diff options
Diffstat (limited to 'deflate.c')
| -rw-r--r-- | deflate.c | 147 |
1 files changed, 99 insertions, 48 deletions
@@ -52,7 +52,7 @@ #include "deflate.h" const char deflate_copyright[] = - " deflate 1.2.0.3 Copyright 1995-2003 Jean-loup Gailly "; + " deflate 1.2.0.4 Copyright 1995-2003 Jean-loup Gailly "; /* 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 @@ -132,12 +132,12 @@ typedef struct config_s { 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}}; /* maximum speed, no lazy matches */ +/* 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}, /* maximum speed, no lazy matches */ +/* 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}, @@ -146,7 +146,7 @@ local const config configuration_table[10] = { /* 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}}; /* maximum compression */ +/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */ #endif /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 @@ -225,7 +225,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, int stream_size; { deflate_state *s; - int noheader = 0; + int wrap = 1; static const char my_version[] = ZLIB_VERSION; ushf *overlay; @@ -252,10 +252,16 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, if (level == Z_DEFAULT_COMPRESSION) level = 6; #endif - if (windowBits < 0) { /* undocumented feature: suppress zlib header */ - noheader = 1; + 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_RLE) { @@ -267,7 +273,7 @@ int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, strm->state = (struct internal_state FAR *)s; s->strm = strm; - s->noheader = noheader; + s->wrap = wrap; s->w_bits = windowBits; s->w_size = 1 << s->w_bits; s->w_mask = s->w_size - 1; @@ -316,11 +322,12 @@ int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) IPos hash_head = 0; if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL || - (!strm->state->noheader && strm->state->status != INIT_STATE)) + strm->state->wrap == 2 || + (strm->state->wrap == 1 && strm->state->status != INIT_STATE)) return Z_STREAM_ERROR; s = strm->state; - if (!s->noheader) + if (s->wrap) strm->adler = adler32(strm->adler, dictionary, dictLength); if (length < MIN_MATCH) return Z_OK; @@ -364,11 +371,15 @@ int ZEXPORT deflateReset (strm) s->pending = 0; s->pending_out = s->pending_buf; - if (s->noheader < 0) { - s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ + if (s->wrap < 0) { + s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ } - s->status = s->noheader ? BUSY_STATE : INIT_STATE; - strm->adler = 1; + s->status = 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 = Z_NO_FLUSH; _tr_init(s); @@ -428,7 +439,7 @@ int ZEXPORT deflateParams(strm, level, strategy) * 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 noheader. + * 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. */ @@ -519,33 +530,53 @@ int ZEXPORT deflate (strm, flush) old_flush = s->last_flush; s->last_flush = flush; - /* Write the zlib header */ + /* Write the header */ if (s->status == INIT_STATE) { - - 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; +#ifdef GZIP + if (s->wrap == 2) { + put_byte(s, 31); + put_byte(s, 139); + put_byte(s, 8); + 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, 255); + s->status = BUSY_STATE; + strm->adler = crc32(0L, Z_NULL, 0); + } else - level_flags = 3; - header |= (level_flags << 6); - if (s->strstart != 0) header |= PRESET_DICT; - header += 31 - (header % 31); - - s->status = BUSY_STATE; - 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)); +#endif + { + 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); + + s->status = BUSY_STATE; + 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); } - strm->adler = 1L; } /* Flush as much pending output as possible */ @@ -622,16 +653,31 @@ int ZEXPORT deflate (strm, flush) Assert(strm->avail_out > 0, "bug2"); if (flush != Z_FINISH) return Z_OK; - if (s->noheader) return Z_STREAM_END; - - /* Write the zlib trailer (adler32) */ - putShortMSB(s, (uInt)(strm->adler >> 16)); - putShortMSB(s, (uInt)(strm->adler & 0xffff)); + 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. */ - s->noheader = -1; /* write the trailer only once! */ + if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ return s->pending != 0 ? Z_OK : Z_STREAM_END; } @@ -740,9 +786,14 @@ local int read_buf(strm, buf, size) strm->avail_in -= len; - if (!strm->state->noheader) { + if (strm->state->wrap == 1) { strm->adler = adler32(strm->adler, strm->next_in, len); } +#ifdef GZIP + else if (strm->state->wrap == 2) { + strm->adler = crc32(strm->adler, strm->next_in, len); + } +#endif zmemcpy(buf, strm->next_in, len); strm->next_in += len; strm->total_in += len; @@ -1044,7 +1095,7 @@ local void fill_window(s) } else if (more == (unsigned)(-1)) { /* Very unlikely, but possible on 16 bit machine if - * strstart == 0 && lookahead == 1 (input done one byte at time) + * strstart == 0 && lookahead == 1 (input done a byte at time) */ more--; } @@ -1271,7 +1322,7 @@ local block_state deflate_fast(s, flush) #ifndef FASTEST if (s->match_length <= s->max_insert_length && s->lookahead >= MIN_MATCH) { - s->match_length--; /* string at strstart already in hash table */ + s->match_length--; /* string at strstart already in table */ do { s->strstart++; INSERT_STRING(s, s->strstart, hash_head); |