/* deflate.c -- compress data using the deflation algorithm
- * Copyright (C) 1995-2005 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
*/
* 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.
#include "deflate.h"
const char deflate_copyright[] =
- " deflate 1.2.3 Copyright 1995-2005 Jean-loup Gailly ";
+ " deflate 1.2.8 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
#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,
#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
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
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;
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);
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;
}
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);
- dictionary += dictLength - length; /* use the tail of the dictionary */
+ /* 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;
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;
gz_headerp head;
}
/* ========================================================================= */
+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;
}
}
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;
* 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;
}
/* =========================================================================
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;
}
}
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;
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);
(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);
}
}
#ifdef GZIP
if (s->status == EXTRA_STATE) {
- if (s->gzhead->extra != NULL) {
+ if (s->gzhead->extra != Z_NULL) {
uInt beg = s->pending; /* start of bytes to update crc */
while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {
s->status = NAME_STATE;
}
if (s->status == NAME_STATE) {
- if (s->gzhead->name != NULL) {
+ if (s->gzhead->name != Z_NULL) {
uInt beg = s->pending; /* start of bytes to update crc */
int val;
s->status = COMMENT_STATE;
}
if (s->status == COMMENT_STATE) {
- if (s->gzhead->comment != NULL) {
+ if (s->gzhead->comment != Z_NULL) {
uInt beg = s->pending; /* start of bytes to update crc */
int val;
* 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);
}
(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;
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);
ss = source->state;
- zmemcpy(dest, source, sizeof(z_stream));
+ 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;
- zmemcpy(ds, ss, sizeof(deflate_state));
+ zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
ds->strm = dest;
ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
}
/* 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);
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;
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;
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 */
{
return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
}
+#endif /* FASTEST */
+
#ifdef DEBUG
/* ===========================================================================
* Check that the match at match_start is indeed a match.
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);
later. (Using level 0 permanently is not an optimal usage of
zlib, so we don't care about this pathological case.)
*/
- /* %%% avoid this when Z_RLE */
n = s->hash_size;
p = &s->head[n];
do {
#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 &&
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; \
}
/* ===========================================================================
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;
}
/* ===========================================================================
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 (;;) {
/* 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);
}
* 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->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->strategy != Z_RLE) {
- 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);
}
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
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. */
/* 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);
}
* 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->strategy != Z_RLE) {
- 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
_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 */
-#if 0
/* ===========================================================================
* 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_state *s;
int flush;
{
- int bflush; /* set if current block must be flushed */
- uInt run; /* length of run */
- uInt max; /* maximum length of run */
- uInt prev; /* byte at distance one to match */
- Bytef *scan; /* scan for end of run */
+ 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 encodable run.
+ * for the longest run, plus one for the unrolled loop.
*/
- if (s->lookahead < MAX_MATCH) {
+ if (s->lookahead <= MAX_MATCH) {
fill_window(s);
- if (s->lookahead < MAX_MATCH && flush == Z_NO_FLUSH) {
+ 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 */
- run = 0;
- if (s->strstart > 0) { /* if there is a previous byte, that is */
- max = s->lookahead < MAX_MATCH ? s->lookahead : MAX_MATCH;
+ s->match_length = 0;
+ if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
scan = s->window + s->strstart - 1;
- prev = *scan++;
- do {
- if (*scan++ != prev)
- break;
- } while (++run < max);
+ 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 (run >= MIN_MATCH) {
- check_match(s, s->strstart, s->strstart - 1, run);
- _tr_tally_dist(s, 1, run - MIN_MATCH, bflush);
- s->lookahead -= run;
- s->strstart += run;
+ 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]));
}
if (bflush) 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 (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;
}
-#endif
Ecere Software / sdk / blobdiff