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Integrate Chromium Zlib changes

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This commit is contained in:
Justine Tunney 2021-08-09 06:59:10 -07:00
parent 798d542f15
commit d86027fe90
3 changed files with 53 additions and 13 deletions
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39
third_party/zlib/deflate.c vendored
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@ -59,6 +59,11 @@ Invented 1990 Phillip Walter Katz\"");
* Windows, Comm.ACM, 32,4 (1989) 490-595
*/
#ifdef FASTEST
/* See http://crbug.com/1113596 */
#error "FASTEST is not supported in Chromium's zlib."
#endif
/* Tail of hash chains */
#define NIL 0
@ -333,7 +338,9 @@ int deflateInit2(z_streamp strm, int level, int method, int windowBits,
s->window =
(Bytef *)ZALLOC(strm, s->w_size + window_padding, 2 * sizeof(Byte));
memset(s->window, 0, (s->w_size + window_padding) * (2 * sizeof(Byte)));
s->prev = (Posf *)ZALLOC(strm, s->w_size, sizeof(Pos));
memset(s->prev, 0, 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 */
@ -517,7 +524,8 @@ int deflateResetKeep(z_streamp strm) {
#ifdef GZIP
s->wrap == 2 ? GZIP_STATE :
#endif
s->wrap ? INIT_STATE : BUSY_STATE;
s->wrap ? INIT_STATE
: BUSY_STATE;
strm->adler =
#ifdef GZIP
s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
@ -956,14 +964,11 @@ int deflate(z_streamp strm, int flush) {
(flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
block_state bstate;
bstate =
s->level == 0
? deflate_stored(s, flush)
: s->strategy == Z_HUFFMAN_ONLY
? deflate_huff(s, flush)
: s->strategy == Z_RLE
? deflate_rle(s, flush)
: (*(configuration_table[s->level].func))(s, flush);
bstate = s->level == 0 ? deflate_stored(s, flush)
: 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;
@ -1239,7 +1244,12 @@ static uInt longest_match(struct DeflateState *s, IPos cur_match) {
* necessary to put more guard bytes at the end of the window, or
* to check more often for insufficient lookahead.
*/
Assert(scan[2] == match[2], "scan[2]?");
/* When using CRC hashing, scan[2] and match[2] may mismatch, but in
* that case at least one of the other hashed bytes will mismatch
* also. Bytes 0 and 1 were already checked above, and we know there
* are at least four bytes to check otherwise the mismatch would have
* been found by the scan_end comparison above, so: */
Assert(scan[2] == match[2] || scan[3] != match[3], "scan[2]??");
scan++, match++;
do {
} while (*(uint16_t *)(scan += 2) == *(ushf *)(match += 2) &&
@ -1253,7 +1263,7 @@ static uInt longest_match(struct DeflateState *s, IPos cur_match) {
if (*scan == *match) scan++;
len = (MAX_MATCH - 1) - (int)(strend - scan);
scan = strend - (MAX_MATCH - 1);
#else /* UNALIGNED_OK */
#else /* UNALIGNED_OK */
if (match[best_len] != scan_end || match[best_len - 1] != scan_end1 ||
*match != *scan || *++match != scan[1])
continue;
@ -1263,6 +1273,7 @@ static uInt longest_match(struct DeflateState *s, IPos cur_match) {
* are always equal when the other bytes match, given that
* the hash keys are equal and that HASH_BITS >= 8.
*/
Assert(*scan == *match || scan[1] != match[1], "match[2]??");
scan += 2, match++;
Assert(*scan == *match, "match[2]?");
/* We check for insufficient lookahead only every 8th comparison;
@ -1710,7 +1721,11 @@ static block_state deflate_slow(struct DeflateState *s, int flush) {
uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
/* Do not insert strings in hash table beyond this. */
check_match(s, s->strstart - 1, s->prev_match, s->prev_length);
if (s->prev_match == -1) {
check_match(s, s->strstart, s->prev_match + 1, s->prev_length - 1);
} else {
check_match(s, s->strstart - 1, s->prev_match, s->prev_length);
}
_tr_tally_dist(s, s->strstart - 1 - s->prev_match,
s->prev_length - MIN_MATCH, bflush);