mchapman/zlib
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

zlib 1.2.0.4

Browse Source
This commit is contained in:
Mark Adler
2011-09-09 23:22:30 -07:00
parent 85e7d7d9ba
commit 086e982175
20 changed files with 335 additions and 92 deletions
Download Patch File Download Diff File Expand all files Collapse all files

147
deflate.c
View File

@@ -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;
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));
#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
#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;
if (s->wrap <= 0) return Z_STREAM_END;
/* Write the zlib trailer (adler32) */
putShortMSB(s, (uInt)(strm->adler >> 16));
putShortMSB(s, (uInt)(strm->adler & 0xffff));
/* 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);