diff --git a/sys/contrib/zlib/deflate.c b/sys/contrib/zlib/deflate.c index 7f2c8a2a2a64..69d6260ad73b 100644 --- a/sys/contrib/zlib/deflate.c +++ b/sys/contrib/zlib/deflate.c @@ -1,2163 +1,2197 @@ /* deflate.c -- compress data using the deflation algorithm * Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h */ /* * ALGORITHM * * The "deflation" process depends on being able to identify portions * of the input text which are identical to earlier input (within a * sliding window trailing behind the input currently being processed). * * The most straightforward technique turns out to be the fastest for * most input files: try all possible matches and select the longest. * The key feature of this algorithm is that insertions into the string * dictionary are very simple and thus fast, and deletions are avoided * completely. Insertions are performed at each input character, whereas * string matches are performed only when the previous match ends. So it * is preferable to spend more time in matches to allow very fast string * insertions and avoid deletions. The matching algorithm for small * strings is inspired from that of Rabin & Karp. A brute force approach * is used to find longer strings when a small match has been found. * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze * (by Leonid Broukhis). * A previous version of this file used a more sophisticated algorithm * (by Fiala and Greene) which is guaranteed to run in linear amortized * time, but has a larger average cost, uses more memory and is patented. * However the F&G algorithm may be faster for some highly redundant * files if the parameter max_chain_length (described below) is too large. * * ACKNOWLEDGEMENTS * * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and * I found it in 'freeze' written by Leonid Broukhis. * Thanks to many people for bug reports and testing. * * REFERENCES * * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". * Available in http://tools.ietf.org/html/rfc1951 * * A description of the Rabin and Karp algorithm is given in the book * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. * * Fiala,E.R., and Greene,D.H. * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 * */ /* @(#) $Id$ */ #include "deflate.h" const char deflate_copyright[] = " deflate 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler "; /* If you use the zlib library in a product, an acknowledgment is welcome in the documentation of your product. If for some reason you cannot include such an acknowledgment, I would appreciate that you keep this copyright string in the executable of your product. */ /* =========================================================================== * Function prototypes. */ typedef enum { need_more, /* block not completed, need more input or more output */ block_done, /* block flush performed */ finish_started, /* finish started, need only more output at next deflate */ finish_done /* finish done, accept no more input or output */ } block_state; typedef block_state (*compress_func) OF((deflate_state *s, int flush)); /* Compression function. Returns the block state after the call. */ local int deflateStateCheck OF((z_streamp strm)); local void slide_hash OF((deflate_state *s)); local void fill_window OF((deflate_state *s)); local block_state deflate_stored OF((deflate_state *s, int flush)); local block_state deflate_fast OF((deflate_state *s, int flush)); #ifndef FASTEST local block_state deflate_slow OF((deflate_state *s, int flush)); #endif local block_state deflate_rle OF((deflate_state *s, int flush)); local block_state deflate_huff OF((deflate_state *s, int flush)); local void lm_init OF((deflate_state *s)); local void putShortMSB OF((deflate_state *s, uInt b)); local void flush_pending OF((z_streamp strm)); local unsigned read_buf OF((z_streamp strm, Bytef *buf, unsigned size)); #ifdef ASMV # pragma message("Assembler code may have bugs -- use at your own risk") void match_init OF((void)); /* asm code initialization */ uInt longest_match OF((deflate_state *s, IPos cur_match)); #else local uInt longest_match OF((deflate_state *s, IPos cur_match)); #endif #ifdef ZLIB_DEBUG local void check_match OF((deflate_state *s, IPos start, IPos match, int length)); #endif /* =========================================================================== * Local data */ #define NIL 0 /* Tail of hash chains */ #ifndef TOO_FAR # define TOO_FAR 4096 #endif /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ /* Values for max_lazy_match, good_match and max_chain_length, depending on * the desired pack level (0..9). The values given below have been tuned to * exclude worst case performance for pathological files. Better values may be * found for specific files. */ typedef struct config_s { ush good_length; /* reduce lazy search above this match length */ ush max_lazy; /* do not perform lazy search above this match length */ ush nice_length; /* quit search above this match length */ ush max_chain; compress_func func; } config; #ifdef FASTEST local const config configuration_table[2] = { /* good lazy nice chain */ /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ /* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */ #else local const config configuration_table[10] = { /* good lazy nice chain */ /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ /* 2 */ {4, 5, 16, 8, deflate_fast}, /* 3 */ {4, 6, 32, 32, deflate_fast}, /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ /* 5 */ {8, 16, 32, 32, deflate_slow}, /* 6 */ {8, 16, 128, 128, deflate_slow}, /* 7 */ {8, 32, 128, 256, deflate_slow}, /* 8 */ {32, 128, 258, 1024, deflate_slow}, /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */ #endif /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different * meaning. */ /* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */ #define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0)) /* =========================================================================== * Update a hash value with the given input byte * IN assertion: all calls to UPDATE_HASH are made with consecutive input * characters, so that a running hash key can be computed from the previous * key instead of complete recalculation each time. */ #define UPDATE_HASH(s,h,c) (h = (((h)<hash_shift) ^ (c)) & s->hash_mask) /* =========================================================================== * Insert string str in the dictionary and set match_head to the previous head * of the hash chain (the most recent string with same hash key). Return * the previous length of the hash chain. * If this file is compiled with -DFASTEST, the compression level is forced * to 1, and no hash chains are maintained. * IN assertion: all calls to INSERT_STRING are made with consecutive input * characters and the first MIN_MATCH bytes of str are valid (except for * the last MIN_MATCH-1 bytes of the input file). */ #ifdef FASTEST #define INSERT_STRING(s, str, match_head) \ (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ match_head = s->head[s->ins_h], \ s->head[s->ins_h] = (Pos)(str)) #else #define INSERT_STRING(s, str, match_head) \ (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \ s->head[s->ins_h] = (Pos)(str)) #endif /* =========================================================================== * Initialize the hash table (avoiding 64K overflow for 16 bit systems). * prev[] will be initialized on the fly. */ #define CLEAR_HASH(s) \ s->head[s->hash_size-1] = NIL; \ zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); /* =========================================================================== * Slide the hash table when sliding the window down (could be avoided with 32 * bit values at the expense of memory usage). We slide even when level == 0 to * keep the hash table consistent if we switch back to level > 0 later. */ local void slide_hash(s) deflate_state *s; { unsigned n, m; Posf *p; uInt wsize = s->w_size; n = s->hash_size; p = &s->head[n]; do { m = *--p; *p = (Pos)(m >= wsize ? m - wsize : NIL); } while (--n); n = wsize; #ifndef FASTEST p = &s->prev[n]; do { m = *--p; *p = (Pos)(m >= wsize ? m - wsize : NIL); /* If n is not on any hash chain, prev[n] is garbage but * its value will never be used. */ } while (--n); #endif } /* ========================================================================= */ int ZEXPORT deflateInit_(strm, level, version, stream_size) z_streamp strm; int level; const char *version; int stream_size; { return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY, version, stream_size); /* To do: ignore strm->next_in if we use it as window */ } /* ========================================================================= */ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, version, stream_size) z_streamp strm; int level; int method; int windowBits; int memLevel; int strategy; const char *version; int stream_size; { deflate_state *s; int wrap = 1; static const char my_version[] = ZLIB_VERSION; - ushf *overlay; - /* We overlay pending_buf and d_buf+l_buf. This works since the average - * output size for (length,distance) codes is <= 24 bits. - */ - if (version == Z_NULL || version[0] != my_version[0] || stream_size != sizeof(z_stream)) { return Z_VERSION_ERROR; } if (strm == Z_NULL) return Z_STREAM_ERROR; strm->msg = Z_NULL; if (strm->zalloc == (alloc_func)0) { #ifdef Z_SOLO return Z_STREAM_ERROR; #else strm->zalloc = zcalloc; strm->opaque = (voidpf)0; #endif } if (strm->zfree == (free_func)0) #ifdef Z_SOLO return Z_STREAM_ERROR; #else strm->zfree = zcfree; #endif #ifdef FASTEST if (level != 0) level = 1; #else if (level == Z_DEFAULT_COMPRESSION) level = 6; #endif if (windowBits < 0) { /* suppress zlib wrapper */ wrap = 0; windowBits = -windowBits; } #ifdef GZIP else if (windowBits > 15) { wrap = 2; /* write gzip wrapper instead */ windowBits -= 16; } #endif if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) { return Z_STREAM_ERROR; } if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); if (s == Z_NULL) return Z_MEM_ERROR; strm->state = (struct internal_state FAR *)s; s->strm = strm; s->status = INIT_STATE; /* to pass state test in deflateReset() */ s->wrap = wrap; s->gzhead = Z_NULL; s->w_bits = (uInt)windowBits; s->w_size = 1 << s->w_bits; s->w_mask = s->w_size - 1; s->hash_bits = (uInt)memLevel + 7; s->hash_size = 1 << s->hash_bits; s->hash_mask = s->hash_size - 1; s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); s->high_water = 0; /* nothing written to s->window yet */ s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ - overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); - s->pending_buf = (uchf *) overlay; - s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); + /* We overlay pending_buf and sym_buf. This works since the average size + * for length/distance pairs over any compressed block is assured to be 31 + * bits or less. + * + * Analysis: The longest fixed codes are a length code of 8 bits plus 5 + * extra bits, for lengths 131 to 257. The longest fixed distance codes are + * 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest + * possible fixed-codes length/distance pair is then 31 bits total. + * + * sym_buf starts one-fourth of the way into pending_buf. So there are + * three bytes in sym_buf for every four bytes in pending_buf. Each symbol + * in sym_buf is three bytes -- two for the distance and one for the + * literal/length. As each symbol is consumed, the pointer to the next + * sym_buf value to read moves forward three bytes. From that symbol, up to + * 31 bits are written to pending_buf. The closest the written pending_buf + * bits gets to the next sym_buf symbol to read is just before the last + * code is written. At that time, 31*(n-2) bits have been written, just + * after 24*(n-2) bits have been consumed from sym_buf. sym_buf starts at + * 8*n bits into pending_buf. (Note that the symbol buffer fills when n-1 + * symbols are written.) The closest the writing gets to what is unread is + * then n+14 bits. Here n is lit_bufsize, which is 16384 by default, and + * can range from 128 to 32768. + * + * Therefore, at a minimum, there are 142 bits of space between what is + * written and what is read in the overlain buffers, so the symbols cannot + * be overwritten by the compressed data. That space is actually 139 bits, + * due to the three-bit fixed-code block header. + * + * That covers the case where either Z_FIXED is specified, forcing fixed + * codes, or when the use of fixed codes is chosen, because that choice + * results in a smaller compressed block than dynamic codes. That latter + * condition then assures that the above analysis also covers all dynamic + * blocks. A dynamic-code block will only be chosen to be emitted if it has + * fewer bits than a fixed-code block would for the same set of symbols. + * Therefore its average symbol length is assured to be less than 31. So + * the compressed data for a dynamic block also cannot overwrite the + * symbols from which it is being constructed. + */ + + s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 4); + s->pending_buf_size = (ulg)s->lit_bufsize * 4; if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || s->pending_buf == Z_NULL) { s->status = FINISH_STATE; strm->msg = ERR_MSG(Z_MEM_ERROR); deflateEnd (strm); return Z_MEM_ERROR; } - s->d_buf = overlay + s->lit_bufsize/sizeof(ush); - s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; + s->sym_buf = s->pending_buf + s->lit_bufsize; + s->sym_end = (s->lit_bufsize - 1) * 3; + /* We avoid equality with lit_bufsize*3 because of wraparound at 64K + * on 16 bit machines and because stored blocks are restricted to + * 64K-1 bytes. + */ s->level = level; s->strategy = strategy; s->method = (Byte)method; return deflateReset(strm); } /* ========================================================================= * Check for a valid deflate stream state. Return 0 if ok, 1 if not. */ local int deflateStateCheck (strm) z_streamp strm; { deflate_state *s; if (strm == Z_NULL || strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) return 1; s = strm->state; if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE && #ifdef GZIP s->status != GZIP_STATE && #endif s->status != EXTRA_STATE && s->status != NAME_STATE && s->status != COMMENT_STATE && s->status != HCRC_STATE && s->status != BUSY_STATE && s->status != FINISH_STATE)) return 1; return 0; } /* ========================================================================= */ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) z_streamp strm; const Bytef *dictionary; uInt dictLength; { deflate_state *s; uInt str, n; int wrap; unsigned avail; z_const unsigned char *next; if (deflateStateCheck(strm) || dictionary == Z_NULL) return Z_STREAM_ERROR; s = strm->state; wrap = s->wrap; if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead) return Z_STREAM_ERROR; /* when using zlib wrappers, compute Adler-32 for provided dictionary */ if (wrap == 1) strm->adler = adler32(strm->adler, dictionary, dictLength); s->wrap = 0; /* avoid computing Adler-32 in read_buf */ /* if dictionary would fill window, just replace the history */ if (dictLength >= s->w_size) { if (wrap == 0) { /* already empty otherwise */ CLEAR_HASH(s); s->strstart = 0; s->block_start = 0L; s->insert = 0; } dictionary += dictLength - s->w_size; /* use the tail */ dictLength = s->w_size; } /* insert dictionary into window and hash */ avail = strm->avail_in; next = strm->next_in; strm->avail_in = dictLength; strm->next_in = (z_const Bytef *)dictionary; fill_window(s); while (s->lookahead >= MIN_MATCH) { str = s->strstart; n = s->lookahead - (MIN_MATCH-1); do { UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); #ifndef FASTEST s->prev[str & s->w_mask] = s->head[s->ins_h]; #endif s->head[s->ins_h] = (Pos)str; str++; } while (--n); s->strstart = str; s->lookahead = MIN_MATCH-1; fill_window(s); } s->strstart += s->lookahead; s->block_start = (long)s->strstart; s->insert = s->lookahead; s->lookahead = 0; s->match_length = s->prev_length = MIN_MATCH-1; s->match_available = 0; strm->next_in = next; strm->avail_in = avail; s->wrap = wrap; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength) z_streamp strm; Bytef *dictionary; uInt *dictLength; { deflate_state *s; uInt len; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; len = s->strstart + s->lookahead; if (len > s->w_size) len = s->w_size; if (dictionary != Z_NULL && len) zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len); if (dictLength != Z_NULL) *dictLength = len; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateResetKeep (strm) z_streamp strm; { deflate_state *s; if (deflateStateCheck(strm)) { return Z_STREAM_ERROR; } strm->total_in = strm->total_out = 0; strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ strm->data_type = Z_UNKNOWN; s = (deflate_state *)strm->state; s->pending = 0; s->pending_out = s->pending_buf; if (s->wrap < 0) { s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ } s->status = #ifdef GZIP s->wrap == 2 ? GZIP_STATE : #endif s->wrap ? INIT_STATE : BUSY_STATE; strm->adler = #ifdef GZIP s->wrap == 2 ? crc32(0L, Z_NULL, 0) : #endif adler32(0L, Z_NULL, 0); s->last_flush = -2; _tr_init(s); return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateReset (strm) z_streamp strm; { int ret; ret = deflateResetKeep(strm); if (ret == Z_OK) lm_init(strm->state); return ret; } /* ========================================================================= */ int ZEXPORT deflateSetHeader (strm, head) z_streamp strm; gz_headerp head; { if (deflateStateCheck(strm) || strm->state->wrap != 2) return Z_STREAM_ERROR; strm->state->gzhead = head; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflatePending (strm, pending, bits) unsigned *pending; int *bits; z_streamp strm; { if (deflateStateCheck(strm)) return Z_STREAM_ERROR; if (pending != Z_NULL) *pending = strm->state->pending; if (bits != Z_NULL) *bits = strm->state->bi_valid; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflatePrime (strm, bits, value) z_streamp strm; int bits; int value; { deflate_state *s; int put; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; - if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3)) + if (s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3)) return Z_BUF_ERROR; do { put = Buf_size - s->bi_valid; if (put > bits) put = bits; s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid); s->bi_valid += put; _tr_flush_bits(s); value >>= put; bits -= put; } while (bits); return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateParams(strm, level, strategy) z_streamp strm; int level; int strategy; { deflate_state *s; compress_func func; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; #ifdef FASTEST if (level != 0) level = 1; #else if (level == Z_DEFAULT_COMPRESSION) level = 6; #endif if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { return Z_STREAM_ERROR; } func = configuration_table[s->level].func; if ((strategy != s->strategy || func != configuration_table[level].func) && s->last_flush != -2) { /* Flush the last buffer: */ int err = deflate(strm, Z_BLOCK); if (err == Z_STREAM_ERROR) return err; if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead) return Z_BUF_ERROR; } if (s->level != level) { if (s->level == 0 && s->matches != 0) { if (s->matches == 1) slide_hash(s); else CLEAR_HASH(s); s->matches = 0; } s->level = level; s->max_lazy_match = configuration_table[level].max_lazy; s->good_match = configuration_table[level].good_length; s->nice_match = configuration_table[level].nice_length; s->max_chain_length = configuration_table[level].max_chain; } s->strategy = strategy; return Z_OK; } /* ========================================================================= */ int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain) z_streamp strm; int good_length; int max_lazy; int nice_length; int max_chain; { deflate_state *s; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; s = strm->state; s->good_match = (uInt)good_length; s->max_lazy_match = (uInt)max_lazy; s->nice_match = nice_length; s->max_chain_length = (uInt)max_chain; return Z_OK; } /* ========================================================================= * For the default windowBits of 15 and memLevel of 8, this function returns * a close to exact, as well as small, upper bound on the compressed size. * They are coded as constants here for a reason--if the #define's are * changed, then this function needs to be changed as well. The return * value for 15 and 8 only works for those exact settings. * * For any setting other than those defaults for windowBits and memLevel, * the value returned is a conservative worst case for the maximum expansion * resulting from using fixed blocks instead of stored blocks, which deflate * can emit on compressed data for some combinations of the parameters. * * This function could be more sophisticated to provide closer upper bounds for * every combination of windowBits and memLevel. But even the conservative * upper bound of about 14% expansion does not seem onerous for output buffer * allocation. */ uLong ZEXPORT deflateBound(strm, sourceLen) z_streamp strm; uLong sourceLen; { deflate_state *s; uLong complen, wraplen; /* conservative upper bound for compressed data */ complen = sourceLen + ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; /* if can't get parameters, return conservative bound plus zlib wrapper */ if (deflateStateCheck(strm)) return complen + 6; /* compute wrapper length */ s = strm->state; switch (s->wrap) { case 0: /* raw deflate */ wraplen = 0; break; case 1: /* zlib wrapper */ wraplen = 6 + (s->strstart ? 4 : 0); break; #ifdef GZIP case 2: /* gzip wrapper */ wraplen = 18; if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ Bytef *str; if (s->gzhead->extra != Z_NULL) wraplen += 2 + s->gzhead->extra_len; str = s->gzhead->name; if (str != Z_NULL) do { wraplen++; } while (*str++); str = s->gzhead->comment; if (str != Z_NULL) do { wraplen++; } while (*str++); if (s->gzhead->hcrc) wraplen += 2; } break; #endif default: /* for compiler happiness */ wraplen = 6; } /* if not default parameters, return conservative bound */ if (s->w_bits != 15 || s->hash_bits != 8 + 7) return complen + wraplen; /* default settings: return tight bound for that case */ return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + (sourceLen >> 25) + 13 - 6 + wraplen; } /* ========================================================================= * Put a short in the pending buffer. The 16-bit value is put in MSB order. * IN assertion: the stream state is correct and there is enough room in * pending_buf. */ local void putShortMSB (s, b) deflate_state *s; uInt b; { put_byte(s, (Byte)(b >> 8)); put_byte(s, (Byte)(b & 0xff)); } /* ========================================================================= * Flush as much pending output as possible. All deflate() output, except for * some deflate_stored() output, goes through this function so some * applications may wish to modify it to avoid allocating a large * strm->next_out buffer and copying into it. (See also read_buf()). */ local void flush_pending(strm) z_streamp strm; { unsigned len; deflate_state *s = strm->state; _tr_flush_bits(s); len = s->pending; if (len > strm->avail_out) len = strm->avail_out; if (len == 0) return; zmemcpy(strm->next_out, s->pending_out, len); strm->next_out += len; s->pending_out += len; strm->total_out += len; strm->avail_out -= len; s->pending -= len; if (s->pending == 0) { s->pending_out = s->pending_buf; } } /* =========================================================================== * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1]. */ #define HCRC_UPDATE(beg) \ do { \ if (s->gzhead->hcrc && s->pending > (beg)) \ strm->adler = crc32(strm->adler, s->pending_buf + (beg), \ s->pending - (beg)); \ } while (0) /* ========================================================================= */ int ZEXPORT deflate (strm, flush) z_streamp strm; int flush; { int old_flush; /* value of flush param for previous deflate call */ deflate_state *s; if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) { return Z_STREAM_ERROR; } s = strm->state; if (strm->next_out == Z_NULL || (strm->avail_in != 0 && strm->next_in == Z_NULL) || (s->status == FINISH_STATE && flush != Z_FINISH)) { ERR_RETURN(strm, Z_STREAM_ERROR); } if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); old_flush = s->last_flush; s->last_flush = flush; /* Flush as much pending output as possible */ if (s->pending != 0) { flush_pending(strm); if (strm->avail_out == 0) { /* Since avail_out is 0, deflate will be called again with * more output space, but possibly with both pending and * avail_in equal to zero. There won't be anything to do, * but this is not an error situation so make sure we * return OK instead of BUF_ERROR at next call of deflate: */ s->last_flush = -1; return Z_OK; } /* Make sure there is something to do and avoid duplicate consecutive * flushes. For repeated and useless calls with Z_FINISH, we keep * returning Z_STREAM_END instead of Z_BUF_ERROR. */ } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) && flush != Z_FINISH) { ERR_RETURN(strm, Z_BUF_ERROR); } /* User must not provide more input after the first FINISH: */ if (s->status == FINISH_STATE && strm->avail_in != 0) { ERR_RETURN(strm, Z_BUF_ERROR); } /* Write the header */ if (s->status == INIT_STATE) { /* zlib header */ uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; uInt level_flags; if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2) level_flags = 0; else if (s->level < 6) level_flags = 1; else if (s->level == 6) level_flags = 2; else level_flags = 3; header |= (level_flags << 6); if (s->strstart != 0) header |= PRESET_DICT; header += 31 - (header % 31); putShortMSB(s, header); /* Save the adler32 of the preset dictionary: */ if (s->strstart != 0) { putShortMSB(s, (uInt)(strm->adler >> 16)); putShortMSB(s, (uInt)(strm->adler & 0xffff)); } strm->adler = adler32(0L, Z_NULL, 0); s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } #ifdef GZIP if (s->status == GZIP_STATE) { /* gzip header */ strm->adler = crc32(0L, Z_NULL, 0); put_byte(s, 31); put_byte(s, 139); put_byte(s, 8); if (s->gzhead == Z_NULL) { put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); put_byte(s, s->level == 9 ? 2 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); put_byte(s, OS_CODE); s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } else { put_byte(s, (s->gzhead->text ? 1 : 0) + (s->gzhead->hcrc ? 2 : 0) + (s->gzhead->extra == Z_NULL ? 0 : 4) + (s->gzhead->name == Z_NULL ? 0 : 8) + (s->gzhead->comment == Z_NULL ? 0 : 16) ); put_byte(s, (Byte)(s->gzhead->time & 0xff)); put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff)); put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff)); put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff)); put_byte(s, s->level == 9 ? 2 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); put_byte(s, s->gzhead->os & 0xff); if (s->gzhead->extra != Z_NULL) { put_byte(s, s->gzhead->extra_len & 0xff); put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); } if (s->gzhead->hcrc) strm->adler = crc32(strm->adler, s->pending_buf, s->pending); s->gzindex = 0; s->status = EXTRA_STATE; } } if (s->status == EXTRA_STATE) { if (s->gzhead->extra != Z_NULL) { ulg beg = s->pending; /* start of bytes to update crc */ uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex; while (s->pending + left > s->pending_buf_size) { uInt copy = s->pending_buf_size - s->pending; zmemcpy(s->pending_buf + s->pending, s->gzhead->extra + s->gzindex, copy); s->pending = s->pending_buf_size; HCRC_UPDATE(beg); s->gzindex += copy; flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } beg = 0; left -= copy; } zmemcpy(s->pending_buf + s->pending, s->gzhead->extra + s->gzindex, left); s->pending += left; HCRC_UPDATE(beg); s->gzindex = 0; } s->status = NAME_STATE; } if (s->status == NAME_STATE) { if (s->gzhead->name != Z_NULL) { ulg beg = s->pending; /* start of bytes to update crc */ int val; do { if (s->pending == s->pending_buf_size) { HCRC_UPDATE(beg); flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } beg = 0; } val = s->gzhead->name[s->gzindex++]; put_byte(s, val); } while (val != 0); HCRC_UPDATE(beg); s->gzindex = 0; } s->status = COMMENT_STATE; } if (s->status == COMMENT_STATE) { if (s->gzhead->comment != Z_NULL) { ulg beg = s->pending; /* start of bytes to update crc */ int val; do { if (s->pending == s->pending_buf_size) { HCRC_UPDATE(beg); flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } beg = 0; } val = s->gzhead->comment[s->gzindex++]; put_byte(s, val); } while (val != 0); HCRC_UPDATE(beg); } s->status = HCRC_STATE; } if (s->status == HCRC_STATE) { if (s->gzhead->hcrc) { if (s->pending + 2 > s->pending_buf_size) { flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } put_byte(s, (Byte)(strm->adler & 0xff)); put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); strm->adler = crc32(0L, Z_NULL, 0); } s->status = BUSY_STATE; /* Compression must start with an empty pending buffer */ flush_pending(strm); if (s->pending != 0) { s->last_flush = -1; return Z_OK; } } #endif /* Start a new block or continue the current one. */ if (strm->avail_in != 0 || s->lookahead != 0 || (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { block_state bstate; bstate = s->level == 0 ? deflate_stored(s, flush) : s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) : s->strategy == Z_RLE ? deflate_rle(s, flush) : (*(configuration_table[s->level].func))(s, flush); if (bstate == finish_started || bstate == finish_done) { s->status = FINISH_STATE; } if (bstate == need_more || bstate == finish_started) { if (strm->avail_out == 0) { s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ } return Z_OK; /* If flush != Z_NO_FLUSH && avail_out == 0, the next call * of deflate should use the same flush parameter to make sure * that the flush is complete. So we don't have to output an * empty block here, this will be done at next call. This also * ensures that for a very small output buffer, we emit at most * one empty block. */ } if (bstate == block_done) { if (flush == Z_PARTIAL_FLUSH) { _tr_align(s); } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ _tr_stored_block(s, (char*)0, 0L, 0); /* For a full flush, this empty block will be recognized * as a special marker by inflate_sync(). */ if (flush == Z_FULL_FLUSH) { CLEAR_HASH(s); /* forget history */ if (s->lookahead == 0) { s->strstart = 0; s->block_start = 0L; s->insert = 0; } } } flush_pending(strm); if (strm->avail_out == 0) { s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ return Z_OK; } } } if (flush != Z_FINISH) return Z_OK; if (s->wrap <= 0) return Z_STREAM_END; /* Write the trailer */ #ifdef GZIP if (s->wrap == 2) { put_byte(s, (Byte)(strm->adler & 0xff)); put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); put_byte(s, (Byte)((strm->adler >> 16) & 0xff)); put_byte(s, (Byte)((strm->adler >> 24) & 0xff)); put_byte(s, (Byte)(strm->total_in & 0xff)); put_byte(s, (Byte)((strm->total_in >> 8) & 0xff)); put_byte(s, (Byte)((strm->total_in >> 16) & 0xff)); put_byte(s, (Byte)((strm->total_in >> 24) & 0xff)); } else #endif { putShortMSB(s, (uInt)(strm->adler >> 16)); putShortMSB(s, (uInt)(strm->adler & 0xffff)); } flush_pending(strm); /* If avail_out is zero, the application will call deflate again * to flush the rest. */ if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ return s->pending != 0 ? Z_OK : Z_STREAM_END; } /* ========================================================================= */ int ZEXPORT deflateEnd (strm) z_streamp strm; { int status; if (deflateStateCheck(strm)) return Z_STREAM_ERROR; status = strm->state->status; /* Deallocate in reverse order of allocations: */ TRY_FREE(strm, strm->state->pending_buf); TRY_FREE(strm, strm->state->head); TRY_FREE(strm, strm->state->prev); TRY_FREE(strm, strm->state->window); ZFREE(strm, strm->state); strm->state = Z_NULL; return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; } /* ========================================================================= * Copy the source state to the destination state. * To simplify the source, this is not supported for 16-bit MSDOS (which * doesn't have enough memory anyway to duplicate compression states). */ int ZEXPORT deflateCopy (dest, source) z_streamp dest; z_streamp source; { #ifdef MAXSEG_64K return Z_STREAM_ERROR; #else deflate_state *ds; deflate_state *ss; - ushf *overlay; if (deflateStateCheck(source) || dest == Z_NULL) { return Z_STREAM_ERROR; } ss = source->state; zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); if (ds == Z_NULL) return Z_MEM_ERROR; dest->state = (struct internal_state FAR *) ds; zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state)); ds->strm = dest; ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); - overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); - ds->pending_buf = (uchf *) overlay; + ds->pending_buf = (uchf *) ZALLOC(dest, ds->lit_bufsize, 4); if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || ds->pending_buf == Z_NULL) { deflateEnd (dest); return Z_MEM_ERROR; } /* following zmemcpy do not work for 16-bit MSDOS */ zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos)); zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos)); zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); - ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); - ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; + ds->sym_buf = ds->pending_buf + ds->lit_bufsize; ds->l_desc.dyn_tree = ds->dyn_ltree; ds->d_desc.dyn_tree = ds->dyn_dtree; ds->bl_desc.dyn_tree = ds->bl_tree; return Z_OK; #endif /* MAXSEG_64K */ } /* =========================================================================== * Read a new buffer from the current input stream, update the adler32 * and total number of bytes read. All deflate() input goes through * this function so some applications may wish to modify it to avoid * allocating a large strm->next_in buffer and copying from it. * (See also flush_pending()). */ local unsigned read_buf(strm, buf, size) z_streamp strm; Bytef *buf; unsigned size; { unsigned len = strm->avail_in; if (len > size) len = size; if (len == 0) return 0; strm->avail_in -= len; zmemcpy(buf, strm->next_in, len); if (strm->state->wrap == 1) { strm->adler = adler32(strm->adler, buf, len); } #ifdef GZIP else if (strm->state->wrap == 2) { strm->adler = crc32(strm->adler, buf, len); } #endif strm->next_in += len; strm->total_in += len; return len; } /* =========================================================================== * Initialize the "longest match" routines for a new zlib stream */ local void lm_init (s) deflate_state *s; { s->window_size = (ulg)2L*s->w_size; CLEAR_HASH(s); /* Set the default configuration parameters: */ s->max_lazy_match = configuration_table[s->level].max_lazy; s->good_match = configuration_table[s->level].good_length; s->nice_match = configuration_table[s->level].nice_length; s->max_chain_length = configuration_table[s->level].max_chain; s->strstart = 0; s->block_start = 0L; s->lookahead = 0; s->insert = 0; s->match_length = s->prev_length = MIN_MATCH-1; s->match_available = 0; s->ins_h = 0; #ifndef FASTEST #ifdef ASMV match_init(); /* initialize the asm code */ #endif #endif } #ifndef FASTEST /* =========================================================================== * Set match_start to the longest match starting at the given string and * return its length. Matches shorter or equal to prev_length are discarded, * in which case the result is equal to prev_length and match_start is * garbage. * IN assertions: cur_match is the head of the hash chain for the current * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 * OUT assertion: the match length is not greater than s->lookahead. */ #ifndef ASMV /* For 80x86 and 680x0, an optimized version will be provided in match.asm or * match.S. The code will be functionally equivalent. */ local uInt longest_match(s, cur_match) deflate_state *s; IPos cur_match; /* current match */ { unsigned chain_length = s->max_chain_length;/* max hash chain length */ register Bytef *scan = s->window + s->strstart; /* current string */ register Bytef *match; /* matched string */ register int len; /* length of current match */ int best_len = (int)s->prev_length; /* best match length so far */ int nice_match = s->nice_match; /* stop if match long enough */ IPos limit = s->strstart > (IPos)MAX_DIST(s) ? s->strstart - (IPos)MAX_DIST(s) : NIL; /* Stop when cur_match becomes <= limit. To simplify the code, * we prevent matches with the string of window index 0. */ Posf *prev = s->prev; uInt wmask = s->w_mask; #ifdef UNALIGNED_OK /* Compare two bytes at a time. Note: this is not always beneficial. * Try with and without -DUNALIGNED_OK to check. */ register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; register ush scan_start = *(ushf*)scan; register ush scan_end = *(ushf*)(scan+best_len-1); #else register Bytef *strend = s->window + s->strstart + MAX_MATCH; register Byte scan_end1 = scan[best_len-1]; register Byte scan_end = scan[best_len]; #endif /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. * It is easy to get rid of this optimization if necessary. */ Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); /* Do not waste too much time if we already have a good match: */ if (s->prev_length >= s->good_match) { chain_length >>= 2; } /* Do not look for matches beyond the end of the input. This is necessary * to make deflate deterministic. */ if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead; Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); do { Assert(cur_match < s->strstart, "no future"); match = s->window + cur_match; /* Skip to next match if the match length cannot increase * or if the match length is less than 2. Note that the checks below * for insufficient lookahead only occur occasionally for performance * reasons. Therefore uninitialized memory will be accessed, and * conditional jumps will be made that depend on those values. * However the length of the match is limited to the lookahead, so * the output of deflate is not affected by the uninitialized values. */ #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) /* This code assumes sizeof(unsigned short) == 2. Do not use * UNALIGNED_OK if your compiler uses a different size. */ if (*(ushf*)(match+best_len-1) != scan_end || *(ushf*)match != scan_start) continue; /* It is not necessary to compare scan[2] and match[2] since they are * always equal when the other bytes match, given that the hash keys * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at * strstart+3, +5, ... up to strstart+257. We check for insufficient * lookahead only every 4th comparison; the 128th check will be made * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is * necessary to put more guard bytes at the end of the window, or * to check more often for insufficient lookahead. */ Assert(scan[2] == match[2], "scan[2]?"); scan++, match++; do { } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && *(ushf*)(scan+=2) == *(ushf*)(match+=2) && *(ushf*)(scan+=2) == *(ushf*)(match+=2) && *(ushf*)(scan+=2) == *(ushf*)(match+=2) && scan < strend); /* The funny "do {}" generates better code on most compilers */ /* Here, scan <= window+strstart+257 */ Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); if (*scan == *match) scan++; len = (MAX_MATCH - 1) - (int)(strend-scan); scan = strend - (MAX_MATCH-1); #else /* UNALIGNED_OK */ if (match[best_len] != scan_end || match[best_len-1] != scan_end1 || *match != *scan || *++match != scan[1]) continue; /* The check at best_len-1 can be removed because it will be made * again later. (This heuristic is not always a win.) * It is not necessary to compare scan[2] and match[2] since they * are always equal when the other bytes match, given that * the hash keys are equal and that HASH_BITS >= 8. */ scan += 2, match++; Assert(*scan == *match, "match[2]?"); /* We check for insufficient lookahead only every 8th comparison; * the 256th check will be made at strstart+258. */ do { } while (*++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && scan < strend); Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); len = MAX_MATCH - (int)(strend - scan); scan = strend - MAX_MATCH; #endif /* UNALIGNED_OK */ if (len > best_len) { s->match_start = cur_match; best_len = len; if (len >= nice_match) break; #ifdef UNALIGNED_OK scan_end = *(ushf*)(scan+best_len-1); #else scan_end1 = scan[best_len-1]; scan_end = scan[best_len]; #endif } } while ((cur_match = prev[cur_match & wmask]) > limit && --chain_length != 0); if ((uInt)best_len <= s->lookahead) return (uInt)best_len; return s->lookahead; } #endif /* ASMV */ #else /* FASTEST */ /* --------------------------------------------------------------------------- * Optimized version for FASTEST only */ local uInt longest_match(s, cur_match) deflate_state *s; IPos cur_match; /* current match */ { register Bytef *scan = s->window + s->strstart; /* current string */ register Bytef *match; /* matched string */ register int len; /* length of current match */ register Bytef *strend = s->window + s->strstart + MAX_MATCH; /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. * It is easy to get rid of this optimization if necessary. */ Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); Assert(cur_match < s->strstart, "no future"); match = s->window + cur_match; /* Return failure if the match length is less than 2: */ if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1; /* The check at best_len-1 can be removed because it will be made * again later. (This heuristic is not always a win.) * It is not necessary to compare scan[2] and match[2] since they * are always equal when the other bytes match, given that * the hash keys are equal and that HASH_BITS >= 8. */ scan += 2, match += 2; Assert(*scan == *match, "match[2]?"); /* We check for insufficient lookahead only every 8th comparison; * the 256th check will be made at strstart+258. */ do { } while (*++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && *++scan == *++match && scan < strend); Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); len = MAX_MATCH - (int)(strend - scan); if (len < MIN_MATCH) return MIN_MATCH - 1; s->match_start = cur_match; return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; } #endif /* FASTEST */ #ifdef ZLIB_DEBUG #define EQUAL 0 /* result of memcmp for equal strings */ /* =========================================================================== * Check that the match at match_start is indeed a match. */ local void check_match(s, start, match, length) deflate_state *s; IPos start, match; int length; { /* check that the match is indeed a match */ if (zmemcmp(s->window + match, s->window + start, length) != EQUAL) { fprintf(stderr, " start %u, match %u, length %d\n", start, match, length); do { fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); } while (--length != 0); z_error("invalid match"); } if (z_verbose > 1) { fprintf(stderr,"\\[%d,%d]", start-match, length); do { putc(s->window[start++], stderr); } while (--length != 0); } } #else # define check_match(s, start, match, length) #endif /* ZLIB_DEBUG */ /* =========================================================================== * Fill the window when the lookahead becomes insufficient. * Updates strstart and lookahead. * * IN assertion: lookahead < MIN_LOOKAHEAD * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD * At least one byte has been read, or avail_in == 0; reads are * performed for at least two bytes (required for the zip translate_eol * option -- not supported here). */ local void fill_window(s) deflate_state *s; { unsigned n; unsigned more; /* Amount of free space at the end of the window. */ uInt wsize = s->w_size; Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead"); do { more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); /* Deal with !@#$% 64K limit: */ if (sizeof(int) <= 2) { if (more == 0 && s->strstart == 0 && s->lookahead == 0) { more = wsize; } else if (more == (unsigned)(-1)) { /* Very unlikely, but possible on 16 bit machine if * strstart == 0 && lookahead == 1 (input done a byte at time) */ more--; } } /* If the window is almost full and there is insufficient lookahead, * move the upper half to the lower one to make room in the upper half. */ if (s->strstart >= wsize+MAX_DIST(s)) { zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more); s->match_start -= wsize; s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ s->block_start -= (long) wsize; slide_hash(s); more += wsize; } if (s->strm->avail_in == 0) break; /* If there was no sliding: * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && * more == window_size - lookahead - strstart * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) * => more >= window_size - 2*WSIZE + 2 * In the BIG_MEM or MMAP case (not yet supported), * window_size == input_size + MIN_LOOKAHEAD && * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. * Otherwise, window_size == 2*WSIZE so more >= 2. * If there was sliding, more >= WSIZE. So in all cases, more >= 2. */ Assert(more >= 2, "more < 2"); n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more); s->lookahead += n; /* Initialize the hash value now that we have some input: */ if (s->lookahead + s->insert >= MIN_MATCH) { uInt str = s->strstart - s->insert; s->ins_h = s->window[str]; UPDATE_HASH(s, s->ins_h, s->window[str + 1]); #if MIN_MATCH != 3 Call UPDATE_HASH() MIN_MATCH-3 more times #endif while (s->insert) { UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); #ifndef FASTEST s->prev[str & s->w_mask] = s->head[s->ins_h]; #endif s->head[s->ins_h] = (Pos)str; str++; s->insert--; if (s->lookahead + s->insert < MIN_MATCH) break; } } /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, * but this is not important since only literal bytes will be emitted. */ } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); /* If the WIN_INIT bytes after the end of the current data have never been * written, then zero those bytes in order to avoid memory check reports of * the use of uninitialized (or uninitialised as Julian writes) bytes by * the longest match routines. Update the high water mark for the next * time through here. WIN_INIT is set to MAX_MATCH since the longest match * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. */ if (s->high_water < s->window_size) { ulg curr = s->strstart + (ulg)(s->lookahead); ulg init; if (s->high_water < curr) { /* Previous high water mark below current data -- zero WIN_INIT * bytes or up to end of window, whichever is less. */ init = s->window_size - curr; if (init > WIN_INIT) init = WIN_INIT; zmemzero(s->window + curr, (unsigned)init); s->high_water = curr + init; } else if (s->high_water < (ulg)curr + WIN_INIT) { /* High water mark at or above current data, but below current data * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up * to end of window, whichever is less. */ init = (ulg)curr + WIN_INIT - s->high_water; if (init > s->window_size - s->high_water) init = s->window_size - s->high_water; zmemzero(s->window + s->high_water, (unsigned)init); s->high_water += init; } } Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD, "not enough room for search"); } /* =========================================================================== * Flush the current block, with given end-of-file flag. * IN assertion: strstart is set to the end of the current match. */ #define FLUSH_BLOCK_ONLY(s, last) { \ _tr_flush_block(s, (s->block_start >= 0L ? \ (charf *)&s->window[(unsigned)s->block_start] : \ (charf *)Z_NULL), \ (ulg)((long)s->strstart - s->block_start), \ (last)); \ s->block_start = s->strstart; \ flush_pending(s->strm); \ Tracev((stderr,"[FLUSH]")); \ } /* Same but force premature exit if necessary. */ #define FLUSH_BLOCK(s, last) { \ FLUSH_BLOCK_ONLY(s, last); \ if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ } /* Maximum stored block length in deflate format (not including header). */ #define MAX_STORED 65535 /* Minimum of a and b. */ #define MIN(a, b) ((a) > (b) ? (b) : (a)) /* =========================================================================== * Copy without compression as much as possible from the input stream, return * the current block state. * * In case deflateParams() is used to later switch to a non-zero compression * level, s->matches (otherwise unused when storing) keeps track of the number * of hash table slides to perform. If s->matches is 1, then one hash table * slide will be done when switching. If s->matches is 2, the maximum value * allowed here, then the hash table will be cleared, since two or more slides * is the same as a clear. * * deflate_stored() is written to minimize the number of times an input byte is * copied. It is most efficient with large input and output buffers, which * maximizes the opportunites to have a single copy from next_in to next_out. */ local block_state deflate_stored(s, flush) deflate_state *s; int flush; { /* Smallest worthy block size when not flushing or finishing. By default * this is 32K. This can be as small as 507 bytes for memLevel == 1. For * large input and output buffers, the stored block size will be larger. */ unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size); /* Copy as many min_block or larger stored blocks directly to next_out as * possible. If flushing, copy the remaining available input to next_out as * stored blocks, if there is enough space. */ unsigned len, left, have, last = 0; unsigned used = s->strm->avail_in; do { /* Set len to the maximum size block that we can copy directly with the * available input data and output space. Set left to how much of that * would be copied from what's left in the window. */ len = MAX_STORED; /* maximum deflate stored block length */ have = (s->bi_valid + 42) >> 3; /* number of header bytes */ if (s->strm->avail_out < have) /* need room for header */ break; /* maximum stored block length that will fit in avail_out: */ have = s->strm->avail_out - have; left = s->strstart - s->block_start; /* bytes left in window */ if (len > (ulg)left + s->strm->avail_in) len = left + s->strm->avail_in; /* limit len to the input */ if (len > have) len = have; /* limit len to the output */ /* If the stored block would be less than min_block in length, or if * unable to copy all of the available input when flushing, then try * copying to the window and the pending buffer instead. Also don't * write an empty block when flushing -- deflate() does that. */ if (len < min_block && ((len == 0 && flush != Z_FINISH) || flush == Z_NO_FLUSH || len != left + s->strm->avail_in)) break; /* Make a dummy stored block in pending to get the header bytes, * including any pending bits. This also updates the debugging counts. */ last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0; _tr_stored_block(s, (char *)0, 0L, last); /* Replace the lengths in the dummy stored block with len. */ s->pending_buf[s->pending - 4] = len; s->pending_buf[s->pending - 3] = len >> 8; s->pending_buf[s->pending - 2] = ~len; s->pending_buf[s->pending - 1] = ~len >> 8; /* Write the stored block header bytes. */ flush_pending(s->strm); #ifdef ZLIB_DEBUG /* Update debugging counts for the data about to be copied. */ s->compressed_len += len << 3; s->bits_sent += len << 3; #endif /* Copy uncompressed bytes from the window to next_out. */ if (left) { if (left > len) left = len; zmemcpy(s->strm->next_out, s->window + s->block_start, left); s->strm->next_out += left; s->strm->avail_out -= left; s->strm->total_out += left; s->block_start += left; len -= left; } /* Copy uncompressed bytes directly from next_in to next_out, updating * the check value. */ if (len) { read_buf(s->strm, s->strm->next_out, len); s->strm->next_out += len; s->strm->avail_out -= len; s->strm->total_out += len; } } while (last == 0); /* Update the sliding window with the last s->w_size bytes of the copied * data, or append all of the copied data to the existing window if less * than s->w_size bytes were copied. Also update the number of bytes to * insert in the hash tables, in the event that deflateParams() switches to * a non-zero compression level. */ used -= s->strm->avail_in; /* number of input bytes directly copied */ if (used) { /* If any input was used, then no unused input remains in the window, * therefore s->block_start == s->strstart. */ if (used >= s->w_size) { /* supplant the previous history */ s->matches = 2; /* clear hash */ zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size); s->strstart = s->w_size; } else { if (s->window_size - s->strstart <= used) { /* Slide the window down. */ s->strstart -= s->w_size; zmemcpy(s->window, s->window + s->w_size, s->strstart); if (s->matches < 2) s->matches++; /* add a pending slide_hash() */ } zmemcpy(s->window + s->strstart, s->strm->next_in - used, used); s->strstart += used; } s->block_start = s->strstart; s->insert += MIN(used, s->w_size - s->insert); } if (s->high_water < s->strstart) s->high_water = s->strstart; /* If the last block was written to next_out, then done. */ if (last) return finish_done; /* If flushing and all input has been consumed, then done. */ if (flush != Z_NO_FLUSH && flush != Z_FINISH && s->strm->avail_in == 0 && (long)s->strstart == s->block_start) return block_done; /* Fill the window with any remaining input. */ have = s->window_size - s->strstart - 1; if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) { /* Slide the window down. */ s->block_start -= s->w_size; s->strstart -= s->w_size; zmemcpy(s->window, s->window + s->w_size, s->strstart); if (s->matches < 2) s->matches++; /* add a pending slide_hash() */ have += s->w_size; /* more space now */ } if (have > s->strm->avail_in) have = s->strm->avail_in; if (have) { read_buf(s->strm, s->window + s->strstart, have); s->strstart += have; } if (s->high_water < s->strstart) s->high_water = s->strstart; /* There was not enough avail_out to write a complete worthy or flushed * stored block to next_out. Write a stored block to pending instead, if we * have enough input for a worthy block, or if flushing and there is enough * room for the remaining input as a stored block in the pending buffer. */ have = (s->bi_valid + 42) >> 3; /* number of header bytes */ /* maximum stored block length that will fit in pending: */ have = MIN(s->pending_buf_size - have, MAX_STORED); min_block = MIN(have, s->w_size); left = s->strstart - s->block_start; if (left >= min_block || ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH && s->strm->avail_in == 0 && left <= have)) { len = MIN(left, have); last = flush == Z_FINISH && s->strm->avail_in == 0 && len == left ? 1 : 0; _tr_stored_block(s, (charf *)s->window + s->block_start, len, last); s->block_start += len; flush_pending(s->strm); } /* We've done all we can with the available input and output. */ return last ? finish_started : need_more; } /* =========================================================================== * Compress as much as possible from the input stream, return the current * block state. * This function does not perform lazy evaluation of matches and inserts * new strings in the dictionary only for unmatched strings or for short * matches. It is used only for the fast compression options. */ local block_state deflate_fast(s, flush) deflate_state *s; int flush; { IPos hash_head; /* head of the hash chain */ int bflush; /* set if current block must be flushed */ for (;;) { /* Make sure that we always have enough lookahead, except * at the end of the input file. We need MAX_MATCH bytes * for the next match, plus MIN_MATCH bytes to insert the * string following the next match. */ if (s->lookahead < MIN_LOOKAHEAD) { fill_window(s); if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { return need_more; } if (s->lookahead == 0) break; /* flush the current block */ } /* Insert the string window[strstart .. strstart+2] in the * dictionary, and set hash_head to the head of the hash chain: */ hash_head = NIL; if (s->lookahead >= MIN_MATCH) { INSERT_STRING(s, s->strstart, hash_head); } /* Find the longest match, discarding those <= prev_length. * At this point we have always match_length < MIN_MATCH */ if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { /* To simplify the code, we prevent matches with the string * of window index 0 (in particular we have to avoid a match * of the string with itself at the start of the input file). */ s->match_length = longest_match (s, hash_head); /* longest_match() sets match_start */ } if (s->match_length >= MIN_MATCH) { check_match(s, s->strstart, s->match_start, s->match_length); _tr_tally_dist(s, s->strstart - s->match_start, s->match_length - MIN_MATCH, bflush); s->lookahead -= s->match_length; /* Insert new strings in the hash table only if the match length * is not too large. This saves time but degrades compression. */ #ifndef FASTEST if (s->match_length <= s->max_insert_length && s->lookahead >= MIN_MATCH) { s->match_length--; /* string at strstart already in table */ do { s->strstart++; INSERT_STRING(s, s->strstart, hash_head); /* strstart never exceeds WSIZE-MAX_MATCH, so there are * always MIN_MATCH bytes ahead. */ } while (--s->match_length != 0); s->strstart++; } else #endif { s->strstart += s->match_length; s->match_length = 0; s->ins_h = s->window[s->strstart]; UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); #if MIN_MATCH != 3 Call UPDATE_HASH() MIN_MATCH-3 more times #endif /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not * matter since it will be recomputed at next deflate call. */ } } else { /* No match, output a literal byte */ Tracevv((stderr,"%c", s->window[s->strstart])); _tr_tally_lit (s, s->window[s->strstart], bflush); s->lookahead--; s->strstart++; } if (bflush) FLUSH_BLOCK(s, 0); } s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } - if (s->last_lit) + if (s->sym_next) FLUSH_BLOCK(s, 0); return block_done; } #ifndef FASTEST /* =========================================================================== * Same as above, but achieves better compression. We use a lazy * evaluation for matches: a match is finally adopted only if there is * no better match at the next window position. */ local block_state deflate_slow(s, flush) deflate_state *s; int flush; { IPos hash_head; /* head of hash chain */ int bflush; /* set if current block must be flushed */ /* Process the input block. */ for (;;) { /* Make sure that we always have enough lookahead, except * at the end of the input file. We need MAX_MATCH bytes * for the next match, plus MIN_MATCH bytes to insert the * string following the next match. */ if (s->lookahead < MIN_LOOKAHEAD) { fill_window(s); if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { return need_more; } if (s->lookahead == 0) break; /* flush the current block */ } /* Insert the string window[strstart .. strstart+2] in the * dictionary, and set hash_head to the head of the hash chain: */ hash_head = NIL; if (s->lookahead >= MIN_MATCH) { INSERT_STRING(s, s->strstart, hash_head); } /* Find the longest match, discarding those <= prev_length. */ s->prev_length = s->match_length, s->prev_match = s->match_start; s->match_length = MIN_MATCH-1; if (hash_head != NIL && s->prev_length < s->max_lazy_match && s->strstart - hash_head <= MAX_DIST(s)) { /* To simplify the code, we prevent matches with the string * of window index 0 (in particular we have to avoid a match * of the string with itself at the start of the input file). */ s->match_length = longest_match (s, hash_head); /* longest_match() sets match_start */ if (s->match_length <= 5 && (s->strategy == Z_FILTERED #if TOO_FAR <= 32767 || (s->match_length == MIN_MATCH && s->strstart - s->match_start > TOO_FAR) #endif )) { /* If prev_match is also MIN_MATCH, match_start is garbage * but we will ignore the current match anyway. */ s->match_length = MIN_MATCH-1; } } /* If there was a match at the previous step and the current * match is not better, output the previous match: */ if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; /* Do not insert strings in hash table beyond this. */ check_match(s, s->strstart-1, s->prev_match, s->prev_length); _tr_tally_dist(s, s->strstart -1 - s->prev_match, s->prev_length - MIN_MATCH, bflush); /* Insert in hash table all strings up to the end of the match. * strstart-1 and strstart are already inserted. If there is not * enough lookahead, the last two strings are not inserted in * the hash table. */ s->lookahead -= s->prev_length-1; s->prev_length -= 2; do { if (++s->strstart <= max_insert) { INSERT_STRING(s, s->strstart, hash_head); } } while (--s->prev_length != 0); s->match_available = 0; s->match_length = MIN_MATCH-1; s->strstart++; if (bflush) FLUSH_BLOCK(s, 0); } else if (s->match_available) { /* If there was no match at the previous position, output a * single literal. If there was a match but the current match * is longer, truncate the previous match to a single literal. */ Tracevv((stderr,"%c", s->window[s->strstart-1])); _tr_tally_lit(s, s->window[s->strstart-1], bflush); if (bflush) { FLUSH_BLOCK_ONLY(s, 0); } s->strstart++; s->lookahead--; if (s->strm->avail_out == 0) return need_more; } else { /* There is no previous match to compare with, wait for * the next step to decide. */ s->match_available = 1; s->strstart++; s->lookahead--; } } Assert (flush != Z_NO_FLUSH, "no flush?"); if (s->match_available) { Tracevv((stderr,"%c", s->window[s->strstart-1])); _tr_tally_lit(s, s->window[s->strstart-1], bflush); s->match_available = 0; } s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } - if (s->last_lit) + if (s->sym_next) FLUSH_BLOCK(s, 0); return block_done; } #endif /* FASTEST */ /* =========================================================================== * For Z_RLE, simply look for runs of bytes, generate matches only of distance * one. Do not maintain a hash table. (It will be regenerated if this run of * deflate switches away from Z_RLE.) */ local block_state deflate_rle(s, flush) deflate_state *s; int flush; { int bflush; /* set if current block must be flushed */ uInt prev; /* byte at distance one to match */ Bytef *scan, *strend; /* scan goes up to strend for length of run */ for (;;) { /* Make sure that we always have enough lookahead, except * at the end of the input file. We need MAX_MATCH bytes * for the longest run, plus one for the unrolled loop. */ if (s->lookahead <= MAX_MATCH) { fill_window(s); if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) { return need_more; } if (s->lookahead == 0) break; /* flush the current block */ } /* See how many times the previous byte repeats */ s->match_length = 0; if (s->lookahead >= MIN_MATCH && s->strstart > 0) { scan = s->window + s->strstart - 1; prev = *scan; if (prev == *++scan && prev == *++scan && prev == *++scan) { strend = s->window + s->strstart + MAX_MATCH; do { } while (prev == *++scan && prev == *++scan && prev == *++scan && prev == *++scan && prev == *++scan && prev == *++scan && prev == *++scan && prev == *++scan && scan < strend); s->match_length = MAX_MATCH - (uInt)(strend - scan); if (s->match_length > s->lookahead) s->match_length = s->lookahead; } Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan"); } /* Emit match if have run of MIN_MATCH or longer, else emit literal */ if (s->match_length >= MIN_MATCH) { check_match(s, s->strstart, s->strstart - 1, s->match_length); _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush); s->lookahead -= s->match_length; s->strstart += s->match_length; s->match_length = 0; } else { /* No match, output a literal byte */ Tracevv((stderr,"%c", s->window[s->strstart])); _tr_tally_lit (s, s->window[s->strstart], bflush); s->lookahead--; s->strstart++; } if (bflush) FLUSH_BLOCK(s, 0); } s->insert = 0; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } - if (s->last_lit) + if (s->sym_next) FLUSH_BLOCK(s, 0); return block_done; } /* =========================================================================== * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. * (It will be regenerated if this run of deflate switches away from Huffman.) */ local block_state deflate_huff(s, flush) deflate_state *s; int flush; { int bflush; /* set if current block must be flushed */ for (;;) { /* Make sure that we have a literal to write. */ if (s->lookahead == 0) { fill_window(s); if (s->lookahead == 0) { if (flush == Z_NO_FLUSH) return need_more; break; /* flush the current block */ } } /* Output a literal byte */ s->match_length = 0; Tracevv((stderr,"%c", s->window[s->strstart])); _tr_tally_lit (s, s->window[s->strstart], bflush); s->lookahead--; s->strstart++; if (bflush) FLUSH_BLOCK(s, 0); } s->insert = 0; if (flush == Z_FINISH) { FLUSH_BLOCK(s, 1); return finish_done; } - if (s->last_lit) + if (s->sym_next) FLUSH_BLOCK(s, 0); return block_done; } diff --git a/sys/contrib/zlib/deflate.h b/sys/contrib/zlib/deflate.h index 23ecdd312bc0..d4cf1a98be4d 100644 --- a/sys/contrib/zlib/deflate.h +++ b/sys/contrib/zlib/deflate.h @@ -1,349 +1,346 @@ /* deflate.h -- internal compression state * Copyright (C) 1995-2016 Jean-loup Gailly * For conditions of distribution and use, see copyright notice in zlib.h */ /* WARNING: this file should *not* be used by applications. It is part of the implementation of the compression library and is subject to change. Applications should only use zlib.h. */ /* @(#) $Id$ */ #ifndef DEFLATE_H #define DEFLATE_H #include "zutil.h" /* define NO_GZIP when compiling if you want to disable gzip header and trailer creation by deflate(). NO_GZIP would be used to avoid linking in the crc code when it is not needed. For shared libraries, gzip encoding should be left enabled. */ #ifndef NO_GZIP # define GZIP #endif /* =========================================================================== * Internal compression state. */ #define LENGTH_CODES 29 /* number of length codes, not counting the special END_BLOCK code */ #define LITERALS 256 /* number of literal bytes 0..255 */ #define L_CODES (LITERALS+1+LENGTH_CODES) /* number of Literal or Length codes, including the END_BLOCK code */ #define D_CODES 30 /* number of distance codes */ #define BL_CODES 19 /* number of codes used to transfer the bit lengths */ #define HEAP_SIZE (2*L_CODES+1) /* maximum heap size */ #define MAX_BITS 15 /* All codes must not exceed MAX_BITS bits */ #define Buf_size 16 /* size of bit buffer in bi_buf */ #define INIT_STATE 42 /* zlib header -> BUSY_STATE */ #ifdef GZIP # define GZIP_STATE 57 /* gzip header -> BUSY_STATE | EXTRA_STATE */ #endif #define EXTRA_STATE 69 /* gzip extra block -> NAME_STATE */ #define NAME_STATE 73 /* gzip file name -> COMMENT_STATE */ #define COMMENT_STATE 91 /* gzip comment -> HCRC_STATE */ #define HCRC_STATE 103 /* gzip header CRC -> BUSY_STATE */ #define BUSY_STATE 113 /* deflate -> FINISH_STATE */ #define FINISH_STATE 666 /* stream complete */ /* Stream status */ /* Data structure describing a single value and its code string. */ typedef struct ct_data_s { union { ush freq; /* frequency count */ ush code; /* bit string */ } fc; union { ush dad; /* father node in Huffman tree */ ush len; /* length of bit string */ } dl; } FAR ct_data; #define Freq fc.freq #define Code fc.code #define Dad dl.dad #define Len dl.len typedef struct static_tree_desc_s static_tree_desc; typedef struct tree_desc_s { ct_data *dyn_tree; /* the dynamic tree */ int max_code; /* largest code with non zero frequency */ const static_tree_desc *stat_desc; /* the corresponding static tree */ } FAR tree_desc; typedef ush Pos; typedef Pos FAR Posf; typedef unsigned IPos; /* A Pos is an index in the character window. We use short instead of int to * save space in the various tables. IPos is used only for parameter passing. */ typedef struct internal_state { z_streamp strm; /* pointer back to this zlib stream */ int status; /* as the name implies */ Bytef *pending_buf; /* output still pending */ ulg pending_buf_size; /* size of pending_buf */ Bytef *pending_out; /* next pending byte to output to the stream */ ulg pending; /* nb of bytes in the pending buffer */ int wrap; /* bit 0 true for zlib, bit 1 true for gzip */ gz_headerp gzhead; /* gzip header information to write */ ulg gzindex; /* where in extra, name, or comment */ Byte method; /* can only be DEFLATED */ int last_flush; /* value of flush param for previous deflate call */ /* used by deflate.c: */ uInt w_size; /* LZ77 window size (32K by default) */ uInt w_bits; /* log2(w_size) (8..16) */ uInt w_mask; /* w_size - 1 */ Bytef *window; /* Sliding window. Input bytes are read into the second half of the window, * and move to the first half later to keep a dictionary of at least wSize * bytes. With this organization, matches are limited to a distance of * wSize-MAX_MATCH bytes, but this ensures that IO is always * performed with a length multiple of the block size. Also, it limits * the window size to 64K, which is quite useful on MSDOS. * To do: use the user input buffer as sliding window. */ ulg window_size; /* Actual size of window: 2*wSize, except when the user input buffer * is directly used as sliding window. */ Posf *prev; /* Link to older string with same hash index. To limit the size of this * array to 64K, this link is maintained only for the last 32K strings. * An index in this array is thus a window index modulo 32K. */ Posf *head; /* Heads of the hash chains or NIL. */ uInt ins_h; /* hash index of string to be inserted */ uInt hash_size; /* number of elements in hash table */ uInt hash_bits; /* log2(hash_size) */ uInt hash_mask; /* hash_size-1 */ uInt hash_shift; /* Number of bits by which ins_h must be shifted at each input * step. It must be such that after MIN_MATCH steps, the oldest * byte no longer takes part in the hash key, that is: * hash_shift * MIN_MATCH >= hash_bits */ long block_start; /* Window position at the beginning of the current output block. Gets * negative when the window is moved backwards. */ uInt match_length; /* length of best match */ IPos prev_match; /* previous match */ int match_available; /* set if previous match exists */ uInt strstart; /* start of string to insert */ uInt match_start; /* start of matching string */ uInt lookahead; /* number of valid bytes ahead in window */ uInt prev_length; /* Length of the best match at previous step. Matches not greater than this * are discarded. This is used in the lazy match evaluation. */ uInt max_chain_length; /* To speed up deflation, hash chains are never searched beyond this * length. A higher limit improves compression ratio but degrades the * speed. */ uInt max_lazy_match; /* Attempt to find a better match only when the current match is strictly * smaller than this value. This mechanism is used only for compression * levels >= 4. */ # define max_insert_length max_lazy_match /* Insert new strings in the hash table only if the match length is not * greater than this length. This saves time but degrades compression. * max_insert_length is used only for compression levels <= 3. */ int level; /* compression level (1..9) */ int strategy; /* favor or force Huffman coding*/ uInt good_match; /* Use a faster search when the previous match is longer than this */ int nice_match; /* Stop searching when current match exceeds this */ /* used by trees.c: */ /* Didn't use ct_data typedef below to suppress compiler warning */ struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ struct tree_desc_s l_desc; /* desc. for literal tree */ struct tree_desc_s d_desc; /* desc. for distance tree */ struct tree_desc_s bl_desc; /* desc. for bit length tree */ ush bl_count[MAX_BITS+1]; /* number of codes at each bit length for an optimal tree */ int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ int heap_len; /* number of elements in the heap */ int heap_max; /* element of largest frequency */ /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. * The same heap array is used to build all trees. */ uch depth[2*L_CODES+1]; /* Depth of each subtree used as tie breaker for trees of equal frequency */ - uchf *l_buf; /* buffer for literals or lengths */ + uchf *sym_buf; /* buffer for distances and literals/lengths */ uInt lit_bufsize; /* Size of match buffer for literals/lengths. There are 4 reasons for * limiting lit_bufsize to 64K: * - frequencies can be kept in 16 bit counters * - if compression is not successful for the first block, all input * data is still in the window so we can still emit a stored block even * when input comes from standard input. (This can also be done for * all blocks if lit_bufsize is not greater than 32K.) * - if compression is not successful for a file smaller than 64K, we can * even emit a stored file instead of a stored block (saving 5 bytes). * This is applicable only for zip (not gzip or zlib). * - creating new Huffman trees less frequently may not provide fast * adaptation to changes in the input data statistics. (Take for * example a binary file with poorly compressible code followed by * a highly compressible string table.) Smaller buffer sizes give * fast adaptation but have of course the overhead of transmitting * trees more frequently. * - I can't count above 4 */ - uInt last_lit; /* running index in l_buf */ - - ushf *d_buf; - /* Buffer for distances. To simplify the code, d_buf and l_buf have - * the same number of elements. To use different lengths, an extra flag - * array would be necessary. - */ + uInt sym_next; /* running index in sym_buf */ + uInt sym_end; /* symbol table full when sym_next reaches this */ ulg opt_len; /* bit length of current block with optimal trees */ ulg static_len; /* bit length of current block with static trees */ uInt matches; /* number of string matches in current block */ uInt insert; /* bytes at end of window left to insert */ #ifdef ZLIB_DEBUG ulg compressed_len; /* total bit length of compressed file mod 2^32 */ ulg bits_sent; /* bit length of compressed data sent mod 2^32 */ #endif ush bi_buf; /* Output buffer. bits are inserted starting at the bottom (least * significant bits). */ int bi_valid; /* Number of valid bits in bi_buf. All bits above the last valid bit * are always zero. */ ulg high_water; /* High water mark offset in window for initialized bytes -- bytes above * this are set to zero in order to avoid memory check warnings when * longest match routines access bytes past the input. This is then * updated to the new high water mark. */ } FAR deflate_state; /* Output a byte on the stream. * IN assertion: there is enough room in pending_buf. */ #define put_byte(s, c) {s->pending_buf[s->pending++] = (Bytef)(c);} #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) /* Minimum amount of lookahead, except at the end of the input file. * See deflate.c for comments about the MIN_MATCH+1. */ #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) /* In order to simplify the code, particularly on 16 bit machines, match * distances are limited to MAX_DIST instead of WSIZE. */ #define WIN_INIT MAX_MATCH /* Number of bytes after end of data in window to initialize in order to avoid memory checker errors from longest match routines */ /* in trees.c */ void ZLIB_INTERNAL _tr_init OF((deflate_state *s)); int ZLIB_INTERNAL _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); void ZLIB_INTERNAL _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, int last)); void ZLIB_INTERNAL _tr_flush_bits OF((deflate_state *s)); void ZLIB_INTERNAL _tr_align OF((deflate_state *s)); void ZLIB_INTERNAL _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, int last)); #define d_code(dist) \ ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)]) /* Mapping from a distance to a distance code. dist is the distance - 1 and * must not have side effects. _dist_code[256] and _dist_code[257] are never * used. */ #ifndef ZLIB_DEBUG /* Inline versions of _tr_tally for speed: */ #if defined(GEN_TREES_H) || !defined(STDC) extern uch ZLIB_INTERNAL _length_code[]; extern uch ZLIB_INTERNAL _dist_code[]; #else extern const uch ZLIB_INTERNAL _length_code[]; extern const uch ZLIB_INTERNAL _dist_code[]; #endif # define _tr_tally_lit(s, c, flush) \ { uch cc = (c); \ - s->d_buf[s->last_lit] = 0; \ - s->l_buf[s->last_lit++] = cc; \ + s->sym_buf[s->sym_next++] = 0; \ + s->sym_buf[s->sym_next++] = 0; \ + s->sym_buf[s->sym_next++] = cc; \ s->dyn_ltree[cc].Freq++; \ - flush = (s->last_lit == s->lit_bufsize-1); \ + flush = (s->sym_next == s->sym_end); \ } # define _tr_tally_dist(s, distance, length, flush) \ { uch len = (uch)(length); \ ush dist = (ush)(distance); \ - s->d_buf[s->last_lit] = dist; \ - s->l_buf[s->last_lit++] = len; \ + s->sym_buf[s->sym_next++] = dist; \ + s->sym_buf[s->sym_next++] = dist >> 8; \ + s->sym_buf[s->sym_next++] = len; \ dist--; \ s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \ s->dyn_dtree[d_code(dist)].Freq++; \ - flush = (s->last_lit == s->lit_bufsize-1); \ + flush = (s->sym_next == s->sym_end); \ } #else # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c) # define _tr_tally_dist(s, distance, length, flush) \ flush = _tr_tally(s, distance, length) #endif #endif /* DEFLATE_H */ diff --git a/sys/contrib/zlib/trees.c b/sys/contrib/zlib/trees.c index 50cf4b4571cf..5f89d056ef96 100644 --- a/sys/contrib/zlib/trees.c +++ b/sys/contrib/zlib/trees.c @@ -1,1203 +1,1181 @@ /* trees.c -- output deflated data using Huffman coding * Copyright (C) 1995-2017 Jean-loup Gailly * detect_data_type() function provided freely by Cosmin Truta, 2006 * For conditions of distribution and use, see copyright notice in zlib.h */ /* * ALGORITHM * * The "deflation" process uses several Huffman trees. The more * common source values are represented by shorter bit sequences. * * Each code tree is stored in a compressed form which is itself * a Huffman encoding of the lengths of all the code strings (in * ascending order by source values). The actual code strings are * reconstructed from the lengths in the inflate process, as described * in the deflate specification. * * REFERENCES * * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc * * Storer, James A. * Data Compression: Methods and Theory, pp. 49-50. * Computer Science Press, 1988. ISBN 0-7167-8156-5. * * Sedgewick, R. * Algorithms, p290. * Addison-Wesley, 1983. ISBN 0-201-06672-6. */ /* @(#) $Id$ */ /* #define GEN_TREES_H */ #include "deflate.h" #ifdef ZLIB_DEBUG # include #endif /* =========================================================================== * Constants */ #define MAX_BL_BITS 7 /* Bit length codes must not exceed MAX_BL_BITS bits */ #define END_BLOCK 256 /* end of block literal code */ #define REP_3_6 16 /* repeat previous bit length 3-6 times (2 bits of repeat count) */ #define REPZ_3_10 17 /* repeat a zero length 3-10 times (3 bits of repeat count) */ #define REPZ_11_138 18 /* repeat a zero length 11-138 times (7 bits of repeat count) */ local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0}; local const int extra_dbits[D_CODES] /* extra bits for each distance code */ = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */ = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; local const uch bl_order[BL_CODES] = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; /* The lengths of the bit length codes are sent in order of decreasing * probability, to avoid transmitting the lengths for unused bit length codes. */ /* =========================================================================== * Local data. These are initialized only once. */ #define DIST_CODE_LEN 512 /* see definition of array dist_code below */ #if defined(GEN_TREES_H) || !defined(STDC) /* non ANSI compilers may not accept trees.h */ local ct_data static_ltree[L_CODES+2]; /* The static literal tree. Since the bit lengths are imposed, there is no * need for the L_CODES extra codes used during heap construction. However * The codes 286 and 287 are needed to build a canonical tree (see _tr_init * below). */ local ct_data static_dtree[D_CODES]; /* The static distance tree. (Actually a trivial tree since all codes use * 5 bits.) */ uch _dist_code[DIST_CODE_LEN]; /* Distance codes. The first 256 values correspond to the distances * 3 .. 258, the last 256 values correspond to the top 8 bits of * the 15 bit distances. */ uch _length_code[MAX_MATCH-MIN_MATCH+1]; /* length code for each normalized match length (0 == MIN_MATCH) */ local int base_length[LENGTH_CODES]; /* First normalized length for each code (0 = MIN_MATCH) */ local int base_dist[D_CODES]; /* First normalized distance for each code (0 = distance of 1) */ #else # include "trees.h" #endif /* GEN_TREES_H */ struct static_tree_desc_s { const ct_data *static_tree; /* static tree or NULL */ const intf *extra_bits; /* extra bits for each code or NULL */ int extra_base; /* base index for extra_bits */ int elems; /* max number of elements in the tree */ int max_length; /* max bit length for the codes */ }; local const static_tree_desc static_l_desc = {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; local const static_tree_desc static_d_desc = {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; local const static_tree_desc static_bl_desc = {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; /* =========================================================================== * Local (static) routines in this file. */ local void tr_static_init OF((void)); local void init_block OF((deflate_state *s)); local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); local void build_tree OF((deflate_state *s, tree_desc *desc)); local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); local int build_bl_tree OF((deflate_state *s)); local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, int blcodes)); local void compress_block OF((deflate_state *s, const ct_data *ltree, const ct_data *dtree)); local int detect_data_type OF((deflate_state *s)); local unsigned bi_reverse OF((unsigned value, int length)); local void bi_windup OF((deflate_state *s)); local void bi_flush OF((deflate_state *s)); #ifdef GEN_TREES_H local void gen_trees_header OF((void)); #endif #ifndef ZLIB_DEBUG # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) /* Send a code of the given tree. c and tree must not have side effects */ #else /* !ZLIB_DEBUG */ # define send_code(s, c, tree) \ { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ send_bits(s, tree[c].Code, tree[c].Len); } #endif /* =========================================================================== * Output a short LSB first on the stream. * IN assertion: there is enough room in pendingBuf. */ #define put_short(s, w) { \ put_byte(s, (uch)((w) & 0xff)); \ put_byte(s, (uch)((ush)(w) >> 8)); \ } /* =========================================================================== * Send a value on a given number of bits. * IN assertion: length <= 16 and value fits in length bits. */ #ifdef ZLIB_DEBUG local void send_bits OF((deflate_state *s, int value, int length)); local void send_bits(s, value, length) deflate_state *s; int value; /* value to send */ int length; /* number of bits */ { Tracevv((stderr," l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); s->bits_sent += (ulg)length; /* If not enough room in bi_buf, use (valid) bits from bi_buf and * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) * unused bits in value. */ if (s->bi_valid > (int)Buf_size - length) { s->bi_buf |= (ush)value << s->bi_valid; put_short(s, s->bi_buf); s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); s->bi_valid += length - Buf_size; } else { s->bi_buf |= (ush)value << s->bi_valid; s->bi_valid += length; } } #else /* !ZLIB_DEBUG */ #define send_bits(s, value, length) \ { int len = length;\ if (s->bi_valid > (int)Buf_size - len) {\ int val = (int)value;\ s->bi_buf |= (ush)val << s->bi_valid;\ put_short(s, s->bi_buf);\ s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ s->bi_valid += len - Buf_size;\ } else {\ s->bi_buf |= (ush)(value) << s->bi_valid;\ s->bi_valid += len;\ }\ } #endif /* ZLIB_DEBUG */ /* the arguments must not have side effects */ /* =========================================================================== * Initialize the various 'constant' tables. */ local void tr_static_init() { #if defined(GEN_TREES_H) || !defined(STDC) static int static_init_done = 0; int n; /* iterates over tree elements */ int bits; /* bit counter */ int length; /* length value */ int code; /* code value */ int dist; /* distance index */ ush bl_count[MAX_BITS+1]; /* number of codes at each bit length for an optimal tree */ if (static_init_done) return; /* For some embedded targets, global variables are not initialized: */ #ifdef NO_INIT_GLOBAL_POINTERS static_l_desc.static_tree = static_ltree; static_l_desc.extra_bits = extra_lbits; static_d_desc.static_tree = static_dtree; static_d_desc.extra_bits = extra_dbits; static_bl_desc.extra_bits = extra_blbits; #endif /* Initialize the mapping length (0..255) -> length code (0..28) */ length = 0; for (code = 0; code < LENGTH_CODES-1; code++) { base_length[code] = length; for (n = 0; n < (1< dist code (0..29) */ dist = 0; for (code = 0 ; code < 16; code++) { base_dist[code] = dist; for (n = 0; n < (1<>= 7; /* from now on, all distances are divided by 128 */ for ( ; code < D_CODES; code++) { base_dist[code] = dist << 7; for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { _dist_code[256 + dist++] = (uch)code; } } Assert (dist == 256, "tr_static_init: 256+dist != 512"); /* Construct the codes of the static literal tree */ for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; n = 0; while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; /* Codes 286 and 287 do not exist, but we must include them in the * tree construction to get a canonical Huffman tree (longest code * all ones) */ gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); /* The static distance tree is trivial: */ for (n = 0; n < D_CODES; n++) { static_dtree[n].Len = 5; static_dtree[n].Code = bi_reverse((unsigned)n, 5); } static_init_done = 1; # ifdef GEN_TREES_H gen_trees_header(); # endif #endif /* defined(GEN_TREES_H) || !defined(STDC) */ } /* =========================================================================== * Genererate the file trees.h describing the static trees. */ #ifdef GEN_TREES_H # ifndef ZLIB_DEBUG # include # endif # define SEPARATOR(i, last, width) \ ((i) == (last)? "\n};\n\n" : \ ((i) % (width) == (width)-1 ? ",\n" : ", ")) void gen_trees_header() { FILE *header = fopen("trees.h", "w"); int i; Assert (header != NULL, "Can't open trees.h"); fprintf(header, "/* header created automatically with -DGEN_TREES_H */\n\n"); fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n"); for (i = 0; i < L_CODES+2; i++) { fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code, static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5)); } fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n"); for (i = 0; i < D_CODES; i++) { fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code, static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5)); } fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n"); for (i = 0; i < DIST_CODE_LEN; i++) { fprintf(header, "%2u%s", _dist_code[i], SEPARATOR(i, DIST_CODE_LEN-1, 20)); } fprintf(header, "const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n"); for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) { fprintf(header, "%2u%s", _length_code[i], SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20)); } fprintf(header, "local const int base_length[LENGTH_CODES] = {\n"); for (i = 0; i < LENGTH_CODES; i++) { fprintf(header, "%1u%s", base_length[i], SEPARATOR(i, LENGTH_CODES-1, 20)); } fprintf(header, "local const int base_dist[D_CODES] = {\n"); for (i = 0; i < D_CODES; i++) { fprintf(header, "%5u%s", base_dist[i], SEPARATOR(i, D_CODES-1, 10)); } fclose(header); } #endif /* GEN_TREES_H */ /* =========================================================================== * Initialize the tree data structures for a new zlib stream. */ void ZLIB_INTERNAL _tr_init(s) deflate_state *s; { tr_static_init(); s->l_desc.dyn_tree = s->dyn_ltree; s->l_desc.stat_desc = &static_l_desc; s->d_desc.dyn_tree = s->dyn_dtree; s->d_desc.stat_desc = &static_d_desc; s->bl_desc.dyn_tree = s->bl_tree; s->bl_desc.stat_desc = &static_bl_desc; s->bi_buf = 0; s->bi_valid = 0; #ifdef ZLIB_DEBUG s->compressed_len = 0L; s->bits_sent = 0L; #endif /* Initialize the first block of the first file: */ init_block(s); } /* =========================================================================== * Initialize a new block. */ local void init_block(s) deflate_state *s; { int n; /* iterates over tree elements */ /* Initialize the trees. */ for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; s->dyn_ltree[END_BLOCK].Freq = 1; s->opt_len = s->static_len = 0L; - s->last_lit = s->matches = 0; + s->sym_next = s->matches = 0; } #define SMALLEST 1 /* Index within the heap array of least frequent node in the Huffman tree */ /* =========================================================================== * Remove the smallest element from the heap and recreate the heap with * one less element. Updates heap and heap_len. */ #define pqremove(s, tree, top) \ {\ top = s->heap[SMALLEST]; \ s->heap[SMALLEST] = s->heap[s->heap_len--]; \ pqdownheap(s, tree, SMALLEST); \ } /* =========================================================================== * Compares to subtrees, using the tree depth as tie breaker when * the subtrees have equal frequency. This minimizes the worst case length. */ #define smaller(tree, n, m, depth) \ (tree[n].Freq < tree[m].Freq || \ (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) /* =========================================================================== * Restore the heap property by moving down the tree starting at node k, * exchanging a node with the smallest of its two sons if necessary, stopping * when the heap property is re-established (each father smaller than its * two sons). */ local void pqdownheap(s, tree, k) deflate_state *s; ct_data *tree; /* the tree to restore */ int k; /* node to move down */ { int v = s->heap[k]; int j = k << 1; /* left son of k */ while (j <= s->heap_len) { /* Set j to the smallest of the two sons: */ if (j < s->heap_len && smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { j++; } /* Exit if v is smaller than both sons */ if (smaller(tree, v, s->heap[j], s->depth)) break; /* Exchange v with the smallest son */ s->heap[k] = s->heap[j]; k = j; /* And continue down the tree, setting j to the left son of k */ j <<= 1; } s->heap[k] = v; } /* =========================================================================== * Compute the optimal bit lengths for a tree and update the total bit length * for the current block. * IN assertion: the fields freq and dad are set, heap[heap_max] and * above are the tree nodes sorted by increasing frequency. * OUT assertions: the field len is set to the optimal bit length, the * array bl_count contains the frequencies for each bit length. * The length opt_len is updated; static_len is also updated if stree is * not null. */ local void gen_bitlen(s, desc) deflate_state *s; tree_desc *desc; /* the tree descriptor */ { ct_data *tree = desc->dyn_tree; int max_code = desc->max_code; const ct_data *stree = desc->stat_desc->static_tree; const intf *extra = desc->stat_desc->extra_bits; int base = desc->stat_desc->extra_base; int max_length = desc->stat_desc->max_length; int h; /* heap index */ int n, m; /* iterate over the tree elements */ int bits; /* bit length */ int xbits; /* extra bits */ ush f; /* frequency */ int overflow = 0; /* number of elements with bit length too large */ for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; /* In a first pass, compute the optimal bit lengths (which may * overflow in the case of the bit length tree). */ tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ for (h = s->heap_max+1; h < HEAP_SIZE; h++) { n = s->heap[h]; bits = tree[tree[n].Dad].Len + 1; if (bits > max_length) bits = max_length, overflow++; tree[n].Len = (ush)bits; /* We overwrite tree[n].Dad which is no longer needed */ if (n > max_code) continue; /* not a leaf node */ s->bl_count[bits]++; xbits = 0; if (n >= base) xbits = extra[n-base]; f = tree[n].Freq; s->opt_len += (ulg)f * (unsigned)(bits + xbits); if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits); } if (overflow == 0) return; Tracev((stderr,"\nbit length overflow\n")); /* This happens for example on obj2 and pic of the Calgary corpus */ /* Find the first bit length which could increase: */ do { bits = max_length-1; while (s->bl_count[bits] == 0) bits--; s->bl_count[bits]--; /* move one leaf down the tree */ s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ s->bl_count[max_length]--; /* The brother of the overflow item also moves one step up, * but this does not affect bl_count[max_length] */ overflow -= 2; } while (overflow > 0); /* Now recompute all bit lengths, scanning in increasing frequency. * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all * lengths instead of fixing only the wrong ones. This idea is taken * from 'ar' written by Haruhiko Okumura.) */ for (bits = max_length; bits != 0; bits--) { n = s->bl_count[bits]; while (n != 0) { m = s->heap[--h]; if (m > max_code) continue; if ((unsigned) tree[m].Len != (unsigned) bits) { Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq; tree[m].Len = (ush)bits; } n--; } } } /* =========================================================================== * Generate the codes for a given tree and bit counts (which need not be * optimal). * IN assertion: the array bl_count contains the bit length statistics for * the given tree and the field len is set for all tree elements. * OUT assertion: the field code is set for all tree elements of non * zero code length. */ local void gen_codes (tree, max_code, bl_count) ct_data *tree; /* the tree to decorate */ int max_code; /* largest code with non zero frequency */ ushf *bl_count; /* number of codes at each bit length */ { ush next_code[MAX_BITS+1]; /* next code value for each bit length */ unsigned code = 0; /* running code value */ int bits; /* bit index */ int n; /* code index */ /* The distribution counts are first used to generate the code values * without bit reversal. */ for (bits = 1; bits <= MAX_BITS; bits++) { code = (code + bl_count[bits-1]) << 1; next_code[bits] = (ush)code; } /* Check that the bit counts in bl_count are consistent. The last code * must be all ones. */ Assert (code + bl_count[MAX_BITS]-1 == (1<dyn_tree; const ct_data *stree = desc->stat_desc->static_tree; int elems = desc->stat_desc->elems; int n, m; /* iterate over heap elements */ int max_code = -1; /* largest code with non zero frequency */ int node; /* new node being created */ /* Construct the initial heap, with least frequent element in * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. * heap[0] is not used. */ s->heap_len = 0, s->heap_max = HEAP_SIZE; for (n = 0; n < elems; n++) { if (tree[n].Freq != 0) { s->heap[++(s->heap_len)] = max_code = n; s->depth[n] = 0; } else { tree[n].Len = 0; } } /* The pkzip format requires that at least one distance code exists, * and that at least one bit should be sent even if there is only one * possible code. So to avoid special checks later on we force at least * two codes of non zero frequency. */ while (s->heap_len < 2) { node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); tree[node].Freq = 1; s->depth[node] = 0; s->opt_len--; if (stree) s->static_len -= stree[node].Len; /* node is 0 or 1 so it does not have extra bits */ } desc->max_code = max_code; /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, * establish sub-heaps of increasing lengths: */ for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); /* Construct the Huffman tree by repeatedly combining the least two * frequent nodes. */ node = elems; /* next internal node of the tree */ do { pqremove(s, tree, n); /* n = node of least frequency */ m = s->heap[SMALLEST]; /* m = node of next least frequency */ s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ s->heap[--(s->heap_max)] = m; /* Create a new node father of n and m */ tree[node].Freq = tree[n].Freq + tree[m].Freq; s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ? s->depth[n] : s->depth[m]) + 1); tree[n].Dad = tree[m].Dad = (ush)node; #ifdef DUMP_BL_TREE if (tree == s->bl_tree) { fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); } #endif /* and insert the new node in the heap */ s->heap[SMALLEST] = node++; pqdownheap(s, tree, SMALLEST); } while (s->heap_len >= 2); s->heap[--(s->heap_max)] = s->heap[SMALLEST]; /* At this point, the fields freq and dad are set. We can now * generate the bit lengths. */ gen_bitlen(s, (tree_desc *)desc); /* The field len is now set, we can generate the bit codes */ gen_codes ((ct_data *)tree, max_code, s->bl_count); } /* =========================================================================== * Scan a literal or distance tree to determine the frequencies of the codes * in the bit length tree. */ local void scan_tree (s, tree, max_code) deflate_state *s; ct_data *tree; /* the tree to be scanned */ int max_code; /* and its largest code of non zero frequency */ { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ int curlen; /* length of current code */ int nextlen = tree[0].Len; /* length of next code */ int count = 0; /* repeat count of the current code */ int max_count = 7; /* max repeat count */ int min_count = 4; /* min repeat count */ if (nextlen == 0) max_count = 138, min_count = 3; tree[max_code+1].Len = (ush)0xffff; /* guard */ for (n = 0; n <= max_code; n++) { curlen = nextlen; nextlen = tree[n+1].Len; if (++count < max_count && curlen == nextlen) { continue; } else if (count < min_count) { s->bl_tree[curlen].Freq += count; } else if (curlen != 0) { if (curlen != prevlen) s->bl_tree[curlen].Freq++; s->bl_tree[REP_3_6].Freq++; } else if (count <= 10) { s->bl_tree[REPZ_3_10].Freq++; } else { s->bl_tree[REPZ_11_138].Freq++; } count = 0; prevlen = curlen; if (nextlen == 0) { max_count = 138, min_count = 3; } else if (curlen == nextlen) { max_count = 6, min_count = 3; } else { max_count = 7, min_count = 4; } } } /* =========================================================================== * Send a literal or distance tree in compressed form, using the codes in * bl_tree. */ local void send_tree (s, tree, max_code) deflate_state *s; ct_data *tree; /* the tree to be scanned */ int max_code; /* and its largest code of non zero frequency */ { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ int curlen; /* length of current code */ int nextlen = tree[0].Len; /* length of next code */ int count = 0; /* repeat count of the current code */ int max_count = 7; /* max repeat count */ int min_count = 4; /* min repeat count */ /* tree[max_code+1].Len = -1; */ /* guard already set */ if (nextlen == 0) max_count = 138, min_count = 3; for (n = 0; n <= max_code; n++) { curlen = nextlen; nextlen = tree[n+1].Len; if (++count < max_count && curlen == nextlen) { continue; } else if (count < min_count) { do { send_code(s, curlen, s->bl_tree); } while (--count != 0); } else if (curlen != 0) { if (curlen != prevlen) { send_code(s, curlen, s->bl_tree); count--; } Assert(count >= 3 && count <= 6, " 3_6?"); send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); } else if (count <= 10) { send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); } else { send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); } count = 0; prevlen = curlen; if (nextlen == 0) { max_count = 138, min_count = 3; } else if (curlen == nextlen) { max_count = 6, min_count = 3; } else { max_count = 7, min_count = 4; } } } /* =========================================================================== * Construct the Huffman tree for the bit lengths and return the index in * bl_order of the last bit length code to send. */ local int build_bl_tree(s) deflate_state *s; { int max_blindex; /* index of last bit length code of non zero freq */ /* Determine the bit length frequencies for literal and distance trees */ scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); /* Build the bit length tree: */ build_tree(s, (tree_desc *)(&(s->bl_desc))); /* opt_len now includes the length of the tree representations, except * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. */ /* Determine the number of bit length codes to send. The pkzip format * requires that at least 4 bit length codes be sent. (appnote.txt says * 3 but the actual value used is 4.) */ for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; } /* Update opt_len to include the bit length tree and counts */ s->opt_len += 3*((ulg)max_blindex+1) + 5+5+4; Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", s->opt_len, s->static_len)); return max_blindex; } /* =========================================================================== * Send the header for a block using dynamic Huffman trees: the counts, the * lengths of the bit length codes, the literal tree and the distance tree. * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. */ local void send_all_trees(s, lcodes, dcodes, blcodes) deflate_state *s; int lcodes, dcodes, blcodes; /* number of codes for each tree */ { int rank; /* index in bl_order */ Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, "too many codes"); Tracev((stderr, "\nbl counts: ")); send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ send_bits(s, dcodes-1, 5); send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ for (rank = 0; rank < blcodes; rank++) { Tracev((stderr, "\nbl code %2d ", bl_order[rank])); send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); } Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); } /* =========================================================================== * Send a stored block */ void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last) deflate_state *s; charf *buf; /* input block */ ulg stored_len; /* length of input block */ int last; /* one if this is the last block for a file */ { send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */ bi_windup(s); /* align on byte boundary */ put_short(s, (ush)stored_len); put_short(s, (ush)~stored_len); zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len); s->pending += stored_len; #ifdef ZLIB_DEBUG s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; s->compressed_len += (stored_len + 4) << 3; s->bits_sent += 2*16; s->bits_sent += stored_len<<3; #endif } /* =========================================================================== * Flush the bits in the bit buffer to pending output (leaves at most 7 bits) */ void ZLIB_INTERNAL _tr_flush_bits(s) deflate_state *s; { bi_flush(s); } /* =========================================================================== * Send one empty static block to give enough lookahead for inflate. * This takes 10 bits, of which 7 may remain in the bit buffer. */ void ZLIB_INTERNAL _tr_align(s) deflate_state *s; { send_bits(s, STATIC_TREES<<1, 3); send_code(s, END_BLOCK, static_ltree); #ifdef ZLIB_DEBUG s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ #endif bi_flush(s); } /* =========================================================================== * Determine the best encoding for the current block: dynamic trees, static * trees or store, and write out the encoded block. */ void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last) deflate_state *s; charf *buf; /* input block, or NULL if too old */ ulg stored_len; /* length of input block */ int last; /* one if this is the last block for a file */ { ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ int max_blindex = 0; /* index of last bit length code of non zero freq */ /* Build the Huffman trees unless a stored block is forced */ if (s->level > 0) { /* Check if the file is binary or text */ if (s->strm->data_type == Z_UNKNOWN) s->strm->data_type = detect_data_type(s); /* Construct the literal and distance trees */ build_tree(s, (tree_desc *)(&(s->l_desc))); Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, s->static_len)); build_tree(s, (tree_desc *)(&(s->d_desc))); Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, s->static_len)); /* At this point, opt_len and static_len are the total bit lengths of * the compressed block data, excluding the tree representations. */ /* Build the bit length tree for the above two trees, and get the index * in bl_order of the last bit length code to send. */ max_blindex = build_bl_tree(s); /* Determine the best encoding. Compute the block lengths in bytes. */ opt_lenb = (s->opt_len+3+7)>>3; static_lenb = (s->static_len+3+7)>>3; Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, - s->last_lit)); + s->sym_next / 3)); if (static_lenb <= opt_lenb) opt_lenb = static_lenb; } else { Assert(buf != (char*)0, "lost buf"); opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ } #ifdef FORCE_STORED if (buf != (char*)0) { /* force stored block */ #else if (stored_len+4 <= opt_lenb && buf != (char*)0) { /* 4: two words for the lengths */ #endif /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. * Otherwise we can't have processed more than WSIZE input bytes since * the last block flush, because compression would have been * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to * transform a block into a stored block. */ _tr_stored_block(s, buf, stored_len, last); #ifdef FORCE_STATIC } else if (static_lenb >= 0) { /* force static trees */ #else } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) { #endif send_bits(s, (STATIC_TREES<<1)+last, 3); compress_block(s, (const ct_data *)static_ltree, (const ct_data *)static_dtree); #ifdef ZLIB_DEBUG s->compressed_len += 3 + s->static_len; #endif } else { send_bits(s, (DYN_TREES<<1)+last, 3); send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, max_blindex+1); compress_block(s, (const ct_data *)s->dyn_ltree, (const ct_data *)s->dyn_dtree); #ifdef ZLIB_DEBUG s->compressed_len += 3 + s->opt_len; #endif } Assert (s->compressed_len == s->bits_sent, "bad compressed size"); /* The above check is made mod 2^32, for files larger than 512 MB * and uLong implemented on 32 bits. */ init_block(s); if (last) { bi_windup(s); #ifdef ZLIB_DEBUG s->compressed_len += 7; /* align on byte boundary */ #endif } Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, s->compressed_len-7*last)); } /* =========================================================================== * Save the match info and tally the frequency counts. Return true if * the current block must be flushed. */ int ZLIB_INTERNAL _tr_tally (s, dist, lc) deflate_state *s; unsigned dist; /* distance of matched string */ unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ { - s->d_buf[s->last_lit] = (ush)dist; - s->l_buf[s->last_lit++] = (uch)lc; + s->sym_buf[s->sym_next++] = dist; + s->sym_buf[s->sym_next++] = dist >> 8; + s->sym_buf[s->sym_next++] = lc; if (dist == 0) { /* lc is the unmatched char */ s->dyn_ltree[lc].Freq++; } else { s->matches++; /* Here, lc is the match length - MIN_MATCH */ dist--; /* dist = match distance - 1 */ Assert((ush)dist < (ush)MAX_DIST(s) && (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++; s->dyn_dtree[d_code(dist)].Freq++; } - -#ifdef TRUNCATE_BLOCK - /* Try to guess if it is profitable to stop the current block here */ - if ((s->last_lit & 0x1fff) == 0 && s->level > 2) { - /* Compute an upper bound for the compressed length */ - ulg out_length = (ulg)s->last_lit*8L; - ulg in_length = (ulg)((long)s->strstart - s->block_start); - int dcode; - for (dcode = 0; dcode < D_CODES; dcode++) { - out_length += (ulg)s->dyn_dtree[dcode].Freq * - (5L+extra_dbits[dcode]); - } - out_length >>= 3; - Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", - s->last_lit, in_length, out_length, - 100L - out_length*100L/in_length)); - if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; - } -#endif - return (s->last_lit == s->lit_bufsize-1); - /* We avoid equality with lit_bufsize because of wraparound at 64K - * on 16 bit machines and because stored blocks are restricted to - * 64K-1 bytes. - */ + return (s->sym_next == s->sym_end); } /* =========================================================================== * Send the block data compressed using the given Huffman trees */ local void compress_block(s, ltree, dtree) deflate_state *s; const ct_data *ltree; /* literal tree */ const ct_data *dtree; /* distance tree */ { unsigned dist; /* distance of matched string */ int lc; /* match length or unmatched char (if dist == 0) */ - unsigned lx = 0; /* running index in l_buf */ + unsigned sx = 0; /* running index in sym_buf */ unsigned code; /* the code to send */ int extra; /* number of extra bits to send */ - if (s->last_lit != 0) do { - dist = s->d_buf[lx]; - lc = s->l_buf[lx++]; + if (s->sym_next != 0) do { + dist = s->sym_buf[sx++] & 0xff; + dist += (unsigned)(s->sym_buf[sx++] & 0xff) << 8; + lc = s->sym_buf[sx++]; if (dist == 0) { send_code(s, lc, ltree); /* send a literal byte */ Tracecv(isgraph(lc), (stderr," '%c' ", lc)); } else { /* Here, lc is the match length - MIN_MATCH */ code = _length_code[lc]; send_code(s, code+LITERALS+1, ltree); /* send the length code */ extra = extra_lbits[code]; if (extra != 0) { lc -= base_length[code]; send_bits(s, lc, extra); /* send the extra length bits */ } dist--; /* dist is now the match distance - 1 */ code = d_code(dist); Assert (code < D_CODES, "bad d_code"); send_code(s, code, dtree); /* send the distance code */ extra = extra_dbits[code]; if (extra != 0) { dist -= (unsigned)base_dist[code]; send_bits(s, dist, extra); /* send the extra distance bits */ } } /* literal or match pair ? */ - /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ - Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx, - "pendingBuf overflow"); + /* Check that the overlay between pending_buf and sym_buf is ok: */ + Assert(s->pending < s->lit_bufsize + sx, "pendingBuf overflow"); - } while (lx < s->last_lit); + } while (sx < s->sym_next); send_code(s, END_BLOCK, ltree); } /* =========================================================================== * Check if the data type is TEXT or BINARY, using the following algorithm: * - TEXT if the two conditions below are satisfied: * a) There are no non-portable control characters belonging to the * "black list" (0..6, 14..25, 28..31). * b) There is at least one printable character belonging to the * "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255). * - BINARY otherwise. * - The following partially-portable control characters form a * "gray list" that is ignored in this detection algorithm: * (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}). * IN assertion: the fields Freq of dyn_ltree are set. */ local int detect_data_type(s) deflate_state *s; { /* black_mask is the bit mask of black-listed bytes * set bits 0..6, 14..25, and 28..31 * 0xf3ffc07f = binary 11110011111111111100000001111111 */ unsigned long black_mask = 0xf3ffc07fUL; int n; /* Check for non-textual ("black-listed") bytes. */ for (n = 0; n <= 31; n++, black_mask >>= 1) if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0)) return Z_BINARY; /* Check for textual ("white-listed") bytes. */ if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0 || s->dyn_ltree[13].Freq != 0) return Z_TEXT; for (n = 32; n < LITERALS; n++) if (s->dyn_ltree[n].Freq != 0) return Z_TEXT; /* There are no "black-listed" or "white-listed" bytes: * this stream either is empty or has tolerated ("gray-listed") bytes only. */ return Z_BINARY; } /* =========================================================================== * Reverse the first len bits of a code, using straightforward code (a faster * method would use a table) * IN assertion: 1 <= len <= 15 */ local unsigned bi_reverse(code, len) unsigned code; /* the value to invert */ int len; /* its bit length */ { register unsigned res = 0; do { res |= code & 1; code >>= 1, res <<= 1; } while (--len > 0); return res >> 1; } /* =========================================================================== * Flush the bit buffer, keeping at most 7 bits in it. */ local void bi_flush(s) deflate_state *s; { if (s->bi_valid == 16) { put_short(s, s->bi_buf); s->bi_buf = 0; s->bi_valid = 0; } else if (s->bi_valid >= 8) { put_byte(s, (Byte)s->bi_buf); s->bi_buf >>= 8; s->bi_valid -= 8; } } /* =========================================================================== * Flush the bit buffer and align the output on a byte boundary */ local void bi_windup(s) deflate_state *s; { if (s->bi_valid > 8) { put_short(s, s->bi_buf); } else if (s->bi_valid > 0) { put_byte(s, (Byte)s->bi_buf); } s->bi_buf = 0; s->bi_valid = 0; #ifdef ZLIB_DEBUG s->bits_sent = (s->bits_sent+7) & ~7; #endif }