X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=deflate.c;h=65d910195d97454faa95c7f5eba105304765ec9c;hb=0b166094092efa2b92200cbb67f390e86c181ab4;hp=cb723a1d290b9891e2cbda1e779efd8cdc40c688;hpb=9811b53dd9e8f67015c7199fff12b5bfc6965330;p=zlib.git diff --git a/deflate.c b/deflate.c index cb723a1..65d9101 100644 --- a/deflate.c +++ b/deflate.c @@ -1,5 +1,5 @@ /* deflate.c -- compress data using the deflation algorithm - * Copyright (C) 1995-2004 Jean-loup Gailly. + * Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -37,7 +37,7 @@ * REFERENCES * * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". - * Available in http://www.ietf.org/rfc/rfc1951.txt + * 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. @@ -52,7 +52,7 @@ #include "deflate.h" const char deflate_copyright[] = - " deflate 1.2.2.1 Copyright 1995-2004 Jean-loup Gailly "; + " deflate 1.2.7.1 Copyright 1995-2013 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 @@ -161,6 +155,9 @@ local const config configuration_table[10] = { struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ #endif +/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */ +#define RANK(f) (((f) << 1) - ((f) > 4 ? 9 : 0)) + /* =========================================================================== * Update a hash value with the given input byte * IN assertion: all calls to to UPDATE_HASH are made with consecutive @@ -241,10 +238,19 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, 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) strm->zfree = zcfree; + 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; @@ -264,7 +270,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, #endif if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || - strategy < 0 || strategy > Z_RLE) { + strategy < 0 || strategy > Z_FIXED) { return Z_STREAM_ERROR; } if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ @@ -288,6 +294,8 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, 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); @@ -297,7 +305,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || s->pending_buf == Z_NULL) { s->status = FINISH_STATE; - strm->msg = (char*)ERR_MSG(Z_MEM_ERROR); + strm->msg = ERR_MSG(Z_MEM_ERROR); deflateEnd (strm); return Z_MEM_ERROR; } @@ -318,45 +326,70 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) uInt dictLength; { deflate_state *s; - uInt length = dictLength; - uInt n; - IPos hash_head = 0; + uInt str, n; + int wrap; + unsigned avail; + z_const unsigned char *next; - if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL || - strm->state->wrap == 2 || - (strm->state->wrap == 1 && strm->state->status != INIT_STATE)) + if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) return Z_STREAM_ERROR; - s = strm->state; - if (s->wrap) - strm->adler = adler32(strm->adler, dictionary, dictLength); + wrap = s->wrap; + if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead) + return Z_STREAM_ERROR; - if (length < MIN_MATCH) return Z_OK; - if (length > MAX_DIST(s)) { - length = MAX_DIST(s); -#ifndef USE_DICT_HEAD - dictionary += dictLength - length; /* use the tail of the dictionary */ -#endif + /* 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; } - zmemcpy(s->window, dictionary, length); - s->strstart = length; - s->block_start = (long)length; - /* Insert all strings in the hash table (except for the last two bytes). - * s->lookahead stays null, so s->ins_h will be recomputed at the next - * call of fill_window. - */ - s->ins_h = s->window[0]; - UPDATE_HASH(s, s->ins_h, s->window[1]); - for (n = 0; n <= length - MIN_MATCH; n++) { - INSERT_STRING(s, n, hash_head); + /* 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); } - if (hash_head) hash_head = 0; /* to make compiler happy */ + 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 deflateReset (strm) +int ZEXPORT deflateResetKeep (strm) z_streamp strm; { deflate_state *s; @@ -386,11 +419,22 @@ int ZEXPORT deflateReset (strm) s->last_flush = Z_NO_FLUSH; _tr_init(s); - lm_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; @@ -402,15 +446,43 @@ int ZEXPORT deflateSetHeader (strm, head) return Z_OK; } +/* ========================================================================= */ +int ZEXPORT deflatePending (strm, pending, bits) + unsigned *pending; + int *bits; + z_streamp strm; +{ + if (strm == Z_NULL || strm->state == Z_NULL) 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 (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; - strm->state->bi_valid = bits; - strm->state->bi_buf = (ush)(value & ((1 << bits) - 1)); + s = strm->state; + if ((Bytef *)(s->d_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; } @@ -432,14 +504,17 @@ int ZEXPORT deflateParams(strm, level, strategy) #else if (level == Z_DEFAULT_COMPRESSION) level = 6; #endif - if (level < 0 || level > 9 || strategy < 0 || strategy > Z_RLE) { + if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { return Z_STREAM_ERROR; } 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 (err == Z_BUF_ERROR && s->pending == 0) + err = Z_OK; } if (s->level != level) { s->level = level; @@ -452,6 +527,25 @@ int ZEXPORT deflateParams(strm, level, strategy) return err; } +/* ========================================================================= */ +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 (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; + s = strm->state; + s->good_match = good_length; + s->max_lazy_match = max_lazy; + s->nice_match = nice_length; + s->max_chain_length = 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. @@ -464,33 +558,66 @@ int ZEXPORT deflateParams(strm, level, strategy) * 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(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; } /* ========================================================================= @@ -515,19 +642,22 @@ local void putShortMSB (s, b) local void flush_pending(strm) z_streamp strm; { - unsigned len = strm->state->pending; + 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, strm->state->pending_out, len); + zmemcpy(strm->next_out, s->pending_out, len); strm->next_out += len; - strm->state->pending_out += len; + s->pending_out += len; strm->total_out += len; strm->avail_out -= len; - strm->state->pending -= len; - if (strm->state->pending == 0) { - strm->state->pending_out = strm->state->pending_buf; + s->pending -= len; + if (s->pending == 0) { + s->pending_out = s->pending_buf; } } @@ -540,7 +670,7 @@ int ZEXPORT deflate (strm, flush) 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; @@ -564,7 +694,7 @@ int ZEXPORT deflate (strm, flush) 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); @@ -573,7 +703,7 @@ int ZEXPORT deflate (strm, flush) put_byte(s, s->level == 9 ? 2 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? 4 : 0)); - put_byte(s, 255); + put_byte(s, OS_CODE); s->status = BUSY_STATE; } else { @@ -583,15 +713,15 @@ int ZEXPORT deflate (strm, flush) (s->gzhead->name == Z_NULL ? 0 : 8) + (s->gzhead->comment == Z_NULL ? 0 : 16) ); - put_byte(s, s->gzhead->time & 0xff); - put_byte(s, (s->gzhead->time >> 8) & 0xff); - put_byte(s, (s->gzhead->time >> 16) & 0xff); - put_byte(s, (s->gzhead->time >> 24) & 0xff); + 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 != NULL) { + if (s->gzhead->extra != Z_NULL) { put_byte(s, s->gzhead->extra_len & 0xff); put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); } @@ -633,8 +763,8 @@ int ZEXPORT deflate (strm, flush) } #ifdef GZIP if (s->status == EXTRA_STATE) { - if (s->gzhead->extra != NULL) { - int beg = s->pending; /* start of bytes to update crc */ + if (s->gzhead->extra != Z_NULL) { + uInt beg = s->pending; /* start of bytes to update crc */ while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { if (s->pending == s->pending_buf_size) { @@ -661,8 +791,8 @@ int ZEXPORT deflate (strm, flush) s->status = NAME_STATE; } if (s->status == NAME_STATE) { - if (s->gzhead->name != NULL) { - int beg = s->pending; /* start of bytes to update crc */ + if (s->gzhead->name != Z_NULL) { + uInt beg = s->pending; /* start of bytes to update crc */ int val; do { @@ -692,8 +822,8 @@ int ZEXPORT deflate (strm, flush) s->status = COMMENT_STATE; } if (s->status == COMMENT_STATE) { - if (s->gzhead->comment != NULL) { - int beg = s->pending; /* start of bytes to update crc */ + if (s->gzhead->comment != Z_NULL) { + uInt beg = s->pending; /* start of bytes to update crc */ int val; do { @@ -725,8 +855,8 @@ int ZEXPORT deflate (strm, flush) if (s->pending + 2 > s->pending_buf_size) flush_pending(strm); if (s->pending + 2 <= s->pending_buf_size) { - put_byte(s, strm->adler & 0xff); - put_byte(s, (strm->adler >> 8) & 0xff); + 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; } @@ -754,7 +884,7 @@ int ZEXPORT deflate (strm, flush) * 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 && flush <= old_flush && + } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) && flush != Z_FINISH) { ERR_RETURN(strm, Z_BUF_ERROR); } @@ -770,7 +900,9 @@ int ZEXPORT deflate (strm, flush) (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; @@ -791,13 +923,18 @@ int ZEXPORT deflate (strm, flush) 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; + s->insert = 0; + } } } flush_pending(strm); @@ -892,12 +1029,12 @@ int ZEXPORT deflateCopy (dest, source) ss = source->state; - *dest = *source; + 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; - *ds = *ss; + zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state)); ds->strm = dest; ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); @@ -913,8 +1050,8 @@ int ZEXPORT deflateCopy (dest, source) } /* following zmemcpy do not work for 16-bit MSDOS */ zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); - zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); - zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); + 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); @@ -948,15 +1085,15 @@ local int read_buf(strm, buf, size) strm->avail_in -= len; + zmemcpy(buf, strm->next_in, len); if (strm->state->wrap == 1) { - strm->adler = adler32(strm->adler, strm->next_in, len); + strm->adler = adler32(strm->adler, buf, len); } #ifdef GZIP else if (strm->state->wrap == 2) { - strm->adler = crc32(strm->adler, strm->next_in, len); + strm->adler = crc32(strm->adler, buf, len); } #endif - zmemcpy(buf, strm->next_in, len); strm->next_in += len; strm->total_in += len; @@ -983,12 +1120,15 @@ local void lm_init (s) 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 @@ -1057,7 +1197,12 @@ local uInt longest_match(s, cur_match) match = s->window + cur_match; /* Skip to next match if the match length cannot increase - * or if the match length is less than 2: + * 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 @@ -1143,12 +1288,13 @@ local uInt longest_match(s, cur_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(s, cur_match) +local uInt longest_match(s, cur_match) deflate_state *s; IPos cur_match; /* current match */ { @@ -1201,6 +1347,8 @@ local uInt longest_match_fast(s, cur_match) return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; } +#endif /* FASTEST */ + #ifdef DEBUG /* =========================================================================== * Check that the match at match_start is indeed a match. @@ -1247,6 +1395,8 @@ local void fill_window(s) 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); @@ -1299,7 +1449,7 @@ local void fill_window(s) #endif more += wsize; } - if (s->strm->avail_in == 0) return; + if (s->strm->avail_in == 0) break; /* If there was no sliding: * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && @@ -1318,39 +1468,88 @@ local void fill_window(s) s->lookahead += n; /* Initialize the hash value now that we have some input: */ - if (s->lookahead >= MIN_MATCH) { - s->ins_h = s->window[s->strstart]; - UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); + 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, 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; \ } /* =========================================================================== @@ -1409,8 +1608,14 @@ local block_state deflate_stored(s, flush) FLUSH_BLOCK(s, 0); } } - FLUSH_BLOCK(s, flush == Z_FINISH); - return flush == Z_FINISH ? finish_done : block_done; + s->insert = 0; + if (flush == Z_FINISH) { + FLUSH_BLOCK(s, 1); + return finish_done; + } + if ((long)s->strstart > s->block_start) + FLUSH_BLOCK(s, 0); + return block_done; } /* =========================================================================== @@ -1424,7 +1629,7 @@ 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 (;;) { @@ -1444,6 +1649,7 @@ local block_state deflate_fast(s, flush) /* 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); } @@ -1456,19 +1662,8 @@ local block_state deflate_fast(s, flush) * 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->strstart - hash_head == 1)) { - s->match_length = longest_match_fast (s, hash_head); - } -#else - if (s->strategy < Z_HUFFMAN_ONLY) { - 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); @@ -1516,8 +1711,14 @@ local block_state deflate_fast(s, flush) } if (bflush) FLUSH_BLOCK(s, 0); } - FLUSH_BLOCK(s, flush == Z_FINISH); - return flush == Z_FINISH ? finish_done : block_done; + 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) + FLUSH_BLOCK(s, 0); + return block_done; } #ifndef FASTEST @@ -1530,7 +1731,7 @@ 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. */ @@ -1551,6 +1752,7 @@ local block_state deflate_slow(s, flush) /* 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); } @@ -1566,12 +1768,8 @@ local block_state deflate_slow(s, flush) * 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->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 @@ -1644,7 +1842,126 @@ local block_state deflate_slow(s, flush) _tr_tally_lit(s, s->window[s->strstart-1], bflush); s->match_available = 0; } - FLUSH_BLOCK(s, flush == Z_FINISH); - return flush == Z_FINISH ? finish_done : block_done; + 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) + 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 - (int)(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) + 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) + FLUSH_BLOCK(s, 0); + return block_done; +}