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zlib 0.92

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This commit is contained in:
Mark Adler
2011-09-09 23:08:07 -07:00
parent 1c71d8b13b
commit bdde4e09d2
25 changed files with 884 additions and 910 deletions
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195
deflate.c
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@@ -47,7 +47,7 @@
*
*/
/* $Id: deflate.c,v 1.7 1995/05/02 13:28:18 jloup Exp $ */
/* $Id: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp $ */
#include "deflate.h"
@@ -127,7 +127,7 @@ local int read_buf __P((z_stream *strm, char *buf, unsigned size));
#ifdef DEBUG
local void check_match __P((deflate_state *s, IPos start, IPos match,
int length));
int length));
#endif
@@ -190,12 +190,12 @@ int deflateInit2 (strm, level, method, windowBits, memLevel, strategy)
if (level == Z_DEFAULT_COMPRESSION) level = 6;
if (windowBits < 0) { /* undocumented feature: suppress zlib header */
noheader = 1;
windowBits = -windowBits;
noheader = 1;
windowBits = -windowBits;
}
if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
return Z_STREAM_ERROR;
windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
return Z_STREAM_ERROR;
}
s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
if (s == Z_NULL) return Z_MEM_ERROR;
@@ -221,10 +221,10 @@ int deflateInit2 (strm, level, method, windowBits, memLevel, strategy)
s->pending_buf = (uch*) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
s->pending_buf == Z_NULL) {
strm->msg = z_errmsg[1-Z_MEM_ERROR];
deflateEnd (strm);
return Z_MEM_ERROR;
s->pending_buf == Z_NULL) {
strm->msg = z_errmsg[1-Z_MEM_ERROR];
deflateEnd (strm);
return Z_MEM_ERROR;
}
s->d_buf = (ush*) &(s->pending_buf[s->lit_bufsize]);
s->l_buf = (uch*) &(s->pending_buf[3*s->lit_bufsize]);
@@ -247,7 +247,7 @@ int deflateReset (strm)
deflate_state *s;
if (strm == Z_NULL || strm->state == Z_NULL ||
strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
strm->total_in = strm->total_out = 0;
strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
@@ -297,7 +297,7 @@ local void flush_pending(strm)
strm->avail_out -= len;
strm->state->pending -= len;
if (strm->state->pending == 0) {
strm->state->pending_out = strm->state->pending_buf;
strm->state->pending_out = strm->state->pending_buf;
}
}
@@ -309,7 +309,7 @@ int deflate (strm, flush)
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
if (strm->next_out == Z_NULL || strm->next_in == Z_NULL) {
ERR_RETURN(strm, Z_STREAM_ERROR);
ERR_RETURN(strm, Z_STREAM_ERROR);
}
if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
@@ -318,49 +318,49 @@ int deflate (strm, flush)
/* Write the zlib header */
if (strm->state->status == INIT_STATE) {
uInt header = (DEFLATED + ((strm->state->w_bits-8)<<4)) << 8;
uInt header = (DEFLATED + ((strm->state->w_bits-8)<<4)) << 8;
uInt level_flags = (strm->state->level-1) >> 1;
if (level_flags > 3) level_flags = 3;
header |= (level_flags << 6);
header += 31 - (header % 31);
if (level_flags > 3) level_flags = 3;
header |= (level_flags << 6);
header += 31 - (header % 31);
strm->state->status = BUSY_STATE;
putShortMSB(strm->state, header);
strm->state->status = BUSY_STATE;
putShortMSB(strm->state, header);
}
/* Flush as much pending output as possible */
if (strm->state->pending != 0) {
flush_pending(strm);
if (strm->avail_out == 0) return Z_OK;
flush_pending(strm);
if (strm->avail_out == 0) return Z_OK;
}
/* User must not provide more input after the first FINISH: */
if (strm->state->status == FINISH_STATE && strm->avail_in != 0) {
ERR_RETURN(strm, Z_BUF_ERROR);
ERR_RETURN(strm, Z_BUF_ERROR);
}
/* Start a new block or continue the current one.
*/
if (strm->avail_in != 0 ||
(flush == Z_FINISH && strm->state->status != FINISH_STATE)) {
int quit;
if (flush == Z_FINISH) {
strm->state->status = FINISH_STATE;
}
(flush == Z_FINISH && strm->state->status != FINISH_STATE)) {
int quit;
if (flush == Z_FINISH) {
strm->state->status = FINISH_STATE;
}
if (strm->state->level <= 3) {
quit = deflate_fast(strm->state, flush);
} else {
quit = deflate_slow(strm->state, flush);
}
if (flush == Z_FULL_FLUSH) {
ct_stored_block(strm->state, (char*)0, 0L, 0); /* special marker */
flush_pending(strm);
CLEAR_HASH(strm->state); /* forget history */
if (strm->avail_out == 0) return Z_OK;
}
if (quit) return Z_OK;
quit = deflate_fast(strm->state, flush);
} else {
quit = deflate_slow(strm->state, flush);
}
if (flush == Z_FULL_FLUSH) {
ct_stored_block(strm->state, (char*)0, 0L, 0); /* special marker */
flush_pending(strm);
CLEAR_HASH(strm->state); /* forget history */
if (strm->avail_out == 0) return Z_OK;
}
if (quit) return Z_OK;
}
Assert(strm->avail_out > 0, "bug2");
@@ -401,13 +401,13 @@ int deflateCopy (dest, source)
z_stream *source;
{
if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
return Z_STREAM_ERROR;
return Z_STREAM_ERROR;
}
*dest = *source;
return Z_STREAM_ERROR; /* to be implemented */
#if 0
dest->state = (struct internal_state *)
(*dest->zalloc)(1, sizeof(deflate_state));
(*dest->zalloc)(1, sizeof(deflate_state));
if (dest->state == Z_NULL) return Z_MEM_ERROR;
*(dest->state) = *(source->state);
@@ -432,7 +432,7 @@ local int read_buf(strm, buf, size)
strm->avail_in -= len;
if (!strm->state->noheader) {
strm->state->adler = adler32(strm->state->adler, strm->next_in, len);
strm->state->adler = adler32(strm->state->adler, strm->next_in, len);
}
zmemcpy(buf, strm->next_in, len);
strm->next_in += len;
@@ -488,7 +488,7 @@ local void lm_init (s)
/* For 80x86 and 680x0, an optimized version will be provided in match.asm or
* match.S. The code will be functionally equivalent.
*/
local int longest_match(s, cur_match)
local INLINE int longest_match(s, cur_match)
deflate_state *s;
IPos cur_match; /* current match */
{
@@ -498,10 +498,12 @@ local int longest_match(s, cur_match)
register int len; /* length of current match */
int best_len = s->prev_length; /* best match length so far */
IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
s->strstart - (IPos)MAX_DIST(s) : NIL;
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.
*/
Pos *prev = s->prev;
uInt wmask = s->w_mask;
#ifdef UNALIGNED_OK
/* Compare two bytes at a time. Note: this is not always beneficial.
@@ -609,7 +611,7 @@ local int longest_match(s, cur_match)
scan_end = scan[best_len];
#endif
}
} while ((cur_match = s->prev[cur_match & s->w_mask]) > limit
} while ((cur_match = prev[cur_match & wmask]) > limit
&& --chain_length != 0);
return best_len;
@@ -634,8 +636,8 @@ local void check_match(s, start, match, length)
z_error("invalid match");
}
if (verbose > 1) {
fprintf(stderr,"\\[%d,%d]", start-match, length);
do { putc(s->window[start++], stderr); } while (--length != 0);
fprintf(stderr,"\\[%d,%d]", start-match, length);
do { putc(s->window[start++], stderr); } while (--length != 0);
}
}
#else
@@ -656,14 +658,16 @@ local void fill_window(s)
deflate_state *s;
{
register unsigned n, m;
register Pos *p;
unsigned more; /* Amount of free space at the end of the window. */
uInt wsize = s->w_size;
do {
more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
/* Deal with !@#$% 64K limit: */
if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
more = s->w_size;
/* Deal with !@#$% 64K limit: */
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
* and lookahead == 1 (input done one byte at time)
@@ -673,30 +677,39 @@ local void fill_window(s)
/* 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.
*/
} else if (s->strstart >= s->w_size+MAX_DIST(s)) {
} else if (s->strstart >= wsize+MAX_DIST(s)) {
/* By the IN assertion, the window is not empty so we can't confuse
* more == 0 with more == 64K on a 16 bit machine.
*/
memcpy((char*)s->window, (char*)s->window+s->w_size,
(unsigned)s->w_size);
s->match_start -= s->w_size;
s->strstart -= s->w_size; /* we now have strstart >= MAX_DIST */
zmemcpy((char*)s->window, (char*)s->window+wsize,
(unsigned)wsize);
s->match_start -= wsize;
s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
s->block_start -= (long) s->w_size;
s->block_start -= (long) wsize;
for (n = 0; n < s->hash_size; n++) {
m = s->head[n];
s->head[n] = (Pos)(m >= s->w_size ? m-s->w_size : NIL);
}
for (n = 0; n < s->w_size; n++) {
m = s->prev[n];
s->prev[n] = (Pos)(m >= s->w_size ? m-s->w_size : NIL);
/* Slide the hash table (could be avoided with 32 bit values
at the expense of memory usage):
*/
n = s->hash_size;
p = &s->head[n-1];
do {
m = *p;
*p-- = (Pos)(m >= wsize ? m-wsize : NIL);
} while (--n);
n = wsize;
p = &s->prev[n-1];
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.
*/
}
more += s->w_size;
} while (--n);
more += wsize;
}
if (s->strm->avail_in == 0) return;
@@ -714,8 +727,8 @@ local void fill_window(s)
Assert(more >= 2, "more < 2");
n = read_buf(s->strm, (char*)s->window + s->strstart + s->lookahead,
more);
s->lookahead += n;
more);
s->lookahead += n;
} while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
}
@@ -726,7 +739,7 @@ local void fill_window(s)
*/
#define FLUSH_BLOCK_ONLY(s, eof) { \
ct_flush_block(s, (s->block_start >= 0L ? \
(char*)&s->window[(unsigned)s->block_start] : \
(char*)&s->window[(unsigned)s->block_start] : \
(char*)Z_NULL), (long)s->strstart - s->block_start, (eof)); \
s->block_start = s->strstart; \
flush_pending(s->strm); \
@@ -761,11 +774,11 @@ local int deflate_fast(s, flush)
* string following the next match.
*/
if (s->lookahead < MIN_LOOKAHEAD) {
fill_window(s);
if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
fill_window(s);
if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
if (s->lookahead == 0) break; /* flush the current block */
}
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:
@@ -780,9 +793,9 @@ local int 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).
*/
if (s->strategy != Z_HUFFMAN_ONLY) {
s->match_length = longest_match (s, hash_head);
}
if (s->strategy != Z_HUFFMAN_ONLY) {
s->match_length = longest_match (s, hash_head);
}
/* longest_match() sets match_start */
if (s->match_length > s->lookahead) s->match_length = s->lookahead;
@@ -791,7 +804,7 @@ local int deflate_fast(s, flush)
check_match(s, s->strstart, s->match_start, s->match_length);
bflush = ct_tally(s, s->strstart - s->match_start,
s->match_length - MIN_MATCH);
s->match_length - MIN_MATCH);
s->lookahead -= s->match_length;
@@ -852,11 +865,11 @@ local int deflate_slow(s, flush)
* string following the next match.
*/
if (s->lookahead < MIN_LOOKAHEAD) {
fill_window(s);
if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
fill_window(s);
if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
if (s->lookahead == 0) break; /* flush the current block */
}
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:
@@ -874,15 +887,15 @@ local int 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);
}
if (s->strategy != Z_HUFFMAN_ONLY) {
s->match_length = longest_match (s, hash_head);
}
/* longest_match() sets match_start */
if (s->match_length > s->lookahead) s->match_length = s->lookahead;
if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
(s->match_length == MIN_MATCH &&
s->strstart - s->match_start > TOO_FAR))) {
(s->match_length == MIN_MATCH &&
s->strstart - s->match_start > TOO_FAR))) {
/* If prev_match is also MIN_MATCH, match_start is garbage
* but we will ignore the current match anyway.
@@ -898,7 +911,7 @@ local int deflate_slow(s, flush)
check_match(s, s->strstart-1, s->prev_match, s->prev_length);
bflush = ct_tally(s, s->strstart -1 - s->prev_match,
s->prev_length - MIN_MATCH);
s->prev_length - MIN_MATCH);
/* Insert in hash table all strings up to the end of the match.
* strstart-1 and strstart are already inserted.
@@ -927,11 +940,11 @@ local int deflate_slow(s, flush)
*/
Tracevv((stderr,"%c", s->window[s->strstart-1]));
if (ct_tally (s, 0, s->window[s->strstart-1])) {
FLUSH_BLOCK_ONLY(s, 0);
FLUSH_BLOCK_ONLY(s, 0);
}
s->strstart++;
s->lookahead--;
if (s->strm->avail_out == 0) return 1;
if (s->strm->avail_out == 0) return 1;
} else {
/* There is no previous match to compare with, wait for
* the next step to decide.
@@ -942,8 +955,8 @@ local int deflate_slow(s, flush)
}
}
if (s->match_available) {
ct_tally (s, 0, s->window[s->strstart-1]);
s->match_available = 0;
ct_tally (s, 0, s->window[s->strstart-1]);
s->match_available = 0;
}
FLUSH_BLOCK(s, flush == Z_FINISH);
return 0;