diff options
Diffstat (limited to 'cpan/Compress-Raw-Zlib/zlib-src/deflate.c')
| -rw-r--r-- | cpan/Compress-Raw-Zlib/zlib-src/deflate.c | 434 |
1 files changed, 266 insertions, 168 deletions
diff --git a/cpan/Compress-Raw-Zlib/zlib-src/deflate.c b/cpan/Compress-Raw-Zlib/zlib-src/deflate.c index 3a8f388add..5c4022f3d4 100644 --- a/cpan/Compress-Raw-Zlib/zlib-src/deflate.c +++ b/cpan/Compress-Raw-Zlib/zlib-src/deflate.c @@ -1,5 +1,5 @@ /* deflate.c -- compress data using the deflation algorithm - * Copyright (C) 1995-2005 Jean-loup Gailly. + * Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -52,7 +52,7 @@ #include "deflate.h" const char deflate_copyright[] = - " deflate 1.2.3 Copyright 1995-2005 Jean-loup Gailly "; + " deflate 1.2.5 Copyright 1995-2010 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 @@ -79,19 +79,18 @@ 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 int read_buf OF((z_streamp strm, Bytef *buf, unsigned size)); -#ifndef FASTEST #ifdef ASMV 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 -#endif -local uInt longest_match_fast OF((deflate_state *s, IPos cur_match)); #ifdef DEBUG local void check_match OF((deflate_state *s, IPos start, IPos match, @@ -110,11 +109,6 @@ local void check_match OF((deflate_state *s, IPos start, IPos match, #endif /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ -#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. - */ - /* 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 @@ -201,11 +195,11 @@ struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); /* ========================================================================= */ -int ZEXPORT deflateInit_( - z_streamp strm, - int level, - const char *version, - int stream_size) +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); @@ -213,15 +207,16 @@ int ZEXPORT deflateInit_( } /* ========================================================================= */ -int ZEXPORT deflateInit2_( - z_streamp strm, - int level, - int method, - int windowBits, - int memLevel, - int strategy, - const char *version, - int stream_size) +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; @@ -287,6 +282,8 @@ int ZEXPORT deflateInit2_( 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); @@ -311,10 +308,10 @@ int ZEXPORT deflateInit2_( } /* ========================================================================= */ -int ZEXPORT deflateSetDictionary ( - z_streamp strm, - const Bytef *dictionary, - uInt dictLength) +int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) + z_streamp strm; + const Bytef *dictionary; + uInt dictLength; { deflate_state *s; uInt length = dictLength; @@ -331,8 +328,8 @@ int ZEXPORT deflateSetDictionary ( strm->adler = adler32(strm->adler, dictionary, dictLength); if (length < MIN_MATCH) return Z_OK; - if (length > MAX_DIST(s)) { - length = MAX_DIST(s); + if (length > s->w_size) { + length = s->w_size; dictionary += dictLength - length; /* use the tail of the dictionary */ } zmemcpy(s->window, dictionary, length); @@ -353,8 +350,8 @@ int ZEXPORT deflateSetDictionary ( } /* ========================================================================= */ -int ZEXPORT deflateReset ( - z_streamp strm) +int ZEXPORT deflateReset (strm) + z_streamp strm; { deflate_state *s; @@ -389,9 +386,9 @@ int ZEXPORT deflateReset ( } /* ========================================================================= */ -int ZEXPORT deflateSetHeader ( - z_streamp strm, - gz_headerp head) +int ZEXPORT deflateSetHeader (strm, head) + z_streamp strm; + gz_headerp head; { if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; if (strm->state->wrap != 2) return Z_STREAM_ERROR; @@ -400,10 +397,10 @@ int ZEXPORT deflateSetHeader ( } /* ========================================================================= */ -int ZEXPORT deflatePrime ( - z_streamp strm, - int bits, - int value) +int ZEXPORT deflatePrime (strm, bits, value) + z_streamp strm; + int bits; + int value; { if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; strm->state->bi_valid = bits; @@ -412,10 +409,10 @@ int ZEXPORT deflatePrime ( } /* ========================================================================= */ -int ZEXPORT deflateParams( - z_streamp strm, - int level, - int strategy) +int ZEXPORT deflateParams(strm, level, strategy) + z_streamp strm; + int level; + int strategy; { deflate_state *s; compress_func func; @@ -434,9 +431,10 @@ int ZEXPORT deflateParams( } func = configuration_table[s->level].func; - if (func != configuration_table[level].func && strm->total_in != 0) { + if ((strategy != s->strategy || func != configuration_table[level].func) && + strm->total_in != 0) { /* Flush the last buffer: */ - err = deflate(strm, Z_PARTIAL_FLUSH); + err = deflate(strm, Z_BLOCK); } if (s->level != level) { s->level = level; @@ -450,12 +448,12 @@ int ZEXPORT deflateParams( } /* ========================================================================= */ -int ZEXPORT deflateTune( - z_streamp strm, - int good_length, - int max_lazy, - int nice_length, - int max_chain) +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; @@ -480,33 +478,66 @@ int ZEXPORT deflateTune( * 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, as well as wrap. - * But even the conservative upper bound of about 14% expansion does not - * seem onerous for output buffer allocation. + * 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( - z_streamp strm, - uLong sourceLen) +uLong ZEXPORT deflateBound(strm, sourceLen) + z_streamp strm; + uLong sourceLen; { deflate_state *s; - uLong destLen; + uLong complen, wraplen; + Bytef *str; - /* conservative upper bound */ - destLen = sourceLen + - ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 11; + /* conservative upper bound for compressed data */ + complen = sourceLen + + ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; - /* if can't get parameters, return conservative bound */ + /* if can't get parameters, return conservative bound plus zlib wrapper */ if (strm == Z_NULL || strm->state == Z_NULL) - return destLen; + return complen + 6; - /* if not default parameters, return conservative bound */ + /* 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; + case 2: /* gzip wrapper */ + wraplen = 18; + if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ + 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; + default: /* for compiler happiness */ + wraplen = 6; + } + + /* if not default parameters, return conservative bound */ if (s->w_bits != 15 || s->hash_bits != 8 + 7) - return destLen; + return complen + wraplen; /* default settings: return tight bound for that case */ - return compressBound(sourceLen); + return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + + (sourceLen >> 25) + 13 - 6 + wraplen; } /* ========================================================================= @@ -514,9 +545,9 @@ uLong ZEXPORT deflateBound( * IN assertion: the stream state is correct and there is enough room in * pending_buf. */ -local void putShortMSB ( - deflate_state *s, - uInt b) +local void putShortMSB (s, b) + deflate_state *s; + uInt b; { put_byte(s, (Byte)(b >> 8)); put_byte(s, (Byte)(b & 0xff)); @@ -528,8 +559,8 @@ local void putShortMSB ( * to avoid allocating a large strm->next_out buffer and copying into it. * (See also read_buf()). */ -local void flush_pending( - z_streamp strm) +local void flush_pending(strm) + z_streamp strm; { unsigned len = strm->state->pending; @@ -548,15 +579,15 @@ local void flush_pending( } /* ========================================================================= */ -int ZEXPORT deflate ( - z_streamp strm, - int flush) +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 (strm == Z_NULL || strm->state == Z_NULL || - flush > Z_FINISH || flush < 0) { + flush > Z_BLOCK || flush < 0) { return Z_STREAM_ERROR; } s = strm->state; @@ -580,7 +611,7 @@ int ZEXPORT deflate ( put_byte(s, 31); put_byte(s, 139); put_byte(s, 8); - if (s->gzhead == NULL) { + if (s->gzhead == Z_NULL) { put_byte(s, 0); put_byte(s, 0); put_byte(s, 0); @@ -607,7 +638,7 @@ int ZEXPORT deflate ( (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); put_byte(s, s->gzhead->os & 0xff); - if (s->gzhead->extra != NULL) { + if (s->gzhead->extra != Z_NULL) { put_byte(s, s->gzhead->extra_len & 0xff); put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); } @@ -649,7 +680,7 @@ int ZEXPORT deflate ( } #ifdef GZIP if (s->status == EXTRA_STATE) { - if (s->gzhead->extra != NULL) { + if (s->gzhead->extra != Z_NULL) { uInt beg = s->pending; /* start of bytes to update crc */ while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { @@ -677,7 +708,7 @@ int ZEXPORT deflate ( s->status = NAME_STATE; } if (s->status == NAME_STATE) { - if (s->gzhead->name != NULL) { + if (s->gzhead->name != Z_NULL) { uInt beg = s->pending; /* start of bytes to update crc */ int val; @@ -708,7 +739,7 @@ int ZEXPORT deflate ( s->status = COMMENT_STATE; } if (s->status == COMMENT_STATE) { - if (s->gzhead->comment != NULL) { + if (s->gzhead->comment != Z_NULL) { uInt beg = s->pending; /* start of bytes to update crc */ int val; @@ -786,7 +817,9 @@ int ZEXPORT deflate ( (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { block_state bstate; - bstate = (*(configuration_table[s->level].func))(s, flush); + bstate = 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; @@ -807,13 +840,17 @@ int ZEXPORT deflate ( if (bstate == block_done) { if (flush == Z_PARTIAL_FLUSH) { _tr_align(s); - } else { /* FULL_FLUSH or SYNC_FLUSH */ + } 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; + } } } flush_pending(strm); @@ -855,8 +892,8 @@ int ZEXPORT deflate ( } /* ========================================================================= */ -int ZEXPORT deflateEnd ( - z_streamp strm) +int ZEXPORT deflateEnd (strm) + z_streamp strm; { int status; @@ -890,9 +927,9 @@ int ZEXPORT deflateEnd ( * 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 ( - z_streamp dest, - z_streamp source) +int ZEXPORT deflateCopy (dest, source) + z_streamp dest; + z_streamp source; { #ifdef MAXSEG_64K return Z_STREAM_ERROR; @@ -952,10 +989,10 @@ int ZEXPORT deflateCopy ( * allocating a large strm->next_in buffer and copying from it. * (See also flush_pending()). */ -local int read_buf( - z_streamp strm, - Bytef *buf, - unsigned size) +local int read_buf(strm, buf, size) + z_streamp strm; + Bytef *buf; + unsigned size; { unsigned len = strm->avail_in; @@ -982,8 +1019,8 @@ local int read_buf( /* =========================================================================== * Initialize the "longest match" routines for a new zlib stream */ -local void lm_init ( - deflate_state *s) +local void lm_init (s) + deflate_state *s; { s->window_size = (ulg)2L*s->w_size; @@ -1023,9 +1060,9 @@ local void lm_init ( /* 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( - deflate_state *s, - IPos cur_match) +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 */ @@ -1166,14 +1203,15 @@ local uInt longest_match( return s->lookahead; } #endif /* ASMV */ -#endif /* FASTEST */ + +#else /* FASTEST */ /* --------------------------------------------------------------------------- - * Optimized version for level == 1 or strategy == Z_RLE only + * Optimized version for FASTEST only */ -local uInt longest_match_fast( - deflate_state *s, - IPos cur_match) +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 */ @@ -1224,15 +1262,16 @@ local uInt longest_match_fast( return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; } +#endif /* FASTEST */ + #ifdef DEBUG /* =========================================================================== * Check that the match at match_start is indeed a match. */ -local void check_match( - deflate_state *s, - IPos start, - IPos match, - int length) +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, @@ -1263,8 +1302,8 @@ local void check_match( * performed for at least two bytes (required for the zip translate_eol * option -- not supported here). */ -local void fill_window( - deflate_state *s) +local void fill_window(s) + deflate_state *s; { register unsigned n, m; register Posf *p; @@ -1303,7 +1342,6 @@ local void fill_window( later. (Using level 0 permanently is not an optimal usage of zlib, so we don't care about this pathological case.) */ - /* %%% avoid this when Z_RLE */ n = s->hash_size; p = &s->head[n]; do { @@ -1355,27 +1393,61 @@ local void fill_window( */ } 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; + } + } } /* =========================================================================== * 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, eof) { \ +#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), \ - (eof)); \ + (last)); \ s->block_start = s->strstart; \ flush_pending(s->strm); \ Tracev((stderr,"[FLUSH]")); \ } /* Same but force premature exit if necessary. */ -#define FLUSH_BLOCK(s, eof) { \ - FLUSH_BLOCK_ONLY(s, eof); \ - if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ +#define FLUSH_BLOCK(s, last) { \ + FLUSH_BLOCK_ONLY(s, last); \ + if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ } /* =========================================================================== @@ -1387,9 +1459,9 @@ local void fill_window( * NOTE: this function should be optimized to avoid extra copying from * window to pending_buf. */ -local block_state deflate_stored( - deflate_state *s, - int flush) +local block_state deflate_stored(s, flush) + deflate_state *s; + int flush; { /* Stored blocks are limited to 0xffff bytes, pending_buf is limited * to pending_buf_size, and each stored block has a 5 byte header: @@ -1445,11 +1517,11 @@ local block_state deflate_stored( * 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( - deflate_state *s, - int flush) +local block_state deflate_fast(s, flush) + deflate_state *s; + int flush; { - IPos hash_head = NIL; /* head of the hash chain */ + IPos hash_head; /* head of the hash chain */ int bflush; /* set if current block must be flushed */ for (;;) { @@ -1469,6 +1541,7 @@ local block_state deflate_fast( /* 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); } @@ -1481,19 +1554,8 @@ local block_state deflate_fast( * of window index 0 (in particular we have to avoid a match * of the string with itself at the start of the input file). */ -#ifdef FASTEST - if ((s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) || - (s->strategy == Z_RLE && s->strstart - hash_head == 1)) { - s->match_length = longest_match_fast (s, hash_head); - } -#else - if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) { - s->match_length = longest_match (s, hash_head); - } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) { - s->match_length = longest_match_fast (s, hash_head); - } -#endif - /* longest_match() or longest_match_fast() sets match_start */ + 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); @@ -1551,11 +1613,11 @@ local block_state deflate_fast( * 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( - deflate_state *s, - int flush) +local block_state deflate_slow(s, flush) + deflate_state *s; + int flush; { - IPos hash_head = NIL; /* head of hash chain */ + IPos hash_head; /* head of hash chain */ int bflush; /* set if current block must be flushed */ /* Process the input block. */ @@ -1576,6 +1638,7 @@ local block_state deflate_slow( /* 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); } @@ -1591,12 +1654,8 @@ local block_state deflate_slow( * of window index 0 (in particular we have to avoid a match * of the string with itself at the start of the input file). */ - if (s->strategy != Z_HUFFMAN_ONLY && s->strategy != Z_RLE) { - s->match_length = longest_match (s, hash_head); - } else if (s->strategy == Z_RLE && s->strstart - hash_head == 1) { - s->match_length = longest_match_fast (s, hash_head); - } - /* longest_match() or longest_match_fast() sets match_start */ + 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 @@ -1674,21 +1733,18 @@ local block_state deflate_slow( } #endif /* FASTEST */ -#if 0 /* =========================================================================== * 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( - deflate_state *s, - int flush) +local block_state deflate_rle(s, flush) + deflate_state *s; + int flush; { - int bflush; /* set if current block must be flushed */ - uInt run; /* length of run */ - uInt max; /* maximum length of run */ - uInt prev; /* byte at distance one to match */ - Bytef *scan; /* scan for end of run */ + 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 @@ -1704,23 +1760,33 @@ local block_state deflate_rle( } /* See how many times the previous byte repeats */ - run = 0; - if (s->strstart > 0) { /* if there is a previous byte, that is */ - max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH; + s->match_length = 0; + if (s->lookahead >= MIN_MATCH && s->strstart > 0) { scan = s->window + s->strstart - 1; - prev = *scan++; - do { - if (*scan++ != prev) - break; - } while (++run < max); + 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 - (int)(strend - scan); + if (s->match_length > s->lookahead) + s->match_length = s->lookahead; + } } /* Emit match if have run of MIN_MATCH or longer, else emit literal */ - if (run >= MIN_MATCH) { - check_match(s, s->strstart, s->strstart - 1, run); - _tr_tally_dist(s, 1, run - MIN_MATCH, bflush); - s->lookahead -= run; - s->strstart += run; + 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])); @@ -1733,4 +1799,36 @@ local block_state deflate_rle( FLUSH_BLOCK(s, flush == Z_FINISH); return flush == Z_FINISH ? finish_done : block_done; } -#endif + +/* =========================================================================== + * 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); + } + FLUSH_BLOCK(s, flush == Z_FINISH); + return flush == Z_FINISH ? finish_done : block_done; +} |