE) c     ]++;
-            Counting2[(BYTE)(c>>8) ]++;
-            Counting3[(BYTE)(c>>16)]++;
-            Counting4[       c>>24 ]++;
-            c = cached; cached = MEM_read32(ip); ip += 4;
-            Counting1[(BYTE) c     ]++;
-            Counting2[(BYTE)(c>>8) ]++;
-            Counting3[(BYTE)(c>>16)]++;
-            Counting4[       c>>24 ]++;
-        }
-        ip-=4;
-    }
-
-    /* finish last symbols */
-    while (ipmaxSymbolValue; s--) {
-            Counting1[s] += Counting2[s] + Counting3[s] + Counting4[s];
-            if (Counting1[s]) return ERROR(maxSymbolValue_tooSmall);
-    }   }
-
-    {   U32 s;
-        if (maxSymbolValue > 255) maxSymbolValue = 255;
-        for (s=0; s<=maxSymbolValue; s++) {
-            count[s] = Counting1[s] + Counting2[s] + Counting3[s] + Counting4[s];
-            if (count[s] > max) max = count[s];
-    }   }
-
-    while (!count[maxSymbolValue]) maxSymbolValue--;
-    *maxSymbolValuePtr = maxSymbolValue;
-    return (size_t)max;
-}
-
-/* FSE_countFast_wksp() :
- * Same as FSE_countFast(), but using an externally provided scratch buffer.
- * `workSpace` size must be table of >= `1024` unsigned */
-size_t FSE_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
-                          const void* source, size_t sourceSize,
-                          unsigned* workSpace)
-{
-    if (sourceSize < 1500) /* heuristic threshold */
-        return FSE_count_simple(count, maxSymbolValuePtr, source, sourceSize);
-    return FSE_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 0, workSpace);
-}
-
-/* fast variant (unsafe : won't check if src contains values beyond count[] limit) */
-size_t FSE_countFast(unsigned* count, unsigned* maxSymbolValuePtr,
-                     const void* source, size_t sourceSize)
-{
-    unsigned tmpCounters[1024];
-    return FSE_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, tmpCounters);
-}
-
-/* FSE_count_wksp() :
- * Same as FSE_count(), but using an externally provided scratch buffer.
- * `workSpace` size must be table of >= `1024` unsigned */
-size_t FSE_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
-                 const void* source, size_t sourceSize, unsigned* workSpace)
-{
-    if (*maxSymbolValuePtr < 255)
-        return FSE_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 1, workSpace);
-    *maxSymbolValuePtr = 255;
-    return FSE_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, workSpace);
-}
-
-size_t FSE_count(unsigned* count, unsigned* maxSymbolValuePtr,
-                 const void* src, size_t srcSize)
-{
-    unsigned tmpCounters[1024];
-    return FSE_count_wksp(count, maxSymbolValuePtr, src, srcSize, tmpCounters);
-}
-
-
-
-/*-**************************************************************
 *  FSE Compression Code
 ****************************************************************/
-/*! FSE_sizeof_CTable() :
-    FSE_CTable is a variable size structure which contains :
-    `U16 tableLog;`
-    `U16 maxSymbolValue;`
-    `U16 nextStateNumber[1 << tableLog];`                         // This size is variable
-    `FSE_symbolCompressionTransform symbolTT[maxSymbolValue+1];`  // This size is variable
-Allocation is manual (C standard does not support variable-size structures).
-*/
-size_t FSE_sizeof_CTable (unsigned maxSymbolValue, unsigned tableLog)
-{
-    if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
-    return FSE_CTABLE_SIZE_U32 (tableLog, maxSymbolValue) * sizeof(U32);
-}
 
 FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog)
 {
     size_t size;
     if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX;
     size = FSE_CTABLE_SIZE_U32 (tableLog, maxSymbolValue) * sizeof(U32);
     return (FSE_CTable*)malloc(size);
 }
 
 void FSE_freeCTable (FSE_CTable* ct) { free(ct); }
 
 /* provides the minimum logSize to safely represent a distribution */
 static unsigned FSE_minTableLog(size_t srcSize, unsigned maxSymbolValue)
 {
-    U32 minBitsSrc = BIT_highbit32((U32)(srcSize - 1)) + 1;
+    U32 minBitsSrc = BIT_highbit32((U32)(srcSize)) + 1;
     U32 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2;
     U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols;
     assert(srcSize > 1); /* Not supported, RLE should be used instead */
     return minBits;
 }
 
 unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus)
 {
     U32 maxBitsSrc = BIT_highbit32((U32)(srcSize - 1)) - minus;
     U32 tableLog = maxTableLog;
     U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue);
     assert(srcSize > 1); /* Not supported, RLE should be used instead */
     if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG;
     if (maxBitsSrc < tableLog) tableLog = maxBitsSrc;   /* Accuracy can be reduced */
     if (minBits > tableLog) tableLog = minBits;   /* Need a minimum to safely represent all symbol values */
     if (tableLog < FSE_MIN_TABLELOG) tableLog = FSE_MIN_TABLELOG;
     if (tableLog > FSE_MAX_TABLELOG) tableLog = FSE_MAX_TABLELOG;
     return tableLog;
 }
 
 unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue)
 {
     return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 2);
 }
 
 
 /* Secondary normalization method.
    To be used when primary method fails. */
 
 static size_t FSE_normalizeM2(short* norm, U32 tableLog, const unsigned* count, size_t total, U32 maxSymbolValue)
 {
     short const NOT_YET_ASSIGNED = -2;
     U32 s;
     U32 distributed = 0;
     U32 ToDistribute;
 
     /* Init */
     U32 const lowThreshold = (U32)(total >> tableLog);
     U32 lowOne = (U32)((total * 3) >> (tableLog + 1));
 
     for (s=0; s<=maxSymbolValue; s++) {
         if (count[s] == 0) {
             norm[s]=0;
             continue;
         }
         if (count[s] <= lowThreshold) {
             norm[s] = -1;
             distributed++;
             total -= count[s];
             continue;
         }
         if (count[s] <= lowOne) {
             norm[s] = 1;
             distributed++;
             total -= count[s];
             continue;
         }
 
         norm[s]=NOT_YET_ASSIGNED;
     }
     ToDistribute = (1 << tableLog) - distributed;
 
+    if (ToDistribute == 0)
+        return 0;
+
     if ((total / ToDistribute) > lowOne) {
         /* risk of rounding to zero */
         lowOne = (U32)((total * 3) / (ToDistribute * 2));
         for (s=0; s<=maxSymbolValue; s++) {
             if ((norm[s] == NOT_YET_ASSIGNED) && (count[s] <= lowOne)) {
                 norm[s] = 1;
                 distributed++;
                 total -= count[s];
                 continue;
         }   }
         ToDistribute = (1 << tableLog) - distributed;
     }
 
     if (distributed == maxSymbolValue+1) {
         /* all values are pretty poor;
            probably incompressible data (should have already been detected);
            find max, then give all remaining points to max */
         U32 maxV = 0, maxC = 0;
         for (s=0; s<=maxSymbolValue; s++)
             if (count[s] > maxC) { maxV=s; maxC=count[s]; }
         norm[maxV] += (short)ToDistribute;
         return 0;
     }
 
     if (total == 0) {
         /* all of the symbols were low enough for the lowOne or lowThreshold */
         for (s=0; ToDistribute > 0; s = (s+1)%(maxSymbolValue+1))
             if (norm[s] > 0) { ToDistribute--; norm[s]++; }
         return 0;
     }
 
     {   U64 const vStepLog = 62 - tableLog;
         U64 const mid = (1ULL << (vStepLog-1)) - 1;
         U64 const rStep = ((((U64)1<> vStepLog);
                 U32 const sEnd = (U32)(end >> vStepLog);
                 U32 const weight = sEnd - sStart;
                 if (weight < 1)
                     return ERROR(GENERIC);
                 norm[s] = (short)weight;
                 tmpTotal = end;
     }   }   }
 
     return 0;
 }
 
 
 size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog,
                            const unsigned* count, size_t total,
                            unsigned maxSymbolValue)
 {
     /* Sanity checks */
     if (tableLog==0) tableLog = FSE_DEFAULT_TABLELOG;
     if (tableLog < FSE_MIN_TABLELOG) return ERROR(GENERIC);   /* Unsupported size */
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);   /* Unsupported size */
     if (tableLog < FSE_minTableLog(total, maxSymbolValue)) return ERROR(GENERIC);   /* Too small tableLog, compression potentially impossible */
 
     {   static U32 const rtbTable[] = {     0, 473195, 504333, 520860, 550000, 700000, 750000, 830000 };
         U64 const scale = 62 - tableLog;
         U64 const step = ((U64)1<<62) / total;   /* <== here, one division ! */
         U64 const vStep = 1ULL<<(scale-20);
         int stillToDistribute = 1<> tableLog);
 
         for (s=0; s<=maxSymbolValue; s++) {
             if (count[s] == total) return 0;   /* rle special case */
             if (count[s] == 0) { normalizedCounter[s]=0; continue; }
             if (count[s] <= lowThreshold) {
                 normalizedCounter[s] = -1;
                 stillToDistribute--;
             } else {
                 short proba = (short)((count[s]*step) >> scale);
                 if (proba<8) {
                     U64 restToBeat = vStep * rtbTable[proba];
                     proba += (count[s]*step) - ((U64)proba< restToBeat;
                 }
                 if (proba > largestP) { largestP=proba; largest=s; }
                 normalizedCounter[s] = proba;
                 stillToDistribute -= proba;
         }   }
         if (-stillToDistribute >= (normalizedCounter[largest] >> 1)) {
             /* corner case, need another normalization method */
             size_t const errorCode = FSE_normalizeM2(normalizedCounter, tableLog, count, total, maxSymbolValue);
             if (FSE_isError(errorCode)) return errorCode;
         }
         else normalizedCounter[largest] += (short)stillToDistribute;
     }
 
 #if 0
     {   /* Print Table (debug) */
         U32 s;
         U32 nTotal = 0;
         for (s=0; s<=maxSymbolValue; s++)
-            printf("%3i: %4i \n", s, normalizedCounter[s]);
+            RAWLOG(2, "%3i: %4i \n", s, normalizedCounter[s]);
         for (s=0; s<=maxSymbolValue; s++)
             nTotal += abs(normalizedCounter[s]);
         if (nTotal != (1U<>1);   /* assumption : tableLog >= 1 */
     FSE_symbolCompressionTransform* const symbolTT = (FSE_symbolCompressionTransform*) (FSCT);
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return ERROR(GENERIC);             /* min size */
 
     /* header */
     tableU16[-2] = (U16) nbBits;
     tableU16[-1] = (U16) maxSymbolValue;
 
     /* Build table */
     for (s=0; s FSE_MAX_TABLELOG*4+7 ) && (srcSize & 2)) {  /* test bit 2 */
         FSE_encodeSymbol(&bitC, &CState2, *--ip);
         FSE_encodeSymbol(&bitC, &CState1, *--ip);
         FSE_FLUSHBITS(&bitC);
     }
 
     /* 2 or 4 encoding per loop */
     while ( ip>istart ) {
 
         FSE_encodeSymbol(&bitC, &CState2, *--ip);
 
         if (sizeof(bitC.bitContainer)*8 < FSE_MAX_TABLELOG*2+7 )   /* this test must be static */
             FSE_FLUSHBITS(&bitC);
 
         FSE_encodeSymbol(&bitC, &CState1, *--ip);
 
         if (sizeof(bitC.bitContainer)*8 > FSE_MAX_TABLELOG*4+7 ) {  /* this test must be static */
             FSE_encodeSymbol(&bitC, &CState2, *--ip);
             FSE_encodeSymbol(&bitC, &CState1, *--ip);
         }
 
         FSE_FLUSHBITS(&bitC);
     }
 
     FSE_flushCState(&bitC, &CState2);
     FSE_flushCState(&bitC, &CState1);
     return BIT_closeCStream(&bitC);
 }
 
 size_t FSE_compress_usingCTable (void* dst, size_t dstSize,
                            const void* src, size_t srcSize,
                            const FSE_CTable* ct)
 {
     unsigned const fast = (dstSize >= FSE_BLOCKBOUND(srcSize));
 
     if (fast)
         return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 1);
     else
         return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 0);
 }
 
 
 size_t FSE_compressBound(size_t size) { return FSE_COMPRESSBOUND(size); }
 
 #define CHECK_V_F(e, f) size_t const e = f; if (ERR_isError(e)) return e
 #define CHECK_F(f)   { CHECK_V_F(_var_err__, f); }
 
 /* FSE_compress_wksp() :
  * Same as FSE_compress2(), but using an externally allocated scratch buffer (`workSpace`).
  * `wkspSize` size must be `(1< not compressible */
         if (maxCount < (srcSize >> 7)) return 0;   /* Heuristic : not compressible enough */
     }
 
     tableLog = FSE_optimalTableLog(tableLog, srcSize, maxSymbolValue);
     CHECK_F( FSE_normalizeCount(norm, tableLog, count, srcSize, maxSymbolValue) );
 
     /* Write table description header */
     {   CHECK_V_F(nc_err, FSE_writeNCount(op, oend-op, norm, maxSymbolValue, tableLog) );
         op += nc_err;
     }
 
     /* Compress */
     CHECK_F( FSE_buildCTable_wksp(CTable, norm, maxSymbolValue, tableLog, scratchBuffer, scratchBufferSize) );
     {   CHECK_V_F(cSize, FSE_compress_usingCTable(op, oend - op, src, srcSize, CTable) );
         if (cSize == 0) return 0;   /* not enough space for compressed data */
         op += cSize;
     }
 
     /* check compressibility */
     if ( (size_t)(op-ostart) >= srcSize-1 ) return 0;
 
     return op-ostart;
 }
 
 typedef struct {
     FSE_CTable CTable_max[FSE_CTABLE_SIZE_U32(FSE_MAX_TABLELOG, FSE_MAX_SYMBOL_VALUE)];
     BYTE scratchBuffer[1 << FSE_MAX_TABLELOG];
 } fseWkspMax_t;
 
 size_t FSE_compress2 (void* dst, size_t dstCapacity, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog)
 {
     fseWkspMax_t scratchBuffer;
-    FSE_STATIC_ASSERT(sizeof(scratchBuffer) >= FSE_WKSP_SIZE_U32(FSE_MAX_TABLELOG, FSE_MAX_SYMBOL_VALUE));   /* compilation failures here means scratchBuffer is not large enough */
+    DEBUG_STATIC_ASSERT(sizeof(scratchBuffer) >= FSE_WKSP_SIZE_U32(FSE_MAX_TABLELOG, FSE_MAX_SYMBOL_VALUE));   /* compilation failures here means scratchBuffer is not large enough */
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
     return FSE_compress_wksp(dst, dstCapacity, src, srcSize, maxSymbolValue, tableLog, &scratchBuffer, sizeof(scratchBuffer));
 }
 
 size_t FSE_compress (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     return FSE_compress2(dst, dstCapacity, src, srcSize, FSE_MAX_SYMBOL_VALUE, FSE_DEFAULT_TABLELOG);
 }
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
Index: vendor/zstd/dist/lib/compress/hist.c
===================================================================
--- vendor/zstd/dist/lib/compress/hist.c	(nonexistent)
+++ vendor/zstd/dist/lib/compress/hist.c	(revision 339614)
@@ -0,0 +1,195 @@
+/* ******************************************************************
+   hist : Histogram functions
+   part of Finite State Entropy project
+   Copyright (C) 2013-present, Yann Collet.
+
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    You can contact the author at :
+    - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
+    - Public forum : https://groups.google.com/forum/#!forum/lz4c
+****************************************************************** */
+
+/* --- dependencies --- */
+#include "mem.h"             /* U32, BYTE, etc. */
+#include "debug.h"           /* assert, DEBUGLOG */
+#include "error_private.h"   /* ERROR */
+#include "hist.h"
+
+
+/* --- Error management --- */
+unsigned HIST_isError(size_t code) { return ERR_isError(code); }
+
+/*-**************************************************************
+ *  Histogram functions
+ ****************************************************************/
+unsigned HIST_count_simple(unsigned* count, unsigned* maxSymbolValuePtr,
+                           const void* src, size_t srcSize)
+{
+    const BYTE* ip = (const BYTE*)src;
+    const BYTE* const end = ip + srcSize;
+    unsigned maxSymbolValue = *maxSymbolValuePtr;
+    unsigned largestCount=0;
+
+    memset(count, 0, (maxSymbolValue+1) * sizeof(*count));
+    if (srcSize==0) { *maxSymbolValuePtr = 0; return 0; }
+
+    while (ip largestCount) largestCount = count[s];
+    }
+
+    return largestCount;
+}
+
+
+/* HIST_count_parallel_wksp() :
+ * store histogram into 4 intermediate tables, recombined at the end.
+ * this design makes better use of OoO cpus,
+ * and is noticeably faster when some values are heavily repeated.
+ * But it needs some additional workspace for intermediate tables.
+ * `workSpace` size must be a table of size >= HIST_WKSP_SIZE_U32.
+ * @return : largest histogram frequency,
+ *           or an error code (notably when histogram would be larger than *maxSymbolValuePtr). */
+static size_t HIST_count_parallel_wksp(
+                                unsigned* count, unsigned* maxSymbolValuePtr,
+                                const void* source, size_t sourceSize,
+                                unsigned checkMax,
+                                unsigned* const workSpace)
+{
+    const BYTE* ip = (const BYTE*)source;
+    const BYTE* const iend = ip+sourceSize;
+    unsigned maxSymbolValue = *maxSymbolValuePtr;
+    unsigned max=0;
+    U32* const Counting1 = workSpace;
+    U32* const Counting2 = Counting1 + 256;
+    U32* const Counting3 = Counting2 + 256;
+    U32* const Counting4 = Counting3 + 256;
+
+    memset(workSpace, 0, 4*256*sizeof(unsigned));
+
+    /* safety checks */
+    if (!sourceSize) {
+        memset(count, 0, maxSymbolValue + 1);
+        *maxSymbolValuePtr = 0;
+        return 0;
+    }
+    if (!maxSymbolValue) maxSymbolValue = 255;            /* 0 == default */
+
+    /* by stripes of 16 bytes */
+    {   U32 cached = MEM_read32(ip); ip += 4;
+        while (ip < iend-15) {
+            U32 c = cached; cached = MEM_read32(ip); ip += 4;
+            Counting1[(BYTE) c     ]++;
+            Counting2[(BYTE)(c>>8) ]++;
+            Counting3[(BYTE)(c>>16)]++;
+            Counting4[       c>>24 ]++;
+            c = cached; cached = MEM_read32(ip); ip += 4;
+            Counting1[(BYTE) c     ]++;
+            Counting2[(BYTE)(c>>8) ]++;
+            Counting3[(BYTE)(c>>16)]++;
+            Counting4[       c>>24 ]++;
+            c = cached; cached = MEM_read32(ip); ip += 4;
+            Counting1[(BYTE) c     ]++;
+            Counting2[(BYTE)(c>>8) ]++;
+            Counting3[(BYTE)(c>>16)]++;
+            Counting4[       c>>24 ]++;
+            c = cached; cached = MEM_read32(ip); ip += 4;
+            Counting1[(BYTE) c     ]++;
+            Counting2[(BYTE)(c>>8) ]++;
+            Counting3[(BYTE)(c>>16)]++;
+            Counting4[       c>>24 ]++;
+        }
+        ip-=4;
+    }
+
+    /* finish last symbols */
+    while (ipmaxSymbolValue; s--) {
+            Counting1[s] += Counting2[s] + Counting3[s] + Counting4[s];
+            if (Counting1[s]) return ERROR(maxSymbolValue_tooSmall);
+    }   }
+
+    {   U32 s;
+        if (maxSymbolValue > 255) maxSymbolValue = 255;
+        for (s=0; s<=maxSymbolValue; s++) {
+            count[s] = Counting1[s] + Counting2[s] + Counting3[s] + Counting4[s];
+            if (count[s] > max) max = count[s];
+    }   }
+
+    while (!count[maxSymbolValue]) maxSymbolValue--;
+    *maxSymbolValuePtr = maxSymbolValue;
+    return (size_t)max;
+}
+
+/* HIST_countFast_wksp() :
+ * Same as HIST_countFast(), but using an externally provided scratch buffer.
+ * `workSpace` size must be table of >= HIST_WKSP_SIZE_U32 unsigned */
+size_t HIST_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
+                          const void* source, size_t sourceSize,
+                          unsigned* workSpace)
+{
+    if (sourceSize < 1500) /* heuristic threshold */
+        return HIST_count_simple(count, maxSymbolValuePtr, source, sourceSize);
+    return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 0, workSpace);
+}
+
+/* fast variant (unsafe : won't check if src contains values beyond count[] limit) */
+size_t HIST_countFast(unsigned* count, unsigned* maxSymbolValuePtr,
+                     const void* source, size_t sourceSize)
+{
+    unsigned tmpCounters[HIST_WKSP_SIZE_U32];
+    return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, tmpCounters);
+}
+
+/* HIST_count_wksp() :
+ * Same as HIST_count(), but using an externally provided scratch buffer.
+ * `workSpace` size must be table of >= HIST_WKSP_SIZE_U32 unsigned */
+size_t HIST_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
+                 const void* source, size_t sourceSize, unsigned* workSpace)
+{
+    if (*maxSymbolValuePtr < 255)
+        return HIST_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 1, workSpace);
+    *maxSymbolValuePtr = 255;
+    return HIST_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, workSpace);
+}
+
+size_t HIST_count(unsigned* count, unsigned* maxSymbolValuePtr,
+                 const void* src, size_t srcSize)
+{
+    unsigned tmpCounters[HIST_WKSP_SIZE_U32];
+    return HIST_count_wksp(count, maxSymbolValuePtr, src, srcSize, tmpCounters);
+}

Property changes on: vendor/zstd/dist/lib/compress/hist.c
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
Index: vendor/zstd/dist/lib/compress/hist.h
===================================================================
--- vendor/zstd/dist/lib/compress/hist.h	(nonexistent)
+++ vendor/zstd/dist/lib/compress/hist.h	(revision 339614)
@@ -0,0 +1,92 @@
+/* ******************************************************************
+   hist : Histogram functions
+   part of Finite State Entropy project
+   Copyright (C) 2013-present, Yann Collet.
+
+   BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions are
+   met:
+
+       * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above
+   copyright notice, this list of conditions and the following disclaimer
+   in the documentation and/or other materials provided with the
+   distribution.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    You can contact the author at :
+    - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
+    - Public forum : https://groups.google.com/forum/#!forum/lz4c
+****************************************************************** */
+
+/* --- dependencies --- */
+#include    /* size_t */
+
+
+/* --- simple histogram functions --- */
+
+/*! HIST_count():
+ *  Provides the precise count of each byte within a table 'count'.
+ *  'count' is a table of unsigned int, of minimum size (*maxSymbolValuePtr+1).
+ *  Updates *maxSymbolValuePtr with actual largest symbol value detected.
+ *  @return : count of the most frequent symbol (which isn't identified).
+ *            or an error code, which can be tested using HIST_isError().
+ *            note : if return == srcSize, there is only one symbol.
+ */
+size_t HIST_count(unsigned* count, unsigned* maxSymbolValuePtr,
+                  const void* src, size_t srcSize);
+
+unsigned HIST_isError(size_t code);  /**< tells if a return value is an error code */
+
+
+/* --- advanced histogram functions --- */
+
+#define HIST_WKSP_SIZE_U32 1024
+/** HIST_count_wksp() :
+ *  Same as HIST_count(), but using an externally provided scratch buffer.
+ *  Benefit is this function will use very little stack space.
+ * `workSpace` must be a table of unsigned of size >= HIST_WKSP_SIZE_U32
+ */
+size_t HIST_count_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
+                       const void* src, size_t srcSize,
+                       unsigned* workSpace);
+
+/** HIST_countFast() :
+ *  same as HIST_count(), but blindly trusts that all byte values within src are <= *maxSymbolValuePtr.
+ *  This function is unsafe, and will segfault if any value within `src` is `> *maxSymbolValuePtr`
+ */
+size_t HIST_countFast(unsigned* count, unsigned* maxSymbolValuePtr,
+                      const void* src, size_t srcSize);
+
+/** HIST_countFast_wksp() :
+ *  Same as HIST_countFast(), but using an externally provided scratch buffer.
+ * `workSpace` must be a table of unsigned of size >= HIST_WKSP_SIZE_U32
+ */
+size_t HIST_countFast_wksp(unsigned* count, unsigned* maxSymbolValuePtr,
+                           const void* src, size_t srcSize,
+                           unsigned* workSpace);
+
+/*! HIST_count_simple() :
+ *  Same as HIST_countFast(), this function is unsafe,
+ *  and will segfault if any value within `src` is `> *maxSymbolValuePtr`.
+ *  It is also a bit slower for large inputs.
+ *  However, it does not need any additional memory (not even on stack).
+ * @return : count of the most frequent symbol.
+ *  Note this function doesn't produce any error (i.e. it must succeed).
+ */
+unsigned HIST_count_simple(unsigned* count, unsigned* maxSymbolValuePtr,
+                           const void* src, size_t srcSize);

Property changes on: vendor/zstd/dist/lib/compress/hist.h
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
Index: vendor/zstd/dist/lib/compress/huf_compress.c
===================================================================
--- vendor/zstd/dist/lib/compress/huf_compress.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/huf_compress.c	(revision 339614)
@@ -1,788 +1,796 @@
 /* ******************************************************************
    Huffman encoder, part of New Generation Entropy library
    Copyright (C) 2013-2016, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 /* **************************************************************
 *  Compiler specifics
 ****************************************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #endif
 
 
 /* **************************************************************
 *  Includes
 ****************************************************************/
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
-#include "bitstream.h"
 #include "compiler.h"
+#include "bitstream.h"
+#include "hist.h"
 #define FSE_STATIC_LINKING_ONLY   /* FSE_optimalTableLog_internal */
 #include "fse.h"        /* header compression */
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "error_private.h"
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #define HUF_isError ERR_isError
-#define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
+#define HUF_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)   /* use only *after* variable declarations */
 #define CHECK_V_F(e, f) size_t const e = f; if (ERR_isError(e)) return e
 #define CHECK_F(f)   { CHECK_V_F(_var_err__, f); }
 
 
 /* **************************************************************
 *  Utils
 ****************************************************************/
 unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue)
 {
     return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 1);
 }
 
 
 /* *******************************************************
 *  HUF : Huffman block compression
 *********************************************************/
 /* HUF_compressWeights() :
  * Same as FSE_compress(), but dedicated to huff0's weights compression.
  * The use case needs much less stack memory.
  * Note : all elements within weightTable are supposed to be <= HUF_TABLELOG_MAX.
  */
 #define MAX_FSE_TABLELOG_FOR_HUFF_HEADER 6
-size_t HUF_compressWeights (void* dst, size_t dstSize, const void* weightTable, size_t wtSize)
+static size_t HUF_compressWeights (void* dst, size_t dstSize, const void* weightTable, size_t wtSize)
 {
     BYTE* const ostart = (BYTE*) dst;
     BYTE* op = ostart;
     BYTE* const oend = ostart + dstSize;
 
     U32 maxSymbolValue = HUF_TABLELOG_MAX;
     U32 tableLog = MAX_FSE_TABLELOG_FOR_HUFF_HEADER;
 
     FSE_CTable CTable[FSE_CTABLE_SIZE_U32(MAX_FSE_TABLELOG_FOR_HUFF_HEADER, HUF_TABLELOG_MAX)];
     BYTE scratchBuffer[1< not compressible */
+        if (maxCount == 1) return 0;        /* each symbol present maximum once => not compressible */
     }
 
     tableLog = FSE_optimalTableLog(tableLog, wtSize, maxSymbolValue);
     CHECK_F( FSE_normalizeCount(norm, tableLog, count, wtSize, maxSymbolValue) );
 
     /* Write table description header */
     {   CHECK_V_F(hSize, FSE_writeNCount(op, oend-op, norm, maxSymbolValue, tableLog) );
         op += hSize;
     }
 
     /* Compress */
     CHECK_F( FSE_buildCTable_wksp(CTable, norm, maxSymbolValue, tableLog, scratchBuffer, sizeof(scratchBuffer)) );
     {   CHECK_V_F(cSize, FSE_compress_usingCTable(op, oend - op, weightTable, wtSize, CTable) );
         if (cSize == 0) return 0;   /* not enough space for compressed data */
         op += cSize;
     }
 
     return op-ostart;
 }
 
 
 struct HUF_CElt_s {
   U16  val;
   BYTE nbBits;
 };   /* typedef'd to HUF_CElt within "huf.h" */
 
 /*! HUF_writeCTable() :
     `CTable` : Huffman tree to save, using huf representation.
     @return : size of saved CTable */
 size_t HUF_writeCTable (void* dst, size_t maxDstSize,
                         const HUF_CElt* CTable, U32 maxSymbolValue, U32 huffLog)
 {
     BYTE bitsToWeight[HUF_TABLELOG_MAX + 1];   /* precomputed conversion table */
     BYTE huffWeight[HUF_SYMBOLVALUE_MAX];
     BYTE* op = (BYTE*)dst;
     U32 n;
 
      /* check conditions */
     if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
 
     /* convert to weight */
     bitsToWeight[0] = 0;
     for (n=1; n1) & (hSize < maxSymbolValue/2)) {   /* FSE compressed */
             op[0] = (BYTE)hSize;
             return hSize+1;
     }   }
 
     /* write raw values as 4-bits (max : 15) */
     if (maxSymbolValue > (256-128)) return ERROR(GENERIC);   /* should not happen : likely means source cannot be compressed */
     if (((maxSymbolValue+1)/2) + 1 > maxDstSize) return ERROR(dstSize_tooSmall);   /* not enough space within dst buffer */
     op[0] = (BYTE)(128 /*special case*/ + (maxSymbolValue-1));
     huffWeight[maxSymbolValue] = 0;   /* to be sure it doesn't cause msan issue in final combination */
     for (n=0; n HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
     if (nbSymbols > *maxSymbolValuePtr+1) return ERROR(maxSymbolValue_tooSmall);
 
     /* Prepare base value per rank */
     {   U32 n, nextRankStart = 0;
         for (n=1; n<=tableLog; n++) {
             U32 current = nextRankStart;
             nextRankStart += (rankVal[n] << (n-1));
             rankVal[n] = current;
     }   }
 
     /* fill nbBits */
     {   U32 n; for (n=0; nn=tableLog+1 */
         U16 valPerRank[HUF_TABLELOG_MAX+2] = {0};
         { U32 n; for (n=0; n0; n--) {  /* start at n=tablelog <-> w=1 */
                 valPerRank[n] = min;     /* get starting value within each rank */
                 min += nbPerRank[n];
                 min >>= 1;
         }   }
         /* assign value within rank, symbol order */
         { U32 n; for (n=0; n maxNbBits */
 
     /* there are several too large elements (at least >= 2) */
     {   int totalCost = 0;
         const U32 baseCost = 1 << (largestBits - maxNbBits);
         U32 n = lastNonNull;
 
         while (huffNode[n].nbBits > maxNbBits) {
             totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits));
             huffNode[n].nbBits = (BYTE)maxNbBits;
             n --;
         }  /* n stops at huffNode[n].nbBits <= maxNbBits */
         while (huffNode[n].nbBits == maxNbBits) n--;   /* n end at index of smallest symbol using < maxNbBits */
 
         /* renorm totalCost */
         totalCost >>= (largestBits - maxNbBits);  /* note : totalCost is necessarily a multiple of baseCost */
 
         /* repay normalized cost */
         {   U32 const noSymbol = 0xF0F0F0F0;
             U32 rankLast[HUF_TABLELOG_MAX+2];
             int pos;
 
             /* Get pos of last (smallest) symbol per rank */
             memset(rankLast, 0xF0, sizeof(rankLast));
             {   U32 currentNbBits = maxNbBits;
                 for (pos=n ; pos >= 0; pos--) {
                     if (huffNode[pos].nbBits >= currentNbBits) continue;
                     currentNbBits = huffNode[pos].nbBits;   /* < maxNbBits */
                     rankLast[maxNbBits-currentNbBits] = pos;
             }   }
 
             while (totalCost > 0) {
                 U32 nBitsToDecrease = BIT_highbit32(totalCost) + 1;
                 for ( ; nBitsToDecrease > 1; nBitsToDecrease--) {
                     U32 highPos = rankLast[nBitsToDecrease];
                     U32 lowPos = rankLast[nBitsToDecrease-1];
                     if (highPos == noSymbol) continue;
                     if (lowPos == noSymbol) break;
                     {   U32 const highTotal = huffNode[highPos].count;
                         U32 const lowTotal = 2 * huffNode[lowPos].count;
                         if (highTotal <= lowTotal) break;
                 }   }
                 /* only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !) */
                 /* HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary */
                 while ((nBitsToDecrease<=HUF_TABLELOG_MAX) && (rankLast[nBitsToDecrease] == noSymbol))
                     nBitsToDecrease ++;
                 totalCost -= 1 << (nBitsToDecrease-1);
                 if (rankLast[nBitsToDecrease-1] == noSymbol)
                     rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease];   /* this rank is no longer empty */
                 huffNode[rankLast[nBitsToDecrease]].nbBits ++;
                 if (rankLast[nBitsToDecrease] == 0)    /* special case, reached largest symbol */
                     rankLast[nBitsToDecrease] = noSymbol;
                 else {
                     rankLast[nBitsToDecrease]--;
                     if (huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits-nBitsToDecrease)
                         rankLast[nBitsToDecrease] = noSymbol;   /* this rank is now empty */
             }   }   /* while (totalCost > 0) */
 
             while (totalCost < 0) {  /* Sometimes, cost correction overshoot */
                 if (rankLast[1] == noSymbol) {  /* special case : no rank 1 symbol (using maxNbBits-1); let's create one from largest rank 0 (using maxNbBits) */
                     while (huffNode[n].nbBits == maxNbBits) n--;
                     huffNode[n+1].nbBits--;
                     rankLast[1] = n+1;
                     totalCost++;
                     continue;
                 }
                 huffNode[ rankLast[1] + 1 ].nbBits--;
                 rankLast[1]++;
                 totalCost ++;
     }   }   }   /* there are several too large elements (at least >= 2) */
 
     return maxNbBits;
 }
 
 
 typedef struct {
     U32 base;
     U32 current;
 } rankPos;
 
 static void HUF_sort(nodeElt* huffNode, const U32* count, U32 maxSymbolValue)
 {
     rankPos rank[32];
     U32 n;
 
     memset(rank, 0, sizeof(rank));
     for (n=0; n<=maxSymbolValue; n++) {
         U32 r = BIT_highbit32(count[n] + 1);
         rank[r].base ++;
     }
     for (n=30; n>0; n--) rank[n-1].base += rank[n].base;
     for (n=0; n<32; n++) rank[n].current = rank[n].base;
     for (n=0; n<=maxSymbolValue; n++) {
         U32 const c = count[n];
         U32 const r = BIT_highbit32(c+1) + 1;
         U32 pos = rank[r].current++;
         while ((pos > rank[r].base) && (c > huffNode[pos-1].count)) {
             huffNode[pos] = huffNode[pos-1];
             pos--;
         }
         huffNode[pos].count = c;
         huffNode[pos].byte  = (BYTE)n;
     }
 }
 
 
 /** HUF_buildCTable_wksp() :
  *  Same as HUF_buildCTable(), but using externally allocated scratch buffer.
  *  `workSpace` must be aligned on 4-bytes boundaries, and be at least as large as a table of HUF_CTABLE_WORKSPACE_SIZE_U32 unsigned.
  */
 #define STARTNODE (HUF_SYMBOLVALUE_MAX+1)
 typedef nodeElt huffNodeTable[HUF_CTABLE_WORKSPACE_SIZE_U32];
 size_t HUF_buildCTable_wksp (HUF_CElt* tree, const U32* count, U32 maxSymbolValue, U32 maxNbBits, void* workSpace, size_t wkspSize)
 {
     nodeElt* const huffNode0 = (nodeElt*)workSpace;
     nodeElt* const huffNode = huffNode0+1;
     U32 n, nonNullRank;
     int lowS, lowN;
     U16 nodeNb = STARTNODE;
     U32 nodeRoot;
 
     /* safety checks */
     if (((size_t)workSpace & 3) != 0) return ERROR(GENERIC);  /* must be aligned on 4-bytes boundaries */
     if (wkspSize < sizeof(huffNodeTable)) return ERROR(workSpace_tooSmall);
     if (maxNbBits == 0) maxNbBits = HUF_TABLELOG_DEFAULT;
     if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
     memset(huffNode0, 0, sizeof(huffNodeTable));
 
     /* sort, decreasing order */
     HUF_sort(huffNode, count, maxSymbolValue);
 
     /* init for parents */
     nonNullRank = maxSymbolValue;
     while(huffNode[nonNullRank].count == 0) nonNullRank--;
     lowS = nonNullRank; nodeRoot = nodeNb + lowS - 1; lowN = nodeNb;
     huffNode[nodeNb].count = huffNode[lowS].count + huffNode[lowS-1].count;
     huffNode[lowS].parent = huffNode[lowS-1].parent = nodeNb;
     nodeNb++; lowS-=2;
     for (n=nodeNb; n<=nodeRoot; n++) huffNode[n].count = (U32)(1U<<30);
     huffNode0[0].count = (U32)(1U<<31);  /* fake entry, strong barrier */
 
     /* create parents */
     while (nodeNb <= nodeRoot) {
         U32 n1 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
         U32 n2 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
         huffNode[nodeNb].count = huffNode[n1].count + huffNode[n2].count;
         huffNode[n1].parent = huffNode[n2].parent = nodeNb;
         nodeNb++;
     }
 
     /* distribute weights (unlimited tree height) */
     huffNode[nodeRoot].nbBits = 0;
     for (n=nodeRoot-1; n>=STARTNODE; n--)
         huffNode[n].nbBits = huffNode[ huffNode[n].parent ].nbBits + 1;
     for (n=0; n<=nonNullRank; n++)
         huffNode[n].nbBits = huffNode[ huffNode[n].parent ].nbBits + 1;
 
     /* enforce maxTableLog */
     maxNbBits = HUF_setMaxHeight(huffNode, nonNullRank, maxNbBits);
 
     /* fill result into tree (val, nbBits) */
     {   U16 nbPerRank[HUF_TABLELOG_MAX+1] = {0};
         U16 valPerRank[HUF_TABLELOG_MAX+1] = {0};
         if (maxNbBits > HUF_TABLELOG_MAX) return ERROR(GENERIC);   /* check fit into table */
         for (n=0; n<=nonNullRank; n++)
             nbPerRank[huffNode[n].nbBits]++;
         /* determine stating value per rank */
         {   U16 min = 0;
             for (n=maxNbBits; n>0; n--) {
                 valPerRank[n] = min;      /* get starting value within each rank */
                 min += nbPerRank[n];
                 min >>= 1;
         }   }
         for (n=0; n<=maxSymbolValue; n++)
             tree[huffNode[n].byte].nbBits = huffNode[n].nbBits;   /* push nbBits per symbol, symbol order */
         for (n=0; n<=maxSymbolValue; n++)
             tree[n].val = valPerRank[tree[n].nbBits]++;   /* assign value within rank, symbol order */
     }
 
     return maxNbBits;
 }
 
 /** HUF_buildCTable() :
  * @return : maxNbBits
  *  Note : count is used before tree is written, so they can safely overlap
  */
 size_t HUF_buildCTable (HUF_CElt* tree, const U32* count, U32 maxSymbolValue, U32 maxNbBits)
 {
     huffNodeTable nodeTable;
     return HUF_buildCTable_wksp(tree, count, maxSymbolValue, maxNbBits, nodeTable, sizeof(nodeTable));
 }
 
 static size_t HUF_estimateCompressedSize(HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue)
 {
     size_t nbBits = 0;
     int s;
     for (s = 0; s <= (int)maxSymbolValue; ++s) {
         nbBits += CTable[s].nbBits * count[s];
     }
     return nbBits >> 3;
 }
 
 static int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue) {
   int bad = 0;
   int s;
   for (s = 0; s <= (int)maxSymbolValue; ++s) {
     bad |= (count[s] != 0) & (CTable[s].nbBits == 0);
   }
   return !bad;
 }
 
 size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); }
 
 FORCE_INLINE_TEMPLATE void
 HUF_encodeSymbol(BIT_CStream_t* bitCPtr, U32 symbol, const HUF_CElt* CTable)
 {
     BIT_addBitsFast(bitCPtr, CTable[symbol].val, CTable[symbol].nbBits);
 }
 
 #define HUF_FLUSHBITS(s)  BIT_flushBits(s)
 
 #define HUF_FLUSHBITS_1(stream) \
     if (sizeof((stream)->bitContainer)*8 < HUF_TABLELOG_MAX*2+7) HUF_FLUSHBITS(stream)
 
 #define HUF_FLUSHBITS_2(stream) \
     if (sizeof((stream)->bitContainer)*8 < HUF_TABLELOG_MAX*4+7) HUF_FLUSHBITS(stream)
 
 FORCE_INLINE_TEMPLATE size_t
 HUF_compress1X_usingCTable_internal_body(void* dst, size_t dstSize,
                                    const void* src, size_t srcSize,
                                    const HUF_CElt* CTable)
 {
     const BYTE* ip = (const BYTE*) src;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* const oend = ostart + dstSize;
     BYTE* op = ostart;
     size_t n;
     BIT_CStream_t bitC;
 
     /* init */
     if (dstSize < 8) return 0;   /* not enough space to compress */
     { size_t const initErr = BIT_initCStream(&bitC, op, oend-op);
       if (HUF_isError(initErr)) return 0; }
 
     n = srcSize & ~3;  /* join to mod 4 */
     switch (srcSize & 3)
     {
         case 3 : HUF_encodeSymbol(&bitC, ip[n+ 2], CTable);
                  HUF_FLUSHBITS_2(&bitC);
 		 /* fall-through */
         case 2 : HUF_encodeSymbol(&bitC, ip[n+ 1], CTable);
                  HUF_FLUSHBITS_1(&bitC);
 		 /* fall-through */
         case 1 : HUF_encodeSymbol(&bitC, ip[n+ 0], CTable);
                  HUF_FLUSHBITS(&bitC);
 		 /* fall-through */
         case 0 : /* fall-through */
         default: break;
     }
 
     for (; n>0; n-=4) {  /* note : n&3==0 at this stage */
         HUF_encodeSymbol(&bitC, ip[n- 1], CTable);
         HUF_FLUSHBITS_1(&bitC);
         HUF_encodeSymbol(&bitC, ip[n- 2], CTable);
         HUF_FLUSHBITS_2(&bitC);
         HUF_encodeSymbol(&bitC, ip[n- 3], CTable);
         HUF_FLUSHBITS_1(&bitC);
         HUF_encodeSymbol(&bitC, ip[n- 4], CTable);
         HUF_FLUSHBITS(&bitC);
     }
 
     return BIT_closeCStream(&bitC);
 }
 
 #if DYNAMIC_BMI2
 
 static TARGET_ATTRIBUTE("bmi2") size_t
 HUF_compress1X_usingCTable_internal_bmi2(void* dst, size_t dstSize,
                                    const void* src, size_t srcSize,
                                    const HUF_CElt* CTable)
 {
     return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
 }
 
 static size_t
 HUF_compress1X_usingCTable_internal_default(void* dst, size_t dstSize,
                                       const void* src, size_t srcSize,
                                       const HUF_CElt* CTable)
 {
     return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
 }
 
 static size_t
 HUF_compress1X_usingCTable_internal(void* dst, size_t dstSize,
                               const void* src, size_t srcSize,
                               const HUF_CElt* CTable, const int bmi2)
 {
     if (bmi2) {
         return HUF_compress1X_usingCTable_internal_bmi2(dst, dstSize, src, srcSize, CTable);
     }
     return HUF_compress1X_usingCTable_internal_default(dst, dstSize, src, srcSize, CTable);
 }
 
 #else
 
 static size_t
 HUF_compress1X_usingCTable_internal(void* dst, size_t dstSize,
                               const void* src, size_t srcSize,
                               const HUF_CElt* CTable, const int bmi2)
 {
     (void)bmi2;
     return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
 }
 
 #endif
 
 size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable)
 {
     return HUF_compress1X_usingCTable_internal(dst, dstSize, src, srcSize, CTable, /* bmi2 */ 0);
 }
 
 
 static size_t
 HUF_compress4X_usingCTable_internal(void* dst, size_t dstSize,
                               const void* src, size_t srcSize,
                               const HUF_CElt* CTable, int bmi2)
 {
     size_t const segmentSize = (srcSize+3)/4;   /* first 3 segments */
     const BYTE* ip = (const BYTE*) src;
     const BYTE* const iend = ip + srcSize;
     BYTE* const ostart = (BYTE*) dst;
     BYTE* const oend = ostart + dstSize;
     BYTE* op = ostart;
 
     if (dstSize < 6 + 1 + 1 + 1 + 8) return 0;   /* minimum space to compress successfully */
     if (srcSize < 12) return 0;   /* no saving possible : too small input */
     op += 6;   /* jumpTable */
 
     {   CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, oend-op, ip, segmentSize, CTable, bmi2) );
         if (cSize==0) return 0;
         assert(cSize <= 65535);
         MEM_writeLE16(ostart, (U16)cSize);
         op += cSize;
     }
 
     ip += segmentSize;
     {   CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, oend-op, ip, segmentSize, CTable, bmi2) );
         if (cSize==0) return 0;
         assert(cSize <= 65535);
         MEM_writeLE16(ostart+2, (U16)cSize);
         op += cSize;
     }
 
     ip += segmentSize;
     {   CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, oend-op, ip, segmentSize, CTable, bmi2) );
         if (cSize==0) return 0;
         assert(cSize <= 65535);
         MEM_writeLE16(ostart+4, (U16)cSize);
         op += cSize;
     }
 
     ip += segmentSize;
     {   CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, oend-op, ip, iend-ip, CTable, bmi2) );
         if (cSize==0) return 0;
         op += cSize;
     }
 
     return op-ostart;
 }
 
 size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable)
 {
     return HUF_compress4X_usingCTable_internal(dst, dstSize, src, srcSize, CTable, /* bmi2 */ 0);
 }
 
 
 static size_t HUF_compressCTable_internal(
                 BYTE* const ostart, BYTE* op, BYTE* const oend,
                 const void* src, size_t srcSize,
                 unsigned singleStream, const HUF_CElt* CTable, const int bmi2)
 {
     size_t const cSize = singleStream ?
                          HUF_compress1X_usingCTable_internal(op, oend - op, src, srcSize, CTable, bmi2) :
                          HUF_compress4X_usingCTable_internal(op, oend - op, src, srcSize, CTable, bmi2);
     if (HUF_isError(cSize)) { return cSize; }
     if (cSize==0) { return 0; }   /* uncompressible */
     op += cSize;
     /* check compressibility */
     if ((size_t)(op-ostart) >= srcSize-1) { return 0; }
     return op-ostart;
 }
 
 typedef struct {
     U32 count[HUF_SYMBOLVALUE_MAX + 1];
     HUF_CElt CTable[HUF_SYMBOLVALUE_MAX + 1];
     huffNodeTable nodeTable;
 } HUF_compress_tables_t;
 
 /* HUF_compress_internal() :
  * `workSpace` must a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */
 static size_t HUF_compress_internal (
                 void* dst, size_t dstSize,
                 const void* src, size_t srcSize,
                 unsigned maxSymbolValue, unsigned huffLog,
                 unsigned singleStream,
                 void* workSpace, size_t wkspSize,
                 HUF_CElt* oldHufTable, HUF_repeat* repeat, int preferRepeat,
                 const int bmi2)
 {
     HUF_compress_tables_t* const table = (HUF_compress_tables_t*)workSpace;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* const oend = ostart + dstSize;
     BYTE* op = ostart;
 
     /* checks & inits */
     if (((size_t)workSpace & 3) != 0) return ERROR(GENERIC);  /* must be aligned on 4-bytes boundaries */
     if (wkspSize < sizeof(*table)) return ERROR(workSpace_tooSmall);
     if (!srcSize) return 0;  /* Uncompressed */
     if (!dstSize) return 0;  /* cannot fit anything within dst budget */
     if (srcSize > HUF_BLOCKSIZE_MAX) return ERROR(srcSize_wrong);   /* current block size limit */
     if (huffLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
     if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
     if (!maxSymbolValue) maxSymbolValue = HUF_SYMBOLVALUE_MAX;
     if (!huffLog) huffLog = HUF_TABLELOG_DEFAULT;
 
     /* Heuristic : If old table is valid, use it for small inputs */
     if (preferRepeat && repeat && *repeat == HUF_repeat_valid) {
         return HUF_compressCTable_internal(ostart, op, oend,
                                            src, srcSize,
                                            singleStream, oldHufTable, bmi2);
     }
 
     /* Scan input and build symbol stats */
-    {   CHECK_V_F(largest, FSE_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, table->count) );
+    {   CHECK_V_F(largest, HIST_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, table->count) );
         if (largest == srcSize) { *ostart = ((const BYTE*)src)[0]; return 1; }   /* single symbol, rle */
-        if (largest <= (srcSize >> 7)+1) return 0;   /* heuristic : probably not compressible enough */
+        if (largest <= (srcSize >> 7)+4) return 0;   /* heuristic : probably not compressible enough */
     }
 
     /* Check validity of previous table */
     if ( repeat
       && *repeat == HUF_repeat_check
       && !HUF_validateCTable(oldHufTable, table->count, maxSymbolValue)) {
         *repeat = HUF_repeat_none;
     }
     /* Heuristic : use existing table for small inputs */
     if (preferRepeat && repeat && *repeat != HUF_repeat_none) {
         return HUF_compressCTable_internal(ostart, op, oend,
                                            src, srcSize,
                                            singleStream, oldHufTable, bmi2);
     }
 
     /* Build Huffman Tree */
     huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
     {   CHECK_V_F(maxBits, HUF_buildCTable_wksp(table->CTable, table->count,
                                                 maxSymbolValue, huffLog,
                                                 table->nodeTable, sizeof(table->nodeTable)) );
         huffLog = (U32)maxBits;
         /* Zero unused symbols in CTable, so we can check it for validity */
         memset(table->CTable + (maxSymbolValue + 1), 0,
                sizeof(table->CTable) - ((maxSymbolValue + 1) * sizeof(HUF_CElt)));
     }
 
     /* Write table description header */
     {   CHECK_V_F(hSize, HUF_writeCTable (op, dstSize, table->CTable, maxSymbolValue, huffLog) );
         /* Check if using previous huffman table is beneficial */
         if (repeat && *repeat != HUF_repeat_none) {
             size_t const oldSize = HUF_estimateCompressedSize(oldHufTable, table->count, maxSymbolValue);
             size_t const newSize = HUF_estimateCompressedSize(table->CTable, table->count, maxSymbolValue);
             if (oldSize <= hSize + newSize || hSize + 12 >= srcSize) {
                 return HUF_compressCTable_internal(ostart, op, oend,
                                                    src, srcSize,
                                                    singleStream, oldHufTable, bmi2);
         }   }
 
         /* Use the new huffman table */
         if (hSize + 12ul >= srcSize) { return 0; }
         op += hSize;
         if (repeat) { *repeat = HUF_repeat_none; }
         if (oldHufTable)
             memcpy(oldHufTable, table->CTable, sizeof(table->CTable));  /* Save new table */
     }
     return HUF_compressCTable_internal(ostart, op, oend,
                                        src, srcSize,
                                        singleStream, table->CTable, bmi2);
 }
 
 
 size_t HUF_compress1X_wksp (void* dst, size_t dstSize,
                       const void* src, size_t srcSize,
                       unsigned maxSymbolValue, unsigned huffLog,
                       void* workSpace, size_t wkspSize)
 {
     return HUF_compress_internal(dst, dstSize, src, srcSize,
                                  maxSymbolValue, huffLog, 1 /*single stream*/,
                                  workSpace, wkspSize,
                                  NULL, NULL, 0, 0 /*bmi2*/);
 }
 
 size_t HUF_compress1X_repeat (void* dst, size_t dstSize,
                       const void* src, size_t srcSize,
                       unsigned maxSymbolValue, unsigned huffLog,
                       void* workSpace, size_t wkspSize,
                       HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2)
 {
     return HUF_compress_internal(dst, dstSize, src, srcSize,
                                  maxSymbolValue, huffLog, 1 /*single stream*/,
                                  workSpace, wkspSize, hufTable,
                                  repeat, preferRepeat, bmi2);
 }
 
 size_t HUF_compress1X (void* dst, size_t dstSize,
                  const void* src, size_t srcSize,
                  unsigned maxSymbolValue, unsigned huffLog)
 {
     unsigned workSpace[HUF_WORKSPACE_SIZE_U32];
     return HUF_compress1X_wksp(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, workSpace, sizeof(workSpace));
 }
 
 /* HUF_compress4X_repeat():
  * compress input using 4 streams.
  * provide workspace to generate compression tables */
 size_t HUF_compress4X_wksp (void* dst, size_t dstSize,
                       const void* src, size_t srcSize,
                       unsigned maxSymbolValue, unsigned huffLog,
                       void* workSpace, size_t wkspSize)
 {
     return HUF_compress_internal(dst, dstSize, src, srcSize,
                                  maxSymbolValue, huffLog, 0 /*4 streams*/,
                                  workSpace, wkspSize,
                                  NULL, NULL, 0, 0 /*bmi2*/);
 }
 
 /* HUF_compress4X_repeat():
  * compress input using 4 streams.
  * re-use an existing huffman compression table */
 size_t HUF_compress4X_repeat (void* dst, size_t dstSize,
                       const void* src, size_t srcSize,
                       unsigned maxSymbolValue, unsigned huffLog,
                       void* workSpace, size_t wkspSize,
                       HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2)
 {
     return HUF_compress_internal(dst, dstSize, src, srcSize,
                                  maxSymbolValue, huffLog, 0 /* 4 streams */,
                                  workSpace, wkspSize,
                                  hufTable, repeat, preferRepeat, bmi2);
 }
 
 size_t HUF_compress2 (void* dst, size_t dstSize,
                 const void* src, size_t srcSize,
                 unsigned maxSymbolValue, unsigned huffLog)
 {
     unsigned workSpace[HUF_WORKSPACE_SIZE_U32];
     return HUF_compress4X_wksp(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, workSpace, sizeof(workSpace));
 }
 
 size_t HUF_compress (void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     return HUF_compress2(dst, maxDstSize, src, srcSize, 255, HUF_TABLELOG_DEFAULT);
 }
Index: vendor/zstd/dist/lib/compress/zstd_compress.c
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_compress.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_compress.c	(revision 339614)
@@ -1,3449 +1,4040 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
-
 /*-*************************************
-*  Tuning parameters
-***************************************/
-#ifndef ZSTD_CLEVEL_DEFAULT
-#  define ZSTD_CLEVEL_DEFAULT 3
-#endif
-
-
-/*-*************************************
 *  Dependencies
 ***************************************/
 #include          /* memset */
 #include "cpu.h"
 #include "mem.h"
+#include "hist.h"           /* HIST_countFast_wksp */
 #define FSE_STATIC_LINKING_ONLY   /* FSE_encodeSymbol */
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_compress_internal.h"
 #include "zstd_fast.h"
 #include "zstd_double_fast.h"
 #include "zstd_lazy.h"
 #include "zstd_opt.h"
 #include "zstd_ldm.h"
 
 
 /*-*************************************
 *  Helper functions
 ***************************************/
 size_t ZSTD_compressBound(size_t srcSize) {
     return ZSTD_COMPRESSBOUND(srcSize);
 }
 
 
 /*-*************************************
 *  Context memory management
 ***************************************/
 struct ZSTD_CDict_s {
     void* dictBuffer;
     const void* dictContent;
     size_t dictContentSize;
     void* workspace;
     size_t workspaceSize;
     ZSTD_matchState_t matchState;
     ZSTD_compressedBlockState_t cBlockState;
-    ZSTD_compressionParameters cParams;
     ZSTD_customMem customMem;
     U32 dictID;
 };  /* typedef'd to ZSTD_CDict within "zstd.h" */
 
 ZSTD_CCtx* ZSTD_createCCtx(void)
 {
     return ZSTD_createCCtx_advanced(ZSTD_defaultCMem);
 }
 
+static void ZSTD_initCCtx(ZSTD_CCtx* cctx, ZSTD_customMem memManager)
+{
+    assert(cctx != NULL);
+    memset(cctx, 0, sizeof(*cctx));
+    cctx->customMem = memManager;
+    cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
+    {   size_t const err = ZSTD_CCtx_resetParameters(cctx);
+        assert(!ZSTD_isError(err));
+        (void)err;
+    }
+}
+
 ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem)
 {
     ZSTD_STATIC_ASSERT(zcss_init==0);
     ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN==(0ULL - 1));
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
-    {   ZSTD_CCtx* const cctx = (ZSTD_CCtx*)ZSTD_calloc(sizeof(ZSTD_CCtx), customMem);
+    {   ZSTD_CCtx* const cctx = (ZSTD_CCtx*)ZSTD_malloc(sizeof(ZSTD_CCtx), customMem);
         if (!cctx) return NULL;
-        cctx->customMem = customMem;
-        cctx->requestedParams.compressionLevel = ZSTD_CLEVEL_DEFAULT;
-        cctx->requestedParams.fParams.contentSizeFlag = 1;
-        cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
+        ZSTD_initCCtx(cctx, customMem);
         return cctx;
     }
 }
 
 ZSTD_CCtx* ZSTD_initStaticCCtx(void *workspace, size_t workspaceSize)
 {
     ZSTD_CCtx* const cctx = (ZSTD_CCtx*) workspace;
     if (workspaceSize <= sizeof(ZSTD_CCtx)) return NULL;  /* minimum size */
     if ((size_t)workspace & 7) return NULL;  /* must be 8-aligned */
     memset(workspace, 0, workspaceSize);   /* may be a bit generous, could memset be smaller ? */
     cctx->staticSize = workspaceSize;
     cctx->workSpace = (void*)(cctx+1);
     cctx->workSpaceSize = workspaceSize - sizeof(ZSTD_CCtx);
 
     /* statically sized space. entropyWorkspace never moves (but prev/next block swap places) */
     if (cctx->workSpaceSize < HUF_WORKSPACE_SIZE + 2 * sizeof(ZSTD_compressedBlockState_t)) return NULL;
     assert(((size_t)cctx->workSpace & (sizeof(void*)-1)) == 0);   /* ensure correct alignment */
     cctx->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)cctx->workSpace;
     cctx->blockState.nextCBlock = cctx->blockState.prevCBlock + 1;
     {
         void* const ptr = cctx->blockState.nextCBlock + 1;
         cctx->entropyWorkspace = (U32*)ptr;
     }
     cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
     return cctx;
 }
 
-size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
+static void ZSTD_freeCCtxContent(ZSTD_CCtx* cctx)
 {
-    if (cctx==NULL) return 0;   /* support free on NULL */
-    if (cctx->staticSize) return ERROR(memory_allocation);   /* not compatible with static CCtx */
+    assert(cctx != NULL);
+    assert(cctx->staticSize == 0);
     ZSTD_free(cctx->workSpace, cctx->customMem); cctx->workSpace = NULL;
     ZSTD_freeCDict(cctx->cdictLocal); cctx->cdictLocal = NULL;
 #ifdef ZSTD_MULTITHREAD
     ZSTDMT_freeCCtx(cctx->mtctx); cctx->mtctx = NULL;
 #endif
+}
+
+size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
+{
+    if (cctx==NULL) return 0;   /* support free on NULL */
+    if (cctx->staticSize) return ERROR(memory_allocation);   /* not compatible with static CCtx */
+    ZSTD_freeCCtxContent(cctx);
     ZSTD_free(cctx, cctx->customMem);
-    return 0;   /* reserved as a potential error code in the future */
+    return 0;
 }
 
 
 static size_t ZSTD_sizeof_mtctx(const ZSTD_CCtx* cctx)
 {
 #ifdef ZSTD_MULTITHREAD
     return ZSTDMT_sizeof_CCtx(cctx->mtctx);
 #else
     (void) cctx;
     return 0;
 #endif
 }
 
 
 size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return 0;   /* support sizeof on NULL */
     return sizeof(*cctx) + cctx->workSpaceSize
            + ZSTD_sizeof_CDict(cctx->cdictLocal)
            + ZSTD_sizeof_mtctx(cctx);
 }
 
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
 {
     return ZSTD_sizeof_CCtx(zcs);  /* same object */
 }
 
 /* private API call, for dictBuilder only */
 const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) { return &(ctx->seqStore); }
 
-ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
-        const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize)
-{
-    ZSTD_compressionParameters cParams = ZSTD_getCParams(CCtxParams->compressionLevel, srcSizeHint, dictSize);
-    if (CCtxParams->ldmParams.enableLdm) cParams.windowLog = ZSTD_LDM_DEFAULT_WINDOW_LOG;
-    if (CCtxParams->cParams.windowLog) cParams.windowLog = CCtxParams->cParams.windowLog;
-    if (CCtxParams->cParams.hashLog) cParams.hashLog = CCtxParams->cParams.hashLog;
-    if (CCtxParams->cParams.chainLog) cParams.chainLog = CCtxParams->cParams.chainLog;
-    if (CCtxParams->cParams.searchLog) cParams.searchLog = CCtxParams->cParams.searchLog;
-    if (CCtxParams->cParams.searchLength) cParams.searchLength = CCtxParams->cParams.searchLength;
-    if (CCtxParams->cParams.targetLength) cParams.targetLength = CCtxParams->cParams.targetLength;
-    if (CCtxParams->cParams.strategy) cParams.strategy = CCtxParams->cParams.strategy;
-    return cParams;
-}
-
 static ZSTD_CCtx_params ZSTD_makeCCtxParamsFromCParams(
         ZSTD_compressionParameters cParams)
 {
     ZSTD_CCtx_params cctxParams;
     memset(&cctxParams, 0, sizeof(cctxParams));
     cctxParams.cParams = cParams;
     cctxParams.compressionLevel = ZSTD_CLEVEL_DEFAULT;  /* should not matter, as all cParams are presumed properly defined */
     assert(!ZSTD_checkCParams(cParams));
     cctxParams.fParams.contentSizeFlag = 1;
     return cctxParams;
 }
 
 static ZSTD_CCtx_params* ZSTD_createCCtxParams_advanced(
         ZSTD_customMem customMem)
 {
     ZSTD_CCtx_params* params;
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
     params = (ZSTD_CCtx_params*)ZSTD_calloc(
             sizeof(ZSTD_CCtx_params), customMem);
     if (!params) { return NULL; }
     params->customMem = customMem;
     params->compressionLevel = ZSTD_CLEVEL_DEFAULT;
     params->fParams.contentSizeFlag = 1;
     return params;
 }
 
 ZSTD_CCtx_params* ZSTD_createCCtxParams(void)
 {
     return ZSTD_createCCtxParams_advanced(ZSTD_defaultCMem);
 }
 
 size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params)
 {
     if (params == NULL) { return 0; }
     ZSTD_free(params, params->customMem);
     return 0;
 }
 
 size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params)
 {
     return ZSTD_CCtxParams_init(params, ZSTD_CLEVEL_DEFAULT);
 }
 
 size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel) {
     if (!cctxParams) { return ERROR(GENERIC); }
     memset(cctxParams, 0, sizeof(*cctxParams));
     cctxParams->compressionLevel = compressionLevel;
     cctxParams->fParams.contentSizeFlag = 1;
     return 0;
 }
 
 size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params)
 {
     if (!cctxParams) { return ERROR(GENERIC); }
     CHECK_F( ZSTD_checkCParams(params.cParams) );
     memset(cctxParams, 0, sizeof(*cctxParams));
     cctxParams->cParams = params.cParams;
     cctxParams->fParams = params.fParams;
     cctxParams->compressionLevel = ZSTD_CLEVEL_DEFAULT;   /* should not matter, as all cParams are presumed properly defined */
     assert(!ZSTD_checkCParams(params.cParams));
     return 0;
 }
 
 /* ZSTD_assignParamsToCCtxParams() :
  * params is presumed valid at this stage */
 static ZSTD_CCtx_params ZSTD_assignParamsToCCtxParams(
         ZSTD_CCtx_params cctxParams, ZSTD_parameters params)
 {
     ZSTD_CCtx_params ret = cctxParams;
     ret.cParams = params.cParams;
     ret.fParams = params.fParams;
     ret.compressionLevel = ZSTD_CLEVEL_DEFAULT;   /* should not matter, as all cParams are presumed properly defined */
     assert(!ZSTD_checkCParams(params.cParams));
     return ret;
 }
 
 #define CLAMPCHECK(val,min,max) {            \
     if (((val)<(min)) | ((val)>(max))) {     \
         return ERROR(parameter_outOfBound);  \
 }   }
 
 
 static int ZSTD_isUpdateAuthorized(ZSTD_cParameter param)
 {
     switch(param)
     {
     case ZSTD_p_compressionLevel:
     case ZSTD_p_hashLog:
     case ZSTD_p_chainLog:
     case ZSTD_p_searchLog:
     case ZSTD_p_minMatch:
     case ZSTD_p_targetLength:
     case ZSTD_p_compressionStrategy:
-    case ZSTD_p_compressLiterals:
         return 1;
 
     case ZSTD_p_format:
     case ZSTD_p_windowLog:
     case ZSTD_p_contentSizeFlag:
     case ZSTD_p_checksumFlag:
     case ZSTD_p_dictIDFlag:
     case ZSTD_p_forceMaxWindow :
     case ZSTD_p_nbWorkers:
     case ZSTD_p_jobSize:
     case ZSTD_p_overlapSizeLog:
     case ZSTD_p_enableLongDistanceMatching:
     case ZSTD_p_ldmHashLog:
     case ZSTD_p_ldmMinMatch:
     case ZSTD_p_ldmBucketSizeLog:
     case ZSTD_p_ldmHashEveryLog:
+    case ZSTD_p_forceAttachDict:
     default:
         return 0;
     }
 }
 
 size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value)
 {
     DEBUGLOG(4, "ZSTD_CCtx_setParameter (%u, %u)", (U32)param, value);
     if (cctx->streamStage != zcss_init) {
         if (ZSTD_isUpdateAuthorized(param)) {
             cctx->cParamsChanged = 1;
         } else {
             return ERROR(stage_wrong);
     }   }
 
     switch(param)
     {
     case ZSTD_p_format :
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
     case ZSTD_p_compressionLevel:
         if (cctx->cdict) return ERROR(stage_wrong);
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
     case ZSTD_p_windowLog:
     case ZSTD_p_hashLog:
     case ZSTD_p_chainLog:
     case ZSTD_p_searchLog:
     case ZSTD_p_minMatch:
     case ZSTD_p_targetLength:
     case ZSTD_p_compressionStrategy:
         if (cctx->cdict) return ERROR(stage_wrong);
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
-    case ZSTD_p_compressLiterals:
     case ZSTD_p_contentSizeFlag:
     case ZSTD_p_checksumFlag:
     case ZSTD_p_dictIDFlag:
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
     case ZSTD_p_forceMaxWindow :  /* Force back-references to remain < windowSize,
                                    * even when referencing into Dictionary content.
                                    * default : 0 when using a CDict, 1 when using a Prefix */
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
+    case ZSTD_p_forceAttachDict:
+        return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
+
     case ZSTD_p_nbWorkers:
         if ((value>0) && cctx->staticSize) {
             return ERROR(parameter_unsupported);  /* MT not compatible with static alloc */
         }
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
     case ZSTD_p_jobSize:
     case ZSTD_p_overlapSizeLog:
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
     case ZSTD_p_enableLongDistanceMatching:
     case ZSTD_p_ldmHashLog:
     case ZSTD_p_ldmMinMatch:
     case ZSTD_p_ldmBucketSizeLog:
     case ZSTD_p_ldmHashEveryLog:
         if (cctx->cdict) return ERROR(stage_wrong);
         return ZSTD_CCtxParam_setParameter(&cctx->requestedParams, param, value);
 
     default: return ERROR(parameter_unsupported);
     }
 }
 
 size_t ZSTD_CCtxParam_setParameter(
         ZSTD_CCtx_params* CCtxParams, ZSTD_cParameter param, unsigned value)
 {
     DEBUGLOG(4, "ZSTD_CCtxParam_setParameter (%u, %u)", (U32)param, value);
     switch(param)
     {
     case ZSTD_p_format :
         if (value > (unsigned)ZSTD_f_zstd1_magicless)
             return ERROR(parameter_unsupported);
         CCtxParams->format = (ZSTD_format_e)value;
         return (size_t)CCtxParams->format;
 
     case ZSTD_p_compressionLevel : {
         int cLevel = (int)value;  /* cast expected to restore negative sign */
         if (cLevel > ZSTD_maxCLevel()) cLevel = ZSTD_maxCLevel();
         if (cLevel) {  /* 0 : does not change current level */
-            CCtxParams->disableLiteralCompression = (cLevel<0);  /* negative levels disable huffman */
             CCtxParams->compressionLevel = cLevel;
         }
         if (CCtxParams->compressionLevel >= 0) return CCtxParams->compressionLevel;
         return 0;  /* return type (size_t) cannot represent negative values */
     }
 
     case ZSTD_p_windowLog :
         if (value>0)   /* 0 => use default */
             CLAMPCHECK(value, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
         CCtxParams->cParams.windowLog = value;
         return CCtxParams->cParams.windowLog;
 
     case ZSTD_p_hashLog :
         if (value>0)   /* 0 => use default */
             CLAMPCHECK(value, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
         CCtxParams->cParams.hashLog = value;
         return CCtxParams->cParams.hashLog;
 
     case ZSTD_p_chainLog :
         if (value>0)   /* 0 => use default */
             CLAMPCHECK(value, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
         CCtxParams->cParams.chainLog = value;
         return CCtxParams->cParams.chainLog;
 
     case ZSTD_p_searchLog :
         if (value>0)   /* 0 => use default */
             CLAMPCHECK(value, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
         CCtxParams->cParams.searchLog = value;
         return value;
 
     case ZSTD_p_minMatch :
         if (value>0)   /* 0 => use default */
             CLAMPCHECK(value, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
         CCtxParams->cParams.searchLength = value;
         return CCtxParams->cParams.searchLength;
 
     case ZSTD_p_targetLength :
         /* all values are valid. 0 => use default */
         CCtxParams->cParams.targetLength = value;
         return CCtxParams->cParams.targetLength;
 
     case ZSTD_p_compressionStrategy :
         if (value>0)   /* 0 => use default */
             CLAMPCHECK(value, (unsigned)ZSTD_fast, (unsigned)ZSTD_btultra);
         CCtxParams->cParams.strategy = (ZSTD_strategy)value;
         return (size_t)CCtxParams->cParams.strategy;
 
-    case ZSTD_p_compressLiterals:
-        CCtxParams->disableLiteralCompression = !value;
-        return !CCtxParams->disableLiteralCompression;
-
     case ZSTD_p_contentSizeFlag :
         /* Content size written in frame header _when known_ (default:1) */
         DEBUGLOG(4, "set content size flag = %u", (value>0));
         CCtxParams->fParams.contentSizeFlag = value > 0;
         return CCtxParams->fParams.contentSizeFlag;
 
     case ZSTD_p_checksumFlag :
         /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */
         CCtxParams->fParams.checksumFlag = value > 0;
         return CCtxParams->fParams.checksumFlag;
 
     case ZSTD_p_dictIDFlag : /* When applicable, dictionary's dictID is provided in frame header (default:1) */
         DEBUGLOG(4, "set dictIDFlag = %u", (value>0));
         CCtxParams->fParams.noDictIDFlag = !value;
         return !CCtxParams->fParams.noDictIDFlag;
 
     case ZSTD_p_forceMaxWindow :
         CCtxParams->forceWindow = (value > 0);
         return CCtxParams->forceWindow;
 
+    case ZSTD_p_forceAttachDict :
+        CCtxParams->attachDictPref = value ?
+                                    (value > 0 ? ZSTD_dictForceAttach : ZSTD_dictForceCopy) :
+                                     ZSTD_dictDefaultAttach;
+        return CCtxParams->attachDictPref;
+
     case ZSTD_p_nbWorkers :
 #ifndef ZSTD_MULTITHREAD
         if (value>0) return ERROR(parameter_unsupported);
         return 0;
 #else
         return ZSTDMT_CCtxParam_setNbWorkers(CCtxParams, value);
 #endif
 
     case ZSTD_p_jobSize :
 #ifndef ZSTD_MULTITHREAD
         return ERROR(parameter_unsupported);
 #else
         return ZSTDMT_CCtxParam_setMTCtxParameter(CCtxParams, ZSTDMT_p_jobSize, value);
 #endif
 
     case ZSTD_p_overlapSizeLog :
 #ifndef ZSTD_MULTITHREAD
         return ERROR(parameter_unsupported);
 #else
         return ZSTDMT_CCtxParam_setMTCtxParameter(CCtxParams, ZSTDMT_p_overlapSectionLog, value);
 #endif
 
     case ZSTD_p_enableLongDistanceMatching :
         CCtxParams->ldmParams.enableLdm = (value>0);
         return CCtxParams->ldmParams.enableLdm;
 
     case ZSTD_p_ldmHashLog :
         if (value>0)   /* 0 ==> auto */
             CLAMPCHECK(value, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
         CCtxParams->ldmParams.hashLog = value;
         return CCtxParams->ldmParams.hashLog;
 
     case ZSTD_p_ldmMinMatch :
         if (value>0)   /* 0 ==> default */
             CLAMPCHECK(value, ZSTD_LDM_MINMATCH_MIN, ZSTD_LDM_MINMATCH_MAX);
         CCtxParams->ldmParams.minMatchLength = value;
         return CCtxParams->ldmParams.minMatchLength;
 
     case ZSTD_p_ldmBucketSizeLog :
         if (value > ZSTD_LDM_BUCKETSIZELOG_MAX)
             return ERROR(parameter_outOfBound);
         CCtxParams->ldmParams.bucketSizeLog = value;
         return CCtxParams->ldmParams.bucketSizeLog;
 
     case ZSTD_p_ldmHashEveryLog :
         if (value > ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN)
             return ERROR(parameter_outOfBound);
         CCtxParams->ldmParams.hashEveryLog = value;
         return CCtxParams->ldmParams.hashEveryLog;
 
     default: return ERROR(parameter_unsupported);
     }
 }
 
+size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned* value)
+{
+    return ZSTD_CCtxParam_getParameter(&cctx->requestedParams, param, value);
+}
+
+size_t ZSTD_CCtxParam_getParameter(
+        ZSTD_CCtx_params* CCtxParams, ZSTD_cParameter param, unsigned* value)
+{
+    switch(param)
+    {
+    case ZSTD_p_format :
+        *value = CCtxParams->format;
+        break;
+    case ZSTD_p_compressionLevel :
+        *value = CCtxParams->compressionLevel;
+        break;
+    case ZSTD_p_windowLog :
+        *value = CCtxParams->cParams.windowLog;
+        break;
+    case ZSTD_p_hashLog :
+        *value = CCtxParams->cParams.hashLog;
+        break;
+    case ZSTD_p_chainLog :
+        *value = CCtxParams->cParams.chainLog;
+        break;
+    case ZSTD_p_searchLog :
+        *value = CCtxParams->cParams.searchLog;
+        break;
+    case ZSTD_p_minMatch :
+        *value = CCtxParams->cParams.searchLength;
+        break;
+    case ZSTD_p_targetLength :
+        *value = CCtxParams->cParams.targetLength;
+        break;
+    case ZSTD_p_compressionStrategy :
+        *value = (unsigned)CCtxParams->cParams.strategy;
+        break;
+    case ZSTD_p_contentSizeFlag :
+        *value = CCtxParams->fParams.contentSizeFlag;
+        break;
+    case ZSTD_p_checksumFlag :
+        *value = CCtxParams->fParams.checksumFlag;
+        break;
+    case ZSTD_p_dictIDFlag :
+        *value = !CCtxParams->fParams.noDictIDFlag;
+        break;
+    case ZSTD_p_forceMaxWindow :
+        *value = CCtxParams->forceWindow;
+        break;
+    case ZSTD_p_forceAttachDict :
+        *value = CCtxParams->attachDictPref;
+        break;
+    case ZSTD_p_nbWorkers :
+#ifndef ZSTD_MULTITHREAD
+        assert(CCtxParams->nbWorkers == 0);
+#endif
+        *value = CCtxParams->nbWorkers;
+        break;
+    case ZSTD_p_jobSize :
+#ifndef ZSTD_MULTITHREAD
+        return ERROR(parameter_unsupported);
+#else
+        *value = CCtxParams->jobSize;
+        break;
+#endif
+    case ZSTD_p_overlapSizeLog :
+#ifndef ZSTD_MULTITHREAD
+        return ERROR(parameter_unsupported);
+#else
+        *value = CCtxParams->overlapSizeLog;
+        break;
+#endif
+    case ZSTD_p_enableLongDistanceMatching :
+        *value = CCtxParams->ldmParams.enableLdm;
+        break;
+    case ZSTD_p_ldmHashLog :
+        *value = CCtxParams->ldmParams.hashLog;
+        break;
+    case ZSTD_p_ldmMinMatch :
+        *value = CCtxParams->ldmParams.minMatchLength;
+        break;
+    case ZSTD_p_ldmBucketSizeLog :
+        *value = CCtxParams->ldmParams.bucketSizeLog;
+        break;
+    case ZSTD_p_ldmHashEveryLog :
+        *value = CCtxParams->ldmParams.hashEveryLog;
+        break;
+    default: return ERROR(parameter_unsupported);
+    }
+    return 0;
+}
+
 /** ZSTD_CCtx_setParametersUsingCCtxParams() :
  *  just applies `params` into `cctx`
  *  no action is performed, parameters are merely stored.
  *  If ZSTDMT is enabled, parameters are pushed to cctx->mtctx.
  *    This is possible even if a compression is ongoing.
  *    In which case, new parameters will be applied on the fly, starting with next compression job.
  */
 size_t ZSTD_CCtx_setParametersUsingCCtxParams(
         ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params)
 {
+    DEBUGLOG(4, "ZSTD_CCtx_setParametersUsingCCtxParams");
     if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
     if (cctx->cdict) return ERROR(stage_wrong);
 
     cctx->requestedParams = *params;
     return 0;
 }
 
 ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_CCtx_setPledgedSrcSize to %u bytes", (U32)pledgedSrcSize);
     if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
     cctx->pledgedSrcSizePlusOne = pledgedSrcSize+1;
     return 0;
 }
 
 size_t ZSTD_CCtx_loadDictionary_advanced(
         ZSTD_CCtx* cctx, const void* dict, size_t dictSize,
         ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType)
 {
     if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
     if (cctx->staticSize) return ERROR(memory_allocation);  /* no malloc for static CCtx */
     DEBUGLOG(4, "ZSTD_CCtx_loadDictionary_advanced (size: %u)", (U32)dictSize);
     ZSTD_freeCDict(cctx->cdictLocal);  /* in case one already exists */
     if (dict==NULL || dictSize==0) {   /* no dictionary mode */
         cctx->cdictLocal = NULL;
         cctx->cdict = NULL;
     } else {
         ZSTD_compressionParameters const cParams =
                 ZSTD_getCParamsFromCCtxParams(&cctx->requestedParams, cctx->pledgedSrcSizePlusOne-1, dictSize);
         cctx->cdictLocal = ZSTD_createCDict_advanced(
                                 dict, dictSize,
                                 dictLoadMethod, dictContentType,
                                 cParams, cctx->customMem);
         cctx->cdict = cctx->cdictLocal;
         if (cctx->cdictLocal == NULL)
             return ERROR(memory_allocation);
     }
     return 0;
 }
 
 ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary_byReference(
       ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
     return ZSTD_CCtx_loadDictionary_advanced(
             cctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
 }
 
 ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
     return ZSTD_CCtx_loadDictionary_advanced(
             cctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
 }
 
 
 size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
 {
     if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
     cctx->cdict = cdict;
     memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));  /* exclusive */
     return 0;
 }
 
 size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
 {
     return ZSTD_CCtx_refPrefix_advanced(cctx, prefix, prefixSize, ZSTD_dct_rawContent);
 }
 
 size_t ZSTD_CCtx_refPrefix_advanced(
         ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
 {
     if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
     cctx->cdict = NULL;   /* prefix discards any prior cdict */
     cctx->prefixDict.dict = prefix;
     cctx->prefixDict.dictSize = prefixSize;
     cctx->prefixDict.dictContentType = dictContentType;
     return 0;
 }
 
-static void ZSTD_startNewCompression(ZSTD_CCtx* cctx)
+/*! ZSTD_CCtx_reset() :
+ *  Also dumps dictionary */
+void ZSTD_CCtx_reset(ZSTD_CCtx* cctx)
 {
     cctx->streamStage = zcss_init;
     cctx->pledgedSrcSizePlusOne = 0;
 }
 
-/*! ZSTD_CCtx_reset() :
- *  Also dumps dictionary */
-void ZSTD_CCtx_reset(ZSTD_CCtx* cctx)
+size_t ZSTD_CCtx_resetParameters(ZSTD_CCtx* cctx)
 {
-    ZSTD_startNewCompression(cctx);
+    if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
     cctx->cdict = NULL;
+    return ZSTD_CCtxParams_reset(&cctx->requestedParams);
 }
 
 /** ZSTD_checkCParams() :
     control CParam values remain within authorized range.
     @return : 0, or an error code if one value is beyond authorized range */
 size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
 {
     CLAMPCHECK(cParams.windowLog, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
     CLAMPCHECK(cParams.chainLog, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
     CLAMPCHECK(cParams.hashLog, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
     CLAMPCHECK(cParams.searchLog, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
     CLAMPCHECK(cParams.searchLength, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
-    if ((U32)(cParams.targetLength) < ZSTD_TARGETLENGTH_MIN)
-        return ERROR(parameter_unsupported);
+    ZSTD_STATIC_ASSERT(ZSTD_TARGETLENGTH_MIN == 0);
+    if (cParams.targetLength > ZSTD_TARGETLENGTH_MAX)
+        return ERROR(parameter_outOfBound);
     if ((U32)(cParams.strategy) > (U32)ZSTD_btultra)
         return ERROR(parameter_unsupported);
     return 0;
 }
 
 /** ZSTD_clampCParams() :
  *  make CParam values within valid range.
  *  @return : valid CParams */
-static ZSTD_compressionParameters ZSTD_clampCParams(ZSTD_compressionParameters cParams)
+static ZSTD_compressionParameters
+ZSTD_clampCParams(ZSTD_compressionParameters cParams)
 {
 #   define CLAMP(val,min,max) {      \
         if (valmax) val=max;   \
     }
     CLAMP(cParams.windowLog, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
     CLAMP(cParams.chainLog, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
     CLAMP(cParams.hashLog, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
     CLAMP(cParams.searchLog, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
     CLAMP(cParams.searchLength, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
-    if ((U32)(cParams.targetLength) < ZSTD_TARGETLENGTH_MIN) cParams.targetLength = ZSTD_TARGETLENGTH_MIN;
-    if ((U32)(cParams.strategy) > (U32)ZSTD_btultra) cParams.strategy = ZSTD_btultra;
+    ZSTD_STATIC_ASSERT(ZSTD_TARGETLENGTH_MIN == 0);
+    if (cParams.targetLength > ZSTD_TARGETLENGTH_MAX)
+        cParams.targetLength = ZSTD_TARGETLENGTH_MAX;
+    CLAMP(cParams.strategy, ZSTD_fast, ZSTD_btultra);
     return cParams;
 }
 
 /** ZSTD_cycleLog() :
  *  condition for correct operation : hashLog > 1 */
 static U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat)
 {
     U32 const btScale = ((U32)strat >= (U32)ZSTD_btlazy2);
     return hashLog - btScale;
 }
 
 /** ZSTD_adjustCParams_internal() :
     optimize `cPar` for a given input (`srcSize` and `dictSize`).
     mostly downsizing to reduce memory consumption and initialization latency.
     Both `srcSize` and `dictSize` are optional (use 0 if unknown).
-    Note : cPar is considered validated at this stage. Use ZSTD_checkCParams() to ensure that condition. */
-ZSTD_compressionParameters ZSTD_adjustCParams_internal(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize)
+    Note : cPar is assumed validated. Use ZSTD_checkCParams() to ensure this condition. */
+static ZSTD_compressionParameters
+ZSTD_adjustCParams_internal(ZSTD_compressionParameters cPar,
+                            unsigned long long srcSize,
+                            size_t dictSize)
 {
     static const U64 minSrcSize = 513; /* (1<<9) + 1 */
     static const U64 maxWindowResize = 1ULL << (ZSTD_WINDOWLOG_MAX-1);
     assert(ZSTD_checkCParams(cPar)==0);
 
     if (dictSize && (srcSize+1<2) /* srcSize unknown */ )
         srcSize = minSrcSize;  /* presumed small when there is a dictionary */
     else if (srcSize == 0)
         srcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* 0 == unknown : presumed large */
 
     /* resize windowLog if input is small enough, to use less memory */
     if ( (srcSize < maxWindowResize)
       && (dictSize < maxWindowResize) )  {
         U32 const tSize = (U32)(srcSize + dictSize);
         static U32 const hashSizeMin = 1 << ZSTD_HASHLOG_MIN;
         U32 const srcLog = (tSize < hashSizeMin) ? ZSTD_HASHLOG_MIN :
                             ZSTD_highbit32(tSize-1) + 1;
         if (cPar.windowLog > srcLog) cPar.windowLog = srcLog;
     }
-    if (cPar.hashLog > cPar.windowLog) cPar.hashLog = cPar.windowLog;
+    if (cPar.hashLog > cPar.windowLog+1) cPar.hashLog = cPar.windowLog+1;
     {   U32 const cycleLog = ZSTD_cycleLog(cPar.chainLog, cPar.strategy);
         if (cycleLog > cPar.windowLog)
             cPar.chainLog -= (cycleLog - cPar.windowLog);
     }
 
     if (cPar.windowLog < ZSTD_WINDOWLOG_ABSOLUTEMIN)
         cPar.windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN;  /* required for frame header */
 
     return cPar;
 }
 
-ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize)
+ZSTD_compressionParameters
+ZSTD_adjustCParams(ZSTD_compressionParameters cPar,
+                   unsigned long long srcSize,
+                   size_t dictSize)
 {
     cPar = ZSTD_clampCParams(cPar);
     return ZSTD_adjustCParams_internal(cPar, srcSize, dictSize);
 }
 
-static size_t ZSTD_sizeof_matchState(ZSTD_compressionParameters const* cParams, const U32 forCCtx)
+ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
+        const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize)
 {
+    ZSTD_compressionParameters cParams = ZSTD_getCParams(CCtxParams->compressionLevel, srcSizeHint, dictSize);
+    if (CCtxParams->ldmParams.enableLdm) cParams.windowLog = ZSTD_LDM_DEFAULT_WINDOW_LOG;
+    if (CCtxParams->cParams.windowLog) cParams.windowLog = CCtxParams->cParams.windowLog;
+    if (CCtxParams->cParams.hashLog) cParams.hashLog = CCtxParams->cParams.hashLog;
+    if (CCtxParams->cParams.chainLog) cParams.chainLog = CCtxParams->cParams.chainLog;
+    if (CCtxParams->cParams.searchLog) cParams.searchLog = CCtxParams->cParams.searchLog;
+    if (CCtxParams->cParams.searchLength) cParams.searchLength = CCtxParams->cParams.searchLength;
+    if (CCtxParams->cParams.targetLength) cParams.targetLength = CCtxParams->cParams.targetLength;
+    if (CCtxParams->cParams.strategy) cParams.strategy = CCtxParams->cParams.strategy;
+    assert(!ZSTD_checkCParams(cParams));
+    return ZSTD_adjustCParams_internal(cParams, srcSizeHint, dictSize);
+}
+
+static size_t
+ZSTD_sizeof_matchState(const ZSTD_compressionParameters* const cParams,
+                       const U32 forCCtx)
+{
     size_t const chainSize = (cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cParams->chainLog);
     size_t const hSize = ((size_t)1) << cParams->hashLog;
     U32    const hashLog3 = (forCCtx && cParams->searchLength==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
     size_t const h3Size = ((size_t)1) << hashLog3;
     size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
     size_t const optPotentialSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<strategy == ZSTD_btopt) ||
                                          (cParams->strategy == ZSTD_btultra)))
                                 ? optPotentialSpace
                                 : 0;
     DEBUGLOG(4, "chainSize: %u - hSize: %u - h3Size: %u",
                 (U32)chainSize, (U32)hSize, (U32)h3Size);
     return tableSpace + optSpace;
 }
 
 size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params)
 {
     /* Estimate CCtx size is supported for single-threaded compression only. */
     if (params->nbWorkers > 0) { return ERROR(GENERIC); }
     {   ZSTD_compressionParameters const cParams =
                 ZSTD_getCParamsFromCCtxParams(params, 0, 0);
         size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
         U32    const divider = (cParams.searchLength==3) ? 3 : 4;
         size_t const maxNbSeq = blockSize / divider;
-        size_t const tokenSpace = blockSize + 11*maxNbSeq;
+        size_t const tokenSpace = WILDCOPY_OVERLENGTH + blockSize + 11*maxNbSeq;
         size_t const entropySpace = HUF_WORKSPACE_SIZE;
         size_t const blockStateSpace = 2 * sizeof(ZSTD_compressedBlockState_t);
         size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 1);
 
         size_t const ldmSpace = ZSTD_ldm_getTableSize(params->ldmParams);
         size_t const ldmSeqSpace = ZSTD_ldm_getMaxNbSeq(params->ldmParams, blockSize) * sizeof(rawSeq);
 
         size_t const neededSpace = entropySpace + blockStateSpace + tokenSpace +
                                    matchStateSize + ldmSpace + ldmSeqSpace;
 
         DEBUGLOG(5, "sizeof(ZSTD_CCtx) : %u", (U32)sizeof(ZSTD_CCtx));
         DEBUGLOG(5, "estimate workSpace : %u", (U32)neededSpace);
         return sizeof(ZSTD_CCtx) + neededSpace;
     }
 }
 
 size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams)
 {
     ZSTD_CCtx_params const params = ZSTD_makeCCtxParamsFromCParams(cParams);
     return ZSTD_estimateCCtxSize_usingCCtxParams(¶ms);
 }
 
 static size_t ZSTD_estimateCCtxSize_internal(int compressionLevel)
 {
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, 0);
     return ZSTD_estimateCCtxSize_usingCParams(cParams);
 }
 
 size_t ZSTD_estimateCCtxSize(int compressionLevel)
 {
     int level;
     size_t memBudget = 0;
     for (level=1; level<=compressionLevel; level++) {
         size_t const newMB = ZSTD_estimateCCtxSize_internal(level);
         if (newMB > memBudget) memBudget = newMB;
     }
     return memBudget;
 }
 
 size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params)
 {
     if (params->nbWorkers > 0) { return ERROR(GENERIC); }
     {   size_t const CCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(params);
         size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << params->cParams.windowLog);
         size_t const inBuffSize = ((size_t)1 << params->cParams.windowLog) + blockSize;
         size_t const outBuffSize = ZSTD_compressBound(blockSize) + 1;
         size_t const streamingSize = inBuffSize + outBuffSize;
 
         return CCtxSize + streamingSize;
     }
 }
 
 size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams)
 {
     ZSTD_CCtx_params const params = ZSTD_makeCCtxParamsFromCParams(cParams);
     return ZSTD_estimateCStreamSize_usingCCtxParams(¶ms);
 }
 
-static size_t ZSTD_estimateCStreamSize_internal(int compressionLevel) {
+static size_t ZSTD_estimateCStreamSize_internal(int compressionLevel)
+{
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, 0);
     return ZSTD_estimateCStreamSize_usingCParams(cParams);
 }
 
-size_t ZSTD_estimateCStreamSize(int compressionLevel) {
+size_t ZSTD_estimateCStreamSize(int compressionLevel)
+{
     int level;
     size_t memBudget = 0;
     for (level=1; level<=compressionLevel; level++) {
         size_t const newMB = ZSTD_estimateCStreamSize_internal(level);
         if (newMB > memBudget) memBudget = newMB;
     }
     return memBudget;
 }
 
 /* ZSTD_getFrameProgression():
  * tells how much data has been consumed (input) and produced (output) for current frame.
  * able to count progression inside worker threads (non-blocking mode).
  */
 ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx)
 {
 #ifdef ZSTD_MULTITHREAD
     if (cctx->appliedParams.nbWorkers > 0) {
         return ZSTDMT_getFrameProgression(cctx->mtctx);
     }
 #endif
     {   ZSTD_frameProgression fp;
         size_t const buffered = (cctx->inBuff == NULL) ? 0 :
                                 cctx->inBuffPos - cctx->inToCompress;
         if (buffered) assert(cctx->inBuffPos >= cctx->inToCompress);
         assert(buffered <= ZSTD_BLOCKSIZE_MAX);
         fp.ingested = cctx->consumedSrcSize + buffered;
         fp.consumed = cctx->consumedSrcSize;
         fp.produced = cctx->producedCSize;
+        fp.flushed  = cctx->producedCSize;   /* simplified; some data might still be left within streaming output buffer */
+        fp.currentJobID = 0;
+        fp.nbActiveWorkers = 0;
         return fp;
 }   }
 
+/*! ZSTD_toFlushNow()
+ *  Only useful for multithreading scenarios currently (nbWorkers >= 1).
+ */
+size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx)
+{
+#ifdef ZSTD_MULTITHREAD
+    if (cctx->appliedParams.nbWorkers > 0) {
+        return ZSTDMT_toFlushNow(cctx->mtctx);
+    }
+#endif
+    (void)cctx;
+    return 0;   /* over-simplification; could also check if context is currently running in streaming mode, and in which case, report how many bytes are left to be flushed within output buffer */
+}
 
+
+
 static U32 ZSTD_equivalentCParams(ZSTD_compressionParameters cParams1,
                                   ZSTD_compressionParameters cParams2)
 {
     return (cParams1.hashLog  == cParams2.hashLog)
          & (cParams1.chainLog == cParams2.chainLog)
          & (cParams1.strategy == cParams2.strategy)   /* opt parser space */
          & ((cParams1.searchLength==3) == (cParams2.searchLength==3));  /* hashlog3 space */
 }
 
+static void ZSTD_assertEqualCParams(ZSTD_compressionParameters cParams1,
+                                    ZSTD_compressionParameters cParams2)
+{
+    (void)cParams1;
+    (void)cParams2;
+    assert(cParams1.windowLog    == cParams2.windowLog);
+    assert(cParams1.chainLog     == cParams2.chainLog);
+    assert(cParams1.hashLog      == cParams2.hashLog);
+    assert(cParams1.searchLog    == cParams2.searchLog);
+    assert(cParams1.searchLength == cParams2.searchLength);
+    assert(cParams1.targetLength == cParams2.targetLength);
+    assert(cParams1.strategy     == cParams2.strategy);
+}
+
 /** The parameters are equivalent if ldm is not enabled in both sets or
  *  all the parameters are equivalent. */
 static U32 ZSTD_equivalentLdmParams(ldmParams_t ldmParams1,
                                     ldmParams_t ldmParams2)
 {
     return (!ldmParams1.enableLdm && !ldmParams2.enableLdm) ||
            (ldmParams1.enableLdm == ldmParams2.enableLdm &&
             ldmParams1.hashLog == ldmParams2.hashLog &&
             ldmParams1.bucketSizeLog == ldmParams2.bucketSizeLog &&
             ldmParams1.minMatchLength == ldmParams2.minMatchLength &&
             ldmParams1.hashEveryLog == ldmParams2.hashEveryLog);
 }
 
 typedef enum { ZSTDb_not_buffered, ZSTDb_buffered } ZSTD_buffered_policy_e;
 
 /* ZSTD_sufficientBuff() :
  * check internal buffers exist for streaming if buffPol == ZSTDb_buffered .
  * Note : they are assumed to be correctly sized if ZSTD_equivalentCParams()==1 */
-static U32 ZSTD_sufficientBuff(size_t bufferSize1, size_t blockSize1,
+static U32 ZSTD_sufficientBuff(size_t bufferSize1, size_t maxNbSeq1,
+                            size_t maxNbLit1,
                             ZSTD_buffered_policy_e buffPol2,
                             ZSTD_compressionParameters cParams2,
                             U64 pledgedSrcSize)
 {
     size_t const windowSize2 = MAX(1, (size_t)MIN(((U64)1 << cParams2.windowLog), pledgedSrcSize));
     size_t const blockSize2 = MIN(ZSTD_BLOCKSIZE_MAX, windowSize2);
+    size_t const maxNbSeq2 = blockSize2 / ((cParams2.searchLength == 3) ? 3 : 4);
+    size_t const maxNbLit2 = blockSize2;
     size_t const neededBufferSize2 = (buffPol2==ZSTDb_buffered) ? windowSize2 + blockSize2 : 0;
-    DEBUGLOG(4, "ZSTD_sufficientBuff: is windowSize2=%u <= wlog1=%u",
-                (U32)windowSize2, cParams2.windowLog);
-    DEBUGLOG(4, "ZSTD_sufficientBuff: is blockSize2=%u <= blockSize1=%u",
-                (U32)blockSize2, (U32)blockSize1);
-    return (blockSize2 <= blockSize1) /* seqStore space depends on blockSize */
+    DEBUGLOG(4, "ZSTD_sufficientBuff: is neededBufferSize2=%u <= bufferSize1=%u",
+                (U32)neededBufferSize2, (U32)bufferSize1);
+    DEBUGLOG(4, "ZSTD_sufficientBuff: is maxNbSeq2=%u <= maxNbSeq1=%u",
+                (U32)maxNbSeq2, (U32)maxNbSeq1);
+    DEBUGLOG(4, "ZSTD_sufficientBuff: is maxNbLit2=%u <= maxNbLit1=%u",
+                (U32)maxNbLit2, (U32)maxNbLit1);
+    return (maxNbLit2 <= maxNbLit1)
+         & (maxNbSeq2 <= maxNbSeq1)
          & (neededBufferSize2 <= bufferSize1);
 }
 
 /** Equivalence for resetCCtx purposes */
 static U32 ZSTD_equivalentParams(ZSTD_CCtx_params params1,
                                  ZSTD_CCtx_params params2,
-                                 size_t buffSize1, size_t blockSize1,
+                                 size_t buffSize1,
+                                 size_t maxNbSeq1, size_t maxNbLit1,
                                  ZSTD_buffered_policy_e buffPol2,
                                  U64 pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_equivalentParams: pledgedSrcSize=%u", (U32)pledgedSrcSize);
-    return ZSTD_equivalentCParams(params1.cParams, params2.cParams) &&
-           ZSTD_equivalentLdmParams(params1.ldmParams, params2.ldmParams) &&
-           ZSTD_sufficientBuff(buffSize1, blockSize1, buffPol2, params2.cParams, pledgedSrcSize);
+    if (!ZSTD_equivalentCParams(params1.cParams, params2.cParams)) {
+      DEBUGLOG(4, "ZSTD_equivalentCParams() == 0");
+      return 0;
+    }
+    if (!ZSTD_equivalentLdmParams(params1.ldmParams, params2.ldmParams)) {
+      DEBUGLOG(4, "ZSTD_equivalentLdmParams() == 0");
+      return 0;
+    }
+    if (!ZSTD_sufficientBuff(buffSize1, maxNbSeq1, maxNbLit1, buffPol2,
+                             params2.cParams, pledgedSrcSize)) {
+      DEBUGLOG(4, "ZSTD_sufficientBuff() == 0");
+      return 0;
+    }
+    return 1;
 }
 
 static void ZSTD_reset_compressedBlockState(ZSTD_compressedBlockState_t* bs)
 {
     int i;
     for (i = 0; i < ZSTD_REP_NUM; ++i)
         bs->rep[i] = repStartValue[i];
-    bs->entropy.hufCTable_repeatMode = HUF_repeat_none;
-    bs->entropy.offcode_repeatMode = FSE_repeat_none;
-    bs->entropy.matchlength_repeatMode = FSE_repeat_none;
-    bs->entropy.litlength_repeatMode = FSE_repeat_none;
+    bs->entropy.huf.repeatMode = HUF_repeat_none;
+    bs->entropy.fse.offcode_repeatMode = FSE_repeat_none;
+    bs->entropy.fse.matchlength_repeatMode = FSE_repeat_none;
+    bs->entropy.fse.litlength_repeatMode = FSE_repeat_none;
 }
 
 /*! ZSTD_invalidateMatchState()
  * Invalidate all the matches in the match finder tables.
  * Requires nextSrc and base to be set (can be NULL).
  */
 static void ZSTD_invalidateMatchState(ZSTD_matchState_t* ms)
 {
     ZSTD_window_clear(&ms->window);
 
     ms->nextToUpdate = ms->window.dictLimit + 1;
+    ms->nextToUpdate3 = ms->window.dictLimit + 1;
     ms->loadedDictEnd = 0;
     ms->opt.litLengthSum = 0;  /* force reset of btopt stats */
+    ms->dictMatchState = NULL;
 }
 
 /*! ZSTD_continueCCtx() :
  *  reuse CCtx without reset (note : requires no dictionary) */
 static size_t ZSTD_continueCCtx(ZSTD_CCtx* cctx, ZSTD_CCtx_params params, U64 pledgedSrcSize)
 {
     size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params.cParams.windowLog), pledgedSrcSize));
     size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
     DEBUGLOG(4, "ZSTD_continueCCtx: re-use context in place");
 
     cctx->blockSize = blockSize;   /* previous block size could be different even for same windowLog, due to pledgedSrcSize */
     cctx->appliedParams = params;
+    cctx->blockState.matchState.cParams = params.cParams;
     cctx->pledgedSrcSizePlusOne = pledgedSrcSize+1;
     cctx->consumedSrcSize = 0;
     cctx->producedCSize = 0;
     if (pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN)
         cctx->appliedParams.fParams.contentSizeFlag = 0;
     DEBUGLOG(4, "pledged content size : %u ; flag : %u",
         (U32)pledgedSrcSize, cctx->appliedParams.fParams.contentSizeFlag);
     cctx->stage = ZSTDcs_init;
     cctx->dictID = 0;
     if (params.ldmParams.enableLdm)
         ZSTD_window_clear(&cctx->ldmState.window);
     ZSTD_referenceExternalSequences(cctx, NULL, 0);
     ZSTD_invalidateMatchState(&cctx->blockState.matchState);
     ZSTD_reset_compressedBlockState(cctx->blockState.prevCBlock);
     XXH64_reset(&cctx->xxhState, 0);
     return 0;
 }
 
 typedef enum { ZSTDcrp_continue, ZSTDcrp_noMemset } ZSTD_compResetPolicy_e;
 
-static void* ZSTD_reset_matchState(ZSTD_matchState_t* ms, void* ptr, ZSTD_compressionParameters const* cParams, ZSTD_compResetPolicy_e const crp, U32 const forCCtx)
+static void*
+ZSTD_reset_matchState(ZSTD_matchState_t* ms,
+                      void* ptr,
+                const ZSTD_compressionParameters* cParams,
+                      ZSTD_compResetPolicy_e const crp, U32 const forCCtx)
 {
     size_t const chainSize = (cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cParams->chainLog);
     size_t const hSize = ((size_t)1) << cParams->hashLog;
     U32    const hashLog3 = (forCCtx && cParams->searchLength==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
     size_t const h3Size = ((size_t)1) << hashLog3;
     size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
 
     assert(((size_t)ptr & 3) == 0);
 
     ms->hashLog3 = hashLog3;
     memset(&ms->window, 0, sizeof(ms->window));
+    ms->window.dictLimit = 1;    /* start from 1, so that 1st position is valid */
+    ms->window.lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
+    ms->window.nextSrc = ms->window.base + 1;   /* see issue #1241 */
     ZSTD_invalidateMatchState(ms);
 
     /* opt parser space */
     if (forCCtx && ((cParams->strategy == ZSTD_btopt) | (cParams->strategy == ZSTD_btultra))) {
         DEBUGLOG(4, "reserving optimal parser space");
         ms->opt.litFreq = (U32*)ptr;
         ms->opt.litLengthFreq = ms->opt.litFreq + (1<opt.matchLengthFreq = ms->opt.litLengthFreq + (MaxLL+1);
         ms->opt.offCodeFreq = ms->opt.matchLengthFreq + (MaxML+1);
         ptr = ms->opt.offCodeFreq + (MaxOff+1);
         ms->opt.matchTable = (ZSTD_match_t*)ptr;
         ptr = ms->opt.matchTable + ZSTD_OPT_NUM+1;
         ms->opt.priceTable = (ZSTD_optimal_t*)ptr;
         ptr = ms->opt.priceTable + ZSTD_OPT_NUM+1;
     }
 
     /* table Space */
     DEBUGLOG(4, "reset table : %u", crp!=ZSTDcrp_noMemset);
     assert(((size_t)ptr & 3) == 0);  /* ensure ptr is properly aligned */
     if (crp!=ZSTDcrp_noMemset) memset(ptr, 0, tableSpace);   /* reset tables only */
     ms->hashTable = (U32*)(ptr);
     ms->chainTable = ms->hashTable + hSize;
     ms->hashTable3 = ms->chainTable + chainSize;
     ptr = ms->hashTable3 + h3Size;
 
+    ms->cParams = *cParams;
+
     assert(((size_t)ptr & 3) == 0);
     return ptr;
 }
 
+#define ZSTD_WORKSPACETOOLARGE_FACTOR 3 /* define "workspace is too large" as this number of times larger than needed */
+#define ZSTD_WORKSPACETOOLARGE_MAXDURATION 128  /* when workspace is continuously too large
+                                         * during at least this number of times,
+                                         * context's memory usage is considered wasteful,
+                                         * because it's sized to handle a worst case scenario which rarely happens.
+                                         * In which case, resize it down to free some memory */
+
 /*! ZSTD_resetCCtx_internal() :
     note : `params` are assumed fully validated at this stage */
 static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
-                                      ZSTD_CCtx_params params, U64 pledgedSrcSize,
+                                      ZSTD_CCtx_params params,
+                                      U64 pledgedSrcSize,
                                       ZSTD_compResetPolicy_e const crp,
                                       ZSTD_buffered_policy_e const zbuff)
 {
     DEBUGLOG(4, "ZSTD_resetCCtx_internal: pledgedSrcSize=%u, wlog=%u",
                 (U32)pledgedSrcSize, params.cParams.windowLog);
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
 
     if (crp == ZSTDcrp_continue) {
         if (ZSTD_equivalentParams(zc->appliedParams, params,
-                                zc->inBuffSize, zc->blockSize,
-                                zbuff, pledgedSrcSize)) {
-            DEBUGLOG(4, "ZSTD_equivalentParams()==1 -> continue mode (wLog1=%u, blockSize1=%u)",
-                        zc->appliedParams.cParams.windowLog, (U32)zc->blockSize);
-            return ZSTD_continueCCtx(zc, params, pledgedSrcSize);
+                                  zc->inBuffSize,
+                                  zc->seqStore.maxNbSeq, zc->seqStore.maxNbLit,
+                                  zbuff, pledgedSrcSize)) {
+            DEBUGLOG(4, "ZSTD_equivalentParams()==1 -> continue mode (wLog1=%u, blockSize1=%zu)",
+                        zc->appliedParams.cParams.windowLog, zc->blockSize);
+            zc->workSpaceOversizedDuration += (zc->workSpaceOversizedDuration > 0);   /* if it was too large, it still is */
+            if (zc->workSpaceOversizedDuration <= ZSTD_WORKSPACETOOLARGE_MAXDURATION)
+                return ZSTD_continueCCtx(zc, params, pledgedSrcSize);
     }   }
     DEBUGLOG(4, "ZSTD_equivalentParams()==0 -> reset CCtx");
 
     if (params.ldmParams.enableLdm) {
         /* Adjust long distance matching parameters */
-        params.ldmParams.windowLog = params.cParams.windowLog;
         ZSTD_ldm_adjustParameters(¶ms.ldmParams, ¶ms.cParams);
         assert(params.ldmParams.hashLog >= params.ldmParams.bucketSizeLog);
         assert(params.ldmParams.hashEveryLog < 32);
-        zc->ldmState.hashPower =
-                ZSTD_ldm_getHashPower(params.ldmParams.minMatchLength);
+        zc->ldmState.hashPower = ZSTD_ldm_getHashPower(params.ldmParams.minMatchLength);
     }
 
     {   size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params.cParams.windowLog), pledgedSrcSize));
         size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
         U32    const divider = (params.cParams.searchLength==3) ? 3 : 4;
         size_t const maxNbSeq = blockSize / divider;
-        size_t const tokenSpace = blockSize + 11*maxNbSeq;
+        size_t const tokenSpace = WILDCOPY_OVERLENGTH + blockSize + 11*maxNbSeq;
         size_t const buffOutSize = (zbuff==ZSTDb_buffered) ? ZSTD_compressBound(blockSize)+1 : 0;
         size_t const buffInSize = (zbuff==ZSTDb_buffered) ? windowSize + blockSize : 0;
         size_t const matchStateSize = ZSTD_sizeof_matchState(¶ms.cParams, /* forCCtx */ 1);
         size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params.ldmParams, blockSize);
-        void* ptr;
+        void* ptr;   /* used to partition workSpace */
 
         /* Check if workSpace is large enough, alloc a new one if needed */
         {   size_t const entropySpace = HUF_WORKSPACE_SIZE;
             size_t const blockStateSpace = 2 * sizeof(ZSTD_compressedBlockState_t);
             size_t const bufferSpace = buffInSize + buffOutSize;
             size_t const ldmSpace = ZSTD_ldm_getTableSize(params.ldmParams);
             size_t const ldmSeqSpace = maxNbLdmSeq * sizeof(rawSeq);
 
             size_t const neededSpace = entropySpace + blockStateSpace + ldmSpace +
                                        ldmSeqSpace + matchStateSize + tokenSpace +
                                        bufferSpace;
-            DEBUGLOG(4, "Need %uKB workspace, including %uKB for match state, and %uKB for buffers",
-                        (U32)(neededSpace>>10), (U32)(matchStateSize>>10), (U32)(bufferSpace>>10));
-            DEBUGLOG(4, "windowSize: %u - blockSize: %u", (U32)windowSize, (U32)blockSize);
 
-            if (zc->workSpaceSize < neededSpace) {  /* too small : resize */
-                DEBUGLOG(4, "Need to update workSpaceSize from %uK to %uK",
-                            (unsigned)(zc->workSpaceSize>>10),
-                            (unsigned)(neededSpace>>10));
+            int const workSpaceTooSmall = zc->workSpaceSize < neededSpace;
+            int const workSpaceTooLarge = zc->workSpaceSize > ZSTD_WORKSPACETOOLARGE_FACTOR * neededSpace;
+            int const workSpaceWasteful = workSpaceTooLarge && (zc->workSpaceOversizedDuration > ZSTD_WORKSPACETOOLARGE_MAXDURATION);
+            zc->workSpaceOversizedDuration = workSpaceTooLarge ? zc->workSpaceOversizedDuration+1 : 0;
+
+            DEBUGLOG(4, "Need %zuKB workspace, including %zuKB for match state, and %zuKB for buffers",
+                        neededSpace>>10, matchStateSize>>10, bufferSpace>>10);
+            DEBUGLOG(4, "windowSize: %zu - blockSize: %zu", windowSize, blockSize);
+
+            if (workSpaceTooSmall || workSpaceWasteful) {
+                DEBUGLOG(4, "Need to resize workSpaceSize from %zuKB to %zuKB",
+                            zc->workSpaceSize >> 10,
+                            neededSpace >> 10);
                 /* static cctx : no resize, error out */
                 if (zc->staticSize) return ERROR(memory_allocation);
 
                 zc->workSpaceSize = 0;
                 ZSTD_free(zc->workSpace, zc->customMem);
                 zc->workSpace = ZSTD_malloc(neededSpace, zc->customMem);
                 if (zc->workSpace == NULL) return ERROR(memory_allocation);
                 zc->workSpaceSize = neededSpace;
-                ptr = zc->workSpace;
+                zc->workSpaceOversizedDuration = 0;
 
-                /* Statically sized space. entropyWorkspace never moves (but prev/next block swap places) */
+                /* Statically sized space.
+                 * entropyWorkspace never moves,
+                 * though prev/next block swap places */
                 assert(((size_t)zc->workSpace & 3) == 0);   /* ensure correct alignment */
                 assert(zc->workSpaceSize >= 2 * sizeof(ZSTD_compressedBlockState_t));
                 zc->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)zc->workSpace;
                 zc->blockState.nextCBlock = zc->blockState.prevCBlock + 1;
                 ptr = zc->blockState.nextCBlock + 1;
                 zc->entropyWorkspace = (U32*)ptr;
         }   }
 
         /* init params */
         zc->appliedParams = params;
+        zc->blockState.matchState.cParams = params.cParams;
         zc->pledgedSrcSizePlusOne = pledgedSrcSize+1;
         zc->consumedSrcSize = 0;
         zc->producedCSize = 0;
         if (pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN)
             zc->appliedParams.fParams.contentSizeFlag = 0;
         DEBUGLOG(4, "pledged content size : %u ; flag : %u",
             (U32)pledgedSrcSize, zc->appliedParams.fParams.contentSizeFlag);
         zc->blockSize = blockSize;
 
         XXH64_reset(&zc->xxhState, 0);
         zc->stage = ZSTDcs_init;
         zc->dictID = 0;
 
         ZSTD_reset_compressedBlockState(zc->blockState.prevCBlock);
 
         ptr = zc->entropyWorkspace + HUF_WORKSPACE_SIZE_U32;
 
         /* ldm hash table */
         /* initialize bucketOffsets table later for pointer alignment */
         if (params.ldmParams.enableLdm) {
             size_t const ldmHSize = ((size_t)1) << params.ldmParams.hashLog;
             memset(ptr, 0, ldmHSize * sizeof(ldmEntry_t));
             assert(((size_t)ptr & 3) == 0); /* ensure ptr is properly aligned */
             zc->ldmState.hashTable = (ldmEntry_t*)ptr;
             ptr = zc->ldmState.hashTable + ldmHSize;
             zc->ldmSequences = (rawSeq*)ptr;
             ptr = zc->ldmSequences + maxNbLdmSeq;
             zc->maxNbLdmSequences = maxNbLdmSeq;
 
             memset(&zc->ldmState.window, 0, sizeof(zc->ldmState.window));
         }
         assert(((size_t)ptr & 3) == 0); /* ensure ptr is properly aligned */
 
         ptr = ZSTD_reset_matchState(&zc->blockState.matchState, ptr, ¶ms.cParams, crp, /* forCCtx */ 1);
 
         /* sequences storage */
+        zc->seqStore.maxNbSeq = maxNbSeq;
         zc->seqStore.sequencesStart = (seqDef*)ptr;
         ptr = zc->seqStore.sequencesStart + maxNbSeq;
         zc->seqStore.llCode = (BYTE*) ptr;
         zc->seqStore.mlCode = zc->seqStore.llCode + maxNbSeq;
         zc->seqStore.ofCode = zc->seqStore.mlCode + maxNbSeq;
         zc->seqStore.litStart = zc->seqStore.ofCode + maxNbSeq;
-        ptr = zc->seqStore.litStart + blockSize;
+        /* ZSTD_wildcopy() is used to copy into the literals buffer,
+         * so we have to oversize the buffer by WILDCOPY_OVERLENGTH bytes.
+         */
+        zc->seqStore.maxNbLit = blockSize;
+        ptr = zc->seqStore.litStart + blockSize + WILDCOPY_OVERLENGTH;
 
         /* ldm bucketOffsets table */
         if (params.ldmParams.enableLdm) {
             size_t const ldmBucketSize =
                   ((size_t)1) << (params.ldmParams.hashLog -
                                   params.ldmParams.bucketSizeLog);
             memset(ptr, 0, ldmBucketSize);
             zc->ldmState.bucketOffsets = (BYTE*)ptr;
             ptr = zc->ldmState.bucketOffsets + ldmBucketSize;
             ZSTD_window_clear(&zc->ldmState.window);
         }
         ZSTD_referenceExternalSequences(zc, NULL, 0);
 
         /* buffers */
         zc->inBuffSize = buffInSize;
         zc->inBuff = (char*)ptr;
         zc->outBuffSize = buffOutSize;
         zc->outBuff = zc->inBuff + buffInSize;
 
         return 0;
     }
 }
 
 /* ZSTD_invalidateRepCodes() :
  * ensures next compression will not use repcodes from previous block.
  * Note : only works with regular variant;
  *        do not use with extDict variant ! */
 void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
     int i;
     for (i=0; iblockState.prevCBlock->rep[i] = 0;
     assert(!ZSTD_window_hasExtDict(cctx->blockState.matchState.window));
 }
 
-static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
+/* These are the approximate sizes for each strategy past which copying the
+ * dictionary tables into the working context is faster than using them
+ * in-place.
+ */
+static const size_t attachDictSizeCutoffs[(unsigned)ZSTD_btultra+1] = {
+    8 KB, /* unused */
+    8 KB, /* ZSTD_fast */
+    16 KB, /* ZSTD_dfast */
+    32 KB, /* ZSTD_greedy */
+    32 KB, /* ZSTD_lazy */
+    32 KB, /* ZSTD_lazy2 */
+    32 KB, /* ZSTD_btlazy2 */
+    32 KB, /* ZSTD_btopt */
+    8 KB /* ZSTD_btultra */
+};
+
+static int ZSTD_shouldAttachDict(const ZSTD_CDict* cdict,
+                                 ZSTD_CCtx_params params,
+                                 U64 pledgedSrcSize)
+{
+    size_t cutoff = attachDictSizeCutoffs[cdict->matchState.cParams.strategy];
+    return ( pledgedSrcSize <= cutoff
+          || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
+          || params.attachDictPref == ZSTD_dictForceAttach )
+        && params.attachDictPref != ZSTD_dictForceCopy
+        && !params.forceWindow; /* dictMatchState isn't correctly
+                                 * handled in _enforceMaxDist */
+}
+
+static size_t ZSTD_resetCCtx_byAttachingCDict(
+    ZSTD_CCtx* cctx,
+    const ZSTD_CDict* cdict,
+    ZSTD_CCtx_params params,
+    U64 pledgedSrcSize,
+    ZSTD_buffered_policy_e zbuff)
+{
+    {
+        const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
+        unsigned const windowLog = params.cParams.windowLog;
+        assert(windowLog != 0);
+        /* Resize working context table params for input only, since the dict
+         * has its own tables. */
+        params.cParams = ZSTD_adjustCParams_internal(*cdict_cParams, pledgedSrcSize, 0);
+        params.cParams.windowLog = windowLog;
+        ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
+                                ZSTDcrp_continue, zbuff);
+        assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
+    }
+
+    {
+        const U32 cdictEnd = (U32)( cdict->matchState.window.nextSrc
+                                  - cdict->matchState.window.base);
+        const U32 cdictLen = cdictEnd - cdict->matchState.window.dictLimit;
+        if (cdictLen == 0) {
+            /* don't even attach dictionaries with no contents */
+            DEBUGLOG(4, "skipping attaching empty dictionary");
+        } else {
+            DEBUGLOG(4, "attaching dictionary into context");
+            cctx->blockState.matchState.dictMatchState = &cdict->matchState;
+
+            /* prep working match state so dict matches never have negative indices
+             * when they are translated to the working context's index space. */
+            if (cctx->blockState.matchState.window.dictLimit < cdictEnd) {
+                cctx->blockState.matchState.window.nextSrc =
+                    cctx->blockState.matchState.window.base + cdictEnd;
+                ZSTD_window_clear(&cctx->blockState.matchState.window);
+            }
+            cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
+        }
+    }
+
+    cctx->dictID = cdict->dictID;
+
+    /* copy block state */
+    memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
+
+    return 0;
+}
+
+static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
                             const ZSTD_CDict* cdict,
-                            unsigned windowLog,
-                            ZSTD_frameParameters fParams,
+                            ZSTD_CCtx_params params,
                             U64 pledgedSrcSize,
                             ZSTD_buffered_policy_e zbuff)
 {
-    {   ZSTD_CCtx_params params = cctx->requestedParams;
+    const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
+
+    DEBUGLOG(4, "copying dictionary into context");
+
+    {   unsigned const windowLog = params.cParams.windowLog;
+        assert(windowLog != 0);
         /* Copy only compression parameters related to tables. */
-        params.cParams = cdict->cParams;
-        if (windowLog) params.cParams.windowLog = windowLog;
-        params.fParams = fParams;
+        params.cParams = *cdict_cParams;
+        params.cParams.windowLog = windowLog;
         ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
                                 ZSTDcrp_noMemset, zbuff);
-        assert(cctx->appliedParams.cParams.strategy == cdict->cParams.strategy);
-        assert(cctx->appliedParams.cParams.hashLog == cdict->cParams.hashLog);
-        assert(cctx->appliedParams.cParams.chainLog == cdict->cParams.chainLog);
+        assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
+        assert(cctx->appliedParams.cParams.hashLog == cdict_cParams->hashLog);
+        assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
     }
 
     /* copy tables */
-    {   size_t const chainSize = (cdict->cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict->cParams.chainLog);
-        size_t const hSize =  (size_t)1 << cdict->cParams.hashLog;
+    {   size_t const chainSize = (cdict_cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict_cParams->chainLog);
+        size_t const hSize =  (size_t)1 << cdict_cParams->hashLog;
         size_t const tableSpace = (chainSize + hSize) * sizeof(U32);
         assert((U32*)cctx->blockState.matchState.chainTable == (U32*)cctx->blockState.matchState.hashTable + hSize);  /* chainTable must follow hashTable */
         assert((U32*)cctx->blockState.matchState.hashTable3 == (U32*)cctx->blockState.matchState.chainTable + chainSize);
         assert((U32*)cdict->matchState.chainTable == (U32*)cdict->matchState.hashTable + hSize);  /* chainTable must follow hashTable */
         assert((U32*)cdict->matchState.hashTable3 == (U32*)cdict->matchState.chainTable + chainSize);
         memcpy(cctx->blockState.matchState.hashTable, cdict->matchState.hashTable, tableSpace);   /* presumes all tables follow each other */
     }
+
     /* Zero the hashTable3, since the cdict never fills it */
     {   size_t const h3Size = (size_t)1 << cctx->blockState.matchState.hashLog3;
         assert(cdict->matchState.hashLog3 == 0);
         memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
     }
 
     /* copy dictionary offsets */
-    {
-        ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
+    {   ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
         ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
         dstMatchState->window       = srcMatchState->window;
         dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
         dstMatchState->nextToUpdate3= srcMatchState->nextToUpdate3;
         dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
     }
+
     cctx->dictID = cdict->dictID;
 
     /* copy block state */
     memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
 
     return 0;
 }
 
+/* We have a choice between copying the dictionary context into the working
+ * context, or referencing the dictionary context from the working context
+ * in-place. We decide here which strategy to use. */
+static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
+                            const ZSTD_CDict* cdict,
+                            ZSTD_CCtx_params params,
+                            U64 pledgedSrcSize,
+                            ZSTD_buffered_policy_e zbuff)
+{
+
+    DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)", (U32)pledgedSrcSize);
+
+    if (ZSTD_shouldAttachDict(cdict, params, pledgedSrcSize)) {
+        return ZSTD_resetCCtx_byAttachingCDict(
+            cctx, cdict, params, pledgedSrcSize, zbuff);
+    } else {
+        return ZSTD_resetCCtx_byCopyingCDict(
+            cctx, cdict, params, pledgedSrcSize, zbuff);
+    }
+}
+
 /*! ZSTD_copyCCtx_internal() :
  *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
  *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
  *  The "context", in this case, refers to the hash and chain tables,
  *  entropy tables, and dictionary references.
  * `windowLog` value is enforced if != 0, otherwise value is copied from srcCCtx.
  * @return : 0, or an error code */
 static size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx,
                             const ZSTD_CCtx* srcCCtx,
                             ZSTD_frameParameters fParams,
                             U64 pledgedSrcSize,
                             ZSTD_buffered_policy_e zbuff)
 {
     DEBUGLOG(5, "ZSTD_copyCCtx_internal");
     if (srcCCtx->stage!=ZSTDcs_init) return ERROR(stage_wrong);
 
     memcpy(&dstCCtx->customMem, &srcCCtx->customMem, sizeof(ZSTD_customMem));
     {   ZSTD_CCtx_params params = dstCCtx->requestedParams;
         /* Copy only compression parameters related to tables. */
         params.cParams = srcCCtx->appliedParams.cParams;
         params.fParams = fParams;
         ZSTD_resetCCtx_internal(dstCCtx, params, pledgedSrcSize,
                                 ZSTDcrp_noMemset, zbuff);
         assert(dstCCtx->appliedParams.cParams.windowLog == srcCCtx->appliedParams.cParams.windowLog);
         assert(dstCCtx->appliedParams.cParams.strategy == srcCCtx->appliedParams.cParams.strategy);
         assert(dstCCtx->appliedParams.cParams.hashLog == srcCCtx->appliedParams.cParams.hashLog);
         assert(dstCCtx->appliedParams.cParams.chainLog == srcCCtx->appliedParams.cParams.chainLog);
         assert(dstCCtx->blockState.matchState.hashLog3 == srcCCtx->blockState.matchState.hashLog3);
     }
 
     /* copy tables */
     {   size_t const chainSize = (srcCCtx->appliedParams.cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << srcCCtx->appliedParams.cParams.chainLog);
         size_t const hSize =  (size_t)1 << srcCCtx->appliedParams.cParams.hashLog;
         size_t const h3Size = (size_t)1 << srcCCtx->blockState.matchState.hashLog3;
         size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
         assert((U32*)dstCCtx->blockState.matchState.chainTable == (U32*)dstCCtx->blockState.matchState.hashTable + hSize);  /* chainTable must follow hashTable */
         assert((U32*)dstCCtx->blockState.matchState.hashTable3 == (U32*)dstCCtx->blockState.matchState.chainTable + chainSize);
         memcpy(dstCCtx->blockState.matchState.hashTable, srcCCtx->blockState.matchState.hashTable, tableSpace);   /* presumes all tables follow each other */
     }
 
     /* copy dictionary offsets */
     {
-        ZSTD_matchState_t const* srcMatchState = &srcCCtx->blockState.matchState;
+        const ZSTD_matchState_t* srcMatchState = &srcCCtx->blockState.matchState;
         ZSTD_matchState_t* dstMatchState = &dstCCtx->blockState.matchState;
         dstMatchState->window       = srcMatchState->window;
         dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
         dstMatchState->nextToUpdate3= srcMatchState->nextToUpdate3;
         dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
     }
     dstCCtx->dictID = srcCCtx->dictID;
 
     /* copy block state */
     memcpy(dstCCtx->blockState.prevCBlock, srcCCtx->blockState.prevCBlock, sizeof(*srcCCtx->blockState.prevCBlock));
 
     return 0;
 }
 
 /*! ZSTD_copyCCtx() :
  *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
  *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
  *  pledgedSrcSize==0 means "unknown".
 *   @return : 0, or an error code */
 size_t ZSTD_copyCCtx(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx, unsigned long long pledgedSrcSize)
 {
     ZSTD_frameParameters fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
     ZSTD_buffered_policy_e const zbuff = (ZSTD_buffered_policy_e)(srcCCtx->inBuffSize>0);
     ZSTD_STATIC_ASSERT((U32)ZSTDb_buffered==1);
     if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
     fParams.contentSizeFlag = (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN);
 
     return ZSTD_copyCCtx_internal(dstCCtx, srcCCtx,
                                 fParams, pledgedSrcSize,
                                 zbuff);
 }
 
 
 #define ZSTD_ROWSIZE 16
 /*! ZSTD_reduceTable() :
  *  reduce table indexes by `reducerValue`, or squash to zero.
  *  PreserveMark preserves "unsorted mark" for btlazy2 strategy.
  *  It must be set to a clear 0/1 value, to remove branch during inlining.
  *  Presume table size is a multiple of ZSTD_ROWSIZE
  *  to help auto-vectorization */
 FORCE_INLINE_TEMPLATE void
 ZSTD_reduceTable_internal (U32* const table, U32 const size, U32 const reducerValue, int const preserveMark)
 {
     int const nbRows = (int)size / ZSTD_ROWSIZE;
     int cellNb = 0;
     int rowNb;
     assert((size & (ZSTD_ROWSIZE-1)) == 0);  /* multiple of ZSTD_ROWSIZE */
     assert(size < (1U<<31));   /* can be casted to int */
     for (rowNb=0 ; rowNb < nbRows ; rowNb++) {
         int column;
         for (column=0; columnblockState.matchState;
     {   U32 const hSize = (U32)1 << zc->appliedParams.cParams.hashLog;
         ZSTD_reduceTable(ms->hashTable, hSize, reducerValue);
     }
 
     if (zc->appliedParams.cParams.strategy != ZSTD_fast) {
         U32 const chainSize = (U32)1 << zc->appliedParams.cParams.chainLog;
         if (zc->appliedParams.cParams.strategy == ZSTD_btlazy2)
             ZSTD_reduceTable_btlazy2(ms->chainTable, chainSize, reducerValue);
         else
             ZSTD_reduceTable(ms->chainTable, chainSize, reducerValue);
     }
 
     if (ms->hashLog3) {
         U32 const h3Size = (U32)1 << ms->hashLog3;
         ZSTD_reduceTable(ms->hashTable3, h3Size, reducerValue);
     }
 }
 
 
 /*-*******************************************************
 *  Block entropic compression
 *********************************************************/
 
 /* See doc/zstd_compression_format.md for detailed format description */
 
-size_t ZSTD_noCompressBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
+static size_t ZSTD_noCompressBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize, U32 lastBlock)
 {
+    U32 const cBlockHeader24 = lastBlock + (((U32)bt_raw)<<1) + (U32)(srcSize << 3);
     if (srcSize + ZSTD_blockHeaderSize > dstCapacity) return ERROR(dstSize_tooSmall);
+    MEM_writeLE24(dst, cBlockHeader24);
     memcpy((BYTE*)dst + ZSTD_blockHeaderSize, src, srcSize);
-    MEM_writeLE24(dst, (U32)(srcSize << 2) + (U32)bt_raw);
-    return ZSTD_blockHeaderSize+srcSize;
+    return ZSTD_blockHeaderSize + srcSize;
 }
 
-
 static size_t ZSTD_noCompressLiterals (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     BYTE* const ostart = (BYTE* const)dst;
     U32   const flSize = 1 + (srcSize>31) + (srcSize>4095);
 
     if (srcSize + flSize > dstCapacity) return ERROR(dstSize_tooSmall);
 
     switch(flSize)
     {
         case 1: /* 2 - 1 - 5 */
             ostart[0] = (BYTE)((U32)set_basic + (srcSize<<3));
             break;
         case 2: /* 2 - 2 - 12 */
             MEM_writeLE16(ostart, (U16)((U32)set_basic + (1<<2) + (srcSize<<4)));
             break;
         case 3: /* 2 - 2 - 20 */
             MEM_writeLE32(ostart, (U32)((U32)set_basic + (3<<2) + (srcSize<<4)));
             break;
         default:   /* not necessary : flSize is {1,2,3} */
             assert(0);
     }
 
     memcpy(ostart + flSize, src, srcSize);
     return srcSize + flSize;
 }
 
 static size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     BYTE* const ostart = (BYTE* const)dst;
     U32   const flSize = 1 + (srcSize>31) + (srcSize>4095);
 
     (void)dstCapacity;  /* dstCapacity already guaranteed to be >=4, hence large enough */
 
     switch(flSize)
     {
         case 1: /* 2 - 1 - 5 */
             ostart[0] = (BYTE)((U32)set_rle + (srcSize<<3));
             break;
         case 2: /* 2 - 2 - 12 */
             MEM_writeLE16(ostart, (U16)((U32)set_rle + (1<<2) + (srcSize<<4)));
             break;
         case 3: /* 2 - 2 - 20 */
             MEM_writeLE32(ostart, (U32)((U32)set_rle + (3<<2) + (srcSize<<4)));
             break;
         default:   /* not necessary : flSize is {1,2,3} */
             assert(0);
     }
 
     ostart[flSize] = *(const BYTE*)src;
     return flSize+1;
 }
 
 
-static size_t ZSTD_minGain(size_t srcSize) { return (srcSize >> 6) + 2; }
+/* ZSTD_minGain() :
+ * minimum compression required
+ * to generate a compress block or a compressed literals section.
+ * note : use same formula for both situations */
+static size_t ZSTD_minGain(size_t srcSize, ZSTD_strategy strat)
+{
+    U32 const minlog = (strat==ZSTD_btultra) ? 7 : 6;
+    return (srcSize >> minlog) + 2;
+}
 
-static size_t ZSTD_compressLiterals (ZSTD_entropyCTables_t const* prevEntropy,
-                                     ZSTD_entropyCTables_t* nextEntropy,
+static size_t ZSTD_compressLiterals (ZSTD_hufCTables_t const* prevHuf,
+                                     ZSTD_hufCTables_t* nextHuf,
                                      ZSTD_strategy strategy, int disableLiteralCompression,
                                      void* dst, size_t dstCapacity,
                                const void* src, size_t srcSize,
                                      U32* workspace, const int bmi2)
 {
-    size_t const minGain = ZSTD_minGain(srcSize);
+    size_t const minGain = ZSTD_minGain(srcSize, strategy);
     size_t const lhSize = 3 + (srcSize >= 1 KB) + (srcSize >= 16 KB);
     BYTE*  const ostart = (BYTE*)dst;
     U32 singleStream = srcSize < 256;
     symbolEncodingType_e hType = set_compressed;
     size_t cLitSize;
 
     DEBUGLOG(5,"ZSTD_compressLiterals (disableLiteralCompression=%i)",
                 disableLiteralCompression);
 
     /* Prepare nextEntropy assuming reusing the existing table */
-    nextEntropy->hufCTable_repeatMode = prevEntropy->hufCTable_repeatMode;
-    memcpy(nextEntropy->hufCTable, prevEntropy->hufCTable,
-           sizeof(prevEntropy->hufCTable));
+    memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
 
     if (disableLiteralCompression)
         return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
 
     /* small ? don't even attempt compression (speed opt) */
 #   define COMPRESS_LITERALS_SIZE_MIN 63
-    {   size_t const minLitSize = (prevEntropy->hufCTable_repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
+    {   size_t const minLitSize = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
         if (srcSize <= minLitSize) return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
     }
 
     if (dstCapacity < lhSize+1) return ERROR(dstSize_tooSmall);   /* not enough space for compression */
-    {   HUF_repeat repeat = prevEntropy->hufCTable_repeatMode;
+    {   HUF_repeat repeat = prevHuf->repeatMode;
         int const preferRepeat = strategy < ZSTD_lazy ? srcSize <= 1024 : 0;
         if (repeat == HUF_repeat_valid && lhSize == 3) singleStream = 1;
         cLitSize = singleStream ? HUF_compress1X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
-                                      workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextEntropy->hufCTable, &repeat, preferRepeat, bmi2)
+                                      workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2)
                                 : HUF_compress4X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
-                                      workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextEntropy->hufCTable, &repeat, preferRepeat, bmi2);
+                                      workspace, HUF_WORKSPACE_SIZE, (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2);
         if (repeat != HUF_repeat_none) {
             /* reused the existing table */
             hType = set_repeat;
         }
     }
 
     if ((cLitSize==0) | (cLitSize >= srcSize - minGain) | ERR_isError(cLitSize)) {
-        memcpy(nextEntropy->hufCTable, prevEntropy->hufCTable, sizeof(prevEntropy->hufCTable));
+        memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
         return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
     }
     if (cLitSize==1) {
-        memcpy(nextEntropy->hufCTable, prevEntropy->hufCTable, sizeof(prevEntropy->hufCTable));
+        memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
         return ZSTD_compressRleLiteralsBlock(dst, dstCapacity, src, srcSize);
     }
 
     if (hType == set_compressed) {
         /* using a newly constructed table */
-        nextEntropy->hufCTable_repeatMode = HUF_repeat_check;
+        nextHuf->repeatMode = HUF_repeat_check;
     }
 
     /* Build header */
     switch(lhSize)
     {
     case 3: /* 2 - 2 - 10 - 10 */
         {   U32 const lhc = hType + ((!singleStream) << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<14);
             MEM_writeLE24(ostart, lhc);
             break;
         }
     case 4: /* 2 - 2 - 14 - 14 */
         {   U32 const lhc = hType + (2 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<18);
             MEM_writeLE32(ostart, lhc);
             break;
         }
     case 5: /* 2 - 2 - 18 - 18 */
         {   U32 const lhc = hType + (3 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<22);
             MEM_writeLE32(ostart, lhc);
             ostart[4] = (BYTE)(cLitSize >> 10);
             break;
         }
     default:  /* not possible : lhSize is {3,4,5} */
         assert(0);
     }
     return lhSize+cLitSize;
 }
 
 
 void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
 {
     const seqDef* const sequences = seqStorePtr->sequencesStart;
     BYTE* const llCodeTable = seqStorePtr->llCode;
     BYTE* const ofCodeTable = seqStorePtr->ofCode;
     BYTE* const mlCodeTable = seqStorePtr->mlCode;
     U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     U32 u;
+    assert(nbSeq <= seqStorePtr->maxNbSeq);
     for (u=0; ulongLengthID==1)
         llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
     if (seqStorePtr->longLengthID==2)
         mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
 }
 
+
+/**
+ * -log2(x / 256) lookup table for x in [0, 256).
+ * If x == 0: Return 0
+ * Else: Return floor(-log2(x / 256) * 256)
+ */
+static unsigned const kInverseProbabiltyLog256[256] = {
+    0,    2048, 1792, 1642, 1536, 1453, 1386, 1329, 1280, 1236, 1197, 1162,
+    1130, 1100, 1073, 1047, 1024, 1001, 980,  960,  941,  923,  906,  889,
+    874,  859,  844,  830,  817,  804,  791,  779,  768,  756,  745,  734,
+    724,  714,  704,  694,  685,  676,  667,  658,  650,  642,  633,  626,
+    618,  610,  603,  595,  588,  581,  574,  567,  561,  554,  548,  542,
+    535,  529,  523,  517,  512,  506,  500,  495,  489,  484,  478,  473,
+    468,  463,  458,  453,  448,  443,  438,  434,  429,  424,  420,  415,
+    411,  407,  402,  398,  394,  390,  386,  382,  377,  373,  370,  366,
+    362,  358,  354,  350,  347,  343,  339,  336,  332,  329,  325,  322,
+    318,  315,  311,  308,  305,  302,  298,  295,  292,  289,  286,  282,
+    279,  276,  273,  270,  267,  264,  261,  258,  256,  253,  250,  247,
+    244,  241,  239,  236,  233,  230,  228,  225,  222,  220,  217,  215,
+    212,  209,  207,  204,  202,  199,  197,  194,  192,  190,  187,  185,
+    182,  180,  178,  175,  173,  171,  168,  166,  164,  162,  159,  157,
+    155,  153,  151,  149,  146,  144,  142,  140,  138,  136,  134,  132,
+    130,  128,  126,  123,  121,  119,  117,  115,  114,  112,  110,  108,
+    106,  104,  102,  100,  98,   96,   94,   93,   91,   89,   87,   85,
+    83,   82,   80,   78,   76,   74,   73,   71,   69,   67,   66,   64,
+    62,   61,   59,   57,   55,   54,   52,   50,   49,   47,   46,   44,
+    42,   41,   39,   37,   36,   34,   33,   31,   30,   28,   26,   25,
+    23,   22,   20,   19,   17,   16,   14,   13,   11,   10,   8,    7,
+    5,    4,    2,    1,
+};
+
+
+/**
+ * Returns the cost in bits of encoding the distribution described by count
+ * using the entropy bound.
+ */
+static size_t ZSTD_entropyCost(unsigned const* count, unsigned const max, size_t const total)
+{
+    unsigned cost = 0;
+    unsigned s;
+    for (s = 0; s <= max; ++s) {
+        unsigned norm = (unsigned)((256 * count[s]) / total);
+        if (count[s] != 0 && norm == 0)
+            norm = 1;
+        assert(count[s] < total);
+        cost += count[s] * kInverseProbabiltyLog256[norm];
+    }
+    return cost >> 8;
+}
+
+
+/**
+ * Returns the cost in bits of encoding the distribution in count using the
+ * table described by norm. The max symbol support by norm is assumed >= max.
+ * norm must be valid for every symbol with non-zero probability in count.
+ */
+static size_t ZSTD_crossEntropyCost(short const* norm, unsigned accuracyLog,
+                                    unsigned const* count, unsigned const max)
+{
+    unsigned const shift = 8 - accuracyLog;
+    size_t cost = 0;
+    unsigned s;
+    assert(accuracyLog <= 8);
+    for (s = 0; s <= max; ++s) {
+        unsigned const normAcc = norm[s] != -1 ? norm[s] : 1;
+        unsigned const norm256 = normAcc << shift;
+        assert(norm256 > 0);
+        assert(norm256 < 256);
+        cost += count[s] * kInverseProbabiltyLog256[norm256];
+    }
+    return cost >> 8;
+}
+
+
+static unsigned ZSTD_getFSEMaxSymbolValue(FSE_CTable const* ctable) {
+  void const* ptr = ctable;
+  U16 const* u16ptr = (U16 const*)ptr;
+  U32 const maxSymbolValue = MEM_read16(u16ptr + 1);
+  return maxSymbolValue;
+}
+
+
+/**
+ * Returns the cost in bits of encoding the distribution in count using ctable.
+ * Returns an error if ctable cannot represent all the symbols in count.
+ */
+static size_t ZSTD_fseBitCost(
+    FSE_CTable const* ctable,
+    unsigned const* count,
+    unsigned const max)
+{
+    unsigned const kAccuracyLog = 8;
+    size_t cost = 0;
+    unsigned s;
+    FSE_CState_t cstate;
+    FSE_initCState(&cstate, ctable);
+    if (ZSTD_getFSEMaxSymbolValue(ctable) < max) {
+        DEBUGLOG(5, "Repeat FSE_CTable has maxSymbolValue %u < %u",
+                    ZSTD_getFSEMaxSymbolValue(ctable), max);
+        return ERROR(GENERIC);
+    }
+    for (s = 0; s <= max; ++s) {
+        unsigned const tableLog = cstate.stateLog;
+        unsigned const badCost = (tableLog + 1) << kAccuracyLog;
+        unsigned const bitCost = FSE_bitCost(cstate.symbolTT, tableLog, s, kAccuracyLog);
+        if (count[s] == 0)
+            continue;
+        if (bitCost >= badCost) {
+            DEBUGLOG(5, "Repeat FSE_CTable has Prob[%u] == 0", s);
+            return ERROR(GENERIC);
+        }
+        cost += count[s] * bitCost;
+    }
+    return cost >> kAccuracyLog;
+}
+
+/**
+ * Returns the cost in bytes of encoding the normalized count header.
+ * Returns an error if any of the helper functions return an error.
+ */
+static size_t ZSTD_NCountCost(unsigned const* count, unsigned const max,
+                              size_t const nbSeq, unsigned const FSELog)
+{
+    BYTE wksp[FSE_NCOUNTBOUND];
+    S16 norm[MaxSeq + 1];
+    const U32 tableLog = FSE_optimalTableLog(FSELog, nbSeq, max);
+    CHECK_F(FSE_normalizeCount(norm, tableLog, count, nbSeq, max));
+    return FSE_writeNCount(wksp, sizeof(wksp), norm, max, tableLog);
+}
+
+
 typedef enum {
     ZSTD_defaultDisallowed = 0,
     ZSTD_defaultAllowed = 1
 } ZSTD_defaultPolicy_e;
 
-MEM_STATIC
-symbolEncodingType_e ZSTD_selectEncodingType(
-        FSE_repeat* repeatMode, size_t const mostFrequent, size_t nbSeq,
-        U32 defaultNormLog, ZSTD_defaultPolicy_e const isDefaultAllowed)
+MEM_STATIC symbolEncodingType_e
+ZSTD_selectEncodingType(
+        FSE_repeat* repeatMode, unsigned const* count, unsigned const max,
+        size_t const mostFrequent, size_t nbSeq, unsigned const FSELog,
+        FSE_CTable const* prevCTable,
+        short const* defaultNorm, U32 defaultNormLog,
+        ZSTD_defaultPolicy_e const isDefaultAllowed,
+        ZSTD_strategy const strategy)
 {
-#define MIN_SEQ_FOR_DYNAMIC_FSE   64
-#define MAX_SEQ_FOR_STATIC_FSE  1000
     ZSTD_STATIC_ASSERT(ZSTD_defaultDisallowed == 0 && ZSTD_defaultAllowed != 0);
-    if ((mostFrequent == nbSeq) && (!isDefaultAllowed || nbSeq > 2)) {
+    if (mostFrequent == nbSeq) {
+        *repeatMode = FSE_repeat_none;
+        if (isDefaultAllowed && nbSeq <= 2) {
+            /* Prefer set_basic over set_rle when there are 2 or less symbols,
+             * since RLE uses 1 byte, but set_basic uses 5-6 bits per symbol.
+             * If basic encoding isn't possible, always choose RLE.
+             */
+            DEBUGLOG(5, "Selected set_basic");
+            return set_basic;
+        }
         DEBUGLOG(5, "Selected set_rle");
-        /* Prefer set_basic over set_rle when there are 2 or less symbols,
-         * since RLE uses 1 byte, but set_basic uses 5-6 bits per symbol.
-         * If basic encoding isn't possible, always choose RLE.
-         */
-        *repeatMode = FSE_repeat_check;
         return set_rle;
     }
-    if ( isDefaultAllowed
-      && (*repeatMode == FSE_repeat_valid) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
-        DEBUGLOG(5, "Selected set_repeat");
-        return set_repeat;
+    if (strategy < ZSTD_lazy) {
+        if (isDefaultAllowed) {
+            size_t const staticFse_nbSeq_max = 1000;
+            size_t const mult = 10 - strategy;
+            size_t const baseLog = 3;
+            size_t const dynamicFse_nbSeq_min = (((size_t)1 << defaultNormLog) * mult) >> baseLog;  /* 28-36 for offset, 56-72 for lengths */
+            assert(defaultNormLog >= 5 && defaultNormLog <= 6);  /* xx_DEFAULTNORMLOG */
+            assert(mult <= 9 && mult >= 7);
+            if ( (*repeatMode == FSE_repeat_valid)
+              && (nbSeq < staticFse_nbSeq_max) ) {
+                DEBUGLOG(5, "Selected set_repeat");
+                return set_repeat;
+            }
+            if ( (nbSeq < dynamicFse_nbSeq_min)
+              || (mostFrequent < (nbSeq >> (defaultNormLog-1))) ) {
+                DEBUGLOG(5, "Selected set_basic");
+                /* The format allows default tables to be repeated, but it isn't useful.
+                 * When using simple heuristics to select encoding type, we don't want
+                 * to confuse these tables with dictionaries. When running more careful
+                 * analysis, we don't need to waste time checking both repeating tables
+                 * and default tables.
+                 */
+                *repeatMode = FSE_repeat_none;
+                return set_basic;
+            }
+        }
+    } else {
+        size_t const basicCost = isDefaultAllowed ? ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, count, max) : ERROR(GENERIC);
+        size_t const repeatCost = *repeatMode != FSE_repeat_none ? ZSTD_fseBitCost(prevCTable, count, max) : ERROR(GENERIC);
+        size_t const NCountCost = ZSTD_NCountCost(count, max, nbSeq, FSELog);
+        size_t const compressedCost = (NCountCost << 3) + ZSTD_entropyCost(count, max, nbSeq);
+
+        if (isDefaultAllowed) {
+            assert(!ZSTD_isError(basicCost));
+            assert(!(*repeatMode == FSE_repeat_valid && ZSTD_isError(repeatCost)));
+        }
+        assert(!ZSTD_isError(NCountCost));
+        assert(compressedCost < ERROR(maxCode));
+        DEBUGLOG(5, "Estimated bit costs: basic=%u\trepeat=%u\tcompressed=%u",
+                    (U32)basicCost, (U32)repeatCost, (U32)compressedCost);
+        if (basicCost <= repeatCost && basicCost <= compressedCost) {
+            DEBUGLOG(5, "Selected set_basic");
+            assert(isDefaultAllowed);
+            *repeatMode = FSE_repeat_none;
+            return set_basic;
+        }
+        if (repeatCost <= compressedCost) {
+            DEBUGLOG(5, "Selected set_repeat");
+            assert(!ZSTD_isError(repeatCost));
+            return set_repeat;
+        }
+        assert(compressedCost < basicCost && compressedCost < repeatCost);
     }
-    if ( isDefaultAllowed
-      && ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (defaultNormLog-1)))) ) {
-        DEBUGLOG(5, "Selected set_basic");
-        /* The format allows default tables to be repeated, but it isn't useful.
-         * When using simple heuristics to select encoding type, we don't want
-         * to confuse these tables with dictionaries. When running more careful
-         * analysis, we don't need to waste time checking both repeating tables
-         * and default tables.
-         */
-        *repeatMode = FSE_repeat_none;
-        return set_basic;
-    }
     DEBUGLOG(5, "Selected set_compressed");
     *repeatMode = FSE_repeat_check;
     return set_compressed;
 }
 
-MEM_STATIC
-size_t ZSTD_buildCTable(void* dst, size_t dstCapacity,
-        FSE_CTable* nextCTable, U32 FSELog, symbolEncodingType_e type,
-        U32* count, U32 max,
-        BYTE const* codeTable, size_t nbSeq,
-        S16 const* defaultNorm, U32 defaultNormLog, U32 defaultMax,
-        FSE_CTable const* prevCTable, size_t prevCTableSize,
-        void* workspace, size_t workspaceSize)
+MEM_STATIC size_t
+ZSTD_buildCTable(void* dst, size_t dstCapacity,
+                FSE_CTable* nextCTable, U32 FSELog, symbolEncodingType_e type,
+                U32* count, U32 max,
+                const BYTE* codeTable, size_t nbSeq,
+                const S16* defaultNorm, U32 defaultNormLog, U32 defaultMax,
+                const FSE_CTable* prevCTable, size_t prevCTableSize,
+                void* workspace, size_t workspaceSize)
 {
     BYTE* op = (BYTE*)dst;
-    BYTE const* const oend = op + dstCapacity;
+    const BYTE* const oend = op + dstCapacity;
 
     switch (type) {
     case set_rle:
         *op = codeTable[0];
         CHECK_F(FSE_buildCTable_rle(nextCTable, (BYTE)max));
         return 1;
     case set_repeat:
         memcpy(nextCTable, prevCTable, prevCTableSize);
         return 0;
     case set_basic:
         CHECK_F(FSE_buildCTable_wksp(nextCTable, defaultNorm, defaultMax, defaultNormLog, workspace, workspaceSize));  /* note : could be pre-calculated */
         return 0;
     case set_compressed: {
         S16 norm[MaxSeq + 1];
         size_t nbSeq_1 = nbSeq;
         const U32 tableLog = FSE_optimalTableLog(FSELog, nbSeq, max);
         if (count[codeTable[nbSeq-1]] > 1) {
             count[codeTable[nbSeq-1]]--;
             nbSeq_1--;
         }
         assert(nbSeq_1 > 1);
         CHECK_F(FSE_normalizeCount(norm, tableLog, count, nbSeq_1, max));
         {   size_t const NCountSize = FSE_writeNCount(op, oend - op, norm, max, tableLog);   /* overflow protected */
             if (FSE_isError(NCountSize)) return NCountSize;
             CHECK_F(FSE_buildCTable_wksp(nextCTable, norm, max, tableLog, workspace, workspaceSize));
             return NCountSize;
         }
     }
     default: return assert(0), ERROR(GENERIC);
     }
 }
 
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_encodeSequences_body(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets)
 {
     BIT_CStream_t blockStream;
     FSE_CState_t  stateMatchLength;
     FSE_CState_t  stateOffsetBits;
     FSE_CState_t  stateLitLength;
 
     CHECK_E(BIT_initCStream(&blockStream, dst, dstCapacity), dstSize_tooSmall); /* not enough space remaining */
 
     /* first symbols */
     FSE_initCState2(&stateMatchLength, CTable_MatchLength, mlCodeTable[nbSeq-1]);
     FSE_initCState2(&stateOffsetBits,  CTable_OffsetBits,  ofCodeTable[nbSeq-1]);
     FSE_initCState2(&stateLitLength,   CTable_LitLength,   llCodeTable[nbSeq-1]);
     BIT_addBits(&blockStream, sequences[nbSeq-1].litLength, LL_bits[llCodeTable[nbSeq-1]]);
     if (MEM_32bits()) BIT_flushBits(&blockStream);
     BIT_addBits(&blockStream, sequences[nbSeq-1].matchLength, ML_bits[mlCodeTable[nbSeq-1]]);
     if (MEM_32bits()) BIT_flushBits(&blockStream);
     if (longOffsets) {
         U32 const ofBits = ofCodeTable[nbSeq-1];
         int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN-1);
         if (extraBits) {
             BIT_addBits(&blockStream, sequences[nbSeq-1].offset, extraBits);
             BIT_flushBits(&blockStream);
         }
         BIT_addBits(&blockStream, sequences[nbSeq-1].offset >> extraBits,
                     ofBits - extraBits);
     } else {
         BIT_addBits(&blockStream, sequences[nbSeq-1].offset, ofCodeTable[nbSeq-1]);
     }
     BIT_flushBits(&blockStream);
 
     {   size_t n;
         for (n=nbSeq-2 ; n= 64-7-(LLFSELog+MLFSELog+OffFSELog)))
                 BIT_flushBits(&blockStream);                                /* (7)*/
             BIT_addBits(&blockStream, sequences[n].litLength, llBits);
             if (MEM_32bits() && ((llBits+mlBits)>24)) BIT_flushBits(&blockStream);
             BIT_addBits(&blockStream, sequences[n].matchLength, mlBits);
             if (MEM_32bits() || (ofBits+mlBits+llBits > 56)) BIT_flushBits(&blockStream);
             if (longOffsets) {
                 int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN-1);
                 if (extraBits) {
                     BIT_addBits(&blockStream, sequences[n].offset, extraBits);
                     BIT_flushBits(&blockStream);                            /* (7)*/
                 }
                 BIT_addBits(&blockStream, sequences[n].offset >> extraBits,
                             ofBits - extraBits);                            /* 31 */
             } else {
                 BIT_addBits(&blockStream, sequences[n].offset, ofBits);     /* 31 */
             }
             BIT_flushBits(&blockStream);                                    /* (7)*/
     }   }
 
     DEBUGLOG(6, "ZSTD_encodeSequences: flushing ML state with %u bits", stateMatchLength.stateLog);
     FSE_flushCState(&blockStream, &stateMatchLength);
     DEBUGLOG(6, "ZSTD_encodeSequences: flushing Off state with %u bits", stateOffsetBits.stateLog);
     FSE_flushCState(&blockStream, &stateOffsetBits);
     DEBUGLOG(6, "ZSTD_encodeSequences: flushing LL state with %u bits", stateLitLength.stateLog);
     FSE_flushCState(&blockStream, &stateLitLength);
 
     {   size_t const streamSize = BIT_closeCStream(&blockStream);
         if (streamSize==0) return ERROR(dstSize_tooSmall);   /* not enough space */
         return streamSize;
     }
 }
 
 static size_t
 ZSTD_encodeSequences_default(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets)
 {
     return ZSTD_encodeSequences_body(dst, dstCapacity,
                                     CTable_MatchLength, mlCodeTable,
                                     CTable_OffsetBits, ofCodeTable,
                                     CTable_LitLength, llCodeTable,
                                     sequences, nbSeq, longOffsets);
 }
 
 
 #if DYNAMIC_BMI2
 
 static TARGET_ATTRIBUTE("bmi2") size_t
 ZSTD_encodeSequences_bmi2(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets)
 {
     return ZSTD_encodeSequences_body(dst, dstCapacity,
                                     CTable_MatchLength, mlCodeTable,
                                     CTable_OffsetBits, ofCodeTable,
                                     CTable_LitLength, llCodeTable,
                                     sequences, nbSeq, longOffsets);
 }
 
 #endif
 
-size_t ZSTD_encodeSequences(
+static size_t ZSTD_encodeSequences(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets, int bmi2)
 {
 #if DYNAMIC_BMI2
     if (bmi2) {
         return ZSTD_encodeSequences_bmi2(dst, dstCapacity,
                                          CTable_MatchLength, mlCodeTable,
                                          CTable_OffsetBits, ofCodeTable,
                                          CTable_LitLength, llCodeTable,
                                          sequences, nbSeq, longOffsets);
     }
 #endif
     (void)bmi2;
     return ZSTD_encodeSequences_default(dst, dstCapacity,
                                         CTable_MatchLength, mlCodeTable,
                                         CTable_OffsetBits, ofCodeTable,
                                         CTable_LitLength, llCodeTable,
                                         sequences, nbSeq, longOffsets);
 }
 
 MEM_STATIC size_t ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
                               ZSTD_entropyCTables_t const* prevEntropy,
                               ZSTD_entropyCTables_t* nextEntropy,
                               ZSTD_CCtx_params const* cctxParams,
                               void* dst, size_t dstCapacity, U32* workspace,
                               const int bmi2)
 {
     const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
+    ZSTD_strategy const strategy = cctxParams->cParams.strategy;
     U32 count[MaxSeq+1];
-    FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
-    FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
-    FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
+    FSE_CTable* CTable_LitLength = nextEntropy->fse.litlengthCTable;
+    FSE_CTable* CTable_OffsetBits = nextEntropy->fse.offcodeCTable;
+    FSE_CTable* CTable_MatchLength = nextEntropy->fse.matchlengthCTable;
     U32 LLtype, Offtype, MLtype;   /* compressed, raw or rle */
     const seqDef* const sequences = seqStorePtr->sequencesStart;
     const BYTE* const ofCodeTable = seqStorePtr->ofCode;
     const BYTE* const llCodeTable = seqStorePtr->llCode;
     const BYTE* const mlCodeTable = seqStorePtr->mlCode;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* const oend = ostart + dstCapacity;
     BYTE* op = ostart;
     size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
     BYTE* seqHead;
+    BYTE* lastNCount = NULL;
 
     ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<litStart;
         size_t const litSize = seqStorePtr->lit - literals;
+        int const disableLiteralCompression = (cctxParams->cParams.strategy == ZSTD_fast) && (cctxParams->cParams.targetLength > 0);
         size_t const cSize = ZSTD_compressLiterals(
-                                    prevEntropy, nextEntropy,
-                                    cctxParams->cParams.strategy, cctxParams->disableLiteralCompression,
+                                    &prevEntropy->huf, &nextEntropy->huf,
+                                    cctxParams->cParams.strategy, disableLiteralCompression,
                                     op, dstCapacity,
                                     literals, litSize,
                                     workspace, bmi2);
         if (ZSTD_isError(cSize))
           return cSize;
         assert(cSize <= dstCapacity);
         op += cSize;
     }
 
     /* Sequences Header */
     if ((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead*/) return ERROR(dstSize_tooSmall);
     if (nbSeq < 0x7F)
         *op++ = (BYTE)nbSeq;
     else if (nbSeq < LONGNBSEQ)
         op[0] = (BYTE)((nbSeq>>8) + 0x80), op[1] = (BYTE)nbSeq, op+=2;
     else
         op[0]=0xFF, MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ)), op+=3;
     if (nbSeq==0) {
-      memcpy(nextEntropy->litlengthCTable, prevEntropy->litlengthCTable, sizeof(prevEntropy->litlengthCTable));
-      nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
-      memcpy(nextEntropy->offcodeCTable, prevEntropy->offcodeCTable, sizeof(prevEntropy->offcodeCTable));
-      nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
-      memcpy(nextEntropy->matchlengthCTable, prevEntropy->matchlengthCTable, sizeof(prevEntropy->matchlengthCTable));
-      nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
-      return op - ostart;
+        /* Copy the old tables over as if we repeated them */
+        memcpy(&nextEntropy->fse, &prevEntropy->fse, sizeof(prevEntropy->fse));
+        return op - ostart;
     }
 
     /* seqHead : flags for FSE encoding type */
     seqHead = op++;
 
     /* convert length/distances into codes */
     ZSTD_seqToCodes(seqStorePtr);
     /* build CTable for Literal Lengths */
     {   U32 max = MaxLL;
-        size_t const mostFrequent = FSE_countFast_wksp(count, &max, llCodeTable, nbSeq, workspace);
+        size_t const mostFrequent = HIST_countFast_wksp(count, &max, llCodeTable, nbSeq, workspace);   /* can't fail */
         DEBUGLOG(5, "Building LL table");
-        nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
-        LLtype = ZSTD_selectEncodingType(&nextEntropy->litlength_repeatMode, mostFrequent, nbSeq, LL_defaultNormLog, ZSTD_defaultAllowed);
+        nextEntropy->fse.litlength_repeatMode = prevEntropy->fse.litlength_repeatMode;
+        LLtype = ZSTD_selectEncodingType(&nextEntropy->fse.litlength_repeatMode, count, max, mostFrequent, nbSeq, LLFSELog, prevEntropy->fse.litlengthCTable, LL_defaultNorm, LL_defaultNormLog, ZSTD_defaultAllowed, strategy);
+        assert(set_basic < set_compressed && set_rle < set_compressed);
+        assert(!(LLtype < set_compressed && nextEntropy->fse.litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
         {   size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
-                    count, max, llCodeTable, nbSeq, LL_defaultNorm, LL_defaultNormLog, MaxLL,
-                    prevEntropy->litlengthCTable, sizeof(prevEntropy->litlengthCTable),
-                    workspace, HUF_WORKSPACE_SIZE);
+                                                    count, max, llCodeTable, nbSeq, LL_defaultNorm, LL_defaultNormLog, MaxLL,
+                                                    prevEntropy->fse.litlengthCTable, sizeof(prevEntropy->fse.litlengthCTable),
+                                                    workspace, HUF_WORKSPACE_SIZE);
             if (ZSTD_isError(countSize)) return countSize;
+            if (LLtype == set_compressed)
+                lastNCount = op;
             op += countSize;
     }   }
     /* build CTable for Offsets */
     {   U32 max = MaxOff;
-        size_t const mostFrequent = FSE_countFast_wksp(count, &max, ofCodeTable, nbSeq, workspace);
+        size_t const mostFrequent = HIST_countFast_wksp(count, &max, ofCodeTable, nbSeq, workspace);  /* can't fail */
         /* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
         ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
         DEBUGLOG(5, "Building OF table");
-        nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
-        Offtype = ZSTD_selectEncodingType(&nextEntropy->offcode_repeatMode, mostFrequent, nbSeq, OF_defaultNormLog, defaultPolicy);
+        nextEntropy->fse.offcode_repeatMode = prevEntropy->fse.offcode_repeatMode;
+        Offtype = ZSTD_selectEncodingType(&nextEntropy->fse.offcode_repeatMode, count, max, mostFrequent, nbSeq, OffFSELog, prevEntropy->fse.offcodeCTable, OF_defaultNorm, OF_defaultNormLog, defaultPolicy, strategy);
+        assert(!(Offtype < set_compressed && nextEntropy->fse.offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
         {   size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
-                    count, max, ofCodeTable, nbSeq, OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
-                    prevEntropy->offcodeCTable, sizeof(prevEntropy->offcodeCTable),
-                    workspace, HUF_WORKSPACE_SIZE);
+                                                    count, max, ofCodeTable, nbSeq, OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
+                                                    prevEntropy->fse.offcodeCTable, sizeof(prevEntropy->fse.offcodeCTable),
+                                                    workspace, HUF_WORKSPACE_SIZE);
             if (ZSTD_isError(countSize)) return countSize;
+            if (Offtype == set_compressed)
+                lastNCount = op;
             op += countSize;
     }   }
     /* build CTable for MatchLengths */
     {   U32 max = MaxML;
-        size_t const mostFrequent = FSE_countFast_wksp(count, &max, mlCodeTable, nbSeq, workspace);
+        size_t const mostFrequent = HIST_countFast_wksp(count, &max, mlCodeTable, nbSeq, workspace);   /* can't fail */
         DEBUGLOG(5, "Building ML table");
-        nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
-        MLtype = ZSTD_selectEncodingType(&nextEntropy->matchlength_repeatMode, mostFrequent, nbSeq, ML_defaultNormLog, ZSTD_defaultAllowed);
+        nextEntropy->fse.matchlength_repeatMode = prevEntropy->fse.matchlength_repeatMode;
+        MLtype = ZSTD_selectEncodingType(&nextEntropy->fse.matchlength_repeatMode, count, max, mostFrequent, nbSeq, MLFSELog, prevEntropy->fse.matchlengthCTable, ML_defaultNorm, ML_defaultNormLog, ZSTD_defaultAllowed, strategy);
+        assert(!(MLtype < set_compressed && nextEntropy->fse.matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
         {   size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
-                    count, max, mlCodeTable, nbSeq, ML_defaultNorm, ML_defaultNormLog, MaxML,
-                    prevEntropy->matchlengthCTable, sizeof(prevEntropy->matchlengthCTable),
-                    workspace, HUF_WORKSPACE_SIZE);
+                                                    count, max, mlCodeTable, nbSeq, ML_defaultNorm, ML_defaultNormLog, MaxML,
+                                                    prevEntropy->fse.matchlengthCTable, sizeof(prevEntropy->fse.matchlengthCTable),
+                                                    workspace, HUF_WORKSPACE_SIZE);
             if (ZSTD_isError(countSize)) return countSize;
+            if (MLtype == set_compressed)
+                lastNCount = op;
             op += countSize;
     }   }
 
     *seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
 
     {   size_t const bitstreamSize = ZSTD_encodeSequences(
                                         op, oend - op,
                                         CTable_MatchLength, mlCodeTable,
                                         CTable_OffsetBits, ofCodeTable,
                                         CTable_LitLength, llCodeTable,
                                         sequences, nbSeq,
                                         longOffsets, bmi2);
         if (ZSTD_isError(bitstreamSize)) return bitstreamSize;
         op += bitstreamSize;
+        /* zstd versions <= 1.3.4 mistakenly report corruption when
+         * FSE_readNCount() recieves a buffer < 4 bytes.
+         * Fixed by https://github.com/facebook/zstd/pull/1146.
+         * This can happen when the last set_compressed table present is 2
+         * bytes and the bitstream is only one byte.
+         * In this exceedingly rare case, we will simply emit an uncompressed
+         * block, since it isn't worth optimizing.
+         */
+        if (lastNCount && (op - lastNCount) < 4) {
+            /* NCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
+            assert(op - lastNCount == 3);
+            DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
+                        "emitting an uncompressed block.");
+            return 0;
+        }
     }
 
     return op - ostart;
 }
 
 MEM_STATIC size_t ZSTD_compressSequences(seqStore_t* seqStorePtr,
-                              ZSTD_entropyCTables_t const* prevEntropy,
+                        const ZSTD_entropyCTables_t* prevEntropy,
                               ZSTD_entropyCTables_t* nextEntropy,
-                              ZSTD_CCtx_params const* cctxParams,
+                        const ZSTD_CCtx_params* cctxParams,
                               void* dst, size_t dstCapacity,
                               size_t srcSize, U32* workspace, int bmi2)
 {
     size_t const cSize = ZSTD_compressSequences_internal(
             seqStorePtr, prevEntropy, nextEntropy, cctxParams, dst, dstCapacity,
             workspace, bmi2);
+    if (cSize == 0) return 0;
     /* When srcSize <= dstCapacity, there is enough space to write a raw uncompressed block.
      * Since we ran out of space, block must be not compressible, so fall back to raw uncompressed block.
      */
     if ((cSize == ERROR(dstSize_tooSmall)) & (srcSize <= dstCapacity))
         return 0;  /* block not compressed */
     if (ZSTD_isError(cSize)) return cSize;
 
     /* Check compressibility */
-    {   size_t const maxCSize = srcSize - ZSTD_minGain(srcSize);  /* note : fixed formula, maybe should depend on compression level, or strategy */
+    {   size_t const maxCSize = srcSize - ZSTD_minGain(srcSize, cctxParams->cParams.strategy);
         if (cSize >= maxCSize) return 0;  /* block not compressed */
     }
 
-    /* We check that dictionaries have offset codes available for the first
-     * block. After the first block, the offcode table might not have large
-     * enough codes to represent the offsets in the data.
-     */
-    if (nextEntropy->offcode_repeatMode == FSE_repeat_valid)
-        nextEntropy->offcode_repeatMode = FSE_repeat_check;
-
     return cSize;
 }
 
 /* ZSTD_selectBlockCompressor() :
  * Not static, but internal use only (used by long distance matcher)
  * assumption : strat is a valid strategy */
-ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, int extDict)
+ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_dictMode_e dictMode)
 {
-    static const ZSTD_blockCompressor blockCompressor[2][(unsigned)ZSTD_btultra+1] = {
+    static const ZSTD_blockCompressor blockCompressor[3][(unsigned)ZSTD_btultra+1] = {
         { ZSTD_compressBlock_fast  /* default for 0 */,
-          ZSTD_compressBlock_fast, ZSTD_compressBlock_doubleFast, ZSTD_compressBlock_greedy,
-          ZSTD_compressBlock_lazy, ZSTD_compressBlock_lazy2, ZSTD_compressBlock_btlazy2,
-          ZSTD_compressBlock_btopt, ZSTD_compressBlock_btultra },
+          ZSTD_compressBlock_fast,
+          ZSTD_compressBlock_doubleFast,
+          ZSTD_compressBlock_greedy,
+          ZSTD_compressBlock_lazy,
+          ZSTD_compressBlock_lazy2,
+          ZSTD_compressBlock_btlazy2,
+          ZSTD_compressBlock_btopt,
+          ZSTD_compressBlock_btultra },
         { ZSTD_compressBlock_fast_extDict  /* default for 0 */,
-          ZSTD_compressBlock_fast_extDict, ZSTD_compressBlock_doubleFast_extDict, ZSTD_compressBlock_greedy_extDict,
-          ZSTD_compressBlock_lazy_extDict,ZSTD_compressBlock_lazy2_extDict, ZSTD_compressBlock_btlazy2_extDict,
-          ZSTD_compressBlock_btopt_extDict, ZSTD_compressBlock_btultra_extDict }
+          ZSTD_compressBlock_fast_extDict,
+          ZSTD_compressBlock_doubleFast_extDict,
+          ZSTD_compressBlock_greedy_extDict,
+          ZSTD_compressBlock_lazy_extDict,
+          ZSTD_compressBlock_lazy2_extDict,
+          ZSTD_compressBlock_btlazy2_extDict,
+          ZSTD_compressBlock_btopt_extDict,
+          ZSTD_compressBlock_btultra_extDict },
+        { ZSTD_compressBlock_fast_dictMatchState  /* default for 0 */,
+          ZSTD_compressBlock_fast_dictMatchState,
+          ZSTD_compressBlock_doubleFast_dictMatchState,
+          ZSTD_compressBlock_greedy_dictMatchState,
+          ZSTD_compressBlock_lazy_dictMatchState,
+          ZSTD_compressBlock_lazy2_dictMatchState,
+          ZSTD_compressBlock_btlazy2_dictMatchState,
+          ZSTD_compressBlock_btopt_dictMatchState,
+          ZSTD_compressBlock_btultra_dictMatchState }
     };
+    ZSTD_blockCompressor selectedCompressor;
     ZSTD_STATIC_ASSERT((unsigned)ZSTD_fast == 1);
 
     assert((U32)strat >= (U32)ZSTD_fast);
     assert((U32)strat <= (U32)ZSTD_btultra);
-    return blockCompressor[extDict!=0][(U32)strat];
+    selectedCompressor = blockCompressor[(int)dictMode][(U32)strat];
+    assert(selectedCompressor != NULL);
+    return selectedCompressor;
 }
 
 static void ZSTD_storeLastLiterals(seqStore_t* seqStorePtr,
                                    const BYTE* anchor, size_t lastLLSize)
 {
     memcpy(seqStorePtr->lit, anchor, lastLLSize);
     seqStorePtr->lit += lastLLSize;
 }
 
-static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
+void ZSTD_resetSeqStore(seqStore_t* ssPtr)
 {
     ssPtr->lit = ssPtr->litStart;
     ssPtr->sequences = ssPtr->sequencesStart;
     ssPtr->longLengthID = 0;
 }
 
 static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
                                         void* dst, size_t dstCapacity,
                                         const void* src, size_t srcSize)
 {
     ZSTD_matchState_t* const ms = &zc->blockState.matchState;
-    DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
-                (U32)dstCapacity, ms->window.dictLimit, ms->nextToUpdate);
+    size_t cSize;
+    DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%zu, dictLimit=%u, nextToUpdate=%u)",
+                dstCapacity, ms->window.dictLimit, ms->nextToUpdate);
+    assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
+
+    /* Assert that we have correctly flushed the ctx params into the ms's copy */
+    ZSTD_assertEqualCParams(zc->appliedParams.cParams, ms->cParams);
+
     if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
         ZSTD_ldm_skipSequences(&zc->externSeqStore, srcSize, zc->appliedParams.cParams.searchLength);
-        return 0;   /* don't even attempt compression below a certain srcSize */
+        cSize = 0;
+        goto out;  /* don't even attempt compression below a certain srcSize */
     }
     ZSTD_resetSeqStore(&(zc->seqStore));
+    ms->opt.symbolCosts = &zc->blockState.prevCBlock->entropy;   /* required for optimal parser to read stats from dictionary */
 
+    /* a gap between an attached dict and the current window is not safe,
+     * they must remain adjacent, and when that stops being the case, the dict
+     * must be unset */
+    assert(ms->dictMatchState == NULL || ms->loadedDictEnd == ms->window.dictLimit);
+
     /* limited update after a very long match */
     {   const BYTE* const base = ms->window.base;
         const BYTE* const istart = (const BYTE*)src;
         const U32 current = (U32)(istart-base);
+        if (sizeof(ptrdiff_t)==8) assert(istart - base < (ptrdiff_t)(U32)(-1));   /* ensure no overflow */
         if (current > ms->nextToUpdate + 384)
             ms->nextToUpdate = current - MIN(192, (U32)(current - ms->nextToUpdate - 384));
     }
 
     /* select and store sequences */
-    {   U32 const extDict = ZSTD_window_hasExtDict(ms->window);
+    {   ZSTD_dictMode_e const dictMode = ZSTD_matchState_dictMode(ms);
         size_t lastLLSize;
         {   int i;
             for (i = 0; i < ZSTD_REP_NUM; ++i)
                 zc->blockState.nextCBlock->rep[i] = zc->blockState.prevCBlock->rep[i];
         }
         if (zc->externSeqStore.pos < zc->externSeqStore.size) {
             assert(!zc->appliedParams.ldmParams.enableLdm);
             /* Updates ldmSeqStore.pos */
             lastLLSize =
                 ZSTD_ldm_blockCompress(&zc->externSeqStore,
                                        ms, &zc->seqStore,
                                        zc->blockState.nextCBlock->rep,
-                                       &zc->appliedParams.cParams,
-                                       src, srcSize, extDict);
+                                       src, srcSize);
             assert(zc->externSeqStore.pos <= zc->externSeqStore.size);
         } else if (zc->appliedParams.ldmParams.enableLdm) {
             rawSeqStore_t ldmSeqStore = {NULL, 0, 0, 0};
 
             ldmSeqStore.seq = zc->ldmSequences;
             ldmSeqStore.capacity = zc->maxNbLdmSequences;
             /* Updates ldmSeqStore.size */
             CHECK_F(ZSTD_ldm_generateSequences(&zc->ldmState, &ldmSeqStore,
                                                &zc->appliedParams.ldmParams,
                                                src, srcSize));
             /* Updates ldmSeqStore.pos */
             lastLLSize =
                 ZSTD_ldm_blockCompress(&ldmSeqStore,
                                        ms, &zc->seqStore,
                                        zc->blockState.nextCBlock->rep,
-                                       &zc->appliedParams.cParams,
-                                       src, srcSize, extDict);
+                                       src, srcSize);
             assert(ldmSeqStore.pos == ldmSeqStore.size);
         } else {   /* not long range mode */
-            ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy, extDict);
-            lastLLSize = blockCompressor(ms, &zc->seqStore, zc->blockState.nextCBlock->rep, &zc->appliedParams.cParams, src, srcSize);
+            ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy, dictMode);
+            lastLLSize = blockCompressor(ms, &zc->seqStore, zc->blockState.nextCBlock->rep, src, srcSize);
         }
         {   const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
             ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, lastLLSize);
     }   }
 
     /* encode sequences and literals */
-    {   size_t const cSize = ZSTD_compressSequences(&zc->seqStore,
-                                &zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
-                                &zc->appliedParams,
-                                dst, dstCapacity,
-                                srcSize, zc->entropyWorkspace, zc->bmi2);
-        if (ZSTD_isError(cSize) || cSize == 0) return cSize;
-        /* confirm repcodes and entropy tables */
-        {   ZSTD_compressedBlockState_t* const tmp = zc->blockState.prevCBlock;
-            zc->blockState.prevCBlock = zc->blockState.nextCBlock;
-            zc->blockState.nextCBlock = tmp;
-        }
-        return cSize;
+    cSize = ZSTD_compressSequences(&zc->seqStore,
+            &zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
+            &zc->appliedParams,
+            dst, dstCapacity,
+            srcSize, zc->entropyWorkspace, zc->bmi2);
+
+out:
+    if (!ZSTD_isError(cSize) && cSize != 0) {
+        /* confirm repcodes and entropy tables when emitting a compressed block */
+        ZSTD_compressedBlockState_t* const tmp = zc->blockState.prevCBlock;
+        zc->blockState.prevCBlock = zc->blockState.nextCBlock;
+        zc->blockState.nextCBlock = tmp;
     }
+    /* We check that dictionaries have offset codes available for the first
+     * block. After the first block, the offcode table might not have large
+     * enough codes to represent the offsets in the data.
+     */
+    if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
+        zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
+
+    return cSize;
 }
 
 
 /*! ZSTD_compress_frameChunk() :
 *   Compress a chunk of data into one or multiple blocks.
 *   All blocks will be terminated, all input will be consumed.
 *   Function will issue an error if there is not enough `dstCapacity` to hold the compressed content.
 *   Frame is supposed already started (header already produced)
 *   @return : compressed size, or an error code
 */
 static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
                                      void* dst, size_t dstCapacity,
                                const void* src, size_t srcSize,
                                      U32 lastFrameChunk)
 {
     size_t blockSize = cctx->blockSize;
     size_t remaining = srcSize;
     const BYTE* ip = (const BYTE*)src;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* op = ostart;
     U32 const maxDist = (U32)1 << cctx->appliedParams.cParams.windowLog;
     assert(cctx->appliedParams.cParams.windowLog <= 31);
 
     DEBUGLOG(5, "ZSTD_compress_frameChunk (blockSize=%u)", (U32)blockSize);
     if (cctx->appliedParams.fParams.checksumFlag && srcSize)
         XXH64_update(&cctx->xxhState, src, srcSize);
 
     while (remaining) {
         ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
         U32 const lastBlock = lastFrameChunk & (blockSize >= remaining);
 
         if (dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE)
             return ERROR(dstSize_tooSmall);   /* not enough space to store compressed block */
         if (remaining < blockSize) blockSize = remaining;
 
         if (ZSTD_window_needOverflowCorrection(ms->window, ip + blockSize)) {
             U32 const cycleLog = ZSTD_cycleLog(cctx->appliedParams.cParams.chainLog, cctx->appliedParams.cParams.strategy);
             U32 const correction = ZSTD_window_correctOverflow(&ms->window, cycleLog, maxDist, ip);
             ZSTD_STATIC_ASSERT(ZSTD_CHAINLOG_MAX <= 30);
             ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_32 <= 30);
             ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
-
             ZSTD_reduceIndex(cctx, correction);
             if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
             else ms->nextToUpdate -= correction;
             ms->loadedDictEnd = 0;
+            ms->dictMatchState = NULL;
         }
-        ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd);
+        ZSTD_window_enforceMaxDist(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
         if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
 
         {   size_t cSize = ZSTD_compressBlock_internal(cctx,
                                 op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
                                 ip, blockSize);
             if (ZSTD_isError(cSize)) return cSize;
 
             if (cSize == 0) {  /* block is not compressible */
-                U32 const cBlockHeader24 = lastBlock + (((U32)bt_raw)<<1) + (U32)(blockSize << 3);
-                if (blockSize + ZSTD_blockHeaderSize > dstCapacity) return ERROR(dstSize_tooSmall);
-                MEM_writeLE32(op, cBlockHeader24);   /* 4th byte will be overwritten */
-                memcpy(op + ZSTD_blockHeaderSize, ip, blockSize);
-                cSize = ZSTD_blockHeaderSize + blockSize;
+                cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
+                if (ZSTD_isError(cSize)) return cSize;
             } else {
                 U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
                 MEM_writeLE24(op, cBlockHeader24);
                 cSize += ZSTD_blockHeaderSize;
             }
 
             ip += blockSize;
             assert(remaining >= blockSize);
             remaining -= blockSize;
             op += cSize;
             assert(dstCapacity >= cSize);
             dstCapacity -= cSize;
             DEBUGLOG(5, "ZSTD_compress_frameChunk: adding a block of size %u",
                         (U32)cSize);
     }   }
 
     if (lastFrameChunk && (op>ostart)) cctx->stage = ZSTDcs_ending;
     return op-ostart;
 }
 
 
 static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
                                     ZSTD_CCtx_params params, U64 pledgedSrcSize, U32 dictID)
 {   BYTE* const op = (BYTE*)dst;
     U32   const dictIDSizeCodeLength = (dictID>0) + (dictID>=256) + (dictID>=65536);   /* 0-3 */
     U32   const dictIDSizeCode = params.fParams.noDictIDFlag ? 0 : dictIDSizeCodeLength;   /* 0-3 */
     U32   const checksumFlag = params.fParams.checksumFlag>0;
     U32   const windowSize = (U32)1 << params.cParams.windowLog;
     U32   const singleSegment = params.fParams.contentSizeFlag && (windowSize >= pledgedSrcSize);
     BYTE  const windowLogByte = (BYTE)((params.cParams.windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN) << 3);
     U32   const fcsCode = params.fParams.contentSizeFlag ?
                      (pledgedSrcSize>=256) + (pledgedSrcSize>=65536+256) + (pledgedSrcSize>=0xFFFFFFFFU) : 0;  /* 0-3 */
     BYTE  const frameHeaderDecriptionByte = (BYTE)(dictIDSizeCode + (checksumFlag<<2) + (singleSegment<<5) + (fcsCode<<6) );
     size_t pos=0;
 
+    assert(!(params.fParams.contentSizeFlag && pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN));
     if (dstCapacity < ZSTD_frameHeaderSize_max) return ERROR(dstSize_tooSmall);
     DEBUGLOG(4, "ZSTD_writeFrameHeader : dictIDFlag : %u ; dictID : %u ; dictIDSizeCode : %u",
                 !params.fParams.noDictIDFlag, dictID,  dictIDSizeCode);
 
     if (params.format == ZSTD_f_zstd1) {
         MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
         pos = 4;
     }
     op[pos++] = frameHeaderDecriptionByte;
     if (!singleSegment) op[pos++] = windowLogByte;
     switch(dictIDSizeCode)
     {
         default:  assert(0); /* impossible */
         case 0 : break;
         case 1 : op[pos] = (BYTE)(dictID); pos++; break;
         case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break;
         case 3 : MEM_writeLE32(op+pos, dictID); pos+=4; break;
     }
     switch(fcsCode)
     {
         default:  assert(0); /* impossible */
         case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break;
         case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break;
         case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break;
         case 3 : MEM_writeLE64(op+pos, (U64)(pledgedSrcSize)); pos+=8; break;
     }
     return pos;
 }
 
 /* ZSTD_writeLastEmptyBlock() :
  * output an empty Block with end-of-frame mark to complete a frame
  * @return : size of data written into `dst` (== ZSTD_blockHeaderSize (defined in zstd_internal.h))
  *           or an error code if `dstCapcity` is too small (stage != ZSTDcs_init)
         return ERROR(stage_wrong);
     if (cctx->appliedParams.ldmParams.enableLdm)
         return ERROR(parameter_unsupported);
     cctx->externSeqStore.seq = seq;
     cctx->externSeqStore.size = nbSeq;
     cctx->externSeqStore.capacity = nbSeq;
     cctx->externSeqStore.pos = 0;
     return 0;
 }
 
 
 static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize,
                                U32 frame, U32 lastFrameChunk)
 {
-    ZSTD_matchState_t* ms = &cctx->blockState.matchState;
+    ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
     size_t fhSize = 0;
 
     DEBUGLOG(5, "ZSTD_compressContinue_internal, stage: %u, srcSize: %u",
                 cctx->stage, (U32)srcSize);
     if (cctx->stage==ZSTDcs_created) return ERROR(stage_wrong);   /* missing init (ZSTD_compressBegin) */
 
     if (frame && (cctx->stage==ZSTDcs_init)) {
         fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, cctx->appliedParams,
                                        cctx->pledgedSrcSizePlusOne-1, cctx->dictID);
         if (ZSTD_isError(fhSize)) return fhSize;
         dstCapacity -= fhSize;
         dst = (char*)dst + fhSize;
         cctx->stage = ZSTDcs_ongoing;
     }
 
     if (!srcSize) return fhSize;  /* do not generate an empty block if no input */
 
     if (!ZSTD_window_update(&ms->window, src, srcSize)) {
         ms->nextToUpdate = ms->window.dictLimit;
     }
-    if (cctx->appliedParams.ldmParams.enableLdm)
+    if (cctx->appliedParams.ldmParams.enableLdm) {
         ZSTD_window_update(&cctx->ldmState.window, src, srcSize);
+    }
 
+    if (!frame) {
+        /* overflow check and correction for block mode */
+        if (ZSTD_window_needOverflowCorrection(ms->window, (const char*)src + srcSize)) {
+            U32 const cycleLog = ZSTD_cycleLog(cctx->appliedParams.cParams.chainLog, cctx->appliedParams.cParams.strategy);
+            U32 const correction = ZSTD_window_correctOverflow(&ms->window, cycleLog, 1 << cctx->appliedParams.cParams.windowLog, src);
+            ZSTD_STATIC_ASSERT(ZSTD_CHAINLOG_MAX <= 30);
+            ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_32 <= 30);
+            ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
+            ZSTD_reduceIndex(cctx, correction);
+            if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
+            else ms->nextToUpdate -= correction;
+            ms->loadedDictEnd = 0;
+            ms->dictMatchState = NULL;
+        }
+    }
+
     DEBUGLOG(5, "ZSTD_compressContinue_internal (blockSize=%u)", (U32)cctx->blockSize);
     {   size_t const cSize = frame ?
                              ZSTD_compress_frameChunk (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
                              ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize);
         if (ZSTD_isError(cSize)) return cSize;
         cctx->consumedSrcSize += srcSize;
         cctx->producedCSize += (cSize + fhSize);
-        if (cctx->appliedParams.fParams.contentSizeFlag) {  /* control src size */
+        assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
+        if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
+            ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
             if (cctx->consumedSrcSize+1 > cctx->pledgedSrcSizePlusOne) {
                 DEBUGLOG(4, "error : pledgedSrcSize = %u, while realSrcSize >= %u",
                     (U32)cctx->pledgedSrcSizePlusOne-1, (U32)cctx->consumedSrcSize);
                 return ERROR(srcSize_wrong);
             }
         }
         return cSize + fhSize;
     }
 }
 
 size_t ZSTD_compressContinue (ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_compressContinue (srcSize=%u)", (U32)srcSize);
     return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1 /* frame mode */, 0 /* last chunk */);
 }
 
 
 size_t ZSTD_getBlockSize(const ZSTD_CCtx* cctx)
 {
     ZSTD_compressionParameters const cParams = cctx->appliedParams.cParams;
     assert(!ZSTD_checkCParams(cParams));
     return MIN (ZSTD_BLOCKSIZE_MAX, (U32)1 << cParams.windowLog);
 }
 
 size_t ZSTD_compressBlock(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     size_t const blockSizeMax = ZSTD_getBlockSize(cctx);
     if (srcSize > blockSizeMax) return ERROR(srcSize_wrong);
+
     return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0 /* frame mode */, 0 /* last chunk */);
 }
 
 /*! ZSTD_loadDictionaryContent() :
  *  @return : 0, or an error code
  */
-static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms, ZSTD_CCtx_params const* params, const void* src, size_t srcSize)
+static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms,
+                                         ZSTD_CCtx_params const* params,
+                                         const void* src, size_t srcSize,
+                                         ZSTD_dictTableLoadMethod_e dtlm)
 {
     const BYTE* const ip = (const BYTE*) src;
     const BYTE* const iend = ip + srcSize;
-    ZSTD_compressionParameters const* cParams = ¶ms->cParams;
 
     ZSTD_window_update(&ms->window, src, srcSize);
     ms->loadedDictEnd = params->forceWindow ? 0 : (U32)(iend - ms->window.base);
 
+    /* Assert that we the ms params match the params we're being given */
+    ZSTD_assertEqualCParams(params->cParams, ms->cParams);
+
     if (srcSize <= HASH_READ_SIZE) return 0;
 
     switch(params->cParams.strategy)
     {
     case ZSTD_fast:
-        ZSTD_fillHashTable(ms, cParams, iend);
+        ZSTD_fillHashTable(ms, iend, dtlm);
         break;
     case ZSTD_dfast:
-        ZSTD_fillDoubleHashTable(ms, cParams, iend);
+        ZSTD_fillDoubleHashTable(ms, iend, dtlm);
         break;
 
     case ZSTD_greedy:
     case ZSTD_lazy:
     case ZSTD_lazy2:
         if (srcSize >= HASH_READ_SIZE)
-            ZSTD_insertAndFindFirstIndex(ms, cParams, iend-HASH_READ_SIZE);
+            ZSTD_insertAndFindFirstIndex(ms, iend-HASH_READ_SIZE);
         break;
 
     case ZSTD_btlazy2:   /* we want the dictionary table fully sorted */
     case ZSTD_btopt:
     case ZSTD_btultra:
         if (srcSize >= HASH_READ_SIZE)
-            ZSTD_updateTree(ms, cParams, iend-HASH_READ_SIZE, iend);
+            ZSTD_updateTree(ms, iend-HASH_READ_SIZE, iend);
         break;
 
     default:
         assert(0);  /* not possible : not a valid strategy id */
     }
 
     ms->nextToUpdate = (U32)(iend - ms->window.base);
     return 0;
 }
 
 
 /* Dictionaries that assign zero probability to symbols that show up causes problems
    when FSE encoding.  Refuse dictionaries that assign zero probability to symbols
    that we may encounter during compression.
    NOTE: This behavior is not standard and could be improved in the future. */
 static size_t ZSTD_checkDictNCount(short* normalizedCounter, unsigned dictMaxSymbolValue, unsigned maxSymbolValue) {
     U32 s;
     if (dictMaxSymbolValue < maxSymbolValue) return ERROR(dictionary_corrupted);
     for (s = 0; s <= maxSymbolValue; ++s) {
         if (normalizedCounter[s] == 0) return ERROR(dictionary_corrupted);
     }
     return 0;
 }
 
 
 /* Dictionary format :
  * See :
  * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
  */
 /*! ZSTD_loadZstdDictionary() :
  * @return : dictID, or an error code
  *  assumptions : magic number supposed already checked
  *                dictSize supposed > 8
  */
-static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs, ZSTD_matchState_t* ms, ZSTD_CCtx_params const* params, const void* dict, size_t dictSize, void* workspace)
+static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
+                                      ZSTD_matchState_t* ms,
+                                      ZSTD_CCtx_params const* params,
+                                      const void* dict, size_t dictSize,
+                                      ZSTD_dictTableLoadMethod_e dtlm,
+                                      void* workspace)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
     short offcodeNCount[MaxOff+1];
     unsigned offcodeMaxValue = MaxOff;
     size_t dictID;
 
     ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1< 8);
+    assert(MEM_readLE32(dictPtr) == ZSTD_MAGIC_DICTIONARY);
 
     dictPtr += 4;   /* skip magic number */
     dictID = params->fParams.noDictIDFlag ? 0 :  MEM_readLE32(dictPtr);
     dictPtr += 4;
 
     {   unsigned maxSymbolValue = 255;
-        size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.hufCTable, &maxSymbolValue, dictPtr, dictEnd-dictPtr);
+        size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.huf.CTable, &maxSymbolValue, dictPtr, dictEnd-dictPtr);
         if (HUF_isError(hufHeaderSize)) return ERROR(dictionary_corrupted);
         if (maxSymbolValue < 255) return ERROR(dictionary_corrupted);
         dictPtr += hufHeaderSize;
     }
 
     {   unsigned offcodeLog;
         size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted);
         if (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted);
         /* Defer checking offcodeMaxValue because we need to know the size of the dictionary content */
-        CHECK_E( FSE_buildCTable_wksp(bs->entropy.offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog, workspace, HUF_WORKSPACE_SIZE),
+        /* fill all offset symbols to avoid garbage at end of table */
+        CHECK_E( FSE_buildCTable_wksp(bs->entropy.fse.offcodeCTable, offcodeNCount, MaxOff, offcodeLog, workspace, HUF_WORKSPACE_SIZE),
                  dictionary_corrupted);
         dictPtr += offcodeHeaderSize;
     }
 
     {   short matchlengthNCount[MaxML+1];
         unsigned matchlengthMaxValue = MaxML, matchlengthLog;
         size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted);
         if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted);
         /* Every match length code must have non-zero probability */
         CHECK_F( ZSTD_checkDictNCount(matchlengthNCount, matchlengthMaxValue, MaxML));
-        CHECK_E( FSE_buildCTable_wksp(bs->entropy.matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, workspace, HUF_WORKSPACE_SIZE),
+        CHECK_E( FSE_buildCTable_wksp(bs->entropy.fse.matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, workspace, HUF_WORKSPACE_SIZE),
                  dictionary_corrupted);
         dictPtr += matchlengthHeaderSize;
     }
 
     {   short litlengthNCount[MaxLL+1];
         unsigned litlengthMaxValue = MaxLL, litlengthLog;
         size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted);
         if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted);
         /* Every literal length code must have non-zero probability */
         CHECK_F( ZSTD_checkDictNCount(litlengthNCount, litlengthMaxValue, MaxLL));
-        CHECK_E( FSE_buildCTable_wksp(bs->entropy.litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, workspace, HUF_WORKSPACE_SIZE),
+        CHECK_E( FSE_buildCTable_wksp(bs->entropy.fse.litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, workspace, HUF_WORKSPACE_SIZE),
                  dictionary_corrupted);
         dictPtr += litlengthHeaderSize;
     }
 
     if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
     bs->rep[0] = MEM_readLE32(dictPtr+0);
     bs->rep[1] = MEM_readLE32(dictPtr+4);
     bs->rep[2] = MEM_readLE32(dictPtr+8);
     dictPtr += 12;
 
     {   size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
         U32 offcodeMax = MaxOff;
         if (dictContentSize <= ((U32)-1) - 128 KB) {
             U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
             offcodeMax = ZSTD_highbit32(maxOffset); /* Calculate minimum offset code required to represent maxOffset */
         }
         /* All offset values <= dictContentSize + 128 KB must be representable */
         CHECK_F (ZSTD_checkDictNCount(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff)));
         /* All repCodes must be <= dictContentSize and != 0*/
         {   U32 u;
             for (u=0; u<3; u++) {
                 if (bs->rep[u] == 0) return ERROR(dictionary_corrupted);
                 if (bs->rep[u] > dictContentSize) return ERROR(dictionary_corrupted);
         }   }
 
-        bs->entropy.hufCTable_repeatMode = HUF_repeat_valid;
-        bs->entropy.offcode_repeatMode = FSE_repeat_valid;
-        bs->entropy.matchlength_repeatMode = FSE_repeat_valid;
-        bs->entropy.litlength_repeatMode = FSE_repeat_valid;
-        CHECK_F(ZSTD_loadDictionaryContent(ms, params, dictPtr, dictContentSize));
+        bs->entropy.huf.repeatMode = HUF_repeat_valid;
+        bs->entropy.fse.offcode_repeatMode = FSE_repeat_valid;
+        bs->entropy.fse.matchlength_repeatMode = FSE_repeat_valid;
+        bs->entropy.fse.litlength_repeatMode = FSE_repeat_valid;
+        CHECK_F(ZSTD_loadDictionaryContent(ms, params, dictPtr, dictContentSize, dtlm));
         return dictID;
     }
 }
 
 /** ZSTD_compress_insertDictionary() :
 *   @return : dictID, or an error code */
-static size_t ZSTD_compress_insertDictionary(ZSTD_compressedBlockState_t* bs, ZSTD_matchState_t* ms,
-                                             ZSTD_CCtx_params const* params,
-                                       const void* dict, size_t dictSize,
-                                             ZSTD_dictContentType_e dictContentType,
-                                             void* workspace)
+static size_t
+ZSTD_compress_insertDictionary(ZSTD_compressedBlockState_t* bs,
+                               ZSTD_matchState_t* ms,
+                         const ZSTD_CCtx_params* params,
+                         const void* dict, size_t dictSize,
+                               ZSTD_dictContentType_e dictContentType,
+                               ZSTD_dictTableLoadMethod_e dtlm,
+                               void* workspace)
 {
     DEBUGLOG(4, "ZSTD_compress_insertDictionary (dictSize=%u)", (U32)dictSize);
     if ((dict==NULL) || (dictSize<=8)) return 0;
 
     ZSTD_reset_compressedBlockState(bs);
 
     /* dict restricted modes */
     if (dictContentType == ZSTD_dct_rawContent)
-        return ZSTD_loadDictionaryContent(ms, params, dict, dictSize);
+        return ZSTD_loadDictionaryContent(ms, params, dict, dictSize, dtlm);
 
     if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) {
         if (dictContentType == ZSTD_dct_auto) {
             DEBUGLOG(4, "raw content dictionary detected");
-            return ZSTD_loadDictionaryContent(ms, params, dict, dictSize);
+            return ZSTD_loadDictionaryContent(ms, params, dict, dictSize, dtlm);
         }
         if (dictContentType == ZSTD_dct_fullDict)
             return ERROR(dictionary_wrong);
         assert(0);   /* impossible */
     }
 
     /* dict as full zstd dictionary */
-    return ZSTD_loadZstdDictionary(bs, ms, params, dict, dictSize, workspace);
+    return ZSTD_loadZstdDictionary(bs, ms, params, dict, dictSize, dtlm, workspace);
 }
 
 /*! ZSTD_compressBegin_internal() :
  * @return : 0, or an error code */
-size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
-                             const void* dict, size_t dictSize,
-                             ZSTD_dictContentType_e dictContentType,
-                             const ZSTD_CDict* cdict,
-                             ZSTD_CCtx_params params, U64 pledgedSrcSize,
-                             ZSTD_buffered_policy_e zbuff)
+static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
+                                    const void* dict, size_t dictSize,
+                                    ZSTD_dictContentType_e dictContentType,
+                                    ZSTD_dictTableLoadMethod_e dtlm,
+                                    const ZSTD_CDict* cdict,
+                                    ZSTD_CCtx_params params, U64 pledgedSrcSize,
+                                    ZSTD_buffered_policy_e zbuff)
 {
     DEBUGLOG(4, "ZSTD_compressBegin_internal: wlog=%u", params.cParams.windowLog);
     /* params are supposed to be fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
 
     if (cdict && cdict->dictContentSize>0) {
-        cctx->requestedParams = params;
-        return ZSTD_resetCCtx_usingCDict(cctx, cdict, params.cParams.windowLog,
-                                         params.fParams, pledgedSrcSize, zbuff);
+        return ZSTD_resetCCtx_usingCDict(cctx, cdict, params, pledgedSrcSize, zbuff);
     }
 
     CHECK_F( ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
                                      ZSTDcrp_continue, zbuff) );
     {
         size_t const dictID = ZSTD_compress_insertDictionary(
                 cctx->blockState.prevCBlock, &cctx->blockState.matchState,
-                ¶ms, dict, dictSize, dictContentType, cctx->entropyWorkspace);
+                ¶ms, dict, dictSize, dictContentType, dtlm, cctx->entropyWorkspace);
         if (ZSTD_isError(dictID)) return dictID;
         assert(dictID <= (size_t)(U32)-1);
         cctx->dictID = (U32)dictID;
     }
     return 0;
 }
 
 size_t ZSTD_compressBegin_advanced_internal(ZSTD_CCtx* cctx,
                                     const void* dict, size_t dictSize,
                                     ZSTD_dictContentType_e dictContentType,
+                                    ZSTD_dictTableLoadMethod_e dtlm,
                                     const ZSTD_CDict* cdict,
                                     ZSTD_CCtx_params params,
                                     unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_compressBegin_advanced_internal: wlog=%u", params.cParams.windowLog);
     /* compression parameters verification and optimization */
     CHECK_F( ZSTD_checkCParams(params.cParams) );
     return ZSTD_compressBegin_internal(cctx,
-                                       dict, dictSize, dictContentType,
+                                       dict, dictSize, dictContentType, dtlm,
                                        cdict,
                                        params, pledgedSrcSize,
                                        ZSTDb_not_buffered);
 }
 
 /*! ZSTD_compressBegin_advanced() :
 *   @return : 0, or an error code */
 size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx,
                              const void* dict, size_t dictSize,
                                    ZSTD_parameters params, unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params const cctxParams =
             ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
     return ZSTD_compressBegin_advanced_internal(cctx,
-                                            dict, dictSize, ZSTD_dct_auto,
+                                            dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast,
                                             NULL /*cdict*/,
                                             cctxParams, pledgedSrcSize);
 }
 
 size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize);
     ZSTD_CCtx_params const cctxParams =
             ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
     DEBUGLOG(4, "ZSTD_compressBegin_usingDict (dictSize=%u)", (U32)dictSize);
-    return ZSTD_compressBegin_internal(cctx, dict, dictSize, ZSTD_dct_auto, NULL,
+    return ZSTD_compressBegin_internal(cctx, dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
                                        cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, ZSTDb_not_buffered);
 }
 
 size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel)
 {
     return ZSTD_compressBegin_usingDict(cctx, NULL, 0, compressionLevel);
 }
 
 
 /*! ZSTD_writeEpilogue() :
 *   Ends a frame.
 *   @return : nb of bytes written into dst (or an error code) */
 static size_t ZSTD_writeEpilogue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity)
 {
     BYTE* const ostart = (BYTE*)dst;
     BYTE* op = ostart;
     size_t fhSize = 0;
 
     DEBUGLOG(4, "ZSTD_writeEpilogue");
     if (cctx->stage == ZSTDcs_created) return ERROR(stage_wrong);  /* init missing */
 
     /* special case : empty frame */
     if (cctx->stage == ZSTDcs_init) {
         fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, cctx->appliedParams, 0, 0);
         if (ZSTD_isError(fhSize)) return fhSize;
         dstCapacity -= fhSize;
         op += fhSize;
         cctx->stage = ZSTDcs_ongoing;
     }
 
     if (cctx->stage != ZSTDcs_ending) {
         /* write one last empty block, make it the "last" block */
         U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1) + 0;
         if (dstCapacity<4) return ERROR(dstSize_tooSmall);
         MEM_writeLE32(op, cBlockHeader24);
         op += ZSTD_blockHeaderSize;
         dstCapacity -= ZSTD_blockHeaderSize;
     }
 
     if (cctx->appliedParams.fParams.checksumFlag) {
         U32 const checksum = (U32) XXH64_digest(&cctx->xxhState);
         if (dstCapacity<4) return ERROR(dstSize_tooSmall);
         DEBUGLOG(4, "ZSTD_writeEpilogue: write checksum : %08X", checksum);
         MEM_writeLE32(op, checksum);
         op += 4;
     }
 
     cctx->stage = ZSTDcs_created;  /* return to "created but no init" status */
     return op-ostart;
 }
 
 size_t ZSTD_compressEnd (ZSTD_CCtx* cctx,
                          void* dst, size_t dstCapacity,
                    const void* src, size_t srcSize)
 {
     size_t endResult;
     size_t const cSize = ZSTD_compressContinue_internal(cctx,
                                 dst, dstCapacity, src, srcSize,
                                 1 /* frame mode */, 1 /* last chunk */);
     if (ZSTD_isError(cSize)) return cSize;
     endResult = ZSTD_writeEpilogue(cctx, (char*)dst + cSize, dstCapacity-cSize);
     if (ZSTD_isError(endResult)) return endResult;
-    if (cctx->appliedParams.fParams.contentSizeFlag) {  /* control src size */
+    assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
+    if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
+        ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
         DEBUGLOG(4, "end of frame : controlling src size");
         if (cctx->pledgedSrcSizePlusOne != cctx->consumedSrcSize+1) {
             DEBUGLOG(4, "error : pledgedSrcSize = %u, while realSrcSize = %u",
                 (U32)cctx->pledgedSrcSizePlusOne-1, (U32)cctx->consumedSrcSize);
             return ERROR(srcSize_wrong);
     }   }
     return cSize + endResult;
 }
 
 
 static size_t ZSTD_compress_internal (ZSTD_CCtx* cctx,
-                               void* dst, size_t dstCapacity,
-                         const void* src, size_t srcSize,
-                         const void* dict,size_t dictSize,
-                               ZSTD_parameters params)
+                                      void* dst, size_t dstCapacity,
+                                const void* src, size_t srcSize,
+                                const void* dict,size_t dictSize,
+                                      ZSTD_parameters params)
 {
     ZSTD_CCtx_params const cctxParams =
             ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
     DEBUGLOG(4, "ZSTD_compress_internal");
     return ZSTD_compress_advanced_internal(cctx,
-                                          dst, dstCapacity,
-                                          src, srcSize,
-                                          dict, dictSize,
-                                          cctxParams);
+                                           dst, dstCapacity,
+                                           src, srcSize,
+                                           dict, dictSize,
+                                           cctxParams);
 }
 
-size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
+size_t ZSTD_compress_advanced (ZSTD_CCtx* cctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const void* dict,size_t dictSize,
                                ZSTD_parameters params)
 {
     DEBUGLOG(4, "ZSTD_compress_advanced");
     CHECK_F(ZSTD_checkCParams(params.cParams));
-    return ZSTD_compress_internal(ctx, dst, dstCapacity, src, srcSize, dict, dictSize, params);
+    return ZSTD_compress_internal(cctx,
+                                  dst, dstCapacity,
+                                  src, srcSize,
+                                  dict, dictSize,
+                                  params);
 }
 
 /* Internal */
 size_t ZSTD_compress_advanced_internal(
         ZSTD_CCtx* cctx,
         void* dst, size_t dstCapacity,
         const void* src, size_t srcSize,
         const void* dict,size_t dictSize,
         ZSTD_CCtx_params params)
 {
-    DEBUGLOG(4, "ZSTD_compress_advanced_internal (srcSize:%u)",
-                (U32)srcSize);
-    CHECK_F( ZSTD_compressBegin_internal(cctx, dict, dictSize, ZSTD_dct_auto, NULL,
-                                         params, srcSize, ZSTDb_not_buffered) );
+    DEBUGLOG(4, "ZSTD_compress_advanced_internal (srcSize:%u)", (U32)srcSize);
+    CHECK_F( ZSTD_compressBegin_internal(cctx,
+                         dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
+                         params, srcSize, ZSTDb_not_buffered) );
     return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
 }
 
-size_t ZSTD_compress_usingDict(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize,
-                               const void* dict, size_t dictSize, int compressionLevel)
+size_t ZSTD_compress_usingDict(ZSTD_CCtx* cctx,
+                               void* dst, size_t dstCapacity,
+                         const void* src, size_t srcSize,
+                         const void* dict, size_t dictSize,
+                               int compressionLevel)
 {
-    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize ? srcSize : 1, dict ? dictSize : 0);
+    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize + (!srcSize), dict ? dictSize : 0);
     ZSTD_CCtx_params cctxParams = ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
     assert(params.fParams.contentSizeFlag == 1);
-    ZSTD_CCtxParam_setParameter(&cctxParams, ZSTD_p_compressLiterals, compressionLevel>=0);
     return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, dict, dictSize, cctxParams);
 }
 
-size_t ZSTD_compressCCtx (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel)
+size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
+                         void* dst, size_t dstCapacity,
+                   const void* src, size_t srcSize,
+                         int compressionLevel)
 {
     DEBUGLOG(4, "ZSTD_compressCCtx (srcSize=%u)", (U32)srcSize);
+    assert(cctx != NULL);
     return ZSTD_compress_usingDict(cctx, dst, dstCapacity, src, srcSize, NULL, 0, compressionLevel);
 }
 
-size_t ZSTD_compress(void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel)
+size_t ZSTD_compress(void* dst, size_t dstCapacity,
+               const void* src, size_t srcSize,
+                     int compressionLevel)
 {
     size_t result;
     ZSTD_CCtx ctxBody;
-    memset(&ctxBody, 0, sizeof(ctxBody));
-    ctxBody.customMem = ZSTD_defaultCMem;
+    ZSTD_initCCtx(&ctxBody, ZSTD_defaultCMem);
     result = ZSTD_compressCCtx(&ctxBody, dst, dstCapacity, src, srcSize, compressionLevel);
-    ZSTD_free(ctxBody.workSpace, ZSTD_defaultCMem);  /* can't free ctxBody itself, as it's on stack; free only heap content */
+    ZSTD_freeCCtxContent(&ctxBody);   /* can't free ctxBody itself, as it's on stack; free only heap content */
     return result;
 }
 
 
 /* =====  Dictionary API  ===== */
 
 /*! ZSTD_estimateCDictSize_advanced() :
  *  Estimate amount of memory that will be needed to create a dictionary with following arguments */
 size_t ZSTD_estimateCDictSize_advanced(
         size_t dictSize, ZSTD_compressionParameters cParams,
         ZSTD_dictLoadMethod_e dictLoadMethod)
 {
     DEBUGLOG(5, "sizeof(ZSTD_CDict) : %u", (U32)sizeof(ZSTD_CDict));
     return sizeof(ZSTD_CDict) + HUF_WORKSPACE_SIZE + ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0)
            + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
 }
 
 size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel)
 {
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
     return ZSTD_estimateCDictSize_advanced(dictSize, cParams, ZSTD_dlm_byCopy);
 }
 
 size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)
 {
     if (cdict==NULL) return 0;   /* support sizeof on NULL */
     DEBUGLOG(5, "sizeof(*cdict) : %u", (U32)sizeof(*cdict));
     return cdict->workspaceSize + (cdict->dictBuffer ? cdict->dictContentSize : 0) + sizeof(*cdict);
 }
 
 static size_t ZSTD_initCDict_internal(
                     ZSTD_CDict* cdict,
               const void* dictBuffer, size_t dictSize,
                     ZSTD_dictLoadMethod_e dictLoadMethod,
                     ZSTD_dictContentType_e dictContentType,
                     ZSTD_compressionParameters cParams)
 {
-    DEBUGLOG(3, "ZSTD_initCDict_internal, dictContentType %u", (U32)dictContentType);
+    DEBUGLOG(3, "ZSTD_initCDict_internal (dictContentType:%u)", (U32)dictContentType);
     assert(!ZSTD_checkCParams(cParams));
-    cdict->cParams = cParams;
+    cdict->matchState.cParams = cParams;
     if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dictBuffer) || (!dictSize)) {
         cdict->dictBuffer = NULL;
         cdict->dictContent = dictBuffer;
     } else {
         void* const internalBuffer = ZSTD_malloc(dictSize, cdict->customMem);
         cdict->dictBuffer = internalBuffer;
         cdict->dictContent = internalBuffer;
         if (!internalBuffer) return ERROR(memory_allocation);
         memcpy(internalBuffer, dictBuffer, dictSize);
     }
     cdict->dictContentSize = dictSize;
 
     /* Reset the state to no dictionary */
     ZSTD_reset_compressedBlockState(&cdict->cBlockState);
     {   void* const end = ZSTD_reset_matchState(
                 &cdict->matchState,
                 (U32*)cdict->workspace + HUF_WORKSPACE_SIZE_U32,
                 &cParams, ZSTDcrp_continue, /* forCCtx */ 0);
         assert(end == (char*)cdict->workspace + cdict->workspaceSize);
         (void)end;
     }
     /* (Maybe) load the dictionary
      * Skips loading the dictionary if it is <= 8 bytes.
      */
     {   ZSTD_CCtx_params params;
         memset(¶ms, 0, sizeof(params));
         params.compressionLevel = ZSTD_CLEVEL_DEFAULT;
         params.fParams.contentSizeFlag = 1;
         params.cParams = cParams;
         {   size_t const dictID = ZSTD_compress_insertDictionary(
                     &cdict->cBlockState, &cdict->matchState, ¶ms,
                     cdict->dictContent, cdict->dictContentSize,
-                    dictContentType, cdict->workspace);
+                    dictContentType, ZSTD_dtlm_full, cdict->workspace);
             if (ZSTD_isError(dictID)) return dictID;
             assert(dictID <= (size_t)(U32)-1);
             cdict->dictID = (U32)dictID;
         }
     }
 
     return 0;
 }
 
 ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize,
                                       ZSTD_dictLoadMethod_e dictLoadMethod,
                                       ZSTD_dictContentType_e dictContentType,
                                       ZSTD_compressionParameters cParams, ZSTD_customMem customMem)
 {
     DEBUGLOG(3, "ZSTD_createCDict_advanced, mode %u", (U32)dictContentType);
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
 
     {   ZSTD_CDict* const cdict = (ZSTD_CDict*)ZSTD_malloc(sizeof(ZSTD_CDict), customMem);
         size_t const workspaceSize = HUF_WORKSPACE_SIZE + ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0);
         void* const workspace = ZSTD_malloc(workspaceSize, customMem);
 
         if (!cdict || !workspace) {
             ZSTD_free(cdict, customMem);
             ZSTD_free(workspace, customMem);
             return NULL;
         }
         cdict->customMem = customMem;
         cdict->workspace = workspace;
         cdict->workspaceSize = workspaceSize;
         if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                         dictBuffer, dictSize,
                                         dictLoadMethod, dictContentType,
                                         cParams) )) {
             ZSTD_freeCDict(cdict);
             return NULL;
         }
 
         return cdict;
     }
 }
 
 ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
     return ZSTD_createCDict_advanced(dict, dictSize,
                                      ZSTD_dlm_byCopy, ZSTD_dct_auto,
                                      cParams, ZSTD_defaultCMem);
 }
 
 ZSTD_CDict* ZSTD_createCDict_byReference(const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
     return ZSTD_createCDict_advanced(dict, dictSize,
                                      ZSTD_dlm_byRef, ZSTD_dct_auto,
                                      cParams, ZSTD_defaultCMem);
 }
 
 size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
 {
     if (cdict==NULL) return 0;   /* support free on NULL */
     {   ZSTD_customMem const cMem = cdict->customMem;
         ZSTD_free(cdict->workspace, cMem);
         ZSTD_free(cdict->dictBuffer, cMem);
         ZSTD_free(cdict, cMem);
         return 0;
     }
 }
 
 /*! ZSTD_initStaticCDict_advanced() :
  *  Generate a digested dictionary in provided memory area.
  *  workspace: The memory area to emplace the dictionary into.
  *             Provided pointer must 8-bytes aligned.
  *             It must outlive dictionary usage.
  *  workspaceSize: Use ZSTD_estimateCDictSize()
  *                 to determine how large workspace must be.
  *  cParams : use ZSTD_getCParams() to transform a compression level
  *            into its relevants cParams.
  * @return : pointer to ZSTD_CDict*, or NULL if error (size too small)
  *  Note : there is no corresponding "free" function.
  *         Since workspace was allocated externally, it must be freed externally.
  */
 const ZSTD_CDict* ZSTD_initStaticCDict(
                                  void* workspace, size_t workspaceSize,
                            const void* dict, size_t dictSize,
                                  ZSTD_dictLoadMethod_e dictLoadMethod,
                                  ZSTD_dictContentType_e dictContentType,
                                  ZSTD_compressionParameters cParams)
 {
     size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0);
     size_t const neededSize = sizeof(ZSTD_CDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize)
                             + HUF_WORKSPACE_SIZE + matchStateSize;
     ZSTD_CDict* const cdict = (ZSTD_CDict*) workspace;
     void* ptr;
     if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
     DEBUGLOG(4, "(workspaceSize < neededSize) : (%u < %u) => %u",
         (U32)workspaceSize, (U32)neededSize, (U32)(workspaceSize < neededSize));
     if (workspaceSize < neededSize) return NULL;
 
     if (dictLoadMethod == ZSTD_dlm_byCopy) {
         memcpy(cdict+1, dict, dictSize);
         dict = cdict+1;
         ptr = (char*)workspace + sizeof(ZSTD_CDict) + dictSize;
     } else {
         ptr = cdict+1;
     }
     cdict->workspace = ptr;
     cdict->workspaceSize = HUF_WORKSPACE_SIZE + matchStateSize;
 
     if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                               dict, dictSize,
                                               ZSTD_dlm_byRef, dictContentType,
                                               cParams) ))
         return NULL;
 
     return cdict;
 }
 
 ZSTD_compressionParameters ZSTD_getCParamsFromCDict(const ZSTD_CDict* cdict)
 {
     assert(cdict != NULL);
-    return cdict->cParams;
+    return cdict->matchState.cParams;
 }
 
 /* ZSTD_compressBegin_usingCDict_advanced() :
  * cdict must be != NULL */
 size_t ZSTD_compressBegin_usingCDict_advanced(
     ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict,
     ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_compressBegin_usingCDict_advanced");
     if (cdict==NULL) return ERROR(dictionary_wrong);
     {   ZSTD_CCtx_params params = cctx->requestedParams;
         params.cParams = ZSTD_getCParamsFromCDict(cdict);
         /* Increase window log to fit the entire dictionary and source if the
          * source size is known. Limit the increase to 19, which is the
          * window log for compression level 1 with the largest source size.
          */
         if (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN) {
             U32 const limitedSrcSize = (U32)MIN(pledgedSrcSize, 1U << 19);
             U32 const limitedSrcLog = limitedSrcSize > 1 ? ZSTD_highbit32(limitedSrcSize - 1) + 1 : 1;
             params.cParams.windowLog = MAX(params.cParams.windowLog, limitedSrcLog);
         }
         params.fParams = fParams;
         return ZSTD_compressBegin_internal(cctx,
-                                           NULL, 0, ZSTD_dct_auto,
+                                           NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast,
                                            cdict,
                                            params, pledgedSrcSize,
                                            ZSTDb_not_buffered);
     }
 }
 
 /* ZSTD_compressBegin_usingCDict() :
  * pledgedSrcSize=0 means "unknown"
  * if pledgedSrcSize>0, it will enable contentSizeFlag */
 size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
 {
     ZSTD_frameParameters const fParams = { 0 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
     DEBUGLOG(4, "ZSTD_compressBegin_usingCDict : dictIDFlag == %u", !fParams.noDictIDFlag);
-    return ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, 0);
+    return ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, ZSTD_CONTENTSIZE_UNKNOWN);
 }
 
 size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize,
                                 const ZSTD_CDict* cdict, ZSTD_frameParameters fParams)
 {
     CHECK_F (ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, srcSize));   /* will check if cdict != NULL */
     return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
 }
 
 /*! ZSTD_compress_usingCDict() :
  *  Compression using a digested Dictionary.
  *  Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
  *  Note that compression parameters are decided at CDict creation time
  *  while frame parameters are hardcoded */
 size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize,
                                 const ZSTD_CDict* cdict)
 {
     ZSTD_frameParameters const fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
     return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, fParams);
 }
 
 
 
 /* ******************************************************************
 *  Streaming
 ********************************************************************/
 
 ZSTD_CStream* ZSTD_createCStream(void)
 {
     DEBUGLOG(3, "ZSTD_createCStream");
     return ZSTD_createCStream_advanced(ZSTD_defaultCMem);
 }
 
 ZSTD_CStream* ZSTD_initStaticCStream(void *workspace, size_t workspaceSize)
 {
     return ZSTD_initStaticCCtx(workspace, workspaceSize);
 }
 
 ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
 {   /* CStream and CCtx are now same object */
     return ZSTD_createCCtx_advanced(customMem);
 }
 
 size_t ZSTD_freeCStream(ZSTD_CStream* zcs)
 {
     return ZSTD_freeCCtx(zcs);   /* same object */
 }
 
 
 
 /*======   Initialization   ======*/
 
 size_t ZSTD_CStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX; }
 
 size_t ZSTD_CStreamOutSize(void)
 {
     return ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ;
 }
 
 static size_t ZSTD_resetCStream_internal(ZSTD_CStream* cctx,
                     const void* const dict, size_t const dictSize, ZSTD_dictContentType_e const dictContentType,
                     const ZSTD_CDict* const cdict,
-                    ZSTD_CCtx_params const params, unsigned long long const pledgedSrcSize)
+                    ZSTD_CCtx_params params, unsigned long long const pledgedSrcSize)
 {
-    DEBUGLOG(4, "ZSTD_resetCStream_internal (disableLiteralCompression=%i)",
-                params.disableLiteralCompression);
+    DEBUGLOG(4, "ZSTD_resetCStream_internal");
+    /* Finalize the compression parameters */
+    params.cParams = ZSTD_getCParamsFromCCtxParams(¶ms, pledgedSrcSize, dictSize);
     /* params are supposed to be fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
 
     CHECK_F( ZSTD_compressBegin_internal(cctx,
-                                         dict, dictSize, dictContentType,
+                                         dict, dictSize, dictContentType, ZSTD_dtlm_fast,
                                          cdict,
                                          params, pledgedSrcSize,
                                          ZSTDb_buffered) );
 
     cctx->inToCompress = 0;
     cctx->inBuffPos = 0;
     cctx->inBuffTarget = cctx->blockSize
                       + (cctx->blockSize == pledgedSrcSize);   /* for small input: avoid automatic flush on reaching end of block, since it would require to add a 3-bytes null block to end frame */
     cctx->outBuffContentSize = cctx->outBuffFlushedSize = 0;
     cctx->streamStage = zcss_load;
     cctx->frameEnded = 0;
     return 0;   /* ready to go */
 }
 
 /* ZSTD_resetCStream():
  * pledgedSrcSize == 0 means "unknown" */
 size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params params = zcs->requestedParams;
     DEBUGLOG(4, "ZSTD_resetCStream: pledgedSrcSize = %u", (U32)pledgedSrcSize);
     if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
     params.fParams.contentSizeFlag = 1;
-    params.cParams = ZSTD_getCParamsFromCCtxParams(¶ms, pledgedSrcSize, 0);
     return ZSTD_resetCStream_internal(zcs, NULL, 0, ZSTD_dct_auto, zcs->cdict, params, pledgedSrcSize);
 }
 
 /*! ZSTD_initCStream_internal() :
  *  Note : for lib/compress only. Used by zstdmt_compress.c.
  *  Assumption 1 : params are valid
  *  Assumption 2 : either dict, or cdict, is defined, not both */
 size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
                     const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
                     ZSTD_CCtx_params params, unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_initCStream_internal");
+    params.cParams = ZSTD_getCParamsFromCCtxParams(¶ms, pledgedSrcSize, dictSize);
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
 
     if (dict && dictSize >= 8) {
         DEBUGLOG(4, "loading dictionary of size %u", (U32)dictSize);
         if (zcs->staticSize) {   /* static CCtx : never uses malloc */
             /* incompatible with internal cdict creation */
             return ERROR(memory_allocation);
         }
         ZSTD_freeCDict(zcs->cdictLocal);
         zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize,
                                             ZSTD_dlm_byCopy, ZSTD_dct_auto,
                                             params.cParams, zcs->customMem);
         zcs->cdict = zcs->cdictLocal;
         if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);
     } else {
         if (cdict) {
             params.cParams = ZSTD_getCParamsFromCDict(cdict);  /* cParams are enforced from cdict; it includes windowLog */
         }
         ZSTD_freeCDict(zcs->cdictLocal);
         zcs->cdictLocal = NULL;
         zcs->cdict = cdict;
     }
 
     return ZSTD_resetCStream_internal(zcs, NULL, 0, ZSTD_dct_auto, zcs->cdict, params, pledgedSrcSize);
 }
 
 /* ZSTD_initCStream_usingCDict_advanced() :
  * same as ZSTD_initCStream_usingCDict(), with control over frame parameters */
 size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs,
                                             const ZSTD_CDict* cdict,
                                             ZSTD_frameParameters fParams,
                                             unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_initCStream_usingCDict_advanced");
     if (!cdict) return ERROR(dictionary_wrong); /* cannot handle NULL cdict (does not know what to do) */
     {   ZSTD_CCtx_params params = zcs->requestedParams;
         params.cParams = ZSTD_getCParamsFromCDict(cdict);
         params.fParams = fParams;
         return ZSTD_initCStream_internal(zcs,
                                 NULL, 0, cdict,
                                 params, pledgedSrcSize);
     }
 }
 
 /* note : cdict must outlive compression session */
 size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict)
 {
     ZSTD_frameParameters const fParams = { 0 /* contentSizeFlag */, 0 /* checksum */, 0 /* hideDictID */ };
     DEBUGLOG(4, "ZSTD_initCStream_usingCDict");
     return ZSTD_initCStream_usingCDict_advanced(zcs, cdict, fParams, ZSTD_CONTENTSIZE_UNKNOWN);  /* note : will check that cdict != NULL */
 }
 
 
 /* ZSTD_initCStream_advanced() :
  * pledgedSrcSize must be exact.
  * if srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
  * dict is loaded with default parameters ZSTD_dm_auto and ZSTD_dlm_byCopy. */
 size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
                                  const void* dict, size_t dictSize,
                                  ZSTD_parameters params, unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_initCStream_advanced: pledgedSrcSize=%u, flag=%u",
                 (U32)pledgedSrcSize, params.fParams.contentSizeFlag);
     CHECK_F( ZSTD_checkCParams(params.cParams) );
     if ((pledgedSrcSize==0) && (params.fParams.contentSizeFlag==0)) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* for compatibility with older programs relying on this behavior. Users should now specify ZSTD_CONTENTSIZE_UNKNOWN. This line will be removed in the future. */
-    {   ZSTD_CCtx_params const cctxParams = ZSTD_assignParamsToCCtxParams(zcs->requestedParams, params);
-        return ZSTD_initCStream_internal(zcs, dict, dictSize, NULL /*cdict*/, cctxParams, pledgedSrcSize);
-    }
+    zcs->requestedParams = ZSTD_assignParamsToCCtxParams(zcs->requestedParams, params);
+    return ZSTD_initCStream_internal(zcs, dict, dictSize, NULL /*cdict*/, zcs->requestedParams, pledgedSrcSize);
 }
 
 size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel)
 {
-    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, dictSize);
-    ZSTD_CCtx_params const cctxParams =
-            ZSTD_assignParamsToCCtxParams(zcs->requestedParams, params);
-    return ZSTD_initCStream_internal(zcs, dict, dictSize, NULL, cctxParams, ZSTD_CONTENTSIZE_UNKNOWN);
+    ZSTD_CCtxParams_init(&zcs->requestedParams, compressionLevel);
+    return ZSTD_initCStream_internal(zcs, dict, dictSize, NULL, zcs->requestedParams, ZSTD_CONTENTSIZE_UNKNOWN);
 }
 
 size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pss)
 {
     U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;  /* temporary : 0 interpreted as "unknown" during transition period. Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN. `0` will be interpreted as "empty" in the future */
-    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, pledgedSrcSize, 0);
-    ZSTD_CCtx_params const cctxParams = ZSTD_assignParamsToCCtxParams(zcs->requestedParams, params);
-    return ZSTD_initCStream_internal(zcs, NULL, 0, NULL, cctxParams, pledgedSrcSize);
+    ZSTD_CCtxParams_init(&zcs->requestedParams, compressionLevel);
+    return ZSTD_initCStream_internal(zcs, NULL, 0, NULL, zcs->requestedParams, pledgedSrcSize);
 }
 
 size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
 {
     DEBUGLOG(4, "ZSTD_initCStream");
     return ZSTD_initCStream_srcSize(zcs, compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN);
 }
 
 /*======   Compression   ======*/
 
 MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize)
 {
     size_t const length = MIN(dstCapacity, srcSize);
     if (length) memcpy(dst, src, length);
     return length;
 }
 
 /** ZSTD_compressStream_generic():
  *  internal function for all *compressStream*() variants and *compress_generic()
  *  non-static, because can be called from zstdmt_compress.c
  * @return : hint size for next input */
 size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                    ZSTD_outBuffer* output,
                                    ZSTD_inBuffer* input,
                                    ZSTD_EndDirective const flushMode)
 {
     const char* const istart = (const char*)input->src;
     const char* const iend = istart + input->size;
     const char* ip = istart + input->pos;
     char* const ostart = (char*)output->dst;
     char* const oend = ostart + output->size;
     char* op = ostart + output->pos;
     U32 someMoreWork = 1;
 
     /* check expectations */
     DEBUGLOG(5, "ZSTD_compressStream_generic, flush=%u", (U32)flushMode);
     assert(zcs->inBuff != NULL);
     assert(zcs->inBuffSize > 0);
     assert(zcs->outBuff !=  NULL);
     assert(zcs->outBuffSize > 0);
     assert(output->pos <= output->size);
     assert(input->pos <= input->size);
 
     while (someMoreWork) {
         switch(zcs->streamStage)
         {
         case zcss_init:
             /* call ZSTD_initCStream() first ! */
             return ERROR(init_missing);
 
         case zcss_load:
             if ( (flushMode == ZSTD_e_end)
               && ((size_t)(oend-op) >= ZSTD_compressBound(iend-ip))  /* enough dstCapacity */
               && (zcs->inBuffPos == 0) ) {
                 /* shortcut to compression pass directly into output buffer */
                 size_t const cSize = ZSTD_compressEnd(zcs,
                                                 op, oend-op, ip, iend-ip);
                 DEBUGLOG(4, "ZSTD_compressEnd : %u", (U32)cSize);
                 if (ZSTD_isError(cSize)) return cSize;
                 ip = iend;
                 op += cSize;
                 zcs->frameEnded = 1;
-                ZSTD_startNewCompression(zcs);
+                ZSTD_CCtx_reset(zcs);
                 someMoreWork = 0; break;
             }
             /* complete loading into inBuffer */
             {   size_t const toLoad = zcs->inBuffTarget - zcs->inBuffPos;
                 size_t const loaded = ZSTD_limitCopy(
                                         zcs->inBuff + zcs->inBuffPos, toLoad,
                                         ip, iend-ip);
                 zcs->inBuffPos += loaded;
                 ip += loaded;
                 if ( (flushMode == ZSTD_e_continue)
                   && (zcs->inBuffPos < zcs->inBuffTarget) ) {
                     /* not enough input to fill full block : stop here */
                     someMoreWork = 0; break;
                 }
                 if ( (flushMode == ZSTD_e_flush)
                   && (zcs->inBuffPos == zcs->inToCompress) ) {
                     /* empty */
                     someMoreWork = 0; break;
                 }
             }
             /* compress current block (note : this stage cannot be stopped in the middle) */
             DEBUGLOG(5, "stream compression stage (flushMode==%u)", flushMode);
             {   void* cDst;
                 size_t cSize;
                 size_t const iSize = zcs->inBuffPos - zcs->inToCompress;
                 size_t oSize = oend-op;
                 unsigned const lastBlock = (flushMode == ZSTD_e_end) && (ip==iend);
                 if (oSize >= ZSTD_compressBound(iSize))
                     cDst = op;   /* compress into output buffer, to skip flush stage */
                 else
                     cDst = zcs->outBuff, oSize = zcs->outBuffSize;
                 cSize = lastBlock ?
                         ZSTD_compressEnd(zcs, cDst, oSize,
                                     zcs->inBuff + zcs->inToCompress, iSize) :
                         ZSTD_compressContinue(zcs, cDst, oSize,
                                     zcs->inBuff + zcs->inToCompress, iSize);
                 if (ZSTD_isError(cSize)) return cSize;
                 zcs->frameEnded = lastBlock;
                 /* prepare next block */
                 zcs->inBuffTarget = zcs->inBuffPos + zcs->blockSize;
                 if (zcs->inBuffTarget > zcs->inBuffSize)
                     zcs->inBuffPos = 0, zcs->inBuffTarget = zcs->blockSize;
                 DEBUGLOG(5, "inBuffTarget:%u / inBuffSize:%u",
                          (U32)zcs->inBuffTarget, (U32)zcs->inBuffSize);
                 if (!lastBlock)
                     assert(zcs->inBuffTarget <= zcs->inBuffSize);
                 zcs->inToCompress = zcs->inBuffPos;
                 if (cDst == op) {  /* no need to flush */
                     op += cSize;
                     if (zcs->frameEnded) {
                         DEBUGLOG(5, "Frame completed directly in outBuffer");
                         someMoreWork = 0;
-                        ZSTD_startNewCompression(zcs);
+                        ZSTD_CCtx_reset(zcs);
                     }
                     break;
                 }
                 zcs->outBuffContentSize = cSize;
                 zcs->outBuffFlushedSize = 0;
                 zcs->streamStage = zcss_flush; /* pass-through to flush stage */
             }
 	    /* fall-through */
         case zcss_flush:
             DEBUGLOG(5, "flush stage");
             {   size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
                 size_t const flushed = ZSTD_limitCopy(op, oend-op,
                             zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
                 DEBUGLOG(5, "toFlush: %u into %u ==> flushed: %u",
                             (U32)toFlush, (U32)(oend-op), (U32)flushed);
                 op += flushed;
                 zcs->outBuffFlushedSize += flushed;
                 if (toFlush!=flushed) {
                     /* flush not fully completed, presumably because dst is too small */
                     assert(op==oend);
                     someMoreWork = 0;
                     break;
                 }
                 zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
                 if (zcs->frameEnded) {
                     DEBUGLOG(5, "Frame completed on flush");
                     someMoreWork = 0;
-                    ZSTD_startNewCompression(zcs);
+                    ZSTD_CCtx_reset(zcs);
                     break;
                 }
                 zcs->streamStage = zcss_load;
                 break;
             }
 
         default: /* impossible */
             assert(0);
         }
     }
 
     input->pos = ip - istart;
     output->pos = op - ostart;
     if (zcs->frameEnded) return 0;
     {   size_t hintInSize = zcs->inBuffTarget - zcs->inBuffPos;
         if (hintInSize==0) hintInSize = zcs->blockSize;
         return hintInSize;
     }
 }
 
 size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     /* check conditions */
     if (output->pos > output->size) return ERROR(GENERIC);
     if (input->pos  > input->size)  return ERROR(GENERIC);
 
     return ZSTD_compressStream_generic(zcs, output, input, ZSTD_e_continue);
 }
 
 
 size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
                               ZSTD_outBuffer* output,
                               ZSTD_inBuffer* input,
                               ZSTD_EndDirective endOp)
 {
     DEBUGLOG(5, "ZSTD_compress_generic, endOp=%u ", (U32)endOp);
     /* check conditions */
     if (output->pos > output->size) return ERROR(GENERIC);
     if (input->pos  > input->size)  return ERROR(GENERIC);
     assert(cctx!=NULL);
 
     /* transparent initialization stage */
     if (cctx->streamStage == zcss_init) {
         ZSTD_CCtx_params params = cctx->requestedParams;
         ZSTD_prefixDict const prefixDict = cctx->prefixDict;
         memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));  /* single usage */
         assert(prefixDict.dict==NULL || cctx->cdict==NULL);   /* only one can be set */
         DEBUGLOG(4, "ZSTD_compress_generic : transparent init stage");
         if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = input->size + 1;  /* auto-fix pledgedSrcSize */
         params.cParams = ZSTD_getCParamsFromCCtxParams(
                 &cctx->requestedParams, cctx->pledgedSrcSizePlusOne-1, 0 /*dictSize*/);
 
+
 #ifdef ZSTD_MULTITHREAD
         if ((cctx->pledgedSrcSizePlusOne-1) <= ZSTDMT_JOBSIZE_MIN) {
             params.nbWorkers = 0; /* do not invoke multi-threading when src size is too small */
         }
         if (params.nbWorkers > 0) {
             /* mt context creation */
-            if (cctx->mtctx == NULL || (params.nbWorkers != ZSTDMT_getNbWorkers(cctx->mtctx))) {
+            if (cctx->mtctx == NULL) {
                 DEBUGLOG(4, "ZSTD_compress_generic: creating new mtctx for nbWorkers=%u",
                             params.nbWorkers);
-                if (cctx->mtctx != NULL)
-                    DEBUGLOG(4, "ZSTD_compress_generic: previous nbWorkers was %u",
-                                ZSTDMT_getNbWorkers(cctx->mtctx));
-                ZSTDMT_freeCCtx(cctx->mtctx);
                 cctx->mtctx = ZSTDMT_createCCtx_advanced(params.nbWorkers, cctx->customMem);
                 if (cctx->mtctx == NULL) return ERROR(memory_allocation);
             }
             /* mt compression */
             DEBUGLOG(4, "call ZSTDMT_initCStream_internal as nbWorkers=%u", params.nbWorkers);
             CHECK_F( ZSTDMT_initCStream_internal(
                         cctx->mtctx,
                         prefixDict.dict, prefixDict.dictSize, ZSTD_dct_rawContent,
                         cctx->cdict, params, cctx->pledgedSrcSizePlusOne-1) );
             cctx->streamStage = zcss_load;
             cctx->appliedParams.nbWorkers = params.nbWorkers;
         } else
 #endif
         {   CHECK_F( ZSTD_resetCStream_internal(cctx,
                             prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType,
                             cctx->cdict,
                             params, cctx->pledgedSrcSizePlusOne-1) );
             assert(cctx->streamStage == zcss_load);
             assert(cctx->appliedParams.nbWorkers == 0);
     }   }
 
     /* compression stage */
 #ifdef ZSTD_MULTITHREAD
     if (cctx->appliedParams.nbWorkers > 0) {
         if (cctx->cParamsChanged) {
             ZSTDMT_updateCParams_whileCompressing(cctx->mtctx, &cctx->requestedParams);
             cctx->cParamsChanged = 0;
         }
         {   size_t const flushMin = ZSTDMT_compressStream_generic(cctx->mtctx, output, input, endOp);
             if ( ZSTD_isError(flushMin)
               || (endOp == ZSTD_e_end && flushMin == 0) ) { /* compression completed */
-                ZSTD_startNewCompression(cctx);
+                ZSTD_CCtx_reset(cctx);
             }
+            DEBUGLOG(5, "completed ZSTD_compress_generic delegating to ZSTDMT_compressStream_generic");
             return flushMin;
     }   }
 #endif
     CHECK_F( ZSTD_compressStream_generic(cctx, output, input, endOp) );
     DEBUGLOG(5, "completed ZSTD_compress_generic");
     return cctx->outBuffContentSize - cctx->outBuffFlushedSize; /* remaining to flush */
 }
 
 size_t ZSTD_compress_generic_simpleArgs (
                             ZSTD_CCtx* cctx,
                             void* dst, size_t dstCapacity, size_t* dstPos,
                       const void* src, size_t srcSize, size_t* srcPos,
                             ZSTD_EndDirective endOp)
 {
     ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
     ZSTD_inBuffer  input  = { src, srcSize, *srcPos };
     /* ZSTD_compress_generic() will check validity of dstPos and srcPos */
     size_t const cErr = ZSTD_compress_generic(cctx, &output, &input, endOp);
     *dstPos = output.pos;
     *srcPos = input.pos;
     return cErr;
 }
 
 
 /*======   Finalize   ======*/
 
 /*! ZSTD_flushStream() :
  * @return : amount of data remaining to flush */
 size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 {
     ZSTD_inBuffer input = { NULL, 0, 0 };
     if (output->pos > output->size) return ERROR(GENERIC);
     CHECK_F( ZSTD_compressStream_generic(zcs, output, &input, ZSTD_e_flush) );
     return zcs->outBuffContentSize - zcs->outBuffFlushedSize;  /* remaining to flush */
 }
 
 
 size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 {
     ZSTD_inBuffer input = { NULL, 0, 0 };
     if (output->pos > output->size) return ERROR(GENERIC);
     CHECK_F( ZSTD_compressStream_generic(zcs, output, &input, ZSTD_e_end) );
     {   size_t const lastBlockSize = zcs->frameEnded ? 0 : ZSTD_BLOCKHEADERSIZE;
         size_t const checksumSize = zcs->frameEnded ? 0 : zcs->appliedParams.fParams.checksumFlag * 4;
         size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize + lastBlockSize + checksumSize;
         DEBUGLOG(4, "ZSTD_endStream : remaining to flush : %u", (U32)toFlush);
         return toFlush;
     }
 }
 
 
 /*-=====  Pre-defined compression levels  =====-*/
 
 #define ZSTD_MAX_CLEVEL     22
 int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
+int ZSTD_minCLevel(void) { return (int)-ZSTD_TARGETLENGTH_MAX; }
 
 static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEVEL+1] = {
 {   /* "default" - guarantees a monotonically increasing memory budget */
     /* W,  C,  H,  S,  L, TL, strat */
     { 19, 12, 13,  1,  6,  1, ZSTD_fast    },  /* base for negative levels */
-    { 19, 13, 14,  1,  7,  1, ZSTD_fast    },  /* level  1 */
-    { 19, 15, 16,  1,  6,  1, ZSTD_fast    },  /* level  2 */
-    { 20, 16, 17,  1,  5,  8, ZSTD_dfast   },  /* level  3 */
-    { 20, 17, 18,  1,  5,  8, ZSTD_dfast   },  /* level  4 */
-    { 20, 17, 18,  2,  5, 16, ZSTD_greedy  },  /* level  5 */
-    { 21, 17, 19,  2,  5, 16, ZSTD_lazy    },  /* level  6 */
-    { 21, 18, 19,  3,  5, 16, ZSTD_lazy    },  /* level  7 */
-    { 21, 18, 20,  3,  5, 16, ZSTD_lazy2   },  /* level  8 */
-    { 21, 19, 20,  3,  5, 16, ZSTD_lazy2   },  /* level  9 */
-    { 21, 19, 21,  4,  5, 16, ZSTD_lazy2   },  /* level 10 */
-    { 22, 20, 22,  4,  5, 16, ZSTD_lazy2   },  /* level 11 */
+    { 19, 13, 14,  1,  7,  0, ZSTD_fast    },  /* level  1 */
+    { 19, 15, 16,  1,  6,  0, ZSTD_fast    },  /* level  2 */
+    { 20, 16, 17,  1,  5,  1, ZSTD_dfast   },  /* level  3 */
+    { 20, 18, 18,  1,  5,  1, ZSTD_dfast   },  /* level  4 */
+    { 20, 18, 18,  2,  5,  2, ZSTD_greedy  },  /* level  5 */
+    { 21, 18, 19,  2,  5,  4, ZSTD_lazy    },  /* level  6 */
+    { 21, 18, 19,  3,  5,  8, ZSTD_lazy2   },  /* level  7 */
+    { 21, 19, 19,  3,  5, 16, ZSTD_lazy2   },  /* level  8 */
+    { 21, 19, 20,  4,  5, 16, ZSTD_lazy2   },  /* level  9 */
+    { 21, 20, 21,  4,  5, 16, ZSTD_lazy2   },  /* level 10 */
+    { 21, 21, 22,  4,  5, 16, ZSTD_lazy2   },  /* level 11 */
     { 22, 20, 22,  5,  5, 16, ZSTD_lazy2   },  /* level 12 */
     { 22, 21, 22,  4,  5, 32, ZSTD_btlazy2 },  /* level 13 */
     { 22, 21, 22,  5,  5, 32, ZSTD_btlazy2 },  /* level 14 */
     { 22, 22, 22,  6,  5, 32, ZSTD_btlazy2 },  /* level 15 */
     { 22, 21, 22,  4,  5, 48, ZSTD_btopt   },  /* level 16 */
-    { 23, 22, 22,  4,  4, 48, ZSTD_btopt   },  /* level 17 */
-    { 23, 22, 22,  5,  3, 64, ZSTD_btopt   },  /* level 18 */
-    { 23, 23, 22,  7,  3,128, ZSTD_btopt   },  /* level 19 */
-    { 25, 25, 23,  7,  3,128, ZSTD_btultra },  /* level 20 */
-    { 26, 26, 24,  7,  3,256, ZSTD_btultra },  /* level 21 */
-    { 27, 27, 25,  9,  3,512, ZSTD_btultra },  /* level 22 */
+    { 23, 22, 22,  4,  4, 64, ZSTD_btopt   },  /* level 17 */
+    { 23, 23, 22,  6,  3,256, ZSTD_btopt   },  /* level 18 */
+    { 23, 24, 22,  7,  3,256, ZSTD_btultra },  /* level 19 */
+    { 25, 25, 23,  7,  3,256, ZSTD_btultra },  /* level 20 */
+    { 26, 26, 24,  7,  3,512, ZSTD_btultra },  /* level 21 */
+    { 27, 27, 25,  9,  3,999, ZSTD_btultra },  /* level 22 */
 },
 {   /* for srcSize <= 256 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 18, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
-    { 18, 13, 14,  1,  6,  1, ZSTD_fast    },  /* level  1 */
-    { 18, 14, 13,  1,  5,  8, ZSTD_dfast   },  /* level  2 */
-    { 18, 16, 15,  1,  5,  8, ZSTD_dfast   },  /* level  3 */
-    { 18, 15, 17,  1,  5,  8, ZSTD_greedy  },  /* level  4.*/
-    { 18, 16, 17,  4,  5,  8, ZSTD_greedy  },  /* level  5.*/
-    { 18, 16, 17,  3,  5,  8, ZSTD_lazy    },  /* level  6.*/
-    { 18, 17, 17,  4,  4,  8, ZSTD_lazy    },  /* level  7 */
-    { 18, 17, 17,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
-    { 18, 17, 17,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
-    { 18, 17, 17,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
-    { 18, 18, 17,  6,  4,  8, ZSTD_lazy2   },  /* level 11.*/
-    { 18, 18, 17,  5,  4,  8, ZSTD_btlazy2 },  /* level 12.*/
-    { 18, 19, 17,  7,  4,  8, ZSTD_btlazy2 },  /* level 13 */
-    { 18, 18, 18,  4,  4, 16, ZSTD_btopt   },  /* level 14.*/
-    { 18, 18, 18,  4,  3, 16, ZSTD_btopt   },  /* level 15.*/
-    { 18, 19, 18,  6,  3, 32, ZSTD_btopt   },  /* level 16.*/
-    { 18, 19, 18,  8,  3, 64, ZSTD_btopt   },  /* level 17.*/
-    { 18, 19, 18,  9,  3,128, ZSTD_btopt   },  /* level 18.*/
-    { 18, 19, 18, 10,  3,256, ZSTD_btopt   },  /* level 19.*/
-    { 18, 19, 18, 11,  3,512, ZSTD_btultra },  /* level 20.*/
-    { 18, 19, 18, 12,  3,512, ZSTD_btultra },  /* level 21.*/
-    { 18, 19, 18, 13,  3,512, ZSTD_btultra },  /* level 22.*/
+    { 18, 13, 14,  1,  6,  0, ZSTD_fast    },  /* level  1 */
+    { 18, 14, 14,  1,  5,  1, ZSTD_dfast   },  /* level  2 */
+    { 18, 16, 16,  1,  4,  1, ZSTD_dfast   },  /* level  3 */
+    { 18, 16, 17,  2,  5,  2, ZSTD_greedy  },  /* level  4.*/
+    { 18, 18, 18,  3,  5,  2, ZSTD_greedy  },  /* level  5.*/
+    { 18, 18, 19,  3,  5,  4, ZSTD_lazy    },  /* level  6.*/
+    { 18, 18, 19,  4,  4,  4, ZSTD_lazy    },  /* level  7 */
+    { 18, 18, 19,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
+    { 18, 18, 19,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
+    { 18, 18, 19,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
+    { 18, 18, 19,  5,  4, 16, ZSTD_btlazy2 },  /* level 11.*/
+    { 18, 19, 19,  6,  4, 16, ZSTD_btlazy2 },  /* level 12.*/
+    { 18, 19, 19,  8,  4, 16, ZSTD_btlazy2 },  /* level 13 */
+    { 18, 18, 19,  4,  4, 24, ZSTD_btopt   },  /* level 14.*/
+    { 18, 18, 19,  4,  3, 24, ZSTD_btopt   },  /* level 15.*/
+    { 18, 19, 19,  6,  3, 64, ZSTD_btopt   },  /* level 16.*/
+    { 18, 19, 19,  8,  3,128, ZSTD_btopt   },  /* level 17.*/
+    { 18, 19, 19, 10,  3,256, ZSTD_btopt   },  /* level 18.*/
+    { 18, 19, 19, 10,  3,256, ZSTD_btultra },  /* level 19.*/
+    { 18, 19, 19, 11,  3,512, ZSTD_btultra },  /* level 20.*/
+    { 18, 19, 19, 12,  3,512, ZSTD_btultra },  /* level 21.*/
+    { 18, 19, 19, 13,  3,999, ZSTD_btultra },  /* level 22.*/
 },
 {   /* for srcSize <= 128 KB */
     /* W,  C,  H,  S,  L,  T, strat */
-    { 17, 12, 12,  1,  5,  1, ZSTD_fast    },  /* level  0 - not used */
-    { 17, 12, 13,  1,  6,  1, ZSTD_fast    },  /* level  1 */
-    { 17, 13, 16,  1,  5,  1, ZSTD_fast    },  /* level  2 */
-    { 17, 16, 16,  2,  5,  8, ZSTD_dfast   },  /* level  3 */
-    { 17, 13, 15,  3,  4,  8, ZSTD_greedy  },  /* level  4 */
-    { 17, 15, 17,  4,  4,  8, ZSTD_greedy  },  /* level  5 */
-    { 17, 16, 17,  3,  4,  8, ZSTD_lazy    },  /* level  6 */
-    { 17, 15, 17,  4,  4,  8, ZSTD_lazy2   },  /* level  7 */
+    { 17, 12, 12,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
+    { 17, 12, 13,  1,  6,  0, ZSTD_fast    },  /* level  1 */
+    { 17, 13, 15,  1,  5,  0, ZSTD_fast    },  /* level  2 */
+    { 17, 15, 16,  2,  5,  1, ZSTD_dfast   },  /* level  3 */
+    { 17, 17, 17,  2,  4,  1, ZSTD_dfast   },  /* level  4 */
+    { 17, 16, 17,  3,  4,  2, ZSTD_greedy  },  /* level  5 */
+    { 17, 17, 17,  3,  4,  4, ZSTD_lazy    },  /* level  6 */
+    { 17, 17, 17,  3,  4,  8, ZSTD_lazy2   },  /* level  7 */
     { 17, 17, 17,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
     { 17, 17, 17,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
     { 17, 17, 17,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
     { 17, 17, 17,  7,  4,  8, ZSTD_lazy2   },  /* level 11 */
-    { 17, 17, 17,  8,  4,  8, ZSTD_lazy2   },  /* level 12 */
-    { 17, 18, 17,  6,  4,  8, ZSTD_btlazy2 },  /* level 13.*/
-    { 17, 17, 17,  7,  3,  8, ZSTD_btopt   },  /* level 14.*/
-    { 17, 17, 17,  7,  3, 16, ZSTD_btopt   },  /* level 15.*/
-    { 17, 18, 17,  7,  3, 32, ZSTD_btopt   },  /* level 16.*/
-    { 17, 18, 17,  7,  3, 64, ZSTD_btopt   },  /* level 17.*/
-    { 17, 18, 17,  7,  3,256, ZSTD_btopt   },  /* level 18.*/
-    { 17, 18, 17,  8,  3,256, ZSTD_btopt   },  /* level 19.*/
+    { 17, 18, 17,  6,  4, 16, ZSTD_btlazy2 },  /* level 12 */
+    { 17, 18, 17,  8,  4, 16, ZSTD_btlazy2 },  /* level 13.*/
+    { 17, 18, 17,  4,  4, 32, ZSTD_btopt   },  /* level 14.*/
+    { 17, 18, 17,  6,  3, 64, ZSTD_btopt   },  /* level 15.*/
+    { 17, 18, 17,  7,  3,128, ZSTD_btopt   },  /* level 16.*/
+    { 17, 18, 17,  7,  3,256, ZSTD_btopt   },  /* level 17.*/
+    { 17, 18, 17,  8,  3,256, ZSTD_btopt   },  /* level 18.*/
+    { 17, 18, 17,  8,  3,256, ZSTD_btultra },  /* level 19.*/
     { 17, 18, 17,  9,  3,256, ZSTD_btultra },  /* level 20.*/
     { 17, 18, 17, 10,  3,256, ZSTD_btultra },  /* level 21.*/
     { 17, 18, 17, 11,  3,512, ZSTD_btultra },  /* level 22.*/
 },
 {   /* for srcSize <= 16 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 14, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
-    { 14, 14, 14,  1,  6,  1, ZSTD_fast    },  /* level  1 */
-    { 14, 14, 14,  1,  4,  1, ZSTD_fast    },  /* level  2 */
-    { 14, 14, 14,  1,  4,  6, ZSTD_dfast   },  /* level  3.*/
-    { 14, 14, 14,  4,  4,  6, ZSTD_greedy  },  /* level  4.*/
-    { 14, 14, 14,  3,  4,  6, ZSTD_lazy    },  /* level  5.*/
-    { 14, 14, 14,  4,  4,  6, ZSTD_lazy2   },  /* level  6 */
-    { 14, 14, 14,  5,  4,  6, ZSTD_lazy2   },  /* level  7 */
-    { 14, 14, 14,  6,  4,  6, ZSTD_lazy2   },  /* level  8.*/
-    { 14, 15, 14,  6,  4,  6, ZSTD_btlazy2 },  /* level  9.*/
-    { 14, 15, 14,  3,  3,  6, ZSTD_btopt   },  /* level 10.*/
-    { 14, 15, 14,  6,  3,  8, ZSTD_btopt   },  /* level 11.*/
+    { 14, 14, 15,  1,  5,  0, ZSTD_fast    },  /* level  1 */
+    { 14, 14, 15,  1,  4,  0, ZSTD_fast    },  /* level  2 */
+    { 14, 14, 14,  2,  4,  1, ZSTD_dfast   },  /* level  3.*/
+    { 14, 14, 14,  4,  4,  2, ZSTD_greedy  },  /* level  4.*/
+    { 14, 14, 14,  3,  4,  4, ZSTD_lazy    },  /* level  5.*/
+    { 14, 14, 14,  4,  4,  8, ZSTD_lazy2   },  /* level  6 */
+    { 14, 14, 14,  6,  4,  8, ZSTD_lazy2   },  /* level  7 */
+    { 14, 14, 14,  8,  4,  8, ZSTD_lazy2   },  /* level  8.*/
+    { 14, 15, 14,  5,  4,  8, ZSTD_btlazy2 },  /* level  9.*/
+    { 14, 15, 14,  9,  4,  8, ZSTD_btlazy2 },  /* level 10.*/
+    { 14, 15, 14,  3,  4, 12, ZSTD_btopt   },  /* level 11.*/
     { 14, 15, 14,  6,  3, 16, ZSTD_btopt   },  /* level 12.*/
     { 14, 15, 14,  6,  3, 24, ZSTD_btopt   },  /* level 13.*/
     { 14, 15, 15,  6,  3, 48, ZSTD_btopt   },  /* level 14.*/
     { 14, 15, 15,  6,  3, 64, ZSTD_btopt   },  /* level 15.*/
     { 14, 15, 15,  6,  3, 96, ZSTD_btopt   },  /* level 16.*/
     { 14, 15, 15,  6,  3,128, ZSTD_btopt   },  /* level 17.*/
-    { 14, 15, 15,  6,  3,256, ZSTD_btopt   },  /* level 18.*/
-    { 14, 15, 15,  7,  3,256, ZSTD_btopt   },  /* level 19.*/
+    { 14, 15, 15,  8,  3,256, ZSTD_btopt   },  /* level 18.*/
+    { 14, 15, 15,  6,  3,256, ZSTD_btultra },  /* level 19.*/
     { 14, 15, 15,  8,  3,256, ZSTD_btultra },  /* level 20.*/
     { 14, 15, 15,  9,  3,256, ZSTD_btultra },  /* level 21.*/
-    { 14, 15, 15, 10,  3,256, ZSTD_btultra },  /* level 22.*/
+    { 14, 15, 15, 10,  3,512, ZSTD_btultra },  /* level 22.*/
 },
 };
 
 /*! ZSTD_getCParams() :
 *  @return ZSTD_compressionParameters structure for a selected compression level, srcSize and dictSize.
 *   Size values are optional, provide 0 if not known or unused */
 ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize)
 {
     size_t const addedSize = srcSizeHint ? 0 : 500;
     U64 const rSize = srcSizeHint+dictSize ? srcSizeHint+dictSize+addedSize : (U64)-1;
     U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);   /* intentional underflow for srcSizeHint == 0 */
     int row = compressionLevel;
     DEBUGLOG(5, "ZSTD_getCParams (cLevel=%i)", compressionLevel);
     if (compressionLevel == 0) row = ZSTD_CLEVEL_DEFAULT;   /* 0 == default */
     if (compressionLevel < 0) row = 0;   /* entry 0 is baseline for fast mode */
     if (compressionLevel > ZSTD_MAX_CLEVEL) row = ZSTD_MAX_CLEVEL;
     {   ZSTD_compressionParameters cp = ZSTD_defaultCParameters[tableID][row];
         if (compressionLevel < 0) cp.targetLength = (unsigned)(-compressionLevel);   /* acceleration factor */
         return ZSTD_adjustCParams_internal(cp, srcSizeHint, dictSize); }
 
 }
 
 /*! ZSTD_getParams() :
 *   same as ZSTD_getCParams(), but @return a `ZSTD_parameters` object (instead of `ZSTD_compressionParameters`).
 *   All fields of `ZSTD_frameParameters` are set to default (0) */
 ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize) {
     ZSTD_parameters params;
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, srcSizeHint, dictSize);
     DEBUGLOG(5, "ZSTD_getParams (cLevel=%i)", compressionLevel);
     memset(¶ms, 0, sizeof(params));
     params.cParams = cParams;
     params.fParams.contentSizeFlag = 1;
     return params;
 }
Index: vendor/zstd/dist/lib/compress/zstd_compress_internal.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_compress_internal.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_compress_internal.h	(revision 339614)
@@ -1,709 +1,798 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /* This header contains definitions
  * that shall **only** be used by modules within lib/compress.
  */
 
 #ifndef ZSTD_COMPRESS_H
 #define ZSTD_COMPRESS_H
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include "zstd_internal.h"
 #ifdef ZSTD_MULTITHREAD
 #  include "zstdmt_compress.h"
 #endif
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
+
 /*-*************************************
 *  Constants
 ***************************************/
 #define kSearchStrength      8
 #define HASH_READ_SIZE       8
 #define ZSTD_DUBT_UNSORTED_MARK 1   /* For btlazy2 strategy, index 1 now means "unsorted".
                                        It could be confused for a real successor at index "1", if sorted as larger than its predecessor.
                                        It's not a big deal though : candidate will just be sorted again.
                                        Additionnally, candidate position 1 will be lost.
                                        But candidate 1 cannot hide a large tree of candidates, so it's a minimal loss.
-                                       The benefit is that ZSTD_DUBT_UNSORTED_MARK cannot be misdhandled after table re-use with a different strategy */
+                                       The benefit is that ZSTD_DUBT_UNSORTED_MARK cannot be misdhandled after table re-use with a different strategy
+                                       Constant required by ZSTD_compressBlock_btlazy2() and ZSTD_reduceTable_internal() */
 
 
 /*-*************************************
 *  Context memory management
 ***************************************/
 typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZSTD_compressionStage_e;
 typedef enum { zcss_init=0, zcss_load, zcss_flush } ZSTD_cStreamStage;
 
+typedef enum {
+    ZSTD_dictDefaultAttach = 0,
+    ZSTD_dictForceAttach = 1,
+    ZSTD_dictForceCopy = -1,
+} ZSTD_dictAttachPref_e;
+
 typedef struct ZSTD_prefixDict_s {
     const void* dict;
     size_t dictSize;
     ZSTD_dictContentType_e dictContentType;
 } ZSTD_prefixDict;
 
 typedef struct {
-    U32 hufCTable[HUF_CTABLE_SIZE_U32(255)];
+    U32 CTable[HUF_CTABLE_SIZE_U32(255)];
+    HUF_repeat repeatMode;
+} ZSTD_hufCTables_t;
+
+typedef struct {
     FSE_CTable offcodeCTable[FSE_CTABLE_SIZE_U32(OffFSELog, MaxOff)];
     FSE_CTable matchlengthCTable[FSE_CTABLE_SIZE_U32(MLFSELog, MaxML)];
     FSE_CTable litlengthCTable[FSE_CTABLE_SIZE_U32(LLFSELog, MaxLL)];
-    HUF_repeat hufCTable_repeatMode;
     FSE_repeat offcode_repeatMode;
     FSE_repeat matchlength_repeatMode;
     FSE_repeat litlength_repeatMode;
+} ZSTD_fseCTables_t;
+
+typedef struct {
+    ZSTD_hufCTables_t huf;
+    ZSTD_fseCTables_t fse;
 } ZSTD_entropyCTables_t;
 
 typedef struct {
     U32 off;
     U32 len;
 } ZSTD_match_t;
 
 typedef struct {
     int price;
     U32 off;
     U32 mlen;
     U32 litlen;
     U32 rep[ZSTD_REP_NUM];
 } ZSTD_optimal_t;
 
+typedef enum { zop_dynamic=0, zop_predef } ZSTD_OptPrice_e;
+
 typedef struct {
     /* All tables are allocated inside cctx->workspace by ZSTD_resetCCtx_internal() */
-    U32* litFreq;               /* table of literals statistics, of size 256 */
-    U32* litLengthFreq;         /* table of litLength statistics, of size (MaxLL+1) */
-    U32* matchLengthFreq;       /* table of matchLength statistics, of size (MaxML+1) */
-    U32* offCodeFreq;           /* table of offCode statistics, of size (MaxOff+1) */
-    ZSTD_match_t* matchTable;   /* list of found matches, of size ZSTD_OPT_NUM+1 */
-    ZSTD_optimal_t* priceTable; /* All positions tracked by optimal parser, of size ZSTD_OPT_NUM+1 */
+    U32* litFreq;                /* table of literals statistics, of size 256 */
+    U32* litLengthFreq;          /* table of litLength statistics, of size (MaxLL+1) */
+    U32* matchLengthFreq;        /* table of matchLength statistics, of size (MaxML+1) */
+    U32* offCodeFreq;            /* table of offCode statistics, of size (MaxOff+1) */
+    ZSTD_match_t* matchTable;    /* list of found matches, of size ZSTD_OPT_NUM+1 */
+    ZSTD_optimal_t* priceTable;  /* All positions tracked by optimal parser, of size ZSTD_OPT_NUM+1 */
 
     U32  litSum;                 /* nb of literals */
     U32  litLengthSum;           /* nb of litLength codes */
     U32  matchLengthSum;         /* nb of matchLength codes */
     U32  offCodeSum;             /* nb of offset codes */
-    /* begin updated by ZSTD_setLog2Prices */
-    U32  log2litSum;             /* pow2 to compare log2(litfreq) to */
-    U32  log2litLengthSum;       /* pow2 to compare log2(llfreq) to */
-    U32  log2matchLengthSum;     /* pow2 to compare log2(mlfreq) to */
-    U32  log2offCodeSum;         /* pow2 to compare log2(offreq) to */
-    /* end : updated by ZSTD_setLog2Prices */
-    U32  staticPrices;           /* prices follow a pre-defined cost structure, statistics are irrelevant */
+    U32  litSumBasePrice;        /* to compare to log2(litfreq) */
+    U32  litLengthSumBasePrice;  /* to compare to log2(llfreq)  */
+    U32  matchLengthSumBasePrice;/* to compare to log2(mlfreq)  */
+    U32  offCodeSumBasePrice;    /* to compare to log2(offreq)  */
+    ZSTD_OptPrice_e priceType;   /* prices can be determined dynamically, or follow a pre-defined cost structure */
+    const ZSTD_entropyCTables_t* symbolCosts;  /* pre-calculated dictionary statistics */
 } optState_t;
 
 typedef struct {
   ZSTD_entropyCTables_t entropy;
   U32 rep[ZSTD_REP_NUM];
 } ZSTD_compressedBlockState_t;
 
 typedef struct {
     BYTE const* nextSrc;    /* next block here to continue on current prefix */
     BYTE const* base;       /* All regular indexes relative to this position */
     BYTE const* dictBase;   /* extDict indexes relative to this position */
     U32 dictLimit;          /* below that point, need extDict */
     U32 lowLimit;           /* below that point, no more data */
 } ZSTD_window_t;
 
-typedef struct {
-    ZSTD_window_t window;      /* State for window round buffer management */
-    U32 loadedDictEnd;         /* index of end of dictionary */
-    U32 nextToUpdate;          /* index from which to continue table update */
-    U32 nextToUpdate3;         /* index from which to continue table update */
-    U32 hashLog3;              /* dispatch table : larger == faster, more memory */
+typedef struct ZSTD_matchState_t ZSTD_matchState_t;
+struct ZSTD_matchState_t {
+    ZSTD_window_t window;   /* State for window round buffer management */
+    U32 loadedDictEnd;      /* index of end of dictionary */
+    U32 nextToUpdate;       /* index from which to continue table update */
+    U32 nextToUpdate3;      /* index from which to continue table update */
+    U32 hashLog3;           /* dispatch table : larger == faster, more memory */
     U32* hashTable;
     U32* hashTable3;
     U32* chainTable;
     optState_t opt;         /* optimal parser state */
-} ZSTD_matchState_t;
+    const ZSTD_matchState_t *dictMatchState;
+    ZSTD_compressionParameters cParams;
+};
 
 typedef struct {
     ZSTD_compressedBlockState_t* prevCBlock;
     ZSTD_compressedBlockState_t* nextCBlock;
     ZSTD_matchState_t matchState;
 } ZSTD_blockState_t;
 
 typedef struct {
     U32 offset;
     U32 checksum;
 } ldmEntry_t;
 
 typedef struct {
     ZSTD_window_t window;   /* State for the window round buffer management */
     ldmEntry_t* hashTable;
     BYTE* bucketOffsets;    /* Next position in bucket to insert entry */
     U64 hashPower;          /* Used to compute the rolling hash.
                              * Depends on ldmParams.minMatchLength */
 } ldmState_t;
 
 typedef struct {
     U32 enableLdm;          /* 1 if enable long distance matching */
     U32 hashLog;            /* Log size of hashTable */
     U32 bucketSizeLog;      /* Log bucket size for collision resolution, at most 8 */
     U32 minMatchLength;     /* Minimum match length */
     U32 hashEveryLog;       /* Log number of entries to skip */
     U32 windowLog;          /* Window log for the LDM */
 } ldmParams_t;
 
 typedef struct {
     U32 offset;
     U32 litLength;
     U32 matchLength;
 } rawSeq;
 
 typedef struct {
   rawSeq* seq;     /* The start of the sequences */
   size_t pos;      /* The position where reading stopped. <= size. */
   size_t size;     /* The number of sequences. <= capacity. */
-  size_t capacity; /* The capacity of the `seq` pointer */
+  size_t capacity; /* The capacity starting from `seq` pointer */
 } rawSeqStore_t;
 
 struct ZSTD_CCtx_params_s {
     ZSTD_format_e format;
     ZSTD_compressionParameters cParams;
     ZSTD_frameParameters fParams;
 
     int compressionLevel;
-    int disableLiteralCompression;
     int forceWindow;           /* force back-references to respect limit of
                                 * 1< 63) ? ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
 }
 
 /* ZSTD_MLcode() :
  * note : mlBase = matchLength - MINMATCH;
  *        because it's the format it's stored in seqStore->sequences */
 MEM_STATIC U32 ZSTD_MLcode(U32 mlBase)
 {
     static const BYTE ML_Code[128] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
                                       16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
                                       32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 37, 37, 37, 37,
                                       38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39,
                                       40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
                                       41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41,
                                       42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
                                       42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42 };
     static const U32 ML_deltaCode = 36;
     return (mlBase > 127) ? ZSTD_highbit32(mlBase) + ML_deltaCode : ML_Code[mlBase];
 }
 
 /*! ZSTD_storeSeq() :
  *  Store a sequence (literal length, literals, offset code and match length code) into seqStore_t.
  *  `offsetCode` : distance to match + 3 (values 1-3 are repCodes).
  *  `mlBase` : matchLength - MINMATCH
 */
 MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t mlBase)
 {
-#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG >= 6)
+#if defined(DEBUGLEVEL) && (DEBUGLEVEL >= 6)
     static const BYTE* g_start = NULL;
     if (g_start==NULL) g_start = (const BYTE*)literals;  /* note : index only works for compression within a single segment */
     {   U32 const pos = (U32)((const BYTE*)literals - g_start);
-        DEBUGLOG(6, "Cpos%7u :%3u literals, match%3u bytes at dist.code%7u",
+        DEBUGLOG(6, "Cpos%7u :%3u literals, match%4u bytes at offCode%7u",
                pos, (U32)litLength, (U32)mlBase+MINMATCH, (U32)offsetCode);
     }
 #endif
+    assert((size_t)(seqStorePtr->sequences - seqStorePtr->sequencesStart) < seqStorePtr->maxNbSeq);
     /* copy Literals */
-    assert(seqStorePtr->lit + litLength <= seqStorePtr->litStart + 128 KB);
+    assert(seqStorePtr->maxNbLit <= 128 KB);
+    assert(seqStorePtr->lit + litLength <= seqStorePtr->litStart + seqStorePtr->maxNbLit);
     ZSTD_wildcopy(seqStorePtr->lit, literals, litLength);
     seqStorePtr->lit += litLength;
 
     /* literal Length */
     if (litLength>0xFFFF) {
         assert(seqStorePtr->longLengthID == 0); /* there can only be a single long length */
         seqStorePtr->longLengthID = 1;
         seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     }
     seqStorePtr->sequences[0].litLength = (U16)litLength;
 
     /* match offset */
     seqStorePtr->sequences[0].offset = offsetCode + 1;
 
     /* match Length */
     if (mlBase>0xFFFF) {
         assert(seqStorePtr->longLengthID == 0); /* there can only be a single long length */
         seqStorePtr->longLengthID = 2;
         seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     }
     seqStorePtr->sequences[0].matchLength = (U16)mlBase;
 
     seqStorePtr->sequences++;
 }
 
 
 /*-*************************************
 *  Match length counter
 ***************************************/
 static unsigned ZSTD_NbCommonBytes (size_t val)
 {
     if (MEM_isLittleEndian()) {
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanForward64( &r, (U64)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 4)
             return (__builtin_ctzll((U64)val) >> 3);
 #       else
             static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2,
                                                      0, 3, 1, 3, 1, 4, 2, 7,
                                                      0, 2, 3, 6, 1, 5, 3, 5,
                                                      1, 3, 4, 4, 2, 5, 6, 7,
                                                      7, 0, 1, 2, 3, 3, 4, 6,
                                                      2, 6, 5, 5, 3, 4, 5, 6,
                                                      7, 1, 2, 4, 6, 4, 4, 5,
                                                      7, 2, 6, 5, 7, 6, 7, 7 };
             return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r=0;
             _BitScanForward( &r, (U32)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_ctz((U32)val) >> 3);
 #       else
             static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0,
                                                      3, 2, 2, 1, 3, 2, 0, 1,
                                                      3, 3, 1, 2, 2, 2, 2, 0,
                                                      3, 1, 2, 0, 1, 0, 1, 1 };
             return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
 #       endif
         }
     } else {  /* Big Endian CPU */
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanReverse64( &r, val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 4)
             return (__builtin_clzll(val) >> 3);
 #       else
             unsigned r;
             const unsigned n32 = sizeof(size_t)*4;   /* calculate this way due to compiler complaining in 32-bits mode */
             if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
             if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
             r += (!val);
             return r;
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r = 0;
             _BitScanReverse( &r, (unsigned long)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_clz((U32)val) >> 3);
 #       else
             unsigned r;
             if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
             r += (!val);
             return r;
 #       endif
     }   }
 }
 
 
 MEM_STATIC size_t ZSTD_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* const pInLimit)
 {
     const BYTE* const pStart = pIn;
     const BYTE* const pInLoopLimit = pInLimit - (sizeof(size_t)-1);
 
     if (pIn < pInLoopLimit) {
         { size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
           if (diff) return ZSTD_NbCommonBytes(diff); }
         pIn+=sizeof(size_t); pMatch+=sizeof(size_t);
         while (pIn < pInLoopLimit) {
             size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
             if (!diff) { pIn+=sizeof(size_t); pMatch+=sizeof(size_t); continue; }
             pIn += ZSTD_NbCommonBytes(diff);
             return (size_t)(pIn - pStart);
     }   }
     if (MEM_64bits() && (pIn<(pInLimit-3)) && (MEM_read32(pMatch) == MEM_read32(pIn))) { pIn+=4; pMatch+=4; }
     if ((pIn<(pInLimit-1)) && (MEM_read16(pMatch) == MEM_read16(pIn))) { pIn+=2; pMatch+=2; }
     if ((pIn> (32-h) ; }
 MEM_STATIC size_t ZSTD_hash3Ptr(const void* ptr, U32 h) { return ZSTD_hash3(MEM_readLE32(ptr), h); } /* only in zstd_opt.h */
 
 static const U32 prime4bytes = 2654435761U;
 static U32    ZSTD_hash4(U32 u, U32 h) { return (u * prime4bytes) >> (32-h) ; }
 static size_t ZSTD_hash4Ptr(const void* ptr, U32 h) { return ZSTD_hash4(MEM_read32(ptr), h); }
 
 static const U64 prime5bytes = 889523592379ULL;
 static size_t ZSTD_hash5(U64 u, U32 h) { return (size_t)(((u  << (64-40)) * prime5bytes) >> (64-h)) ; }
 static size_t ZSTD_hash5Ptr(const void* p, U32 h) { return ZSTD_hash5(MEM_readLE64(p), h); }
 
 static const U64 prime6bytes = 227718039650203ULL;
 static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u  << (64-48)) * prime6bytes) >> (64-h)) ; }
 static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
 
 static const U64 prime7bytes = 58295818150454627ULL;
 static size_t ZSTD_hash7(U64 u, U32 h) { return (size_t)(((u  << (64-56)) * prime7bytes) >> (64-h)) ; }
 static size_t ZSTD_hash7Ptr(const void* p, U32 h) { return ZSTD_hash7(MEM_readLE64(p), h); }
 
 static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
 static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
 static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
 
 MEM_STATIC size_t ZSTD_hashPtr(const void* p, U32 hBits, U32 mls)
 {
     switch(mls)
     {
     default:
     case 4: return ZSTD_hash4Ptr(p, hBits);
     case 5: return ZSTD_hash5Ptr(p, hBits);
     case 6: return ZSTD_hash6Ptr(p, hBits);
     case 7: return ZSTD_hash7Ptr(p, hBits);
     case 8: return ZSTD_hash8Ptr(p, hBits);
     }
 }
 
 /*-*************************************
 *  Round buffer management
 ***************************************/
 /* Max current allowed */
 #define ZSTD_CURRENT_MAX ((3U << 29) + (1U << ZSTD_WINDOWLOG_MAX))
 /* Maximum chunk size before overflow correction needs to be called again */
 #define ZSTD_CHUNKSIZE_MAX                                                     \
     ( ((U32)-1)                  /* Maximum ending current index */            \
     - ZSTD_CURRENT_MAX)          /* Maximum beginning lowLimit */
 
 /**
  * ZSTD_window_clear():
  * Clears the window containing the history by simply setting it to empty.
  */
 MEM_STATIC void ZSTD_window_clear(ZSTD_window_t* window)
 {
     size_t const endT = (size_t)(window->nextSrc - window->base);
     U32 const end = (U32)endT;
 
     window->lowLimit = end;
     window->dictLimit = end;
 }
 
 /**
  * ZSTD_window_hasExtDict():
  * Returns non-zero if the window has a non-empty extDict.
  */
 MEM_STATIC U32 ZSTD_window_hasExtDict(ZSTD_window_t const window)
 {
     return window.lowLimit < window.dictLimit;
 }
 
 /**
+ * ZSTD_matchState_dictMode():
+ * Inspects the provided matchState and figures out what dictMode should be
+ * passed to the compressor.
+ */
+MEM_STATIC ZSTD_dictMode_e ZSTD_matchState_dictMode(const ZSTD_matchState_t *ms)
+{
+    return ZSTD_window_hasExtDict(ms->window) ?
+        ZSTD_extDict :
+        ms->dictMatchState != NULL ?
+            ZSTD_dictMatchState :
+            ZSTD_noDict;
+}
+
+/**
  * ZSTD_window_needOverflowCorrection():
  * Returns non-zero if the indices are getting too large and need overflow
  * protection.
  */
 MEM_STATIC U32 ZSTD_window_needOverflowCorrection(ZSTD_window_t const window,
                                                   void const* srcEnd)
 {
     U32 const current = (U32)((BYTE const*)srcEnd - window.base);
     return current > ZSTD_CURRENT_MAX;
 }
 
 /**
  * ZSTD_window_correctOverflow():
  * Reduces the indices to protect from index overflow.
  * Returns the correction made to the indices, which must be applied to every
  * stored index.
  *
  * The least significant cycleLog bits of the indices must remain the same,
  * which may be 0. Every index up to maxDist in the past must be valid.
  * NOTE: (maxDist & cycleMask) must be zero.
  */
 MEM_STATIC U32 ZSTD_window_correctOverflow(ZSTD_window_t* window, U32 cycleLog,
                                            U32 maxDist, void const* src)
 {
     /* preemptive overflow correction:
      * 1. correction is large enough:
      *    lowLimit > (3<<29) ==> current > 3<<29 + 1< (3<<29 + 1< (3<<29) - (1< (3<<29) - (1<<30)             (NOTE: chainLog <= 30)
      *    > 1<<29
      *
      * 2. (ip+ZSTD_CHUNKSIZE_MAX - cctx->base) doesn't overflow:
      *    After correction, current is less than (1<base < 1<<32.
      * 3. (cctx->lowLimit + 1< 3<<29 + 1<base);
     U32 const newCurrent = (current & cycleMask) + maxDist;
     U32 const correction = current - newCurrent;
     assert((maxDist & cycleMask) == 0);
     assert(current > newCurrent);
     /* Loose bound, should be around 1<<29 (see above) */
     assert(correction > 1<<28);
 
     window->base += correction;
     window->dictBase += correction;
     window->lowLimit -= correction;
     window->dictLimit -= correction;
 
     DEBUGLOG(4, "Correction of 0x%x bytes to lowLimit=0x%x", correction,
              window->lowLimit);
     return correction;
 }
 
 /**
  * ZSTD_window_enforceMaxDist():
  * Updates lowLimit so that:
  *    (srcEnd - base) - lowLimit == maxDist + loadedDictEnd
+ *
  * This allows a simple check that index >= lowLimit to see if index is valid.
  * This must be called before a block compression call, with srcEnd as the block
  * source end.
+ *
  * If loadedDictEndPtr is not NULL, we set it to zero once we update lowLimit.
  * This is because dictionaries are allowed to be referenced as long as the last
  * byte of the dictionary is in the window, but once they are out of range,
  * they cannot be referenced. If loadedDictEndPtr is NULL, we use
  * loadedDictEnd == 0.
+ *
+ * In normal dict mode, the dict is between lowLimit and dictLimit. In
+ * dictMatchState mode, lowLimit and dictLimit are the same, and the dictionary
+ * is below them. forceWindow and dictMatchState are therefore incompatible.
  */
 MEM_STATIC void ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
                                            void const* srcEnd, U32 maxDist,
-                                           U32* loadedDictEndPtr)
+                                           U32* loadedDictEndPtr,
+                                           const ZSTD_matchState_t** dictMatchStatePtr)
 {
     U32 const current = (U32)((BYTE const*)srcEnd - window->base);
     U32 loadedDictEnd = loadedDictEndPtr != NULL ? *loadedDictEndPtr : 0;
+    DEBUGLOG(5, "ZSTD_window_enforceMaxDist: current=%u, maxDist=%u", current, maxDist);
     if (current > maxDist + loadedDictEnd) {
         U32 const newLowLimit = current - maxDist;
         if (window->lowLimit < newLowLimit) window->lowLimit = newLowLimit;
         if (window->dictLimit < window->lowLimit) {
-            DEBUGLOG(5, "Update dictLimit from %u to %u", window->dictLimit,
-                     window->lowLimit);
+            DEBUGLOG(5, "Update dictLimit to match lowLimit, from %u to %u",
+                        window->dictLimit, window->lowLimit);
             window->dictLimit = window->lowLimit;
         }
         if (loadedDictEndPtr)
             *loadedDictEndPtr = 0;
+        if (dictMatchStatePtr)
+            *dictMatchStatePtr = NULL;
     }
 }
 
 /**
  * ZSTD_window_update():
  * Updates the window by appending [src, src + srcSize) to the window.
  * If it is not contiguous, the current prefix becomes the extDict, and we
  * forget about the extDict. Handles overlap of the prefix and extDict.
  * Returns non-zero if the segment is contiguous.
  */
 MEM_STATIC U32 ZSTD_window_update(ZSTD_window_t* window,
                                   void const* src, size_t srcSize)
 {
     BYTE const* const ip = (BYTE const*)src;
     U32 contiguous = 1;
+    DEBUGLOG(5, "ZSTD_window_update");
     /* Check if blocks follow each other */
     if (src != window->nextSrc) {
         /* not contiguous */
         size_t const distanceFromBase = (size_t)(window->nextSrc - window->base);
-        DEBUGLOG(5, "Non contiguous blocks, new segment starts at %u",
-                 window->dictLimit);
+        DEBUGLOG(5, "Non contiguous blocks, new segment starts at %u", window->dictLimit);
         window->lowLimit = window->dictLimit;
         assert(distanceFromBase == (size_t)(U32)distanceFromBase);  /* should never overflow */
         window->dictLimit = (U32)distanceFromBase;
         window->dictBase = window->base;
         window->base = ip - distanceFromBase;
         // ms->nextToUpdate = window->dictLimit;
         if (window->dictLimit - window->lowLimit < HASH_READ_SIZE) window->lowLimit = window->dictLimit;   /* too small extDict */
         contiguous = 0;
     }
     window->nextSrc = ip + srcSize;
     /* if input and dictionary overlap : reduce dictionary (area presumed modified by input) */
     if ( (ip+srcSize > window->dictBase + window->lowLimit)
        & (ip < window->dictBase + window->dictLimit)) {
         ptrdiff_t const highInputIdx = (ip + srcSize) - window->dictBase;
         U32 const lowLimitMax = (highInputIdx > (ptrdiff_t)window->dictLimit) ? window->dictLimit : (U32)highInputIdx;
         window->lowLimit = lowLimitMax;
+        DEBUGLOG(5, "Overlapping extDict and input : new lowLimit = %u", window->lowLimit);
     }
     return contiguous;
 }
 
+
+/* debug functions */
+
+MEM_STATIC double ZSTD_fWeight(U32 rawStat)
+{
+    U32 const fp_accuracy = 8;
+    U32 const fp_multiplier = (1 << fp_accuracy);
+    U32 const stat = rawStat + 1;
+    U32 const hb = ZSTD_highbit32(stat);
+    U32 const BWeight = hb * fp_multiplier;
+    U32 const FWeight = (stat << fp_accuracy) >> hb;
+    U32 const weight = BWeight + FWeight;
+    assert(hb + fp_accuracy < 31);
+    return (double)weight / fp_multiplier;
+}
+
+MEM_STATIC void ZSTD_debugTable(const U32* table, U32 max)
+{
+    unsigned u, sum;
+    for (u=0, sum=0; u<=max; u++) sum += table[u];
+    DEBUGLOG(2, "total nb elts: %u", sum);
+    for (u=0; u<=max; u++) {
+        DEBUGLOG(2, "%2u: %5u  (%.2f)",
+                u, table[u], ZSTD_fWeight(sum) - ZSTD_fWeight(table[u]) );
+    }
+}
+
 #if defined (__cplusplus)
 }
 #endif
 
 
 /* ==============================================================
  * Private declarations
  * These prototypes shall only be called from within lib/compress
  * ============================================================== */
 
 /* ZSTD_getCParamsFromCCtxParams() :
- * cParams are built depending on compressionLevel, src size hints, 
+ * cParams are built depending on compressionLevel, src size hints,
  * LDM and manually set compression parameters.
  */
 ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
         const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize);
 
 /*! ZSTD_initCStream_internal() :
  *  Private use only. Init streaming operation.
  *  expects params to be valid.
  *  must receive dict, or cdict, or none, but not both.
  *  @return : 0, or an error code */
 size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
                      const void* dict, size_t dictSize,
                      const ZSTD_CDict* cdict,
                      ZSTD_CCtx_params  params, unsigned long long pledgedSrcSize);
 
+void ZSTD_resetSeqStore(seqStore_t* ssPtr);
+
 /*! ZSTD_compressStream_generic() :
  *  Private use only. To be called from zstdmt_compress.c in single-thread mode. */
 size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                    ZSTD_outBuffer* output,
                                    ZSTD_inBuffer* input,
                                    ZSTD_EndDirective const flushMode);
 
 /*! ZSTD_getCParamsFromCDict() :
  *  as the name implies */
 ZSTD_compressionParameters ZSTD_getCParamsFromCDict(const ZSTD_CDict* cdict);
 
 /* ZSTD_compressBegin_advanced_internal() :
  * Private use only. To be called from zstdmt_compress.c. */
 size_t ZSTD_compressBegin_advanced_internal(ZSTD_CCtx* cctx,
                                     const void* dict, size_t dictSize,
                                     ZSTD_dictContentType_e dictContentType,
+                                    ZSTD_dictTableLoadMethod_e dtlm,
                                     const ZSTD_CDict* cdict,
                                     ZSTD_CCtx_params params,
                                     unsigned long long pledgedSrcSize);
 
 /* ZSTD_compress_advanced_internal() :
  * Private use only. To be called from zstdmt_compress.c. */
 size_t ZSTD_compress_advanced_internal(ZSTD_CCtx* cctx,
                                        void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                  const void* dict,size_t dictSize,
                                  ZSTD_CCtx_params params);
 
 
 /* ZSTD_writeLastEmptyBlock() :
  * output an empty Block with end-of-frame mark to complete a frame
  * @return : size of data written into `dst` (== ZSTD_blockHeaderSize (defined in zstd_internal.h))
  *           or an error code if `dstCapcity` is too small (cParams;
     U32* const hashLarge = ms->hashTable;
     U32  const hBitsL = cParams->hashLog;
     U32  const mls = cParams->searchLength;
     U32* const hashSmall = ms->chainTable;
     U32  const hBitsS = cParams->chainLog;
     const BYTE* const base = ms->window.base;
     const BYTE* ip = base + ms->nextToUpdate;
     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
     const U32 fastHashFillStep = 3;
 
     /* Always insert every fastHashFillStep position into the hash tables.
      * Insert the other positions into the large hash table if their entry
      * is empty.
      */
     for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
         U32 const current = (U32)(ip - base);
         U32 i;
         for (i = 0; i < fastHashFillStep; ++i) {
             size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls);
             size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8);
             if (i == 0)
                 hashSmall[smHash] = current + i;
             if (i == 0 || hashLarge[lgHash] == 0)
                 hashLarge[lgHash] = current + i;
+            /* Only load extra positions for ZSTD_dtlm_full */
+            if (dtlm == ZSTD_dtlm_fast)
+                break;
         }
     }
 }
 
 
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_doubleFast_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize,
-        U32 const mls /* template */)
+        void const* src, size_t srcSize,
+        U32 const mls /* template */, ZSTD_dictMode_e const dictMode)
 {
+    ZSTD_compressionParameters const* cParams = &ms->cParams;
     U32* const hashLong = ms->hashTable;
     const U32 hBitsL = cParams->hashLog;
     U32* const hashSmall = ms->chainTable;
     const U32 hBitsS = cParams->chainLog;
     const BYTE* const base = ms->window.base;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
-    const U32 lowestIndex = ms->window.dictLimit;
-    const BYTE* const lowest = base + lowestIndex;
+    const U32 prefixLowestIndex = ms->window.dictLimit;
+    const BYTE* const prefixLowest = base + prefixLowestIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=rep[0], offset_2=rep[1];
     U32 offsetSaved = 0;
 
+    const ZSTD_matchState_t* const dms = ms->dictMatchState;
+    const ZSTD_compressionParameters* const dictCParams =
+                                     dictMode == ZSTD_dictMatchState ?
+                                     &dms->cParams : NULL;
+    const U32* const dictHashLong  = dictMode == ZSTD_dictMatchState ?
+                                     dms->hashTable : NULL;
+    const U32* const dictHashSmall = dictMode == ZSTD_dictMatchState ?
+                                     dms->chainTable : NULL;
+    const U32 dictStartIndex       = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.dictLimit : 0;
+    const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.base : NULL;
+    const BYTE* const dictStart    = dictMode == ZSTD_dictMatchState ?
+                                     dictBase + dictStartIndex : NULL;
+    const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.nextSrc : NULL;
+    const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
+                                     prefixLowestIndex - (U32)(dictEnd - dictBase) :
+                                     0;
+    const U32 dictHBitsL           = dictMode == ZSTD_dictMatchState ?
+                                     dictCParams->hashLog : hBitsL;
+    const U32 dictHBitsS           = dictMode == ZSTD_dictMatchState ?
+                                     dictCParams->chainLog : hBitsS;
+    const U32 dictAndPrefixLength  = (U32)(ip - prefixLowest + dictEnd - dictStart);
+
+    assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
+
     /* init */
-    ip += (ip==lowest);
-    {   U32 const maxRep = (U32)(ip-lowest);
+    ip += (dictAndPrefixLength == 0);
+    if (dictMode == ZSTD_noDict) {
+        U32 const maxRep = (U32)(ip - prefixLowest);
         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
     }
+    if (dictMode == ZSTD_dictMatchState) {
+        /* dictMatchState repCode checks don't currently handle repCode == 0
+         * disabling. */
+        assert(offset_1 <= dictAndPrefixLength);
+        assert(offset_2 <= dictAndPrefixLength);
+    }
 
     /* Main Search Loop */
     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
         size_t mLength;
+        U32 offset;
         size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
         size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
+        size_t const dictHL = ZSTD_hashPtr(ip, dictHBitsL, 8);
+        size_t const dictHS = ZSTD_hashPtr(ip, dictHBitsS, mls);
         U32 const current = (U32)(ip-base);
         U32 const matchIndexL = hashLong[h2];
-        U32 const matchIndexS = hashSmall[h];
+        U32 matchIndexS = hashSmall[h];
         const BYTE* matchLong = base + matchIndexL;
         const BYTE* match = base + matchIndexS;
+        const U32 repIndex = current + 1 - offset_1;
+        const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
+                            && repIndex < prefixLowestIndex) ?
+                               dictBase + (repIndex - dictIndexDelta) :
+                               base + repIndex;
         hashLong[h2] = hashSmall[h] = current;   /* update hash tables */
 
-        assert(offset_1 <= current);   /* supposed guaranteed by construction */
-        if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
-            /* favor repcode */
+        /* check dictMatchState repcode */
+        if (dictMode == ZSTD_dictMatchState
+            && ((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
+            && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
+            const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
+            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
+            ip++;
+            ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
+            goto _match_stored;
+        }
+
+        /* check noDict repcode */
+        if ( dictMode == ZSTD_noDict
+          && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
             mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
             ip++;
             ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
-        } else {
-            U32 offset;
-            if ( (matchIndexL > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip)) ) {
+            goto _match_stored;
+        }
+
+        if (matchIndexL > prefixLowestIndex) {
+            /* check prefix long match */
+            if (MEM_read64(matchLong) == MEM_read64(ip)) {
                 mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
                 offset = (U32)(ip-matchLong);
-                while (((ip>anchor) & (matchLong>lowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
-            } else if ( (matchIndexS > lowestIndex) && (MEM_read32(match) == MEM_read32(ip)) ) {
-                size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
-                U32 const matchIndexL3 = hashLong[hl3];
-                const BYTE* matchL3 = base + matchIndexL3;
-                hashLong[hl3] = current + 1;
-                if ( (matchIndexL3 > lowestIndex) && (MEM_read64(matchL3) == MEM_read64(ip+1)) ) {
+                while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
+                goto _match_found;
+            }
+        } else if (dictMode == ZSTD_dictMatchState) {
+            /* check dictMatchState long match */
+            U32 const dictMatchIndexL = dictHashLong[dictHL];
+            const BYTE* dictMatchL = dictBase + dictMatchIndexL;
+            assert(dictMatchL < dictEnd);
+
+            if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) {
+                mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
+                offset = (U32)(current - dictMatchIndexL - dictIndexDelta);
+                while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
+                goto _match_found;
+            }
+        }
+
+        if (matchIndexS > prefixLowestIndex) {
+            /* check prefix short match */
+            if (MEM_read32(match) == MEM_read32(ip)) {
+                goto _search_next_long;
+            }
+        } else if (dictMode == ZSTD_dictMatchState) {
+            /* check dictMatchState short match */
+            U32 const dictMatchIndexS = dictHashSmall[dictHS];
+            match = dictBase + dictMatchIndexS;
+            matchIndexS = dictMatchIndexS + dictIndexDelta;
+
+            if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) {
+                goto _search_next_long;
+            }
+        }
+
+        ip += ((ip-anchor) >> kSearchStrength) + 1;
+        continue;
+
+_search_next_long:
+
+        {
+            size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
+            size_t const dictHLNext = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
+            U32 const matchIndexL3 = hashLong[hl3];
+            const BYTE* matchL3 = base + matchIndexL3;
+            hashLong[hl3] = current + 1;
+
+            /* check prefix long +1 match */
+            if (matchIndexL3 > prefixLowestIndex) {
+                if (MEM_read64(matchL3) == MEM_read64(ip+1)) {
                     mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
                     ip++;
                     offset = (U32)(ip-matchL3);
-                    while (((ip>anchor) & (matchL3>lowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
-                } else {
-                    mLength = ZSTD_count(ip+4, match+4, iend) + 4;
-                    offset = (U32)(ip-match);
-                    while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
+                    while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
+                    goto _match_found;
                 }
-            } else {
-                ip += ((ip-anchor) >> kSearchStrength) + 1;
-                continue;
+            } else if (dictMode == ZSTD_dictMatchState) {
+                /* check dict long +1 match */
+                U32 const dictMatchIndexL3 = dictHashLong[dictHLNext];
+                const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3;
+                assert(dictMatchL3 < dictEnd);
+                if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) {
+                    mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8;
+                    ip++;
+                    offset = (U32)(current + 1 - dictMatchIndexL3 - dictIndexDelta);
+                    while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */
+                    goto _match_found;
+                }
             }
+        }
 
-            offset_2 = offset_1;
-            offset_1 = offset;
-
-            ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+        /* if no long +1 match, explore the short match we found */
+        if (dictMode == ZSTD_dictMatchState && matchIndexS < prefixLowestIndex) {
+            mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4;
+            offset = (U32)(current - matchIndexS);
+            while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
+        } else {
+            mLength = ZSTD_count(ip+4, match+4, iend) + 4;
+            offset = (U32)(ip - match);
+            while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
         }
 
+        /* fall-through */
+
+_match_found:
+        offset_2 = offset_1;
+        offset_1 = offset;
+
+        ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+
+_match_stored:
         /* match found */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Fill Table */
             hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] =
                 hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2;  /* here because current+2 could be > iend-8 */
             hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] =
                 hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
 
             /* check immediate repcode */
-            while ( (ip <= ilimit)
-                 && ( (offset_2>0)
-                 & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
-                /* store sequence */
-                size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
-                { U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; } /* swap offset_2 <=> offset_1 */
-                hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
-                hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
-                ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
-                ip += rLength;
-                anchor = ip;
-                continue;   /* faster when present ... (?) */
-    }   }   }
+            if (dictMode == ZSTD_dictMatchState) {
+                while (ip <= ilimit) {
+                    U32 const current2 = (U32)(ip-base);
+                    U32 const repIndex2 = current2 - offset_2;
+                    const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
+                        && repIndex2 < prefixLowestIndex ?
+                            dictBase - dictIndexDelta + repIndex2 :
+                            base + repIndex2;
+                    if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
+                       && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
+                        const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
+                        size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
+                        U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
+                        ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
+                        hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
+                        hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
+                        ip += repLength2;
+                        anchor = ip;
+                        continue;
+                    }
+                    break;
+                }
+            }
 
+            if (dictMode == ZSTD_noDict) {
+                while ( (ip <= ilimit)
+                     && ( (offset_2>0)
+                        & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
+                    /* store sequence */
+                    size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
+                    U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff;  /* swap offset_2 <=> offset_1 */
+                    hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
+                    hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
+                    ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
+                    ip += rLength;
+                    anchor = ip;
+                    continue;   /* faster when present ... (?) */
+    }   }   }   }
+
     /* save reps for next block */
     rep[0] = offset_1 ? offset_1 : offsetSaved;
     rep[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_doubleFast(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    const U32 mls = cParams->searchLength;
+    const U32 mls = ms->cParams.searchLength;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
-        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 4);
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_noDict);
     case 5 :
-        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 5);
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_noDict);
     case 6 :
-        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 6);
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_noDict);
     case 7 :
-        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, cParams, src, srcSize, 7);
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_noDict);
     }
 }
 
 
+size_t ZSTD_compressBlock_doubleFast_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize)
+{
+    const U32 mls = ms->cParams.searchLength;
+    switch(mls)
+    {
+    default: /* includes case 3 */
+    case 4 :
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_dictMatchState);
+    case 5 :
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_dictMatchState);
+    case 6 :
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_dictMatchState);
+    case 7 :
+        return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_dictMatchState);
+    }
+}
+
+
 static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize,
+        void const* src, size_t srcSize,
         U32 const mls /* template */)
 {
+    ZSTD_compressionParameters const* cParams = &ms->cParams;
     U32* const hashLong = ms->hashTable;
     U32  const hBitsL = cParams->hashLog;
     U32* const hashSmall = ms->chainTable;
     U32  const hBitsS = cParams->chainLog;
-    const BYTE* const base = ms->window.base;
-    const BYTE* const dictBase = ms->window.dictBase;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
-    const U32   lowestIndex = ms->window.lowLimit;
-    const BYTE* const dictStart = dictBase + lowestIndex;
-    const U32   dictLimit = ms->window.dictLimit;
-    const BYTE* const lowPrefixPtr = base + dictLimit;
-    const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
+    const U32   prefixStartIndex = ms->window.dictLimit;
+    const BYTE* const base = ms->window.base;
+    const BYTE* const prefixStart = base + prefixStartIndex;
+    const U32   dictStartIndex = ms->window.lowLimit;
+    const BYTE* const dictBase = ms->window.dictBase;
+    const BYTE* const dictStart = dictBase + dictStartIndex;
+    const BYTE* const dictEnd = dictBase + prefixStartIndex;
     U32 offset_1=rep[0], offset_2=rep[1];
 
+    DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
+
     /* Search Loop */
     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
         const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
         const U32 matchIndex = hashSmall[hSmall];
-        const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base;
+        const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
         const BYTE* match = matchBase + matchIndex;
 
         const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
         const U32 matchLongIndex = hashLong[hLong];
-        const BYTE* matchLongBase = matchLongIndex < dictLimit ? dictBase : base;
+        const BYTE* const matchLongBase = matchLongIndex < prefixStartIndex ? dictBase : base;
         const BYTE* matchLong = matchLongBase + matchLongIndex;
 
         const U32 current = (U32)(ip-base);
         const U32 repIndex = current + 1 - offset_1;   /* offset_1 expected <= current +1 */
-        const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
-        const BYTE* repMatch = repBase + repIndex;
+        const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
+        const BYTE* const repMatch = repBase + repIndex;
         size_t mLength;
         hashSmall[hSmall] = hashLong[hLong] = current;   /* update hash table */
 
-        if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex))
-           && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
-            const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
-            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4;
+        if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
+            & (repIndex > dictStartIndex))
+          && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
+            const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
+            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
             ip++;
             ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
         } else {
-            if ((matchLongIndex > lowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
-                const BYTE* matchEnd = matchLongIndex < dictLimit ? dictEnd : iend;
-                const BYTE* lowMatchPtr = matchLongIndex < dictLimit ? dictStart : lowPrefixPtr;
+            if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
+                const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
+                const BYTE* const lowMatchPtr = matchLongIndex < prefixStartIndex ? dictStart : prefixStart;
                 U32 offset;
-                mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, lowPrefixPtr) + 8;
+                mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, prefixStart) + 8;
                 offset = current - matchLongIndex;
                 while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; }   /* catch up */
                 offset_2 = offset_1;
                 offset_1 = offset;
                 ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
-            } else if ((matchIndex > lowestIndex) && (MEM_read32(match) == MEM_read32(ip))) {
+            } else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
                 size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
                 U32 const matchIndex3 = hashLong[h3];
-                const BYTE* const match3Base = matchIndex3 < dictLimit ? dictBase : base;
+                const BYTE* const match3Base = matchIndex3 < prefixStartIndex ? dictBase : base;
                 const BYTE* match3 = match3Base + matchIndex3;
                 U32 offset;
                 hashLong[h3] = current + 1;
-                if ( (matchIndex3 > lowestIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
-                    const BYTE* matchEnd = matchIndex3 < dictLimit ? dictEnd : iend;
-                    const BYTE* lowMatchPtr = matchIndex3 < dictLimit ? dictStart : lowPrefixPtr;
-                    mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, lowPrefixPtr) + 8;
+                if ( (matchIndex3 > dictStartIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
+                    const BYTE* const matchEnd = matchIndex3 < prefixStartIndex ? dictEnd : iend;
+                    const BYTE* const lowMatchPtr = matchIndex3 < prefixStartIndex ? dictStart : prefixStart;
+                    mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, prefixStart) + 8;
                     ip++;
                     offset = current+1 - matchIndex3;
                     while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
                 } else {
-                    const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
-                    const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
-                    mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 4;
+                    const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
+                    const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
+                    mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
                     offset = current - matchIndex;
                     while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; }   /* catch up */
                 }
                 offset_2 = offset_1;
                 offset_1 = offset;
                 ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
             } else {
                 ip += ((ip-anchor) >> kSearchStrength) + 1;
                 continue;
         }   }
 
         /* found a match : store it */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Fill Table */
             hashSmall[ZSTD_hashPtr(base+current+2, hBitsS, mls)] = current+2;
             hashLong[ZSTD_hashPtr(base+current+2, hBitsL, 8)] = current+2;
             hashSmall[ZSTD_hashPtr(ip-2, hBitsS, mls)] = (U32)(ip-2-base);
             hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
             /* check immediate repcode */
             while (ip <= ilimit) {
                 U32 const current2 = (U32)(ip-base);
                 U32 const repIndex2 = current2 - offset_2;
-                const BYTE* repMatch2 = repIndex2 < dictLimit ? dictBase + repIndex2 : base + repIndex2;
-                if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex))  /* intentional overflow */
-                   && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
-                    const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
-                    size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, lowPrefixPtr) + 4;
-                    U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
+                const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
+                if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3)   /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
+                    & (repIndex2 > dictStartIndex))
+                  && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
+                    const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
+                    size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
+                    U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
                     ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
                     hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
                     hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
                     ip += repLength2;
                     anchor = ip;
                     continue;
                 }
                 break;
     }   }   }
 
     /* save reps for next block */
     rep[0] = offset_1;
     rep[1] = offset_2;
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_doubleFast_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    U32 const mls = cParams->searchLength;
+    U32 const mls = ms->cParams.searchLength;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
-        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 4);
+        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
     case 5 :
-        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 5);
+        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
     case 6 :
-        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 6);
+        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
     case 7 :
-        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 7);
+        return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
     }
 }
Index: vendor/zstd/dist/lib/compress/zstd_double_fast.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_double_fast.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_double_fast.h	(revision 339614)
@@ -1,36 +1,38 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_DOUBLE_FAST_H
 #define ZSTD_DOUBLE_FAST_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #include "mem.h"      /* U32 */
 #include "zstd_compress_internal.h"     /* ZSTD_CCtx, size_t */
 
 void ZSTD_fillDoubleHashTable(ZSTD_matchState_t* ms,
-                              ZSTD_compressionParameters const* cParams,
-                              void const* end);
+                              void const* end, ZSTD_dictTableLoadMethod_e dtlm);
 size_t ZSTD_compressBlock_doubleFast(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
+size_t ZSTD_compressBlock_doubleFast_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_doubleFast_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ZSTD_DOUBLE_FAST_H */
Index: vendor/zstd/dist/lib/compress/zstd_fast.c
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_fast.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_fast.c	(revision 339614)
@@ -1,259 +1,391 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #include "zstd_compress_internal.h"
 #include "zstd_fast.h"
 
 
 void ZSTD_fillHashTable(ZSTD_matchState_t* ms,
-                        ZSTD_compressionParameters const* cParams,
-                        void const* end)
+                        void const* end, ZSTD_dictTableLoadMethod_e dtlm)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32  const hBits = cParams->hashLog;
     U32  const mls = cParams->searchLength;
     const BYTE* const base = ms->window.base;
     const BYTE* ip = base + ms->nextToUpdate;
     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
     const U32 fastHashFillStep = 3;
 
     /* Always insert every fastHashFillStep position into the hash table.
      * Insert the other positions if their hash entry is empty.
      */
     for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
         U32 const current = (U32)(ip - base);
         U32 i;
         for (i = 0; i < fastHashFillStep; ++i) {
             size_t const hash = ZSTD_hashPtr(ip + i, hBits, mls);
             if (i == 0 || hashTable[hash] == 0)
                 hashTable[hash] = current + i;
+            /* Only load extra positions for ZSTD_dtlm_full */
+            if (dtlm == ZSTD_dtlm_fast)
+                break;
         }
     }
 }
 
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_fast_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize,
-        U32 const hlog, U32 const stepSize, U32 const mls)
+        U32 const mls, ZSTD_dictMode_e const dictMode)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
+    U32 const hlog = cParams->hashLog;
+    /* support stepSize of 0 */
+    U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
     const BYTE* const base = ms->window.base;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
-    const U32   lowestIndex = ms->window.dictLimit;
-    const BYTE* const lowest = base + lowestIndex;
+    const U32   prefixStartIndex = ms->window.dictLimit;
+    const BYTE* const prefixStart = base + prefixStartIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=rep[0], offset_2=rep[1];
     U32 offsetSaved = 0;
 
+    const ZSTD_matchState_t* const dms = ms->dictMatchState;
+    const ZSTD_compressionParameters* const dictCParams =
+                                     dictMode == ZSTD_dictMatchState ?
+                                     &dms->cParams : NULL;
+    const U32* const dictHashTable = dictMode == ZSTD_dictMatchState ?
+                                     dms->hashTable : NULL;
+    const U32 dictStartIndex       = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.dictLimit : 0;
+    const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.base : NULL;
+    const BYTE* const dictStart    = dictMode == ZSTD_dictMatchState ?
+                                     dictBase + dictStartIndex : NULL;
+    const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.nextSrc : NULL;
+    const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
+                                     prefixStartIndex - (U32)(dictEnd - dictBase) :
+                                     0;
+    const U32 dictAndPrefixLength  = (U32)(ip - prefixStart + dictEnd - dictStart);
+    const U32 dictHLog             = dictMode == ZSTD_dictMatchState ?
+                                     dictCParams->hashLog : hlog;
+
+    assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
+
+    /* otherwise, we would get index underflow when translating a dict index
+     * into a local index */
+    assert(dictMode != ZSTD_dictMatchState
+        || prefixStartIndex >= (U32)(dictEnd - dictBase));
+
     /* init */
-    ip += (ip==lowest);
-    {   U32 const maxRep = (U32)(ip-lowest);
+    ip += (dictAndPrefixLength == 0);
+    if (dictMode == ZSTD_noDict) {
+        U32 const maxRep = (U32)(ip - prefixStart);
         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
     }
+    if (dictMode == ZSTD_dictMatchState) {
+        /* dictMatchState repCode checks don't currently handle repCode == 0
+         * disabling. */
+        assert(offset_1 <= dictAndPrefixLength);
+        assert(offset_2 <= dictAndPrefixLength);
+    }
 
     /* Main Search Loop */
     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
         size_t mLength;
         size_t const h = ZSTD_hashPtr(ip, hlog, mls);
         U32 const current = (U32)(ip-base);
         U32 const matchIndex = hashTable[h];
         const BYTE* match = base + matchIndex;
+        const U32 repIndex = current + 1 - offset_1;
+        const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
+                            && repIndex < prefixStartIndex) ?
+                               dictBase + (repIndex - dictIndexDelta) :
+                               base + repIndex;
         hashTable[h] = current;   /* update hash table */
 
-        if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
+        if ( (dictMode == ZSTD_dictMatchState)
+          && ((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex isn't overlapping dict + prefix */
+          && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
+            const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
+            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
+            ip++;
+            ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
+        } else if ( dictMode == ZSTD_noDict
+                 && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
             mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
             ip++;
             ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
-        } else {
-            if ( (matchIndex <= lowestIndex)
-              || (MEM_read32(match) != MEM_read32(ip)) ) {
+        } else if ( (matchIndex <= prefixStartIndex) ) {
+            if (dictMode == ZSTD_dictMatchState) {
+                size_t const dictHash = ZSTD_hashPtr(ip, dictHLog, mls);
+                U32 const dictMatchIndex = dictHashTable[dictHash];
+                const BYTE* dictMatch = dictBase + dictMatchIndex;
+                if (dictMatchIndex <= dictStartIndex ||
+                    MEM_read32(dictMatch) != MEM_read32(ip)) {
+                    assert(stepSize >= 1);
+                    ip += ((ip-anchor) >> kSearchStrength) + stepSize;
+                    continue;
+                } else {
+                    /* found a dict match */
+                    U32 const offset = (U32)(current-dictMatchIndex-dictIndexDelta);
+                    mLength = ZSTD_count_2segments(ip+4, dictMatch+4, iend, dictEnd, prefixStart) + 4;
+                    while (((ip>anchor) & (dictMatch>dictStart))
+                         && (ip[-1] == dictMatch[-1])) {
+                        ip--; dictMatch--; mLength++;
+                    } /* catch up */
+                    offset_2 = offset_1;
+                    offset_1 = offset;
+                    ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+                }
+            } else {
                 assert(stepSize >= 1);
                 ip += ((ip-anchor) >> kSearchStrength) + stepSize;
                 continue;
             }
+        } else if (MEM_read32(match) != MEM_read32(ip)) {
+            /* it's not a match, and we're not going to check the dictionary */
+            assert(stepSize >= 1);
+            ip += ((ip-anchor) >> kSearchStrength) + stepSize;
+            continue;
+        } else {
+            /* found a regular match */
+            U32 const offset = (U32)(ip-match);
             mLength = ZSTD_count(ip+4, match+4, iend) + 4;
-            {   U32 const offset = (U32)(ip-match);
-                while (((ip>anchor) & (match>lowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
-                offset_2 = offset_1;
-                offset_1 = offset;
-                ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
-        }   }
+            while (((ip>anchor) & (match>prefixStart))
+                 && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
+            offset_2 = offset_1;
+            offset_1 = offset;
+            ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+        }
 
         /* match found */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Fill Table */
+            assert(base+current+2 > istart);  /* check base overflow */
             hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2;  /* here because current+2 could be > iend-8 */
             hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
+
             /* check immediate repcode */
-            while ( (ip <= ilimit)
-                 && ( (offset_2>0)
-                 & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
-                /* store sequence */
-                size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
-                { U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; }  /* swap offset_2 <=> offset_1 */
-                hashTable[ZSTD_hashPtr(ip, hlog, mls)] = (U32)(ip-base);
-                ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
-                ip += rLength;
-                anchor = ip;
-                continue;   /* faster when present ... (?) */
-    }   }   }
+            if (dictMode == ZSTD_dictMatchState) {
+                while (ip <= ilimit) {
+                    U32 const current2 = (U32)(ip-base);
+                    U32 const repIndex2 = current2 - offset_2;
+                    const BYTE* repMatch2 = repIndex2 < prefixStartIndex ?
+                            dictBase - dictIndexDelta + repIndex2 :
+                            base + repIndex2;
+                    if ( ((U32)((prefixStartIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
+                       && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
+                        const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
+                        size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
+                        U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
+                        ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
+                        hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
+                        ip += repLength2;
+                        anchor = ip;
+                        continue;
+                    }
+                    break;
+                }
+            }
 
+            if (dictMode == ZSTD_noDict) {
+                while ( (ip <= ilimit)
+                     && ( (offset_2>0)
+                        & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
+                    /* store sequence */
+                    size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
+                    U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff;  /* swap offset_2 <=> offset_1 */
+                    hashTable[ZSTD_hashPtr(ip, hlog, mls)] = (U32)(ip-base);
+                    ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
+                    ip += rLength;
+                    anchor = ip;
+                    continue;   /* faster when present ... (?) */
+    }   }   }   }
+
     /* save reps for next block */
     rep[0] = offset_1 ? offset_1 : offsetSaved;
     rep[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_fast(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    U32 const hlog = cParams->hashLog;
+    ZSTD_compressionParameters const* cParams = &ms->cParams;
     U32 const mls = cParams->searchLength;
-    U32 const stepSize = cParams->targetLength;
+    assert(ms->dictMatchState == NULL);
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
-        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 4);
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_noDict);
     case 5 :
-        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 5);
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_noDict);
     case 6 :
-        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 6);
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_noDict);
     case 7 :
-        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 7);
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_noDict);
     }
 }
 
+size_t ZSTD_compressBlock_fast_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize)
+{
+    ZSTD_compressionParameters const* cParams = &ms->cParams;
+    U32 const mls = cParams->searchLength;
+    assert(ms->dictMatchState != NULL);
+    switch(mls)
+    {
+    default: /* includes case 3 */
+    case 4 :
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_dictMatchState);
+    case 5 :
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_dictMatchState);
+    case 6 :
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_dictMatchState);
+    case 7 :
+        return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_dictMatchState);
+    }
+}
 
+
 static size_t ZSTD_compressBlock_fast_extDict_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        void const* src, size_t srcSize,
-        U32 const hlog, U32 const stepSize, U32 const mls)
+        void const* src, size_t srcSize, U32 const mls)
 {
-    U32* hashTable = ms->hashTable;
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
+    U32* const hashTable = ms->hashTable;
+    U32 const hlog = cParams->hashLog;
+    /* support stepSize of 0 */
+    U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
-    const U32   lowestIndex = ms->window.lowLimit;
-    const BYTE* const dictStart = dictBase + lowestIndex;
-    const U32   dictLimit = ms->window.dictLimit;
-    const BYTE* const lowPrefixPtr = base + dictLimit;
-    const BYTE* const dictEnd = dictBase + dictLimit;
+    const U32   dictStartIndex = ms->window.lowLimit;
+    const BYTE* const dictStart = dictBase + dictStartIndex;
+    const U32   prefixStartIndex = ms->window.dictLimit;
+    const BYTE* const prefixStart = base + prefixStartIndex;
+    const BYTE* const dictEnd = dictBase + prefixStartIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     U32 offset_1=rep[0], offset_2=rep[1];
 
     /* Search Loop */
     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
         const size_t h = ZSTD_hashPtr(ip, hlog, mls);
-        const U32 matchIndex = hashTable[h];
-        const BYTE* matchBase = matchIndex < dictLimit ? dictBase : base;
-        const BYTE* match = matchBase + matchIndex;
-        const U32 current = (U32)(ip-base);
-        const U32 repIndex = current + 1 - offset_1;   /* offset_1 expected <= current +1 */
-        const BYTE* repBase = repIndex < dictLimit ? dictBase : base;
-        const BYTE* repMatch = repBase + repIndex;
+        const U32    matchIndex = hashTable[h];
+        const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
+        const BYTE*  match = matchBase + matchIndex;
+        const U32    current = (U32)(ip-base);
+        const U32    repIndex = current + 1 - offset_1;
+        const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
+        const BYTE* const repMatch = repBase + repIndex;
         size_t mLength;
         hashTable[h] = current;   /* update hash table */
+        assert(offset_1 <= current +1);   /* check repIndex */
 
-        if ( (((U32)((dictLimit-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > lowestIndex))
+        if ( (((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > dictStartIndex))
            && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
-            const BYTE* repMatchEnd = repIndex < dictLimit ? dictEnd : iend;
-            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4;
+            const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
+            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
             ip++;
             ZSTD_storeSeq(seqStore, ip-anchor, anchor, 0, mLength-MINMATCH);
         } else {
-            if ( (matchIndex < lowestIndex) ||
+            if ( (matchIndex < dictStartIndex) ||
                  (MEM_read32(match) != MEM_read32(ip)) ) {
                 assert(stepSize >= 1);
                 ip += ((ip-anchor) >> kSearchStrength) + stepSize;
                 continue;
             }
-            {   const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
-                const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
+            {   const BYTE* matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
+                const BYTE* lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
                 U32 offset;
-                mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 4;
+                mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
                 while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; }   /* catch up */
                 offset = current - matchIndex;
                 offset_2 = offset_1;
                 offset_1 = offset;
                 ZSTD_storeSeq(seqStore, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
         }   }
 
         /* found a match : store it */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Fill Table */
             hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2;
             hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
             /* check immediate repcode */
             while (ip <= ilimit) {
                 U32 const current2 = (U32)(ip-base);
                 U32 const repIndex2 = current2 - offset_2;
-                const BYTE* repMatch2 = repIndex2 < dictLimit ? dictBase + repIndex2 : base + repIndex2;
-                if ( (((U32)((dictLimit-1) - repIndex2) >= 3) & (repIndex2 > lowestIndex))  /* intentional overflow */
+                const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
+                if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (repIndex2 > dictStartIndex))  /* intentional overflow */
                    && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
-                    const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
-                    size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, lowPrefixPtr) + 4;
+                    const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
+                    size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
                     U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
                     ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
                     hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
                     ip += repLength2;
                     anchor = ip;
                     continue;
                 }
                 break;
     }   }   }
 
     /* save reps for next block */
     rep[0] = offset_1;
     rep[1] = offset_2;
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_fast_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    U32 const hlog = cParams->hashLog;
+    ZSTD_compressionParameters const* cParams = &ms->cParams;
     U32 const mls = cParams->searchLength;
-    U32 const stepSize = cParams->targetLength;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
-        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 4);
+        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
     case 5 :
-        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 5);
+        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
     case 6 :
-        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 6);
+        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
     case 7 :
-        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, hlog, stepSize, 7);
+        return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
     }
 }
Index: vendor/zstd/dist/lib/compress/zstd_fast.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_fast.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_fast.h	(revision 339614)
@@ -1,35 +1,37 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_FAST_H
 #define ZSTD_FAST_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #include "mem.h"      /* U32 */
 #include "zstd_compress_internal.h"
 
 void ZSTD_fillHashTable(ZSTD_matchState_t* ms,
-                        ZSTD_compressionParameters const* cParams,
-                        void const* end);
+                        void const* end, ZSTD_dictTableLoadMethod_e dtlm);
 size_t ZSTD_compressBlock_fast(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
+size_t ZSTD_compressBlock_fast_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_fast_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ZSTD_FAST_H */
Index: vendor/zstd/dist/lib/compress/zstd_lazy.c
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_lazy.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_lazy.c	(revision 339614)
@@ -1,824 +1,1099 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #include "zstd_compress_internal.h"
 #include "zstd_lazy.h"
 
 
 /*-*************************************
 *  Binary Tree search
 ***************************************/
 
-void ZSTD_updateDUBT(
-                ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+static void
+ZSTD_updateDUBT(ZSTD_matchState_t* ms,
                 const BYTE* ip, const BYTE* iend,
                 U32 mls)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32  const hashLog = cParams->hashLog;
 
     U32* const bt = ms->chainTable;
     U32  const btLog  = cParams->chainLog - 1;
     U32  const btMask = (1 << btLog) - 1;
 
     const BYTE* const base = ms->window.base;
     U32 const target = (U32)(ip - base);
     U32 idx = ms->nextToUpdate;
 
     if (idx != target)
         DEBUGLOG(7, "ZSTD_updateDUBT, from %u to %u (dictLimit:%u)",
                     idx, target, ms->window.dictLimit);
     assert(ip + 8 <= iend);   /* condition for ZSTD_hashPtr */
     (void)iend;
 
     assert(idx >= ms->window.dictLimit);   /* condition for valid base+idx */
     for ( ; idx < target ; idx++) {
         size_t const h  = ZSTD_hashPtr(base + idx, hashLog, mls);   /* assumption : ip + 8 <= iend */
         U32    const matchIndex = hashTable[h];
 
         U32*   const nextCandidatePtr = bt + 2*(idx&btMask);
         U32*   const sortMarkPtr  = nextCandidatePtr + 1;
 
         DEBUGLOG(8, "ZSTD_updateDUBT: insert %u", idx);
         hashTable[h] = idx;   /* Update Hash Table */
         *nextCandidatePtr = matchIndex;   /* update BT like a chain */
         *sortMarkPtr = ZSTD_DUBT_UNSORTED_MARK;
     }
     ms->nextToUpdate = target;
 }
 
 
 /** ZSTD_insertDUBT1() :
  *  sort one already inserted but unsorted position
  *  assumption : current >= btlow == (current - btmask)
  *  doesn't fail */
-static void ZSTD_insertDUBT1(
-                 ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+static void
+ZSTD_insertDUBT1(ZSTD_matchState_t* ms,
                  U32 current, const BYTE* inputEnd,
-                 U32 nbCompares, U32 btLow, int extDict)
+                 U32 nbCompares, U32 btLow, const ZSTD_dictMode_e dictMode)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32*   const bt = ms->chainTable;
     U32    const btLog  = cParams->chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const U32 dictLimit = ms->window.dictLimit;
     const BYTE* const ip = (current>=dictLimit) ? base + current : dictBase + current;
     const BYTE* const iend = (current>=dictLimit) ? inputEnd : dictBase + dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* match;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = smallerPtr + 1;
     U32 matchIndex = *smallerPtr;
     U32 dummy32;   /* to be nullified at the end */
     U32 const windowLow = ms->window.lowLimit;
 
     DEBUGLOG(8, "ZSTD_insertDUBT1(%u) (dictLimit=%u, lowLimit=%u)",
                 current, dictLimit, windowLow);
     assert(current >= btLow);
     assert(ip < iend);   /* condition for ZSTD_count */
 
     while (nbCompares-- && (matchIndex > windowLow)) {
         U32* const nextPtr = bt + 2*(matchIndex & btMask);
         size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         assert(matchIndex < current);
 
-        if ( (!extDict)
+        if ( (dictMode != ZSTD_extDict)
           || (matchIndex+matchLength >= dictLimit)  /* both in current segment*/
           || (current < dictLimit) /* both in extDict */) {
-            const BYTE* const mBase = !extDict || ((matchIndex+matchLength) >= dictLimit) ? base : dictBase;
+            const BYTE* const mBase = ( (dictMode != ZSTD_extDict)
+                                     || (matchIndex+matchLength >= dictLimit)) ?
+                                        base : dictBase;
             assert( (matchIndex+matchLength >= dictLimit)   /* might be wrong if extDict is incorrectly set to 0 */
                  || (current < dictLimit) );
             match = mBase + matchIndex;
             matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
         } else {
             match = dictBase + matchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
             if (matchIndex+matchLength >= dictLimit)
                 match = base + matchIndex;   /* to prepare for next usage of match[matchLength] */
         }
 
         DEBUGLOG(8, "ZSTD_insertDUBT1: comparing %u with %u : found %u common bytes ",
                     current, matchIndex, (U32)matchLength);
 
         if (ip+matchLength == iend) {   /* equal : no way to know if inf or sup */
             break;   /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
         }
 
         if (match[matchLength] < ip[matchLength]) {  /* necessarily within buffer */
             /* match is smaller than current */
             *smallerPtr = matchIndex;             /* update smaller idx */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is smaller : next => %u",
                         matchIndex, btLow, nextPtr[1]);
             smallerPtr = nextPtr+1;               /* new "candidate" => larger than match, which was smaller than target */
             matchIndex = nextPtr[1];              /* new matchIndex, larger than previous and closer to current */
         } else {
             /* match is larger than current */
             *largerPtr = matchIndex;
             commonLengthLarger = matchLength;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is larger => %u",
                         matchIndex, btLow, nextPtr[0]);
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
     }   }
 
     *smallerPtr = *largerPtr = 0;
 }
 
 
-static size_t ZSTD_DUBT_findBestMatch (
-                            ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                            const BYTE* const ip, const BYTE* const iend,
-                            size_t* offsetPtr,
-                            U32 const mls,
-                            U32 const extDict)
+static size_t
+ZSTD_DUBT_findBetterDictMatch (
+        ZSTD_matchState_t* ms,
+        const BYTE* const ip, const BYTE* const iend,
+        size_t* offsetPtr,
+        size_t bestLength,
+        U32 nbCompares,
+        U32 const mls,
+        const ZSTD_dictMode_e dictMode)
 {
+    const ZSTD_matchState_t * const dms = ms->dictMatchState;
+    const ZSTD_compressionParameters* const dmsCParams = &dms->cParams;
+    const U32 * const dictHashTable = dms->hashTable;
+    U32         const hashLog = dmsCParams->hashLog;
+    size_t      const h  = ZSTD_hashPtr(ip, hashLog, mls);
+    U32               dictMatchIndex = dictHashTable[h];
+
+    const BYTE* const base = ms->window.base;
+    const BYTE* const prefixStart = base + ms->window.dictLimit;
+    U32         const current = (U32)(ip-base);
+    const BYTE* const dictBase = dms->window.base;
+    const BYTE* const dictEnd = dms->window.nextSrc;
+    U32         const dictHighLimit = (U32)(dms->window.nextSrc - dms->window.base);
+    U32         const dictLowLimit = dms->window.lowLimit;
+    U32         const dictIndexDelta = ms->window.lowLimit - dictHighLimit;
+
+    U32*        const dictBt = dms->chainTable;
+    U32         const btLog  = dmsCParams->chainLog - 1;
+    U32         const btMask = (1 << btLog) - 1;
+    U32         const btLow = (btMask >= dictHighLimit - dictLowLimit) ? dictLowLimit : dictHighLimit - btMask;
+
+    size_t commonLengthSmaller=0, commonLengthLarger=0;
+
+    (void)dictMode;
+    assert(dictMode == ZSTD_dictMatchState);
+
+    while (nbCompares-- && (dictMatchIndex > dictLowLimit)) {
+        U32* const nextPtr = dictBt + 2*(dictMatchIndex & btMask);
+        size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
+        const BYTE* match = dictBase + dictMatchIndex;
+        matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
+        if (dictMatchIndex+matchLength >= dictHighLimit)
+            match = base + dictMatchIndex + dictIndexDelta;   /* to prepare for next usage of match[matchLength] */
+
+        if (matchLength > bestLength) {
+            U32 matchIndex = dictMatchIndex + dictIndexDelta;
+            if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) {
+                DEBUGLOG(9, "ZSTD_DUBT_findBetterDictMatch(%u) : found better match length %u -> %u and offsetCode %u -> %u (dictMatchIndex %u, matchIndex %u)",
+                    current, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, ZSTD_REP_MOVE + current - matchIndex, dictMatchIndex, matchIndex);
+                bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
+            }
+            if (ip+matchLength == iend) {   /* reached end of input : ip[matchLength] is not valid, no way to know if it's larger or smaller than match */
+                break;   /* drop, to guarantee consistency (miss a little bit of compression) */
+            }
+        }
+
+        if (match[matchLength] < ip[matchLength]) {
+            if (dictMatchIndex <= btLow) { break; }   /* beyond tree size, stop the search */
+            commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
+            dictMatchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
+        } else {
+            /* match is larger than current */
+            if (dictMatchIndex <= btLow) { break; }   /* beyond tree size, stop the search */
+            commonLengthLarger = matchLength;
+            dictMatchIndex = nextPtr[0];
+        }
+    }
+
+    if (bestLength >= MINMATCH) {
+        U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
+        DEBUGLOG(8, "ZSTD_DUBT_findBetterDictMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
+                    current, (U32)bestLength, (U32)*offsetPtr, mIndex);
+    }
+    return bestLength;
+
+}
+
+
+static size_t
+ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms,
+                        const BYTE* const ip, const BYTE* const iend,
+                        size_t* offsetPtr,
+                        U32 const mls,
+                        const ZSTD_dictMode_e dictMode)
+{
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32*   const hashTable = ms->hashTable;
     U32    const hashLog = cParams->hashLog;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32          matchIndex  = hashTable[h];
 
     const BYTE* const base = ms->window.base;
     U32    const current = (U32)(ip-base);
     U32    const windowLow = ms->window.lowLimit;
 
     U32*   const bt = ms->chainTable;
     U32    const btLog  = cParams->chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     U32    const btLow = (btMask >= current) ? 0 : current - btMask;
     U32    const unsortLimit = MAX(btLow, windowLow);
 
     U32*         nextCandidate = bt + 2*(matchIndex&btMask);
     U32*         unsortedMark = bt + 2*(matchIndex&btMask) + 1;
     U32          nbCompares = 1U << cParams->searchLog;
     U32          nbCandidates = nbCompares;
     U32          previousCandidate = 0;
 
     DEBUGLOG(7, "ZSTD_DUBT_findBestMatch (%u) ", current);
     assert(ip <= iend-8);   /* required for h calculation */
 
     /* reach end of unsorted candidates list */
     while ( (matchIndex > unsortLimit)
          && (*unsortedMark == ZSTD_DUBT_UNSORTED_MARK)
          && (nbCandidates > 1) ) {
         DEBUGLOG(8, "ZSTD_DUBT_findBestMatch: candidate %u is unsorted",
                     matchIndex);
         *unsortedMark = previousCandidate;
         previousCandidate = matchIndex;
         matchIndex = *nextCandidate;
         nextCandidate = bt + 2*(matchIndex&btMask);
         unsortedMark = bt + 2*(matchIndex&btMask) + 1;
         nbCandidates --;
     }
 
     if ( (matchIndex > unsortLimit)
       && (*unsortedMark==ZSTD_DUBT_UNSORTED_MARK) ) {
         DEBUGLOG(7, "ZSTD_DUBT_findBestMatch: nullify last unsorted candidate %u",
                     matchIndex);
         *nextCandidate = *unsortedMark = 0;   /* nullify next candidate if it's still unsorted (note : simplification, detrimental to compression ratio, beneficial for speed) */
     }
 
     /* batch sort stacked candidates */
     matchIndex = previousCandidate;
     while (matchIndex) {  /* will end on matchIndex == 0 */
         U32* const nextCandidateIdxPtr = bt + 2*(matchIndex&btMask) + 1;
         U32 const nextCandidateIdx = *nextCandidateIdxPtr;
-        ZSTD_insertDUBT1(ms, cParams, matchIndex, iend,
-                         nbCandidates, unsortLimit, extDict);
+        ZSTD_insertDUBT1(ms, matchIndex, iend,
+                         nbCandidates, unsortLimit, dictMode);
         matchIndex = nextCandidateIdx;
         nbCandidates++;
     }
 
     /* find longest match */
     {   size_t commonLengthSmaller=0, commonLengthLarger=0;
         const BYTE* const dictBase = ms->window.dictBase;
         const U32 dictLimit = ms->window.dictLimit;
         const BYTE* const dictEnd = dictBase + dictLimit;
         const BYTE* const prefixStart = base + dictLimit;
         U32* smallerPtr = bt + 2*(current&btMask);
         U32* largerPtr  = bt + 2*(current&btMask) + 1;
         U32 matchEndIdx = current+8+1;
         U32 dummy32;   /* to be nullified at the end */
         size_t bestLength = 0;
 
         matchIndex  = hashTable[h];
         hashTable[h] = current;   /* Update Hash Table */
 
         while (nbCompares-- && (matchIndex > windowLow)) {
             U32* const nextPtr = bt + 2*(matchIndex & btMask);
             size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
             const BYTE* match;
 
-            if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
+            if ((dictMode != ZSTD_extDict) || (matchIndex+matchLength >= dictLimit)) {
                 match = base + matchIndex;
                 matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
             } else {
                 match = dictBase + matchIndex;
                 matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
                 if (matchIndex+matchLength >= dictLimit)
                     match = base + matchIndex;   /* to prepare for next usage of match[matchLength] */
             }
 
             if (matchLength > bestLength) {
                 if (matchLength > matchEndIdx - matchIndex)
                     matchEndIdx = matchIndex + (U32)matchLength;
                 if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) )
                     bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
                 if (ip+matchLength == iend) {   /* equal : no way to know if inf or sup */
+                    if (dictMode == ZSTD_dictMatchState) {
+                        nbCompares = 0; /* in addition to avoiding checking any
+                                         * further in this loop, make sure we
+                                         * skip checking in the dictionary. */
+                    }
                     break;   /* drop, to guarantee consistency (miss a little bit of compression) */
                 }
             }
 
             if (match[matchLength] < ip[matchLength]) {
                 /* match is smaller than current */
                 *smallerPtr = matchIndex;             /* update smaller idx */
                 commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
                 if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
                 smallerPtr = nextPtr+1;               /* new "smaller" => larger of match */
                 matchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
             } else {
                 /* match is larger than current */
                 *largerPtr = matchIndex;
                 commonLengthLarger = matchLength;
                 if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
                 largerPtr = nextPtr;
                 matchIndex = nextPtr[0];
         }   }
 
         *smallerPtr = *largerPtr = 0;
 
+        if (dictMode == ZSTD_dictMatchState && nbCompares) {
+            bestLength = ZSTD_DUBT_findBetterDictMatch(
+                    ms, ip, iend,
+                    offsetPtr, bestLength, nbCompares,
+                    mls, dictMode);
+        }
+
         assert(matchEndIdx > current+8); /* ensure nextToUpdate is increased */
         ms->nextToUpdate = matchEndIdx - 8;   /* skip repetitive patterns */
         if (bestLength >= MINMATCH) {
             U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
             DEBUGLOG(8, "ZSTD_DUBT_findBestMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
                         current, (U32)bestLength, (U32)*offsetPtr, mIndex);
         }
         return bestLength;
     }
 }
 
 
 /** ZSTD_BtFindBestMatch() : Tree updater, providing best match */
-static size_t ZSTD_BtFindBestMatch (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                        const BYTE* const ip, const BYTE* const iLimit,
-                        size_t* offsetPtr,
-                        const U32 mls /* template */)
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_BtFindBestMatch( ZSTD_matchState_t* ms,
+                const BYTE* const ip, const BYTE* const iLimit,
+                      size_t* offsetPtr,
+                const U32 mls /* template */,
+                const ZSTD_dictMode_e dictMode)
 {
     DEBUGLOG(7, "ZSTD_BtFindBestMatch");
     if (ip < ms->window.base + ms->nextToUpdate) return 0;   /* skipped area */
-    ZSTD_updateDUBT(ms, cParams, ip, iLimit, mls);
-    return ZSTD_DUBT_findBestMatch(ms, cParams, ip, iLimit, offsetPtr, mls, 0);
+    ZSTD_updateDUBT(ms, ip, iLimit, mls);
+    return ZSTD_DUBT_findBestMatch(ms, ip, iLimit, offsetPtr, mls, dictMode);
 }
 
 
-static size_t ZSTD_BtFindBestMatch_selectMLS (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                        const BYTE* ip, const BYTE* const iLimit,
-                        size_t* offsetPtr)
+static size_t
+ZSTD_BtFindBestMatch_selectMLS (  ZSTD_matchState_t* ms,
+                            const BYTE* ip, const BYTE* const iLimit,
+                                  size_t* offsetPtr)
 {
-    switch(cParams->searchLength)
+    switch(ms->cParams.searchLength)
     {
     default : /* includes case 3 */
-    case 4 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 4);
-    case 5 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 5);
+    case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
+    case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
     case 7 :
-    case 6 : return ZSTD_BtFindBestMatch(ms, cParams, ip, iLimit, offsetPtr, 6);
+    case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
     }
 }
 
 
-/** Tree updater, providing best match */
-static size_t ZSTD_BtFindBestMatch_extDict (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                        const BYTE* const ip, const BYTE* const iLimit,
-                        size_t* offsetPtr,
-                        const U32 mls)
+static size_t ZSTD_BtFindBestMatch_dictMatchState_selectMLS (
+                        ZSTD_matchState_t* ms,
+                        const BYTE* ip, const BYTE* const iLimit,
+                        size_t* offsetPtr)
 {
-    DEBUGLOG(7, "ZSTD_BtFindBestMatch_extDict");
-    if (ip < ms->window.base + ms->nextToUpdate) return 0;   /* skipped area */
-    ZSTD_updateDUBT(ms, cParams, ip, iLimit, mls);
-    return ZSTD_DUBT_findBestMatch(ms, cParams, ip, iLimit, offsetPtr, mls, 1);
+    switch(ms->cParams.searchLength)
+    {
+    default : /* includes case 3 */
+    case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
+    case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
+    case 7 :
+    case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
+    }
 }
 
 
-static size_t ZSTD_BtFindBestMatch_selectMLS_extDict (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+static size_t ZSTD_BtFindBestMatch_extDict_selectMLS (
+                        ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
-    switch(cParams->searchLength)
+    switch(ms->cParams.searchLength)
     {
     default : /* includes case 3 */
-    case 4 : return ZSTD_BtFindBestMatch_extDict(ms, cParams, ip, iLimit, offsetPtr, 4);
-    case 5 : return ZSTD_BtFindBestMatch_extDict(ms, cParams, ip, iLimit, offsetPtr, 5);
+    case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
+    case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
     case 7 :
-    case 6 : return ZSTD_BtFindBestMatch_extDict(ms, cParams, ip, iLimit, offsetPtr, 6);
+    case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
     }
 }
 
 
 
 /* *********************************
 *  Hash Chain
 ***********************************/
 #define NEXT_IN_CHAIN(d, mask)   chainTable[(d) & mask]
 
 /* Update chains up to ip (excluded)
    Assumption : always within prefix (i.e. not within extDict) */
 static U32 ZSTD_insertAndFindFirstIndex_internal(
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                        ZSTD_matchState_t* ms,
+                        const ZSTD_compressionParameters* const cParams,
                         const BYTE* ip, U32 const mls)
 {
     U32* const hashTable  = ms->hashTable;
     const U32 hashLog = cParams->hashLog;
     U32* const chainTable = ms->chainTable;
     const U32 chainMask = (1 << cParams->chainLog) - 1;
     const BYTE* const base = ms->window.base;
     const U32 target = (U32)(ip - base);
     U32 idx = ms->nextToUpdate;
 
     while(idx < target) { /* catch up */
         size_t const h = ZSTD_hashPtr(base+idx, hashLog, mls);
         NEXT_IN_CHAIN(idx, chainMask) = hashTable[h];
         hashTable[h] = idx;
         idx++;
     }
 
     ms->nextToUpdate = target;
     return hashTable[ZSTD_hashPtr(ip, hashLog, mls)];
 }
 
-U32 ZSTD_insertAndFindFirstIndex(
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                        const BYTE* ip)
-{
-    return ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, cParams->searchLength);
+U32 ZSTD_insertAndFindFirstIndex(ZSTD_matchState_t* ms, const BYTE* ip) {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
+    return ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, ms->cParams.searchLength);
 }
 
 
 /* inlining is important to hardwire a hot branch (template emulation) */
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_HcFindBestMatch_generic (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                        ZSTD_matchState_t* ms,
                         const BYTE* const ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
-                        const U32 mls, const U32 extDict)
+                        const U32 mls, const ZSTD_dictMode_e dictMode)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const chainTable = ms->chainTable;
     const U32 chainSize = (1 << cParams->chainLog);
     const U32 chainMask = chainSize-1;
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const U32 dictLimit = ms->window.dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const U32 lowLimit = ms->window.lowLimit;
     const U32 current = (U32)(ip-base);
     const U32 minChain = current > chainSize ? current - chainSize : 0;
     U32 nbAttempts = 1U << cParams->searchLog;
     size_t ml=4-1;
 
     /* HC4 match finder */
     U32 matchIndex = ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, mls);
 
     for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
         size_t currentMl=0;
-        if ((!extDict) || matchIndex >= dictLimit) {
+        if ((dictMode != ZSTD_extDict) || matchIndex >= dictLimit) {
             const BYTE* const match = base + matchIndex;
             if (match[ml] == ip[ml])   /* potentially better */
                 currentMl = ZSTD_count(ip, match, iLimit);
         } else {
             const BYTE* const match = dictBase + matchIndex;
             assert(match+4 <= dictEnd);
             if (MEM_read32(match) == MEM_read32(ip))   /* assumption : matchIndex <= dictLimit-4 (by table construction) */
                 currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dictEnd, prefixStart) + 4;
         }
 
         /* save best solution */
         if (currentMl > ml) {
             ml = currentMl;
             *offsetPtr = current - matchIndex + ZSTD_REP_MOVE;
             if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
         }
 
         if (matchIndex <= minChain) break;
         matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
     }
 
+    if (dictMode == ZSTD_dictMatchState) {
+        const ZSTD_matchState_t* const dms = ms->dictMatchState;
+        const U32* const dmsChainTable = dms->chainTable;
+        const U32 dmsChainSize         = (1 << dms->cParams.chainLog);
+        const U32 dmsChainMask         = dmsChainSize - 1;
+        const U32 dmsLowestIndex       = dms->window.dictLimit;
+        const BYTE* const dmsBase      = dms->window.base;
+        const BYTE* const dmsEnd       = dms->window.nextSrc;
+        const U32 dmsSize              = (U32)(dmsEnd - dmsBase);
+        const U32 dmsIndexDelta        = dictLimit - dmsSize;
+        const U32 dmsMinChain = dmsSize > dmsChainSize ? dmsSize - dmsChainSize : 0;
+
+        matchIndex = dms->hashTable[ZSTD_hashPtr(ip, dms->cParams.hashLog, mls)];
+
+        for ( ; (matchIndex>dmsLowestIndex) & (nbAttempts>0) ; nbAttempts--) {
+            size_t currentMl=0;
+            const BYTE* const match = dmsBase + matchIndex;
+            assert(match+4 <= dmsEnd);
+            if (MEM_read32(match) == MEM_read32(ip))   /* assumption : matchIndex <= dictLimit-4 (by table construction) */
+                currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dmsEnd, prefixStart) + 4;
+
+            /* save best solution */
+            if (currentMl > ml) {
+                ml = currentMl;
+                *offsetPtr = current - (matchIndex + dmsIndexDelta) + ZSTD_REP_MOVE;
+                if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
+            }
+
+            if (matchIndex <= dmsMinChain) break;
+            matchIndex = dmsChainTable[matchIndex & dmsChainMask];
+        }
+    }
+
     return ml;
 }
 
 
 FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                        ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
-    switch(cParams->searchLength)
+    switch(ms->cParams.searchLength)
     {
     default : /* includes case 3 */
-    case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, 0);
-    case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, 0);
+    case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
+    case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
     case 7 :
-    case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, 0);
+    case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
     }
 }
 
 
+static size_t ZSTD_HcFindBestMatch_dictMatchState_selectMLS (
+                        ZSTD_matchState_t* ms,
+                        const BYTE* ip, const BYTE* const iLimit,
+                        size_t* offsetPtr)
+{
+    switch(ms->cParams.searchLength)
+    {
+    default : /* includes case 3 */
+    case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
+    case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
+    case 7 :
+    case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
+    }
+}
+
+
 FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                        ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
-                        size_t* const offsetPtr)
+                        size_t* offsetPtr)
 {
-    switch(cParams->searchLength)
+    switch(ms->cParams.searchLength)
     {
     default : /* includes case 3 */
-    case 4 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 4, 1);
-    case 5 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 5, 1);
+    case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
+    case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
     case 7 :
-    case 6 : return ZSTD_HcFindBestMatch_generic(ms, cParams, ip, iLimit, offsetPtr, 6, 1);
+    case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
     }
 }
 
 
 /* *******************************
 *  Common parser - lazy strategy
 *********************************/
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_lazy_generic(
                         ZSTD_matchState_t* ms, seqStore_t* seqStore,
                         U32 rep[ZSTD_REP_NUM],
-                        ZSTD_compressionParameters const* cParams,
                         const void* src, size_t srcSize,
-                        const U32 searchMethod, const U32 depth)
+                        const U32 searchMethod, const U32 depth,
+                        ZSTD_dictMode_e const dictMode)
 {
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
-    const BYTE* const base = ms->window.base + ms->window.dictLimit;
+    const BYTE* const base = ms->window.base;
+    const U32 prefixLowestIndex = ms->window.dictLimit;
+    const BYTE* const prefixLowest = base + prefixLowestIndex;
 
     typedef size_t (*searchMax_f)(
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                        ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
-    searchMax_f const searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
+    searchMax_f const searchMax = dictMode == ZSTD_dictMatchState ?
+        (searchMethod ? ZSTD_BtFindBestMatch_dictMatchState_selectMLS : ZSTD_HcFindBestMatch_dictMatchState_selectMLS) :
+        (searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS);
     U32 offset_1 = rep[0], offset_2 = rep[1], savedOffset=0;
 
+    const ZSTD_matchState_t* const dms = ms->dictMatchState;
+    const U32 dictLowestIndex      = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.dictLimit : 0;
+    const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.base : NULL;
+    const BYTE* const dictLowest   = dictMode == ZSTD_dictMatchState ?
+                                     dictBase + dictLowestIndex : NULL;
+    const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
+                                     dms->window.nextSrc : NULL;
+    const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
+                                     prefixLowestIndex - (U32)(dictEnd - dictBase) :
+                                     0;
+    const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
+
     /* init */
-    ip += (ip==base);
+    ip += (dictAndPrefixLength == 0);
     ms->nextToUpdate3 = ms->nextToUpdate;
-    {   U32 const maxRep = (U32)(ip-base);
+    if (dictMode == ZSTD_noDict) {
+        U32 const maxRep = (U32)(ip - prefixLowest);
         if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
     }
+    if (dictMode == ZSTD_dictMatchState) {
+        /* dictMatchState repCode checks don't currently handle repCode == 0
+         * disabling. */
+        assert(offset_1 <= dictAndPrefixLength);
+        assert(offset_2 <= dictAndPrefixLength);
+    }
 
     /* Match Loop */
     while (ip < ilimit) {
         size_t matchLength=0;
         size_t offset=0;
         const BYTE* start=ip+1;
 
         /* check repCode */
-        if ((offset_1>0) & (MEM_read32(ip+1) == MEM_read32(ip+1 - offset_1))) {
-            /* repcode : we take it */
+        if (dictMode == ZSTD_dictMatchState) {
+            const U32 repIndex = (U32)(ip - base) + 1 - offset_1;
+            const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
+                                && repIndex < prefixLowestIndex) ?
+                                   dictBase + (repIndex - dictIndexDelta) :
+                                   base + repIndex;
+            if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
+                && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
+                const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
+                matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
+                if (depth==0) goto _storeSequence;
+            }
+        }
+        if ( dictMode == ZSTD_noDict
+          && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
             matchLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
             if (depth==0) goto _storeSequence;
         }
 
         /* first search (depth 0) */
-        {   size_t offsetFound = 99999999;
-            size_t const ml2 = searchMax(ms, cParams, ip, iend, &offsetFound);
+        {   size_t offsetFound = 999999999;
+            size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
             if (ml2 > matchLength)
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
         if (matchLength < 4) {
             ip += ((ip-anchor) >> kSearchStrength) + 1;   /* jump faster over incompressible sections */
             continue;
         }
 
         /* let's try to find a better solution */
         if (depth>=1)
         while (ip0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
+            if ( (dictMode == ZSTD_noDict)
+              && (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
                 size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
                 int const gain2 = (int)(mlRep * 3);
                 int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
                 if ((mlRep >= 4) && (gain2 > gain1))
                     matchLength = mlRep, offset = 0, start = ip;
             }
-            {   size_t offset2=99999999;
-                size_t const ml2 = searchMax(ms, cParams, ip, iend, &offset2);
+            if (dictMode == ZSTD_dictMatchState) {
+                const U32 repIndex = (U32)(ip - base) - offset_1;
+                const BYTE* repMatch = repIndex < prefixLowestIndex ?
+                               dictBase + (repIndex - dictIndexDelta) :
+                               base + repIndex;
+                if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
+                    && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
+                    const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
+                    size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
+                    int const gain2 = (int)(mlRep * 3);
+                    int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
+                    if ((mlRep >= 4) && (gain2 > gain1))
+                        matchLength = mlRep, offset = 0, start = ip;
+                }
+            }
+            {   size_t offset2=999999999;
+                size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                 int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                 int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
                 if ((ml2 >= 4) && (gain2 > gain1)) {
                     matchLength = ml2, offset = offset2, start = ip;
                     continue;   /* search a better one */
             }   }
 
             /* let's find an even better one */
             if ((depth==2) && (ip0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
-                    size_t const ml2 = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
-                    int const gain2 = (int)(ml2 * 4);
+                if ( (dictMode == ZSTD_noDict)
+                  && (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
+                    size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
+                    int const gain2 = (int)(mlRep * 4);
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
-                    if ((ml2 >= 4) && (gain2 > gain1))
-                        matchLength = ml2, offset = 0, start = ip;
+                    if ((mlRep >= 4) && (gain2 > gain1))
+                        matchLength = mlRep, offset = 0, start = ip;
                 }
-                {   size_t offset2=99999999;
-                    size_t const ml2 = searchMax(ms, cParams, ip, iend, &offset2);
+                if (dictMode == ZSTD_dictMatchState) {
+                    const U32 repIndex = (U32)(ip - base) - offset_1;
+                    const BYTE* repMatch = repIndex < prefixLowestIndex ?
+                                   dictBase + (repIndex - dictIndexDelta) :
+                                   base + repIndex;
+                    if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
+                        && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
+                        const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
+                        size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
+                        int const gain2 = (int)(mlRep * 4);
+                        int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
+                        if ((mlRep >= 4) && (gain2 > gain1))
+                            matchLength = mlRep, offset = 0, start = ip;
+                    }
+                }
+                {   size_t offset2=999999999;
+                    size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                     int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
                     if ((ml2 >= 4) && (gain2 > gain1)) {
                         matchLength = ml2, offset = offset2, start = ip;
                         continue;
             }   }   }
             break;  /* nothing found : store previous solution */
         }
 
         /* NOTE:
          * start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
          * (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
          * overflows the pointer, which is undefined behavior.
          */
         /* catch up */
         if (offset) {
-            while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > base))
-                 && (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) )  /* only search for offset within prefix */
-                { start--; matchLength++; }
+            if (dictMode == ZSTD_noDict) {
+                while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > prefixLowest))
+                     && (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) )  /* only search for offset within prefix */
+                    { start--; matchLength++; }
+            }
+            if (dictMode == ZSTD_dictMatchState) {
+                U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
+                const BYTE* match = (matchIndex < prefixLowestIndex) ? dictBase + matchIndex - dictIndexDelta : base + matchIndex;
+                const BYTE* const mStart = (matchIndex < prefixLowestIndex) ? dictLowest : prefixLowest;
+                while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; }  /* catch up */
+            }
             offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
         }
         /* store sequence */
 _storeSequence:
         {   size_t const litLength = start - anchor;
             ZSTD_storeSeq(seqStore, litLength, anchor, (U32)offset, matchLength-MINMATCH);
             anchor = ip = start + matchLength;
         }
 
         /* check immediate repcode */
-        while ( ((ip <= ilimit) & (offset_2>0))
-             && (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
-            /* store sequence */
-            matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
-            offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
-            ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
-            ip += matchLength;
-            anchor = ip;
-            continue;   /* faster when present ... (?) */
-    }   }
+        if (dictMode == ZSTD_dictMatchState) {
+            while (ip <= ilimit) {
+                U32 const current2 = (U32)(ip-base);
+                U32 const repIndex = current2 - offset_2;
+                const BYTE* repMatch = dictMode == ZSTD_dictMatchState
+                    && repIndex < prefixLowestIndex ?
+                        dictBase - dictIndexDelta + repIndex :
+                        base + repIndex;
+                if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex) >= 3 /* intentional overflow */)
+                   && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
+                    const BYTE* const repEnd2 = repIndex < prefixLowestIndex ? dictEnd : iend;
+                    matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd2, prefixLowest) + 4;
+                    offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset;   /* swap offset_2 <=> offset_1 */
+                    ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
+                    ip += matchLength;
+                    anchor = ip;
+                    continue;
+                }
+                break;
+            }
+        }
 
+        if (dictMode == ZSTD_noDict) {
+            while ( ((ip <= ilimit) & (offset_2>0))
+                 && (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
+                /* store sequence */
+                matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
+                offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
+                ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
+                ip += matchLength;
+                anchor = ip;
+                continue;   /* faster when present ... (?) */
+    }   }   }
+
     /* Save reps for next block */
     rep[0] = offset_1 ? offset_1 : savedOffset;
     rep[1] = offset_2 ? offset_2 : savedOffset;
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_btlazy2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 1, 2);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 1, 2, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_lazy2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 2);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 2, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_lazy(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 1);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 1, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_greedy(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 0);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 0, ZSTD_noDict);
 }
 
+size_t ZSTD_compressBlock_btlazy2_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize)
+{
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 1, 2, ZSTD_dictMatchState);
+}
 
+size_t ZSTD_compressBlock_lazy2_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize)
+{
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 2, ZSTD_dictMatchState);
+}
+
+size_t ZSTD_compressBlock_lazy_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize)
+{
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 1, ZSTD_dictMatchState);
+}
+
+size_t ZSTD_compressBlock_greedy_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize)
+{
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 0, ZSTD_dictMatchState);
+}
+
+
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_lazy_extDict_generic(
                         ZSTD_matchState_t* ms, seqStore_t* seqStore,
                         U32 rep[ZSTD_REP_NUM],
-                        ZSTD_compressionParameters const* cParams,
                         const void* src, size_t srcSize,
                         const U32 searchMethod, const U32 depth)
 {
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     const BYTE* const base = ms->window.base;
     const U32 dictLimit = ms->window.dictLimit;
     const U32 lowestIndex = ms->window.lowLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictBase = ms->window.dictBase;
     const BYTE* const dictEnd  = dictBase + dictLimit;
     const BYTE* const dictStart  = dictBase + lowestIndex;
 
     typedef size_t (*searchMax_f)(
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                        ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
-    searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS_extDict : ZSTD_HcFindBestMatch_extDict_selectMLS;
+    searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_extDict_selectMLS : ZSTD_HcFindBestMatch_extDict_selectMLS;
 
     U32 offset_1 = rep[0], offset_2 = rep[1];
 
     /* init */
     ms->nextToUpdate3 = ms->nextToUpdate;
     ip += (ip == prefixStart);
 
     /* Match Loop */
     while (ip < ilimit) {
         size_t matchLength=0;
         size_t offset=0;
         const BYTE* start=ip+1;
         U32 current = (U32)(ip-base);
 
         /* check repCode */
         {   const U32 repIndex = (U32)(current+1 - offset_1);
             const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
             const BYTE* const repMatch = repBase + repIndex;
             if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex))   /* intentional overflow */
             if (MEM_read32(ip+1) == MEM_read32(repMatch)) {
                 /* repcode detected we should take it */
                 const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                 matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                 if (depth==0) goto _storeSequence;
         }   }
 
         /* first search (depth 0) */
-        {   size_t offsetFound = 99999999;
-            size_t const ml2 = searchMax(ms, cParams, ip, iend, &offsetFound);
+        {   size_t offsetFound = 999999999;
+            size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
             if (ml2 > matchLength)
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
          if (matchLength < 4) {
             ip += ((ip-anchor) >> kSearchStrength) + 1;   /* jump faster over incompressible sections */
             continue;
         }
 
         /* let's try to find a better solution */
         if (depth>=1)
         while (ip= 3) & (repIndex > lowestIndex))  /* intentional overflow */
                 if (MEM_read32(ip) == MEM_read32(repMatch)) {
                     /* repcode detected */
                     const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                     size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                     int const gain2 = (int)(repLength * 3);
                     int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
                     if ((repLength >= 4) && (gain2 > gain1))
                         matchLength = repLength, offset = 0, start = ip;
             }   }
 
             /* search match, depth 1 */
-            {   size_t offset2=99999999;
-                size_t const ml2 = searchMax(ms, cParams, ip, iend, &offset2);
+            {   size_t offset2=999999999;
+                size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                 int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                 int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
                 if ((ml2 >= 4) && (gain2 > gain1)) {
                     matchLength = ml2, offset = offset2, start = ip;
                     continue;   /* search a better one */
             }   }
 
             /* let's find an even better one */
             if ((depth==2) && (ip= 3) & (repIndex > lowestIndex))  /* intentional overflow */
                     if (MEM_read32(ip) == MEM_read32(repMatch)) {
                         /* repcode detected */
                         const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                         size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                         int const gain2 = (int)(repLength * 4);
                         int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
                         if ((repLength >= 4) && (gain2 > gain1))
                             matchLength = repLength, offset = 0, start = ip;
                 }   }
 
                 /* search match, depth 2 */
-                {   size_t offset2=99999999;
-                    size_t const ml2 = searchMax(ms, cParams, ip, iend, &offset2);
+                {   size_t offset2=999999999;
+                    size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                     int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
                     if ((ml2 >= 4) && (gain2 > gain1)) {
                         matchLength = ml2, offset = offset2, start = ip;
                         continue;
             }   }   }
             break;  /* nothing found : store previous solution */
         }
 
         /* catch up */
         if (offset) {
             U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
             const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex;
             const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart;
             while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; }  /* catch up */
             offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
         }
 
         /* store sequence */
 _storeSequence:
         {   size_t const litLength = start - anchor;
             ZSTD_storeSeq(seqStore, litLength, anchor, (U32)offset, matchLength-MINMATCH);
             anchor = ip = start + matchLength;
         }
 
         /* check immediate repcode */
         while (ip <= ilimit) {
             const U32 repIndex = (U32)((ip-base) - offset_2);
             const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
             const BYTE* const repMatch = repBase + repIndex;
             if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex))  /* intentional overflow */
             if (MEM_read32(ip) == MEM_read32(repMatch)) {
                 /* repcode detected we should take it */
                 const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                 matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                 offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset;   /* swap offset history */
                 ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
                 ip += matchLength;
                 anchor = ip;
                 continue;   /* faster when present ... (?) */
             }
             break;
     }   }
 
     /* Save reps for next block */
     rep[0] = offset_1;
     rep[1] = offset_2;
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_greedy_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 0);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 0);
 }
 
 size_t ZSTD_compressBlock_lazy_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 1);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 1);
 }
 
 size_t ZSTD_compressBlock_lazy2_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 0, 2);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 2);
 }
 
 size_t ZSTD_compressBlock_btlazy2_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        void const* src, size_t srcSize)
 
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, cParams, src, srcSize, 1, 2);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 1, 2);
 }
Index: vendor/zstd/dist/lib/compress/zstd_lazy.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_lazy.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_lazy.h	(revision 339614)
@@ -1,56 +1,67 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_LAZY_H
 #define ZSTD_LAZY_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #include "zstd_compress_internal.h"
 
-U32 ZSTD_insertAndFindFirstIndex(
-        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-        const BYTE* ip);
+U32 ZSTD_insertAndFindFirstIndex(ZSTD_matchState_t* ms, const BYTE* ip);
 
 void ZSTD_preserveUnsortedMark (U32* const table, U32 const size, U32 const reducerValue);  /*! used in ZSTD_reduceIndex(). pre-emptively increase value of ZSTD_DUBT_UNSORTED_MARK */
 
 size_t ZSTD_compressBlock_btlazy2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_lazy2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_lazy(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_greedy(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 
+size_t ZSTD_compressBlock_btlazy2_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
+size_t ZSTD_compressBlock_lazy2_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
+size_t ZSTD_compressBlock_lazy_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
+size_t ZSTD_compressBlock_greedy_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
+
 size_t ZSTD_compressBlock_greedy_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_lazy_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_lazy2_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_btlazy2_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ZSTD_LAZY_H */
Index: vendor/zstd/dist/lib/compress/zstd_ldm.c
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_ldm.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_ldm.c	(revision 339614)
@@ -1,653 +1,646 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  */
 
 #include "zstd_ldm.h"
 
+#include "debug.h"
 #include "zstd_fast.h"          /* ZSTD_fillHashTable() */
 #include "zstd_double_fast.h"   /* ZSTD_fillDoubleHashTable() */
 
 #define LDM_BUCKET_SIZE_LOG 3
 #define LDM_MIN_MATCH_LENGTH 64
 #define LDM_HASH_RLOG 7
 #define LDM_HASH_CHAR_OFFSET 10
 
 void ZSTD_ldm_adjustParameters(ldmParams_t* params,
                                ZSTD_compressionParameters const* cParams)
 {
-    U32 const windowLog = cParams->windowLog;
+    params->windowLog = cParams->windowLog;
     ZSTD_STATIC_ASSERT(LDM_BUCKET_SIZE_LOG <= ZSTD_LDM_BUCKETSIZELOG_MAX);
     DEBUGLOG(4, "ZSTD_ldm_adjustParameters");
     if (!params->bucketSizeLog) params->bucketSizeLog = LDM_BUCKET_SIZE_LOG;
     if (!params->minMatchLength) params->minMatchLength = LDM_MIN_MATCH_LENGTH;
     if (cParams->strategy >= ZSTD_btopt) {
       /* Get out of the way of the optimal parser */
       U32 const minMatch = MAX(cParams->targetLength, params->minMatchLength);
       assert(minMatch >= ZSTD_LDM_MINMATCH_MIN);
       assert(minMatch <= ZSTD_LDM_MINMATCH_MAX);
       params->minMatchLength = minMatch;
     }
     if (params->hashLog == 0) {
-        params->hashLog = MAX(ZSTD_HASHLOG_MIN, windowLog - LDM_HASH_RLOG);
+        params->hashLog = MAX(ZSTD_HASHLOG_MIN, params->windowLog - LDM_HASH_RLOG);
         assert(params->hashLog <= ZSTD_HASHLOG_MAX);
     }
     if (params->hashEveryLog == 0) {
-        params->hashEveryLog =
-                windowLog < params->hashLog ? 0 : windowLog - params->hashLog;
+        params->hashEveryLog = params->windowLog < params->hashLog
+                                   ? 0
+                                   : params->windowLog - params->hashLog;
     }
     params->bucketSizeLog = MIN(params->bucketSizeLog, params->hashLog);
 }
 
 size_t ZSTD_ldm_getTableSize(ldmParams_t params)
 {
     size_t const ldmHSize = ((size_t)1) << params.hashLog;
     size_t const ldmBucketSizeLog = MIN(params.bucketSizeLog, params.hashLog);
     size_t const ldmBucketSize =
         ((size_t)1) << (params.hashLog - ldmBucketSizeLog);
     size_t const totalSize = ldmBucketSize + ldmHSize * sizeof(ldmEntry_t);
     return params.enableLdm ? totalSize : 0;
 }
 
 size_t ZSTD_ldm_getMaxNbSeq(ldmParams_t params, size_t maxChunkSize)
 {
     return params.enableLdm ? (maxChunkSize / params.minMatchLength) : 0;
 }
 
 /** ZSTD_ldm_getSmallHash() :
  *  numBits should be <= 32
  *  If numBits==0, returns 0.
  *  @return : the most significant numBits of value. */
 static U32 ZSTD_ldm_getSmallHash(U64 value, U32 numBits)
 {
     assert(numBits <= 32);
     return numBits == 0 ? 0 : (U32)(value >> (64 - numBits));
 }
 
 /** ZSTD_ldm_getChecksum() :
  *  numBitsToDiscard should be <= 32
  *  @return : the next most significant 32 bits after numBitsToDiscard */
 static U32 ZSTD_ldm_getChecksum(U64 hash, U32 numBitsToDiscard)
 {
     assert(numBitsToDiscard <= 32);
     return (hash >> (64 - 32 - numBitsToDiscard)) & 0xFFFFFFFF;
 }
 
 /** ZSTD_ldm_getTag() ;
  *  Given the hash, returns the most significant numTagBits bits
  *  after (32 + hbits) bits.
  *
  *  If there are not enough bits remaining, return the last
  *  numTagBits bits. */
 static U32 ZSTD_ldm_getTag(U64 hash, U32 hbits, U32 numTagBits)
 {
     assert(numTagBits < 32 && hbits <= 32);
     if (32 - hbits < numTagBits) {
         return hash & (((U32)1 << numTagBits) - 1);
     } else {
         return (hash >> (32 - hbits - numTagBits)) & (((U32)1 << numTagBits) - 1);
     }
 }
 
 /** ZSTD_ldm_getBucket() :
  *  Returns a pointer to the start of the bucket associated with hash. */
 static ldmEntry_t* ZSTD_ldm_getBucket(
         ldmState_t* ldmState, size_t hash, ldmParams_t const ldmParams)
 {
     return ldmState->hashTable + (hash << ldmParams.bucketSizeLog);
 }
 
 /** ZSTD_ldm_insertEntry() :
  *  Insert the entry with corresponding hash into the hash table */
 static void ZSTD_ldm_insertEntry(ldmState_t* ldmState,
                                  size_t const hash, const ldmEntry_t entry,
                                  ldmParams_t const ldmParams)
 {
     BYTE* const bucketOffsets = ldmState->bucketOffsets;
     *(ZSTD_ldm_getBucket(ldmState, hash, ldmParams) + bucketOffsets[hash]) = entry;
     bucketOffsets[hash]++;
     bucketOffsets[hash] &= ((U32)1 << ldmParams.bucketSizeLog) - 1;
 }
 
 /** ZSTD_ldm_makeEntryAndInsertByTag() :
  *
  *  Gets the small hash, checksum, and tag from the rollingHash.
  *
  *  If the tag matches (1 << ldmParams.hashEveryLog)-1, then
  *  creates an ldmEntry from the offset, and inserts it into the hash table.
  *
  *  hBits is the length of the small hash, which is the most significant hBits
  *  of rollingHash. The checksum is the next 32 most significant bits, followed
  *  by ldmParams.hashEveryLog bits that make up the tag. */
 static void ZSTD_ldm_makeEntryAndInsertByTag(ldmState_t* ldmState,
                                              U64 const rollingHash,
                                              U32 const hBits,
                                              U32 const offset,
                                              ldmParams_t const ldmParams)
 {
     U32 const tag = ZSTD_ldm_getTag(rollingHash, hBits, ldmParams.hashEveryLog);
     U32 const tagMask = ((U32)1 << ldmParams.hashEveryLog) - 1;
     if (tag == tagMask) {
         U32 const hash = ZSTD_ldm_getSmallHash(rollingHash, hBits);
         U32 const checksum = ZSTD_ldm_getChecksum(rollingHash, hBits);
         ldmEntry_t entry;
         entry.offset = offset;
         entry.checksum = checksum;
         ZSTD_ldm_insertEntry(ldmState, hash, entry, ldmParams);
     }
 }
 
 /** ZSTD_ldm_getRollingHash() :
  *  Get a 64-bit hash using the first len bytes from buf.
  *
  *  Giving bytes s = s_1, s_2, ... s_k, the hash is defined to be
  *  H(s) = s_1*(a^(k-1)) + s_2*(a^(k-2)) + ... + s_k*(a^0)
  *
  *  where the constant a is defined to be prime8bytes.
  *
  *  The implementation adds an offset to each byte, so
  *  H(s) = (s_1 + HASH_CHAR_OFFSET)*(a^(k-1)) + ... */
 static U64 ZSTD_ldm_getRollingHash(const BYTE* buf, U32 len)
 {
     U64 ret = 0;
     U32 i;
     for (i = 0; i < len; i++) {
         ret *= prime8bytes;
         ret += buf[i] + LDM_HASH_CHAR_OFFSET;
     }
     return ret;
 }
 
 /** ZSTD_ldm_ipow() :
  *  Return base^exp. */
 static U64 ZSTD_ldm_ipow(U64 base, U64 exp)
 {
     U64 ret = 1;
     while (exp) {
         if (exp & 1) { ret *= base; }
         exp >>= 1;
         base *= base;
     }
     return ret;
 }
 
 U64 ZSTD_ldm_getHashPower(U32 minMatchLength) {
     DEBUGLOG(4, "ZSTD_ldm_getHashPower: mml=%u", minMatchLength);
     assert(minMatchLength >= ZSTD_LDM_MINMATCH_MIN);
     return ZSTD_ldm_ipow(prime8bytes, minMatchLength - 1);
 }
 
 /** ZSTD_ldm_updateHash() :
  *  Updates hash by removing toRemove and adding toAdd. */
 static U64 ZSTD_ldm_updateHash(U64 hash, BYTE toRemove, BYTE toAdd, U64 hashPower)
 {
     hash -= ((toRemove + LDM_HASH_CHAR_OFFSET) * hashPower);
     hash *= prime8bytes;
     hash += toAdd + LDM_HASH_CHAR_OFFSET;
     return hash;
 }
 
 /** ZSTD_ldm_countBackwardsMatch() :
  *  Returns the number of bytes that match backwards before pIn and pMatch.
  *
  *  We count only bytes where pMatch >= pBase and pIn >= pAnchor. */
 static size_t ZSTD_ldm_countBackwardsMatch(
             const BYTE* pIn, const BYTE* pAnchor,
             const BYTE* pMatch, const BYTE* pBase)
 {
     size_t matchLength = 0;
     while (pIn > pAnchor && pMatch > pBase && pIn[-1] == pMatch[-1]) {
         pIn--;
         pMatch--;
         matchLength++;
     }
     return matchLength;
 }
 
 /** ZSTD_ldm_fillFastTables() :
  *
  *  Fills the relevant tables for the ZSTD_fast and ZSTD_dfast strategies.
  *  This is similar to ZSTD_loadDictionaryContent.
  *
  *  The tables for the other strategies are filled within their
  *  block compressors. */
 static size_t ZSTD_ldm_fillFastTables(ZSTD_matchState_t* ms,
-                                      ZSTD_compressionParameters const* cParams,
                                       void const* end)
 {
     const BYTE* const iend = (const BYTE*)end;
 
-    switch(cParams->strategy)
+    switch(ms->cParams.strategy)
     {
     case ZSTD_fast:
-        ZSTD_fillHashTable(ms, cParams, iend);
-        ms->nextToUpdate = (U32)(iend - ms->window.base);
+        ZSTD_fillHashTable(ms, iend, ZSTD_dtlm_fast);
         break;
 
     case ZSTD_dfast:
-        ZSTD_fillDoubleHashTable(ms, cParams, iend);
-        ms->nextToUpdate = (U32)(iend - ms->window.base);
+        ZSTD_fillDoubleHashTable(ms, iend, ZSTD_dtlm_fast);
         break;
 
     case ZSTD_greedy:
     case ZSTD_lazy:
     case ZSTD_lazy2:
     case ZSTD_btlazy2:
     case ZSTD_btopt:
     case ZSTD_btultra:
         break;
     default:
         assert(0);  /* not possible : not a valid strategy id */
     }
 
     return 0;
 }
 
 /** ZSTD_ldm_fillLdmHashTable() :
  *
  *  Fills hashTable from (lastHashed + 1) to iend (non-inclusive).
  *  lastHash is the rolling hash that corresponds to lastHashed.
  *
  *  Returns the rolling hash corresponding to position iend-1. */
 static U64 ZSTD_ldm_fillLdmHashTable(ldmState_t* state,
                                      U64 lastHash, const BYTE* lastHashed,
                                      const BYTE* iend, const BYTE* base,
                                      U32 hBits, ldmParams_t const ldmParams)
 {
     U64 rollingHash = lastHash;
     const BYTE* cur = lastHashed + 1;
 
     while (cur < iend) {
         rollingHash = ZSTD_ldm_updateHash(rollingHash, cur[-1],
                                           cur[ldmParams.minMatchLength-1],
                                           state->hashPower);
         ZSTD_ldm_makeEntryAndInsertByTag(state,
                                          rollingHash, hBits,
                                          (U32)(cur - base), ldmParams);
         ++cur;
     }
     return rollingHash;
 }
 
 
 /** ZSTD_ldm_limitTableUpdate() :
  *
  *  Sets cctx->nextToUpdate to a position corresponding closer to anchor
  *  if it is far way
  *  (after a long match, only update tables a limited amount). */
 static void ZSTD_ldm_limitTableUpdate(ZSTD_matchState_t* ms, const BYTE* anchor)
 {
     U32 const current = (U32)(anchor - ms->window.base);
     if (current > ms->nextToUpdate + 1024) {
         ms->nextToUpdate =
             current - MIN(512, current - ms->nextToUpdate - 1024);
     }
 }
 
 static size_t ZSTD_ldm_generateSequences_internal(
         ldmState_t* ldmState, rawSeqStore_t* rawSeqStore,
         ldmParams_t const* params, void const* src, size_t srcSize)
 {
     /* LDM parameters */
     int const extDict = ZSTD_window_hasExtDict(ldmState->window);
     U32 const minMatchLength = params->minMatchLength;
     U64 const hashPower = ldmState->hashPower;
     U32 const hBits = params->hashLog - params->bucketSizeLog;
     U32 const ldmBucketSize = 1U << params->bucketSizeLog;
     U32 const hashEveryLog = params->hashEveryLog;
     U32 const ldmTagMask = (1U << params->hashEveryLog) - 1;
     /* Prefix and extDict parameters */
     U32 const dictLimit = ldmState->window.dictLimit;
     U32 const lowestIndex = extDict ? ldmState->window.lowLimit : dictLimit;
     BYTE const* const base = ldmState->window.base;
     BYTE const* const dictBase = extDict ? ldmState->window.dictBase : NULL;
     BYTE const* const dictStart = extDict ? dictBase + lowestIndex : NULL;
     BYTE const* const dictEnd = extDict ? dictBase + dictLimit : NULL;
     BYTE const* const lowPrefixPtr = base + dictLimit;
     /* Input bounds */
     BYTE const* const istart = (BYTE const*)src;
     BYTE const* const iend = istart + srcSize;
     BYTE const* const ilimit = iend - MAX(minMatchLength, HASH_READ_SIZE);
     /* Input positions */
     BYTE const* anchor = istart;
     BYTE const* ip = istart;
     /* Rolling hash */
     BYTE const* lastHashed = NULL;
     U64 rollingHash = 0;
 
     while (ip <= ilimit) {
         size_t mLength;
         U32 const current = (U32)(ip - base);
         size_t forwardMatchLength = 0, backwardMatchLength = 0;
         ldmEntry_t* bestEntry = NULL;
         if (ip != istart) {
             rollingHash = ZSTD_ldm_updateHash(rollingHash, lastHashed[0],
                                               lastHashed[minMatchLength],
                                               hashPower);
         } else {
             rollingHash = ZSTD_ldm_getRollingHash(ip, minMatchLength);
         }
         lastHashed = ip;
 
         /* Do not insert and do not look for a match */
         if (ZSTD_ldm_getTag(rollingHash, hBits, hashEveryLog) != ldmTagMask) {
            ip++;
            continue;
         }
 
         /* Get the best entry and compute the match lengths */
         {
             ldmEntry_t* const bucket =
                 ZSTD_ldm_getBucket(ldmState,
                                    ZSTD_ldm_getSmallHash(rollingHash, hBits),
                                    *params);
             ldmEntry_t* cur;
             size_t bestMatchLength = 0;
             U32 const checksum = ZSTD_ldm_getChecksum(rollingHash, hBits);
 
             for (cur = bucket; cur < bucket + ldmBucketSize; ++cur) {
                 size_t curForwardMatchLength, curBackwardMatchLength,
                        curTotalMatchLength;
                 if (cur->checksum != checksum || cur->offset <= lowestIndex) {
                     continue;
                 }
                 if (extDict) {
                     BYTE const* const curMatchBase =
                         cur->offset < dictLimit ? dictBase : base;
                     BYTE const* const pMatch = curMatchBase + cur->offset;
                     BYTE const* const matchEnd =
                         cur->offset < dictLimit ? dictEnd : iend;
                     BYTE const* const lowMatchPtr =
                         cur->offset < dictLimit ? dictStart : lowPrefixPtr;
 
                     curForwardMatchLength = ZSTD_count_2segments(
                                                 ip, pMatch, iend,
                                                 matchEnd, lowPrefixPtr);
                     if (curForwardMatchLength < minMatchLength) {
                         continue;
                     }
                     curBackwardMatchLength =
                         ZSTD_ldm_countBackwardsMatch(ip, anchor, pMatch,
                                                      lowMatchPtr);
                     curTotalMatchLength = curForwardMatchLength +
                                           curBackwardMatchLength;
                 } else { /* !extDict */
                     BYTE const* const pMatch = base + cur->offset;
                     curForwardMatchLength = ZSTD_count(ip, pMatch, iend);
                     if (curForwardMatchLength < minMatchLength) {
                         continue;
                     }
                     curBackwardMatchLength =
                         ZSTD_ldm_countBackwardsMatch(ip, anchor, pMatch,
                                                      lowPrefixPtr);
                     curTotalMatchLength = curForwardMatchLength +
                                           curBackwardMatchLength;
                 }
 
                 if (curTotalMatchLength > bestMatchLength) {
                     bestMatchLength = curTotalMatchLength;
                     forwardMatchLength = curForwardMatchLength;
                     backwardMatchLength = curBackwardMatchLength;
                     bestEntry = cur;
                 }
             }
         }
 
         /* No match found -- continue searching */
         if (bestEntry == NULL) {
             ZSTD_ldm_makeEntryAndInsertByTag(ldmState, rollingHash,
                                              hBits, current,
                                              *params);
             ip++;
             continue;
         }
 
         /* Match found */
         mLength = forwardMatchLength + backwardMatchLength;
         ip -= backwardMatchLength;
 
         {
             /* Store the sequence:
              * ip = current - backwardMatchLength
              * The match is at (bestEntry->offset - backwardMatchLength)
              */
             U32 const matchIndex = bestEntry->offset;
             U32 const offset = current - matchIndex;
             rawSeq* const seq = rawSeqStore->seq + rawSeqStore->size;
 
             /* Out of sequence storage */
             if (rawSeqStore->size == rawSeqStore->capacity)
                 return ERROR(dstSize_tooSmall);
             seq->litLength = (U32)(ip - anchor);
             seq->matchLength = (U32)mLength;
             seq->offset = offset;
             rawSeqStore->size++;
         }
 
         /* Insert the current entry into the hash table */
         ZSTD_ldm_makeEntryAndInsertByTag(ldmState, rollingHash, hBits,
                                          (U32)(lastHashed - base),
                                          *params);
 
         assert(ip + backwardMatchLength == lastHashed);
 
         /* Fill the hash table from lastHashed+1 to ip+mLength*/
         /* Heuristic: don't need to fill the entire table at end of block */
         if (ip + mLength <= ilimit) {
             rollingHash = ZSTD_ldm_fillLdmHashTable(
                               ldmState, rollingHash, lastHashed,
                               ip + mLength, base, hBits, *params);
             lastHashed = ip + mLength - 1;
         }
         ip += mLength;
         anchor = ip;
     }
     return iend - anchor;
 }
 
 /*! ZSTD_ldm_reduceTable() :
  *  reduce table indexes by `reducerValue` */
 static void ZSTD_ldm_reduceTable(ldmEntry_t* const table, U32 const size,
                                  U32 const reducerValue)
 {
     U32 u;
     for (u = 0; u < size; u++) {
         if (table[u].offset < reducerValue) table[u].offset = 0;
         else table[u].offset -= reducerValue;
     }
 }
 
 size_t ZSTD_ldm_generateSequences(
         ldmState_t* ldmState, rawSeqStore_t* sequences,
         ldmParams_t const* params, void const* src, size_t srcSize)
 {
     U32 const maxDist = 1U << params->windowLog;
     BYTE const* const istart = (BYTE const*)src;
     BYTE const* const iend = istart + srcSize;
     size_t const kMaxChunkSize = 1 << 20;
     size_t const nbChunks = (srcSize / kMaxChunkSize) + ((srcSize % kMaxChunkSize) != 0);
     size_t chunk;
     size_t leftoverSize = 0;
 
     assert(ZSTD_CHUNKSIZE_MAX >= kMaxChunkSize);
     /* Check that ZSTD_window_update() has been called for this chunk prior
      * to passing it to this function.
      */
     assert(ldmState->window.nextSrc >= (BYTE const*)src + srcSize);
     /* The input could be very large (in zstdmt), so it must be broken up into
      * chunks to enforce the maximmum distance and handle overflow correction.
      */
     assert(sequences->pos <= sequences->size);
     assert(sequences->size <= sequences->capacity);
     for (chunk = 0; chunk < nbChunks && sequences->size < sequences->capacity; ++chunk) {
         BYTE const* const chunkStart = istart + chunk * kMaxChunkSize;
         size_t const remaining = (size_t)(iend - chunkStart);
         BYTE const *const chunkEnd =
             (remaining < kMaxChunkSize) ? iend : chunkStart + kMaxChunkSize;
         size_t const chunkSize = chunkEnd - chunkStart;
         size_t newLeftoverSize;
         size_t const prevSize = sequences->size;
 
         assert(chunkStart < iend);
         /* 1. Perform overflow correction if necessary. */
         if (ZSTD_window_needOverflowCorrection(ldmState->window, chunkEnd)) {
             U32 const ldmHSize = 1U << params->hashLog;
             U32 const correction = ZSTD_window_correctOverflow(
                 &ldmState->window, /* cycleLog */ 0, maxDist, src);
             ZSTD_ldm_reduceTable(ldmState->hashTable, ldmHSize, correction);
         }
         /* 2. We enforce the maximum offset allowed.
          *
          * kMaxChunkSize should be small enough that we don't lose too much of
          * the window through early invalidation.
          * TODO: * Test the chunk size.
          *       * Try invalidation after the sequence generation and test the
          *         the offset against maxDist directly.
          */
-        ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL);
+        ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL, NULL);
         /* 3. Generate the sequences for the chunk, and get newLeftoverSize. */
         newLeftoverSize = ZSTD_ldm_generateSequences_internal(
             ldmState, sequences, params, chunkStart, chunkSize);
         if (ZSTD_isError(newLeftoverSize))
             return newLeftoverSize;
         /* 4. We add the leftover literals from previous iterations to the first
          *    newly generated sequence, or add the `newLeftoverSize` if none are
          *    generated.
          */
         /* Prepend the leftover literals from the last call */
         if (prevSize < sequences->size) {
             sequences->seq[prevSize].litLength += (U32)leftoverSize;
             leftoverSize = newLeftoverSize;
         } else {
             assert(newLeftoverSize == chunkSize);
             leftoverSize += chunkSize;
         }
     }
     return 0;
 }
 
 void ZSTD_ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize, U32 const minMatch) {
     while (srcSize > 0 && rawSeqStore->pos < rawSeqStore->size) {
         rawSeq* seq = rawSeqStore->seq + rawSeqStore->pos;
         if (srcSize <= seq->litLength) {
             /* Skip past srcSize literals */
             seq->litLength -= (U32)srcSize;
             return;
         }
         srcSize -= seq->litLength;
         seq->litLength = 0;
         if (srcSize < seq->matchLength) {
             /* Skip past the first srcSize of the match */
             seq->matchLength -= (U32)srcSize;
             if (seq->matchLength < minMatch) {
                 /* The match is too short, omit it */
                 if (rawSeqStore->pos + 1 < rawSeqStore->size) {
                     seq[1].litLength += seq[0].matchLength;
                 }
                 rawSeqStore->pos++;
             }
             return;
         }
         srcSize -= seq->matchLength;
         seq->matchLength = 0;
         rawSeqStore->pos++;
     }
 }
 
 /**
  * If the sequence length is longer than remaining then the sequence is split
  * between this block and the next.
  *
  * Returns the current sequence to handle, or if the rest of the block should
  * be literals, it returns a sequence with offset == 0.
  */
 static rawSeq maybeSplitSequence(rawSeqStore_t* rawSeqStore,
                                  U32 const remaining, U32 const minMatch)
 {
     rawSeq sequence = rawSeqStore->seq[rawSeqStore->pos];
     assert(sequence.offset > 0);
     /* Likely: No partial sequence */
     if (remaining >= sequence.litLength + sequence.matchLength) {
         rawSeqStore->pos++;
         return sequence;
     }
     /* Cut the sequence short (offset == 0 ==> rest is literals). */
     if (remaining <= sequence.litLength) {
         sequence.offset = 0;
     } else if (remaining < sequence.litLength + sequence.matchLength) {
         sequence.matchLength = remaining - sequence.litLength;
         if (sequence.matchLength < minMatch) {
             sequence.offset = 0;
         }
     }
     /* Skip past `remaining` bytes for the future sequences. */
     ZSTD_ldm_skipSequences(rawSeqStore, remaining, minMatch);
     return sequence;
 }
 
 size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
     ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-    ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize,
-    int const extDict)
+    void const* src, size_t srcSize)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     unsigned const minMatch = cParams->searchLength;
     ZSTD_blockCompressor const blockCompressor =
-        ZSTD_selectBlockCompressor(cParams->strategy, extDict);
-    BYTE const* const base = ms->window.base;
+        ZSTD_selectBlockCompressor(cParams->strategy, ZSTD_matchState_dictMode(ms));
     /* Input bounds */
     BYTE const* const istart = (BYTE const*)src;
     BYTE const* const iend = istart + srcSize;
     /* Input positions */
     BYTE const* ip = istart;
 
+    DEBUGLOG(5, "ZSTD_ldm_blockCompress: srcSize=%zu", srcSize);
     assert(rawSeqStore->pos <= rawSeqStore->size);
     assert(rawSeqStore->size <= rawSeqStore->capacity);
     /* Loop through each sequence and apply the block compressor to the lits */
     while (rawSeqStore->pos < rawSeqStore->size && ip < iend) {
         /* maybeSplitSequence updates rawSeqStore->pos */
         rawSeq const sequence = maybeSplitSequence(rawSeqStore,
                                                    (U32)(iend - ip), minMatch);
         int i;
         /* End signal */
         if (sequence.offset == 0)
             break;
 
         assert(sequence.offset <= (1U << cParams->windowLog));
         assert(ip + sequence.litLength + sequence.matchLength <= iend);
 
         /* Fill tables for block compressor */
         ZSTD_ldm_limitTableUpdate(ms, ip);
-        ZSTD_ldm_fillFastTables(ms, cParams, ip);
+        ZSTD_ldm_fillFastTables(ms, ip);
         /* Run the block compressor */
+        DEBUGLOG(5, "calling block compressor on segment of size %u", sequence.litLength);
         {
             size_t const newLitLength =
-                blockCompressor(ms, seqStore, rep, cParams, ip,
-                                sequence.litLength);
+                blockCompressor(ms, seqStore, rep, ip, sequence.litLength);
             ip += sequence.litLength;
-            ms->nextToUpdate = (U32)(ip - base);
             /* Update the repcodes */
             for (i = ZSTD_REP_NUM - 1; i > 0; i--)
                 rep[i] = rep[i-1];
             rep[0] = sequence.offset;
             /* Store the sequence */
             ZSTD_storeSeq(seqStore, newLitLength, ip - newLitLength,
                           sequence.offset + ZSTD_REP_MOVE,
                           sequence.matchLength - MINMATCH);
             ip += sequence.matchLength;
         }
     }
     /* Fill the tables for the block compressor */
     ZSTD_ldm_limitTableUpdate(ms, ip);
-    ZSTD_ldm_fillFastTables(ms, cParams, ip);
+    ZSTD_ldm_fillFastTables(ms, ip);
     /* Compress the last literals */
-    {
-        size_t const lastLiterals = blockCompressor(ms, seqStore, rep, cParams,
-                                                    ip, iend - ip);
-        ms->nextToUpdate = (U32)(iend - base);
-        return lastLiterals;
-    }
+    return blockCompressor(ms, seqStore, rep, ip, iend - ip);
 }
Index: vendor/zstd/dist/lib/compress/zstd_ldm.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_ldm.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_ldm.h	(revision 339614)
@@ -1,111 +1,109 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  */
 
 #ifndef ZSTD_LDM_H
 #define ZSTD_LDM_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #include "zstd_compress_internal.h"   /* ldmParams_t, U32 */
 #include "zstd.h"   /* ZSTD_CCtx, size_t */
 
 /*-*************************************
 *  Long distance matching
 ***************************************/
 
 #define ZSTD_LDM_DEFAULT_WINDOW_LOG ZSTD_WINDOWLOG_DEFAULTMAX
 
 /**
  * ZSTD_ldm_generateSequences():
  *
  * Generates the sequences using the long distance match finder.
  * Generates long range matching sequences in `sequences`, which parse a prefix
  * of the source. `sequences` must be large enough to store every sequence,
  * which can be checked with `ZSTD_ldm_getMaxNbSeq()`.
  * @returns 0 or an error code.
  *
  * NOTE: The user must have called ZSTD_window_update() for all of the input
  * they have, even if they pass it to ZSTD_ldm_generateSequences() in chunks.
  * NOTE: This function returns an error if it runs out of space to store
  *       sequences.
  */
 size_t ZSTD_ldm_generateSequences(
             ldmState_t* ldms, rawSeqStore_t* sequences,
             ldmParams_t const* params, void const* src, size_t srcSize);
 
 /**
  * ZSTD_ldm_blockCompress():
  *
  * Compresses a block using the predefined sequences, along with a secondary
  * block compressor. The literals section of every sequence is passed to the
  * secondary block compressor, and those sequences are interspersed with the
  * predefined sequences. Returns the length of the last literals.
  * Updates `rawSeqStore.pos` to indicate how many sequences have been consumed.
  * `rawSeqStore.seq` may also be updated to split the last sequence between two
  * blocks.
  * @return The length of the last literals.
  *
  * NOTE: The source must be at most the maximum block size, but the predefined
  * sequences can be any size, and may be longer than the block. In the case that
  * they are longer than the block, the last sequences may need to be split into
  * two. We handle that case correctly, and update `rawSeqStore` appropriately.
  * NOTE: This function does not return any errors.
  */
 size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
             ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-            ZSTD_compressionParameters const* cParams,
-            void const* src, size_t srcSize,
-            int const extDict);
+            void const* src, size_t srcSize);
 
 /**
  * ZSTD_ldm_skipSequences():
  *
  * Skip past `srcSize` bytes worth of sequences in `rawSeqStore`.
  * Avoids emitting matches less than `minMatch` bytes.
  * Must be called for data with is not passed to ZSTD_ldm_blockCompress().
  */
 void ZSTD_ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize,
     U32 const minMatch);
 
 
 /** ZSTD_ldm_getTableSize() :
  *  Estimate the space needed for long distance matching tables or 0 if LDM is
  *  disabled.
  */
 size_t ZSTD_ldm_getTableSize(ldmParams_t params);
 
 /** ZSTD_ldm_getSeqSpace() :
  *  Return an upper bound on the number of sequences that can be produced by
  *  the long distance matcher, or 0 if LDM is disabled.
  */
 size_t ZSTD_ldm_getMaxNbSeq(ldmParams_t params, size_t maxChunkSize);
 
 /** ZSTD_ldm_getTableSize() :
  *  Return prime8bytes^(minMatchLength-1) */
 U64 ZSTD_ldm_getHashPower(U32 minMatchLength);
 
 /** ZSTD_ldm_adjustParameters() :
  *  If the params->hashEveryLog is not set, set it to its default value based on
  *  windowLog and params->hashLog.
  *
  *  Ensures that params->bucketSizeLog is <= params->hashLog (setting it to
  *  params->hashLog if it is not).
  *
  *  Ensures that the minMatchLength >= targetLength during optimal parsing.
  */
 void ZSTD_ldm_adjustParameters(ldmParams_t* params,
                                ZSTD_compressionParameters const* cParams);
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ZSTD_FAST_H */
Index: vendor/zstd/dist/lib/compress/zstd_opt.c
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_opt.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_opt.c	(revision 339614)
@@ -1,923 +1,1132 @@
 /*
  * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #include "zstd_compress_internal.h"
+#include "hist.h"
 #include "zstd_opt.h"
 
 
-#define ZSTD_LITFREQ_ADD    2   /* scaling factor for litFreq, so that frequencies adapt faster to new stats. Also used for matchSum (?) */
+#define ZSTD_LITFREQ_ADD    2   /* scaling factor for litFreq, so that frequencies adapt faster to new stats */
 #define ZSTD_FREQ_DIV       4   /* log factor when using previous stats to init next stats */
 #define ZSTD_MAX_PRICE     (1<<30)
 
 
 /*-*************************************
 *  Price functions for optimal parser
 ***************************************/
-static void ZSTD_setLog2Prices(optState_t* optPtr)
+
+#if 0    /* approximation at bit level */
+#  define BITCOST_ACCURACY 0
+#  define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
+#  define WEIGHT(stat)  ((void)opt, ZSTD_bitWeight(stat))
+#elif 0  /* fractional bit accuracy */
+#  define BITCOST_ACCURACY 8
+#  define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
+#  define WEIGHT(stat,opt) ((void)opt, ZSTD_fracWeight(stat))
+#else    /* opt==approx, ultra==accurate */
+#  define BITCOST_ACCURACY 8
+#  define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
+#  define WEIGHT(stat,opt) (opt ? ZSTD_fracWeight(stat) : ZSTD_bitWeight(stat))
+#endif
+
+MEM_STATIC U32 ZSTD_bitWeight(U32 stat)
 {
-    optPtr->log2litSum = ZSTD_highbit32(optPtr->litSum+1);
-    optPtr->log2litLengthSum = ZSTD_highbit32(optPtr->litLengthSum+1);
-    optPtr->log2matchLengthSum = ZSTD_highbit32(optPtr->matchLengthSum+1);
-    optPtr->log2offCodeSum = ZSTD_highbit32(optPtr->offCodeSum+1);
+    return (ZSTD_highbit32(stat+1) * BITCOST_MULTIPLIER);
 }
 
+MEM_STATIC U32 ZSTD_fracWeight(U32 rawStat)
+{
+    U32 const stat = rawStat + 1;
+    U32 const hb = ZSTD_highbit32(stat);
+    U32 const BWeight = hb * BITCOST_MULTIPLIER;
+    U32 const FWeight = (stat << BITCOST_ACCURACY) >> hb;
+    U32 const weight = BWeight + FWeight;
+    assert(hb + BITCOST_ACCURACY < 31);
+    return weight;
+}
 
+/* debugging function, @return price in bytes */
+MEM_STATIC double ZSTD_fCost(U32 price)
+{
+    return (double)price / (BITCOST_MULTIPLIER*8);
+}
+
+static void ZSTD_setBasePrices(optState_t* optPtr, int optLevel)
+{
+    optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel);
+    optPtr->litLengthSumBasePrice = WEIGHT(optPtr->litLengthSum, optLevel);
+    optPtr->matchLengthSumBasePrice = WEIGHT(optPtr->matchLengthSum, optLevel);
+    optPtr->offCodeSumBasePrice = WEIGHT(optPtr->offCodeSum, optLevel);
+}
+
+
+static U32 ZSTD_downscaleStat(U32* table, U32 lastEltIndex, int malus)
+{
+    U32 s, sum=0;
+    assert(ZSTD_FREQ_DIV+malus > 0 && ZSTD_FREQ_DIV+malus < 31);
+    for (s=0; s<=lastEltIndex; s++) {
+        table[s] = 1 + (table[s] >> (ZSTD_FREQ_DIV+malus));
+        sum += table[s];
+    }
+    return sum;
+}
+
 static void ZSTD_rescaleFreqs(optState_t* const optPtr,
-                              const BYTE* const src, size_t const srcSize)
+                              const BYTE* const src, size_t const srcSize,
+                              int optLevel)
 {
-    optPtr->staticPrices = 0;
+    optPtr->priceType = zop_dynamic;
 
-    if (optPtr->litLengthSum == 0) {  /* first init */
-        unsigned u;
-        if (srcSize <= 1024) optPtr->staticPrices = 1;
+    if (optPtr->litLengthSum == 0) {  /* first block : init */
+        if (srcSize <= 1024)   /* heuristic */
+            optPtr->priceType = zop_predef;
 
-        assert(optPtr->litFreq!=NULL);
-        for (u=0; u<=MaxLit; u++)
-            optPtr->litFreq[u] = 0;
-        for (u=0; ulitFreq[src[u]]++;
-        optPtr->litSum = 0;
-        for (u=0; u<=MaxLit; u++) {
-            optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> ZSTD_FREQ_DIV);
-            optPtr->litSum += optPtr->litFreq[u];
-        }
+        assert(optPtr->symbolCosts != NULL);
+        if (optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid) { /* huffman table presumed generated by dictionary */
+            optPtr->priceType = zop_dynamic;
 
-        for (u=0; u<=MaxLL; u++)
-            optPtr->litLengthFreq[u] = 1;
-        optPtr->litLengthSum = MaxLL+1;
-        for (u=0; u<=MaxML; u++)
-            optPtr->matchLengthFreq[u] = 1;
-        optPtr->matchLengthSum = MaxML+1;
-        for (u=0; u<=MaxOff; u++)
-            optPtr->offCodeFreq[u] = 1;
-        optPtr->offCodeSum = (MaxOff+1);
+            assert(optPtr->litFreq != NULL);
+            optPtr->litSum = 0;
+            {   unsigned lit;
+                for (lit=0; lit<=MaxLit; lit++) {
+                    U32 const scaleLog = 11;   /* scale to 2K */
+                    U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->huf.CTable, lit);
+                    assert(bitCost <= scaleLog);
+                    optPtr->litFreq[lit] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+                    optPtr->litSum += optPtr->litFreq[lit];
+            }   }
 
-    } else {
-        unsigned u;
+            {   unsigned ll;
+                FSE_CState_t llstate;
+                FSE_initCState(&llstate, optPtr->symbolCosts->fse.litlengthCTable);
+                optPtr->litLengthSum = 0;
+                for (ll=0; ll<=MaxLL; ll++) {
+                    U32 const scaleLog = 10;   /* scale to 1K */
+                    U32 const bitCost = FSE_getMaxNbBits(llstate.symbolTT, ll);
+                    assert(bitCost < scaleLog);
+                    optPtr->litLengthFreq[ll] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+                    optPtr->litLengthSum += optPtr->litLengthFreq[ll];
+            }   }
 
-        optPtr->litSum = 0;
-        for (u=0; u<=MaxLit; u++) {
-            optPtr->litFreq[u] = 1 + (optPtr->litFreq[u] >> (ZSTD_FREQ_DIV+1));
-            optPtr->litSum += optPtr->litFreq[u];
+            {   unsigned ml;
+                FSE_CState_t mlstate;
+                FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable);
+                optPtr->matchLengthSum = 0;
+                for (ml=0; ml<=MaxML; ml++) {
+                    U32 const scaleLog = 10;
+                    U32 const bitCost = FSE_getMaxNbBits(mlstate.symbolTT, ml);
+                    assert(bitCost < scaleLog);
+                    optPtr->matchLengthFreq[ml] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+                    optPtr->matchLengthSum += optPtr->matchLengthFreq[ml];
+            }   }
+
+            {   unsigned of;
+                FSE_CState_t ofstate;
+                FSE_initCState(&ofstate, optPtr->symbolCosts->fse.offcodeCTable);
+                optPtr->offCodeSum = 0;
+                for (of=0; of<=MaxOff; of++) {
+                    U32 const scaleLog = 10;
+                    U32 const bitCost = FSE_getMaxNbBits(ofstate.symbolTT, of);
+                    assert(bitCost < scaleLog);
+                    optPtr->offCodeFreq[of] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
+                    optPtr->offCodeSum += optPtr->offCodeFreq[of];
+            }   }
+
+        } else {  /* not a dictionary */
+
+            assert(optPtr->litFreq != NULL);
+            {   unsigned lit = MaxLit;
+                HIST_count_simple(optPtr->litFreq, &lit, src, srcSize);   /* use raw first block to init statistics */
+            }
+            optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
+
+            {   unsigned ll;
+                for (ll=0; ll<=MaxLL; ll++)
+                    optPtr->litLengthFreq[ll] = 1;
+            }
+            optPtr->litLengthSum = MaxLL+1;
+
+            {   unsigned ml;
+                for (ml=0; ml<=MaxML; ml++)
+                    optPtr->matchLengthFreq[ml] = 1;
+            }
+            optPtr->matchLengthSum = MaxML+1;
+
+            {   unsigned of;
+                for (of=0; of<=MaxOff; of++)
+                    optPtr->offCodeFreq[of] = 1;
+            }
+            optPtr->offCodeSum = MaxOff+1;
+
         }
-        optPtr->litLengthSum = 0;
-        for (u=0; u<=MaxLL; u++) {
-            optPtr->litLengthFreq[u] = 1 + (optPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1));
-            optPtr->litLengthSum += optPtr->litLengthFreq[u];
-        }
-        optPtr->matchLengthSum = 0;
-        for (u=0; u<=MaxML; u++) {
-            optPtr->matchLengthFreq[u] = 1 + (optPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV);
-            optPtr->matchLengthSum += optPtr->matchLengthFreq[u];
-        }
-        optPtr->offCodeSum = 0;
-        for (u=0; u<=MaxOff; u++) {
-            optPtr->offCodeFreq[u] = 1 + (optPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV);
-            optPtr->offCodeSum += optPtr->offCodeFreq[u];
-        }
+
+    } else {   /* new block : re-use previous statistics, scaled down */
+
+        optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
+        optPtr->litLengthSum = ZSTD_downscaleStat(optPtr->litLengthFreq, MaxLL, 0);
+        optPtr->matchLengthSum = ZSTD_downscaleStat(optPtr->matchLengthFreq, MaxML, 0);
+        optPtr->offCodeSum = ZSTD_downscaleStat(optPtr->offCodeFreq, MaxOff, 0);
     }
 
-    ZSTD_setLog2Prices(optPtr);
+    ZSTD_setBasePrices(optPtr, optLevel);
 }
 
-
 /* ZSTD_rawLiteralsCost() :
- * cost of literals (only) in given segment (which length can be null)
- * does not include cost of literalLength symbol */
+ * price of literals (only) in specified segment (which length can be 0).
+ * does not include price of literalLength symbol */
 static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength,
-                                const optState_t* const optPtr)
+                                const optState_t* const optPtr,
+                                int optLevel)
 {
-    if (optPtr->staticPrices) return (litLength*6);  /* 6 bit per literal - no statistic used */
     if (litLength == 0) return 0;
+    if (optPtr->priceType == zop_predef)
+        return (litLength*6) * BITCOST_MULTIPLIER;  /* 6 bit per literal - no statistic used */
 
-    /* literals */
-    {   U32 u;
-        U32 cost = litLength * optPtr->log2litSum;
-        for (u=0; u < litLength; u++)
-            cost -= ZSTD_highbit32(optPtr->litFreq[literals[u]]+1);
-        return cost;
+    /* dynamic statistics */
+    {   U32 price = litLength * optPtr->litSumBasePrice;
+        U32 u;
+        for (u=0; u < litLength; u++) {
+            assert(WEIGHT(optPtr->litFreq[literals[u]], optLevel) <= optPtr->litSumBasePrice);   /* literal cost should never be negative */
+            price -= WEIGHT(optPtr->litFreq[literals[u]], optLevel);
+        }
+        return price;
     }
 }
 
 /* ZSTD_litLengthPrice() :
  * cost of literalLength symbol */
-static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr)
+static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr, int optLevel)
 {
-    if (optPtr->staticPrices) return ZSTD_highbit32((U32)litLength+1);
+    if (optPtr->priceType == zop_predef) return WEIGHT(litLength, optLevel);
 
-    /* literal Length */
+    /* dynamic statistics */
     {   U32 const llCode = ZSTD_LLcode(litLength);
-        U32 const price = LL_bits[llCode] + optPtr->log2litLengthSum - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
-        return price;
+        return (LL_bits[llCode] * BITCOST_MULTIPLIER) + (optPtr->litLengthSumBasePrice - WEIGHT(optPtr->litLengthFreq[llCode], optLevel));
     }
 }
 
-/* ZSTD_litLengthPrice() :
- * cost of the literal part of a sequence,
- * including literals themselves, and literalLength symbol */
-static U32 ZSTD_fullLiteralsCost(const BYTE* const literals, U32 const litLength,
-                                 const optState_t* const optPtr)
-{
-    return ZSTD_rawLiteralsCost(literals, litLength, optPtr)
-         + ZSTD_litLengthPrice(litLength, optPtr);
-}
-
 /* ZSTD_litLengthContribution() :
  * @return ( cost(litlength) - cost(0) )
  * this value can then be added to rawLiteralsCost()
  * to provide a cost which is directly comparable to a match ending at same position */
-static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr)
+static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr, int optLevel)
 {
-    if (optPtr->staticPrices) return ZSTD_highbit32(litLength+1);
+    if (optPtr->priceType >= zop_predef) return WEIGHT(litLength, optLevel);
 
-    /* literal Length */
+    /* dynamic statistics */
     {   U32 const llCode = ZSTD_LLcode(litLength);
-        int const contribution = LL_bits[llCode]
-                        + ZSTD_highbit32(optPtr->litLengthFreq[0]+1)
-                        - ZSTD_highbit32(optPtr->litLengthFreq[llCode]+1);
+        int const contribution = (LL_bits[llCode] * BITCOST_MULTIPLIER)
+                               + WEIGHT(optPtr->litLengthFreq[0], optLevel)   /* note: log2litLengthSum cancel out */
+                               - WEIGHT(optPtr->litLengthFreq[llCode], optLevel);
 #if 1
         return contribution;
 #else
         return MAX(0, contribution); /* sometimes better, sometimes not ... */
 #endif
     }
 }
 
 /* ZSTD_literalsContribution() :
  * creates a fake cost for the literals part of a sequence
  * which can be compared to the ending cost of a match
  * should a new match start at this position */
 static int ZSTD_literalsContribution(const BYTE* const literals, U32 const litLength,
-                                     const optState_t* const optPtr)
+                                     const optState_t* const optPtr,
+                                     int optLevel)
 {
-    int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr)
-                           + ZSTD_litLengthContribution(litLength, optPtr);
+    int const contribution = ZSTD_rawLiteralsCost(literals, litLength, optPtr, optLevel)
+                           + ZSTD_litLengthContribution(litLength, optPtr, optLevel);
     return contribution;
 }
 
 /* ZSTD_getMatchPrice() :
  * Provides the cost of the match part (offset + matchLength) of a sequence
  * Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence.
  * optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */
-FORCE_INLINE_TEMPLATE U32 ZSTD_getMatchPrice(
-                                    U32 const offset, U32 const matchLength,
-                                    const optState_t* const optPtr,
-                                    int const optLevel)
+FORCE_INLINE_TEMPLATE U32
+ZSTD_getMatchPrice(U32 const offset,
+                   U32 const matchLength,
+                   const optState_t* const optPtr,
+                   int const optLevel)
 {
     U32 price;
     U32 const offCode = ZSTD_highbit32(offset+1);
     U32 const mlBase = matchLength - MINMATCH;
     assert(matchLength >= MINMATCH);
 
-    if (optPtr->staticPrices)  /* fixed scheme, do not use statistics */
-        return ZSTD_highbit32((U32)mlBase+1) + 16 + offCode;
+    if (optPtr->priceType == zop_predef)  /* fixed scheme, do not use statistics */
+        return WEIGHT(mlBase, optLevel) + ((16 + offCode) * BITCOST_MULTIPLIER);
 
-    price = offCode + optPtr->log2offCodeSum - ZSTD_highbit32(optPtr->offCodeFreq[offCode]+1);
-    if ((optLevel<2) /*static*/ && offCode >= 20) price += (offCode-19)*2; /* handicap for long distance offsets, favor decompression speed */
+    /* dynamic statistics */
+    price = (offCode * BITCOST_MULTIPLIER) + (optPtr->offCodeSumBasePrice - WEIGHT(optPtr->offCodeFreq[offCode], optLevel));
+    if ((optLevel<2) /*static*/ && offCode >= 20)
+        price += (offCode-19)*2 * BITCOST_MULTIPLIER; /* handicap for long distance offsets, favor decompression speed */
 
     /* match Length */
     {   U32 const mlCode = ZSTD_MLcode(mlBase);
-        price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
+        price += (ML_bits[mlCode] * BITCOST_MULTIPLIER) + (optPtr->matchLengthSumBasePrice - WEIGHT(optPtr->matchLengthFreq[mlCode], optLevel));
     }
 
+    price += BITCOST_MULTIPLIER / 5;   /* heuristic : make matches a bit more costly to favor less sequences -> faster decompression speed */
+
     DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price);
     return price;
 }
 
+/* ZSTD_updateStats() :
+ * assumption : literals + litLengtn <= iend */
 static void ZSTD_updateStats(optState_t* const optPtr,
                              U32 litLength, const BYTE* literals,
                              U32 offsetCode, U32 matchLength)
 {
     /* literals */
     {   U32 u;
         for (u=0; u < litLength; u++)
             optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
         optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
     }
 
     /* literal Length */
     {   U32 const llCode = ZSTD_LLcode(litLength);
         optPtr->litLengthFreq[llCode]++;
         optPtr->litLengthSum++;
     }
 
     /* match offset code (0-2=>repCode; 3+=>offset+2) */
     {   U32 const offCode = ZSTD_highbit32(offsetCode+1);
         assert(offCode <= MaxOff);
         optPtr->offCodeFreq[offCode]++;
         optPtr->offCodeSum++;
     }
 
     /* match Length */
     {   U32 const mlBase = matchLength - MINMATCH;
         U32 const mlCode = ZSTD_MLcode(mlBase);
         optPtr->matchLengthFreq[mlCode]++;
         optPtr->matchLengthSum++;
     }
 }
 
 
 /* ZSTD_readMINMATCH() :
  * function safe only for comparisons
  * assumption : memPtr must be at least 4 bytes before end of buffer */
 MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
 {
     switch (length)
     {
     default :
     case 4 : return MEM_read32(memPtr);
     case 3 : if (MEM_isLittleEndian())
                 return MEM_read32(memPtr)<<8;
              else
                 return MEM_read32(memPtr)>>8;
     }
 }
 
 
 /* Update hashTable3 up to ip (excluded)
    Assumption : always within prefix (i.e. not within extDict) */
 static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms, const BYTE* const ip)
 {
     U32* const hashTable3 = ms->hashTable3;
     U32 const hashLog3 = ms->hashLog3;
     const BYTE* const base = ms->window.base;
     U32 idx = ms->nextToUpdate3;
     U32 const target = ms->nextToUpdate3 = (U32)(ip - base);
     size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3);
     assert(hashLog3 > 0);
 
     while(idx < target) {
         hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
         idx++;
     }
 
     return hashTable3[hash3];
 }
 
 
 /*-*************************************
 *  Binary Tree search
 ***************************************/
 /** ZSTD_insertBt1() : add one or multiple positions to tree.
  *  ip : assumed <= iend-8 .
  * @return : nb of positions added */
 static U32 ZSTD_insertBt1(
-                ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                ZSTD_matchState_t* ms,
                 const BYTE* const ip, const BYTE* const iend,
-                U32 const mls, U32 const extDict)
+                U32 const mls, const int extDict)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32*   const hashTable = ms->hashTable;
     U32    const hashLog = cParams->hashLog;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32*   const bt = ms->chainTable;
     U32    const btLog  = cParams->chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     U32 matchIndex = hashTable[h];
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const U32 dictLimit = ms->window.dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* match;
     const U32 current = (U32)(ip-base);
     const U32 btLow = btMask >= current ? 0 : current - btMask;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = smallerPtr + 1;
     U32 dummy32;   /* to be nullified at the end */
     U32 const windowLow = ms->window.lowLimit;
+    U32 const matchLow = windowLow ? windowLow : 1;
     U32 matchEndIdx = current+8+1;
     size_t bestLength = 8;
     U32 nbCompares = 1U << cParams->searchLog;
 #ifdef ZSTD_C_PREDICT
     U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0);
     U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1);
     predictedSmall += (predictedSmall>0);
     predictedLarge += (predictedLarge>0);
 #endif /* ZSTD_C_PREDICT */
 
     DEBUGLOG(8, "ZSTD_insertBt1 (%u)", current);
 
     assert(ip <= iend-8);   /* required for h calculation */
     hashTable[h] = current;   /* Update Hash Table */
 
-    while (nbCompares-- && (matchIndex > windowLow)) {
+    while (nbCompares-- && (matchIndex >= matchLow)) {
         U32* const nextPtr = bt + 2*(matchIndex & btMask);
         size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         assert(matchIndex < current);
 
 #ifdef ZSTD_C_PREDICT   /* note : can create issues when hlog small <= 11 */
         const U32* predictPtr = bt + 2*((matchIndex-1) & btMask);   /* written this way, as bt is a roll buffer */
         if (matchIndex == predictedSmall) {
             /* no need to check length, result known */
             *smallerPtr = matchIndex;
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             smallerPtr = nextPtr+1;               /* new "smaller" => larger of match */
             matchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
             predictedSmall = predictPtr[1] + (predictPtr[1]>0);
             continue;
         }
         if (matchIndex == predictedLarge) {
             *largerPtr = matchIndex;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
             predictedLarge = predictPtr[0] + (predictPtr[0]>0);
             continue;
         }
 #endif
 
-        if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
-            assert(matchIndex+matchLength >= dictLimit);   /* might be wrong if extDict is incorrectly set to 0 */
+        if (!extDict || (matchIndex+matchLength >= dictLimit)) {
+            assert(matchIndex+matchLength >= dictLimit);   /* might be wrong if actually extDict */
             match = base + matchIndex;
             matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
         } else {
             match = dictBase + matchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
             if (matchIndex+matchLength >= dictLimit)
                 match = base + matchIndex;   /* to prepare for next usage of match[matchLength] */
         }
 
         if (matchLength > bestLength) {
             bestLength = matchLength;
             if (matchLength > matchEndIdx - matchIndex)
                 matchEndIdx = matchIndex + (U32)matchLength;
         }
 
         if (ip+matchLength == iend) {   /* equal : no way to know if inf or sup */
             break;   /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
         }
 
         if (match[matchLength] < ip[matchLength]) {  /* necessarily within buffer */
             /* match is smaller than current */
             *smallerPtr = matchIndex;             /* update smaller idx */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             smallerPtr = nextPtr+1;               /* new "candidate" => larger than match, which was smaller than target */
             matchIndex = nextPtr[1];              /* new matchIndex, larger than previous and closer to current */
         } else {
             /* match is larger than current */
             *largerPtr = matchIndex;
             commonLengthLarger = matchLength;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
     }   }
 
     *smallerPtr = *largerPtr = 0;
     if (bestLength > 384) return MIN(192, (U32)(bestLength - 384));   /* speed optimization */
     assert(matchEndIdx > current + 8);
     return matchEndIdx - (current + 8);
 }
 
 FORCE_INLINE_TEMPLATE
 void ZSTD_updateTree_internal(
-                ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
+                ZSTD_matchState_t* ms,
                 const BYTE* const ip, const BYTE* const iend,
-                const U32 mls, const U32 extDict)
+                const U32 mls, const ZSTD_dictMode_e dictMode)
 {
     const BYTE* const base = ms->window.base;
     U32 const target = (U32)(ip - base);
     U32 idx = ms->nextToUpdate;
-    DEBUGLOG(7, "ZSTD_updateTree_internal, from %u to %u  (extDict:%u)",
-                idx, target, extDict);
+    DEBUGLOG(5, "ZSTD_updateTree_internal, from %u to %u  (dictMode:%u)",
+                idx, target, dictMode);
 
     while(idx < target)
-        idx += ZSTD_insertBt1(ms, cParams, base+idx, iend, mls, extDict);
+        idx += ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict);
     ms->nextToUpdate = target;
 }
 
-void ZSTD_updateTree(
-                ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                const BYTE* ip, const BYTE* iend)
-{
-    ZSTD_updateTree_internal(ms, cParams, ip, iend, cParams->searchLength, 0 /*extDict*/);
+void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend) {
+    ZSTD_updateTree_internal(ms, ip, iend, ms->cParams.searchLength, ZSTD_noDict);
 }
 
 FORCE_INLINE_TEMPLATE
 U32 ZSTD_insertBtAndGetAllMatches (
-                    ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                    const BYTE* const ip, const BYTE* const iLimit, int const extDict,
+                    ZSTD_matchState_t* ms,
+                    const BYTE* const ip, const BYTE* const iLimit, const ZSTD_dictMode_e dictMode,
                     U32 rep[ZSTD_REP_NUM], U32 const ll0,
                     ZSTD_match_t* matches, const U32 lengthToBeat, U32 const mls /* template */)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
     const BYTE* const base = ms->window.base;
     U32 const current = (U32)(ip-base);
     U32 const hashLog = cParams->hashLog;
     U32 const minMatch = (mls==3) ? 3 : 4;
     U32* const hashTable = ms->hashTable;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32 matchIndex  = hashTable[h];
     U32* const bt   = ms->chainTable;
     U32 const btLog = cParams->chainLog - 1;
     U32 const btMask= (1U << btLog) - 1;
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const dictBase = ms->window.dictBase;
     U32 const dictLimit = ms->window.dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     U32 const btLow = btMask >= current ? 0 : current - btMask;
     U32 const windowLow = ms->window.lowLimit;
+    U32 const matchLow = windowLow ? windowLow : 1;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = bt + 2*(current&btMask) + 1;
     U32 matchEndIdx = current+8+1;   /* farthest referenced position of any match => detects repetitive patterns */
     U32 dummy32;   /* to be nullified at the end */
     U32 mnum = 0;
     U32 nbCompares = 1U << cParams->searchLog;
 
+    const ZSTD_matchState_t* dms    = dictMode == ZSTD_dictMatchState ? ms->dictMatchState : NULL;
+    const ZSTD_compressionParameters* const dmsCParams =
+                                      dictMode == ZSTD_dictMatchState ? &dms->cParams : NULL;
+    const BYTE* const dmsBase       = dictMode == ZSTD_dictMatchState ? dms->window.base : NULL;
+    const BYTE* const dmsEnd        = dictMode == ZSTD_dictMatchState ? dms->window.nextSrc : NULL;
+    U32         const dmsHighLimit  = dictMode == ZSTD_dictMatchState ? (U32)(dmsEnd - dmsBase) : 0;
+    U32         const dmsLowLimit   = dictMode == ZSTD_dictMatchState ? dms->window.lowLimit : 0;
+    U32         const dmsIndexDelta = dictMode == ZSTD_dictMatchState ? windowLow - dmsHighLimit : 0;
+    U32         const dmsHashLog    = dictMode == ZSTD_dictMatchState ? dmsCParams->hashLog : hashLog;
+    U32         const dmsBtLog      = dictMode == ZSTD_dictMatchState ? dmsCParams->chainLog - 1 : btLog;
+    U32         const dmsBtMask     = dictMode == ZSTD_dictMatchState ? (1U << dmsBtLog) - 1 : 0;
+    U32         const dmsBtLow      = dictMode == ZSTD_dictMatchState && dmsBtMask < dmsHighLimit - dmsLowLimit ? dmsHighLimit - dmsBtMask : dmsLowLimit;
+
     size_t bestLength = lengthToBeat-1;
-    DEBUGLOG(7, "ZSTD_insertBtAndGetAllMatches");
+    DEBUGLOG(8, "ZSTD_insertBtAndGetAllMatches: current=%u", current);
 
     /* check repCode */
     {   U32 const lastR = ZSTD_REP_NUM + ll0;
         U32 repCode;
         for (repCode = ll0; repCode < lastR; repCode++) {
             U32 const repOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
             U32 const repIndex = current - repOffset;
             U32 repLen = 0;
             assert(current >= dictLimit);
             if (repOffset-1 /* intentional overflow, discards 0 and -1 */ < current-dictLimit) {  /* equivalent to `current > repIndex >= dictLimit` */
                 if (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch)) {
                     repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch;
                 }
             } else {  /* repIndex < dictLimit || repIndex >= current */
-                const BYTE* const repMatch = dictBase + repIndex;
+                const BYTE* const repMatch = dictMode == ZSTD_dictMatchState ?
+                                             dmsBase + repIndex - dmsIndexDelta :
+                                             dictBase + repIndex;
                 assert(current >= windowLow);
-                if ( extDict /* this case only valid in extDict mode */
+                if ( dictMode == ZSTD_extDict
                   && ( ((repOffset-1) /*intentional overflow*/ < current - windowLow)  /* equivalent to `current > repIndex >= windowLow` */
                      & (((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */)
                   && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
                     repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dictEnd, prefixStart) + minMatch;
+                }
+                if (dictMode == ZSTD_dictMatchState
+                  && ( ((repOffset-1) /*intentional overflow*/ < current - (dmsLowLimit + dmsIndexDelta))  /* equivalent to `current > repIndex >= dmsLowLimit` */
+                     & ((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */
+                  && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
+                    repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dmsEnd, prefixStart) + minMatch;
             }   }
             /* save longer solution */
             if (repLen > bestLength) {
-                DEBUGLOG(8, "found rep-match %u of length %u",
-                            repCode - ll0, (U32)repLen);
+                DEBUGLOG(8, "found repCode %u (ll0:%u, offset:%u) of length %u",
+                            repCode, ll0, repOffset, repLen);
                 bestLength = repLen;
                 matches[mnum].off = repCode - ll0;
                 matches[mnum].len = (U32)repLen;
                 mnum++;
                 if ( (repLen > sufficient_len)
                    | (ip+repLen == iLimit) ) {  /* best possible */
                     return mnum;
     }   }   }   }
 
     /* HC3 match finder */
     if ((mls == 3) /*static*/ && (bestLength < mls)) {
         U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, ip);
-        if ((matchIndex3 > windowLow)
+        if ((matchIndex3 >= matchLow)
           & (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) {
             size_t mlen;
-            if ((!extDict) /*static*/ || (matchIndex3 >= dictLimit)) {
+            if ((dictMode == ZSTD_noDict) /*static*/ || (dictMode == ZSTD_dictMatchState) /*static*/ || (matchIndex3 >= dictLimit)) {
                 const BYTE* const match = base + matchIndex3;
                 mlen = ZSTD_count(ip, match, iLimit);
             } else {
                 const BYTE* const match = dictBase + matchIndex3;
                 mlen = ZSTD_count_2segments(ip, match, iLimit, dictEnd, prefixStart);
             }
 
             /* save best solution */
             if (mlen >= mls /* == 3 > bestLength */) {
                 DEBUGLOG(8, "found small match with hlog3, of length %u",
                             (U32)mlen);
                 bestLength = mlen;
                 assert(current > matchIndex3);
                 assert(mnum==0);  /* no prior solution */
                 matches[0].off = (current - matchIndex3) + ZSTD_REP_MOVE;
                 matches[0].len = (U32)mlen;
                 mnum = 1;
                 if ( (mlen > sufficient_len) |
                      (ip+mlen == iLimit) ) {  /* best possible length */
                     ms->nextToUpdate = current+1;  /* skip insertion */
                     return 1;
-    }   }   }   }
+                }
+            }
+        }
+        /* no dictMatchState lookup: dicts don't have a populated HC3 table */
+    }
 
     hashTable[h] = current;   /* Update Hash Table */
 
-    while (nbCompares-- && (matchIndex > windowLow)) {
+    while (nbCompares-- && (matchIndex >= matchLow)) {
         U32* const nextPtr = bt + 2*(matchIndex & btMask);
         size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         const BYTE* match;
         assert(current > matchIndex);
 
-        if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
+        if ((dictMode == ZSTD_noDict) || (dictMode == ZSTD_dictMatchState) || (matchIndex+matchLength >= dictLimit)) {
             assert(matchIndex+matchLength >= dictLimit);  /* ensure the condition is correct when !extDict */
             match = base + matchIndex;
             matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit);
         } else {
             match = dictBase + matchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart);
             if (matchIndex+matchLength >= dictLimit)
                 match = base + matchIndex;   /* prepare for match[matchLength] */
         }
 
         if (matchLength > bestLength) {
-            DEBUGLOG(8, "found match of length %u at distance %u",
-                    (U32)matchLength, current - matchIndex);
+            DEBUGLOG(8, "found match of length %u at distance %u (offCode=%u)",
+                    (U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE);
             assert(matchEndIdx > matchIndex);
             if (matchLength > matchEndIdx - matchIndex)
                 matchEndIdx = matchIndex + (U32)matchLength;
             bestLength = matchLength;
             matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE;
             matches[mnum].len = (U32)matchLength;
             mnum++;
-            if (matchLength > ZSTD_OPT_NUM) break;
-            if (ip+matchLength == iLimit) {  /* equal : no way to know if inf or sup */
-                break;   /* drop, to preserve bt consistency (miss a little bit of compression) */
+            if ( (matchLength > ZSTD_OPT_NUM)
+               | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
+                if (dictMode == ZSTD_dictMatchState) nbCompares = 0; /* break should also skip searching dms */
+                break; /* drop, to preserve bt consistency (miss a little bit of compression) */
             }
         }
 
         if (match[matchLength] < ip[matchLength]) {
             /* match smaller than current */
             *smallerPtr = matchIndex;             /* update smaller idx */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             smallerPtr = nextPtr+1;               /* new candidate => larger than match, which was smaller than current */
             matchIndex = nextPtr[1];              /* new matchIndex, larger than previous, closer to current */
         } else {
             *largerPtr = matchIndex;
             commonLengthLarger = matchLength;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
     }   }
 
     *smallerPtr = *largerPtr = 0;
 
+    if (dictMode == ZSTD_dictMatchState && nbCompares) {
+        size_t const dmsH = ZSTD_hashPtr(ip, dmsHashLog, mls);
+        U32 dictMatchIndex = dms->hashTable[dmsH];
+        const U32* const dmsBt = dms->chainTable;
+        commonLengthSmaller = commonLengthLarger = 0;
+        while (nbCompares-- && (dictMatchIndex > dmsLowLimit)) {
+            const U32* const nextPtr = dmsBt + 2*(dictMatchIndex & dmsBtMask);
+            size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
+            const BYTE* match = dmsBase + dictMatchIndex;
+            matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dmsEnd, prefixStart);
+            if (dictMatchIndex+matchLength >= dmsHighLimit)
+                match = base + dictMatchIndex + dmsIndexDelta;   /* to prepare for next usage of match[matchLength] */
+
+            if (matchLength > bestLength) {
+                matchIndex = dictMatchIndex + dmsIndexDelta;
+                DEBUGLOG(8, "found dms match of length %u at distance %u (offCode=%u)",
+                        (U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE);
+                if (matchLength > matchEndIdx - matchIndex)
+                    matchEndIdx = matchIndex + (U32)matchLength;
+                bestLength = matchLength;
+                matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE;
+                matches[mnum].len = (U32)matchLength;
+                mnum++;
+                if ( (matchLength > ZSTD_OPT_NUM)
+                   | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
+                    break;   /* drop, to guarantee consistency (miss a little bit of compression) */
+                }
+            }
+
+            if (dictMatchIndex <= dmsBtLow) { break; }   /* beyond tree size, stop the search */
+            if (match[matchLength] < ip[matchLength]) {
+                commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
+                dictMatchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
+            } else {
+                /* match is larger than current */
+                commonLengthLarger = matchLength;
+                dictMatchIndex = nextPtr[0];
+            }
+        }
+    }
+
     assert(matchEndIdx > current+8);
     ms->nextToUpdate = matchEndIdx - 8;  /* skip repetitive patterns */
     return mnum;
 }
 
 
 FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
-                        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-                        const BYTE* ip, const BYTE* const iHighLimit, int const extDict,
+                        ZSTD_matchState_t* ms,
+                        const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode,
                         U32 rep[ZSTD_REP_NUM], U32 const ll0,
                         ZSTD_match_t* matches, U32 const lengthToBeat)
 {
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32 const matchLengthSearch = cParams->searchLength;
-    DEBUGLOG(7, "ZSTD_BtGetAllMatches");
+    DEBUGLOG(8, "ZSTD_BtGetAllMatches");
     if (ip < ms->window.base + ms->nextToUpdate) return 0;   /* skipped area */
-    ZSTD_updateTree_internal(ms, cParams, ip, iHighLimit, matchLengthSearch, extDict);
+    ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode);
     switch(matchLengthSearch)
     {
-    case 3 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 3);
+    case 3 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 3);
     default :
-    case 4 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 4);
-    case 5 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 5);
+    case 4 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 4);
+    case 5 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 5);
     case 7 :
-    case 6 : return ZSTD_insertBtAndGetAllMatches(ms, cParams, ip, iHighLimit, extDict, rep, ll0, matches, lengthToBeat, 6);
+    case 6 : return ZSTD_insertBtAndGetAllMatches(ms, ip, iHighLimit, dictMode, rep, ll0, matches, lengthToBeat, 6);
     }
 }
 
 
 /*-*******************************
 *  Optimal parser
 *********************************/
 typedef struct repcodes_s {
     U32 rep[3];
 } repcodes_t;
 
-repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0)
+static repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0)
 {
     repcodes_t newReps;
     if (offset >= ZSTD_REP_NUM) {  /* full offset */
         newReps.rep[2] = rep[1];
         newReps.rep[1] = rep[0];
         newReps.rep[0] = offset - ZSTD_REP_MOVE;
     } else {   /* repcode */
         U32 const repCode = offset + ll0;
         if (repCode > 0) {  /* note : if repCode==0, no change */
             U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
             newReps.rep[2] = (repCode >= 2) ? rep[1] : rep[2];
             newReps.rep[1] = rep[0];
             newReps.rep[0] = currentOffset;
         } else {   /* repCode == 0 */
             memcpy(&newReps, rep, sizeof(newReps));
         }
     }
     return newReps;
 }
 
 
-typedef struct {
-    const BYTE* anchor;
-    U32 litlen;
-    U32 rawLitCost;
-} cachedLiteralPrice_t;
-
-static U32 ZSTD_rawLiteralsCost_cached(
-                            cachedLiteralPrice_t* const cachedLitPrice,
-                            const BYTE* const anchor, U32 const litlen,
-                            const optState_t* const optStatePtr)
+static U32 ZSTD_totalLen(ZSTD_optimal_t sol)
 {
-    U32 startCost;
-    U32 remainingLength;
-    const BYTE* startPosition;
-
-    if (anchor == cachedLitPrice->anchor) {
-        startCost = cachedLitPrice->rawLitCost;
-        startPosition = anchor + cachedLitPrice->litlen;
-        assert(litlen >= cachedLitPrice->litlen);
-        remainingLength = litlen - cachedLitPrice->litlen;
-    } else {
-        startCost = 0;
-        startPosition = anchor;
-        remainingLength = litlen;
-    }
-
-    {   U32 const rawLitCost = startCost + ZSTD_rawLiteralsCost(startPosition, remainingLength, optStatePtr);
-        cachedLitPrice->anchor = anchor;
-        cachedLitPrice->litlen = litlen;
-        cachedLitPrice->rawLitCost = rawLitCost;
-        return rawLitCost;
-    }
+    return sol.litlen + sol.mlen;
 }
 
-static U32 ZSTD_fullLiteralsCost_cached(
-                            cachedLiteralPrice_t* const cachedLitPrice,
-                            const BYTE* const anchor, U32 const litlen,
-                            const optState_t* const optStatePtr)
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
+                               seqStore_t* seqStore,
+                               U32 rep[ZSTD_REP_NUM],
+                               const void* src, size_t srcSize,
+                               const int optLevel, const ZSTD_dictMode_e dictMode)
 {
-    return ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr)
-         + ZSTD_litLengthPrice(litlen, optStatePtr);
-}
-
-static int ZSTD_literalsContribution_cached(
-                            cachedLiteralPrice_t* const cachedLitPrice,
-                            const BYTE* const anchor, U32 const litlen,
-                            const optState_t* const optStatePtr)
-{
-    int const contribution = ZSTD_rawLiteralsCost_cached(cachedLitPrice, anchor, litlen, optStatePtr)
-                           + ZSTD_litLengthContribution(litlen, optStatePtr);
-    return contribution;
-}
-
-FORCE_INLINE_TEMPLATE
-size_t ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,seqStore_t* seqStore,
-                                      U32 rep[ZSTD_REP_NUM],
-                                      ZSTD_compressionParameters const* cParams,
-                                      const void* src, size_t srcSize,
-                                      const int optLevel, const int extDict)
-{
     optState_t* const optStatePtr = &ms->opt;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     const BYTE* const base = ms->window.base;
     const BYTE* const prefixStart = base + ms->window.dictLimit;
+    const ZSTD_compressionParameters* const cParams = &ms->cParams;
 
     U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
     U32 const minMatch = (cParams->searchLength == 3) ? 3 : 4;
 
     ZSTD_optimal_t* const opt = optStatePtr->priceTable;
     ZSTD_match_t* const matches = optStatePtr->matchTable;
-    cachedLiteralPrice_t cachedLitPrice;
+    ZSTD_optimal_t lastSequence;
 
     /* init */
     DEBUGLOG(5, "ZSTD_compressBlock_opt_generic");
+    assert(optLevel <= 2);
     ms->nextToUpdate3 = ms->nextToUpdate;
-    ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize);
+    ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize, optLevel);
     ip += (ip==prefixStart);
-    memset(&cachedLitPrice, 0, sizeof(cachedLitPrice));
 
     /* Match Loop */
     while (ip < ilimit) {
         U32 cur, last_pos = 0;
-        U32 best_mlen, best_off;
 
         /* find first match */
         {   U32 const litlen = (U32)(ip - anchor);
             U32 const ll0 = !litlen;
-            U32 const nbMatches = ZSTD_BtGetAllMatches(ms, cParams, ip, iend, extDict, rep, ll0, matches, minMatch);
+            U32 const nbMatches = ZSTD_BtGetAllMatches(ms, ip, iend, dictMode, rep, ll0, matches, minMatch);
             if (!nbMatches) { ip++; continue; }
 
             /* initialize opt[0] */
             { U32 i ; for (i=0; i immediate encoding */
             {   U32 const maxML = matches[nbMatches-1].len;
-                DEBUGLOG(7, "found %u matches of maxLength=%u and offset=%u at cPos=%u => start new serie",
-                            nbMatches, maxML, matches[nbMatches-1].off, (U32)(ip-prefixStart));
+                U32 const maxOffset = matches[nbMatches-1].off;
+                DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new serie",
+                            nbMatches, maxML, maxOffset, (U32)(ip-prefixStart));
 
                 if (maxML > sufficient_len) {
-                    best_mlen = maxML;
-                    best_off = matches[nbMatches-1].off;
-                    DEBUGLOG(7, "large match (%u>%u), immediate encoding",
-                                best_mlen, sufficient_len);
+                    lastSequence.litlen = litlen;
+                    lastSequence.mlen = maxML;
+                    lastSequence.off = maxOffset;
+                    DEBUGLOG(6, "large match (%u>%u), immediate encoding",
+                                maxML, sufficient_len);
                     cur = 0;
-                    last_pos = 1;
+                    last_pos = ZSTD_totalLen(lastSequence);
                     goto _shortestPath;
             }   }
 
             /* set prices for first matches starting position == 0 */
-            {   U32 const literalsPrice = ZSTD_fullLiteralsCost_cached(&cachedLitPrice, anchor, litlen, optStatePtr);
+            {   U32 const literalsPrice = opt[0].price + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
                 U32 pos;
                 U32 matchNb;
-                for (pos = 0; pos < minMatch; pos++) {
-                    opt[pos].mlen = 1;
-                    opt[pos].price = ZSTD_MAX_PRICE;
+                for (pos = 1; pos < minMatch; pos++) {
+                    opt[pos].price = ZSTD_MAX_PRICE;   /* mlen, litlen and price will be fixed during forward scanning */
                 }
                 for (matchNb = 0; matchNb < nbMatches; matchNb++) {
                     U32 const offset = matches[matchNb].off;
                     U32 const end = matches[matchNb].len;
                     repcodes_t const repHistory = ZSTD_updateRep(rep, offset, ll0);
                     for ( ; pos <= end ; pos++ ) {
-                        U32 const matchPrice = literalsPrice + ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
-                        DEBUGLOG(7, "rPos:%u => set initial price : %u",
-                                    pos, matchPrice);
+                        U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
+                        U32 const sequencePrice = literalsPrice + matchPrice;
+                        DEBUGLOG(7, "rPos:%u => set initial price : %.2f",
+                                    pos, ZSTD_fCost(sequencePrice));
                         opt[pos].mlen = pos;
                         opt[pos].off = offset;
                         opt[pos].litlen = litlen;
-                        opt[pos].price = matchPrice;
+                        opt[pos].price = sequencePrice;
+                        ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
                         memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
                 }   }
                 last_pos = pos-1;
             }
         }
 
         /* check further positions */
         for (cur = 1; cur <= last_pos; cur++) {
             const BYTE* const inr = ip + cur;
             assert(cur < ZSTD_OPT_NUM);
+            DEBUGLOG(7, "cPos:%zi==rPos:%u", inr-istart, cur)
 
             /* Fix current position with one literal if cheaper */
-            {   U32 const litlen = (opt[cur-1].mlen == 1) ? opt[cur-1].litlen + 1 : 1;
-                int price;  /* note : contribution can be negative */
-                if (cur > litlen) {
-                    price = opt[cur - litlen].price + ZSTD_literalsContribution(inr-litlen, litlen, optStatePtr);
-                } else {
-                    price = ZSTD_literalsContribution_cached(&cachedLitPrice, anchor, litlen, optStatePtr);
-                }
+            {   U32 const litlen = (opt[cur-1].mlen == 0) ? opt[cur-1].litlen + 1 : 1;
+                int const price = opt[cur-1].price
+                                + ZSTD_rawLiteralsCost(ip+cur-1, 1, optStatePtr, optLevel)
+                                + ZSTD_litLengthPrice(litlen, optStatePtr, optLevel)
+                                - ZSTD_litLengthPrice(litlen-1, optStatePtr, optLevel);
                 assert(price < 1000000000); /* overflow check */
                 if (price <= opt[cur].price) {
-                    DEBUGLOG(7, "rPos:%u : better price (%u<%u) using literal",
-                                cur, price, opt[cur].price);
-                    opt[cur].mlen = 1;
+                    DEBUGLOG(7, "cPos:%zi==rPos:%u : better price (%.2f<=%.2f) using literal (ll==%u) (hist:%u,%u,%u)",
+                                inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), litlen,
+                                opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]);
+                    opt[cur].mlen = 0;
                     opt[cur].off = 0;
                     opt[cur].litlen = litlen;
                     opt[cur].price = price;
                     memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep));
-            }   }
+                } else {
+                    DEBUGLOG(7, "cPos:%zi==rPos:%u : literal would cost more (%.2f>%.2f) (hist:%u,%u,%u)",
+                                inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price),
+                                opt[cur].rep[0], opt[cur].rep[1], opt[cur].rep[2]);
+                }
+            }
 
             /* last match must start at a minimum distance of 8 from oend */
             if (inr > ilimit) continue;
 
             if (cur == last_pos) break;
 
-             if ( (optLevel==0) /*static*/
-               && (opt[cur+1].price <= opt[cur].price) )
+            if ( (optLevel==0) /*static_test*/
+              && (opt[cur+1].price <= opt[cur].price + (BITCOST_MULTIPLIER/2)) ) {
+                DEBUGLOG(7, "move to next rPos:%u : price is <=", cur+1);
                 continue;  /* skip unpromising positions; about ~+6% speed, -0.01 ratio */
+            }
 
-            {   U32 const ll0 = (opt[cur].mlen != 1);
-                U32 const litlen = (opt[cur].mlen == 1) ? opt[cur].litlen : 0;
-                U32 const previousPrice = (cur > litlen) ? opt[cur-litlen].price : 0;
-                U32 const basePrice = previousPrice + ZSTD_fullLiteralsCost(inr-litlen, litlen, optStatePtr);
-                U32 const nbMatches = ZSTD_BtGetAllMatches(ms, cParams, inr, iend, extDict, opt[cur].rep, ll0, matches, minMatch);
+            {   U32 const ll0 = (opt[cur].mlen != 0);
+                U32 const litlen = (opt[cur].mlen == 0) ? opt[cur].litlen : 0;
+                U32 const previousPrice = opt[cur].price;
+                U32 const basePrice = previousPrice + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
+                U32 const nbMatches = ZSTD_BtGetAllMatches(ms, inr, iend, dictMode, opt[cur].rep, ll0, matches, minMatch);
                 U32 matchNb;
-                if (!nbMatches) continue;
+                if (!nbMatches) {
+                    DEBUGLOG(7, "rPos:%u : no match found", cur);
+                    continue;
+                }
 
                 {   U32 const maxML = matches[nbMatches-1].len;
-                    DEBUGLOG(7, "rPos:%u, found %u matches, of maxLength=%u",
-                                cur, nbMatches, maxML);
+                    DEBUGLOG(7, "cPos:%zi==rPos:%u, found %u matches, of maxLength=%u",
+                                inr-istart, cur, nbMatches, maxML);
 
                     if ( (maxML > sufficient_len)
-                       | (cur + maxML >= ZSTD_OPT_NUM) ) {
-                        best_mlen = maxML;
-                        best_off = matches[nbMatches-1].off;
-                        last_pos = cur + 1;
+                      || (cur + maxML >= ZSTD_OPT_NUM) ) {
+                        lastSequence.mlen = maxML;
+                        lastSequence.off = matches[nbMatches-1].off;
+                        lastSequence.litlen = litlen;
+                        cur -= (opt[cur].mlen==0) ? opt[cur].litlen : 0;  /* last sequence is actually only literals, fix cur to last match - note : may underflow, in which case, it's first sequence, and it's okay */
+                        last_pos = cur + ZSTD_totalLen(lastSequence);
+                        if (cur > ZSTD_OPT_NUM) cur = 0;   /* underflow => first match */
                         goto _shortestPath;
-                    }
-                }
+                }   }
 
                 /* set prices using matches found at position == cur */
                 for (matchNb = 0; matchNb < nbMatches; matchNb++) {
                     U32 const offset = matches[matchNb].off;
                     repcodes_t const repHistory = ZSTD_updateRep(opt[cur].rep, offset, ll0);
                     U32 const lastML = matches[matchNb].len;
                     U32 const startML = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch;
                     U32 mlen;
 
-                    DEBUGLOG(7, "testing match %u => offCode=%u, mlen=%u, llen=%u",
+                    DEBUGLOG(7, "testing match %u => offCode=%4u, mlen=%2u, llen=%2u",
                                 matchNb, matches[matchNb].off, lastML, litlen);
 
-                    for (mlen = lastML; mlen >= startML; mlen--) {
+                    for (mlen = lastML; mlen >= startML; mlen--) {  /* scan downward */
                         U32 const pos = cur + mlen;
                         int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel);
 
                         if ((pos > last_pos) || (price < opt[pos].price)) {
-                            DEBUGLOG(7, "rPos:%u => new better price (%u<%u)",
-                                        pos, price, opt[pos].price);
-                            while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; }
+                            DEBUGLOG(7, "rPos:%u (ml=%2u) => new better price (%.2f<%.2f)",
+                                        pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
+                            while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; }   /* fill empty positions */
                             opt[pos].mlen = mlen;
                             opt[pos].off = offset;
                             opt[pos].litlen = litlen;
                             opt[pos].price = price;
+                            ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
                             memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
                         } else {
-                            if (optLevel==0) break;  /* gets ~+10% speed for about -0.01 ratio loss */
+                            DEBUGLOG(7, "rPos:%u (ml=%2u) => new price is worse (%.2f>=%.2f)",
+                                        pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
+                            if (optLevel==0) break;  /* early update abort; gets ~+10% speed for about -0.01 ratio loss */
                         }
             }   }   }
         }  /* for (cur = 1; cur <= last_pos; cur++) */
 
-        best_mlen = opt[last_pos].mlen;
-        best_off = opt[last_pos].off;
-        cur = last_pos - best_mlen;
+        lastSequence = opt[last_pos];
+        cur = last_pos > ZSTD_totalLen(lastSequence) ? last_pos - ZSTD_totalLen(lastSequence) : 0;  /* single sequence, and it starts before `ip` */
+        assert(cur < ZSTD_OPT_NUM);  /* control overflow*/
 
 _shortestPath:   /* cur, last_pos, best_mlen, best_off have to be set */
-        assert(opt[0].mlen == 1);
+        assert(opt[0].mlen == 0);
 
-        /* reverse traversal */
-        DEBUGLOG(7, "start reverse traversal (last_pos:%u, cur:%u)",
-                    last_pos, cur);
-        {   U32 selectedMatchLength = best_mlen;
-            U32 selectedOffset = best_off;
-            U32 pos = cur;
-            while (1) {
-                U32 const mlen = opt[pos].mlen;
-                U32 const off = opt[pos].off;
-                opt[pos].mlen = selectedMatchLength;
-                opt[pos].off = selectedOffset;
-                selectedMatchLength = mlen;
-                selectedOffset = off;
-                if (mlen > pos) break;
-                pos -= mlen;
-        }   }
+        {   U32 const storeEnd = cur + 1;
+            U32 storeStart = storeEnd;
+            U32 seqPos = cur;
 
-        /* save sequences */
-        {   U32 pos;
-            for (pos=0; pos < last_pos; ) {
-                U32 const llen = (U32)(ip - anchor);
-                U32 const mlen = opt[pos].mlen;
-                U32 const offset = opt[pos].off;
-                if (mlen == 1) { ip++; pos++; continue; }  /* literal position => move on */
-                pos += mlen; ip += mlen;
+            DEBUGLOG(6, "start reverse traversal (last_pos:%u, cur:%u)",
+                        last_pos, cur); (void)last_pos;
+            assert(storeEnd < ZSTD_OPT_NUM);
+            DEBUGLOG(6, "last sequence copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
+                        storeEnd, lastSequence.litlen, lastSequence.mlen, lastSequence.off);
+            opt[storeEnd] = lastSequence;
+            while (seqPos > 0) {
+                U32 const backDist = ZSTD_totalLen(opt[seqPos]);
+                storeStart--;
+                DEBUGLOG(6, "sequence from rPos=%u copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
+                            seqPos, storeStart, opt[seqPos].litlen, opt[seqPos].mlen, opt[seqPos].off);
+                opt[storeStart] = opt[seqPos];
+                seqPos = (seqPos > backDist) ? seqPos - backDist : 0;
+            }
 
-                /* repcodes update : like ZSTD_updateRep(), but update in place */
-                if (offset >= ZSTD_REP_NUM) {  /* full offset */
-                    rep[2] = rep[1];
-                    rep[1] = rep[0];
-                    rep[0] = offset - ZSTD_REP_MOVE;
-                } else {   /* repcode */
-                    U32 const repCode = offset + (llen==0);
-                    if (repCode) {  /* note : if repCode==0, no change */
-                        U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
-                        if (repCode >= 2) rep[2] = rep[1];
-                        rep[1] = rep[0];
-                        rep[0] = currentOffset;
+            /* save sequences */
+            DEBUGLOG(6, "sending selected sequences into seqStore")
+            {   U32 storePos;
+                for (storePos=storeStart; storePos <= storeEnd; storePos++) {
+                    U32 const llen = opt[storePos].litlen;
+                    U32 const mlen = opt[storePos].mlen;
+                    U32 const offCode = opt[storePos].off;
+                    U32 const advance = llen + mlen;
+                    DEBUGLOG(6, "considering seq starting at %zi, llen=%u, mlen=%u",
+                                anchor - istart, llen, mlen);
+
+                    if (mlen==0) {  /* only literals => must be last "sequence", actually starting a new stream of sequences */
+                        assert(storePos == storeEnd);   /* must be last sequence */
+                        ip = anchor + llen;     /* last "sequence" is a bunch of literals => don't progress anchor */
+                        continue;   /* will finish */
                     }
-                }
 
-                ZSTD_updateStats(optStatePtr, llen, anchor, offset, mlen);
-                ZSTD_storeSeq(seqStore, llen, anchor, offset, mlen-MINMATCH);
-                anchor = ip;
-        }   }
-        ZSTD_setLog2Prices(optStatePtr);
+                    /* repcodes update : like ZSTD_updateRep(), but update in place */
+                    if (offCode >= ZSTD_REP_NUM) {  /* full offset */
+                        rep[2] = rep[1];
+                        rep[1] = rep[0];
+                        rep[0] = offCode - ZSTD_REP_MOVE;
+                    } else {   /* repcode */
+                        U32 const repCode = offCode + (llen==0);
+                        if (repCode) {  /* note : if repCode==0, no change */
+                            U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
+                            if (repCode >= 2) rep[2] = rep[1];
+                            rep[1] = rep[0];
+                            rep[0] = currentOffset;
+                    }   }
+
+                    assert(anchor + llen <= iend);
+                    ZSTD_updateStats(optStatePtr, llen, anchor, offCode, mlen);
+                    ZSTD_storeSeq(seqStore, llen, anchor, offCode, mlen-MINMATCH);
+                    anchor += advance;
+                    ip = anchor;
+            }   }
+            ZSTD_setBasePrices(optStatePtr, optLevel);
+        }
+
     }   /* while (ip < ilimit) */
 
     /* Return the last literals size */
     return iend - anchor;
 }
 
 
 size_t ZSTD_compressBlock_btopt(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_compressBlock_btopt");
-    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 0 /*extDict*/);
+    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_noDict);
 }
 
+
+/* used in 2-pass strategy */
+static U32 ZSTD_upscaleStat(U32* table, U32 lastEltIndex, int bonus)
+{
+    U32 s, sum=0;
+    assert(ZSTD_FREQ_DIV+bonus > 0);
+    for (s=0; s<=lastEltIndex; s++) {
+        table[s] <<= ZSTD_FREQ_DIV+bonus;
+        table[s]--;
+        sum += table[s];
+    }
+    return sum;
+}
+
+/* used in 2-pass strategy */
+MEM_STATIC void ZSTD_upscaleStats(optState_t* optPtr)
+{
+    optPtr->litSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0);
+    optPtr->litLengthSum = ZSTD_upscaleStat(optPtr->litLengthFreq, MaxLL, 1);
+    optPtr->matchLengthSum = ZSTD_upscaleStat(optPtr->matchLengthFreq, MaxML, 1);
+    optPtr->offCodeSum = ZSTD_upscaleStat(optPtr->offCodeFreq, MaxOff, 1);
+}
+
 size_t ZSTD_compressBlock_btultra(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        const void* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 0 /*extDict*/);
+    DEBUGLOG(5, "ZSTD_compressBlock_btultra (srcSize=%zu)", srcSize);
+#if 0
+    /* 2-pass strategy (disabled)
+     * this strategy makes a first pass over first block to collect statistics
+     * and seed next round's statistics with it.
+     * The compression ratio gain is generally small (~0.5% on first block),
+     * the cost is 2x cpu time on first block. */
+    assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
+    if ( (ms->opt.litLengthSum==0)   /* first block */
+      && (seqStore->sequences == seqStore->sequencesStart)   /* no ldm */
+      && (ms->window.dictLimit == ms->window.lowLimit) ) {   /* no dictionary */
+        U32 tmpRep[ZSTD_REP_NUM];
+        DEBUGLOG(5, "ZSTD_compressBlock_btultra: first block: collecting statistics");
+        assert(ms->nextToUpdate >= ms->window.dictLimit
+            && ms->nextToUpdate <= ms->window.dictLimit + 1);
+        memcpy(tmpRep, rep, sizeof(tmpRep));
+        ZSTD_compressBlock_opt_generic(ms, seqStore, tmpRep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);   /* generate stats into ms->opt*/
+        ZSTD_resetSeqStore(seqStore);
+        /* invalidate first scan from history */
+        ms->window.base -= srcSize;
+        ms->window.dictLimit += (U32)srcSize;
+        ms->window.lowLimit = ms->window.dictLimit;
+        ms->nextToUpdate = ms->window.dictLimit;
+        ms->nextToUpdate3 = ms->window.dictLimit;
+        /* re-inforce weight of collected statistics */
+        ZSTD_upscaleStats(&ms->opt);
+    }
+#endif
+    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
 }
 
+size_t ZSTD_compressBlock_btopt_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        const void* src, size_t srcSize)
+{
+    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_dictMatchState);
+}
+
+size_t ZSTD_compressBlock_btultra_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        const void* src, size_t srcSize)
+{
+    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_dictMatchState);
+}
+
 size_t ZSTD_compressBlock_btopt_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        const void* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 0 /*optLevel*/, 1 /*extDict*/);
+    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_extDict);
 }
 
 size_t ZSTD_compressBlock_btultra_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize)
+        const void* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, cParams, src, srcSize, 2 /*optLevel*/, 1 /*extDict*/);
+    return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_extDict);
 }
Index: vendor/zstd/dist/lib/compress/zstd_opt.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstd_opt.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstd_opt.h	(revision 339614)
@@ -1,42 +1,48 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_OPT_H
 #define ZSTD_OPT_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #include "zstd_compress_internal.h"
 
-void ZSTD_updateTree(
-        ZSTD_matchState_t* ms, ZSTD_compressionParameters const* cParams,
-        const BYTE* ip, const BYTE* iend);  /* used in ZSTD_loadDictionaryContent() */
+/* used in ZSTD_loadDictionaryContent() */
+void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend);
 
 size_t ZSTD_compressBlock_btopt(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_btultra(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 
+size_t ZSTD_compressBlock_btopt_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
+size_t ZSTD_compressBlock_btultra_dictMatchState(
+        ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
+        void const* src, size_t srcSize);
+
 size_t ZSTD_compressBlock_btopt_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 size_t ZSTD_compressBlock_btultra_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
-        ZSTD_compressionParameters const* cParams, void const* src, size_t srcSize);
+        void const* src, size_t srcSize);
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ZSTD_OPT_H */
Index: vendor/zstd/dist/lib/compress/zstdmt_compress.c
===================================================================
--- vendor/zstd/dist/lib/compress/zstdmt_compress.c	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstdmt_compress.c	(revision 339614)
@@ -1,1831 +1,1951 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /* ======   Tuning parameters   ====== */
 #define ZSTDMT_NBWORKERS_MAX 200
 #define ZSTDMT_JOBSIZE_MAX  (MEM_32bits() ? (512 MB) : (2 GB))  /* note : limited by `jobSize` type, which is `unsigned` */
 #define ZSTDMT_OVERLAPLOG_DEFAULT 6
 
 
 /* ======   Compiler specifics   ====== */
 #if defined(_MSC_VER)
 #  pragma warning(disable : 4204)   /* disable: C4204: non-constant aggregate initializer */
 #endif
 
 
 /* ======   Dependencies   ====== */
 #include       /* memcpy, memset */
 #include       /* INT_MAX */
 #include "pool.h"        /* threadpool */
 #include "threading.h"   /* mutex */
 #include "zstd_compress_internal.h"  /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
 #include "zstd_ldm.h"
 #include "zstdmt_compress.h"
 
 /* Guards code to support resizing the SeqPool.
  * We will want to resize the SeqPool to save memory in the future.
  * Until then, comment the code out since it is unused.
  */
 #define ZSTD_RESIZE_SEQPOOL 0
 
 /* ======   Debug   ====== */
-#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=2)
+#if defined(DEBUGLEVEL) && (DEBUGLEVEL>=2) \
+    && !defined(_MSC_VER) \
+    && !defined(__MINGW32__)
 
 #  include 
 #  include 
 #  include 
-#  define DEBUGLOGRAW(l, ...) if (l<=ZSTD_DEBUG) { fprintf(stderr, __VA_ARGS__); }
 
 #  define DEBUG_PRINTHEX(l,p,n) {            \
     unsigned debug_u;                        \
     for (debug_u=0; debug_u<(n); debug_u++)  \
-        DEBUGLOGRAW(l, "%02X ", ((const unsigned char*)(p))[debug_u]); \
-    DEBUGLOGRAW(l, " \n");                   \
+        RAWLOG(l, "%02X ", ((const unsigned char*)(p))[debug_u]); \
+    RAWLOG(l, " \n");                        \
 }
 
 static unsigned long long GetCurrentClockTimeMicroseconds(void)
 {
    static clock_t _ticksPerSecond = 0;
    if (_ticksPerSecond <= 0) _ticksPerSecond = sysconf(_SC_CLK_TCK);
 
    { struct tms junk; clock_t newTicks = (clock_t) times(&junk);
      return ((((unsigned long long)newTicks)*(1000000))/_ticksPerSecond); }
 }
 
 #define MUTEX_WAIT_TIME_DLEVEL 6
 #define ZSTD_PTHREAD_MUTEX_LOCK(mutex) {          \
-    if (ZSTD_DEBUG >= MUTEX_WAIT_TIME_DLEVEL) {   \
+    if (DEBUGLEVEL >= MUTEX_WAIT_TIME_DLEVEL) {   \
         unsigned long long const beforeTime = GetCurrentClockTimeMicroseconds(); \
         ZSTD_pthread_mutex_lock(mutex);           \
         {   unsigned long long const afterTime = GetCurrentClockTimeMicroseconds(); \
             unsigned long long const elapsedTime = (afterTime-beforeTime); \
             if (elapsedTime > 1000) {  /* or whatever threshold you like; I'm using 1 millisecond here */ \
                 DEBUGLOG(MUTEX_WAIT_TIME_DLEVEL, "Thread took %llu microseconds to acquire mutex %s \n", \
                    elapsedTime, #mutex);          \
         }   }                                     \
     } else {                                      \
         ZSTD_pthread_mutex_lock(mutex);           \
     }                                             \
 }
 
 #else
 
 #  define ZSTD_PTHREAD_MUTEX_LOCK(m) ZSTD_pthread_mutex_lock(m)
 #  define DEBUG_PRINTHEX(l,p,n) {}
 
 #endif
 
 
 /* =====   Buffer Pool   ===== */
 /* a single Buffer Pool can be invoked from multiple threads in parallel */
 
 typedef struct buffer_s {
     void* start;
     size_t capacity;
 } buffer_t;
 
 static const buffer_t g_nullBuffer = { NULL, 0 };
 
 typedef struct ZSTDMT_bufferPool_s {
     ZSTD_pthread_mutex_t poolMutex;
     size_t bufferSize;
     unsigned totalBuffers;
     unsigned nbBuffers;
     ZSTD_customMem cMem;
     buffer_t bTable[1];   /* variable size */
 } ZSTDMT_bufferPool;
 
 static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned nbWorkers, ZSTD_customMem cMem)
 {
     unsigned const maxNbBuffers = 2*nbWorkers + 3;
     ZSTDMT_bufferPool* const bufPool = (ZSTDMT_bufferPool*)ZSTD_calloc(
         sizeof(ZSTDMT_bufferPool) + (maxNbBuffers-1) * sizeof(buffer_t), cMem);
     if (bufPool==NULL) return NULL;
     if (ZSTD_pthread_mutex_init(&bufPool->poolMutex, NULL)) {
         ZSTD_free(bufPool, cMem);
         return NULL;
     }
     bufPool->bufferSize = 64 KB;
     bufPool->totalBuffers = maxNbBuffers;
     bufPool->nbBuffers = 0;
     bufPool->cMem = cMem;
     return bufPool;
 }
 
 static void ZSTDMT_freeBufferPool(ZSTDMT_bufferPool* bufPool)
 {
     unsigned u;
     DEBUGLOG(3, "ZSTDMT_freeBufferPool (address:%08X)", (U32)(size_t)bufPool);
     if (!bufPool) return;   /* compatibility with free on NULL */
     for (u=0; utotalBuffers; u++) {
         DEBUGLOG(4, "free buffer %2u (address:%08X)", u, (U32)(size_t)bufPool->bTable[u].start);
         ZSTD_free(bufPool->bTable[u].start, bufPool->cMem);
     }
     ZSTD_pthread_mutex_destroy(&bufPool->poolMutex);
     ZSTD_free(bufPool, bufPool->cMem);
 }
 
 /* only works at initialization, not during compression */
 static size_t ZSTDMT_sizeof_bufferPool(ZSTDMT_bufferPool* bufPool)
 {
     size_t const poolSize = sizeof(*bufPool)
                           + (bufPool->totalBuffers - 1) * sizeof(buffer_t);
     unsigned u;
     size_t totalBufferSize = 0;
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     for (u=0; utotalBuffers; u++)
         totalBufferSize += bufPool->bTable[u].capacity;
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
 
     return poolSize + totalBufferSize;
 }
 
 /* ZSTDMT_setBufferSize() :
  * all future buffers provided by this buffer pool will have _at least_ this size
  * note : it's better for all buffers to have same size,
  * as they become freely interchangeable, reducing malloc/free usages and memory fragmentation */
 static void ZSTDMT_setBufferSize(ZSTDMT_bufferPool* const bufPool, size_t const bSize)
 {
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     DEBUGLOG(4, "ZSTDMT_setBufferSize: bSize = %u", (U32)bSize);
     bufPool->bufferSize = bSize;
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
 }
 
+
+static ZSTDMT_bufferPool* ZSTDMT_expandBufferPool(ZSTDMT_bufferPool* srcBufPool, U32 nbWorkers)
+{
+    unsigned const maxNbBuffers = 2*nbWorkers + 3;
+    if (srcBufPool==NULL) return NULL;
+    if (srcBufPool->totalBuffers >= maxNbBuffers) /* good enough */
+        return srcBufPool;
+    /* need a larger buffer pool */
+    {   ZSTD_customMem const cMem = srcBufPool->cMem;
+        size_t const bSize = srcBufPool->bufferSize;   /* forward parameters */
+        ZSTDMT_bufferPool* newBufPool;
+        ZSTDMT_freeBufferPool(srcBufPool);
+        newBufPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
+        if (newBufPool==NULL) return newBufPool;
+        ZSTDMT_setBufferSize(newBufPool, bSize);
+        return newBufPool;
+    }
+}
+
 /** ZSTDMT_getBuffer() :
  *  assumption : bufPool must be valid
  * @return : a buffer, with start pointer and size
  *  note: allocation may fail, in this case, start==NULL and size==0 */
 static buffer_t ZSTDMT_getBuffer(ZSTDMT_bufferPool* bufPool)
 {
     size_t const bSize = bufPool->bufferSize;
     DEBUGLOG(5, "ZSTDMT_getBuffer: bSize = %u", (U32)bufPool->bufferSize);
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     if (bufPool->nbBuffers) {   /* try to use an existing buffer */
         buffer_t const buf = bufPool->bTable[--(bufPool->nbBuffers)];
         size_t const availBufferSize = buf.capacity;
         bufPool->bTable[bufPool->nbBuffers] = g_nullBuffer;
         if ((availBufferSize >= bSize) & ((availBufferSize>>3) <= bSize)) {
             /* large enough, but not too much */
             DEBUGLOG(5, "ZSTDMT_getBuffer: provide buffer %u of size %u",
                         bufPool->nbBuffers, (U32)buf.capacity);
             ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
             return buf;
         }
         /* size conditions not respected : scratch this buffer, create new one */
         DEBUGLOG(5, "ZSTDMT_getBuffer: existing buffer does not meet size conditions => freeing");
         ZSTD_free(buf.start, bufPool->cMem);
     }
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
     /* create new buffer */
     DEBUGLOG(5, "ZSTDMT_getBuffer: create a new buffer");
     {   buffer_t buffer;
         void* const start = ZSTD_malloc(bSize, bufPool->cMem);
         buffer.start = start;   /* note : start can be NULL if malloc fails ! */
         buffer.capacity = (start==NULL) ? 0 : bSize;
         if (start==NULL) {
             DEBUGLOG(5, "ZSTDMT_getBuffer: buffer allocation failure !!");
         } else {
             DEBUGLOG(5, "ZSTDMT_getBuffer: created buffer of size %u", (U32)bSize);
         }
         return buffer;
     }
 }
 
 #if ZSTD_RESIZE_SEQPOOL
 /** ZSTDMT_resizeBuffer() :
  * assumption : bufPool must be valid
  * @return : a buffer that is at least the buffer pool buffer size.
  *           If a reallocation happens, the data in the input buffer is copied.
  */
 static buffer_t ZSTDMT_resizeBuffer(ZSTDMT_bufferPool* bufPool, buffer_t buffer)
 {
     size_t const bSize = bufPool->bufferSize;
     if (buffer.capacity < bSize) {
         void* const start = ZSTD_malloc(bSize, bufPool->cMem);
         buffer_t newBuffer;
         newBuffer.start = start;
         newBuffer.capacity = start == NULL ? 0 : bSize;
         if (start != NULL) {
             assert(newBuffer.capacity >= buffer.capacity);
             memcpy(newBuffer.start, buffer.start, buffer.capacity);
             DEBUGLOG(5, "ZSTDMT_resizeBuffer: created buffer of size %u", (U32)bSize);
             return newBuffer;
         }
         DEBUGLOG(5, "ZSTDMT_resizeBuffer: buffer allocation failure !!");
     }
     return buffer;
 }
 #endif
 
 /* store buffer for later re-use, up to pool capacity */
 static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* bufPool, buffer_t buf)
 {
-    if (buf.start == NULL) return;   /* compatible with release on NULL */
     DEBUGLOG(5, "ZSTDMT_releaseBuffer");
+    if (buf.start == NULL) return;   /* compatible with release on NULL */
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     if (bufPool->nbBuffers < bufPool->totalBuffers) {
         bufPool->bTable[bufPool->nbBuffers++] = buf;  /* stored for later use */
         DEBUGLOG(5, "ZSTDMT_releaseBuffer: stored buffer of size %u in slot %u",
                     (U32)buf.capacity, (U32)(bufPool->nbBuffers-1));
         ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
         return;
     }
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
     /* Reached bufferPool capacity (should not happen) */
     DEBUGLOG(5, "ZSTDMT_releaseBuffer: pool capacity reached => freeing ");
     ZSTD_free(buf.start, bufPool->cMem);
 }
 
 
 /* =====   Seq Pool Wrapper   ====== */
 
 static rawSeqStore_t kNullRawSeqStore = {NULL, 0, 0, 0};
 
 typedef ZSTDMT_bufferPool ZSTDMT_seqPool;
 
 static size_t ZSTDMT_sizeof_seqPool(ZSTDMT_seqPool* seqPool)
 {
     return ZSTDMT_sizeof_bufferPool(seqPool);
 }
 
 static rawSeqStore_t bufferToSeq(buffer_t buffer)
 {
     rawSeqStore_t seq = {NULL, 0, 0, 0};
     seq.seq = (rawSeq*)buffer.start;
     seq.capacity = buffer.capacity / sizeof(rawSeq);
     return seq;
 }
 
 static buffer_t seqToBuffer(rawSeqStore_t seq)
 {
     buffer_t buffer;
     buffer.start = seq.seq;
     buffer.capacity = seq.capacity * sizeof(rawSeq);
     return buffer;
 }
 
 static rawSeqStore_t ZSTDMT_getSeq(ZSTDMT_seqPool* seqPool)
 {
     if (seqPool->bufferSize == 0) {
         return kNullRawSeqStore;
     }
     return bufferToSeq(ZSTDMT_getBuffer(seqPool));
 }
 
 #if ZSTD_RESIZE_SEQPOOL
 static rawSeqStore_t ZSTDMT_resizeSeq(ZSTDMT_seqPool* seqPool, rawSeqStore_t seq)
 {
   return bufferToSeq(ZSTDMT_resizeBuffer(seqPool, seqToBuffer(seq)));
 }
 #endif
 
 static void ZSTDMT_releaseSeq(ZSTDMT_seqPool* seqPool, rawSeqStore_t seq)
 {
   ZSTDMT_releaseBuffer(seqPool, seqToBuffer(seq));
 }
 
 static void ZSTDMT_setNbSeq(ZSTDMT_seqPool* const seqPool, size_t const nbSeq)
 {
   ZSTDMT_setBufferSize(seqPool, nbSeq * sizeof(rawSeq));
 }
 
 static ZSTDMT_seqPool* ZSTDMT_createSeqPool(unsigned nbWorkers, ZSTD_customMem cMem)
 {
-    ZSTDMT_seqPool* seqPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
+    ZSTDMT_seqPool* const seqPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
+    if (seqPool == NULL) return NULL;
     ZSTDMT_setNbSeq(seqPool, 0);
     return seqPool;
 }
 
 static void ZSTDMT_freeSeqPool(ZSTDMT_seqPool* seqPool)
 {
     ZSTDMT_freeBufferPool(seqPool);
 }
 
+static ZSTDMT_seqPool* ZSTDMT_expandSeqPool(ZSTDMT_seqPool* pool, U32 nbWorkers)
+{
+    return ZSTDMT_expandBufferPool(pool, nbWorkers);
+}
 
 
 /* =====   CCtx Pool   ===== */
 /* a single CCtx Pool can be invoked from multiple threads in parallel */
 
 typedef struct {
     ZSTD_pthread_mutex_t poolMutex;
     unsigned totalCCtx;
     unsigned availCCtx;
     ZSTD_customMem cMem;
     ZSTD_CCtx* cctx[1];   /* variable size */
 } ZSTDMT_CCtxPool;
 
 /* note : all CCtx borrowed from the pool should be released back to the pool _before_ freeing the pool */
 static void ZSTDMT_freeCCtxPool(ZSTDMT_CCtxPool* pool)
 {
     unsigned u;
     for (u=0; utotalCCtx; u++)
         ZSTD_freeCCtx(pool->cctx[u]);  /* note : compatible with free on NULL */
     ZSTD_pthread_mutex_destroy(&pool->poolMutex);
     ZSTD_free(pool, pool->cMem);
 }
 
 /* ZSTDMT_createCCtxPool() :
  * implies nbWorkers >= 1 , checked by caller ZSTDMT_createCCtx() */
 static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(unsigned nbWorkers,
                                               ZSTD_customMem cMem)
 {
     ZSTDMT_CCtxPool* const cctxPool = (ZSTDMT_CCtxPool*) ZSTD_calloc(
         sizeof(ZSTDMT_CCtxPool) + (nbWorkers-1)*sizeof(ZSTD_CCtx*), cMem);
     assert(nbWorkers > 0);
     if (!cctxPool) return NULL;
     if (ZSTD_pthread_mutex_init(&cctxPool->poolMutex, NULL)) {
         ZSTD_free(cctxPool, cMem);
         return NULL;
     }
     cctxPool->cMem = cMem;
     cctxPool->totalCCtx = nbWorkers;
     cctxPool->availCCtx = 1;   /* at least one cctx for single-thread mode */
     cctxPool->cctx[0] = ZSTD_createCCtx_advanced(cMem);
     if (!cctxPool->cctx[0]) { ZSTDMT_freeCCtxPool(cctxPool); return NULL; }
     DEBUGLOG(3, "cctxPool created, with %u workers", nbWorkers);
     return cctxPool;
 }
 
+static ZSTDMT_CCtxPool* ZSTDMT_expandCCtxPool(ZSTDMT_CCtxPool* srcPool,
+                                              unsigned nbWorkers)
+{
+    if (srcPool==NULL) return NULL;
+    if (nbWorkers <= srcPool->totalCCtx) return srcPool;   /* good enough */
+    /* need a larger cctx pool */
+    {   ZSTD_customMem const cMem = srcPool->cMem;
+        ZSTDMT_freeCCtxPool(srcPool);
+        return ZSTDMT_createCCtxPool(nbWorkers, cMem);
+    }
+}
+
 /* only works during initialization phase, not during compression */
 static size_t ZSTDMT_sizeof_CCtxPool(ZSTDMT_CCtxPool* cctxPool)
 {
     ZSTD_pthread_mutex_lock(&cctxPool->poolMutex);
     {   unsigned const nbWorkers = cctxPool->totalCCtx;
         size_t const poolSize = sizeof(*cctxPool)
                                 + (nbWorkers-1) * sizeof(ZSTD_CCtx*);
         unsigned u;
         size_t totalCCtxSize = 0;
         for (u=0; ucctx[u]);
         }
         ZSTD_pthread_mutex_unlock(&cctxPool->poolMutex);
         assert(nbWorkers > 0);
         return poolSize + totalCCtxSize;
     }
 }
 
 static ZSTD_CCtx* ZSTDMT_getCCtx(ZSTDMT_CCtxPool* cctxPool)
 {
     DEBUGLOG(5, "ZSTDMT_getCCtx");
     ZSTD_pthread_mutex_lock(&cctxPool->poolMutex);
     if (cctxPool->availCCtx) {
         cctxPool->availCCtx--;
         {   ZSTD_CCtx* const cctx = cctxPool->cctx[cctxPool->availCCtx];
             ZSTD_pthread_mutex_unlock(&cctxPool->poolMutex);
             return cctx;
     }   }
     ZSTD_pthread_mutex_unlock(&cctxPool->poolMutex);
     DEBUGLOG(5, "create one more CCtx");
     return ZSTD_createCCtx_advanced(cctxPool->cMem);   /* note : can be NULL, when creation fails ! */
 }
 
 static void ZSTDMT_releaseCCtx(ZSTDMT_CCtxPool* pool, ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return;   /* compatibility with release on NULL */
     ZSTD_pthread_mutex_lock(&pool->poolMutex);
     if (pool->availCCtx < pool->totalCCtx)
         pool->cctx[pool->availCCtx++] = cctx;
     else {
         /* pool overflow : should not happen, since totalCCtx==nbWorkers */
         DEBUGLOG(4, "CCtx pool overflow : free cctx");
         ZSTD_freeCCtx(cctx);
     }
     ZSTD_pthread_mutex_unlock(&pool->poolMutex);
 }
 
 /* ====   Serial State   ==== */
 
 typedef struct {
     void const* start;
     size_t size;
 } range_t;
 
 typedef struct {
     /* All variables in the struct are protected by mutex. */
     ZSTD_pthread_mutex_t mutex;
     ZSTD_pthread_cond_t cond;
     ZSTD_CCtx_params params;
     ldmState_t ldmState;
     XXH64_state_t xxhState;
     unsigned nextJobID;
     /* Protects ldmWindow.
      * Must be acquired after the main mutex when acquiring both.
      */
     ZSTD_pthread_mutex_t ldmWindowMutex;
     ZSTD_pthread_cond_t ldmWindowCond;  /* Signaled when ldmWindow is udpated */
     ZSTD_window_t ldmWindow;  /* A thread-safe copy of ldmState.window */
 } serialState_t;
 
-static int ZSTDMT_serialState_reset(serialState_t* serialState, ZSTDMT_seqPool* seqPool, ZSTD_CCtx_params params)
+static int ZSTDMT_serialState_reset(serialState_t* serialState, ZSTDMT_seqPool* seqPool, ZSTD_CCtx_params params, size_t jobSize)
 {
     /* Adjust parameters */
     if (params.ldmParams.enableLdm) {
         DEBUGLOG(4, "LDM window size = %u KB", (1U << params.cParams.windowLog) >> 10);
-        params.ldmParams.windowLog = params.cParams.windowLog;
         ZSTD_ldm_adjustParameters(¶ms.ldmParams, ¶ms.cParams);
         assert(params.ldmParams.hashLog >= params.ldmParams.bucketSizeLog);
         assert(params.ldmParams.hashEveryLog < 32);
         serialState->ldmState.hashPower =
                 ZSTD_ldm_getHashPower(params.ldmParams.minMatchLength);
     } else {
         memset(¶ms.ldmParams, 0, sizeof(params.ldmParams));
     }
     serialState->nextJobID = 0;
     if (params.fParams.checksumFlag)
         XXH64_reset(&serialState->xxhState, 0);
     if (params.ldmParams.enableLdm) {
         ZSTD_customMem cMem = params.customMem;
         unsigned const hashLog = params.ldmParams.hashLog;
         size_t const hashSize = ((size_t)1 << hashLog) * sizeof(ldmEntry_t);
         unsigned const bucketLog =
             params.ldmParams.hashLog - params.ldmParams.bucketSizeLog;
         size_t const bucketSize = (size_t)1 << bucketLog;
         unsigned const prevBucketLog =
             serialState->params.ldmParams.hashLog -
             serialState->params.ldmParams.bucketSizeLog;
         /* Size the seq pool tables */
-        ZSTDMT_setNbSeq(seqPool, ZSTD_ldm_getMaxNbSeq(params.ldmParams, params.jobSize));
+        ZSTDMT_setNbSeq(seqPool, ZSTD_ldm_getMaxNbSeq(params.ldmParams, jobSize));
         /* Reset the window */
         ZSTD_window_clear(&serialState->ldmState.window);
         serialState->ldmWindow = serialState->ldmState.window;
         /* Resize tables and output space if necessary. */
         if (serialState->ldmState.hashTable == NULL || serialState->params.ldmParams.hashLog < hashLog) {
             ZSTD_free(serialState->ldmState.hashTable, cMem);
             serialState->ldmState.hashTable = (ldmEntry_t*)ZSTD_malloc(hashSize, cMem);
         }
         if (serialState->ldmState.bucketOffsets == NULL || prevBucketLog < bucketLog) {
             ZSTD_free(serialState->ldmState.bucketOffsets, cMem);
             serialState->ldmState.bucketOffsets = (BYTE*)ZSTD_malloc(bucketSize, cMem);
         }
         if (!serialState->ldmState.hashTable || !serialState->ldmState.bucketOffsets)
             return 1;
         /* Zero the tables */
         memset(serialState->ldmState.hashTable, 0, hashSize);
         memset(serialState->ldmState.bucketOffsets, 0, bucketSize);
     }
     serialState->params = params;
+    serialState->params.jobSize = (U32)jobSize;
     return 0;
 }
 
 static int ZSTDMT_serialState_init(serialState_t* serialState)
 {
     int initError = 0;
     memset(serialState, 0, sizeof(*serialState));
     initError |= ZSTD_pthread_mutex_init(&serialState->mutex, NULL);
     initError |= ZSTD_pthread_cond_init(&serialState->cond, NULL);
     initError |= ZSTD_pthread_mutex_init(&serialState->ldmWindowMutex, NULL);
     initError |= ZSTD_pthread_cond_init(&serialState->ldmWindowCond, NULL);
     return initError;
 }
 
 static void ZSTDMT_serialState_free(serialState_t* serialState)
 {
     ZSTD_customMem cMem = serialState->params.customMem;
     ZSTD_pthread_mutex_destroy(&serialState->mutex);
     ZSTD_pthread_cond_destroy(&serialState->cond);
     ZSTD_pthread_mutex_destroy(&serialState->ldmWindowMutex);
     ZSTD_pthread_cond_destroy(&serialState->ldmWindowCond);
     ZSTD_free(serialState->ldmState.hashTable, cMem);
     ZSTD_free(serialState->ldmState.bucketOffsets, cMem);
 }
 
 static void ZSTDMT_serialState_update(serialState_t* serialState,
                                       ZSTD_CCtx* jobCCtx, rawSeqStore_t seqStore,
                                       range_t src, unsigned jobID)
 {
     /* Wait for our turn */
     ZSTD_PTHREAD_MUTEX_LOCK(&serialState->mutex);
     while (serialState->nextJobID < jobID) {
+        DEBUGLOG(5, "wait for serialState->cond");
         ZSTD_pthread_cond_wait(&serialState->cond, &serialState->mutex);
     }
     /* A future job may error and skip our job */
     if (serialState->nextJobID == jobID) {
         /* It is now our turn, do any processing necessary */
         if (serialState->params.ldmParams.enableLdm) {
             size_t error;
             assert(seqStore.seq != NULL && seqStore.pos == 0 &&
                    seqStore.size == 0 && seqStore.capacity > 0);
+            assert(src.size <= serialState->params.jobSize);
             ZSTD_window_update(&serialState->ldmState.window, src.start, src.size);
             error = ZSTD_ldm_generateSequences(
                 &serialState->ldmState, &seqStore,
                 &serialState->params.ldmParams, src.start, src.size);
             /* We provide a large enough buffer to never fail. */
             assert(!ZSTD_isError(error)); (void)error;
             /* Update ldmWindow to match the ldmState.window and signal the main
              * thread if it is waiting for a buffer.
              */
             ZSTD_PTHREAD_MUTEX_LOCK(&serialState->ldmWindowMutex);
             serialState->ldmWindow = serialState->ldmState.window;
             ZSTD_pthread_cond_signal(&serialState->ldmWindowCond);
             ZSTD_pthread_mutex_unlock(&serialState->ldmWindowMutex);
         }
         if (serialState->params.fParams.checksumFlag && src.size > 0)
             XXH64_update(&serialState->xxhState, src.start, src.size);
     }
     /* Now it is the next jobs turn */
     serialState->nextJobID++;
     ZSTD_pthread_cond_broadcast(&serialState->cond);
     ZSTD_pthread_mutex_unlock(&serialState->mutex);
 
     if (seqStore.size > 0) {
         size_t const err = ZSTD_referenceExternalSequences(
             jobCCtx, seqStore.seq, seqStore.size);
         assert(serialState->params.ldmParams.enableLdm);
         assert(!ZSTD_isError(err));
         (void)err;
     }
 }
 
 static void ZSTDMT_serialState_ensureFinished(serialState_t* serialState,
                                               unsigned jobID, size_t cSize)
 {
     ZSTD_PTHREAD_MUTEX_LOCK(&serialState->mutex);
     if (serialState->nextJobID <= jobID) {
         assert(ZSTD_isError(cSize)); (void)cSize;
         DEBUGLOG(5, "Skipping past job %u because of error", jobID);
         serialState->nextJobID = jobID + 1;
         ZSTD_pthread_cond_broadcast(&serialState->cond);
 
         ZSTD_PTHREAD_MUTEX_LOCK(&serialState->ldmWindowMutex);
         ZSTD_window_clear(&serialState->ldmWindow);
         ZSTD_pthread_cond_signal(&serialState->ldmWindowCond);
         ZSTD_pthread_mutex_unlock(&serialState->ldmWindowMutex);
     }
     ZSTD_pthread_mutex_unlock(&serialState->mutex);
 
 }
 
 
 /* ------------------------------------------ */
 /* =====          Worker thread         ===== */
 /* ------------------------------------------ */
 
 static const range_t kNullRange = { NULL, 0 };
 
 typedef struct {
     size_t   consumed;                   /* SHARED - set0 by mtctx, then modified by worker AND read by mtctx */
     size_t   cSize;                      /* SHARED - set0 by mtctx, then modified by worker AND read by mtctx, then set0 by mtctx */
     ZSTD_pthread_mutex_t job_mutex;      /* Thread-safe - used by mtctx and worker */
     ZSTD_pthread_cond_t job_cond;        /* Thread-safe - used by mtctx and worker */
     ZSTDMT_CCtxPool* cctxPool;           /* Thread-safe - used by mtctx and (all) workers */
     ZSTDMT_bufferPool* bufPool;          /* Thread-safe - used by mtctx and (all) workers */
     ZSTDMT_seqPool* seqPool;             /* Thread-safe - used by mtctx and (all) workers */
     serialState_t* serial;               /* Thread-safe - used by mtctx and (all) workers */
     buffer_t dstBuff;                    /* set by worker (or mtctx), then read by worker & mtctx, then modified by mtctx => no barrier */
     range_t prefix;                      /* set by mtctx, then read by worker & mtctx => no barrier */
     range_t src;                         /* set by mtctx, then read by worker & mtctx => no barrier */
     unsigned jobID;                      /* set by mtctx, then read by worker => no barrier */
     unsigned firstJob;                   /* set by mtctx, then read by worker => no barrier */
     unsigned lastJob;                    /* set by mtctx, then read by worker => no barrier */
     ZSTD_CCtx_params params;             /* set by mtctx, then read by worker => no barrier */
     const ZSTD_CDict* cdict;             /* set by mtctx, then read by worker => no barrier */
     unsigned long long fullFrameSize;    /* set by mtctx, then read by worker => no barrier */
     size_t   dstFlushed;                 /* used only by mtctx */
     unsigned frameChecksumNeeded;        /* used only by mtctx */
 } ZSTDMT_jobDescription;
 
+#define JOB_ERROR(e) {                          \
+    ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);   \
+    job->cSize = e;                             \
+    ZSTD_pthread_mutex_unlock(&job->job_mutex); \
+    goto _endJob;                               \
+}
+
 /* ZSTDMT_compressionJob() is a POOL_function type */
-void ZSTDMT_compressionJob(void* jobDescription)
+static void ZSTDMT_compressionJob(void* jobDescription)
 {
     ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)jobDescription;
     ZSTD_CCtx_params jobParams = job->params;   /* do not modify job->params ! copy it, modify the copy */
     ZSTD_CCtx* const cctx = ZSTDMT_getCCtx(job->cctxPool);
     rawSeqStore_t rawSeqStore = ZSTDMT_getSeq(job->seqPool);
     buffer_t dstBuff = job->dstBuff;
+    size_t lastCBlockSize = 0;
 
+    /* ressources */
+    if (cctx==NULL) JOB_ERROR(ERROR(memory_allocation));
+    if (dstBuff.start == NULL) {   /* streaming job : doesn't provide a dstBuffer */
+        dstBuff = ZSTDMT_getBuffer(job->bufPool);
+        if (dstBuff.start==NULL) JOB_ERROR(ERROR(memory_allocation));
+        job->dstBuff = dstBuff;   /* this value can be read in ZSTDMT_flush, when it copies the whole job */
+    }
+    if (jobParams.ldmParams.enableLdm && rawSeqStore.seq == NULL)
+        JOB_ERROR(ERROR(memory_allocation));
+
     /* Don't compute the checksum for chunks, since we compute it externally,
      * but write it in the header.
      */
     if (job->jobID != 0) jobParams.fParams.checksumFlag = 0;
     /* Don't run LDM for the chunks, since we handle it externally */
     jobParams.ldmParams.enableLdm = 0;
 
-    /* ressources */
-    if (cctx==NULL) {
-        job->cSize = ERROR(memory_allocation);
-        goto _endJob;
-    }
-    if (dstBuff.start == NULL) {   /* streaming job : doesn't provide a dstBuffer */
-        dstBuff = ZSTDMT_getBuffer(job->bufPool);
-        if (dstBuff.start==NULL) {
-            job->cSize = ERROR(memory_allocation);
-            goto _endJob;
-        }
-        job->dstBuff = dstBuff;   /* this value can be read in ZSTDMT_flush, when it copies the whole job */
-    }
 
     /* init */
     if (job->cdict) {
-        size_t const initError = ZSTD_compressBegin_advanced_internal(cctx, NULL, 0, ZSTD_dct_auto, job->cdict, jobParams, job->fullFrameSize);
+        size_t const initError = ZSTD_compressBegin_advanced_internal(cctx, NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast, job->cdict, jobParams, job->fullFrameSize);
         assert(job->firstJob);  /* only allowed for first job */
-        if (ZSTD_isError(initError)) { job->cSize = initError; goto _endJob; }
+        if (ZSTD_isError(initError)) JOB_ERROR(initError);
     } else {  /* srcStart points at reloaded section */
         U64 const pledgedSrcSize = job->firstJob ? job->fullFrameSize : job->src.size;
         {   size_t const forceWindowError = ZSTD_CCtxParam_setParameter(&jobParams, ZSTD_p_forceMaxWindow, !job->firstJob);
-            if (ZSTD_isError(forceWindowError)) {
-                job->cSize = forceWindowError;
-                goto _endJob;
-        }   }
+            if (ZSTD_isError(forceWindowError)) JOB_ERROR(forceWindowError);
+        }
         {   size_t const initError = ZSTD_compressBegin_advanced_internal(cctx,
                                         job->prefix.start, job->prefix.size, ZSTD_dct_rawContent, /* load dictionary in "content-only" mode (no header analysis) */
+                                        ZSTD_dtlm_fast,
                                         NULL, /*cdict*/
                                         jobParams, pledgedSrcSize);
-            if (ZSTD_isError(initError)) {
-                job->cSize = initError;
-                goto _endJob;
-    }   }   }
+            if (ZSTD_isError(initError)) JOB_ERROR(initError);
+    }   }
 
     /* Perform serial step as early as possible, but after CCtx initialization */
     ZSTDMT_serialState_update(job->serial, cctx, rawSeqStore, job->src, job->jobID);
 
     if (!job->firstJob) {  /* flush and overwrite frame header when it's not first job */
         size_t const hSize = ZSTD_compressContinue(cctx, dstBuff.start, dstBuff.capacity, job->src.start, 0);
-        if (ZSTD_isError(hSize)) { job->cSize = hSize; /* save error code */ goto _endJob; }
+        if (ZSTD_isError(hSize)) JOB_ERROR(hSize);
         DEBUGLOG(5, "ZSTDMT_compressionJob: flush and overwrite %u bytes of frame header (not first job)", (U32)hSize);
         ZSTD_invalidateRepCodes(cctx);
     }
 
     /* compress */
     {   size_t const chunkSize = 4*ZSTD_BLOCKSIZE_MAX;
         int const nbChunks = (int)((job->src.size + (chunkSize-1)) / chunkSize);
         const BYTE* ip = (const BYTE*) job->src.start;
         BYTE* const ostart = (BYTE*)dstBuff.start;
         BYTE* op = ostart;
         BYTE* oend = op + dstBuff.capacity;
         int chunkNb;
         if (sizeof(size_t) > sizeof(int)) assert(job->src.size < ((size_t)INT_MAX) * chunkSize);   /* check overflow */
         DEBUGLOG(5, "ZSTDMT_compressionJob: compress %u bytes in %i blocks", (U32)job->src.size, nbChunks);
         assert(job->cSize == 0);
         for (chunkNb = 1; chunkNb < nbChunks; chunkNb++) {
             size_t const cSize = ZSTD_compressContinue(cctx, op, oend-op, ip, chunkSize);
-            if (ZSTD_isError(cSize)) { job->cSize = cSize; goto _endJob; }
+            if (ZSTD_isError(cSize)) JOB_ERROR(cSize);
             ip += chunkSize;
             op += cSize; assert(op < oend);
             /* stats */
             ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
             job->cSize += cSize;
             job->consumed = chunkSize * chunkNb;
             DEBUGLOG(5, "ZSTDMT_compressionJob: compress new block : cSize==%u bytes (total: %u)",
                         (U32)cSize, (U32)job->cSize);
             ZSTD_pthread_cond_signal(&job->job_cond);   /* warns some more data is ready to be flushed */
             ZSTD_pthread_mutex_unlock(&job->job_mutex);
         }
         /* last block */
-        assert(chunkSize > 0); assert((chunkSize & (chunkSize - 1)) == 0);  /* chunkSize must be power of 2 for mask==(chunkSize-1) to work */
+        assert(chunkSize > 0);
+        assert((chunkSize & (chunkSize - 1)) == 0);  /* chunkSize must be power of 2 for mask==(chunkSize-1) to work */
         if ((nbChunks > 0) | job->lastJob /*must output a "last block" flag*/ ) {
             size_t const lastBlockSize1 = job->src.size & (chunkSize-1);
             size_t const lastBlockSize = ((lastBlockSize1==0) & (job->src.size>=chunkSize)) ? chunkSize : lastBlockSize1;
             size_t const cSize = (job->lastJob) ?
                  ZSTD_compressEnd     (cctx, op, oend-op, ip, lastBlockSize) :
                  ZSTD_compressContinue(cctx, op, oend-op, ip, lastBlockSize);
-            if (ZSTD_isError(cSize)) { job->cSize = cSize; goto _endJob; }
-            /* stats */
-            ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
-            job->cSize += cSize;
-            ZSTD_pthread_mutex_unlock(&job->job_mutex);
+            if (ZSTD_isError(cSize)) JOB_ERROR(cSize);
+            lastCBlockSize = cSize;
     }   }
 
 _endJob:
     ZSTDMT_serialState_ensureFinished(job->serial, job->jobID, job->cSize);
     if (job->prefix.size > 0)
         DEBUGLOG(5, "Finished with prefix: %zx", (size_t)job->prefix.start);
     DEBUGLOG(5, "Finished with source: %zx", (size_t)job->src.start);
     /* release resources */
     ZSTDMT_releaseSeq(job->seqPool, rawSeqStore);
     ZSTDMT_releaseCCtx(job->cctxPool, cctx);
     /* report */
     ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
-    job->consumed = job->src.size;
+    if (ZSTD_isError(job->cSize)) assert(lastCBlockSize == 0);
+    job->cSize += lastCBlockSize;
+    job->consumed = job->src.size;  /* when job->consumed == job->src.size , compression job is presumed completed */
     ZSTD_pthread_cond_signal(&job->job_cond);
     ZSTD_pthread_mutex_unlock(&job->job_mutex);
 }
 
 
 /* ------------------------------------------ */
 /* =====   Multi-threaded compression   ===== */
 /* ------------------------------------------ */
 
 typedef struct {
     range_t prefix;         /* read-only non-owned prefix buffer */
     buffer_t buffer;
     size_t filled;
 } inBuff_t;
 
 typedef struct {
   BYTE* buffer;     /* The round input buffer. All jobs get references
                      * to pieces of the buffer. ZSTDMT_tryGetInputRange()
                      * handles handing out job input buffers, and makes
                      * sure it doesn't overlap with any pieces still in use.
                      */
   size_t capacity;  /* The capacity of buffer. */
   size_t pos;       /* The position of the current inBuff in the round
                      * buffer. Updated past the end if the inBuff once
                      * the inBuff is sent to the worker thread.
                      * pos <= capacity.
                      */
 } roundBuff_t;
 
 static const roundBuff_t kNullRoundBuff = {NULL, 0, 0};
 
 struct ZSTDMT_CCtx_s {
     POOL_ctx* factory;
     ZSTDMT_jobDescription* jobs;
     ZSTDMT_bufferPool* bufPool;
     ZSTDMT_CCtxPool* cctxPool;
     ZSTDMT_seqPool* seqPool;
     ZSTD_CCtx_params params;
     size_t targetSectionSize;
     size_t targetPrefixSize;
-    roundBuff_t roundBuff;
+    int jobReady;        /* 1 => one job is already prepared, but pool has shortage of workers. Don't create a new job. */
     inBuff_t inBuff;
-    int jobReady;        /* 1 => one job is already prepared, but pool has shortage of workers. Don't create another one. */
+    roundBuff_t roundBuff;
     serialState_t serial;
     unsigned singleBlockingThread;
     unsigned jobIDMask;
     unsigned doneJobID;
     unsigned nextJobID;
     unsigned frameEnded;
     unsigned allJobsCompleted;
     unsigned long long frameContentSize;
     unsigned long long consumed;
     unsigned long long produced;
     ZSTD_customMem cMem;
     ZSTD_CDict* cdictLocal;
     const ZSTD_CDict* cdict;
 };
 
 static void ZSTDMT_freeJobsTable(ZSTDMT_jobDescription* jobTable, U32 nbJobs, ZSTD_customMem cMem)
 {
     U32 jobNb;
     if (jobTable == NULL) return;
     for (jobNb=0; jobNb mtctx->jobIDMask+1) {  /* need more job capacity */
+        ZSTDMT_freeJobsTable(mtctx->jobs, mtctx->jobIDMask+1, mtctx->cMem);
+        mtctx->jobIDMask = 0;
+        mtctx->jobs = ZSTDMT_createJobsTable(&nbJobs, mtctx->cMem);
+        if (mtctx->jobs==NULL) return ERROR(memory_allocation);
+        assert((nbJobs != 0) && ((nbJobs & (nbJobs - 1)) == 0));  /* ensure nbJobs is a power of 2 */
+        mtctx->jobIDMask = nbJobs - 1;
+    }
+    return 0;
+}
+
+
 /* ZSTDMT_CCtxParam_setNbWorkers():
  * Internal use only */
 size_t ZSTDMT_CCtxParam_setNbWorkers(ZSTD_CCtx_params* params, unsigned nbWorkers)
 {
     if (nbWorkers > ZSTDMT_NBWORKERS_MAX) nbWorkers = ZSTDMT_NBWORKERS_MAX;
     params->nbWorkers = nbWorkers;
     params->overlapSizeLog = ZSTDMT_OVERLAPLOG_DEFAULT;
     params->jobSize = 0;
     return nbWorkers;
 }
 
 ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced(unsigned nbWorkers, ZSTD_customMem cMem)
 {
     ZSTDMT_CCtx* mtctx;
     U32 nbJobs = nbWorkers + 2;
     int initError;
     DEBUGLOG(3, "ZSTDMT_createCCtx_advanced (nbWorkers = %u)", nbWorkers);
 
     if (nbWorkers < 1) return NULL;
     nbWorkers = MIN(nbWorkers , ZSTDMT_NBWORKERS_MAX);
     if ((cMem.customAlloc!=NULL) ^ (cMem.customFree!=NULL))
         /* invalid custom allocator */
         return NULL;
 
     mtctx = (ZSTDMT_CCtx*) ZSTD_calloc(sizeof(ZSTDMT_CCtx), cMem);
     if (!mtctx) return NULL;
     ZSTDMT_CCtxParam_setNbWorkers(&mtctx->params, nbWorkers);
     mtctx->cMem = cMem;
     mtctx->allJobsCompleted = 1;
     mtctx->factory = POOL_create_advanced(nbWorkers, 0, cMem);
     mtctx->jobs = ZSTDMT_createJobsTable(&nbJobs, cMem);
     assert(nbJobs > 0); assert((nbJobs & (nbJobs - 1)) == 0);  /* ensure nbJobs is a power of 2 */
     mtctx->jobIDMask = nbJobs - 1;
     mtctx->bufPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
     mtctx->cctxPool = ZSTDMT_createCCtxPool(nbWorkers, cMem);
     mtctx->seqPool = ZSTDMT_createSeqPool(nbWorkers, cMem);
     initError = ZSTDMT_serialState_init(&mtctx->serial);
     mtctx->roundBuff = kNullRoundBuff;
     if (!mtctx->factory | !mtctx->jobs | !mtctx->bufPool | !mtctx->cctxPool | !mtctx->seqPool | initError) {
         ZSTDMT_freeCCtx(mtctx);
         return NULL;
     }
     DEBUGLOG(3, "mt_cctx created, for %u threads", nbWorkers);
     return mtctx;
 }
 
 ZSTDMT_CCtx* ZSTDMT_createCCtx(unsigned nbWorkers)
 {
     return ZSTDMT_createCCtx_advanced(nbWorkers, ZSTD_defaultCMem);
 }
 
 
 /* ZSTDMT_releaseAllJobResources() :
  * note : ensure all workers are killed first ! */
 static void ZSTDMT_releaseAllJobResources(ZSTDMT_CCtx* mtctx)
 {
     unsigned jobID;
     DEBUGLOG(3, "ZSTDMT_releaseAllJobResources");
     for (jobID=0; jobID <= mtctx->jobIDMask; jobID++) {
         DEBUGLOG(4, "job%02u: release dst address %08X", jobID, (U32)(size_t)mtctx->jobs[jobID].dstBuff.start);
         ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].dstBuff);
         mtctx->jobs[jobID].dstBuff = g_nullBuffer;
         mtctx->jobs[jobID].cSize = 0;
     }
     memset(mtctx->jobs, 0, (mtctx->jobIDMask+1)*sizeof(ZSTDMT_jobDescription));
     mtctx->inBuff.buffer = g_nullBuffer;
     mtctx->inBuff.filled = 0;
     mtctx->allJobsCompleted = 1;
 }
 
 static void ZSTDMT_waitForAllJobsCompleted(ZSTDMT_CCtx* mtctx)
 {
     DEBUGLOG(4, "ZSTDMT_waitForAllJobsCompleted");
     while (mtctx->doneJobID < mtctx->nextJobID) {
         unsigned const jobID = mtctx->doneJobID & mtctx->jobIDMask;
         ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->jobs[jobID].job_mutex);
         while (mtctx->jobs[jobID].consumed < mtctx->jobs[jobID].src.size) {
-            DEBUGLOG(5, "waiting for jobCompleted signal from job %u", mtctx->doneJobID);   /* we want to block when waiting for data to flush */
+            DEBUGLOG(4, "waiting for jobCompleted signal from job %u", mtctx->doneJobID);   /* we want to block when waiting for data to flush */
             ZSTD_pthread_cond_wait(&mtctx->jobs[jobID].job_cond, &mtctx->jobs[jobID].job_mutex);
         }
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[jobID].job_mutex);
         mtctx->doneJobID++;
     }
 }
 
 size_t ZSTDMT_freeCCtx(ZSTDMT_CCtx* mtctx)
 {
     if (mtctx==NULL) return 0;   /* compatible with free on NULL */
     POOL_free(mtctx->factory);   /* stop and free worker threads */
     ZSTDMT_releaseAllJobResources(mtctx);  /* release job resources into pools first */
     ZSTDMT_freeJobsTable(mtctx->jobs, mtctx->jobIDMask+1, mtctx->cMem);
     ZSTDMT_freeBufferPool(mtctx->bufPool);
     ZSTDMT_freeCCtxPool(mtctx->cctxPool);
     ZSTDMT_freeSeqPool(mtctx->seqPool);
     ZSTDMT_serialState_free(&mtctx->serial);
     ZSTD_freeCDict(mtctx->cdictLocal);
     if (mtctx->roundBuff.buffer)
         ZSTD_free(mtctx->roundBuff.buffer, mtctx->cMem);
     ZSTD_free(mtctx, mtctx->cMem);
     return 0;
 }
 
 size_t ZSTDMT_sizeof_CCtx(ZSTDMT_CCtx* mtctx)
 {
     if (mtctx == NULL) return 0;   /* supports sizeof NULL */
     return sizeof(*mtctx)
             + POOL_sizeof(mtctx->factory)
             + ZSTDMT_sizeof_bufferPool(mtctx->bufPool)
             + (mtctx->jobIDMask+1) * sizeof(ZSTDMT_jobDescription)
             + ZSTDMT_sizeof_CCtxPool(mtctx->cctxPool)
             + ZSTDMT_sizeof_seqPool(mtctx->seqPool)
             + ZSTD_sizeof_CDict(mtctx->cdictLocal)
             + mtctx->roundBuff.capacity;
 }
 
 /* Internal only */
 size_t ZSTDMT_CCtxParam_setMTCtxParameter(ZSTD_CCtx_params* params,
                                 ZSTDMT_parameter parameter, unsigned value) {
     DEBUGLOG(4, "ZSTDMT_CCtxParam_setMTCtxParameter");
     switch(parameter)
     {
     case ZSTDMT_p_jobSize :
         DEBUGLOG(4, "ZSTDMT_CCtxParam_setMTCtxParameter : set jobSize to %u", value);
         if ( (value > 0)  /* value==0 => automatic job size */
            & (value < ZSTDMT_JOBSIZE_MIN) )
             value = ZSTDMT_JOBSIZE_MIN;
+        if (value > ZSTDMT_JOBSIZE_MAX)
+            value = ZSTDMT_JOBSIZE_MAX;
         params->jobSize = value;
         return value;
     case ZSTDMT_p_overlapSectionLog :
         if (value > 9) value = 9;
         DEBUGLOG(4, "ZSTDMT_p_overlapSectionLog : %u", value);
         params->overlapSizeLog = (value >= 9) ? 9 : value;
         return value;
     default :
         return ERROR(parameter_unsupported);
     }
 }
 
 size_t ZSTDMT_setMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSTDMT_parameter parameter, unsigned value)
 {
     DEBUGLOG(4, "ZSTDMT_setMTCtxParameter");
     switch(parameter)
     {
     case ZSTDMT_p_jobSize :
         return ZSTDMT_CCtxParam_setMTCtxParameter(&mtctx->params, parameter, value);
     case ZSTDMT_p_overlapSectionLog :
         return ZSTDMT_CCtxParam_setMTCtxParameter(&mtctx->params, parameter, value);
     default :
         return ERROR(parameter_unsupported);
     }
 }
 
+size_t ZSTDMT_getMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSTDMT_parameter parameter, unsigned* value)
+{
+    switch (parameter) {
+    case ZSTDMT_p_jobSize:
+        *value = mtctx->params.jobSize;
+        break;
+    case ZSTDMT_p_overlapSectionLog:
+        *value = mtctx->params.overlapSizeLog;
+        break;
+    default:
+        return ERROR(parameter_unsupported);
+    }
+    return 0;
+}
+
 /* Sets parameters relevant to the compression job,
  * initializing others to default values. */
 static ZSTD_CCtx_params ZSTDMT_initJobCCtxParams(ZSTD_CCtx_params const params)
 {
     ZSTD_CCtx_params jobParams;
     memset(&jobParams, 0, sizeof(jobParams));
 
     jobParams.cParams = params.cParams;
     jobParams.fParams = params.fParams;
     jobParams.compressionLevel = params.compressionLevel;
-    jobParams.disableLiteralCompression = params.disableLiteralCompression;
 
     return jobParams;
 }
 
+
+/* ZSTDMT_resize() :
+ * @return : error code if fails, 0 on success */
+static size_t ZSTDMT_resize(ZSTDMT_CCtx* mtctx, unsigned nbWorkers)
+{
+    if (POOL_resize(mtctx->factory, nbWorkers)) return ERROR(memory_allocation);
+    CHECK_F( ZSTDMT_expandJobsTable(mtctx, nbWorkers) );
+    mtctx->bufPool = ZSTDMT_expandBufferPool(mtctx->bufPool, nbWorkers);
+    if (mtctx->bufPool == NULL) return ERROR(memory_allocation);
+    mtctx->cctxPool = ZSTDMT_expandCCtxPool(mtctx->cctxPool, nbWorkers);
+    if (mtctx->cctxPool == NULL) return ERROR(memory_allocation);
+    mtctx->seqPool = ZSTDMT_expandSeqPool(mtctx->seqPool, nbWorkers);
+    if (mtctx->seqPool == NULL) return ERROR(memory_allocation);
+    ZSTDMT_CCtxParam_setNbWorkers(&mtctx->params, nbWorkers);
+    return 0;
+}
+
+
 /*! ZSTDMT_updateCParams_whileCompressing() :
- *  Updates only a selected set of compression parameters, to remain compatible with current frame.
+ *  Updates a selected set of compression parameters, remaining compatible with currently active frame.
  *  New parameters will be applied to next compression job. */
 void ZSTDMT_updateCParams_whileCompressing(ZSTDMT_CCtx* mtctx, const ZSTD_CCtx_params* cctxParams)
 {
     U32 const saved_wlog = mtctx->params.cParams.windowLog;   /* Do not modify windowLog while compressing */
     int const compressionLevel = cctxParams->compressionLevel;
     DEBUGLOG(5, "ZSTDMT_updateCParams_whileCompressing (level:%i)",
                 compressionLevel);
     mtctx->params.compressionLevel = compressionLevel;
     {   ZSTD_compressionParameters cParams = ZSTD_getCParamsFromCCtxParams(cctxParams, 0, 0);
         cParams.windowLog = saved_wlog;
         mtctx->params.cParams = cParams;
     }
 }
 
-/* ZSTDMT_getNbWorkers():
- * @return nb threads currently active in mtctx.
- * mtctx must be valid */
-unsigned ZSTDMT_getNbWorkers(const ZSTDMT_CCtx* mtctx)
-{
-    assert(mtctx != NULL);
-    return mtctx->params.nbWorkers;
-}
-
 /* ZSTDMT_getFrameProgression():
  * tells how much data has been consumed (input) and produced (output) for current frame.
  * able to count progression inside worker threads.
- * Note : mutex will be acquired during statistics collection. */
+ * Note : mutex will be acquired during statistics collection inside workers. */
 ZSTD_frameProgression ZSTDMT_getFrameProgression(ZSTDMT_CCtx* mtctx)
 {
     ZSTD_frameProgression fps;
-    DEBUGLOG(6, "ZSTDMT_getFrameProgression");
-    fps.consumed = mtctx->consumed;
-    fps.produced = mtctx->produced;
+    DEBUGLOG(5, "ZSTDMT_getFrameProgression");
     fps.ingested = mtctx->consumed + mtctx->inBuff.filled;
+    fps.consumed = mtctx->consumed;
+    fps.produced = fps.flushed = mtctx->produced;
+    fps.currentJobID = mtctx->nextJobID;
+    fps.nbActiveWorkers = 0;
     {   unsigned jobNb;
         unsigned lastJobNb = mtctx->nextJobID + mtctx->jobReady; assert(mtctx->jobReady <= 1);
         DEBUGLOG(6, "ZSTDMT_getFrameProgression: jobs: from %u to <%u (jobReady:%u)",
                     mtctx->doneJobID, lastJobNb, mtctx->jobReady)
         for (jobNb = mtctx->doneJobID ; jobNb < lastJobNb ; jobNb++) {
             unsigned const wJobID = jobNb & mtctx->jobIDMask;
-            ZSTD_pthread_mutex_lock(&mtctx->jobs[wJobID].job_mutex);
-            {   size_t const cResult = mtctx->jobs[wJobID].cSize;
+            ZSTDMT_jobDescription* jobPtr = &mtctx->jobs[wJobID];
+            ZSTD_pthread_mutex_lock(&jobPtr->job_mutex);
+            {   size_t const cResult = jobPtr->cSize;
                 size_t const produced = ZSTD_isError(cResult) ? 0 : cResult;
-                fps.consumed += mtctx->jobs[wJobID].consumed;
-                fps.ingested += mtctx->jobs[wJobID].src.size;
+                size_t const flushed = ZSTD_isError(cResult) ? 0 : jobPtr->dstFlushed;
+                assert(flushed <= produced);
+                fps.ingested += jobPtr->src.size;
+                fps.consumed += jobPtr->consumed;
                 fps.produced += produced;
+                fps.flushed  += flushed;
+                fps.nbActiveWorkers += (jobPtr->consumed < jobPtr->src.size);
             }
             ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
         }
     }
     return fps;
 }
 
 
+size_t ZSTDMT_toFlushNow(ZSTDMT_CCtx* mtctx)
+{
+    size_t toFlush;
+    unsigned const jobID = mtctx->doneJobID;
+    assert(jobID <= mtctx->nextJobID);
+    if (jobID == mtctx->nextJobID) return 0;   /* no active job => nothing to flush */
+
+    /* look into oldest non-fully-flushed job */
+    {   unsigned const wJobID = jobID & mtctx->jobIDMask;
+        ZSTDMT_jobDescription* const jobPtr = &mtctx->jobs[wJobID];
+        ZSTD_pthread_mutex_lock(&jobPtr->job_mutex);
+        {   size_t const cResult = jobPtr->cSize;
+            size_t const produced = ZSTD_isError(cResult) ? 0 : cResult;
+            size_t const flushed = ZSTD_isError(cResult) ? 0 : jobPtr->dstFlushed;
+            assert(flushed <= produced);
+            toFlush = produced - flushed;
+            if (toFlush==0 && (jobPtr->consumed >= jobPtr->src.size)) {
+                /* doneJobID is not-fully-flushed, but toFlush==0 : doneJobID should be compressing some more data */
+                assert(jobPtr->consumed < jobPtr->src.size);
+            }
+        }
+        ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
+    }
+
+    return toFlush;
+}
+
+
 /* ------------------------------------------ */
 /* =====   Multi-threaded compression   ===== */
 /* ------------------------------------------ */
 
 static size_t ZSTDMT_computeTargetJobLog(ZSTD_CCtx_params const params)
 {
     if (params.ldmParams.enableLdm)
         return MAX(21, params.cParams.chainLog + 4);
     return MAX(20, params.cParams.windowLog + 2);
 }
 
 static size_t ZSTDMT_computeOverlapLog(ZSTD_CCtx_params const params)
 {
     unsigned const overlapRLog = (params.overlapSizeLog>9) ? 0 : 9-params.overlapSizeLog;
     if (params.ldmParams.enableLdm)
         return (MIN(params.cParams.windowLog, ZSTDMT_computeTargetJobLog(params) - 2) - overlapRLog);
     return overlapRLog >= 9 ? 0 : (params.cParams.windowLog - overlapRLog);
 }
 
 static unsigned ZSTDMT_computeNbJobs(ZSTD_CCtx_params params, size_t srcSize, unsigned nbWorkers) {
     assert(nbWorkers>0);
     {   size_t const jobSizeTarget = (size_t)1 << ZSTDMT_computeTargetJobLog(params);
         size_t const jobMaxSize = jobSizeTarget << 2;
         size_t const passSizeMax = jobMaxSize * nbWorkers;
         unsigned const multiplier = (unsigned)(srcSize / passSizeMax) + 1;
         unsigned const nbJobsLarge = multiplier * nbWorkers;
         unsigned const nbJobsMax = (unsigned)(srcSize / jobSizeTarget) + 1;
         unsigned const nbJobsSmall = MIN(nbJobsMax, nbWorkers);
         return (multiplier>1) ? nbJobsLarge : nbJobsSmall;
 }   }
 
 /* ZSTDMT_compress_advanced_internal() :
  * This is a blocking function : it will only give back control to caller after finishing its compression job.
  */
 static size_t ZSTDMT_compress_advanced_internal(
                 ZSTDMT_CCtx* mtctx,
                 void* dst, size_t dstCapacity,
           const void* src, size_t srcSize,
           const ZSTD_CDict* cdict,
                 ZSTD_CCtx_params params)
 {
     ZSTD_CCtx_params const jobParams = ZSTDMT_initJobCCtxParams(params);
     size_t const overlapSize = (size_t)1 << ZSTDMT_computeOverlapLog(params);
     unsigned const nbJobs = ZSTDMT_computeNbJobs(params, srcSize, params.nbWorkers);
     size_t const proposedJobSize = (srcSize + (nbJobs-1)) / nbJobs;
     size_t const avgJobSize = (((proposedJobSize-1) & 0x1FFFF) < 0x7FFF) ? proposedJobSize + 0xFFFF : proposedJobSize;   /* avoid too small last block */
     const char* const srcStart = (const char*)src;
     size_t remainingSrcSize = srcSize;
     unsigned const compressWithinDst = (dstCapacity >= ZSTD_compressBound(srcSize)) ? nbJobs : (unsigned)(dstCapacity / ZSTD_compressBound(avgJobSize));  /* presumes avgJobSize >= 256 KB, which should be the case */
     size_t frameStartPos = 0, dstBufferPos = 0;
     assert(jobParams.nbWorkers == 0);
     assert(mtctx->cctxPool->totalCCtx == params.nbWorkers);
 
     params.jobSize = (U32)avgJobSize;
     DEBUGLOG(4, "ZSTDMT_compress_advanced_internal: nbJobs=%2u (rawSize=%u bytes; fixedSize=%u) ",
                 nbJobs, (U32)proposedJobSize, (U32)avgJobSize);
 
     if ((nbJobs==1) | (params.nbWorkers<=1)) {   /* fallback to single-thread mode : this is a blocking invocation anyway */
         ZSTD_CCtx* const cctx = mtctx->cctxPool->cctx[0];
         DEBUGLOG(4, "ZSTDMT_compress_advanced_internal: fallback to single-thread mode");
         if (cdict) return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, jobParams.fParams);
         return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, NULL, 0, jobParams);
     }
 
     assert(avgJobSize >= 256 KB);  /* condition for ZSTD_compressBound(A) + ZSTD_compressBound(B) <= ZSTD_compressBound(A+B), required to compress directly into Dst (no additional buffer) */
     ZSTDMT_setBufferSize(mtctx->bufPool, ZSTD_compressBound(avgJobSize) );
-    if (ZSTDMT_serialState_reset(&mtctx->serial, mtctx->seqPool, params))
+    if (ZSTDMT_serialState_reset(&mtctx->serial, mtctx->seqPool, params, avgJobSize))
         return ERROR(memory_allocation);
 
-    if (nbJobs > mtctx->jobIDMask+1) {  /* enlarge job table */
-        U32 jobsTableSize = nbJobs;
-        ZSTDMT_freeJobsTable(mtctx->jobs, mtctx->jobIDMask+1, mtctx->cMem);
-        mtctx->jobIDMask = 0;
-        mtctx->jobs = ZSTDMT_createJobsTable(&jobsTableSize, mtctx->cMem);
-        if (mtctx->jobs==NULL) return ERROR(memory_allocation);
-        assert((jobsTableSize != 0) && ((jobsTableSize & (jobsTableSize - 1)) == 0));  /* ensure jobsTableSize is a power of 2 */
-        mtctx->jobIDMask = jobsTableSize - 1;
-    }
+    CHECK_F( ZSTDMT_expandJobsTable(mtctx, nbJobs) );  /* only expands if necessary */
 
     {   unsigned u;
         for (u=0; ujobs[u].prefix.start = srcStart + frameStartPos - dictSize;
             mtctx->jobs[u].prefix.size = dictSize;
             mtctx->jobs[u].src.start = srcStart + frameStartPos;
             mtctx->jobs[u].src.size = jobSize; assert(jobSize > 0);  /* avoid job.src.size == 0 */
             mtctx->jobs[u].consumed = 0;
             mtctx->jobs[u].cSize = 0;
             mtctx->jobs[u].cdict = (u==0) ? cdict : NULL;
             mtctx->jobs[u].fullFrameSize = srcSize;
             mtctx->jobs[u].params = jobParams;
             /* do not calculate checksum within sections, but write it in header for first section */
             mtctx->jobs[u].dstBuff = dstBuffer;
             mtctx->jobs[u].cctxPool = mtctx->cctxPool;
             mtctx->jobs[u].bufPool = mtctx->bufPool;
             mtctx->jobs[u].seqPool = mtctx->seqPool;
             mtctx->jobs[u].serial = &mtctx->serial;
             mtctx->jobs[u].jobID = u;
             mtctx->jobs[u].firstJob = (u==0);
             mtctx->jobs[u].lastJob = (u==nbJobs-1);
 
             DEBUGLOG(5, "ZSTDMT_compress_advanced_internal: posting job %u  (%u bytes)", u, (U32)jobSize);
             DEBUG_PRINTHEX(6, mtctx->jobs[u].prefix.start, 12);
             POOL_add(mtctx->factory, ZSTDMT_compressionJob, &mtctx->jobs[u]);
 
             frameStartPos += jobSize;
             dstBufferPos += dstBufferCapacity;
             remainingSrcSize -= jobSize;
     }   }
 
     /* collect result */
     {   size_t error = 0, dstPos = 0;
         unsigned jobID;
         for (jobID=0; jobIDjobs[jobID].job_mutex);
             while (mtctx->jobs[jobID].consumed < mtctx->jobs[jobID].src.size) {
                 DEBUGLOG(5, "waiting for jobCompleted signal from job %u", jobID);
                 ZSTD_pthread_cond_wait(&mtctx->jobs[jobID].job_cond, &mtctx->jobs[jobID].job_mutex);
             }
             ZSTD_pthread_mutex_unlock(&mtctx->jobs[jobID].job_mutex);
             DEBUGLOG(5, "ready to write job %u ", jobID);
 
             {   size_t const cSize = mtctx->jobs[jobID].cSize;
                 if (ZSTD_isError(cSize)) error = cSize;
                 if ((!error) && (dstPos + cSize > dstCapacity)) error = ERROR(dstSize_tooSmall);
                 if (jobID) {   /* note : job 0 is written directly at dst, which is correct position */
                     if (!error)
                         memmove((char*)dst + dstPos, mtctx->jobs[jobID].dstBuff.start, cSize);  /* may overlap when job compressed within dst */
                     if (jobID >= compressWithinDst) {  /* job compressed into its own buffer, which must be released */
                         DEBUGLOG(5, "releasing buffer %u>=%u", jobID, compressWithinDst);
                         ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].dstBuff);
                 }   }
                 mtctx->jobs[jobID].dstBuff = g_nullBuffer;
                 mtctx->jobs[jobID].cSize = 0;
                 dstPos += cSize ;
             }
         }  /* for (jobID=0; jobIDserial.xxhState);
             if (dstPos + 4 > dstCapacity) {
                 error = ERROR(dstSize_tooSmall);
             } else {
                 DEBUGLOG(4, "writing checksum : %08X \n", checksum);
                 MEM_writeLE32((char*)dst + dstPos, checksum);
                 dstPos += 4;
         }   }
 
         if (!error) DEBUGLOG(4, "compressed size : %u  ", (U32)dstPos);
         return error ? error : dstPos;
     }
 }
 
 size_t ZSTDMT_compress_advanced(ZSTDMT_CCtx* mtctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const ZSTD_CDict* cdict,
                                ZSTD_parameters params,
                                unsigned overlapLog)
 {
     ZSTD_CCtx_params cctxParams = mtctx->params;
     cctxParams.cParams = params.cParams;
     cctxParams.fParams = params.fParams;
     cctxParams.overlapSizeLog = overlapLog;
     return ZSTDMT_compress_advanced_internal(mtctx,
                                              dst, dstCapacity,
                                              src, srcSize,
                                              cdict, cctxParams);
 }
 
 
 size_t ZSTDMT_compressCCtx(ZSTDMT_CCtx* mtctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize,
                            int compressionLevel)
 {
     U32 const overlapLog = (compressionLevel >= ZSTD_maxCLevel()) ? 9 : ZSTDMT_OVERLAPLOG_DEFAULT;
     ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, 0);
     params.fParams.contentSizeFlag = 1;
     return ZSTDMT_compress_advanced(mtctx, dst, dstCapacity, src, srcSize, NULL, params, overlapLog);
 }
 
 
 /* ====================================== */
 /* =======      Streaming API     ======= */
 /* ====================================== */
 
 size_t ZSTDMT_initCStream_internal(
         ZSTDMT_CCtx* mtctx,
         const void* dict, size_t dictSize, ZSTD_dictContentType_e dictContentType,
         const ZSTD_CDict* cdict, ZSTD_CCtx_params params,
         unsigned long long pledgedSrcSize)
 {
-    DEBUGLOG(4, "ZSTDMT_initCStream_internal (pledgedSrcSize=%u, nbWorkers=%u, cctxPool=%u, disableLiteralCompression=%i)",
-                (U32)pledgedSrcSize, params.nbWorkers, mtctx->cctxPool->totalCCtx, params.disableLiteralCompression);
-    /* params are supposed to be fully validated at this point */
+    DEBUGLOG(4, "ZSTDMT_initCStream_internal (pledgedSrcSize=%u, nbWorkers=%u, cctxPool=%u)",
+                (U32)pledgedSrcSize, params.nbWorkers, mtctx->cctxPool->totalCCtx);
+
+    /* params supposed partially fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
-    assert(mtctx->cctxPool->totalCCtx == params.nbWorkers);
 
     /* init */
-    if (params.jobSize == 0) {
-        params.jobSize = 1U << ZSTDMT_computeTargetJobLog(params);
-    }
+    if (params.nbWorkers != mtctx->params.nbWorkers)
+        CHECK_F( ZSTDMT_resize(mtctx, params.nbWorkers) );
+
+    if (params.jobSize > 0 && params.jobSize < ZSTDMT_JOBSIZE_MIN) params.jobSize = ZSTDMT_JOBSIZE_MIN;
     if (params.jobSize > ZSTDMT_JOBSIZE_MAX) params.jobSize = ZSTDMT_JOBSIZE_MAX;
 
     mtctx->singleBlockingThread = (pledgedSrcSize <= ZSTDMT_JOBSIZE_MIN);  /* do not trigger multi-threading when srcSize is too small */
     if (mtctx->singleBlockingThread) {
         ZSTD_CCtx_params const singleThreadParams = ZSTDMT_initJobCCtxParams(params);
         DEBUGLOG(5, "ZSTDMT_initCStream_internal: switch to single blocking thread mode");
         assert(singleThreadParams.nbWorkers == 0);
         return ZSTD_initCStream_internal(mtctx->cctxPool->cctx[0],
                                          dict, dictSize, cdict,
                                          singleThreadParams, pledgedSrcSize);
     }
 
     DEBUGLOG(4, "ZSTDMT_initCStream_internal: %u workers", params.nbWorkers);
 
     if (mtctx->allJobsCompleted == 0) {   /* previous compression not correctly finished */
         ZSTDMT_waitForAllJobsCompleted(mtctx);
         ZSTDMT_releaseAllJobResources(mtctx);
         mtctx->allJobsCompleted = 1;
     }
 
     mtctx->params = params;
     mtctx->frameContentSize = pledgedSrcSize;
     if (dict) {
         ZSTD_freeCDict(mtctx->cdictLocal);
         mtctx->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize,
                                                     ZSTD_dlm_byCopy, dictContentType, /* note : a loadPrefix becomes an internal CDict */
                                                     params.cParams, mtctx->cMem);
         mtctx->cdict = mtctx->cdictLocal;
         if (mtctx->cdictLocal == NULL) return ERROR(memory_allocation);
     } else {
         ZSTD_freeCDict(mtctx->cdictLocal);
         mtctx->cdictLocal = NULL;
         mtctx->cdict = cdict;
     }
 
     mtctx->targetPrefixSize = (size_t)1 << ZSTDMT_computeOverlapLog(params);
     DEBUGLOG(4, "overlapLog=%u => %u KB", params.overlapSizeLog, (U32)(mtctx->targetPrefixSize>>10));
     mtctx->targetSectionSize = params.jobSize;
-    if (mtctx->targetSectionSize < ZSTDMT_JOBSIZE_MIN) mtctx->targetSectionSize = ZSTDMT_JOBSIZE_MIN;
+    if (mtctx->targetSectionSize == 0) {
+        mtctx->targetSectionSize = 1ULL << ZSTDMT_computeTargetJobLog(params);
+    }
     if (mtctx->targetSectionSize < mtctx->targetPrefixSize) mtctx->targetSectionSize = mtctx->targetPrefixSize;  /* job size must be >= overlap size */
     DEBUGLOG(4, "Job Size : %u KB (note : set to %u)", (U32)(mtctx->targetSectionSize>>10), params.jobSize);
     DEBUGLOG(4, "inBuff Size : %u KB", (U32)(mtctx->targetSectionSize>>10));
     ZSTDMT_setBufferSize(mtctx->bufPool, ZSTD_compressBound(mtctx->targetSectionSize));
     {
         /* If ldm is enabled we need windowSize space. */
         size_t const windowSize = mtctx->params.ldmParams.enableLdm ? (1U << mtctx->params.cParams.windowLog) : 0;
         /* Two buffers of slack, plus extra space for the overlap
          * This is the minimum slack that LDM works with. One extra because
          * flush might waste up to targetSectionSize-1 bytes. Another extra
          * for the overlap (if > 0), then one to fill which doesn't overlap
          * with the LDM window.
          */
         size_t const nbSlackBuffers = 2 + (mtctx->targetPrefixSize > 0);
         size_t const slackSize = mtctx->targetSectionSize * nbSlackBuffers;
         /* Compute the total size, and always have enough slack */
         size_t const nbWorkers = MAX(mtctx->params.nbWorkers, 1);
         size_t const sectionsSize = mtctx->targetSectionSize * nbWorkers;
         size_t const capacity = MAX(windowSize, sectionsSize) + slackSize;
         if (mtctx->roundBuff.capacity < capacity) {
             if (mtctx->roundBuff.buffer)
                 ZSTD_free(mtctx->roundBuff.buffer, mtctx->cMem);
             mtctx->roundBuff.buffer = (BYTE*)ZSTD_malloc(capacity, mtctx->cMem);
             if (mtctx->roundBuff.buffer == NULL) {
                 mtctx->roundBuff.capacity = 0;
                 return ERROR(memory_allocation);
             }
             mtctx->roundBuff.capacity = capacity;
         }
     }
     DEBUGLOG(4, "roundBuff capacity : %u KB", (U32)(mtctx->roundBuff.capacity>>10));
     mtctx->roundBuff.pos = 0;
     mtctx->inBuff.buffer = g_nullBuffer;
     mtctx->inBuff.filled = 0;
     mtctx->inBuff.prefix = kNullRange;
     mtctx->doneJobID = 0;
     mtctx->nextJobID = 0;
     mtctx->frameEnded = 0;
     mtctx->allJobsCompleted = 0;
     mtctx->consumed = 0;
     mtctx->produced = 0;
-    if (ZSTDMT_serialState_reset(&mtctx->serial, mtctx->seqPool, params))
+    if (ZSTDMT_serialState_reset(&mtctx->serial, mtctx->seqPool, params, mtctx->targetSectionSize))
         return ERROR(memory_allocation);
     return 0;
 }
 
 size_t ZSTDMT_initCStream_advanced(ZSTDMT_CCtx* mtctx,
                              const void* dict, size_t dictSize,
                                    ZSTD_parameters params,
                                    unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params cctxParams = mtctx->params;  /* retrieve sticky params */
     DEBUGLOG(4, "ZSTDMT_initCStream_advanced (pledgedSrcSize=%u)", (U32)pledgedSrcSize);
     cctxParams.cParams = params.cParams;
     cctxParams.fParams = params.fParams;
     return ZSTDMT_initCStream_internal(mtctx, dict, dictSize, ZSTD_dct_auto, NULL,
                                        cctxParams, pledgedSrcSize);
 }
 
 size_t ZSTDMT_initCStream_usingCDict(ZSTDMT_CCtx* mtctx,
                                const ZSTD_CDict* cdict,
                                      ZSTD_frameParameters fParams,
                                      unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params cctxParams = mtctx->params;
     if (cdict==NULL) return ERROR(dictionary_wrong);   /* method incompatible with NULL cdict */
     cctxParams.cParams = ZSTD_getCParamsFromCDict(cdict);
     cctxParams.fParams = fParams;
     return ZSTDMT_initCStream_internal(mtctx, NULL, 0 /*dictSize*/, ZSTD_dct_auto, cdict,
                                        cctxParams, pledgedSrcSize);
 }
 
 
 /* ZSTDMT_resetCStream() :
  * pledgedSrcSize can be zero == unknown (for the time being)
  * prefer using ZSTD_CONTENTSIZE_UNKNOWN,
  * as `0` might mean "empty" in the future */
 size_t ZSTDMT_resetCStream(ZSTDMT_CCtx* mtctx, unsigned long long pledgedSrcSize)
 {
     if (!pledgedSrcSize) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
     return ZSTDMT_initCStream_internal(mtctx, NULL, 0, ZSTD_dct_auto, 0, mtctx->params,
                                        pledgedSrcSize);
 }
 
 size_t ZSTDMT_initCStream(ZSTDMT_CCtx* mtctx, int compressionLevel) {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, 0);
     ZSTD_CCtx_params cctxParams = mtctx->params;   /* retrieve sticky params */
     DEBUGLOG(4, "ZSTDMT_initCStream (cLevel=%i)", compressionLevel);
     cctxParams.cParams = params.cParams;
     cctxParams.fParams = params.fParams;
     return ZSTDMT_initCStream_internal(mtctx, NULL, 0, ZSTD_dct_auto, NULL, cctxParams, ZSTD_CONTENTSIZE_UNKNOWN);
 }
 
 
 /* ZSTDMT_writeLastEmptyBlock()
  * Write a single empty block with an end-of-frame to finish a frame.
  * Job must be created from streaming variant.
  * This function is always successfull if expected conditions are fulfilled.
  */
 static void ZSTDMT_writeLastEmptyBlock(ZSTDMT_jobDescription* job)
 {
     assert(job->lastJob == 1);
     assert(job->src.size == 0);   /* last job is empty -> will be simplified into a last empty block */
     assert(job->firstJob == 0);   /* cannot be first job, as it also needs to create frame header */
     assert(job->dstBuff.start == NULL);   /* invoked from streaming variant only (otherwise, dstBuff might be user's output) */
     job->dstBuff = ZSTDMT_getBuffer(job->bufPool);
     if (job->dstBuff.start == NULL) {
       job->cSize = ERROR(memory_allocation);
       return;
     }
     assert(job->dstBuff.capacity >= ZSTD_blockHeaderSize);   /* no buffer should ever be that small */
     job->src = kNullRange;
     job->cSize = ZSTD_writeLastEmptyBlock(job->dstBuff.start, job->dstBuff.capacity);
     assert(!ZSTD_isError(job->cSize));
     assert(job->consumed == 0);
 }
 
 static size_t ZSTDMT_createCompressionJob(ZSTDMT_CCtx* mtctx, size_t srcSize, ZSTD_EndDirective endOp)
 {
     unsigned const jobID = mtctx->nextJobID & mtctx->jobIDMask;
     int const endFrame = (endOp == ZSTD_e_end);
 
     if (mtctx->nextJobID > mtctx->doneJobID + mtctx->jobIDMask) {
         DEBUGLOG(5, "ZSTDMT_createCompressionJob: will not create new job : table is full");
         assert((mtctx->nextJobID & mtctx->jobIDMask) == (mtctx->doneJobID & mtctx->jobIDMask));
         return 0;
     }
 
     if (!mtctx->jobReady) {
         BYTE const* src = (BYTE const*)mtctx->inBuff.buffer.start;
         DEBUGLOG(5, "ZSTDMT_createCompressionJob: preparing job %u to compress %u bytes with %u preload ",
                     mtctx->nextJobID, (U32)srcSize, (U32)mtctx->inBuff.prefix.size);
         mtctx->jobs[jobID].src.start = src;
         mtctx->jobs[jobID].src.size = srcSize;
         assert(mtctx->inBuff.filled >= srcSize);
         mtctx->jobs[jobID].prefix = mtctx->inBuff.prefix;
         mtctx->jobs[jobID].consumed = 0;
         mtctx->jobs[jobID].cSize = 0;
         mtctx->jobs[jobID].params = mtctx->params;
         mtctx->jobs[jobID].cdict = mtctx->nextJobID==0 ? mtctx->cdict : NULL;
         mtctx->jobs[jobID].fullFrameSize = mtctx->frameContentSize;
         mtctx->jobs[jobID].dstBuff = g_nullBuffer;
         mtctx->jobs[jobID].cctxPool = mtctx->cctxPool;
         mtctx->jobs[jobID].bufPool = mtctx->bufPool;
         mtctx->jobs[jobID].seqPool = mtctx->seqPool;
         mtctx->jobs[jobID].serial = &mtctx->serial;
         mtctx->jobs[jobID].jobID = mtctx->nextJobID;
         mtctx->jobs[jobID].firstJob = (mtctx->nextJobID==0);
         mtctx->jobs[jobID].lastJob = endFrame;
-        mtctx->jobs[jobID].frameChecksumNeeded = endFrame && (mtctx->nextJobID>0) && mtctx->params.fParams.checksumFlag;
+        mtctx->jobs[jobID].frameChecksumNeeded = mtctx->params.fParams.checksumFlag && endFrame && (mtctx->nextJobID>0);
         mtctx->jobs[jobID].dstFlushed = 0;
 
         /* Update the round buffer pos and clear the input buffer to be reset */
         mtctx->roundBuff.pos += srcSize;
         mtctx->inBuff.buffer = g_nullBuffer;
         mtctx->inBuff.filled = 0;
         /* Set the prefix */
         if (!endFrame) {
             size_t const newPrefixSize = MIN(srcSize, mtctx->targetPrefixSize);
             mtctx->inBuff.prefix.start = src + srcSize - newPrefixSize;
             mtctx->inBuff.prefix.size = newPrefixSize;
         } else {   /* endFrame==1 => no need for another input buffer */
             mtctx->inBuff.prefix = kNullRange;
             mtctx->frameEnded = endFrame;
             if (mtctx->nextJobID == 0) {
                 /* single job exception : checksum is already calculated directly within worker thread */
                 mtctx->params.fParams.checksumFlag = 0;
         }   }
 
         if ( (srcSize == 0)
           && (mtctx->nextJobID>0)/*single job must also write frame header*/ ) {
             DEBUGLOG(5, "ZSTDMT_createCompressionJob: creating a last empty block to end frame");
             assert(endOp == ZSTD_e_end);  /* only possible case : need to end the frame with an empty last block */
             ZSTDMT_writeLastEmptyBlock(mtctx->jobs + jobID);
             mtctx->nextJobID++;
             return 0;
         }
     }
 
     DEBUGLOG(5, "ZSTDMT_createCompressionJob: posting job %u : %u bytes  (end:%u, jobNb == %u (mod:%u))",
                 mtctx->nextJobID,
                 (U32)mtctx->jobs[jobID].src.size,
                 mtctx->jobs[jobID].lastJob,
                 mtctx->nextJobID,
                 jobID);
     if (POOL_tryAdd(mtctx->factory, ZSTDMT_compressionJob, &mtctx->jobs[jobID])) {
         mtctx->nextJobID++;
         mtctx->jobReady = 0;
     } else {
         DEBUGLOG(5, "ZSTDMT_createCompressionJob: no worker available for job %u", mtctx->nextJobID);
         mtctx->jobReady = 1;
     }
     return 0;
 }
 
 
 /*! ZSTDMT_flushProduced() :
+ *  flush whatever data has been produced but not yet flushed in current job.
+ *  move to next job if current one is fully flushed.
  * `output` : `pos` will be updated with amount of data flushed .
  * `blockToFlush` : if >0, the function will block and wait if there is no data available to flush .
  * @return : amount of data remaining within internal buffer, 0 if no more, 1 if unknown but > 0, or an error code */
 static size_t ZSTDMT_flushProduced(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, unsigned blockToFlush, ZSTD_EndDirective end)
 {
     unsigned const wJobID = mtctx->doneJobID & mtctx->jobIDMask;
     DEBUGLOG(5, "ZSTDMT_flushProduced (blocking:%u , job %u <= %u)",
                 blockToFlush, mtctx->doneJobID, mtctx->nextJobID);
     assert(output->size >= output->pos);
 
     ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->jobs[wJobID].job_mutex);
     if (  blockToFlush
       && (mtctx->doneJobID < mtctx->nextJobID) ) {
         assert(mtctx->jobs[wJobID].dstFlushed <= mtctx->jobs[wJobID].cSize);
         while (mtctx->jobs[wJobID].dstFlushed == mtctx->jobs[wJobID].cSize) {  /* nothing to flush */
             if (mtctx->jobs[wJobID].consumed == mtctx->jobs[wJobID].src.size) {
                 DEBUGLOG(5, "job %u is completely consumed (%u == %u) => don't wait for cond, there will be none",
                             mtctx->doneJobID, (U32)mtctx->jobs[wJobID].consumed, (U32)mtctx->jobs[wJobID].src.size);
                 break;
             }
             DEBUGLOG(5, "waiting for something to flush from job %u (currently flushed: %u bytes)",
                         mtctx->doneJobID, (U32)mtctx->jobs[wJobID].dstFlushed);
             ZSTD_pthread_cond_wait(&mtctx->jobs[wJobID].job_cond, &mtctx->jobs[wJobID].job_mutex);  /* block when nothing to flush but some to come */
     }   }
 
     /* try to flush something */
     {   size_t cSize = mtctx->jobs[wJobID].cSize;                  /* shared */
         size_t const srcConsumed = mtctx->jobs[wJobID].consumed;   /* shared */
-        size_t const srcSize = mtctx->jobs[wJobID].src.size;        /* read-only, could be done after mutex lock, but no-declaration-after-statement */
+        size_t const srcSize = mtctx->jobs[wJobID].src.size;       /* read-only, could be done after mutex lock, but no-declaration-after-statement */
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
         if (ZSTD_isError(cSize)) {
             DEBUGLOG(5, "ZSTDMT_flushProduced: job %u : compression error detected : %s",
                         mtctx->doneJobID, ZSTD_getErrorName(cSize));
             ZSTDMT_waitForAllJobsCompleted(mtctx);
             ZSTDMT_releaseAllJobResources(mtctx);
             return cSize;
         }
         /* add frame checksum if necessary (can only happen once) */
         assert(srcConsumed <= srcSize);
         if ( (srcConsumed == srcSize)   /* job completed -> worker no longer active */
           && mtctx->jobs[wJobID].frameChecksumNeeded ) {
             U32 const checksum = (U32)XXH64_digest(&mtctx->serial.xxhState);
             DEBUGLOG(4, "ZSTDMT_flushProduced: writing checksum : %08X \n", checksum);
             MEM_writeLE32((char*)mtctx->jobs[wJobID].dstBuff.start + mtctx->jobs[wJobID].cSize, checksum);
             cSize += 4;
             mtctx->jobs[wJobID].cSize += 4;  /* can write this shared value, as worker is no longer active */
             mtctx->jobs[wJobID].frameChecksumNeeded = 0;
         }
+
         if (cSize > 0) {   /* compression is ongoing or completed */
             size_t const toFlush = MIN(cSize - mtctx->jobs[wJobID].dstFlushed, output->size - output->pos);
             DEBUGLOG(5, "ZSTDMT_flushProduced: Flushing %u bytes from job %u (completion:%u/%u, generated:%u)",
                         (U32)toFlush, mtctx->doneJobID, (U32)srcConsumed, (U32)srcSize, (U32)cSize);
             assert(mtctx->doneJobID < mtctx->nextJobID);
             assert(cSize >= mtctx->jobs[wJobID].dstFlushed);
             assert(mtctx->jobs[wJobID].dstBuff.start != NULL);
             memcpy((char*)output->dst + output->pos,
                    (const char*)mtctx->jobs[wJobID].dstBuff.start + mtctx->jobs[wJobID].dstFlushed,
                    toFlush);
             output->pos += toFlush;
             mtctx->jobs[wJobID].dstFlushed += toFlush;  /* can write : this value is only used by mtctx */
 
-            if ( (srcConsumed == srcSize)    /* job completed */
+            if ( (srcConsumed == srcSize)    /* job is completed */
               && (mtctx->jobs[wJobID].dstFlushed == cSize) ) {   /* output buffer fully flushed => free this job position */
                 DEBUGLOG(5, "Job %u completed (%u bytes), moving to next one",
                         mtctx->doneJobID, (U32)mtctx->jobs[wJobID].dstFlushed);
                 ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[wJobID].dstBuff);
+                DEBUGLOG(5, "dstBuffer released");
                 mtctx->jobs[wJobID].dstBuff = g_nullBuffer;
                 mtctx->jobs[wJobID].cSize = 0;   /* ensure this job slot is considered "not started" in future check */
                 mtctx->consumed += srcSize;
                 mtctx->produced += cSize;
                 mtctx->doneJobID++;
         }   }
 
         /* return value : how many bytes left in buffer ; fake it to 1 when unknown but >0 */
         if (cSize > mtctx->jobs[wJobID].dstFlushed) return (cSize - mtctx->jobs[wJobID].dstFlushed);
         if (srcSize > srcConsumed) return 1;   /* current job not completely compressed */
     }
     if (mtctx->doneJobID < mtctx->nextJobID) return 1;   /* some more jobs ongoing */
     if (mtctx->jobReady) return 1;      /* one job is ready to push, just not yet in the list */
     if (mtctx->inBuff.filled > 0) return 1;   /* input is not empty, and still needs to be converted into a job */
     mtctx->allJobsCompleted = mtctx->frameEnded;   /* all jobs are entirely flushed => if this one is last one, frame is completed */
     if (end == ZSTD_e_end) return !mtctx->frameEnded;  /* for ZSTD_e_end, question becomes : is frame completed ? instead of : are internal buffers fully flushed ? */
     return 0;   /* internal buffers fully flushed */
 }
 
 /**
  * Returns the range of data used by the earliest job that is not yet complete.
  * If the data of the first job is broken up into two segments, we cover both
  * sections.
  */
 static range_t ZSTDMT_getInputDataInUse(ZSTDMT_CCtx* mtctx)
 {
     unsigned const firstJobID = mtctx->doneJobID;
     unsigned const lastJobID = mtctx->nextJobID;
     unsigned jobID;
 
     for (jobID = firstJobID; jobID < lastJobID; ++jobID) {
         unsigned const wJobID = jobID & mtctx->jobIDMask;
         size_t consumed;
 
         ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->jobs[wJobID].job_mutex);
         consumed = mtctx->jobs[wJobID].consumed;
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
 
         if (consumed < mtctx->jobs[wJobID].src.size) {
             range_t range = mtctx->jobs[wJobID].prefix;
             if (range.size == 0) {
                 /* Empty prefix */
                 range = mtctx->jobs[wJobID].src;
             }
             /* Job source in multiple segments not supported yet */
             assert(range.start <= mtctx->jobs[wJobID].src.start);
             return range;
         }
     }
     return kNullRange;
 }
 
 /**
  * Returns non-zero iff buffer and range overlap.
  */
 static int ZSTDMT_isOverlapped(buffer_t buffer, range_t range)
 {
     BYTE const* const bufferStart = (BYTE const*)buffer.start;
     BYTE const* const bufferEnd = bufferStart + buffer.capacity;
     BYTE const* const rangeStart = (BYTE const*)range.start;
     BYTE const* const rangeEnd = rangeStart + range.size;
 
     if (rangeStart == NULL || bufferStart == NULL)
         return 0;
     /* Empty ranges cannot overlap */
     if (bufferStart == bufferEnd || rangeStart == rangeEnd)
         return 0;
 
     return bufferStart < rangeEnd && rangeStart < bufferEnd;
 }
 
 static int ZSTDMT_doesOverlapWindow(buffer_t buffer, ZSTD_window_t window)
 {
     range_t extDict;
     range_t prefix;
 
+    DEBUGLOG(5, "ZSTDMT_doesOverlapWindow");
     extDict.start = window.dictBase + window.lowLimit;
     extDict.size = window.dictLimit - window.lowLimit;
 
     prefix.start = window.base + window.dictLimit;
     prefix.size = window.nextSrc - (window.base + window.dictLimit);
     DEBUGLOG(5, "extDict [0x%zx, 0x%zx)",
                 (size_t)extDict.start,
                 (size_t)extDict.start + extDict.size);
     DEBUGLOG(5, "prefix  [0x%zx, 0x%zx)",
                 (size_t)prefix.start,
                 (size_t)prefix.start + prefix.size);
 
     return ZSTDMT_isOverlapped(buffer, extDict)
         || ZSTDMT_isOverlapped(buffer, prefix);
 }
 
 static void ZSTDMT_waitForLdmComplete(ZSTDMT_CCtx* mtctx, buffer_t buffer)
 {
     if (mtctx->params.ldmParams.enableLdm) {
         ZSTD_pthread_mutex_t* mutex = &mtctx->serial.ldmWindowMutex;
+        DEBUGLOG(5, "ZSTDMT_waitForLdmComplete");
         DEBUGLOG(5, "source  [0x%zx, 0x%zx)",
                     (size_t)buffer.start,
                     (size_t)buffer.start + buffer.capacity);
         ZSTD_PTHREAD_MUTEX_LOCK(mutex);
         while (ZSTDMT_doesOverlapWindow(buffer, mtctx->serial.ldmWindow)) {
-            DEBUGLOG(6, "Waiting for LDM to finish...");
+            DEBUGLOG(5, "Waiting for LDM to finish...");
             ZSTD_pthread_cond_wait(&mtctx->serial.ldmWindowCond, mutex);
         }
         DEBUGLOG(6, "Done waiting for LDM to finish");
         ZSTD_pthread_mutex_unlock(mutex);
     }
 }
 
 /**
  * Attempts to set the inBuff to the next section to fill.
  * If any part of the new section is still in use we give up.
  * Returns non-zero if the buffer is filled.
  */
 static int ZSTDMT_tryGetInputRange(ZSTDMT_CCtx* mtctx)
 {
     range_t const inUse = ZSTDMT_getInputDataInUse(mtctx);
     size_t const spaceLeft = mtctx->roundBuff.capacity - mtctx->roundBuff.pos;
     size_t const target = mtctx->targetSectionSize;
     buffer_t buffer;
 
+    DEBUGLOG(5, "ZSTDMT_tryGetInputRange");
     assert(mtctx->inBuff.buffer.start == NULL);
     assert(mtctx->roundBuff.capacity >= target);
 
     if (spaceLeft < target) {
         /* ZSTD_invalidateRepCodes() doesn't work for extDict variants.
          * Simply copy the prefix to the beginning in that case.
          */
         BYTE* const start = (BYTE*)mtctx->roundBuff.buffer;
         size_t const prefixSize = mtctx->inBuff.prefix.size;
 
         buffer.start = start;
         buffer.capacity = prefixSize;
         if (ZSTDMT_isOverlapped(buffer, inUse)) {
-            DEBUGLOG(6, "Waiting for buffer...");
+            DEBUGLOG(5, "Waiting for buffer...");
             return 0;
         }
         ZSTDMT_waitForLdmComplete(mtctx, buffer);
         memmove(start, mtctx->inBuff.prefix.start, prefixSize);
         mtctx->inBuff.prefix.start = start;
         mtctx->roundBuff.pos = prefixSize;
     }
     buffer.start = mtctx->roundBuff.buffer + mtctx->roundBuff.pos;
     buffer.capacity = target;
 
     if (ZSTDMT_isOverlapped(buffer, inUse)) {
-        DEBUGLOG(6, "Waiting for buffer...");
+        DEBUGLOG(5, "Waiting for buffer...");
         return 0;
     }
     assert(!ZSTDMT_isOverlapped(buffer, mtctx->inBuff.prefix));
 
     ZSTDMT_waitForLdmComplete(mtctx, buffer);
 
     DEBUGLOG(5, "Using prefix range [%zx, %zx)",
                 (size_t)mtctx->inBuff.prefix.start,
                 (size_t)mtctx->inBuff.prefix.start + mtctx->inBuff.prefix.size);
     DEBUGLOG(5, "Using source range [%zx, %zx)",
                 (size_t)buffer.start,
                 (size_t)buffer.start + buffer.capacity);
 
 
     mtctx->inBuff.buffer = buffer;
     mtctx->inBuff.filled = 0;
     assert(mtctx->roundBuff.pos + buffer.capacity <= mtctx->roundBuff.capacity);
     return 1;
 }
 
 
 /** ZSTDMT_compressStream_generic() :
  *  internal use only - exposed to be invoked from zstd_compress.c
  *  assumption : output and input are valid (pos <= size)
  * @return : minimum amount of data remaining to flush, 0 if none */
 size_t ZSTDMT_compressStream_generic(ZSTDMT_CCtx* mtctx,
                                      ZSTD_outBuffer* output,
                                      ZSTD_inBuffer* input,
                                      ZSTD_EndDirective endOp)
 {
     unsigned forwardInputProgress = 0;
     DEBUGLOG(5, "ZSTDMT_compressStream_generic (endOp=%u, srcSize=%u)",
                 (U32)endOp, (U32)(input->size - input->pos));
     assert(output->pos <= output->size);
     assert(input->pos  <= input->size);
 
     if (mtctx->singleBlockingThread) {  /* delegate to single-thread (synchronous) */
         return ZSTD_compressStream_generic(mtctx->cctxPool->cctx[0], output, input, endOp);
     }
 
     if ((mtctx->frameEnded) && (endOp==ZSTD_e_continue)) {
         /* current frame being ended. Only flush/end are allowed */
         return ERROR(stage_wrong);
     }
 
     /* single-pass shortcut (note : synchronous-mode) */
     if ( (mtctx->nextJobID == 0)      /* just started */
       && (mtctx->inBuff.filled == 0)  /* nothing buffered */
       && (!mtctx->jobReady)           /* no job already created */
       && (endOp == ZSTD_e_end)        /* end order */
       && (output->size - output->pos >= ZSTD_compressBound(input->size - input->pos)) ) { /* enough space in dst */
         size_t const cSize = ZSTDMT_compress_advanced_internal(mtctx,
                 (char*)output->dst + output->pos, output->size - output->pos,
                 (const char*)input->src + input->pos, input->size - input->pos,
                 mtctx->cdict, mtctx->params);
         if (ZSTD_isError(cSize)) return cSize;
         input->pos = input->size;
         output->pos += cSize;
         mtctx->allJobsCompleted = 1;
         mtctx->frameEnded = 1;
         return 0;
     }
 
     /* fill input buffer */
     if ( (!mtctx->jobReady)
       && (input->size > input->pos) ) {   /* support NULL input */
         if (mtctx->inBuff.buffer.start == NULL) {
             assert(mtctx->inBuff.filled == 0); /* Can't fill an empty buffer */
             if (!ZSTDMT_tryGetInputRange(mtctx)) {
                 /* It is only possible for this operation to fail if there are
                  * still compression jobs ongoing.
                  */
+                DEBUGLOG(5, "ZSTDMT_tryGetInputRange failed");
                 assert(mtctx->doneJobID != mtctx->nextJobID);
-            }
+            } else
+                DEBUGLOG(5, "ZSTDMT_tryGetInputRange completed successfully : mtctx->inBuff.buffer.start = %p", mtctx->inBuff.buffer.start);
         }
         if (mtctx->inBuff.buffer.start != NULL) {
             size_t const toLoad = MIN(input->size - input->pos, mtctx->targetSectionSize - mtctx->inBuff.filled);
             assert(mtctx->inBuff.buffer.capacity >= mtctx->targetSectionSize);
             DEBUGLOG(5, "ZSTDMT_compressStream_generic: adding %u bytes on top of %u to buffer of size %u",
                         (U32)toLoad, (U32)mtctx->inBuff.filled, (U32)mtctx->targetSectionSize);
             memcpy((char*)mtctx->inBuff.buffer.start + mtctx->inBuff.filled, (const char*)input->src + input->pos, toLoad);
             input->pos += toLoad;
             mtctx->inBuff.filled += toLoad;
             forwardInputProgress = toLoad>0;
         }
         if ((input->pos < input->size) && (endOp == ZSTD_e_end))
             endOp = ZSTD_e_flush;   /* can't end now : not all input consumed */
     }
 
     if ( (mtctx->jobReady)
       || (mtctx->inBuff.filled >= mtctx->targetSectionSize)  /* filled enough : let's compress */
       || ((endOp != ZSTD_e_continue) && (mtctx->inBuff.filled > 0))  /* something to flush : let's go */
       || ((endOp == ZSTD_e_end) && (!mtctx->frameEnded)) ) {   /* must finish the frame with a zero-size block */
         size_t const jobSize = mtctx->inBuff.filled;
         assert(mtctx->inBuff.filled <= mtctx->targetSectionSize);
         CHECK_F( ZSTDMT_createCompressionJob(mtctx, jobSize, endOp) );
     }
 
     /* check for potential compressed data ready to be flushed */
     {   size_t const remainingToFlush = ZSTDMT_flushProduced(mtctx, output, !forwardInputProgress, endOp); /* block if there was no forward input progress */
         if (input->pos < input->size) return MAX(remainingToFlush, 1);  /* input not consumed : do not end flush yet */
+        DEBUGLOG(5, "end of ZSTDMT_compressStream_generic: remainingToFlush = %u", (U32)remainingToFlush);
         return remainingToFlush;
     }
 }
 
 
 size_t ZSTDMT_compressStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     CHECK_F( ZSTDMT_compressStream_generic(mtctx, output, input, ZSTD_e_continue) );
 
     /* recommended next input size : fill current input buffer */
     return mtctx->targetSectionSize - mtctx->inBuff.filled;   /* note : could be zero when input buffer is fully filled and no more availability to create new job */
 }
 
 
 static size_t ZSTDMT_flushStream_internal(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, ZSTD_EndDirective endFrame)
 {
     size_t const srcSize = mtctx->inBuff.filled;
     DEBUGLOG(5, "ZSTDMT_flushStream_internal");
 
     if ( mtctx->jobReady     /* one job ready for a worker to pick up */
       || (srcSize > 0)       /* still some data within input buffer */
       || ((endFrame==ZSTD_e_end) && !mtctx->frameEnded)) {  /* need a last 0-size block to end frame */
            DEBUGLOG(5, "ZSTDMT_flushStream_internal : create a new job (%u bytes, end:%u)",
                         (U32)srcSize, (U32)endFrame);
         CHECK_F( ZSTDMT_createCompressionJob(mtctx, srcSize, endFrame) );
     }
 
     /* check if there is any data available to flush */
     return ZSTDMT_flushProduced(mtctx, output, 1 /* blockToFlush */, endFrame);
 }
 
 
 size_t ZSTDMT_flushStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output)
 {
     DEBUGLOG(5, "ZSTDMT_flushStream");
     if (mtctx->singleBlockingThread)
         return ZSTD_flushStream(mtctx->cctxPool->cctx[0], output);
     return ZSTDMT_flushStream_internal(mtctx, output, ZSTD_e_flush);
 }
 
 size_t ZSTDMT_endStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output)
 {
     DEBUGLOG(4, "ZSTDMT_endStream");
     if (mtctx->singleBlockingThread)
         return ZSTD_endStream(mtctx->cctxPool->cctx[0], output);
     return ZSTDMT_flushStream_internal(mtctx, output, ZSTD_e_end);
 }
Index: vendor/zstd/dist/lib/compress/zstdmt_compress.h
===================================================================
--- vendor/zstd/dist/lib/compress/zstdmt_compress.h	(revision 339613)
+++ vendor/zstd/dist/lib/compress/zstdmt_compress.h	(revision 339614)
@@ -1,156 +1,166 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
  #ifndef ZSTDMT_COMPRESS_H
  #define ZSTDMT_COMPRESS_H
 
  #if defined (__cplusplus)
  extern "C" {
  #endif
 
 
 /* Note : This is an internal API.
  *        Some methods are still exposed (ZSTDLIB_API),
  *        because it used to be the only way to invoke MT compression.
  *        Now, it's recommended to use ZSTD_compress_generic() instead.
  *        These methods will stop being exposed in a future version */
 
 /* ===   Dependencies   === */
 #include                 /* size_t */
 #define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_parameters */
 #include "zstd.h"            /* ZSTD_inBuffer, ZSTD_outBuffer, ZSTDLIB_API */
 
 
 /* ===   Memory management   === */
 typedef struct ZSTDMT_CCtx_s ZSTDMT_CCtx;
 ZSTDLIB_API ZSTDMT_CCtx* ZSTDMT_createCCtx(unsigned nbWorkers);
 ZSTDLIB_API ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced(unsigned nbWorkers,
                                                     ZSTD_customMem cMem);
 ZSTDLIB_API size_t ZSTDMT_freeCCtx(ZSTDMT_CCtx* mtctx);
 
 ZSTDLIB_API size_t ZSTDMT_sizeof_CCtx(ZSTDMT_CCtx* mtctx);
 
 
 /* ===   Simple one-pass compression function   === */
 
 ZSTDLIB_API size_t ZSTDMT_compressCCtx(ZSTDMT_CCtx* mtctx,
                                        void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                        int compressionLevel);
 
 
 
 /* ===   Streaming functions   === */
 
 ZSTDLIB_API size_t ZSTDMT_initCStream(ZSTDMT_CCtx* mtctx, int compressionLevel);
 ZSTDLIB_API size_t ZSTDMT_resetCStream(ZSTDMT_CCtx* mtctx, unsigned long long pledgedSrcSize);  /**< if srcSize is not known at reset time, use ZSTD_CONTENTSIZE_UNKNOWN. Note: for compatibility with older programs, 0 means the same as ZSTD_CONTENTSIZE_UNKNOWN, but it will change in the future to mean "empty" */
 
 ZSTDLIB_API size_t ZSTDMT_compressStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
 
 ZSTDLIB_API size_t ZSTDMT_flushStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output);   /**< @return : 0 == all flushed; >0 : still some data to be flushed; or an error code (ZSTD_isError()) */
 ZSTDLIB_API size_t ZSTDMT_endStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output);     /**< @return : 0 == all flushed; >0 : still some data to be flushed; or an error code (ZSTD_isError()) */
 
 
 /* ===   Advanced functions and parameters  === */
 
 #ifndef ZSTDMT_JOBSIZE_MIN
 #  define ZSTDMT_JOBSIZE_MIN (1U << 20)   /* 1 MB - Minimum size of each compression job */
 #endif
 
 ZSTDLIB_API size_t ZSTDMT_compress_advanced(ZSTDMT_CCtx* mtctx,
                                            void* dst, size_t dstCapacity,
                                      const void* src, size_t srcSize,
                                      const ZSTD_CDict* cdict,
                                            ZSTD_parameters params,
                                            unsigned overlapLog);
 
 ZSTDLIB_API size_t ZSTDMT_initCStream_advanced(ZSTDMT_CCtx* mtctx,
                                         const void* dict, size_t dictSize,   /* dict can be released after init, a local copy is preserved within zcs */
                                         ZSTD_parameters params,
                                         unsigned long long pledgedSrcSize);  /* pledgedSrcSize is optional and can be zero == unknown */
 
 ZSTDLIB_API size_t ZSTDMT_initCStream_usingCDict(ZSTDMT_CCtx* mtctx,
                                         const ZSTD_CDict* cdict,
                                         ZSTD_frameParameters fparams,
                                         unsigned long long pledgedSrcSize);  /* note : zero means empty */
 
 /* ZSTDMT_parameter :
  * List of parameters that can be set using ZSTDMT_setMTCtxParameter() */
 typedef enum {
     ZSTDMT_p_jobSize,           /* Each job is compressed in parallel. By default, this value is dynamically determined depending on compression parameters. Can be set explicitly here. */
     ZSTDMT_p_overlapSectionLog  /* Each job may reload a part of previous job to enhance compressionr ratio; 0 == no overlap, 6(default) == use 1/8th of window, >=9 == use full window. This is a "sticky" parameter : its value will be re-used on next compression job */
 } ZSTDMT_parameter;
 
 /* ZSTDMT_setMTCtxParameter() :
  * allow setting individual parameters, one at a time, among a list of enums defined in ZSTDMT_parameter.
  * The function must be called typically after ZSTD_createCCtx() but __before ZSTDMT_init*() !__
  * Parameters not explicitly reset by ZSTDMT_init*() remain the same in consecutive compression sessions.
  * @return : 0, or an error code (which can be tested using ZSTD_isError()) */
 ZSTDLIB_API size_t ZSTDMT_setMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSTDMT_parameter parameter, unsigned value);
 
+/* ZSTDMT_getMTCtxParameter() :
+ * Query the ZSTDMT_CCtx for a parameter value.
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()) */
+ZSTDLIB_API size_t ZSTDMT_getMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSTDMT_parameter parameter, unsigned* value);
 
+
 /*! ZSTDMT_compressStream_generic() :
  *  Combines ZSTDMT_compressStream() with optional ZSTDMT_flushStream() or ZSTDMT_endStream()
  *  depending on flush directive.
  * @return : minimum amount of data still to be flushed
  *           0 if fully flushed
  *           or an error code
  *  note : needs to be init using any ZSTD_initCStream*() variant */
 ZSTDLIB_API size_t ZSTDMT_compressStream_generic(ZSTDMT_CCtx* mtctx,
                                                 ZSTD_outBuffer* output,
                                                 ZSTD_inBuffer* input,
                                                 ZSTD_EndDirective endOp);
 
 
 /* ========================================================
  * ===  Private interface, for use by ZSTD_compress.c   ===
  * ===  Not exposed in libzstd. Never invoke directly   ===
  * ======================================================== */
 
+ /*! ZSTDMT_toFlushNow()
+  *  Tell how many bytes are ready to be flushed immediately.
+  *  Probe the oldest active job (not yet entirely flushed) and check its output buffer.
+  *  If return 0, it means there is no active job,
+  *  or, it means oldest job is still active, but everything produced has been flushed so far,
+  *  therefore flushing is limited by speed of oldest job. */
+size_t ZSTDMT_toFlushNow(ZSTDMT_CCtx* mtctx);
+
+/*! ZSTDMT_CCtxParam_setMTCtxParameter()
+ *  like ZSTDMT_setMTCtxParameter(), but into a ZSTD_CCtx_Params */
 size_t ZSTDMT_CCtxParam_setMTCtxParameter(ZSTD_CCtx_params* params, ZSTDMT_parameter parameter, unsigned value);
 
-/* ZSTDMT_CCtxParam_setNbWorkers()
- * Set nbWorkers, and clamp it.
- * Also reset jobSize and overlapLog */
+/*! ZSTDMT_CCtxParam_setNbWorkers()
+ *  Set nbWorkers, and clamp it.
+ *  Also reset jobSize and overlapLog */
 size_t ZSTDMT_CCtxParam_setNbWorkers(ZSTD_CCtx_params* params, unsigned nbWorkers);
 
 /*! ZSTDMT_updateCParams_whileCompressing() :
  *  Updates only a selected set of compression parameters, to remain compatible with current frame.
  *  New parameters will be applied to next compression job. */
 void ZSTDMT_updateCParams_whileCompressing(ZSTDMT_CCtx* mtctx, const ZSTD_CCtx_params* cctxParams);
 
-/* ZSTDMT_getNbWorkers():
- * @return nb threads currently active in mtctx.
- * mtctx must be valid */
-unsigned ZSTDMT_getNbWorkers(const ZSTDMT_CCtx* mtctx);
-
-/* ZSTDMT_getFrameProgression():
- * tells how much data has been consumed (input) and produced (output) for current frame.
- * able to count progression inside worker threads.
+/*! ZSTDMT_getFrameProgression():
+ *  tells how much data has been consumed (input) and produced (output) for current frame.
+ *  able to count progression inside worker threads.
  */
 ZSTD_frameProgression ZSTDMT_getFrameProgression(ZSTDMT_CCtx* mtctx);
 
 
 /*! ZSTDMT_initCStream_internal() :
  *  Private use only. Init streaming operation.
  *  expects params to be valid.
  *  must receive dict, or cdict, or none, but not both.
  *  @return : 0, or an error code */
 size_t ZSTDMT_initCStream_internal(ZSTDMT_CCtx* zcs,
                     const void* dict, size_t dictSize, ZSTD_dictContentType_e dictContentType,
                     const ZSTD_CDict* cdict,
                     ZSTD_CCtx_params params, unsigned long long pledgedSrcSize);
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif   /* ZSTDMT_COMPRESS_H */
Index: vendor/zstd/dist/lib/decompress/huf_decompress.c
===================================================================
--- vendor/zstd/dist/lib/decompress/huf_decompress.c	(revision 339613)
+++ vendor/zstd/dist/lib/decompress/huf_decompress.c	(revision 339614)
@@ -1,1096 +1,1096 @@
 /* ******************************************************************
-   Huffman decoder, part of New Generation Entropy library
-   Copyright (C) 2013-2016, Yann Collet.
+   huff0 huffman decoder,
+   part of Finite State Entropy library
+   Copyright (C) 2013-present, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
-    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 /* **************************************************************
 *  Dependencies
 ****************************************************************/
 #include      /* memcpy, memset */
-#include "bitstream.h"  /* BIT_* */
 #include "compiler.h"
-#include "fse.h"        /* header compression */
+#include "bitstream.h"  /* BIT_* */
+#include "fse.h"        /* to compress headers */
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "error_private.h"
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #define HUF_isError ERR_isError
-#define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 #define CHECK_F(f) { size_t const err_ = (f); if (HUF_isError(err_)) return err_; }
 
 
 /* **************************************************************
 *  Byte alignment for workSpace management
 ****************************************************************/
 #define HUF_ALIGN(x, a)         HUF_ALIGN_MASK((x), (a) - 1)
 #define HUF_ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))
 
 
 /*-***************************/
 /*  generic DTableDesc       */
 /*-***************************/
 typedef struct { BYTE maxTableLog; BYTE tableType; BYTE tableLog; BYTE reserved; } DTableDesc;
 
 static DTableDesc HUF_getDTableDesc(const HUF_DTable* table)
 {
     DTableDesc dtd;
     memcpy(&dtd, table, sizeof(dtd));
     return dtd;
 }
 
 
 /*-***************************/
 /*  single-symbol decoding   */
 /*-***************************/
-typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
+typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX1;   /* single-symbol decoding */
 
-size_t HUF_readDTableX2_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize)
+size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize)
 {
     U32 tableLog = 0;
     U32 nbSymbols = 0;
     size_t iSize;
     void* const dtPtr = DTable + 1;
-    HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
+    HUF_DEltX1* const dt = (HUF_DEltX1*)dtPtr;
 
     U32* rankVal;
     BYTE* huffWeight;
     size_t spaceUsed32 = 0;
 
     rankVal = (U32 *)workSpace + spaceUsed32;
     spaceUsed32 += HUF_TABLELOG_ABSOLUTEMAX + 1;
     huffWeight = (BYTE *)((U32 *)workSpace + spaceUsed32);
     spaceUsed32 += HUF_ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2;
 
     if ((spaceUsed32 << 2) > wkspSize) return ERROR(tableLog_tooLarge);
 
-    HUF_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUF_DTable));
+    DEBUG_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUF_DTable));
     /* memset(huffWeight, 0, sizeof(huffWeight)); */   /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* Table header */
     {   DTableDesc dtd = HUF_getDTableDesc(DTable);
         if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge);   /* DTable too small, Huffman tree cannot fit in */
         dtd.tableType = 0;
         dtd.tableLog = (BYTE)tableLog;
         memcpy(DTable, &dtd, sizeof(dtd));
     }
 
     /* Calculate starting value for each rank */
     {   U32 n, nextRankStart = 0;
         for (n=1; n> 1;
             U32 u;
-            HUF_DEltX2 D;
+            HUF_DEltX1 D;
             D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
             for (u = rankVal[w]; u < rankVal[w] + length; u++)
                 dt[u] = D;
             rankVal[w] += length;
     }   }
 
     return iSize;
 }
 
-size_t HUF_readDTableX2(HUF_DTable* DTable, const void* src, size_t srcSize)
+size_t HUF_readDTableX1(HUF_DTable* DTable, const void* src, size_t srcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
-    return HUF_readDTableX2_wksp(DTable, src, srcSize,
+    return HUF_readDTableX1_wksp(DTable, src, srcSize,
                                  workSpace, sizeof(workSpace));
 }
 
-typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
-
 FORCE_INLINE_TEMPLATE BYTE
-HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
+HUF_decodeSymbolX1(BIT_DStream_t* Dstream, const HUF_DEltX1* dt, const U32 dtLog)
 {
     size_t const val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
     BYTE const c = dt[val].byte;
     BIT_skipBits(Dstream, dt[val].nbBits);
     return c;
 }
 
-#define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
-    *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
+#define HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) \
+    *ptr++ = HUF_decodeSymbolX1(DStreamPtr, dt, dtLog)
 
-#define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr)  \
+#define HUF_DECODE_SYMBOLX1_1(ptr, DStreamPtr)  \
     if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \
-        HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
+        HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr)
 
-#define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
+#define HUF_DECODE_SYMBOLX1_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
-        HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
+        HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr)
 
 HINT_INLINE size_t
-HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
+HUF_decodeStreamX1(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX1* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 4 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-3)) {
-        HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
-        HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
-        HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
-        HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
+        HUF_DECODE_SYMBOLX1_2(p, bitDPtr);
+        HUF_DECODE_SYMBOLX1_1(p, bitDPtr);
+        HUF_DECODE_SYMBOLX1_2(p, bitDPtr);
+        HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
     }
 
     /* [0-3] symbols remaining */
     if (MEM_32bits())
         while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd))
-            HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
+            HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
 
     /* no more data to retrieve from bitstream, no need to reload */
     while (p < pEnd)
-        HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
+        HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
 
     return pEnd-pStart;
 }
 
 FORCE_INLINE_TEMPLATE size_t
-HUF_decompress1X2_usingDTable_internal_body(
+HUF_decompress1X1_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     BYTE* op = (BYTE*)dst;
     BYTE* const oend = op + dstSize;
     const void* dtPtr = DTable + 1;
-    const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
+    const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;
     BIT_DStream_t bitD;
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
     U32 const dtLog = dtd.tableLog;
 
     CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );
 
-    HUF_decodeStreamX2(op, &bitD, oend, dt, dtLog);
+    HUF_decodeStreamX1(op, &bitD, oend, dt, dtLog);
 
     if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);
 
     return dstSize;
 }
 
 FORCE_INLINE_TEMPLATE size_t
-HUF_decompress4X2_usingDTable_internal_body(
+HUF_decompress4X1_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     /* Check */
     if (cSrcSize < 10) return ERROR(corruption_detected);  /* strict minimum : jump table + 1 byte per stream */
 
     {   const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
         const void* const dtPtr = DTable + 1;
-        const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
+        const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         size_t const length1 = MEM_readLE16(istart);
         size_t const length2 = MEM_readLE16(istart+2);
         size_t const length3 = MEM_readLE16(istart+4);
         size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         const size_t segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal = BIT_DStream_unfinished;
         DTableDesc const dtd = HUF_getDTableDesc(DTable);
         U32 const dtLog = dtd.tableLog;
 
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
         CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
         CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
         CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );
 
         /* up to 16 symbols per loop (4 symbols per stream) in 64-bit mode */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         while ( (endSignal==BIT_DStream_unfinished) && (op4<(oend-3)) ) {
-            HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
-            HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
-            HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
-            HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
-            HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
-            HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
-            HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
-            HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
-            HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
-            HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
-            HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
-            HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
-            HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
-            HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
-            HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
-            HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
+            HUF_DECODE_SYMBOLX1_2(op1, &bitD1);
+            HUF_DECODE_SYMBOLX1_2(op2, &bitD2);
+            HUF_DECODE_SYMBOLX1_2(op3, &bitD3);
+            HUF_DECODE_SYMBOLX1_2(op4, &bitD4);
+            HUF_DECODE_SYMBOLX1_1(op1, &bitD1);
+            HUF_DECODE_SYMBOLX1_1(op2, &bitD2);
+            HUF_DECODE_SYMBOLX1_1(op3, &bitD3);
+            HUF_DECODE_SYMBOLX1_1(op4, &bitD4);
+            HUF_DECODE_SYMBOLX1_2(op1, &bitD1);
+            HUF_DECODE_SYMBOLX1_2(op2, &bitD2);
+            HUF_DECODE_SYMBOLX1_2(op3, &bitD3);
+            HUF_DECODE_SYMBOLX1_2(op4, &bitD4);
+            HUF_DECODE_SYMBOLX1_0(op1, &bitD1);
+            HUF_DECODE_SYMBOLX1_0(op2, &bitD2);
+            HUF_DECODE_SYMBOLX1_0(op3, &bitD3);
+            HUF_DECODE_SYMBOLX1_0(op4, &bitD4);
             BIT_reloadDStream(&bitD1);
             BIT_reloadDStream(&bitD2);
             BIT_reloadDStream(&bitD3);
             BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         /* note : should not be necessary : op# advance in lock step, and we control op4.
          *        but curiously, binary generated by gcc 7.2 & 7.3 with -mbmi2 runs faster when >=1 test is present */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 supposed already verified within main loop */
 
         /* finish bitStreams one by one */
-        HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
-        HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
-        HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
-        HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
+        HUF_decodeStreamX1(op1, &bitD1, opStart2, dt, dtLog);
+        HUF_decodeStreamX1(op2, &bitD2, opStart3, dt, dtLog);
+        HUF_decodeStreamX1(op3, &bitD3, opStart4, dt, dtLog);
+        HUF_decodeStreamX1(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
           if (!endCheck) return ERROR(corruption_detected); }
 
         /* decoded size */
         return dstSize;
     }
 }
 
 
-FORCE_INLINE_TEMPLATE U32
-HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
-{
-    size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
-    memcpy(op, dt+val, 2);
-    BIT_skipBits(DStream, dt[val].nbBits);
-    return dt[val].length;
-}
-
-FORCE_INLINE_TEMPLATE U32
-HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
-{
-    size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
-    memcpy(op, dt+val, 1);
-    if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
-    else {
-        if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) {
-            BIT_skipBits(DStream, dt[val].nbBits);
-            if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
-                /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
-                DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);
-    }   }
-    return 1;
-}
-
-#define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
-    ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
-
-#define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
-    if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \
-        ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
-
-#define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
-    if (MEM_64bits()) \
-        ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
-
-HINT_INLINE size_t
-HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd,
-                const HUF_DEltX4* const dt, const U32 dtLog)
-{
-    BYTE* const pStart = p;
-
-    /* up to 8 symbols at a time */
-    while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) {
-        HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
-        HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
-        HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
-        HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
-    }
-
-    /* closer to end : up to 2 symbols at a time */
-    while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p <= pEnd-2))
-        HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
-
-    while (p <= pEnd-2)
-        HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
-
-    if (p < pEnd)
-        p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
-
-    return p-pStart;
-}
-
-FORCE_INLINE_TEMPLATE size_t
-HUF_decompress1X4_usingDTable_internal_body(
-          void* dst,  size_t dstSize,
-    const void* cSrc, size_t cSrcSize,
-    const HUF_DTable* DTable)
-{
-    BIT_DStream_t bitD;
-
-    /* Init */
-    CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );
-
-    /* decode */
-    {   BYTE* const ostart = (BYTE*) dst;
-        BYTE* const oend = ostart + dstSize;
-        const void* const dtPtr = DTable+1;   /* force compiler to not use strict-aliasing */
-        const HUF_DEltX4* const dt = (const HUF_DEltX4*)dtPtr;
-        DTableDesc const dtd = HUF_getDTableDesc(DTable);
-        HUF_decodeStreamX4(ostart, &bitD, oend, dt, dtd.tableLog);
-    }
-
-    /* check */
-    if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);
-
-    /* decoded size */
-    return dstSize;
-}
-
-
-FORCE_INLINE_TEMPLATE size_t
-HUF_decompress4X4_usingDTable_internal_body(
-          void* dst,  size_t dstSize,
-    const void* cSrc, size_t cSrcSize,
-    const HUF_DTable* DTable)
-{
-    if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
-
-    {   const BYTE* const istart = (const BYTE*) cSrc;
-        BYTE* const ostart = (BYTE*) dst;
-        BYTE* const oend = ostart + dstSize;
-        const void* const dtPtr = DTable+1;
-        const HUF_DEltX4* const dt = (const HUF_DEltX4*)dtPtr;
-
-        /* Init */
-        BIT_DStream_t bitD1;
-        BIT_DStream_t bitD2;
-        BIT_DStream_t bitD3;
-        BIT_DStream_t bitD4;
-        size_t const length1 = MEM_readLE16(istart);
-        size_t const length2 = MEM_readLE16(istart+2);
-        size_t const length3 = MEM_readLE16(istart+4);
-        size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
-        const BYTE* const istart1 = istart + 6;  /* jumpTable */
-        const BYTE* const istart2 = istart1 + length1;
-        const BYTE* const istart3 = istart2 + length2;
-        const BYTE* const istart4 = istart3 + length3;
-        size_t const segmentSize = (dstSize+3) / 4;
-        BYTE* const opStart2 = ostart + segmentSize;
-        BYTE* const opStart3 = opStart2 + segmentSize;
-        BYTE* const opStart4 = opStart3 + segmentSize;
-        BYTE* op1 = ostart;
-        BYTE* op2 = opStart2;
-        BYTE* op3 = opStart3;
-        BYTE* op4 = opStart4;
-        U32 endSignal;
-        DTableDesc const dtd = HUF_getDTableDesc(DTable);
-        U32 const dtLog = dtd.tableLog;
-
-        if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
-        CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
-        CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
-        CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
-        CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );
-
-        /* 16-32 symbols per loop (4-8 symbols per stream) */
-        endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
-        for ( ; (endSignal==BIT_DStream_unfinished) & (op4<(oend-(sizeof(bitD4.bitContainer)-1))) ; ) {
-            HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
-            HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
-            HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
-            HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
-            HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
-            HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
-            HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
-            HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
-            HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
-            HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
-            HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
-            HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
-            HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
-            HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
-            HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
-            HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
-
-            endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
-        }
-
-        /* check corruption */
-        if (op1 > opStart2) return ERROR(corruption_detected);
-        if (op2 > opStart3) return ERROR(corruption_detected);
-        if (op3 > opStart4) return ERROR(corruption_detected);
-        /* note : op4 already verified within main loop */
-
-        /* finish bitStreams one by one */
-        HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
-        HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
-        HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
-        HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
-
-        /* check */
-        { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
-          if (!endCheck) return ERROR(corruption_detected); }
-
-        /* decoded size */
-        return dstSize;
-    }
-}
-
-
 typedef size_t (*HUF_decompress_usingDTable_t)(void *dst, size_t dstSize,
                                                const void *cSrc,
                                                size_t cSrcSize,
                                                const HUF_DTable *DTable);
 #if DYNAMIC_BMI2
 
-#define X(fn)                                                               \
+#define HUF_DGEN(fn)                                                               \
                                                                             \
     static size_t fn##_default(                                             \
                   void* dst,  size_t dstSize,                               \
             const void* cSrc, size_t cSrcSize,                              \
             const HUF_DTable* DTable)                                       \
     {                                                                       \
         return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
     }                                                                       \
                                                                             \
     static TARGET_ATTRIBUTE("bmi2") size_t fn##_bmi2(                       \
                   void* dst,  size_t dstSize,                               \
             const void* cSrc, size_t cSrcSize,                              \
             const HUF_DTable* DTable)                                       \
     {                                                                       \
         return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
     }                                                                       \
                                                                             \
     static size_t fn(void* dst, size_t dstSize, void const* cSrc,           \
                      size_t cSrcSize, HUF_DTable const* DTable, int bmi2)   \
     {                                                                       \
         if (bmi2) {                                                         \
             return fn##_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);         \
         }                                                                   \
         return fn##_default(dst, dstSize, cSrc, cSrcSize, DTable);          \
     }
 
 #else
 
-#define X(fn)                                                               \
+#define HUF_DGEN(fn)                                                               \
     static size_t fn(void* dst, size_t dstSize, void const* cSrc,           \
                      size_t cSrcSize, HUF_DTable const* DTable, int bmi2)   \
     {                                                                       \
         (void)bmi2;                                                         \
         return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
     }
 
 #endif
 
-X(HUF_decompress1X2_usingDTable_internal)
-X(HUF_decompress4X2_usingDTable_internal)
-X(HUF_decompress1X4_usingDTable_internal)
-X(HUF_decompress4X4_usingDTable_internal)
+HUF_DGEN(HUF_decompress1X1_usingDTable_internal)
+HUF_DGEN(HUF_decompress4X1_usingDTable_internal)
 
-#undef X
 
 
-size_t HUF_decompress1X2_usingDTable(
+size_t HUF_decompress1X1_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 0) return ERROR(GENERIC);
-    return HUF_decompress1X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
+    return HUF_decompress1X1_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
-size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
+size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
-    size_t const hSize = HUF_readDTableX2_wksp(DCtx, cSrc, cSrcSize, workSpace, wkspSize);
+    size_t const hSize = HUF_readDTableX1_wksp(DCtx, cSrc, cSrcSize, workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
-    return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, /* bmi2 */ 0);
+    return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, /* bmi2 */ 0);
 }
 
 
-size_t HUF_decompress1X2_DCtx(HUF_DTable* DCtx, void* dst, size_t dstSize,
+size_t HUF_decompress1X1_DCtx(HUF_DTable* DCtx, void* dst, size_t dstSize,
                               const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
-    return HUF_decompress1X2_DCtx_wksp(DCtx, dst, dstSize, cSrc, cSrcSize,
+    return HUF_decompress1X1_DCtx_wksp(DCtx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 
-size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
+size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
-    HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_TABLELOG_MAX);
-    return HUF_decompress1X2_DCtx (DTable, dst, dstSize, cSrc, cSrcSize);
+    HUF_CREATE_STATIC_DTABLEX1(DTable, HUF_TABLELOG_MAX);
+    return HUF_decompress1X1_DCtx (DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
-size_t HUF_decompress4X2_usingDTable(
+size_t HUF_decompress4X1_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 0) return ERROR(GENERIC);
-    return HUF_decompress4X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
+    return HUF_decompress4X1_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
-static size_t HUF_decompress4X2_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize,
+static size_t HUF_decompress4X1_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize, int bmi2)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
-    size_t const hSize = HUF_readDTableX2_wksp (dctx, cSrc, cSrcSize,
+    size_t const hSize = HUF_readDTableX1_wksp (dctx, cSrc, cSrcSize,
                                                 workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
-    return HUF_decompress4X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
+    return HUF_decompress4X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
 }
 
-size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
+size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
-    return HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, 0);
+    return HUF_decompress4X1_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, 0);
 }
 
 
-size_t HUF_decompress4X2_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
+size_t HUF_decompress4X1_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
-    return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
+    return HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
-size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
+size_t HUF_decompress4X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
-    HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_TABLELOG_MAX);
-    return HUF_decompress4X2_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
+    HUF_CREATE_STATIC_DTABLEX1(DTable, HUF_TABLELOG_MAX);
+    return HUF_decompress4X1_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
 
 /* *************************/
 /* double-symbols decoding */
 /* *************************/
+
+typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX2;  /* double-symbols decoding */
 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
+typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1];
+typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX];
 
-/* HUF_fillDTableX4Level2() :
+
+/* HUF_fillDTableX2Level2() :
  * `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */
-static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
+static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 consumed,
                            const U32* rankValOrigin, const int minWeight,
                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
                            U32 nbBitsBaseline, U16 baseSeq)
 {
-    HUF_DEltX4 DElt;
+    HUF_DEltX2 DElt;
     U32 rankVal[HUF_TABLELOG_MAX + 1];
 
     /* get pre-calculated rankVal */
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill skipped values */
     if (minWeight>1) {
         U32 i, skipSize = rankVal[minWeight];
         MEM_writeLE16(&(DElt.sequence), baseSeq);
         DElt.nbBits   = (BYTE)(consumed);
         DElt.length   = 1;
         for (i = 0; i < skipSize; i++)
             DTable[i] = DElt;
     }
 
     /* fill DTable */
     {   U32 s; for (s=0; s= 1 */
 
             rankVal[weight] += length;
     }   }
 }
 
-typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1];
-typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX];
 
-static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
+static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
                            const U32 nbBitsBaseline)
 {
     U32 rankVal[HUF_TABLELOG_MAX + 1];
     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
     const U32 minBits  = nbBitsBaseline - maxWeight;
     U32 s;
 
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill DTable */
     for (s=0; s= minBits) {   /* enough room for a second symbol */
             U32 sortedRank;
             int minWeight = nbBits + scaleLog;
             if (minWeight < 1) minWeight = 1;
             sortedRank = rankStart[minWeight];
-            HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
+            HUF_fillDTableX2Level2(DTable+start, targetLog-nbBits, nbBits,
                            rankValOrigin[nbBits], minWeight,
                            sortedList+sortedRank, sortedListSize-sortedRank,
                            nbBitsBaseline, symbol);
         } else {
-            HUF_DEltX4 DElt;
+            HUF_DEltX2 DElt;
             MEM_writeLE16(&(DElt.sequence), symbol);
             DElt.nbBits = (BYTE)(nbBits);
             DElt.length = 1;
             {   U32 const end = start + length;
                 U32 u;
                 for (u = start; u < end; u++) DTable[u] = DElt;
         }   }
         rankVal[weight] += length;
     }
 }
 
-size_t HUF_readDTableX4_wksp(HUF_DTable* DTable, const void* src,
-                             size_t srcSize, void* workSpace,
-                             size_t wkspSize)
+size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
+                       const void* src, size_t srcSize,
+                             void* workSpace, size_t wkspSize)
 {
     U32 tableLog, maxW, sizeOfSort, nbSymbols;
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     U32 const maxTableLog = dtd.maxTableLog;
     size_t iSize;
     void* dtPtr = DTable+1;   /* force compiler to avoid strict-aliasing */
-    HUF_DEltX4* const dt = (HUF_DEltX4*)dtPtr;
+    HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
     U32 *rankStart;
 
     rankValCol_t* rankVal;
     U32* rankStats;
     U32* rankStart0;
     sortedSymbol_t* sortedSymbol;
     BYTE* weightList;
     size_t spaceUsed32 = 0;
 
     rankVal = (rankValCol_t *)((U32 *)workSpace + spaceUsed32);
     spaceUsed32 += (sizeof(rankValCol_t) * HUF_TABLELOG_MAX) >> 2;
     rankStats = (U32 *)workSpace + spaceUsed32;
     spaceUsed32 += HUF_TABLELOG_MAX + 1;
     rankStart0 = (U32 *)workSpace + spaceUsed32;
     spaceUsed32 += HUF_TABLELOG_MAX + 2;
     sortedSymbol = (sortedSymbol_t *)workSpace + (spaceUsed32 * sizeof(U32)) / sizeof(sortedSymbol_t);
     spaceUsed32 += HUF_ALIGN(sizeof(sortedSymbol_t) * (HUF_SYMBOLVALUE_MAX + 1), sizeof(U32)) >> 2;
     weightList = (BYTE *)((U32 *)workSpace + spaceUsed32);
     spaceUsed32 += HUF_ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2;
 
     if ((spaceUsed32 << 2) > wkspSize) return ERROR(tableLog_tooLarge);
 
     rankStart = rankStart0 + 1;
     memset(rankStats, 0, sizeof(U32) * (2 * HUF_TABLELOG_MAX + 2 + 1));
 
-    HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(HUF_DTable));   /* if compiler fails here, assertion is wrong */
+    DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(HUF_DTable));   /* if compiler fails here, assertion is wrong */
     if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
     /* memset(weightList, 0, sizeof(weightList)); */  /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(weightList, HUF_SYMBOLVALUE_MAX + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
     if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
 
     /* find maxWeight */
     for (maxW = tableLog; rankStats[maxW]==0; maxW--) {}  /* necessarily finds a solution before 0 */
 
     /* Get start index of each weight */
     {   U32 w, nextRankStart = 0;
         for (w=1; w> consumed;
     }   }   }   }
 
-    HUF_fillDTableX4(dt, maxTableLog,
+    HUF_fillDTableX2(dt, maxTableLog,
                    sortedSymbol, sizeOfSort,
                    rankStart0, rankVal, maxW,
                    tableLog+1);
 
     dtd.tableLog = (BYTE)maxTableLog;
     dtd.tableType = 1;
     memcpy(DTable, &dtd, sizeof(dtd));
     return iSize;
 }
 
-size_t HUF_readDTableX4(HUF_DTable* DTable, const void* src, size_t srcSize)
+size_t HUF_readDTableX2(HUF_DTable* DTable, const void* src, size_t srcSize)
 {
   U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
-  return HUF_readDTableX4_wksp(DTable, src, srcSize,
+  return HUF_readDTableX2_wksp(DTable, src, srcSize,
                                workSpace, sizeof(workSpace));
 }
 
-size_t HUF_decompress1X4_usingDTable(
+
+FORCE_INLINE_TEMPLATE U32
+HUF_decodeSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
+{
+    size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
+    memcpy(op, dt+val, 2);
+    BIT_skipBits(DStream, dt[val].nbBits);
+    return dt[val].length;
+}
+
+FORCE_INLINE_TEMPLATE U32
+HUF_decodeLastSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
+{
+    size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
+    memcpy(op, dt+val, 1);
+    if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
+    else {
+        if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) {
+            BIT_skipBits(DStream, dt[val].nbBits);
+            if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
+                /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
+                DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);
+    }   }
+    return 1;
+}
+
+#define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
+    ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog)
+
+#define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
+    if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \
+        ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog)
+
+#define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
+    if (MEM_64bits()) \
+        ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog)
+
+HINT_INLINE size_t
+HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd,
+                const HUF_DEltX2* const dt, const U32 dtLog)
+{
+    BYTE* const pStart = p;
+
+    /* up to 8 symbols at a time */
+    while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) {
+        HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
+        HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
+        HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
+        HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
+    }
+
+    /* closer to end : up to 2 symbols at a time */
+    while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p <= pEnd-2))
+        HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
+
+    while (p <= pEnd-2)
+        HUF_DECODE_SYMBOLX2_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
+
+    if (p < pEnd)
+        p += HUF_decodeLastSymbolX2(p, bitDPtr, dt, dtLog);
+
+    return p-pStart;
+}
+
+FORCE_INLINE_TEMPLATE size_t
+HUF_decompress1X2_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
+    BIT_DStream_t bitD;
+
+    /* Init */
+    CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );
+
+    /* decode */
+    {   BYTE* const ostart = (BYTE*) dst;
+        BYTE* const oend = ostart + dstSize;
+        const void* const dtPtr = DTable+1;   /* force compiler to not use strict-aliasing */
+        const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
+        DTableDesc const dtd = HUF_getDTableDesc(DTable);
+        HUF_decodeStreamX2(ostart, &bitD, oend, dt, dtd.tableLog);
+    }
+
+    /* check */
+    if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);
+
+    /* decoded size */
+    return dstSize;
+}
+
+
+FORCE_INLINE_TEMPLATE size_t
+HUF_decompress4X2_usingDTable_internal_body(
+          void* dst,  size_t dstSize,
+    const void* cSrc, size_t cSrcSize,
+    const HUF_DTable* DTable)
+{
+    if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
+
+    {   const BYTE* const istart = (const BYTE*) cSrc;
+        BYTE* const ostart = (BYTE*) dst;
+        BYTE* const oend = ostart + dstSize;
+        const void* const dtPtr = DTable+1;
+        const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
+
+        /* Init */
+        BIT_DStream_t bitD1;
+        BIT_DStream_t bitD2;
+        BIT_DStream_t bitD3;
+        BIT_DStream_t bitD4;
+        size_t const length1 = MEM_readLE16(istart);
+        size_t const length2 = MEM_readLE16(istart+2);
+        size_t const length3 = MEM_readLE16(istart+4);
+        size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
+        const BYTE* const istart1 = istart + 6;  /* jumpTable */
+        const BYTE* const istart2 = istart1 + length1;
+        const BYTE* const istart3 = istart2 + length2;
+        const BYTE* const istart4 = istart3 + length3;
+        size_t const segmentSize = (dstSize+3) / 4;
+        BYTE* const opStart2 = ostart + segmentSize;
+        BYTE* const opStart3 = opStart2 + segmentSize;
+        BYTE* const opStart4 = opStart3 + segmentSize;
+        BYTE* op1 = ostart;
+        BYTE* op2 = opStart2;
+        BYTE* op3 = opStart3;
+        BYTE* op4 = opStart4;
+        U32 endSignal;
+        DTableDesc const dtd = HUF_getDTableDesc(DTable);
+        U32 const dtLog = dtd.tableLog;
+
+        if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
+        CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
+        CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
+        CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
+        CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );
+
+        /* 16-32 symbols per loop (4-8 symbols per stream) */
+        endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
+        for ( ; (endSignal==BIT_DStream_unfinished) & (op4<(oend-(sizeof(bitD4.bitContainer)-1))) ; ) {
+            HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
+            HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
+            HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
+            HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
+            HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
+            HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
+            HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
+            HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
+            HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
+            HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
+            HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
+            HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
+            HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
+            HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
+            HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
+            HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
+
+            endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
+        }
+
+        /* check corruption */
+        if (op1 > opStart2) return ERROR(corruption_detected);
+        if (op2 > opStart3) return ERROR(corruption_detected);
+        if (op3 > opStart4) return ERROR(corruption_detected);
+        /* note : op4 already verified within main loop */
+
+        /* finish bitStreams one by one */
+        HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
+        HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
+        HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
+        HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
+
+        /* check */
+        { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
+          if (!endCheck) return ERROR(corruption_detected); }
+
+        /* decoded size */
+        return dstSize;
+    }
+}
+
+HUF_DGEN(HUF_decompress1X2_usingDTable_internal)
+HUF_DGEN(HUF_decompress4X2_usingDTable_internal)
+
+size_t HUF_decompress1X2_usingDTable(
+          void* dst,  size_t dstSize,
+    const void* cSrc, size_t cSrcSize,
+    const HUF_DTable* DTable)
+{
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 1) return ERROR(GENERIC);
-    return HUF_decompress1X4_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
+    return HUF_decompress1X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
-size_t HUF_decompress1X4_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
+size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
-    size_t const hSize = HUF_readDTableX4_wksp(DCtx, cSrc, cSrcSize,
+    size_t const hSize = HUF_readDTableX2_wksp(DCtx, cSrc, cSrcSize,
                                                workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
-    return HUF_decompress1X4_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, /* bmi2 */ 0);
+    return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, /* bmi2 */ 0);
 }
 
 
-size_t HUF_decompress1X4_DCtx(HUF_DTable* DCtx, void* dst, size_t dstSize,
+size_t HUF_decompress1X2_DCtx(HUF_DTable* DCtx, void* dst, size_t dstSize,
                               const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
-    return HUF_decompress1X4_DCtx_wksp(DCtx, dst, dstSize, cSrc, cSrcSize,
+    return HUF_decompress1X2_DCtx_wksp(DCtx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 
-size_t HUF_decompress1X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
+size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
-    HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_TABLELOG_MAX);
-    return HUF_decompress1X4_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
+    HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_TABLELOG_MAX);
+    return HUF_decompress1X2_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
-size_t HUF_decompress4X4_usingDTable(
+size_t HUF_decompress4X2_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 1) return ERROR(GENERIC);
-    return HUF_decompress4X4_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
+    return HUF_decompress4X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
-static size_t HUF_decompress4X4_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize,
+static size_t HUF_decompress4X2_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize, int bmi2)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
-    size_t hSize = HUF_readDTableX4_wksp(dctx, cSrc, cSrcSize,
+    size_t hSize = HUF_readDTableX2_wksp(dctx, cSrc, cSrcSize,
                                          workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
-    return HUF_decompress4X4_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
+    return HUF_decompress4X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
 }
 
-size_t HUF_decompress4X4_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
+size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
-    return HUF_decompress4X4_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, /* bmi2 */ 0);
+    return HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, /* bmi2 */ 0);
 }
 
 
-size_t HUF_decompress4X4_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize,
+size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize,
                               const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
-    return HUF_decompress4X4_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
+    return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 
-size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
+size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
-    HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_TABLELOG_MAX);
-    return HUF_decompress4X4_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
+    HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_TABLELOG_MAX);
+    return HUF_decompress4X2_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
 
-/* ********************************/
-/* Generic decompression selector */
-/* ********************************/
+/* ***********************************/
+/* Universal decompression selectors */
+/* ***********************************/
 
 size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize,
                                     const void* cSrc, size_t cSrcSize,
                                     const HUF_DTable* DTable)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
-    return dtd.tableType ? HUF_decompress1X4_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0) :
-                           HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
+    return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0) :
+                           HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
 size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize,
                                     const void* cSrc, size_t cSrcSize,
                                     const HUF_DTable* DTable)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
-    return dtd.tableType ? HUF_decompress4X4_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0) :
-                           HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
+    return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0) :
+                           HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
 
 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
 {
     /* single, double, quad */
     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
 };
 
 /** HUF_selectDecoder() :
  *  Tells which decoder is likely to decode faster,
  *  based on a set of pre-computed metrics.
- * @return : 0==HUF_decompress4X2, 1==HUF_decompress4X4 .
+ * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
  *  Assumption : 0 < dstSize <= 128 KB */
 U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize)
 {
     assert(dstSize > 0);
-    assert(dstSize <= 128 KB);
+    assert(dstSize <= 128*1024);
     /* decoder timing evaluation */
     {   U32 const Q = (cSrcSize >= dstSize) ? 15 : (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 */
         U32 const D256 = (U32)(dstSize >> 8);
         U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256);
         U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256);
         DTime1 += DTime1 >> 3;  /* advantage to algorithm using less memory, to reduce cache eviction */
         return DTime1 < DTime0;
 }   }
 
 
 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
 
 size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
-    static const decompressionAlgo decompress[2] = { HUF_decompress4X2, HUF_decompress4X4 };
+    static const decompressionAlgo decompress[2] = { HUF_decompress4X1, HUF_decompress4X2 };
 
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
         return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
     }
 }
 
 size_t HUF_decompress4X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
-        return algoNb ? HUF_decompress4X4_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) :
-                        HUF_decompress4X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) ;
+        return algoNb ? HUF_decompress4X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) :
+                        HUF_decompress4X1_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) ;
     }
 }
 
 size_t HUF_decompress4X_hufOnly(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress4X_hufOnly_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                          workSpace, sizeof(workSpace));
 }
 
 
 size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst,
                                      size_t dstSize, const void* cSrc,
                                      size_t cSrcSize, void* workSpace,
                                      size_t wkspSize)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize == 0) return ERROR(corruption_detected);
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
-        return algoNb ? HUF_decompress4X4_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize):
-                        HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize);
+        return algoNb ? HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize):
+                        HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize);
     }
 }
 
 size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                   const void* cSrc, size_t cSrcSize,
                                   void* workSpace, size_t wkspSize)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
-        return algoNb ? HUF_decompress1X4_DCtx_wksp(dctx, dst, dstSize, cSrc,
+        return algoNb ? HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                 cSrcSize, workSpace, wkspSize):
-                        HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
+                        HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                 cSrcSize, workSpace, wkspSize);
     }
 }
 
 size_t HUF_decompress1X_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize,
                              const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress1X_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                       workSpace, sizeof(workSpace));
 }
 
 
 size_t HUF_decompress1X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
-    return dtd.tableType ? HUF_decompress1X4_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2) :
-                           HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
+    return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2) :
+                           HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 }
 
-size_t HUF_decompress1X2_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2)
+size_t HUF_decompress1X1_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
-    size_t const hSize = HUF_readDTableX2_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize);
+    size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
-    return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
+    return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
 }
 
 size_t HUF_decompress4X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
-    return dtd.tableType ? HUF_decompress4X4_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2) :
-                           HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
+    return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2) :
+                           HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 }
 
 size_t HUF_decompress4X_hufOnly_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize == 0) return ERROR(corruption_detected);
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
-        return algoNb ? HUF_decompress4X4_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2) :
-                        HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2);
+        return algoNb ? HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2) :
+                        HUF_decompress4X1_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2);
     }
 }
Index: vendor/zstd/dist/lib/decompress/zstd_decompress.c
===================================================================
--- vendor/zstd/dist/lib/decompress/zstd_decompress.c	(revision 339613)
+++ vendor/zstd/dist/lib/decompress/zstd_decompress.c	(revision 339614)
@@ -1,3003 +1,3108 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /* ***************************************************************
 *  Tuning parameters
 *****************************************************************/
 /*!
  * HEAPMODE :
  * Select how default decompression function ZSTD_decompress() allocates its context,
  * on stack (0), or into heap (1, default; requires malloc()).
  * Note that functions with explicit context such as ZSTD_decompressDCtx() are unaffected.
  */
 #ifndef ZSTD_HEAPMODE
 #  define ZSTD_HEAPMODE 1
 #endif
 
 /*!
 *  LEGACY_SUPPORT :
 *  if set to 1+, ZSTD_decompress() can decode older formats (v0.1+)
 */
 #ifndef ZSTD_LEGACY_SUPPORT
 #  define ZSTD_LEGACY_SUPPORT 0
 #endif
 
 /*!
  *  MAXWINDOWSIZE_DEFAULT :
  *  maximum window size accepted by DStream __by default__.
  *  Frames requiring more memory will be rejected.
  *  It's possible to set a different limit using ZSTD_DCtx_setMaxWindowSize().
  */
 #ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
 #  define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_DEFAULTMAX) + 1)
 #endif
 
+/*!
+ *  NO_FORWARD_PROGRESS_MAX :
+ *  maximum allowed nb of calls to ZSTD_decompressStream() and ZSTD_decompress_generic()
+ *  without any forward progress
+ *  (defined as: no byte read from input, and no byte flushed to output)
+ *  before triggering an error.
+ */
+#ifndef ZSTD_NO_FORWARD_PROGRESS_MAX
+#  define ZSTD_NO_FORWARD_PROGRESS_MAX 16
+#endif
 
+
 /*-*******************************************************
 *  Dependencies
 *********************************************************/
 #include       /* memcpy, memmove, memset */
-#include "cpu.h"
+#include "compiler.h"    /* prefetch */
+#include "cpu.h"         /* bmi2 */
 #include "mem.h"         /* low level memory routines */
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_internal.h"
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
 #  include "zstd_legacy.h"
 #endif
 
+static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict);
+static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict);
 
+
 /*-*************************************
 *  Errors
 ***************************************/
 #define ZSTD_isError ERR_isError   /* for inlining */
 #define FSE_isError  ERR_isError
 #define HUF_isError  ERR_isError
 
 
 /*_*******************************************************
 *  Memory operations
 **********************************************************/
 static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
 
 
 /*-*************************************************************
 *   Context management
 ***************************************************************/
 typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
                ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
                ZSTDds_decompressLastBlock, ZSTDds_checkChecksum,
                ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage;
 
 typedef enum { zdss_init=0, zdss_loadHeader,
                zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
 
 
 typedef struct {
     U32 fastMode;
     U32 tableLog;
 } ZSTD_seqSymbol_header;
 
 typedef struct {
     U16  nextState;
     BYTE nbAdditionalBits;
     BYTE nbBits;
     U32  baseValue;
 } ZSTD_seqSymbol;
 
 #define SEQSYMBOL_TABLE_SIZE(log)   (1 + (1 << (log)))
 
 typedef struct {
-    ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)];
-    ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)];
-    ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)];
+    ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)];    /* Note : Space reserved for FSE Tables */
+    ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)];   /* is also used as temporary workspace while building hufTable during DDict creation */
+    ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)];    /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */
     HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)];  /* can accommodate HUF_decompress4X */
-    U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     U32 rep[ZSTD_REP_NUM];
 } ZSTD_entropyDTables_t;
 
 struct ZSTD_DCtx_s
 {
     const ZSTD_seqSymbol* LLTptr;
     const ZSTD_seqSymbol* MLTptr;
     const ZSTD_seqSymbol* OFTptr;
     const HUF_DTable* HUFptr;
     ZSTD_entropyDTables_t entropy;
+    U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];   /* space needed when building huffman tables */
     const void* previousDstEnd;   /* detect continuity */
-    const void* base;             /* start of current segment */
-    const void* vBase;            /* virtual start of previous segment if it was just before current one */
+    const void* prefixStart;      /* start of current segment */
+    const void* virtualStart;     /* virtual start of previous segment if it was just before current one */
     const void* dictEnd;          /* end of previous segment */
     size_t expected;
     ZSTD_frameHeader fParams;
     U64 decodedSize;
     blockType_e bType;            /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */
     ZSTD_dStage stage;
     U32 litEntropy;
     U32 fseEntropy;
     XXH64_state_t xxhState;
     size_t headerSize;
-    U32 dictID;
     ZSTD_format_e format;
     const BYTE* litPtr;
     ZSTD_customMem customMem;
     size_t litSize;
     size_t rleSize;
     size_t staticSize;
     int bmi2;                     /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */
 
-    /* streaming */
+    /* dictionary */
     ZSTD_DDict* ddictLocal;
-    const ZSTD_DDict* ddict;
+    const ZSTD_DDict* ddict;     /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */
+    U32 dictID;
+    int ddictIsCold;             /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */
+
+    /* streaming */
     ZSTD_dStreamStage streamStage;
     char*  inBuff;
     size_t inBuffSize;
     size_t inPos;
     size_t maxWindowSize;
     char*  outBuff;
     size_t outBuffSize;
     size_t outStart;
     size_t outEnd;
     size_t lhSize;
     void* legacyContext;
     U32 previousLegacyVersion;
     U32 legacyVersion;
     U32 hostageByte;
+    int noForwardProgress;
 
     /* workspace */
     BYTE litBuffer[ZSTD_BLOCKSIZE_MAX + WILDCOPY_OVERLENGTH];
     BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
 };  /* typedef'd to ZSTD_DCtx within "zstd.h" */
 
 size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
 {
     if (dctx==NULL) return 0;   /* support sizeof NULL */
     return sizeof(*dctx)
            + ZSTD_sizeof_DDict(dctx->ddictLocal)
            + dctx->inBuffSize + dctx->outBuffSize;
 }
 
 size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
 
 
 static size_t ZSTD_startingInputLength(ZSTD_format_e format)
 {
     size_t const startingInputLength = (format==ZSTD_f_zstd1_magicless) ?
-                    ZSTD_frameHeaderSize_prefix - ZSTD_frameIdSize :
+                    ZSTD_frameHeaderSize_prefix - ZSTD_FRAMEIDSIZE :
                     ZSTD_frameHeaderSize_prefix;
     ZSTD_STATIC_ASSERT(ZSTD_FRAMEHEADERSIZE_PREFIX >= ZSTD_FRAMEIDSIZE);
     /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
     assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
     return startingInputLength;
 }
 
 static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
 {
     dctx->format = ZSTD_f_zstd1;  /* ZSTD_decompressBegin() invokes ZSTD_startingInputLength() with argument dctx->format */
     dctx->staticSize  = 0;
     dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
     dctx->ddict       = NULL;
     dctx->ddictLocal  = NULL;
+    dctx->dictEnd     = NULL;
+    dctx->ddictIsCold = 0;
     dctx->inBuff      = NULL;
     dctx->inBuffSize  = 0;
     dctx->outBuffSize = 0;
     dctx->streamStage = zdss_init;
+    dctx->legacyContext = NULL;
+    dctx->previousLegacyVersion = 0;
+    dctx->noForwardProgress = 0;
     dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
 }
 
 ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize)
 {
     ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace;
 
     if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
     if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL;  /* minimum size */
 
     ZSTD_initDCtx_internal(dctx);
     dctx->staticSize = workspaceSize;
     dctx->inBuff = (char*)(dctx+1);
     return dctx;
 }
 
 ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
 {
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
 
     {   ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_malloc(sizeof(*dctx), customMem);
         if (!dctx) return NULL;
         dctx->customMem = customMem;
-        dctx->legacyContext = NULL;
-        dctx->previousLegacyVersion = 0;
         ZSTD_initDCtx_internal(dctx);
         return dctx;
     }
 }
 
 ZSTD_DCtx* ZSTD_createDCtx(void)
 {
     DEBUGLOG(3, "ZSTD_createDCtx");
     return ZSTD_createDCtx_advanced(ZSTD_defaultCMem);
 }
 
 size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
 {
     if (dctx==NULL) return 0;   /* support free on NULL */
     if (dctx->staticSize) return ERROR(memory_allocation);   /* not compatible with static DCtx */
     {   ZSTD_customMem const cMem = dctx->customMem;
         ZSTD_freeDDict(dctx->ddictLocal);
         dctx->ddictLocal = NULL;
         ZSTD_free(dctx->inBuff, cMem);
         dctx->inBuff = NULL;
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
         if (dctx->legacyContext)
             ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion);
 #endif
         ZSTD_free(dctx, cMem);
         return 0;
     }
 }
 
 /* no longer useful */
 void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
 {
     size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx);
     memcpy(dstDCtx, srcDCtx, toCopy);  /* no need to copy workspace */
 }
 
 
 /*-*************************************************************
  *   Frame header decoding
  ***************************************************************/
 
 /*! ZSTD_isFrame() :
  *  Tells if the content of `buffer` starts with a valid Frame Identifier.
  *  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
  *  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
  *  Note 3 : Skippable Frame Identifiers are considered valid. */
 unsigned ZSTD_isFrame(const void* buffer, size_t size)
 {
-    if (size < ZSTD_frameIdSize) return 0;
+    if (size < ZSTD_FRAMEIDSIZE) return 0;
     {   U32 const magic = MEM_readLE32(buffer);
         if (magic == ZSTD_MAGICNUMBER) return 1;
         if ((magic & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
     }
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(buffer, size)) return 1;
 #endif
     return 0;
 }
 
 /** ZSTD_frameHeaderSize_internal() :
  *  srcSize must be large enough to reach header size fields.
  *  note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless.
  * @return : size of the Frame Header
  *           or an error code, which can be tested with ZSTD_isError() */
 static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format)
 {
     size_t const minInputSize = ZSTD_startingInputLength(format);
     if (srcSize < minInputSize) return ERROR(srcSize_wrong);
 
     {   BYTE const fhd = ((const BYTE*)src)[minInputSize-1];
         U32 const dictID= fhd & 3;
         U32 const singleSegment = (fhd >> 5) & 1;
         U32 const fcsId = fhd >> 6;
         return minInputSize + !singleSegment
              + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId]
              + (singleSegment && !fcsId);
     }
 }
 
 /** ZSTD_frameHeaderSize() :
  *  srcSize must be >= ZSTD_frameHeaderSize_prefix.
- * @return : size of the Frame Header */
+ * @return : size of the Frame Header,
+ *           or an error code (if srcSize is too small) */
 size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
 {
     return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1);
 }
 
 
-/** ZSTD_getFrameHeader_internal() :
+/** ZSTD_getFrameHeader_advanced() :
  *  decode Frame Header, or require larger `srcSize`.
  *  note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless
  * @return : 0, `zfhPtr` is correctly filled,
  *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
  *           or an error code, which can be tested using ZSTD_isError() */
-static size_t ZSTD_getFrameHeader_internal(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
+size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t const minInputSize = ZSTD_startingInputLength(format);
 
+    memset(zfhPtr, 0, sizeof(*zfhPtr));   /* not strictly necessary, but static analyzer do not understand that zfhPtr is only going to be read only if return value is zero, since they are 2 different signals */
     if (srcSize < minInputSize) return minInputSize;
+    if (src==NULL) return ERROR(GENERIC);   /* invalid parameter */
 
     if ( (format != ZSTD_f_zstd1_magicless)
       && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) {
         if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
             /* skippable frame */
             if (srcSize < ZSTD_skippableHeaderSize)
                 return ZSTD_skippableHeaderSize; /* magic number + frame length */
             memset(zfhPtr, 0, sizeof(*zfhPtr));
-            zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_frameIdSize);
+            zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_FRAMEIDSIZE);
             zfhPtr->frameType = ZSTD_skippableFrame;
             return 0;
         }
         return ERROR(prefix_unknown);
     }
 
     /* ensure there is enough `srcSize` to fully read/decode frame header */
     {   size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format);
         if (srcSize < fhsize) return fhsize;
         zfhPtr->headerSize = (U32)fhsize;
     }
 
     {   BYTE const fhdByte = ip[minInputSize-1];
         size_t pos = minInputSize;
         U32 const dictIDSizeCode = fhdByte&3;
         U32 const checksumFlag = (fhdByte>>2)&1;
         U32 const singleSegment = (fhdByte>>5)&1;
         U32 const fcsID = fhdByte>>6;
         U64 windowSize = 0;
         U32 dictID = 0;
         U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN;
         if ((fhdByte & 0x08) != 0)
             return ERROR(frameParameter_unsupported); /* reserved bits, must be zero */
 
         if (!singleSegment) {
             BYTE const wlByte = ip[pos++];
             U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
             if (windowLog > ZSTD_WINDOWLOG_MAX)
                 return ERROR(frameParameter_windowTooLarge);
             windowSize = (1ULL << windowLog);
             windowSize += (windowSize >> 3) * (wlByte&7);
         }
         switch(dictIDSizeCode)
         {
             default: assert(0);  /* impossible */
             case 0 : break;
             case 1 : dictID = ip[pos]; pos++; break;
             case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
             case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
         }
         switch(fcsID)
         {
             default: assert(0);  /* impossible */
             case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
             case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
             case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
             case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
         }
         if (singleSegment) windowSize = frameContentSize;
 
         zfhPtr->frameType = ZSTD_frame;
         zfhPtr->frameContentSize = frameContentSize;
         zfhPtr->windowSize = windowSize;
         zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
         zfhPtr->dictID = dictID;
         zfhPtr->checksumFlag = checksumFlag;
     }
     return 0;
 }
 
 /** ZSTD_getFrameHeader() :
  *  decode Frame Header, or require larger `srcSize`.
  *  note : this function does not consume input, it only reads it.
  * @return : 0, `zfhPtr` is correctly filled,
  *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
  *           or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize)
 {
-    return ZSTD_getFrameHeader_internal(zfhPtr, src, srcSize, ZSTD_f_zstd1);
+    return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1);
 }
 
 
 /** ZSTD_getFrameContentSize() :
  *  compatible with legacy mode
  * @return : decompressed size of the single frame pointed to be `src` if known, otherwise
  *         - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
  *         - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
 unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize)
 {
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(src, srcSize)) {
         unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize);
         return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret;
     }
 #endif
     {   ZSTD_frameHeader zfh;
         if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0)
             return ZSTD_CONTENTSIZE_ERROR;
         if (zfh.frameType == ZSTD_skippableFrame) {
             return 0;
         } else {
             return zfh.frameContentSize;
     }   }
 }
 
 /** ZSTD_findDecompressedSize() :
  *  compatible with legacy mode
  *  `srcSize` must be the exact length of some number of ZSTD compressed and/or
  *      skippable frames
  *  @return : decompressed size of the frames contained */
 unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize)
 {
     unsigned long long totalDstSize = 0;
 
     while (srcSize >= ZSTD_frameHeaderSize_prefix) {
         U32 const magicNumber = MEM_readLE32(src);
 
         if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
             size_t skippableSize;
             if (srcSize < ZSTD_skippableHeaderSize)
                 return ERROR(srcSize_wrong);
-            skippableSize = MEM_readLE32((const BYTE *)src + ZSTD_frameIdSize)
+            skippableSize = MEM_readLE32((const BYTE *)src + ZSTD_FRAMEIDSIZE)
                           + ZSTD_skippableHeaderSize;
             if (srcSize < skippableSize) {
                 return ZSTD_CONTENTSIZE_ERROR;
             }
 
             src = (const BYTE *)src + skippableSize;
             srcSize -= skippableSize;
             continue;
         }
 
         {   unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
             if (ret >= ZSTD_CONTENTSIZE_ERROR) return ret;
 
             /* check for overflow */
             if (totalDstSize + ret < totalDstSize) return ZSTD_CONTENTSIZE_ERROR;
             totalDstSize += ret;
         }
         {   size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize);
             if (ZSTD_isError(frameSrcSize)) {
                 return ZSTD_CONTENTSIZE_ERROR;
             }
 
             src = (const BYTE *)src + frameSrcSize;
             srcSize -= frameSrcSize;
         }
     }  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
 
     if (srcSize) return ZSTD_CONTENTSIZE_ERROR;
 
     return totalDstSize;
 }
 
 /** ZSTD_getDecompressedSize() :
 *   compatible with legacy mode
 *   @return : decompressed size if known, 0 otherwise
               note : 0 can mean any of the following :
                    - frame content is empty
                    - decompressed size field is not present in frame header
                    - frame header unknown / not supported
                    - frame header not complete (`srcSize` too small) */
 unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
 {
     unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
     ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN);
     return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret;
 }
 
 
 /** ZSTD_decodeFrameHeader() :
 *   `headerSize` must be the size provided by ZSTD_frameHeaderSize().
 *   @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
 static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize)
 {
-    size_t const result = ZSTD_getFrameHeader_internal(&(dctx->fParams), src, headerSize, dctx->format);
+    size_t const result = ZSTD_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format);
     if (ZSTD_isError(result)) return result;    /* invalid header */
     if (result>0) return ERROR(srcSize_wrong);  /* headerSize too small */
     if (dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID))
         return ERROR(dictionary_wrong);
     if (dctx->fParams.checksumFlag) XXH64_reset(&dctx->xxhState, 0);
     return 0;
 }
 
 
 /*-*************************************************************
  *   Block decoding
  ***************************************************************/
 
 /*! ZSTD_getcBlockSize() :
 *   Provides the size of compressed block from block header `src` */
 size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
                           blockProperties_t* bpPtr)
 {
     if (srcSize < ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
     {   U32 const cBlockHeader = MEM_readLE24(src);
         U32 const cSize = cBlockHeader >> 3;
         bpPtr->lastBlock = cBlockHeader & 1;
         bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
         bpPtr->origSize = cSize;   /* only useful for RLE */
         if (bpPtr->blockType == bt_rle) return 1;
         if (bpPtr->blockType == bt_reserved) return ERROR(corruption_detected);
         return cSize;
     }
 }
 
 
 static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize)
 {
+    if (dst==NULL) return ERROR(dstSize_tooSmall);
     if (srcSize > dstCapacity) return ERROR(dstSize_tooSmall);
     memcpy(dst, src, srcSize);
     return srcSize;
 }
 
 
 static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                                size_t regenSize)
 {
     if (srcSize != 1) return ERROR(srcSize_wrong);
     if (regenSize > dstCapacity) return ERROR(dstSize_tooSmall);
     memset(dst, *(const BYTE*)src, regenSize);
     return regenSize;
 }
 
+/* Hidden declaration for fullbench */
+size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
+                          const void* src, size_t srcSize);
 /*! ZSTD_decodeLiteralsBlock() :
  * @return : nb of bytes read from src (< srcSize )
  *  note : symbol not declared but exposed for fullbench */
 size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
                           const void* src, size_t srcSize)   /* note : srcSize < BLOCKSIZE */
 {
     if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
 
     {   const BYTE* const istart = (const BYTE*) src;
         symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3);
 
         switch(litEncType)
         {
         case set_repeat:
             if (dctx->litEntropy==0) return ERROR(dictionary_corrupted);
             /* fall-through */
+
         case set_compressed:
             if (srcSize < 5) return ERROR(corruption_detected);   /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3 */
             {   size_t lhSize, litSize, litCSize;
                 U32 singleStream=0;
                 U32 const lhlCode = (istart[0] >> 2) & 3;
                 U32 const lhc = MEM_readLE32(istart);
                 switch(lhlCode)
                 {
                 case 0: case 1: default:   /* note : default is impossible, since lhlCode into [0..3] */
                     /* 2 - 2 - 10 - 10 */
                     singleStream = !lhlCode;
                     lhSize = 3;
                     litSize  = (lhc >> 4) & 0x3FF;
                     litCSize = (lhc >> 14) & 0x3FF;
                     break;
                 case 2:
                     /* 2 - 2 - 14 - 14 */
                     lhSize = 4;
                     litSize  = (lhc >> 4) & 0x3FFF;
                     litCSize = lhc >> 18;
                     break;
                 case 3:
                     /* 2 - 2 - 18 - 18 */
                     lhSize = 5;
                     litSize  = (lhc >> 4) & 0x3FFFF;
                     litCSize = (lhc >> 22) + (istart[4] << 10);
                     break;
                 }
                 if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected);
                 if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
 
+                /* prefetch huffman table if cold */
+                if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) {
+                    PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable));
+                }
+
                 if (HUF_isError((litEncType==set_repeat) ?
                                     ( singleStream ?
                                         HUF_decompress1X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) :
                                         HUF_decompress4X_usingDTable_bmi2(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr, dctx->bmi2) ) :
                                     ( singleStream ?
-                                        HUF_decompress1X2_DCtx_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize,
-                                                                         dctx->entropy.workspace, sizeof(dctx->entropy.workspace), dctx->bmi2) :
+                                        HUF_decompress1X1_DCtx_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize,
+                                                                         dctx->workspace, sizeof(dctx->workspace), dctx->bmi2) :
                                         HUF_decompress4X_hufOnly_wksp_bmi2(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize,
-                                                                           dctx->entropy.workspace, sizeof(dctx->entropy.workspace), dctx->bmi2))))
+                                                                           dctx->workspace, sizeof(dctx->workspace), dctx->bmi2))))
                     return ERROR(corruption_detected);
 
                 dctx->litPtr = dctx->litBuffer;
                 dctx->litSize = litSize;
                 dctx->litEntropy = 1;
                 if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable;
                 memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
                 return litCSize + lhSize;
             }
 
         case set_basic:
             {   size_t litSize, lhSize;
                 U32 const lhlCode = ((istart[0]) >> 2) & 3;
                 switch(lhlCode)
                 {
                 case 0: case 2: default:   /* note : default is impossible, since lhlCode into [0..3] */
                     lhSize = 1;
                     litSize = istart[0] >> 3;
                     break;
                 case 1:
                     lhSize = 2;
                     litSize = MEM_readLE16(istart) >> 4;
                     break;
                 case 3:
                     lhSize = 3;
                     litSize = MEM_readLE24(istart) >> 4;
                     break;
                 }
 
                 if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) {  /* risk reading beyond src buffer with wildcopy */
                     if (litSize+lhSize > srcSize) return ERROR(corruption_detected);
                     memcpy(dctx->litBuffer, istart+lhSize, litSize);
                     dctx->litPtr = dctx->litBuffer;
                     dctx->litSize = litSize;
                     memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
                     return lhSize+litSize;
                 }
                 /* direct reference into compressed stream */
                 dctx->litPtr = istart+lhSize;
                 dctx->litSize = litSize;
                 return lhSize+litSize;
             }
 
         case set_rle:
             {   U32 const lhlCode = ((istart[0]) >> 2) & 3;
                 size_t litSize, lhSize;
                 switch(lhlCode)
                 {
                 case 0: case 2: default:   /* note : default is impossible, since lhlCode into [0..3] */
                     lhSize = 1;
                     litSize = istart[0] >> 3;
                     break;
                 case 1:
                     lhSize = 2;
                     litSize = MEM_readLE16(istart) >> 4;
                     break;
                 case 3:
                     lhSize = 3;
                     litSize = MEM_readLE24(istart) >> 4;
                     if (srcSize<4) return ERROR(corruption_detected);   /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
                     break;
                 }
                 if (litSize > ZSTD_BLOCKSIZE_MAX) return ERROR(corruption_detected);
                 memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH);
                 dctx->litPtr = dctx->litBuffer;
                 dctx->litSize = litSize;
                 return lhSize+1;
             }
         default:
             return ERROR(corruption_detected);   /* impossible */
         }
     }
 }
 
 /* Default FSE distribution tables.
  * These are pre-calculated FSE decoding tables using default distributions as defined in specification :
  * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#default-distributions
  * They were generated programmatically with following method :
  * - start from default distributions, present in /lib/common/zstd_internal.h
  * - generate tables normally, using ZSTD_buildFSETable()
  * - printout the content of tables
  * - pretify output, report below, test with fuzzer to ensure it's correct */
 
 /* Default FSE distribution table for Literal Lengths */
 static const ZSTD_seqSymbol LL_defaultDTable[(1<tableLog = 0;
     DTableH->fastMode = 0;
 
     cell->nbBits = 0;
     cell->nextState = 0;
     assert(nbAddBits < 255);
     cell->nbAdditionalBits = (BYTE)nbAddBits;
     cell->baseValue = baseValue;
 }
 
 
 /* ZSTD_buildFSETable() :
  * generate FSE decoding table for one symbol (ll, ml or off) */
 static void
 ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
     const short* normalizedCounter, unsigned maxSymbolValue,
     const U32* baseValue, const U32* nbAdditionalBits,
     unsigned tableLog)
 {
     ZSTD_seqSymbol* const tableDecode = dt+1;
     U16 symbolNext[MaxSeq+1];
 
     U32 const maxSV1 = maxSymbolValue + 1;
     U32 const tableSize = 1 << tableLog;
     U32 highThreshold = tableSize-1;
 
     /* Sanity Checks */
     assert(maxSymbolValue <= MaxSeq);
     assert(tableLog <= MaxFSELog);
 
     /* Init, lay down lowprob symbols */
     {   ZSTD_seqSymbol_header DTableH;
         DTableH.tableLog = tableLog;
         DTableH.fastMode = 1;
         {   S16 const largeLimit= (S16)(1 << (tableLog-1));
             U32 s;
             for (s=0; s= largeLimit) DTableH.fastMode=0;
                     symbolNext[s] = normalizedCounter[s];
         }   }   }
         memcpy(dt, &DTableH, sizeof(DTableH));
     }
 
     /* Spread symbols */
     {   U32 const tableMask = tableSize-1;
         U32 const step = FSE_TABLESTEP(tableSize);
         U32 s, position = 0;
         for (s=0; s highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }   }
         assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
     }
 
     /* Build Decoding table */
     {   U32 u;
         for (u=0; u max) return ERROR(corruption_detected);
         {   U32 const symbol = *(const BYTE*)src;
             U32 const baseline = baseValue[symbol];
             U32 const nbBits = nbAdditionalBits[symbol];
             ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits);
         }
         *DTablePtr = DTableSpace;
         return 1;
     case set_basic :
         *DTablePtr = defaultTable;
         return 0;
     case set_repeat:
         if (!flagRepeatTable) return ERROR(corruption_detected);
+        /* prefetch FSE table if used */
+        if (ddictIsCold && (nbSeq > 24 /* heuristic */)) {
+            const void* const pStart = *DTablePtr;
+            size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog));
+            PREFETCH_AREA(pStart, pSize);
+        }
         return 0;
     case set_compressed :
         {   U32 tableLog;
             S16 norm[MaxSeq+1];
             size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
             if (FSE_isError(headerSize)) return ERROR(corruption_detected);
             if (tableLog > maxLog) return ERROR(corruption_detected);
             ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog);
             *DTablePtr = DTableSpace;
             return headerSize;
         }
     default :   /* impossible */
         assert(0);
         return ERROR(GENERIC);
     }
 }
 
 static const U32 LL_base[MaxLL+1] = {
                  0,    1,    2,     3,     4,     5,     6,      7,
                  8,    9,   10,    11,    12,    13,    14,     15,
                 16,   18,   20,    22,    24,    28,    32,     40,
                 48,   64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
                 0x2000, 0x4000, 0x8000, 0x10000 };
 
 static const U32 OF_base[MaxOff+1] = {
                  0,        1,       1,       5,     0xD,     0x1D,     0x3D,     0x7D,
                  0xFD,   0x1FD,   0x3FD,   0x7FD,   0xFFD,   0x1FFD,   0x3FFD,   0x7FFD,
                  0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
                  0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD };
 
 static const U32 OF_bits[MaxOff+1] = {
                      0,  1,  2,  3,  4,  5,  6,  7,
                      8,  9, 10, 11, 12, 13, 14, 15,
                     16, 17, 18, 19, 20, 21, 22, 23,
                     24, 25, 26, 27, 28, 29, 30, 31 };
 
 static const U32 ML_base[MaxML+1] = {
                      3,  4,  5,    6,     7,     8,     9,    10,
                     11, 12, 13,   14,    15,    16,    17,    18,
                     19, 20, 21,   22,    23,    24,    25,    26,
                     27, 28, 29,   30,    31,    32,    33,    34,
                     35, 37, 39,   41,    43,    47,    51,    59,
                     67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
                     0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };
 
+/* Hidden delcaration for fullbench */
+size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
+                             const void* src, size_t srcSize);
 
 size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
                              const void* src, size_t srcSize)
 {
     const BYTE* const istart = (const BYTE* const)src;
     const BYTE* const iend = istart + srcSize;
     const BYTE* ip = istart;
+    int nbSeq;
     DEBUGLOG(5, "ZSTD_decodeSeqHeaders");
 
     /* check */
     if (srcSize < MIN_SEQUENCES_SIZE) return ERROR(srcSize_wrong);
 
     /* SeqHead */
-    {   int nbSeq = *ip++;
-        if (!nbSeq) { *nbSeqPtr=0; return 1; }
-        if (nbSeq > 0x7F) {
-            if (nbSeq == 0xFF) {
-                if (ip+2 > iend) return ERROR(srcSize_wrong);
-                nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2;
-            } else {
-                if (ip >= iend) return ERROR(srcSize_wrong);
-                nbSeq = ((nbSeq-0x80)<<8) + *ip++;
-            }
+    nbSeq = *ip++;
+    if (!nbSeq) { *nbSeqPtr=0; return 1; }
+    if (nbSeq > 0x7F) {
+        if (nbSeq == 0xFF) {
+            if (ip+2 > iend) return ERROR(srcSize_wrong);
+            nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2;
+        } else {
+            if (ip >= iend) return ERROR(srcSize_wrong);
+            nbSeq = ((nbSeq-0x80)<<8) + *ip++;
         }
-        *nbSeqPtr = nbSeq;
     }
+    *nbSeqPtr = nbSeq;
 
     /* FSE table descriptors */
     if (ip+4 > iend) return ERROR(srcSize_wrong); /* minimum possible size */
     {   symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6);
         symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3);
         symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3);
         ip++;
 
         /* Build DTables */
         {   size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
                                                       LLtype, MaxLL, LLFSELog,
                                                       ip, iend-ip,
                                                       LL_base, LL_bits,
-                                                      LL_defaultDTable, dctx->fseEntropy);
+                                                      LL_defaultDTable, dctx->fseEntropy,
+                                                      dctx->ddictIsCold, nbSeq);
             if (ZSTD_isError(llhSize)) return ERROR(corruption_detected);
             ip += llhSize;
         }
 
         {   size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
                                                       OFtype, MaxOff, OffFSELog,
                                                       ip, iend-ip,
                                                       OF_base, OF_bits,
-                                                      OF_defaultDTable, dctx->fseEntropy);
+                                                      OF_defaultDTable, dctx->fseEntropy,
+                                                      dctx->ddictIsCold, nbSeq);
             if (ZSTD_isError(ofhSize)) return ERROR(corruption_detected);
             ip += ofhSize;
         }
 
         {   size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
                                                       MLtype, MaxML, MLFSELog,
                                                       ip, iend-ip,
                                                       ML_base, ML_bits,
-                                                      ML_defaultDTable, dctx->fseEntropy);
+                                                      ML_defaultDTable, dctx->fseEntropy,
+                                                      dctx->ddictIsCold, nbSeq);
             if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected);
             ip += mlhSize;
         }
     }
 
+    /* prefetch dictionary content */
+    if (dctx->ddictIsCold) {
+        size_t const dictSize = (const char*)dctx->prefixStart - (const char*)dctx->virtualStart;
+        size_t const psmin = MIN(dictSize, (size_t)(64*nbSeq) /* heuristic */ );
+        size_t const pSize = MIN(psmin, 128 KB /* protection */ );
+        const void* const pStart = (const char*)dctx->dictEnd - pSize;
+        PREFETCH_AREA(pStart, pSize);
+        dctx->ddictIsCold = 0;
+    }
+
     return ip-istart;
 }
 
 
 typedef struct {
     size_t litLength;
     size_t matchLength;
     size_t offset;
     const BYTE* match;
 } seq_t;
 
 typedef struct {
     size_t state;
     const ZSTD_seqSymbol* table;
 } ZSTD_fseState;
 
 typedef struct {
     BIT_DStream_t DStream;
     ZSTD_fseState stateLL;
     ZSTD_fseState stateOffb;
     ZSTD_fseState stateML;
     size_t prevOffset[ZSTD_REP_NUM];
     const BYTE* prefixStart;
     const BYTE* dictEnd;
     size_t pos;
 } seqState_t;
 
 
 FORCE_NOINLINE
 size_t ZSTD_execSequenceLast7(BYTE* op,
                               BYTE* const oend, seq_t sequence,
                               const BYTE** litPtr, const BYTE* const litLimit,
                               const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
 {
     BYTE* const oLitEnd = op + sequence.litLength;
     size_t const sequenceLength = sequence.litLength + sequence.matchLength;
     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
     BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
     const BYTE* const iLitEnd = *litPtr + sequence.litLength;
     const BYTE* match = oLitEnd - sequence.offset;
 
     /* check */
     if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
     if (iLitEnd > litLimit) return ERROR(corruption_detected);   /* over-read beyond lit buffer */
     if (oLitEnd <= oend_w) return ERROR(GENERIC);   /* Precondition */
 
     /* copy literals */
     if (op < oend_w) {
         ZSTD_wildcopy(op, *litPtr, oend_w - op);
         *litPtr += oend_w - op;
         op = oend_w;
     }
     while (op < oLitEnd) *op++ = *(*litPtr)++;
 
     /* copy Match */
     if (sequence.offset > (size_t)(oLitEnd - base)) {
         /* offset beyond prefix */
         if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(corruption_detected);
         match = dictEnd - (base-match);
         if (match + sequence.matchLength <= dictEnd) {
             memmove(oLitEnd, match, sequence.matchLength);
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
         {   size_t const length1 = dictEnd - match;
             memmove(oLitEnd, match, length1);
             op = oLitEnd + length1;
             sequence.matchLength -= length1;
             match = base;
     }   }
     while (op < oMatchEnd) *op++ = *match++;
     return sequenceLength;
 }
 
 
 HINT_INLINE
 size_t ZSTD_execSequence(BYTE* op,
                          BYTE* const oend, seq_t sequence,
                          const BYTE** litPtr, const BYTE* const litLimit,
-                         const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
+                         const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
 {
     BYTE* const oLitEnd = op + sequence.litLength;
     size_t const sequenceLength = sequence.litLength + sequence.matchLength;
     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
     BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
     const BYTE* const iLitEnd = *litPtr + sequence.litLength;
     const BYTE* match = oLitEnd - sequence.offset;
 
     /* check */
     if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
     if (iLitEnd > litLimit) return ERROR(corruption_detected);   /* over-read beyond lit buffer */
-    if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd);
+    if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);
 
     /* copy Literals */
     ZSTD_copy8(op, *litPtr);
     if (sequence.litLength > 8)
         ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8);   /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
     op = oLitEnd;
     *litPtr = iLitEnd;   /* update for next sequence */
 
     /* copy Match */
-    if (sequence.offset > (size_t)(oLitEnd - base)) {
+    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
         /* offset beyond prefix -> go into extDict */
-        if (sequence.offset > (size_t)(oLitEnd - vBase))
+        if (sequence.offset > (size_t)(oLitEnd - virtualStart))
             return ERROR(corruption_detected);
-        match = dictEnd + (match - base);
+        match = dictEnd + (match - prefixStart);
         if (match + sequence.matchLength <= dictEnd) {
             memmove(oLitEnd, match, sequence.matchLength);
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
         {   size_t const length1 = dictEnd - match;
             memmove(oLitEnd, match, length1);
             op = oLitEnd + length1;
             sequence.matchLength -= length1;
-            match = base;
+            match = prefixStart;
             if (op > oend_w || sequence.matchLength < MINMATCH) {
               U32 i;
               for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
               return sequenceLength;
             }
     }   }
     /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */
 
     /* match within prefix */
     if (sequence.offset < 8) {
         /* close range match, overlap */
         static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
         static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
         int const sub2 = dec64table[sequence.offset];
         op[0] = match[0];
         op[1] = match[1];
         op[2] = match[2];
         op[3] = match[3];
         match += dec32table[sequence.offset];
         ZSTD_copy4(op+4, match);
         match -= sub2;
     } else {
         ZSTD_copy8(op, match);
     }
     op += 8; match += 8;
 
     if (oMatchEnd > oend-(16-MINMATCH)) {
         if (op < oend_w) {
             ZSTD_wildcopy(op, match, oend_w - op);
             match += oend_w - op;
             op = oend_w;
         }
         while (op < oMatchEnd) *op++ = *match++;
     } else {
         ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
     }
     return sequenceLength;
 }
 
 
 HINT_INLINE
 size_t ZSTD_execSequenceLong(BYTE* op,
                              BYTE* const oend, seq_t sequence,
                              const BYTE** litPtr, const BYTE* const litLimit,
                              const BYTE* const prefixStart, const BYTE* const dictStart, const BYTE* const dictEnd)
 {
     BYTE* const oLitEnd = op + sequence.litLength;
     size_t const sequenceLength = sequence.litLength + sequence.matchLength;
     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
     BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
     const BYTE* const iLitEnd = *litPtr + sequence.litLength;
     const BYTE* match = sequence.match;
 
     /* check */
     if (oMatchEnd > oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
     if (iLitEnd > litLimit) return ERROR(corruption_detected);   /* over-read beyond lit buffer */
     if (oLitEnd > oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, dictStart, dictEnd);
 
     /* copy Literals */
     ZSTD_copy8(op, *litPtr);  /* note : op <= oLitEnd <= oend_w == oend - 8 */
     if (sequence.litLength > 8)
         ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8);   /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
     op = oLitEnd;
     *litPtr = iLitEnd;   /* update for next sequence */
 
     /* copy Match */
     if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
         /* offset beyond prefix */
         if (sequence.offset > (size_t)(oLitEnd - dictStart)) return ERROR(corruption_detected);
         if (match + sequence.matchLength <= dictEnd) {
             memmove(oLitEnd, match, sequence.matchLength);
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
         {   size_t const length1 = dictEnd - match;
             memmove(oLitEnd, match, length1);
             op = oLitEnd + length1;
             sequence.matchLength -= length1;
             match = prefixStart;
             if (op > oend_w || sequence.matchLength < MINMATCH) {
               U32 i;
               for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
               return sequenceLength;
             }
     }   }
     assert(op <= oend_w);
     assert(sequence.matchLength >= MINMATCH);
 
     /* match within prefix */
     if (sequence.offset < 8) {
         /* close range match, overlap */
         static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
         static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
         int const sub2 = dec64table[sequence.offset];
         op[0] = match[0];
         op[1] = match[1];
         op[2] = match[2];
         op[3] = match[3];
         match += dec32table[sequence.offset];
         ZSTD_copy4(op+4, match);
         match -= sub2;
     } else {
         ZSTD_copy8(op, match);
     }
     op += 8; match += 8;
 
     if (oMatchEnd > oend-(16-MINMATCH)) {
         if (op < oend_w) {
             ZSTD_wildcopy(op, match, oend_w - op);
             match += oend_w - op;
             op = oend_w;
         }
         while (op < oMatchEnd) *op++ = *match++;
     } else {
         ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8);   /* works even if matchLength < 8 */
     }
     return sequenceLength;
 }
 
 static void
 ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt)
 {
     const void* ptr = dt;
     const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr;
     DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
     DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits",
                 (U32)DStatePtr->state, DTableH->tableLog);
     BIT_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 FORCE_INLINE_TEMPLATE void
 ZSTD_updateFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD)
 {
     ZSTD_seqSymbol const DInfo = DStatePtr->table[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     size_t const lowBits = BIT_readBits(bitD, nbBits);
     DStatePtr->state = DInfo.nextState + lowBits;
 }
 
 /* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum
  * offset bits. But we can only read at most (STREAM_ACCUMULATOR_MIN_32 - 1)
  * bits before reloading. This value is the maximum number of bytes we read
  * after reloading when we are decoding long offets.
  */
 #define LONG_OFFSETS_MAX_EXTRA_BITS_32                       \
     (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32       \
         ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32  \
         : 0)
 
 typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
 
 FORCE_INLINE_TEMPLATE seq_t
 ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
 {
     seq_t seq;
     U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
     U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
     U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
     U32 const totalBits = llBits+mlBits+ofBits;
     U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
     U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
     U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
 
     /* sequence */
     {   size_t offset;
         if (!ofBits)
             offset = 0;
         else {
             ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
             ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
             assert(ofBits <= MaxOff);
             if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
                 U32 const extraBits = ofBits - MIN(ofBits, 32 - seqState->DStream.bitsConsumed);
                 offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
                 BIT_reloadDStream(&seqState->DStream);
                 if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
                 assert(extraBits <= LONG_OFFSETS_MAX_EXTRA_BITS_32);   /* to avoid another reload */
             } else {
                 offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
                 if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
             }
         }
 
         if (ofBits <= 1) {
             offset += (llBase==0);
             if (offset) {
                 size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
                 temp += !temp;   /* 0 is not valid; input is corrupted; force offset to 1 */
                 if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
                 seqState->prevOffset[1] = seqState->prevOffset[0];
                 seqState->prevOffset[0] = offset = temp;
             } else {  /* offset == 0 */
                 offset = seqState->prevOffset[0];
             }
         } else {
             seqState->prevOffset[2] = seqState->prevOffset[1];
             seqState->prevOffset[1] = seqState->prevOffset[0];
             seqState->prevOffset[0] = offset;
         }
         seq.offset = offset;
     }
 
     seq.matchLength = mlBase
                     + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0);  /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
         BIT_reloadDStream(&seqState->DStream);
     if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
         BIT_reloadDStream(&seqState->DStream);
     /* Ensure there are enough bits to read the rest of data in 64-bit mode. */
     ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
 
     seq.litLength = llBase
                   + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0);    /* <=  16 bits */
     if (MEM_32bits())
         BIT_reloadDStream(&seqState->DStream);
 
     DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
                 (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
 
     /* ANS state update */
     ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream);    /* <=  9 bits */
     ZSTD_updateFseState(&seqState->stateML, &seqState->DStream);    /* <=  9 bits */
     if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
     ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream);  /* <=  8 bits */
 
     return seq;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
                                void* dst, size_t maxDstSize,
                          const void* seqStart, size_t seqSize, int nbSeq,
                          const ZSTD_longOffset_e isLongOffset)
 {
     const BYTE* ip = (const BYTE*)seqStart;
     const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + maxDstSize;
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* const litEnd = litPtr + dctx->litSize;
-    const BYTE* const base = (const BYTE*) (dctx->base);
-    const BYTE* const vBase = (const BYTE*) (dctx->vBase);
+    const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
+    const BYTE* const vBase = (const BYTE*) (dctx->virtualStart);
     const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
-    DEBUGLOG(5, "ZSTD_decompressSequences");
+    DEBUGLOG(5, "ZSTD_decompressSequences_body");
 
     /* Regen sequences */
     if (nbSeq) {
         seqState_t seqState;
         dctx->fseEntropy = 1;
         { U32 i; for (i=0; ientropy.rep[i]; }
         CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected);
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
         ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
 
         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) {
             nbSeq--;
             {   seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
-                size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
+                size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
                 DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
                 if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
                 op += oneSeqSize;
         }   }
 
         /* check if reached exact end */
-        DEBUGLOG(5, "ZSTD_decompressSequences: after decode loop, remaining nbSeq : %i", nbSeq);
+        DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq);
         if (nbSeq) return ERROR(corruption_detected);
         /* save reps for next block */
         { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); }
     }
 
     /* last literal segment */
     {   size_t const lastLLSize = litEnd - litPtr;
         if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall);
         memcpy(op, litPtr, lastLLSize);
         op += lastLLSize;
     }
 
     return op-ostart;
 }
 
 static size_t
 ZSTD_decompressSequences_default(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 
 
 
 FORCE_INLINE_TEMPLATE seq_t
 ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets)
 {
     seq_t seq;
     U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
     U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
     U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
     U32 const totalBits = llBits+mlBits+ofBits;
     U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
     U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
     U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
 
     /* sequence */
     {   size_t offset;
         if (!ofBits)
             offset = 0;
         else {
             ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
             ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
             assert(ofBits <= MaxOff);
             if (MEM_32bits() && longOffsets) {
                 U32 const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN_32-1);
                 offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
                 if (MEM_32bits() || extraBits) BIT_reloadDStream(&seqState->DStream);
                 if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
             } else {
                 offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
                 if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
             }
         }
 
         if (ofBits <= 1) {
             offset += (llBase==0);
             if (offset) {
                 size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
                 temp += !temp;   /* 0 is not valid; input is corrupted; force offset to 1 */
                 if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
                 seqState->prevOffset[1] = seqState->prevOffset[0];
                 seqState->prevOffset[0] = offset = temp;
             } else {
                 offset = seqState->prevOffset[0];
             }
         } else {
             seqState->prevOffset[2] = seqState->prevOffset[1];
             seqState->prevOffset[1] = seqState->prevOffset[0];
             seqState->prevOffset[0] = offset;
         }
         seq.offset = offset;
     }
 
     seq.matchLength = mlBase + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0);  /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
         BIT_reloadDStream(&seqState->DStream);
     if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
         BIT_reloadDStream(&seqState->DStream);
     /* Verify that there is enough bits to read the rest of the data in 64-bit mode. */
     ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
 
     seq.litLength = llBase + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0);    /* <=  16 bits */
     if (MEM_32bits())
         BIT_reloadDStream(&seqState->DStream);
 
     {   size_t const pos = seqState->pos + seq.litLength;
         const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart;
         seq.match = matchBase + pos - seq.offset;  /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
                                                     * No consequence though : no memory access will occur, overly large offset will be detected in ZSTD_execSequenceLong() */
         seqState->pos = pos + seq.matchLength;
     }
 
     /* ANS state update */
     ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream);    /* <=  9 bits */
     ZSTD_updateFseState(&seqState->stateML, &seqState->DStream);    /* <=  9 bits */
     if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
     ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream);  /* <=  8 bits */
 
     return seq;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_decompressSequencesLong_body(
                                ZSTD_DCtx* dctx,
                                void* dst, size_t maxDstSize,
                          const void* seqStart, size_t seqSize, int nbSeq,
                          const ZSTD_longOffset_e isLongOffset)
 {
     const BYTE* ip = (const BYTE*)seqStart;
     const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + maxDstSize;
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* const litEnd = litPtr + dctx->litSize;
-    const BYTE* const prefixStart = (const BYTE*) (dctx->base);
-    const BYTE* const dictStart = (const BYTE*) (dctx->vBase);
+    const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
+    const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart);
     const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
 
     /* Regen sequences */
     if (nbSeq) {
 #define STORED_SEQS 4
 #define STOSEQ_MASK (STORED_SEQS-1)
 #define ADVANCED_SEQS 4
         seq_t sequences[STORED_SEQS];
         int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
         seqState_t seqState;
         int seqNb;
         dctx->fseEntropy = 1;
         { U32 i; for (i=0; ientropy.rep[i]; }
         seqState.prefixStart = prefixStart;
         seqState.pos = (size_t)(op-prefixStart);
         seqState.dictEnd = dictEnd;
         CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected);
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
         ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
 
         /* prepare in advance */
         for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNbentropy.rep[i] = (U32)(seqState.prevOffset[i]); }
 #undef STORED_SEQS
 #undef STOSEQ_MASK
 #undef ADVANCED_SEQS
     }
 
     /* last literal segment */
     {   size_t const lastLLSize = litEnd - litPtr;
         if (lastLLSize > (size_t)(oend-op)) return ERROR(dstSize_tooSmall);
         memcpy(op, litPtr, lastLLSize);
         op += lastLLSize;
     }
 
     return op-ostart;
 }
 
 static size_t
 ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 
 
 
 #if DYNAMIC_BMI2
 
 static TARGET_ATTRIBUTE("bmi2") size_t
 ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 
 static TARGET_ATTRIBUTE("bmi2") size_t
 ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 
 #endif
 
 typedef size_t (*ZSTD_decompressSequences_t)(
     ZSTD_DCtx *dctx, void *dst, size_t maxDstSize,
     const void *seqStart, size_t seqSize, int nbSeq,
     const ZSTD_longOffset_e isLongOffset);
 
 static size_t ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
                                 const void* seqStart, size_t seqSize, int nbSeq,
                                 const ZSTD_longOffset_e isLongOffset)
 {
     DEBUGLOG(5, "ZSTD_decompressSequences");
 #if DYNAMIC_BMI2
     if (dctx->bmi2) {
         return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
     }
 #endif
   return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 
 static size_t ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx,
                                 void* dst, size_t maxDstSize,
                                 const void* seqStart, size_t seqSize, int nbSeq,
                                 const ZSTD_longOffset_e isLongOffset)
 {
     DEBUGLOG(5, "ZSTD_decompressSequencesLong");
 #if DYNAMIC_BMI2
     if (dctx->bmi2) {
         return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
     }
 #endif
   return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 
 /* ZSTD_getLongOffsetsShare() :
  * condition : offTable must be valid
  * @return : "share" of long offsets (arbitrarily defined as > (1<<23))
  *           compared to maximum possible of (1< 22) total += 1;
     }
 
     assert(tableLog <= OffFSELog);
     total <<= (OffFSELog - tableLog);  /* scale to OffFSELog */
 
     return total;
 }
 
 
 static size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
                             void* dst, size_t dstCapacity,
                       const void* src, size_t srcSize, const int frame)
 {   /* blockType == blockCompressed */
     const BYTE* ip = (const BYTE*)src;
     /* isLongOffset must be true if there are long offsets.
      * Offsets are long if they are larger than 2^STREAM_ACCUMULATOR_MIN.
      * We don't expect that to be the case in 64-bit mode.
-     * In block mode, window size is not known, so we have to be conservative. (note: but it could be evaluated from current-lowLimit)
+     * In block mode, window size is not known, so we have to be conservative.
+     * (note: but it could be evaluated from current-lowLimit)
      */
     ZSTD_longOffset_e const isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (!frame || dctx->fParams.windowSize > (1ULL << STREAM_ACCUMULATOR_MIN)));
     DEBUGLOG(5, "ZSTD_decompressBlock_internal (size : %u)", (U32)srcSize);
 
     if (srcSize >= ZSTD_BLOCKSIZE_MAX) return ERROR(srcSize_wrong);
 
     /* Decode literals section */
     {   size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
         DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : %u", (U32)litCSize);
         if (ZSTD_isError(litCSize)) return litCSize;
         ip += litCSize;
         srcSize -= litCSize;
     }
 
     /* Build Decoding Tables */
     {   int nbSeq;
         size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize);
         if (ZSTD_isError(seqHSize)) return seqHSize;
         ip += seqHSize;
         srcSize -= seqHSize;
 
         if ( (!frame || dctx->fParams.windowSize > (1<<24))
           && (nbSeq>0) ) {  /* could probably use a larger nbSeq limit */
             U32 const shareLongOffsets = ZSTD_getLongOffsetsShare(dctx->OFTptr);
             U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */
             if (shareLongOffsets >= minShare)
                 return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
         }
 
         return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
     }
 }
 
 
 static void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst)
 {
     if (dst != dctx->previousDstEnd) {   /* not contiguous */
         dctx->dictEnd = dctx->previousDstEnd;
-        dctx->vBase = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
-        dctx->base = dst;
+        dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
+        dctx->prefixStart = dst;
         dctx->previousDstEnd = dst;
     }
 }
 
 size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
                             void* dst, size_t dstCapacity,
                       const void* src, size_t srcSize)
 {
     size_t dSize;
     ZSTD_checkContinuity(dctx, dst);
     dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0);
     dctx->previousDstEnd = (char*)dst + dSize;
     return dSize;
 }
 
 
 /** ZSTD_insertBlock() :
     insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
 ZSTDLIB_API size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize)
 {
     ZSTD_checkContinuity(dctx, blockStart);
     dctx->previousDstEnd = (const char*)blockStart + blockSize;
     return blockSize;
 }
 
 
-static size_t ZSTD_generateNxBytes(void* dst, size_t dstCapacity, BYTE byte, size_t length)
+static size_t ZSTD_generateNxBytes(void* dst, size_t dstCapacity, BYTE value, size_t length)
 {
     if (length > dstCapacity) return ERROR(dstSize_tooSmall);
-    memset(dst, byte, length);
+    memset(dst, value, length);
     return length;
 }
 
 /** ZSTD_findFrameCompressedSize() :
  *  compatible with legacy mode
  *  `src` must point to the start of a ZSTD frame, ZSTD legacy frame, or skippable frame
  *  `srcSize` must be at least as large as the frame contained
  *  @return : the compressed size of the frame starting at `src` */
 size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
 {
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(src, srcSize))
         return ZSTD_findFrameCompressedSizeLegacy(src, srcSize);
 #endif
     if ( (srcSize >= ZSTD_skippableHeaderSize)
       && (MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START ) {
-        return ZSTD_skippableHeaderSize + MEM_readLE32((const BYTE*)src + ZSTD_frameIdSize);
+        return ZSTD_skippableHeaderSize + MEM_readLE32((const BYTE*)src + ZSTD_FRAMEIDSIZE);
     } else {
         const BYTE* ip = (const BYTE*)src;
         const BYTE* const ipstart = ip;
         size_t remainingSize = srcSize;
         ZSTD_frameHeader zfh;
 
         /* Extract Frame Header */
         {   size_t const ret = ZSTD_getFrameHeader(&zfh, src, srcSize);
             if (ZSTD_isError(ret)) return ret;
             if (ret > 0) return ERROR(srcSize_wrong);
         }
 
         ip += zfh.headerSize;
         remainingSize -= zfh.headerSize;
 
         /* Loop on each block */
         while (1) {
             blockProperties_t blockProperties;
             size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
             if (ZSTD_isError(cBlockSize)) return cBlockSize;
 
             if (ZSTD_blockHeaderSize + cBlockSize > remainingSize)
                 return ERROR(srcSize_wrong);
 
             ip += ZSTD_blockHeaderSize + cBlockSize;
             remainingSize -= ZSTD_blockHeaderSize + cBlockSize;
 
             if (blockProperties.lastBlock) break;
         }
 
         if (zfh.checksumFlag) {   /* Final frame content checksum */
             if (remainingSize < 4) return ERROR(srcSize_wrong);
             ip += 4;
-            remainingSize -= 4;
         }
 
         return ip - ipstart;
     }
 }
 
 /*! ZSTD_decompressFrame() :
 *   @dctx must be properly initialized */
 static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
                                    void* dst, size_t dstCapacity,
                              const void** srcPtr, size_t *srcSizePtr)
 {
     const BYTE* ip = (const BYTE*)(*srcPtr);
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + dstCapacity;
     BYTE* op = ostart;
     size_t remainingSize = *srcSizePtr;
 
     /* check */
     if (remainingSize < ZSTD_frameHeaderSize_min+ZSTD_blockHeaderSize)
         return ERROR(srcSize_wrong);
 
     /* Frame Header */
     {   size_t const frameHeaderSize = ZSTD_frameHeaderSize(ip, ZSTD_frameHeaderSize_prefix);
         if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
         if (remainingSize < frameHeaderSize+ZSTD_blockHeaderSize)
             return ERROR(srcSize_wrong);
         CHECK_F( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) );
         ip += frameHeaderSize; remainingSize -= frameHeaderSize;
     }
 
     /* Loop on each block */
     while (1) {
         size_t decodedSize;
         blockProperties_t blockProperties;
         size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
         if (ZSTD_isError(cBlockSize)) return cBlockSize;
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
         if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
 
         switch(blockProperties.blockType)
         {
         case bt_compressed:
             decodedSize = ZSTD_decompressBlock_internal(dctx, op, oend-op, ip, cBlockSize, /* frame */ 1);
             break;
         case bt_raw :
             decodedSize = ZSTD_copyRawBlock(op, oend-op, ip, cBlockSize);
             break;
         case bt_rle :
             decodedSize = ZSTD_generateNxBytes(op, oend-op, *ip, blockProperties.origSize);
             break;
         case bt_reserved :
         default:
             return ERROR(corruption_detected);
         }
 
         if (ZSTD_isError(decodedSize)) return decodedSize;
         if (dctx->fParams.checksumFlag)
             XXH64_update(&dctx->xxhState, op, decodedSize);
         op += decodedSize;
         ip += cBlockSize;
         remainingSize -= cBlockSize;
         if (blockProperties.lastBlock) break;
     }
 
     if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) {
         if ((U64)(op-ostart) != dctx->fParams.frameContentSize) {
             return ERROR(corruption_detected);
     }   }
     if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */
         U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState);
         U32 checkRead;
         if (remainingSize<4) return ERROR(checksum_wrong);
         checkRead = MEM_readLE32(ip);
         if (checkRead != checkCalc) return ERROR(checksum_wrong);
         ip += 4;
         remainingSize -= 4;
     }
 
     /* Allow caller to get size read */
     *srcPtr = ip;
     *srcSizePtr = remainingSize;
     return op-ostart;
 }
 
-static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict);
-static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict);
-
 static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
                                         void* dst, size_t dstCapacity,
                                   const void* src, size_t srcSize,
                                   const void* dict, size_t dictSize,
                                   const ZSTD_DDict* ddict)
 {
     void* const dststart = dst;
+    int moreThan1Frame = 0;
+
+    DEBUGLOG(5, "ZSTD_decompressMultiFrame");
     assert(dict==NULL || ddict==NULL);  /* either dict or ddict set, not both */
 
     if (ddict) {
         dict = ZSTD_DDictDictContent(ddict);
         dictSize = ZSTD_DDictDictSize(ddict);
     }
 
     while (srcSize >= ZSTD_frameHeaderSize_prefix) {
-        U32 magicNumber;
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
         if (ZSTD_isLegacy(src, srcSize)) {
             size_t decodedSize;
             size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize);
             if (ZSTD_isError(frameSize)) return frameSize;
             /* legacy support is not compatible with static dctx */
             if (dctx->staticSize) return ERROR(memory_allocation);
 
             decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize);
 
             dst = (BYTE*)dst + decodedSize;
             dstCapacity -= decodedSize;
 
             src = (const BYTE*)src + frameSize;
             srcSize -= frameSize;
 
             continue;
         }
 #endif
 
-        magicNumber = MEM_readLE32(src);
-        DEBUGLOG(4, "reading magic number %08X (expecting %08X)",
-                    (U32)magicNumber, (U32)ZSTD_MAGICNUMBER);
-        if (magicNumber != ZSTD_MAGICNUMBER) {
+        {   U32 const magicNumber = MEM_readLE32(src);
+            DEBUGLOG(4, "reading magic number %08X (expecting %08X)",
+                        (U32)magicNumber, (U32)ZSTD_MAGICNUMBER);
             if ((magicNumber & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
                 size_t skippableSize;
                 if (srcSize < ZSTD_skippableHeaderSize)
                     return ERROR(srcSize_wrong);
-                skippableSize = MEM_readLE32((const BYTE*)src + ZSTD_frameIdSize)
+                skippableSize = MEM_readLE32((const BYTE*)src + ZSTD_FRAMEIDSIZE)
                               + ZSTD_skippableHeaderSize;
                 if (srcSize < skippableSize) return ERROR(srcSize_wrong);
 
                 src = (const BYTE *)src + skippableSize;
                 srcSize -= skippableSize;
                 continue;
-            }
-            return ERROR(prefix_unknown);
-        }
+        }   }
 
         if (ddict) {
             /* we were called from ZSTD_decompress_usingDDict */
             CHECK_F(ZSTD_decompressBegin_usingDDict(dctx, ddict));
         } else {
             /* this will initialize correctly with no dict if dict == NULL, so
              * use this in all cases but ddict */
             CHECK_F(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize));
         }
         ZSTD_checkContinuity(dctx, dst);
 
         {   const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity,
                                                     &src, &srcSize);
+            if ( (ZSTD_getErrorCode(res) == ZSTD_error_prefix_unknown)
+              && (moreThan1Frame==1) ) {
+                /* at least one frame successfully completed,
+                 * but following bytes are garbage :
+                 * it's more likely to be a srcSize error,
+                 * specifying more bytes than compressed size of frame(s).
+                 * This error message replaces ERROR(prefix_unknown),
+                 * which would be confusing, as the first header is actually correct.
+                 * Note that one could be unlucky, it might be a corruption error instead,
+                 * happening right at the place where we expect zstd magic bytes.
+                 * But this is _much_ less likely than a srcSize field error. */
+                return ERROR(srcSize_wrong);
+            }
             if (ZSTD_isError(res)) return res;
             /* no need to bound check, ZSTD_decompressFrame already has */
             dst = (BYTE*)dst + res;
             dstCapacity -= res;
         }
+        moreThan1Frame = 1;
     }  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
 
     if (srcSize) return ERROR(srcSize_wrong); /* input not entirely consumed */
 
     return (BYTE*)dst - (BYTE*)dststart;
 }
 
 size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
                                  void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize,
                            const void* dict, size_t dictSize)
 {
     return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL);
 }
 
 
 size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     return ZSTD_decompress_usingDict(dctx, dst, dstCapacity, src, srcSize, NULL, 0);
 }
 
 
 size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
 #if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1)
     size_t regenSize;
     ZSTD_DCtx* const dctx = ZSTD_createDCtx();
     if (dctx==NULL) return ERROR(memory_allocation);
     regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
     ZSTD_freeDCtx(dctx);
     return regenSize;
 #else   /* stack mode */
     ZSTD_DCtx dctx;
+    ZSTD_initDCtx_internal(&dctx);
     return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
 #endif
 }
 
 
 /*-**************************************
 *   Advanced Streaming Decompression API
 *   Bufferless and synchronous
 ****************************************/
 size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; }
 
 ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
     switch(dctx->stage)
     {
     default:   /* should not happen */
         assert(0);
     case ZSTDds_getFrameHeaderSize:
     case ZSTDds_decodeFrameHeader:
         return ZSTDnit_frameHeader;
     case ZSTDds_decodeBlockHeader:
         return ZSTDnit_blockHeader;
     case ZSTDds_decompressBlock:
         return ZSTDnit_block;
     case ZSTDds_decompressLastBlock:
         return ZSTDnit_lastBlock;
     case ZSTDds_checkChecksum:
         return ZSTDnit_checksum;
     case ZSTDds_decodeSkippableHeader:
     case ZSTDds_skipFrame:
         return ZSTDnit_skippableFrame;
     }
 }
 
 static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; }
 
 /** ZSTD_decompressContinue() :
  *  srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress())
  *  @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
  *            or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (U32)srcSize);
     /* Sanity check */
     if (srcSize != dctx->expected) return ERROR(srcSize_wrong);  /* not allowed */
     if (dstCapacity) ZSTD_checkContinuity(dctx, dst);
 
     switch (dctx->stage)
     {
     case ZSTDds_getFrameHeaderSize :
         assert(src != NULL);
         if (dctx->format == ZSTD_f_zstd1) {  /* allows header */
-            assert(srcSize >= ZSTD_frameIdSize);  /* to read skippable magic number */
+            assert(srcSize >= ZSTD_FRAMEIDSIZE);  /* to read skippable magic number */
             if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {        /* skippable frame */
                 memcpy(dctx->headerBuffer, src, srcSize);
                 dctx->expected = ZSTD_skippableHeaderSize - srcSize;  /* remaining to load to get full skippable frame header */
                 dctx->stage = ZSTDds_decodeSkippableHeader;
                 return 0;
         }   }
         dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format);
         if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize;
         memcpy(dctx->headerBuffer, src, srcSize);
         dctx->expected = dctx->headerSize - srcSize;
         dctx->stage = ZSTDds_decodeFrameHeader;
         return 0;
 
     case ZSTDds_decodeFrameHeader:
         assert(src != NULL);
         memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize);
         CHECK_F(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize));
         dctx->expected = ZSTD_blockHeaderSize;
         dctx->stage = ZSTDds_decodeBlockHeader;
         return 0;
 
     case ZSTDds_decodeBlockHeader:
         {   blockProperties_t bp;
             size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
             if (ZSTD_isError(cBlockSize)) return cBlockSize;
             dctx->expected = cBlockSize;
             dctx->bType = bp.blockType;
             dctx->rleSize = bp.origSize;
             if (cBlockSize) {
                 dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock;
                 return 0;
             }
             /* empty block */
             if (bp.lastBlock) {
                 if (dctx->fParams.checksumFlag) {
                     dctx->expected = 4;
                     dctx->stage = ZSTDds_checkChecksum;
                 } else {
                     dctx->expected = 0; /* end of frame */
                     dctx->stage = ZSTDds_getFrameHeaderSize;
                 }
             } else {
                 dctx->expected = ZSTD_blockHeaderSize;  /* jump to next header */
                 dctx->stage = ZSTDds_decodeBlockHeader;
             }
             return 0;
         }
 
     case ZSTDds_decompressLastBlock:
     case ZSTDds_decompressBlock:
         DEBUGLOG(5, "ZSTD_decompressContinue: case ZSTDds_decompressBlock");
         {   size_t rSize;
             switch(dctx->bType)
             {
             case bt_compressed:
                 DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed");
                 rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1);
                 break;
             case bt_raw :
                 rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize);
                 break;
             case bt_rle :
                 rSize = ZSTD_setRleBlock(dst, dstCapacity, src, srcSize, dctx->rleSize);
                 break;
             case bt_reserved :   /* should never happen */
             default:
                 return ERROR(corruption_detected);
             }
             if (ZSTD_isError(rSize)) return rSize;
             DEBUGLOG(5, "ZSTD_decompressContinue: decoded size from block : %u", (U32)rSize);
             dctx->decodedSize += rSize;
             if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize);
 
             if (dctx->stage == ZSTDds_decompressLastBlock) {   /* end of frame */
                 DEBUGLOG(4, "ZSTD_decompressContinue: decoded size from frame : %u", (U32)dctx->decodedSize);
                 if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) {
                     if (dctx->decodedSize != dctx->fParams.frameContentSize) {
                         return ERROR(corruption_detected);
                 }   }
                 if (dctx->fParams.checksumFlag) {  /* another round for frame checksum */
                     dctx->expected = 4;
                     dctx->stage = ZSTDds_checkChecksum;
                 } else {
                     dctx->expected = 0;   /* ends here */
                     dctx->stage = ZSTDds_getFrameHeaderSize;
                 }
             } else {
                 dctx->stage = ZSTDds_decodeBlockHeader;
                 dctx->expected = ZSTD_blockHeaderSize;
                 dctx->previousDstEnd = (char*)dst + rSize;
             }
             return rSize;
         }
 
     case ZSTDds_checkChecksum:
         assert(srcSize == 4);  /* guaranteed by dctx->expected */
         {   U32 const h32 = (U32)XXH64_digest(&dctx->xxhState);
             U32 const check32 = MEM_readLE32(src);
             DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", h32, check32);
             if (check32 != h32) return ERROR(checksum_wrong);
             dctx->expected = 0;
             dctx->stage = ZSTDds_getFrameHeaderSize;
             return 0;
         }
 
     case ZSTDds_decodeSkippableHeader:
         assert(src != NULL);
         assert(srcSize <= ZSTD_skippableHeaderSize);
         memcpy(dctx->headerBuffer + (ZSTD_skippableHeaderSize - srcSize), src, srcSize);   /* complete skippable header */
-        dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_frameIdSize);   /* note : dctx->expected can grow seriously large, beyond local buffer size */
+        dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_FRAMEIDSIZE);   /* note : dctx->expected can grow seriously large, beyond local buffer size */
         dctx->stage = ZSTDds_skipFrame;
         return 0;
 
     case ZSTDds_skipFrame:
         dctx->expected = 0;
         dctx->stage = ZSTDds_getFrameHeaderSize;
         return 0;
 
     default:
         return ERROR(GENERIC);   /* impossible */
     }
 }
 
 
 static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     dctx->dictEnd = dctx->previousDstEnd;
-    dctx->vBase = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->base));
-    dctx->base = dict;
+    dctx->virtualStart = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
+    dctx->prefixStart = dict;
     dctx->previousDstEnd = (const char*)dict + dictSize;
     return 0;
 }
 
-/* ZSTD_loadEntropy() :
- * dict : must point at beginning of a valid zstd dictionary
+/*! ZSTD_loadEntropy() :
+ *  dict : must point at beginning of a valid zstd dictionary.
  * @return : size of entropy tables read */
-static size_t ZSTD_loadEntropy(ZSTD_entropyDTables_t* entropy, const void* const dict, size_t const dictSize)
+static size_t ZSTD_loadEntropy(ZSTD_entropyDTables_t* entropy,
+                         const void* const dict, size_t const dictSize)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
 
     if (dictSize <= 8) return ERROR(dictionary_corrupted);
+    assert(MEM_readLE32(dict) == ZSTD_MAGIC_DICTIONARY);   /* dict must be valid */
     dictPtr += 8;   /* skip header = magic + dictID */
 
-
-    {   size_t const hSize = HUF_readDTableX4_wksp(
-            entropy->hufTable, dictPtr, dictEnd - dictPtr,
-            entropy->workspace, sizeof(entropy->workspace));
+    ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, OFTable) == offsetof(ZSTD_entropyDTables_t, LLTable) + sizeof(entropy->LLTable));
+    ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, MLTable) == offsetof(ZSTD_entropyDTables_t, OFTable) + sizeof(entropy->OFTable));
+    ZSTD_STATIC_ASSERT(sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable) >= HUF_DECOMPRESS_WORKSPACE_SIZE);
+    {   void* const workspace = &entropy->LLTable;   /* use fse tables as temporary workspace; implies fse tables are grouped together */
+        size_t const workspaceSize = sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable);
+        size_t const hSize = HUF_readDTableX2_wksp(entropy->hufTable,
+                                                dictPtr, dictEnd - dictPtr,
+                                                workspace, workspaceSize);
         if (HUF_isError(hSize)) return ERROR(dictionary_corrupted);
         dictPtr += hSize;
     }
 
     {   short offcodeNCount[MaxOff+1];
         U32 offcodeMaxValue = MaxOff, offcodeLog;
         size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(offcodeHeaderSize)) return ERROR(dictionary_corrupted);
         if (offcodeMaxValue > MaxOff) return ERROR(dictionary_corrupted);
         if (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted);
-        ZSTD_buildFSETable(entropy->OFTable,
+        ZSTD_buildFSETable( entropy->OFTable,
                             offcodeNCount, offcodeMaxValue,
                             OF_base, OF_bits,
                             offcodeLog);
         dictPtr += offcodeHeaderSize;
     }
 
     {   short matchlengthNCount[MaxML+1];
         unsigned matchlengthMaxValue = MaxML, matchlengthLog;
         size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(matchlengthHeaderSize)) return ERROR(dictionary_corrupted);
         if (matchlengthMaxValue > MaxML) return ERROR(dictionary_corrupted);
         if (matchlengthLog > MLFSELog) return ERROR(dictionary_corrupted);
-        ZSTD_buildFSETable(entropy->MLTable,
+        ZSTD_buildFSETable( entropy->MLTable,
                             matchlengthNCount, matchlengthMaxValue,
                             ML_base, ML_bits,
                             matchlengthLog);
         dictPtr += matchlengthHeaderSize;
     }
 
     {   short litlengthNCount[MaxLL+1];
         unsigned litlengthMaxValue = MaxLL, litlengthLog;
         size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
         if (FSE_isError(litlengthHeaderSize)) return ERROR(dictionary_corrupted);
         if (litlengthMaxValue > MaxLL) return ERROR(dictionary_corrupted);
         if (litlengthLog > LLFSELog) return ERROR(dictionary_corrupted);
-        ZSTD_buildFSETable(entropy->LLTable,
+        ZSTD_buildFSETable( entropy->LLTable,
                             litlengthNCount, litlengthMaxValue,
                             LL_base, LL_bits,
                             litlengthLog);
         dictPtr += litlengthHeaderSize;
     }
 
     if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
     {   int i;
         size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12));
         for (i=0; i<3; i++) {
             U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4;
             if (rep==0 || rep >= dictContentSize) return ERROR(dictionary_corrupted);
             entropy->rep[i] = rep;
     }   }
 
     return dictPtr - (const BYTE*)dict;
 }
 
 static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize);
     {   U32 const magic = MEM_readLE32(dict);
         if (magic != ZSTD_MAGIC_DICTIONARY) {
             return ZSTD_refDictContent(dctx, dict, dictSize);   /* pure content mode */
     }   }
-    dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_frameIdSize);
+    dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
 
     /* load entropy tables */
     {   size_t const eSize = ZSTD_loadEntropy(&dctx->entropy, dict, dictSize);
         if (ZSTD_isError(eSize)) return ERROR(dictionary_corrupted);
         dict = (const char*)dict + eSize;
         dictSize -= eSize;
     }
     dctx->litEntropy = dctx->fseEntropy = 1;
 
     /* reference dictionary content */
     return ZSTD_refDictContent(dctx, dict, dictSize);
 }
 
-/* Note : this function cannot fail */
 size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
 {
     assert(dctx != NULL);
     dctx->expected = ZSTD_startingInputLength(dctx->format);  /* dctx->format must be properly set */
     dctx->stage = ZSTDds_getFrameHeaderSize;
     dctx->decodedSize = 0;
     dctx->previousDstEnd = NULL;
-    dctx->base = NULL;
-    dctx->vBase = NULL;
+    dctx->prefixStart = NULL;
+    dctx->virtualStart = NULL;
     dctx->dictEnd = NULL;
     dctx->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001);  /* cover both little and big endian */
     dctx->litEntropy = dctx->fseEntropy = 0;
     dctx->dictID = 0;
     ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue));
     memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue));  /* initial repcodes */
     dctx->LLTptr = dctx->entropy.LLTable;
     dctx->MLTptr = dctx->entropy.MLTable;
     dctx->OFTptr = dctx->entropy.OFTable;
     dctx->HUFptr = dctx->entropy.hufTable;
     return 0;
 }
 
 size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     CHECK_F( ZSTD_decompressBegin(dctx) );
     if (dict && dictSize)
         CHECK_E(ZSTD_decompress_insertDictionary(dctx, dict, dictSize), dictionary_corrupted);
     return 0;
 }
 
 
 /* ======   ZSTD_DDict   ====== */
 
 struct ZSTD_DDict_s {
     void* dictBuffer;
     const void* dictContent;
     size_t dictSize;
     ZSTD_entropyDTables_t entropy;
     U32 dictID;
     U32 entropyPresent;
     ZSTD_customMem cMem;
 };  /* typedef'd to ZSTD_DDict within "zstd.h" */
 
 static const void* ZSTD_DDictDictContent(const ZSTD_DDict* ddict)
 {
+    assert(ddict != NULL);
     return ddict->dictContent;
 }
 
 static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict)
 {
+    assert(ddict != NULL);
     return ddict->dictSize;
 }
 
-size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dstDCtx, const ZSTD_DDict* ddict)
+size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
 {
-    CHECK_F( ZSTD_decompressBegin(dstDCtx) );
-    if (ddict) {   /* support begin on NULL */
-        dstDCtx->dictID = ddict->dictID;
-        dstDCtx->base = ddict->dictContent;
-        dstDCtx->vBase = ddict->dictContent;
-        dstDCtx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize;
-        dstDCtx->previousDstEnd = dstDCtx->dictEnd;
+    DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict");
+    assert(dctx != NULL);
+    if (ddict) {
+        dctx->ddictIsCold = (dctx->dictEnd != (const char*)ddict->dictContent + ddict->dictSize);
+        DEBUGLOG(4, "DDict is %s",
+                    dctx->ddictIsCold ? "~cold~" : "hot!");
+    }
+    CHECK_F( ZSTD_decompressBegin(dctx) );
+    if (ddict) {   /* NULL ddict is equivalent to no dictionary */
+        dctx->dictID = ddict->dictID;
+        dctx->prefixStart = ddict->dictContent;
+        dctx->virtualStart = ddict->dictContent;
+        dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize;
+        dctx->previousDstEnd = dctx->dictEnd;
         if (ddict->entropyPresent) {
-            dstDCtx->litEntropy = 1;
-            dstDCtx->fseEntropy = 1;
-            dstDCtx->LLTptr = ddict->entropy.LLTable;
-            dstDCtx->MLTptr = ddict->entropy.MLTable;
-            dstDCtx->OFTptr = ddict->entropy.OFTable;
-            dstDCtx->HUFptr = ddict->entropy.hufTable;
-            dstDCtx->entropy.rep[0] = ddict->entropy.rep[0];
-            dstDCtx->entropy.rep[1] = ddict->entropy.rep[1];
-            dstDCtx->entropy.rep[2] = ddict->entropy.rep[2];
+            dctx->litEntropy = 1;
+            dctx->fseEntropy = 1;
+            dctx->LLTptr = ddict->entropy.LLTable;
+            dctx->MLTptr = ddict->entropy.MLTable;
+            dctx->OFTptr = ddict->entropy.OFTable;
+            dctx->HUFptr = ddict->entropy.hufTable;
+            dctx->entropy.rep[0] = ddict->entropy.rep[0];
+            dctx->entropy.rep[1] = ddict->entropy.rep[1];
+            dctx->entropy.rep[2] = ddict->entropy.rep[2];
         } else {
-            dstDCtx->litEntropy = 0;
-            dstDCtx->fseEntropy = 0;
+            dctx->litEntropy = 0;
+            dctx->fseEntropy = 0;
         }
     }
     return 0;
 }
 
-static size_t ZSTD_loadEntropy_inDDict(ZSTD_DDict* ddict, ZSTD_dictContentType_e dictContentType)
+static size_t
+ZSTD_loadEntropy_inDDict(ZSTD_DDict* ddict,
+                         ZSTD_dictContentType_e dictContentType)
 {
     ddict->dictID = 0;
     ddict->entropyPresent = 0;
     if (dictContentType == ZSTD_dct_rawContent) return 0;
 
     if (ddict->dictSize < 8) {
         if (dictContentType == ZSTD_dct_fullDict)
             return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
         return 0;   /* pure content mode */
     }
     {   U32 const magic = MEM_readLE32(ddict->dictContent);
         if (magic != ZSTD_MAGIC_DICTIONARY) {
             if (dictContentType == ZSTD_dct_fullDict)
                 return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
             return 0;   /* pure content mode */
         }
     }
-    ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_frameIdSize);
+    ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE);
 
     /* load entropy tables */
-    CHECK_E( ZSTD_loadEntropy(&ddict->entropy, ddict->dictContent, ddict->dictSize), dictionary_corrupted );
+    CHECK_E( ZSTD_loadEntropy(&ddict->entropy,
+                              ddict->dictContent, ddict->dictSize),
+             dictionary_corrupted );
     ddict->entropyPresent = 1;
     return 0;
 }
 
 
 static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict,
                                       const void* dict, size_t dictSize,
                                       ZSTD_dictLoadMethod_e dictLoadMethod,
                                       ZSTD_dictContentType_e dictContentType)
 {
     if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) {
         ddict->dictBuffer = NULL;
         ddict->dictContent = dict;
+        if (!dict) dictSize = 0;
     } else {
         void* const internalBuffer = ZSTD_malloc(dictSize, ddict->cMem);
         ddict->dictBuffer = internalBuffer;
         ddict->dictContent = internalBuffer;
         if (!internalBuffer) return ERROR(memory_allocation);
         memcpy(internalBuffer, dict, dictSize);
     }
     ddict->dictSize = dictSize;
     ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001);  /* cover both little and big endian */
 
     /* parse dictionary content */
     CHECK_F( ZSTD_loadEntropy_inDDict(ddict, dictContentType) );
 
     return 0;
 }
 
 ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
                                       ZSTD_dictLoadMethod_e dictLoadMethod,
                                       ZSTD_dictContentType_e dictContentType,
                                       ZSTD_customMem customMem)
 {
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
 
     {   ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem);
-        if (!ddict) return NULL;
+        if (ddict == NULL) return NULL;
         ddict->cMem = customMem;
-
-        if (ZSTD_isError( ZSTD_initDDict_internal(ddict, dict, dictSize, dictLoadMethod, dictContentType) )) {
-            ZSTD_freeDDict(ddict);
-            return NULL;
-        }
-
+        {   size_t const initResult = ZSTD_initDDict_internal(ddict,
+                                            dict, dictSize,
+                                            dictLoadMethod, dictContentType);
+            if (ZSTD_isError(initResult)) {
+                ZSTD_freeDDict(ddict);
+                return NULL;
+        }   }
         return ddict;
     }
 }
 
 /*! ZSTD_createDDict() :
 *   Create a digested dictionary, to start decompression without startup delay.
 *   `dict` content is copied inside DDict.
 *   Consequently, `dict` can be released after `ZSTD_DDict` creation */
 ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize)
 {
     ZSTD_customMem const allocator = { NULL, NULL, NULL };
     return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator);
 }
 
 /*! ZSTD_createDDict_byReference() :
  *  Create a digested dictionary, to start decompression without startup delay.
  *  Dictionary content is simply referenced, it will be accessed during decompression.
  *  Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */
 ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize)
 {
     ZSTD_customMem const allocator = { NULL, NULL, NULL };
     return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator);
 }
 
 
 const ZSTD_DDict* ZSTD_initStaticDDict(
-                                void* workspace, size_t workspaceSize,
+                                void* sBuffer, size_t sBufferSize,
                                 const void* dict, size_t dictSize,
                                 ZSTD_dictLoadMethod_e dictLoadMethod,
                                 ZSTD_dictContentType_e dictContentType)
 {
-    size_t const neededSpace =
-            sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
-    ZSTD_DDict* const ddict = (ZSTD_DDict*)workspace;
-    assert(workspace != NULL);
+    size_t const neededSpace = sizeof(ZSTD_DDict)
+                             + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
+    ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer;
+    assert(sBuffer != NULL);
     assert(dict != NULL);
-    if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
-    if (workspaceSize < neededSpace) return NULL;
+    if ((size_t)sBuffer & 7) return NULL;   /* 8-aligned */
+    if (sBufferSize < neededSpace) return NULL;
     if (dictLoadMethod == ZSTD_dlm_byCopy) {
         memcpy(ddict+1, dict, dictSize);  /* local copy */
         dict = ddict+1;
     }
-    if (ZSTD_isError( ZSTD_initDDict_internal(ddict, dict, dictSize, ZSTD_dlm_byRef, dictContentType) ))
+    if (ZSTD_isError( ZSTD_initDDict_internal(ddict,
+                                              dict, dictSize,
+                                              ZSTD_dlm_byRef, dictContentType) ))
         return NULL;
     return ddict;
 }
 
 
 size_t ZSTD_freeDDict(ZSTD_DDict* ddict)
 {
     if (ddict==NULL) return 0;   /* support free on NULL */
     {   ZSTD_customMem const cMem = ddict->cMem;
         ZSTD_free(ddict->dictBuffer, cMem);
         ZSTD_free(ddict, cMem);
         return 0;
     }
 }
 
 /*! ZSTD_estimateDDictSize() :
  *  Estimate amount of memory that will be needed to create a dictionary for decompression.
  *  Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */
 size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod)
 {
     return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
 }
 
 size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict)
 {
     if (ddict==NULL) return 0;   /* support sizeof on NULL */
     return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ;
 }
 
 /*! ZSTD_getDictID_fromDict() :
  *  Provides the dictID stored within dictionary.
  *  if @return == 0, the dictionary is not conformant with Zstandard specification.
  *  It can still be loaded, but as a content-only dictionary. */
 unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize)
 {
     if (dictSize < 8) return 0;
     if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0;
-    return MEM_readLE32((const char*)dict + ZSTD_frameIdSize);
+    return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
 }
 
 /*! ZSTD_getDictID_fromDDict() :
  *  Provides the dictID of the dictionary loaded into `ddict`.
  *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
  *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
 unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict)
 {
     if (ddict==NULL) return 0;
     return ZSTD_getDictID_fromDict(ddict->dictContent, ddict->dictSize);
 }
 
 /*! ZSTD_getDictID_fromFrame() :
  *  Provides the dictID required to decompresse frame stored within `src`.
  *  If @return == 0, the dictID could not be decoded.
  *  This could for one of the following reasons :
  *  - The frame does not require a dictionary (most common case).
  *  - The frame was built with dictID intentionally removed.
  *    Needed dictionary is a hidden information.
  *    Note : this use case also happens when using a non-conformant dictionary.
  *  - `srcSize` is too small, and as a result, frame header could not be decoded.
  *    Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`.
  *  - This is not a Zstandard frame.
  *  When identifying the exact failure cause, it's possible to use
  *  ZSTD_getFrameHeader(), which will provide a more precise error code. */
 unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize)
 {
     ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0 };
     size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize);
     if (ZSTD_isError(hError)) return 0;
     return zfp.dictID;
 }
 
 
 /*! ZSTD_decompress_usingDDict() :
 *   Decompression using a pre-digested Dictionary
 *   Use dictionary without significant overhead. */
 size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
                                   void* dst, size_t dstCapacity,
                             const void* src, size_t srcSize,
                             const ZSTD_DDict* ddict)
 {
     /* pass content and size in case legacy frames are encountered */
     return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize,
                                      NULL, 0,
                                      ddict);
 }
 
 
 /*=====================================
 *   Streaming decompression
 *====================================*/
 
 ZSTD_DStream* ZSTD_createDStream(void)
 {
     DEBUGLOG(3, "ZSTD_createDStream");
     return ZSTD_createDStream_advanced(ZSTD_defaultCMem);
 }
 
 ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize)
 {
     return ZSTD_initStaticDCtx(workspace, workspaceSize);
 }
 
 ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
 {
     return ZSTD_createDCtx_advanced(customMem);
 }
 
 size_t ZSTD_freeDStream(ZSTD_DStream* zds)
 {
     return ZSTD_freeDCtx(zds);
 }
 
 
-/* *** Initialization *** */
+/* ***  Initialization  *** */
 
 size_t ZSTD_DStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; }
 size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; }
 
-size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType)
+size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx,
+                                   const void* dict, size_t dictSize,
+                                         ZSTD_dictLoadMethod_e dictLoadMethod,
+                                         ZSTD_dictContentType_e dictContentType)
 {
     if (dctx->streamStage != zdss_init) return ERROR(stage_wrong);
     ZSTD_freeDDict(dctx->ddictLocal);
     if (dict && dictSize >= 8) {
         dctx->ddictLocal = ZSTD_createDDict_advanced(dict, dictSize, dictLoadMethod, dictContentType, dctx->customMem);
         if (dctx->ddictLocal == NULL) return ERROR(memory_allocation);
     } else {
         dctx->ddictLocal = NULL;
     }
     dctx->ddict = dctx->ddictLocal;
     return 0;
 }
 
 size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
 }
 
 size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
 }
 
 size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
 {
     return ZSTD_DCtx_loadDictionary_advanced(dctx, prefix, prefixSize, ZSTD_dlm_byRef, dictContentType);
 }
 
 size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize)
 {
     return ZSTD_DCtx_refPrefix_advanced(dctx, prefix, prefixSize, ZSTD_dct_rawContent);
 }
 
 
 /* ZSTD_initDStream_usingDict() :
  * return : expected size, aka ZSTD_frameHeaderSize_prefix.
  * this function cannot fail */
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
 {
     DEBUGLOG(4, "ZSTD_initDStream_usingDict");
     zds->streamStage = zdss_init;
+    zds->noForwardProgress = 0;
     CHECK_F( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) );
     return ZSTD_frameHeaderSize_prefix;
 }
 
 /* note : this variant can't fail */
 size_t ZSTD_initDStream(ZSTD_DStream* zds)
 {
     DEBUGLOG(4, "ZSTD_initDStream");
     return ZSTD_initDStream_usingDict(zds, NULL, 0);
 }
 
-size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
-{
-    if (dctx->streamStage != zdss_init) return ERROR(stage_wrong);
-    dctx->ddict = ddict;
-    return 0;
-}
-
 /* ZSTD_initDStream_usingDDict() :
  * ddict will just be referenced, and must outlive decompression session
  * this function cannot fail */
 size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict)
 {
     size_t const initResult = ZSTD_initDStream(dctx);
     dctx->ddict = ddict;
     return initResult;
 }
 
 /* ZSTD_resetDStream() :
  * return : expected size, aka ZSTD_frameHeaderSize_prefix.
  * this function cannot fail */
 size_t ZSTD_resetDStream(ZSTD_DStream* dctx)
 {
     DEBUGLOG(4, "ZSTD_resetDStream");
     dctx->streamStage = zdss_loadHeader;
     dctx->lhSize = dctx->inPos = dctx->outStart = dctx->outEnd = 0;
     dctx->legacyVersion = 0;
     dctx->hostageByte = 0;
     return ZSTD_frameHeaderSize_prefix;
 }
 
 size_t ZSTD_setDStreamParameter(ZSTD_DStream* dctx,
                                 ZSTD_DStreamParameter_e paramType, unsigned paramValue)
 {
     if (dctx->streamStage != zdss_init) return ERROR(stage_wrong);
     switch(paramType)
     {
         default : return ERROR(parameter_unsupported);
         case DStream_p_maxWindowSize :
             DEBUGLOG(4, "setting maxWindowSize = %u KB", paramValue >> 10);
             dctx->maxWindowSize = paramValue ? paramValue : (U32)(-1);
             break;
     }
     return 0;
 }
 
+size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
+{
+    if (dctx->streamStage != zdss_init) return ERROR(stage_wrong);
+    dctx->ddict = ddict;
+    return 0;
+}
+
 size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize)
 {
     if (dctx->streamStage != zdss_init) return ERROR(stage_wrong);
     dctx->maxWindowSize = maxWindowSize;
     return 0;
 }
 
 size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format)
 {
     DEBUGLOG(4, "ZSTD_DCtx_setFormat : %u", (unsigned)format);
     if (dctx->streamStage != zdss_init) return ERROR(stage_wrong);
     dctx->format = format;
     return 0;
 }
 
 
 size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx)
 {
     return ZSTD_sizeof_DCtx(dctx);
 }
 
 size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize)
 {
     size_t const blockSize = (size_t) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
     unsigned long long const neededRBSize = windowSize + blockSize + (WILDCOPY_OVERLENGTH * 2);
     unsigned long long const neededSize = MIN(frameContentSize, neededRBSize);
     size_t const minRBSize = (size_t) neededSize;
     if ((unsigned long long)minRBSize != neededSize) return ERROR(frameParameter_windowTooLarge);
     return minRBSize;
 }
 
 size_t ZSTD_estimateDStreamSize(size_t windowSize)
 {
     size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
     size_t const inBuffSize = blockSize;  /* no block can be larger */
     size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN);
     return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize;
 }
 
 size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize)
 {
     U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX;   /* note : should be user-selectable */
     ZSTD_frameHeader zfh;
     size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize);
     if (ZSTD_isError(err)) return err;
     if (err>0) return ERROR(srcSize_wrong);
     if (zfh.windowSize > windowSizeMax)
         return ERROR(frameParameter_windowTooLarge);
     return ZSTD_estimateDStreamSize((size_t)zfh.windowSize);
 }
 
 
 /* *****   Decompression   ***** */
 
 MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     size_t const length = MIN(dstCapacity, srcSize);
     memcpy(dst, src, length);
     return length;
 }
 
 
 size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     const char* const istart = (const char*)(input->src) + input->pos;
     const char* const iend = (const char*)(input->src) + input->size;
     const char* ip = istart;
     char* const ostart = (char*)(output->dst) + output->pos;
     char* const oend = (char*)(output->dst) + output->size;
     char* op = ostart;
     U32 someMoreWork = 1;
 
     DEBUGLOG(5, "ZSTD_decompressStream");
     if (input->pos > input->size) {  /* forbidden */
         DEBUGLOG(5, "in: pos: %u   vs size: %u",
                     (U32)input->pos, (U32)input->size);
         return ERROR(srcSize_wrong);
     }
     if (output->pos > output->size) {  /* forbidden */
         DEBUGLOG(5, "out: pos: %u   vs size: %u",
                     (U32)output->pos, (U32)output->size);
         return ERROR(dstSize_tooSmall);
     }
     DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos));
 
     while (someMoreWork) {
         switch(zds->streamStage)
         {
         case zdss_init :
             DEBUGLOG(5, "stage zdss_init => transparent reset ");
             ZSTD_resetDStream(zds);   /* transparent reset on starting decoding a new frame */
             /* fall-through */
 
         case zdss_loadHeader :
             DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip));
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
             if (zds->legacyVersion) {
                 /* legacy support is incompatible with static dctx */
                 if (zds->staticSize) return ERROR(memory_allocation);
                 {   size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
                     if (hint==0) zds->streamStage = zdss_init;
                     return hint;
             }   }
 #endif
-            {   size_t const hSize = ZSTD_getFrameHeader_internal(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
+            {   size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
                 DEBUGLOG(5, "header size : %u", (U32)hSize);
                 if (ZSTD_isError(hSize)) {
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
                     U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
                     if (legacyVersion) {
                         const void* const dict = zds->ddict ? zds->ddict->dictContent : NULL;
                         size_t const dictSize = zds->ddict ? zds->ddict->dictSize : 0;
                         DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion);
                         /* legacy support is incompatible with static dctx */
                         if (zds->staticSize) return ERROR(memory_allocation);
                         CHECK_F(ZSTD_initLegacyStream(&zds->legacyContext,
                                     zds->previousLegacyVersion, legacyVersion,
                                     dict, dictSize));
                         zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
                         {   size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input);
                             if (hint==0) zds->streamStage = zdss_init;   /* or stay in stage zdss_loadHeader */
                             return hint;
                     }   }
 #endif
                     return hSize;   /* error */
                 }
                 if (hSize != 0) {   /* need more input */
                     size_t const toLoad = hSize - zds->lhSize;   /* if hSize!=0, hSize > zds->lhSize */
                     size_t const remainingInput = (size_t)(iend-ip);
                     assert(iend >= ip);
                     if (toLoad > remainingInput) {   /* not enough input to load full header */
                         if (remainingInput > 0) {
                             memcpy(zds->headerBuffer + zds->lhSize, ip, remainingInput);
                             zds->lhSize += remainingInput;
                         }
                         input->pos = input->size;
                         return (MAX(ZSTD_frameHeaderSize_min, hSize) - zds->lhSize) + ZSTD_blockHeaderSize;   /* remaining header bytes + next block header */
                     }
                     assert(ip != NULL);
                     memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad;
                     break;
             }   }
 
             /* check for single-pass mode opportunity */
             if (zds->fParams.frameContentSize && zds->fParams.windowSize /* skippable frame if == 0 */
                 && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) {
                 size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend-istart);
                 if (cSize <= (size_t)(iend-istart)) {
                     /* shortcut : using single-pass mode */
                     size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, oend-op, istart, cSize, zds->ddict);
                     if (ZSTD_isError(decompressedSize)) return decompressedSize;
                     DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()")
                     ip = istart + cSize;
                     op += decompressedSize;
                     zds->expected = 0;
                     zds->streamStage = zdss_init;
                     someMoreWork = 0;
                     break;
             }   }
 
             /* Consume header (see ZSTDds_decodeFrameHeader) */
             DEBUGLOG(4, "Consume header");
             CHECK_F(ZSTD_decompressBegin_usingDDict(zds, zds->ddict));
 
             if ((MEM_readLE32(zds->headerBuffer) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {  /* skippable frame */
-                zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_frameIdSize);
+                zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_FRAMEIDSIZE);
                 zds->stage = ZSTDds_skipFrame;
             } else {
                 CHECK_F(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize));
                 zds->expected = ZSTD_blockHeaderSize;
                 zds->stage = ZSTDds_decodeBlockHeader;
             }
 
             /* control buffer memory usage */
             DEBUGLOG(4, "Control max memory usage (%u KB <= max %u KB)",
                         (U32)(zds->fParams.windowSize >>10),
                         (U32)(zds->maxWindowSize >> 10) );
             zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
             if (zds->fParams.windowSize > zds->maxWindowSize) return ERROR(frameParameter_windowTooLarge);
 
             /* Adapt buffer sizes to frame header instructions */
             {   size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */);
                 size_t const neededOutBuffSize = ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize);
                 if ((zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize)) {
                     size_t const bufferSize = neededInBuffSize + neededOutBuffSize;
                     DEBUGLOG(4, "inBuff  : from %u to %u",
                                 (U32)zds->inBuffSize, (U32)neededInBuffSize);
                     DEBUGLOG(4, "outBuff : from %u to %u",
                                 (U32)zds->outBuffSize, (U32)neededOutBuffSize);
                     if (zds->staticSize) {  /* static DCtx */
                         DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize);
                         assert(zds->staticSize >= sizeof(ZSTD_DCtx));  /* controlled at init */
                         if (bufferSize > zds->staticSize - sizeof(ZSTD_DCtx))
                             return ERROR(memory_allocation);
                     } else {
                         ZSTD_free(zds->inBuff, zds->customMem);
                         zds->inBuffSize = 0;
                         zds->outBuffSize = 0;
                         zds->inBuff = (char*)ZSTD_malloc(bufferSize, zds->customMem);
                         if (zds->inBuff == NULL) return ERROR(memory_allocation);
                     }
                     zds->inBuffSize = neededInBuffSize;
                     zds->outBuff = zds->inBuff + zds->inBuffSize;
                     zds->outBuffSize = neededOutBuffSize;
             }   }
             zds->streamStage = zdss_read;
             /* fall-through */
 
         case zdss_read:
             DEBUGLOG(5, "stage zdss_read");
             {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
                 DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize);
                 if (neededInSize==0) {  /* end of frame */
                     zds->streamStage = zdss_init;
                     someMoreWork = 0;
                     break;
                 }
                 if ((size_t)(iend-ip) >= neededInSize) {  /* decode directly from src */
                     int const isSkipFrame = ZSTD_isSkipFrame(zds);
                     size_t const decodedSize = ZSTD_decompressContinue(zds,
                         zds->outBuff + zds->outStart, (isSkipFrame ? 0 : zds->outBuffSize - zds->outStart),
                         ip, neededInSize);
                     if (ZSTD_isError(decodedSize)) return decodedSize;
                     ip += neededInSize;
                     if (!decodedSize && !isSkipFrame) break;   /* this was just a header */
                     zds->outEnd = zds->outStart + decodedSize;
                     zds->streamStage = zdss_flush;
                     break;
             }   }
             if (ip==iend) { someMoreWork = 0; break; }   /* no more input */
             zds->streamStage = zdss_load;
             /* fall-through */
 
         case zdss_load:
             {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
                 size_t const toLoad = neededInSize - zds->inPos;
                 int const isSkipFrame = ZSTD_isSkipFrame(zds);
                 size_t loadedSize;
                 if (isSkipFrame) {
                     loadedSize = MIN(toLoad, (size_t)(iend-ip));
                 } else {
                     if (toLoad > zds->inBuffSize - zds->inPos) return ERROR(corruption_detected);   /* should never happen */
                     loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, iend-ip);
                 }
                 ip += loadedSize;
                 zds->inPos += loadedSize;
                 if (loadedSize < toLoad) { someMoreWork = 0; break; }   /* not enough input, wait for more */
 
                 /* decode loaded input */
                 {   size_t const decodedSize = ZSTD_decompressContinue(zds,
                         zds->outBuff + zds->outStart, zds->outBuffSize - zds->outStart,
                         zds->inBuff, neededInSize);
                     if (ZSTD_isError(decodedSize)) return decodedSize;
                     zds->inPos = 0;   /* input is consumed */
                     if (!decodedSize && !isSkipFrame) { zds->streamStage = zdss_read; break; }   /* this was just a header */
                     zds->outEnd = zds->outStart +  decodedSize;
             }   }
             zds->streamStage = zdss_flush;
             /* fall-through */
 
         case zdss_flush:
             {   size_t const toFlushSize = zds->outEnd - zds->outStart;
                 size_t const flushedSize = ZSTD_limitCopy(op, oend-op, zds->outBuff + zds->outStart, toFlushSize);
                 op += flushedSize;
                 zds->outStart += flushedSize;
                 if (flushedSize == toFlushSize) {  /* flush completed */
                     zds->streamStage = zdss_read;
                     if ( (zds->outBuffSize < zds->fParams.frameContentSize)
                       && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) {
                         DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)",
                                 (int)(zds->outBuffSize - zds->outStart),
                                 (U32)zds->fParams.blockSizeMax);
                         zds->outStart = zds->outEnd = 0;
                     }
                     break;
             }   }
             /* cannot complete flush */
             someMoreWork = 0;
             break;
 
         default: return ERROR(GENERIC);   /* impossible */
     }   }
 
     /* result */
-    input->pos += (size_t)(ip-istart);
-    output->pos += (size_t)(op-ostart);
+    input->pos = (size_t)(ip - (const char*)(input->src));
+    output->pos = (size_t)(op - (char*)(output->dst));
+    if ((ip==istart) && (op==ostart)) {  /* no forward progress */
+        zds->noForwardProgress ++;
+        if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) {
+            if (op==oend) return ERROR(dstSize_tooSmall);
+            if (ip==iend) return ERROR(srcSize_wrong);
+            assert(0);
+        }
+    } else {
+        zds->noForwardProgress = 0;
+    }
     {   size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds);
         if (!nextSrcSizeHint) {   /* frame fully decoded */
             if (zds->outEnd == zds->outStart) {  /* output fully flushed */
                 if (zds->hostageByte) {
                     if (input->pos >= input->size) {
                         /* can't release hostage (not present) */
                         zds->streamStage = zdss_read;
                         return 1;
                     }
                     input->pos++;  /* release hostage */
                 }   /* zds->hostageByte */
                 return 0;
             }  /* zds->outEnd == zds->outStart */
             if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */
                 input->pos--;   /* note : pos > 0, otherwise, impossible to finish reading last block */
                 zds->hostageByte=1;
             }
             return 1;
         }  /* nextSrcSizeHint==0 */
         nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block);   /* preload header of next block */
         assert(zds->inPos <= nextSrcSizeHint);
         nextSrcSizeHint -= zds->inPos;   /* part already loaded*/
         return nextSrcSizeHint;
     }
 }
 
 
 size_t ZSTD_decompress_generic(ZSTD_DCtx* dctx, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     return ZSTD_decompressStream(dctx, output, input);
 }
 
 size_t ZSTD_decompress_generic_simpleArgs (
                             ZSTD_DCtx* dctx,
                             void* dst, size_t dstCapacity, size_t* dstPos,
                       const void* src, size_t srcSize, size_t* srcPos)
 {
     ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
     ZSTD_inBuffer  input  = { src, srcSize, *srcPos };
     /* ZSTD_compress_generic() will check validity of dstPos and srcPos */
     size_t const cErr = ZSTD_decompress_generic(dctx, &output, &input);
     *dstPos = output.pos;
     *srcPos = input.pos;
     return cErr;
 }
 
 void ZSTD_DCtx_reset(ZSTD_DCtx* dctx)
 {
     (void)ZSTD_initDStream(dctx);
     dctx->format = ZSTD_f_zstd1;
     dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
 }
Index: vendor/zstd/dist/lib/dictBuilder/cover.c
===================================================================
--- vendor/zstd/dist/lib/dictBuilder/cover.c	(revision 339613)
+++ vendor/zstd/dist/lib/dictBuilder/cover.c	(revision 339614)
@@ -1,1048 +1,1079 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /* *****************************************************************************
  * Constructs a dictionary using a heuristic based on the following paper:
  *
  * Liao, Petri, Moffat, Wirth
  * Effective Construction of Relative Lempel-Ziv Dictionaries
  * Published in WWW 2016.
  *
  * Adapted from code originally written by @ot (Giuseppe Ottaviano).
  ******************************************************************************/
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include   /* fprintf */
 #include  /* malloc, free, qsort */
 #include  /* memset */
 #include    /* clock */
 
 #include "mem.h" /* read */
 #include "pool.h"
 #include "threading.h"
+#include "cover.h"
 #include "zstd_internal.h" /* includes zstd.h */
 #ifndef ZDICT_STATIC_LINKING_ONLY
 #define ZDICT_STATIC_LINKING_ONLY
 #endif
 #include "zdict.h"
 
 /*-*************************************
 *  Constants
 ***************************************/
 #define COVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((U32)-1) : ((U32)1 GB))
+#define DEFAULT_SPLITPOINT 1.0
 
 /*-*************************************
 *  Console display
 ***************************************/
 static int g_displayLevel = 2;
 #define DISPLAY(...)                                                           \
   {                                                                            \
     fprintf(stderr, __VA_ARGS__);                                              \
     fflush(stderr);                                                            \
   }
 #define LOCALDISPLAYLEVEL(displayLevel, l, ...)                                \
   if (displayLevel >= l) {                                                     \
     DISPLAY(__VA_ARGS__);                                                      \
   } /* 0 : no display;   1: errors;   2: default;  3: details;  4: debug */
 #define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
 
 #define LOCALDISPLAYUPDATE(displayLevel, l, ...)                               \
   if (displayLevel >= l) {                                                     \
     if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) {             \
       g_time = clock();                                                        \
       DISPLAY(__VA_ARGS__);                                                    \
     }                                                                          \
   }
 #define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
 static const clock_t refreshRate = CLOCKS_PER_SEC * 15 / 100;
 static clock_t g_time = 0;
 
 /*-*************************************
 * Hash table
 ***************************************
 * A small specialized hash map for storing activeDmers.
 * The map does not resize, so if it becomes full it will loop forever.
 * Thus, the map must be large enough to store every value.
 * The map implements linear probing and keeps its load less than 0.5.
 */
 
 #define MAP_EMPTY_VALUE ((U32)-1)
 typedef struct COVER_map_pair_t_s {
   U32 key;
   U32 value;
 } COVER_map_pair_t;
 
 typedef struct COVER_map_s {
   COVER_map_pair_t *data;
   U32 sizeLog;
   U32 size;
   U32 sizeMask;
 } COVER_map_t;
 
 /**
  * Clear the map.
  */
 static void COVER_map_clear(COVER_map_t *map) {
   memset(map->data, MAP_EMPTY_VALUE, map->size * sizeof(COVER_map_pair_t));
 }
 
 /**
  * Initializes a map of the given size.
  * Returns 1 on success and 0 on failure.
  * The map must be destroyed with COVER_map_destroy().
  * The map is only guaranteed to be large enough to hold size elements.
  */
 static int COVER_map_init(COVER_map_t *map, U32 size) {
   map->sizeLog = ZSTD_highbit32(size) + 2;
   map->size = (U32)1 << map->sizeLog;
   map->sizeMask = map->size - 1;
   map->data = (COVER_map_pair_t *)malloc(map->size * sizeof(COVER_map_pair_t));
   if (!map->data) {
     map->sizeLog = 0;
     map->size = 0;
     return 0;
   }
   COVER_map_clear(map);
   return 1;
 }
 
 /**
  * Internal hash function
  */
 static const U32 prime4bytes = 2654435761U;
 static U32 COVER_map_hash(COVER_map_t *map, U32 key) {
   return (key * prime4bytes) >> (32 - map->sizeLog);
 }
 
 /**
  * Helper function that returns the index that a key should be placed into.
  */
 static U32 COVER_map_index(COVER_map_t *map, U32 key) {
   const U32 hash = COVER_map_hash(map, key);
   U32 i;
   for (i = hash;; i = (i + 1) & map->sizeMask) {
     COVER_map_pair_t *pos = &map->data[i];
     if (pos->value == MAP_EMPTY_VALUE) {
       return i;
     }
     if (pos->key == key) {
       return i;
     }
   }
 }
 
 /**
  * Returns the pointer to the value for key.
  * If key is not in the map, it is inserted and the value is set to 0.
  * The map must not be full.
  */
 static U32 *COVER_map_at(COVER_map_t *map, U32 key) {
   COVER_map_pair_t *pos = &map->data[COVER_map_index(map, key)];
   if (pos->value == MAP_EMPTY_VALUE) {
     pos->key = key;
     pos->value = 0;
   }
   return &pos->value;
 }
 
 /**
  * Deletes key from the map if present.
  */
 static void COVER_map_remove(COVER_map_t *map, U32 key) {
   U32 i = COVER_map_index(map, key);
   COVER_map_pair_t *del = &map->data[i];
   U32 shift = 1;
   if (del->value == MAP_EMPTY_VALUE) {
     return;
   }
   for (i = (i + 1) & map->sizeMask;; i = (i + 1) & map->sizeMask) {
     COVER_map_pair_t *const pos = &map->data[i];
     /* If the position is empty we are done */
     if (pos->value == MAP_EMPTY_VALUE) {
       del->value = MAP_EMPTY_VALUE;
       return;
     }
     /* If pos can be moved to del do so */
     if (((i - COVER_map_hash(map, pos->key)) & map->sizeMask) >= shift) {
       del->key = pos->key;
       del->value = pos->value;
       del = pos;
       shift = 1;
     } else {
       ++shift;
     }
   }
 }
 
 /**
- * Destroyes a map that is inited with COVER_map_init().
+ * Destroys a map that is inited with COVER_map_init().
  */
 static void COVER_map_destroy(COVER_map_t *map) {
   if (map->data) {
     free(map->data);
   }
   map->data = NULL;
   map->size = 0;
 }
 
 /*-*************************************
 * Context
 ***************************************/
 
 typedef struct {
   const BYTE *samples;
   size_t *offsets;
   const size_t *samplesSizes;
   size_t nbSamples;
+  size_t nbTrainSamples;
+  size_t nbTestSamples;
   U32 *suffix;
   size_t suffixSize;
   U32 *freqs;
   U32 *dmerAt;
   unsigned d;
 } COVER_ctx_t;
 
 /* We need a global context for qsort... */
 static COVER_ctx_t *g_ctx = NULL;
 
 /*-*************************************
 *  Helper functions
 ***************************************/
 
 /**
  * Returns the sum of the sample sizes.
  */
-static size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) {
+size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) {
   size_t sum = 0;
-  size_t i;
+  unsigned i;
   for (i = 0; i < nbSamples; ++i) {
     sum += samplesSizes[i];
   }
   return sum;
 }
 
 /**
  * Returns -1 if the dmer at lp is less than the dmer at rp.
  * Return 0 if the dmers at lp and rp are equal.
  * Returns 1 if the dmer at lp is greater than the dmer at rp.
  */
 static int COVER_cmp(COVER_ctx_t *ctx, const void *lp, const void *rp) {
   U32 const lhs = *(U32 const *)lp;
   U32 const rhs = *(U32 const *)rp;
   return memcmp(ctx->samples + lhs, ctx->samples + rhs, ctx->d);
 }
 /**
  * Faster version for d <= 8.
  */
 static int COVER_cmp8(COVER_ctx_t *ctx, const void *lp, const void *rp) {
   U64 const mask = (ctx->d == 8) ? (U64)-1 : (((U64)1 << (8 * ctx->d)) - 1);
   U64 const lhs = MEM_readLE64(ctx->samples + *(U32 const *)lp) & mask;
   U64 const rhs = MEM_readLE64(ctx->samples + *(U32 const *)rp) & mask;
   if (lhs < rhs) {
     return -1;
   }
   return (lhs > rhs);
 }
 
 /**
  * Same as COVER_cmp() except ties are broken by pointer value
  * NOTE: g_ctx must be set to call this function.  A global is required because
  * qsort doesn't take an opaque pointer.
  */
 static int COVER_strict_cmp(const void *lp, const void *rp) {
   int result = COVER_cmp(g_ctx, lp, rp);
   if (result == 0) {
     result = lp < rp ? -1 : 1;
   }
   return result;
 }
 /**
  * Faster version for d <= 8.
  */
 static int COVER_strict_cmp8(const void *lp, const void *rp) {
   int result = COVER_cmp8(g_ctx, lp, rp);
   if (result == 0) {
     result = lp < rp ? -1 : 1;
   }
   return result;
 }
 
 /**
  * Returns the first pointer in [first, last) whose element does not compare
  * less than value.  If no such element exists it returns last.
  */
 static const size_t *COVER_lower_bound(const size_t *first, const size_t *last,
                                        size_t value) {
   size_t count = last - first;
   while (count != 0) {
     size_t step = count / 2;
     const size_t *ptr = first;
     ptr += step;
     if (*ptr < value) {
       first = ++ptr;
       count -= step + 1;
     } else {
       count = step;
     }
   }
   return first;
 }
 
 /**
  * Generic groupBy function.
  * Groups an array sorted by cmp into groups with equivalent values.
  * Calls grp for each group.
  */
 static void
 COVER_groupBy(const void *data, size_t count, size_t size, COVER_ctx_t *ctx,
               int (*cmp)(COVER_ctx_t *, const void *, const void *),
               void (*grp)(COVER_ctx_t *, const void *, const void *)) {
   const BYTE *ptr = (const BYTE *)data;
   size_t num = 0;
   while (num < count) {
     const BYTE *grpEnd = ptr + size;
     ++num;
     while (num < count && cmp(ctx, ptr, grpEnd) == 0) {
       grpEnd += size;
       ++num;
     }
     grp(ctx, ptr, grpEnd);
     ptr = grpEnd;
   }
 }
 
 /*-*************************************
 *  Cover functions
 ***************************************/
 
 /**
  * Called on each group of positions with the same dmer.
  * Counts the frequency of each dmer and saves it in the suffix array.
  * Fills `ctx->dmerAt`.
  */
 static void COVER_group(COVER_ctx_t *ctx, const void *group,
                         const void *groupEnd) {
   /* The group consists of all the positions with the same first d bytes. */
   const U32 *grpPtr = (const U32 *)group;
   const U32 *grpEnd = (const U32 *)groupEnd;
   /* The dmerId is how we will reference this dmer.
    * This allows us to map the whole dmer space to a much smaller space, the
    * size of the suffix array.
    */
   const U32 dmerId = (U32)(grpPtr - ctx->suffix);
   /* Count the number of samples this dmer shows up in */
   U32 freq = 0;
   /* Details */
   const size_t *curOffsetPtr = ctx->offsets;
   const size_t *offsetsEnd = ctx->offsets + ctx->nbSamples;
   /* Once *grpPtr >= curSampleEnd this occurrence of the dmer is in a
    * different sample than the last.
    */
   size_t curSampleEnd = ctx->offsets[0];
   for (; grpPtr != grpEnd; ++grpPtr) {
     /* Save the dmerId for this position so we can get back to it. */
     ctx->dmerAt[*grpPtr] = dmerId;
     /* Dictionaries only help for the first reference to the dmer.
      * After that zstd can reference the match from the previous reference.
      * So only count each dmer once for each sample it is in.
      */
     if (*grpPtr < curSampleEnd) {
       continue;
     }
     freq += 1;
     /* Binary search to find the end of the sample *grpPtr is in.
      * In the common case that grpPtr + 1 == grpEnd we can skip the binary
      * search because the loop is over.
      */
     if (grpPtr + 1 != grpEnd) {
       const size_t *sampleEndPtr =
           COVER_lower_bound(curOffsetPtr, offsetsEnd, *grpPtr);
       curSampleEnd = *sampleEndPtr;
       curOffsetPtr = sampleEndPtr + 1;
     }
   }
   /* At this point we are never going to look at this segment of the suffix
    * array again.  We take advantage of this fact to save memory.
    * We store the frequency of the dmer in the first position of the group,
    * which is dmerId.
    */
   ctx->suffix[dmerId] = freq;
 }
 
-/**
- * A segment is a range in the source as well as the score of the segment.
- */
-typedef struct {
-  U32 begin;
-  U32 end;
-  U32 score;
-} COVER_segment_t;
 
 /**
  * Selects the best segment in an epoch.
  * Segments of are scored according to the function:
  *
  * Let F(d) be the frequency of dmer d.
  * Let S_i be the dmer at position i of segment S which has length k.
  *
  *     Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1})
  *
  * Once the dmer d is in the dictionay we set F(d) = 0.
  */
 static COVER_segment_t COVER_selectSegment(const COVER_ctx_t *ctx, U32 *freqs,
                                            COVER_map_t *activeDmers, U32 begin,
                                            U32 end,
                                            ZDICT_cover_params_t parameters) {
   /* Constants */
   const U32 k = parameters.k;
   const U32 d = parameters.d;
   const U32 dmersInK = k - d + 1;
   /* Try each segment (activeSegment) and save the best (bestSegment) */
   COVER_segment_t bestSegment = {0, 0, 0};
   COVER_segment_t activeSegment;
   /* Reset the activeDmers in the segment */
   COVER_map_clear(activeDmers);
   /* The activeSegment starts at the beginning of the epoch. */
   activeSegment.begin = begin;
   activeSegment.end = begin;
   activeSegment.score = 0;
   /* Slide the activeSegment through the whole epoch.
    * Save the best segment in bestSegment.
    */
   while (activeSegment.end < end) {
     /* The dmerId for the dmer at the next position */
     U32 newDmer = ctx->dmerAt[activeSegment.end];
     /* The entry in activeDmers for this dmerId */
     U32 *newDmerOcc = COVER_map_at(activeDmers, newDmer);
     /* If the dmer isn't already present in the segment add its score. */
     if (*newDmerOcc == 0) {
       /* The paper suggest using the L-0.5 norm, but experiments show that it
        * doesn't help.
        */
       activeSegment.score += freqs[newDmer];
     }
     /* Add the dmer to the segment */
     activeSegment.end += 1;
     *newDmerOcc += 1;
 
     /* If the window is now too large, drop the first position */
     if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
       U32 delDmer = ctx->dmerAt[activeSegment.begin];
       U32 *delDmerOcc = COVER_map_at(activeDmers, delDmer);
       activeSegment.begin += 1;
       *delDmerOcc -= 1;
       /* If this is the last occurence of the dmer, subtract its score */
       if (*delDmerOcc == 0) {
         COVER_map_remove(activeDmers, delDmer);
         activeSegment.score -= freqs[delDmer];
       }
     }
 
     /* If this segment is the best so far save it */
     if (activeSegment.score > bestSegment.score) {
       bestSegment = activeSegment;
     }
   }
   {
     /* Trim off the zero frequency head and tail from the segment. */
     U32 newBegin = bestSegment.end;
     U32 newEnd = bestSegment.begin;
     U32 pos;
     for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
       U32 freq = freqs[ctx->dmerAt[pos]];
       if (freq != 0) {
         newBegin = MIN(newBegin, pos);
         newEnd = pos + 1;
       }
     }
     bestSegment.begin = newBegin;
     bestSegment.end = newEnd;
   }
   {
     /* Zero out the frequency of each dmer covered by the chosen segment. */
     U32 pos;
     for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
       freqs[ctx->dmerAt[pos]] = 0;
     }
   }
   return bestSegment;
 }
 
 /**
  * Check the validity of the parameters.
  * Returns non-zero if the parameters are valid and 0 otherwise.
  */
 static int COVER_checkParameters(ZDICT_cover_params_t parameters,
                                  size_t maxDictSize) {
   /* k and d are required parameters */
   if (parameters.d == 0 || parameters.k == 0) {
     return 0;
   }
   /* k <= maxDictSize */
   if (parameters.k > maxDictSize) {
     return 0;
   }
   /* d <= k */
   if (parameters.d > parameters.k) {
     return 0;
   }
+  /* 0 < splitPoint <= 1 */
+  if (parameters.splitPoint <= 0 || parameters.splitPoint > 1){
+    return 0;
+  }
   return 1;
 }
 
 /**
  * Clean up a context initialized with `COVER_ctx_init()`.
  */
 static void COVER_ctx_destroy(COVER_ctx_t *ctx) {
   if (!ctx) {
     return;
   }
   if (ctx->suffix) {
     free(ctx->suffix);
     ctx->suffix = NULL;
   }
   if (ctx->freqs) {
     free(ctx->freqs);
     ctx->freqs = NULL;
   }
   if (ctx->dmerAt) {
     free(ctx->dmerAt);
     ctx->dmerAt = NULL;
   }
   if (ctx->offsets) {
     free(ctx->offsets);
     ctx->offsets = NULL;
   }
 }
 
 /**
  * Prepare a context for dictionary building.
  * The context is only dependent on the parameter `d` and can used multiple
  * times.
  * Returns 1 on success or zero on error.
  * The context must be destroyed with `COVER_ctx_destroy()`.
  */
 static int COVER_ctx_init(COVER_ctx_t *ctx, const void *samplesBuffer,
                           const size_t *samplesSizes, unsigned nbSamples,
-                          unsigned d) {
+                          unsigned d, double splitPoint) {
   const BYTE *const samples = (const BYTE *)samplesBuffer;
   const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
+  /* Split samples into testing and training sets */
+  const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
+  const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
+  const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
+  const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
   /* Checks */
   if (totalSamplesSize < MAX(d, sizeof(U64)) ||
       totalSamplesSize >= (size_t)COVER_MAX_SAMPLES_SIZE) {
     DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
                  (U32)(totalSamplesSize>>20), (COVER_MAX_SAMPLES_SIZE >> 20));
     return 0;
   }
+  /* Check if there are at least 5 training samples */
+  if (nbTrainSamples < 5) {
+    DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid.", nbTrainSamples);
+    return 0;
+  }
+  /* Check if there's testing sample */
+  if (nbTestSamples < 1) {
+    DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.", nbTestSamples);
+    return 0;
+  }
   /* Zero the context */
   memset(ctx, 0, sizeof(*ctx));
-  DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbSamples,
-               (U32)totalSamplesSize);
+  DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
+               (U32)trainingSamplesSize);
+  DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples,
+               (U32)testSamplesSize);
   ctx->samples = samples;
   ctx->samplesSizes = samplesSizes;
   ctx->nbSamples = nbSamples;
+  ctx->nbTrainSamples = nbTrainSamples;
+  ctx->nbTestSamples = nbTestSamples;
   /* Partial suffix array */
-  ctx->suffixSize = totalSamplesSize - MAX(d, sizeof(U64)) + 1;
+  ctx->suffixSize = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
   ctx->suffix = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
   /* Maps index to the dmerID */
   ctx->dmerAt = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
   /* The offsets of each file */
   ctx->offsets = (size_t *)malloc((nbSamples + 1) * sizeof(size_t));
   if (!ctx->suffix || !ctx->dmerAt || !ctx->offsets) {
     DISPLAYLEVEL(1, "Failed to allocate scratch buffers\n");
     COVER_ctx_destroy(ctx);
     return 0;
   }
   ctx->freqs = NULL;
   ctx->d = d;
 
-  /* Fill offsets from the samlesSizes */
+  /* Fill offsets from the samplesSizes */
   {
     U32 i;
     ctx->offsets[0] = 0;
     for (i = 1; i <= nbSamples; ++i) {
       ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
     }
   }
   DISPLAYLEVEL(2, "Constructing partial suffix array\n");
   {
     /* suffix is a partial suffix array.
      * It only sorts suffixes by their first parameters.d bytes.
      * The sort is stable, so each dmer group is sorted by position in input.
      */
     U32 i;
     for (i = 0; i < ctx->suffixSize; ++i) {
       ctx->suffix[i] = i;
     }
-    /* qsort doesn't take an opaque pointer, so pass as a global */
+    /* qsort doesn't take an opaque pointer, so pass as a global.
+     * On OpenBSD qsort() is not guaranteed to be stable, their mergesort() is.
+     */
     g_ctx = ctx;
+#if defined(__OpenBSD__)
+    mergesort(ctx->suffix, ctx->suffixSize, sizeof(U32),
+          (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+#else
     qsort(ctx->suffix, ctx->suffixSize, sizeof(U32),
           (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
+#endif
   }
   DISPLAYLEVEL(2, "Computing frequencies\n");
   /* For each dmer group (group of positions with the same first d bytes):
    * 1. For each position we set dmerAt[position] = dmerID.  The dmerID is
    *    (groupBeginPtr - suffix).  This allows us to go from position to
    *    dmerID so we can look up values in freq.
    * 2. We calculate how many samples the dmer occurs in and save it in
    *    freqs[dmerId].
    */
   COVER_groupBy(ctx->suffix, ctx->suffixSize, sizeof(U32), ctx,
                 (ctx->d <= 8 ? &COVER_cmp8 : &COVER_cmp), &COVER_group);
   ctx->freqs = ctx->suffix;
   ctx->suffix = NULL;
   return 1;
 }
 
 /**
  * Given the prepared context build the dictionary.
  */
 static size_t COVER_buildDictionary(const COVER_ctx_t *ctx, U32 *freqs,
                                     COVER_map_t *activeDmers, void *dictBuffer,
                                     size_t dictBufferCapacity,
                                     ZDICT_cover_params_t parameters) {
   BYTE *const dict = (BYTE *)dictBuffer;
   size_t tail = dictBufferCapacity;
   /* Divide the data up into epochs of equal size.
    * We will select at least one segment from each epoch.
    */
-  const U32 epochs = (U32)(dictBufferCapacity / parameters.k);
+  const U32 epochs = MAX(1, (U32)(dictBufferCapacity / parameters.k / 4));
   const U32 epochSize = (U32)(ctx->suffixSize / epochs);
   size_t epoch;
   DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n", epochs,
                epochSize);
   /* Loop through the epochs until there are no more segments or the dictionary
    * is full.
    */
   for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs) {
     const U32 epochBegin = (U32)(epoch * epochSize);
     const U32 epochEnd = epochBegin + epochSize;
     size_t segmentSize;
     /* Select a segment */
     COVER_segment_t segment = COVER_selectSegment(
         ctx, freqs, activeDmers, epochBegin, epochEnd, parameters);
     /* If the segment covers no dmers, then we are out of content */
     if (segment.score == 0) {
       break;
     }
     /* Trim the segment if necessary and if it is too small then we are done */
     segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
     if (segmentSize < parameters.d) {
       break;
     }
     /* We fill the dictionary from the back to allow the best segments to be
      * referenced with the smallest offsets.
      */
     tail -= segmentSize;
     memcpy(dict + tail, ctx->samples + segment.begin, segmentSize);
     DISPLAYUPDATE(
         2, "\r%u%%       ",
         (U32)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity));
   }
   DISPLAYLEVEL(2, "\r%79s\r", "");
   return tail;
 }
 
 ZDICTLIB_API size_t ZDICT_trainFromBuffer_cover(
     void *dictBuffer, size_t dictBufferCapacity,
     const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
     ZDICT_cover_params_t parameters)
 {
   BYTE* const dict = (BYTE*)dictBuffer;
   COVER_ctx_t ctx;
   COVER_map_t activeDmers;
-
+  parameters.splitPoint = 1.0;
   /* Initialize global data */
   g_displayLevel = parameters.zParams.notificationLevel;
   /* Checks */
   if (!COVER_checkParameters(parameters, dictBufferCapacity)) {
     DISPLAYLEVEL(1, "Cover parameters incorrect\n");
     return ERROR(GENERIC);
   }
   if (nbSamples == 0) {
     DISPLAYLEVEL(1, "Cover must have at least one input file\n");
     return ERROR(GENERIC);
   }
   if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
     DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
                  ZDICT_DICTSIZE_MIN);
     return ERROR(dstSize_tooSmall);
   }
   /* Initialize context and activeDmers */
   if (!COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
-                      parameters.d)) {
+                      parameters.d, parameters.splitPoint)) {
     return ERROR(GENERIC);
   }
   if (!COVER_map_init(&activeDmers, parameters.k - parameters.d + 1)) {
     DISPLAYLEVEL(1, "Failed to allocate dmer map: out of memory\n");
     COVER_ctx_destroy(&ctx);
     return ERROR(GENERIC);
   }
 
   DISPLAYLEVEL(2, "Building dictionary\n");
   {
     const size_t tail =
         COVER_buildDictionary(&ctx, ctx.freqs, &activeDmers, dictBuffer,
                               dictBufferCapacity, parameters);
     const size_t dictionarySize = ZDICT_finalizeDictionary(
         dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
         samplesBuffer, samplesSizes, nbSamples, parameters.zParams);
     if (!ZSTD_isError(dictionarySize)) {
       DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
                    (U32)dictionarySize);
     }
     COVER_ctx_destroy(&ctx);
     COVER_map_destroy(&activeDmers);
     return dictionarySize;
   }
 }
 
-/**
- * COVER_best_t is used for two purposes:
- * 1. Synchronizing threads.
- * 2. Saving the best parameters and dictionary.
- *
- * All of the methods except COVER_best_init() are thread safe if zstd is
- * compiled with multithreaded support.
- */
-typedef struct COVER_best_s {
-  ZSTD_pthread_mutex_t mutex;
-  ZSTD_pthread_cond_t cond;
-  size_t liveJobs;
-  void *dict;
-  size_t dictSize;
-  ZDICT_cover_params_t parameters;
-  size_t compressedSize;
-} COVER_best_t;
 
+
+size_t COVER_checkTotalCompressedSize(const ZDICT_cover_params_t parameters,
+                                    const size_t *samplesSizes, const BYTE *samples,
+                                    size_t *offsets,
+                                    size_t nbTrainSamples, size_t nbSamples,
+                                    BYTE *const dict, size_t dictBufferCapacity) {
+  size_t totalCompressedSize = ERROR(GENERIC);
+  /* Pointers */
+  ZSTD_CCtx *cctx;
+  ZSTD_CDict *cdict;
+  void *dst;
+  /* Local variables */
+  size_t dstCapacity;
+  size_t i;
+  /* Allocate dst with enough space to compress the maximum sized sample */
+  {
+    size_t maxSampleSize = 0;
+    i = parameters.splitPoint < 1.0 ? nbTrainSamples : 0;
+    for (; i < nbSamples; ++i) {
+      maxSampleSize = MAX(samplesSizes[i], maxSampleSize);
+    }
+    dstCapacity = ZSTD_compressBound(maxSampleSize);
+    dst = malloc(dstCapacity);
+  }
+  /* Create the cctx and cdict */
+  cctx = ZSTD_createCCtx();
+  cdict = ZSTD_createCDict(dict, dictBufferCapacity,
+                           parameters.zParams.compressionLevel);
+  if (!dst || !cctx || !cdict) {
+    goto _compressCleanup;
+  }
+  /* Compress each sample and sum their sizes (or error) */
+  totalCompressedSize = dictBufferCapacity;
+  i = parameters.splitPoint < 1.0 ? nbTrainSamples : 0;
+  for (; i < nbSamples; ++i) {
+    const size_t size = ZSTD_compress_usingCDict(
+        cctx, dst, dstCapacity, samples + offsets[i],
+        samplesSizes[i], cdict);
+    if (ZSTD_isError(size)) {
+      totalCompressedSize = ERROR(GENERIC);
+      goto _compressCleanup;
+    }
+    totalCompressedSize += size;
+  }
+_compressCleanup:
+  ZSTD_freeCCtx(cctx);
+  ZSTD_freeCDict(cdict);
+  if (dst) {
+    free(dst);
+  }
+  return totalCompressedSize;
+}
+
+
 /**
  * Initialize the `COVER_best_t`.
  */
-static void COVER_best_init(COVER_best_t *best) {
+void COVER_best_init(COVER_best_t *best) {
   if (best==NULL) return; /* compatible with init on NULL */
   (void)ZSTD_pthread_mutex_init(&best->mutex, NULL);
   (void)ZSTD_pthread_cond_init(&best->cond, NULL);
   best->liveJobs = 0;
   best->dict = NULL;
   best->dictSize = 0;
   best->compressedSize = (size_t)-1;
   memset(&best->parameters, 0, sizeof(best->parameters));
 }
 
 /**
  * Wait until liveJobs == 0.
  */
-static void COVER_best_wait(COVER_best_t *best) {
+void COVER_best_wait(COVER_best_t *best) {
   if (!best) {
     return;
   }
   ZSTD_pthread_mutex_lock(&best->mutex);
   while (best->liveJobs != 0) {
     ZSTD_pthread_cond_wait(&best->cond, &best->mutex);
   }
   ZSTD_pthread_mutex_unlock(&best->mutex);
 }
 
 /**
  * Call COVER_best_wait() and then destroy the COVER_best_t.
  */
-static void COVER_best_destroy(COVER_best_t *best) {
+void COVER_best_destroy(COVER_best_t *best) {
   if (!best) {
     return;
   }
   COVER_best_wait(best);
   if (best->dict) {
     free(best->dict);
   }
   ZSTD_pthread_mutex_destroy(&best->mutex);
   ZSTD_pthread_cond_destroy(&best->cond);
 }
 
 /**
  * Called when a thread is about to be launched.
  * Increments liveJobs.
  */
-static void COVER_best_start(COVER_best_t *best) {
+void COVER_best_start(COVER_best_t *best) {
   if (!best) {
     return;
   }
   ZSTD_pthread_mutex_lock(&best->mutex);
   ++best->liveJobs;
   ZSTD_pthread_mutex_unlock(&best->mutex);
 }
 
 /**
  * Called when a thread finishes executing, both on error or success.
  * Decrements liveJobs and signals any waiting threads if liveJobs == 0.
  * If this dictionary is the best so far save it and its parameters.
  */
-static void COVER_best_finish(COVER_best_t *best, size_t compressedSize,
+void COVER_best_finish(COVER_best_t *best, size_t compressedSize,
                               ZDICT_cover_params_t parameters, void *dict,
                               size_t dictSize) {
   if (!best) {
     return;
   }
   {
     size_t liveJobs;
     ZSTD_pthread_mutex_lock(&best->mutex);
     --best->liveJobs;
     liveJobs = best->liveJobs;
     /* If the new dictionary is better */
     if (compressedSize < best->compressedSize) {
       /* Allocate space if necessary */
       if (!best->dict || best->dictSize < dictSize) {
         if (best->dict) {
           free(best->dict);
         }
         best->dict = malloc(dictSize);
         if (!best->dict) {
           best->compressedSize = ERROR(GENERIC);
           best->dictSize = 0;
           return;
         }
       }
       /* Save the dictionary, parameters, and size */
       memcpy(best->dict, dict, dictSize);
       best->dictSize = dictSize;
       best->parameters = parameters;
       best->compressedSize = compressedSize;
     }
-    ZSTD_pthread_mutex_unlock(&best->mutex);
     if (liveJobs == 0) {
       ZSTD_pthread_cond_broadcast(&best->cond);
     }
+    ZSTD_pthread_mutex_unlock(&best->mutex);
   }
 }
 
 /**
  * Parameters for COVER_tryParameters().
  */
 typedef struct COVER_tryParameters_data_s {
   const COVER_ctx_t *ctx;
   COVER_best_t *best;
   size_t dictBufferCapacity;
   ZDICT_cover_params_t parameters;
 } COVER_tryParameters_data_t;
 
 /**
- * Tries a set of parameters and upates the COVER_best_t with the results.
+ * Tries a set of parameters and updates the COVER_best_t with the results.
  * This function is thread safe if zstd is compiled with multithreaded support.
  * It takes its parameters as an *OWNING* opaque pointer to support threading.
  */
 static void COVER_tryParameters(void *opaque) {
   /* Save parameters as local variables */
   COVER_tryParameters_data_t *const data = (COVER_tryParameters_data_t *)opaque;
   const COVER_ctx_t *const ctx = data->ctx;
   const ZDICT_cover_params_t parameters = data->parameters;
   size_t dictBufferCapacity = data->dictBufferCapacity;
   size_t totalCompressedSize = ERROR(GENERIC);
   /* Allocate space for hash table, dict, and freqs */
   COVER_map_t activeDmers;
   BYTE *const dict = (BYTE * const)malloc(dictBufferCapacity);
   U32 *freqs = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
   if (!COVER_map_init(&activeDmers, parameters.k - parameters.d + 1)) {
     DISPLAYLEVEL(1, "Failed to allocate dmer map: out of memory\n");
     goto _cleanup;
   }
   if (!dict || !freqs) {
     DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n");
     goto _cleanup;
   }
   /* Copy the frequencies because we need to modify them */
   memcpy(freqs, ctx->freqs, ctx->suffixSize * sizeof(U32));
   /* Build the dictionary */
   {
     const size_t tail = COVER_buildDictionary(ctx, freqs, &activeDmers, dict,
                                               dictBufferCapacity, parameters);
     dictBufferCapacity = ZDICT_finalizeDictionary(
         dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
-        ctx->samples, ctx->samplesSizes, (unsigned)ctx->nbSamples,
+        ctx->samples, ctx->samplesSizes, (unsigned)ctx->nbTrainSamples,
         parameters.zParams);
     if (ZDICT_isError(dictBufferCapacity)) {
       DISPLAYLEVEL(1, "Failed to finalize dictionary\n");
       goto _cleanup;
     }
   }
   /* Check total compressed size */
-  {
-    /* Pointers */
-    ZSTD_CCtx *cctx;
-    ZSTD_CDict *cdict;
-    void *dst;
-    /* Local variables */
-    size_t dstCapacity;
-    size_t i;
-    /* Allocate dst with enough space to compress the maximum sized sample */
-    {
-      size_t maxSampleSize = 0;
-      for (i = 0; i < ctx->nbSamples; ++i) {
-        maxSampleSize = MAX(ctx->samplesSizes[i], maxSampleSize);
-      }
-      dstCapacity = ZSTD_compressBound(maxSampleSize);
-      dst = malloc(dstCapacity);
-    }
-    /* Create the cctx and cdict */
-    cctx = ZSTD_createCCtx();
-    cdict = ZSTD_createCDict(dict, dictBufferCapacity,
-                             parameters.zParams.compressionLevel);
-    if (!dst || !cctx || !cdict) {
-      goto _compressCleanup;
-    }
-    /* Compress each sample and sum their sizes (or error) */
-    totalCompressedSize = dictBufferCapacity;
-    for (i = 0; i < ctx->nbSamples; ++i) {
-      const size_t size = ZSTD_compress_usingCDict(
-          cctx, dst, dstCapacity, ctx->samples + ctx->offsets[i],
-          ctx->samplesSizes[i], cdict);
-      if (ZSTD_isError(size)) {
-        totalCompressedSize = ERROR(GENERIC);
-        goto _compressCleanup;
-      }
-      totalCompressedSize += size;
-    }
-  _compressCleanup:
-    ZSTD_freeCCtx(cctx);
-    ZSTD_freeCDict(cdict);
-    if (dst) {
-      free(dst);
-    }
-  }
+  totalCompressedSize = COVER_checkTotalCompressedSize(parameters, ctx->samplesSizes,
+                                                       ctx->samples, ctx->offsets,
+                                                       ctx->nbTrainSamples, ctx->nbSamples,
+                                                       dict, dictBufferCapacity);
 
 _cleanup:
   COVER_best_finish(data->best, totalCompressedSize, parameters, dict,
                     dictBufferCapacity);
   free(data);
   COVER_map_destroy(&activeDmers);
   if (dict) {
     free(dict);
   }
   if (freqs) {
     free(freqs);
   }
 }
 
 ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_cover(
     void *dictBuffer, size_t dictBufferCapacity, const void *samplesBuffer,
     const size_t *samplesSizes, unsigned nbSamples,
     ZDICT_cover_params_t *parameters) {
   /* constants */
   const unsigned nbThreads = parameters->nbThreads;
+  const double splitPoint =
+      parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint;
   const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
   const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
   const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
   const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k;
   const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps;
   const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1);
   const unsigned kIterations =
       (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
   /* Local variables */
   const int displayLevel = parameters->zParams.notificationLevel;
   unsigned iteration = 1;
   unsigned d;
   unsigned k;
   COVER_best_t best;
   POOL_ctx *pool = NULL;
 
   /* Checks */
+  if (splitPoint <= 0 || splitPoint > 1) {
+    LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect parameters\n");
+    return ERROR(GENERIC);
+  }
   if (kMinK < kMaxD || kMaxK < kMinK) {
     LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect parameters\n");
     return ERROR(GENERIC);
   }
   if (nbSamples == 0) {
     DISPLAYLEVEL(1, "Cover must have at least one input file\n");
     return ERROR(GENERIC);
   }
   if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
     DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
                  ZDICT_DICTSIZE_MIN);
     return ERROR(dstSize_tooSmall);
   }
   if (nbThreads > 1) {
     pool = POOL_create(nbThreads, 1);
     if (!pool) {
       return ERROR(memory_allocation);
     }
   }
   /* Initialization */
   COVER_best_init(&best);
   /* Turn down global display level to clean up display at level 2 and below */
   g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1;
   /* Loop through d first because each new value needs a new context */
   LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n",
                     kIterations);
   for (d = kMinD; d <= kMaxD; d += 2) {
     /* Initialize the context for this value of d */
     COVER_ctx_t ctx;
     LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
-    if (!COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d)) {
+    if (!COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint)) {
       LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n");
       COVER_best_destroy(&best);
       POOL_free(pool);
       return ERROR(GENERIC);
     }
     /* Loop through k reusing the same context */
     for (k = kMinK; k <= kMaxK; k += kStepSize) {
       /* Prepare the arguments */
       COVER_tryParameters_data_t *data = (COVER_tryParameters_data_t *)malloc(
           sizeof(COVER_tryParameters_data_t));
       LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
       if (!data) {
         LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
         COVER_best_destroy(&best);
         COVER_ctx_destroy(&ctx);
         POOL_free(pool);
         return ERROR(GENERIC);
       }
       data->ctx = &ctx;
       data->best = &best;
       data->dictBufferCapacity = dictBufferCapacity;
       data->parameters = *parameters;
       data->parameters.k = k;
       data->parameters.d = d;
+      data->parameters.splitPoint = splitPoint;
       data->parameters.steps = kSteps;
       data->parameters.zParams.notificationLevel = g_displayLevel;
       /* Check the parameters */
       if (!COVER_checkParameters(data->parameters, dictBufferCapacity)) {
         DISPLAYLEVEL(1, "Cover parameters incorrect\n");
         free(data);
         continue;
       }
       /* Call the function and pass ownership of data to it */
       COVER_best_start(&best);
       if (pool) {
         POOL_add(pool, &COVER_tryParameters, data);
       } else {
         COVER_tryParameters(data);
       }
       /* Print status */
       LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%%       ",
                          (U32)((iteration * 100) / kIterations));
       ++iteration;
     }
     COVER_best_wait(&best);
     COVER_ctx_destroy(&ctx);
   }
   LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", "");
   /* Fill the output buffer and parameters with output of the best parameters */
   {
     const size_t dictSize = best.dictSize;
     if (ZSTD_isError(best.compressedSize)) {
       const size_t compressedSize = best.compressedSize;
       COVER_best_destroy(&best);
       POOL_free(pool);
       return compressedSize;
     }
     *parameters = best.parameters;
     memcpy(dictBuffer, best.dict, dictSize);
     COVER_best_destroy(&best);
     POOL_free(pool);
     return dictSize;
   }
 }
Index: vendor/zstd/dist/lib/dictBuilder/cover.h
===================================================================
--- vendor/zstd/dist/lib/dictBuilder/cover.h	(nonexistent)
+++ vendor/zstd/dist/lib/dictBuilder/cover.h	(revision 339614)
@@ -0,0 +1,83 @@
+#include   /* fprintf */
+#include  /* malloc, free, qsort */
+#include  /* memset */
+#include    /* clock */
+#include "mem.h" /* read */
+#include "pool.h"
+#include "threading.h"
+#include "zstd_internal.h" /* includes zstd.h */
+#ifndef ZDICT_STATIC_LINKING_ONLY
+#define ZDICT_STATIC_LINKING_ONLY
+#endif
+#include "zdict.h"
+
+/**
+ * COVER_best_t is used for two purposes:
+ * 1. Synchronizing threads.
+ * 2. Saving the best parameters and dictionary.
+ *
+ * All of the methods except COVER_best_init() are thread safe if zstd is
+ * compiled with multithreaded support.
+ */
+typedef struct COVER_best_s {
+  ZSTD_pthread_mutex_t mutex;
+  ZSTD_pthread_cond_t cond;
+  size_t liveJobs;
+  void *dict;
+  size_t dictSize;
+  ZDICT_cover_params_t parameters;
+  size_t compressedSize;
+} COVER_best_t;
+
+/**
+ * A segment is a range in the source as well as the score of the segment.
+ */
+typedef struct {
+  U32 begin;
+  U32 end;
+  U32 score;
+} COVER_segment_t;
+
+/**
+ *  Checks total compressed size of a dictionary
+ */
+size_t COVER_checkTotalCompressedSize(const ZDICT_cover_params_t parameters,
+                                      const size_t *samplesSizes, const BYTE *samples,
+                                      size_t *offsets,
+                                      size_t nbTrainSamples, size_t nbSamples,
+                                      BYTE *const dict, size_t dictBufferCapacity);
+
+/**
+ * Returns the sum of the sample sizes.
+ */
+size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) ;
+
+/**
+ * Initialize the `COVER_best_t`.
+ */
+void COVER_best_init(COVER_best_t *best);
+
+/**
+ * Wait until liveJobs == 0.
+ */
+void COVER_best_wait(COVER_best_t *best);
+
+/**
+ * Call COVER_best_wait() and then destroy the COVER_best_t.
+ */
+void COVER_best_destroy(COVER_best_t *best);
+
+/**
+ * Called when a thread is about to be launched.
+ * Increments liveJobs.
+ */
+void COVER_best_start(COVER_best_t *best);
+
+/**
+ * Called when a thread finishes executing, both on error or success.
+ * Decrements liveJobs and signals any waiting threads if liveJobs == 0.
+ * If this dictionary is the best so far save it and its parameters.
+ */
+void COVER_best_finish(COVER_best_t *best, size_t compressedSize,
+                       ZDICT_cover_params_t parameters, void *dict,
+                       size_t dictSize);

Property changes on: vendor/zstd/dist/lib/dictBuilder/cover.h
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
Index: vendor/zstd/dist/lib/dictBuilder/divsufsort.c
===================================================================
--- vendor/zstd/dist/lib/dictBuilder/divsufsort.c	(revision 339613)
+++ vendor/zstd/dist/lib/dictBuilder/divsufsort.c	(revision 339614)
@@ -1,1913 +1,1913 @@
 /*
  * divsufsort.c for libdivsufsort-lite
  * Copyright (c) 2003-2008 Yuta Mori All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
  * files (the "Software"), to deal in the Software without
  * restriction, including without limitation the rights to use,
  * copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following
  * conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
 /*- Compiler specifics -*/
 #ifdef __clang__
 #pragma clang diagnostic ignored "-Wshorten-64-to-32"
 #endif
 
 #if defined(_MSC_VER)
 #  pragma warning(disable : 4244)
 #  pragma warning(disable : 4127)    /* C4127 : Condition expression is constant */
 #endif
 
 
 /*- Dependencies -*/
 #include 
 #include 
 #include 
 
 #include "divsufsort.h"
 
 /*- Constants -*/
 #if defined(INLINE)
 # undef INLINE
 #endif
 #if !defined(INLINE)
 # define INLINE __inline
 #endif
 #if defined(ALPHABET_SIZE) && (ALPHABET_SIZE < 1)
 # undef ALPHABET_SIZE
 #endif
 #if !defined(ALPHABET_SIZE)
 # define ALPHABET_SIZE (256)
 #endif
 #define BUCKET_A_SIZE (ALPHABET_SIZE)
 #define BUCKET_B_SIZE (ALPHABET_SIZE * ALPHABET_SIZE)
 #if defined(SS_INSERTIONSORT_THRESHOLD)
 # if SS_INSERTIONSORT_THRESHOLD < 1
 #  undef SS_INSERTIONSORT_THRESHOLD
 #  define SS_INSERTIONSORT_THRESHOLD (1)
 # endif
 #else
 # define SS_INSERTIONSORT_THRESHOLD (8)
 #endif
 #if defined(SS_BLOCKSIZE)
 # if SS_BLOCKSIZE < 0
 #  undef SS_BLOCKSIZE
 #  define SS_BLOCKSIZE (0)
 # elif 32768 <= SS_BLOCKSIZE
 #  undef SS_BLOCKSIZE
 #  define SS_BLOCKSIZE (32767)
 # endif
 #else
 # define SS_BLOCKSIZE (1024)
 #endif
 /* minstacksize = log(SS_BLOCKSIZE) / log(3) * 2 */
 #if SS_BLOCKSIZE == 0
 # define SS_MISORT_STACKSIZE (96)
 #elif SS_BLOCKSIZE <= 4096
 # define SS_MISORT_STACKSIZE (16)
 #else
 # define SS_MISORT_STACKSIZE (24)
 #endif
 #define SS_SMERGE_STACKSIZE (32)
 #define TR_INSERTIONSORT_THRESHOLD (8)
 #define TR_STACKSIZE (64)
 
 
 /*- Macros -*/
 #ifndef SWAP
 # define SWAP(_a, _b) do { t = (_a); (_a) = (_b); (_b) = t; } while(0)
 #endif /* SWAP */
 #ifndef MIN
 # define MIN(_a, _b) (((_a) < (_b)) ? (_a) : (_b))
 #endif /* MIN */
 #ifndef MAX
 # define MAX(_a, _b) (((_a) > (_b)) ? (_a) : (_b))
 #endif /* MAX */
 #define STACK_PUSH(_a, _b, _c, _d)\
   do {\
     assert(ssize < STACK_SIZE);\
     stack[ssize].a = (_a), stack[ssize].b = (_b),\
     stack[ssize].c = (_c), stack[ssize++].d = (_d);\
   } while(0)
 #define STACK_PUSH5(_a, _b, _c, _d, _e)\
   do {\
     assert(ssize < STACK_SIZE);\
     stack[ssize].a = (_a), stack[ssize].b = (_b),\
     stack[ssize].c = (_c), stack[ssize].d = (_d), stack[ssize++].e = (_e);\
   } while(0)
 #define STACK_POP(_a, _b, _c, _d)\
   do {\
     assert(0 <= ssize);\
     if(ssize == 0) { return; }\
     (_a) = stack[--ssize].a, (_b) = stack[ssize].b,\
     (_c) = stack[ssize].c, (_d) = stack[ssize].d;\
   } while(0)
 #define STACK_POP5(_a, _b, _c, _d, _e)\
   do {\
     assert(0 <= ssize);\
     if(ssize == 0) { return; }\
     (_a) = stack[--ssize].a, (_b) = stack[ssize].b,\
     (_c) = stack[ssize].c, (_d) = stack[ssize].d, (_e) = stack[ssize].e;\
   } while(0)
 #define BUCKET_A(_c0) bucket_A[(_c0)]
 #if ALPHABET_SIZE == 256
 #define BUCKET_B(_c0, _c1) (bucket_B[((_c1) << 8) | (_c0)])
 #define BUCKET_BSTAR(_c0, _c1) (bucket_B[((_c0) << 8) | (_c1)])
 #else
 #define BUCKET_B(_c0, _c1) (bucket_B[(_c1) * ALPHABET_SIZE + (_c0)])
 #define BUCKET_BSTAR(_c0, _c1) (bucket_B[(_c0) * ALPHABET_SIZE + (_c1)])
 #endif
 
 
 /*- Private Functions -*/
 
 static const int lg_table[256]= {
  -1,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
   5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
   6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
   6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
   7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
 };
 
 #if (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE)
 
 static INLINE
 int
 ss_ilg(int n) {
 #if SS_BLOCKSIZE == 0
   return (n & 0xffff0000) ?
           ((n & 0xff000000) ?
             24 + lg_table[(n >> 24) & 0xff] :
             16 + lg_table[(n >> 16) & 0xff]) :
           ((n & 0x0000ff00) ?
              8 + lg_table[(n >>  8) & 0xff] :
              0 + lg_table[(n >>  0) & 0xff]);
 #elif SS_BLOCKSIZE < 256
   return lg_table[n];
 #else
   return (n & 0xff00) ?
           8 + lg_table[(n >> 8) & 0xff] :
           0 + lg_table[(n >> 0) & 0xff];
 #endif
 }
 
 #endif /* (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE) */
 
 #if SS_BLOCKSIZE != 0
 
 static const int sqq_table[256] = {
   0,  16,  22,  27,  32,  35,  39,  42,  45,  48,  50,  53,  55,  57,  59,  61,
  64,  65,  67,  69,  71,  73,  75,  76,  78,  80,  81,  83,  84,  86,  87,  89,
  90,  91,  93,  94,  96,  97,  98,  99, 101, 102, 103, 104, 106, 107, 108, 109,
 110, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126,
 128, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142,
 143, 144, 144, 145, 146, 147, 148, 149, 150, 150, 151, 152, 153, 154, 155, 155,
 156, 157, 158, 159, 160, 160, 161, 162, 163, 163, 164, 165, 166, 167, 167, 168,
 169, 170, 170, 171, 172, 173, 173, 174, 175, 176, 176, 177, 178, 178, 179, 180,
 181, 181, 182, 183, 183, 184, 185, 185, 186, 187, 187, 188, 189, 189, 190, 191,
 192, 192, 193, 193, 194, 195, 195, 196, 197, 197, 198, 199, 199, 200, 201, 201,
 202, 203, 203, 204, 204, 205, 206, 206, 207, 208, 208, 209, 209, 210, 211, 211,
 212, 212, 213, 214, 214, 215, 215, 216, 217, 217, 218, 218, 219, 219, 220, 221,
 221, 222, 222, 223, 224, 224, 225, 225, 226, 226, 227, 227, 228, 229, 229, 230,
 230, 231, 231, 232, 232, 233, 234, 234, 235, 235, 236, 236, 237, 237, 238, 238,
 239, 240, 240, 241, 241, 242, 242, 243, 243, 244, 244, 245, 245, 246, 246, 247,
 247, 248, 248, 249, 249, 250, 250, 251, 251, 252, 252, 253, 253, 254, 254, 255
 };
 
 static INLINE
 int
 ss_isqrt(int x) {
   int y, e;
 
   if(x >= (SS_BLOCKSIZE * SS_BLOCKSIZE)) { return SS_BLOCKSIZE; }
   e = (x & 0xffff0000) ?
         ((x & 0xff000000) ?
           24 + lg_table[(x >> 24) & 0xff] :
           16 + lg_table[(x >> 16) & 0xff]) :
         ((x & 0x0000ff00) ?
            8 + lg_table[(x >>  8) & 0xff] :
            0 + lg_table[(x >>  0) & 0xff]);
 
   if(e >= 16) {
     y = sqq_table[x >> ((e - 6) - (e & 1))] << ((e >> 1) - 7);
     if(e >= 24) { y = (y + 1 + x / y) >> 1; }
     y = (y + 1 + x / y) >> 1;
   } else if(e >= 8) {
     y = (sqq_table[x >> ((e - 6) - (e & 1))] >> (7 - (e >> 1))) + 1;
   } else {
     return sqq_table[x] >> 4;
   }
 
   return (x < (y * y)) ? y - 1 : y;
 }
 
 #endif /* SS_BLOCKSIZE != 0 */
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Compares two suffixes. */
 static INLINE
 int
 ss_compare(const unsigned char *T,
            const int *p1, const int *p2,
            int depth) {
   const unsigned char *U1, *U2, *U1n, *U2n;
 
   for(U1 = T + depth + *p1,
       U2 = T + depth + *p2,
       U1n = T + *(p1 + 1) + 2,
       U2n = T + *(p2 + 1) + 2;
       (U1 < U1n) && (U2 < U2n) && (*U1 == *U2);
       ++U1, ++U2) {
   }
 
   return U1 < U1n ?
         (U2 < U2n ? *U1 - *U2 : 1) :
         (U2 < U2n ? -1 : 0);
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 #if (SS_BLOCKSIZE != 1) && (SS_INSERTIONSORT_THRESHOLD != 1)
 
 /* Insertionsort for small size groups */
 static
 void
 ss_insertionsort(const unsigned char *T, const int *PA,
                  int *first, int *last, int depth) {
   int *i, *j;
   int t;
   int r;
 
   for(i = last - 2; first <= i; --i) {
     for(t = *i, j = i + 1; 0 < (r = ss_compare(T, PA + t, PA + *j, depth));) {
       do { *(j - 1) = *j; } while((++j < last) && (*j < 0));
       if(last <= j) { break; }
     }
     if(r == 0) { *j = ~*j; }
     *(j - 1) = t;
   }
 }
 
 #endif /* (SS_BLOCKSIZE != 1) && (SS_INSERTIONSORT_THRESHOLD != 1) */
 
 
 /*---------------------------------------------------------------------------*/
 
 #if (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE)
 
 static INLINE
 void
 ss_fixdown(const unsigned char *Td, const int *PA,
            int *SA, int i, int size) {
   int j, k;
   int v;
   int c, d, e;
 
   for(v = SA[i], c = Td[PA[v]]; (j = 2 * i + 1) < size; SA[i] = SA[k], i = k) {
     d = Td[PA[SA[k = j++]]];
     if(d < (e = Td[PA[SA[j]]])) { k = j; d = e; }
     if(d <= c) { break; }
   }
   SA[i] = v;
 }
 
 /* Simple top-down heapsort. */
 static
 void
 ss_heapsort(const unsigned char *Td, const int *PA, int *SA, int size) {
   int i, m;
   int t;
 
   m = size;
   if((size % 2) == 0) {
     m--;
     if(Td[PA[SA[m / 2]]] < Td[PA[SA[m]]]) { SWAP(SA[m], SA[m / 2]); }
   }
 
   for(i = m / 2 - 1; 0 <= i; --i) { ss_fixdown(Td, PA, SA, i, m); }
   if((size % 2) == 0) { SWAP(SA[0], SA[m]); ss_fixdown(Td, PA, SA, 0, m); }
   for(i = m - 1; 0 < i; --i) {
     t = SA[0], SA[0] = SA[i];
     ss_fixdown(Td, PA, SA, 0, i);
     SA[i] = t;
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Returns the median of three elements. */
 static INLINE
 int *
 ss_median3(const unsigned char *Td, const int *PA,
            int *v1, int *v2, int *v3) {
   int *t;
   if(Td[PA[*v1]] > Td[PA[*v2]]) { SWAP(v1, v2); }
   if(Td[PA[*v2]] > Td[PA[*v3]]) {
     if(Td[PA[*v1]] > Td[PA[*v3]]) { return v1; }
     else { return v3; }
   }
   return v2;
 }
 
 /* Returns the median of five elements. */
 static INLINE
 int *
 ss_median5(const unsigned char *Td, const int *PA,
            int *v1, int *v2, int *v3, int *v4, int *v5) {
   int *t;
   if(Td[PA[*v2]] > Td[PA[*v3]]) { SWAP(v2, v3); }
   if(Td[PA[*v4]] > Td[PA[*v5]]) { SWAP(v4, v5); }
   if(Td[PA[*v2]] > Td[PA[*v4]]) { SWAP(v2, v4); SWAP(v3, v5); }
   if(Td[PA[*v1]] > Td[PA[*v3]]) { SWAP(v1, v3); }
   if(Td[PA[*v1]] > Td[PA[*v4]]) { SWAP(v1, v4); SWAP(v3, v5); }
   if(Td[PA[*v3]] > Td[PA[*v4]]) { return v4; }
   return v3;
 }
 
 /* Returns the pivot element. */
 static INLINE
 int *
 ss_pivot(const unsigned char *Td, const int *PA, int *first, int *last) {
   int *middle;
   int t;
 
   t = last - first;
   middle = first + t / 2;
 
   if(t <= 512) {
     if(t <= 32) {
       return ss_median3(Td, PA, first, middle, last - 1);
     } else {
       t >>= 2;
       return ss_median5(Td, PA, first, first + t, middle, last - 1 - t, last - 1);
     }
   }
   t >>= 3;
   first  = ss_median3(Td, PA, first, first + t, first + (t << 1));
   middle = ss_median3(Td, PA, middle - t, middle, middle + t);
   last   = ss_median3(Td, PA, last - 1 - (t << 1), last - 1 - t, last - 1);
   return ss_median3(Td, PA, first, middle, last);
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Binary partition for substrings. */
 static INLINE
 int *
 ss_partition(const int *PA,
                     int *first, int *last, int depth) {
   int *a, *b;
   int t;
   for(a = first - 1, b = last;;) {
     for(; (++a < b) && ((PA[*a] + depth) >= (PA[*a + 1] + 1));) { *a = ~*a; }
     for(; (a < --b) && ((PA[*b] + depth) <  (PA[*b + 1] + 1));) { }
     if(b <= a) { break; }
     t = ~*b;
     *b = *a;
     *a = t;
   }
   if(first < a) { *first = ~*first; }
   return a;
 }
 
 /* Multikey introsort for medium size groups. */
 static
 void
 ss_mintrosort(const unsigned char *T, const int *PA,
               int *first, int *last,
               int depth) {
 #define STACK_SIZE SS_MISORT_STACKSIZE
   struct { int *a, *b, c; int d; } stack[STACK_SIZE];
   const unsigned char *Td;
   int *a, *b, *c, *d, *e, *f;
   int s, t;
   int ssize;
   int limit;
   int v, x = 0;
 
   for(ssize = 0, limit = ss_ilg(last - first);;) {
 
     if((last - first) <= SS_INSERTIONSORT_THRESHOLD) {
 #if 1 < SS_INSERTIONSORT_THRESHOLD
       if(1 < (last - first)) { ss_insertionsort(T, PA, first, last, depth); }
 #endif
       STACK_POP(first, last, depth, limit);
       continue;
     }
 
     Td = T + depth;
     if(limit-- == 0) { ss_heapsort(Td, PA, first, last - first); }
     if(limit < 0) {
       for(a = first + 1, v = Td[PA[*first]]; a < last; ++a) {
         if((x = Td[PA[*a]]) != v) {
           if(1 < (a - first)) { break; }
           v = x;
           first = a;
         }
       }
       if(Td[PA[*first] - 1] < v) {
         first = ss_partition(PA, first, a, depth);
       }
       if((a - first) <= (last - a)) {
         if(1 < (a - first)) {
           STACK_PUSH(a, last, depth, -1);
           last = a, depth += 1, limit = ss_ilg(a - first);
         } else {
           first = a, limit = -1;
         }
       } else {
         if(1 < (last - a)) {
           STACK_PUSH(first, a, depth + 1, ss_ilg(a - first));
           first = a, limit = -1;
         } else {
           last = a, depth += 1, limit = ss_ilg(a - first);
         }
       }
       continue;
     }
 
     /* choose pivot */
     a = ss_pivot(Td, PA, first, last);
     v = Td[PA[*a]];
     SWAP(*first, *a);
 
     /* partition */
     for(b = first; (++b < last) && ((x = Td[PA[*b]]) == v);) { }
     if(((a = b) < last) && (x < v)) {
       for(; (++b < last) && ((x = Td[PA[*b]]) <= v);) {
         if(x == v) { SWAP(*b, *a); ++a; }
       }
     }
     for(c = last; (b < --c) && ((x = Td[PA[*c]]) == v);) { }
     if((b < (d = c)) && (x > v)) {
       for(; (b < --c) && ((x = Td[PA[*c]]) >= v);) {
         if(x == v) { SWAP(*c, *d); --d; }
       }
     }
     for(; b < c;) {
       SWAP(*b, *c);
       for(; (++b < c) && ((x = Td[PA[*b]]) <= v);) {
         if(x == v) { SWAP(*b, *a); ++a; }
       }
       for(; (b < --c) && ((x = Td[PA[*c]]) >= v);) {
         if(x == v) { SWAP(*c, *d); --d; }
       }
     }
 
     if(a <= d) {
       c = b - 1;
 
       if((s = a - first) > (t = b - a)) { s = t; }
       for(e = first, f = b - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
       if((s = d - c) > (t = last - d - 1)) { s = t; }
       for(e = b, f = last - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
 
       a = first + (b - a), c = last - (d - c);
       b = (v <= Td[PA[*a] - 1]) ? a : ss_partition(PA, a, c, depth);
 
       if((a - first) <= (last - c)) {
         if((last - c) <= (c - b)) {
           STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
           STACK_PUSH(c, last, depth, limit);
           last = a;
         } else if((a - first) <= (c - b)) {
           STACK_PUSH(c, last, depth, limit);
           STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
           last = a;
         } else {
           STACK_PUSH(c, last, depth, limit);
           STACK_PUSH(first, a, depth, limit);
           first = b, last = c, depth += 1, limit = ss_ilg(c - b);
         }
       } else {
         if((a - first) <= (c - b)) {
           STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
           STACK_PUSH(first, a, depth, limit);
           first = c;
         } else if((last - c) <= (c - b)) {
           STACK_PUSH(first, a, depth, limit);
           STACK_PUSH(b, c, depth + 1, ss_ilg(c - b));
           first = c;
         } else {
           STACK_PUSH(first, a, depth, limit);
           STACK_PUSH(c, last, depth, limit);
           first = b, last = c, depth += 1, limit = ss_ilg(c - b);
         }
       }
     } else {
       limit += 1;
       if(Td[PA[*first] - 1] < v) {
         first = ss_partition(PA, first, last, depth);
         limit = ss_ilg(last - first);
       }
       depth += 1;
     }
   }
 #undef STACK_SIZE
 }
 
 #endif /* (SS_BLOCKSIZE == 0) || (SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE) */
 
 
 /*---------------------------------------------------------------------------*/
 
 #if SS_BLOCKSIZE != 0
 
 static INLINE
 void
 ss_blockswap(int *a, int *b, int n) {
   int t;
   for(; 0 < n; --n, ++a, ++b) {
     t = *a, *a = *b, *b = t;
   }
 }
 
 static INLINE
 void
 ss_rotate(int *first, int *middle, int *last) {
   int *a, *b, t;
   int l, r;
   l = middle - first, r = last - middle;
   for(; (0 < l) && (0 < r);) {
     if(l == r) { ss_blockswap(first, middle, l); break; }
     if(l < r) {
       a = last - 1, b = middle - 1;
       t = *a;
       do {
         *a-- = *b, *b-- = *a;
         if(b < first) {
           *a = t;
           last = a;
           if((r -= l + 1) <= l) { break; }
           a -= 1, b = middle - 1;
           t = *a;
         }
       } while(1);
     } else {
       a = first, b = middle;
       t = *a;
       do {
         *a++ = *b, *b++ = *a;
         if(last <= b) {
           *a = t;
           first = a + 1;
           if((l -= r + 1) <= r) { break; }
           a += 1, b = middle;
           t = *a;
         }
       } while(1);
     }
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 static
 void
 ss_inplacemerge(const unsigned char *T, const int *PA,
                 int *first, int *middle, int *last,
                 int depth) {
   const int *p;
   int *a, *b;
   int len, half;
   int q, r;
   int x;
 
   for(;;) {
     if(*(last - 1) < 0) { x = 1; p = PA + ~*(last - 1); }
     else                { x = 0; p = PA +  *(last - 1); }
     for(a = first, len = middle - first, half = len >> 1, r = -1;
         0 < len;
         len = half, half >>= 1) {
       b = a + half;
       q = ss_compare(T, PA + ((0 <= *b) ? *b : ~*b), p, depth);
       if(q < 0) {
         a = b + 1;
         half -= (len & 1) ^ 1;
       } else {
         r = q;
       }
     }
     if(a < middle) {
       if(r == 0) { *a = ~*a; }
       ss_rotate(a, middle, last);
       last -= middle - a;
       middle = a;
       if(first == middle) { break; }
     }
     --last;
     if(x != 0) { while(*--last < 0) { } }
     if(middle == last) { break; }
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Merge-forward with internal buffer. */
 static
 void
 ss_mergeforward(const unsigned char *T, const int *PA,
                 int *first, int *middle, int *last,
                 int *buf, int depth) {
   int *a, *b, *c, *bufend;
   int t;
   int r;
 
   bufend = buf + (middle - first) - 1;
   ss_blockswap(buf, first, middle - first);
 
   for(t = *(a = first), b = buf, c = middle;;) {
     r = ss_compare(T, PA + *b, PA + *c, depth);
     if(r < 0) {
       do {
         *a++ = *b;
         if(bufend <= b) { *bufend = t; return; }
         *b++ = *a;
       } while(*b < 0);
     } else if(r > 0) {
       do {
         *a++ = *c, *c++ = *a;
         if(last <= c) {
           while(b < bufend) { *a++ = *b, *b++ = *a; }
           *a = *b, *b = t;
           return;
         }
       } while(*c < 0);
     } else {
       *c = ~*c;
       do {
         *a++ = *b;
         if(bufend <= b) { *bufend = t; return; }
         *b++ = *a;
       } while(*b < 0);
 
       do {
         *a++ = *c, *c++ = *a;
         if(last <= c) {
           while(b < bufend) { *a++ = *b, *b++ = *a; }
           *a = *b, *b = t;
           return;
         }
       } while(*c < 0);
     }
   }
 }
 
 /* Merge-backward with internal buffer. */
 static
 void
 ss_mergebackward(const unsigned char *T, const int *PA,
                  int *first, int *middle, int *last,
                  int *buf, int depth) {
   const int *p1, *p2;
   int *a, *b, *c, *bufend;
   int t;
   int r;
   int x;
 
   bufend = buf + (last - middle) - 1;
   ss_blockswap(buf, middle, last - middle);
 
   x = 0;
   if(*bufend < 0)       { p1 = PA + ~*bufend; x |= 1; }
   else                  { p1 = PA +  *bufend; }
   if(*(middle - 1) < 0) { p2 = PA + ~*(middle - 1); x |= 2; }
   else                  { p2 = PA +  *(middle - 1); }
   for(t = *(a = last - 1), b = bufend, c = middle - 1;;) {
     r = ss_compare(T, p1, p2, depth);
     if(0 < r) {
       if(x & 1) { do { *a-- = *b, *b-- = *a; } while(*b < 0); x ^= 1; }
       *a-- = *b;
       if(b <= buf) { *buf = t; break; }
       *b-- = *a;
       if(*b < 0) { p1 = PA + ~*b; x |= 1; }
       else       { p1 = PA +  *b; }
     } else if(r < 0) {
       if(x & 2) { do { *a-- = *c, *c-- = *a; } while(*c < 0); x ^= 2; }
       *a-- = *c, *c-- = *a;
       if(c < first) {
         while(buf < b) { *a-- = *b, *b-- = *a; }
         *a = *b, *b = t;
         break;
       }
       if(*c < 0) { p2 = PA + ~*c; x |= 2; }
       else       { p2 = PA +  *c; }
     } else {
       if(x & 1) { do { *a-- = *b, *b-- = *a; } while(*b < 0); x ^= 1; }
       *a-- = ~*b;
       if(b <= buf) { *buf = t; break; }
       *b-- = *a;
       if(x & 2) { do { *a-- = *c, *c-- = *a; } while(*c < 0); x ^= 2; }
       *a-- = *c, *c-- = *a;
       if(c < first) {
         while(buf < b) { *a-- = *b, *b-- = *a; }
         *a = *b, *b = t;
         break;
       }
       if(*b < 0) { p1 = PA + ~*b; x |= 1; }
       else       { p1 = PA +  *b; }
       if(*c < 0) { p2 = PA + ~*c; x |= 2; }
       else       { p2 = PA +  *c; }
     }
   }
 }
 
 /* D&C based merge. */
 static
 void
 ss_swapmerge(const unsigned char *T, const int *PA,
              int *first, int *middle, int *last,
              int *buf, int bufsize, int depth) {
 #define STACK_SIZE SS_SMERGE_STACKSIZE
 #define GETIDX(a) ((0 <= (a)) ? (a) : (~(a)))
 #define MERGE_CHECK(a, b, c)\
   do {\
     if(((c) & 1) ||\
        (((c) & 2) && (ss_compare(T, PA + GETIDX(*((a) - 1)), PA + *(a), depth) == 0))) {\
       *(a) = ~*(a);\
     }\
     if(((c) & 4) && ((ss_compare(T, PA + GETIDX(*((b) - 1)), PA + *(b), depth) == 0))) {\
       *(b) = ~*(b);\
     }\
   } while(0)
   struct { int *a, *b, *c; int d; } stack[STACK_SIZE];
   int *l, *r, *lm, *rm;
   int m, len, half;
   int ssize;
   int check, next;
 
   for(check = 0, ssize = 0;;) {
     if((last - middle) <= bufsize) {
       if((first < middle) && (middle < last)) {
         ss_mergebackward(T, PA, first, middle, last, buf, depth);
       }
       MERGE_CHECK(first, last, check);
       STACK_POP(first, middle, last, check);
       continue;
     }
 
     if((middle - first) <= bufsize) {
       if(first < middle) {
         ss_mergeforward(T, PA, first, middle, last, buf, depth);
       }
       MERGE_CHECK(first, last, check);
       STACK_POP(first, middle, last, check);
       continue;
     }
 
     for(m = 0, len = MIN(middle - first, last - middle), half = len >> 1;
         0 < len;
         len = half, half >>= 1) {
       if(ss_compare(T, PA + GETIDX(*(middle + m + half)),
                        PA + GETIDX(*(middle - m - half - 1)), depth) < 0) {
         m += half + 1;
         half -= (len & 1) ^ 1;
       }
     }
 
     if(0 < m) {
       lm = middle - m, rm = middle + m;
       ss_blockswap(lm, middle, m);
       l = r = middle, next = 0;
       if(rm < last) {
         if(*rm < 0) {
           *rm = ~*rm;
           if(first < lm) { for(; *--l < 0;) { } next |= 4; }
           next |= 1;
         } else if(first < lm) {
           for(; *r < 0; ++r) { }
           next |= 2;
         }
       }
 
       if((l - first) <= (last - r)) {
         STACK_PUSH(r, rm, last, (next & 3) | (check & 4));
         middle = lm, last = l, check = (check & 3) | (next & 4);
       } else {
         if((next & 2) && (r == middle)) { next ^= 6; }
         STACK_PUSH(first, lm, l, (check & 3) | (next & 4));
         first = r, middle = rm, check = (next & 3) | (check & 4);
       }
     } else {
       if(ss_compare(T, PA + GETIDX(*(middle - 1)), PA + *middle, depth) == 0) {
         *middle = ~*middle;
       }
       MERGE_CHECK(first, last, check);
       STACK_POP(first, middle, last, check);
     }
   }
 #undef STACK_SIZE
 }
 
 #endif /* SS_BLOCKSIZE != 0 */
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Substring sort */
 static
 void
 sssort(const unsigned char *T, const int *PA,
        int *first, int *last,
        int *buf, int bufsize,
        int depth, int n, int lastsuffix) {
   int *a;
 #if SS_BLOCKSIZE != 0
   int *b, *middle, *curbuf;
   int j, k, curbufsize, limit;
 #endif
   int i;
 
   if(lastsuffix != 0) { ++first; }
 
 #if SS_BLOCKSIZE == 0
   ss_mintrosort(T, PA, first, last, depth);
 #else
   if((bufsize < SS_BLOCKSIZE) &&
       (bufsize < (last - first)) &&
       (bufsize < (limit = ss_isqrt(last - first)))) {
     if(SS_BLOCKSIZE < limit) { limit = SS_BLOCKSIZE; }
     buf = middle = last - limit, bufsize = limit;
   } else {
     middle = last, limit = 0;
   }
   for(a = first, i = 0; SS_BLOCKSIZE < (middle - a); a += SS_BLOCKSIZE, ++i) {
 #if SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE
     ss_mintrosort(T, PA, a, a + SS_BLOCKSIZE, depth);
 #elif 1 < SS_BLOCKSIZE
     ss_insertionsort(T, PA, a, a + SS_BLOCKSIZE, depth);
 #endif
     curbufsize = last - (a + SS_BLOCKSIZE);
     curbuf = a + SS_BLOCKSIZE;
     if(curbufsize <= bufsize) { curbufsize = bufsize, curbuf = buf; }
     for(b = a, k = SS_BLOCKSIZE, j = i; j & 1; b -= k, k <<= 1, j >>= 1) {
       ss_swapmerge(T, PA, b - k, b, b + k, curbuf, curbufsize, depth);
     }
   }
 #if SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE
   ss_mintrosort(T, PA, a, middle, depth);
 #elif 1 < SS_BLOCKSIZE
   ss_insertionsort(T, PA, a, middle, depth);
 #endif
   for(k = SS_BLOCKSIZE; i != 0; k <<= 1, i >>= 1) {
     if(i & 1) {
       ss_swapmerge(T, PA, a - k, a, middle, buf, bufsize, depth);
       a -= k;
     }
   }
   if(limit != 0) {
 #if SS_INSERTIONSORT_THRESHOLD < SS_BLOCKSIZE
     ss_mintrosort(T, PA, middle, last, depth);
 #elif 1 < SS_BLOCKSIZE
     ss_insertionsort(T, PA, middle, last, depth);
 #endif
     ss_inplacemerge(T, PA, first, middle, last, depth);
   }
 #endif
 
   if(lastsuffix != 0) {
     /* Insert last type B* suffix. */
     int PAi[2]; PAi[0] = PA[*(first - 1)], PAi[1] = n - 2;
     for(a = first, i = *(first - 1);
         (a < last) && ((*a < 0) || (0 < ss_compare(T, &(PAi[0]), PA + *a, depth)));
         ++a) {
       *(a - 1) = *a;
     }
     *(a - 1) = i;
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 static INLINE
 int
 tr_ilg(int n) {
   return (n & 0xffff0000) ?
           ((n & 0xff000000) ?
             24 + lg_table[(n >> 24) & 0xff] :
             16 + lg_table[(n >> 16) & 0xff]) :
           ((n & 0x0000ff00) ?
              8 + lg_table[(n >>  8) & 0xff] :
              0 + lg_table[(n >>  0) & 0xff]);
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Simple insertionsort for small size groups. */
 static
 void
 tr_insertionsort(const int *ISAd, int *first, int *last) {
   int *a, *b;
   int t, r;
 
   for(a = first + 1; a < last; ++a) {
     for(t = *a, b = a - 1; 0 > (r = ISAd[t] - ISAd[*b]);) {
       do { *(b + 1) = *b; } while((first <= --b) && (*b < 0));
       if(b < first) { break; }
     }
     if(r == 0) { *b = ~*b; }
     *(b + 1) = t;
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 static INLINE
 void
 tr_fixdown(const int *ISAd, int *SA, int i, int size) {
   int j, k;
   int v;
   int c, d, e;
 
   for(v = SA[i], c = ISAd[v]; (j = 2 * i + 1) < size; SA[i] = SA[k], i = k) {
     d = ISAd[SA[k = j++]];
     if(d < (e = ISAd[SA[j]])) { k = j; d = e; }
     if(d <= c) { break; }
   }
   SA[i] = v;
 }
 
 /* Simple top-down heapsort. */
 static
 void
 tr_heapsort(const int *ISAd, int *SA, int size) {
   int i, m;
   int t;
 
   m = size;
   if((size % 2) == 0) {
     m--;
     if(ISAd[SA[m / 2]] < ISAd[SA[m]]) { SWAP(SA[m], SA[m / 2]); }
   }
 
   for(i = m / 2 - 1; 0 <= i; --i) { tr_fixdown(ISAd, SA, i, m); }
   if((size % 2) == 0) { SWAP(SA[0], SA[m]); tr_fixdown(ISAd, SA, 0, m); }
   for(i = m - 1; 0 < i; --i) {
     t = SA[0], SA[0] = SA[i];
     tr_fixdown(ISAd, SA, 0, i);
     SA[i] = t;
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Returns the median of three elements. */
 static INLINE
 int *
 tr_median3(const int *ISAd, int *v1, int *v2, int *v3) {
   int *t;
   if(ISAd[*v1] > ISAd[*v2]) { SWAP(v1, v2); }
   if(ISAd[*v2] > ISAd[*v3]) {
     if(ISAd[*v1] > ISAd[*v3]) { return v1; }
     else { return v3; }
   }
   return v2;
 }
 
 /* Returns the median of five elements. */
 static INLINE
 int *
 tr_median5(const int *ISAd,
            int *v1, int *v2, int *v3, int *v4, int *v5) {
   int *t;
   if(ISAd[*v2] > ISAd[*v3]) { SWAP(v2, v3); }
   if(ISAd[*v4] > ISAd[*v5]) { SWAP(v4, v5); }
   if(ISAd[*v2] > ISAd[*v4]) { SWAP(v2, v4); SWAP(v3, v5); }
   if(ISAd[*v1] > ISAd[*v3]) { SWAP(v1, v3); }
   if(ISAd[*v1] > ISAd[*v4]) { SWAP(v1, v4); SWAP(v3, v5); }
   if(ISAd[*v3] > ISAd[*v4]) { return v4; }
   return v3;
 }
 
 /* Returns the pivot element. */
 static INLINE
 int *
 tr_pivot(const int *ISAd, int *first, int *last) {
   int *middle;
   int t;
 
   t = last - first;
   middle = first + t / 2;
 
   if(t <= 512) {
     if(t <= 32) {
       return tr_median3(ISAd, first, middle, last - 1);
     } else {
       t >>= 2;
       return tr_median5(ISAd, first, first + t, middle, last - 1 - t, last - 1);
     }
   }
   t >>= 3;
   first  = tr_median3(ISAd, first, first + t, first + (t << 1));
   middle = tr_median3(ISAd, middle - t, middle, middle + t);
   last   = tr_median3(ISAd, last - 1 - (t << 1), last - 1 - t, last - 1);
   return tr_median3(ISAd, first, middle, last);
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 typedef struct _trbudget_t trbudget_t;
 struct _trbudget_t {
   int chance;
   int remain;
   int incval;
   int count;
 };
 
 static INLINE
 void
 trbudget_init(trbudget_t *budget, int chance, int incval) {
   budget->chance = chance;
   budget->remain = budget->incval = incval;
 }
 
 static INLINE
 int
 trbudget_check(trbudget_t *budget, int size) {
   if(size <= budget->remain) { budget->remain -= size; return 1; }
   if(budget->chance == 0) { budget->count += size; return 0; }
   budget->remain += budget->incval - size;
   budget->chance -= 1;
   return 1;
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 static INLINE
 void
 tr_partition(const int *ISAd,
              int *first, int *middle, int *last,
              int **pa, int **pb, int v) {
   int *a, *b, *c, *d, *e, *f;
   int t, s;
   int x = 0;
 
   for(b = middle - 1; (++b < last) && ((x = ISAd[*b]) == v);) { }
   if(((a = b) < last) && (x < v)) {
     for(; (++b < last) && ((x = ISAd[*b]) <= v);) {
       if(x == v) { SWAP(*b, *a); ++a; }
     }
   }
   for(c = last; (b < --c) && ((x = ISAd[*c]) == v);) { }
   if((b < (d = c)) && (x > v)) {
     for(; (b < --c) && ((x = ISAd[*c]) >= v);) {
       if(x == v) { SWAP(*c, *d); --d; }
     }
   }
   for(; b < c;) {
     SWAP(*b, *c);
     for(; (++b < c) && ((x = ISAd[*b]) <= v);) {
       if(x == v) { SWAP(*b, *a); ++a; }
     }
     for(; (b < --c) && ((x = ISAd[*c]) >= v);) {
       if(x == v) { SWAP(*c, *d); --d; }
     }
   }
 
   if(a <= d) {
     c = b - 1;
     if((s = a - first) > (t = b - a)) { s = t; }
     for(e = first, f = b - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
     if((s = d - c) > (t = last - d - 1)) { s = t; }
     for(e = b, f = last - s; 0 < s; --s, ++e, ++f) { SWAP(*e, *f); }
     first += (b - a), last -= (d - c);
   }
   *pa = first, *pb = last;
 }
 
 static
 void
 tr_copy(int *ISA, const int *SA,
         int *first, int *a, int *b, int *last,
         int depth) {
   /* sort suffixes of middle partition
      by using sorted order of suffixes of left and right partition. */
   int *c, *d, *e;
   int s, v;
 
   v = b - SA - 1;
   for(c = first, d = a - 1; c <= d; ++c) {
     if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
       *++d = s;
       ISA[s] = d - SA;
     }
   }
   for(c = last - 1, e = d + 1, d = b; e < d; --c) {
     if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
       *--d = s;
       ISA[s] = d - SA;
     }
   }
 }
 
 static
 void
 tr_partialcopy(int *ISA, const int *SA,
                int *first, int *a, int *b, int *last,
                int depth) {
   int *c, *d, *e;
   int s, v;
   int rank, lastrank, newrank = -1;
 
   v = b - SA - 1;
   lastrank = -1;
   for(c = first, d = a - 1; c <= d; ++c) {
     if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
       *++d = s;
       rank = ISA[s + depth];
       if(lastrank != rank) { lastrank = rank; newrank = d - SA; }
       ISA[s] = newrank;
     }
   }
 
   lastrank = -1;
   for(e = d; first <= e; --e) {
     rank = ISA[*e];
     if(lastrank != rank) { lastrank = rank; newrank = e - SA; }
     if(newrank != rank) { ISA[*e] = newrank; }
   }
 
   lastrank = -1;
   for(c = last - 1, e = d + 1, d = b; e < d; --c) {
     if((0 <= (s = *c - depth)) && (ISA[s] == v)) {
       *--d = s;
       rank = ISA[s + depth];
       if(lastrank != rank) { lastrank = rank; newrank = d - SA; }
       ISA[s] = newrank;
     }
   }
 }
 
 static
 void
 tr_introsort(int *ISA, const int *ISAd,
              int *SA, int *first, int *last,
              trbudget_t *budget) {
 #define STACK_SIZE TR_STACKSIZE
   struct { const int *a; int *b, *c; int d, e; }stack[STACK_SIZE];
   int *a, *b, *c;
   int t;
   int v, x = 0;
   int incr = ISAd - ISA;
   int limit, next;
   int ssize, trlink = -1;
 
   for(ssize = 0, limit = tr_ilg(last - first);;) {
 
     if(limit < 0) {
       if(limit == -1) {
         /* tandem repeat partition */
         tr_partition(ISAd - incr, first, first, last, &a, &b, last - SA - 1);
 
         /* update ranks */
         if(a < last) {
           for(c = first, v = a - SA - 1; c < a; ++c) { ISA[*c] = v; }
         }
         if(b < last) {
           for(c = a, v = b - SA - 1; c < b; ++c) { ISA[*c] = v; }
         }
 
         /* push */
         if(1 < (b - a)) {
           STACK_PUSH5(NULL, a, b, 0, 0);
           STACK_PUSH5(ISAd - incr, first, last, -2, trlink);
           trlink = ssize - 2;
         }
         if((a - first) <= (last - b)) {
           if(1 < (a - first)) {
             STACK_PUSH5(ISAd, b, last, tr_ilg(last - b), trlink);
             last = a, limit = tr_ilg(a - first);
           } else if(1 < (last - b)) {
             first = b, limit = tr_ilg(last - b);
           } else {
             STACK_POP5(ISAd, first, last, limit, trlink);
           }
         } else {
           if(1 < (last - b)) {
             STACK_PUSH5(ISAd, first, a, tr_ilg(a - first), trlink);
             first = b, limit = tr_ilg(last - b);
           } else if(1 < (a - first)) {
             last = a, limit = tr_ilg(a - first);
           } else {
             STACK_POP5(ISAd, first, last, limit, trlink);
           }
         }
       } else if(limit == -2) {
         /* tandem repeat copy */
         a = stack[--ssize].b, b = stack[ssize].c;
         if(stack[ssize].d == 0) {
           tr_copy(ISA, SA, first, a, b, last, ISAd - ISA);
         } else {
           if(0 <= trlink) { stack[trlink].d = -1; }
           tr_partialcopy(ISA, SA, first, a, b, last, ISAd - ISA);
         }
         STACK_POP5(ISAd, first, last, limit, trlink);
       } else {
         /* sorted partition */
         if(0 <= *first) {
           a = first;
           do { ISA[*a] = a - SA; } while((++a < last) && (0 <= *a));
           first = a;
         }
         if(first < last) {
           a = first; do { *a = ~*a; } while(*++a < 0);
           next = (ISA[*a] != ISAd[*a]) ? tr_ilg(a - first + 1) : -1;
           if(++a < last) { for(b = first, v = a - SA - 1; b < a; ++b) { ISA[*b] = v; } }
 
           /* push */
           if(trbudget_check(budget, a - first)) {
             if((a - first) <= (last - a)) {
               STACK_PUSH5(ISAd, a, last, -3, trlink);
               ISAd += incr, last = a, limit = next;
             } else {
               if(1 < (last - a)) {
                 STACK_PUSH5(ISAd + incr, first, a, next, trlink);
                 first = a, limit = -3;
               } else {
                 ISAd += incr, last = a, limit = next;
               }
             }
           } else {
             if(0 <= trlink) { stack[trlink].d = -1; }
             if(1 < (last - a)) {
               first = a, limit = -3;
             } else {
               STACK_POP5(ISAd, first, last, limit, trlink);
             }
           }
         } else {
           STACK_POP5(ISAd, first, last, limit, trlink);
         }
       }
       continue;
     }
 
     if((last - first) <= TR_INSERTIONSORT_THRESHOLD) {
       tr_insertionsort(ISAd, first, last);
       limit = -3;
       continue;
     }
 
     if(limit-- == 0) {
       tr_heapsort(ISAd, first, last - first);
       for(a = last - 1; first < a; a = b) {
         for(x = ISAd[*a], b = a - 1; (first <= b) && (ISAd[*b] == x); --b) { *b = ~*b; }
       }
       limit = -3;
       continue;
     }
 
     /* choose pivot */
     a = tr_pivot(ISAd, first, last);
     SWAP(*first, *a);
     v = ISAd[*first];
 
     /* partition */
     tr_partition(ISAd, first, first + 1, last, &a, &b, v);
     if((last - first) != (b - a)) {
       next = (ISA[*a] != v) ? tr_ilg(b - a) : -1;
 
       /* update ranks */
       for(c = first, v = a - SA - 1; c < a; ++c) { ISA[*c] = v; }
       if(b < last) { for(c = a, v = b - SA - 1; c < b; ++c) { ISA[*c] = v; } }
 
       /* push */
       if((1 < (b - a)) && (trbudget_check(budget, b - a))) {
         if((a - first) <= (last - b)) {
           if((last - b) <= (b - a)) {
             if(1 < (a - first)) {
               STACK_PUSH5(ISAd + incr, a, b, next, trlink);
               STACK_PUSH5(ISAd, b, last, limit, trlink);
               last = a;
             } else if(1 < (last - b)) {
               STACK_PUSH5(ISAd + incr, a, b, next, trlink);
               first = b;
             } else {
               ISAd += incr, first = a, last = b, limit = next;
             }
           } else if((a - first) <= (b - a)) {
             if(1 < (a - first)) {
               STACK_PUSH5(ISAd, b, last, limit, trlink);
               STACK_PUSH5(ISAd + incr, a, b, next, trlink);
               last = a;
             } else {
               STACK_PUSH5(ISAd, b, last, limit, trlink);
               ISAd += incr, first = a, last = b, limit = next;
             }
           } else {
             STACK_PUSH5(ISAd, b, last, limit, trlink);
             STACK_PUSH5(ISAd, first, a, limit, trlink);
             ISAd += incr, first = a, last = b, limit = next;
           }
         } else {
           if((a - first) <= (b - a)) {
             if(1 < (last - b)) {
               STACK_PUSH5(ISAd + incr, a, b, next, trlink);
               STACK_PUSH5(ISAd, first, a, limit, trlink);
               first = b;
             } else if(1 < (a - first)) {
               STACK_PUSH5(ISAd + incr, a, b, next, trlink);
               last = a;
             } else {
               ISAd += incr, first = a, last = b, limit = next;
             }
           } else if((last - b) <= (b - a)) {
             if(1 < (last - b)) {
               STACK_PUSH5(ISAd, first, a, limit, trlink);
               STACK_PUSH5(ISAd + incr, a, b, next, trlink);
               first = b;
             } else {
               STACK_PUSH5(ISAd, first, a, limit, trlink);
               ISAd += incr, first = a, last = b, limit = next;
             }
           } else {
             STACK_PUSH5(ISAd, first, a, limit, trlink);
             STACK_PUSH5(ISAd, b, last, limit, trlink);
             ISAd += incr, first = a, last = b, limit = next;
           }
         }
       } else {
         if((1 < (b - a)) && (0 <= trlink)) { stack[trlink].d = -1; }
         if((a - first) <= (last - b)) {
           if(1 < (a - first)) {
             STACK_PUSH5(ISAd, b, last, limit, trlink);
             last = a;
           } else if(1 < (last - b)) {
             first = b;
           } else {
             STACK_POP5(ISAd, first, last, limit, trlink);
           }
         } else {
           if(1 < (last - b)) {
             STACK_PUSH5(ISAd, first, a, limit, trlink);
             first = b;
           } else if(1 < (a - first)) {
             last = a;
           } else {
             STACK_POP5(ISAd, first, last, limit, trlink);
           }
         }
       }
     } else {
       if(trbudget_check(budget, last - first)) {
         limit = tr_ilg(last - first), ISAd += incr;
       } else {
         if(0 <= trlink) { stack[trlink].d = -1; }
         STACK_POP5(ISAd, first, last, limit, trlink);
       }
     }
   }
 #undef STACK_SIZE
 }
 
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Tandem repeat sort */
 static
 void
 trsort(int *ISA, int *SA, int n, int depth) {
   int *ISAd;
   int *first, *last;
   trbudget_t budget;
   int t, skip, unsorted;
 
   trbudget_init(&budget, tr_ilg(n) * 2 / 3, n);
 /*  trbudget_init(&budget, tr_ilg(n) * 3 / 4, n); */
   for(ISAd = ISA + depth; -n < *SA; ISAd += ISAd - ISA) {
     first = SA;
     skip = 0;
     unsorted = 0;
     do {
       if((t = *first) < 0) { first -= t; skip += t; }
       else {
         if(skip != 0) { *(first + skip) = skip; skip = 0; }
         last = SA + ISA[t] + 1;
         if(1 < (last - first)) {
           budget.count = 0;
           tr_introsort(ISA, ISAd, SA, first, last, &budget);
           if(budget.count != 0) { unsorted += budget.count; }
           else { skip = first - last; }
         } else if((last - first) == 1) {
           skip = -1;
         }
         first = last;
       }
     } while(first < (SA + n));
     if(skip != 0) { *(first + skip) = skip; }
     if(unsorted == 0) { break; }
   }
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /* Sorts suffixes of type B*. */
 static
 int
 sort_typeBstar(const unsigned char *T, int *SA,
                int *bucket_A, int *bucket_B,
                int n, int openMP) {
   int *PAb, *ISAb, *buf;
 #ifdef LIBBSC_OPENMP
   int *curbuf;
   int l;
 #endif
   int i, j, k, t, m, bufsize;
   int c0, c1;
 #ifdef LIBBSC_OPENMP
   int d0, d1;
 #endif
   (void)openMP;
 
   /* Initialize bucket arrays. */
   for(i = 0; i < BUCKET_A_SIZE; ++i) { bucket_A[i] = 0; }
   for(i = 0; i < BUCKET_B_SIZE; ++i) { bucket_B[i] = 0; }
 
   /* Count the number of occurrences of the first one or two characters of each
      type A, B and B* suffix. Moreover, store the beginning position of all
      type B* suffixes into the array SA. */
   for(i = n - 1, m = n, c0 = T[n - 1]; 0 <= i;) {
     /* type A suffix. */
     do { ++BUCKET_A(c1 = c0); } while((0 <= --i) && ((c0 = T[i]) >= c1));
     if(0 <= i) {
       /* type B* suffix. */
       ++BUCKET_BSTAR(c0, c1);
       SA[--m] = i;
       /* type B suffix. */
       for(--i, c1 = c0; (0 <= i) && ((c0 = T[i]) <= c1); --i, c1 = c0) {
         ++BUCKET_B(c0, c1);
       }
     }
   }
   m = n - m;
 /*
 note:
   A type B* suffix is lexicographically smaller than a type B suffix that
   begins with the same first two characters.
 */
 
   /* Calculate the index of start/end point of each bucket. */
   for(c0 = 0, i = 0, j = 0; c0 < ALPHABET_SIZE; ++c0) {
     t = i + BUCKET_A(c0);
     BUCKET_A(c0) = i + j; /* start point */
     i = t + BUCKET_B(c0, c0);
     for(c1 = c0 + 1; c1 < ALPHABET_SIZE; ++c1) {
       j += BUCKET_BSTAR(c0, c1);
       BUCKET_BSTAR(c0, c1) = j; /* end point */
       i += BUCKET_B(c0, c1);
     }
   }
 
   if(0 < m) {
     /* Sort the type B* suffixes by their first two characters. */
     PAb = SA + n - m; ISAb = SA + m;
     for(i = m - 2; 0 <= i; --i) {
       t = PAb[i], c0 = T[t], c1 = T[t + 1];
       SA[--BUCKET_BSTAR(c0, c1)] = i;
     }
     t = PAb[m - 1], c0 = T[t], c1 = T[t + 1];
     SA[--BUCKET_BSTAR(c0, c1)] = m - 1;
 
     /* Sort the type B* substrings using sssort. */
 #ifdef LIBBSC_OPENMP
     if (openMP)
     {
         buf = SA + m;
         c0 = ALPHABET_SIZE - 2, c1 = ALPHABET_SIZE - 1, j = m;
 #pragma omp parallel default(shared) private(bufsize, curbuf, k, l, d0, d1)
         {
           bufsize = (n - (2 * m)) / omp_get_num_threads();
           curbuf = buf + omp_get_thread_num() * bufsize;
           k = 0;
           for(;;) {
             #pragma omp critical(sssort_lock)
             {
               if(0 < (l = j)) {
                 d0 = c0, d1 = c1;
                 do {
                   k = BUCKET_BSTAR(d0, d1);
                   if(--d1 <= d0) {
                     d1 = ALPHABET_SIZE - 1;
                     if(--d0 < 0) { break; }
                   }
                 } while(((l - k) <= 1) && (0 < (l = k)));
                 c0 = d0, c1 = d1, j = k;
               }
             }
             if(l == 0) { break; }
             sssort(T, PAb, SA + k, SA + l,
                    curbuf, bufsize, 2, n, *(SA + k) == (m - 1));
           }
         }
     }
     else
     {
         buf = SA + m, bufsize = n - (2 * m);
         for(c0 = ALPHABET_SIZE - 2, j = m; 0 < j; --c0) {
           for(c1 = ALPHABET_SIZE - 1; c0 < c1; j = i, --c1) {
             i = BUCKET_BSTAR(c0, c1);
             if(1 < (j - i)) {
               sssort(T, PAb, SA + i, SA + j,
                      buf, bufsize, 2, n, *(SA + i) == (m - 1));
             }
           }
         }
     }
 #else
     buf = SA + m, bufsize = n - (2 * m);
     for(c0 = ALPHABET_SIZE - 2, j = m; 0 < j; --c0) {
       for(c1 = ALPHABET_SIZE - 1; c0 < c1; j = i, --c1) {
         i = BUCKET_BSTAR(c0, c1);
         if(1 < (j - i)) {
           sssort(T, PAb, SA + i, SA + j,
                  buf, bufsize, 2, n, *(SA + i) == (m - 1));
         }
       }
     }
 #endif
 
     /* Compute ranks of type B* substrings. */
     for(i = m - 1; 0 <= i; --i) {
       if(0 <= SA[i]) {
         j = i;
         do { ISAb[SA[i]] = i; } while((0 <= --i) && (0 <= SA[i]));
         SA[i + 1] = i - j;
         if(i <= 0) { break; }
       }
       j = i;
       do { ISAb[SA[i] = ~SA[i]] = j; } while(SA[--i] < 0);
       ISAb[SA[i]] = j;
     }
 
     /* Construct the inverse suffix array of type B* suffixes using trsort. */
     trsort(ISAb, SA, m, 1);
 
     /* Set the sorted order of tyoe B* suffixes. */
     for(i = n - 1, j = m, c0 = T[n - 1]; 0 <= i;) {
       for(--i, c1 = c0; (0 <= i) && ((c0 = T[i]) >= c1); --i, c1 = c0) { }
       if(0 <= i) {
         t = i;
         for(--i, c1 = c0; (0 <= i) && ((c0 = T[i]) <= c1); --i, c1 = c0) { }
         SA[ISAb[--j]] = ((t == 0) || (1 < (t - i))) ? t : ~t;
       }
     }
 
     /* Calculate the index of start/end point of each bucket. */
     BUCKET_B(ALPHABET_SIZE - 1, ALPHABET_SIZE - 1) = n; /* end point */
     for(c0 = ALPHABET_SIZE - 2, k = m - 1; 0 <= c0; --c0) {
       i = BUCKET_A(c0 + 1) - 1;
       for(c1 = ALPHABET_SIZE - 1; c0 < c1; --c1) {
         t = i - BUCKET_B(c0, c1);
         BUCKET_B(c0, c1) = i; /* end point */
 
         /* Move all type B* suffixes to the correct position. */
         for(i = t, j = BUCKET_BSTAR(c0, c1);
             j <= k;
             --i, --k) { SA[i] = SA[k]; }
       }
       BUCKET_BSTAR(c0, c0 + 1) = i - BUCKET_B(c0, c0) + 1; /* start point */
       BUCKET_B(c0, c0) = i; /* end point */
     }
   }
 
   return m;
 }
 
 /* Constructs the suffix array by using the sorted order of type B* suffixes. */
 static
 void
 construct_SA(const unsigned char *T, int *SA,
              int *bucket_A, int *bucket_B,
              int n, int m) {
   int *i, *j, *k;
   int s;
   int c0, c1, c2;
 
   if(0 < m) {
     /* Construct the sorted order of type B suffixes by using
        the sorted order of type B* suffixes. */
     for(c1 = ALPHABET_SIZE - 2; 0 <= c1; --c1) {
       /* Scan the suffix array from right to left. */
       for(i = SA + BUCKET_BSTAR(c1, c1 + 1),
           j = SA + BUCKET_A(c1 + 1) - 1, k = NULL, c2 = -1;
           i <= j;
           --j) {
         if(0 < (s = *j)) {
           assert(T[s] == c1);
           assert(((s + 1) < n) && (T[s] <= T[s + 1]));
           assert(T[s - 1] <= T[s]);
           *j = ~s;
           c0 = T[--s];
           if((0 < s) && (T[s - 1] > c0)) { s = ~s; }
           if(c0 != c2) {
             if(0 <= c2) { BUCKET_B(c2, c1) = k - SA; }
             k = SA + BUCKET_B(c2 = c0, c1);
           }
-          assert(k < j);
+          assert(k < j); assert(k != NULL);
           *k-- = s;
         } else {
           assert(((s == 0) && (T[s] == c1)) || (s < 0));
           *j = ~s;
         }
       }
     }
   }
 
   /* Construct the suffix array by using
      the sorted order of type B suffixes. */
   k = SA + BUCKET_A(c2 = T[n - 1]);
   *k++ = (T[n - 2] < c2) ? ~(n - 1) : (n - 1);
   /* Scan the suffix array from left to right. */
   for(i = SA, j = SA + n; i < j; ++i) {
     if(0 < (s = *i)) {
       assert(T[s - 1] >= T[s]);
       c0 = T[--s];
       if((s == 0) || (T[s - 1] < c0)) { s = ~s; }
       if(c0 != c2) {
         BUCKET_A(c2) = k - SA;
         k = SA + BUCKET_A(c2 = c0);
       }
       assert(i < k);
       *k++ = s;
     } else {
       assert(s < 0);
       *i = ~s;
     }
   }
 }
 
 /* Constructs the burrows-wheeler transformed string directly
    by using the sorted order of type B* suffixes. */
 static
 int
 construct_BWT(const unsigned char *T, int *SA,
               int *bucket_A, int *bucket_B,
               int n, int m) {
   int *i, *j, *k, *orig;
   int s;
   int c0, c1, c2;
 
   if(0 < m) {
     /* Construct the sorted order of type B suffixes by using
        the sorted order of type B* suffixes. */
     for(c1 = ALPHABET_SIZE - 2; 0 <= c1; --c1) {
       /* Scan the suffix array from right to left. */
       for(i = SA + BUCKET_BSTAR(c1, c1 + 1),
           j = SA + BUCKET_A(c1 + 1) - 1, k = NULL, c2 = -1;
           i <= j;
           --j) {
         if(0 < (s = *j)) {
           assert(T[s] == c1);
           assert(((s + 1) < n) && (T[s] <= T[s + 1]));
           assert(T[s - 1] <= T[s]);
           c0 = T[--s];
           *j = ~((int)c0);
           if((0 < s) && (T[s - 1] > c0)) { s = ~s; }
           if(c0 != c2) {
             if(0 <= c2) { BUCKET_B(c2, c1) = k - SA; }
             k = SA + BUCKET_B(c2 = c0, c1);
           }
-          assert(k < j);
+          assert(k < j); assert(k != NULL);
           *k-- = s;
         } else if(s != 0) {
           *j = ~s;
 #ifndef NDEBUG
         } else {
           assert(T[s] == c1);
 #endif
         }
       }
     }
   }
 
   /* Construct the BWTed string by using
      the sorted order of type B suffixes. */
   k = SA + BUCKET_A(c2 = T[n - 1]);
   *k++ = (T[n - 2] < c2) ? ~((int)T[n - 2]) : (n - 1);
   /* Scan the suffix array from left to right. */
   for(i = SA, j = SA + n, orig = SA; i < j; ++i) {
     if(0 < (s = *i)) {
       assert(T[s - 1] >= T[s]);
       c0 = T[--s];
       *i = c0;
       if((0 < s) && (T[s - 1] < c0)) { s = ~((int)T[s - 1]); }
       if(c0 != c2) {
         BUCKET_A(c2) = k - SA;
         k = SA + BUCKET_A(c2 = c0);
       }
       assert(i < k);
       *k++ = s;
     } else if(s != 0) {
       *i = ~s;
     } else {
       orig = i;
     }
   }
 
   return orig - SA;
 }
 
 /* Constructs the burrows-wheeler transformed string directly
    by using the sorted order of type B* suffixes. */
 static
 int
 construct_BWT_indexes(const unsigned char *T, int *SA,
                       int *bucket_A, int *bucket_B,
                       int n, int m,
                       unsigned char * num_indexes, int * indexes) {
   int *i, *j, *k, *orig;
   int s;
   int c0, c1, c2;
 
   int mod = n / 8;
   {
       mod |= mod >> 1;  mod |= mod >> 2;
       mod |= mod >> 4;  mod |= mod >> 8;
       mod |= mod >> 16; mod >>= 1;
 
       *num_indexes = (unsigned char)((n - 1) / (mod + 1));
   }
 
   if(0 < m) {
     /* Construct the sorted order of type B suffixes by using
        the sorted order of type B* suffixes. */
     for(c1 = ALPHABET_SIZE - 2; 0 <= c1; --c1) {
       /* Scan the suffix array from right to left. */
       for(i = SA + BUCKET_BSTAR(c1, c1 + 1),
           j = SA + BUCKET_A(c1 + 1) - 1, k = NULL, c2 = -1;
           i <= j;
           --j) {
         if(0 < (s = *j)) {
           assert(T[s] == c1);
           assert(((s + 1) < n) && (T[s] <= T[s + 1]));
           assert(T[s - 1] <= T[s]);
 
           if ((s & mod) == 0) indexes[s / (mod + 1) - 1] = j - SA;
 
           c0 = T[--s];
           *j = ~((int)c0);
           if((0 < s) && (T[s - 1] > c0)) { s = ~s; }
           if(c0 != c2) {
             if(0 <= c2) { BUCKET_B(c2, c1) = k - SA; }
             k = SA + BUCKET_B(c2 = c0, c1);
           }
-          assert(k < j);
+          assert(k < j); assert(k != NULL);
           *k-- = s;
         } else if(s != 0) {
           *j = ~s;
 #ifndef NDEBUG
         } else {
           assert(T[s] == c1);
 #endif
         }
       }
     }
   }
 
   /* Construct the BWTed string by using
      the sorted order of type B suffixes. */
   k = SA + BUCKET_A(c2 = T[n - 1]);
   if (T[n - 2] < c2) {
     if (((n - 1) & mod) == 0) indexes[(n - 1) / (mod + 1) - 1] = k - SA;
     *k++ = ~((int)T[n - 2]);
   }
   else {
     *k++ = n - 1;
   }
 
   /* Scan the suffix array from left to right. */
   for(i = SA, j = SA + n, orig = SA; i < j; ++i) {
     if(0 < (s = *i)) {
       assert(T[s - 1] >= T[s]);
 
       if ((s & mod) == 0) indexes[s / (mod + 1) - 1] = i - SA;
 
       c0 = T[--s];
       *i = c0;
       if(c0 != c2) {
         BUCKET_A(c2) = k - SA;
         k = SA + BUCKET_A(c2 = c0);
       }
       assert(i < k);
       if((0 < s) && (T[s - 1] < c0)) {
           if ((s & mod) == 0) indexes[s / (mod + 1) - 1] = k - SA;
           *k++ = ~((int)T[s - 1]);
       } else
         *k++ = s;
     } else if(s != 0) {
       *i = ~s;
     } else {
       orig = i;
     }
   }
 
   return orig - SA;
 }
 
 
 /*---------------------------------------------------------------------------*/
 
 /*- Function -*/
 
 int
 divsufsort(const unsigned char *T, int *SA, int n, int openMP) {
   int *bucket_A, *bucket_B;
   int m;
   int err = 0;
 
   /* Check arguments. */
   if((T == NULL) || (SA == NULL) || (n < 0)) { return -1; }
   else if(n == 0) { return 0; }
   else if(n == 1) { SA[0] = 0; return 0; }
   else if(n == 2) { m = (T[0] < T[1]); SA[m ^ 1] = 0, SA[m] = 1; return 0; }
 
   bucket_A = (int *)malloc(BUCKET_A_SIZE * sizeof(int));
   bucket_B = (int *)malloc(BUCKET_B_SIZE * sizeof(int));
 
   /* Suffixsort. */
   if((bucket_A != NULL) && (bucket_B != NULL)) {
     m = sort_typeBstar(T, SA, bucket_A, bucket_B, n, openMP);
     construct_SA(T, SA, bucket_A, bucket_B, n, m);
   } else {
     err = -2;
   }
 
   free(bucket_B);
   free(bucket_A);
 
   return err;
 }
 
 int
 divbwt(const unsigned char *T, unsigned char *U, int *A, int n, unsigned char * num_indexes, int * indexes, int openMP) {
   int *B;
   int *bucket_A, *bucket_B;
   int m, pidx, i;
 
   /* Check arguments. */
   if((T == NULL) || (U == NULL) || (n < 0)) { return -1; }
   else if(n <= 1) { if(n == 1) { U[0] = T[0]; } return n; }
 
   if((B = A) == NULL) { B = (int *)malloc((size_t)(n + 1) * sizeof(int)); }
   bucket_A = (int *)malloc(BUCKET_A_SIZE * sizeof(int));
   bucket_B = (int *)malloc(BUCKET_B_SIZE * sizeof(int));
 
   /* Burrows-Wheeler Transform. */
   if((B != NULL) && (bucket_A != NULL) && (bucket_B != NULL)) {
     m = sort_typeBstar(T, B, bucket_A, bucket_B, n, openMP);
 
     if (num_indexes == NULL || indexes == NULL) {
         pidx = construct_BWT(T, B, bucket_A, bucket_B, n, m);
     } else {
         pidx = construct_BWT_indexes(T, B, bucket_A, bucket_B, n, m, num_indexes, indexes);
     }
 
     /* Copy to output string. */
     U[0] = T[n - 1];
     for(i = 0; i < pidx; ++i) { U[i + 1] = (unsigned char)B[i]; }
     for(i += 1; i < n; ++i) { U[i] = (unsigned char)B[i]; }
     pidx += 1;
   } else {
     pidx = -2;
   }
 
   free(bucket_B);
   free(bucket_A);
   if(A == NULL) { free(B); }
 
   return pidx;
 }
Index: vendor/zstd/dist/lib/dictBuilder/fastcover.c
===================================================================
--- vendor/zstd/dist/lib/dictBuilder/fastcover.c	(nonexistent)
+++ vendor/zstd/dist/lib/dictBuilder/fastcover.c	(revision 339614)
@@ -0,0 +1,728 @@
+/*-*************************************
+*  Dependencies
+***************************************/
+#include   /* fprintf */
+#include  /* malloc, free, qsort */
+#include  /* memset */
+#include    /* clock */
+
+#include "mem.h" /* read */
+#include "pool.h"
+#include "threading.h"
+#include "cover.h"
+#include "zstd_internal.h" /* includes zstd.h */
+#ifndef ZDICT_STATIC_LINKING_ONLY
+#define ZDICT_STATIC_LINKING_ONLY
+#endif
+#include "zdict.h"
+
+
+/*-*************************************
+*  Constants
+***************************************/
+#define FASTCOVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((U32)-1) : ((U32)1 GB))
+#define FASTCOVER_MAX_F 31
+#define FASTCOVER_MAX_ACCEL 10
+#define DEFAULT_SPLITPOINT 0.75
+#define DEFAULT_F 20
+#define DEFAULT_ACCEL 1
+
+
+/*-*************************************
+*  Console display
+***************************************/
+static int g_displayLevel = 2;
+#define DISPLAY(...)                                                           \
+  {                                                                            \
+    fprintf(stderr, __VA_ARGS__);                                              \
+    fflush(stderr);                                                            \
+  }
+#define LOCALDISPLAYLEVEL(displayLevel, l, ...)                                \
+  if (displayLevel >= l) {                                                     \
+    DISPLAY(__VA_ARGS__);                                                      \
+  } /* 0 : no display;   1: errors;   2: default;  3: details;  4: debug */
+#define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
+
+#define LOCALDISPLAYUPDATE(displayLevel, l, ...)                               \
+  if (displayLevel >= l) {                                                     \
+    if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) {             \
+      g_time = clock();                                                        \
+      DISPLAY(__VA_ARGS__);                                                    \
+    }                                                                          \
+  }
+#define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
+static const clock_t refreshRate = CLOCKS_PER_SEC * 15 / 100;
+static clock_t g_time = 0;
+
+
+/*-*************************************
+* Hash Functions
+***************************************/
+static const U64 prime6bytes = 227718039650203ULL;
+static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u  << (64-48)) * prime6bytes) >> (64-h)) ; }
+static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
+
+static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
+static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
+static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
+
+
+/**
+ * Hash the d-byte value pointed to by p and mod 2^f
+ */
+static size_t FASTCOVER_hashPtrToIndex(const void* p, U32 h, unsigned d) {
+  if (d == 6) {
+    return ZSTD_hash6Ptr(p, h) & ((1 << h) - 1);
+  }
+  return ZSTD_hash8Ptr(p, h) & ((1 << h) - 1);
+}
+
+
+/*-*************************************
+* Acceleration
+***************************************/
+typedef struct {
+  unsigned finalize;    /* Percentage of training samples used for ZDICT_finalizeDictionary */
+  unsigned skip;        /* Number of dmer skipped between each dmer counted in computeFrequency */
+} FASTCOVER_accel_t;
+
+
+static const FASTCOVER_accel_t FASTCOVER_defaultAccelParameters[FASTCOVER_MAX_ACCEL+1] = {
+  { 100, 0 },   /* accel = 0, should not happen because accel = 0 defaults to accel = 1 */
+  { 100, 0 },   /* accel = 1 */
+  { 50, 1 },   /* accel = 2 */
+  { 34, 2 },   /* accel = 3 */
+  { 25, 3 },   /* accel = 4 */
+  { 20, 4 },   /* accel = 5 */
+  { 17, 5 },   /* accel = 6 */
+  { 14, 6 },   /* accel = 7 */
+  { 13, 7 },   /* accel = 8 */
+  { 11, 8 },   /* accel = 9 */
+  { 10, 9 },   /* accel = 10 */
+};
+
+
+/*-*************************************
+* Context
+***************************************/
+typedef struct {
+  const BYTE *samples;
+  size_t *offsets;
+  const size_t *samplesSizes;
+  size_t nbSamples;
+  size_t nbTrainSamples;
+  size_t nbTestSamples;
+  size_t nbDmers;
+  U32 *freqs;
+  unsigned d;
+  unsigned f;
+  FASTCOVER_accel_t accelParams;
+} FASTCOVER_ctx_t;
+
+
+/*-*************************************
+*  Helper functions
+***************************************/
+/**
+ * Selects the best segment in an epoch.
+ * Segments of are scored according to the function:
+ *
+ * Let F(d) be the frequency of all dmers with hash value d.
+ * Let S_i be hash value of the dmer at position i of segment S which has length k.
+ *
+ *     Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1})
+ *
+ * Once the dmer with hash value d is in the dictionay we set F(d) = 0.
+ */
+static COVER_segment_t FASTCOVER_selectSegment(const FASTCOVER_ctx_t *ctx,
+                                              U32 *freqs, U32 begin, U32 end,
+                                              ZDICT_cover_params_t parameters,
+                                              U16* segmentFreqs) {
+  /* Constants */
+  const U32 k = parameters.k;
+  const U32 d = parameters.d;
+  const U32 f = ctx->f;
+  const U32 dmersInK = k - d + 1;
+
+  /* Try each segment (activeSegment) and save the best (bestSegment) */
+  COVER_segment_t bestSegment = {0, 0, 0};
+  COVER_segment_t activeSegment;
+
+  /* Reset the activeDmers in the segment */
+  /* The activeSegment starts at the beginning of the epoch. */
+  activeSegment.begin = begin;
+  activeSegment.end = begin;
+  activeSegment.score = 0;
+
+  /* Slide the activeSegment through the whole epoch.
+   * Save the best segment in bestSegment.
+   */
+  while (activeSegment.end < end) {
+    /* Get hash value of current dmer */
+    const size_t index = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.end, f, d);
+
+    /* Add frequency of this index to score if this is the first occurence of index in active segment */
+    if (segmentFreqs[index] == 0) {
+      activeSegment.score += freqs[index];
+    }
+    /* Increment end of segment and segmentFreqs*/
+    activeSegment.end += 1;
+    segmentFreqs[index] += 1;
+    /* If the window is now too large, drop the first position */
+    if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
+      /* Get hash value of the dmer to be eliminated from active segment */
+      const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
+      segmentFreqs[delIndex] -= 1;
+      /* Subtract frequency of this index from score if this is the last occurrence of this index in active segment */
+      if (segmentFreqs[delIndex] == 0) {
+        activeSegment.score -= freqs[delIndex];
+      }
+      /* Increment start of segment */
+      activeSegment.begin += 1;
+    }
+
+    /* If this segment is the best so far save it */
+    if (activeSegment.score > bestSegment.score) {
+      bestSegment = activeSegment;
+    }
+  }
+
+  /* Zero out rest of segmentFreqs array */
+  while (activeSegment.begin < end) {
+    const size_t delIndex = FASTCOVER_hashPtrToIndex(ctx->samples + activeSegment.begin, f, d);
+    segmentFreqs[delIndex] -= 1;
+    activeSegment.begin += 1;
+  }
+
+  {
+    /*  Zero the frequency of hash value of each dmer covered by the chosen segment. */
+    U32 pos;
+    for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
+      const size_t i = FASTCOVER_hashPtrToIndex(ctx->samples + pos, f, d);
+      freqs[i] = 0;
+    }
+  }
+
+  return bestSegment;
+}
+
+
+static int FASTCOVER_checkParameters(ZDICT_cover_params_t parameters,
+                                     size_t maxDictSize, unsigned f,
+                                     unsigned accel) {
+  /* k, d, and f are required parameters */
+  if (parameters.d == 0 || parameters.k == 0) {
+    return 0;
+  }
+  /* d has to be 6 or 8 */
+  if (parameters.d != 6 && parameters.d != 8) {
+    return 0;
+  }
+  /* k <= maxDictSize */
+  if (parameters.k > maxDictSize) {
+    return 0;
+  }
+  /* d <= k */
+  if (parameters.d > parameters.k) {
+    return 0;
+  }
+  /* 0 < f <= FASTCOVER_MAX_F*/
+  if (f > FASTCOVER_MAX_F || f == 0) {
+    return 0;
+  }
+  /* 0 < splitPoint <= 1 */
+  if (parameters.splitPoint <= 0 || parameters.splitPoint > 1) {
+    return 0;
+  }
+  /* 0 < accel <= 10 */
+  if (accel > 10 || accel == 0) {
+    return 0;
+  }
+  return 1;
+}
+
+
+/**
+ * Clean up a context initialized with `FASTCOVER_ctx_init()`.
+ */
+static void
+FASTCOVER_ctx_destroy(FASTCOVER_ctx_t* ctx)
+{
+    if (!ctx) return;
+
+    free(ctx->freqs);
+    ctx->freqs = NULL;
+
+    free(ctx->offsets);
+    ctx->offsets = NULL;
+}
+
+
+/**
+ * Calculate for frequency of hash value of each dmer in ctx->samples
+ */
+static void
+FASTCOVER_computeFrequency(U32* freqs, const FASTCOVER_ctx_t* ctx)
+{
+    const unsigned f = ctx->f;
+    const unsigned d = ctx->d;
+    const unsigned skip = ctx->accelParams.skip;
+    const unsigned readLength = MAX(d, 8);
+    size_t i;
+    assert(ctx->nbTrainSamples >= 5);
+    assert(ctx->nbTrainSamples <= ctx->nbSamples);
+    for (i = 0; i < ctx->nbTrainSamples; i++) {
+        size_t start = ctx->offsets[i];  /* start of current dmer */
+        size_t const currSampleEnd = ctx->offsets[i+1];
+        while (start + readLength <= currSampleEnd) {
+            const size_t dmerIndex = FASTCOVER_hashPtrToIndex(ctx->samples + start, f, d);
+            freqs[dmerIndex]++;
+            start = start + skip + 1;
+        }
+    }
+}
+
+
+/**
+ * Prepare a context for dictionary building.
+ * The context is only dependent on the parameter `d` and can used multiple
+ * times.
+ * Returns 1 on success or zero on error.
+ * The context must be destroyed with `FASTCOVER_ctx_destroy()`.
+ */
+static int
+FASTCOVER_ctx_init(FASTCOVER_ctx_t* ctx,
+                   const void* samplesBuffer,
+                   const size_t* samplesSizes, unsigned nbSamples,
+                   unsigned d, double splitPoint, unsigned f,
+                   FASTCOVER_accel_t accelParams)
+{
+    const BYTE* const samples = (const BYTE*)samplesBuffer;
+    const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
+    /* Split samples into testing and training sets */
+    const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
+    const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
+    const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
+    const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
+
+    /* Checks */
+    if (totalSamplesSize < MAX(d, sizeof(U64)) ||
+        totalSamplesSize >= (size_t)FASTCOVER_MAX_SAMPLES_SIZE) {
+        DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
+                    (U32)(totalSamplesSize >> 20), (FASTCOVER_MAX_SAMPLES_SIZE >> 20));
+        return 0;
+    }
+
+    /* Check if there are at least 5 training samples */
+    if (nbTrainSamples < 5) {
+        DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid\n", nbTrainSamples);
+        return 0;
+    }
+
+    /* Check if there's testing sample */
+    if (nbTestSamples < 1) {
+        DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.\n", nbTestSamples);
+        return 0;
+    }
+
+    /* Zero the context */
+    memset(ctx, 0, sizeof(*ctx));
+    DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
+                    (U32)trainingSamplesSize);
+    DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples,
+                    (U32)testSamplesSize);
+
+    ctx->samples = samples;
+    ctx->samplesSizes = samplesSizes;
+    ctx->nbSamples = nbSamples;
+    ctx->nbTrainSamples = nbTrainSamples;
+    ctx->nbTestSamples = nbTestSamples;
+    ctx->nbDmers = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
+    ctx->d = d;
+    ctx->f = f;
+    ctx->accelParams = accelParams;
+
+    /* The offsets of each file */
+    ctx->offsets = (size_t*)calloc((nbSamples + 1), sizeof(size_t));
+    if (ctx->offsets == NULL) {
+        DISPLAYLEVEL(1, "Failed to allocate scratch buffers \n");
+        FASTCOVER_ctx_destroy(ctx);
+        return 0;
+    }
+
+    /* Fill offsets from the samplesSizes */
+    {   U32 i;
+        ctx->offsets[0] = 0;
+        assert(nbSamples >= 5);
+        for (i = 1; i <= nbSamples; ++i) {
+            ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
+        }
+    }
+
+    /* Initialize frequency array of size 2^f */
+    ctx->freqs = (U32*)calloc(((U64)1 << f), sizeof(U32));
+    if (ctx->freqs == NULL) {
+        DISPLAYLEVEL(1, "Failed to allocate frequency table \n");
+        FASTCOVER_ctx_destroy(ctx);
+        return 0;
+    }
+
+    DISPLAYLEVEL(2, "Computing frequencies\n");
+    FASTCOVER_computeFrequency(ctx->freqs, ctx);
+
+    return 1;
+}
+
+
+/**
+ * Given the prepared context build the dictionary.
+ */
+static size_t
+FASTCOVER_buildDictionary(const FASTCOVER_ctx_t* ctx,
+                          U32* freqs,
+                          void* dictBuffer, size_t dictBufferCapacity,
+                          ZDICT_cover_params_t parameters,
+                          U16* segmentFreqs)
+{
+  BYTE *const dict = (BYTE *)dictBuffer;
+  size_t tail = dictBufferCapacity;
+  /* Divide the data up into epochs of equal size.
+   * We will select at least one segment from each epoch.
+   */
+  const U32 epochs = MAX(1, (U32)(dictBufferCapacity / parameters.k));
+  const U32 epochSize = (U32)(ctx->nbDmers / epochs);
+  size_t epoch;
+  DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n", epochs,
+               epochSize);
+  /* Loop through the epochs until there are no more segments or the dictionary
+   * is full.
+   */
+  for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs) {
+    const U32 epochBegin = (U32)(epoch * epochSize);
+    const U32 epochEnd = epochBegin + epochSize;
+    size_t segmentSize;
+    /* Select a segment */
+    COVER_segment_t segment = FASTCOVER_selectSegment(
+        ctx, freqs, epochBegin, epochEnd, parameters, segmentFreqs);
+
+    /* If the segment covers no dmers, then we are out of content */
+    if (segment.score == 0) {
+      break;
+    }
+
+    /* Trim the segment if necessary and if it is too small then we are done */
+    segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
+    if (segmentSize < parameters.d) {
+      break;
+    }
+
+    /* We fill the dictionary from the back to allow the best segments to be
+     * referenced with the smallest offsets.
+     */
+    tail -= segmentSize;
+    memcpy(dict + tail, ctx->samples + segment.begin, segmentSize);
+    DISPLAYUPDATE(
+        2, "\r%u%%       ",
+        (U32)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity));
+  }
+  DISPLAYLEVEL(2, "\r%79s\r", "");
+  return tail;
+}
+
+
+/**
+ * Parameters for FASTCOVER_tryParameters().
+ */
+typedef struct FASTCOVER_tryParameters_data_s {
+    const FASTCOVER_ctx_t* ctx;
+    COVER_best_t* best;
+    size_t dictBufferCapacity;
+    ZDICT_cover_params_t parameters;
+} FASTCOVER_tryParameters_data_t;
+
+
+/**
+ * Tries a set of parameters and updates the COVER_best_t with the results.
+ * This function is thread safe if zstd is compiled with multithreaded support.
+ * It takes its parameters as an *OWNING* opaque pointer to support threading.
+ */
+static void FASTCOVER_tryParameters(void *opaque)
+{
+  /* Save parameters as local variables */
+  FASTCOVER_tryParameters_data_t *const data = (FASTCOVER_tryParameters_data_t *)opaque;
+  const FASTCOVER_ctx_t *const ctx = data->ctx;
+  const ZDICT_cover_params_t parameters = data->parameters;
+  size_t dictBufferCapacity = data->dictBufferCapacity;
+  size_t totalCompressedSize = ERROR(GENERIC);
+  /* Initialize array to keep track of frequency of dmer within activeSegment */
+  U16* segmentFreqs = (U16 *)calloc(((U64)1 << ctx->f), sizeof(U16));
+  /* Allocate space for hash table, dict, and freqs */
+  BYTE *const dict = (BYTE * const)malloc(dictBufferCapacity);
+  U32 *freqs = (U32*) malloc(((U64)1 << ctx->f) * sizeof(U32));
+  if (!segmentFreqs || !dict || !freqs) {
+    DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n");
+    goto _cleanup;
+  }
+  /* Copy the frequencies because we need to modify them */
+  memcpy(freqs, ctx->freqs, ((U64)1 << ctx->f) * sizeof(U32));
+  /* Build the dictionary */
+  { const size_t tail = FASTCOVER_buildDictionary(ctx, freqs, dict, dictBufferCapacity,
+                                                  parameters, segmentFreqs);
+    const unsigned nbFinalizeSamples = (unsigned)(ctx->nbTrainSamples * ctx->accelParams.finalize / 100);
+    dictBufferCapacity = ZDICT_finalizeDictionary(
+        dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
+        ctx->samples, ctx->samplesSizes, nbFinalizeSamples, parameters.zParams);
+    if (ZDICT_isError(dictBufferCapacity)) {
+      DISPLAYLEVEL(1, "Failed to finalize dictionary\n");
+      goto _cleanup;
+    }
+  }
+  /* Check total compressed size */
+  totalCompressedSize = COVER_checkTotalCompressedSize(parameters, ctx->samplesSizes,
+                                                       ctx->samples, ctx->offsets,
+                                                       ctx->nbTrainSamples, ctx->nbSamples,
+                                                       dict, dictBufferCapacity);
+_cleanup:
+  COVER_best_finish(data->best, totalCompressedSize, parameters, dict,
+                    dictBufferCapacity);
+  free(data);
+  free(segmentFreqs);
+  free(dict);
+  free(freqs);
+}
+
+
+static void
+FASTCOVER_convertToCoverParams(ZDICT_fastCover_params_t fastCoverParams,
+                               ZDICT_cover_params_t* coverParams)
+{
+    coverParams->k = fastCoverParams.k;
+    coverParams->d = fastCoverParams.d;
+    coverParams->steps = fastCoverParams.steps;
+    coverParams->nbThreads = fastCoverParams.nbThreads;
+    coverParams->splitPoint = fastCoverParams.splitPoint;
+    coverParams->zParams = fastCoverParams.zParams;
+}
+
+
+static void
+FASTCOVER_convertToFastCoverParams(ZDICT_cover_params_t coverParams,
+                                   ZDICT_fastCover_params_t* fastCoverParams,
+                                   unsigned f, unsigned accel)
+{
+    fastCoverParams->k = coverParams.k;
+    fastCoverParams->d = coverParams.d;
+    fastCoverParams->steps = coverParams.steps;
+    fastCoverParams->nbThreads = coverParams.nbThreads;
+    fastCoverParams->splitPoint = coverParams.splitPoint;
+    fastCoverParams->f = f;
+    fastCoverParams->accel = accel;
+    fastCoverParams->zParams = coverParams.zParams;
+}
+
+
+ZDICTLIB_API size_t
+ZDICT_trainFromBuffer_fastCover(void* dictBuffer, size_t dictBufferCapacity,
+                                const void* samplesBuffer,
+                                const size_t* samplesSizes, unsigned nbSamples,
+                                ZDICT_fastCover_params_t parameters)
+{
+    BYTE* const dict = (BYTE*)dictBuffer;
+    FASTCOVER_ctx_t ctx;
+    ZDICT_cover_params_t coverParams;
+    FASTCOVER_accel_t accelParams;
+    /* Initialize global data */
+    g_displayLevel = parameters.zParams.notificationLevel;
+    /* Assign splitPoint and f if not provided */
+    parameters.splitPoint = 1.0;
+    parameters.f = parameters.f == 0 ? DEFAULT_F : parameters.f;
+    parameters.accel = parameters.accel == 0 ? DEFAULT_ACCEL : parameters.accel;
+    /* Convert to cover parameter */
+    memset(&coverParams, 0 , sizeof(coverParams));
+    FASTCOVER_convertToCoverParams(parameters, &coverParams);
+    /* Checks */
+    if (!FASTCOVER_checkParameters(coverParams, dictBufferCapacity, parameters.f,
+                                   parameters.accel)) {
+      DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
+      return ERROR(GENERIC);
+    }
+    if (nbSamples == 0) {
+      DISPLAYLEVEL(1, "FASTCOVER must have at least one input file\n");
+      return ERROR(GENERIC);
+    }
+    if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
+      DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
+                   ZDICT_DICTSIZE_MIN);
+      return ERROR(dstSize_tooSmall);
+    }
+    /* Assign corresponding FASTCOVER_accel_t to accelParams*/
+    accelParams = FASTCOVER_defaultAccelParameters[parameters.accel];
+    /* Initialize context */
+    if (!FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
+                            coverParams.d, parameters.splitPoint, parameters.f,
+                            accelParams)) {
+      DISPLAYLEVEL(1, "Failed to initialize context\n");
+      return ERROR(GENERIC);
+    }
+    /* Build the dictionary */
+    DISPLAYLEVEL(2, "Building dictionary\n");
+    {
+      /* Initialize array to keep track of frequency of dmer within activeSegment */
+      U16* segmentFreqs = (U16 *)calloc(((U64)1 << parameters.f), sizeof(U16));
+      const size_t tail = FASTCOVER_buildDictionary(&ctx, ctx.freqs, dictBuffer,
+                                                dictBufferCapacity, coverParams, segmentFreqs);
+      const unsigned nbFinalizeSamples = (unsigned)(ctx.nbTrainSamples * ctx.accelParams.finalize / 100);
+      const size_t dictionarySize = ZDICT_finalizeDictionary(
+          dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
+          samplesBuffer, samplesSizes, nbFinalizeSamples, coverParams.zParams);
+      if (!ZSTD_isError(dictionarySize)) {
+          DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
+                      (U32)dictionarySize);
+      }
+      FASTCOVER_ctx_destroy(&ctx);
+      free(segmentFreqs);
+      return dictionarySize;
+    }
+}
+
+
+ZDICTLIB_API size_t
+ZDICT_optimizeTrainFromBuffer_fastCover(
+                    void* dictBuffer, size_t dictBufferCapacity,
+                    const void* samplesBuffer,
+                    const size_t* samplesSizes, unsigned nbSamples,
+                    ZDICT_fastCover_params_t* parameters)
+{
+    ZDICT_cover_params_t coverParams;
+    FASTCOVER_accel_t accelParams;
+    /* constants */
+    const unsigned nbThreads = parameters->nbThreads;
+    const double splitPoint =
+        parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint;
+    const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
+    const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
+    const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
+    const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k;
+    const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps;
+    const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1);
+    const unsigned kIterations =
+        (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
+    const unsigned f = parameters->f == 0 ? DEFAULT_F : parameters->f;
+    const unsigned accel = parameters->accel == 0 ? DEFAULT_ACCEL : parameters->accel;
+    /* Local variables */
+    const int displayLevel = parameters->zParams.notificationLevel;
+    unsigned iteration = 1;
+    unsigned d;
+    unsigned k;
+    COVER_best_t best;
+    POOL_ctx *pool = NULL;
+    /* Checks */
+    if (splitPoint <= 0 || splitPoint > 1) {
+      LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect splitPoint\n");
+      return ERROR(GENERIC);
+    }
+    if (accel == 0 || accel > FASTCOVER_MAX_ACCEL) {
+      LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect accel\n");
+      return ERROR(GENERIC);
+    }
+    if (kMinK < kMaxD || kMaxK < kMinK) {
+      LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect k\n");
+      return ERROR(GENERIC);
+    }
+    if (nbSamples == 0) {
+      LOCALDISPLAYLEVEL(displayLevel, 1, "FASTCOVER must have at least one input file\n");
+      return ERROR(GENERIC);
+    }
+    if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
+      LOCALDISPLAYLEVEL(displayLevel, 1, "dictBufferCapacity must be at least %u\n",
+                   ZDICT_DICTSIZE_MIN);
+      return ERROR(dstSize_tooSmall);
+    }
+    if (nbThreads > 1) {
+      pool = POOL_create(nbThreads, 1);
+      if (!pool) {
+        return ERROR(memory_allocation);
+      }
+    }
+    /* Initialization */
+    COVER_best_init(&best);
+    memset(&coverParams, 0 , sizeof(coverParams));
+    FASTCOVER_convertToCoverParams(*parameters, &coverParams);
+    accelParams = FASTCOVER_defaultAccelParameters[accel];
+    /* Turn down global display level to clean up display at level 2 and below */
+    g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1;
+    /* Loop through d first because each new value needs a new context */
+    LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n",
+                      kIterations);
+    for (d = kMinD; d <= kMaxD; d += 2) {
+      /* Initialize the context for this value of d */
+      FASTCOVER_ctx_t ctx;
+      LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
+      if (!FASTCOVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint, f, accelParams)) {
+        LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n");
+        COVER_best_destroy(&best);
+        POOL_free(pool);
+        return ERROR(GENERIC);
+      }
+      /* Loop through k reusing the same context */
+      for (k = kMinK; k <= kMaxK; k += kStepSize) {
+        /* Prepare the arguments */
+        FASTCOVER_tryParameters_data_t *data = (FASTCOVER_tryParameters_data_t *)malloc(
+            sizeof(FASTCOVER_tryParameters_data_t));
+        LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
+        if (!data) {
+          LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
+          COVER_best_destroy(&best);
+          FASTCOVER_ctx_destroy(&ctx);
+          POOL_free(pool);
+          return ERROR(GENERIC);
+        }
+        data->ctx = &ctx;
+        data->best = &best;
+        data->dictBufferCapacity = dictBufferCapacity;
+        data->parameters = coverParams;
+        data->parameters.k = k;
+        data->parameters.d = d;
+        data->parameters.splitPoint = splitPoint;
+        data->parameters.steps = kSteps;
+        data->parameters.zParams.notificationLevel = g_displayLevel;
+        /* Check the parameters */
+        if (!FASTCOVER_checkParameters(data->parameters, dictBufferCapacity,
+                                       data->ctx->f, accel)) {
+          DISPLAYLEVEL(1, "FASTCOVER parameters incorrect\n");
+          free(data);
+          continue;
+        }
+        /* Call the function and pass ownership of data to it */
+        COVER_best_start(&best);
+        if (pool) {
+          POOL_add(pool, &FASTCOVER_tryParameters, data);
+        } else {
+          FASTCOVER_tryParameters(data);
+        }
+        /* Print status */
+        LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%%       ",
+                           (U32)((iteration * 100) / kIterations));
+        ++iteration;
+      }
+      COVER_best_wait(&best);
+      FASTCOVER_ctx_destroy(&ctx);
+    }
+    LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", "");
+    /* Fill the output buffer and parameters with output of the best parameters */
+    {
+      const size_t dictSize = best.dictSize;
+      if (ZSTD_isError(best.compressedSize)) {
+        const size_t compressedSize = best.compressedSize;
+        COVER_best_destroy(&best);
+        POOL_free(pool);
+        return compressedSize;
+      }
+      FASTCOVER_convertToFastCoverParams(best.parameters, parameters, f, accel);
+      memcpy(dictBuffer, best.dict, dictSize);
+      COVER_best_destroy(&best);
+      POOL_free(pool);
+      return dictSize;
+    }
+
+}

Property changes on: vendor/zstd/dist/lib/dictBuilder/fastcover.c
___________________________________________________________________
Added: svn:eol-style
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+native
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Added: svn:keywords
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+FreeBSD=%H
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Index: vendor/zstd/dist/lib/dictBuilder/zdict.c
===================================================================
--- vendor/zstd/dist/lib/dictBuilder/zdict.c	(revision 339613)
+++ vendor/zstd/dist/lib/dictBuilder/zdict.c	(revision 339614)
@@ -1,1108 +1,1111 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /*-**************************************
 *  Tuning parameters
 ****************************************/
 #define MINRATIO 4   /* minimum nb of apparition to be selected in dictionary */
 #define ZDICT_MAX_SAMPLES_SIZE (2000U << 20)
 #define ZDICT_MIN_SAMPLES_SIZE (ZDICT_CONTENTSIZE_MIN * MINRATIO)
 
 
 /*-**************************************
 *  Compiler Options
 ****************************************/
 /* Unix Large Files support (>4GB) */
 #define _FILE_OFFSET_BITS 64
 #if (defined(__sun__) && (!defined(__LP64__)))   /* Sun Solaris 32-bits requires specific definitions */
 #  define _LARGEFILE_SOURCE
 #elif ! defined(__LP64__)                        /* No point defining Large file for 64 bit */
 #  define _LARGEFILE64_SOURCE
 #endif
 
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include         /* malloc, free */
 #include         /* memset */
 #include          /* fprintf, fopen, ftello64 */
 #include           /* clock */
 
 #include "mem.h"           /* read */
 #include "fse.h"           /* FSE_normalizeCount, FSE_writeNCount */
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"           /* HUF_buildCTable, HUF_writeCTable */
 #include "zstd_internal.h" /* includes zstd.h */
 #include "xxhash.h"        /* XXH64 */
 #include "divsufsort.h"
 #ifndef ZDICT_STATIC_LINKING_ONLY
 #  define ZDICT_STATIC_LINKING_ONLY
 #endif
 #include "zdict.h"
 
 
 /*-*************************************
 *  Constants
 ***************************************/
 #define KB *(1 <<10)
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
 #define DICTLISTSIZE_DEFAULT 10000
 
 #define NOISELENGTH 32
 
 static const int g_compressionLevel_default = 3;
 static const U32 g_selectivity_default = 9;
 
 
 /*-*************************************
 *  Console display
 ***************************************/
 #define DISPLAY(...)         { fprintf(stderr, __VA_ARGS__); fflush( stderr ); }
 #define DISPLAYLEVEL(l, ...) if (notificationLevel>=l) { DISPLAY(__VA_ARGS__); }    /* 0 : no display;   1: errors;   2: default;  3: details;  4: debug */
 
 static clock_t ZDICT_clockSpan(clock_t nPrevious) { return clock() - nPrevious; }
 
 static void ZDICT_printHex(const void* ptr, size_t length)
 {
     const BYTE* const b = (const BYTE*)ptr;
     size_t u;
     for (u=0; u126) c = '.';   /* non-printable char */
         DISPLAY("%c", c);
     }
 }
 
 
 /*-********************************************************
 *  Helper functions
 **********************************************************/
 unsigned ZDICT_isError(size_t errorCode) { return ERR_isError(errorCode); }
 
 const char* ZDICT_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
 
 unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize)
 {
     if (dictSize < 8) return 0;
     if (MEM_readLE32(dictBuffer) != ZSTD_MAGIC_DICTIONARY) return 0;
     return MEM_readLE32((const char*)dictBuffer + 4);
 }
 
 
 /*-********************************************************
 *  Dictionary training functions
 **********************************************************/
 static unsigned ZDICT_NbCommonBytes (size_t val)
 {
     if (MEM_isLittleEndian()) {
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanForward64( &r, (U64)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_ctzll((U64)val) >> 3);
 #       else
             static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
             return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r=0;
             _BitScanForward( &r, (U32)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_ctz((U32)val) >> 3);
 #       else
             static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
             return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
 #       endif
         }
     } else {  /* Big Endian CPU */
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanReverse64( &r, val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_clzll(val) >> 3);
 #       else
             unsigned r;
             const unsigned n32 = sizeof(size_t)*4;   /* calculate this way due to compiler complaining in 32-bits mode */
             if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
             if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
             r += (!val);
             return r;
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r = 0;
             _BitScanReverse( &r, (unsigned long)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_clz((U32)val) >> 3);
 #       else
             unsigned r;
             if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
             r += (!val);
             return r;
 #       endif
     }   }
 }
 
 
 /*! ZDICT_count() :
     Count the nb of common bytes between 2 pointers.
     Note : this function presumes end of buffer followed by noisy guard band.
 */
 static size_t ZDICT_count(const void* pIn, const void* pMatch)
 {
     const char* const pStart = (const char*)pIn;
     for (;;) {
         size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
         if (!diff) {
             pIn = (const char*)pIn+sizeof(size_t);
             pMatch = (const char*)pMatch+sizeof(size_t);
             continue;
         }
         pIn = (const char*)pIn+ZDICT_NbCommonBytes(diff);
         return (size_t)((const char*)pIn - pStart);
     }
 }
 
 
 typedef struct {
     U32 pos;
     U32 length;
     U32 savings;
 } dictItem;
 
 static void ZDICT_initDictItem(dictItem* d)
 {
     d->pos = 1;
     d->length = 0;
     d->savings = (U32)(-1);
 }
 
 
 #define LLIMIT 64          /* heuristic determined experimentally */
 #define MINMATCHLENGTH 7   /* heuristic determined experimentally */
 static dictItem ZDICT_analyzePos(
                        BYTE* doneMarks,
                        const int* suffix, U32 start,
                        const void* buffer, U32 minRatio, U32 notificationLevel)
 {
     U32 lengthList[LLIMIT] = {0};
     U32 cumulLength[LLIMIT] = {0};
     U32 savings[LLIMIT] = {0};
     const BYTE* b = (const BYTE*)buffer;
     size_t maxLength = LLIMIT;
     size_t pos = suffix[start];
     U32 end = start;
     dictItem solution;
 
     /* init */
     memset(&solution, 0, sizeof(solution));
     doneMarks[pos] = 1;
 
     /* trivial repetition cases */
     if ( (MEM_read16(b+pos+0) == MEM_read16(b+pos+2))
        ||(MEM_read16(b+pos+1) == MEM_read16(b+pos+3))
        ||(MEM_read16(b+pos+2) == MEM_read16(b+pos+4)) ) {
         /* skip and mark segment */
         U16 const pattern16 = MEM_read16(b+pos+4);
         U32 u, patternEnd = 6;
         while (MEM_read16(b+pos+patternEnd) == pattern16) patternEnd+=2 ;
         if (b[pos+patternEnd] == b[pos+patternEnd-1]) patternEnd++;
         for (u=1; u= MINMATCHLENGTH);
     }
 
     /* look backward */
     {   size_t length;
         do {
             length = ZDICT_count(b + pos, b + *(suffix+start-1));
             if (length >=MINMATCHLENGTH) start--;
         } while(length >= MINMATCHLENGTH);
     }
 
     /* exit if not found a minimum nb of repetitions */
     if (end-start < minRatio) {
         U32 idx;
         for(idx=start; idx= %i at pos %7u  ", (U32)(end-start), MINMATCHLENGTH, (U32)pos);
         DISPLAYLEVEL(4, "\n");
 
         for (searchLength = MINMATCHLENGTH ; ; searchLength++) {
             BYTE currentChar = 0;
             U32 currentCount = 0;
             U32 currentID = refinedStart;
             U32 id;
             U32 selectedCount = 0;
             U32 selectedID = currentID;
             for (id =refinedStart; id < refinedEnd; id++) {
                 if (b[suffix[id] + searchLength] != currentChar) {
                     if (currentCount > selectedCount) {
                         selectedCount = currentCount;
                         selectedID = currentID;
                     }
                     currentID = id;
                     currentChar = b[ suffix[id] + searchLength];
                     currentCount = 0;
                 }
                 currentCount ++;
             }
             if (currentCount > selectedCount) {  /* for last */
                 selectedCount = currentCount;
                 selectedID = currentID;
             }
 
             if (selectedCount < minRatio)
                 break;
             refinedStart = selectedID;
             refinedEnd = refinedStart + selectedCount;
         }
 
-        /* evaluate gain based on new ref */
+        /* evaluate gain based on new dict */
         start = refinedStart;
         pos = suffix[refinedStart];
         end = start;
         memset(lengthList, 0, sizeof(lengthList));
 
         /* look forward */
         {   size_t length;
             do {
                 end++;
                 length = ZDICT_count(b + pos, b + suffix[end]);
                 if (length >= LLIMIT) length = LLIMIT-1;
                 lengthList[length]++;
             } while (length >=MINMATCHLENGTH);
         }
 
         /* look backward */
         {   size_t length = MINMATCHLENGTH;
             while ((length >= MINMATCHLENGTH) & (start > 0)) {
                 length = ZDICT_count(b + pos, b + suffix[start - 1]);
                 if (length >= LLIMIT) length = LLIMIT - 1;
                 lengthList[length]++;
                 if (length >= MINMATCHLENGTH) start--;
             }
         }
 
         /* largest useful length */
         memset(cumulLength, 0, sizeof(cumulLength));
         cumulLength[maxLength-1] = lengthList[maxLength-1];
         for (i=(int)(maxLength-2); i>=0; i--)
             cumulLength[i] = cumulLength[i+1] + lengthList[i];
 
         for (i=LLIMIT-1; i>=MINMATCHLENGTH; i--) if (cumulLength[i]>=minRatio) break;
         maxLength = i;
 
         /* reduce maxLength in case of final into repetitive data */
         {   U32 l = (U32)maxLength;
             BYTE const c = b[pos + maxLength-1];
             while (b[pos+l-2]==c) l--;
             maxLength = l;
         }
         if (maxLength < MINMATCHLENGTH) return solution;   /* skip : no long-enough solution */
 
         /* calculate savings */
         savings[5] = 0;
         for (i=MINMATCHLENGTH; i<=(int)maxLength; i++)
             savings[i] = savings[i-1] + (lengthList[i] * (i-3));
 
-        DISPLAYLEVEL(4, "Selected ref at position %u, of length %u : saves %u (ratio: %.2f)  \n",
+        DISPLAYLEVEL(4, "Selected dict at position %u, of length %u : saves %u (ratio: %.2f)  \n",
                      (U32)pos, (U32)maxLength, savings[maxLength], (double)savings[maxLength] / maxLength);
 
         solution.pos = (U32)pos;
         solution.length = (U32)maxLength;
         solution.savings = savings[maxLength];
 
         /* mark positions done */
         {   U32 id;
             for (id=start; id solution.length) length = solution.length;
                 }
                 pEnd = (U32)(testedPos + length);
                 for (p=testedPos; ppos;
     const U32 eltEnd = elt.pos + elt.length;
     const char* const buf = (const char*) buffer;
 
     /* tail overlap */
     U32 u; for (u=1; u elt.pos) && (table[u].pos <= eltEnd)) {  /* overlap, existing > new */
             /* append */
             U32 const addedLength = table[u].pos - elt.pos;
             table[u].length += addedLength;
             table[u].pos = elt.pos;
             table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
             table[u].savings += elt.length / 8;    /* rough approx bonus */
             elt = table[u];
             /* sort : improve rank */
             while ((u>1) && (table[u-1].savings < elt.savings))
             table[u] = table[u-1], u--;
             table[u] = elt;
             return u;
     }   }
 
     /* front overlap */
     for (u=1; u= elt.pos) && (table[u].pos < elt.pos)) {  /* overlap, existing < new */
             /* append */
             int const addedLength = (int)eltEnd - (table[u].pos + table[u].length);
             table[u].savings += elt.length / 8;    /* rough approx bonus */
             if (addedLength > 0) {   /* otherwise, elt fully included into existing */
                 table[u].length += addedLength;
                 table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
             }
             /* sort : improve rank */
             elt = table[u];
             while ((u>1) && (table[u-1].savings < elt.savings))
                 table[u] = table[u-1], u--;
             table[u] = elt;
             return u;
         }
 
         if (MEM_read64(buf + table[u].pos) == MEM_read64(buf + elt.pos + 1)) {
             if (isIncluded(buf + table[u].pos, buf + elt.pos + 1, table[u].length)) {
                 size_t const addedLength = MAX( (int)elt.length - (int)table[u].length , 1 );
                 table[u].pos = elt.pos;
                 table[u].savings += (U32)(elt.savings * addedLength / elt.length);
                 table[u].length = MIN(elt.length, table[u].length + 1);
                 return u;
             }
         }
     }
 
     return 0;
 }
 
 
 static void ZDICT_removeDictItem(dictItem* table, U32 id)
 {
     /* convention : table[0].pos stores nb of elts */
     U32 const max = table[0].pos;
     U32 u;
     if (!id) return;   /* protection, should never happen */
     for (u=id; upos--;
 }
 
 
 static void ZDICT_insertDictItem(dictItem* table, U32 maxSize, dictItem elt, const void* buffer)
 {
     /* merge if possible */
     U32 mergeId = ZDICT_tryMerge(table, elt, 0, buffer);
     if (mergeId) {
         U32 newMerge = 1;
         while (newMerge) {
             newMerge = ZDICT_tryMerge(table, table[mergeId], mergeId, buffer);
             if (newMerge) ZDICT_removeDictItem(table, mergeId);
             mergeId = newMerge;
         }
         return;
     }
 
     /* insert */
     {   U32 current;
         U32 nextElt = table->pos;
         if (nextElt >= maxSize) nextElt = maxSize-1;
         current = nextElt-1;
         while (table[current].savings < elt.savings) {
             table[current+1] = table[current];
             current--;
         }
         table[current+1] = elt;
         table->pos = nextElt+1;
     }
 }
 
 
 static U32 ZDICT_dictSize(const dictItem* dictList)
 {
     U32 u, dictSize = 0;
     for (u=1; u=l) { \
             if (ZDICT_clockSpan(displayClock) > refreshRate)  \
             { displayClock = clock(); DISPLAY(__VA_ARGS__); \
             if (notificationLevel>=4) fflush(stderr); } }
 
     /* init */
     DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
     if (!suffix0 || !reverseSuffix || !doneMarks || !filePos) {
         result = ERROR(memory_allocation);
         goto _cleanup;
     }
     if (minRatio < MINRATIO) minRatio = MINRATIO;
     memset(doneMarks, 0, bufferSize+16);
 
     /* limit sample set size (divsufsort limitation)*/
     if (bufferSize > ZDICT_MAX_SAMPLES_SIZE) DISPLAYLEVEL(3, "sample set too large : reduced to %u MB ...\n", (U32)(ZDICT_MAX_SAMPLES_SIZE>>20));
     while (bufferSize > ZDICT_MAX_SAMPLES_SIZE) bufferSize -= fileSizes[--nbFiles];
 
     /* sort */
     DISPLAYLEVEL(2, "sorting %u files of total size %u MB ...\n", nbFiles, (U32)(bufferSize>>20));
     {   int const divSuftSortResult = divsufsort((const unsigned char*)buffer, suffix, (int)bufferSize, 0);
         if (divSuftSortResult != 0) { result = ERROR(GENERIC); goto _cleanup; }
     }
     suffix[bufferSize] = (int)bufferSize;   /* leads into noise */
     suffix0[0] = (int)bufferSize;           /* leads into noise */
     /* build reverse suffix sort */
     {   size_t pos;
         for (pos=0; pos < bufferSize; pos++)
             reverseSuffix[suffix[pos]] = (U32)pos;
         /* note filePos tracks borders between samples.
            It's not used at this stage, but planned to become useful in a later update */
         filePos[0] = 0;
         for (pos=1; pos> 21);
     }
 }
 
 
 typedef struct
 {
-    ZSTD_CCtx* ref;    /* contains reference to dictionary */
+    ZSTD_CDict* dict;    /* dictionary */
     ZSTD_CCtx* zc;     /* working context */
     void* workPlace;   /* must be ZSTD_BLOCKSIZE_MAX allocated */
 } EStats_ress_t;
 
 #define MAXREPOFFSET 1024
 
 static void ZDICT_countEStats(EStats_ress_t esr, ZSTD_parameters params,
                               U32* countLit, U32* offsetcodeCount, U32* matchlengthCount, U32* litlengthCount, U32* repOffsets,
                               const void* src, size_t srcSize,
                               U32 notificationLevel)
 {
     size_t const blockSizeMax = MIN (ZSTD_BLOCKSIZE_MAX, 1 << params.cParams.windowLog);
     size_t cSize;
 
     if (srcSize > blockSizeMax) srcSize = blockSizeMax;   /* protection vs large samples */
-    {   size_t const errorCode = ZSTD_copyCCtx(esr.zc, esr.ref, 0);
-        if (ZSTD_isError(errorCode)) { DISPLAYLEVEL(1, "warning : ZSTD_copyCCtx failed \n"); return; }
+    {   size_t const errorCode = ZSTD_compressBegin_usingCDict(esr.zc, esr.dict);
+        if (ZSTD_isError(errorCode)) { DISPLAYLEVEL(1, "warning : ZSTD_compressBegin_usingCDict failed \n"); return; }
+
     }
     cSize = ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_MAX, src, srcSize);
     if (ZSTD_isError(cSize)) { DISPLAYLEVEL(3, "warning : could not compress sample size %u \n", (U32)srcSize); return; }
 
     if (cSize) {  /* if == 0; block is not compressible */
         const seqStore_t* const seqStorePtr = ZSTD_getSeqStore(esr.zc);
 
         /* literals stats */
         {   const BYTE* bytePtr;
             for(bytePtr = seqStorePtr->litStart; bytePtr < seqStorePtr->lit; bytePtr++)
                 countLit[*bytePtr]++;
         }
 
         /* seqStats */
         {   U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
             ZSTD_seqToCodes(seqStorePtr);
 
             {   const BYTE* codePtr = seqStorePtr->ofCode;
                 U32 u;
                 for (u=0; umlCode;
                 U32 u;
                 for (u=0; ullCode;
                 U32 u;
                 for (u=0; u= 2) { /* rep offsets */
                 const seqDef* const seq = seqStorePtr->sequencesStart;
                 U32 offset1 = seq[0].offset - 3;
                 U32 offset2 = seq[1].offset - 3;
                 if (offset1 >= MAXREPOFFSET) offset1 = 0;
                 if (offset2 >= MAXREPOFFSET) offset2 = 0;
                 repOffsets[offset1] += 3;
                 repOffsets[offset2] += 1;
     }   }   }
 }
 
 static size_t ZDICT_totalSampleSize(const size_t* fileSizes, unsigned nbFiles)
 {
     size_t total=0;
     unsigned u;
     for (u=0; u0; u--) {
         offsetCount_t tmp;
         if (table[u-1].count >= table[u].count) break;
         tmp = table[u-1];
         table[u-1] = table[u];
         table[u] = tmp;
     }
 }
 
 /* ZDICT_flatLit() :
  * rewrite `countLit` to contain a mostly flat but still compressible distribution of literals.
  * necessary to avoid generating a non-compressible distribution that HUF_writeCTable() cannot encode.
  */
 static void ZDICT_flatLit(U32* countLit)
 {
     int u;
     for (u=1; u<256; u++) countLit[u] = 2;
     countLit[0]   = 4;
     countLit[253] = 1;
     countLit[254] = 1;
 }
 
 #define OFFCODE_MAX 30  /* only applicable to first block */
 static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
                                    unsigned compressionLevel,
                              const void*  srcBuffer, const size_t* fileSizes, unsigned nbFiles,
                              const void* dictBuffer, size_t  dictBufferSize,
                                    unsigned notificationLevel)
 {
     U32 countLit[256];
     HUF_CREATE_STATIC_CTABLE(hufTable, 255);
     U32 offcodeCount[OFFCODE_MAX+1];
     short offcodeNCount[OFFCODE_MAX+1];
     U32 offcodeMax = ZSTD_highbit32((U32)(dictBufferSize + 128 KB));
     U32 matchLengthCount[MaxML+1];
     short matchLengthNCount[MaxML+1];
     U32 litLengthCount[MaxLL+1];
     short litLengthNCount[MaxLL+1];
     U32 repOffset[MAXREPOFFSET];
     offsetCount_t bestRepOffset[ZSTD_REP_NUM+1];
-    EStats_ress_t esr;
+    EStats_ress_t esr = { NULL, NULL, NULL };
     ZSTD_parameters params;
     U32 u, huffLog = 11, Offlog = OffFSELog, mlLog = MLFSELog, llLog = LLFSELog, total;
     size_t pos = 0, errorCode;
     size_t eSize = 0;
     size_t const totalSrcSize = ZDICT_totalSampleSize(fileSizes, nbFiles);
     size_t const averageSampleSize = totalSrcSize / (nbFiles + !nbFiles);
     BYTE* dstPtr = (BYTE*)dstBuffer;
 
     /* init */
     DEBUGLOG(4, "ZDICT_analyzeEntropy");
-    esr.ref = ZSTD_createCCtx();
-    esr.zc = ZSTD_createCCtx();
-    esr.workPlace = malloc(ZSTD_BLOCKSIZE_MAX);
-    if (!esr.ref || !esr.zc || !esr.workPlace) {
-        eSize = ERROR(memory_allocation);
-        DISPLAYLEVEL(1, "Not enough memory \n");
-        goto _cleanup;
-    }
     if (offcodeMax>OFFCODE_MAX) { eSize = ERROR(dictionaryCreation_failed); goto _cleanup; }   /* too large dictionary */
     for (u=0; u<256; u++) countLit[u] = 1;   /* any character must be described */
     for (u=0; u<=offcodeMax; u++) offcodeCount[u] = 1;
     for (u=0; u<=MaxML; u++) matchLengthCount[u] = 1;
     for (u=0; u<=MaxLL; u++) litLengthCount[u] = 1;
     memset(repOffset, 0, sizeof(repOffset));
     repOffset[1] = repOffset[4] = repOffset[8] = 1;
     memset(bestRepOffset, 0, sizeof(bestRepOffset));
-    if (compressionLevel<=0) compressionLevel = g_compressionLevel_default;
+    if (compressionLevel==0) compressionLevel = g_compressionLevel_default;
     params = ZSTD_getParams(compressionLevel, averageSampleSize, dictBufferSize);
-    {   size_t const beginResult = ZSTD_compressBegin_advanced(esr.ref, dictBuffer, dictBufferSize, params, 0);
-        if (ZSTD_isError(beginResult)) {
-            DISPLAYLEVEL(1, "error : ZSTD_compressBegin_advanced() failed : %s \n", ZSTD_getErrorName(beginResult));
-            eSize = ERROR(GENERIC);
-            goto _cleanup;
-    }   }
 
+    esr.dict = ZSTD_createCDict_advanced(dictBuffer, dictBufferSize, ZSTD_dlm_byRef, ZSTD_dct_rawContent, params.cParams, ZSTD_defaultCMem);
+    esr.zc = ZSTD_createCCtx();
+    esr.workPlace = malloc(ZSTD_BLOCKSIZE_MAX);
+    if (!esr.dict || !esr.zc || !esr.workPlace) {
+        eSize = ERROR(memory_allocation);
+        DISPLAYLEVEL(1, "Not enough memory \n");
+        goto _cleanup;
+    }
+
     /* collect stats on all samples */
     for (u=0; u dictBufferCapacity) dictContentSize = dictBufferCapacity - hSize;
     {   size_t const dictSize = hSize + dictContentSize;
         char* dictEnd = (char*)dictBuffer + dictSize;
         memmove(dictEnd - dictContentSize, customDictContent, dictContentSize);
         memcpy(dictBuffer, header, hSize);
         return dictSize;
     }
 }
 
 
-size_t ZDICT_addEntropyTablesFromBuffer_advanced(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
-                                                 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
-                                                 ZDICT_params_t params)
+static size_t ZDICT_addEntropyTablesFromBuffer_advanced(
+        void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
+        const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
+        ZDICT_params_t params)
 {
-    int const compressionLevel = (params.compressionLevel <= 0) ? g_compressionLevel_default : params.compressionLevel;
+    int const compressionLevel = (params.compressionLevel == 0) ? g_compressionLevel_default : params.compressionLevel;
     U32 const notificationLevel = params.notificationLevel;
     size_t hSize = 8;
 
     /* calculate entropy tables */
     DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
     DISPLAYLEVEL(2, "statistics ... \n");
     {   size_t const eSize = ZDICT_analyzeEntropy((char*)dictBuffer+hSize, dictBufferCapacity-hSize,
                                   compressionLevel,
                                   samplesBuffer, samplesSizes, nbSamples,
                                   (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize,
                                   notificationLevel);
         if (ZDICT_isError(eSize)) return eSize;
         hSize += eSize;
     }
 
     /* add dictionary header (after entropy tables) */
     MEM_writeLE32(dictBuffer, ZSTD_MAGIC_DICTIONARY);
     {   U64 const randomID = XXH64((char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize, 0);
         U32 const compliantID = (randomID % ((1U<<31)-32768)) + 32768;
         U32 const dictID = params.dictID ? params.dictID : compliantID;
         MEM_writeLE32((char*)dictBuffer+4, dictID);
     }
 
     if (hSize + dictContentSize < dictBufferCapacity)
         memmove((char*)dictBuffer + hSize, (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize);
     return MIN(dictBufferCapacity, hSize+dictContentSize);
 }
 
-
+/* Hidden declaration for dbio.c */
+size_t ZDICT_trainFromBuffer_unsafe_legacy(
+                            void* dictBuffer, size_t maxDictSize,
+                            const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
+                            ZDICT_legacy_params_t params);
 /*! ZDICT_trainFromBuffer_unsafe_legacy() :
 *   Warning : `samplesBuffer` must be followed by noisy guard band.
 *   @return : size of dictionary, or an error code which can be tested with ZDICT_isError()
 */
 size_t ZDICT_trainFromBuffer_unsafe_legacy(
                             void* dictBuffer, size_t maxDictSize,
                             const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                             ZDICT_legacy_params_t params)
 {
     U32 const dictListSize = MAX(MAX(DICTLISTSIZE_DEFAULT, nbSamples), (U32)(maxDictSize/16));
     dictItem* const dictList = (dictItem*)malloc(dictListSize * sizeof(*dictList));
     unsigned const selectivity = params.selectivityLevel == 0 ? g_selectivity_default : params.selectivityLevel;
     unsigned const minRep = (selectivity > 30) ? MINRATIO : nbSamples >> selectivity;
     size_t const targetDictSize = maxDictSize;
     size_t const samplesBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
     size_t dictSize = 0;
     U32 const notificationLevel = params.zParams.notificationLevel;
 
     /* checks */
     if (!dictList) return ERROR(memory_allocation);
     if (maxDictSize < ZDICT_DICTSIZE_MIN) { free(dictList); return ERROR(dstSize_tooSmall); }   /* requested dictionary size is too small */
     if (samplesBuffSize < ZDICT_MIN_SAMPLES_SIZE) { free(dictList); return ERROR(dictionaryCreation_failed); }   /* not enough source to create dictionary */
 
     /* init */
     ZDICT_initDictItem(dictList);
 
     /* build dictionary */
     ZDICT_trainBuffer_legacy(dictList, dictListSize,
                        samplesBuffer, samplesBuffSize,
                        samplesSizes, nbSamples,
                        minRep, notificationLevel);
 
     /* display best matches */
     if (params.zParams.notificationLevel>= 3) {
         U32 const nb = MIN(25, dictList[0].pos);
         U32 const dictContentSize = ZDICT_dictSize(dictList);
         U32 u;
         DISPLAYLEVEL(3, "\n %u segments found, of total size %u \n", dictList[0].pos-1, dictContentSize);
         DISPLAYLEVEL(3, "list %u best segments \n", nb-1);
         for (u=1; u samplesBuffSize) || ((pos + length) > samplesBuffSize))
+            if ((pos > samplesBuffSize) || ((pos + length) > samplesBuffSize)) {
+                free(dictList);
                 return ERROR(GENERIC);   /* should never happen */
+            }
             DISPLAYLEVEL(3, "%3u:%3u bytes at pos %8u, savings %7u bytes |",
                          u, length, pos, dictList[u].savings);
             ZDICT_printHex((const char*)samplesBuffer+pos, printedLength);
             DISPLAYLEVEL(3, "| \n");
     }   }
 
 
     /* create dictionary */
     {   U32 dictContentSize = ZDICT_dictSize(dictList);
         if (dictContentSize < ZDICT_CONTENTSIZE_MIN) { free(dictList); return ERROR(dictionaryCreation_failed); }   /* dictionary content too small */
         if (dictContentSize < targetDictSize/4) {
             DISPLAYLEVEL(2, "!  warning : selected content significantly smaller than requested (%u < %u) \n", dictContentSize, (U32)maxDictSize);
             if (samplesBuffSize < 10 * targetDictSize)
                 DISPLAYLEVEL(2, "!  consider increasing the number of samples (total size : %u MB)\n", (U32)(samplesBuffSize>>20));
             if (minRep > MINRATIO) {
                 DISPLAYLEVEL(2, "!  consider increasing selectivity to produce larger dictionary (-s%u) \n", selectivity+1);
                 DISPLAYLEVEL(2, "!  note : larger dictionaries are not necessarily better, test its efficiency on samples \n");
             }
         }
 
         if ((dictContentSize > targetDictSize*3) && (nbSamples > 2*MINRATIO) && (selectivity>1)) {
             U32 proposedSelectivity = selectivity-1;
             while ((nbSamples >> proposedSelectivity) <= MINRATIO) { proposedSelectivity--; }
             DISPLAYLEVEL(2, "!  note : calculated dictionary significantly larger than requested (%u > %u) \n", dictContentSize, (U32)maxDictSize);
             DISPLAYLEVEL(2, "!  consider increasing dictionary size, or produce denser dictionary (-s%u) \n", proposedSelectivity);
             DISPLAYLEVEL(2, "!  always test dictionary efficiency on real samples \n");
         }
 
         /* limit dictionary size */
         {   U32 const max = dictList->pos;   /* convention : nb of useful elts within dictList */
             U32 currentSize = 0;
             U32 n; for (n=1; n targetDictSize) { currentSize -= dictList[n].length; break; }
             }
             dictList->pos = n;
             dictContentSize = currentSize;
         }
 
         /* build dict content */
         {   U32 u;
             BYTE* ptr = (BYTE*)dictBuffer + maxDictSize;
             for (u=1; upos; u++) {
                 U32 l = dictList[u].length;
                 ptr -= l;
                 if (ptr<(BYTE*)dictBuffer) { free(dictList); return ERROR(GENERIC); }   /* should not happen */
                 memcpy(ptr, (const char*)samplesBuffer+dictList[u].pos, l);
         }   }
 
         dictSize = ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, maxDictSize,
                                                              samplesBuffer, samplesSizes, nbSamples,
                                                              params.zParams);
     }
 
     /* clean up */
     free(dictList);
     return dictSize;
 }
 
 
 /* ZDICT_trainFromBuffer_legacy() :
  * issue : samplesBuffer need to be followed by a noisy guard band.
  * work around : duplicate the buffer, and add the noise */
 size_t ZDICT_trainFromBuffer_legacy(void* dictBuffer, size_t dictBufferCapacity,
                               const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                               ZDICT_legacy_params_t params)
 {
     size_t result;
     void* newBuff;
     size_t const sBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
     if (sBuffSize < ZDICT_MIN_SAMPLES_SIZE) return 0;   /* not enough content => no dictionary */
 
     newBuff = malloc(sBuffSize + NOISELENGTH);
     if (!newBuff) return ERROR(memory_allocation);
 
     memcpy(newBuff, samplesBuffer, sBuffSize);
     ZDICT_fillNoise((char*)newBuff + sBuffSize, NOISELENGTH);   /* guard band, for end of buffer condition */
 
     result =
         ZDICT_trainFromBuffer_unsafe_legacy(dictBuffer, dictBufferCapacity, newBuff,
                                             samplesSizes, nbSamples, params);
     free(newBuff);
     return result;
 }
 
 
 size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
                              const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples)
 {
-    ZDICT_cover_params_t params;
+    ZDICT_fastCover_params_t params;
     DEBUGLOG(3, "ZDICT_trainFromBuffer");
     memset(¶ms, 0, sizeof(params));
     params.d = 8;
     params.steps = 4;
     /* Default to level 6 since no compression level information is available */
-    params.zParams.compressionLevel = 6;
-#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=1)
-    params.zParams.notificationLevel = ZSTD_DEBUG;
+    params.zParams.compressionLevel = 3;
+#if defined(DEBUGLEVEL) && (DEBUGLEVEL>=1)
+    params.zParams.notificationLevel = DEBUGLEVEL;
 #endif
-    return ZDICT_optimizeTrainFromBuffer_cover(dictBuffer, dictBufferCapacity,
+    return ZDICT_optimizeTrainFromBuffer_fastCover(dictBuffer, dictBufferCapacity,
                                                samplesBuffer, samplesSizes, nbSamples,
                                                ¶ms);
 }
 
 size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
                                   const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples)
 {
     ZDICT_params_t params;
     memset(¶ms, 0, sizeof(params));
     return ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, dictBufferCapacity,
                                                      samplesBuffer, samplesSizes, nbSamples,
                                                      params);
 }
Index: vendor/zstd/dist/lib/dictBuilder/zdict.h
===================================================================
--- vendor/zstd/dist/lib/dictBuilder/zdict.h	(revision 339613)
+++ vendor/zstd/dist/lib/dictBuilder/zdict.h	(revision 339614)
@@ -1,212 +1,267 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef DICTBUILDER_H_001
 #define DICTBUILDER_H_001
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /*======  Dependencies  ======*/
 #include   /* size_t */
 
 
 /* =====   ZDICTLIB_API : control library symbols visibility   ===== */
 #ifndef ZDICTLIB_VISIBILITY
 #  if defined(__GNUC__) && (__GNUC__ >= 4)
 #    define ZDICTLIB_VISIBILITY __attribute__ ((visibility ("default")))
 #  else
 #    define ZDICTLIB_VISIBILITY
 #  endif
 #endif
 #if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
 #  define ZDICTLIB_API __declspec(dllexport) ZDICTLIB_VISIBILITY
 #elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
 #  define ZDICTLIB_API __declspec(dllimport) ZDICTLIB_VISIBILITY /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
 #else
 #  define ZDICTLIB_API ZDICTLIB_VISIBILITY
 #endif
 
 
 /*! ZDICT_trainFromBuffer():
  *  Train a dictionary from an array of samples.
- *  Redirect towards ZDICT_optimizeTrainFromBuffer_cover() single-threaded, with d=8 and steps=4.
+ *  Redirect towards ZDICT_optimizeTrainFromBuffer_fastCover() single-threaded, with d=8, steps=4,
+ *  f=20, and accel=1.
  *  Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
  *  supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
  *  The resulting dictionary will be saved into `dictBuffer`.
  * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
  *          or an error code, which can be tested with ZDICT_isError().
  *  Note: ZDICT_trainFromBuffer() requires about 9 bytes of memory for each input byte.
  *  Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
  *        It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
  *        In general, it's recommended to provide a few thousands samples, though this can vary a lot.
  *        It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
  */
 ZDICTLIB_API size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
-                                    const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples);
+                                    const void* samplesBuffer,
+                                    const size_t* samplesSizes, unsigned nbSamples);
 
 
 /*======   Helper functions   ======*/
 ZDICTLIB_API unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize);  /**< extracts dictID; @return zero if error (not a valid dictionary) */
 ZDICTLIB_API unsigned ZDICT_isError(size_t errorCode);
 ZDICTLIB_API const char* ZDICT_getErrorName(size_t errorCode);
 
 
 
 #ifdef ZDICT_STATIC_LINKING_ONLY
 
 /* ====================================================================================
  * The definitions in this section are considered experimental.
  * They should never be used with a dynamic library, as they may change in the future.
  * They are provided for advanced usages.
  * Use them only in association with static linking.
  * ==================================================================================== */
 
 typedef struct {
     int      compressionLevel;   /* optimize for a specific zstd compression level; 0 means default */
     unsigned notificationLevel;  /* Write log to stderr; 0 = none (default); 1 = errors; 2 = progression; 3 = details; 4 = debug; */
     unsigned dictID;             /* force dictID value; 0 means auto mode (32-bits random value) */
 } ZDICT_params_t;
 
 /*! ZDICT_cover_params_t:
  *  k and d are the only required parameters.
  *  For others, value 0 means default.
  */
 typedef struct {
     unsigned k;                  /* Segment size : constraint: 0 < k : Reasonable range [16, 2048+] */
     unsigned d;                  /* dmer size : constraint: 0 < d <= k : Reasonable range [6, 16] */
-    unsigned steps;              /* Number of steps : Only used for optimization : 0 means default (32) : Higher means more parameters checked */
+    unsigned steps;              /* Number of steps : Only used for optimization : 0 means default (40) : Higher means more parameters checked */
     unsigned nbThreads;          /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
+    double splitPoint;           /* Percentage of samples used for training: Only used for optimization : the first nbSamples * splitPoint samples will be used to training, the last nbSamples * (1 - splitPoint) samples will be used for testing, 0 means default (1.0), 1.0 when all samples are used for both training and testing */
     ZDICT_params_t zParams;
 } ZDICT_cover_params_t;
 
+typedef struct {
+    unsigned k;                  /* Segment size : constraint: 0 < k : Reasonable range [16, 2048+] */
+    unsigned d;                  /* dmer size : constraint: 0 < d <= k : Reasonable range [6, 16] */
+    unsigned f;                  /* log of size of frequency array : constraint: 0 < f <= 31 : 1 means default(20)*/
+    unsigned steps;              /* Number of steps : Only used for optimization : 0 means default (40) : Higher means more parameters checked */
+    unsigned nbThreads;          /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
+    double splitPoint;           /* Percentage of samples used for training: Only used for optimization : the first nbSamples * splitPoint samples will be used to training, the last nbSamples * (1 - splitPoint) samples will be used for testing, 0 means default (0.75), 1.0 when all samples are used for both training and testing */
+    unsigned accel;              /* Acceleration level: constraint: 0 < accel <= 10, higher means faster and less accurate, 0 means default(1) */
+    ZDICT_params_t zParams;
+} ZDICT_fastCover_params_t;
 
 /*! ZDICT_trainFromBuffer_cover():
  *  Train a dictionary from an array of samples using the COVER algorithm.
  *  Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
  *  supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
  *  The resulting dictionary will be saved into `dictBuffer`.
  * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
  *          or an error code, which can be tested with ZDICT_isError().
  *  Note: ZDICT_trainFromBuffer_cover() requires about 9 bytes of memory for each input byte.
  *  Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
  *        It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
  *        In general, it's recommended to provide a few thousands samples, though this can vary a lot.
  *        It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
  */
 ZDICTLIB_API size_t ZDICT_trainFromBuffer_cover(
           void *dictBuffer, size_t dictBufferCapacity,
     const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
           ZDICT_cover_params_t parameters);
 
 /*! ZDICT_optimizeTrainFromBuffer_cover():
  * The same requirements as above hold for all the parameters except `parameters`.
  * This function tries many parameter combinations and picks the best parameters.
  * `*parameters` is filled with the best parameters found,
  * dictionary constructed with those parameters is stored in `dictBuffer`.
  *
  * All of the parameters d, k, steps are optional.
- * If d is non-zero then we don't check multiple values of d, otherwise we check d = {6, 8, 10, 12, 14, 16}.
+ * If d is non-zero then we don't check multiple values of d, otherwise we check d = {6, 8}.
  * if steps is zero it defaults to its default value.
- * If k is non-zero then we don't check multiple values of k, otherwise we check steps values in [16, 2048].
+ * If k is non-zero then we don't check multiple values of k, otherwise we check steps values in [50, 2000].
  *
  * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
  *           or an error code, which can be tested with ZDICT_isError().
  *           On success `*parameters` contains the parameters selected.
  * Note: ZDICT_optimizeTrainFromBuffer_cover() requires about 8 bytes of memory for each input byte and additionally another 5 bytes of memory for each byte of memory for each thread.
  */
 ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_cover(
           void* dictBuffer, size_t dictBufferCapacity,
     const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
           ZDICT_cover_params_t* parameters);
+
+/*! ZDICT_trainFromBuffer_fastCover():
+ *  Train a dictionary from an array of samples using a modified version of COVER algorithm.
+ *  Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
+ *  supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
+ *  d and k are required.
+ *  All other parameters are optional, will use default values if not provided
+ *  The resulting dictionary will be saved into `dictBuffer`.
+ * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
+ *          or an error code, which can be tested with ZDICT_isError().
+ *  Note: ZDICT_trainFromBuffer_fastCover() requires about 1 bytes of memory for each input byte and additionally another 6 * 2^f bytes of memory .
+ *  Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
+ *        It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
+ *        In general, it's recommended to provide a few thousands samples, though this can vary a lot.
+ *        It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
+ */
+ZDICTLIB_API size_t ZDICT_trainFromBuffer_fastCover(void *dictBuffer,
+                    size_t dictBufferCapacity, const void *samplesBuffer,
+                    const size_t *samplesSizes, unsigned nbSamples,
+                    ZDICT_fastCover_params_t parameters);
+
+/*! ZDICT_optimizeTrainFromBuffer_fastCover():
+ * The same requirements as above hold for all the parameters except `parameters`.
+ * This function tries many parameter combinations (specifically, k and d combinations)
+ * and picks the best parameters. `*parameters` is filled with the best parameters found,
+ * dictionary constructed with those parameters is stored in `dictBuffer`.
+ * All of the parameters d, k, steps, f, and accel are optional.
+ * If d is non-zero then we don't check multiple values of d, otherwise we check d = {6, 8}.
+ * if steps is zero it defaults to its default value.
+ * If k is non-zero then we don't check multiple values of k, otherwise we check steps values in [50, 2000].
+ * If f is zero, default value of 20 is used.
+ * If accel is zero, default value of 1 is used.
+ *
+ * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
+ *           or an error code, which can be tested with ZDICT_isError().
+ *           On success `*parameters` contains the parameters selected.
+ * Note: ZDICT_optimizeTrainFromBuffer_fastCover() requires about 1 byte of memory for each input byte and additionally another 6 * 2^f bytes of memory for each thread.
+ */
+ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_fastCover(void* dictBuffer,
+                    size_t dictBufferCapacity, const void* samplesBuffer,
+                    const size_t* samplesSizes, unsigned nbSamples,
+                    ZDICT_fastCover_params_t* parameters);
 
 /*! ZDICT_finalizeDictionary():
  * Given a custom content as a basis for dictionary, and a set of samples,
  * finalize dictionary by adding headers and statistics.
  *
  * Samples must be stored concatenated in a flat buffer `samplesBuffer`,
  * supplied with an array of sizes `samplesSizes`, providing the size of each sample in order.
  *
  * dictContentSize must be >= ZDICT_CONTENTSIZE_MIN bytes.
  * maxDictSize must be >= dictContentSize, and must be >= ZDICT_DICTSIZE_MIN bytes.
  *
  * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`),
  *           or an error code, which can be tested by ZDICT_isError().
  * Note: ZDICT_finalizeDictionary() will push notifications into stderr if instructed to, using notificationLevel>0.
  * Note 2: dictBuffer and dictContent can overlap
  */
 #define ZDICT_CONTENTSIZE_MIN 128
 #define ZDICT_DICTSIZE_MIN    256
 ZDICTLIB_API size_t ZDICT_finalizeDictionary(void* dictBuffer, size_t dictBufferCapacity,
                                 const void* dictContent, size_t dictContentSize,
                                 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                                 ZDICT_params_t parameters);
 
 typedef struct {
     unsigned selectivityLevel;   /* 0 means default; larger => select more => larger dictionary */
     ZDICT_params_t zParams;
 } ZDICT_legacy_params_t;
 
 /*! ZDICT_trainFromBuffer_legacy():
  *  Train a dictionary from an array of samples.
  *  Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
  *  supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
  *  The resulting dictionary will be saved into `dictBuffer`.
  * `parameters` is optional and can be provided with values set to 0 to mean "default".
  * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
  *          or an error code, which can be tested with ZDICT_isError().
  *  Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
  *        It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
  *        In general, it's recommended to provide a few thousands samples, though this can vary a lot.
  *        It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
  *  Note: ZDICT_trainFromBuffer_legacy() will send notifications into stderr if instructed to, using notificationLevel>0.
  */
 ZDICTLIB_API size_t ZDICT_trainFromBuffer_legacy(
     void *dictBuffer, size_t dictBufferCapacity,
     const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
     ZDICT_legacy_params_t parameters);
 
 /* Deprecation warnings */
 /* It is generally possible to disable deprecation warnings from compiler,
    for example with -Wno-deprecated-declarations for gcc
    or _CRT_SECURE_NO_WARNINGS in Visual.
    Otherwise, it's also possible to manually define ZDICT_DISABLE_DEPRECATE_WARNINGS */
 #ifdef ZDICT_DISABLE_DEPRECATE_WARNINGS
 #  define ZDICT_DEPRECATED(message) ZDICTLIB_API   /* disable deprecation warnings */
 #else
 #  define ZDICT_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
 #  if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
 #    define ZDICT_DEPRECATED(message) [[deprecated(message)]] ZDICTLIB_API
 #  elif (ZDICT_GCC_VERSION >= 405) || defined(__clang__)
 #    define ZDICT_DEPRECATED(message) ZDICTLIB_API __attribute__((deprecated(message)))
 #  elif (ZDICT_GCC_VERSION >= 301)
 #    define ZDICT_DEPRECATED(message) ZDICTLIB_API __attribute__((deprecated))
 #  elif defined(_MSC_VER)
 #    define ZDICT_DEPRECATED(message) ZDICTLIB_API __declspec(deprecated(message))
 #  else
 #    pragma message("WARNING: You need to implement ZDICT_DEPRECATED for this compiler")
 #    define ZDICT_DEPRECATED(message) ZDICTLIB_API
 #  endif
 #endif /* ZDICT_DISABLE_DEPRECATE_WARNINGS */
 
 ZDICT_DEPRECATED("use ZDICT_finalizeDictionary() instead")
 size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
                                   const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples);
 
 
 #endif   /* ZDICT_STATIC_LINKING_ONLY */
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif   /* DICTBUILDER_H_001 */
Index: vendor/zstd/dist/lib/legacy/zstd_v01.c
===================================================================
--- vendor/zstd/dist/lib/legacy/zstd_v01.c	(revision 339613)
+++ vendor/zstd/dist/lib/legacy/zstd_v01.c	(revision 339614)
@@ -1,2127 +1,2133 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /******************************************
 *  Includes
 ******************************************/
 #include     /* size_t, ptrdiff_t */
 #include "zstd_v01.h"
 #include "error_private.h"
 
 
 /******************************************
 *  Static allocation
 ******************************************/
 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect
 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
 #define FSE_MAX_MEMORY_USAGE 14
 #define FSE_DEFAULT_MEMORY_USAGE 13
 
 /* FSE_MAX_SYMBOL_VALUE :
 *  Maximum symbol value authorized.
 *  Required for proper stack allocation */
 #define FSE_MAX_SYMBOL_VALUE 255
 
 
 /****************************************************************
 *  template functions type & suffix
 ****************************************************************/
 #define FSE_FUNCTION_TYPE BYTE
 #define FSE_FUNCTION_EXTENSION
 
 
 /****************************************************************
 *  Byte symbol type
 ****************************************************************/
 typedef struct
 {
     unsigned short newState;
     unsigned char  symbol;
     unsigned char  nbBits;
 } FSE_decode_t;   /* size == U32 */
 
 
 
 /****************************************************************
 *  Compiler specifics
 ****************************************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  define FORCE_INLINE static __forceinline
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #else
 #  define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #    ifdef __GNUC__
 #      define FORCE_INLINE static inline __attribute__((always_inline))
 #    else
 #      define FORCE_INLINE static inline
 #    endif
 #  else
 #    define FORCE_INLINE static
 #  endif /* __STDC_VERSION__ */
 #endif
 
 
 /****************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
 
 
 #ifndef MEM_ACCESS_MODULE
 #define MEM_ACCESS_MODULE
 /****************************************************************
 *  Basic Types
 *****************************************************************/
 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 # include 
 typedef  uint8_t BYTE;
 typedef uint16_t U16;
 typedef  int16_t S16;
 typedef uint32_t U32;
 typedef  int32_t S32;
 typedef uint64_t U64;
 typedef  int64_t S64;
 #else
 typedef unsigned char       BYTE;
 typedef unsigned short      U16;
 typedef   signed short      S16;
 typedef unsigned int        U32;
 typedef   signed int        S32;
 typedef unsigned long long  U64;
 typedef   signed long long  S64;
 #endif
 
 #endif   /* MEM_ACCESS_MODULE */
 
 /****************************************************************
 *  Memory I/O
 *****************************************************************/
 /* FSE_FORCE_MEMORY_ACCESS
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
  *            It can generate buggy code on targets generating assembly depending on alignment.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef FSE_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define FSE_FORCE_MEMORY_ACCESS 2
 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
 #    define FSE_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 
 static unsigned FSE_32bits(void)
 {
     return sizeof(void*)==4;
 }
 
 static unsigned FSE_isLittleEndian(void)
 {
     const union { U32 i; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
     return one.c[0];
 }
 
 #if defined(FSE_FORCE_MEMORY_ACCESS) && (FSE_FORCE_MEMORY_ACCESS==2)
 
 static U16 FSE_read16(const void* memPtr) { return *(const U16*) memPtr; }
 static U32 FSE_read32(const void* memPtr) { return *(const U32*) memPtr; }
 static U64 FSE_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 #elif defined(FSE_FORCE_MEMORY_ACCESS) && (FSE_FORCE_MEMORY_ACCESS==1)
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
 
 static U16 FSE_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
 static U32 FSE_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 static U64 FSE_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
 
 #else
 
 static U16 FSE_read16(const void* memPtr)
 {
     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 static U32 FSE_read32(const void* memPtr)
 {
     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 static U64 FSE_read64(const void* memPtr)
 {
     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 #endif // FSE_FORCE_MEMORY_ACCESS
 
 static U16 FSE_readLE16(const void* memPtr)
 {
     if (FSE_isLittleEndian())
         return FSE_read16(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U16)(p[0] + (p[1]<<8));
     }
 }
 
 static U32 FSE_readLE32(const void* memPtr)
 {
     if (FSE_isLittleEndian())
         return FSE_read32(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
     }
 }
 
 
 static U64 FSE_readLE64(const void* memPtr)
 {
     if (FSE_isLittleEndian())
         return FSE_read64(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
     }
 }
 
 static size_t FSE_readLEST(const void* memPtr)
 {
     if (FSE_32bits())
         return (size_t)FSE_readLE32(memPtr);
     else
         return (size_t)FSE_readLE64(memPtr);
 }
 
 
 
 /****************************************************************
 *  Constants
 *****************************************************************/
 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
 #define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX
 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
 #endif
 
 
 /****************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /****************************************************************
 *  Complex types
 ****************************************************************/
 typedef struct
 {
     int deltaFindState;
     U32 deltaNbBits;
 } FSE_symbolCompressionTransform; /* total 8 bytes */
 
 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
 
 /****************************************************************
 *  Internal functions
 ****************************************************************/
 FORCE_INLINE unsigned FSE_highbit32 (U32 val)
 {
 #   if defined(_MSC_VER)   /* Visual */
     unsigned long r;
     _BitScanReverse ( &r, val );
     return (unsigned) r;
 #   elif defined(__GNUC__) && (GCC_VERSION >= 304)   /* GCC Intrinsic */
     return 31 - __builtin_clz (val);
 #   else   /* Software version */
     static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
     U32 v = val;
     unsigned r;
     v |= v >> 1;
     v |= v >> 2;
     v |= v >> 4;
     v |= v >> 8;
     v |= v >> 16;
     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
     return r;
 #   endif
 }
 
 
 /****************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 
 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
 
 #define FSE_DECODE_TYPE FSE_decode_t
 
 
 typedef struct {
     U16 tableLog;
     U16 fastMode;
 } FSE_DTableHeader;   /* sizeof U32 */
 
 static size_t FSE_buildDTable
 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)(ptr) + 1;   /* because dt is unsigned, 32-bits aligned on 32-bits */
     const U32 tableSize = 1 << tableLog;
     const U32 tableMask = tableSize-1;
     const U32 step = FSE_tableStep(tableSize);
     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
     U32 position = 0;
     U32 highThreshold = tableSize-1;
     const S16 largeLimit= (S16)(1 << (tableLog-1));
     U32 noLarge = 1;
     U32 s;
 
     /* Sanity Checks */
     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return (size_t)-FSE_ERROR_maxSymbolValue_tooLarge;
     if (tableLog > FSE_MAX_TABLELOG) return (size_t)-FSE_ERROR_tableLog_tooLarge;
 
     /* Init, lay down lowprob symbols */
     DTableH[0].tableLog = (U16)tableLog;
     for (s=0; s<=maxSymbolValue; s++)
     {
         if (normalizedCounter[s]==-1)
         {
             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
             symbolNext[s] = 1;
         }
         else
         {
             if (normalizedCounter[s] >= largeLimit) noLarge=0;
             symbolNext[s] = normalizedCounter[s];
         }
     }
 
     /* Spread symbols */
     for (s=0; s<=maxSymbolValue; s++)
     {
         int i;
         for (i=0; i highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }
     }
 
     if (position!=0) return (size_t)-FSE_ERROR_GENERIC;   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
 
     /* Build Decoding table */
     {
         U32 i;
         for (i=0; ifastMode = (U16)noLarge;
     return 0;
 }
 
 
 /******************************************
 *  FSE byte symbol
 ******************************************/
 #ifndef FSE_COMMONDEFS_ONLY
 
 static unsigned FSE_isError(size_t code) { return (code > (size_t)(-FSE_ERROR_maxCode)); }
 
 static short FSE_abs(short a)
 {
     return a<0? -a : a;
 }
 
 
 /****************************************************************
 *  Header bitstream management
 ****************************************************************/
 static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
                  const void* headerBuffer, size_t hbSize)
 {
     const BYTE* const istart = (const BYTE*) headerBuffer;
     const BYTE* const iend = istart + hbSize;
     const BYTE* ip = istart;
     int nbBits;
     int remaining;
     int threshold;
     U32 bitStream;
     int bitCount;
     unsigned charnum = 0;
     int previous0 = 0;
 
     if (hbSize < 4) return (size_t)-FSE_ERROR_srcSize_wrong;
     bitStream = FSE_readLE32(ip);
     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return (size_t)-FSE_ERROR_tableLog_tooLarge;
     bitStream >>= 4;
     bitCount = 4;
     *tableLogPtr = nbBits;
     remaining = (1<1) && (charnum<=*maxSVPtr))
     {
         if (previous0)
         {
             unsigned n0 = charnum;
             while ((bitStream & 0xFFFF) == 0xFFFF)
             {
                 n0+=24;
                 if (ip < iend-5)
                 {
                     ip+=2;
                     bitStream = FSE_readLE32(ip) >> bitCount;
                 }
                 else
                 {
                     bitStream >>= 16;
                     bitCount+=16;
                 }
             }
             while ((bitStream & 3) == 3)
             {
                 n0+=3;
                 bitStream>>=2;
                 bitCount+=2;
             }
             n0 += bitStream & 3;
             bitCount += 2;
             if (n0 > *maxSVPtr) return (size_t)-FSE_ERROR_maxSymbolValue_tooSmall;
             while (charnum < n0) normalizedCounter[charnum++] = 0;
             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
             {
                 ip += bitCount>>3;
                 bitCount &= 7;
                 bitStream = FSE_readLE32(ip) >> bitCount;
             }
             else
                 bitStream >>= 2;
         }
         {
             const short max = (short)((2*threshold-1)-remaining);
             short count;
 
             if ((bitStream & (threshold-1)) < (U32)max)
             {
                 count = (short)(bitStream & (threshold-1));
                 bitCount   += nbBits-1;
             }
             else
             {
                 count = (short)(bitStream & (2*threshold-1));
                 if (count >= threshold) count -= max;
                 bitCount   += nbBits;
             }
 
             count--;   /* extra accuracy */
             remaining -= FSE_abs(count);
             normalizedCounter[charnum++] = count;
             previous0 = !count;
             while (remaining < threshold)
             {
                 nbBits--;
                 threshold >>= 1;
             }
 
             {
                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
                 {
                     ip += bitCount>>3;
                     bitCount &= 7;
                 }
                 else
                 {
                     bitCount -= (int)(8 * (iend - 4 - ip));
                     ip = iend - 4;
                 }
                 bitStream = FSE_readLE32(ip) >> (bitCount & 31);
             }
         }
     }
     if (remaining != 1) return (size_t)-FSE_ERROR_GENERIC;
     *maxSVPtr = charnum-1;
 
     ip += (bitCount+7)>>3;
     if ((size_t)(ip-istart) > hbSize) return (size_t)-FSE_ERROR_srcSize_wrong;
     return ip-istart;
 }
 
 
 /*********************************************************
 *  Decompression (Byte symbols)
 *********************************************************/
 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
 
     DTableH->tableLog = 0;
     DTableH->fastMode = 0;
 
     cell->newState = 0;
     cell->symbol = symbolValue;
     cell->nbBits = 0;
 
     return 0;
 }
 
 
 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
     const unsigned tableSize = 1 << nbBits;
     const unsigned tableMask = tableSize - 1;
     const unsigned maxSymbolValue = tableMask;
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return (size_t)-FSE_ERROR_GENERIC;             /* min size */
 
     /* Build Decoding Table */
     DTableH->tableLog = (U16)nbBits;
     DTableH->fastMode = 1;
     for (s=0; s<=maxSymbolValue; s++)
     {
         dinfo[s].newState = 0;
         dinfo[s].symbol = (BYTE)s;
         dinfo[s].nbBits = (BYTE)nbBits;
     }
 
     return 0;
 }
 
 
 /* FSE_initDStream
  * Initialize a FSE_DStream_t.
  * srcBuffer must point at the beginning of an FSE block.
  * The function result is the size of the FSE_block (== srcSize).
  * If srcSize is too small, the function will return an errorCode;
  */
 static size_t FSE_initDStream(FSE_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
 {
     if (srcSize < 1) return (size_t)-FSE_ERROR_srcSize_wrong;
 
     if (srcSize >=  sizeof(size_t))
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
         bitD->bitContainer = FSE_readLEST(bitD->ptr);
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC;   /* stop bit not present */
         bitD->bitsConsumed = 8 - FSE_highbit32(contain32);
     }
     else
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = bitD->start;
         bitD->bitContainer = *(const BYTE*)(bitD->start);
         switch(srcSize)
         {
             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
+                    /* fallthrough */
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
+                    /* fallthrough */
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
+                    /* fallthrough */
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
+                    /* fallthrough */
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
+                    /* fallthrough */
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
+                    /* fallthrough */
             default:;
         }
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC;   /* stop bit not present */
         bitD->bitsConsumed = 8 - FSE_highbit32(contain32);
         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
     }
 
     return srcSize;
 }
 
 
 /*!FSE_lookBits
  * Provides next n bits from the bitContainer.
  * bitContainer is not modified (bits are still present for next read/look)
  * On 32-bits, maxNbBits==25
  * On 64-bits, maxNbBits==57
  * return : value extracted.
  */
 static size_t FSE_lookBits(FSE_DStream_t* bitD, U32 nbBits)
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
 }
 
 static size_t FSE_lookBitsFast(FSE_DStream_t* bitD, U32 nbBits)   /* only if nbBits >= 1 !! */
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
 }
 
 static void FSE_skipBits(FSE_DStream_t* bitD, U32 nbBits)
 {
     bitD->bitsConsumed += nbBits;
 }
 
 
 /*!FSE_readBits
  * Read next n bits from the bitContainer.
  * On 32-bits, don't read more than maxNbBits==25
  * On 64-bits, don't read more than maxNbBits==57
  * Use the fast variant *only* if n >= 1.
  * return : value extracted.
  */
 static size_t FSE_readBits(FSE_DStream_t* bitD, U32 nbBits)
 {
     size_t value = FSE_lookBits(bitD, nbBits);
     FSE_skipBits(bitD, nbBits);
     return value;
 }
 
 static size_t FSE_readBitsFast(FSE_DStream_t* bitD, U32 nbBits)   /* only if nbBits >= 1 !! */
 {
     size_t value = FSE_lookBitsFast(bitD, nbBits);
     FSE_skipBits(bitD, nbBits);
     return value;
 }
 
 static unsigned FSE_reloadDStream(FSE_DStream_t* bitD)
 {
     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
         return FSE_DStream_tooFar;
 
     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
     {
         bitD->ptr -= bitD->bitsConsumed >> 3;
         bitD->bitsConsumed &= 7;
         bitD->bitContainer = FSE_readLEST(bitD->ptr);
         return FSE_DStream_unfinished;
     }
     if (bitD->ptr == bitD->start)
     {
         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return FSE_DStream_endOfBuffer;
         return FSE_DStream_completed;
     }
     {
         U32 nbBytes = bitD->bitsConsumed >> 3;
         U32 result = FSE_DStream_unfinished;
         if (bitD->ptr - nbBytes < bitD->start)
         {
             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
             result = FSE_DStream_endOfBuffer;
         }
         bitD->ptr -= nbBytes;
         bitD->bitsConsumed -= nbBytes*8;
         bitD->bitContainer = FSE_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
         return result;
     }
 }
 
 
 static void FSE_initDState(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD, const FSE_DTable* dt)
 {
     const void* ptr = dt;
     const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
     DStatePtr->state = FSE_readBits(bitD, DTableH->tableLog);
     FSE_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 static BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32  nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = FSE_readBits(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 static BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32 nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = FSE_readBitsFast(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 /* FSE_endOfDStream
    Tells if bitD has reached end of bitStream or not */
 
 static unsigned FSE_endOfDStream(const FSE_DStream_t* bitD)
 {
     return ((bitD->ptr == bitD->start) && (bitD->bitsConsumed == sizeof(bitD->bitContainer)*8));
 }
 
 static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
 {
     return DStatePtr->state == 0;
 }
 
 
 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
           void* dst, size_t maxDstSize,
     const void* cSrc, size_t cSrcSize,
     const FSE_DTable* dt, const unsigned fast)
 {
     BYTE* const ostart = (BYTE*) dst;
     BYTE* op = ostart;
     BYTE* const omax = op + maxDstSize;
     BYTE* const olimit = omax-3;
 
     FSE_DStream_t bitD;
     FSE_DState_t state1;
     FSE_DState_t state2;
     size_t errorCode;
 
     /* Init */
     errorCode = FSE_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
     if (FSE_isError(errorCode)) return errorCode;
 
     FSE_initDState(&state1, &bitD, dt);
     FSE_initDState(&state2, &bitD, dt);
 
 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
 
     /* 4 symbols per loop */
     for ( ; (FSE_reloadDStream(&bitD)==FSE_DStream_unfinished) && (op sizeof(bitD.bitContainer)*8)    /* This test must be static */
             FSE_reloadDStream(&bitD);
 
         op[1] = FSE_GETSYMBOL(&state2);
 
         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             { if (FSE_reloadDStream(&bitD) > FSE_DStream_unfinished) { op+=2; break; } }
 
         op[2] = FSE_GETSYMBOL(&state1);
 
         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             FSE_reloadDStream(&bitD);
 
         op[3] = FSE_GETSYMBOL(&state2);
     }
 
     /* tail */
     /* note : FSE_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly FSE_DStream_completed */
     while (1)
     {
         if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state1);
 
         if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state2);
     }
 
     /* end ? */
     if (FSE_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
         return op-ostart;
 
     if (op==omax) return (size_t)-FSE_ERROR_dstSize_tooSmall;   /* dst buffer is full, but cSrc unfinished */
 
     return (size_t)-FSE_ERROR_corruptionDetected;
 }
 
 
 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
                             const void* cSrc, size_t cSrcSize,
                             const FSE_DTable* dt)
 {
     FSE_DTableHeader DTableH;
     memcpy(&DTableH, dt, sizeof(DTableH));   /* memcpy() into local variable, to avoid strict aliasing warning */
 
     /* select fast mode (static) */
     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
 }
 
 
 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
 {
     const BYTE* const istart = (const BYTE*)cSrc;
     const BYTE* ip = istart;
     short counting[FSE_MAX_SYMBOL_VALUE+1];
     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
     size_t errorCode;
 
     if (cSrcSize<2) return (size_t)-FSE_ERROR_srcSize_wrong;   /* too small input size */
 
     /* normal FSE decoding mode */
     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
     if (FSE_isError(errorCode)) return errorCode;
     if (errorCode >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong;   /* too small input size */
     ip += errorCode;
     cSrcSize -= errorCode;
 
     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
     if (FSE_isError(errorCode)) return errorCode;
 
     /* always return, even if it is an error code */
     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
 }
 
 
 
 /* *******************************************************
 *  Huff0 : Huffman block compression
 *********************************************************/
 #define HUF_MAX_SYMBOL_VALUE 255
 #define HUF_DEFAULT_TABLELOG  12       /* used by default, when not specified */
 #define HUF_MAX_TABLELOG  12           /* max possible tableLog; for allocation purpose; can be modified */
 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
 #  error "HUF_MAX_TABLELOG is too large !"
 #endif
 
 typedef struct HUF_CElt_s {
   U16  val;
   BYTE nbBits;
 } HUF_CElt ;
 
 typedef struct nodeElt_s {
     U32 count;
     U16 parent;
     BYTE byte;
     BYTE nbBits;
 } nodeElt;
 
 
 /* *******************************************************
 *  Huff0 : Huffman block decompression
 *********************************************************/
 typedef struct {
     BYTE byte;
     BYTE nbBits;
 } HUF_DElt;
 
 static size_t HUF_readDTable (U16* DTable, const void* src, size_t srcSize)
 {
     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];  /* large enough for values from 0 to 16 */
     U32 weightTotal;
     U32 maxBits;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize;
     size_t oSize;
     U32 n;
     U32 nextRankStart;
     void* ptr = DTable+1;
     HUF_DElt* const dt = (HUF_DElt*)ptr;
 
     if (!srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
     iSize = ip[0];
 
     FSE_STATIC_ASSERT(sizeof(HUF_DElt) == sizeof(U16));   /* if compilation fails here, assertion is false */
     //memset(huffWeight, 0, sizeof(huffWeight));   /* should not be necessary, but some analyzer complain ... */
     if (iSize >= 128)  /* special header */
     {
         if (iSize >= (242))   /* RLE */
         {
             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
             oSize = l[iSize-242];
             memset(huffWeight, 1, sizeof(huffWeight));
             iSize = 0;
         }
         else   /* Incompressible */
         {
             oSize = iSize - 127;
             iSize = ((oSize+1)/2);
             if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
             ip += 1;
             for (n=0; n> 4;
                 huffWeight[n+1] = ip[n/2] & 15;
             }
         }
     }
     else  /* header compressed with FSE (normal case) */
     {
         if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
         oSize = FSE_decompress(huffWeight, HUF_MAX_SYMBOL_VALUE, ip+1, iSize);   /* max 255 values decoded, last one is implied */
         if (FSE_isError(oSize)) return oSize;
     }
 
     /* collect weight stats */
     memset(rankVal, 0, sizeof(rankVal));
     weightTotal = 0;
     for (n=0; n= HUF_ABSOLUTEMAX_TABLELOG) return (size_t)-FSE_ERROR_corruptionDetected;
         rankVal[huffWeight[n]]++;
         weightTotal += (1 << huffWeight[n]) >> 1;
     }
     if (weightTotal == 0) return (size_t)-FSE_ERROR_corruptionDetected;
 
     /* get last non-null symbol weight (implied, total must be 2^n) */
     maxBits = FSE_highbit32(weightTotal) + 1;
     if (maxBits > DTable[0]) return (size_t)-FSE_ERROR_tableLog_tooLarge;   /* DTable is too small */
     DTable[0] = (U16)maxBits;
     {
         U32 total = 1 << maxBits;
         U32 rest = total - weightTotal;
         U32 verif = 1 << FSE_highbit32(rest);
         U32 lastWeight = FSE_highbit32(rest) + 1;
         if (verif != rest) return (size_t)-FSE_ERROR_corruptionDetected;    /* last value must be a clean power of 2 */
         huffWeight[oSize] = (BYTE)lastWeight;
         rankVal[lastWeight]++;
     }
 
     /* check tree construction validity */
     if ((rankVal[1] < 2) || (rankVal[1] & 1)) return (size_t)-FSE_ERROR_corruptionDetected;   /* by construction : at least 2 elts of rank 1, must be even */
 
     /* Prepare ranks */
     nextRankStart = 0;
     for (n=1; n<=maxBits; n++)
     {
         U32 current = nextRankStart;
         nextRankStart += (rankVal[n] << (n-1));
         rankVal[n] = current;
     }
 
     /* fill DTable */
     for (n=0; n<=oSize; n++)
     {
         const U32 w = huffWeight[n];
         const U32 length = (1 << w) >> 1;
         U32 i;
         HUF_DElt D;
         D.byte = (BYTE)n; D.nbBits = (BYTE)(maxBits + 1 - w);
         for (i = rankVal[w]; i < rankVal[w] + length; i++)
             dt[i] = D;
         rankVal[w] += length;
     }
 
     return iSize+1;
 }
 
 
 static BYTE HUF_decodeSymbol(FSE_DStream_t* Dstream, const HUF_DElt* dt, const U32 dtLog)
 {
         const size_t val = FSE_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
         const BYTE c = dt[val].byte;
         FSE_skipBits(Dstream, dt[val].nbBits);
         return c;
 }
 
 static size_t HUF_decompress_usingDTable(   /* -3% slower when non static */
           void* dst, size_t maxDstSize,
     const void* cSrc, size_t cSrcSize,
     const U16* DTable)
 {
     BYTE* const ostart = (BYTE*) dst;
     BYTE* op = ostart;
     BYTE* const omax = op + maxDstSize;
     BYTE* const olimit = omax-15;
 
     const void* ptr = DTable;
     const HUF_DElt* const dt = (const HUF_DElt*)(ptr)+1;
     const U32 dtLog = DTable[0];
     size_t errorCode;
     U32 reloadStatus;
 
     /* Init */
 
     const U16* jumpTable = (const U16*)cSrc;
     const size_t length1 = FSE_readLE16(jumpTable);
     const size_t length2 = FSE_readLE16(jumpTable+1);
     const size_t length3 = FSE_readLE16(jumpTable+2);
     const size_t length4 = cSrcSize - 6 - length1 - length2 - length3;   // check coherency !!
     const char* const start1 = (const char*)(cSrc) + 6;
     const char* const start2 = start1 + length1;
     const char* const start3 = start2 + length2;
     const char* const start4 = start3 + length3;
     FSE_DStream_t bitD1, bitD2, bitD3, bitD4;
 
     if (length1+length2+length3+6 >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
 
     errorCode = FSE_initDStream(&bitD1, start1, length1);
     if (FSE_isError(errorCode)) return errorCode;
     errorCode = FSE_initDStream(&bitD2, start2, length2);
     if (FSE_isError(errorCode)) return errorCode;
     errorCode = FSE_initDStream(&bitD3, start3, length3);
     if (FSE_isError(errorCode)) return errorCode;
     errorCode = FSE_initDStream(&bitD4, start4, length4);
     if (FSE_isError(errorCode)) return errorCode;
 
     reloadStatus=FSE_reloadDStream(&bitD2);
 
     /* 16 symbols per loop */
     for ( ; (reloadStatus12)) FSE_reloadDStream(&Dstream)
 
 #define HUF_DECODE_SYMBOL_2(n, Dstream) \
         op[n] = HUF_decodeSymbol(&Dstream, dt, dtLog); \
         if (FSE_32bits()) FSE_reloadDStream(&Dstream)
 
         HUF_DECODE_SYMBOL_1( 0, bitD1);
         HUF_DECODE_SYMBOL_1( 1, bitD2);
         HUF_DECODE_SYMBOL_1( 2, bitD3);
         HUF_DECODE_SYMBOL_1( 3, bitD4);
         HUF_DECODE_SYMBOL_2( 4, bitD1);
         HUF_DECODE_SYMBOL_2( 5, bitD2);
         HUF_DECODE_SYMBOL_2( 6, bitD3);
         HUF_DECODE_SYMBOL_2( 7, bitD4);
         HUF_DECODE_SYMBOL_1( 8, bitD1);
         HUF_DECODE_SYMBOL_1( 9, bitD2);
         HUF_DECODE_SYMBOL_1(10, bitD3);
         HUF_DECODE_SYMBOL_1(11, bitD4);
         HUF_DECODE_SYMBOL_0(12, bitD1);
         HUF_DECODE_SYMBOL_0(13, bitD2);
         HUF_DECODE_SYMBOL_0(14, bitD3);
         HUF_DECODE_SYMBOL_0(15, bitD4);
     }
 
     if (reloadStatus!=FSE_DStream_completed)   /* not complete : some bitStream might be FSE_DStream_unfinished */
         return (size_t)-FSE_ERROR_corruptionDetected;
 
     /* tail */
     {
         // bitTail = bitD1;   // *much* slower : -20% !??!
         FSE_DStream_t bitTail;
         bitTail.ptr = bitD1.ptr;
         bitTail.bitsConsumed = bitD1.bitsConsumed;
         bitTail.bitContainer = bitD1.bitContainer;   // required in case of FSE_DStream_endOfBuffer
         bitTail.start = start1;
         for ( ; (FSE_reloadDStream(&bitTail) < FSE_DStream_completed) && (op= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
     ip += errorCode;
     cSrcSize -= errorCode;
 
     return HUF_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, DTable);
 }
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
 
 /*
     zstd - standard compression library
     Copyright (C) 2014-2015, Yann Collet.
 
     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are
     met:
     * Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the above
     copyright notice, this list of conditions and the following disclaimer
     in the documentation and/or other materials provided with the
     distribution.
     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - zstd source repository : https://github.com/Cyan4973/zstd
     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
 */
 
 /****************************************************************
 *  Tuning parameters
 *****************************************************************/
 /* MEMORY_USAGE :
 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect */
 #define ZSTD_MEMORY_USAGE 17
 
 
 /**************************************
    CPU Feature Detection
 **************************************/
 /*
  * Automated efficient unaligned memory access detection
  * Based on known hardware architectures
  * This list will be updated thanks to feedbacks
  */
 #if defined(CPU_HAS_EFFICIENT_UNALIGNED_MEMORY_ACCESS) \
     || defined(__ARM_FEATURE_UNALIGNED) \
     || defined(__i386__) || defined(__x86_64__) \
     || defined(_M_IX86) || defined(_M_X64) \
     || defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_8__) \
     || (defined(_M_ARM) && (_M_ARM >= 7))
 #  define ZSTD_UNALIGNED_ACCESS 1
 #else
 #  define ZSTD_UNALIGNED_ACCESS 0
 #endif
 
 
 /********************************************************
 *  Includes
 *********************************************************/
 #include       /* calloc */
 #include       /* memcpy, memmove */
 #include        /* debug : printf */
 
 
 /********************************************************
 *  Compiler specifics
 *********************************************************/
 #ifdef __AVX2__
 #  include    /* AVX2 intrinsics */
 #endif
 
 #ifdef _MSC_VER    /* Visual Studio */
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
 #endif
 
 
 #ifndef MEM_ACCESS_MODULE
 #define MEM_ACCESS_MODULE
 /********************************************************
 *  Basic Types
 *********************************************************/
 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 # include 
 typedef  uint8_t BYTE;
 typedef uint16_t U16;
 typedef  int16_t S16;
 typedef uint32_t U32;
 typedef  int32_t S32;
 typedef uint64_t U64;
 #else
 typedef unsigned char       BYTE;
 typedef unsigned short      U16;
 typedef   signed short      S16;
 typedef unsigned int        U32;
 typedef   signed int        S32;
 typedef unsigned long long  U64;
 #endif
 
 #endif   /* MEM_ACCESS_MODULE */
 
 
 /********************************************************
 *  Constants
 *********************************************************/
 static const U32 ZSTD_magicNumber = 0xFD2FB51E;   /* 3rd version : seqNb header */
 
 #define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
 #define HASH_TABLESIZE (1 << HASH_LOG)
 #define HASH_MASK (HASH_TABLESIZE - 1)
 
 #define KNUTH 2654435761
 
 #define BIT7 128
 #define BIT6  64
 #define BIT5  32
 #define BIT4  16
 
 #define KB *(1 <<10)
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
 
 #define WORKPLACESIZE (BLOCKSIZE*3)
 #define MINMATCH 4
 #define MLbits   7
 #define LLbits   6
 #define Offbits  5
 #define MaxML  ((1<>3];
 #else
     U32 hashTable[HASH_TABLESIZE];
 #endif
     BYTE buffer[WORKPLACESIZE];
 } cctxi_t;
 
 
 
 
 /**************************************
 *  Error Management
 **************************************/
 /* published entry point */
 unsigned ZSTDv01_isError(size_t code) { return ERR_isError(code); }
 
 
 /**************************************
 *  Tool functions
 **************************************/
 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
 #define ZSTD_VERSION_MINOR    1    /* for new (non-breaking) interface capabilities */
 #define ZSTD_VERSION_RELEASE  3    /* for tweaks, bug-fixes, or development */
 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
 
 /**************************************************************
 *   Decompression code
 **************************************************************/
 
-size_t ZSTDv01_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
+static size_t ZSTDv01_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
 {
     const BYTE* const in = (const BYTE* const)src;
     BYTE headerFlags;
     U32 cSize;
 
     if (srcSize < 3) return ERROR(srcSize_wrong);
 
     headerFlags = *in;
     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
 
     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
 
     if (bpPtr->blockType == bt_end) return 0;
     if (bpPtr->blockType == bt_rle) return 1;
     return cSize;
 }
 
 
 static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
     memcpy(dst, src, srcSize);
     return srcSize;
 }
 
 
 static size_t ZSTD_decompressLiterals(void* ctx,
                                       void* dst, size_t maxDstSize,
                                 const void* src, size_t srcSize)
 {
     BYTE* op = (BYTE*)dst;
     BYTE* const oend = op + maxDstSize;
     const BYTE* ip = (const BYTE*)src;
     size_t errorCode;
     size_t litSize;
 
     /* check : minimum 2, for litSize, +1, for content */
     if (srcSize <= 3) return ERROR(corruption_detected);
 
     litSize = ip[1] + (ip[0]<<8);
     litSize += ((ip[-3] >> 3) & 7) << 16;   // mmmmh....
     op = oend - litSize;
 
     (void)ctx;
     if (litSize > maxDstSize) return ERROR(dstSize_tooSmall);
     errorCode = HUF_decompress(op, litSize, ip+2, srcSize-2);
     if (FSE_isError(errorCode)) return ERROR(GENERIC);
     return litSize;
 }
 
 
-size_t ZSTDv01_decodeLiteralsBlock(void* ctx,
+static size_t ZSTDv01_decodeLiteralsBlock(void* ctx,
                                 void* dst, size_t maxDstSize,
                           const BYTE** litStart, size_t* litSize,
                           const void* src, size_t srcSize)
 {
     const BYTE* const istart = (const BYTE* const)src;
     const BYTE* ip = istart;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + maxDstSize;
     blockProperties_t litbp;
 
     size_t litcSize = ZSTDv01_getcBlockSize(src, srcSize, &litbp);
     if (ZSTDv01_isError(litcSize)) return litcSize;
     if (litcSize > srcSize - ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
     ip += ZSTD_blockHeaderSize;
 
     switch(litbp.blockType)
     {
     case bt_raw:
         *litStart = ip;
         ip += litcSize;
         *litSize = litcSize;
         break;
     case bt_rle:
         {
             size_t rleSize = litbp.origSize;
             if (rleSize>maxDstSize) return ERROR(dstSize_tooSmall);
             if (!srcSize) return ERROR(srcSize_wrong);
             memset(oend - rleSize, *ip, rleSize);
             *litStart = oend - rleSize;
             *litSize = rleSize;
             ip++;
             break;
         }
     case bt_compressed:
         {
             size_t decodedLitSize = ZSTD_decompressLiterals(ctx, dst, maxDstSize, ip, litcSize);
             if (ZSTDv01_isError(decodedLitSize)) return decodedLitSize;
             *litStart = oend - decodedLitSize;
             *litSize = decodedLitSize;
             ip += litcSize;
             break;
         }
     case bt_end:
     default:
         return ERROR(GENERIC);
     }
 
     return ip-istart;
 }
 
 
-size_t ZSTDv01_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
+static size_t ZSTDv01_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
                          const void* src, size_t srcSize)
 {
     const BYTE* const istart = (const BYTE* const)src;
     const BYTE* ip = istart;
     const BYTE* const iend = istart + srcSize;
     U32 LLtype, Offtype, MLtype;
     U32 LLlog, Offlog, MLlog;
     size_t dumpsLength;
 
     /* check */
     if (srcSize < 5) return ERROR(srcSize_wrong);
 
     /* SeqHead */
     *nbSeq = ZSTD_readLE16(ip); ip+=2;
     LLtype  = *ip >> 6;
     Offtype = (*ip >> 4) & 3;
     MLtype  = (*ip >> 2) & 3;
     if (*ip & 2)
     {
         dumpsLength  = ip[2];
         dumpsLength += ip[1] << 8;
         ip += 3;
     }
     else
     {
         dumpsLength  = ip[1];
         dumpsLength += (ip[0] & 1) << 8;
         ip += 2;
     }
     *dumpsPtr = ip;
     ip += dumpsLength;
     *dumpsLengthPtr = dumpsLength;
 
     /* check */
     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
 
     /* sequences */
     {
         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL and MaxOff */
         size_t headerSize;
 
         /* Build DTables */
         switch(LLtype)
         {
         case bt_rle :
             LLlog = 0;
             FSE_buildDTable_rle(DTableLL, *ip++); break;
         case bt_raw :
             LLlog = LLbits;
             FSE_buildDTable_raw(DTableLL, LLbits); break;
         default :
             {   U32 max = MaxLL;
                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
                 ip += headerSize;
                 FSE_buildDTable(DTableLL, norm, max, LLlog);
         }   }
 
         switch(Offtype)
         {
         case bt_rle :
             Offlog = 0;
             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
             FSE_buildDTable_rle(DTableOffb, *ip++); break;
         case bt_raw :
             Offlog = Offbits;
             FSE_buildDTable_raw(DTableOffb, Offbits); break;
         default :
             {   U32 max = MaxOff;
                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
                 ip += headerSize;
                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
         }   }
 
         switch(MLtype)
         {
         case bt_rle :
             MLlog = 0;
             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
             FSE_buildDTable_rle(DTableML, *ip++); break;
         case bt_raw :
             MLlog = MLbits;
             FSE_buildDTable_raw(DTableML, MLbits); break;
         default :
             {   U32 max = MaxML;
                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
                 ip += headerSize;
                 FSE_buildDTable(DTableML, norm, max, MLlog);
     }   }   }
 
     return ip-istart;
 }
 
 
 typedef struct {
     size_t litLength;
     size_t offset;
     size_t matchLength;
 } seq_t;
 
 typedef struct {
     FSE_DStream_t DStream;
     FSE_DState_t stateLL;
     FSE_DState_t stateOffb;
     FSE_DState_t stateML;
     size_t prevOffset;
     const BYTE* dumps;
     const BYTE* dumpsEnd;
 } seqState_t;
 
 
 static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
 {
     size_t litLength;
     size_t prevOffset;
     size_t offset;
     size_t matchLength;
     const BYTE* dumps = seqState->dumps;
     const BYTE* const de = seqState->dumpsEnd;
 
     /* Literal length */
     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
     prevOffset = litLength ? seq->offset : seqState->prevOffset;
     seqState->prevOffset = seq->offset;
     if (litLength == MaxLL)
     {
         U32 add = dumps 1 byte */
                 dumps += 3;
             }
         }
     }
 
     /* Offset */
     {
         U32 offsetCode, nbBits;
         offsetCode = FSE_decodeSymbol(&(seqState->stateOffb), &(seqState->DStream));
         if (ZSTD_32bits()) FSE_reloadDStream(&(seqState->DStream));
         nbBits = offsetCode - 1;
         if (offsetCode==0) nbBits = 0;   /* cmove */
         offset = ((size_t)1 << (nbBits & ((sizeof(offset)*8)-1))) + FSE_readBits(&(seqState->DStream), nbBits);
         if (ZSTD_32bits()) FSE_reloadDStream(&(seqState->DStream));
         if (offsetCode==0) offset = prevOffset;
     }
 
     /* MatchLength */
     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
     if (matchLength == MaxML)
     {
         U32 add = dumps 1 byte */
                 dumps += 3;
             }
         }
     }
     matchLength += MINMATCH;
 
     /* save result */
     seq->litLength = litLength;
     seq->offset = offset;
     seq->matchLength = matchLength;
     seqState->dumps = dumps;
 }
 
 
 static size_t ZSTD_execSequence(BYTE* op,
                                 seq_t sequence,
                                 const BYTE** litPtr, const BYTE* const litLimit,
                                 BYTE* const base, BYTE* const oend)
 {
     static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
     static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11};   /* substracted */
     const BYTE* const ostart = op;
     const size_t litLength = sequence.litLength;
     BYTE* const endMatch = op + litLength + sequence.matchLength;    /* risk : address space overflow (32-bits) */
     const BYTE* const litEnd = *litPtr + litLength;
 
     /* check */
     if (endMatch > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
     if (litEnd > litLimit) return ERROR(corruption_detected);
     if (sequence.matchLength > (size_t)(*litPtr-op))  return ERROR(dstSize_tooSmall);    /* overwrite literal segment */
 
     /* copy Literals */
     if (((size_t)(*litPtr - op) < 8) || ((size_t)(oend-litEnd) < 8) || (op+litLength > oend-8))
         memmove(op, *litPtr, litLength);   /* overwrite risk */
     else
         ZSTD_wildcopy(op, *litPtr, litLength);
     op += litLength;
     *litPtr = litEnd;   /* update for next sequence */
 
     /* check : last match must be at a minimum distance of 8 from end of dest buffer */
     if (oend-op < 8) return ERROR(dstSize_tooSmall);
 
     /* copy Match */
     {
         const U32 overlapRisk = (((size_t)(litEnd - endMatch)) < 12);
         const BYTE* match = op - sequence.offset;            /* possible underflow at op - offset ? */
         size_t qutt = 12;
         U64 saved[2];
 
         /* check */
         if (match < base) return ERROR(corruption_detected);
         if (sequence.offset > (size_t)base) return ERROR(corruption_detected);
 
         /* save beginning of literal sequence, in case of write overlap */
         if (overlapRisk)
         {
             if ((endMatch + qutt) > oend) qutt = oend-endMatch;
             memcpy(saved, endMatch, qutt);
         }
 
         if (sequence.offset < 8)
         {
             const int dec64 = dec64table[sequence.offset];
             op[0] = match[0];
             op[1] = match[1];
             op[2] = match[2];
             op[3] = match[3];
             match += dec32table[sequence.offset];
             ZSTD_copy4(op+4, match);
             match -= dec64;
         } else { ZSTD_copy8(op, match); }
         op += 8; match += 8;
 
         if (endMatch > oend-(16-MINMATCH))
         {
             if (op < oend-8)
             {
                 ZSTD_wildcopy(op, match, (oend-8) - op);
                 match += (oend-8) - op;
                 op = oend-8;
             }
             while (opLLTable;
     U32* DTableML = dctx->MLTable;
     U32* DTableOffb = dctx->OffTable;
     BYTE* const base = (BYTE*) (dctx->base);
 
     /* Build Decoding Tables */
     errorCode = ZSTDv01_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
                                       DTableLL, DTableML, DTableOffb,
                                       ip, iend-ip);
     if (ZSTDv01_isError(errorCode)) return errorCode;
     ip += errorCode;
 
     /* Regen sequences */
     {
         seq_t sequence;
         seqState_t seqState;
 
         memset(&sequence, 0, sizeof(sequence));
         seqState.dumps = dumps;
         seqState.dumpsEnd = dumps + dumpsLength;
         seqState.prevOffset = 1;
         errorCode = FSE_initDStream(&(seqState.DStream), ip, iend-ip);
         if (FSE_isError(errorCode)) return ERROR(corruption_detected);
         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
 
         for ( ; (FSE_reloadDStream(&(seqState.DStream)) <= FSE_DStream_completed) && (nbSeq>0) ; )
         {
             size_t oneSeqSize;
             nbSeq--;
             ZSTD_decodeSequence(&sequence, &seqState);
             oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend);
             if (ZSTDv01_isError(oneSeqSize)) return oneSeqSize;
             op += oneSeqSize;
         }
 
         /* check if reached exact end */
         if ( !FSE_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* requested too much : data is corrupted */
         if (nbSeq<0) return ERROR(corruption_detected);   /* requested too many sequences : data is corrupted */
 
         /* last literal segment */
         {
             size_t lastLLSize = litEnd - litPtr;
             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
             if (op != litPtr) memmove(op, litPtr, lastLLSize);
             op += lastLLSize;
         }
     }
 
     return op-ostart;
 }
 
 
 static size_t ZSTD_decompressBlock(
                             void* ctx,
                             void* dst, size_t maxDstSize,
                       const void* src, size_t srcSize)
 {
     /* blockType == blockCompressed, srcSize is trusted */
     const BYTE* ip = (const BYTE*)src;
     const BYTE* litPtr = NULL;
     size_t litSize = 0;
     size_t errorCode;
 
     /* Decode literals sub-block */
     errorCode = ZSTDv01_decodeLiteralsBlock(ctx, dst, maxDstSize, &litPtr, &litSize, src, srcSize);
     if (ZSTDv01_isError(errorCode)) return errorCode;
     ip += errorCode;
     srcSize -= errorCode;
 
     return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize, litPtr, litSize);
 }
 
 
 size_t ZSTDv01_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     const BYTE* ip = (const BYTE*)src;
     const BYTE* iend = ip + srcSize;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* op = ostart;
     BYTE* const oend = ostart + maxDstSize;
     size_t remainingSize = srcSize;
     U32 magicNumber;
     size_t errorCode=0;
     blockProperties_t blockProperties;
 
     /* Frame Header */
     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
     magicNumber = ZSTD_readBE32(src);
     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t blockSize = ZSTDv01_getcBlockSize(ip, iend-ip, &blockProperties);
         if (ZSTDv01_isError(blockSize)) return blockSize;
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
         if (blockSize > remainingSize) return ERROR(srcSize_wrong);
 
         switch(blockProperties.blockType)
         {
         case bt_compressed:
             errorCode = ZSTD_decompressBlock(ctx, op, oend-op, ip, blockSize);
             break;
         case bt_raw :
             errorCode = ZSTD_copyUncompressedBlock(op, oend-op, ip, blockSize);
             break;
         case bt_rle :
             return ERROR(GENERIC);   /* not yet supported */
             break;
         case bt_end :
             /* end of frame */
             if (remainingSize) return ERROR(srcSize_wrong);
             break;
         default:
             return ERROR(GENERIC);
         }
         if (blockSize == 0) break;   /* bt_end */
 
         if (ZSTDv01_isError(errorCode)) return errorCode;
         op += errorCode;
         ip += blockSize;
         remainingSize -= blockSize;
     }
 
     return op-ostart;
 }
 
 size_t ZSTDv01_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     dctx_t ctx;
     ctx.base = dst;
     return ZSTDv01_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
 }
 
 size_t ZSTDv01_findFrameCompressedSize(const void* src, size_t srcSize)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
     U32 magicNumber;
     blockProperties_t blockProperties;
 
     /* Frame Header */
     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
     magicNumber = ZSTD_readBE32(src);
     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t blockSize = ZSTDv01_getcBlockSize(ip, remainingSize, &blockProperties);
         if (ZSTDv01_isError(blockSize)) return blockSize;
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
         if (blockSize > remainingSize) return ERROR(srcSize_wrong);
 
         if (blockSize == 0) break;   /* bt_end */
 
         ip += blockSize;
         remainingSize -= blockSize;
     }
 
     return ip - (const BYTE*)src;
 }
 
 /*******************************
 *  Streaming Decompression API
 *******************************/
 
 size_t ZSTDv01_resetDCtx(ZSTDv01_Dctx* dctx)
 {
     dctx->expected = ZSTD_frameHeaderSize;
     dctx->phase = 0;
     dctx->previousDstEnd = NULL;
     dctx->base = NULL;
     return 0;
 }
 
 ZSTDv01_Dctx* ZSTDv01_createDCtx(void)
 {
     ZSTDv01_Dctx* dctx = (ZSTDv01_Dctx*)malloc(sizeof(ZSTDv01_Dctx));
     if (dctx==NULL) return NULL;
     ZSTDv01_resetDCtx(dctx);
     return dctx;
 }
 
 size_t ZSTDv01_freeDCtx(ZSTDv01_Dctx* dctx)
 {
     free(dctx);
     return 0;
 }
 
 size_t ZSTDv01_nextSrcSizeToDecompress(ZSTDv01_Dctx* dctx)
 {
     return ((dctx_t*)dctx)->expected;
 }
 
 size_t ZSTDv01_decompressContinue(ZSTDv01_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     dctx_t* ctx = (dctx_t*)dctx;
 
     /* Sanity check */
     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
     if (dst != ctx->previousDstEnd)  /* not contiguous */
         ctx->base = dst;
 
     /* Decompress : frame header */
     if (ctx->phase == 0)
     {
         /* Check frame magic header */
         U32 magicNumber = ZSTD_readBE32(src);
         if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
         ctx->phase = 1;
         ctx->expected = ZSTD_blockHeaderSize;
         return 0;
     }
 
     /* Decompress : block header */
     if (ctx->phase == 1)
     {
         blockProperties_t bp;
         size_t blockSize = ZSTDv01_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
         if (ZSTDv01_isError(blockSize)) return blockSize;
         if (bp.blockType == bt_end)
         {
             ctx->expected = 0;
             ctx->phase = 0;
         }
         else
         {
             ctx->expected = blockSize;
             ctx->bType = bp.blockType;
             ctx->phase = 2;
         }
 
         return 0;
     }
 
     /* Decompress : block content */
     {
         size_t rSize;
         switch(ctx->bType)
         {
         case bt_compressed:
             rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
             break;
         case bt_raw :
             rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize);
             break;
         case bt_rle :
             return ERROR(GENERIC);   /* not yet handled */
             break;
         case bt_end :   /* should never happen (filtered at phase 1) */
             rSize = 0;
             break;
         default:
             return ERROR(GENERIC);
         }
         ctx->phase = 1;
         ctx->expected = ZSTD_blockHeaderSize;
         ctx->previousDstEnd = (void*)( ((char*)dst) + rSize);
         return rSize;
     }
 
 }
Index: vendor/zstd/dist/lib/legacy/zstd_v02.c
===================================================================
--- vendor/zstd/dist/lib/legacy/zstd_v02.c	(revision 339613)
+++ vendor/zstd/dist/lib/legacy/zstd_v02.c	(revision 339614)
@@ -1,3483 +1,3489 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 #include     /* size_t, ptrdiff_t */
 #include "zstd_v02.h"
 #include "error_private.h"
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
 #if defined(_MSC_VER)   /* Visual Studio */
 #   include   /* _byteswap_ulong */
 #   include   /* _byteswap_* */
 #endif
 
 
 /* ******************************************************************
    mem.h
    low-level memory access routines
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #ifndef MEM_H_MODULE
 #define MEM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /******************************************
 *  Includes
 ******************************************/
 #include     /* size_t, ptrdiff_t */
 #include     /* memcpy */
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
 #if defined(__GNUC__)
 #  define MEM_STATIC static __attribute__((unused))
 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 #  define MEM_STATIC static inline
 #elif defined(_MSC_VER)
 #  define MEM_STATIC static __inline
 #else
 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
 #endif
 
 
 /****************************************************************
 *  Basic Types
 *****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 # include 
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
   typedef uint32_t U32;
   typedef  int32_t S32;
   typedef uint64_t U64;
   typedef  int64_t S64;
 #else
   typedef unsigned char       BYTE;
   typedef unsigned short      U16;
   typedef   signed short      S16;
   typedef unsigned int        U32;
   typedef   signed int        S32;
   typedef unsigned long long  U64;
   typedef   signed long long  S64;
 #endif
 
 
 /****************************************************************
 *  Memory I/O
 *****************************************************************/
 /* MEM_FORCE_MEMORY_ACCESS
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
  *            It can generate buggy code on targets generating assembly depending on alignment.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define MEM_FORCE_MEMORY_ACCESS 2
 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
 #    define MEM_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
 
 MEM_STATIC unsigned MEM_isLittleEndian(void)
 {
     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
     return one.c[0];
 }
 
 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
 
 /* violates C standard on structure alignment.
 Only use if no other choice to achieve best performance on target platform */
 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
 
 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
 
 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
 
 #else
 
 /* default method, safe and standard.
    can sometimes prove slower */
 
 MEM_STATIC U16 MEM_read16(const void* memPtr)
 {
     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U32 MEM_read32(const void* memPtr)
 {
     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U64 MEM_read64(const void* memPtr)
 {
     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 #endif // MEM_FORCE_MEMORY_ACCESS
 
 
 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read16(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U16)(p[0] + (p[1]<<8));
     }
 }
 
 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
 {
     if (MEM_isLittleEndian())
     {
         MEM_write16(memPtr, val);
     }
     else
     {
         BYTE* p = (BYTE*)memPtr;
         p[0] = (BYTE)val;
         p[1] = (BYTE)(val>>8);
     }
 }
 
 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read32(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
     }
 }
 
 
 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read64(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
     }
 }
 
 
 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
 {
     if (MEM_32bits())
         return (size_t)MEM_readLE32(memPtr);
     else
         return (size_t)MEM_readLE64(memPtr);
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* MEM_H_MODULE */
 
 
 /* ******************************************************************
    bitstream
    Part of NewGen Entropy library
    header file (to include)
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #ifndef BITSTREAM_H_MODULE
 #define BITSTREAM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /*
 *  This API consists of small unitary functions, which highly benefit from being inlined.
 *  Since link-time-optimization is not available for all compilers,
 *  these functions are defined into a .h to be included.
 */
 
 
 /**********************************************
 *  bitStream decompression API (read backward)
 **********************************************/
 typedef struct
 {
     size_t   bitContainer;
     unsigned bitsConsumed;
     const char* ptr;
     const char* start;
 } BIT_DStream_t;
 
 typedef enum { BIT_DStream_unfinished = 0,
                BIT_DStream_endOfBuffer = 1,
                BIT_DStream_completed = 2,
                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
 
 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
 
 
 /******************************************
 *  unsafe API
 ******************************************/
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
 /* faster, but works only if nbBits >= 1 */
 
 
 
 /****************************************************************
 *  Helper functions
 ****************************************************************/
 MEM_STATIC unsigned BIT_highbit32 (U32 val)
 {
 #   if defined(_MSC_VER)   /* Visual */
     unsigned long r=0;
     _BitScanReverse ( &r, val );
     return (unsigned) r;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
     return 31 - __builtin_clz (val);
 #   else   /* Software version */
     static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
     U32 v = val;
     unsigned r;
     v |= v >> 1;
     v |= v >> 2;
     v |= v >> 4;
     v |= v >> 8;
     v |= v >> 16;
     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
     return r;
 #   endif
 }
 
 
 
 /**********************************************************
 * bitStream decoding
 **********************************************************/
 
 /*!BIT_initDStream
 *  Initialize a BIT_DStream_t.
 *  @bitD : a pointer to an already allocated BIT_DStream_t structure
 *  @srcBuffer must point at the beginning of a bitStream
 *  @srcSize must be the exact size of the bitStream
 *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
 */
 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
 {
     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
 
     if (srcSize >=  sizeof(size_t))   /* normal case */
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
     }
     else
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = bitD->start;
         bitD->bitContainer = *(const BYTE*)(bitD->start);
         switch(srcSize)
         {
             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
+                    /* fallthrough */
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
+                    /* fallthrough */
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
+                    /* fallthrough */
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
+                    /* fallthrough */
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
+                    /* fallthrough */
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
+                    /* fallthrough */
             default:;
         }
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
     }
 
     return srcSize;
 }
 
 MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
 }
 
 /*! BIT_lookBitsFast :
 *   unsafe version; only works only if nbBits >= 1 */
 MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
 }
 
 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     bitD->bitsConsumed += nbBits;
 }
 
 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     size_t value = BIT_lookBits(bitD, nbBits);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 /*!BIT_readBitsFast :
 *  unsafe version; only works only if nbBits >= 1 */
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
 {
     size_t value = BIT_lookBitsFast(bitD, nbBits);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
 {
     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
         return BIT_DStream_overflow;
 
     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
     {
         bitD->ptr -= bitD->bitsConsumed >> 3;
         bitD->bitsConsumed &= 7;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         return BIT_DStream_unfinished;
     }
     if (bitD->ptr == bitD->start)
     {
         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
         return BIT_DStream_completed;
     }
     {
         U32 nbBytes = bitD->bitsConsumed >> 3;
         BIT_DStream_status result = BIT_DStream_unfinished;
         if (bitD->ptr - nbBytes < bitD->start)
         {
             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
             result = BIT_DStream_endOfBuffer;
         }
         bitD->ptr -= nbBytes;
         bitD->bitsConsumed -= nbBytes*8;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
         return result;
     }
 }
 
 /*! BIT_endOfDStream
 *   @return Tells if DStream has reached its exact end
 */
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
 {
     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* BITSTREAM_H_MODULE */
 /* ******************************************************************
    Error codes and messages
    Copyright (C) 2013-2015, Yann Collet
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #ifndef ERROR_H_MODULE
 #define ERROR_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 #  define ERR_STATIC static inline
 #elif defined(_MSC_VER)
 #  define ERR_STATIC static __inline
 #elif defined(__GNUC__)
 #  define ERR_STATIC static __attribute__((unused))
 #else
 #  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
 #endif
 
 
 /******************************************
 *  Error Management
 ******************************************/
 #define PREFIX(name) ZSTD_error_##name
 
 #define ERROR(name) (size_t)-PREFIX(name)
 
 #define ERROR_LIST(ITEM) \
         ITEM(PREFIX(No_Error)) ITEM(PREFIX(GENERIC)) \
         ITEM(PREFIX(dstSize_tooSmall)) ITEM(PREFIX(srcSize_wrong)) \
         ITEM(PREFIX(prefix_unknown)) ITEM(PREFIX(corruption_detected)) \
         ITEM(PREFIX(tableLog_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooSmall)) \
         ITEM(PREFIX(maxCode))
 
 #define ERROR_GENERATE_ENUM(ENUM) ENUM,
 typedef enum { ERROR_LIST(ERROR_GENERATE_ENUM) } ERR_codes;  /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
 
 #define ERROR_CONVERTTOSTRING(STRING) #STRING,
 #define ERROR_GENERATE_STRING(EXPR) ERROR_CONVERTTOSTRING(EXPR)
 static const char* ERR_strings[] = { ERROR_LIST(ERROR_GENERATE_STRING) };
 
 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
 
 ERR_STATIC const char* ERR_getErrorName(size_t code)
 {
     static const char* codeError = "Unspecified error code";
     if (ERR_isError(code)) return ERR_strings[-(int)(code)];
     return codeError;
 }
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ERROR_H_MODULE */
 /*
 Constructor and Destructor of type FSE_CTable
     Note that its size depends on 'tableLog' and 'maxSymbolValue' */
 typedef unsigned FSE_CTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
 
 
 /* ******************************************************************
    FSE : Finite State Entropy coder
    header file for static linking (only)
    Copyright (C) 2013-2015, Yann Collet
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /******************************************
 *  Static allocation
 ******************************************/
 /* FSE buffer bounds */
 #define FSE_NCOUNTBOUND 512
 #define FSE_BLOCKBOUND(size) (size + (size>>7))
 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<= 1 (otherwise, result will be corrupted) */
 
 
 /******************************************
 *  Implementation of inline functions
 ******************************************/
 
 /* decompression */
 
 typedef struct {
     U16 tableLog;
     U16 fastMode;
 } FSE_DTableHeader;   /* sizeof U32 */
 
 typedef struct
 {
     unsigned short newState;
     unsigned char  symbol;
     unsigned char  nbBits;
 } FSE_decode_t;   /* size == U32 */
 
 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
 {
     FSE_DTableHeader DTableH;
     memcpy(&DTableH, dt, sizeof(DTableH));
     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
     BIT_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32  nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = BIT_readBits(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32 nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
 {
     return DStatePtr->state == 0;
 }
 
 
 #if defined (__cplusplus)
 }
 #endif
 /* ******************************************************************
    Huff0 : Huffman coder, part of New Generation Entropy library
    header file for static linking (only)
    Copyright (C) 2013-2015, Yann Collet
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /******************************************
 *  Static allocation macros
 ******************************************/
 /* Huff0 buffer bounds */
 #define HUF_CTABLEBOUND 129
 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* static allocation of Huff0's DTable */
 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<   /* size_t */
 
 
 /* *************************************
 *  Version
 ***************************************/
 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
 #define ZSTD_VERSION_MINOR    2    /* for new (non-breaking) interface capabilities */
 #define ZSTD_VERSION_RELEASE  2    /* for tweaks, bug-fixes, or development */
 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
 
 
 /* *************************************
 *  Advanced functions
 ***************************************/
 typedef struct ZSTD_CCtx_s ZSTD_CCtx;   /* incomplete type */
 
 #if defined (__cplusplus)
 }
 #endif
 /*
     zstd - standard compression library
     Header File for static linking only
     Copyright (C) 2014-2015, Yann Collet.
 
     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are
     met:
     * Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the above
     copyright notice, this list of conditions and the following disclaimer
     in the documentation and/or other materials provided with the
     distribution.
     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - zstd source repository : https://github.com/Cyan4973/zstd
     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
 */
 
 /* The objects defined into this file should be considered experimental.
  * They are not labelled stable, as their prototype may change in the future.
  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
  */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /* *************************************
 *  Streaming functions
 ***************************************/
 
 typedef struct ZSTD_DCtx_s ZSTD_DCtx;
 
 /*
   Use above functions alternatively.
   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
   ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
   Result is the number of bytes regenerated within 'dst'.
   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
 */
 
 /* *************************************
 *  Prefix - version detection
 ***************************************/
 #define ZSTD_magicNumber 0xFD2FB522   /* v0.2 (current)*/
 
 
 #if defined (__cplusplus)
 }
 #endif
 /* ******************************************************************
    FSE : Finite State Entropy coder
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 #ifndef FSE_COMMONDEFS_ONLY
 
 /****************************************************************
 *  Tuning parameters
 ****************************************************************/
 /* MEMORY_USAGE :
 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect
 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
 #define FSE_MAX_MEMORY_USAGE 14
 #define FSE_DEFAULT_MEMORY_USAGE 13
 
 /* FSE_MAX_SYMBOL_VALUE :
 *  Maximum symbol value authorized.
 *  Required for proper stack allocation */
 #define FSE_MAX_SYMBOL_VALUE 255
 
 
 /****************************************************************
 *  template functions type & suffix
 ****************************************************************/
 #define FSE_FUNCTION_TYPE BYTE
 #define FSE_FUNCTION_EXTENSION
 
 
 /****************************************************************
 *  Byte symbol type
 ****************************************************************/
 #endif   /* !FSE_COMMONDEFS_ONLY */
 
 
 /****************************************************************
 *  Compiler specifics
 ****************************************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  define FORCE_INLINE static __forceinline
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #else
 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #    ifdef __GNUC__
 #      define FORCE_INLINE static inline __attribute__((always_inline))
 #    else
 #      define FORCE_INLINE static inline
 #    endif
 #  else
 #    define FORCE_INLINE static
 #  endif /* __STDC_VERSION__ */
 #endif
 
 
 /****************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
 
 /****************************************************************
 *  Constants
 *****************************************************************/
 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
 #define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX
 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
 #endif
 
 
 /****************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /****************************************************************
 *  Complex types
 ****************************************************************/
 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
 
 
 /****************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 /* Function templates */
 
 #define FSE_DECODE_TYPE FSE_decode_t
 
 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
 
 static size_t FSE_buildDTable
 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     void* ptr = dt+1;
     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)ptr;
     FSE_DTableHeader DTableH;
     const U32 tableSize = 1 << tableLog;
     const U32 tableMask = tableSize-1;
     const U32 step = FSE_tableStep(tableSize);
     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
     U32 position = 0;
     U32 highThreshold = tableSize-1;
     const S16 largeLimit= (S16)(1 << (tableLog-1));
     U32 noLarge = 1;
     U32 s;
 
     /* Sanity Checks */
     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
 
     /* Init, lay down lowprob symbols */
     DTableH.tableLog = (U16)tableLog;
     for (s=0; s<=maxSymbolValue; s++)
     {
         if (normalizedCounter[s]==-1)
         {
             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
             symbolNext[s] = 1;
         }
         else
         {
             if (normalizedCounter[s] >= largeLimit) noLarge=0;
             symbolNext[s] = normalizedCounter[s];
         }
     }
 
     /* Spread symbols */
     for (s=0; s<=maxSymbolValue; s++)
     {
         int i;
         for (i=0; i highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }
     }
 
     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
 
     /* Build Decoding table */
     {
         U32 i;
         for (i=0; i FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
     bitStream >>= 4;
     bitCount = 4;
     *tableLogPtr = nbBits;
     remaining = (1<1) && (charnum<=*maxSVPtr))
     {
         if (previous0)
         {
             unsigned n0 = charnum;
             while ((bitStream & 0xFFFF) == 0xFFFF)
             {
                 n0+=24;
                 if (ip < iend-5)
                 {
                     ip+=2;
                     bitStream = MEM_readLE32(ip) >> bitCount;
                 }
                 else
                 {
                     bitStream >>= 16;
                     bitCount+=16;
                 }
             }
             while ((bitStream & 3) == 3)
             {
                 n0+=3;
                 bitStream>>=2;
                 bitCount+=2;
             }
             n0 += bitStream & 3;
             bitCount += 2;
             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
             while (charnum < n0) normalizedCounter[charnum++] = 0;
             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
             {
                 ip += bitCount>>3;
                 bitCount &= 7;
                 bitStream = MEM_readLE32(ip) >> bitCount;
             }
             else
                 bitStream >>= 2;
         }
         {
             const short max = (short)((2*threshold-1)-remaining);
             short count;
 
             if ((bitStream & (threshold-1)) < (U32)max)
             {
                 count = (short)(bitStream & (threshold-1));
                 bitCount   += nbBits-1;
             }
             else
             {
                 count = (short)(bitStream & (2*threshold-1));
                 if (count >= threshold) count -= max;
                 bitCount   += nbBits;
             }
 
             count--;   /* extra accuracy */
             remaining -= FSE_abs(count);
             normalizedCounter[charnum++] = count;
             previous0 = !count;
             while (remaining < threshold)
             {
                 nbBits--;
                 threshold >>= 1;
             }
 
             {
                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
                 {
                     ip += bitCount>>3;
                     bitCount &= 7;
                 }
                 else
                 {
                     bitCount -= (int)(8 * (iend - 4 - ip));
                     ip = iend - 4;
                 }
                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
             }
         }
     }
     if (remaining != 1) return ERROR(GENERIC);
     *maxSVPtr = charnum-1;
 
     ip += (bitCount+7)>>3;
     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
     return ip-istart;
 }
 
 
 /*********************************************************
 *  Decompression (Byte symbols)
 *********************************************************/
 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
 
     DTableH->tableLog = 0;
     DTableH->fastMode = 0;
 
     cell->newState = 0;
     cell->symbol = symbolValue;
     cell->nbBits = 0;
 
     return 0;
 }
 
 
 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
     const unsigned tableSize = 1 << nbBits;
     const unsigned tableMask = tableSize - 1;
     const unsigned maxSymbolValue = tableMask;
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
 
     /* Build Decoding Table */
     DTableH->tableLog = (U16)nbBits;
     DTableH->fastMode = 1;
     for (s=0; s<=maxSymbolValue; s++)
     {
         dinfo[s].newState = 0;
         dinfo[s].symbol = (BYTE)s;
         dinfo[s].nbBits = (BYTE)nbBits;
     }
 
     return 0;
 }
 
 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
           void* dst, size_t maxDstSize,
     const void* cSrc, size_t cSrcSize,
     const FSE_DTable* dt, const unsigned fast)
 {
     BYTE* const ostart = (BYTE*) dst;
     BYTE* op = ostart;
     BYTE* const omax = op + maxDstSize;
     BYTE* const olimit = omax-3;
 
     BIT_DStream_t bitD;
     FSE_DState_t state1;
     FSE_DState_t state2;
     size_t errorCode;
 
     /* Init */
     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
     if (FSE_isError(errorCode)) return errorCode;
 
     FSE_initDState(&state1, &bitD, dt);
     FSE_initDState(&state2, &bitD, dt);
 
 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
 
     /* 4 symbols per loop */
     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[1] = FSE_GETSYMBOL(&state2);
 
         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
 
         op[2] = FSE_GETSYMBOL(&state1);
 
         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[3] = FSE_GETSYMBOL(&state2);
     }
 
     /* tail */
     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
     while (1)
     {
         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state1);
 
         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state2);
     }
 
     /* end ? */
     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
         return op-ostart;
 
     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
 
     return ERROR(corruption_detected);
 }
 
 
 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
                             const void* cSrc, size_t cSrcSize,
                             const FSE_DTable* dt)
 {
     FSE_DTableHeader DTableH;
     memcpy(&DTableH, dt, sizeof(DTableH));
 
     /* select fast mode (static) */
     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
 }
 
 
 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
 {
     const BYTE* const istart = (const BYTE*)cSrc;
     const BYTE* ip = istart;
     short counting[FSE_MAX_SYMBOL_VALUE+1];
     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
     size_t errorCode;
 
     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
 
     /* normal FSE decoding mode */
     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
     if (FSE_isError(errorCode)) return errorCode;
     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
     ip += errorCode;
     cSrcSize -= errorCode;
 
     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
     if (FSE_isError(errorCode)) return errorCode;
 
     /* always return, even if it is an error code */
     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
 }
 
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
 /* ******************************************************************
    Huff0 : Huffman coder, part of New Generation Entropy library
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 /****************************************************************
 *  Compiler specifics
 ****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 /* inline is defined */
 #elif defined(_MSC_VER)
 #  define inline __inline
 #else
 #  define inline /* disable inline */
 #endif
 
 
 #ifdef _MSC_VER    /* Visual Studio */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #endif
 
 
 /****************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
 
 /****************************************************************
 *  Error Management
 ****************************************************************/
 #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /******************************************
 *  Helper functions
 ******************************************/
 static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
 
 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
 #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
 #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
 #define HUF_MAX_SYMBOL_VALUE 255
 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
 #  error "HUF_MAX_TABLELOG is too large !"
 #endif
 
 
 
 /*********************************************************
 *  Huff0 : Huffman block decompression
 *********************************************************/
 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
 
 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
 
 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
 
 /*! HUF_readStats
     Read compact Huffman tree, saved by HUF_writeCTable
     @huffWeight : destination buffer
     @return : size read from `src`
 */
 static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                             U32* nbSymbolsPtr, U32* tableLogPtr,
                             const void* src, size_t srcSize)
 {
     U32 weightTotal;
     U32 tableLog;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize;
     size_t oSize;
     U32 n;
 
     if (!srcSize) return ERROR(srcSize_wrong);
     iSize = ip[0];
     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
 
     if (iSize >= 128)  /* special header */
     {
         if (iSize >= (242))   /* RLE */
         {
             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
             oSize = l[iSize-242];
             memset(huffWeight, 1, hwSize);
             iSize = 0;
         }
         else   /* Incompressible */
         {
             oSize = iSize - 127;
             iSize = ((oSize+1)/2);
             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
             if (oSize >= hwSize) return ERROR(corruption_detected);
             ip += 1;
             for (n=0; n> 4;
                 huffWeight[n+1] = ip[n/2] & 15;
             }
         }
     }
     else  /* header compressed with FSE (normal case) */
     {
         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
         if (FSE_isError(oSize)) return oSize;
     }
 
     /* collect weight stats */
     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
     weightTotal = 0;
     for (n=0; n= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
         rankStats[huffWeight[n]]++;
         weightTotal += (1 << huffWeight[n]) >> 1;
     }
     if (weightTotal == 0) return ERROR(corruption_detected);
 
     /* get last non-null symbol weight (implied, total must be 2^n) */
     tableLog = BIT_highbit32(weightTotal) + 1;
     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
     {
         U32 total = 1 << tableLog;
         U32 rest = total - weightTotal;
         U32 verif = 1 << BIT_highbit32(rest);
         U32 lastWeight = BIT_highbit32(rest) + 1;
         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
         huffWeight[oSize] = (BYTE)lastWeight;
         rankStats[lastWeight]++;
     }
 
     /* check tree construction validity */
     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
 
     /* results */
     *nbSymbolsPtr = (U32)(oSize+1);
     *tableLogPtr = tableLog;
     return iSize+1;
 }
 
 
 /**************************/
 /* single-symbol decoding */
 /**************************/
 
 static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
 {
     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
     U32 tableLog = 0;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize = ip[0];
     U32 nbSymbols = 0;
     U32 n;
     U32 nextRankStart;
     void* ptr = DTable+1;
     HUF_DEltX2* const dt = (HUF_DEltX2*)ptr;
 
     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
 
     /* Prepare ranks */
     nextRankStart = 0;
     for (n=1; n<=tableLog; n++)
     {
         U32 current = nextRankStart;
         nextRankStart += (rankVal[n] << (n-1));
         rankVal[n] = current;
     }
 
     /* fill DTable */
     for (n=0; n> 1;
         U32 i;
         HUF_DEltX2 D;
         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
         for (i = rankVal[w]; i < rankVal[w] + length; i++)
             dt[i] = D;
         rankVal[w] += length;
     }
 
     return iSize;
 }
 
 static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
 {
         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
         const BYTE c = dt[val].byte;
         BIT_skipBits(Dstream, dt[val].nbBits);
         return c;
 }
 
 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
 
 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
 
 static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 4 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
     {
         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
     }
 
     /* closer to the end */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
 
     /* no more data to retrieve from bitstream, hence no need to reload */
     while (p < pEnd)
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
 
     return pEnd-pStart;
 }
 
 
 static size_t HUF_decompress4X2_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const U16* DTable)
 {
     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
 
     {
         const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
 
         const void* ptr = DTable;
         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)ptr) +1;
         const U32 dtLog = DTable[0];
         size_t errorCode;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         const size_t length1 = MEM_readLE16(istart);
         const size_t length2 = MEM_readLE16(istart+2);
         const size_t length3 = MEM_readLE16(istart+4);
         size_t length4;
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         const size_t segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal;
 
         length4 = cSrcSize - (length1 + length2 + length3 + 6);
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         errorCode = BIT_initDStream(&bitD1, istart1, length1);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD2, istart2, length2);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD3, istart3, length3);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD4, istart4, length4);
         if (HUF_isError(errorCode)) return errorCode;
 
         /* 16-32 symbols per loop (4-8 symbols per stream) */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
         {
             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
 
             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 supposed already verified within main loop */
 
         /* finish bitStreams one by one */
         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
         if (!endSignal) return ERROR(corruption_detected);
 
         /* decoded size */
         return dstSize;
     }
 }
 
 
 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
     const BYTE* ip = (const BYTE*) cSrc;
     size_t errorCode;
 
     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
     if (HUF_isError(errorCode)) return errorCode;
     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
     ip += errorCode;
     cSrcSize -= errorCode;
 
     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
 }
 
 
 /***************************/
 /* double-symbols decoding */
 /***************************/
 
 static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
                            const U32* rankValOrigin, const int minWeight,
                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
                            U32 nbBitsBaseline, U16 baseSeq)
 {
     HUF_DEltX4 DElt;
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
     U32 s;
 
     /* get pre-calculated rankVal */
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill skipped values */
     if (minWeight>1)
     {
         U32 i, skipSize = rankVal[minWeight];
         MEM_writeLE16(&(DElt.sequence), baseSeq);
         DElt.nbBits   = (BYTE)(consumed);
         DElt.length   = 1;
         for (i = 0; i < skipSize; i++)
             DTable[i] = DElt;
     }
 
     /* fill DTable */
     for (s=0; s= 1 */
 
         rankVal[weight] += length;
     }
 }
 
 typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
 
 static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
                            const U32 nbBitsBaseline)
 {
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
     const U32 minBits  = nbBitsBaseline - maxWeight;
     U32 s;
 
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill DTable */
     for (s=0; s= minBits)   /* enough room for a second symbol */
         {
             U32 sortedRank;
             int minWeight = nbBits + scaleLog;
             if (minWeight < 1) minWeight = 1;
             sortedRank = rankStart[minWeight];
             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
                            rankValOrigin[nbBits], minWeight,
                            sortedList+sortedRank, sortedListSize-sortedRank,
                            nbBitsBaseline, symbol);
         }
         else
         {
             U32 i;
             const U32 end = start + length;
             HUF_DEltX4 DElt;
 
             MEM_writeLE16(&(DElt.sequence), symbol);
             DElt.nbBits   = (BYTE)(nbBits);
             DElt.length   = 1;
             for (i = start; i < end; i++)
                 DTable[i] = DElt;
         }
         rankVal[weight] += length;
     }
 }
 
 static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
 {
     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
     U32* const rankStart = rankStart0+1;
     rankVal_t rankVal;
     U32 tableLog, maxW, sizeOfSort, nbSymbols;
     const U32 memLog = DTable[0];
     const BYTE* ip = (const BYTE*) src;
     size_t iSize = ip[0];
     void* ptr = DTable;
     HUF_DEltX4* const dt = ((HUF_DEltX4*)ptr) + 1;
 
     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
 
     /* find maxWeight */
     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
         {if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
 
     /* Get start index of each weight */
     {
         U32 w, nextRankStart = 0;
         for (w=1; w<=maxW; w++)
         {
             U32 current = nextRankStart;
             nextRankStart += rankStats[w];
             rankStart[w] = current;
         }
         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
         sizeOfSort = nextRankStart;
     }
 
     /* sort symbols by weight */
     {
         U32 s;
         for (s=0; s> consumed;
             }
         }
     }
 
     HUF_fillDTableX4(dt, memLog,
                    sortedSymbol, sizeOfSort,
                    rankStart0, rankVal, maxW,
                    tableLog+1);
 
     return iSize;
 }
 
 
 static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
 {
     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
     memcpy(op, dt+val, 2);
     BIT_skipBits(DStream, dt[val].nbBits);
     return dt[val].length;
 }
 
 static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
 {
     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
     memcpy(op, dt+val, 1);
     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
     else
     {
         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
         {
             BIT_skipBits(DStream, dt[val].nbBits);
             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
                 DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);   /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
         }
     }
     return 1;
 }
 
 
 #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
 
 static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 8 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
     {
         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
     }
 
     /* closer to the end */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
 
     while (p <= pEnd-2)
         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
 
     if (p < pEnd)
         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
 
     return p-pStart;
 }
 
 
 
 static size_t HUF_decompress4X4_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const U32* DTable)
 {
     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
 
     {
         const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
 
         const void* ptr = DTable;
         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)ptr) +1;
         const U32 dtLog = DTable[0];
         size_t errorCode;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         const size_t length1 = MEM_readLE16(istart);
         const size_t length2 = MEM_readLE16(istart+2);
         const size_t length3 = MEM_readLE16(istart+4);
         size_t length4;
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         const size_t segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal;
 
         length4 = cSrcSize - (length1 + length2 + length3 + 6);
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         errorCode = BIT_initDStream(&bitD1, istart1, length1);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD2, istart2, length2);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD3, istart3, length3);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD4, istart4, length4);
         if (HUF_isError(errorCode)) return errorCode;
 
         /* 16-32 symbols per loop (4-8 symbols per stream) */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
         {
             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
 
             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 supposed already verified within main loop */
 
         /* finish bitStreams one by one */
         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
         if (!endSignal) return ERROR(corruption_detected);
 
         /* decoded size */
         return dstSize;
     }
 }
 
 
 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize;
     cSrcSize -= hSize;
 
     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
 }
 
 
 /**********************************/
 /* quad-symbol decoding           */
 /**********************************/
 typedef struct { BYTE nbBits; BYTE nbBytes; } HUF_DDescX6;
 typedef union { BYTE byte[4]; U32 sequence; } HUF_DSeqX6;
 
 /* recursive, up to level 3; may benefit from