Index: head/contrib/zstd/.travis.yml =================================================================== --- head/contrib/zstd/.travis.yml (revision 317876) +++ head/contrib/zstd/.travis.yml (nonexistent) @@ -1,51 +0,0 @@ -# Long tests: run on commits to master branch/cron builds - -language: c -sudo: required -dist: trusty -matrix: - include: - # Ubuntu 14.04 - - env: Cmd='make gcc6install && CC=gcc-6 make clean uasan-test' - - env: Cmd='make gcc6install libc6install && CC=gcc-6 make clean uasan-test32' - - env: Cmd='make clang38install && CC=clang-3.8 make clean msan-test' - - env: Cmd='make clang38install && CC=clang-3.8 make clean tsan-test-zstream' - - env: Cmd='make valgrindinstall && make -C tests clean valgrindTest' - - - env: Cmd='make arminstall && make armtest' - - env: Cmd='make arminstall && make aarch64test' - - env: Cmd='make ppcinstall && make ppctest' - - env: Cmd='make ppcinstall && make ppc64test' - - - - env: Cmd='make gpp6install valgrindinstall && make -C zlibWrapper test && make -C zlibWrapper valgrindTest' - - env: Cmd='make -C tests versionsTest' - - env: Cmd='make gpp6install && cd contrib/pzstd && make test-pzstd && make test-pzstd32 && make test-pzstd-tsan && make test-pzstd-asan' - install: - - export CXX="g++-6" CC="gcc-6" - - env: Cmd='make gcc6install && CC=gcc-6 make uasan-test-zstd-nolegacy' - - env: Cmd='make gcc6install && CC=gcc-6 make uasan-test-zbuff' - - # OS X Mavericks - - env: Cmd="make gnu90build && make clean && make test && make clean && make travis-install" - os: osx - -git: - depth: 1 - -branches: - only: - - dev - - master - -script: - - JOB_NUMBER=$(echo $TRAVIS_JOB_NUMBER | sed -e 's:[0-9][0-9]*\.\(.*\):\1:') - - echo JOB_NUMBER=$JOB_NUMBER TRAVIS_BRANCH=$TRAVIS_BRANCH TRAVIS_EVENT_TYPE=$TRAVIS_EVENT_TYPE TRAVIS_PULL_REQUEST=$TRAVIS_PULL_REQUEST - - export FUZZERTEST=-T5mn; - export ZSTREAM_TESTTIME=-T5mn; - export DECODECORPUS_TESTTIME=-T1mn; - if [ "$TRAVIS_EVENT_TYPE" = "cron" ]; then - git fetch origin dev; - git checkout -f FETCH_HEAD; - fi; - sh -c "$Cmd" || travis_terminate 1; Index: head/contrib/zstd/.gitignore =================================================================== --- head/contrib/zstd/.gitignore (revision 317876) +++ head/contrib/zstd/.gitignore (nonexistent) @@ -1,41 +0,0 @@ -# Object files -*.o -*.ko -*.dSYM - -# Libraries -*.lib -*.a - -# Shared objects (inc. Windows DLLs) -*.dll -*.so -*.so.* -*.dylib - -# Executables -zstd -zstdmt -*.exe -*.out -*.app - -# Test artefacts -tmp* -dictionary* - -# Other files -.directory -_codelite/ -_zstdbench/ -.clang_complete -*.idea -*.swp -.DS_Store -googletest/ -*.d - -# Directories -bin/ -.buckd/ -buck-out/ Index: head/contrib/zstd/Makefile =================================================================== --- head/contrib/zstd/Makefile (revision 317876) +++ head/contrib/zstd/Makefile (revision 317877) @@ -1,315 +1,325 @@ # ################################################################ # Copyright (c) 2016-present, Yann Collet, Facebook, Inc. # All rights reserved. # # This source code is licensed under the BSD-style license found in the # LICENSE file in the root directory of this source tree. An additional grant # of patent rights can be found in the PATENTS file in the same directory. # ################################################################ PRGDIR = programs ZSTDDIR = lib BUILDIR = build ZWRAPDIR = zlibWrapper TESTDIR = tests # Define nul output VOID = /dev/null ifneq (,$(filter Windows%,$(OS))) EXT =.exe else EXT = endif .PHONY: default default: lib-release zstd-release .PHONY: all all: | allmost examples manual .PHONY: allmost allmost: $(MAKE) -C $(ZSTDDIR) all $(MAKE) -C $(PRGDIR) all $(MAKE) -C $(TESTDIR) all $(MAKE) -C $(ZWRAPDIR) all #skip zwrapper, can't build that on alternate architectures without the proper zlib installed .PHONY: allarch allarch: $(MAKE) -C $(ZSTDDIR) all $(MAKE) -C $(PRGDIR) all $(MAKE) -C $(TESTDIR) all .PHONY: all32 all32: $(MAKE) -C $(PRGDIR) zstd32 $(MAKE) -C $(TESTDIR) all32 .PHONY: lib lib: @$(MAKE) -C $(ZSTDDIR) $@ .PHONY: lib-release lib-release: @$(MAKE) -C $(ZSTDDIR) .PHONY: zstd zstd: @$(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 .PHONY: shortest shortest: $(MAKE) -C $(TESTDIR) $@ .PHONY: test test: $(MAKE) -C $(TESTDIR) $@ .PHONY: examples examples: CPPFLAGS=-I../lib LDFLAGS=-L../lib $(MAKE) -C examples/ all .PHONY: manual manual: $(MAKE) -C contrib/gen_html $@ +.PHONY: cleanTabs +cleanTabs: + cd contrib; ./cleanTabs + .PHONY: clean clean: @$(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 $@ > $(VOID) @$(RM) zstd$(EXT) zstdmt$(EXT) tmp* @echo Cleaning completed #------------------------------------------------------------------------------ # make install is validated only for Linux, OSX, Hurd and some BSD targets #------------------------------------------------------------------------------ ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU FreeBSD DragonFly NetBSD)) + HOST_OS = POSIX -.PHONY: install uninstall travis-install clangtest gpptest armtest usan asan uasan +CMAKE_PARAMS = -DZSTD_BUILD_CONTRIB:BOOL=ON -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON -DZSTD_ZLIB_SUPPORT:BOOL=ON -DZSTD_LZMA_SUPPORT:BOOL=ON +.PHONY: list +list: + @$(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 + +.PHONY: install uninstall travis-install clangtest gpptest armtest usan asan uasan install: @$(MAKE) -C $(ZSTDDIR) $@ @$(MAKE) -C $(PRGDIR) $@ uninstall: @$(MAKE) -C $(ZSTDDIR) $@ @$(MAKE) -C $(PRGDIR) $@ travis-install: $(MAKE) install PREFIX=~/install_test_dir gppbuild: clean g++ -v CC=g++ $(MAKE) -C programs all CFLAGS="-O3 -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror" gcc5build: clean gcc-5 -v CC=gcc-5 $(MAKE) all MOREFLAGS="-Werror" gcc6build: clean gcc-6 -v CC=gcc-6 $(MAKE) all MOREFLAGS="-Werror" 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) allarch aarch64build: clean CC=aarch64-linux-gnu-gcc CFLAGS="-Werror" $(MAKE) allarch ppcbuild: clean CC=powerpc-linux-gnu-gcc CLAGS="-m32 -Wno-attributes -Werror" $(MAKE) allarch ppc64build: clean CC=powerpc-linux-gnu-gcc CFLAGS="-m64 -Werror" $(MAKE) allarch armfuzz: clean - CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static MOREFLAGS="-static" $(MAKE) -C $(TESTDIR) fuzztest + CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest aarch64fuzz: clean - CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static MOREFLAGS="-static" $(MAKE) -C $(TESTDIR) fuzztest + 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" $(MAKE) -C $(TESTDIR) fuzztest + 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" $(MAKE) -C $(TESTDIR) fuzztest + CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest gpptest: clean CC=g++ $(MAKE) -C $(PRGDIR) all CFLAGS="-O3 -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror" 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" 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" + $(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" + $(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" + $(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" + $(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" # 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" asan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fsanitize=address" asan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=address" $(MAKE) -C $(TESTDIR) $* msan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fsanitize=memory -fno-omit-frame-pointer" # datagen.c fails this test for no obvious reason msan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-fno-sanitize-recover=all -fsanitize=memory -fno-omit-frame-pointer" $(MAKE) -C $(TESTDIR) $* 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" uasan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-Og -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=address,undefined" $(MAKE) -C $(TESTDIR) $* tsan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=thread" $(MAKE) -C $(TESTDIR) $* 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 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" $(MAKE) apt-install endif ifneq (,$(filter MSYS%,$(shell uname))) HOST_OS = MSYS -CMAKE_PARAMS = -G"MSYS Makefiles" +CMAKE_PARAMS = -G"MSYS Makefiles" -DZSTD_MULTITHREAD_SUPPORT:BOOL=OFF -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON endif #------------------------------------------------------------------------ #make tests validated only for MSYS, Linux, OSX, kFreeBSD and Hurd targets #------------------------------------------------------------------------ ifneq (,$(filter $(HOST_OS),MSYS POSIX)) cmakebuild: cmake --version $(RM) -r $(BUILDIR)/cmake/build mkdir $(BUILDIR)/cmake/build - cd $(BUILDIR)/cmake/build ; cmake -DPREFIX:STRING=~/install_test_dir $(CMAKE_PARAMS) .. ; $(MAKE) install ; $(MAKE) uninstall + cd $(BUILDIR)/cmake/build ; cmake -DCMAKE_INSTALL_PREFIX:PATH=~/install_test_dir $(CMAKE_PARAMS) .. ; $(MAKE) install ; $(MAKE) uninstall c90build: clean gcc -v CFLAGS="-std=c90" $(MAKE) allmost # will fail, due to missing support for `long long` gnu90build: clean gcc -v CFLAGS="-std=gnu90" $(MAKE) allmost c99build: clean gcc -v CFLAGS="-std=c99" $(MAKE) allmost gnu99build: clean gcc -v CFLAGS="-std=gnu99" $(MAKE) allmost c11build: clean gcc -v CFLAGS="-std=c11" $(MAKE) allmost bmix64build: clean gcc -v CFLAGS="-O3 -mbmi -Werror" $(MAKE) -C $(TESTDIR) test bmix32build: clean gcc -v CFLAGS="-O3 -mbmi -mx32 -Werror" $(MAKE) -C $(TESTDIR) test bmi32build: clean gcc -v CFLAGS="-O3 -mbmi -m32 -Werror" $(MAKE) -C $(TESTDIR) test staticAnalyze: clean gcc -v CPPFLAGS=-g scan-build --status-bugs -v $(MAKE) all endif Index: head/contrib/zstd/NEWS =================================================================== --- head/contrib/zstd/NEWS (revision 317876) +++ head/contrib/zstd/NEWS (revision 317877) @@ -1,261 +1,283 @@ +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 +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 +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: head/contrib/zstd/README.md =================================================================== --- head/contrib/zstd/README.md (revision 317876) +++ head/contrib/zstd/README.md (revision 317877) @@ -1,141 +1,146 @@ __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 is provided as an open-source BSD-licensed **C** library, and a command line utility producing and decoding `.zst` and `.gz` files. For other programming languages, you can consult a list of known ports on [Zstandard homepage](http://www.zstd.net/#other-languages). |Branch |Status | |------------|---------| |master | [![Build Status](https://travis-ci.org/facebook/zstd.svg?branch=master)](https://travis-ci.org/facebook/zstd) | |dev | [![Build Status](https://travis-ci.org/facebook/zstd.svg?branch=dev)](https://travis-ci.org/facebook/zstd) | As a reference, several fast compression algorithms were tested and compared -on a server running Linux Mint Debian Edition (`Linux version 4.8.0-1-amd64`), +on a server running Linux Debian (`Linux version 4.8.0-1-amd64`), with a Core i7-6700K CPU @ 4.0GHz, -using [lzbench v1.6], an open-source in-memory benchmark by @inikep +using [lzbench], an open-source in-memory benchmark by @inikep compiled with GCC 6.3.0, on the [Silesia compression corpus]. -[lzbench v1.6]: https://github.com/inikep/lzbench +[lzbench]: https://github.com/inikep/lzbench [Silesia compression corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia | Compressor name | Ratio | Compression| Decompress.| | --------------- | ------| -----------| ---------- | | **zstd 1.1.3 -1** | 2.877 | 430 MB/s | 1110 MB/s | | zlib 1.2.8 -1 | 2.743 | 110 MB/s | 400 MB/s | | brotli 0.5.2 -0 | 2.708 | 400 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 1.7.5 | 2.101 | 720 MB/s | 3600 MB/s | | snappy 1.1.3 | 2.091 | 500 MB/s | 1650 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 Core i7-3930K CPU @ 4.5GHz, using [lzbench], an open-source in-memory benchmark by @inikep compiled with GCC 5.2.1, on the [Silesia compression corpus]. +The following tests were run +on a server running Linux Debian (`Linux version 4.8.0-1-amd64`) +with a Core i7-6700K CPU @ 4.0GHz, +using [lzbench], an open-source in-memory benchmark by @inikep +compiled with GCC 6.3.0, +on the [Silesia compression corpus]. Compression Speed vs Ratio | Decompression Speed ---------------------------|-------------------- ![Compression Speed vs Ratio](doc/images/Cspeed4.png "Compression Speed vs Ratio") | ![Decompression Speed](doc/images/Dspeed4.png "Decompression Speed") Several algorithms can produce higher compression ratios, but at slower speeds, falling outside of the graph. For a larger picture including very 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 provide 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 weighting 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 Once you have the repository cloned, there are multiple ways provided to build Zstandard. #### Makefile If your system is compatible with a standard `make` (or `gmake`) binary generator, you can simply run it at the root directory. It will generate `zstd` within root directory. Other available options include : - `make install` : create and install zstd binary, library and man page - `make test` : create and run `zstd` and test tools 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. #### 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 and VS2015 - Automated build scripts for Visual compiler by @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 daily to compress and decompress very large amounts of data in multiple formats and use cases. Zstandard is considered safe for production environments. ### License Zstandard is [BSD-licensed](LICENSE). We also provide an [additional patent grant](PATENTS). ### Contributing The "dev" branch is the one where all contributions will be 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). ### Miscellaneous Zstd entropy stage is provided by [Huff0 and FSE, from Finite State Entropy library](https://github.com/Cyan4973/FiniteStateEntropy). Index: head/contrib/zstd/appveyor.yml =================================================================== --- head/contrib/zstd/appveyor.yml (revision 317876) +++ head/contrib/zstd/appveyor.yml (revision 317877) @@ -1,178 +1,255 @@ -version: 1.0.{build} -environment: - matrix: - - COMPILER: "gcc" - PLATFORM: "mingw64" - MAKE_PARAMS: '"make test && make lib && make -C tests test-symbols fullbench-dll fullbench-lib"' - - COMPILER: "gcc" - PLATFORM: "mingw32" - MAKE_PARAMS: '"make -C tests test-zstd test-fullbench test-fuzzer test-invalidDictionaries"' - - COMPILER: "gcc" - PLATFORM: "clang" - MAKE_PARAMS: '"make -C tests zstd fullbench fuzzer paramgrill datagen CC=clang MOREFLAGS="--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion""' - - COMPILER: "visual" - CONFIGURATION: "Debug" - PLATFORM: "x64" - - COMPILER: "visual" - CONFIGURATION: "Debug" - PLATFORM: "Win32" - - COMPILER: "visual" - CONFIGURATION: "Release" - PLATFORM: "x64" - - COMPILER: "visual" - CONFIGURATION: "Release" - PLATFORM: "Win32" +- + version: 1.0.{build} + branches: + only: + - dev + - master + environment: + matrix: + - COMPILER: "gcc" + HOST: "mingw" + PLATFORM: "x64" + SCRIPT: "make allarch && make -C tests test-symbols fullbench-dll fullbench-lib" + ARTIFACT: "true" + BUILD: "true" + - COMPILER: "gcc" + HOST: "mingw" + PLATFORM: "x86" + SCRIPT: "make allarch" + ARTIFACT: "true" + BUILD: "true" + - COMPILER: "clang" + HOST: "mingw" + PLATFORM: "x64" + SCRIPT: "MOREFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make allarch" + BUILD: "true" -install: + - COMPILER: "gcc" + HOST: "mingw" + PLATFORM: "x64" + SCRIPT: "" + TEST: "cmake" + + - COMPILER: "gcc" + HOST: "mingw" + PLATFORM: "x64" + SCRIPT: "" + TEST: "pzstd" + + - 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% - - MKDIR bin - - if [%COMPILER%]==[gcc] SET PATH_ORIGINAL=%PATH% - - if [%COMPILER%]==[gcc] ( - SET "PATH_MINGW32=c:\MinGW\bin;c:\MinGW\usr\bin" && - SET "PATH_MINGW64=c:\msys64\mingw64\bin;c:\msys64\usr\bin" && - COPY C:\msys64\usr\bin\make.exe C:\MinGW\bin\make.exe && - COPY C:\MinGW\bin\gcc.exe C:\MinGW\bin\cc.exe - ) else ( - 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;") + - 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 [%PLATFORM%]==[mingw32] SET PATH=%PATH_MINGW32%;%PATH_ORIGINAL% - - if [%PLATFORM%]==[mingw64] SET PATH=%PATH_MINGW64%;%PATH_ORIGINAL% - - if [%PLATFORM%]==[clang] SET PATH=%PATH_MINGW64%;%PATH_ORIGINAL% - - if [%COMPILER%]==[gcc] ( - ECHO *** && - ECHO *** Building %PLATFORM% && - ECHO *** && + 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 && - cc -v && - ECHO %MAKE_PARAMS% && - sh -c %MAKE_PARAMS% + 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] + lib\dll\example\build_package.bat && + make -C programs DEBUGFLAGS= clean zstd && + cp programs\zstd.exe zstd_%PLATFORM%.exe && + appveyor PushArtifact zstd_%PLATFORM%.exe && + cp programs\zstd.exe bin\zstd.exe && + make -C programs DEBUGFLAGS= clean zstdmt && + cp programs\zstd.exe bin\zstdmt.exe && + cd bin\ && 7z a -tzip zstd-win-release-%PLATFORM%.zip * && + appveyor PushArtifact zstd-win-release-%PLATFORM%.zip + ) ) - - if [%PLATFORM%]==[clang] COPY tests\fuzzer.exe tests\fuzzer_clang.exe - - if [%COMPILER%]==[gcc] if [%PLATFORM%]==[mingw64] ( - COPY programs\zstd.exe bin\zstd.exe && - appveyor PushArtifact bin\zstd.exe - ) - - if [%COMPILER%]==[gcc] if [%PLATFORM%]==[mingw32] ( - COPY programs\zstd.exe bin\zstd32.exe && - appveyor PushArtifact bin\zstd32.exe - ) - - if [%COMPILER%]==[gcc] make clean - - if [%COMPILER%]==[visual] ( + - 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: + test_script: - ECHO Testing %COMPILER% %PLATFORM% %CONFIGURATION% - - SET FUZZERTEST=-T1mn - - if [%COMPILER%]==[gcc] if [%PLATFORM%]==[clang] ( - tests\fuzzer_clang.exe %FUZZERTEST% && - ECHO *** && - ECHO *** Building cmake for %PLATFORM% && - ECHO *** && + - 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 && - ECHO *** && - ECHO *** Building pzstd for %PLATFORM% && - ECHO *** && + make clean + ) + - if [%TEST%]==[pzstd] ( make -C contrib\pzstd googletest-mingw64 && make -C contrib\pzstd pzstd.exe && make -C contrib\pzstd tests && make -C contrib\pzstd check && make -C contrib\pzstd clean ) - - if [%COMPILER%]==[visual] if [%CONFIGURATION%]==[Release] ( + - 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% ) -branches: - only: - - dev - - master +- + version: 1.0.{build} + environment: + matrix: + - COMPILER: "gcc" + HOST: "mingw" + PLATFORM: "x64" + SCRIPT: "make allarch" + - COMPILER: "gcc" + HOST: "mingw" + PLATFORM: "x86" + SCRIPT: "make allarch" + - COMPILER: "clang" + HOST: "mingw" + PLATFORM: "x64" + SCRIPT: "MOREFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make allarch" -artifacts: - - path: bin\zstd.exe - - path: bin\zstd32.exe + - 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" -deploy: -- provider: GitHub - auth_token: - secure: LgJo8emYc3sFnlNWkGl4/VYK3nk/8+RagcsqDlAi3xeqNGNutnKjcftjg84uJoT4 - artifact: bin\zstd.exe - force_update: true - on: - branch: autobuild - COMPILER: gcc - PLATFORM: "mingw64" - appveyor_repo_tag: true -- provider: GitHub - auth_token: - secure: LgJo8emYc3sFnlNWkGl4/VYK3nk/8+RagcsqDlAi3xeqNGNutnKjcftjg84uJoT4 - artifact: bin\zstd32.exe - force_update: true - on: - branch: autobuild - COMPILER: gcc - PLATFORM: "mingw32" - appveyor_repo_tag: true + 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: head/contrib/zstd/circle.yml =================================================================== --- head/contrib/zstd/circle.yml (revision 317876) +++ head/contrib/zstd/circle.yml (revision 317877) @@ -1,75 +1,75 @@ 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 - - sudo apt-get -y install libstdc++-6-dev clang gcc g++ gcc-5 gcc-6 + - sudo apt-get -y install libstdc++-6-dev clang gcc g++ gcc-5 gcc-6 zlib1g-dev liblzma-dev - sudo apt-get -y install linux-libc-dev:i386 libc6-dev-i386 test: override: - ? | if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then cc -v; 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 cmakebuild && make clean; fi : parallel: true - ? | if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make gppbuild && make clean; fi && if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make gcc5build && make clean; fi : parallel: true - ? | if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make gcc6build && make clean; fi && if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make clangbuild && make clean; fi : parallel: true - ? | if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make m32build && make clean; fi && if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make armbuild && make clean; fi : parallel: true - ? | if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make aarch64build && make clean; fi && if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make ppcbuild && make clean; fi : parallel: true - ? | if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make ppc64build && make clean; fi && if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then true && make clean; fi #could add another test here : parallel: true - ? | if [[ "$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 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: head/contrib/zstd/contrib/cleanTabs =================================================================== --- head/contrib/zstd/contrib/cleanTabs (nonexistent) +++ head/contrib/zstd/contrib/cleanTabs (revision 317877) @@ -0,0 +1,2 @@ +#!/bin/sh +sed -i '' $'s/\t/ /g' ../lib/**/*.{h,c} ../programs/*.{h,c} ../tests/*.c ./**/*.{h,cpp} ../examples/*.c ../zlibWrapper/*.{h,c} Property changes on: head/contrib/zstd/contrib/cleanTabs ___________________________________________________________________ Added: svn:executable ## -0,0 +1 ## +* \ No newline at end of property Index: head/contrib/zstd/contrib/pzstd/Options.cpp =================================================================== --- head/contrib/zstd/contrib/pzstd/Options.cpp (revision 317876) +++ head/contrib/zstd/contrib/pzstd/Options.cpp (revision 317877) @@ -1,421 +1,439 @@ /** * Copyright (c) 2016-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ #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, "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\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); + &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: head/contrib/zstd/contrib/pzstd/utils/test/ThreadPoolTest.cpp =================================================================== --- head/contrib/zstd/contrib/pzstd/utils/test/ThreadPoolTest.cpp (revision 317876) +++ head/contrib/zstd/contrib/pzstd/utils/test/ThreadPoolTest.cpp (revision 317877) @@ -1,67 +1,71 @@ /** * Copyright (c) 2016-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ #include "utils/ThreadPool.h" #include #include +#include #include #include using namespace pzstd; TEST(ThreadPool, Ordering) { std::vector results; { ThreadPool executor(1); for (int i = 0; i < 10; ++i) { executor.add([ &results, i ] { results.push_back(i); }); } } for (int i = 0; i < 10; ++i) { EXPECT_EQ(i, results[i]); } } TEST(ThreadPool, AllJobsFinished) { std::atomic numFinished{0}; std::atomic start{false}; { + std::cerr << "Creating executor" << std::endl; ThreadPool executor(5); for (int i = 0; i < 10; ++i) { executor.add([ &numFinished, &start ] { while (!start.load()) { - // spin + std::this_thread::yield(); } ++numFinished; }); } + std::cerr << "Starting" << std::endl; start.store(true); + std::cerr << "Finishing" << std::endl; } EXPECT_EQ(10, numFinished.load()); } TEST(ThreadPool, AddJobWhileJoining) { std::atomic done{false}; { ThreadPool executor(1); executor.add([&executor, &done] { while (!done.load()) { std::this_thread::yield(); } // Sleep for a second to be sure that we are joining std::this_thread::sleep_for(std::chrono::seconds(1)); executor.add([] { EXPECT_TRUE(false); }); }); done.store(true); } } Index: head/contrib/zstd/contrib/pzstd/utils/test/WorkQueueTest.cpp =================================================================== --- head/contrib/zstd/contrib/pzstd/utils/test/WorkQueueTest.cpp (revision 317876) +++ head/contrib/zstd/contrib/pzstd/utils/test/WorkQueueTest.cpp (revision 317877) @@ -1,275 +1,282 @@ /** * Copyright (c) 2016-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ #include "utils/Buffer.h" #include "utils/WorkQueue.h" #include +#include #include #include #include #include using namespace pzstd; namespace { struct Popper { WorkQueue* queue; int* results; std::mutex* mutex; void operator()() { int result; while (queue->pop(result)) { std::lock_guard lock(*mutex); results[result] = result; } } }; } TEST(WorkQueue, SingleThreaded) { WorkQueue queue; int result; queue.push(5); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(5, result); queue.push(1); queue.push(2); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(1, result); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(2, result); queue.push(1); queue.push(2); queue.finish(); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(1, result); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(2, result); EXPECT_FALSE(queue.pop(result)); queue.waitUntilFinished(); } TEST(WorkQueue, SPSC) { WorkQueue queue; const int max = 100; for (int i = 0; i < 10; ++i) { queue.push(int{i}); } std::thread thread([ &queue, max ] { int result; for (int i = 0;; ++i) { if (!queue.pop(result)) { EXPECT_EQ(i, max); break; } EXPECT_EQ(i, result); } }); std::this_thread::yield(); for (int i = 10; i < max; ++i) { queue.push(int{i}); } queue.finish(); thread.join(); } TEST(WorkQueue, SPMC) { WorkQueue queue; std::vector results(50, -1); std::mutex mutex; std::vector threads; for (int i = 0; i < 5; ++i) { threads.emplace_back(Popper{&queue, results.data(), &mutex}); } for (int i = 0; i < 50; ++i) { queue.push(int{i}); } queue.finish(); for (auto& thread : threads) { thread.join(); } for (int i = 0; i < 50; ++i) { EXPECT_EQ(i, results[i]); } } TEST(WorkQueue, MPMC) { WorkQueue queue; std::vector results(100, -1); std::mutex mutex; std::vector popperThreads; for (int i = 0; i < 4; ++i) { popperThreads.emplace_back(Popper{&queue, results.data(), &mutex}); } std::vector pusherThreads; for (int i = 0; i < 2; ++i) { auto min = i * 50; auto max = (i + 1) * 50; pusherThreads.emplace_back( [ &queue, min, max ] { for (int i = min; i < max; ++i) { queue.push(int{i}); } }); } for (auto& thread : pusherThreads) { thread.join(); } queue.finish(); for (auto& thread : popperThreads) { thread.join(); } for (int i = 0; i < 100; ++i) { EXPECT_EQ(i, results[i]); } } TEST(WorkQueue, BoundedSizeWorks) { WorkQueue queue(1); int result; queue.push(5); queue.pop(result); queue.push(5); queue.pop(result); queue.push(5); queue.finish(); queue.pop(result); EXPECT_EQ(5, result); } TEST(WorkQueue, BoundedSizePushAfterFinish) { WorkQueue queue(1); int result; queue.push(5); std::thread pusher([&queue] { queue.push(6); }); // Dirtily try and make sure that pusher has run. std::this_thread::sleep_for(std::chrono::seconds(1)); queue.finish(); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(5, result); EXPECT_FALSE(queue.pop(result)); pusher.join(); } TEST(WorkQueue, SetMaxSize) { WorkQueue queue(2); int result; queue.push(5); queue.push(6); queue.setMaxSize(1); std::thread pusher([&queue] { queue.push(7); }); // Dirtily try and make sure that pusher has run. std::this_thread::sleep_for(std::chrono::seconds(1)); queue.finish(); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(5, result); EXPECT_TRUE(queue.pop(result)); EXPECT_EQ(6, result); EXPECT_FALSE(queue.pop(result)); pusher.join(); } TEST(WorkQueue, BoundedSizeMPMC) { WorkQueue queue(10); std::vector results(200, -1); std::mutex mutex; + std::cerr << "Creating popperThreads" << std::endl; std::vector popperThreads; for (int i = 0; i < 4; ++i) { popperThreads.emplace_back(Popper{&queue, results.data(), &mutex}); } + std::cerr << "Creating pusherThreads" << std::endl; std::vector pusherThreads; for (int i = 0; i < 2; ++i) { auto min = i * 100; auto max = (i + 1) * 100; pusherThreads.emplace_back( [ &queue, min, max ] { for (int i = min; i < max; ++i) { queue.push(int{i}); } }); } + std::cerr << "Joining pusherThreads" << std::endl; for (auto& thread : pusherThreads) { thread.join(); } + std::cerr << "Finishing queue" << std::endl; queue.finish(); + std::cerr << "Joining popperThreads" << std::endl; for (auto& thread : popperThreads) { thread.join(); } + std::cerr << "Inspecting results" << std::endl; for (int i = 0; i < 200; ++i) { EXPECT_EQ(i, results[i]); } } TEST(WorkQueue, FailedPush) { WorkQueue> queue; std::unique_ptr x(new int{5}); EXPECT_TRUE(queue.push(std::move(x))); EXPECT_EQ(nullptr, x); queue.finish(); x.reset(new int{6}); EXPECT_FALSE(queue.push(std::move(x))); EXPECT_NE(nullptr, x); EXPECT_EQ(6, *x); } TEST(BufferWorkQueue, SizeCalculatedCorrectly) { { BufferWorkQueue queue; queue.finish(); EXPECT_EQ(0, queue.size()); } { BufferWorkQueue queue; queue.push(Buffer(10)); queue.finish(); EXPECT_EQ(10, queue.size()); } { BufferWorkQueue queue; queue.push(Buffer(10)); queue.push(Buffer(5)); queue.finish(); EXPECT_EQ(15, queue.size()); } { BufferWorkQueue queue; queue.push(Buffer(10)); queue.push(Buffer(5)); queue.finish(); Buffer buffer; queue.pop(buffer); EXPECT_EQ(5, queue.size()); } } Index: head/contrib/zstd/doc/educational_decoder/zstd_decompress.c =================================================================== --- head/contrib/zstd/doc/educational_decoder/zstd_decompress.c (revision 317876) +++ head/contrib/zstd/doc/educational_decoder/zstd_decompress.c (revision 317877) @@ -1,2345 +1,2358 @@ /* * Copyright (c) 2017-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ /// Zstandard educational decoder implementation /// See https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md #include #include #include #include /// Zstandard decompression functions. /// `dst` must point to a space at least as large as the reconstructed output. size_t ZSTD_decompress(void *const dst, const size_t dst_len, const void *const src, const size_t src_len); /// If `dict != NULL` and `dict_len >= 8`, does the same thing as /// `ZSTD_decompress` but uses the provided dict size_t ZSTD_decompress_with_dict(void *const dst, const size_t dst_len, const void *const src, const size_t src_len, const void *const dict, const size_t dict_len); /// Get the decompressed size of an input stream so memory can be allocated in /// advance +/// Returns -1 if the size can't be determined size_t ZSTD_get_decompressed_size(const void *const src, const size_t src_len); /******* UTILITY MACROS AND TYPES *********************************************/ -// Max block size decompressed size is 128 KB and literal blocks must be smaller -// than that +// Max block size decompressed size is 128 KB and literal blocks can't be +// larger than their block #define MAX_LITERALS_SIZE ((size_t)128 * 1024) #define MAX(a, b) ((a) > (b) ? (a) : (b)) #define MIN(a, b) ((a) < (b) ? (a) : (b)) +/// This decoder calls exit(1) when it encounters an error, however a production +/// library should propagate error codes #define ERROR(s) \ do { \ fprintf(stderr, "Error: %s\n", s); \ exit(1); \ } while (0) #define INP_SIZE() \ ERROR("Input buffer smaller than it should be or input is " \ "corrupted") #define OUT_SIZE() ERROR("Output buffer too small for output") #define CORRUPTION() ERROR("Corruption detected while decompressing") #define BAD_ALLOC() ERROR("Memory allocation error") #define IMPOSSIBLE() ERROR("An impossibility has occurred") typedef uint8_t u8; typedef uint16_t u16; typedef uint32_t u32; typedef uint64_t u64; typedef int8_t i8; typedef int16_t i16; typedef int32_t i32; typedef int64_t i64; /******* END UTILITY MACROS AND TYPES *****************************************/ /******* IMPLEMENTATION PRIMITIVE PROTOTYPES **********************************/ /// The implementations for these functions can be found at the bottom of this /// file. They implement low-level functionality needed for the higher level /// decompression functions. /*** IO STREAM OPERATIONS *************/ -/// These structs are the interface for IO, and do bounds checking on all -/// operations. They should be used opaquely to ensure safety. -/// Output is always done byte-by-byte +/// ostream_t/istream_t are used to wrap the pointers/length data passed into +/// ZSTD_decompress, so that all IO operations are safely bounds checked +/// They are written/read forward, and reads are treated as little-endian +/// They should be used opaquely to ensure safety typedef struct { u8 *ptr; size_t len; } ostream_t; -/// Input often reads a few bits at a time, so maintain an internal offset typedef struct { const u8 *ptr; - int bit_offset; size_t len; + + // Input often reads a few bits at a time, so maintain an internal offset + int bit_offset; } istream_t; /// The following two functions are the only ones that allow the istream to be /// non-byte aligned /// Reads `num` bits from a bitstream, and updates the internal offset -static inline u64 IO_read_bits(istream_t *const in, const int num); -/// Rewinds the stream by `num` bits -static inline void IO_rewind_bits(istream_t *const in, const int num); +static inline u64 IO_read_bits(istream_t *const in, const int num_bits); +/// Backs-up the stream by `num` bits so they can be read again +static inline void IO_rewind_bits(istream_t *const in, const int num_bits); /// If the remaining bits in a byte will be unused, advance to the end of the /// byte static inline void IO_align_stream(istream_t *const in); /// Write the given byte into the output stream static inline void IO_write_byte(ostream_t *const out, u8 symb); /// Returns the number of bytes left to be read in this stream. The stream must /// be byte aligned. static inline size_t IO_istream_len(const istream_t *const in); -/// Returns a pointer where `len` bytes can be read, and advances the internal -/// state. The stream must be byte aligned. +/// Advances the stream by `len` bytes, and returns a pointer to the chunk that +/// was skipped. The stream must be byte aligned. static inline const u8 *IO_read_bytes(istream_t *const in, size_t len); -/// Returns a pointer where `len` bytes can be written, and advances the internal -/// state. The stream must be byte aligned. +/// Advances the stream by `len` bytes, and returns a pointer to the chunk that +/// was skipped so it can be written to. static inline u8 *IO_write_bytes(ostream_t *const out, size_t len); /// Advance the inner state by `len` bytes. The stream must be byte aligned. static inline void IO_advance_input(istream_t *const in, size_t len); -/// Returns an `ostream_t` constructed from the given pointer and length +/// Returns an `ostream_t` constructed from the given pointer and length. static inline ostream_t IO_make_ostream(u8 *out, size_t len); -/// Returns an `istream_t` constructed from the given pointer and length +/// Returns an `istream_t` constructed from the given pointer and length. static inline istream_t IO_make_istream(const u8 *in, size_t len); -/// Returns an `istream_t` with the same base as `in`, and length `len` -/// Then, advance `in` to account for the consumed bytes -/// `in` must be byte aligned +/// Returns an `istream_t` with the same base as `in`, and length `len`. +/// Then, advance `in` to account for the consumed bytes. +/// `in` must be byte aligned. static inline istream_t IO_make_sub_istream(istream_t *const in, size_t len); /*** END IO STREAM OPERATIONS *********/ /*** BITSTREAM OPERATIONS *************/ -/// Read `num` bits (up to 64) from `src + offset`, where `offset` is in bits -static inline u64 read_bits_LE(const u8 *src, const int num, +/// Read `num` bits (up to 64) from `src + offset`, where `offset` is in bits, +/// and return them interpreted as a little-endian unsigned integer. +static inline u64 read_bits_LE(const u8 *src, const int num_bits, const size_t offset); /// Read bits from the end of a HUF or FSE bitstream. `offset` is in bits, so /// it updates `offset` to `offset - bits`, and then reads `bits` bits from /// `src + offset`. If the offset becomes negative, the extra bits at the /// bottom are filled in with `0` bits instead of reading from before `src`. static inline u64 STREAM_read_bits(const u8 *src, const int bits, i64 *const offset); /*** END BITSTREAM OPERATIONS *********/ /*** BIT COUNTING OPERATIONS **********/ -/// Returns `x`, where `2^x` is the largest power of 2 less than or equal to -/// `num`, or `-1` if `num == 0`. -static inline int log2inf(const u64 num); +/// Returns the index of the highest set bit in `num`, or `-1` if `num == 0` +static inline int highest_set_bit(const u64 num); /*** END BIT COUNTING OPERATIONS ******/ /*** HUFFMAN PRIMITIVES ***************/ // Table decode method uses exponential memory, so we need to limit depth #define HUF_MAX_BITS (16) // Limit the maximum number of symbols to 256 so we can store a symbol in a byte #define HUF_MAX_SYMBS (256) /// Structure containing all tables necessary for efficient Huffman decoding typedef struct { u8 *symbols; u8 *num_bits; int max_bits; } HUF_dtable; /// Decode a single symbol and read in enough bits to refresh the state static inline u8 HUF_decode_symbol(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Read in a full state's worth of bits to initialize it static inline void HUF_init_state(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Decompresses a single Huffman stream, returns the number of bytes decoded. /// `src_len` must be the exact length of the Huffman-coded block. static size_t HUF_decompress_1stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in); /// Same as previous but decodes 4 streams, formatted as in the Zstandard /// specification. /// `src_len` must be the exact length of the Huffman-coded block. static size_t HUF_decompress_4stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in); /// Initialize a Huffman decoding table using the table of bit counts provided static void HUF_init_dtable(HUF_dtable *const table, const u8 *const bits, const int num_symbs); /// Initialize a Huffman decoding table using the table of weights provided /// Weights follow the definition provided in the Zstandard specification static void HUF_init_dtable_usingweights(HUF_dtable *const table, const u8 *const weights, const int num_symbs); /// Free the malloc'ed parts of a decoding table static void HUF_free_dtable(HUF_dtable *const dtable); /// Deep copy a decoding table, so that it can be used and free'd without /// impacting the source table. static void HUF_copy_dtable(HUF_dtable *const dst, const HUF_dtable *const src); /*** END HUFFMAN PRIMITIVES ***********/ /*** FSE PRIMITIVES *******************/ /// For more description of FSE see /// https://github.com/Cyan4973/FiniteStateEntropy/ // FSE table decoding uses exponential memory, so limit the maximum accuracy #define FSE_MAX_ACCURACY_LOG (15) // Limit the maximum number of symbols so they can be stored in a single byte #define FSE_MAX_SYMBS (256) /// The tables needed to decode FSE encoded streams typedef struct { u8 *symbols; u8 *num_bits; u16 *new_state_base; int accuracy_log; } FSE_dtable; /// Return the symbol for the current state static inline u8 FSE_peek_symbol(const FSE_dtable *const dtable, const u16 state); /// Read the number of bits necessary to update state, update, and shift offset /// back to reflect the bits read static inline void FSE_update_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Combine peek and update: decode a symbol and update the state static inline u8 FSE_decode_symbol(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Read bits from the stream to initialize the state and shift offset back static inline void FSE_init_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Decompress two interleaved bitstreams (e.g. compressed Huffman weights) /// using an FSE decoding table. `src_len` must be the exact length of the /// block. static size_t FSE_decompress_interleaved2(const FSE_dtable *const dtable, ostream_t *const out, istream_t *const in); /// Initialize a decoding table using normalized frequencies. static void FSE_init_dtable(FSE_dtable *const dtable, const i16 *const norm_freqs, const int num_symbs, const int accuracy_log); /// Decode an FSE header as defined in the Zstandard format specification and /// use the decoded frequencies to initialize a decoding table. static void FSE_decode_header(FSE_dtable *const dtable, istream_t *const in, const int max_accuracy_log); /// Initialize an FSE table that will always return the same symbol and consume /// 0 bits per symbol, to be used for RLE mode in sequence commands static void FSE_init_dtable_rle(FSE_dtable *const dtable, const u8 symb); /// Free the malloc'ed parts of a decoding table static void FSE_free_dtable(FSE_dtable *const dtable); /// Deep copy a decoding table, so that it can be used and free'd without /// impacting the source table. static void FSE_copy_dtable(FSE_dtable *const dst, const FSE_dtable *const src); /*** END FSE PRIMITIVES ***************/ /******* END IMPLEMENTATION PRIMITIVE PROTOTYPES ******************************/ /******* ZSTD HELPER STRUCTS AND PROTOTYPES ***********************************/ /// A small structure that can be reused in various places that need to access /// frame header information typedef struct { // The size of window that we need to be able to contiguously store for // references size_t window_size; // The total output size of this compressed frame size_t frame_content_size; // The dictionary id if this frame uses one u32 dictionary_id; // Whether or not the content of this frame has a checksum int content_checksum_flag; // Whether or not the output for this frame is in a single segment int single_segment_flag; } frame_header_t; /// The context needed to decode blocks in a frame typedef struct { frame_header_t header; // The total amount of data available for backreferences, to determine if an // offset too large to be correct size_t current_total_output; const u8 *dict_content; size_t dict_content_len; // Entropy encoding tables so they can be repeated by future blocks instead // of retransmitting HUF_dtable literals_dtable; FSE_dtable ll_dtable; FSE_dtable ml_dtable; FSE_dtable of_dtable; // The last 3 offsets for the special "repeat offsets". u64 previous_offsets[3]; } frame_context_t; /// The decoded contents of a dictionary so that it doesn't have to be repeated /// for each frame that uses it typedef struct { // Entropy tables HUF_dtable literals_dtable; FSE_dtable ll_dtable; FSE_dtable ml_dtable; FSE_dtable of_dtable; // Raw content for backreferences u8 *content; size_t content_size; // Offset history to prepopulate the frame's history u64 previous_offsets[3]; u32 dictionary_id; } dictionary_t; /// A tuple containing the parts necessary to decode and execute a ZSTD sequence /// command typedef struct { u32 literal_length; u32 match_length; u32 offset; } sequence_command_t; /// The decoder works top-down, starting at the high level like Zstd frames, and /// working down to lower more technical levels such as blocks, literals, and /// sequences. The high-level functions roughly follow the outline of the /// format specification: /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md /// Before the implementation of each high-level function declared here, the /// prototypes for their helper functions are defined and explained /// Decode a single Zstd frame, or error if the input is not a valid frame. /// Accepts a dict argument, which may be NULL indicating no dictionary. /// See /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#frame-concatenation static void decode_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict); // Decode data in a compressed block static void decompress_block(frame_context_t *const ctx, ostream_t *const out, istream_t *const in); // Decode the literals section of a block static size_t decode_literals(frame_context_t *const ctx, istream_t *const in, u8 **const literals); // Decode the sequences part of a block static size_t decode_sequences(frame_context_t *const ctx, istream_t *const in, sequence_command_t **const sequences); // Execute the decoded sequences on the literals block static void execute_sequences(frame_context_t *const ctx, ostream_t *const out, const u8 *const literals, const size_t literals_len, const sequence_command_t *const sequences, const size_t num_sequences); // Parse a provided dictionary blob for use in decompression static void parse_dictionary(dictionary_t *const dict, const u8 *src, size_t src_len); static void free_dictionary(dictionary_t *const dict); /******* END ZSTD HELPER STRUCTS AND PROTOTYPES *******************************/ size_t ZSTD_decompress(void *const dst, const size_t dst_len, const void *const src, const size_t src_len) { return ZSTD_decompress_with_dict(dst, dst_len, src, src_len, NULL, 0); } size_t ZSTD_decompress_with_dict(void *const dst, const size_t dst_len, const void *const src, const size_t src_len, const void *const dict, const size_t dict_len) { dictionary_t parsed_dict; memset(&parsed_dict, 0, sizeof(dictionary_t)); // dict_len < 8 is not a valid dictionary if (dict && dict_len > 8) { parse_dictionary(&parsed_dict, (const u8 *)dict, dict_len); } - istream_t in = {(const u8 *)src, 0, src_len}; - ostream_t out = {(u8 *)dst, dst_len}; + istream_t in = IO_make_istream(src, src_len); + ostream_t out = IO_make_ostream(dst, dst_len); // "A content compressed by Zstandard is transformed into a Zstandard frame. // Multiple frames can be appended into a single file or stream. A frame is // totally independent, has a defined beginning and end, and a set of // parameters which tells the decoder how to decompress it." while (IO_istream_len(&in) > 0) { decode_frame(&out, &in, &parsed_dict); } free_dictionary(&parsed_dict); return out.ptr - (u8 *)dst; } /******* FRAME DECODING ******************************************************/ static void decode_data_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict); static void init_frame_context(frame_context_t *const context, istream_t *const in, const dictionary_t *const dict); static void free_frame_context(frame_context_t *const context); static void parse_frame_header(frame_header_t *const header, istream_t *const in); static void frame_context_apply_dict(frame_context_t *const ctx, const dictionary_t *const dict); static void decompress_data(frame_context_t *const ctx, ostream_t *const out, istream_t *const in); static void decode_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict) { const u32 magic_number = IO_read_bits(in, 32); // Skippable frame // // "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." if ((magic_number & ~0xFU) == 0x184D2A50U) { // "Skippable frames allow the insertion of user-defined data 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." const size_t frame_size = IO_read_bits(in, 32); // skip over frame IO_advance_input(in, frame_size); return; } // Zstandard frame // // "Magic_Number // // 4 Bytes, little-endian format. Value : 0xFD2FB528" if (magic_number == 0xFD2FB528U) { // ZSTD frame decode_data_frame(out, in, dict); return; } // not a real frame ERROR("Invalid magic number"); } /// Decode a frame that contains compressed data. Not all frames do as there /// are skippable frames. /// See /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#general-structure-of-zstandard-frame-format static void decode_data_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict) { frame_context_t ctx; // Initialize the context that needs to be carried from block to block init_frame_context(&ctx, in, dict); if (ctx.header.frame_content_size != 0 && ctx.header.frame_content_size > out->len) { OUT_SIZE(); } decompress_data(&ctx, out, in); free_frame_context(&ctx); } /// Takes the information provided in the header and dictionary, and initializes /// the context for this frame static void init_frame_context(frame_context_t *const context, istream_t *const in, const dictionary_t *const dict) { // Most fields in context are correct when initialized to 0 memset(context, 0, sizeof(frame_context_t)); // Parse data from the frame header parse_frame_header(&context->header, in); // Set up the offset history for the repeat offset commands context->previous_offsets[0] = 1; context->previous_offsets[1] = 4; context->previous_offsets[2] = 8; // Apply details from the dict if it exists frame_context_apply_dict(context, dict); } static void free_frame_context(frame_context_t *const context) { HUF_free_dtable(&context->literals_dtable); FSE_free_dtable(&context->ll_dtable); FSE_free_dtable(&context->ml_dtable); FSE_free_dtable(&context->of_dtable); memset(context, 0, sizeof(frame_context_t)); } static void parse_frame_header(frame_header_t *const header, istream_t *const in) { // "The first header's byte is called the Frame_Header_Descriptor. It tells // 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" const u8 descriptor = IO_read_bits(in, 8); // decode frame header descriptor into flags const u8 frame_content_size_flag = descriptor >> 6; const u8 single_segment_flag = (descriptor >> 5) & 1; const u8 reserved_bit = (descriptor >> 3) & 1; const u8 content_checksum_flag = (descriptor >> 2) & 1; const u8 dictionary_id_flag = descriptor & 3; if (reserved_bit != 0) { CORRUPTION(); } header->single_segment_flag = single_segment_flag; header->content_checksum_flag = content_checksum_flag; // decode window size if (!single_segment_flag) { // "Provides guarantees on maximum back-reference distance that will be // used within compressed data. This information is important for // decoders to allocate enough memory. // // Bit numbers 7-3 2-0 // Field name Exponent Mantissa" u8 window_descriptor = IO_read_bits(in, 8); u8 exponent = window_descriptor >> 3; u8 mantissa = window_descriptor & 7; // Use the algorithm from the specification to compute window size // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#window_descriptor size_t window_base = (size_t)1 << (10 + exponent); size_t window_add = (window_base / 8) * mantissa; header->window_size = window_base + window_add; } // decode dictionary id if it exists if (dictionary_id_flag) { // "This is a variable size field, which contains the ID of the // dictionary required to properly decode the frame. Note that this // field is optional. When it's not present, it's up to the caller to // make sure it uses the correct dictionary. Format is little-endian." const int bytes_array[] = {0, 1, 2, 4}; const int bytes = bytes_array[dictionary_id_flag]; header->dictionary_id = IO_read_bits(in, bytes * 8); } else { header->dictionary_id = 0; } // decode frame content size if it exists if (single_segment_flag || frame_content_size_flag) { // "This is the original (uncompressed) size. This information is // optional. The Field_Size is provided according to value of // Frame_Content_Size_flag. The Field_Size can be equal to 0 (not // present), 1, 2, 4 or 8 bytes. Format is little-endian." // // if frame_content_size_flag == 0 but single_segment_flag is set, we // still have a 1 byte field const int bytes_array[] = {1, 2, 4, 8}; const int bytes = bytes_array[frame_content_size_flag]; header->frame_content_size = IO_read_bits(in, bytes * 8); if (bytes == 2) { // "When Field_Size is 2, the offset of 256 is added." header->frame_content_size += 256; } } else { header->frame_content_size = 0; } if (single_segment_flag) { // "The Window_Descriptor byte is optional. It is absent when // Single_Segment_flag is set. In this case, the maximum back-reference // distance is the content size itself, which can be any value from 1 to // 2^64-1 bytes (16 EB)." header->window_size = header->frame_content_size; } } /// A dictionary acts as initializing values for the frame context before /// decompression, so we implement it by applying it's predetermined /// tables and content to the context before beginning decompression static void frame_context_apply_dict(frame_context_t *const ctx, const dictionary_t *const dict) { // If the content pointer is NULL then it must be an empty dict if (!dict || !dict->content) return; // If the requested dictionary_id is non-zero, the correct dictionary must // be present if (ctx->header.dictionary_id != 0 && ctx->header.dictionary_id != dict->dictionary_id) { ERROR("Wrong dictionary provided"); } // Copy the dict content to the context for references during sequence // execution ctx->dict_content = dict->content; ctx->dict_content_len = dict->content_size; // If it's a formatted dict copy the precomputed tables in so they can // be used in the table repeat modes if (dict->dictionary_id != 0) { // Deep copy the entropy tables so they can be freed independently of // the dictionary struct HUF_copy_dtable(&ctx->literals_dtable, &dict->literals_dtable); FSE_copy_dtable(&ctx->ll_dtable, &dict->ll_dtable); FSE_copy_dtable(&ctx->of_dtable, &dict->of_dtable); FSE_copy_dtable(&ctx->ml_dtable, &dict->ml_dtable); + // Copy the repeated offsets memcpy(ctx->previous_offsets, dict->previous_offsets, sizeof(ctx->previous_offsets)); } } /// Decompress the data from a frame block by block static void decompress_data(frame_context_t *const ctx, ostream_t *const out, istream_t *const in) { // "A frame encapsulates one or multiple blocks. Each block can be // compressed or not, 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." int last_block = 0; do { // "Last_Block // // The lowest bit signals if this block is the last one. Frame ends // right after this block. // // Block_Type and Block_Size // // The next 2 bits represent the Block_Type, while the remaining 21 bits // represent the Block_Size. Format is little-endian." last_block = IO_read_bits(in, 1); const int block_type = IO_read_bits(in, 2); const size_t block_len = IO_read_bits(in, 21); switch (block_type) { case 0: { // "Raw_Block - this is an uncompressed block. Block_Size is the // number of bytes to read and copy." const u8 *const read_ptr = IO_read_bytes(in, block_len); u8 *const write_ptr = IO_write_bytes(out, block_len); - // + // Copy the raw data into the output memcpy(write_ptr, read_ptr, block_len); ctx->current_total_output += block_len; break; } case 1: { // "RLE_Block - this is a single byte, repeated N times. In which // case, Block_Size is the size to regenerate, while the // "compressed" block is just 1 byte (the byte to repeat)." const u8 *const read_ptr = IO_read_bytes(in, 1); u8 *const write_ptr = IO_write_bytes(out, block_len); - // Copy `block_len` copies of `streams->src[0]` to the output + // Copy `block_len` copies of `read_ptr[0]` to the output memset(write_ptr, read_ptr[0], block_len); ctx->current_total_output += block_len; break; } case 2: { // "Compressed_Block - this is a Zstandard compressed block, // detailed in another section of this specification. Block_Size is // the compressed size. // Create a sub-stream for the block istream_t block_stream = IO_make_sub_istream(in, block_len); decompress_block(ctx, out, &block_stream); break; } case 3: // "Reserved - this is not a block. This value cannot be used with // current version of this specification." CORRUPTION(); break; default: IMPOSSIBLE(); } } while (!last_block); if (ctx->header.content_checksum_flag) { // This program does not support checking the checksum, so skip over it // if it's present IO_advance_input(in, 4); } } /******* END FRAME DECODING ***************************************************/ /******* BLOCK DECOMPRESSION **************************************************/ static void decompress_block(frame_context_t *const ctx, ostream_t *const out, istream_t *const in) { // "A compressed block consists of 2 sections : // // Literals_Section // Sequences_Section" // Part 1: decode the literals block u8 *literals = NULL; const size_t literals_size = decode_literals(ctx, in, &literals); // Part 2: decode the sequences block sequence_command_t *sequences = NULL; const size_t num_sequences = decode_sequences(ctx, in, &sequences); // Part 3: combine literals and sequence commands to generate output execute_sequences(ctx, out, literals, literals_size, sequences, num_sequences); free(literals); free(sequences); } /******* END BLOCK DECOMPRESSION **********************************************/ /******* LITERALS DECODING ****************************************************/ static size_t decode_literals_simple(istream_t *const in, u8 **const literals, const int block_type, const int size_format); static size_t decode_literals_compressed(frame_context_t *const ctx, istream_t *const in, u8 **const literals, const int block_type, const int size_format); -static void decode_huf_table(istream_t *const in, HUF_dtable *const dtable); +static void decode_huf_table(HUF_dtable *const dtable, istream_t *const in); static void fse_decode_hufweights(ostream_t *weights, istream_t *const in, int *const num_symbs); static size_t decode_literals(frame_context_t *const ctx, istream_t *const in, u8 **const literals) { // "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 // // 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 // // This field uses 2 lowest bits of first byte, describing 4 different block // types" // // size_format takes between 1 and 2 bits int block_type = IO_read_bits(in, 2); int size_format = IO_read_bits(in, 2); if (block_type <= 1) { // Raw or RLE literals block return decode_literals_simple(in, literals, block_type, size_format); } else { // Huffman compressed literals return decode_literals_compressed(ctx, in, literals, block_type, size_format); } } /// Decodes literals blocks in raw or RLE form static size_t decode_literals_simple(istream_t *const in, u8 **const literals, const int block_type, const int size_format) { size_t size; switch (size_format) { // These cases are in the form ?0 // In this case, the ? bit is actually part of the size field case 0: case 2: // "Size_Format uses 1 bit. Regenerated_Size uses 5 bits (0-31)." IO_rewind_bits(in, 1); size = IO_read_bits(in, 5); break; case 1: // "Size_Format uses 2 bits. Regenerated_Size uses 12 bits (0-4095)." size = IO_read_bits(in, 12); break; case 3: // "Size_Format uses 2 bits. Regenerated_Size uses 20 bits (0-1048575)." size = IO_read_bits(in, 20); break; default: // Size format is in range 0-3 IMPOSSIBLE(); } if (size > MAX_LITERALS_SIZE) { CORRUPTION(); } *literals = malloc(size); if (!*literals) { BAD_ALLOC(); } switch (block_type) { case 0: { // "Raw_Literals_Block - Literals are stored uncompressed." const u8 *const read_ptr = IO_read_bytes(in, size); memcpy(*literals, read_ptr, size); break; } case 1: { // "RLE_Literals_Block - Literals consist of a single byte value repeated N times." const u8 *const read_ptr = IO_read_bytes(in, 1); memset(*literals, read_ptr[0], size); break; } default: IMPOSSIBLE(); } return size; } /// Decodes Huffman compressed literals static size_t decode_literals_compressed(frame_context_t *const ctx, istream_t *const in, u8 **const literals, const int block_type, const int size_format) { size_t regenerated_size, compressed_size; // Only size_format=0 has 1 stream, so default to 4 int num_streams = 4; switch (size_format) { case 0: // "A single stream. Both Compressed_Size and Regenerated_Size use 10 // bits (0-1023)." num_streams = 1; // Fall through as it has the same size format case 1: // "4 streams. Both Compressed_Size and Regenerated_Size use 10 bits // (0-1023)." regenerated_size = IO_read_bits(in, 10); compressed_size = IO_read_bits(in, 10); break; case 2: // "4 streams. Both Compressed_Size and Regenerated_Size use 14 bits // (0-16383)." regenerated_size = IO_read_bits(in, 14); compressed_size = IO_read_bits(in, 14); break; case 3: // "4 streams. Both Compressed_Size and Regenerated_Size use 18 bits // (0-262143)." regenerated_size = IO_read_bits(in, 18); compressed_size = IO_read_bits(in, 18); break; default: // Impossible IMPOSSIBLE(); } if (regenerated_size > MAX_LITERALS_SIZE || compressed_size >= regenerated_size) { CORRUPTION(); } *literals = malloc(regenerated_size); if (!*literals) { BAD_ALLOC(); } ostream_t lit_stream = IO_make_ostream(*literals, regenerated_size); istream_t huf_stream = IO_make_sub_istream(in, compressed_size); if (block_type == 2) { - // Decode provided Huffman table + // Decode the provided Huffman table // "This section is only present when Literals_Block_Type type is // Compressed_Literals_Block (2)." HUF_free_dtable(&ctx->literals_dtable); - decode_huf_table(&huf_stream, &ctx->literals_dtable); + decode_huf_table(&ctx->literals_dtable, &huf_stream); } else { // If the previous Huffman table is being repeated, ensure it exists if (!ctx->literals_dtable.symbols) { CORRUPTION(); } } size_t symbols_decoded; if (num_streams == 1) { symbols_decoded = HUF_decompress_1stream(&ctx->literals_dtable, &lit_stream, &huf_stream); } else { symbols_decoded = HUF_decompress_4stream(&ctx->literals_dtable, &lit_stream, &huf_stream); } if (symbols_decoded != regenerated_size) { CORRUPTION(); } return regenerated_size; } // Decode the Huffman table description -static void decode_huf_table(istream_t *const in, HUF_dtable *const dtable) { - const u8 header = IO_read_bits(in, 8); - +static void decode_huf_table(HUF_dtable *const dtable, istream_t *const in) { // "All literal values from zero (included) to last present one (excluded) // are represented by Weight with values from 0 to Max_Number_of_Bits." // "This is a single byte value (0-255), which describes how to decode the list of weights." + const u8 header = IO_read_bits(in, 8); + u8 weights[HUF_MAX_SYMBS]; memset(weights, 0, sizeof(weights)); int num_symbs; if (header >= 128) { // "This is a direct representation, where each Weight is written // directly as a 4 bits field (0-15). 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" num_symbs = header - 127; const size_t bytes = (num_symbs + 1) / 2; const u8 *const weight_src = IO_read_bytes(in, bytes); for (int i = 0; i < num_symbs; i++) { // "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.)." if (i % 2 == 0) { weights[i] = weight_src[i / 2] >> 4; } else { weights[i] = weight_src[i / 2] & 0xf; } } } else { // The weights are FSE encoded, decode them before we can construct the // table istream_t fse_stream = IO_make_sub_istream(in, header); ostream_t weight_stream = IO_make_ostream(weights, HUF_MAX_SYMBS); fse_decode_hufweights(&weight_stream, &fse_stream, &num_symbs); } // Construct the table using the decoded weights HUF_init_dtable_usingweights(dtable, weights, num_symbs); } static void fse_decode_hufweights(ostream_t *weights, istream_t *const in, int *const num_symbs) { const int MAX_ACCURACY_LOG = 7; FSE_dtable dtable; // "An FSE bitstream starts by a header, describing probabilities // distribution. It will create a Decoding Table. For a list of Huffman // weights, maximum accuracy is 7 bits." FSE_decode_header(&dtable, in, MAX_ACCURACY_LOG); // Decode the weights *num_symbs = FSE_decompress_interleaved2(&dtable, weights, in); FSE_free_dtable(&dtable); } /******* END LITERALS DECODING ************************************************/ /******* SEQUENCE DECODING ****************************************************/ /// The combination of FSE states needed to decode sequences typedef struct { FSE_dtable ll_table; FSE_dtable of_table; FSE_dtable ml_table; u16 ll_state; u16 of_state; u16 ml_state; -} sequence_state_t; +} sequence_states_t; /// Different modes to signal to decode_seq_tables what to do typedef enum { seq_literal_length = 0, seq_offset = 1, seq_match_length = 2, } seq_part_t; typedef enum { seq_predefined = 0, seq_rle = 1, seq_fse = 2, seq_repeat = 3, } seq_mode_t; /// The predefined FSE distribution tables for `seq_predefined` mode static const i16 SEQ_LITERAL_LENGTH_DEFAULT_DIST[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}; static const i16 SEQ_OFFSET_DEFAULT_DIST[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}; static const i16 SEQ_MATCH_LENGTH_DEFAULT_DIST[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}; /// The sequence decoding baseline and number of additional bits to read/add /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#the-codes-for-literals-lengths-match-lengths-and-offsets static const u32 SEQ_LITERAL_LENGTH_BASELINES[36] = { 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, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65538}; static const u8 SEQ_LITERAL_LENGTH_EXTRA_BITS[36] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}; static const u32 SEQ_MATCH_LENGTH_BASELINES[53] = { 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, 131, 259, 515, 1027, 2051, 4099, 8195, 16387, 32771, 65539}; static const u8 SEQ_MATCH_LENGTH_EXTRA_BITS[53] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}; /// Offset decoding is simpler so we just need a maximum code value static const u8 SEQ_MAX_CODES[3] = {35, -1, 52}; static void decompress_sequences(frame_context_t *const ctx, istream_t *const in, sequence_command_t *const sequences, const size_t num_sequences); -static sequence_command_t decode_sequence(sequence_state_t *const state, +static sequence_command_t decode_sequence(sequence_states_t *const state, const u8 *const src, i64 *const offset); -static void decode_seq_table(istream_t *const in, FSE_dtable *const table, +static void decode_seq_table(FSE_dtable *const table, istream_t *const in, const seq_part_t type, const seq_mode_t mode); static size_t decode_sequences(frame_context_t *const ctx, istream_t *in, sequence_command_t **const sequences) { // "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 literal section. A match copy command specifies an // offset and a length. The offset gives the position to copy from, which // can be within a previous block." size_t num_sequences; // "Number_of_Sequences // // This is a variable size field using between 1 and 3 bytes. Let's call its // first byte byte0." u8 header = IO_read_bits(in, 8); if (header == 0) { // "There are no sequences. The sequence section stops there. // Regenerated content is defined entirely by literals section." *sequences = NULL; return 0; } else if (header < 128) { // "Number_of_Sequences = byte0 . Uses 1 byte." num_sequences = header; } else if (header < 255) { // "Number_of_Sequences = ((byte0-128) << 8) + byte1 . Uses 2 bytes." num_sequences = ((header - 128) << 8) + IO_read_bits(in, 8); } else { // "Number_of_Sequences = byte1 + (byte2<<8) + 0x7F00 . Uses 3 bytes." num_sequences = IO_read_bits(in, 16) + 0x7F00; } *sequences = malloc(num_sequences * sizeof(sequence_command_t)); if (!*sequences) { BAD_ALLOC(); } decompress_sequences(ctx, in, *sequences, num_sequences); return num_sequences; } /// Decompress the FSE encoded sequence commands static void decompress_sequences(frame_context_t *const ctx, istream_t *in, sequence_command_t *const sequences, const size_t num_sequences) { // "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." // "Symbol compression modes // // This is a single byte, defining the compression mode of each symbol // type." // // Bit number : Field name // 7-6 : Literals_Lengths_Mode // 5-4 : Offsets_Mode // 3-2 : Match_Lengths_Mode // 1-0 : Reserved u8 compression_modes = IO_read_bits(in, 8); if ((compression_modes & 3) != 0) { // Reserved bits set CORRUPTION(); } // "Following the header, up to 3 distribution tables can be described. When // present, they are in this order : // // Literals lengths // Offsets // Match Lengths" // Update the tables we have stored in the context - decode_seq_table(in, &ctx->ll_dtable, seq_literal_length, + decode_seq_table(&ctx->ll_dtable, in, seq_literal_length, (compression_modes >> 6) & 3); - decode_seq_table(in, &ctx->of_dtable, seq_offset, + decode_seq_table(&ctx->of_dtable, in, seq_offset, (compression_modes >> 4) & 3); - decode_seq_table(in, &ctx->ml_dtable, seq_match_length, + decode_seq_table(&ctx->ml_dtable, in, seq_match_length, (compression_modes >> 2) & 3); - // Check to make sure none of the tables are uninitialized - if (!ctx->ll_dtable.symbols || !ctx->of_dtable.symbols || - !ctx->ml_dtable.symbols) { - CORRUPTION(); - } - sequence_state_t state; - // Copy the context's tables into the local state - memcpy(&state.ll_table, &ctx->ll_dtable, sizeof(FSE_dtable)); - memcpy(&state.of_table, &ctx->of_dtable, sizeof(FSE_dtable)); - memcpy(&state.ml_table, &ctx->ml_dtable, sizeof(FSE_dtable)); + sequence_states_t states; - size_t len = IO_istream_len(in); + // Initialize the decoding tables + { + states.ll_table = ctx->ll_dtable; + states.of_table = ctx->of_dtable; + states.ml_table = ctx->ml_dtable; + } + + const size_t len = IO_istream_len(in); const u8 *const src = IO_read_bytes(in, len); // "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." - const int padding = 8 - log2inf(src[len - 1]); - i64 offset = len * 8 - padding; + const int padding = 8 - highest_set_bit(src[len - 1]); + // The offset starts at the end because FSE streams are read backwards + i64 bit_offset = len * 8 - padding; // "The bitstream starts with initial 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." - FSE_init_state(&state.ll_table, &state.ll_state, src, &offset); - FSE_init_state(&state.of_table, &state.of_state, src, &offset); - FSE_init_state(&state.ml_table, &state.ml_state, src, &offset); + FSE_init_state(&states.ll_table, &states.ll_state, src, &bit_offset); + FSE_init_state(&states.of_table, &states.of_state, src, &bit_offset); + FSE_init_state(&states.ml_table, &states.ml_state, src, &bit_offset); for (size_t i = 0; i < num_sequences; i++) { // Decode sequences one by one - sequences[i] = decode_sequence(&state, src, &offset); + sequences[i] = decode_sequence(&states, src, &bit_offset); } - if (offset != 0) { + if (bit_offset != 0) { CORRUPTION(); } - - // Don't free tables so they can be used in the next block } // Decode a single sequence and update the state -static sequence_command_t decode_sequence(sequence_state_t *const state, +static sequence_command_t decode_sequence(sequence_states_t *const states, const u8 *const src, i64 *const offset) { // "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." // Decode symbols, but don't update states - const u8 of_code = FSE_peek_symbol(&state->of_table, state->of_state); - const u8 ll_code = FSE_peek_symbol(&state->ll_table, state->ll_state); - const u8 ml_code = FSE_peek_symbol(&state->ml_table, state->ml_state); + const u8 of_code = FSE_peek_symbol(&states->of_table, states->of_state); + const u8 ll_code = FSE_peek_symbol(&states->ll_table, states->ll_state); + const u8 ml_code = FSE_peek_symbol(&states->ml_table, states->ml_state); // Offset doesn't need a max value as it's not decoded using a table if (ll_code > SEQ_MAX_CODES[seq_literal_length] || ml_code > SEQ_MAX_CODES[seq_match_length]) { CORRUPTION(); } // Read the interleaved bits sequence_command_t seq; // "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." seq.offset = ((u32)1 << of_code) + STREAM_read_bits(src, of_code, offset); seq.match_length = SEQ_MATCH_LENGTH_BASELINES[ml_code] + STREAM_read_bits(src, SEQ_MATCH_LENGTH_EXTRA_BITS[ml_code], offset); seq.literal_length = SEQ_LITERAL_LENGTH_BASELINES[ll_code] + STREAM_read_bits(src, SEQ_LITERAL_LENGTH_EXTRA_BITS[ll_code], offset); // "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." // If the stream is complete don't read bits to update state if (*offset != 0) { - FSE_update_state(&state->ll_table, &state->ll_state, src, offset); - FSE_update_state(&state->ml_table, &state->ml_state, src, offset); - FSE_update_state(&state->of_table, &state->of_state, src, offset); + FSE_update_state(&states->ll_table, &states->ll_state, src, offset); + FSE_update_state(&states->ml_table, &states->ml_state, src, offset); + FSE_update_state(&states->of_table, &states->of_state, src, offset); } return seq; } /// Given a sequence part and table mode, decode the FSE distribution -static void decode_seq_table(istream_t *const in, FSE_dtable *const table, - const seq_part_t type, const seq_mode_t mode) { +/// Errors if the mode is `seq_repeat` without a pre-existing table in `table` +static void decode_seq_table(FSE_dtable *const table, istream_t *const in, + const seq_part_t type, const seq_mode_t mode) { // Constant arrays indexed by seq_part_t const i16 *const default_distributions[] = {SEQ_LITERAL_LENGTH_DEFAULT_DIST, SEQ_OFFSET_DEFAULT_DIST, SEQ_MATCH_LENGTH_DEFAULT_DIST}; const size_t default_distribution_lengths[] = {36, 29, 53}; const size_t default_distribution_accuracies[] = {6, 5, 6}; const size_t max_accuracies[] = {9, 8, 9}; if (mode != seq_repeat) { // Free old one before overwriting FSE_free_dtable(table); } switch (mode) { case seq_predefined: { // "Predefined_Mode : uses a predefined distribution table." const i16 *distribution = default_distributions[type]; const size_t symbs = default_distribution_lengths[type]; const size_t accuracy_log = default_distribution_accuracies[type]; FSE_init_dtable(table, distribution, symbs, accuracy_log); break; } case seq_rle: { // "RLE_Mode : it's a single code, repeated Number_of_Sequences times." const u8 symb = IO_read_bytes(in, 1)[0]; FSE_init_dtable_rle(table, symb); break; } case seq_fse: { // "FSE_Compressed_Mode : standard FSE compression. A distribution table // will be present " FSE_decode_header(table, in, max_accuracies[type]); break; } case seq_repeat: // "Repeat_Mode : re-use distribution table from previous compressed // block." // Nothing to do here, table will be unchanged + if (!table->symbols) { + // This mode is invalid if we don't already have a table + CORRUPTION(); + } break; default: // Impossible, as mode is from 0-3 IMPOSSIBLE(); break; } + } /******* END SEQUENCE DECODING ************************************************/ /******* SEQUENCE EXECUTION ***************************************************/ static void execute_sequences(frame_context_t *const ctx, ostream_t *const out, const u8 *const literals, const size_t literals_len, const sequence_command_t *const sequences, const size_t num_sequences) { istream_t litstream = IO_make_istream(literals, literals_len); u64 *const offset_hist = ctx->previous_offsets; size_t total_output = ctx->current_total_output; for (size_t i = 0; i < num_sequences; i++) { const sequence_command_t seq = sequences[i]; { + // If the sequence asks for more literals than are left, the + // sequence must be corrupted if (seq.literal_length > IO_istream_len(&litstream)) { CORRUPTION(); } u8 *const write_ptr = IO_write_bytes(out, seq.literal_length); const u8 *const read_ptr = IO_read_bytes(&litstream, seq.literal_length); // Copy literals to output memcpy(write_ptr, read_ptr, seq.literal_length); total_output += seq.literal_length; } size_t offset; // Offsets are special, we need to handle the repeat offsets if (seq.offset <= 3) { // "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'". // Use 0 indexing for the array u32 idx = seq.offset - 1; if (seq.literal_length == 0) { // "There is an exception though, when current sequence's // literals length is 0. In this case, repeated offsets are // shifted by one, so Repeated_Offset1 becomes Repeated_Offset2, // Repeated_Offset2 becomes Repeated_Offset3, and // Repeated_Offset3 becomes Repeated_Offset1 - 1_byte." idx++; } if (idx == 0) { offset = offset_hist[0]; } else { // If idx == 3 then literal length was 0 and the offset was 3, // as per the exception listed above offset = idx < 3 ? offset_hist[idx] : offset_hist[0] - 1; - // If idx == 1 we don't need to modify offset_hist[2] + // If idx == 1 we don't need to modify offset_hist[2], since + // we're using the second-most recent code if (idx > 1) { offset_hist[2] = offset_hist[1]; } offset_hist[1] = offset_hist[0]; offset_hist[0] = offset; } } else { + // When it's not a repeat offset: + // "if (Offset_Value > 3) offset = Offset_Value - 3;" offset = seq.offset - 3; // Shift back history offset_hist[2] = offset_hist[1]; offset_hist[1] = offset_hist[0]; offset_hist[0] = offset; } size_t match_length = seq.match_length; u8 *write_ptr = IO_write_bytes(out, match_length); if (total_output <= ctx->header.window_size) { // In this case offset might go back into the dictionary if (offset > total_output + ctx->dict_content_len) { // The offset goes beyond even the dictionary CORRUPTION(); } if (offset > total_output) { // "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." const size_t dict_copy = MIN(offset - total_output, match_length); const size_t dict_offset = ctx->dict_content_len - (offset - total_output); memcpy(write_ptr, ctx->dict_content + dict_offset, dict_copy); write_ptr += dict_copy; match_length -= dict_copy; } } else if (offset > ctx->header.window_size) { CORRUPTION(); } // We must copy byte by byte because the match length might be larger // than the offset // ex: if the output so far was "abc", a command with offset=3 and // match_length=6 would produce "abcabcabc" as the new output for (size_t i = 0; i < match_length; i++) { *write_ptr = *(write_ptr - offset); write_ptr++; } total_output += seq.match_length; } + // Copy any leftover literals { size_t len = IO_istream_len(&litstream); u8 *const write_ptr = IO_write_bytes(out, len); const u8 *const read_ptr = IO_read_bytes(&litstream, len); - // Copy any leftover literals memcpy(write_ptr, read_ptr, len); total_output += len; } ctx->current_total_output = total_output; } /******* END SEQUENCE EXECUTION ***********************************************/ /******* OUTPUT SIZE COUNTING *************************************************/ static void traverse_frame(const frame_header_t *const header, istream_t *const in); /// Get the decompressed size of an input stream so memory can be allocated in /// advance. /// This is more complex than the implementation in the reference /// implementation, as this API allows for the decompression of multiple /// concatenated frames. size_t ZSTD_get_decompressed_size(const void *src, const size_t src_len) { istream_t in = IO_make_istream(src, src_len); size_t dst_size = 0; // Each frame header only gives us the size of its frame, so iterate over // all // frames while (IO_istream_len(&in) > 0) { const u32 magic_number = IO_read_bits(&in, 32); if ((magic_number & ~0xFU) == 0x184D2A50U) { // skippable frame, this has no impact on output size const size_t frame_size = IO_read_bits(&in, 32); IO_advance_input(&in, frame_size); } else if (magic_number == 0xFD2FB528U) { // ZSTD frame frame_header_t header; parse_frame_header(&header, &in); if (header.frame_content_size == 0 && !header.single_segment_flag) { // Content size not provided, we can't tell return -1; } dst_size += header.frame_content_size; // Consume the input from the frame to reach the start of the next traverse_frame(&header, &in); } else { // not a real frame ERROR("Invalid magic number"); } } return dst_size; } /// Iterate over each block in a frame to find the end of it, to get to the /// start of the next frame static void traverse_frame(const frame_header_t *const header, istream_t *const in) { int last_block = 0; do { // Parse the block header last_block = IO_read_bits(in, 1); const int block_type = IO_read_bits(in, 2); const size_t block_len = IO_read_bits(in, 21); switch (block_type) { case 0: // Raw block, block_len bytes IO_advance_input(in, block_len); break; case 1: // RLE block, 1 byte IO_advance_input(in, 1); break; case 2: // Compressed block, compressed size is block_len IO_advance_input(in, block_len); break; case 3: // Reserved block type CORRUPTION(); break; default: IMPOSSIBLE(); } } while (!last_block); if (header->content_checksum_flag) { IO_advance_input(in, 4); } } /******* END OUTPUT SIZE COUNTING *********************************************/ /******* DICTIONARY PARSING ***************************************************/ static void init_dictionary_content(dictionary_t *const dict, istream_t *const in); static void parse_dictionary(dictionary_t *const dict, const u8 *src, size_t src_len) { memset(dict, 0, sizeof(dictionary_t)); if (src_len < 8) { INP_SIZE(); } istream_t in = IO_make_istream(src, src_len); const u32 magic_number = IO_read_bits(&in, 32); if (magic_number != 0xEC30A437) { // raw content dict IO_rewind_bits(&in, 32); init_dictionary_content(dict, &in); return; } dict->dictionary_id = IO_read_bits(&in, 32); // "Entropy_Tables : following the same format as the tables in compressed // blocks. 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. 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." - decode_huf_table(&in, &dict->literals_dtable); - decode_seq_table(&in, &dict->of_dtable, seq_offset, seq_fse); - decode_seq_table(&in, &dict->ml_dtable, seq_match_length, seq_fse); - decode_seq_table(&in, &dict->ll_dtable, seq_literal_length, seq_fse); + decode_huf_table(&dict->literals_dtable, &in); + decode_seq_table(&dict->of_dtable, &in, seq_offset, seq_fse); + decode_seq_table(&dict->ml_dtable, &in, seq_match_length, seq_fse); + decode_seq_table(&dict->ll_dtable, &in, seq_literal_length, seq_fse); // Read in the previous offset history dict->previous_offsets[0] = IO_read_bits(&in, 32); dict->previous_offsets[1] = IO_read_bits(&in, 32); dict->previous_offsets[2] = IO_read_bits(&in, 32); // Ensure the provided offsets aren't too large // "Each recent offset must have a value < dictionary size." for (int i = 0; i < 3; i++) { if (dict->previous_offsets[i] > src_len) { ERROR("Dictionary corrupted"); } } // "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." init_dictionary_content(dict, &in); } static void init_dictionary_content(dictionary_t *const dict, istream_t *const in) { // Copy in the content dict->content_size = IO_istream_len(in); dict->content = malloc(dict->content_size); if (!dict->content) { BAD_ALLOC(); } const u8 *const content = IO_read_bytes(in, dict->content_size); memcpy(dict->content, content, dict->content_size); } /// Free an allocated dictionary static void free_dictionary(dictionary_t *const dict) { HUF_free_dtable(&dict->literals_dtable); FSE_free_dtable(&dict->ll_dtable); FSE_free_dtable(&dict->of_dtable); FSE_free_dtable(&dict->ml_dtable); free(dict->content); memset(dict, 0, sizeof(dictionary_t)); } /******* END DICTIONARY PARSING ***********************************************/ /******* IO STREAM OPERATIONS *************************************************/ #define UNALIGNED() ERROR("Attempting to operate on a non-byte aligned stream") /// Reads `num` bits from a bitstream, and updates the internal offset -static inline u64 IO_read_bits(istream_t *const in, const int num) { - if (num > 64 || num <= 0) { +static inline u64 IO_read_bits(istream_t *const in, const int num_bits) { + if (num_bits > 64 || num_bits <= 0) { ERROR("Attempt to read an invalid number of bits"); } - const size_t bytes = (num + in->bit_offset + 7) / 8; - const size_t full_bytes = (num + in->bit_offset) / 8; + const size_t bytes = (num_bits + in->bit_offset + 7) / 8; + const size_t full_bytes = (num_bits + in->bit_offset) / 8; if (bytes > in->len) { INP_SIZE(); } - const u64 result = read_bits_LE(in->ptr, num, in->bit_offset); + const u64 result = read_bits_LE(in->ptr, num_bits, in->bit_offset); - in->bit_offset = (num + in->bit_offset) % 8; + in->bit_offset = (num_bits + in->bit_offset) % 8; in->ptr += full_bytes; in->len -= full_bytes; return result; } /// If a non-zero number of bits have been read from the current byte, advance /// the offset to the next byte -static inline void IO_rewind_bits(istream_t *const in, int num) { - if (num < 0) { +static inline void IO_rewind_bits(istream_t *const in, int num_bits) { + if (num_bits < 0) { ERROR("Attempting to rewind stream by a negative number of bits"); } - const int new_offset = in->bit_offset - num; - const i64 bytes = (new_offset - 7) / 8; + // move the offset back by `num_bits` bits + const int new_offset = in->bit_offset - num_bits; + // determine the number of whole bytes we have to rewind, rounding up to an + // integer number (e.g. if `new_offset == -5`, `bytes == 1`) + const i64 bytes = -(new_offset - 7) / 8; - in->ptr += bytes; - in->len -= bytes; + in->ptr -= bytes; + in->len += bytes; + // make sure the resulting `bit_offset` is positive, as mod in C does not + // convert numbers from negative to positive (e.g. -22 % 8 == -6) in->bit_offset = ((new_offset % 8) + 8) % 8; } /// If the remaining bits in a byte will be unused, advance to the end of the /// byte static inline void IO_align_stream(istream_t *const in) { if (in->bit_offset != 0) { if (in->len == 0) { INP_SIZE(); } in->ptr++; in->len--; in->bit_offset = 0; } } /// Write the given byte into the output stream static inline void IO_write_byte(ostream_t *const out, u8 symb) { if (out->len == 0) { OUT_SIZE(); } out->ptr[0] = symb; out->ptr++; out->len--; } /// Returns the number of bytes left to be read in this stream. The stream must /// be byte aligned. static inline size_t IO_istream_len(const istream_t *const in) { return in->len; } /// Returns a pointer where `len` bytes can be read, and advances the internal /// state. The stream must be byte aligned. static inline const u8 *IO_read_bytes(istream_t *const in, size_t len) { if (len > in->len) { INP_SIZE(); } if (in->bit_offset != 0) { UNALIGNED(); } const u8 *const ptr = in->ptr; in->ptr += len; in->len -= len; return ptr; } /// Returns a pointer to write `len` bytes to, and advances the internal state static inline u8 *IO_write_bytes(ostream_t *const out, size_t len) { if (len > out->len) { OUT_SIZE(); } u8 *const ptr = out->ptr; out->ptr += len; out->len -= len; return ptr; } /// Advance the inner state by `len` bytes static inline void IO_advance_input(istream_t *const in, size_t len) { if (len > in->len) { INP_SIZE(); } if (in->bit_offset != 0) { UNALIGNED(); } in->ptr += len; in->len -= len; } /// Returns an `ostream_t` constructed from the given pointer and length static inline ostream_t IO_make_ostream(u8 *out, size_t len) { return (ostream_t) { out, len }; } /// Returns an `istream_t` constructed from the given pointer and length static inline istream_t IO_make_istream(const u8 *in, size_t len) { - return (istream_t) { in, 0, len }; + return (istream_t) { in, len, 0 }; } /// Returns an `istream_t` with the same base as `in`, and length `len` /// Then, advance `in` to account for the consumed bytes /// `in` must be byte aligned static inline istream_t IO_make_sub_istream(istream_t *const in, size_t len) { - if (len > in->len) { - INP_SIZE(); - } - if (in->bit_offset != 0) { - UNALIGNED(); - } - const istream_t sub = { in->ptr, in->bit_offset, len }; + // Consume `len` bytes of the parent stream + const u8 *const ptr = IO_read_bytes(in, len); - in->ptr += len; - in->len -= len; - - return sub; + // Make a substream using the pointer to those `len` bytes + return IO_make_istream(ptr, len); } /******* END IO STREAM OPERATIONS *********************************************/ /******* BITSTREAM OPERATIONS *************************************************/ /// Read `num` bits (up to 64) from `src + offset`, where `offset` is in bits -static inline u64 read_bits_LE(const u8 *src, const int num, +static inline u64 read_bits_LE(const u8 *src, const int num_bits, const size_t offset) { - if (num > 64) { + if (num_bits > 64) { ERROR("Attempt to read an invalid number of bits"); } // Skip over bytes that aren't in range src += offset / 8; size_t bit_offset = offset % 8; u64 res = 0; int shift = 0; - int left = num; + int left = num_bits; while (left > 0) { u64 mask = left >= 8 ? 0xff : (((u64)1 << left) - 1); - // Dead the next byte, shift it to account for the offset, and then mask + // Read the next byte, shift it to account for the offset, and then mask // out the top part if we don't need all the bits res += (((u64)*src++ >> bit_offset) & mask) << shift; shift += 8 - bit_offset; left -= 8 - bit_offset; bit_offset = 0; } return res; } /// Read bits from the end of a HUF or FSE bitstream. `offset` is in bits, so /// it updates `offset` to `offset - bits`, and then reads `bits` bits from /// `src + offset`. If the offset becomes negative, the extra bits at the /// bottom are filled in with `0` bits instead of reading from before `src`. static inline u64 STREAM_read_bits(const u8 *const src, const int bits, i64 *const offset) { *offset = *offset - bits; size_t actual_off = *offset; size_t actual_bits = bits; // Don't actually read bits from before the start of src, so if `*offset < // 0` fix actual_off and actual_bits to reflect the quantity to read if (*offset < 0) { actual_bits += *offset; actual_off = 0; } u64 res = read_bits_LE(src, actual_bits, actual_off); if (*offset < 0) { // Fill in the bottom "overflowed" bits with 0's res = -*offset >= 64 ? 0 : (res << -*offset); } return res; } /******* END BITSTREAM OPERATIONS *********************************************/ /******* BIT COUNTING OPERATIONS **********************************************/ /// Returns `x`, where `2^x` is the largest power of 2 less than or equal to /// `num`, or `-1` if `num == 0`. -static inline int log2inf(const u64 num) { +static inline int highest_set_bit(const u64 num) { for (int i = 63; i >= 0; i--) { if (((u64)1 << i) <= num) { return i; } } return -1; } /******* END BIT COUNTING OPERATIONS ******************************************/ /******* HUFFMAN PRIMITIVES ***************************************************/ static inline u8 HUF_decode_symbol(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { // Look up the symbol and number of bits to read const u8 symb = dtable->symbols[*state]; const u8 bits = dtable->num_bits[*state]; const u16 rest = STREAM_read_bits(src, bits, offset); // Shift `bits` bits out of the state, keeping the low order bits that // weren't necessary to determine this symbol. Then add in the new bits // read from the stream. *state = ((*state << bits) + rest) & (((u16)1 << dtable->max_bits) - 1); return symb; } static inline void HUF_init_state(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { // Read in a full `dtable->max_bits` bits to initialize the state const u8 bits = dtable->max_bits; *state = STREAM_read_bits(src, bits, offset); } static size_t HUF_decompress_1stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in) { const size_t len = IO_istream_len(in); if (len == 0) { INP_SIZE(); } const u8 *const src = IO_read_bytes(in, len); // "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. 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." - const int padding = 8 - log2inf(src[len - 1]); + const int padding = 8 - highest_set_bit(src[len - 1]); - i64 offset = len * 8 - padding; + // Offset starts at the end because HUF streams are read backwards + i64 bit_offset = len * 8 - padding; u16 state; - HUF_init_state(dtable, &state, src, &offset); + HUF_init_state(dtable, &state, src, &bit_offset); size_t symbols_written = 0; - while (offset > -dtable->max_bits) { + while (bit_offset > -dtable->max_bits) { // Iterate over the stream, decoding one symbol at a time - IO_write_byte(out, HUF_decode_symbol(dtable, &state, src, &offset)); + IO_write_byte(out, HUF_decode_symbol(dtable, &state, src, &bit_offset)); symbols_written++; } // "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." // When all symbols have been decoded, the final state value shouldn't have // any data from the stream, so it should have "read" dtable->max_bits from // before the start of `src` // Therefore `offset`, the edge to start reading new bits at, should be // dtable->max_bits before the start of the stream - if (offset != -dtable->max_bits) { + if (bit_offset != -dtable->max_bits) { CORRUPTION(); } return symbols_written; } static size_t HUF_decompress_4stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in) { // "Compressed size is provided explicitly : in the 4-streams variant, // bitstreams are preceded by 3 unsigned little-endian 16-bits values. Each // value represents the compressed size of one stream, in order. The last // stream size is deducted from total compressed size and from previously // decoded stream sizes" const size_t csize1 = IO_read_bits(in, 16); const size_t csize2 = IO_read_bits(in, 16); const size_t csize3 = IO_read_bits(in, 16); istream_t in1 = IO_make_sub_istream(in, csize1); istream_t in2 = IO_make_sub_istream(in, csize2); istream_t in3 = IO_make_sub_istream(in, csize3); istream_t in4 = IO_make_sub_istream(in, IO_istream_len(in)); size_t total_output = 0; // Decode each stream independently for simplicity // If we wanted to we could decode all 4 at the same time for speed, // utilizing more execution units total_output += HUF_decompress_1stream(dtable, out, &in1); total_output += HUF_decompress_1stream(dtable, out, &in2); total_output += HUF_decompress_1stream(dtable, out, &in3); total_output += HUF_decompress_1stream(dtable, out, &in4); return total_output; } /// Initializes a Huffman table using canonical Huffman codes /// For more explanation on canonical Huffman codes see /// http://www.cs.uofs.edu/~mccloske/courses/cmps340/huff_canonical_dec2015.html /// Codes within a level are allocated in symbol order (i.e. smaller symbols get /// earlier codes) static void HUF_init_dtable(HUF_dtable *const table, const u8 *const bits, const int num_symbs) { memset(table, 0, sizeof(HUF_dtable)); if (num_symbs > HUF_MAX_SYMBS) { ERROR("Too many symbols for Huffman"); } u8 max_bits = 0; u16 rank_count[HUF_MAX_BITS + 1]; memset(rank_count, 0, sizeof(rank_count)); // Count the number of symbols for each number of bits, and determine the // depth of the tree for (int i = 0; i < num_symbs; i++) { if (bits[i] > HUF_MAX_BITS) { ERROR("Huffman table depth too large"); } max_bits = MAX(max_bits, bits[i]); rank_count[bits[i]]++; } const size_t table_size = 1 << max_bits; table->max_bits = max_bits; table->symbols = malloc(table_size); table->num_bits = malloc(table_size); if (!table->symbols || !table->num_bits) { free(table->symbols); free(table->num_bits); BAD_ALLOC(); } // "Symbols are sorted by Weight. Within same Weight, symbols keep natural // order. Symbols with a Weight of zero are removed. Then, starting from // lowest weight, prefix codes are distributed in order." u32 rank_idx[HUF_MAX_BITS + 1]; // Initialize the starting codes for each rank (number of bits) rank_idx[max_bits] = 0; for (int i = max_bits; i >= 1; i--) { rank_idx[i - 1] = rank_idx[i] + rank_count[i] * (1 << (max_bits - i)); // The entire range takes the same number of bits so we can memset it memset(&table->num_bits[rank_idx[i]], i, rank_idx[i - 1] - rank_idx[i]); } if (rank_idx[0] != table_size) { CORRUPTION(); } // Allocate codes and fill in the table for (int i = 0; i < num_symbs; i++) { if (bits[i] != 0) { // Allocate a code for this symbol and set its range in the table const u16 code = rank_idx[bits[i]]; // Since the code doesn't care about the bottom `max_bits - bits[i]` // bits of state, it gets a range that spans all possible values of // the lower bits const u16 len = 1 << (max_bits - bits[i]); memset(&table->symbols[code], i, len); rank_idx[bits[i]] += len; } } } static void HUF_init_dtable_usingweights(HUF_dtable *const table, const u8 *const weights, const int num_symbs) { // +1 because the last weight is not transmitted in the header if (num_symbs + 1 > HUF_MAX_SYMBS) { ERROR("Too many symbols for Huffman"); } u8 bits[HUF_MAX_SYMBS]; u64 weight_sum = 0; for (int i = 0; i < num_symbs; i++) { // Weights are in the same range as bit count if (weights[i] > HUF_MAX_BITS) { CORRUPTION(); } weight_sum += weights[i] > 0 ? (u64)1 << (weights[i] - 1) : 0; } // Find the first power of 2 larger than the sum - const int max_bits = log2inf(weight_sum) + 1; + const int max_bits = highest_set_bit(weight_sum) + 1; const u64 left_over = ((u64)1 << max_bits) - weight_sum; // If the left over isn't a power of 2, the weights are invalid if (left_over & (left_over - 1)) { CORRUPTION(); } // left_over is used to find the last weight as it's not transmitted // by inverting 2^(weight - 1) we can determine the value of last_weight - const int last_weight = log2inf(left_over) + 1; + const int last_weight = highest_set_bit(left_over) + 1; for (int i = 0; i < num_symbs; i++) { // "Number_of_Bits = Number_of_Bits ? Max_Number_of_Bits + 1 - Weight : 0" bits[i] = weights[i] > 0 ? (max_bits + 1 - weights[i]) : 0; } bits[num_symbs] = max_bits + 1 - last_weight; // Last weight is always non-zero HUF_init_dtable(table, bits, num_symbs + 1); } static void HUF_free_dtable(HUF_dtable *const dtable) { free(dtable->symbols); free(dtable->num_bits); memset(dtable, 0, sizeof(HUF_dtable)); } static void HUF_copy_dtable(HUF_dtable *const dst, const HUF_dtable *const src) { if (src->max_bits == 0) { memset(dst, 0, sizeof(HUF_dtable)); return; } const size_t size = (size_t)1 << src->max_bits; dst->max_bits = src->max_bits; dst->symbols = malloc(size); dst->num_bits = malloc(size); if (!dst->symbols || !dst->num_bits) { BAD_ALLOC(); } memcpy(dst->symbols, src->symbols, size); memcpy(dst->num_bits, src->num_bits, size); } /******* END HUFFMAN PRIMITIVES ***********************************************/ /******* FSE PRIMITIVES *******************************************************/ /// For more description of FSE see /// https://github.com/Cyan4973/FiniteStateEntropy/ /// Allow a symbol to be decoded without updating state static inline u8 FSE_peek_symbol(const FSE_dtable *const dtable, const u16 state) { return dtable->symbols[state]; } /// Consumes bits from the input and uses the current state to determine the /// next state static inline void FSE_update_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { const u8 bits = dtable->num_bits[*state]; const u16 rest = STREAM_read_bits(src, bits, offset); *state = dtable->new_state_base[*state] + rest; } /// Decodes a single FSE symbol and updates the offset static inline u8 FSE_decode_symbol(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { const u8 symb = FSE_peek_symbol(dtable, *state); FSE_update_state(dtable, state, src, offset); return symb; } static inline void FSE_init_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { // Read in a full `accuracy_log` bits to initialize the state const u8 bits = dtable->accuracy_log; *state = STREAM_read_bits(src, bits, offset); } static size_t FSE_decompress_interleaved2(const FSE_dtable *const dtable, ostream_t *const out, istream_t *const in) { const size_t len = IO_istream_len(in); if (len == 0) { INP_SIZE(); } const u8 *const src = IO_read_bytes(in, len); // "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. 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." - const int padding = 8 - log2inf(src[len - 1]); + const int padding = 8 - highest_set_bit(src[len - 1]); i64 offset = len * 8 - padding; u16 state1, state2; // "The first state (State1) encodes the even indexed symbols, and the // second (State2) encodes the odd indexes. State1 is initialized first, and // then State2, and they take turns decoding a single symbol and updating // their state." FSE_init_state(dtable, &state1, src, &offset); FSE_init_state(dtable, &state2, src, &offset); // Decode until we overflow the stream // Since we decode in reverse order, overflowing the stream is offset going // negative size_t symbols_written = 0; while (1) { // "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 the extra // bits are 0. Then, the symbols for each of the final states are // decoded and the process is complete." IO_write_byte(out, FSE_decode_symbol(dtable, &state1, src, &offset)); symbols_written++; if (offset < 0) { // There's still a symbol to decode in state2 IO_write_byte(out, FSE_peek_symbol(dtable, state2)); symbols_written++; break; } IO_write_byte(out, FSE_decode_symbol(dtable, &state2, src, &offset)); symbols_written++; if (offset < 0) { // There's still a symbol to decode in state1 IO_write_byte(out, FSE_peek_symbol(dtable, state1)); symbols_written++; break; } } return symbols_written; } static void FSE_init_dtable(FSE_dtable *const dtable, const i16 *const norm_freqs, const int num_symbs, const int accuracy_log) { if (accuracy_log > FSE_MAX_ACCURACY_LOG) { ERROR("FSE accuracy too large"); } if (num_symbs > FSE_MAX_SYMBS) { ERROR("Too many symbols for FSE"); } dtable->accuracy_log = accuracy_log; const size_t size = (size_t)1 << accuracy_log; dtable->symbols = malloc(size * sizeof(u8)); dtable->num_bits = malloc(size * sizeof(u8)); dtable->new_state_base = malloc(size * sizeof(u16)); if (!dtable->symbols || !dtable->num_bits || !dtable->new_state_base) { BAD_ALLOC(); } // Used to determine how many bits need to be read for each state, // and where the destination range should start // Needs to be u16 because max value is 2 * max number of symbols, // which can be larger than a byte can store u16 state_desc[FSE_MAX_SYMBS]; // "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. These symbols define a // full state reset, reading Accuracy_Log bits." int high_threshold = size; for (int s = 0; s < num_symbs; s++) { // Scan for low probability symbols to put at the top if (norm_freqs[s] == -1) { dtable->symbols[--high_threshold] = s; state_desc[s] = 1; } } // "All remaining symbols are sorted in their natural order. Starting from // symbol 0 and table position 0, each symbol gets attributed as many cells // as its probability. Cell allocation is spreaded, not linear." // Place the rest in the table const u16 step = (size >> 1) + (size >> 3) + 3; const u16 mask = size - 1; u16 pos = 0; for (int s = 0; s < num_symbs; s++) { if (norm_freqs[s] <= 0) { continue; } state_desc[s] = norm_freqs[s]; for (int i = 0; i < norm_freqs[s]; i++) { // Give `norm_freqs[s]` states to symbol s dtable->symbols[pos] = s; // "A position is skipped if already occupied, typically by a "less // than 1" probability symbol." do { pos = (pos + step) & mask; } while (pos >= high_threshold); // Note: no other collision checking is necessary as `step` is // coprime to `size`, so the cycle will visit each position exactly // once } } if (pos != 0) { CORRUPTION(); } // Now we can fill baseline and num bits for (int i = 0; i < size; i++) { u8 symbol = dtable->symbols[i]; u16 next_state_desc = state_desc[symbol]++; // Fills in the table appropriately, next_state_desc increases by symbol // over time, decreasing number of bits - dtable->num_bits[i] = (u8)(accuracy_log - log2inf(next_state_desc)); + dtable->num_bits[i] = (u8)(accuracy_log - highest_set_bit(next_state_desc)); // Baseline increases until the bit threshold is passed, at which point // it resets to 0 dtable->new_state_base[i] = ((u16)next_state_desc << dtable->num_bits[i]) - size; } } /// Decode an FSE header as defined in the Zstandard format specification and /// use the decoded frequencies to initialize a decoding table. static void FSE_decode_header(FSE_dtable *const dtable, istream_t *const in, const int max_accuracy_log) { // "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 . // // 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. if (max_accuracy_log > FSE_MAX_ACCURACY_LOG) { ERROR("FSE accuracy too large"); } // The bitstream starts by reporting on which scale it operates. // Accuracy_Log = low4bits + 5. Note that maximum Accuracy_Log for literal // and match lengths is 9, and for offsets is 8. Higher values are // considered errors." const int accuracy_log = 5 + IO_read_bits(in, 4); if (accuracy_log > max_accuracy_log) { ERROR("FSE accuracy too large"); } // "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. // // 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. 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. " i32 remaining = 1 << accuracy_log; i16 frequencies[FSE_MAX_SYMBS]; int symb = 0; while (remaining > 0 && symb < FSE_MAX_SYMBS) { // Log of the number of possible values we could read - int bits = log2inf(remaining + 1) + 1; + int bits = highest_set_bit(remaining + 1) + 1; u16 val = IO_read_bits(in, bits); // Try to mask out the lower bits to see if it qualifies for the "small // value" threshold const u16 lower_mask = ((u16)1 << (bits - 1)) - 1; const u16 threshold = ((u16)1 << bits) - 1 - (remaining + 1); if ((val & lower_mask) < threshold) { IO_rewind_bits(in, 1); val = val & lower_mask; } else if (val > lower_mask) { val = val - threshold; } // "Probability is obtained from Value decoded by following formula : // Proba = value - 1" const i16 proba = (i16)val - 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 next paragraph. For the purpose of calculating // cumulated distribution, it counts as one." remaining -= proba < 0 ? -proba : proba; frequencies[symb] = proba; symb++; // "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." if (proba == 0) { // Read the next two bits to see how many more 0s int repeat = IO_read_bits(in, 2); while (1) { for (int i = 0; i < repeat && symb < FSE_MAX_SYMBS; i++) { frequencies[symb++] = 0; } if (repeat == 3) { repeat = IO_read_bits(in, 2); } else { break; } } } } IO_align_stream(in); // "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." if (remaining != 0 || symb >= FSE_MAX_SYMBS) { CORRUPTION(); } // Initialize the decoding table using the determined weights FSE_init_dtable(dtable, frequencies, symb, accuracy_log); } static void FSE_init_dtable_rle(FSE_dtable *const dtable, const u8 symb) { dtable->symbols = malloc(sizeof(u8)); dtable->num_bits = malloc(sizeof(u8)); dtable->new_state_base = malloc(sizeof(u16)); if (!dtable->symbols || !dtable->num_bits || !dtable->new_state_base) { BAD_ALLOC(); } // This setup will always have a state of 0, always return symbol `symb`, // and never consume any bits dtable->symbols[0] = symb; dtable->num_bits[0] = 0; dtable->new_state_base[0] = 0; dtable->accuracy_log = 0; } static void FSE_free_dtable(FSE_dtable *const dtable) { free(dtable->symbols); free(dtable->num_bits); free(dtable->new_state_base); memset(dtable, 0, sizeof(FSE_dtable)); } static void FSE_copy_dtable(FSE_dtable *const dst, const FSE_dtable *const src) { if (src->accuracy_log == 0) { memset(dst, 0, sizeof(FSE_dtable)); return; } size_t size = (size_t)1 << src->accuracy_log; dst->accuracy_log = src->accuracy_log; dst->symbols = malloc(size); dst->num_bits = malloc(size); dst->new_state_base = malloc(size * sizeof(u16)); if (!dst->symbols || !dst->num_bits || !dst->new_state_base) { BAD_ALLOC(); } memcpy(dst->symbols, src->symbols, size); memcpy(dst->num_bits, src->num_bits, size); memcpy(dst->new_state_base, src->new_state_base, size * sizeof(u16)); } /******* END FSE PRIMITIVES ***************************************************/ Index: head/contrib/zstd/doc/images/Cspeed4.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Index: head/contrib/zstd/doc/images/Dspeed4.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Index: head/contrib/zstd/doc/images/dict-cr.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Index: head/contrib/zstd/doc/images/dict-cs.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Index: head/contrib/zstd/doc/images/dict-ds.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = image/png Index: head/contrib/zstd/doc/zstd_compression_format.md =================================================================== --- head/contrib/zstd/doc/zstd_compression_format.md (revision 317876) +++ head/contrib/zstd/doc/zstd_compression_format.md (revision 317877) @@ -1,1506 +1,1527 @@ 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 -0.2.4 (17/02/17) +0.2.5 (31/03/17) + 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 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. ### 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, 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 up one or more __frames__. Each frame is independent and can be decompressed indepedently of other frames. The decompressed content of multiple concatenated frames is the concatenation of each frames 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. ## 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. +4 Bytes, __little-endian__ format. Value : 0xFD2FB528 __`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. +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 the is highest bit, while bit 0 the is lowest. +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 decompressed data size is provided within the header. -The `Flag_Value` can be converted into `Field_Size`, +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 | -| ---------- | ------ | --- | --- | --- | -|`Field_Size`| 0 or 1 | 2 | 4 | 8 | +| `Flag_Value` | 0 | 1 | 2 | 3 | +| -------------- | ------ | --- | --- | --- | +|`FCS_Field_Size`| 0 or 1 | 2 | 4 | 8 | -When `Flag_Value` is `0`, `Field_Size` depends on `Single_Segment_flag` : +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 (content size not provided). +Otherwise, `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, `Frame_Content_Size` is necessarily present, -but `Window_Descriptor` byte is skipped. +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 bigger than `Frame_Content_Size`. In order to preserve the decoder from unreasonable memory requirements, -a decoder can reject a compressed frame +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 just a recommendation, +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. __`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`. |`Flag_Value`| 0 | 1 | 2 | 3 | | ---------- | --- | --- | --- | --- | |`Field_Size`| 0 | 1 | 2 | 4 | #### `Window_Descriptor` -Provides guarantees on maximum back-reference distance -that will be used within compressed data. +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. It is absent when `Single_Segment_flag` is set. -In this case, the maximum back-reference distance is the content size itself, -which can be any value from 1 to 2^64-1 bytes (16 EB). +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` | -Maximum distance is given by the following formulas : +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 size is `15*(1<<38)` bytes, which is 1.875 TB. +The minimum `Window_Size` is 1 KB. +The maximum `Window_Size` is `(1<<41) + 7*(1<<38)` bytes, which is 3.75 TB. 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 can refuse a compressed frame +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 sizes of 8 MB, +decoders are recommended to be compatible with `Window_Size >= 8 MB`, and encoders are recommended to not request more 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. -Note that this field is optional. When it's not present, +`Dictionary_ID` field is optional. When it's not present, it's up to the decoder to make sure it uses the correct dictionary. -Format is little-endian. Field size depends on `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, losing some compacity in the process. +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 for future use and should not be used : -- low range : 1 - 32767 -- high range : >= (2^31) +the following ranges are reserved and shall not be used : +- low range : `<= 32767` +- high range : `>= (1 << 31)` - #### `Frame_Content_Size` This is the original (uncompressed) size. This information is optional. -The `Field_Size` is provided according to value of `Frame_Content_Size_flag`. -The `Field_Size` can be equal to 0 (not present), 1, 2, 4 or 8 bytes. -Format is little-endian. +`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. -| `Field_Size` | Range | -| ------------ | ---------- | -| 1 | 0 - 255 | -| 2 | 256 - 65791| -| 4 | 0 - 2^32-1 | -| 8 | 0 - 2^64-1 | +| `FCS_Field_Size` | Range | +| ---------------- | ---------- | +| 0 | unknown | +| 1 | 0 - 255 | +| 2 | 256 - 65791| +| 4 | 0 - 2^32-1 | +| 8 | 0 - 2^64-1 | -When `Field_Size` is 1, 4 or 8 bytes, the value is read directly. -When `Field_Size` is 2, _the offset of 256 is added_. +`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 the magic number and header of each block, -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. +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: -| `Last_Block` | `Block_Type` | `Block_Size` | `Block_Content` | -|:------------:|:------------:|:------------:|:---------------:| -| 1 bit | 2 bits | 21 bits | n bytes | +| `Block_Header` | `Block_Content` | +|:--------------:|:---------------:| +| 3 bytes | n bytes | -The block header (`Last_Block`, `Block_Type`, and `Block_Size`) uses 3-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 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` and `Block_Size`__ +__`Block_Type`__ -The next 2 bits represent the `Block_Type`, -while the remaining 21 bits represent the `Block_Size`. -Format is __little-endian__. - +The next 2 bits represent the `Block_Type`. There are 4 block types : -| Value | 0 | 1 | 2 | 3 | +| 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 to read and copy - as decoded data. + `Block_Content` contains `Block_Size` bytes. -- `RLE_Block` - this is a single byte, repeated N times. - `Block_Content` consists of a single byte, - and `Block_Size` is the number of times this byte should be repeated. +- `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 unknown, + 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. +__`Block_Size`__ + +The upper 21 bits of `Block_Header` represent the `Block_Size`. + Block sizes must respect a few rules : -- In compressed mode, compressed size is always strictly less than decompressed size. -- Block decompressed size is always <= maximum back-reference distance. +- 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 data block is not necessarily "full" : -since an arbitrary “flush” may happen anytime, -block decompressed content can be any size (even empty), +A block can contain any number of bytes (even empty), up to `Block_Maximum_Decompressed_Size`, which is the smallest of : -- Maximum back-reference distance +- `Window_Size` - 128 KB + Compressed Blocks ----------------- -To decompress a compressed block, the compressed size must be provided from -`Block_Size` field in the block header. +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 previous data when `Single_Segment_flag` is set. -- List of "recent offsets" from the previous compressed block. -- Decoding tables of the previous compressed block for each symbol type + or all previously decoded data when `Single_Segment_flag` is set. +- List of "recent offsets" from previous `Compressed_Block`. +- Decoding tables of previous `Compressed_Block` for each symbol type (literals, literals lengths, match lengths, offsets). Literals Section ---------------- -During sequence execution, symbols from the literals section -During sequence phase, literals will be entangled with match copy operations. All literals are regrouped in the first part of the block. -They can be decoded first, and then copied during sequence operations, -or they can be decoded on the flow, as needed by sequence commands. +They can be decoded first, and then copied during [Sequence Execution], +or they can be decoded on the flow during [Sequence Execution]. -| `Literals_Section_Header` | [`Huffman_Tree_Description`] | Stream1 | [Stream2] | [Stream3] | [Stream4] | -| ------------------------- | ---------------------------- | ------- | --------- | --------- | --------- | - 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` 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. +using __little-endian__ convention. | `Literals_Block_Type` | `Size_Format` | `Regenerated_Size` | [`Compressed_Size`] | -| --------------------- | ------------- | ------------------ | ----------------- | -| 2 bits | 1 - 2 bits | 5 - 20 bits | 0 - 18 bits | +| --------------------- | ------------- | ------------------ | ------------------- | +| 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 | -| `Repeat_Stats_Literals_Block` | 3 | +| `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 N times. +- `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. -- `Repeat_Stats_Literals_Block` - This is a Huffman-compressed block, +- `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 used without any previous Huffman-table in the frame - (or [dictionary](#dictionary-format)), this should be treated as corruption. + `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 enough to decode `Regenerated_Size`. -- For `Compressed_Block`, its required to decode both `Compressed_Size` - and `Regenerated_Size` (the decompressed size). It will also decode the number of streams. +- 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. +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. `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. `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. `Regenerated_Size` uses 20 bits (0-1048575). `Literals_Section_Header` has 3 bytes. `Regenerated_Size = (Header[0]>>4) + (Header[1]<<4) + (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, accepting the increased compressed data size. +using a long format, even if it's less efficient. -__`Size_Format` for `Compressed_Literals_Block` and `Repeat_Stats_Literals_Block`__ : +__`Size_Format` for `Compressed_Literals_Block` and `Treeless_Literals_Block`__ : - Value 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. Both `Regenerated_Size` and `Compressed_Size` use 10 bits (0-1023). `Literals_Section_Header` has 3 bytes. - Value 10 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 14 bits (0-16383). `Literals_Section_Header` has 4 bytes. - Value 11 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 18 bits (0-262143). `Literals_Section_Header` has 5 bytes. -Both `Compressed_Size` and `Regenerated_Size` fields follow little-endian convention. -Note: `Compressed_Size` __includes__ the size of the Huffman Tree description if it -is present. +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 -The data in Stream1 is `Regenerated_Size` bytes long, and contains the raw literals data -to be used in sequence execution. +The data in Stream1 is `Regenerated_Size` bytes long, +it contains the raw literals data to be used during [Sequence Execution]. ### 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 Repeat Stats Literals Block -Both of these modes contain Huffman encoded data +### 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` 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 Huffman Tree description will be determined during the decoding process, -and must be used to determine where the compressed Huffman streams begin. +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`. -If repeat stats mode is used, the Huffman table used in the previous compressed block will -be used to decompress this block as well. +For `Treeless_Literals_Block`, +the Huffman table comes from previously compressed literals block. -Huffman compressed data consists either 1 or 4 Huffman-coded streams. +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 at +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 regenerated and compressed sizes of all four streams combined. -The regenerated size of each stream is equal to `(totalSize+3)/4`, except for the last stream, -which may be up to 3 bytes smaller, to reach a total decompressed size match that described -in the literals header. +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, describing the compressed sizes -of the first three streams. -The last streams size is computed from the total compressed size and the size of the other -three streams. +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, +describing the compressed sizes of the first three streams. +`Stream4_Size` is computed from total `Total_Streams_Size` minus sizes of other streams. -`stream4CSize = totalCSize - 6 - stream1CSize - stream2CSize - stream3CSize`. +`Stream4_Size = Total_Streams_Size - 6 - Stream1_Size - Stream2_Size - Stream3_Size`. -Note: remember that totalCSize may be smaller than the `Compressed_Size` found in the literals -block header as `Compressed_Size` also contains the size of the Huffman Tree description if it -is present. +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. 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 literal section. +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 is are any literals left in the _literal section_, +if there are literals left in the _literal section_, these bytes are added at the end of the block. 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 `blockSize - literalSectionSize`. +This size is deduced from `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. - Regenerated content is defined entirely by literals section. + Decompressed content is defined entirely as Literals Section content. - `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 | +|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 respectively. +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). - The table takes no space in the compressed data. + No distribution table will be present. - `RLE_Mode` : The table description consists of a single byte. - This code will be repeated for every sequence. + 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. + 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. - `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]. + 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. #### 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. +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. +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. -An offset code is also the number of additional bits to read in little-endian fashion, +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` 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 must be kept track of for each of -literal lengths, offsets, and match lengths. +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. 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`. +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. 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 must be at most equal to the window size defined by the frame header. +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`. -In the first block, the 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 the following values : 1, 4 and 8 (in order). -Then each block gets its starting offset history from the ending values of the most recent compressed block. -Note that non-compressed blocks are skipped, -they do not contribute to offset history. +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 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 __`Magic_Number`__ -4 Bytes, little-endian format. +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. __`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 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. FSE --- -FSE, or FiniteStateEntropy is an entropy coding based on [ANS]. +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. 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 three elements: +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. -The next symbol in the stream is the symbol indicated by the table value for that state. + +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. +the decoder should consume `Num_Bits` bits from the stream as a __little-endian__ value and add it to `Baseline`. -To obtain the initial state value, consume `Accuracy_Log` bits from the stream as a little endian value. - [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` . -It's a bitstream which is read forward, in little-endian fashion. +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. The bitstream starts by reporting on which scale it operates. `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. - 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. 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. 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 | 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 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. These symbols define a full state reset, reading `Accuracy_Log` bits. All remaining symbols are sorted in their natural order. Starting from symbol `0` and table position `0`, each symbol gets attributed 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. __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, requiring one more bit in the process. Numbering starts from higher states using less bits. | 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 necessary to +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, +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 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. __Example__ : Let's presume the following Huffman tree must be described : | literal | 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, 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 | 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. 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`. ##### Huffman Tree header This is a single byte value (0-255), which describes how to decode the list of weights. - 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 length of the FSE-compressed series is equal to `headerByte` (0-127). ##### 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. 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 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. -State1 is initialized first, and then State2, and they take turns decoding -a single symbol and updating their state. +`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 the extra bits are 0. Then, +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. ##### 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: ``` Number_of_Bits = Number_of_Bits ? Max_Number_of_Bits + 1 - Weight : 0 ``` Symbols are sorted by `Weight`. Within same `Weight`, symbols keep natural order. Symbols with a `Weight` of zero are removed. Then, starting from lowest weight, prefix codes are distributed in 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, 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. 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. For example, if the literal sequence "0145" was encoded using the prefix codes above, it would be encoded as: ``` 00000001 01110000 ``` |Symbol | 5 | 4 | 1 | 0 | Padding | |--------|------|------|----|---|---------| |Encoding|`0000`|`0001`|`01`|`1`| `10000` | Starting from the end, -it's possible to read the bitstream in a little-endian fashion, +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, by starting at the end the symbols can be read in forward order. Reading the last `Max_Number_of_Bits` bits, it's then 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` block of a formatted -dictionary. +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 +__`Magic_Number`__ : 4 bytes ID, value 0xEC30A437, __little-endian__ format -__`Dictionary_ID`__ : 4 bytes, stored in 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 for future use and should not be used : + the following ranges are reserved and shall not be used : - - low range : 1 - 32767 + - low range : <= 32767 - high range : >= (2^31) __`Entropy_Tables`__ : following the same format as the 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. + 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 the window-size, sequence commands may specify offsets longer - than the lenght of total decoded output so far to reference back to the - dictionary. After the total output has surpassed the window size however, + 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, this is no longer allowed and the dictionary is no longer accessible. [compressed blocks]: #the-format-of-compressed_block + + 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 the -"from normalized distribution to decoding tables" chapter. The tables here can be used as examples -to crosscheck that an implementation implements the decoding table generation algorithm correctly. +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 | Version changes --------------- +- 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: head/contrib/zstd/doc/zstd_manual.html =================================================================== --- head/contrib/zstd/doc/zstd_manual.html (revision 317876) +++ head/contrib/zstd/doc/zstd_manual.html (revision 317877) @@ -1,664 +1,681 @@ -zstd 1.1.4 Manual +zstd 1.2.0 Manual -

zstd 1.1.4 Manual

+

zstd 1.2.0 Manual

Contents

  1. Introduction
  2. Version
  3. Simple API
  4. Explicit memory management
  5. Simple dictionary API
  6. Fast dictionary API
  7. Streaming
  8. Streaming compression - HowTo
  9. Streaming decompression - HowTo
  10. START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
  11. Advanced types
  12. Compressed size functions
  13. Decompressed size functions
  14. Advanced compression functions
  15. Advanced decompression functions
  16. Advanced streaming functions
  17. Buffer-less and synchronous inner streaming functions
  18. Buffer-less streaming compression (synchronous mode)
  19. Buffer-less streaming decompression (synchronous mode)
  20. Block functions

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 22.
   Levels >= 20, labeled `--ultra`, should be used with caution, as they require more memory.
   Compression can be done in:
     - a single step (described as Simple API)
     - a single step, reusing a context (described as Explicit memory management)
     - unbounded multiple steps (described as Streaming compression)
   The compression ratio achievable on small data can be highly improved using compression with a dictionary in:
     - a single step (described as Simple dictionary API)
     - a single step, reusing a dictionary (described as Fast dictionary API)
 
   Advanced experimental functions can be accessed using #define ZSTD_STATIC_LINKING_ONLY before including zstd.h.
   These 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.

Version


 
 
unsigned ZSTD_versionNumber(void);   /**< library version number; to be used when checking dll version */
 


 
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()). 
+
  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.
-    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()). 
+
  `compressedSize` : must be the _exact_ size of some number of compressed and/or skippable frames.
+  `dstCapacity` is an upper bound of originalSize.
+  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()). 
 


 
 
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
-
   NOTE: This function is planned to be obsolete, in favour of ZSTD_getFrameContentSize.
-   ZSTD_getFrameContentSize functions the same way, returning the decompressed size of a single
-   frame, but distinguishes empty frames from frames with an unknown size, or errors.
+
  NOTE: This function is planned to be obsolete, in favour of ZSTD_getFrameContentSize.
+  ZSTD_getFrameContentSize functions the same way, returning the decompressed size of a single
+  frame, but distinguishes empty frames from frames with an unknown size, or errors.
 
-   Additionally, ZSTD_findDecompressedSize can be used instead.  It can handle multiple
-   concatenated frames in one buffer, and so is more general.
-   As a result however, it requires more computation and entire frames to be passed to it,
-   as opposed to ZSTD_getFrameContentSize which requires only a single frame's header.
+  Additionally, ZSTD_findDecompressedSize can be used instead.  It can handle multiple
+  concatenated frames in one buffer, and so is more general.
+  As a result however, it requires more computation and entire frames to be passed to it,
+  as opposed to ZSTD_getFrameContentSize which requires only a single frame's header.
 
-   'src' is the start of a zstd compressed frame.
-   @return : content size to be decompressed, as a 64-bits value _if known_, 0 otherwise.
-    note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
-             When `return==0`, data to decompress could be any size.
-             In which case, it's necessary to use streaming mode to decompress data.
-             Optionally, application can still use ZSTD_decompress() while relying on implied limits.
-             (For example, data may be necessarily cut into blocks <= 16 KB).
-    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 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. 
+  'src' is the start of a zstd compressed frame.
+  @return : content size to be decompressed, as a 64-bits value _if known_, 0 otherwise.
+   note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
+            When `return==0`, data to decompress could be any size.
+            In which case, it's necessary to use streaming mode to decompress data.
+            Optionally, application can still use ZSTD_decompress() while relying on implied limits.
+            (For example, data may be necessarily cut into blocks <= 16 KB).
+   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 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. 
 


 
 
Helper functions
int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
 size_t      ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case 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 */
 


 
Explicit memory management

 
-
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. 
+
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()). 
+
  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 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. 
+
Decompression context
  When decompressing 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_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()). 
+
  Same as ZSTD_decompress(), requires an allocated ZSTD_DCtx (see ZSTD_createDCtx()). 
 


 
 
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. 
 


 
 
Fast 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 used by multiple threads concurrently, as its usage is read-only.
    `dictBuffer` can be released after ZSTD_CDict creation, as its content is copied within CDict 
 


 
 
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. 
+
  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) 
 


 
 
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

 
 
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
   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.
   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 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.
   @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)
             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.
   Similar to ZSTD_flushStream(), it may not be able to flush the full content if `output->size` is too small.
   In which case, call again ZSTD_endStream() to complete the flush.
   @return : nb of bytes still present within internal buffer (0 if it's empty, hence compression completed)
             or an error code, which can be tested using ZSTD_isError().
 
  
 

 
 
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
   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.
   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.
  
 

 
 
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.
  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.
  
 

 
 
Advanced types

 
 
typedef enum { ZSTD_fast, ZSTD_dfast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2, ZSTD_btlazy2, ZSTD_btopt, ZSTD_btopt2 } 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;
 


 
Custom memory allocation functions
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;
 


 
Compressed 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 at least as large as the frame
   @return : the compressed size of the frame pointed to by `src`, suitable to pass to
       `ZSTD_decompress` or similar, or an error code if given invalid input. 
 


 
 
Decompressed size functions

 
 
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.  A value greater than or equal
        to `ZSTD_frameHeaderSize_max` is guaranteed to be large enough in all cases.
    @return : decompressed size of the 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_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 `srcSize` bytes after `src`)
    @return : the decompressed size of all data in the contained frames, as a 64-bit value _if known_
              - 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.
              Optionally, application can still use ZSTD_decompress() while relying on implied limits.
              (For example, data may be necessarily cut into blocks <= 16 KB).
     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 efficient as most of the data is skipped,
              however it does mean that all frame data must be present and valid. 
 


 
 
Advanced compression functions

 
 
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
 
  Gives the amount of memory allocated for a ZSTD_CCtx given a set of compression parameters.
   `frameContentSize` is an optional parameter, provide `0` if unknown 
 


 
 
ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
 
  Create a ZSTD compression context using external alloc and free functions 
 


 
 
size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
 
  Gives the amount of memory used by a given ZSTD_CCtx 
 


 
 
typedef enum {
     ZSTD_p_forceWindow,   /* Force back-references to remain < windowSize, even when referencing Dictionary content (default:0) */
     ZSTD_p_forceRawDict   /* Force loading dictionary in "content-only" mode (no header analysis) */
 } ZSTD_CCtxParameter;
 


 
size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter param, unsigned value);
 
  Set advanced parameters, selected through enum ZSTD_CCtxParameter
   @result : 0, or an error code (which can be tested with ZSTD_isError()) 
 


 
 
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_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize, unsigned byReference,
-                                      ZSTD_parameters params, ZSTD_customMem customMem);
+                                      ZSTD_compressionParameters cParams, ZSTD_customMem customMem);
 
  Create a ZSTD_CDict using external alloc and free, and customized compression parameters 
 


 
 
size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
 
  Gives the amount of memory used by a given ZSTD_sizeof_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 (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* ctx,
-                               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 of each compression parameter 
+
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. 
 


 
 
size_t ZSTD_estimateDCtxSize(void);
 
  Gives the potential amount of memory allocated to create a ZSTD_DCtx 
 


 
 
ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
 
  Create a ZSTD decompression context using external alloc and free functions 
 


 
 
size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
 
  Gives the amount of memory used by a given ZSTD_DCtx 
 


 
 
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 simply referenced, and therefore stays in dictBuffer.
   It is important that dictBuffer outlives DDict, it must remain read accessible throughout the lifetime of DDict 
 


 
 
ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
                                       unsigned byReference, ZSTD_customMem customMem);
 
  Create a ZSTD_DDict using external alloc and free, optionally by reference 
 


 
 
size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
 
  Gives the amount of memory used by a given ZSTD_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 used ZSTD_getFrameParams(), which will provide a more precise error code. 
+  When identifying the exact failure cause, it's possible to use ZSTD_getFrameParams(), which will provide a more precise error code. 
 


 
 
Advanced streaming functions

 
 
Advanced Streaming compression functions
ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
+size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);   /**< size of CStream is variable, depending primarily on compression level */
 size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize);   /**< pledgedSrcSize must be correct, a size of 0 means unknown.  for a frame size of 0 use initCStream_advanced */
 size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); /**< note: a dict will not be used if dict == NULL or dictSize < 8 */
 size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
                                              ZSTD_parameters params, unsigned long long pledgedSrcSize);  /**< pledgedSrcSize is optional and can be 0 (meaning unknown). note: if the contentSizeFlag is set, pledgedSrcSize == 0 means the source size is actually 0 */
 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_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize);  /**< re-use compression parameters from previous init; skip dictionary loading stage; zcs must be init at least once before. note: pledgedSrcSize must be correct, a size of 0 means unknown.  for a frame size of 0 use initCStream_advanced */
-size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
+size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize, ZSTD_frameParameters fParams);  /**< same as ZSTD_initCStream_usingCDict(), with control over frame parameters */
 


+
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..
+  Note that zcs must be init at least once before using ZSTD_resetCStream().
+  pledgedSrcSize==0 means "srcSize unknown".
+  If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end.
+  @return : 0, or an error code (which can be tested using ZSTD_isError()) 
+


+
 
Advanced Streaming decompression functions
typedef enum { DStream_p_maxWindowSize } ZSTD_DStreamParameter_e;
 ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); /**< note: a dict will not be used if dict == NULL or dictSize < 8 */
 size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);
 size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);  /**< note : ddict will just be referenced, and must outlive decompression session */
 size_t ZSTD_resetDStream(ZSTD_DStream* zds);  /**< re-use decompression parameters from previous init; saves dictionary loading */
 size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
 


 
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 many restrictions (documented below).
   Prefer using 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 buffer only.
   - Interface is synchronous : input is consumed entirely and produce 1+ (or more) 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 will be considered unfinished (corrupted) by decoders.
 
   `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress some new frame.
 

 
 
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 is optional and can be 0 (meaning unknown). note: if the contentSizeFlag is set, pledgedSrcSize == 0 means the source size is actually 0 */
+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=0 means null-size */
 size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**<  note: if pledgedSrcSize can be 0, indicating unknown size.  if it is non-zero, it must be accurate.  for 0 size frames, use compressBegin_advanced */
-size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize); /**< note: if pledgedSrcSize can be 0, indicating unknown size.  if it is non-zero, it must be accurate.  for 0 size frames, use compressBegin_advanced */
-size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 


 
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_getFrameParams().
   It fills a ZSTD_frameParams structure which provide important information to correctly decode the frame,
   such as the minimum rolling buffer size to allocate to decompress data (`windowSize`),
   and the dictionary ID used.
   (Note : content size is optional, it may not be present. 0 means : content size unknown).
   Note that these values could be wrong, either because of data malformation, or because an attacker is spoofing deliberate false information.
   As a consequence, check that values remain within valid application range, especially `windowSize`, before allocation.
   Each application can set its own limit, depending on local restrictions. For extended interoperability, it is recommended to support at least 8 MB.
   Frame parameters are extracted from the beginning of the compressed frame.
   Data fragment must be large enough to ensure successful decoding, typically `ZSTD_frameHeaderSize_max` bytes.
   @result : 0 : successful decoding, the `ZSTD_frameParams` 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().
 
   Start decompression, with ZSTD_decompressBegin() or ZSTD_decompressBegin_usingDict().
   Alternatively, you can copy a prepared context, using ZSTD_copyDCtx().
 
   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, which is not an error; it just means ZSTD_decompressContinue() has decoded some metadata item.
   It can also be an error code, which can be tested with ZSTD_isError().
 
   ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize`.
   They should preferably be located contiguously, prior to current block.
   Alternatively, a round buffer of sufficient size is also possible. Sufficient size is determined by frame parameters.
   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.
 
   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 a 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_decompressContinue() always returns 0.
   For skippable frames ZSTD_getFrameParams() returns fparamsPtr->windowLog==0 what means that a frame is skippable.
     Note : If fparamsPtr->frameContentSize==0, it is ambiguous: the frame might actually be a Zstd encoded frame with no content.
            For purposes of decompression, it is valid in both cases to skip the frame using
            ZSTD_findFrameCompressedSize to find its size in bytes.
   It also returns Frame Size as fparamsPtr->frameContentSize.
 

 
 
typedef struct {
     unsigned long long frameContentSize;
     unsigned windowSize;
     unsigned dictID;
     unsigned checksumFlag;
 } ZSTD_frameParams;
 


 
Buffer-less streaming decompression functions
size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize);   /**< doesn't consume input, see details below */
 size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
 size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
 void   ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
 size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
 size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
 ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
 


 
Block functions
     Block functions produce and decode raw zstd blocks, without frame metadata.
     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 : ZSTD_compressBegin()
-      + decompression : ZSTD_decompressBegin()
-      + variants _usingDict() are also allowed
-      + copyCCtx() and copyDCtx() work too
-    - Block size is limited, it must be <= ZSTD_getBlockSizeMax()
-      + If you need to compress more, cut data into multiple blocks
-      + Consider using the regular ZSTD_compress() instead, as frame metadata costs become negligible when source size is large.
+      + 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_getBlockSizeMax() <= ZSTD_BLOCKSIZE_ABSOLUTEMAX
+      + 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, decoder must be informed of uncompressed block existence to follow proper history.
-        Use ZSTD_insertBlock() in such a case.
+      + 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_getBlockSizeMax(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 block into `dctx` history. Useful for uncompressed blocks */
 


 
 
Index: head/contrib/zstd/examples/simple_compression.c
===================================================================
--- head/contrib/zstd/examples/simple_compression.c	(revision 317876)
+++ head/contrib/zstd/examples/simple_compression.c	(revision 317877)
@@ -1,132 +1,133 @@
 /**
  * Copyright 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the license found in the
  * LICENSE-examples file in the root directory of this source tree.
  */
 
 
 
 #include     // malloc, free, exit
 #include      // fprintf, perror, fopen, etc.
 #include     // strlen, strcat, memset, strerror
 #include      // errno
 #include   // stat
 #include       // presumes zstd library is installed
 
 
 static off_t fsize_orDie(const char *filename)
 {
     struct stat st;
     if (stat(filename, &st) == 0) return st.st_size;
     /* error */
     perror(filename);
     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(2);
 }
 
 static void* malloc_orDie(size_t size)
 {
     void* const buff = malloc(size);
     if (buff) return buff;
     /* error */
     perror(NULL);
     exit(3);
 }
 
 static void* loadFile_orDie(const char* fileName, size_t* size)
 {
     off_t const fileSize = fsize_orDie(fileName);
     size_t const buffSize = (size_t)fileSize;
     if ((off_t)buffSize < fileSize) {   /* narrowcast overflow */
         fprintf(stderr, "%s : filesize too large \n", fileName);
         exit(4);
     }
     FILE* const inFile = fopen_orDie(fileName, "rb");
     void* const buffer = malloc_orDie(buffSize);
     size_t const readSize = fread(buffer, 1, buffSize, inFile);
     if (readSize != (size_t)buffSize) {
         fprintf(stderr, "fread: %s : %s \n", fileName, strerror(errno));
         exit(5);
     }
     fclose(inFile);  /* can't fail, read only */
     *size = buffSize;
     return buffer;
 }
 
 
 static void saveFile_orDie(const char* fileName, const void* buff, size_t buffSize)
 {
     FILE* const oFile = fopen_orDie(fileName, "wb");
     size_t const wSize = fwrite(buff, 1, buffSize, oFile);
     if (wSize != (size_t)buffSize) {
         fprintf(stderr, "fwrite: %s : %s \n", fileName, strerror(errno));
         exit(6);
     }
     if (fclose(oFile)) {
         perror(fileName);
         exit(7);
     }
 }
 
 
 static void compress_orDie(const char* fname, const char* oname)
 {
     size_t fSize;
     void* const fBuff = loadFile_orDie(fname, &fSize);
     size_t const cBuffSize = ZSTD_compressBound(fSize);
     void* const cBuff = malloc_orDie(cBuffSize);
 
     size_t const cSize = ZSTD_compress(cBuff, cBuffSize, fBuff, fSize, 1);
     if (ZSTD_isError(cSize)) {
         fprintf(stderr, "error compressing %s : %s \n", fname, ZSTD_getErrorName(cSize));
         exit(8);
     }
 
     saveFile_orDie(oname, cBuff, cSize);
 
     /* success */
     printf("%25s : %6u -> %7u - %s \n", fname, (unsigned)fSize, (unsigned)cSize, oname);
 
     free(fBuff);
     free(cBuff);
 }
 
 
 static char* createOutFilename_orDie(const char* filename)
 {
     size_t const inL = strlen(filename);
     size_t const outL = inL + 5;
     void* const outSpace = malloc_orDie(outL);
     memset(outSpace, 0, outL);
     strcat(outSpace, filename);
     strcat(outSpace, ".zst");
     return (char*)outSpace;
 }
 
 int main(int argc, const char** argv)
 {
     const char* const exeName = argv[0];
-    const char* const inFilename = argv[1];
 
     if (argc!=2) {
         printf("wrong arguments\n");
         printf("usage:\n");
         printf("%s FILE\n", exeName);
         return 1;
     }
+
+    const char* const inFilename = argv[1];
 
     char* const outFilename = createOutFilename_orDie(inFilename);
     compress_orDie(inFilename, outFilename);
     free(outFilename);
     return 0;
 }
Index: head/contrib/zstd/examples/streaming_compression.c
===================================================================
--- head/contrib/zstd/examples/streaming_compression.c	(revision 317876)
+++ head/contrib/zstd/examples/streaming_compression.c	(revision 317877)
@@ -1,128 +1,129 @@
 /**
  * Copyright 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the license found in the
  * LICENSE-examples file in the root directory of this source tree.
  */
 
 
 #include     // malloc, free, exit
 #include      // fprintf, perror, feof, fopen, etc.
 #include     // strlen, memset, strcat
 #include       // presumes zstd library is installed
 
 
 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)
 {
     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_CStream* const cstream = ZSTD_createCStream();
     if (cstream==NULL) { fprintf(stderr, "ZSTD_createCStream() error \n"); exit(10); }
     size_t const initResult = ZSTD_initCStream(cstream, cLevel);
     if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_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_compressStream(cstream, &output , &input);   /* toRead is guaranteed to be <= ZSTD_CStreamInSize() */
             if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_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);
         }
     }
 
     ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
     size_t const remainingToFlush = ZSTD_endStream(cstream, &output);   /* close frame */
     if (remainingToFlush) { fprintf(stderr, "not fully flushed"); exit(13); }
     fwrite_orDie(buffOut, output.pos, fout);
 
     ZSTD_freeCStream(cstream);
     fclose_orDie(fout);
     fclose_orDie(fin);
     free(buffIn);
     free(buffOut);
 }
 
 
 static const 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;
 }
 
 int main(int argc, const char** argv)
 {
     const char* const exeName = argv[0];
-    const char* const inFilename = argv[1];
 
     if (argc!=2) {
         printf("wrong arguments\n");
         printf("usage:\n");
         printf("%s FILE\n", exeName);
         return 1;
     }
+
+    const char* const inFilename = argv[1];
 
     const char* const outFilename = createOutFilename_orDie(inFilename);
     compressFile_orDie(inFilename, outFilename, 1);
 
     return 0;
 }
Index: head/contrib/zstd/examples/streaming_decompression.c
===================================================================
--- head/contrib/zstd/examples/streaming_decompression.c	(revision 317876)
+++ head/contrib/zstd/examples/streaming_decompression.c	(revision 317877)
@@ -1,113 +1,114 @@
 /**
  * Copyright 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the license found in the
  * LICENSE-examples file in the root directory of this source tree.
  */
 
 
 #include     // malloc, exit
 #include      // fprintf, perror, feof
 #include     // strerror
 #include      // errno
 #include       // presumes zstd library is installed
 
 
 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 decompressFile_orDie(const char* fname)
 {
     FILE* const fin  = fopen_orDie(fname, "rb");
     size_t const buffInSize = ZSTD_DStreamInSize();
     void*  const buffIn  = malloc_orDie(buffInSize);
     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_DStream* const dstream = ZSTD_createDStream();
     if (dstream==NULL) { fprintf(stderr, "ZSTD_createDStream() error \n"); exit(10); }
 
     /* In more complex scenarios, a file may consist of multiple appended frames (ex : pzstd).
     *  The following example decompresses only the first frame.
     *  It is compatible with other provided streaming examples */
     size_t const initResult = ZSTD_initDStream(dstream);
     if (ZSTD_isError(initResult)) { fprintf(stderr, "ZSTD_initDStream() error : %s \n", ZSTD_getErrorName(initResult)); exit(11); }
     size_t read, toRead = initResult;
     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_decompressStream(dstream, &output , &input);  /* toRead : size of next compressed block */
             if (ZSTD_isError(toRead)) { fprintf(stderr, "ZSTD_decompressStream() error : %s \n", ZSTD_getErrorName(toRead)); exit(12); }
             fwrite_orDie(buffOut, output.pos, fout);
         }
     }
 
     ZSTD_freeDStream(dstream);
     fclose_orDie(fin);
     fclose_orDie(fout);
     free(buffIn);
     free(buffOut);
 }
 
 
 int main(int argc, const char** argv)
 {
     const char* const exeName = argv[0];
-    const char* const inFilename = argv[1];
 
     if (argc!=2) {
         fprintf(stderr, "wrong arguments\n");
         fprintf(stderr, "usage:\n");
         fprintf(stderr, "%s FILE\n", exeName);
         return 1;
     }
+
+    const char* const inFilename = argv[1];
 
     decompressFile_orDie(inFilename);
     return 0;
 }
Index: head/contrib/zstd/lib/Makefile
===================================================================
--- head/contrib/zstd/lib/Makefile	(revision 317876)
+++ head/contrib/zstd/lib/Makefile	(revision 317877)
@@ -1,163 +1,173 @@
 # ##########################################################################
 # Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
 # All rights reserved.
 #
 # This Makefile is validated for Linux, macOS, *BSD, Hurd, Solaris, MSYS2 targets
 #
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree. An additional grant
 # of patent rights can be found in the PATENTS file in the same directory.
 # ##########################################################################
 
 # 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_
 CFLAGS  ?= -O3
 DEBUGFLAGS = -g -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
            -Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement \
            -Wstrict-prototypes -Wundef -Wpointer-arith -Wformat-security
 CFLAGS  += $(DEBUGFLAGS) $(MOREFLAGS)
 FLAGS    = $(CPPFLAGS) $(CFLAGS)
 
 
 ZSTD_FILES := $(wildcard common/*.c compress/*.c decompress/*.c dictBuilder/*.c deprecated/*.c)
 
 ZSTD_LEGACY_SUPPORT ?= 4
 
 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]')
 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
 # 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_MULTHREAD
+libzstd.a-mt: libzstd.a
+
 $(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
 $(LIBZSTD): $(ZSTD_FILES)
 	@echo compiling dynamic library $(LIBVER)
 ifneq (,$(filter Windows%,$(OS)))
 	@$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -shared $^ -o dll\libzstd.dll
 	dlltool -D dll\libzstd.dll -d dll\libzstd.def -l dll\libzstd.lib
 else
 	@$(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-release: DEBUGFLAGS :=
+lib-mt: CPPFLAGS += -DZSTD_MULTITHREAD
+lib-mt: lib
+
+lib-release lib-release-mt: DEBUGFLAGS :=
 lib-release: lib
+lib-release-mt: lib-mt
 
 clean:
 	@$(RM) -r *.dSYM   # Mac OS-X specific
 	@$(RM) core *.o *.a *.gcda *.$(SHARED_EXT) *.$(SHARED_EXT).* libzstd.pc
 	@$(RM) dll/libzstd.dll dll/libzstd.lib
 	@$(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
 #-----------------------------------------------------------------------------
 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    ?=
 LIBDIR     ?= $(PREFIX)/lib
 INCLUDEDIR ?= $(PREFIX)/include
 
 ifneq (,$(filter $(shell uname),OpenBSD FreeBSD NetBSD DragonFly))
 PKGCONFIGDIR ?= $(PREFIX)/libdata/pkgconfig
 else
 PKGCONFIGDIR ?= $(LIBDIR)/pkgconfig
 endif
 
 INSTALL_LIB  ?= $(INSTALL) -m 755
 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_DATA) libzstd.pc $(DESTDIR)$(PKGCONFIGDIR)/
 	@echo Installing libraries
 	@$(INSTALL_LIB) libzstd.a $(DESTDIR)$(LIBDIR)
 	@$(INSTALL_LIB) libzstd.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)
 	@ln -sf libzstd.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR)
 	@ln -sf libzstd.$(SHARED_EXT_VER) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT)
 	@echo Installing includes
 	@$(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.$(SHARED_EXT_VER)
 	@$(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: head/contrib/zstd/lib/README.md
===================================================================
--- head/contrib/zstd/lib/README.md	(revision 317876)
+++ head/contrib/zstd/lib/README.md	(revision 317877)
@@ -1,77 +1,85 @@
 Zstandard library files
 ================================
 
 The __lib__ directory contains several directories.
 Depending on target use case, it's enough to include only files from relevant directories.
 
 
 #### API
 
 Zstandard's stable API is exposed within [zstd.h](zstd.h),
 at the root of `lib` directory.
 
 
 #### Advanced API
 
 Some additional API may be useful if you're looking into advanced features :
 - common/error_public.h : transforms `size_t` function results into an `enum`,
                           for precise error handling.
 - ZSTD_STATIC_LINKING_ONLY : if you define this macro _before_ including `zstd.h`,
                           it will give access to advanced and experimental API.
                           These APIs shall ___never be used with dynamic library___ !
                           They are not "stable", their definition may change in the future.
                           Only static linking is allowed.
 
+#### ZSTDMT API
+
+To enable multithreaded compression within the library, invoke `make lib-mt` target.
+Prototypes are defined in header file `compress/zstdmt_compress.h`.
+When linking a program that uses ZSTDMT API against libzstd.a on a POSIX system,
+`-pthread` flag must be provided to the compiler and linker.
+Note : ZSTDMT prototypes can still be used with a library built without multithread support,
+but in this case, they will be single threaded only.
 
 #### Modular build
 
 Directory `common/` is required in all circumstances.
 You can select to support compression only, by just adding files from the `compress/` directory,
 In a similar way, you can build a decompressor-only library with the `decompress/` directory.
 
 Other optional functionalities provided are :
 
 - `dictBuilder/`  : source files to create dictionaries.
                     The API can be consulted in `dictBuilder/zdict.h`.
                     This module also depends on `common/` and `compress/` .
 
 - `legacy/` : source code to decompress previous versions of zstd, starting from `v0.1`.
               This module also depends on `common/` and `decompress/` .
               Library compilation must include directive `ZSTD_LEGACY_SUPPORT = 1` .
               The main API can be consulted in `legacy/zstd_legacy.h`.
               Advanced API from each version can be found in their relevant header file.
               For example, advanced API for version `v0.4` is in `legacy/zstd_v04.h` .
 
 
 #### 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`.
 
 
 #### Obsolete streaming API
 
 Streaming is now provided within `zstd.h`.
 Older streaming API is still available within `deprecated/zbuff.h`.
 It will be removed in a future version.
 Consider migrating code towards newer streaming API in `zstd.h`.
 
 
 #### Miscellaneous
 
 The other files are not source code. There are :
 
  - LICENSE : contains the BSD license text
  - Makefile : script to compile or install zstd library (static and dynamic)
  - libzstd.pc.in : for pkg-config (`make install`)
  - README.md : this file
Index: head/contrib/zstd/lib/common/bitstream.h
===================================================================
--- head/contrib/zstd/lib/common/bitstream.h	(revision 317876)
+++ head/contrib/zstd/lib/common/bitstream.h	(revision 317877)
@@ -1,417 +1,446 @@
 /* ******************************************************************
    bitstream
    Part of FSE library
    header file (to include)
-   Copyright (C) 2013-2016, Yann Collet.
+   Copyright (C) 2013-2017, 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 "error_private.h"  /* error codes and messages */
 
 
+/*-*************************************
+*  Debug
+***************************************/
+#if defined(BIT_DEBUG) && (BIT_DEBUG>=1)
+#  include 
+#else
+#  define assert(condition) ((void)0)
+#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
 {
     size_t bitContainer;
-    int    bitPos;
+    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
 {
     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 (register 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 };
+    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 };   /* up to 26 bits */
+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 };   /* up to 26 bits */
 
 
 /*-**************************************************************
 *  bitStream encoding
 ****************************************************************/
 /*! BIT_initCStream() :
- *  `dstCapacity` must be > sizeof(void*)
+ *  `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)
+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->ptr);
-    if (dstCapacity <= sizeof(bitC->ptr)) return ERROR(dstSize_tooSmall);
+    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 26 bits into `bitC`.
     Does not check for register overflow ! */
-MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC, size_t value, unsigned nbBits)
+MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
+                            size_t value, unsigned nbBits)
 {
     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 */
-MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC, size_t value, unsigned nbBits)
+MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC,
+                                size_t value, unsigned nbBits)
 {
+    assert((value>>nbBits) == 0);
     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;   /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
+    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. This will be revealed later on using BIT_closeCStream() */
+ *  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;   /* if bitPos >= sizeof(bitContainer)*8 --> undefined behavior */
+    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; /* doesn't fit within authorized budget : cancel */
-
+    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->start = (const char*)srcBuffer;
         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->start = (const char*)srcBuffer;
         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);
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24;
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16;
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) <<  8;
             default:;
         }
         { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
           bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
           if (lastByte == 0) return ERROR(GENERIC); /* 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
     return (bitContainer >> start) & BIT_mask[nbBits];
 #endif
 }
 
 MEM_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
 {
     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 */
     return BIT_getMiddleBits(bitD->bitContainer, (sizeof(bitD->bitContainer)*8) - bitD->bitsConsumed - nbBits, nbBits);
 #else
-    U32 const bitMask = sizeof(bitD->bitContainer)*8 - 1;
-    return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
+    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 only if nbBits >= 1 */
+ *  unsafe version; only works if nbBits >= 1 */
 MEM_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t* bitD, U32 nbBits)
 {
-    U32 const bitMask = sizeof(bitD->bitContainer)*8 - 1;
-    return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
+    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.
               if status == BIT_DStream_unfinished, internal register is filled with >= (sizeof(bitD->bitContainer)*8 - 7) bits */
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
 {
-	if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should not happen => corruption detected */
-		return BIT_DStream_overflow;
+    if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* overflow detected, like end of stream */
+        return BIT_DStream_overflow;
 
-    if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer)) {
+    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) */
+        bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD->bitContainer), otherwise bitD->ptr == bitD->start */
         return result;
     }
 }
 
 /*! BIT_endOfDStream() :
 *   @return Tells 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: head/contrib/zstd/lib/common/error_private.c
===================================================================
--- head/contrib/zstd/lib/common/error_private.c	(revision 317876)
+++ head/contrib/zstd/lib/common/error_private.c	(revision 317877)
@@ -1,43 +1,44 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 /* The purpose of this file is to have a single list of error strings embedded in binary */
 
 #include "error_private.h"
 
 const char* ERR_getErrorString(ERR_enum code)
 {
     static const char* const notErrorCode = "Unspecified error code";
     switch( code )
     {
     case PREFIX(no_error): return "No error detected";
     case PREFIX(GENERIC):  return "Error (generic)";
     case PREFIX(prefix_unknown): return "Unknown frame descriptor";
     case PREFIX(version_unsupported): return "Version not supported";
     case PREFIX(parameter_unknown): return "Unknown parameter type";
     case PREFIX(frameParameter_unsupported): return "Unsupported frame parameter";
     case PREFIX(frameParameter_unsupportedBy32bits): return "Frame parameter unsupported in 32-bits mode";
     case PREFIX(frameParameter_windowTooLarge): return "Frame requires too much memory for decoding";
     case PREFIX(compressionParameter_unsupported): return "Compression parameter is out of bound";
     case PREFIX(init_missing): return "Context should be init first";
     case PREFIX(memory_allocation): return "Allocation error : not enough memory";
     case PREFIX(stage_wrong): return "Operation not authorized at current processing stage";
     case PREFIX(dstSize_tooSmall): return "Destination buffer is too small";
-    case PREFIX(srcSize_wrong): return "Src size incorrect";
+    case PREFIX(srcSize_wrong): return "Src size is incorrect";
     case PREFIX(corruption_detected): return "Corrupted block detected";
     case PREFIX(checksum_wrong): return "Restored data doesn't match checksum";
     case PREFIX(tableLog_tooLarge): return "tableLog requires too much memory : unsupported";
     case PREFIX(maxSymbolValue_tooLarge): return "Unsupported max Symbol Value : too large";
     case PREFIX(maxSymbolValue_tooSmall): return "Specified maxSymbolValue is too small";
     case PREFIX(dictionary_corrupted): return "Dictionary is corrupted";
     case PREFIX(dictionary_wrong): return "Dictionary mismatch";
+    case PREFIX(dictionaryCreation_failed): return "Cannot create Dictionary from provided samples";
     case PREFIX(maxCode):
     default: return notErrorCode;
     }
 }
Index: head/contrib/zstd/lib/common/fse.h
===================================================================
--- head/contrib/zstd/lib/common/fse.h	(revision 317876)
+++ head/contrib/zstd/lib/common/fse.h	(revision 317877)
@@ -1,694 +1,698 @@
 /* ******************************************************************
    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
 ****************************************************************** */
 #ifndef FSE_H
 #define FSE_H
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /*-*****************************************
 *  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[]
 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_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);
 
 
 /*! 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 tableLog, unsigned maxSymbolValue);
 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);
 
 /*! 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)
 */
 
 
 #ifdef 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_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) + (1<<((maxTableLog>2)?(maxTableLog-2):0)) )
+#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)
 {
-    const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
+    FSE_symbolCompressionTransform const symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
     const U16* const stateTable = (const U16*)(statePtr->stateTable);
-    U32 nbBitsOut  = (U32)((statePtr->value + symbolTT.deltaNbBits) >> 16);
+    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);
 }
 
 
 /* ======    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
 
 #endif  /* FSE_H */
Index: head/contrib/zstd/lib/common/huf.h
===================================================================
--- head/contrib/zstd/lib/common/huf.h	(revision 317876)
+++ head/contrib/zstd/lib/common/huf.h	(revision 317877)
@@ -1,260 +1,283 @@
 /* ******************************************************************
    Huffman coder, part of New Generation Entropy library
    header file
    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
 ****************************************************************** */
 #ifndef HUF_H_298734234
 #define HUF_H_298734234
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /* *** 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 return == 1, srcData is a single repeated byte symbol (RLE compression).
                      if HUF_isError(return), compression failed (more details using HUF_getErrorName())
 */
-size_t HUF_compress(void* dst, size_t dstCapacity,
-              const void* src, size_t srcSize);
+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.
     @return : size of regenerated data (== originalSize),
               or an error code, which can be tested using HUF_isError()
 */
-size_t HUF_decompress(void* dst,  size_t originalSize,
-                const void* cSrc, size_t cSrcSize);
+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 */
-size_t HUF_compressBound(size_t size);       /**< maximum compressed size (worst case) */
+#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 */
-unsigned    HUF_isError(size_t code);        /**< tells if a return value is an error code */
-const char* HUF_getErrorName(size_t code);   /**< provides error code string (useful for debugging) */
+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 direct control over `maxSymbolValue` and `tableLog` .
- *   `tableLog` must be `<= HUF_TABLELOG_MAX` . */
-size_t HUF_compress2 (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
+ *  Same as HUF_compress(), but offers direct control over `maxSymbolValue` and `tableLog`.
+ *  `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`, which must be a table of >= 1024 unsigned */
-size_t HUF_compress4X_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 */
+ *  Same as HUF_compress2(), but uses externally allocated `workSpace`.
+ *  `workspace` must have minimum alignment of 4, and be at least as large as following macro */
+#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);
 
 
 
+/* ******************************************************************
+ *  WARNING !!
+ *  The following section contains advanced and experimental definitions
+ *  which shall never be used in the context of dll
+ *  because they are not guaranteed to remain stable in the future.
+ *  Only consider them in association with static linking.
+ *******************************************************************/
 #ifdef HUF_STATIC_LINKING_ONLY
 
 /* *** Dependencies *** */
 #include "mem.h"   /* U32 */
 
 
 /* *** Constants *** */
 #define HUF_TABLELOG_MAX      12       /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
 #define HUF_TABLELOG_DEFAULT  11       /* tableLog by default, when not 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 if incompressible pre-filtered with fast heuristic */
+#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[maxSymbolValue+1]; \
+    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) \
         HUF_DTable DTable[HUF_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1) * 0x01000001) }
 #define HUF_CREATE_STATIC_DTABLEX4(DTable, maxTableLog) \
         HUF_DTable DTable[HUF_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog) * 0x01000001) }
-
-/* The workspace must have alignment at least 4 and be at least this large */
-#define HUF_WORKSPACE_SIZE (6 << 10)
-#define HUF_WORKSPACE_SIZE_U32 (HUF_WORKSPACE_SIZE / sizeof(U32))
 
 
 /* ****************************************
 *  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_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_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< 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 */
 
 
 /* ****************************************
 *  HUF detailed API
 ******************************************/
 /*!
 HUF_compress() does the following:
 1. count symbol occurrence from source[] into table count[] using FSE_count()
 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.
 */
 /* FSE_count() : find it within "fse.h" */
 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);
 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;
 /** 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, HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat);  /**< `workSpace` must be a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */
 
 /** 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 1024 unsigned.
  */
 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 maxSymbolValue, const void* src, size_t srcSize);
 
 
 /*
 HUF_decompress() does the following:
 1. select the decompression algorithm (X2, X4) based on pre-computed heuristics
 2. build Huffman table from save, using HUF_readDTableXn()
 3. decode 1 or 4 segments in parallel using HUF_decompressSXn_usingDTable
 */
 
 /** HUF_selectDecoder() :
 *   Tells which decoder is likely to decode faster,
 *   based on a set of pre-determined metrics.
 *   @return : 0==HUF_decompress4X2, 1==HUF_decompress4X4 .
 *   Assumption : 0 < cSrcSize < dstSize <= 128 KB */
 U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize);
 
 size_t HUF_readDTableX2 (HUF_DTable* DTable, const void* src, size_t srcSize);
 size_t HUF_readDTableX4 (HUF_DTable* DTable, const void* src, size_t srcSize);
 
 size_t HUF_decompress4X_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, HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat);  /**< `workSpace` must be a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */
 
 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_decompress1X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
 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_decompress1X4_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);   /**< 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_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);
 
 #endif /* HUF_STATIC_LINKING_ONLY */
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif   /* HUF_H_298734234 */
Index: head/contrib/zstd/lib/common/mem.h
===================================================================
--- head/contrib/zstd/lib/common/mem.h	(revision 317876)
+++ head/contrib/zstd/lib/common/mem.h	(revision 317877)
@@ -1,374 +1,373 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 #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
 
 /* 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;
   typedef  intptr_t iPtrDiff;
   typedef uintptr_t uPtrDiff;
 #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;
   typedef ptrdiff_t      iPtrDiff;
   typedef size_t         uPtrDiff;
 #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(_MSC_VER)*/ || \
-  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
+#  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 U64 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) )
+    __pragma( pack(push, 1) )
     typedef union { U16 u16; U32 u32; U64 u64; size_t st; } unalign;
     __pragma( pack(pop) )
 #else
     typedef union { U16 u16; U32 u32; U64 u64; size_t st; } __attribute__((packed)) unalign;
 #endif
 
 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 U64 MEM_readST(const void* ptr) { return ((const unalign*)ptr)->st; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign*)memPtr)->u32 = value; }
 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign*)memPtr)->u64 = 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)
     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)
     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);
 }
 
 
 /* function safe only for comparisons */
 MEM_STATIC U32 MEM_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;
     }
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* MEM_H_MODULE */
Index: head/contrib/zstd/lib/common/zstd_errors.h
===================================================================
--- head/contrib/zstd/lib/common/zstd_errors.h	(revision 317876)
+++ head/contrib/zstd/lib/common/zstd_errors.h	(revision 317877)
@@ -1,74 +1,75 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 #ifndef ZSTD_ERRORS_H_398273423
 #define ZSTD_ERRORS_H_398273423
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /*===== dependency =====*/
 #include    /* size_t */
 
 
 /* =====   ZSTDERRORLIB_API : control library symbols visibility   ===== */
 #if defined(__GNUC__) && (__GNUC__ >= 4)
 #  define ZSTDERRORLIB_VISIBILITY __attribute__ ((visibility ("default")))
 #else
 #  define ZSTDERRORLIB_VISIBILITY
 #endif
 #if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
 #  define ZSTDERRORLIB_API __declspec(dllexport) ZSTDERRORLIB_VISIBILITY
 #elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
 #  define ZSTDERRORLIB_API __declspec(dllimport) ZSTDERRORLIB_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 ZSTDERRORLIB_API ZSTDERRORLIB_VISIBILITY
 #endif
 
 /*-****************************************
 *  error codes list
 ******************************************/
 typedef enum {
   ZSTD_error_no_error,
   ZSTD_error_GENERIC,
   ZSTD_error_prefix_unknown,
   ZSTD_error_version_unsupported,
   ZSTD_error_parameter_unknown,
   ZSTD_error_frameParameter_unsupported,
   ZSTD_error_frameParameter_unsupportedBy32bits,
   ZSTD_error_frameParameter_windowTooLarge,
   ZSTD_error_compressionParameter_unsupported,
   ZSTD_error_init_missing,
   ZSTD_error_memory_allocation,
   ZSTD_error_stage_wrong,
   ZSTD_error_dstSize_tooSmall,
   ZSTD_error_srcSize_wrong,
   ZSTD_error_corruption_detected,
   ZSTD_error_checksum_wrong,
   ZSTD_error_tableLog_tooLarge,
   ZSTD_error_maxSymbolValue_tooLarge,
   ZSTD_error_maxSymbolValue_tooSmall,
   ZSTD_error_dictionary_corrupted,
   ZSTD_error_dictionary_wrong,
+  ZSTD_error_dictionaryCreation_failed,
   ZSTD_error_maxCode
 } ZSTD_ErrorCode;
 
 /*! ZSTD_getErrorCode() :
     convert a `size_t` function result into a `ZSTD_ErrorCode` enum type,
     which can be used to compare directly with enum list published into "error_public.h" */
 ZSTDERRORLIB_API ZSTD_ErrorCode ZSTD_getErrorCode(size_t functionResult);
 ZSTDERRORLIB_API const char* ZSTD_getErrorString(ZSTD_ErrorCode code);
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ZSTD_ERRORS_H_398273423 */
Index: head/contrib/zstd/lib/common/zstd_internal.h
===================================================================
--- head/contrib/zstd/lib/common/zstd_internal.h	(revision 317876)
+++ head/contrib/zstd/lib/common/zstd_internal.h	(revision 317877)
@@ -1,283 +1,284 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 #ifndef ZSTD_CCOMMON_H_MODULE
 #define ZSTD_CCOMMON_H_MODULE
 
 /*-*******************************************************
 *  Compiler specifics
 *********************************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  define FORCE_INLINE static __forceinline
 #  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 : 4324)        /* disable: C4324: padded structure */
-#  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
 #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
 
 #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
 
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include "mem.h"
 #include "error_private.h"
 #define ZSTD_STATIC_LINKING_ONLY
 #include "zstd.h"
 #ifndef XXH_STATIC_LINKING_ONLY
 #  define XXH_STATIC_LINKING_ONLY   /* XXH64_state_t */
 #endif
 #include "xxhash.h"               /* XXH_reset, update, digest */
 
 
 /*-*************************************
 *  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_DICT_MAGIC  0xEC30A437   /* v0.7+ */
 
 #define ZSTD_REP_NUM      3                 /* number of repcodes */
 #define ZSTD_REP_CHECK    (ZSTD_REP_NUM)    /* number of repcodes to check by the optimal parser */
 #define ZSTD_REP_MOVE     (ZSTD_REP_NUM-1)
 #define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)
 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
 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_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 EQUAL_READ32 4
 
 #define Litbits  8
 #define MaxLit ((1<= 3)   /* GCC Intrinsic */
     return 31 - __builtin_clz(val);
 #   else   /* Software version */
     static const int 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;
     int 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
 }
 
 
 /* hidden functions */
 
 /* 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);
 
 
 #endif   /* ZSTD_CCOMMON_H_MODULE */
Index: head/contrib/zstd/lib/compress/fse_compress.c
===================================================================
--- head/contrib/zstd/lib/compress/fse_compress.c	(revision 317876)
+++ head/contrib/zstd/lib/compress/fse_compress.c	(revision 317877)
@@ -1,857 +1,857 @@
 /* ******************************************************************
    FSE : Finite State Entropy encoder
    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
 ****************************************************************** */
 
 /* **************************************************************
 *  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) */
 #include "bitstream.h"
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #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;
 
     /* For explanations on how to distribute symbol values over the table :
     *  http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */
 
     /* 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 */
         }   }
 
         if (position!=0) return ERROR(GENERIC);   /* Must have gone through 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)
 {
     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;
 
     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) {
                 start+=24;
                 bitStream += 0xFFFFU << bitCount;
                 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) {
                 start+=3;
                 bitStream += 3 << bitCount;
                 bitCount += 2;
             }
             bitStream += (charnum-start) << bitCount;
             bitCount += 2;
             if (bitCount>16) {
                 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;
             remaining -= count < 0 ? -count : count;
             count++;   /* +1 for extra accuracy */
             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 */
             out[0] = (BYTE)bitStream;
             out[1] = (BYTE)(bitStream>>8);
             out += 2;
             bitStream >>= 16;
             bitCount -= 16;
     }   }
 
     /* flush remaining bitStream */
     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)
 {
-    if (tableLog > FSE_MAX_TABLELOG) return ERROR(GENERIC);   /* Unsupported */
+    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);
 }
 
 
 
 /*-**************************************************************
 *  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)`` */
 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(Counting1, 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; 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) 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 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2;
-	U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols;
-	return minBits;
+    U32 minBitsSrc = BIT_highbit32((U32)(srcSize - 1)) + 1;
+    U32 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2;
+    U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols;
+    return minBits;
 }
 
 unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus)
 {
-	U32 maxBitsSrc = BIT_highbit32((U32)(srcSize - 1)) - minus;
+    U32 maxBitsSrc = BIT_highbit32((U32)(srcSize - 1)) - minus;
     U32 tableLog = maxTableLog;
-	U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue);
+    U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue);
     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 (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 ((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 */
 
     {   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]);
         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 f
 #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 */
     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: head/contrib/zstd/lib/compress/zstd_compress.c
===================================================================
--- head/contrib/zstd/lib/compress/zstd_compress.c	(revision 317876)
+++ head/contrib/zstd/lib/compress/zstd_compress.c	(revision 317877)
@@ -1,3387 +1,3598 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include          /* memset */
 #include "mem.h"
 #define FSE_STATIC_LINKING_ONLY   /* FSE_encodeSymbol */
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_internal.h"  /* includes zstd.h */
 
 
 /*-*************************************
+*  Debug
+***************************************/
+#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=1)
+#  include 
+#else
+#  define assert(condition) ((void)0)
+#endif
+
+#define ZSTD_STATIC_ASSERT(c) { enum { ZSTD_static_assert = 1/(int)(!!(c)) }; }
+
+#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=2)
+#  include 
+   static unsigned g_debugLevel = ZSTD_DEBUG;
+#  define DEBUGLOG(l, ...) if (l<=g_debugLevel) { fprintf(stderr, __FILE__ ": "); fprintf(stderr, __VA_ARGS__); fprintf(stderr, " \n"); }
+#else
+#  define DEBUGLOG(l, ...)      {}    /* disabled */
+#endif
+
+
+/*-*************************************
 *  Constants
 ***************************************/
 static const U32 g_searchStrength = 8;   /* control skip over incompressible data */
 #define HASH_READ_SIZE 8
 typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZSTD_compressionStage_e;
 
+/* entropy tables always have same size */
+static size_t const hufCTable_size = HUF_CTABLE_SIZE(255);
+static size_t const litlengthCTable_size = FSE_CTABLE_SIZE(LLFSELog, MaxLL);
+static size_t const offcodeCTable_size = FSE_CTABLE_SIZE(OffFSELog, MaxOff);
+static size_t const matchlengthCTable_size = FSE_CTABLE_SIZE(MLFSELog, MaxML);
+static size_t const entropyScratchSpace_size = HUF_WORKSPACE_SIZE;
 
+
 /*-*************************************
 *  Helper functions
 ***************************************/
-#define ZSTD_STATIC_ASSERT(c) { enum { ZSTD_static_assert = 1/(int)(!!(c)) }; }
-size_t ZSTD_compressBound(size_t srcSize) { return FSE_compressBound(srcSize) + 12; }
+size_t ZSTD_compressBound(size_t srcSize) {
+    size_t const lowLimit = 256 KB;
+    size_t const margin = (srcSize < lowLimit) ? (lowLimit-srcSize) >> 12 : 0;  /* from 64 to 0 */
+    return srcSize + (srcSize >> 8) + margin;
+}
 
 
 /*-*************************************
 *  Sequence storage
 ***************************************/
 static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
 {
     ssPtr->lit = ssPtr->litStart;
     ssPtr->sequences = ssPtr->sequencesStart;
     ssPtr->longLengthID = 0;
 }
 
 
 /*-*************************************
 *  Context memory management
 ***************************************/
 struct ZSTD_CCtx_s {
     const BYTE* nextSrc;    /* next block here to continue on current prefix */
     const BYTE* base;       /* All regular indexes relative to this position */
     const BYTE* dictBase;   /* extDict indexes relative to this position */
     U32   dictLimit;        /* below that point, need extDict */
     U32   lowLimit;         /* below that point, no more data */
     U32   nextToUpdate;     /* index from which to continue dictionary update */
     U32   nextToUpdate3;    /* index from which to continue dictionary update */
     U32   hashLog3;         /* dispatch table : larger == faster, more memory */
     U32   loadedDictEnd;    /* index of end of dictionary */
     U32   forceWindow;      /* force back-references to respect limit of 1<customMem = customMem;
     return cctx;
 }
 
 size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return 0;   /* support free on NULL */
     ZSTD_free(cctx->workSpace, cctx->customMem);
     ZSTD_free(cctx, cctx->customMem);
     return 0;   /* reserved as a potential error code in the future */
 }
 
 size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return 0;   /* support sizeof on NULL */
     return sizeof(*cctx) + cctx->workSpaceSize;
 }
 
 size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter param, unsigned value)
 {
     switch(param)
     {
     case ZSTD_p_forceWindow : cctx->forceWindow = value>0; cctx->loadedDictEnd = 0; return 0;
     case ZSTD_p_forceRawDict : cctx->forceRawDict = value>0; return 0;
     default: return ERROR(parameter_unknown);
     }
 }
 
 const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx)   /* hidden interface */
 {
     return &(ctx->seqStore);
 }
 
 static ZSTD_parameters ZSTD_getParamsFromCCtx(const ZSTD_CCtx* cctx)
 {
     return cctx->params;
 }
 
 
 /** ZSTD_checkParams() :
     ensure param 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)
 {
 #   define CLAMPCHECK(val,min,max) { if ((valmax)) return ERROR(compressionParameter_unsupported); }
     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);
-    { U32 const searchLengthMin = ((cParams.strategy == ZSTD_fast) | (cParams.strategy == ZSTD_greedy)) ? ZSTD_SEARCHLENGTH_MIN+1 : ZSTD_SEARCHLENGTH_MIN;
-      U32 const searchLengthMax = (cParams.strategy == ZSTD_fast) ? ZSTD_SEARCHLENGTH_MAX : ZSTD_SEARCHLENGTH_MAX-1;
-      CLAMPCHECK(cParams.searchLength, searchLengthMin, searchLengthMax); }
+    CLAMPCHECK(cParams.searchLength, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
     CLAMPCHECK(cParams.targetLength, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX);
     if ((U32)(cParams.strategy) > (U32)ZSTD_btopt2) return ERROR(compressionParameter_unsupported);
     return 0;
 }
 
 
 /** 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() :
     optimize `cPar` for a given input (`srcSize` and `dictSize`).
     mostly downsizing to reduce memory consumption and initialization.
     Both `srcSize` and `dictSize` are optional (use 0 if unknown),
     but if both are 0, no optimization can be done.
     Note : cPar is considered validated at this stage. Use ZSTD_checkParams() to ensure that. */
 ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize)
 {
     if (srcSize+dictSize == 0) return cPar;   /* no size information available : no adjustment */
 
     /* resize params, to use less memory when necessary */
     {   U32 const minSrcSize = (srcSize==0) ? 500 : 0;
         U64 const rSize = srcSize + dictSize + minSrcSize;
         if (rSize < ((U64)1< srcLog) cPar.windowLog = srcLog;
     }   }
     if (cPar.hashLog > cPar.windowLog) cPar.hashLog = cPar.windowLog;
     {   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;
 }
 
 
 size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams)
 {
     size_t const blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, (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 chainSize = (cParams.strategy == ZSTD_fast) ? 0 : (1 << cParams.chainLog);
     size_t const hSize = ((size_t)1) << cParams.hashLog;
     U32    const hashLog3 = (cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, cParams.windowLog);
     size_t const h3Size = ((size_t)1) << hashLog3;
+    size_t const entropySpace = hufCTable_size + litlengthCTable_size
+                              + offcodeCTable_size + matchlengthCTable_size
+                              + entropyScratchSpace_size;
     size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
 
     size_t const optSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<nextSrc - cctx->base);
     cctx->params = params;
     cctx->frameContentSize = frameContentSize;
+    cctx->consumedSrcSize = 0;
     cctx->lowLimit = end;
     cctx->dictLimit = end;
     cctx->nextToUpdate = end+1;
     cctx->stage = ZSTDcs_init;
     cctx->dictID = 0;
     cctx->loadedDictEnd = 0;
     { int i; for (i=0; irep[i] = repStartValue[i]; }
     cctx->seqStore.litLengthSum = 0;  /* force reset of btopt stats */
     XXH64_reset(&cctx->xxhState, 0);
     return 0;
 }
 
 typedef enum { ZSTDcrp_continue, ZSTDcrp_noMemset, ZSTDcrp_fullReset } ZSTD_compResetPolicy_e;
 
-/*! ZSTD_resetCCtx_advanced() :
+/*! ZSTD_resetCCtx_internal() :
     note : `params` must be validated */
-static size_t ZSTD_resetCCtx_advanced (ZSTD_CCtx* zc,
+static size_t ZSTD_resetCCtx_internal (ZSTD_CCtx* zc,
                                        ZSTD_parameters params, U64 frameContentSize,
                                        ZSTD_compResetPolicy_e const crp)
 {
     if (crp == ZSTDcrp_continue)
         if (ZSTD_equivalentParams(params, zc->params)) {
-            zc->flagStaticTables = 0;
-            zc->flagStaticHufTable = HUF_repeat_none;
+            zc->fseCTables_ready = 0;
+            zc->hufCTable_repeatMode = HUF_repeat_none;
             return ZSTD_continueCCtx(zc, params, frameContentSize);
         }
 
     {   size_t const blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, (size_t)1 << params.cParams.windowLog);
         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 chainSize = (params.cParams.strategy == ZSTD_fast) ? 0 : (1 << params.cParams.chainLog);
         size_t const hSize = ((size_t)1) << params.cParams.hashLog;
         U32    const hashLog3 = (params.cParams.searchLength>3) ? 0 : MIN(ZSTD_HASHLOG3_MAX, params.cParams.windowLog);
         size_t const h3Size = ((size_t)1) << hashLog3;
         size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
         void* ptr;
 
         /* Check if workSpace is large enough, alloc a new one if needed */
-        {   size_t const optSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<workSpaceSize < neededSpace) {
+                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;
+
+                /* entropy space */
+                zc->hufCTable = (HUF_CElt*)ptr;
+                ptr = (char*)zc->hufCTable + hufCTable_size;  /* note : HUF_CElt* is incomplete type, size is estimated via macro */
+                zc->offcodeCTable = (FSE_CTable*) ptr;
+                ptr = (char*)ptr + offcodeCTable_size;
+                zc->matchlengthCTable = (FSE_CTable*) ptr;
+                ptr = (char*)ptr + matchlengthCTable_size;
+                zc->litlengthCTable = (FSE_CTable*) ptr;
+                ptr = (char*)ptr + litlengthCTable_size;
+                assert(((size_t)ptr & 3) == 0);   /* ensure correct alignment */
+                zc->entropyScratchSpace = (unsigned*) ptr;
         }   }
 
-        if (crp!=ZSTDcrp_noMemset) memset(zc->workSpace, 0, tableSpace);   /* reset tables only */
-        XXH64_reset(&zc->xxhState, 0);
-        zc->hashLog3 = hashLog3;
-        zc->hashTable = (U32*)(zc->workSpace);
-        zc->chainTable = zc->hashTable + hSize;
-        zc->hashTable3 = zc->chainTable + chainSize;
-        ptr = zc->hashTable3 + h3Size;
-        zc->hufTable = (HUF_CElt*)ptr;
-        zc->flagStaticTables = 0;
-        zc->flagStaticHufTable = HUF_repeat_none;
-        ptr = ((U32*)ptr) + 256;  /* note : HUF_CElt* is incomplete type, size is simulated using U32 */
+        /* init params */
+        zc->params = params;
+        zc->blockSize = blockSize;
+        zc->frameContentSize = frameContentSize;
+        zc->consumedSrcSize = 0;
 
+        XXH64_reset(&zc->xxhState, 0);
+        zc->stage = ZSTDcs_init;
+        zc->dictID = 0;
+        zc->loadedDictEnd = 0;
+        zc->fseCTables_ready = 0;
+        zc->hufCTable_repeatMode = HUF_repeat_none;
         zc->nextToUpdate = 1;
         zc->nextSrc = NULL;
         zc->base = NULL;
         zc->dictBase = NULL;
         zc->dictLimit = 0;
         zc->lowLimit = 0;
-        zc->params = params;
-        zc->blockSize = blockSize;
-        zc->frameContentSize = frameContentSize;
         { int i; for (i=0; irep[i] = repStartValue[i]; }
+        zc->hashLog3 = hashLog3;
+        zc->seqStore.litLengthSum = 0;
 
+        /* ensure entropy tables are close together at the beginning */
+        assert((void*)zc->hufCTable == zc->workSpace);
+        assert((char*)zc->offcodeCTable == (char*)zc->hufCTable + hufCTable_size);
+        assert((char*)zc->matchlengthCTable == (char*)zc->offcodeCTable + offcodeCTable_size);
+        assert((char*)zc->litlengthCTable == (char*)zc->matchlengthCTable + matchlengthCTable_size);
+        assert((char*)zc->entropyScratchSpace == (char*)zc->litlengthCTable + litlengthCTable_size);
+        ptr = (char*)zc->entropyScratchSpace + entropyScratchSpace_size;
+
+        /* opt parser space */
         if ((params.cParams.strategy == ZSTD_btopt) || (params.cParams.strategy == ZSTD_btopt2)) {
+            assert(((size_t)ptr & 3) == 0);  /* ensure ptr is properly aligned */
             zc->seqStore.litFreq = (U32*)ptr;
             zc->seqStore.litLengthFreq = zc->seqStore.litFreq + (1<seqStore.matchLengthFreq = zc->seqStore.litLengthFreq + (MaxLL+1);
             zc->seqStore.offCodeFreq = zc->seqStore.matchLengthFreq + (MaxML+1);
             ptr = zc->seqStore.offCodeFreq + (MaxOff+1);
             zc->seqStore.matchTable = (ZSTD_match_t*)ptr;
             ptr = zc->seqStore.matchTable + ZSTD_OPT_NUM+1;
             zc->seqStore.priceTable = (ZSTD_optimal_t*)ptr;
             ptr = zc->seqStore.priceTable + ZSTD_OPT_NUM+1;
-            zc->seqStore.litLengthSum = 0;
         }
+
+        /* table Space */
+        if (crp!=ZSTDcrp_noMemset) memset(ptr, 0, tableSpace);   /* reset tables only */
+        assert(((size_t)ptr & 3) == 0);  /* ensure ptr is properly aligned */
+        zc->hashTable = (U32*)(ptr);
+        zc->chainTable = zc->hashTable + hSize;
+        zc->hashTable3 = zc->chainTable + chainSize;
+        ptr = zc->hashTable3 + h3Size;
+
+        /* sequences storage */
         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;
 
-        zc->stage = ZSTDcs_init;
-        zc->dictID = 0;
-        zc->loadedDictEnd = 0;
-
         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; irep[i] = 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()).
-*   @return : 0, or an error code */
-size_t ZSTD_copyCCtx(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx, unsigned long long pledgedSrcSize)
+
+/*! 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()).
+ *  pledgedSrcSize=0 means "empty" if fParams.contentSizeFlag=1
+ *  @return : 0, or an error code */
+size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx,
+                              ZSTD_frameParameters fParams, unsigned long long pledgedSrcSize)
 {
     if (srcCCtx->stage!=ZSTDcs_init) return ERROR(stage_wrong);
 
-
     memcpy(&dstCCtx->customMem, &srcCCtx->customMem, sizeof(ZSTD_customMem));
     {   ZSTD_parameters params = srcCCtx->params;
-        params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
-        ZSTD_resetCCtx_advanced(dstCCtx, params, pledgedSrcSize, ZSTDcrp_noMemset);
+        params.fParams = fParams;
+        DEBUGLOG(5, "ZSTD_resetCCtx_internal : dictIDFlag : %u \n", !fParams.noDictIDFlag);
+        ZSTD_resetCCtx_internal(dstCCtx, params, pledgedSrcSize, ZSTDcrp_noMemset);
     }
 
     /* copy tables */
     {   size_t const chainSize = (srcCCtx->params.cParams.strategy == ZSTD_fast) ? 0 : (1 << srcCCtx->params.cParams.chainLog);
-        size_t const hSize = ((size_t)1) << srcCCtx->params.cParams.hashLog;
+        size_t const hSize =  (size_t)1 << srcCCtx->params.cParams.hashLog;
         size_t const h3Size = (size_t)1 << srcCCtx->hashLog3;
         size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
-        memcpy(dstCCtx->workSpace, srcCCtx->workSpace, tableSpace);
+        assert((U32*)dstCCtx->chainTable == (U32*)dstCCtx->hashTable + hSize);  /* chainTable must follow hashTable */
+        assert((U32*)dstCCtx->hashTable3 == (U32*)dstCCtx->chainTable + chainSize);
+        memcpy(dstCCtx->hashTable, srcCCtx->hashTable, tableSpace);   /* presumes all tables follow each other */
     }
 
     /* copy dictionary offsets */
     dstCCtx->nextToUpdate = srcCCtx->nextToUpdate;
     dstCCtx->nextToUpdate3= srcCCtx->nextToUpdate3;
     dstCCtx->nextSrc      = srcCCtx->nextSrc;
     dstCCtx->base         = srcCCtx->base;
     dstCCtx->dictBase     = srcCCtx->dictBase;
     dstCCtx->dictLimit    = srcCCtx->dictLimit;
     dstCCtx->lowLimit     = srcCCtx->lowLimit;
     dstCCtx->loadedDictEnd= srcCCtx->loadedDictEnd;
     dstCCtx->dictID       = srcCCtx->dictID;
 
     /* copy entropy tables */
-    dstCCtx->flagStaticTables = srcCCtx->flagStaticTables;
-    dstCCtx->flagStaticHufTable = srcCCtx->flagStaticHufTable;
-    if (srcCCtx->flagStaticTables) {
-        memcpy(dstCCtx->litlengthCTable, srcCCtx->litlengthCTable, sizeof(dstCCtx->litlengthCTable));
-        memcpy(dstCCtx->matchlengthCTable, srcCCtx->matchlengthCTable, sizeof(dstCCtx->matchlengthCTable));
-        memcpy(dstCCtx->offcodeCTable, srcCCtx->offcodeCTable, sizeof(dstCCtx->offcodeCTable));
+    dstCCtx->fseCTables_ready = srcCCtx->fseCTables_ready;
+    if (srcCCtx->fseCTables_ready) {
+        memcpy(dstCCtx->litlengthCTable, srcCCtx->litlengthCTable, litlengthCTable_size);
+        memcpy(dstCCtx->matchlengthCTable, srcCCtx->matchlengthCTable, matchlengthCTable_size);
+        memcpy(dstCCtx->offcodeCTable, srcCCtx->offcodeCTable, offcodeCTable_size);
     }
-    if (srcCCtx->flagStaticHufTable) {
-        memcpy(dstCCtx->hufTable, srcCCtx->hufTable, 256*4);
+    dstCCtx->hufCTable_repeatMode = srcCCtx->hufCTable_repeatMode;
+    if (srcCCtx->hufCTable_repeatMode) {
+        memcpy(dstCCtx->hufCTable, srcCCtx->hufCTable, hufCTable_size);
     }
 
     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*/ };
+    fParams.contentSizeFlag = pledgedSrcSize>0;
 
+    return ZSTD_copyCCtx_internal(dstCCtx, srcCCtx, fParams, pledgedSrcSize);
+}
+
+
 /*! ZSTD_reduceTable() :
-*   reduce table indexes by `reducerValue` */
+ *  reduce table indexes by `reducerValue` */
 static void ZSTD_reduceTable (U32* const table, U32 const size, U32 const reducerValue)
 {
     U32 u;
     for (u=0 ; u < size ; u++) {
         if (table[u] < reducerValue) table[u] = 0;
         else table[u] -= reducerValue;
     }
 }
 
 /*! ZSTD_reduceIndex() :
 *   rescale all indexes to avoid future overflow (indexes are U32) */
 static void ZSTD_reduceIndex (ZSTD_CCtx* zc, const U32 reducerValue)
 {
     { U32 const hSize = 1 << zc->params.cParams.hashLog;
       ZSTD_reduceTable(zc->hashTable, hSize, reducerValue); }
 
     { U32 const chainSize = (zc->params.cParams.strategy == ZSTD_fast) ? 0 : (1 << zc->params.cParams.chainLog);
       ZSTD_reduceTable(zc->chainTable, chainSize, reducerValue); }
 
     { U32 const h3Size = (zc->hashLog3) ? 1 << zc->hashLog3 : 0;
       ZSTD_reduceTable(zc->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)
 {
     if (srcSize + ZSTD_blockHeaderSize > dstCapacity) return ERROR(dstSize_tooSmall);
     memcpy((BYTE*)dst + ZSTD_blockHeaderSize, src, srcSize);
     MEM_writeLE24(dst, (U32)(srcSize << 2) + (U32)bt_raw);
     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;
         default:   /*note : should not be necessary : flSize is within {1,2,3} */
         case 3: /* 2 - 2 - 20 */
             MEM_writeLE32(ostart, (U32)((U32)set_basic + (3<<2) + (srcSize<<4)));
             break;
     }
 
     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;
         default:   /*note : should not be necessary : flSize is necessarily within {1,2,3} */
         case 3: /* 2 - 2 - 20 */
             MEM_writeLE32(ostart, (U32)((U32)set_rle + (3<<2) + (srcSize<<4)));
             break;
     }
 
     ostart[flSize] = *(const BYTE*)src;
     return flSize+1;
 }
 
 
 static size_t ZSTD_minGain(size_t srcSize) { return (srcSize >> 6) + 2; }
 
 static size_t ZSTD_compressLiterals (ZSTD_CCtx* zc,
                                      void* dst, size_t dstCapacity,
                                const void* src, size_t srcSize)
 {
     size_t const minGain = ZSTD_minGain(srcSize);
     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;
 
 
     /* small ? don't even attempt compression (speed opt) */
 #   define LITERAL_NOENTROPY 63
-    {   size_t const minLitSize = zc->flagStaticHufTable == HUF_repeat_valid ? 6 : LITERAL_NOENTROPY;
+    {   size_t const minLitSize = zc->hufCTable_repeatMode == HUF_repeat_valid ? 6 : LITERAL_NOENTROPY;
         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 = zc->flagStaticHufTable;
+    {   HUF_repeat repeat = zc->hufCTable_repeatMode;
         int const preferRepeat = zc->params.cParams.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, zc->tmpCounters, sizeof(zc->tmpCounters), zc->hufTable, &repeat, preferRepeat)
-                                : HUF_compress4X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11, zc->tmpCounters, sizeof(zc->tmpCounters), zc->hufTable, &repeat, preferRepeat);
+        cLitSize = singleStream ? HUF_compress1X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
+                                      zc->entropyScratchSpace, entropyScratchSpace_size, zc->hufCTable, &repeat, preferRepeat)
+                                : HUF_compress4X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
+                                      zc->entropyScratchSpace, entropyScratchSpace_size, zc->hufCTable, &repeat, preferRepeat);
         if (repeat != HUF_repeat_none) { hType = set_repeat; }    /* reused the existing table */
-        else { zc->flagStaticHufTable = HUF_repeat_check; }       /* now have a table to reuse */
+        else { zc->hufCTable_repeatMode = HUF_repeat_check; }       /* now have a table to reuse */
     }
 
     if ((cLitSize==0) | (cLitSize >= srcSize - minGain)) {
-        zc->flagStaticHufTable = HUF_repeat_none;
+        zc->hufCTable_repeatMode = HUF_repeat_none;
         return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
     }
     if (cLitSize==1) {
-        zc->flagStaticHufTable = HUF_repeat_none;
+        zc->hufCTable_repeatMode = HUF_repeat_none;
         return ZSTD_compressRleLiteralsBlock(dst, dstCapacity, src, srcSize);
     }
 
     /* 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;
         }
     default:   /* should not be necessary, lhSize is only {3,4,5} */
     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;
         }
     }
     return lhSize+cLitSize;
 }
 
 static const BYTE LL_Code[64] = {  0,  1,  2,  3,  4,  5,  6,  7,
                                    8,  9, 10, 11, 12, 13, 14, 15,
                                   16, 16, 17, 17, 18, 18, 19, 19,
                                   20, 20, 20, 20, 21, 21, 21, 21,
                                   22, 22, 22, 22, 22, 22, 22, 22,
                                   23, 23, 23, 23, 23, 23, 23, 23,
                                   24, 24, 24, 24, 24, 24, 24, 24,
                                   24, 24, 24, 24, 24, 24, 24, 24 };
 
 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 };
 
 
 void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
 {
     BYTE const LL_deltaCode = 19;
     BYTE const ML_deltaCode = 36;
     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;
     for (u=0; u 63) ? (BYTE)ZSTD_highbit32(llv) + LL_deltaCode : LL_Code[llv];
         ofCodeTable[u] = (BYTE)ZSTD_highbit32(sequences[u].offset);
         mlCodeTable[u] = (mlv>127) ? (BYTE)ZSTD_highbit32(mlv) + ML_deltaCode : ML_Code[mlv];
     }
     if (seqStorePtr->longLengthID==1)
         llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
     if (seqStorePtr->longLengthID==2)
         mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
 }
 
 MEM_STATIC size_t ZSTD_compressSequences (ZSTD_CCtx* zc,
                               void* dst, size_t dstCapacity,
                               size_t srcSize)
 {
     const int longOffsets = zc->params.cParams.windowLog > STREAM_ACCUMULATOR_MIN;
     const seqStore_t* seqStorePtr = &(zc->seqStore);
     U32 count[MaxSeq+1];
     S16 norm[MaxSeq+1];
     FSE_CTable* CTable_LitLength = zc->litlengthCTable;
     FSE_CTable* CTable_OffsetBits = zc->offcodeCTable;
     FSE_CTable* CTable_MatchLength = zc->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 scratchBuffer[1<litStart;
         size_t const litSize = seqStorePtr->lit - literals;
         size_t const cSize = ZSTD_compressLiterals(zc, op, dstCapacity, literals, litSize);
         if (ZSTD_isError(cSize)) return cSize;
         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) goto _check_compressibility;
 
     /* seqHead : flags for FSE encoding type */
     seqHead = op++;
 
 #define MIN_SEQ_FOR_DYNAMIC_FSE   64
 #define MAX_SEQ_FOR_STATIC_FSE  1000
 
     /* convert length/distances into codes */
     ZSTD_seqToCodes(seqStorePtr);
 
     /* CTable for Literal Lengths */
     {   U32 max = MaxLL;
-        size_t const mostFrequent = FSE_countFast_wksp(count, &max, llCodeTable, nbSeq, zc->tmpCounters);
+        size_t const mostFrequent = FSE_countFast_wksp(count, &max, llCodeTable, nbSeq, zc->entropyScratchSpace);
         if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
             *op++ = llCodeTable[0];
             FSE_buildCTable_rle(CTable_LitLength, (BYTE)max);
             LLtype = set_rle;
-        } else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
+        } else if ((zc->fseCTables_ready) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
             LLtype = set_repeat;
         } else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (LL_defaultNormLog-1)))) {
             FSE_buildCTable_wksp(CTable_LitLength, LL_defaultNorm, MaxLL, LL_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
             LLtype = set_basic;
         } else {
             size_t nbSeq_1 = nbSeq;
             const U32 tableLog = FSE_optimalTableLog(LLFSELog, nbSeq, max);
             if (count[llCodeTable[nbSeq-1]]>1) { count[llCodeTable[nbSeq-1]]--; nbSeq_1--; }
             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 ERROR(GENERIC);
+              if (FSE_isError(NCountSize)) return NCountSize;
               op += NCountSize; }
             FSE_buildCTable_wksp(CTable_LitLength, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
             LLtype = set_compressed;
     }   }
 
     /* CTable for Offsets */
     {   U32 max = MaxOff;
-        size_t const mostFrequent = FSE_countFast_wksp(count, &max, ofCodeTable, nbSeq, zc->tmpCounters);
+        size_t const mostFrequent = FSE_countFast_wksp(count, &max, ofCodeTable, nbSeq, zc->entropyScratchSpace);
         if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
             *op++ = ofCodeTable[0];
             FSE_buildCTable_rle(CTable_OffsetBits, (BYTE)max);
             Offtype = set_rle;
-        } else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
+        } else if ((zc->fseCTables_ready) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
             Offtype = set_repeat;
         } else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (OF_defaultNormLog-1)))) {
             FSE_buildCTable_wksp(CTable_OffsetBits, OF_defaultNorm, MaxOff, OF_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
             Offtype = set_basic;
         } else {
             size_t nbSeq_1 = nbSeq;
             const U32 tableLog = FSE_optimalTableLog(OffFSELog, nbSeq, max);
             if (count[ofCodeTable[nbSeq-1]]>1) { count[ofCodeTable[nbSeq-1]]--; nbSeq_1--; }
             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 ERROR(GENERIC);
+              if (FSE_isError(NCountSize)) return NCountSize;
               op += NCountSize; }
             FSE_buildCTable_wksp(CTable_OffsetBits, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
             Offtype = set_compressed;
     }   }
 
     /* CTable for MatchLengths */
     {   U32 max = MaxML;
-        size_t const mostFrequent = FSE_countFast_wksp(count, &max, mlCodeTable, nbSeq, zc->tmpCounters);
+        size_t const mostFrequent = FSE_countFast_wksp(count, &max, mlCodeTable, nbSeq, zc->entropyScratchSpace);
         if ((mostFrequent == nbSeq) && (nbSeq > 2)) {
             *op++ = *mlCodeTable;
             FSE_buildCTable_rle(CTable_MatchLength, (BYTE)max);
             MLtype = set_rle;
-        } else if ((zc->flagStaticTables) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
+        } else if ((zc->fseCTables_ready) && (nbSeq < MAX_SEQ_FOR_STATIC_FSE)) {
             MLtype = set_repeat;
         } else if ((nbSeq < MIN_SEQ_FOR_DYNAMIC_FSE) || (mostFrequent < (nbSeq >> (ML_defaultNormLog-1)))) {
             FSE_buildCTable_wksp(CTable_MatchLength, ML_defaultNorm, MaxML, ML_defaultNormLog, scratchBuffer, sizeof(scratchBuffer));
             MLtype = set_basic;
         } else {
             size_t nbSeq_1 = nbSeq;
             const U32 tableLog = FSE_optimalTableLog(MLFSELog, nbSeq, max);
             if (count[mlCodeTable[nbSeq-1]]>1) { count[mlCodeTable[nbSeq-1]]--; nbSeq_1--; }
             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 ERROR(GENERIC);
+              if (FSE_isError(NCountSize)) return NCountSize;
               op += NCountSize; }
             FSE_buildCTable_wksp(CTable_MatchLength, norm, max, tableLog, scratchBuffer, sizeof(scratchBuffer));
             MLtype = set_compressed;
     }   }
 
     *seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
-    zc->flagStaticTables = 0;
+    zc->fseCTables_ready = 0;
 
     /* Encoding Sequences */
     {   BIT_CStream_t blockStream;
         FSE_CState_t  stateMatchLength;
         FSE_CState_t  stateOffsetBits;
         FSE_CState_t  stateLitLength;
 
         CHECK_E(BIT_initCStream(&blockStream, op, oend-op), 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()) BIT_flushBits(&blockStream);                  /* (7)*/
                 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)*/
         }   }
 
         FSE_flushCState(&blockStream, &stateMatchLength);
         FSE_flushCState(&blockStream, &stateOffsetBits);
         FSE_flushCState(&blockStream, &stateLitLength);
 
         {   size_t const streamSize = BIT_closeCStream(&blockStream);
             if (streamSize==0) return ERROR(dstSize_tooSmall);   /* not enough space */
             op += streamSize;
     }   }
 
     /* check compressibility */
 _check_compressibility:
     {   size_t const minGain = ZSTD_minGain(srcSize);
         size_t const maxCSize = srcSize - minGain;
         if ((size_t)(op-ostart) >= maxCSize) {
-            zc->flagStaticHufTable = HUF_repeat_none;
+            zc->hufCTable_repeatMode = HUF_repeat_none;
             return 0;
     }   }
 
     /* confirm repcodes */
     { int i; for (i=0; irep[i] = zc->repToConfirm[i]; }
 
     return op - ostart;
 }
 
 #if 0 /* for debug */
 #  define STORESEQ_DEBUG
 #include    /* fprintf */
 U32 g_startDebug = 0;
 const BYTE* g_start = NULL;
 #endif
 
 /*! ZSTD_storeSeq() :
     Store a sequence (literal length, literals, offset code and match length code) into seqStore_t.
     `offsetCode` : distance to match, or 0 == repCode.
     `matchCode` : matchLength - MINMATCH
 */
 MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t matchCode)
 {
 #ifdef STORESEQ_DEBUG
     if (g_startDebug) {
         const U32 pos = (U32)((const BYTE*)literals - g_start);
         if (g_start==NULL) g_start = (const BYTE*)literals;
         if ((pos > 1895000) && (pos < 1895300))
-            fprintf(stderr, "Cpos %6u :%5u literals & match %3u bytes at distance %6u \n",
+            DEBUGLOG(5, "Cpos %6u :%5u literals & match %3u bytes at distance %6u \n",
                    pos, (U32)litLength, (U32)matchCode+MINMATCH, (U32)offsetCode);
     }
 #endif
     /* copy Literals */
     ZSTD_wildcopy(seqStorePtr->lit, literals, litLength);
     seqStorePtr->lit += litLength;
 
     /* literal Length */
-    if (litLength>0xFFFF) { seqStorePtr->longLengthID = 1; seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); }
+    if (litLength>0xFFFF) {
+        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 (matchCode>0xFFFF) { seqStorePtr->longLengthID = 2; seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); }
+    if (matchCode>0xFFFF) {
+        seqStorePtr->longLengthID = 2;
+        seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
+    }
     seqStorePtr->sequences[0].matchLength = (U16)matchCode;
 
     seqStorePtr->sequences++;
 }
 
 
 /*-*************************************
 *  Match length counter
 ***************************************/
 static unsigned ZSTD_NbCommonBytes (register 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 };
+            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 };
+            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
     }   }
 }
 
 
 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);
 
     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()) if ((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 */
+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); }
 
 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);
     }
 }
 
 
 /*-*************************************
 *  Fast Scan
 ***************************************/
 static void ZSTD_fillHashTable (ZSTD_CCtx* zc, const void* end, const U32 mls)
 {
     U32* const hashTable = zc->hashTable;
     U32  const hBits = zc->params.cParams.hashLog;
     const BYTE* const base = zc->base;
     const BYTE* ip = base + zc->nextToUpdate;
     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
     const size_t fastHashFillStep = 3;
 
     while(ip <= iend) {
         hashTable[ZSTD_hashPtr(ip, hBits, mls)] = (U32)(ip - base);
         ip += fastHashFillStep;
     }
 }
 
 
 FORCE_INLINE
 void ZSTD_compressBlock_fast_generic(ZSTD_CCtx* cctx,
                                const void* src, size_t srcSize,
                                const U32 mls)
 {
     U32* const hashTable = cctx->hashTable;
     U32  const hBits = cctx->params.cParams.hashLog;
     seqStore_t* seqStorePtr = &(cctx->seqStore);
     const BYTE* const base = cctx->base;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32   lowestIndex = cctx->dictLimit;
     const BYTE* const lowest = base + lowestIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=cctx->rep[0], offset_2=cctx->rep[1];
     U32 offsetSaved = 0;
 
     /* init */
     ip += (ip==lowest);
     {   U32 const maxRep = (U32)(ip-lowest);
         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
     }
 
     /* Main Search Loop */
     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
         size_t mLength;
         size_t const h = ZSTD_hashPtr(ip, hBits, mls);
         U32 const current = (U32)(ip-base);
         U32 const matchIndex = hashTable[h];
         const BYTE* match = base + matchIndex;
         hashTable[h] = current;   /* update hash table */
 
         if ((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(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
         } else {
             U32 offset;
             if ( (matchIndex <= lowestIndex) || (MEM_read32(match) != MEM_read32(ip)) ) {
                 ip += ((ip-anchor) >> g_searchStrength) + 1;
                 continue;
             }
             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 */
             offset_2 = offset_1;
             offset_1 = offset;
 
             ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
         }
 
         /* match found */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Fill Table */
             hashTable[ZSTD_hashPtr(base+current+2, hBits, mls)] = current+2;  /* here because current+2 could be > iend-8 */
             hashTable[ZSTD_hashPtr(ip-2, hBits, 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, hBits, mls)] = (U32)(ip-base);
                 ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, rLength-MINMATCH);
                 ip += rLength;
                 anchor = ip;
                 continue;   /* faster when present ... (?) */
     }   }   }
 
     /* save reps for next block */
     cctx->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved;
     cctx->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 static void ZSTD_compressBlock_fast(ZSTD_CCtx* ctx,
                        const void* src, size_t srcSize)
 {
     const U32 mls = ctx->params.cParams.searchLength;
     switch(mls)
     {
-    default:
+    default: /* includes case 3 */
     case 4 :
         ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 4); return;
     case 5 :
         ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 5); return;
     case 6 :
         ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 6); return;
     case 7 :
         ZSTD_compressBlock_fast_generic(ctx, src, srcSize, 7); return;
     }
 }
 
 
 static void ZSTD_compressBlock_fast_extDict_generic(ZSTD_CCtx* ctx,
                                  const void* src, size_t srcSize,
                                  const U32 mls)
 {
     U32* hashTable = ctx->hashTable;
     const U32 hBits = ctx->params.cParams.hashLog;
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     const BYTE* const base = ctx->base;
     const BYTE* const dictBase = ctx->dictBase;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32   lowestIndex = ctx->lowLimit;
     const BYTE* const dictStart = dictBase + lowestIndex;
     const U32   dictLimit = ctx->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;
     U32 offset_1=ctx->rep[0], offset_2=ctx->rep[1];
 
     /* Search Loop */
     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
         const size_t h = ZSTD_hashPtr(ip, hBits, 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;
         size_t mLength;
         hashTable[h] = 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+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repMatchEnd, lowPrefixPtr) + EQUAL_READ32;
+            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, lowPrefixPtr) + 4;
             ip++;
             ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
         } else {
             if ( (matchIndex < lowestIndex) ||
                  (MEM_read32(match) != MEM_read32(ip)) ) {
                 ip += ((ip-anchor) >> g_searchStrength) + 1;
                 continue;
             }
             {   const BYTE* matchEnd = matchIndex < dictLimit ? dictEnd : iend;
                 const BYTE* lowMatchPtr = matchIndex < dictLimit ? dictStart : lowPrefixPtr;
                 U32 offset;
-                mLength = ZSTD_count_2segments(ip+EQUAL_READ32, match+EQUAL_READ32, iend, matchEnd, lowPrefixPtr) + EQUAL_READ32;
+                mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, lowPrefixPtr) + 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(seqStorePtr, 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, hBits, mls)] = current+2;
             hashTable[ZSTD_hashPtr(ip-2, hBits, 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 */
                    && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                     const BYTE* const repEnd2 = repIndex2 < dictLimit ? dictEnd : iend;
-                    size_t repLength2 = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch2+EQUAL_READ32, iend, repEnd2, lowPrefixPtr) + EQUAL_READ32;
+                    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 */
                     ZSTD_storeSeq(seqStorePtr, 0, anchor, 0, repLength2-MINMATCH);
                     hashTable[ZSTD_hashPtr(ip, hBits, mls)] = current2;
                     ip += repLength2;
                     anchor = ip;
                     continue;
                 }
                 break;
     }   }   }
 
     /* save reps for next block */
     ctx->repToConfirm[0] = offset_1; ctx->repToConfirm[1] = offset_2;
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 static void ZSTD_compressBlock_fast_extDict(ZSTD_CCtx* ctx,
                          const void* src, size_t srcSize)
 {
     U32 const mls = ctx->params.cParams.searchLength;
     switch(mls)
     {
-    default:
+    default: /* includes case 3 */
     case 4 :
         ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 4); return;
     case 5 :
         ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 5); return;
     case 6 :
         ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 6); return;
     case 7 :
         ZSTD_compressBlock_fast_extDict_generic(ctx, src, srcSize, 7); return;
     }
 }
 
 
 /*-*************************************
 *  Double Fast
 ***************************************/
 static void ZSTD_fillDoubleHashTable (ZSTD_CCtx* cctx, const void* end, const U32 mls)
 {
     U32* const hashLarge = cctx->hashTable;
     U32  const hBitsL = cctx->params.cParams.hashLog;
     U32* const hashSmall = cctx->chainTable;
     U32  const hBitsS = cctx->params.cParams.chainLog;
     const BYTE* const base = cctx->base;
     const BYTE* ip = base + cctx->nextToUpdate;
     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
     const size_t fastHashFillStep = 3;
 
     while(ip <= iend) {
         hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip - base);
         hashLarge[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip - base);
         ip += fastHashFillStep;
     }
 }
 
 
 FORCE_INLINE
 void ZSTD_compressBlock_doubleFast_generic(ZSTD_CCtx* cctx,
                                  const void* src, size_t srcSize,
                                  const U32 mls)
 {
     U32* const hashLong = cctx->hashTable;
     const U32 hBitsL = cctx->params.cParams.hashLog;
     U32* const hashSmall = cctx->chainTable;
     const U32 hBitsS = cctx->params.cParams.chainLog;
     seqStore_t* seqStorePtr = &(cctx->seqStore);
     const BYTE* const base = cctx->base;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32 lowestIndex = cctx->dictLimit;
     const BYTE* const lowest = base + lowestIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=cctx->rep[0], offset_2=cctx->rep[1];
     U32 offsetSaved = 0;
 
     /* init */
     ip += (ip==lowest);
     {   U32 const maxRep = (U32)(ip-lowest);
         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
     }
 
     /* Main Search Loop */
     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
         size_t mLength;
         size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
         size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
         U32 const current = (U32)(ip-base);
         U32 const matchIndexL = hashLong[h2];
         U32 const matchIndexS = hashSmall[h];
         const BYTE* matchLong = base + matchIndexL;
         const BYTE* match = base + matchIndexS;
         hashLong[h2] = hashSmall[h] = current;   /* update hash tables */
 
-        if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) { /* note : by construction, offset_1 <= current */
+        assert(offset_1 <= current);   /* supposed guaranteed by construction */
+        if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
+            /* favor repcode */
             mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
             ip++;
             ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, 0, mLength-MINMATCH);
         } else {
             U32 offset;
             if ( (matchIndexL > lowestIndex) && (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 h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
-                U32 const matchIndex3 = hashLong[h3];
-                const BYTE* match3 = base + matchIndex3;
-                hashLong[h3] = current + 1;
-                if ( (matchIndex3 > lowestIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
-                    mLength = ZSTD_count(ip+9, match3+8, iend) + 8;
+                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)) ) {
+                    mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
                     ip++;
-                    offset = (U32)(ip-match3);
-                    while (((ip>anchor) & (match3>lowest)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
+                    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 */
                 }
             } else {
                 ip += ((ip-anchor) >> g_searchStrength) + 1;
                 continue;
             }
 
             offset_2 = offset_1;
             offset_1 = offset;
 
             ZSTD_storeSeq(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
         }
 
         /* 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(seqStorePtr, 0, anchor, 0, rLength-MINMATCH);
                 ip += rLength;
                 anchor = ip;
                 continue;   /* faster when present ... (?) */
     }   }   }
 
     /* save reps for next block */
     cctx->repToConfirm[0] = offset_1 ? offset_1 : offsetSaved;
     cctx->repToConfirm[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 static void ZSTD_compressBlock_doubleFast(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     const U32 mls = ctx->params.cParams.searchLength;
     switch(mls)
     {
-    default:
+    default: /* includes case 3 */
     case 4 :
         ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 4); return;
     case 5 :
         ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 5); return;
     case 6 :
         ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 6); return;
     case 7 :
         ZSTD_compressBlock_doubleFast_generic(ctx, src, srcSize, 7); return;
     }
 }
 
 
 static void ZSTD_compressBlock_doubleFast_extDict_generic(ZSTD_CCtx* ctx,
                                  const void* src, size_t srcSize,
                                  const U32 mls)
 {
     U32* const hashLong = ctx->hashTable;
     U32  const hBitsL = ctx->params.cParams.hashLog;
     U32* const hashSmall = ctx->chainTable;
     U32  const hBitsS = ctx->params.cParams.chainLog;
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     const BYTE* const base = ctx->base;
     const BYTE* const dictBase = ctx->dictBase;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32   lowestIndex = ctx->lowLimit;
     const BYTE* const dictStart = dictBase + lowestIndex;
     const U32   dictLimit = ctx->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;
     U32 offset_1=ctx->rep[0], offset_2=ctx->rep[1];
 
     /* 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* 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* 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;
         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;
             ip++;
             ZSTD_storeSeq(seqStorePtr, 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;
                 U32 offset;
                 mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, lowPrefixPtr) + 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(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
             } else if ((matchIndex > lowestIndex) && (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* 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;
                     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;
                     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(seqStorePtr, ip-anchor, anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
             } else {
                 ip += ((ip-anchor) >> g_searchStrength) + 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(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+EQUAL_READ32, repMatch2+EQUAL_READ32, iend, repEnd2, lowPrefixPtr) + EQUAL_READ32;
+                    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 */
                     ZSTD_storeSeq(seqStorePtr, 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 */
     ctx->repToConfirm[0] = offset_1; ctx->repToConfirm[1] = offset_2;
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 static void ZSTD_compressBlock_doubleFast_extDict(ZSTD_CCtx* ctx,
                          const void* src, size_t srcSize)
 {
     U32 const mls = ctx->params.cParams.searchLength;
     switch(mls)
     {
-    default:
+    default: /* includes case 3 */
     case 4 :
         ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 4); return;
     case 5 :
         ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 5); return;
     case 6 :
         ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 6); return;
     case 7 :
         ZSTD_compressBlock_doubleFast_extDict_generic(ctx, src, srcSize, 7); return;
     }
 }
 
 
 /*-*************************************
 *  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_CCtx* zc, const BYTE* const ip, const U32 mls, const BYTE* const iend, U32 nbCompares,
                           U32 extDict)
 {
     U32*   const hashTable = zc->hashTable;
     U32    const hashLog = zc->params.cParams.hashLog;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32*   const bt = zc->chainTable;
     U32    const btLog  = zc->params.cParams.chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     U32 matchIndex = hashTable[h];
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const base = zc->base;
     const BYTE* const dictBase = zc->dictBase;
     const U32 dictLimit = zc->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 = zc->lowLimit;
     U32 matchEndIdx = current+8;
     size_t bestLength = 8;
 #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 */
 
     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 */
 
 #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)) {
             match = base + matchIndex;
             if (match[matchLength] == ip[matchLength])
                 matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
         } 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] */
+                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 the tree */
 
         if (match[matchLength] < ip[matchLength]) {  /* necessarily within correct 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 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 (bestLength > 384) return MIN(192, (U32)(bestLength - 384));   /* speed optimization */
     if (matchEndIdx > current + 8) return matchEndIdx - current - 8;
     return 1;
 }
 
 
 static size_t ZSTD_insertBtAndFindBestMatch (
                         ZSTD_CCtx* zc,
                         const BYTE* const ip, const BYTE* const iend,
                         size_t* offsetPtr,
                         U32 nbCompares, const U32 mls,
                         U32 extDict)
 {
     U32*   const hashTable = zc->hashTable;
     U32    const hashLog = zc->params.cParams.hashLog;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32*   const bt = zc->chainTable;
     U32    const btLog  = zc->params.cParams.chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     U32 matchIndex  = hashTable[h];
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const base = zc->base;
     const BYTE* const dictBase = zc->dictBase;
     const U32 dictLimit = zc->dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const U32 current = (U32)(ip-base);
     const U32 btLow = btMask >= current ? 0 : current - btMask;
     const U32 windowLow = zc->lowLimit;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = bt + 2*(current&btMask) + 1;
     U32 matchEndIdx = current+8;
     U32 dummy32;   /* to be nullified at the end */
     size_t bestLength = 0;
 
     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)) {
             match = base + matchIndex;
             if (match[matchLength] == ip[matchLength])
                 matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iend) +1;
         } 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] */
+                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 */
                 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;
 
     zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
     return bestLength;
 }
 
 
 static void ZSTD_updateTree(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
 {
     const BYTE* const base = zc->base;
     const U32 target = (U32)(ip - base);
     U32 idx = zc->nextToUpdate;
 
     while(idx < target)
         idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares, 0);
 }
 
 /** ZSTD_BtFindBestMatch() : Tree updater, providing best match */
 static size_t ZSTD_BtFindBestMatch (
                         ZSTD_CCtx* zc,
                         const BYTE* const ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 mls)
 {
     if (ip < zc->base + zc->nextToUpdate) return 0;   /* skipped area */
     ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
     return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls, 0);
 }
 
 
 static size_t ZSTD_BtFindBestMatch_selectMLS (
                         ZSTD_CCtx* zc,   /* Index table will be updated */
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 matchLengthSearch)
 {
     switch(matchLengthSearch)
     {
-    default :
+    default : /* includes case 3 */
     case 4 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
     case 5 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
+    case 7 :
     case 6 : return ZSTD_BtFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
     }
 }
 
 
 static void ZSTD_updateTree_extDict(ZSTD_CCtx* zc, const BYTE* const ip, const BYTE* const iend, const U32 nbCompares, const U32 mls)
 {
     const BYTE* const base = zc->base;
     const U32 target = (U32)(ip - base);
     U32 idx = zc->nextToUpdate;
 
     while (idx < target) idx += ZSTD_insertBt1(zc, base+idx, mls, iend, nbCompares, 1);
 }
 
 
 /** Tree updater, providing best match */
 static size_t ZSTD_BtFindBestMatch_extDict (
                         ZSTD_CCtx* zc,
                         const BYTE* const ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 mls)
 {
     if (ip < zc->base + zc->nextToUpdate) return 0;   /* skipped area */
     ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
     return ZSTD_insertBtAndFindBestMatch(zc, ip, iLimit, offsetPtr, maxNbAttempts, mls, 1);
 }
 
 
 static size_t ZSTD_BtFindBestMatch_selectMLS_extDict (
                         ZSTD_CCtx* zc,   /* Index table will be updated */
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 matchLengthSearch)
 {
     switch(matchLengthSearch)
     {
-    default :
+    default : /* includes case 3 */
     case 4 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4);
     case 5 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5);
+    case 7 :
     case 6 : return ZSTD_BtFindBestMatch_extDict(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6);
     }
 }
 
 
 
 /* *********************************
 *  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) */
 FORCE_INLINE
 U32 ZSTD_insertAndFindFirstIndex (ZSTD_CCtx* zc, const BYTE* ip, U32 mls)
 {
     U32* const hashTable  = zc->hashTable;
     const U32 hashLog = zc->params.cParams.hashLog;
     U32* const chainTable = zc->chainTable;
     const U32 chainMask = (1 << zc->params.cParams.chainLog) - 1;
     const BYTE* const base = zc->base;
     const U32 target = (U32)(ip - base);
     U32 idx = zc->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++;
     }
 
     zc->nextToUpdate = target;
     return hashTable[ZSTD_hashPtr(ip, hashLog, mls)];
 }
 
 
 
 FORCE_INLINE /* inlining is important to hardwire a hot branch (template emulation) */
 size_t ZSTD_HcFindBestMatch_generic (
                         ZSTD_CCtx* zc,   /* Index table will be updated */
                         const BYTE* const ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 mls, const U32 extDict)
 {
     U32* const chainTable = zc->chainTable;
     const U32 chainSize = (1 << zc->params.cParams.chainLog);
     const U32 chainMask = chainSize-1;
     const BYTE* const base = zc->base;
     const BYTE* const dictBase = zc->dictBase;
     const U32 dictLimit = zc->dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const U32 lowLimit = zc->lowLimit;
     const U32 current = (U32)(ip-base);
     const U32 minChain = current > chainSize ? current - chainSize : 0;
     int nbAttempts=maxNbAttempts;
-    size_t ml=EQUAL_READ32-1;
+    size_t ml=4-1;
 
     /* HC4 match finder */
     U32 matchIndex = ZSTD_insertAndFindFirstIndex (zc, ip, mls);
 
     for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
         const BYTE* match;
         size_t currentMl=0;
         if ((!extDict) || matchIndex >= dictLimit) {
             match = base + matchIndex;
             if (match[ml] == ip[ml])   /* potentially better */
                 currentMl = ZSTD_count(ip, match, iLimit);
         } else {
             match = dictBase + matchIndex;
             if (MEM_read32(match) == MEM_read32(ip))   /* assumption : matchIndex <= dictLimit-4 (by table construction) */
-                currentMl = ZSTD_count_2segments(ip+EQUAL_READ32, match+EQUAL_READ32, iLimit, dictEnd, prefixStart) + EQUAL_READ32;
+                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, and avoid read overflow*/ }
+        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);
     }
 
     return ml;
 }
 
 
 FORCE_INLINE size_t ZSTD_HcFindBestMatch_selectMLS (
                         ZSTD_CCtx* zc,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 matchLengthSearch)
 {
     switch(matchLengthSearch)
     {
-    default :
+    default : /* includes case 3 */
     case 4 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4, 0);
     case 5 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5, 0);
+    case 7 :
     case 6 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6, 0);
     }
 }
 
 
 FORCE_INLINE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
                         ZSTD_CCtx* zc,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 maxNbAttempts, const U32 matchLengthSearch)
 {
     switch(matchLengthSearch)
     {
-    default :
+    default : /* includes case 3 */
     case 4 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 4, 1);
     case 5 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 5, 1);
+    case 7 :
     case 6 : return ZSTD_HcFindBestMatch_generic(zc, ip, iLimit, offsetPtr, maxNbAttempts, 6, 1);
     }
 }
 
 
 /* *******************************
 *  Common parser - lazy strategy
 *********************************/
 FORCE_INLINE
 void ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
                                      const void* src, size_t srcSize,
                                      const U32 searchMethod, const U32 depth)
 {
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     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 = ctx->base + ctx->dictLimit;
 
     U32 const maxSearches = 1 << ctx->params.cParams.searchLog;
     U32 const mls = ctx->params.cParams.searchLength;
 
     typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
                         size_t* offsetPtr,
                         U32 maxNbAttempts, U32 matchLengthSearch);
     searchMax_f const searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS;
     U32 offset_1 = ctx->rep[0], offset_2 = ctx->rep[1], savedOffset=0;
 
     /* init */
     ip += (ip==base);
     ctx->nextToUpdate3 = ctx->nextToUpdate;
     {   U32 const maxRep = (U32)(ip-base);
         if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
     }
 
     /* 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 */
-            matchLength = ZSTD_count(ip+1+EQUAL_READ32, ip+1+EQUAL_READ32-offset_1, iend) + EQUAL_READ32;
+            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(ctx, ip, iend, &offsetFound, maxSearches, mls);
             if (ml2 > matchLength)
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
-        if (matchLength < EQUAL_READ32) {
+        if (matchLength < 4) {
             ip += ((ip-anchor) >> g_searchStrength) + 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)))) {
-                size_t const mlRep = ZSTD_count(ip+EQUAL_READ32, ip+EQUAL_READ32-offset_1, iend) + EQUAL_READ32;
+                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 >= EQUAL_READ32) && (gain2 > gain1))
+                if ((mlRep >= 4) && (gain2 > gain1))
                     matchLength = mlRep, offset = 0, start = ip;
             }
             {   size_t offset2=99999999;
                 size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
                 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 >= EQUAL_READ32) && (gain2 > gain1)) {
+                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+EQUAL_READ32, ip+EQUAL_READ32-offset_1, iend) + EQUAL_READ32;
+                    size_t const ml2 = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
                     int const gain2 = (int)(ml2 * 4);
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
-                    if ((ml2 >= EQUAL_READ32) && (gain2 > gain1))
+                    if ((ml2 >= 4) && (gain2 > gain1))
                         matchLength = ml2, offset = 0, start = ip;
                 }
                 {   size_t offset2=99999999;
                     size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
                     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 >= EQUAL_READ32) && (gain2 > gain1)) {
+                    if ((ml2 >= 4) && (gain2 > gain1)) {
                         matchLength = ml2, offset = offset2, start = ip;
                         continue;
             }   }   }
             break;  /* nothing found : store previous solution */
         }
 
         /* catch up */
         if (offset) {
-            while ((start>anchor) && (start>base+offset-ZSTD_REP_MOVE) && (start[-1] == start[-1-offset+ZSTD_REP_MOVE]))   /* only search for offset within prefix */
+            while ( (start > anchor)
+                 && (start > base+offset-ZSTD_REP_MOVE)
+                 && (start[-1] == start[-1-offset+ZSTD_REP_MOVE]) )  /* only search for offset within prefix */
                 { start--; matchLength++; }
             offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
         }
 
         /* store sequence */
 _storeSequence:
         {   size_t const litLength = start - anchor;
             ZSTD_storeSeq(seqStorePtr, 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+EQUAL_READ32, ip+EQUAL_READ32-offset_2, iend) + EQUAL_READ32;
+            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(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
             ip += matchLength;
             anchor = ip;
             continue;   /* faster when present ... (?) */
     }   }
 
     /* Save reps for next block */
     ctx->repToConfirm[0] = offset_1 ? offset_1 : savedOffset;
     ctx->repToConfirm[1] = offset_2 ? offset_2 : savedOffset;
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 static void ZSTD_compressBlock_btlazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 1, 2);
 }
 
 static void ZSTD_compressBlock_lazy2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 2);
 }
 
 static void ZSTD_compressBlock_lazy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 1);
 }
 
 static void ZSTD_compressBlock_greedy(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_generic(ctx, src, srcSize, 0, 0);
 }
 
 
 FORCE_INLINE
 void ZSTD_compressBlock_lazy_extDict_generic(ZSTD_CCtx* ctx,
                                      const void* src, size_t srcSize,
                                      const U32 searchMethod, const U32 depth)
 {
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     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 = ctx->base;
     const U32 dictLimit = ctx->dictLimit;
     const U32 lowestIndex = ctx->lowLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictBase = ctx->dictBase;
     const BYTE* const dictEnd  = dictBase + dictLimit;
     const BYTE* const dictStart  = dictBase + ctx->lowLimit;
 
     const U32 maxSearches = 1 << ctx->params.cParams.searchLog;
     const U32 mls = ctx->params.cParams.searchLength;
 
     typedef size_t (*searchMax_f)(ZSTD_CCtx* zc, const BYTE* ip, const BYTE* iLimit,
                         size_t* offsetPtr,
                         U32 maxNbAttempts, U32 matchLengthSearch);
     searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_selectMLS_extDict : ZSTD_HcFindBestMatch_extDict_selectMLS;
 
     U32 offset_1 = ctx->rep[0], offset_2 = ctx->rep[1];
 
     /* init */
     ctx->nextToUpdate3 = ctx->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+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
+                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(ctx, ip, iend, &offsetFound, maxSearches, mls);
             if (ml2 > matchLength)
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
-         if (matchLength < EQUAL_READ32) {
+         if (matchLength < 4) {
             ip += ((ip-anchor) >> g_searchStrength) + 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+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
+                    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 >= EQUAL_READ32) && (gain2 > gain1))
+                    if ((repLength >= 4) && (gain2 > gain1))
                         matchLength = repLength, offset = 0, start = ip;
             }   }
 
             /* search match, depth 1 */
             {   size_t offset2=99999999;
                 size_t const ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
                 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 >= EQUAL_READ32) && (gain2 > gain1)) {
+                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 repLength = ZSTD_count_2segments(ip+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
-                        int gain2 = (int)(repLength * 4);
-                        int gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
-                        if ((repLength >= EQUAL_READ32) && (gain2 > gain1))
+                        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(ctx, ip, iend, &offset2, maxSearches, mls);
                     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 >= EQUAL_READ32) && (gain2 > gain1)) {
+                    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(seqStorePtr, 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+EQUAL_READ32, repMatch+EQUAL_READ32, iend, repEnd, prefixStart) + EQUAL_READ32;
+                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(seqStorePtr, 0, anchor, 0, matchLength-MINMATCH);
                 ip += matchLength;
                 anchor = ip;
                 continue;   /* faster when present ... (?) */
             }
             break;
     }   }
 
     /* Save reps for next block */
     ctx->repToConfirm[0] = offset_1; ctx->repToConfirm[1] = offset_2;
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 void ZSTD_compressBlock_greedy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 0);
 }
 
 static void ZSTD_compressBlock_lazy_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 1);
 }
 
 static void ZSTD_compressBlock_lazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 0, 2);
 }
 
 static void ZSTD_compressBlock_btlazy2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
     ZSTD_compressBlock_lazy_extDict_generic(ctx, src, srcSize, 1, 2);
 }
 
 
 /* The optimal parser */
 #include "zstd_opt.h"
 
 static void ZSTD_compressBlock_btopt(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
 #ifdef ZSTD_OPT_H_91842398743
     ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 0);
 #else
     (void)ctx; (void)src; (void)srcSize;
     return;
 #endif
 }
 
 static void ZSTD_compressBlock_btopt2(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
 #ifdef ZSTD_OPT_H_91842398743
     ZSTD_compressBlock_opt_generic(ctx, src, srcSize, 1);
 #else
     (void)ctx; (void)src; (void)srcSize;
     return;
 #endif
 }
 
 static void ZSTD_compressBlock_btopt_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
 #ifdef ZSTD_OPT_H_91842398743
     ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 0);
 #else
     (void)ctx; (void)src; (void)srcSize;
     return;
 #endif
 }
 
 static void ZSTD_compressBlock_btopt2_extDict(ZSTD_CCtx* ctx, const void* src, size_t srcSize)
 {
 #ifdef ZSTD_OPT_H_91842398743
     ZSTD_compressBlock_opt_extDict_generic(ctx, src, srcSize, 1);
 #else
     (void)ctx; (void)src; (void)srcSize;
     return;
 #endif
 }
 
 
 typedef void (*ZSTD_blockCompressor) (ZSTD_CCtx* ctx, const void* src, size_t srcSize);
 
 static ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, int extDict)
 {
     static const ZSTD_blockCompressor blockCompressor[2][8] = {
-        { ZSTD_compressBlock_fast, ZSTD_compressBlock_doubleFast, ZSTD_compressBlock_greedy, ZSTD_compressBlock_lazy, ZSTD_compressBlock_lazy2, ZSTD_compressBlock_btlazy2, ZSTD_compressBlock_btopt, ZSTD_compressBlock_btopt2 },
-        { 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_btopt2_extDict }
+        { ZSTD_compressBlock_fast, ZSTD_compressBlock_doubleFast, ZSTD_compressBlock_greedy,
+          ZSTD_compressBlock_lazy, ZSTD_compressBlock_lazy2, ZSTD_compressBlock_btlazy2,
+          ZSTD_compressBlock_btopt, ZSTD_compressBlock_btopt2 },
+        { 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_btopt2_extDict }
     };
 
     return blockCompressor[extDict][(U32)strat];
 }
 
 
 static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->params.cParams.strategy, zc->lowLimit < zc->dictLimit);
     const BYTE* const base = zc->base;
     const BYTE* const istart = (const BYTE*)src;
     const U32 current = (U32)(istart-base);
     if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) return 0;   /* don't even attempt compression below a certain srcSize */
     ZSTD_resetSeqStore(&(zc->seqStore));
     if (current > zc->nextToUpdate + 384)
-        zc->nextToUpdate = current - MIN(192, (U32)(current - zc->nextToUpdate - 384));   /* update tree not updated after finding very long rep matches */
+        zc->nextToUpdate = current - MIN(192, (U32)(current - zc->nextToUpdate - 384));   /* limited update after finding a very long match */
     blockCompressor(zc, src, srcSize);
     return ZSTD_compressSequences(zc, dst, dstCapacity, srcSize);
 }
 
 
 /*! ZSTD_compress_generic() :
 *   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_generic (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 = 1 << cctx->params.cParams.windowLog;
 
     if (cctx->params.fParams.checksumFlag && srcSize)
         XXH64_update(&cctx->xxhState, src, srcSize);
 
     while (remaining) {
         U32 const lastBlock = lastFrameChunk & (blockSize >= remaining);
         size_t cSize;
 
-        if (dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE) return ERROR(dstSize_tooSmall);   /* not enough space to store compressed block */
+        if (dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE)
+            return ERROR(dstSize_tooSmall);   /* not enough space to store compressed block */
         if (remaining < blockSize) blockSize = remaining;
 
         /* preemptive overflow correction */
         if (cctx->lowLimit > (3U<<29)) {
             U32 const cycleMask = (1 << ZSTD_cycleLog(cctx->params.cParams.hashLog, cctx->params.cParams.strategy)) - 1;
             U32 const current = (U32)(ip - cctx->base);
             U32 const newCurrent = (current & cycleMask) + (1 << cctx->params.cParams.windowLog);
             U32 const correction = current - newCurrent;
             ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_64 <= 30);
             ZSTD_reduceIndex(cctx, correction);
             cctx->base += correction;
             cctx->dictBase += correction;
             cctx->lowLimit -= correction;
             cctx->dictLimit -= correction;
             if (cctx->nextToUpdate < correction) cctx->nextToUpdate = 0;
             else cctx->nextToUpdate -= correction;
         }
 
         if ((U32)(ip+blockSize - cctx->base) > cctx->loadedDictEnd + maxDist) {
             /* enforce maxDist */
             U32 const newLowLimit = (U32)(ip+blockSize - cctx->base) - maxDist;
             if (cctx->lowLimit < newLowLimit) cctx->lowLimit = newLowLimit;
             if (cctx->dictLimit < cctx->lowLimit) cctx->dictLimit = cctx->lowLimit;
         }
 
         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);   /* no pb, 4th byte will be overwritten */
             memcpy(op + ZSTD_blockHeaderSize, ip, blockSize);
             cSize = ZSTD_blockHeaderSize+blockSize;
         } else {
             U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
             MEM_writeLE24(op, cBlockHeader24);
             cSize += ZSTD_blockHeaderSize;
         }
 
         remaining -= blockSize;
         dstCapacity -= cSize;
         ip += blockSize;
         op += cSize;
     }
 
     if (lastFrameChunk && (op>ostart)) cctx->stage = ZSTDcs_ending;
     return op-ostart;
 }
 
 
 static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
                                     ZSTD_parameters params, U64 pledgedSrcSize, U32 dictID)
 {   BYTE* const op = (BYTE*)dst;
-    U32   const dictIDSizeCode = (dictID>0) + (dictID>=256) + (dictID>=65536);   /* 0-3 */
+    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 = 1U << 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) :   /* 0-3 */
                       0;
     BYTE  const frameHeaderDecriptionByte = (BYTE)(dictIDSizeCode + (checksumFlag<<2) + (singleSegment<<5) + (fcsCode<<6) );
     size_t pos;
 
     if (dstCapacity < ZSTD_frameHeaderSize_max) return ERROR(dstSize_tooSmall);
+    DEBUGLOG(5, "ZSTD_writeFrameHeader : dictIDFlag : %u \n", !params.fParams.noDictIDFlag);
+    DEBUGLOG(5, "ZSTD_writeFrameHeader : dictID : %u \n", dictID);
+    DEBUGLOG(5, "ZSTD_writeFrameHeader : dictIDSizeCode : %u \n", dictIDSizeCode);
 
     MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
     op[4] = frameHeaderDecriptionByte; pos=5;
     if (!singleSegment) op[pos++] = windowLogByte;
     switch(dictIDSizeCode)
     {
         default:   /* 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:   /* 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;
 }
 
 
 static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize,
                                U32 frame, U32 lastFrameChunk)
 {
     const BYTE* const ip = (const BYTE*) src;
     size_t fhSize = 0;
 
     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->params, cctx->frameContentSize, cctx->dictID);
         if (ZSTD_isError(fhSize)) return fhSize;
         dstCapacity -= fhSize;
         dst = (char*)dst + fhSize;
         cctx->stage = ZSTDcs_ongoing;
     }
 
     /* Check if blocks follow each other */
     if (src != cctx->nextSrc) {
         /* not contiguous */
         ptrdiff_t const delta = cctx->nextSrc - ip;
         cctx->lowLimit = cctx->dictLimit;
         cctx->dictLimit = (U32)(cctx->nextSrc - cctx->base);
         cctx->dictBase = cctx->base;
         cctx->base -= delta;
         cctx->nextToUpdate = cctx->dictLimit;
         if (cctx->dictLimit - cctx->lowLimit < HASH_READ_SIZE) cctx->lowLimit = cctx->dictLimit;   /* too small extDict */
     }
 
     /* if input and dictionary overlap : reduce dictionary (area presumed modified by input) */
     if ((ip+srcSize > cctx->dictBase + cctx->lowLimit) & (ip < cctx->dictBase + cctx->dictLimit)) {
         ptrdiff_t const highInputIdx = (ip + srcSize) - cctx->dictBase;
         U32 const lowLimitMax = (highInputIdx > (ptrdiff_t)cctx->dictLimit) ? cctx->dictLimit : (U32)highInputIdx;
         cctx->lowLimit = lowLimitMax;
     }
 
     cctx->nextSrc = ip + srcSize;
 
     if (srcSize) {
         size_t const cSize = frame ?
                              ZSTD_compress_generic (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
                              ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize);
         if (ZSTD_isError(cSize)) return cSize;
+        cctx->consumedSrcSize += srcSize;
         return cSize + fhSize;
     } else
         return fhSize;
 }
 
 
 size_t ZSTD_compressContinue (ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize)
 {
-    return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1, 0);
+    return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1 /* frame mode */, 0 /* last chunk */);
 }
 
 
 size_t ZSTD_getBlockSizeMax(ZSTD_CCtx* cctx)
 {
     return MIN (ZSTD_BLOCKSIZE_ABSOLUTEMAX, 1 << cctx->params.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_getBlockSizeMax(cctx);
     if (srcSize > blockSizeMax) return ERROR(srcSize_wrong);
-    return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0, 0);
+    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_CCtx* zc, const void* src, size_t srcSize)
 {
     const BYTE* const ip = (const BYTE*) src;
     const BYTE* const iend = ip + srcSize;
 
     /* input becomes current prefix */
     zc->lowLimit = zc->dictLimit;
     zc->dictLimit = (U32)(zc->nextSrc - zc->base);
     zc->dictBase = zc->base;
     zc->base += ip - zc->nextSrc;
     zc->nextToUpdate = zc->dictLimit;
     zc->loadedDictEnd = zc->forceWindow ? 0 : (U32)(iend - zc->base);
 
     zc->nextSrc = iend;
     if (srcSize <= HASH_READ_SIZE) return 0;
 
     switch(zc->params.cParams.strategy)
     {
     case ZSTD_fast:
         ZSTD_fillHashTable (zc, iend, zc->params.cParams.searchLength);
         break;
 
     case ZSTD_dfast:
         ZSTD_fillDoubleHashTable (zc, iend, zc->params.cParams.searchLength);
         break;
 
     case ZSTD_greedy:
     case ZSTD_lazy:
     case ZSTD_lazy2:
-        ZSTD_insertAndFindFirstIndex (zc, iend-HASH_READ_SIZE, zc->params.cParams.searchLength);
+        if (srcSize >= HASH_READ_SIZE)
+            ZSTD_insertAndFindFirstIndex(zc, iend-HASH_READ_SIZE, zc->params.cParams.searchLength);
         break;
 
     case ZSTD_btlazy2:
     case ZSTD_btopt:
     case ZSTD_btopt2:
-        ZSTD_updateTree(zc, iend-HASH_READ_SIZE, iend, 1 << zc->params.cParams.searchLog, zc->params.cParams.searchLength);
+        if (srcSize >= HASH_READ_SIZE)
+            ZSTD_updateTree(zc, iend-HASH_READ_SIZE, iend, 1 << zc->params.cParams.searchLog, zc->params.cParams.searchLength);
         break;
 
     default:
         return ERROR(GENERIC);   /* strategy doesn't exist; impossible */
     }
 
     zc->nextToUpdate = (U32)(iend - zc->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 :
-    Magic == ZSTD_DICT_MAGIC (4 bytes)
-    HUF_writeCTable(256)
-    FSE_writeNCount(off)
-    FSE_writeNCount(ml)
-    FSE_writeNCount(ll)
-    RepOffsets
-    Dictionary content
-*/
-/*! ZSTD_loadDictEntropyStats() :
-    @return : size read from dictionary
-    note : magic number supposed already checked */
-static size_t ZSTD_loadDictEntropyStats(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
+ * See :
+ * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
+ */
+/*! ZSTD_loadZstdDictionary() :
+ * @return : 0, or an error code
+ *  assumptions : magic number supposed already checked
+ *                dictSize supposed > 8
+ */
+static size_t ZSTD_loadZstdDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
     short offcodeNCount[MaxOff+1];
     unsigned offcodeMaxValue = MaxOff;
     BYTE scratchBuffer[1<hufTable, 255, dict, dictSize);
+    dictPtr += 4;   /* skip magic number */
+    cctx->dictID = cctx->params.fParams.noDictIDFlag ? 0 :  MEM_readLE32(dictPtr);
+    dictPtr += 4;
+
+    {   size_t const hufHeaderSize = HUF_readCTable(cctx->hufCTable, 255, dictPtr, dictEnd-dictPtr);
         if (HUF_isError(hufHeaderSize)) 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(cctx->offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog, scratchBuffer, sizeof(scratchBuffer)), dictionary_corrupted);
+        CHECK_E( FSE_buildCTable_wksp(cctx->offcodeCTable, offcodeNCount, offcodeMaxValue, offcodeLog, scratchBuffer, sizeof(scratchBuffer)),
+                 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(cctx->matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, scratchBuffer, sizeof(scratchBuffer)), dictionary_corrupted);
+        CHECK_F( ZSTD_checkDictNCount(matchlengthNCount, matchlengthMaxValue, MaxML));
+        CHECK_E( FSE_buildCTable_wksp(cctx->matchlengthCTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog, scratchBuffer, sizeof(scratchBuffer)),
+                 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(cctx->litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, scratchBuffer, sizeof(scratchBuffer)), dictionary_corrupted);
+        CHECK_F( ZSTD_checkDictNCount(litlengthNCount, litlengthMaxValue, MaxLL));
+        CHECK_E( FSE_buildCTable_wksp(cctx->litlengthCTable, litlengthNCount, litlengthMaxValue, litlengthLog, scratchBuffer, sizeof(scratchBuffer)),
+                 dictionary_corrupted);
         dictPtr += litlengthHeaderSize;
     }
 
     if (dictPtr+12 > dictEnd) return ERROR(dictionary_corrupted);
-    cctx->rep[0] = MEM_readLE32(dictPtr+0); if (cctx->rep[0] == 0 || cctx->rep[0] >= dictSize) return ERROR(dictionary_corrupted);
-    cctx->rep[1] = MEM_readLE32(dictPtr+4); if (cctx->rep[1] == 0 || cctx->rep[1] >= dictSize) return ERROR(dictionary_corrupted);
-    cctx->rep[2] = MEM_readLE32(dictPtr+8); if (cctx->rep[2] == 0 || cctx->rep[2] >= dictSize) return ERROR(dictionary_corrupted);
+    cctx->rep[0] = MEM_readLE32(dictPtr+0);
+    cctx->rep[1] = MEM_readLE32(dictPtr+4);
+    cctx->rep[2] = MEM_readLE32(dictPtr+8);
     dictPtr += 12;
 
-    {   U32 offcodeMax = MaxOff;
-        if ((size_t)(dictEnd - dictPtr) <= ((U32)-1) - 128 KB) {
-            U32 const maxOffset = (U32)(dictEnd - dictPtr) + 128 KB; /* The maximum offset that must be supported */
-            /* Calculate minimum offset code required to represent maxOffset */
-            offcodeMax = ZSTD_highbit32(maxOffset);
+    {   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 */
         }
-        /* Every possible supported offset <= dictContentSize + 128 KB must be representable */
+        /* 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 (cctx->rep[u] == 0) return ERROR(dictionary_corrupted);
+                if (cctx->rep[u] > dictContentSize) return ERROR(dictionary_corrupted);
+        }   }
 
-    cctx->flagStaticTables = 1;
-    cctx->flagStaticHufTable = HUF_repeat_valid;
-    return dictPtr - (const BYTE*)dict;
+        cctx->fseCTables_ready = 1;
+        cctx->hufCTable_repeatMode = HUF_repeat_valid;
+        return ZSTD_loadDictionaryContent(cctx, dictPtr, dictContentSize);
+    }
 }
 
 /** ZSTD_compress_insertDictionary() :
 *   @return : 0, or an error code */
-static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* zc, const void* dict, size_t dictSize)
+static size_t ZSTD_compress_insertDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
     if ((dict==NULL) || (dictSize<=8)) return 0;
 
     /* dict as pure content */
-    if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (zc->forceRawDict))
-        return ZSTD_loadDictionaryContent(zc, dict, dictSize);
-    zc->dictID = zc->params.fParams.noDictIDFlag ? 0 :  MEM_readLE32((const char*)dict+4);
+    if ((MEM_readLE32(dict) != ZSTD_DICT_MAGIC) || (cctx->forceRawDict))
+        return ZSTD_loadDictionaryContent(cctx, dict, dictSize);
 
-    /* known magic number : dict is parsed for entropy stats and content */
-    {   size_t const loadError = ZSTD_loadDictEntropyStats(zc, (const char*)dict+8 /* skip dictHeader */, dictSize-8);
-        size_t const eSize = loadError + 8;
-        if (ZSTD_isError(loadError)) return loadError;
-        return ZSTD_loadDictionaryContent(zc, (const char*)dict+eSize, dictSize-eSize);
-    }
+    /* dict as zstd dictionary */
+    return ZSTD_loadZstdDictionary(cctx, dict, dictSize);
 }
 
 /*! ZSTD_compressBegin_internal() :
 *   @return : 0, or an error code */
 static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
                              const void* dict, size_t dictSize,
                                    ZSTD_parameters params, U64 pledgedSrcSize)
 {
     ZSTD_compResetPolicy_e const crp = dictSize ? ZSTDcrp_fullReset : ZSTDcrp_continue;
-    CHECK_F(ZSTD_resetCCtx_advanced(cctx, params, pledgedSrcSize, crp));
+    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
+    CHECK_F(ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize, crp));
     return ZSTD_compress_insertDictionary(cctx, dict, dictSize);
 }
 
 
 /*! 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)
 {
     /* compression parameters verification and optimization */
     CHECK_F(ZSTD_checkCParams(params.cParams));
     return ZSTD_compressBegin_internal(cctx, dict, dictSize, params, pledgedSrcSize);
 }
 
 
 size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, dictSize);
     return ZSTD_compressBegin_internal(cctx, dict, dictSize, params, 0);
 }
 
 
 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;
 
     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->params, 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->params.fParams.checksumFlag) {
         U32 const checksum = (U32) XXH64_digest(&cctx->xxhState);
         if (dstCapacity<4) return ERROR(dstSize_tooSmall);
         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, 1);
+    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->params.fParams.contentSizeFlag) {  /* control src size */
+        if (cctx->frameContentSize != 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)
 {
     CHECK_F(ZSTD_compressBegin_internal(cctx, dict, dictSize, params, srcSize));
     return ZSTD_compressEnd(cctx, dst,  dstCapacity, src, srcSize);
 }
 
 size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const void* dict,size_t dictSize,
                                ZSTD_parameters params)
 {
     CHECK_F(ZSTD_checkCParams(params.cParams));
     return ZSTD_compress_internal(ctx, dst, dstCapacity, src, srcSize, dict, dictSize, params);
 }
 
-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)
+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)
 {
     ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, dict ? dictSize : 0);
     params.fParams.contentSizeFlag = 1;
     return ZSTD_compress_internal(ctx, dst, dstCapacity, src, srcSize, dict, dictSize, params);
 }
 
 size_t ZSTD_compressCCtx (ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel)
 {
     return ZSTD_compress_usingDict(ctx, 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 result;
     ZSTD_CCtx ctxBody;
     memset(&ctxBody, 0, sizeof(ctxBody));
     memcpy(&ctxBody.customMem, &defaultCustomMem, sizeof(ZSTD_customMem));
     result = ZSTD_compressCCtx(&ctxBody, dst, dstCapacity, src, srcSize, compressionLevel);
     ZSTD_free(ctxBody.workSpace, defaultCustomMem);  /* can't free ctxBody itself, as it's on stack; free only heap content */
     return result;
 }
 
 
 /* =====  Dictionary API  ===== */
 
 struct ZSTD_CDict_s {
     void* dictBuffer;
     const void* dictContent;
     size_t dictContentSize;
     ZSTD_CCtx* refContext;
 };  /* typedef'd tp ZSTD_CDict within "zstd.h" */
 
 size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)
 {
     if (cdict==NULL) return 0;   /* support sizeof on NULL */
     return ZSTD_sizeof_CCtx(cdict->refContext) + (cdict->dictBuffer ? cdict->dictContentSize : 0) + sizeof(*cdict);
 }
 
+static ZSTD_parameters ZSTD_makeParams(ZSTD_compressionParameters cParams, ZSTD_frameParameters fParams)
+{
+    ZSTD_parameters params;
+    params.cParams = cParams;
+    params.fParams = fParams;
+    return params;
+}
+
 ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize, unsigned byReference,
-                                      ZSTD_parameters params, ZSTD_customMem customMem)
+                                      ZSTD_compressionParameters cParams, ZSTD_customMem customMem)
 {
     if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
     if (!customMem.customAlloc || !customMem.customFree) return NULL;
 
     {   ZSTD_CDict* const cdict = (ZSTD_CDict*) ZSTD_malloc(sizeof(ZSTD_CDict), customMem);
         ZSTD_CCtx* const cctx = ZSTD_createCCtx_advanced(customMem);
 
         if (!cdict || !cctx) {
             ZSTD_free(cdict, customMem);
             ZSTD_freeCCtx(cctx);
             return NULL;
         }
 
         if ((byReference) || (!dictBuffer) || (!dictSize)) {
             cdict->dictBuffer = NULL;
             cdict->dictContent = dictBuffer;
         } else {
             void* const internalBuffer = ZSTD_malloc(dictSize, customMem);
             if (!internalBuffer) { ZSTD_free(cctx, customMem); ZSTD_free(cdict, customMem); return NULL; }
             memcpy(internalBuffer, dictBuffer, dictSize);
             cdict->dictBuffer = internalBuffer;
             cdict->dictContent = internalBuffer;
         }
 
-        {   size_t const errorCode = ZSTD_compressBegin_advanced(cctx, cdict->dictContent, dictSize, params, 0);
+        {   ZSTD_frameParameters const fParams = { 0 /* contentSizeFlag */, 0 /* checksumFlag */, 0 /* noDictIDFlag */ };   /* dummy */
+            ZSTD_parameters const params = ZSTD_makeParams(cParams, fParams);
+            size_t const errorCode = ZSTD_compressBegin_advanced(cctx, cdict->dictContent, dictSize, params, 0);
             if (ZSTD_isError(errorCode)) {
                 ZSTD_free(cdict->dictBuffer, customMem);
                 ZSTD_free(cdict, customMem);
                 ZSTD_freeCCtx(cctx);
                 return NULL;
         }   }
 
         cdict->refContext = cctx;
         cdict->dictContentSize = dictSize;
         return cdict;
     }
 }
 
 ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_customMem const allocator = { NULL, NULL, NULL };
-    ZSTD_parameters params = ZSTD_getParams(compressionLevel, 0, dictSize);
-    params.fParams.contentSizeFlag = 1;
-    return ZSTD_createCDict_advanced(dict, dictSize, 0, params, allocator);
+    ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
+    return ZSTD_createCDict_advanced(dict, dictSize, 0, cParams, allocator);
 }
 
 ZSTD_CDict* ZSTD_createCDict_byReference(const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_customMem const allocator = { NULL, NULL, NULL };
-    ZSTD_parameters params = ZSTD_getParams(compressionLevel, 0, dictSize);
-    params.fParams.contentSizeFlag = 1;
-    return ZSTD_createCDict_advanced(dict, dictSize, 1, params, allocator);
+    ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
+    return ZSTD_createCDict_advanced(dict, dictSize, 1, cParams, allocator);
 }
 
 size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
 {
     if (cdict==NULL) return 0;   /* support free on NULL */
     {   ZSTD_customMem const cMem = cdict->refContext->customMem;
         ZSTD_freeCCtx(cdict->refContext);
         ZSTD_free(cdict->dictBuffer, cMem);
         ZSTD_free(cdict, cMem);
         return 0;
     }
 }
 
 static ZSTD_parameters ZSTD_getParamsFromCDict(const ZSTD_CDict* cdict) {
     return ZSTD_getParamsFromCCtx(cdict->refContext);
 }
 
-size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize)
+/* 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)
 {
-    if (cdict->dictContentSize) CHECK_F(ZSTD_copyCCtx(cctx, cdict->refContext, pledgedSrcSize))
+    if (cdict==NULL) return ERROR(GENERIC);  /* does not support NULL cdict */
+    DEBUGLOG(5, "ZSTD_compressBegin_usingCDict_advanced : dictIDFlag == %u \n", !fParams.noDictIDFlag);
+    if (cdict->dictContentSize)
+        CHECK_F( ZSTD_copyCCtx_internal(cctx, cdict->refContext, fParams, pledgedSrcSize) )
     else {
         ZSTD_parameters params = cdict->refContext->params;
-        params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
-        CHECK_F(ZSTD_compressBegin_advanced(cctx, NULL, 0, params, pledgedSrcSize));
+        params.fParams = fParams;
+        CHECK_F(ZSTD_compressBegin_internal(cctx, NULL, 0, params, pledgedSrcSize));
     }
     return 0;
 }
 
+/* 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(5, "ZSTD_compressBegin_usingCDict : dictIDFlag == %u \n", !fParams.noDictIDFlag);
+    return ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, 0);
+}
+
+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 level is decided during dictionary creation */
+ *  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)
 {
-    CHECK_F(ZSTD_compressBegin_usingCDict(cctx, cdict, srcSize));
-
-    if (cdict->refContext->params.fParams.contentSizeFlag==1) {
-        cctx->params.fParams.contentSizeFlag = 1;
-        cctx->frameContentSize = srcSize;
-    }
-
-    return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
+    ZSTD_frameParameters const fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
+    return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, fParams);
 }
 
 
 
 /* ******************************************************************
 *  Streaming
 ********************************************************************/
 
 typedef enum { zcss_init, zcss_load, zcss_flush, zcss_final } ZSTD_cStreamStage;
 
 struct ZSTD_CStream_s {
     ZSTD_CCtx* cctx;
     ZSTD_CDict* cdictLocal;
     const ZSTD_CDict* cdict;
     char*  inBuff;
     size_t inBuffSize;
     size_t inToCompress;
     size_t inBuffPos;
     size_t inBuffTarget;
     size_t blockSize;
     char*  outBuff;
     size_t outBuffSize;
     size_t outBuffContentSize;
     size_t outBuffFlushedSize;
     ZSTD_cStreamStage stage;
     U32    checksum;
     U32    frameEnded;
     U64    pledgedSrcSize;
-    U64    inputProcessed;
     ZSTD_parameters params;
     ZSTD_customMem customMem;
 };   /* typedef'd to ZSTD_CStream within "zstd.h" */
 
 ZSTD_CStream* ZSTD_createCStream(void)
 {
     return ZSTD_createCStream_advanced(defaultCustomMem);
 }
 
 ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
 {
     ZSTD_CStream* zcs;
 
     if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
     if (!customMem.customAlloc || !customMem.customFree) return NULL;
 
     zcs = (ZSTD_CStream*)ZSTD_malloc(sizeof(ZSTD_CStream), customMem);
     if (zcs==NULL) return NULL;
     memset(zcs, 0, sizeof(ZSTD_CStream));
     memcpy(&zcs->customMem, &customMem, sizeof(ZSTD_customMem));
     zcs->cctx = ZSTD_createCCtx_advanced(customMem);
     if (zcs->cctx == NULL) { ZSTD_freeCStream(zcs); return NULL; }
     return zcs;
 }
 
 size_t ZSTD_freeCStream(ZSTD_CStream* zcs)
 {
     if (zcs==NULL) return 0;   /* support free on NULL */
     {   ZSTD_customMem const cMem = zcs->customMem;
         ZSTD_freeCCtx(zcs->cctx);
+        zcs->cctx = NULL;
         ZSTD_freeCDict(zcs->cdictLocal);
+        zcs->cdictLocal = NULL;
         ZSTD_free(zcs->inBuff, cMem);
+        zcs->inBuff = NULL;
         ZSTD_free(zcs->outBuff, cMem);
+        zcs->outBuff = NULL;
         ZSTD_free(zcs, cMem);
         return 0;
     }
 }
 
 
 /*======   Initialization   ======*/
 
 size_t ZSTD_CStreamInSize(void)  { return ZSTD_BLOCKSIZE_ABSOLUTEMAX; }
-size_t ZSTD_CStreamOutSize(void) { return ZSTD_compressBound(ZSTD_BLOCKSIZE_ABSOLUTEMAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ; }
 
+size_t ZSTD_CStreamOutSize(void)
+{
+    return ZSTD_compressBound(ZSTD_BLOCKSIZE_ABSOLUTEMAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ;
+}
+
 static size_t ZSTD_resetCStream_internal(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
 {
     if (zcs->inBuffSize==0) return ERROR(stage_wrong);   /* zcs has not been init at least once => can't reset */
 
-    if (zcs->cdict) CHECK_F(ZSTD_compressBegin_usingCDict(zcs->cctx, zcs->cdict, pledgedSrcSize))
-    else CHECK_F(ZSTD_compressBegin_advanced(zcs->cctx, NULL, 0, zcs->params, pledgedSrcSize));
+    DEBUGLOG(5, "ZSTD_resetCStream_internal : dictIDFlag == %u \n", !zcs->params.fParams.noDictIDFlag);
 
+    if (zcs->cdict) CHECK_F(ZSTD_compressBegin_usingCDict_advanced(zcs->cctx, zcs->cdict, zcs->params.fParams, pledgedSrcSize))
+    else CHECK_F(ZSTD_compressBegin_internal(zcs->cctx, NULL, 0, zcs->params, pledgedSrcSize));
+
     zcs->inToCompress = 0;
     zcs->inBuffPos = 0;
     zcs->inBuffTarget = zcs->blockSize;
     zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
     zcs->stage = zcss_load;
     zcs->frameEnded = 0;
     zcs->pledgedSrcSize = pledgedSrcSize;
-    zcs->inputProcessed = 0;
     return 0;   /* ready to go */
 }
 
 size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize)
 {
 
     zcs->params.fParams.contentSizeFlag = (pledgedSrcSize > 0);
-
+    DEBUGLOG(5, "ZSTD_resetCStream : dictIDFlag == %u \n", !zcs->params.fParams.noDictIDFlag);
     return ZSTD_resetCStream_internal(zcs, pledgedSrcSize);
 }
 
-size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
-                                 const void* dict, size_t dictSize,
-                                 ZSTD_parameters params, unsigned long long pledgedSrcSize)
+/* ZSTD_initCStream_internal() :
+ * params are supposed validated at this stage
+ * and zcs->cdict is supposed to be correct */
+static size_t ZSTD_initCStream_stage2(ZSTD_CStream* zcs,
+                                const ZSTD_parameters params,
+                                unsigned long long pledgedSrcSize)
 {
+    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
+
     /* allocate buffers */
     {   size_t const neededInBuffSize = (size_t)1 << params.cParams.windowLog;
         if (zcs->inBuffSize < neededInBuffSize) {
-            zcs->inBuffSize = neededInBuffSize;
+            zcs->inBuffSize = 0;
             ZSTD_free(zcs->inBuff, zcs->customMem);
             zcs->inBuff = (char*) ZSTD_malloc(neededInBuffSize, zcs->customMem);
             if (zcs->inBuff == NULL) return ERROR(memory_allocation);
+            zcs->inBuffSize = neededInBuffSize;
         }
         zcs->blockSize = MIN(ZSTD_BLOCKSIZE_ABSOLUTEMAX, neededInBuffSize);
     }
     if (zcs->outBuffSize < ZSTD_compressBound(zcs->blockSize)+1) {
-        zcs->outBuffSize = ZSTD_compressBound(zcs->blockSize)+1;
+        size_t const outBuffSize = ZSTD_compressBound(zcs->blockSize)+1;
+        zcs->outBuffSize = 0;
         ZSTD_free(zcs->outBuff, zcs->customMem);
-        zcs->outBuff = (char*) ZSTD_malloc(zcs->outBuffSize, zcs->customMem);
+        zcs->outBuff = (char*) ZSTD_malloc(outBuffSize, zcs->customMem);
         if (zcs->outBuff == NULL) return ERROR(memory_allocation);
+        zcs->outBuffSize = outBuffSize;
     }
 
-    if (dict && dictSize >= 8) {
-        ZSTD_freeCDict(zcs->cdictLocal);
-        zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize, 0, params, zcs->customMem);
-        if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);
-        zcs->cdict = zcs->cdictLocal;
-    } else zcs->cdict = NULL;
-
     zcs->checksum = params.fParams.checksumFlag > 0;
     zcs->params = params;
 
+    DEBUGLOG(5, "ZSTD_initCStream_stage2 : dictIDFlag == %u \n", !params.fParams.noDictIDFlag);
     return ZSTD_resetCStream_internal(zcs, 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, unsigned long long pledgedSrcSize, ZSTD_frameParameters fParams)
+{
+    if (!cdict) return ERROR(GENERIC);   /* cannot handle NULL cdict (does not know what to do) */
+    {   ZSTD_parameters params = ZSTD_getParamsFromCDict(cdict);
+        params.fParams = fParams;
+        zcs->cdict = cdict;
+        return ZSTD_initCStream_stage2(zcs, params, pledgedSrcSize);
+    }
+}
+
 /* note : cdict must outlive compression session */
 size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict)
 {
-    ZSTD_parameters const params = ZSTD_getParamsFromCDict(cdict);
-    size_t const initError =  ZSTD_initCStream_advanced(zcs, NULL, 0, params, 0);
-    zcs->cdict = cdict;
-    zcs->cctx->dictID = params.fParams.noDictIDFlag ? 0 : cdict->refContext->dictID;
-    return initError;
+    ZSTD_frameParameters const fParams = { 0 /* content */, 0 /* checksum */, 0 /* noDictID */ };
+    return ZSTD_initCStream_usingCDict_advanced(zcs, cdict, 0, fParams);
 }
 
+static size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
+                                const void* dict, size_t dictSize,
+                                ZSTD_parameters params, unsigned long long pledgedSrcSize)
+{
+    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
+    zcs->cdict = NULL;
+
+    if (dict && dictSize >= 8) {
+        ZSTD_freeCDict(zcs->cdictLocal);
+        zcs->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize, 0 /* copy */, params.cParams, zcs->customMem);
+        if (zcs->cdictLocal == NULL) return ERROR(memory_allocation);
+        zcs->cdict = zcs->cdictLocal;
+    }
+
+    DEBUGLOG(5, "ZSTD_initCStream_internal : dictIDFlag == %u \n", !params.fParams.noDictIDFlag);
+    return ZSTD_initCStream_stage2(zcs, params, pledgedSrcSize);
+}
+
+size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
+                                 const void* dict, size_t dictSize,
+                                 ZSTD_parameters params, unsigned long long pledgedSrcSize)
+{
+    CHECK_F( ZSTD_checkCParams(params.cParams) );
+    DEBUGLOG(5, "ZSTD_initCStream_advanced : dictIDFlag == %u \n", !params.fParams.noDictIDFlag);
+    return ZSTD_initCStream_internal(zcs, dict, dictSize, params, 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);
-    return ZSTD_initCStream_advanced(zcs, dict, dictSize, params, 0);
+    return ZSTD_initCStream_internal(zcs, dict, dictSize, params, 0);
 }
 
 size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize)
 {
     ZSTD_parameters params = ZSTD_getParams(compressionLevel, pledgedSrcSize, 0);
-    if (pledgedSrcSize) params.fParams.contentSizeFlag = 1;
-    return ZSTD_initCStream_advanced(zcs, NULL, 0, params, pledgedSrcSize);
+    params.fParams.contentSizeFlag = (pledgedSrcSize>0);
+    return ZSTD_initCStream_internal(zcs, NULL, 0, params, pledgedSrcSize);
 }
 
 size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
 {
-    return ZSTD_initCStream_usingDict(zcs, NULL, 0, compressionLevel);
+    ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, 0);
+    return ZSTD_initCStream_internal(zcs, NULL, 0, params, 0);
 }
 
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
 {
     if (zcs==NULL) return 0;   /* support sizeof on NULL */
     return sizeof(*zcs) + ZSTD_sizeof_CCtx(zcs->cctx) + ZSTD_sizeof_CDict(zcs->cdictLocal) + zcs->outBuffSize + zcs->inBuffSize;
 }
 
 /*======   Compression   ======*/
 
 typedef enum { zsf_gather, zsf_flush, zsf_end } ZSTD_flush_e;
 
 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;
 }
 
 static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                               void* dst, size_t* dstCapacityPtr,
                         const void* src, size_t* srcSizePtr,
                               ZSTD_flush_e const flush)
 {
     U32 someMoreWork = 1;
     const char* const istart = (const char*)src;
     const char* const iend = istart + *srcSizePtr;
     const char* ip = istart;
     char* const ostart = (char*)dst;
     char* const oend = ostart + *dstCapacityPtr;
     char* op = ostart;
 
     while (someMoreWork) {
         switch(zcs->stage)
         {
         case zcss_init: return ERROR(init_missing);   /* call ZBUFF_compressInit() first ! */
 
         case zcss_load:
             /* complete 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 ( (zcs->inBuffPos==zcs->inToCompress) || (!flush && (toLoad != loaded)) ) {
                     someMoreWork = 0; break;  /* not enough input to get a full block : stop there, wait for more */
             }   }
             /* compress current block (note : this stage cannot be stopped in the middle) */
             {   void* cDst;
                 size_t cSize;
                 size_t const iSize = zcs->inBuffPos - zcs->inToCompress;
                 size_t oSize = oend-op;
                 if (oSize >= ZSTD_compressBound(iSize))
                     cDst = op;   /* compress directly into output buffer (avoid flush stage) */
                 else
                     cDst = zcs->outBuff, oSize = zcs->outBuffSize;
                 cSize = (flush == zsf_end) ?
                         ZSTD_compressEnd(zcs->cctx, cDst, oSize, zcs->inBuff + zcs->inToCompress, iSize) :
                         ZSTD_compressContinue(zcs->cctx, cDst, oSize, zcs->inBuff + zcs->inToCompress, iSize);
                 if (ZSTD_isError(cSize)) return cSize;
                 if (flush == zsf_end) zcs->frameEnded = 1;
                 /* prepare next block */
                 zcs->inBuffTarget = zcs->inBuffPos + zcs->blockSize;
                 if (zcs->inBuffTarget > zcs->inBuffSize)
                     zcs->inBuffPos = 0, zcs->inBuffTarget = zcs->blockSize;   /* note : inBuffSize >= blockSize */
                 zcs->inToCompress = zcs->inBuffPos;
                 if (cDst == op) { op += cSize; break; }   /* no need to flush */
                 zcs->outBuffContentSize = cSize;
                 zcs->outBuffFlushedSize = 0;
                 zcs->stage = zcss_flush;   /* pass-through to flush stage */
             }
 
         case zcss_flush:
             {   size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
                 size_t const flushed = ZSTD_limitCopy(op, oend-op, zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
                 op += flushed;
                 zcs->outBuffFlushedSize += flushed;
                 if (toFlush!=flushed) { someMoreWork = 0; break; }  /* dst too small to store flushed data : stop there */
                 zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
                 zcs->stage = zcss_load;
                 break;
             }
 
         case zcss_final:
             someMoreWork = 0;   /* do nothing */
             break;
 
         default:
             return ERROR(GENERIC);   /* impossible */
         }
     }
 
     *srcSizePtr = ip - istart;
     *dstCapacityPtr = op - ostart;
-    zcs->inputProcessed += *srcSizePtr;
     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)
 {
     size_t sizeRead = input->size - input->pos;
     size_t sizeWritten = output->size - output->pos;
     size_t const result = ZSTD_compressStream_generic(zcs,
                                                       (char*)(output->dst) + output->pos, &sizeWritten,
                                                       (const char*)(input->src) + input->pos, &sizeRead, zsf_gather);
     input->pos += sizeRead;
     output->pos += sizeWritten;
     return result;
 }
 
 
 /*======   Finalize   ======*/
 
 /*! ZSTD_flushStream() :
 *   @return : amount of data remaining to flush */
 size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 {
     size_t srcSize = 0;
     size_t sizeWritten = output->size - output->pos;
     size_t const result = ZSTD_compressStream_generic(zcs,
                                                      (char*)(output->dst) + output->pos, &sizeWritten,
                                                      &srcSize, &srcSize, /* use a valid src address instead of NULL */
                                                       zsf_flush);
     output->pos += sizeWritten;
     if (ZSTD_isError(result)) return result;
     return zcs->outBuffContentSize - zcs->outBuffFlushedSize;   /* remaining to flush */
 }
 
 
 size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 {
     BYTE* const ostart = (BYTE*)(output->dst) + output->pos;
     BYTE* const oend = (BYTE*)(output->dst) + output->size;
     BYTE* op = ostart;
 
-    if ((zcs->pledgedSrcSize) && (zcs->inputProcessed != zcs->pledgedSrcSize))
-        return ERROR(srcSize_wrong);   /* pledgedSrcSize not respected */
-
     if (zcs->stage != zcss_final) {
         /* flush whatever remains */
         size_t srcSize = 0;
         size_t sizeWritten = output->size - output->pos;
-        size_t const notEnded = ZSTD_compressStream_generic(zcs, ostart, &sizeWritten, &srcSize, &srcSize, zsf_end);  /* use a valid src address instead of NULL */
+        size_t const notEnded = ZSTD_compressStream_generic(zcs, ostart, &sizeWritten,
+                                     &srcSize /* use a valid src address instead of NULL */, &srcSize, zsf_end);
         size_t const remainingToFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
         op += sizeWritten;
         if (remainingToFlush) {
             output->pos += sizeWritten;
             return remainingToFlush + ZSTD_BLOCKHEADERSIZE /* final empty block */ + (zcs->checksum * 4);
         }
         /* create epilogue */
         zcs->stage = zcss_final;
         zcs->outBuffContentSize = !notEnded ? 0 :
-            ZSTD_compressEnd(zcs->cctx, zcs->outBuff, zcs->outBuffSize, NULL, 0);  /* write epilogue, including final empty block, into outBuff */
+            /* write epilogue, including final empty block, into outBuff */
+            ZSTD_compressEnd(zcs->cctx, zcs->outBuff, zcs->outBuffSize, NULL, 0);
+        if (ZSTD_isError(zcs->outBuffContentSize)) return zcs->outBuffContentSize;
     }
 
     /* flush epilogue */
     {   size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
         size_t const flushed = ZSTD_limitCopy(op, oend-op, zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
         op += flushed;
         zcs->outBuffFlushedSize += flushed;
         output->pos += op-ostart;
         if (toFlush==flushed) zcs->stage = zcss_init;  /* end reached */
         return toFlush - flushed;
     }
 }
 
 
 
 /*-=====  Pre-defined compression levels  =====-*/
 
 #define ZSTD_DEFAULT_CLEVEL 1
 #define ZSTD_MAX_CLEVEL     22
 int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
 
 static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEVEL+1] = {
 {   /* "default" */
     /* W,  C,  H,  S,  L, TL, strat */
     { 18, 12, 12,  1,  7, 16, ZSTD_fast    },  /* level  0 - never used */
     { 19, 13, 14,  1,  7, 16, ZSTD_fast    },  /* level  1 */
     { 19, 15, 16,  1,  6, 16, ZSTD_fast    },  /* level  2 */
     { 20, 16, 17,  1,  5, 16, ZSTD_dfast   },  /* level  3.*/
     { 20, 18, 18,  1,  5, 16, ZSTD_dfast   },  /* level  4.*/
     { 20, 15, 18,  3,  5, 16, ZSTD_greedy  },  /* level  5 */
     { 21, 16, 19,  2,  5, 16, ZSTD_lazy    },  /* level  6 */
     { 21, 17, 20,  3,  5, 16, ZSTD_lazy    },  /* level  7 */
     { 21, 18, 20,  3,  5, 16, ZSTD_lazy2   },  /* level  8 */
     { 21, 20, 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 */
     { 22, 20, 22,  5,  5, 16, ZSTD_lazy2   },  /* level 12 */
     { 22, 21, 22,  5,  5, 16, ZSTD_lazy2   },  /* level 13 */
     { 22, 21, 22,  6,  5, 16, ZSTD_lazy2   },  /* level 14 */
     { 22, 21, 21,  5,  5, 16, ZSTD_btlazy2 },  /* level 15 */
     { 23, 22, 22,  5,  5, 16, ZSTD_btlazy2 },  /* level 16 */
     { 23, 21, 22,  4,  5, 24, ZSTD_btopt   },  /* level 17 */
-    { 23, 23, 22,  6,  5, 32, ZSTD_btopt   },  /* level 18 */
+    { 23, 22, 22,  5,  4, 32, ZSTD_btopt   },  /* level 18 */
     { 23, 23, 22,  6,  3, 48, ZSTD_btopt   },  /* level 19 */
     { 25, 25, 23,  7,  3, 64, ZSTD_btopt2  },  /* level 20 */
     { 26, 26, 23,  7,  3,256, ZSTD_btopt2  },  /* level 21 */
     { 27, 27, 25,  9,  3,512, ZSTD_btopt2  },  /* level 22 */
 },
 {   /* for srcSize <= 256 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     {  0,  0,  0,  0,  0,  0, ZSTD_fast    },  /* level  0 - not used */
     { 18, 13, 14,  1,  6,  8, 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,  7,  4,  8, ZSTD_lazy2   },  /* level 12.*/
     { 18, 19, 17,  6,  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_btopt2  },  /* level 20.*/
     { 18, 19, 18, 12,  3,512, ZSTD_btopt2  },  /* level 21.*/
     { 18, 19, 18, 13,  3,512, ZSTD_btopt2  },  /* level 22.*/
 },
 {   /* for srcSize <= 128 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 17, 12, 12,  1,  7,  8, ZSTD_fast    },  /* level  0 - not used */
     { 17, 12, 13,  1,  6,  8, ZSTD_fast    },  /* level  1 */
     { 17, 13, 16,  1,  5,  8, 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, 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,  9,  3,256, ZSTD_btopt2  },  /* level 20.*/
     { 17, 18, 17, 10,  3,256, ZSTD_btopt2  },  /* level 21.*/
     { 17, 18, 17, 11,  3,512, ZSTD_btopt2  },  /* level 22.*/
 },
 {   /* for srcSize <= 16 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 14, 12, 12,  1,  7,  6, ZSTD_fast    },  /* level  0 - not used */
     { 14, 14, 14,  1,  6,  6, ZSTD_fast    },  /* level  1 */
     { 14, 14, 14,  1,  4,  6, 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, 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_btopt2  },  /* level 20.*/
     { 14, 15, 15,  9,  3,256, ZSTD_btopt2  },  /* level 21.*/
     { 14, 15, 15, 10,  3,256, ZSTD_btopt2  },  /* 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 srcSize, size_t dictSize)
 {
     ZSTD_compressionParameters cp;
     size_t const addedSize = srcSize ? 0 : 500;
     U64 const rSize = srcSize+dictSize ? srcSize+dictSize+addedSize : (U64)-1;
     U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);   /* intentional underflow for srcSizeHint == 0 */
     if (compressionLevel <= 0) compressionLevel = ZSTD_DEFAULT_CLEVEL;   /* 0 == default; no negative compressionLevel yet */
     if (compressionLevel > ZSTD_MAX_CLEVEL) compressionLevel = ZSTD_MAX_CLEVEL;
     cp = ZSTD_defaultCParameters[tableID][compressionLevel];
     if (MEM_32bits()) {   /* auto-correction, for 32-bits mode */
         if (cp.windowLog > ZSTD_WINDOWLOG_MAX) cp.windowLog = ZSTD_WINDOWLOG_MAX;
         if (cp.chainLog > ZSTD_CHAINLOG_MAX) cp.chainLog = ZSTD_CHAINLOG_MAX;
         if (cp.hashLog > ZSTD_HASHLOG_MAX) cp.hashLog = ZSTD_HASHLOG_MAX;
     }
     cp = ZSTD_adjustCParams(cp, srcSize, dictSize);
     return cp;
 }
 
 /*! 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 srcSize, size_t dictSize) {
     ZSTD_parameters params;
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, srcSize, dictSize);
     memset(¶ms, 0, sizeof(params));
     params.cParams = cParams;
     return params;
 }
Index: head/contrib/zstd/lib/compress/zstd_opt.h
===================================================================
--- head/contrib/zstd/lib/compress/zstd_opt.h	(revision 317876)
+++ head/contrib/zstd/lib/compress/zstd_opt.h	(revision 317877)
@@ -1,919 +1,921 @@
 /**
  * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 /* Note : this file is intended to be included within zstd_compress.c */
 
 
 #ifndef ZSTD_OPT_H_91842398743
 #define ZSTD_OPT_H_91842398743
 
 
 #define ZSTD_LITFREQ_ADD    2
 #define ZSTD_FREQ_DIV       4
 #define ZSTD_MAX_PRICE      (1<<30)
 
 /*-*************************************
 *  Price functions for optimal parser
 ***************************************/
 FORCE_INLINE void ZSTD_setLog2Prices(seqStore_t* ssPtr)
 {
     ssPtr->log2matchLengthSum = ZSTD_highbit32(ssPtr->matchLengthSum+1);
     ssPtr->log2litLengthSum = ZSTD_highbit32(ssPtr->litLengthSum+1);
     ssPtr->log2litSum = ZSTD_highbit32(ssPtr->litSum+1);
     ssPtr->log2offCodeSum = ZSTD_highbit32(ssPtr->offCodeSum+1);
     ssPtr->factor = 1 + ((ssPtr->litSum>>5) / ssPtr->litLengthSum) + ((ssPtr->litSum<<1) / (ssPtr->litSum + ssPtr->matchSum));
 }
 
 
 MEM_STATIC void ZSTD_rescaleFreqs(seqStore_t* ssPtr, const BYTE* src, size_t srcSize)
 {
     unsigned u;
 
     ssPtr->cachedLiterals = NULL;
     ssPtr->cachedPrice = ssPtr->cachedLitLength = 0;
     ssPtr->staticPrices = 0;
 
     if (ssPtr->litLengthSum == 0) {
         if (srcSize <= 1024) ssPtr->staticPrices = 1;
 
         for (u=0; u<=MaxLit; u++)
             ssPtr->litFreq[u] = 0;
         for (u=0; ulitFreq[src[u]]++;
 
         ssPtr->litSum = 0;
         ssPtr->litLengthSum = MaxLL+1;
         ssPtr->matchLengthSum = MaxML+1;
         ssPtr->offCodeSum = (MaxOff+1);
         ssPtr->matchSum = (ZSTD_LITFREQ_ADD<litFreq[u] = 1 + (ssPtr->litFreq[u]>>ZSTD_FREQ_DIV);
             ssPtr->litSum += ssPtr->litFreq[u];
         }
         for (u=0; u<=MaxLL; u++)
             ssPtr->litLengthFreq[u] = 1;
         for (u=0; u<=MaxML; u++)
             ssPtr->matchLengthFreq[u] = 1;
         for (u=0; u<=MaxOff; u++)
             ssPtr->offCodeFreq[u] = 1;
     } else {
         ssPtr->matchLengthSum = 0;
         ssPtr->litLengthSum = 0;
         ssPtr->offCodeSum = 0;
         ssPtr->matchSum = 0;
         ssPtr->litSum = 0;
 
         for (u=0; u<=MaxLit; u++) {
             ssPtr->litFreq[u] = 1 + (ssPtr->litFreq[u]>>(ZSTD_FREQ_DIV+1));
             ssPtr->litSum += ssPtr->litFreq[u];
         }
         for (u=0; u<=MaxLL; u++) {
             ssPtr->litLengthFreq[u] = 1 + (ssPtr->litLengthFreq[u]>>(ZSTD_FREQ_DIV+1));
             ssPtr->litLengthSum += ssPtr->litLengthFreq[u];
         }
         for (u=0; u<=MaxML; u++) {
             ssPtr->matchLengthFreq[u] = 1 + (ssPtr->matchLengthFreq[u]>>ZSTD_FREQ_DIV);
             ssPtr->matchLengthSum += ssPtr->matchLengthFreq[u];
             ssPtr->matchSum += ssPtr->matchLengthFreq[u] * (u + 3);
         }
         ssPtr->matchSum *= ZSTD_LITFREQ_ADD;
         for (u=0; u<=MaxOff; u++) {
             ssPtr->offCodeFreq[u] = 1 + (ssPtr->offCodeFreq[u]>>ZSTD_FREQ_DIV);
             ssPtr->offCodeSum += ssPtr->offCodeFreq[u];
         }
     }
 
     ZSTD_setLog2Prices(ssPtr);
 }
 
 
 FORCE_INLINE U32 ZSTD_getLiteralPrice(seqStore_t* ssPtr, U32 litLength, const BYTE* literals)
 {
     U32 price, u;
 
     if (ssPtr->staticPrices)
         return ZSTD_highbit32((U32)litLength+1) + (litLength*6);
 
     if (litLength == 0)
         return ssPtr->log2litLengthSum - ZSTD_highbit32(ssPtr->litLengthFreq[0]+1);
 
     /* literals */
     if (ssPtr->cachedLiterals == literals) {
         U32 const additional = litLength - ssPtr->cachedLitLength;
         const BYTE* literals2 = ssPtr->cachedLiterals + ssPtr->cachedLitLength;
         price = ssPtr->cachedPrice + additional * ssPtr->log2litSum;
         for (u=0; u < additional; u++)
             price -= ZSTD_highbit32(ssPtr->litFreq[literals2[u]]+1);
         ssPtr->cachedPrice = price;
         ssPtr->cachedLitLength = litLength;
     } else {
         price = litLength * ssPtr->log2litSum;
         for (u=0; u < litLength; u++)
             price -= ZSTD_highbit32(ssPtr->litFreq[literals[u]]+1);
 
         if (litLength >= 12) {
             ssPtr->cachedLiterals = literals;
             ssPtr->cachedPrice = price;
             ssPtr->cachedLitLength = litLength;
         }
     }
 
     /* literal Length */
     {   const BYTE LL_deltaCode = 19;
         const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
         price += LL_bits[llCode] + ssPtr->log2litLengthSum - ZSTD_highbit32(ssPtr->litLengthFreq[llCode]+1);
     }
 
     return price;
 }
 
 
 FORCE_INLINE U32 ZSTD_getPrice(seqStore_t* seqStorePtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength, const int ultra)
 {
     /* offset */
     U32 price;
     BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
 
     if (seqStorePtr->staticPrices)
         return ZSTD_getLiteralPrice(seqStorePtr, litLength, literals) + ZSTD_highbit32((U32)matchLength+1) + 16 + offCode;
 
     price = offCode + seqStorePtr->log2offCodeSum - ZSTD_highbit32(seqStorePtr->offCodeFreq[offCode]+1);
     if (!ultra && offCode >= 20) price += (offCode-19)*2;
 
     /* match Length */
     {   const BYTE ML_deltaCode = 36;
         const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
         price += ML_bits[mlCode] + seqStorePtr->log2matchLengthSum - ZSTD_highbit32(seqStorePtr->matchLengthFreq[mlCode]+1);
     }
 
     return price + ZSTD_getLiteralPrice(seqStorePtr, litLength, literals) + seqStorePtr->factor;
 }
 
 
 MEM_STATIC void ZSTD_updatePrice(seqStore_t* seqStorePtr, U32 litLength, const BYTE* literals, U32 offset, U32 matchLength)
 {
     U32 u;
 
     /* literals */
     seqStorePtr->litSum += litLength*ZSTD_LITFREQ_ADD;
     for (u=0; u < litLength; u++)
         seqStorePtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
 
     /* literal Length */
     {   const BYTE LL_deltaCode = 19;
         const BYTE llCode = (litLength>63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
         seqStorePtr->litLengthFreq[llCode]++;
         seqStorePtr->litLengthSum++;
     }
 
     /* match offset */
-	{   BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
-		seqStorePtr->offCodeSum++;
-		seqStorePtr->offCodeFreq[offCode]++;
-	}
+    {   BYTE const offCode = (BYTE)ZSTD_highbit32(offset+1);
+        seqStorePtr->offCodeSum++;
+        seqStorePtr->offCodeFreq[offCode]++;
+    }
 
     /* match Length */
     {   const BYTE ML_deltaCode = 36;
         const BYTE mlCode = (matchLength>127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
         seqStorePtr->matchLengthFreq[mlCode]++;
         seqStorePtr->matchLengthSum++;
     }
 
     ZSTD_setLog2Prices(seqStorePtr);
 }
 
 
 #define SET_PRICE(pos, mlen_, offset_, litlen_, price_)   \
     {                                                 \
         while (last_pos < pos)  { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \
         opt[pos].mlen = mlen_;                         \
         opt[pos].off = offset_;                        \
         opt[pos].litlen = litlen_;                     \
         opt[pos].price = price_;                       \
     }
 
 
 
 /* Update hashTable3 up to ip (excluded)
    Assumption : always within prefix (i.e. not within extDict) */
 FORCE_INLINE
 U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip)
 {
     U32* const hashTable3  = zc->hashTable3;
     U32 const hashLog3  = zc->hashLog3;
     const BYTE* const base = zc->base;
     U32 idx = zc->nextToUpdate3;
     const U32 target = zc->nextToUpdate3 = (U32)(ip - base);
     const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3);
 
     while(idx < target) {
         hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
         idx++;
     }
 
     return hashTable3[hash3];
 }
 
 
 /*-*************************************
 *  Binary Tree search
 ***************************************/
 static U32 ZSTD_insertBtAndGetAllMatches (
                         ZSTD_CCtx* zc,
                         const BYTE* const ip, const BYTE* const iLimit,
                         U32 nbCompares, const U32 mls,
                         U32 extDict, ZSTD_match_t* matches, const U32 minMatchLen)
 {
     const BYTE* const base = zc->base;
     const U32 current = (U32)(ip-base);
     const U32 hashLog = zc->params.cParams.hashLog;
     const size_t h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32* const hashTable = zc->hashTable;
     U32 matchIndex  = hashTable[h];
     U32* const bt   = zc->chainTable;
     const U32 btLog = zc->params.cParams.chainLog - 1;
     const U32 btMask= (1U << btLog) - 1;
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const dictBase = zc->dictBase;
     const U32 dictLimit = zc->dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const U32 btLow = btMask >= current ? 0 : current - btMask;
     const U32 windowLow = zc->lowLimit;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = bt + 2*(current&btMask) + 1;
     U32 matchEndIdx = current+8;
     U32 dummy32;   /* to be nullified at the end */
     U32 mnum = 0;
 
     const U32 minMatch = (mls == 3) ? 3 : 4;
     size_t bestLength = minMatchLen-1;
 
     if (minMatch == 3) { /* HC3 match finder */
         U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3 (zc, ip);
         if (matchIndex3>windowLow && (current - matchIndex3 < (1<<18))) {
             const BYTE* match;
             size_t currentMl=0;
             if ((!extDict) || matchIndex3 >= dictLimit) {
                 match = base + matchIndex3;
                 if (match[bestLength] == ip[bestLength]) currentMl = ZSTD_count(ip, match, iLimit);
             } else {
                 match = dictBase + matchIndex3;
                 if (MEM_readMINMATCH(match, MINMATCH) == MEM_readMINMATCH(ip, MINMATCH))    /* assumption : matchIndex3 <= dictLimit-4 (by table construction) */
                     currentMl = ZSTD_count_2segments(ip+MINMATCH, match+MINMATCH, iLimit, dictEnd, prefixStart) + MINMATCH;
             }
 
             /* save best solution */
             if (currentMl > bestLength) {
                 bestLength = currentMl;
                 matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex3;
                 matches[mnum].len = (U32)currentMl;
                 mnum++;
                 if (currentMl > ZSTD_OPT_NUM) goto update;
                 if (ip+currentMl == iLimit) goto update; /* best possible, and avoid read overflow*/
             }
         }
     }
 
     hashTable[h] = current;   /* Update Hash Table */
 
     while (nbCompares-- && (matchIndex > windowLow)) {
         U32* 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)) {
             match = base + matchIndex;
             if (match[matchLength] == ip[matchLength]) {
                 matchLength += ZSTD_count(ip+matchLength+1, match+matchLength+1, iLimit) +1;
             }
         } else {
             match = dictBase + matchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, 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;
             bestLength = matchLength;
             matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex;
             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 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;
 
 update:
     zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
     return mnum;
 }
 
 
 /** Tree updater, providing best match */
 static U32 ZSTD_BtGetAllMatches (
                         ZSTD_CCtx* zc,
                         const BYTE* const ip, const BYTE* const iLimit,
                         const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
 {
     if (ip < zc->base + zc->nextToUpdate) return 0;   /* skipped area */
     ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
     return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen);
 }
 
 
 static U32 ZSTD_BtGetAllMatches_selectMLS (
                         ZSTD_CCtx* zc,   /* Index table will be updated */
                         const BYTE* ip, const BYTE* const iHighLimit,
                         const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
 {
     switch(matchLengthSearch)
     {
     case 3 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
     default :
     case 4 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
     case 5 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
+    case 7 :
     case 6 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
     }
 }
 
 /** Tree updater, providing best match */
 static U32 ZSTD_BtGetAllMatches_extDict (
                         ZSTD_CCtx* zc,
                         const BYTE* const ip, const BYTE* const iLimit,
                         const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
 {
     if (ip < zc->base + zc->nextToUpdate) return 0;   /* skipped area */
     ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
     return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen);
 }
 
 
 static U32 ZSTD_BtGetAllMatches_selectMLS_extDict (
                         ZSTD_CCtx* zc,   /* Index table will be updated */
                         const BYTE* ip, const BYTE* const iHighLimit,
                         const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
 {
     switch(matchLengthSearch)
     {
     case 3 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
     default :
     case 4 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
     case 5 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
+    case 7 :
     case 6 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
     }
 }
 
 
 /*-*******************************
 *  Optimal parser
 *********************************/
 FORCE_INLINE
 void ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
                                     const void* src, size_t srcSize, const int ultra)
 {
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     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 = ctx->base;
     const BYTE* const prefixStart = base + ctx->dictLimit;
 
     const U32 maxSearches = 1U << ctx->params.cParams.searchLog;
     const U32 sufficient_len = ctx->params.cParams.targetLength;
     const U32 mls = ctx->params.cParams.searchLength;
     const U32 minMatch = (ctx->params.cParams.searchLength == 3) ? 3 : 4;
 
     ZSTD_optimal_t* opt = seqStorePtr->priceTable;
     ZSTD_match_t* matches = seqStorePtr->matchTable;
     const BYTE* inr;
     U32 offset, rep[ZSTD_REP_NUM];
 
     /* init */
     ctx->nextToUpdate3 = ctx->nextToUpdate;
     ZSTD_rescaleFreqs(seqStorePtr, (const BYTE*)src, srcSize);
     ip += (ip==prefixStart);
     { U32 i; for (i=0; irep[i]; }
 
     /* Match Loop */
     while (ip < ilimit) {
         U32 cur, match_num, last_pos, litlen, price;
         U32 u, mlen, best_mlen, best_off, litLength;
         memset(opt, 0, sizeof(ZSTD_optimal_t));
         last_pos = 0;
         litlen = (U32)(ip - anchor);
 
         /* check repCode */
         {   U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
             for (i=(ip == anchor); i 0) && (repCur < (S32)(ip-prefixStart))
                     && (MEM_readMINMATCH(ip, minMatch) == MEM_readMINMATCH(ip - repCur, minMatch))) {
                     mlen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repCur, iend) + minMatch;
                     if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
                         best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
                         goto _storeSequence;
                     }
                     best_off = i - (ip == anchor);
                     do {
                         price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
                         if (mlen > last_pos || price < opt[mlen].price)
                             SET_PRICE(mlen, mlen, i, litlen, price);   /* note : macro modifies last_pos */
                         mlen--;
                     } while (mlen >= minMatch);
         }   }   }
 
         match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch);
 
         if (!last_pos && !match_num) { ip++; continue; }
 
         if (match_num && (matches[match_num-1].len > sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
             best_mlen = matches[match_num-1].len;
             best_off = matches[match_num-1].off;
             cur = 0;
             last_pos = 1;
             goto _storeSequence;
         }
 
         /* set prices using matches at position = 0 */
         best_mlen = (last_pos) ? last_pos : minMatch;
         for (u = 0; u < match_num; u++) {
             mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
             best_mlen = matches[u].len;
             while (mlen <= best_mlen) {
                 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
                 if (mlen > last_pos || price < opt[mlen].price)
                     SET_PRICE(mlen, mlen, matches[u].off, litlen, price);   /* note : macro modifies last_pos */
                 mlen++;
         }   }
 
         if (last_pos < minMatch) { ip++; continue; }
 
         /* initialize opt[0] */
         { U32 i ; for (i=0; i litlen) {
                     price = opt[cur - litlen].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr-litlen);
                 } else
                     price = ZSTD_getLiteralPrice(seqStorePtr, litlen, anchor);
            } else {
                 litlen = 1;
                 price = opt[cur - 1].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr-1);
            }
 
            if (cur > last_pos || price <= opt[cur].price)
                 SET_PRICE(cur, 1, 0, litlen, price);
 
            if (cur == last_pos) break;
 
            if (inr > ilimit)  /* last match must start at a minimum distance of 8 from oend */
                continue;
 
            mlen = opt[cur].mlen;
            if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
                 opt[cur].rep[2] = opt[cur-mlen].rep[1];
                 opt[cur].rep[1] = opt[cur-mlen].rep[0];
                 opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
            } else {
                 opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
                 opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
                 opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
            }
 
             best_mlen = minMatch;
             {   U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
                 for (i=(opt[cur].mlen != 1); i 0) && (repCur < (S32)(inr-prefixStart))
                        && (MEM_readMINMATCH(inr, minMatch) == MEM_readMINMATCH(inr - repCur, minMatch))) {
                        mlen = (U32)ZSTD_count(inr+minMatch, inr+minMatch - repCur, iend) + minMatch;
 
                        if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
                             best_mlen = mlen; best_off = i; last_pos = cur + 1;
                             goto _storeSequence;
                        }
 
                        best_off = i - (opt[cur].mlen != 1);
                        if (mlen > best_mlen) best_mlen = mlen;
 
                        do {
                            if (opt[cur].mlen == 1) {
                                 litlen = opt[cur].litlen;
                                 if (cur > litlen) {
                                     price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra);
                                 } else
                                     price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
                             } else {
                                 litlen = 0;
                                 price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
                             }
 
                             if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
                                 SET_PRICE(cur + mlen, mlen, i, litlen, price);
                             mlen--;
                         } while (mlen >= minMatch);
             }   }   }
 
             match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen);
 
             if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
                 best_mlen = matches[match_num-1].len;
                 best_off = matches[match_num-1].off;
                 last_pos = cur + 1;
                 goto _storeSequence;
             }
 
             /* set prices using matches at position = cur */
             for (u = 0; u < match_num; u++) {
                 mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
                 best_mlen = matches[u].len;
 
                 while (mlen <= best_mlen) {
                     if (opt[cur].mlen == 1) {
                         litlen = opt[cur].litlen;
                         if (cur > litlen)
                             price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra);
                         else
                             price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
                     } else {
                         litlen = 0;
                         price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra);
                     }
 
                     if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
                         SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
 
                     mlen++;
         }   }   }
 
         best_mlen = opt[last_pos].mlen;
         best_off = opt[last_pos].off;
         cur = last_pos - best_mlen;
 
         /* store sequence */
 _storeSequence:   /* cur, last_pos, best_mlen, best_off have to be set */
         opt[0].mlen = 1;
 
         while (1) {
             mlen = opt[cur].mlen;
             offset = opt[cur].off;
             opt[cur].mlen = best_mlen;
             opt[cur].off = best_off;
             best_mlen = mlen;
             best_off = offset;
             if (mlen > cur) break;
             cur -= mlen;
         }
 
         for (u = 0; u <= last_pos;) {
             u += opt[u].mlen;
         }
 
         for (cur=0; cur < last_pos; ) {
             mlen = opt[cur].mlen;
             if (mlen == 1) { ip++; cur++; continue; }
             offset = opt[cur].off;
             cur += mlen;
             litLength = (U32)(ip - anchor);
 
             if (offset > ZSTD_REP_MOVE_OPT) {
                 rep[2] = rep[1];
                 rep[1] = rep[0];
                 rep[0] = offset - ZSTD_REP_MOVE_OPT;
                 offset--;
             } else {
                 if (offset != 0) {
                     best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
                     if (offset != 1) rep[2] = rep[1];
                     rep[1] = rep[0];
                     rep[0] = best_off;
                 }
                 if (litLength==0) offset--;
             }
 
             ZSTD_updatePrice(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
             ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
             anchor = ip = ip + mlen;
     }    }   /* for (cur=0; cur < last_pos; ) */
 
     /* Save reps for next block */
     { int i; for (i=0; irepToConfirm[i] = rep[i]; }
 
     /* Last Literals */
     {   size_t const lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 
 FORCE_INLINE
 void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
                                      const void* src, size_t srcSize, const int ultra)
 {
     seqStore_t* seqStorePtr = &(ctx->seqStore);
     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 = ctx->base;
     const U32 lowestIndex = ctx->lowLimit;
     const U32 dictLimit = ctx->dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictBase = ctx->dictBase;
     const BYTE* const dictEnd  = dictBase + dictLimit;
 
     const U32 maxSearches = 1U << ctx->params.cParams.searchLog;
     const U32 sufficient_len = ctx->params.cParams.targetLength;
     const U32 mls = ctx->params.cParams.searchLength;
     const U32 minMatch = (ctx->params.cParams.searchLength == 3) ? 3 : 4;
 
     ZSTD_optimal_t* opt = seqStorePtr->priceTable;
     ZSTD_match_t* matches = seqStorePtr->matchTable;
     const BYTE* inr;
 
     /* init */
     U32 offset, rep[ZSTD_REP_NUM];
     { U32 i; for (i=0; irep[i]; }
 
     ctx->nextToUpdate3 = ctx->nextToUpdate;
     ZSTD_rescaleFreqs(seqStorePtr, (const BYTE*)src, srcSize);
     ip += (ip==prefixStart);
 
     /* Match Loop */
     while (ip < ilimit) {
         U32 cur, match_num, last_pos, litlen, price;
         U32 u, mlen, best_mlen, best_off, litLength;
         U32 current = (U32)(ip-base);
         memset(opt, 0, sizeof(ZSTD_optimal_t));
         last_pos = 0;
         opt[0].litlen = (U32)(ip - anchor);
 
         /* check repCode */
         {   U32 i, last_i = ZSTD_REP_CHECK + (ip==anchor);
             for (i = (ip==anchor); i 0 && repCur <= (S32)current)
                    && (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex))  /* intentional overflow */
                    && (MEM_readMINMATCH(ip, minMatch) == MEM_readMINMATCH(repMatch, minMatch)) ) {
                     /* repcode detected we should take it */
                     const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                     mlen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch;
 
                     if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
                         best_mlen = mlen; best_off = i; cur = 0; last_pos = 1;
                         goto _storeSequence;
                     }
 
                     best_off = i - (ip==anchor);
                     litlen = opt[0].litlen;
                     do {
                         price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
                         if (mlen > last_pos || price < opt[mlen].price)
                             SET_PRICE(mlen, mlen, i, litlen, price);   /* note : macro modifies last_pos */
                         mlen--;
                     } while (mlen >= minMatch);
         }   }   }
 
         match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch);  /* first search (depth 0) */
 
         if (!last_pos && !match_num) { ip++; continue; }
 
         { U32 i; for (i=0; i sufficient_len || matches[match_num-1].len >= ZSTD_OPT_NUM)) {
             best_mlen = matches[match_num-1].len;
             best_off = matches[match_num-1].off;
             cur = 0;
             last_pos = 1;
             goto _storeSequence;
         }
 
         best_mlen = (last_pos) ? last_pos : minMatch;
 
         /* set prices using matches at position = 0 */
         for (u = 0; u < match_num; u++) {
             mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
             best_mlen = matches[u].len;
             litlen = opt[0].litlen;
             while (mlen <= best_mlen) {
                 price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
                 if (mlen > last_pos || price < opt[mlen].price)
                     SET_PRICE(mlen, mlen, matches[u].off, litlen, price);
                 mlen++;
         }   }
 
         if (last_pos < minMatch) {
             ip++; continue;
         }
 
         /* check further positions */
         for (cur = 1; cur <= last_pos; cur++) {
             inr = ip + cur;
 
             if (opt[cur-1].mlen == 1) {
                 litlen = opt[cur-1].litlen + 1;
                 if (cur > litlen) {
                     price = opt[cur - litlen].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr-litlen);
                 } else
                     price = ZSTD_getLiteralPrice(seqStorePtr, litlen, anchor);
             } else {
                 litlen = 1;
                 price = opt[cur - 1].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr-1);
             }
 
             if (cur > last_pos || price <= opt[cur].price)
                 SET_PRICE(cur, 1, 0, litlen, price);
 
             if (cur == last_pos) break;
 
             if (inr > ilimit)  /* last match must start at a minimum distance of 8 from oend */
                 continue;
 
             mlen = opt[cur].mlen;
             if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
                 opt[cur].rep[2] = opt[cur-mlen].rep[1];
                 opt[cur].rep[1] = opt[cur-mlen].rep[0];
                 opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
             } else {
                 opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
                 opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
                 opt[cur].rep[0] = ((opt[cur].off==ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
             }
 
             best_mlen = minMatch;
             {   U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
                 for (i = (mlen != 1); i 0 && repCur <= (S32)(current+cur))
                       && (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex>lowestIndex))  /* intentional overflow */
                       && (MEM_readMINMATCH(inr, minMatch) == MEM_readMINMATCH(repMatch, minMatch)) ) {
                         /* repcode detected */
                         const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                         mlen = (U32)ZSTD_count_2segments(inr+minMatch, repMatch+minMatch, iend, repEnd, prefixStart) + minMatch;
 
                         if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
                             best_mlen = mlen; best_off = i; last_pos = cur + 1;
                             goto _storeSequence;
                         }
 
                         best_off = i - (opt[cur].mlen != 1);
                         if (mlen > best_mlen) best_mlen = mlen;
 
                         do {
                             if (opt[cur].mlen == 1) {
                                 litlen = opt[cur].litlen;
                                 if (cur > litlen) {
                                     price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, inr-litlen, best_off, mlen - MINMATCH, ultra);
                                 } else
                                     price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
                             } else {
                                 litlen = 0;
                                 price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
                             }
 
                             if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
                                 SET_PRICE(cur + mlen, mlen, i, litlen, price);
                             mlen--;
                         } while (mlen >= minMatch);
             }   }   }
 
             match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch);
 
             if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
                 best_mlen = matches[match_num-1].len;
                 best_off = matches[match_num-1].off;
                 last_pos = cur + 1;
                 goto _storeSequence;
             }
 
             /* set prices using matches at position = cur */
             for (u = 0; u < match_num; u++) {
                 mlen = (u>0) ? matches[u-1].len+1 : best_mlen;
                 best_mlen = matches[u].len;
 
                 while (mlen <= best_mlen) {
                     if (opt[cur].mlen == 1) {
                         litlen = opt[cur].litlen;
                         if (cur > litlen)
                             price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, ip+cur-litlen, matches[u].off-1, mlen - MINMATCH, ultra);
                         else
                             price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off-1, mlen - MINMATCH, ultra);
                     } else {
                         litlen = 0;
                         price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, matches[u].off-1, mlen - MINMATCH, ultra);
                     }
 
                     if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
                         SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
 
                     mlen++;
         }   }   }   /* for (cur = 1; cur <= last_pos; cur++) */
 
         best_mlen = opt[last_pos].mlen;
         best_off = opt[last_pos].off;
         cur = last_pos - best_mlen;
 
         /* store sequence */
 _storeSequence:   /* cur, last_pos, best_mlen, best_off have to be set */
         opt[0].mlen = 1;
 
         while (1) {
             mlen = opt[cur].mlen;
             offset = opt[cur].off;
             opt[cur].mlen = best_mlen;
             opt[cur].off = best_off;
             best_mlen = mlen;
             best_off = offset;
             if (mlen > cur) break;
             cur -= mlen;
         }
 
         for (u = 0; u <= last_pos; ) {
             u += opt[u].mlen;
         }
 
         for (cur=0; cur < last_pos; ) {
             mlen = opt[cur].mlen;
             if (mlen == 1) { ip++; cur++; continue; }
             offset = opt[cur].off;
             cur += mlen;
             litLength = (U32)(ip - anchor);
 
             if (offset > ZSTD_REP_MOVE_OPT) {
                 rep[2] = rep[1];
                 rep[1] = rep[0];
                 rep[0] = offset - ZSTD_REP_MOVE_OPT;
                 offset--;
             } else {
                 if (offset != 0) {
                     best_off = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
                     if (offset != 1) rep[2] = rep[1];
                     rep[1] = rep[0];
                     rep[0] = best_off;
                 }
 
                 if (litLength==0) offset--;
             }
 
             ZSTD_updatePrice(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
             ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
             anchor = ip = ip + mlen;
     }    }   /* for (cur=0; cur < last_pos; ) */
 
     /* Save reps for next block */
     { int i; for (i=0; irepToConfirm[i] = rep[i]; }
 
     /* Last Literals */
     {   size_t lastLLSize = iend - anchor;
         memcpy(seqStorePtr->lit, anchor, lastLLSize);
         seqStorePtr->lit += lastLLSize;
     }
 }
 
 #endif  /* ZSTD_OPT_H_91842398743 */
Index: head/contrib/zstd/lib/compress/zstdmt_compress.c
===================================================================
--- head/contrib/zstd/lib/compress/zstdmt_compress.c	(revision 317876)
+++ head/contrib/zstd/lib/compress/zstdmt_compress.c	(revision 317877)
@@ -1,739 +1,751 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 /* ======   Tuning parameters   ====== */
 #define ZSTDMT_NBTHREADS_MAX 128
 
 
 /* ======   Compiler specifics   ====== */
 #if defined(_MSC_VER)
 #  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
 #endif
 
 
 /* ======   Dependencies   ====== */
 #include    /* malloc */
 #include    /* memcpy */
 #include "pool.h"     /* threadpool */
 #include "threading.h"  /* mutex */
 #include "zstd_internal.h"   /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
 #include "zstdmt_compress.h"
 
 
 /* ======   Debug   ====== */
 #if 0
 
 #  include 
 #  include 
 #  include 
-   static unsigned g_debugLevel = 3;
+   static unsigned g_debugLevel = 5;
 #  define DEBUGLOGRAW(l, ...) if (l<=g_debugLevel) { fprintf(stderr, __VA_ARGS__); }
 #  define DEBUGLOG(l, ...) if (l<=g_debugLevel) { fprintf(stderr, __FILE__ ": "); fprintf(stderr, __VA_ARGS__); fprintf(stderr, " \n"); }
 
 #  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");       \
 }
 
-static unsigned long long GetCurrentClockTimeMicroseconds()
+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);
+   { struct tms junk; clock_t newTicks = (clock_t) times(&junk);
+     return ((((unsigned long long)newTicks)*(1000000))/_ticksPerSecond); }
 }
 
 #define MUTEX_WAIT_TIME_DLEVEL 5
 #define PTHREAD_MUTEX_LOCK(mutex) \
 if (g_debugLevel>=MUTEX_WAIT_TIME_DLEVEL) { \
-   unsigned long long beforeTime = GetCurrentClockTimeMicroseconds(); \
-   pthread_mutex_lock(mutex); \
-   unsigned long long afterTime = GetCurrentClockTimeMicroseconds(); \
-   unsigned long long 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", \
+    unsigned long long const beforeTime = GetCurrentClockTimeMicroseconds(); \
+    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 pthread_mutex_lock(mutex);
 
 #else
 
 #  define DEBUGLOG(l, ...)      {}    /* disabled */
 #  define PTHREAD_MUTEX_LOCK(m) pthread_mutex_lock(m)
 #  define DEBUG_PRINTHEX(l,p,n) {}
 
 #endif
 
 
 /* =====   Buffer Pool   ===== */
 
 typedef struct buffer_s {
     void* start;
     size_t size;
 } buffer_t;
 
 static const buffer_t g_nullBuffer = { NULL, 0 };
 
 typedef struct ZSTDMT_bufferPool_s {
     unsigned totalBuffers;
     unsigned nbBuffers;
     buffer_t bTable[1];   /* variable size */
 } ZSTDMT_bufferPool;
 
 static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned nbThreads)
 {
     unsigned const maxNbBuffers = 2*nbThreads + 2;
     ZSTDMT_bufferPool* const bufPool = (ZSTDMT_bufferPool*)calloc(1, sizeof(ZSTDMT_bufferPool) + (maxNbBuffers-1) * sizeof(buffer_t));
     if (bufPool==NULL) return NULL;
     bufPool->totalBuffers = maxNbBuffers;
     bufPool->nbBuffers = 0;
     return bufPool;
 }
 
 static void ZSTDMT_freeBufferPool(ZSTDMT_bufferPool* bufPool)
 {
     unsigned u;
     if (!bufPool) return;   /* compatibility with free on NULL */
     for (u=0; utotalBuffers; u++)
         free(bufPool->bTable[u].start);
     free(bufPool);
 }
 
 /* assumption : invocation from main thread only ! */
 static buffer_t ZSTDMT_getBuffer(ZSTDMT_bufferPool* pool, size_t bSize)
 {
     if (pool->nbBuffers) {   /* try to use an existing buffer */
         buffer_t const buf = pool->bTable[--(pool->nbBuffers)];
         size_t const availBufferSize = buf.size;
         if ((availBufferSize >= bSize) & (availBufferSize <= 10*bSize))   /* large enough, but not too much */
             return buf;
         free(buf.start);   /* size conditions not respected : scratch this buffer and create a new one */
     }
     /* create new buffer */
     {   buffer_t buffer;
         void* const start = malloc(bSize);
         if (start==NULL) bSize = 0;
         buffer.start = start;   /* note : start can be NULL if malloc fails ! */
         buffer.size = bSize;
         return buffer;
     }
 }
 
 /* store buffer for later re-use, up to pool capacity */
 static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* pool, buffer_t buf)
 {
     if (buf.start == NULL) return;   /* release on NULL */
     if (pool->nbBuffers < pool->totalBuffers) {
         pool->bTable[pool->nbBuffers++] = buf;   /* store for later re-use */
         return;
     }
     /* Reached bufferPool capacity (should not happen) */
     free(buf.start);
 }
 
 
 /* =====   CCtx Pool   ===== */
 
 typedef struct {
     unsigned totalCCtx;
     unsigned availCCtx;
     ZSTD_CCtx* cctx[1];   /* variable size */
 } ZSTDMT_CCtxPool;
 
 /* assumption : CCtxPool invocation only from main thread */
 
 /* 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 */
     free(pool);
 }
 
 /* ZSTDMT_createCCtxPool() :
  * implies nbThreads >= 1 , checked by caller ZSTDMT_createCCtx() */
 static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(unsigned nbThreads)
 {
     ZSTDMT_CCtxPool* const cctxPool = (ZSTDMT_CCtxPool*) calloc(1, sizeof(ZSTDMT_CCtxPool) + (nbThreads-1)*sizeof(ZSTD_CCtx*));
     if (!cctxPool) return NULL;
     cctxPool->totalCCtx = nbThreads;
     cctxPool->availCCtx = 1;   /* at least one cctx for single-thread mode */
     cctxPool->cctx[0] = ZSTD_createCCtx();
     if (!cctxPool->cctx[0]) { ZSTDMT_freeCCtxPool(cctxPool); return NULL; }
     DEBUGLOG(1, "cctxPool created, with %u threads", nbThreads);
     return cctxPool;
 }
 
 static ZSTD_CCtx* ZSTDMT_getCCtx(ZSTDMT_CCtxPool* pool)
 {
     if (pool->availCCtx) {
         pool->availCCtx--;
         return pool->cctx[pool->availCCtx];
     }
     return ZSTD_createCCtx();   /* 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 */
     if (pool->availCCtx < pool->totalCCtx)
         pool->cctx[pool->availCCtx++] = cctx;
     else
         /* pool overflow : should not happen, since totalCCtx==nbThreads */
         ZSTD_freeCCtx(cctx);
 }
 
 
 /* =====   Thread worker   ===== */
 
 typedef struct {
     buffer_t buffer;
     size_t filled;
 } inBuff_t;
 
 typedef struct {
     ZSTD_CCtx* cctx;
     buffer_t src;
     const void* srcStart;
     size_t   srcSize;
     size_t   dictSize;
     buffer_t dstBuff;
     size_t   cSize;
     size_t   dstFlushed;
     unsigned firstChunk;
     unsigned lastChunk;
     unsigned jobCompleted;
     unsigned jobScanned;
     pthread_mutex_t* jobCompleted_mutex;
     pthread_cond_t* jobCompleted_cond;
     ZSTD_parameters params;
     ZSTD_CDict* cdict;
     unsigned long long fullFrameSize;
 } ZSTDMT_jobDescription;
 
 /* ZSTDMT_compressChunk() : POOL_function type */
 void ZSTDMT_compressChunk(void* jobDescription)
 {
     ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)jobDescription;
     const void* const src = (const char*)job->srcStart + job->dictSize;
     buffer_t const dstBuff = job->dstBuff;
-    DEBUGLOG(3, "job (first:%u) (last:%u) : dictSize %u, srcSize %u", job->firstChunk, job->lastChunk, (U32)job->dictSize, (U32)job->srcSize);
+    DEBUGLOG(3, "job (first:%u) (last:%u) : dictSize %u, srcSize %u",
+                 job->firstChunk, job->lastChunk, (U32)job->dictSize, (U32)job->srcSize);
     if (job->cdict) {  /* should only happen for first segment */
-        size_t const initError = ZSTD_compressBegin_usingCDict(job->cctx, job->cdict, job->fullFrameSize);
+        size_t const initError = ZSTD_compressBegin_usingCDict_advanced(job->cctx, job->cdict, job->params.fParams, job->fullFrameSize);
         if (job->cdict) DEBUGLOG(3, "using CDict ");
         if (ZSTD_isError(initError)) { job->cSize = initError; goto _endJob; }
     } else {  /* srcStart points at reloaded section */
-        size_t const dictModeError = ZSTD_setCCtxParameter(job->cctx, ZSTD_p_forceRawDict, 1);  /* Force loading dictionary in "content-only" mode (no header analysis) */
-        size_t const initError = ZSTD_compressBegin_advanced(job->cctx, job->srcStart, job->dictSize, job->params, 0);
-        if (ZSTD_isError(initError) || ZSTD_isError(dictModeError)) { job->cSize = initError; goto _endJob; }
-        ZSTD_setCCtxParameter(job->cctx, ZSTD_p_forceWindow, 1);
-    }
+        if (!job->firstChunk) job->params.fParams.contentSizeFlag = 0;  /* ensure no srcSize control */
+        {   size_t const dictModeError = ZSTD_setCCtxParameter(job->cctx, ZSTD_p_forceRawDict, 1);  /* Force loading dictionary in "content-only" mode (no header analysis) */
+            size_t const initError = ZSTD_compressBegin_advanced(job->cctx, job->srcStart, job->dictSize, job->params, job->fullFrameSize);
+            if (ZSTD_isError(initError) || ZSTD_isError(dictModeError)) { job->cSize = initError; goto _endJob; }
+            ZSTD_setCCtxParameter(job->cctx, ZSTD_p_forceWindow, 1);
+    }   }
     if (!job->firstChunk) {  /* flush and overwrite frame header when it's not first segment */
         size_t const hSize = ZSTD_compressContinue(job->cctx, dstBuff.start, dstBuff.size, src, 0);
         if (ZSTD_isError(hSize)) { job->cSize = hSize; goto _endJob; }
         ZSTD_invalidateRepCodes(job->cctx);
     }
 
     DEBUGLOG(4, "Compressing : ");
     DEBUG_PRINTHEX(4, job->srcStart, 12);
     job->cSize = (job->lastChunk) ?
                  ZSTD_compressEnd     (job->cctx, dstBuff.start, dstBuff.size, src, job->srcSize) :
                  ZSTD_compressContinue(job->cctx, dstBuff.start, dstBuff.size, src, job->srcSize);
-    DEBUGLOG(3, "compressed %u bytes into %u bytes   (first:%u) (last:%u)", (unsigned)job->srcSize, (unsigned)job->cSize, job->firstChunk, job->lastChunk);
+    DEBUGLOG(3, "compressed %u bytes into %u bytes   (first:%u) (last:%u)",
+                (unsigned)job->srcSize, (unsigned)job->cSize, job->firstChunk, job->lastChunk);
+    DEBUGLOG(5, "dstBuff.size : %u ; => %s", (U32)dstBuff.size, ZSTD_getErrorName(job->cSize));
 
 _endJob:
     PTHREAD_MUTEX_LOCK(job->jobCompleted_mutex);
     job->jobCompleted = 1;
     job->jobScanned = 0;
     pthread_cond_signal(job->jobCompleted_cond);
     pthread_mutex_unlock(job->jobCompleted_mutex);
 }
 
 
 /* ------------------------------------------ */
 /* =====   Multi-threaded compression   ===== */
 /* ------------------------------------------ */
 
 struct ZSTDMT_CCtx_s {
     POOL_ctx* factory;
     ZSTDMT_bufferPool* buffPool;
     ZSTDMT_CCtxPool* cctxPool;
     pthread_mutex_t jobCompleted_mutex;
     pthread_cond_t jobCompleted_cond;
     size_t targetSectionSize;
     size_t marginSize;
     size_t inBuffSize;
     size_t dictSize;
     size_t targetDictSize;
     inBuff_t inBuff;
     ZSTD_parameters params;
     XXH64_state_t xxhState;
     unsigned nbThreads;
     unsigned jobIDMask;
     unsigned doneJobID;
     unsigned nextJobID;
     unsigned frameEnded;
     unsigned allJobsCompleted;
     unsigned overlapRLog;
     unsigned long long frameContentSize;
     size_t sectionSize;
     ZSTD_CDict* cdict;
     ZSTD_CStream* cstream;
     ZSTDMT_jobDescription jobs[1];   /* variable size (must lies at the end) */
 };
 
 ZSTDMT_CCtx *ZSTDMT_createCCtx(unsigned nbThreads)
 {
     ZSTDMT_CCtx* cctx;
     U32 const minNbJobs = nbThreads + 2;
     U32 const nbJobsLog2 = ZSTD_highbit32(minNbJobs) + 1;
     U32 const nbJobs = 1 << nbJobsLog2;
     DEBUGLOG(5, "nbThreads : %u  ; minNbJobs : %u ;  nbJobsLog2 : %u ;  nbJobs : %u  \n",
             nbThreads, minNbJobs, nbJobsLog2, nbJobs);
     if ((nbThreads < 1) | (nbThreads > ZSTDMT_NBTHREADS_MAX)) return NULL;
     cctx = (ZSTDMT_CCtx*) calloc(1, sizeof(ZSTDMT_CCtx) + nbJobs*sizeof(ZSTDMT_jobDescription));
     if (!cctx) return NULL;
     cctx->nbThreads = nbThreads;
     cctx->jobIDMask = nbJobs - 1;
     cctx->allJobsCompleted = 1;
     cctx->sectionSize = 0;
     cctx->overlapRLog = 3;
     cctx->factory = POOL_create(nbThreads, 1);
     cctx->buffPool = ZSTDMT_createBufferPool(nbThreads);
     cctx->cctxPool = ZSTDMT_createCCtxPool(nbThreads);
     if (!cctx->factory | !cctx->buffPool | !cctx->cctxPool) {  /* one object was not created */
         ZSTDMT_freeCCtx(cctx);
         return NULL;
     }
     if (nbThreads==1) {
         cctx->cstream = ZSTD_createCStream();
         if (!cctx->cstream) {
             ZSTDMT_freeCCtx(cctx); return NULL;
     }   }
     pthread_mutex_init(&cctx->jobCompleted_mutex, NULL);   /* Todo : check init function return */
     pthread_cond_init(&cctx->jobCompleted_cond, NULL);
     DEBUGLOG(4, "mt_cctx created, for %u threads \n", nbThreads);
     return cctx;
 }
 
 /* ZSTDMT_releaseAllJobResources() :
  * Ensure all workers are killed first. */
 static void ZSTDMT_releaseAllJobResources(ZSTDMT_CCtx* mtctx)
 {
     unsigned jobID;
     for (jobID=0; jobID <= mtctx->jobIDMask; jobID++) {
         ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[jobID].dstBuff);
         mtctx->jobs[jobID].dstBuff = g_nullBuffer;
         ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[jobID].src);
         mtctx->jobs[jobID].src = g_nullBuffer;
         ZSTDMT_releaseCCtx(mtctx->cctxPool, mtctx->jobs[jobID].cctx);
         mtctx->jobs[jobID].cctx = NULL;
     }
     memset(mtctx->jobs, 0, (mtctx->jobIDMask+1)*sizeof(ZSTDMT_jobDescription));
     ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->inBuff.buffer);
     mtctx->inBuff.buffer = g_nullBuffer;
     mtctx->allJobsCompleted = 1;
 }
 
 size_t ZSTDMT_freeCCtx(ZSTDMT_CCtx* mtctx)
 {
     if (mtctx==NULL) return 0;   /* compatible with free on NULL */
     POOL_free(mtctx->factory);
     if (!mtctx->allJobsCompleted) ZSTDMT_releaseAllJobResources(mtctx); /* stop workers first */
     ZSTDMT_freeBufferPool(mtctx->buffPool);  /* release job resources into pools first */
     ZSTDMT_freeCCtxPool(mtctx->cctxPool);
     ZSTD_freeCDict(mtctx->cdict);
     ZSTD_freeCStream(mtctx->cstream);
     pthread_mutex_destroy(&mtctx->jobCompleted_mutex);
     pthread_cond_destroy(&mtctx->jobCompleted_cond);
     free(mtctx);
     return 0;
 }
 
 size_t ZSTDMT_setMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSDTMT_parameter parameter, unsigned value)
 {
     switch(parameter)
     {
     case ZSTDMT_p_sectionSize :
         mtctx->sectionSize = value;
         return 0;
     case ZSTDMT_p_overlapSectionLog :
     DEBUGLOG(4, "ZSTDMT_p_overlapSectionLog : %u", value);
         mtctx->overlapRLog = (value >= 9) ? 0 : 9 - value;
         return 0;
     default :
         return ERROR(compressionParameter_unsupported);
     }
 }
 
 
 /* ------------------------------------------ */
 /* =====   Multi-threaded compression   ===== */
 /* ------------------------------------------ */
 
 size_t ZSTDMT_compressCCtx(ZSTDMT_CCtx* mtctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize,
                            int compressionLevel)
 {
     ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, 0);
+    U32 const overlapLog = (compressionLevel >= ZSTD_maxCLevel()) ? 0 : 3;
+    size_t const overlapSize = (size_t)1 << (params.cParams.windowLog - overlapLog);
     size_t const chunkTargetSize = (size_t)1 << (params.cParams.windowLog + 2);
-    unsigned const nbChunksMax = (unsigned)(srcSize / chunkTargetSize) + (srcSize < chunkTargetSize) /* min 1 */;
+    unsigned const nbChunksMax = (unsigned)(srcSize / chunkTargetSize) + 1;
     unsigned nbChunks = MIN(nbChunksMax, mtctx->nbThreads);
     size_t const proposedChunkSize = (srcSize + (nbChunks-1)) / nbChunks;
     size_t const avgChunkSize = ((proposedChunkSize & 0x1FFFF) < 0xFFFF) ? proposedChunkSize + 0xFFFF : proposedChunkSize;   /* avoid too small last block */
     size_t remainingSrcSize = srcSize;
     const char* const srcStart = (const char*)src;
-    size_t frameStartPos = 0;
+    unsigned const compressWithinDst = (dstCapacity >= ZSTD_compressBound(srcSize)) ? nbChunks : (unsigned)(dstCapacity / ZSTD_compressBound(avgChunkSize));  /* presumes avgChunkSize >= 256 KB, which should be the case */
+    size_t frameStartPos = 0, dstBufferPos = 0;
 
     DEBUGLOG(3, "windowLog : %2u => chunkTargetSize : %u bytes  ", params.cParams.windowLog, (U32)chunkTargetSize);
     DEBUGLOG(2, "nbChunks  : %2u   (chunkSize : %u bytes)   ", nbChunks, (U32)avgChunkSize);
     params.fParams.contentSizeFlag = 1;
 
     if (nbChunks==1) {   /* fallback to single-thread mode */
         ZSTD_CCtx* const cctx = mtctx->cctxPool->cctx[0];
         return ZSTD_compressCCtx(cctx, dst, dstCapacity, src, srcSize, compressionLevel);
     }
 
     {   unsigned u;
         for (u=0; ubuffPool, dstBufferCapacity) : dstAsBuffer;
+            size_t const dstBufferCapacity = ZSTD_compressBound(chunkSize);
+            buffer_t const dstAsBuffer = { (char*)dst + dstBufferPos, dstBufferCapacity };
+            buffer_t const dstBuffer = u < compressWithinDst ? dstAsBuffer : ZSTDMT_getBuffer(mtctx->buffPool, dstBufferCapacity);
             ZSTD_CCtx* const cctx = ZSTDMT_getCCtx(mtctx->cctxPool);
+            size_t dictSize = u ? overlapSize : 0;
 
             if ((cctx==NULL) || (dstBuffer.start==NULL)) {
                 mtctx->jobs[u].cSize = ERROR(memory_allocation);   /* job result */
                 mtctx->jobs[u].jobCompleted = 1;
                 nbChunks = u+1;
                 break;   /* let's wait for previous jobs to complete, but don't start new ones */
             }
 
-            mtctx->jobs[u].srcStart = srcStart + frameStartPos;
+            mtctx->jobs[u].srcStart = srcStart + frameStartPos - dictSize;
+            mtctx->jobs[u].dictSize = dictSize;
             mtctx->jobs[u].srcSize = chunkSize;
             mtctx->jobs[u].fullFrameSize = srcSize;
             mtctx->jobs[u].params = params;
             mtctx->jobs[u].dstBuff = dstBuffer;
             mtctx->jobs[u].cctx = cctx;
             mtctx->jobs[u].firstChunk = (u==0);
             mtctx->jobs[u].lastChunk = (u==nbChunks-1);
             mtctx->jobs[u].jobCompleted = 0;
             mtctx->jobs[u].jobCompleted_mutex = &mtctx->jobCompleted_mutex;
             mtctx->jobs[u].jobCompleted_cond = &mtctx->jobCompleted_cond;
 
             DEBUGLOG(3, "posting job %u   (%u bytes)", u, (U32)chunkSize);
             DEBUG_PRINTHEX(3, mtctx->jobs[u].srcStart, 12);
             POOL_add(mtctx->factory, ZSTDMT_compressChunk, &mtctx->jobs[u]);
 
             frameStartPos += chunkSize;
+            dstBufferPos += dstBufferCapacity;
             remainingSrcSize -= chunkSize;
     }   }
     /* note : since nbChunks <= nbThreads, all jobs should be running immediately in parallel */
 
     {   unsigned chunkID;
         size_t error = 0, dstPos = 0;
         for (chunkID=0; chunkIDjobCompleted_mutex);
             while (mtctx->jobs[chunkID].jobCompleted==0) {
                 DEBUGLOG(4, "waiting for jobCompleted signal from chunk %u", chunkID);
                 pthread_cond_wait(&mtctx->jobCompleted_cond, &mtctx->jobCompleted_mutex);
             }
             pthread_mutex_unlock(&mtctx->jobCompleted_mutex);
             DEBUGLOG(3, "ready to write chunk %u ", chunkID);
 
             ZSTDMT_releaseCCtx(mtctx->cctxPool, mtctx->jobs[chunkID].cctx);
             mtctx->jobs[chunkID].cctx = NULL;
             mtctx->jobs[chunkID].srcStart = NULL;
             {   size_t const cSize = mtctx->jobs[chunkID].cSize;
                 if (ZSTD_isError(cSize)) error = cSize;
                 if ((!error) && (dstPos + cSize > dstCapacity)) error = ERROR(dstSize_tooSmall);
                 if (chunkID) {   /* note : chunk 0 is already written directly into dst */
-                    if (!error) memcpy((char*)dst + dstPos, mtctx->jobs[chunkID].dstBuff.start, cSize);
-                    ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[chunkID].dstBuff);
+                    if (!error)
+                        memmove((char*)dst + dstPos, mtctx->jobs[chunkID].dstBuff.start, cSize);  /* may overlap if chunk decompressed within dst */
+                    if (chunkID >= compressWithinDst)   /* otherwise, it decompresses within dst */
+                        ZSTDMT_releaseBuffer(mtctx->buffPool, mtctx->jobs[chunkID].dstBuff);
                     mtctx->jobs[chunkID].dstBuff = g_nullBuffer;
                 }
                 dstPos += cSize ;
             }
         }
         if (!error) DEBUGLOG(3, "compressed size : %u  ", (U32)dstPos);
         return error ? error : dstPos;
     }
 
 }
 
 
 /* ====================================== */
 /* =======      Streaming API     ======= */
 /* ====================================== */
 
 static void ZSTDMT_waitForAllJobsCompleted(ZSTDMT_CCtx* zcs) {
     while (zcs->doneJobID < zcs->nextJobID) {
         unsigned const jobID = zcs->doneJobID & zcs->jobIDMask;
         PTHREAD_MUTEX_LOCK(&zcs->jobCompleted_mutex);
         while (zcs->jobs[jobID].jobCompleted==0) {
             DEBUGLOG(4, "waiting for jobCompleted signal from chunk %u", zcs->doneJobID);   /* we want to block when waiting for data to flush */
             pthread_cond_wait(&zcs->jobCompleted_cond, &zcs->jobCompleted_mutex);
         }
         pthread_mutex_unlock(&zcs->jobCompleted_mutex);
         zcs->doneJobID++;
     }
 }
 
 
 static size_t ZSTDMT_initCStream_internal(ZSTDMT_CCtx* zcs,
                                     const void* dict, size_t dictSize, unsigned updateDict,
                                     ZSTD_parameters params, unsigned long long pledgedSrcSize)
 {
     ZSTD_customMem const cmem = { NULL, NULL, NULL };
     DEBUGLOG(3, "Started new compression, with windowLog : %u", params.cParams.windowLog);
     if (zcs->nbThreads==1) return ZSTD_initCStream_advanced(zcs->cstream, dict, dictSize, params, pledgedSrcSize);
     if (zcs->allJobsCompleted == 0) {   /* previous job not correctly finished */
         ZSTDMT_waitForAllJobsCompleted(zcs);
         ZSTDMT_releaseAllJobResources(zcs);
         zcs->allJobsCompleted = 1;
     }
     zcs->params = params;
     if (updateDict) {
         ZSTD_freeCDict(zcs->cdict); zcs->cdict = NULL;
         if (dict && dictSize) {
-            zcs->cdict = ZSTD_createCDict_advanced(dict, dictSize, 0, params, cmem);
+            zcs->cdict = ZSTD_createCDict_advanced(dict, dictSize, 0, params.cParams, cmem);
             if (zcs->cdict == NULL) return ERROR(memory_allocation);
     }   }
     zcs->frameContentSize = pledgedSrcSize;
     zcs->targetDictSize = (zcs->overlapRLog>=9) ? 0 : (size_t)1 << (zcs->params.cParams.windowLog - zcs->overlapRLog);
     DEBUGLOG(4, "overlapRLog : %u ", zcs->overlapRLog);
     DEBUGLOG(3, "overlap Size : %u KB", (U32)(zcs->targetDictSize>>10));
     zcs->targetSectionSize = zcs->sectionSize ? zcs->sectionSize : (size_t)1 << (zcs->params.cParams.windowLog + 2);
     zcs->targetSectionSize = MAX(ZSTDMT_SECTION_SIZE_MIN, zcs->targetSectionSize);
     zcs->targetSectionSize = MAX(zcs->targetDictSize, zcs->targetSectionSize);
     DEBUGLOG(3, "Section Size : %u KB", (U32)(zcs->targetSectionSize>>10));
     zcs->marginSize = zcs->targetSectionSize >> 2;
     zcs->inBuffSize = zcs->targetDictSize + zcs->targetSectionSize + zcs->marginSize;
     zcs->inBuff.buffer = ZSTDMT_getBuffer(zcs->buffPool, zcs->inBuffSize);
     if (zcs->inBuff.buffer.start == NULL) return ERROR(memory_allocation);
     zcs->inBuff.filled = 0;
     zcs->dictSize = 0;
     zcs->doneJobID = 0;
     zcs->nextJobID = 0;
     zcs->frameEnded = 0;
     zcs->allJobsCompleted = 0;
     if (params.fParams.checksumFlag) XXH64_reset(&zcs->xxhState, 0);
     return 0;
 }
 
 size_t ZSTDMT_initCStream_advanced(ZSTDMT_CCtx* zcs,
                                 const void* dict, size_t dictSize,
                                 ZSTD_parameters params, unsigned long long pledgedSrcSize)
 {
     return ZSTDMT_initCStream_internal(zcs, dict, dictSize, 1, params, pledgedSrcSize);
 }
 
 /* ZSTDMT_resetCStream() :
  * pledgedSrcSize is optional and can be zero == unknown */
 size_t ZSTDMT_resetCStream(ZSTDMT_CCtx* zcs, unsigned long long pledgedSrcSize)
 {
     if (zcs->nbThreads==1) return ZSTD_resetCStream(zcs->cstream, pledgedSrcSize);
     return ZSTDMT_initCStream_internal(zcs, NULL, 0, 0, zcs->params, pledgedSrcSize);
 }
 
 size_t ZSTDMT_initCStream(ZSTDMT_CCtx* zcs, int compressionLevel) {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, 0, 0);
     return ZSTDMT_initCStream_internal(zcs, NULL, 0, 1, params, 0);
 }
 
 
 static size_t ZSTDMT_createCompressionJob(ZSTDMT_CCtx* zcs, size_t srcSize, unsigned endFrame)
 {
     size_t const dstBufferCapacity = ZSTD_compressBound(srcSize);
     buffer_t const dstBuffer = ZSTDMT_getBuffer(zcs->buffPool, dstBufferCapacity);
     ZSTD_CCtx* const cctx = ZSTDMT_getCCtx(zcs->cctxPool);
     unsigned const jobID = zcs->nextJobID & zcs->jobIDMask;
 
     if ((cctx==NULL) || (dstBuffer.start==NULL)) {
         zcs->jobs[jobID].jobCompleted = 1;
         zcs->nextJobID++;
         ZSTDMT_waitForAllJobsCompleted(zcs);
         ZSTDMT_releaseAllJobResources(zcs);
         return ERROR(memory_allocation);
     }
 
     DEBUGLOG(4, "preparing job %u to compress %u bytes with %u preload ", zcs->nextJobID, (U32)srcSize, (U32)zcs->dictSize);
     zcs->jobs[jobID].src = zcs->inBuff.buffer;
     zcs->jobs[jobID].srcStart = zcs->inBuff.buffer.start;
     zcs->jobs[jobID].srcSize = srcSize;
     zcs->jobs[jobID].dictSize = zcs->dictSize;   /* note : zcs->inBuff.filled is presumed >= srcSize + dictSize */
     zcs->jobs[jobID].params = zcs->params;
     if (zcs->nextJobID) zcs->jobs[jobID].params.fParams.checksumFlag = 0;  /* do not calculate checksum within sections, just keep it in header for first section */
     zcs->jobs[jobID].cdict = zcs->nextJobID==0 ? zcs->cdict : NULL;
     zcs->jobs[jobID].fullFrameSize = zcs->frameContentSize;
     zcs->jobs[jobID].dstBuff = dstBuffer;
     zcs->jobs[jobID].cctx = cctx;
     zcs->jobs[jobID].firstChunk = (zcs->nextJobID==0);
     zcs->jobs[jobID].lastChunk = endFrame;
     zcs->jobs[jobID].jobCompleted = 0;
     zcs->jobs[jobID].dstFlushed = 0;
     zcs->jobs[jobID].jobCompleted_mutex = &zcs->jobCompleted_mutex;
     zcs->jobs[jobID].jobCompleted_cond = &zcs->jobCompleted_cond;
 
     /* get a new buffer for next input */
     if (!endFrame) {
         size_t const newDictSize = MIN(srcSize + zcs->dictSize, zcs->targetDictSize);
         zcs->inBuff.buffer = ZSTDMT_getBuffer(zcs->buffPool, zcs->inBuffSize);
         if (zcs->inBuff.buffer.start == NULL) {   /* not enough memory to allocate next input buffer */
             zcs->jobs[jobID].jobCompleted = 1;
             zcs->nextJobID++;
             ZSTDMT_waitForAllJobsCompleted(zcs);
             ZSTDMT_releaseAllJobResources(zcs);
             return ERROR(memory_allocation);
         }
         DEBUGLOG(5, "inBuff filled to %u", (U32)zcs->inBuff.filled);
         zcs->inBuff.filled -= srcSize + zcs->dictSize - newDictSize;
         DEBUGLOG(5, "new job : filled to %u, with %u dict and %u src", (U32)zcs->inBuff.filled, (U32)newDictSize, (U32)(zcs->inBuff.filled - newDictSize));
         memmove(zcs->inBuff.buffer.start, (const char*)zcs->jobs[jobID].srcStart + zcs->dictSize + srcSize - newDictSize, zcs->inBuff.filled);
         DEBUGLOG(5, "new inBuff pre-filled");
         zcs->dictSize = newDictSize;
     } else {
         zcs->inBuff.buffer = g_nullBuffer;
         zcs->inBuff.filled = 0;
         zcs->dictSize = 0;
         zcs->frameEnded = 1;
         if (zcs->nextJobID == 0)
             zcs->params.fParams.checksumFlag = 0;   /* single chunk : checksum is calculated directly within worker thread */
     }
 
     DEBUGLOG(3, "posting job %u : %u bytes  (end:%u) (note : doneJob = %u=>%u)", zcs->nextJobID, (U32)zcs->jobs[jobID].srcSize, zcs->jobs[jobID].lastChunk, zcs->doneJobID, zcs->doneJobID & zcs->jobIDMask);
     POOL_add(zcs->factory, ZSTDMT_compressChunk, &zcs->jobs[jobID]);   /* this call is blocking when thread worker pool is exhausted */
     zcs->nextJobID++;
     return 0;
 }
 
 
 /* ZSTDMT_flushNextJob() :
  * output : 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, 1 if unknown but > 0, 0 if no more, or an error code */
 static size_t ZSTDMT_flushNextJob(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output, unsigned blockToFlush)
 {
     unsigned const wJobID = zcs->doneJobID & zcs->jobIDMask;
     if (zcs->doneJobID == zcs->nextJobID) return 0;   /* all flushed ! */
     PTHREAD_MUTEX_LOCK(&zcs->jobCompleted_mutex);
     while (zcs->jobs[wJobID].jobCompleted==0) {
         DEBUGLOG(5, "waiting for jobCompleted signal from job %u", zcs->doneJobID);
         if (!blockToFlush) { pthread_mutex_unlock(&zcs->jobCompleted_mutex); return 0; }  /* nothing ready to be flushed => skip */
         pthread_cond_wait(&zcs->jobCompleted_cond, &zcs->jobCompleted_mutex);  /* block when nothing available to flush */
     }
     pthread_mutex_unlock(&zcs->jobCompleted_mutex);
     /* compression job completed : output can be flushed */
     {   ZSTDMT_jobDescription job = zcs->jobs[wJobID];
         if (!job.jobScanned) {
             if (ZSTD_isError(job.cSize)) {
                 DEBUGLOG(5, "compression error detected ");
                 ZSTDMT_waitForAllJobsCompleted(zcs);
                 ZSTDMT_releaseAllJobResources(zcs);
                 return job.cSize;
             }
             ZSTDMT_releaseCCtx(zcs->cctxPool, job.cctx);
             zcs->jobs[wJobID].cctx = NULL;
             DEBUGLOG(5, "zcs->params.fParams.checksumFlag : %u ", zcs->params.fParams.checksumFlag);
             if (zcs->params.fParams.checksumFlag) {
                 XXH64_update(&zcs->xxhState, (const char*)job.srcStart + job.dictSize, job.srcSize);
                 if (zcs->frameEnded && (zcs->doneJobID+1 == zcs->nextJobID)) {  /* write checksum at end of last section */
                     U32 const checksum = (U32)XXH64_digest(&zcs->xxhState);
                     DEBUGLOG(4, "writing checksum : %08X \n", checksum);
                     MEM_writeLE32((char*)job.dstBuff.start + job.cSize, checksum);
                     job.cSize += 4;
                     zcs->jobs[wJobID].cSize += 4;
             }   }
             ZSTDMT_releaseBuffer(zcs->buffPool, job.src);
             zcs->jobs[wJobID].srcStart = NULL;
             zcs->jobs[wJobID].src = g_nullBuffer;
             zcs->jobs[wJobID].jobScanned = 1;
         }
         {   size_t const toWrite = MIN(job.cSize - job.dstFlushed, output->size - output->pos);
             DEBUGLOG(4, "Flushing %u bytes from job %u ", (U32)toWrite, zcs->doneJobID);
             memcpy((char*)output->dst + output->pos, (const char*)job.dstBuff.start + job.dstFlushed, toWrite);
             output->pos += toWrite;
             job.dstFlushed += toWrite;
         }
         if (job.dstFlushed == job.cSize) {   /* output buffer fully flushed => move to next one */
             ZSTDMT_releaseBuffer(zcs->buffPool, job.dstBuff);
             zcs->jobs[wJobID].dstBuff = g_nullBuffer;
             zcs->jobs[wJobID].jobCompleted = 0;
             zcs->doneJobID++;
         } else {
             zcs->jobs[wJobID].dstFlushed = job.dstFlushed;
         }
         /* return value : how many bytes left in buffer ; fake it to 1 if unknown but >0 */
         if (job.cSize > job.dstFlushed) return (job.cSize - job.dstFlushed);
         if (zcs->doneJobID < zcs->nextJobID) return 1;   /* still some buffer to flush */
         zcs->allJobsCompleted = zcs->frameEnded;   /* frame completed and entirely flushed */
         return 0;   /* everything flushed */
 }   }
 
 
 size_t ZSTDMT_compressStream(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     size_t const newJobThreshold = zcs->dictSize + zcs->targetSectionSize + zcs->marginSize;
     if (zcs->frameEnded) return ERROR(stage_wrong);   /* current frame being ended. Only flush is allowed. Restart with init */
     if (zcs->nbThreads==1) return ZSTD_compressStream(zcs->cstream, output, input);
 
     /* fill input buffer */
     {   size_t const toLoad = MIN(input->size - input->pos, zcs->inBuffSize - zcs->inBuff.filled);
         memcpy((char*)zcs->inBuff.buffer.start + zcs->inBuff.filled, input->src, toLoad);
         input->pos += toLoad;
         zcs->inBuff.filled += toLoad;
     }
 
     if ( (zcs->inBuff.filled >= newJobThreshold)  /* filled enough : let's compress */
         && (zcs->nextJobID <= zcs->doneJobID + zcs->jobIDMask) ) {   /* avoid overwriting job round buffer */
         CHECK_F( ZSTDMT_createCompressionJob(zcs, zcs->targetSectionSize, 0) );
     }
 
     /* check for data to flush */
     CHECK_F( ZSTDMT_flushNextJob(zcs, output, (zcs->inBuff.filled == zcs->inBuffSize)) ); /* block if it wasn't possible to create new job due to saturation */
 
     /* recommended next input size : fill current input buffer */
     return zcs->inBuffSize - zcs->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* zcs, ZSTD_outBuffer* output, unsigned endFrame)
 {
     size_t const srcSize = zcs->inBuff.filled - zcs->dictSize;
 
     if (srcSize) DEBUGLOG(4, "flushing : %u bytes left to compress", (U32)srcSize);
     if ( ((srcSize > 0) || (endFrame && !zcs->frameEnded))
        && (zcs->nextJobID <= zcs->doneJobID + zcs->jobIDMask) ) {
         CHECK_F( ZSTDMT_createCompressionJob(zcs, srcSize, endFrame) );
     }
 
     /* check if there is any data available to flush */
     DEBUGLOG(5, "zcs->doneJobID : %u  ; zcs->nextJobID : %u ", zcs->doneJobID, zcs->nextJobID);
     return ZSTDMT_flushNextJob(zcs, output, 1);
 }
 
 
 size_t ZSTDMT_flushStream(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output)
 {
     if (zcs->nbThreads==1) return ZSTD_flushStream(zcs->cstream, output);
     return ZSTDMT_flushStream_internal(zcs, output, 0);
 }
 
 size_t ZSTDMT_endStream(ZSTDMT_CCtx* zcs, ZSTD_outBuffer* output)
 {
     if (zcs->nbThreads==1) return ZSTD_endStream(zcs->cstream, output);
     return ZSTDMT_flushStream_internal(zcs, output, 1);
 }
Index: head/contrib/zstd/lib/decompress/zstd_decompress.c
===================================================================
--- head/contrib/zstd/lib/decompress/zstd_decompress.c	(revision 317876)
+++ head/contrib/zstd/lib/decompress/zstd_decompress.c	(revision 317877)
@@ -1,2480 +1,2376 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 /* ***************************************************************
 *  Tuning parameters
 *****************************************************************/
 /*!
  * HEAPMODE :
  * Select how default decompression function ZSTD_decompress() will allocate memory,
  * in memory stack (0), or in memory heap (1, requires malloc())
  */
 #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.
 */
 #ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
 #  define ZSTD_MAXWINDOWSIZE_DEFAULT ((1 << ZSTD_WINDOWLOG_MAX) + 1)   /* defined within zstd.h */
 #endif
 
 
 /*-*******************************************************
 *  Dependencies
 *********************************************************/
 #include       /* memcpy, memmove, memset */
 #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
 
 
 #if defined(_MSC_VER)
 #  include    /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
 #  define ZSTD_PREFETCH(ptr)   _mm_prefetch((const char*)ptr, _MM_HINT_T0)
 #elif defined(__GNUC__)
 #  define ZSTD_PREFETCH(ptr)   __builtin_prefetch(ptr, 0, 0)
 #else
 #  define ZSTD_PREFETCH(ptr)   /* disabled */
 #endif
 
 /*-*************************************
 *  Macros
 ***************************************/
 #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 struct {
     FSE_DTable LLTable[FSE_DTABLE_SIZE_U32(LLFSELog)];
     FSE_DTable OFTable[FSE_DTABLE_SIZE_U32(OffFSELog)];
     FSE_DTable MLTable[FSE_DTABLE_SIZE_U32(MLFSELog)];
     HUF_DTable hufTable[HUF_DTABLE_SIZE(HufLog)];  /* can accommodate HUF_decompress4X */
     U32 rep[ZSTD_REP_NUM];
 } ZSTD_entropyTables_t;
 
 struct ZSTD_DCtx_s
 {
     const FSE_DTable* LLTptr;
     const FSE_DTable* MLTptr;
     const FSE_DTable* OFTptr;
     const HUF_DTable* HUFptr;
     ZSTD_entropyTables_t entropy;
     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* dictEnd;          /* end of previous segment */
     size_t expected;
     ZSTD_frameParams fParams;
     blockType_e bType;   /* used in ZSTD_decompressContinue(), to transfer blockType between header decoding and block decoding stages */
     ZSTD_dStage stage;
     U32 litEntropy;
     U32 fseEntropy;
     XXH64_state_t xxhState;
     size_t headerSize;
     U32 dictID;
     const BYTE* litPtr;
     ZSTD_customMem customMem;
     size_t litSize;
     size_t rleSize;
     BYTE litBuffer[ZSTD_BLOCKSIZE_ABSOLUTEMAX + WILDCOPY_OVERLENGTH];
     BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
 };  /* typedef'd to ZSTD_DCtx within "zstd.h" */
 
 size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx) { return (dctx==NULL) ? 0 : sizeof(ZSTD_DCtx); }
 
 size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
 
 size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
 {
     dctx->expected = ZSTD_frameHeaderSize_prefix;
     dctx->stage = ZSTDds_getFrameHeaderSize;
     dctx->previousDstEnd = NULL;
     dctx->base = NULL;
     dctx->vBase = 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;
     MEM_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;
 }
 
 ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
 {
     ZSTD_DCtx* dctx;
 
     if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
     if (!customMem.customAlloc || !customMem.customFree) return NULL;
 
     dctx = (ZSTD_DCtx*)ZSTD_malloc(sizeof(ZSTD_DCtx), customMem);
     if (!dctx) return NULL;
     memcpy(&dctx->customMem, &customMem, sizeof(customMem));
     ZSTD_decompressBegin(dctx);
     return dctx;
 }
 
 ZSTD_DCtx* ZSTD_createDCtx(void)
 {
     return ZSTD_createDCtx_advanced(defaultCustomMem);
 }
 
 size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
 {
     if (dctx==NULL) return 0;   /* support free on NULL */
     ZSTD_free(dctx, dctx->customMem);
     return 0;   /* reserved as a potential error code in the future */
 }
 
 void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
 {
     size_t const workSpaceSize = (ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH) + ZSTD_frameHeaderSize_max;
     memcpy(dstDCtx, srcDCtx, sizeof(ZSTD_DCtx) - workSpaceSize);  /* no need to copy workspace */
 }
 
-#if 0
-/* deprecated */
-static void ZSTD_refDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
-{
-    ZSTD_decompressBegin(dstDCtx);  /* init */
-    if (srcDCtx) {   /* support refDCtx on NULL */
-        dstDCtx->dictEnd = srcDCtx->dictEnd;
-        dstDCtx->vBase = srcDCtx->vBase;
-        dstDCtx->base = srcDCtx->base;
-        dstDCtx->previousDstEnd = srcDCtx->previousDstEnd;
-        dstDCtx->dictID = srcDCtx->dictID;
-        dstDCtx->litEntropy = srcDCtx->litEntropy;
-        dstDCtx->fseEntropy = srcDCtx->fseEntropy;
-        dstDCtx->LLTptr = srcDCtx->entropy.LLTable;
-        dstDCtx->MLTptr = srcDCtx->entropy.MLTable;
-        dstDCtx->OFTptr = srcDCtx->entropy.OFTable;
-        dstDCtx->HUFptr = srcDCtx->entropy.hufTable;
-        dstDCtx->entropy.rep[0] = srcDCtx->entropy.rep[0];
-        dstDCtx->entropy.rep[1] = srcDCtx->entropy.rep[1];
-        dstDCtx->entropy.rep[2] = srcDCtx->entropy.rep[2];
-    }
-}
-#endif
-
 static void ZSTD_refDDict(ZSTD_DCtx* dstDCtx, const ZSTD_DDict* ddict);
 
 
 /*-*************************************************************
 *   Decompression section
 ***************************************************************/
 
 /*! 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 < 4) 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() :
 *   srcSize must be >= ZSTD_frameHeaderSize_prefix.
 *   @return : size of the Frame Header */
 static size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
 {
     if (srcSize < ZSTD_frameHeaderSize_prefix) return ERROR(srcSize_wrong);
     {   BYTE const fhd = ((const BYTE*)src)[4];
         U32 const dictID= fhd & 3;
         U32 const singleSegment = (fhd >> 5) & 1;
         U32 const fcsId = fhd >> 6;
         return ZSTD_frameHeaderSize_prefix + !singleSegment + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId]
                 + (singleSegment && !fcsId);
     }
 }
 
 
 /** ZSTD_getFrameParams() :
 *   decode Frame Header, or require larger `srcSize`.
 *   @return : 0, `fparamsPtr` is correctly filled,
 *            >0, `srcSize` is too small, result is expected `srcSize`,
 *             or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize)
 {
     const BYTE* ip = (const BYTE*)src;
 
     if (srcSize < ZSTD_frameHeaderSize_prefix) return ZSTD_frameHeaderSize_prefix;
     if (MEM_readLE32(src) != ZSTD_MAGICNUMBER) {
         if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
             if (srcSize < ZSTD_skippableHeaderSize) return ZSTD_skippableHeaderSize; /* magic number + skippable frame length */
             memset(fparamsPtr, 0, sizeof(*fparamsPtr));
             fparamsPtr->frameContentSize = MEM_readLE32((const char *)src + 4);
             fparamsPtr->windowSize = 0; /* windowSize==0 means a frame is skippable */
             return 0;
         }
         return ERROR(prefix_unknown);
     }
 
     /* ensure there is enough `srcSize` to fully read/decode frame header */
     { size_t const fhsize = ZSTD_frameHeaderSize(src, srcSize);
       if (srcSize < fhsize) return fhsize; }
 
     {   BYTE const fhdByte = ip[4];
         size_t pos = 5;
         U32 const dictIDSizeCode = fhdByte&3;
         U32 const checksumFlag = (fhdByte>>2)&1;
         U32 const singleSegment = (fhdByte>>5)&1;
         U32 const fcsID = fhdByte>>6;
         U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX;
         U32 windowSize = 0;
         U32 dictID = 0;
         U64 frameContentSize = 0;
         if ((fhdByte & 0x08) != 0) return ERROR(frameParameter_unsupported);   /* reserved bits, which 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);  /* avoids issue with 1 << windowLog */
             windowSize = (1U << windowLog);
             windowSize += (windowSize >> 3) * (wlByte&7);
         }
 
         switch(dictIDSizeCode)
         {
             default:   /* 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:   /* 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 (!windowSize) windowSize = (U32)frameContentSize;
         if (windowSize > windowSizeMax) return ERROR(frameParameter_windowTooLarge);
         fparamsPtr->frameContentSize = frameContentSize;
         fparamsPtr->windowSize = windowSize;
         fparamsPtr->dictID = dictID;
         fparamsPtr->checksumFlag = checksumFlag;
     }
     return 0;
 }
 
 /** 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_frameParams fParams;
         if (ZSTD_getFrameParams(&fParams, src, srcSize) != 0) return ZSTD_CONTENTSIZE_ERROR;
         if (fParams.windowSize == 0) {
             /* Either skippable or empty frame, size == 0 either way */
             return 0;
         } else if (fParams.frameContentSize != 0) {
             return fParams.frameContentSize;
         } else {
             return ZSTD_CONTENTSIZE_UNKNOWN;
         }
     }
 }
 
 /** 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) {
             const U32 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 + 4) +
                                 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;
             }
         }
 
         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 :
                    - decompressed size is not present within 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);
     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_getFrameParams(&(dctx->fParams), src, headerSize);
     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;
 }
 
 
 typedef struct
 {
     blockType_e blockType;
     U32 lastBlock;
     U32 origSize;
 } blockProperties_t;
 
 /*! 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)
+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)
+static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
+                          const void* src, size_t srcSize)
 {
     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)
+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;
 }
 
 /*! ZSTD_decodeLiteralsBlock() :
     @return : nb of bytes read from src (< srcSize ) */
 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_ABSOLUTEMAX) return ERROR(corruption_detected);
                 if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
 
                 if (HUF_isError((litEncType==set_repeat) ?
                                     ( singleStream ?
                                         HUF_decompress1X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr) :
                                         HUF_decompress4X_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->HUFptr) ) :
                                     ( singleStream ?
                                         HUF_decompress1X2_DCtx(dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize) :
                                         HUF_decompress4X_hufOnly (dctx->entropy.hufTable, dctx->litBuffer, litSize, istart+lhSize, litCSize)) ))
                     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_ABSOLUTEMAX) 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 */
         }
     }
 }
 
 
 typedef union {
     FSE_decode_t realData;
     U32 alignedBy4;
 } FSE_decode_t4;
 
+/* Default FSE distribution table for Literal Lengths */
 static const FSE_decode_t4 LL_defaultDTable[(1< max) return ERROR(corruption_detected);
         FSE_buildDTable_rle(DTableSpace, *(const BYTE*)src);
         *DTablePtr = DTableSpace;
         return 1;
     case set_basic :
         *DTablePtr = (const FSE_DTable*)tmpPtr;
         return 0;
     case set_repeat:
         if (!flagRepeatTable) return ERROR(corruption_detected);
         return 0;
     default :   /* impossible */
     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);
             FSE_buildDTable(DTableSpace, norm, max, tableLog);
             *DTablePtr = DTableSpace;
             return headerSize;
     }   }
 }
 
 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;
 
     /* 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++;
             }
         }
         *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_defaultDTable, dctx->fseEntropy);
             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_defaultDTable, dctx->fseEntropy);
             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_defaultDTable, dctx->fseEntropy);
             if (ZSTD_isError(mlhSize)) return ERROR(corruption_detected);
             ip += mlhSize;
         }
     }
 
     return ip-istart;
 }
 
 
 typedef struct {
     size_t litLength;
     size_t matchLength;
     size_t offset;
     const BYTE* match;
 } seq_t;
 
 typedef struct {
     BIT_DStream_t DStream;
     FSE_DState_t stateLL;
     FSE_DState_t stateOffb;
     FSE_DState_t stateML;
     size_t prevOffset[ZSTD_REP_NUM];
     const BYTE* base;
     size_t pos;
     uPtrDiff gotoDict;
 } 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;
 }
 
 
-
-
 static seq_t ZSTD_decodeSequence(seqState_t* seqState)
 {
     seq_t seq;
 
     U32 const llCode = FSE_peekSymbol(&seqState->stateLL);
     U32 const mlCode = FSE_peekSymbol(&seqState->stateML);
     U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb);   /* <= maxOff, by table construction */
 
     U32 const llBits = LL_bits[llCode];
     U32 const mlBits = ML_bits[mlCode];
     U32 const ofBits = ofCode;
     U32 const totalBits = llBits+mlBits+ofBits;
 
     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,
+                             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 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,
+                             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 };
 
     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 };
+                     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 };
 
     /* sequence */
     {   size_t offset;
         if (!ofCode)
             offset = 0;
         else {
             offset = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
             if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
         }
 
         if (ofCode <= 1) {
             offset += (llCode==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 = ML_base[mlCode] + ((mlCode>31) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0);  /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits>24)) BIT_reloadDStream(&seqState->DStream);
 
     seq.litLength = LL_base[llCode] + ((llCode>15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0);    /* <=  16 bits */
     if (MEM_32bits() ||
        (totalBits > 64 - 7 - (LLFSELog+MLFSELog+OffFSELog)) ) BIT_reloadDStream(&seqState->DStream);
 
     /* ANS state update */
     FSE_updateState(&seqState->stateLL, &seqState->DStream);    /* <=  9 bits */
     FSE_updateState(&seqState->stateML, &seqState->DStream);    /* <=  9 bits */
     if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
     FSE_updateState(&seqState->stateOffb, &seqState->DStream);  /* <=  8 bits */
 
     return seq;
 }
 
 
 FORCE_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)
 {
     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);
 
     /* 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)) {
-        /* offset beyond prefix */
+        /* offset beyond prefix -> go into extDict */
         if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(corruption_detected);
         match = dictEnd + (match - base);
         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;
             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;
 }
 
 
 static size_t ZSTD_decompressSequences(
                                ZSTD_DCtx* dctx,
                                void* dst, size_t maxDstSize,
                          const void* seqStart, size_t seqSize)
 {
     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 dictEnd = (const BYTE*) (dctx->dictEnd);
     int nbSeq;
 
     /* Build Decoding Tables */
     {   size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize);
         if (ZSTD_isError(seqHSize)) return seqHSize;
         ip += seqHSize;
     }
 
     /* 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);
         FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
         FSE_initDState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
 
         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) {
             nbSeq--;
             {   seq_t const sequence = ZSTD_decodeSequence(&seqState);
                 size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, base, vBase, dictEnd);
                 if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
                 op += oneSeqSize;
         }   }
 
         /* check if reached exact end */
         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;
 }
 
 
 FORCE_INLINE seq_t ZSTD_decodeSequenceLong_generic(seqState_t* seqState, int const longOffsets)
 {
     seq_t seq;
 
     U32 const llCode = FSE_peekSymbol(&seqState->stateLL);
     U32 const mlCode = FSE_peekSymbol(&seqState->stateML);
     U32 const ofCode = FSE_peekSymbol(&seqState->stateOffb);   /* <= maxOff, by table construction */
 
     U32 const llBits = LL_bits[llCode];
     U32 const mlBits = ML_bits[mlCode];
     U32 const ofBits = ofCode;
     U32 const totalBits = llBits+mlBits+ofBits;
 
     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,
+                             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 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,
+                             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 };
 
     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 };
+                     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 };
 
     /* sequence */
     {   size_t offset;
         if (!ofCode)
             offset = 0;
         else {
             if (longOffsets) {
                 int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN);
                 offset = OF_base[ofCode] + (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 = OF_base[ofCode] + BIT_readBitsFast(&seqState->DStream, ofBits);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
                 if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
             }
         }
 
         if (ofCode <= 1) {
             offset += (llCode==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 = ML_base[mlCode] + ((mlCode>31) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0);  /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits>24)) BIT_reloadDStream(&seqState->DStream);
 
     seq.litLength = LL_base[llCode] + ((llCode>15) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0);    /* <=  16 bits */
     if (MEM_32bits() ||
        (totalBits > 64 - 7 - (LLFSELog+MLFSELog+OffFSELog)) ) BIT_reloadDStream(&seqState->DStream);
 
     {   size_t const pos = seqState->pos + seq.litLength;
         seq.match = seqState->base + pos - seq.offset;    /* single memory segment */
         if (seq.offset > pos) seq.match += seqState->gotoDict;   /* separate memory segment */
         seqState->pos = pos + seq.matchLength;
     }
 
     /* ANS state update */
     FSE_updateState(&seqState->stateLL, &seqState->DStream);    /* <=  9 bits */
     FSE_updateState(&seqState->stateML, &seqState->DStream);    /* <=  9 bits */
     if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
     FSE_updateState(&seqState->stateOffb, &seqState->DStream);  /* <=  8 bits */
 
     return seq;
 }
 
 static seq_t ZSTD_decodeSequenceLong(seqState_t* seqState, unsigned const windowSize) {
     if (ZSTD_highbit32(windowSize) > STREAM_ACCUMULATOR_MIN) {
         return ZSTD_decodeSequenceLong_generic(seqState, 1);
     } else {
         return ZSTD_decodeSequenceLong_generic(seqState, 0);
     }
 }
 
 FORCE_INLINE
 size_t ZSTD_execSequenceLong(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 = sequence.match;
 
     /* check */
 #if 1
     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);
 #endif
 
     /* 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 1
     if (sequence.offset > (size_t)(oLitEnd - base)) {
         /* offset beyond prefix */
         if (sequence.offset > (size_t)(oLitEnd - vBase)) 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 = base;
             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 */
 #endif
 
     /* 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 size_t ZSTD_decompressSequencesLong(
                                ZSTD_DCtx* dctx,
                                void* dst, size_t maxDstSize,
                          const void* seqStart, size_t seqSize)
 {
     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 dictEnd = (const BYTE*) (dctx->dictEnd);
     unsigned const windowSize = dctx->fParams.windowSize;
     int nbSeq;
 
     /* Build Decoding Tables */
     {   size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, seqSize);
         if (ZSTD_isError(seqHSize)) return seqHSize;
         ip += seqHSize;
     }
 
     /* 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.base = base;
         seqState.pos = (size_t)(op-base);
         seqState.gotoDict = (uPtrDiff)dictEnd - (uPtrDiff)base; /* cast to avoid undefined behaviour */
         CHECK_E(BIT_initDStream(&seqState.DStream, ip, iend-ip), corruption_detected);
         FSE_initDState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         FSE_initDState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
         FSE_initDState(&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]); }
     }
 
     /* 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_decompressBlock_internal(ZSTD_DCtx* dctx,
                             void* dst, size_t dstCapacity,
                       const void* src, size_t srcSize)
 {   /* blockType == blockCompressed */
     const BYTE* ip = (const BYTE*)src;
 
     if (srcSize >= ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(srcSize_wrong);
 
     /* Decode literals section */
     {   size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
         if (ZSTD_isError(litCSize)) return litCSize;
         ip += litCSize;
         srcSize -= litCSize;
     }
     if (sizeof(size_t) > 4)  /* do not enable prefetching on 32-bits x86, as it's performance detrimental */
                              /* likely because of register pressure */
                              /* if that's the correct cause, then 32-bits ARM should be affected differently */
                              /* it would be good to test this on ARM real hardware, to see if prefetch version improves speed */
         if (dctx->fParams.windowSize > (1<<23))
             return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize);
     return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize);
 }
 
 
 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->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);
     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;
 }
 
 
 size_t ZSTD_generateNxBytes(void* dst, size_t dstCapacity, BYTE byte, size_t length)
 {
     if (length > dstCapacity) return ERROR(dstSize_tooSmall);
     memset(dst, byte, 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) & 0xFFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
+            (MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {
         return ZSTD_skippableHeaderSize + MEM_readLE32((const BYTE*)src + 4);
     } else {
         const BYTE* ip = (const BYTE*)src;
         const BYTE* const ipstart = ip;
         size_t remainingSize = srcSize;
         ZSTD_frameParams fParams;
 
         size_t const headerSize = ZSTD_frameHeaderSize(ip, remainingSize);
         if (ZSTD_isError(headerSize)) return headerSize;
 
         /* Frame Header */
         {   size_t const ret = ZSTD_getFrameParams(&fParams, ip, remainingSize);
             if (ZSTD_isError(ret)) return ret;
             if (ret > 0) return ERROR(srcSize_wrong);
         }
 
         ip += headerSize;
         remainingSize -= 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 (fParams.checksumFlag) {   /* 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);
             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.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;
 
     if (ddict) {
         if (dict) {
             /* programmer error, these two cases should be mutually exclusive */
             return ERROR(GENERIC);
         }
 
         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;
 
             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);
         if (magicNumber != 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 + 4) +
                                 ZSTD_skippableHeaderSize;
                 if (srcSize < skippableSize) {
                     return ERROR(srcSize_wrong);
                 }
 
                 src = (const BYTE *)src + skippableSize;
                 srcSize -= skippableSize;
                 continue;
             } else {
                 return ERROR(prefix_unknown);
             }
         }
 
         if (ddict) {
             /* we were called from ZSTD_decompress_usingDDict */
             ZSTD_refDDict(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_isError(res)) return res;
             /* don't need to bounds check this, ZSTD_decompressFrame will have
              * already */
             dst = (BYTE*)dst + res;
             dstCapacity -= res;
         }
     }
 
     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;
     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 */
     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;
     }
 }
 
 int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; }   /* for zbuff */
 
 /** ZSTD_decompressContinue() :
 *   @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)
 {
     /* Sanity check */
     if (srcSize != dctx->expected) return ERROR(srcSize_wrong);
     if (dstCapacity) ZSTD_checkContinuity(dctx, dst);
 
     switch (dctx->stage)
     {
     case ZSTDds_getFrameHeaderSize :
         if (srcSize != ZSTD_frameHeaderSize_prefix) return ERROR(srcSize_wrong);      /* impossible */
         if ((MEM_readLE32(src) & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) {        /* skippable frame */
             memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_prefix);
             dctx->expected = ZSTD_skippableHeaderSize - ZSTD_frameHeaderSize_prefix;  /* magic number + skippable frame length */
             dctx->stage = ZSTDds_decodeSkippableHeader;
             return 0;
         }
         dctx->headerSize = ZSTD_frameHeaderSize(src, ZSTD_frameHeaderSize_prefix);
         if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize;
         memcpy(dctx->headerBuffer, src, ZSTD_frameHeaderSize_prefix);
         if (dctx->headerSize > ZSTD_frameHeaderSize_prefix) {
             dctx->expected = dctx->headerSize - ZSTD_frameHeaderSize_prefix;
             dctx->stage = ZSTDds_decodeFrameHeader;
             return 0;
         }
         dctx->expected = 0;   /* not necessary to copy more */
 
     case ZSTDds_decodeFrameHeader:
         memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected);
         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 = 3;  /* go directly to next header */
                 dctx->stage = ZSTDds_decodeBlockHeader;
             }
             return 0;
         }
     case ZSTDds_decompressLastBlock:
     case ZSTDds_decompressBlock:
         {   size_t rSize;
             switch(dctx->bType)
             {
             case bt_compressed:
                 rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize);
                 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;
             if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize);
 
             if (dctx->stage == ZSTDds_decompressLastBlock) {   /* end of frame */
                 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:
         {   U32 const h32 = (U32)XXH64_digest(&dctx->xxhState);
             U32 const check32 = MEM_readLE32(src);   /* srcSize == 4, guaranteed by dctx->expected */
             if (check32 != h32) return ERROR(checksum_wrong);
             dctx->expected = 0;
             dctx->stage = ZSTDds_getFrameHeaderSize;
             return 0;
         }
     case ZSTDds_decodeSkippableHeader:
         {   memcpy(dctx->headerBuffer + ZSTD_frameHeaderSize_prefix, src, dctx->expected);
             dctx->expected = MEM_readLE32(dctx->headerBuffer + 4);
             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->previousDstEnd = (const char*)dict + dictSize;
     return 0;
 }
 
 /* ZSTD_loadEntropy() :
  * dict : must point at beginning of a valid zstd dictionary
  * @return : size of entropy tables read */
 static size_t ZSTD_loadEntropy(ZSTD_entropyTables_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);
     dictPtr += 8;   /* skip header = magic + dictID */
 
 
     {   size_t const hSize = HUF_readDTableX4(entropy->hufTable, dictPtr, dictEnd-dictPtr);
         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 (offcodeLog > OffFSELog) return ERROR(dictionary_corrupted);
         CHECK_E(FSE_buildDTable(entropy->OFTable, offcodeNCount, offcodeMaxValue, offcodeLog), 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);
         CHECK_E(FSE_buildDTable(entropy->MLTable, matchlengthNCount, matchlengthMaxValue, matchlengthLog), 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);
         CHECK_E(FSE_buildDTable(entropy->LLTable, litlengthNCount, litlengthMaxValue, litlengthLog), dictionary_corrupted);
         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_DICT_MAGIC) {
             return ZSTD_refDictContent(dctx, dict, dictSize);   /* pure content mode */
     }   }
     dctx->dictID = MEM_readLE32((const char*)dict + 4);
 
     /* 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);
 }
 
 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_entropyTables_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)
 {
     return ddict->dictContent;
 }
 
 static size_t ZSTD_DDictDictSize(const ZSTD_DDict* ddict)
 {
     return ddict->dictSize;
 }
 
 static void ZSTD_refDDict(ZSTD_DCtx* dstDCtx, const ZSTD_DDict* ddict)
 {
     ZSTD_decompressBegin(dstDCtx);  /* init */
     if (ddict) {   /* support refDDict 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;
         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];
         } else {
             dstDCtx->litEntropy = 0;
             dstDCtx->fseEntropy = 0;
         }
     }
 }
 
 static size_t ZSTD_loadEntropy_inDDict(ZSTD_DDict* ddict)
 {
     ddict->dictID = 0;
     ddict->entropyPresent = 0;
     if (ddict->dictSize < 8) return 0;
     {   U32 const magic = MEM_readLE32(ddict->dictContent);
         if (magic != ZSTD_DICT_MAGIC) return 0;   /* pure content mode */
     }
     ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + 4);
 
     /* load entropy tables */
     CHECK_E( ZSTD_loadEntropy(&ddict->entropy, ddict->dictContent, ddict->dictSize), dictionary_corrupted );
     ddict->entropyPresent = 1;
     return 0;
 }
 
 
 ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize, unsigned byReference, ZSTD_customMem customMem)
 {
     if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
     if (!customMem.customAlloc || !customMem.customFree) return NULL;
 
     {   ZSTD_DDict* const ddict = (ZSTD_DDict*) ZSTD_malloc(sizeof(ZSTD_DDict), customMem);
         if (!ddict) return NULL;
         ddict->cMem = customMem;
 
         if ((byReference) || (!dict) || (!dictSize)) {
             ddict->dictBuffer = NULL;
             ddict->dictContent = dict;
         } else {
             void* const internalBuffer = ZSTD_malloc(dictSize, customMem);
             if (!internalBuffer) { ZSTD_freeDDict(ddict); return NULL; }
             memcpy(internalBuffer, dict, dictSize);
             ddict->dictBuffer = internalBuffer;
             ddict->dictContent = internalBuffer;
         }
         ddict->dictSize = dictSize;
         ddict->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001);  /* cover both little and big endian */
         /* parse dictionary content */
         {   size_t const errorCode = ZSTD_loadEntropy_inDDict(ddict);
             if (ZSTD_isError(errorCode)) {
                 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, 0, 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, 1, allocator);
 }
 
 
 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;
     }
 }
 
 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_DICT_MAGIC) return 0;
     return MEM_readLE32((const char*)dict + 4);
 }
 
 /*! 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 decompressed the frame stored within `src`.
+ *  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 to be decoded (most common case).
- *  - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
+ *  - 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, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
+ *  - `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 used ZSTD_getFrameParams(), which will provide a more precise error code. */
+ *  When identifying the exact failure cause, it's possible to use
+ *  ZSTD_getFrameParams(), which will provide a more precise error code. */
 unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize)
 {
     ZSTD_frameParams zfp = { 0 , 0 , 0 , 0 };
     size_t const hError = ZSTD_getFrameParams(&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
 *====================================*/
 
 typedef enum { zdss_init, zdss_loadHeader,
                zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;
 
 /* *** Resource management *** */
 struct ZSTD_DStream_s {
     ZSTD_DCtx* dctx;
     ZSTD_DDict* ddictLocal;
     const ZSTD_DDict* ddict;
     ZSTD_frameParams fParams;
     ZSTD_dStreamStage stage;
     char*  inBuff;
     size_t inBuffSize;
     size_t inPos;
     size_t maxWindowSize;
     char*  outBuff;
     size_t outBuffSize;
     size_t outStart;
     size_t outEnd;
     size_t blockSize;
     BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];   /* tmp buffer to store frame header */
     size_t lhSize;
     ZSTD_customMem customMem;
     void* legacyContext;
     U32 previousLegacyVersion;
     U32 legacyVersion;
     U32 hostageByte;
 };   /* typedef'd to ZSTD_DStream within "zstd.h" */
 
 
 ZSTD_DStream* ZSTD_createDStream(void)
 {
     return ZSTD_createDStream_advanced(defaultCustomMem);
 }
 
 ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
 {
     ZSTD_DStream* zds;
 
     if (!customMem.customAlloc && !customMem.customFree) customMem = defaultCustomMem;
     if (!customMem.customAlloc || !customMem.customFree) return NULL;
 
     zds = (ZSTD_DStream*) ZSTD_malloc(sizeof(ZSTD_DStream), customMem);
     if (zds==NULL) return NULL;
     memset(zds, 0, sizeof(ZSTD_DStream));
     memcpy(&zds->customMem, &customMem, sizeof(ZSTD_customMem));
     zds->dctx = ZSTD_createDCtx_advanced(customMem);
     if (zds->dctx == NULL) { ZSTD_freeDStream(zds); return NULL; }
     zds->stage = zdss_init;
     zds->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
     return zds;
 }
 
 size_t ZSTD_freeDStream(ZSTD_DStream* zds)
 {
     if (zds==NULL) return 0;   /* support free on null */
     {   ZSTD_customMem const cMem = zds->customMem;
         ZSTD_freeDCtx(zds->dctx);
+        zds->dctx = NULL;
         ZSTD_freeDDict(zds->ddictLocal);
+        zds->ddictLocal = NULL;
         ZSTD_free(zds->inBuff, cMem);
+        zds->inBuff = NULL;
         ZSTD_free(zds->outBuff, cMem);
+        zds->outBuff = NULL;
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
         if (zds->legacyContext)
             ZSTD_freeLegacyStreamContext(zds->legacyContext, zds->previousLegacyVersion);
 #endif
         ZSTD_free(zds, cMem);
         return 0;
     }
 }
 
 
 /* *** Initialization *** */
 
 size_t ZSTD_DStreamInSize(void)  { return ZSTD_BLOCKSIZE_ABSOLUTEMAX + ZSTD_blockHeaderSize; }
 size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_ABSOLUTEMAX; }
 
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
 {
     zds->stage = zdss_loadHeader;
     zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
     ZSTD_freeDDict(zds->ddictLocal);
     if (dict && dictSize >= 8) {
         zds->ddictLocal = ZSTD_createDDict(dict, dictSize);
         if (zds->ddictLocal == NULL) return ERROR(memory_allocation);
     } else zds->ddictLocal = NULL;
     zds->ddict = zds->ddictLocal;
     zds->legacyVersion = 0;
     zds->hostageByte = 0;
     return ZSTD_frameHeaderSize_prefix;
 }
 
 size_t ZSTD_initDStream(ZSTD_DStream* zds)
 {
     return ZSTD_initDStream_usingDict(zds, NULL, 0);
 }
 
-size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict)  /**< note : ddict will just be referenced, and must outlive decompression session */
+/* ZSTD_initDStream_usingDDict() :
+ * ddict will just be referenced, and must outlive decompression session */
+size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict)
 {
     size_t const initResult = ZSTD_initDStream(zds);
     zds->ddict = ddict;
     return initResult;
 }
 
 size_t ZSTD_resetDStream(ZSTD_DStream* zds)
 {
     zds->stage = zdss_loadHeader;
     zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
     zds->legacyVersion = 0;
     zds->hostageByte = 0;
     return ZSTD_frameHeaderSize_prefix;
 }
 
 size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds,
                                 ZSTD_DStreamParameter_e paramType, unsigned paramValue)
 {
     switch(paramType)
     {
         default : return ERROR(parameter_unknown);
         case DStream_p_maxWindowSize : zds->maxWindowSize = paramValue ? paramValue : (U32)(-1); break;
     }
     return 0;
 }
 
 
 size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds)
 {
-    if (zds==NULL) return 0;   /* support sizeof on NULL */
-    return sizeof(*zds) + ZSTD_sizeof_DCtx(zds->dctx) + ZSTD_sizeof_DDict(zds->ddictLocal) + zds->inBuffSize + zds->outBuffSize;
+    if (zds==NULL) return 0;   /* support sizeof NULL */
+    return sizeof(*zds)
+           + ZSTD_sizeof_DCtx(zds->dctx)
+           + ZSTD_sizeof_DDict(zds->ddictLocal)
+           + zds->inBuffSize + zds->outBuffSize;
 }
 
 
 /* *****   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;
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
     if (zds->legacyVersion)
         return ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
 #endif
 
     while (someMoreWork) {
         switch(zds->stage)
         {
         case zdss_init :
             ZSTD_resetDStream(zds);   /* transparent reset on starting decoding a new frame */
             /* fall-through */
 
         case zdss_loadHeader :
             {   size_t const hSize = ZSTD_getFrameParams(&zds->fParams, zds->headerBuffer, zds->lhSize);
                 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;
                         CHECK_F(ZSTD_initLegacyStream(&zds->legacyContext, zds->previousLegacyVersion, legacyVersion,
                                                        dict, dictSize));
                         zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
                         return ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
                     } else {
                         return hSize; /* error */
                 }   }
 #else
                 return hSize;
 #endif
                 if (hSize != 0) {   /* need more input */
                     size_t const toLoad = hSize - zds->lhSize;   /* if hSize!=0, hSize > zds->lhSize */
                     if (toLoad > (size_t)(iend-ip)) {   /* not enough input to load full header */
                         memcpy(zds->headerBuffer + zds->lhSize, ip, iend-ip);
                         zds->lhSize += iend-ip;
                         input->pos = input->size;
                         return (MAX(ZSTD_frameHeaderSize_min, hSize) - zds->lhSize) + ZSTD_blockHeaderSize;   /* remaining header bytes + next block header */
                     }
                     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)) {
                     size_t const decompressedSize = ZSTD_decompress_usingDDict(zds->dctx, op, oend-op, istart, cSize, zds->ddict);
                     if (ZSTD_isError(decompressedSize)) return decompressedSize;
                     ip = istart + cSize;
                     op += decompressedSize;
                     zds->dctx->expected = 0;
                     zds->stage = zdss_init;
                     someMoreWork = 0;
                     break;
             }   }
 
             /* Consume header */
             ZSTD_refDDict(zds->dctx, zds->ddict);
             {   size_t const h1Size = ZSTD_nextSrcSizeToDecompress(zds->dctx);  /* == ZSTD_frameHeaderSize_prefix */
                 CHECK_F(ZSTD_decompressContinue(zds->dctx, NULL, 0, zds->headerBuffer, h1Size));
                 {   size_t const h2Size = ZSTD_nextSrcSizeToDecompress(zds->dctx);
                     CHECK_F(ZSTD_decompressContinue(zds->dctx, NULL, 0, zds->headerBuffer+h1Size, h2Size));
             }   }
 
             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 blockSize = MIN(zds->fParams.windowSize, ZSTD_BLOCKSIZE_ABSOLUTEMAX);
                 size_t const neededOutSize = zds->fParams.windowSize + blockSize + WILDCOPY_OVERLENGTH * 2;
                 zds->blockSize = blockSize;
                 if (zds->inBuffSize < blockSize) {
                     ZSTD_free(zds->inBuff, zds->customMem);
-                    zds->inBuffSize = blockSize;
+                    zds->inBuffSize = 0;
                     zds->inBuff = (char*)ZSTD_malloc(blockSize, zds->customMem);
                     if (zds->inBuff == NULL) return ERROR(memory_allocation);
+                    zds->inBuffSize = blockSize;
                 }
                 if (zds->outBuffSize < neededOutSize) {
                     ZSTD_free(zds->outBuff, zds->customMem);
-                    zds->outBuffSize = neededOutSize;
+                    zds->outBuffSize = 0;
                     zds->outBuff = (char*)ZSTD_malloc(neededOutSize, zds->customMem);
                     if (zds->outBuff == NULL) return ERROR(memory_allocation);
+                    zds->outBuffSize = neededOutSize;
             }   }
             zds->stage = zdss_read;
             /* pass-through */
 
         case zdss_read:
             {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx);
                 if (neededInSize==0) {  /* end of frame */
                     zds->stage = zdss_init;
                     someMoreWork = 0;
                     break;
                 }
                 if ((size_t)(iend-ip) >= neededInSize) {  /* decode directly from src */
                     const int isSkipFrame = ZSTD_isSkipFrame(zds->dctx);
                     size_t const decodedSize = ZSTD_decompressContinue(zds->dctx,
                         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->stage = zdss_flush;
                     break;
                 }
                 if (ip==iend) { someMoreWork = 0; break; }   /* no more input */
                 zds->stage = zdss_load;
                 /* pass-through */
             }
 
         case zdss_load:
             {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds->dctx);
                 size_t const toLoad = neededInSize - zds->inPos;   /* should always be <= remaining space within inBuff */
                 size_t loadedSize;
                 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 */
                 {  const int isSkipFrame = ZSTD_isSkipFrame(zds->dctx);
                    size_t const decodedSize = ZSTD_decompressContinue(zds->dctx,
                         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->stage = zdss_read; break; }   /* this was just a header */
                     zds->outEnd = zds->outStart +  decodedSize;
                     zds->stage = zdss_flush;
                     /* pass-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->stage = zdss_read;
                     if (zds->outStart + zds->blockSize > zds->outBuffSize)
                         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);
     {   size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds->dctx);
         if (!nextSrcSizeHint) {   /* frame fully decoded */
             if (zds->outEnd == zds->outStart) {  /* output fully flushed */
                 if (zds->hostageByte) {
                     if (input->pos >= input->size) { zds->stage = zdss_read; return 1; }  /* can't release hostage (not present) */
                     input->pos++;  /* release hostage */
                 }
                 return 0;
             }
             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 += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds->dctx) == ZSTDnit_block);   /* preload header of next block */
         if (zds->inPos > nextSrcSizeHint) return ERROR(GENERIC);   /* should never happen */
         nextSrcSizeHint -= zds->inPos;   /* already loaded*/
         return nextSrcSizeHint;
     }
 }
Index: head/contrib/zstd/lib/dictBuilder/cover.c
===================================================================
--- head/contrib/zstd/lib/dictBuilder/cover.c	(revision 317876)
+++ head/contrib/zstd/lib/dictBuilder/cover.c	(revision 317877)
@@ -1,1029 +1,1050 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 /* *****************************************************************************
  * 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 "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))
 
 /*-*************************************
 *  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__);                                                    \
-      if (displayLevel >= 4)                                                   \
-        fflush(stdout);                                                        \
     }                                                                          \
   }
 #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().
  */
 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;
   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 sum = 0;
   size_t 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) {
-  const U32 lhs = *(const U32 *)lp;
-  const U32 rhs = *(const U32 *)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;
   double 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, 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(COVER_params_t parameters) {
   /* k and d are required parameters */
   if (parameters.d == 0 || parameters.k == 0) {
     return 0;
   }
   /* d <= k */
   if (parameters.d > parameters.k) {
     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) {
   const BYTE *const samples = (const BYTE *)samplesBuffer;
   const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
   /* Checks */
-  if (totalSamplesSize < d ||
+  if (totalSamplesSize < MAX(d, sizeof(U64)) ||
       totalSamplesSize >= (size_t)COVER_MAX_SAMPLES_SIZE) {
     DISPLAYLEVEL(1, "Total samples size is too large, maximum size is %u MB\n",
                  (COVER_MAX_SAMPLES_SIZE >> 20));
     return 0;
   }
   /* Zero the context */
   memset(ctx, 0, sizeof(*ctx));
   DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbSamples,
                (U32)totalSamplesSize);
   ctx->samples = samples;
   ctx->samplesSizes = samplesSizes;
   ctx->nbSamples = nbSamples;
   /* Partial suffix array */
-  ctx->suffixSize = totalSamplesSize - d + 1;
+  ctx->suffixSize = totalSamplesSize - 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 */
   {
     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 */
     g_ctx = ctx;
-    qsort(ctx->suffix, ctx->suffixSize, sizeof(U32), &COVER_strict_cmp);
+    qsort(ctx->suffix, ctx->suffixSize, sizeof(U32),
+          (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
   }
   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, &COVER_cmp,
-                &COVER_group);
+  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,
                                     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 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);
     /* Trim the segment if necessary and if it is empty then we are done */
     segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
     if (segmentSize == 0) {
       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;
 }
 
 /**
  * Translate from COVER_params_t to ZDICT_params_t required for finalizing the
  * dictionary.
  */
 static ZDICT_params_t COVER_translateParams(COVER_params_t parameters) {
   ZDICT_params_t zdictParams;
   memset(&zdictParams, 0, sizeof(zdictParams));
   zdictParams.notificationLevel = 1;
   zdictParams.dictID = parameters.dictID;
   zdictParams.compressionLevel = parameters.compressionLevel;
   return zdictParams;
 }
 
 ZDICTLIB_API size_t COVER_trainFromBuffer(
     void *dictBuffer, size_t dictBufferCapacity, const void *samplesBuffer,
     const size_t *samplesSizes, unsigned nbSamples, COVER_params_t parameters) {
   BYTE *const dict = (BYTE *)dictBuffer;
   COVER_ctx_t ctx;
   COVER_map_t activeDmers;
   /* Checks */
   if (!COVER_checkParameters(parameters)) {
     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 global data */
   g_displayLevel = parameters.notificationLevel;
   /* Initialize context and activeDmers */
   if (!COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
                       parameters.d)) {
     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);
     ZDICT_params_t zdictParams = COVER_translateParams(parameters);
     const size_t dictionarySize = ZDICT_finalizeDictionary(
         dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
         samplesBuffer, samplesSizes, nbSamples, zdictParams);
     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 {
   pthread_mutex_t mutex;
   pthread_cond_t cond;
   size_t liveJobs;
   void *dict;
   size_t dictSize;
   COVER_params_t parameters;
   size_t compressedSize;
 } COVER_best_t;
 
 /**
  * Initialize the `COVER_best_t`.
  */
 static void COVER_best_init(COVER_best_t *best) {
   if (!best) {
     return;
   }
   pthread_mutex_init(&best->mutex, NULL);
   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) {
   if (!best) {
     return;
   }
   pthread_mutex_lock(&best->mutex);
   while (best->liveJobs != 0) {
     pthread_cond_wait(&best->cond, &best->mutex);
   }
   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) {
   if (!best) {
     return;
   }
   COVER_best_wait(best);
   if (best->dict) {
     free(best->dict);
   }
   pthread_mutex_destroy(&best->mutex);
   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) {
   if (!best) {
     return;
   }
   pthread_mutex_lock(&best->mutex);
   ++best->liveJobs;
   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,
                               COVER_params_t parameters, void *dict,
                               size_t dictSize) {
   if (!best) {
     return;
   }
   {
     size_t liveJobs;
     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;
     }
     pthread_mutex_unlock(&best->mutex);
     if (liveJobs == 0) {
       pthread_cond_broadcast(&best->cond);
     }
   }
 }
 
 /**
  * Parameters for COVER_tryParameters().
  */
 typedef struct COVER_tryParameters_data_s {
   const COVER_ctx_t *ctx;
   COVER_best_t *best;
   size_t dictBufferCapacity;
   COVER_params_t parameters;
 } COVER_tryParameters_data_t;
 
 /**
  * Tries a set of parameters and upates 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 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);
     const ZDICT_params_t zdictParams = COVER_translateParams(parameters);
     dictBufferCapacity = ZDICT_finalizeDictionary(
         dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
         ctx->samples, ctx->samplesSizes, (unsigned)ctx->nbSamples, zdictParams);
     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.compressionLevel);
     if (!dst || !cctx || !cdict) {
       goto _compressCleanup;
     }
     /* Compress each sample and sum their sizes (or error) */
     totalCompressedSize = 0;
     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);
     }
   }
 
 _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 COVER_optimizeTrainFromBuffer(void *dictBuffer,
                                                   size_t dictBufferCapacity,
                                                   const void *samplesBuffer,
                                                   const size_t *samplesSizes,
                                                   unsigned nbSamples,
                                                   COVER_params_t *parameters) {
   /* constants */
   const unsigned nbThreads = parameters->nbThreads;
   const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
-  const unsigned kMaxD = parameters->d == 0 ? 16 : parameters->d;
-  const unsigned kMinK = parameters->k == 0 ? kMaxD : parameters->k;
-  const unsigned kMaxK = parameters->k == 0 ? 2048 : parameters->k;
-  const unsigned kSteps = parameters->steps == 0 ? 32 : parameters->steps;
+  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->notificationLevel;
   unsigned iteration = 1;
   unsigned d;
   unsigned k;
   COVER_best_t best;
   POOL_ctx *pool = NULL;
   /* Checks */
   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 = parameters->notificationLevel - 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)) {
       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.steps = kSteps;
       /* Check the parameters */
       if (!COVER_checkParameters(data->parameters)) {
         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: head/contrib/zstd/lib/dictBuilder/zdict.c
===================================================================
--- head/contrib/zstd/lib/dictBuilder/zdict.c	(revision 317876)
+++ head/contrib/zstd/lib/dictBuilder/zdict.c	(revision 317877)
@@ -1,1060 +1,1082 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 /*-**************************************
 *  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 512
+#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
 
-#define MINRATIO 4
 static const int g_compressionLevel_default = 6;
 static const U32 g_selectivity_default = 9;
-static const size_t g_provision_entropySize = 200;
-static const size_t g_min_fast_dictContent = 192;
 
 
 /*-*************************************
 *  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_DICT_MAGIC) return 0;
     return MEM_readLE32((const char*)dictBuffer + 4);
 }
 
 
 /*-********************************************************
 *  Dictionary training functions
 **********************************************************/
 static unsigned ZDICT_NbCommonBytes (register 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 length;
     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 u16 = MEM_read16(b+pos+4);
         U32 u, e = 6;
         while (MEM_read16(b+pos+e) == u16) e+=2 ;
         if (b[pos+e] == b[pos+e-1]) e++;
         for (u=1; u=MINMATCHLENGTH);
 
     /* look backward */
     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 */
         start = refinedStart;
         pos = suffix[refinedStart];
         end = start;
         memset(lengthList, 0, sizeof(lengthList));
 
         /* look forward */
         do {
             end++;
             length = ZDICT_count(b + pos, b + suffix[end]);
             if (length >= LLIMIT) length = LLIMIT-1;
             lengthList[length]++;
         } while (length >=MINMATCHLENGTH);
 
         /* look backward */
         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--;
+            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",
                      (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 addedLength = table[u].pos - elt.pos;
+            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 addedLength = (int)eltEnd - (table[u].pos + table[u].length);
+            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 : first element is nb of elts */
     U32 const max = table->pos;
     U32 u;
     if (!id) return;   /* protection, should never happen */
     for (u=id; upos--;
 }
 
 
-static void ZDICT_insertDictItem(dictItem* table, U32 maxSize, dictItem elt)
+static void ZDICT_insertDictItem(dictItem* table, U32 maxSize, dictItem elt, const void* buffer)
 {
     /* merge if possible */
-    U32 mergeId = ZDICT_checkMerge(table, elt, 0);
+    U32 mergeId = ZDICT_tryMerge(table, elt, 0, buffer);
     if (mergeId) {
         U32 newMerge = 1;
         while (newMerge) {
-            newMerge = ZDICT_checkMerge(table, table[mergeId], mergeId);
+            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(stdout); } }
+            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;
     ZSTD_CCtx* zc;
     void* workPlace;   /* must be ZSTD_BLOCKSIZE_ABSOLUTEMAX 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_ABSOLUTEMAX, 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; }
     }
     cSize = ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_ABSOLUTEMAX, 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* 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_maxSampleSize(const size_t* fileSizes, unsigned nbFiles)
 {
     unsigned u;
     size_t max=0;
     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;
     }
 }
 
 
 #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;
     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 */
     esr.ref = ZSTD_createCCtx();
     esr.zc = ZSTD_createCCtx();
     esr.workPlace = malloc(ZSTD_BLOCKSIZE_ABSOLUTEMAX);
     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(dictionary_wrong); 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;
+    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)) {
+        if (ZSTD_isError(beginResult)) {
+            DISPLAYLEVEL(1, "error : ZSTD_compressBegin_advanced() failed : %s \n", ZSTD_getErrorName(beginResult));
             eSize = ERROR(GENERIC);
-            DISPLAYLEVEL(1, "error : ZSTD_compressBegin_advanced failed \n");
             goto _cleanup;
     }   }
 
     /* collect stats on all files */
     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)
 {
-    size_t hSize;
     int const compressionLevel = (params.compressionLevel <= 0) ? g_compressionLevel_default : params.compressionLevel;
     U32 const notificationLevel = params.notificationLevel;
+    size_t hSize = 8;
 
-    /* dictionary header */
-    MEM_writeLE32(dictBuffer, ZSTD_DICT_MAGIC);
-    {   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);
-    }
-    hSize = 8;
-
-    /* entropy tables */
+    /* 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_DICT_MAGIC);
+    {   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);
 }
 
 
 /*! ZDICT_trainFromBuffer_unsafe() :
 *   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(
                             void* dictBuffer, size_t maxDictSize,
                             const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                             ZDICT_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.notificationLevel;
 
     /* checks */
     if (!dictList) return ERROR(memory_allocation);
-    if (maxDictSize <= g_provision_entropySize + g_min_fast_dictContent) { free(dictList); return ERROR(dstSize_tooSmall); }
-    if (samplesBuffSize < ZDICT_MIN_SAMPLES_SIZE) { free(dictList); return 0; }   /* not enough source to create dictionary */
+    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(dictList, dictListSize,
                     samplesBuffer, samplesBuffSize,
                     samplesSizes, nbSamples,
                     minRep, notificationLevel);
 
     /* display best matches */
     if (params.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))
                 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 < targetDictSize/3) {
+        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 (samplesBuffSize < 10 * targetDictSize)
-                DISPLAYLEVEL(2, "!  consider increasing the number of samples (total size : %u MB)\n", (U32)(samplesBuffSize>>20));
         }
 
         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 samples \n");
+            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);
     }
 
     /* clean up */
     free(dictList);
     return dictSize;
 }
 
 
 /* issue : samplesBuffer need to be followed by a noisy guard band.
 *  work around : duplicate the buffer, and add the noise */
 size_t ZDICT_trainFromBuffer_advanced(void* dictBuffer, size_t dictBufferCapacity,
                                       const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                                       ZDICT_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(
                                         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_params_t params;
     memset(¶ms, 0, sizeof(params));
     return ZDICT_trainFromBuffer_advanced(dictBuffer, dictBufferCapacity,
                                           samplesBuffer, samplesSizes, nbSamples,
                                           params);
 }
 
 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: head/contrib/zstd/lib/dictBuilder/zdict.h
===================================================================
--- head/contrib/zstd/lib/dictBuilder/zdict.h	(revision 317876)
+++ head/contrib/zstd/lib/dictBuilder/zdict.h	(revision 317877)
@@ -1,201 +1,201 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 #ifndef DICTBUILDER_H_001
 #define DICTBUILDER_H_001
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /*======  Dependencies  ======*/
 #include   /* size_t */
 
 
 /* =====   ZDICTLIB_API : control library symbols visibility   ===== */
 #if defined(__GNUC__) && (__GNUC__ >= 4)
 #  define ZDICTLIB_VISIBILITY __attribute__ ((visibility ("default")))
 #else
 #  define ZDICTLIB_VISIBILITY
 #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.
     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().
     Tips : In general, a reasonable dictionary has a size of ~ 100 KB.
            It's obviously possible to target smaller or larger ones, just by specifying different `dictBufferCapacity`.
            In general, it's recommended to provide a few thousands samples, but 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);
 
 
 /*======   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 {
     unsigned selectivityLevel;   /* 0 means default; larger => select more => larger dictionary */
     int      compressionLevel;   /* 0 means default; target a specific zstd compression level */
     unsigned notificationLevel;  /* Write to stderr; 0 = none (default); 1 = errors; 2 = progression; 3 = details; 4 = debug; */
     unsigned dictID;             /* 0 means auto mode (32-bits random value); other : force dictID value */
     unsigned reserved[2];        /* reserved space for future parameters */
 } ZDICT_params_t;
 
 
 /*! ZDICT_trainFromBuffer_advanced() :
     Same as ZDICT_trainFromBuffer() with control over more parameters.
     `parameters` is optional and can be provided with values set to 0 to mean "default".
     @return : size of dictionary stored into `dictBuffer` (<= `dictBufferSize`),
               or an error code, which can be tested by ZDICT_isError().
     note : ZDICT_trainFromBuffer_advanced() will send notifications into stderr if instructed to, using notificationLevel>0.
 */
 ZDICTLIB_API size_t ZDICT_trainFromBuffer_advanced(void* dictBuffer, size_t dictBufferCapacity,
                                 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                                 ZDICT_params_t parameters);
 
 /*! COVER_params_t :
     For all values 0 means default.
-    kMin and d are the only required parameters.
+    k and d are the only required parameters.
 */
 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 nbThreads;          /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
     unsigned notificationLevel;  /* Write to stderr; 0 = none (default); 1 = errors; 2 = progression; 3 = details; 4 = debug; */
     unsigned dictID;             /* 0 means auto mode (32-bits random value); other : force dictID value */
     int      compressionLevel;   /* 0 means default; target a specific zstd compression level */
 } COVER_params_t;
 
 
 /*! COVER_trainFromBuffer() :
     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 : COVER_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 obviously possible to target smaller or larger ones, just by specifying different `dictBufferCapacity`.
            In general, it's recommended to provide a few thousands samples, but 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 COVER_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
                               const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                               COVER_params_t parameters);
 
 /*! COVER_optimizeTrainFromBuffer() :
     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, and the 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 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].
 
     @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 : COVER_optimizeTrainFromBuffer() 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 COVER_optimizeTrainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
                                      const void* samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
                                      COVER_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.
+    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 customDictContent can overlap
+    note 2 : dictBuffer and dictContent can overlap
 */
-#define ZDICT_CONTENTSIZE_MIN 256
-#define ZDICT_DICTSIZE_MIN    512
+#define ZDICT_CONTENTSIZE_MIN 128
+#define ZDICT_DICTSIZE_MIN    256
 ZDICTLIB_API size_t ZDICT_finalizeDictionary(void* dictBuffer, size_t dictBufferCapacity,
-                                const void* customDictContent, size_t dictContentSize,
+                                const void* dictContent, size_t dictContentSize,
                                 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                                 ZDICT_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: head/contrib/zstd/lib/legacy/zstd_v01.c
===================================================================
--- head/contrib/zstd/lib/legacy/zstd_v01.c	(revision 317876)
+++ head/contrib/zstd/lib/legacy/zstd_v01.c	(revision 317877)
@@ -1,2126 +1,2126 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 /******************************************
 *  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 (register 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);
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
             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];
+    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)
 {
     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,
                                 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,
                          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: head/contrib/zstd/lib/legacy/zstd_v02.c
===================================================================
--- head/contrib/zstd/lib/legacy/zstd_v02.c	(revision 317876)
+++ head/contrib/zstd/lib/legacy/zstd_v02.c	(revision 317877)
@@ -1,3555 +1,3555 @@
 /**
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
 
 #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);
 
 
 /*
 * 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 manually filled from memory by the BIT_reloadDStream() method.
 * A reload guarantee a minimum of ((8*sizeof(size_t))-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 size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
 /* faster, but works only if nbBits >= 1 */
 
 
 
 /****************************************************************
 *  Helper functions
 ****************************************************************/
 MEM_STATIC unsigned BIT_highbit32 (register 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);
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
             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;
 }
 
 /*!BIT_lookBits
  * Provides next n bits from local register
  * local register is not modified (bits are still present for next read/look)
  * On 32-bits, maxNbBits==25
  * On 64-bits, maxNbBits==57
  * @return : value extracted
  */
 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;
 }
 
 /*!BIT_readBits
  * Read next n bits from local register.
  * 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 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->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<= 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 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;
-				}
+                    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