Ruby: ext/zlib/zlib-1.2.13/deflate.c Source File

Ruby 3.0.5p211 (2022-11-24 revision ba5cf0f7c52d4d35cc6a173c89eda98ceffa2dcf)

deflate.c
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1/* deflate.c -- compress data using the deflation algorithm
2 * Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/*
7 * ALGORITHM
8 *
9 * The "deflation" process depends on being able to identify portions
10 * of the input text which are identical to earlier input (within a
11 * sliding window trailing behind the input currently being processed).
12 *
13 * The most straightforward technique turns out to be the fastest for
14 * most input files: try all possible matches and select the longest.
15 * The key feature of this algorithm is that insertions into the string
16 * dictionary are very simple and thus fast, and deletions are avoided
17 * completely. Insertions are performed at each input character, whereas
18 * string matches are performed only when the previous match ends. So it
19 * is preferable to spend more time in matches to allow very fast string
20 * insertions and avoid deletions. The matching algorithm for small
21 * strings is inspired from that of Rabin & Karp. A brute force approach
22 * is used to find longer strings when a small match has been found.
23 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
24 * (by Leonid Broukhis).
25 * A previous version of this file used a more sophisticated algorithm
26 * (by Fiala and Greene) which is guaranteed to run in linear amortized
27 * time, but has a larger average cost, uses more memory and is patented.
28 * However the F&G algorithm may be faster for some highly redundant
29 * files if the parameter max_chain_length (described below) is too large.
30 *
31 * ACKNOWLEDGEMENTS
32 *
33 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
34 * I found it in 'freeze' written by Leonid Broukhis.
35 * Thanks to many people for bug reports and testing.
36 *
37 * REFERENCES
38 *
39 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
40 * Available in http://tools.ietf.org/html/rfc1951
41 *
42 * A description of the Rabin and Karp algorithm is given in the book
43 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
44 *
45 * Fiala,E.R., and Greene,D.H.
46 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
47 *
48 */
49
50/* @(#) $Id$ */
51
52#include "deflate.h"
53
54 const char deflate_copyright[] =
55 " deflate 1.2.13 Copyright 1995-2022 Jean-loup Gailly and Mark Adler ";
56/*
57 If you use the zlib library in a product, an acknowledgment is welcome
58 in the documentation of your product. If for some reason you cannot
59 include such an acknowledgment, I would appreciate that you keep this
60 copyright string in the executable of your product.
61 */
62
63/* ===========================================================================
64 * Function prototypes.
65 */
66 typedef enum {
67 need_more, /* block not completed, need more input or more output */
68 block_done, /* block flush performed */
69 finish_started, /* finish started, need only more output at next deflate */
70 finish_done /* finish done, accept no more input or output */
71} block_state;
72
73 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
74/* Compression function. Returns the block state after the call. */
75
76 local int deflateStateCheck OF((z_streamp strm));
77 local void slide_hash OF((deflate_state *s));
78 local void fill_window OF((deflate_state *s));
79 local block_state deflate_stored OF((deflate_state *s, int flush));
80 local block_state deflate_fast OF((deflate_state *s, int flush));
81#ifndef FASTEST
82 local block_state deflate_slow OF((deflate_state *s, int flush));
83#endif
84 local block_state deflate_rle OF((deflate_state *s, int flush));
85 local block_state deflate_huff OF((deflate_state *s, int flush));
86 local void lm_init OF((deflate_state *s));
87 local void putShortMSB OF((deflate_state *s, uInt b));
88 local void flush_pending OF((z_streamp strm));
89 local unsigned read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
90 local uInt longest_match OF((deflate_state *s, IPos cur_match));
91
92#ifdef ZLIB_DEBUG
93 local void check_match OF((deflate_state *s, IPos start, IPos match,
94 int length));
95#endif
96
97/* ===========================================================================
98 * Local data
99 */
100
101#define NIL 0
102/* Tail of hash chains */
103
104#ifndef TOO_FAR
105# define TOO_FAR 4096
106#endif
107/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
108
109/* Values for max_lazy_match, good_match and max_chain_length, depending on
110 * the desired pack level (0..9). The values given below have been tuned to
111 * exclude worst case performance for pathological files. Better values may be
112 * found for specific files.
113 */
114 typedef struct config_s {
115 ush good_length; /* reduce lazy search above this match length */
116 ush max_lazy; /* do not perform lazy search above this match length */
117 ush nice_length; /* quit search above this match length */
118 ush max_chain;
119 compress_func func;
120} config;
121
122#ifdef FASTEST
123 local const config configuration_table[2] = {
124/* good lazy nice chain */
125/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
126/* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */
127#else
128 local const config configuration_table[10] = {
129/* good lazy nice chain */
130/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
131/* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
132/* 2 */ {4, 5, 16, 8, deflate_fast},
133/* 3 */ {4, 6, 32, 32, deflate_fast},
134
135/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
136/* 5 */ {8, 16, 32, 32, deflate_slow},
137/* 6 */ {8, 16, 128, 128, deflate_slow},
138/* 7 */ {8, 32, 128, 256, deflate_slow},
139/* 8 */ {32, 128, 258, 1024, deflate_slow},
140/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
141#endif
142
143/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
144 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
145 * meaning.
146 */
147
148/* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
149#define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
150
151/* ===========================================================================
152 * Update a hash value with the given input byte
153 * IN assertion: all calls to UPDATE_HASH are made with consecutive input
154 * characters, so that a running hash key can be computed from the previous
155 * key instead of complete recalculation each time.
156 */
157#define UPDATE_HASH(s,h,c) (h = (((h) << s->hash_shift) ^ (c)) & s->hash_mask)
158
159
160/* ===========================================================================
161 * Insert string str in the dictionary and set match_head to the previous head
162 * of the hash chain (the most recent string with same hash key). Return
163 * the previous length of the hash chain.
164 * If this file is compiled with -DFASTEST, the compression level is forced
165 * to 1, and no hash chains are maintained.
166 * IN assertion: all calls to INSERT_STRING are made with consecutive input
167 * characters and the first MIN_MATCH bytes of str are valid (except for
168 * the last MIN_MATCH-1 bytes of the input file).
169 */
170#ifdef FASTEST
171#define INSERT_STRING(s, str, match_head) \
172 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
173 match_head = s->head[s->ins_h], \
174 s->head[s->ins_h] = (Pos)(str))
175#else
176#define INSERT_STRING(s, str, match_head) \
177 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
178 match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
179 s->head[s->ins_h] = (Pos)(str))
180#endif
181
182/* ===========================================================================
183 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
184 * prev[] will be initialized on the fly.
185 */
186#define CLEAR_HASH(s) \
187 do { \
188 s->head[s->hash_size - 1] = NIL; \
189 zmemzero((Bytef *)s->head, \
190 (unsigned)(s->hash_size - 1)*sizeof(*s->head)); \
191 } while (0)
192
193/* ===========================================================================
194 * Slide the hash table when sliding the window down (could be avoided with 32
195 * bit values at the expense of memory usage). We slide even when level == 0 to
196 * keep the hash table consistent if we switch back to level > 0 later.
197 */
198 local void slide_hash(s)
199 deflate_state *s;
200{
201 unsigned n, m;
202 Posf *p;
203 uInt wsize = s->w_size;
204
205 n = s->hash_size;
206 p = &s->head[n];
207 do {
208 m = *--p;
209 *p = (Pos)(m >= wsize ? m - wsize : NIL);
210 } while (--n);
211 n = wsize;
212#ifndef FASTEST
213 p = &s->prev[n];
214 do {
215 m = *--p;
216 *p = (Pos)(m >= wsize ? m - wsize : NIL);
217 /* If n is not on any hash chain, prev[n] is garbage but
218 * its value will never be used.
219 */
220 } while (--n);
221#endif
222}
223
224/* ========================================================================= */
225 int ZEXPORT deflateInit_(strm, level, version, stream_size)
226 z_streamp strm;
227 int level;
228 const char *version;
229 int stream_size;
230{
231 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
232 Z_DEFAULT_STRATEGY, version, stream_size);
233 /* To do: ignore strm->next_in if we use it as window */
234}
235
236/* ========================================================================= */
237 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
238 version, stream_size)
239 z_streamp strm;
240 int level;
241 int method;
242 int windowBits;
243 int memLevel;
244 int strategy;
245 const char *version;
246 int stream_size;
247{
248 deflate_state *s;
249 int wrap = 1;
250 static const char my_version[] = ZLIB_VERSION;
251
252 if (version == Z_NULL || version[0] != my_version[0] ||
253 stream_size != sizeof(z_stream)) {
254 return Z_VERSION_ERROR;
255 }
256 if (strm == Z_NULL) return Z_STREAM_ERROR;
257
258 strm->msg = Z_NULL;
259 if (strm->zalloc == (alloc_func)0) {
260#ifdef Z_SOLO
261 return Z_STREAM_ERROR;
262#else
263 strm->zalloc = zcalloc;
264 strm->opaque = (voidpf)0;
265#endif
266 }
267 if (strm->zfree == (free_func)0)
268#ifdef Z_SOLO
269 return Z_STREAM_ERROR;
270#else
271 strm->zfree = zcfree;
272#endif
273
274#ifdef FASTEST
275 if (level != 0) level = 1;
276#else
277 if (level == Z_DEFAULT_COMPRESSION) level = 6;
278#endif
279
280 if (windowBits < 0) { /* suppress zlib wrapper */
281 wrap = 0;
282 if (windowBits < -15)
283 return Z_STREAM_ERROR;
284 windowBits = -windowBits;
285 }
286#ifdef GZIP
287 else if (windowBits > 15) {
288 wrap = 2; /* write gzip wrapper instead */
289 windowBits -= 16;
290 }
291#endif
292 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
293 windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
294 strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
295 return Z_STREAM_ERROR;
296 }
297 if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */
298 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
299 if (s == Z_NULL) return Z_MEM_ERROR;
300 strm->state = (struct internal_state FAR *)s;
301 s->strm = strm;
302 s->status = INIT_STATE; /* to pass state test in deflateReset() */
303
304 s->wrap = wrap;
305 s->gzhead = Z_NULL;
306 s->w_bits = (uInt)windowBits;
307 s->w_size = 1 << s->w_bits;
308 s->w_mask = s->w_size - 1;
309
310 s->hash_bits = (uInt)memLevel + 7;
311 s->hash_size = 1 << s->hash_bits;
312 s->hash_mask = s->hash_size - 1;
313 s->hash_shift = ((s->hash_bits + MIN_MATCH-1) / MIN_MATCH);
314
315 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
316 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
317 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
318
319 s->high_water = 0; /* nothing written to s->window yet */
320
321 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
322
323 /* We overlay pending_buf and sym_buf. This works since the average size
324 * for length/distance pairs over any compressed block is assured to be 31
325 * bits or less.
326 *
327 * Analysis: The longest fixed codes are a length code of 8 bits plus 5
328 * extra bits, for lengths 131 to 257. The longest fixed distance codes are
329 * 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest
330 * possible fixed-codes length/distance pair is then 31 bits total.
331 *
332 * sym_buf starts one-fourth of the way into pending_buf. So there are
333 * three bytes in sym_buf for every four bytes in pending_buf. Each symbol
334 * in sym_buf is three bytes -- two for the distance and one for the
335 * literal/length. As each symbol is consumed, the pointer to the next
336 * sym_buf value to read moves forward three bytes. From that symbol, up to
337 * 31 bits are written to pending_buf. The closest the written pending_buf
338 * bits gets to the next sym_buf symbol to read is just before the last
339 * code is written. At that time, 31*(n - 2) bits have been written, just
340 * after 24*(n - 2) bits have been consumed from sym_buf. sym_buf starts at
341 * 8*n bits into pending_buf. (Note that the symbol buffer fills when n - 1
342 * symbols are written.) The closest the writing gets to what is unread is
343 * then n + 14 bits. Here n is lit_bufsize, which is 16384 by default, and
344 * can range from 128 to 32768.
345 *
346 * Therefore, at a minimum, there are 142 bits of space between what is
347 * written and what is read in the overlain buffers, so the symbols cannot
348 * be overwritten by the compressed data. That space is actually 139 bits,
349 * due to the three-bit fixed-code block header.
350 *
351 * That covers the case where either Z_FIXED is specified, forcing fixed
352 * codes, or when the use of fixed codes is chosen, because that choice
353 * results in a smaller compressed block than dynamic codes. That latter
354 * condition then assures that the above analysis also covers all dynamic
355 * blocks. A dynamic-code block will only be chosen to be emitted if it has
356 * fewer bits than a fixed-code block would for the same set of symbols.
357 * Therefore its average symbol length is assured to be less than 31. So
358 * the compressed data for a dynamic block also cannot overwrite the
359 * symbols from which it is being constructed.
360 */
361
362 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 4);
363 s->pending_buf_size = (ulg)s->lit_bufsize * 4;
364
365 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
366 s->pending_buf == Z_NULL) {
367 s->status = FINISH_STATE;
368 strm->msg = ERR_MSG(Z_MEM_ERROR);
369 deflateEnd (strm);
370 return Z_MEM_ERROR;
371 }
372 s->sym_buf = s->pending_buf + s->lit_bufsize;
373 s->sym_end = (s->lit_bufsize - 1) * 3;
374 /* We avoid equality with lit_bufsize*3 because of wraparound at 64K
375 * on 16 bit machines and because stored blocks are restricted to
376 * 64K-1 bytes.
377 */
378
379 s->level = level;
380 s->strategy = strategy;
381 s->method = (Byte)method;
382
383 return deflateReset(strm);
384}
385
386/* =========================================================================
387 * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
388 */
389 local int deflateStateCheck(strm)
390 z_streamp strm;
391{
392 deflate_state *s;
393 if (strm == Z_NULL ||
394 strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
395 return 1;
396 s = strm->state;
397 if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
398#ifdef GZIP
399 s->status != GZIP_STATE &&
400#endif
401 s->status != EXTRA_STATE &&
402 s->status != NAME_STATE &&
403 s->status != COMMENT_STATE &&
404 s->status != HCRC_STATE &&
405 s->status != BUSY_STATE &&
406 s->status != FINISH_STATE))
407 return 1;
408 return 0;
409}
410
411/* ========================================================================= */
412 int ZEXPORT deflateSetDictionary(strm, dictionary, dictLength)
413 z_streamp strm;
414 const Bytef *dictionary;
415 uInt dictLength;
416{
417 deflate_state *s;
418 uInt str, n;
419 int wrap;
420 unsigned avail;
421 z_const unsigned char *next;
422
423 if (deflateStateCheck(strm) || dictionary == Z_NULL)
424 return Z_STREAM_ERROR;
425 s = strm->state;
426 wrap = s->wrap;
427 if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
428 return Z_STREAM_ERROR;
429
430 /* when using zlib wrappers, compute Adler-32 for provided dictionary */
431 if (wrap == 1)
432 strm->adler = adler32(strm->adler, dictionary, dictLength);
433 s->wrap = 0; /* avoid computing Adler-32 in read_buf */
434
435 /* if dictionary would fill window, just replace the history */
436 if (dictLength >= s->w_size) {
437 if (wrap == 0) { /* already empty otherwise */
438 CLEAR_HASH(s);
439 s->strstart = 0;
440 s->block_start = 0L;
441 s->insert = 0;
442 }
443 dictionary += dictLength - s->w_size; /* use the tail */
444 dictLength = s->w_size;
445 }
446
447 /* insert dictionary into window and hash */
448 avail = strm->avail_in;
449 next = strm->next_in;
450 strm->avail_in = dictLength;
451 strm->next_in = (z_const Bytef *)dictionary;
452 fill_window(s);
453 while (s->lookahead >= MIN_MATCH) {
454 str = s->strstart;
455 n = s->lookahead - (MIN_MATCH-1);
456 do {
457 UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
458#ifndef FASTEST
459 s->prev[str & s->w_mask] = s->head[s->ins_h];
460#endif
461 s->head[s->ins_h] = (Pos)str;
462 str++;
463 } while (--n);
464 s->strstart = str;
465 s->lookahead = MIN_MATCH-1;
466 fill_window(s);
467 }
468 s->strstart += s->lookahead;
469 s->block_start = (long)s->strstart;
470 s->insert = s->lookahead;
471 s->lookahead = 0;
472 s->match_length = s->prev_length = MIN_MATCH-1;
473 s->match_available = 0;
474 strm->next_in = next;
475 strm->avail_in = avail;
476 s->wrap = wrap;
477 return Z_OK;
478}
479
480/* ========================================================================= */
481 int ZEXPORT deflateGetDictionary(strm, dictionary, dictLength)
482 z_streamp strm;
483 Bytef *dictionary;
484 uInt *dictLength;
485{
486 deflate_state *s;
487 uInt len;
488
489 if (deflateStateCheck(strm))
490 return Z_STREAM_ERROR;
491 s = strm->state;
492 len = s->strstart + s->lookahead;
493 if (len > s->w_size)
494 len = s->w_size;
495 if (dictionary != Z_NULL && len)
496 zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
497 if (dictLength != Z_NULL)
498 *dictLength = len;
499 return Z_OK;
500}
501
502/* ========================================================================= */
503 int ZEXPORT deflateResetKeep(strm)
504 z_streamp strm;
505{
506 deflate_state *s;
507
508 if (deflateStateCheck(strm)) {
509 return Z_STREAM_ERROR;
510 }
511
512 strm->total_in = strm->total_out = 0;
513 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
514 strm->data_type = Z_UNKNOWN;
515
516 s = (deflate_state *)strm->state;
517 s->pending = 0;
518 s->pending_out = s->pending_buf;
519
520 if (s->wrap < 0) {
521 s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
522 }
523 s->status =
524#ifdef GZIP
525 s->wrap == 2 ? GZIP_STATE :
526#endif
527 INIT_STATE;
528 strm->adler =
529#ifdef GZIP
530 s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
531#endif
532 adler32(0L, Z_NULL, 0);
533 s->last_flush = -2;
534
535 _tr_init(s);
536
537 return Z_OK;
538}
539
540/* ========================================================================= */
541 int ZEXPORT deflateReset(strm)
542 z_streamp strm;
543{
544 int ret;
545
546 ret = deflateResetKeep(strm);
547 if (ret == Z_OK)
548 lm_init(strm->state);
549 return ret;
550}
551
552/* ========================================================================= */
553 int ZEXPORT deflateSetHeader(strm, head)
554 z_streamp strm;
555 gz_headerp head;
556{
557 if (deflateStateCheck(strm) || strm->state->wrap != 2)
558 return Z_STREAM_ERROR;
559 strm->state->gzhead = head;
560 return Z_OK;
561}
562
563/* ========================================================================= */
564 int ZEXPORT deflatePending(strm, pending, bits)
565 unsigned *pending;
566 int *bits;
567 z_streamp strm;
568{
569 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
570 if (pending != Z_NULL)
571 *pending = strm->state->pending;
572 if (bits != Z_NULL)
573 *bits = strm->state->bi_valid;
574 return Z_OK;
575}
576
577/* ========================================================================= */
578 int ZEXPORT deflatePrime(strm, bits, value)
579 z_streamp strm;
580 int bits;
581 int value;
582{
583 deflate_state *s;
584 int put;
585
586 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
587 s = strm->state;
588 if (bits < 0 || bits > 16 ||
589 s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3))
590 return Z_BUF_ERROR;
591 do {
592 put = Buf_size - s->bi_valid;
593 if (put > bits)
594 put = bits;
595 s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
596 s->bi_valid += put;
597 _tr_flush_bits(s);
598 value >>= put;
599 bits -= put;
600 } while (bits);
601 return Z_OK;
602}
603
604/* ========================================================================= */
605 int ZEXPORT deflateParams(strm, level, strategy)
606 z_streamp strm;
607 int level;
608 int strategy;
609{
610 deflate_state *s;
611 compress_func func;
612
613 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
614 s = strm->state;
615
616#ifdef FASTEST
617 if (level != 0) level = 1;
618#else
619 if (level == Z_DEFAULT_COMPRESSION) level = 6;
620#endif
621 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
622 return Z_STREAM_ERROR;
623 }
624 func = configuration_table[s->level].func;
625
626 if ((strategy != s->strategy || func != configuration_table[level].func) &&
627 s->last_flush != -2) {
628 /* Flush the last buffer: */
629 int err = deflate(strm, Z_BLOCK);
630 if (err == Z_STREAM_ERROR)
631 return err;
632 if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead)
633 return Z_BUF_ERROR;
634 }
635 if (s->level != level) {
636 if (s->level == 0 && s->matches != 0) {
637 if (s->matches == 1)
638 slide_hash(s);
639 else
640 CLEAR_HASH(s);
641 s->matches = 0;
642 }
643 s->level = level;
644 s->max_lazy_match = configuration_table[level].max_lazy;
645 s->good_match = configuration_table[level].good_length;
646 s->nice_match = configuration_table[level].nice_length;
647 s->max_chain_length = configuration_table[level].max_chain;
648 }
649 s->strategy = strategy;
650 return Z_OK;
651}
652
653/* ========================================================================= */
654 int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
655 z_streamp strm;
656 int good_length;
657 int max_lazy;
658 int nice_length;
659 int max_chain;
660{
661 deflate_state *s;
662
663 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
664 s = strm->state;
665 s->good_match = (uInt)good_length;
666 s->max_lazy_match = (uInt)max_lazy;
667 s->nice_match = nice_length;
668 s->max_chain_length = (uInt)max_chain;
669 return Z_OK;
670}
671
672/* =========================================================================
673 * For the default windowBits of 15 and memLevel of 8, this function returns a
674 * close to exact, as well as small, upper bound on the compressed size. This
675 * is an expansion of ~0.03%, plus a small constant.
676 *
677 * For any setting other than those defaults for windowBits and memLevel, one
678 * of two worst case bounds is returned. This is at most an expansion of ~4% or
679 * ~13%, plus a small constant.
680 *
681 * Both the 0.03% and 4% derive from the overhead of stored blocks. The first
682 * one is for stored blocks of 16383 bytes (memLevel == 8), whereas the second
683 * is for stored blocks of 127 bytes (the worst case memLevel == 1). The
684 * expansion results from five bytes of header for each stored block.
685 *
686 * The larger expansion of 13% results from a window size less than or equal to
687 * the symbols buffer size (windowBits <= memLevel + 7). In that case some of
688 * the data being compressed may have slid out of the sliding window, impeding
689 * a stored block from being emitted. Then the only choice is a fixed or
690 * dynamic block, where a fixed block limits the maximum expansion to 9 bits
691 * per 8-bit byte, plus 10 bits for every block. The smallest block size for
692 * which this can occur is 255 (memLevel == 2).
693 *
694 * Shifts are used to approximate divisions, for speed.
695 */
696 uLong ZEXPORT deflateBound(strm, sourceLen)
697 z_streamp strm;
698 uLong sourceLen;
699{
700 deflate_state *s;
701 uLong fixedlen, storelen, wraplen;
702
703 /* upper bound for fixed blocks with 9-bit literals and length 255
704 (memLevel == 2, which is the lowest that may not use stored blocks) --
705 ~13% overhead plus a small constant */
706 fixedlen = sourceLen + (sourceLen >> 3) + (sourceLen >> 8) +
707 (sourceLen >> 9) + 4;
708
709 /* upper bound for stored blocks with length 127 (memLevel == 1) --
710 ~4% overhead plus a small constant */
711 storelen = sourceLen + (sourceLen >> 5) + (sourceLen >> 7) +
712 (sourceLen >> 11) + 7;
713
714 /* if can't get parameters, return larger bound plus a zlib wrapper */
715 if (deflateStateCheck(strm))
716 return (fixedlen > storelen ? fixedlen : storelen) + 6;
717
718 /* compute wrapper length */
719 s = strm->state;
720 switch (s->wrap) {
721 case 0: /* raw deflate */
722 wraplen = 0;
723 break;
724 case 1: /* zlib wrapper */
725 wraplen = 6 + (s->strstart ? 4 : 0);
726 break;
727#ifdef GZIP
728 case 2: /* gzip wrapper */
729 wraplen = 18;
730 if (s->gzhead != Z_NULL) { /* user-supplied gzip header */
731 Bytef *str;
732 if (s->gzhead->extra != Z_NULL)
733 wraplen += 2 + s->gzhead->extra_len;
734 str = s->gzhead->name;
735 if (str != Z_NULL)
736 do {
737 wraplen++;
738 } while (*str++);
739 str = s->gzhead->comment;
740 if (str != Z_NULL)
741 do {
742 wraplen++;
743 } while (*str++);
744 if (s->gzhead->hcrc)
745 wraplen += 2;
746 }
747 break;
748#endif
749 default: /* for compiler happiness */
750 wraplen = 6;
751 }
752
753 /* if not default parameters, return one of the conservative bounds */
754 if (s->w_bits != 15 || s->hash_bits != 8 + 7)
755 return (s->w_bits <= s->hash_bits ? fixedlen : storelen) + wraplen;
756
757 /* default settings: return tight bound for that case -- ~0.03% overhead
758 plus a small constant */
759 return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
760 (sourceLen >> 25) + 13 - 6 + wraplen;
761}
762
763/* =========================================================================
764 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
765 * IN assertion: the stream state is correct and there is enough room in
766 * pending_buf.
767 */
768 local void putShortMSB(s, b)
769 deflate_state *s;
770 uInt b;
771{
772 put_byte(s, (Byte)(b >> 8));
773 put_byte(s, (Byte)(b & 0xff));
774}
775
776/* =========================================================================
777 * Flush as much pending output as possible. All deflate() output, except for
778 * some deflate_stored() output, goes through this function so some
779 * applications may wish to modify it to avoid allocating a large
780 * strm->next_out buffer and copying into it. (See also read_buf()).
781 */
782 local void flush_pending(strm)
783 z_streamp strm;
784{
785 unsigned len;
786 deflate_state *s = strm->state;
787
788 _tr_flush_bits(s);
789 len = s->pending;
790 if (len > strm->avail_out) len = strm->avail_out;
791 if (len == 0) return;
792
793 zmemcpy(strm->next_out, s->pending_out, len);
794 strm->next_out += len;
795 s->pending_out += len;
796 strm->total_out += len;
797 strm->avail_out -= len;
798 s->pending -= len;
799 if (s->pending == 0) {
800 s->pending_out = s->pending_buf;
801 }
802}
803
804/* ===========================================================================
805 * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
806 */
807#define HCRC_UPDATE(beg) \
808 do { \
809 if (s->gzhead->hcrc && s->pending > (beg)) \
810 strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
811 s->pending - (beg)); \
812 } while (0)
813
814/* ========================================================================= */
815 int ZEXPORT deflate(strm, flush)
816 z_streamp strm;
817 int flush;
818{
819 int old_flush; /* value of flush param for previous deflate call */
820 deflate_state *s;
821
822 if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
823 return Z_STREAM_ERROR;
824 }
825 s = strm->state;
826
827 if (strm->next_out == Z_NULL ||
828 (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
829 (s->status == FINISH_STATE && flush != Z_FINISH)) {
830 ERR_RETURN(strm, Z_STREAM_ERROR);
831 }
832 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
833
834 old_flush = s->last_flush;
835 s->last_flush = flush;
836
837 /* Flush as much pending output as possible */
838 if (s->pending != 0) {
839 flush_pending(strm);
840 if (strm->avail_out == 0) {
841 /* Since avail_out is 0, deflate will be called again with
842 * more output space, but possibly with both pending and
843 * avail_in equal to zero. There won't be anything to do,
844 * but this is not an error situation so make sure we
845 * return OK instead of BUF_ERROR at next call of deflate:
846 */
847 s->last_flush = -1;
848 return Z_OK;
849 }
850
851 /* Make sure there is something to do and avoid duplicate consecutive
852 * flushes. For repeated and useless calls with Z_FINISH, we keep
853 * returning Z_STREAM_END instead of Z_BUF_ERROR.
854 */
855 } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
856 flush != Z_FINISH) {
857 ERR_RETURN(strm, Z_BUF_ERROR);
858 }
859
860 /* User must not provide more input after the first FINISH: */
861 if (s->status == FINISH_STATE && strm->avail_in != 0) {
862 ERR_RETURN(strm, Z_BUF_ERROR);
863 }
864
865 /* Write the header */
866 if (s->status == INIT_STATE && s->wrap == 0)
867 s->status = BUSY_STATE;
868 if (s->status == INIT_STATE) {
869 /* zlib header */
870 uInt header = (Z_DEFLATED + ((s->w_bits - 8) << 4)) << 8;
871 uInt level_flags;
872
873 if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
874 level_flags = 0;
875 else if (s->level < 6)
876 level_flags = 1;
877 else if (s->level == 6)
878 level_flags = 2;
879 else
880 level_flags = 3;
881 header |= (level_flags << 6);
882 if (s->strstart != 0) header |= PRESET_DICT;
883 header += 31 - (header % 31);
884
885 putShortMSB(s, header);
886
887 /* Save the adler32 of the preset dictionary: */
888 if (s->strstart != 0) {
889 putShortMSB(s, (uInt)(strm->adler >> 16));
890 putShortMSB(s, (uInt)(strm->adler & 0xffff));
891 }
892 strm->adler = adler32(0L, Z_NULL, 0);
893 s->status = BUSY_STATE;
894
895 /* Compression must start with an empty pending buffer */
896 flush_pending(strm);
897 if (s->pending != 0) {
898 s->last_flush = -1;
899 return Z_OK;
900 }
901 }
902#ifdef GZIP
903 if (s->status == GZIP_STATE) {
904 /* gzip header */
905 strm->adler = crc32(0L, Z_NULL, 0);
906 put_byte(s, 31);
907 put_byte(s, 139);
908 put_byte(s, 8);
909 if (s->gzhead == Z_NULL) {
910 put_byte(s, 0);
911 put_byte(s, 0);
912 put_byte(s, 0);
913 put_byte(s, 0);
914 put_byte(s, 0);
915 put_byte(s, s->level == 9 ? 2 :
916 (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
917 4 : 0));
918 put_byte(s, OS_CODE);
919 s->status = BUSY_STATE;
920
921 /* Compression must start with an empty pending buffer */
922 flush_pending(strm);
923 if (s->pending != 0) {
924 s->last_flush = -1;
925 return Z_OK;
926 }
927 }
928 else {
929 put_byte(s, (s->gzhead->text ? 1 : 0) +
930 (s->gzhead->hcrc ? 2 : 0) +
931 (s->gzhead->extra == Z_NULL ? 0 : 4) +
932 (s->gzhead->name == Z_NULL ? 0 : 8) +
933 (s->gzhead->comment == Z_NULL ? 0 : 16)
934 );
935 put_byte(s, (Byte)(s->gzhead->time & 0xff));
936 put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
937 put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
938 put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
939 put_byte(s, s->level == 9 ? 2 :
940 (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
941 4 : 0));
942 put_byte(s, s->gzhead->os & 0xff);
943 if (s->gzhead->extra != Z_NULL) {
944 put_byte(s, s->gzhead->extra_len & 0xff);
945 put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
946 }
947 if (s->gzhead->hcrc)
948 strm->adler = crc32(strm->adler, s->pending_buf,
949 s->pending);
950 s->gzindex = 0;
951 s->status = EXTRA_STATE;
952 }
953 }
954 if (s->status == EXTRA_STATE) {
955 if (s->gzhead->extra != Z_NULL) {
956 ulg beg = s->pending; /* start of bytes to update crc */
957 uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
958 while (s->pending + left > s->pending_buf_size) {
959 uInt copy = s->pending_buf_size - s->pending;
960 zmemcpy(s->pending_buf + s->pending,
961 s->gzhead->extra + s->gzindex, copy);
962 s->pending = s->pending_buf_size;
963 HCRC_UPDATE(beg);
964 s->gzindex += copy;
965 flush_pending(strm);
966 if (s->pending != 0) {
967 s->last_flush = -1;
968 return Z_OK;
969 }
970 beg = 0;
971 left -= copy;
972 }
973 zmemcpy(s->pending_buf + s->pending,
974 s->gzhead->extra + s->gzindex, left);
975 s->pending += left;
976 HCRC_UPDATE(beg);
977 s->gzindex = 0;
978 }
979 s->status = NAME_STATE;
980 }
981 if (s->status == NAME_STATE) {
982 if (s->gzhead->name != Z_NULL) {
983 ulg beg = s->pending; /* start of bytes to update crc */
984 int val;
985 do {
986 if (s->pending == s->pending_buf_size) {
987 HCRC_UPDATE(beg);
988 flush_pending(strm);
989 if (s->pending != 0) {
990 s->last_flush = -1;
991 return Z_OK;
992 }
993 beg = 0;
994 }
995 val = s->gzhead->name[s->gzindex++];
996 put_byte(s, val);
997 } while (val != 0);
998 HCRC_UPDATE(beg);
999 s->gzindex = 0;
1000 }
1001 s->status = COMMENT_STATE;
1002 }
1003 if (s->status == COMMENT_STATE) {
1004 if (s->gzhead->comment != Z_NULL) {
1005 ulg beg = s->pending; /* start of bytes to update crc */
1006 int val;
1007 do {
1008 if (s->pending == s->pending_buf_size) {
1009 HCRC_UPDATE(beg);
1010 flush_pending(strm);
1011 if (s->pending != 0) {
1012 s->last_flush = -1;
1013 return Z_OK;
1014 }
1015 beg = 0;
1016 }
1017 val = s->gzhead->comment[s->gzindex++];
1018 put_byte(s, val);
1019 } while (val != 0);
1020 HCRC_UPDATE(beg);
1021 }
1022 s->status = HCRC_STATE;
1023 }
1024 if (s->status == HCRC_STATE) {
1025 if (s->gzhead->hcrc) {
1026 if (s->pending + 2 > s->pending_buf_size) {
1027 flush_pending(strm);
1028 if (s->pending != 0) {
1029 s->last_flush = -1;
1030 return Z_OK;
1031 }
1032 }
1033 put_byte(s, (Byte)(strm->adler & 0xff));
1034 put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
1035 strm->adler = crc32(0L, Z_NULL, 0);
1036 }
1037 s->status = BUSY_STATE;
1038
1039 /* Compression must start with an empty pending buffer */
1040 flush_pending(strm);
1041 if (s->pending != 0) {
1042 s->last_flush = -1;
1043 return Z_OK;
1044 }
1045 }
1046#endif
1047
1048 /* Start a new block or continue the current one.
1049 */
1050 if (strm->avail_in != 0 || s->lookahead != 0 ||
1051 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1052 block_state bstate;
1053
1054 bstate = s->level == 0 ? deflate_stored(s, flush) :
1055 s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
1056 s->strategy == Z_RLE ? deflate_rle(s, flush) :
1057 (*(configuration_table[s->level].func))(s, flush);
1058
1059 if (bstate == finish_started || bstate == finish_done) {
1060 s->status = FINISH_STATE;
1061 }
1062 if (bstate == need_more || bstate == finish_started) {
1063 if (strm->avail_out == 0) {
1064 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1065 }
1066 return Z_OK;
1067 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1068 * of deflate should use the same flush parameter to make sure
1069 * that the flush is complete. So we don't have to output an
1070 * empty block here, this will be done at next call. This also
1071 * ensures that for a very small output buffer, we emit at most
1072 * one empty block.
1073 */
1074 }
1075 if (bstate == block_done) {
1076 if (flush == Z_PARTIAL_FLUSH) {
1077 _tr_align(s);
1078 } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
1079 _tr_stored_block(s, (char*)0, 0L, 0);
1080 /* For a full flush, this empty block will be recognized
1081 * as a special marker by inflate_sync().
1082 */
1083 if (flush == Z_FULL_FLUSH) {
1084 CLEAR_HASH(s); /* forget history */
1085 if (s->lookahead == 0) {
1086 s->strstart = 0;
1087 s->block_start = 0L;
1088 s->insert = 0;
1089 }
1090 }
1091 }
1092 flush_pending(strm);
1093 if (strm->avail_out == 0) {
1094 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1095 return Z_OK;
1096 }
1097 }
1098 }
1099
1100 if (flush != Z_FINISH) return Z_OK;
1101 if (s->wrap <= 0) return Z_STREAM_END;
1102
1103 /* Write the trailer */
1104#ifdef GZIP
1105 if (s->wrap == 2) {
1106 put_byte(s, (Byte)(strm->adler & 0xff));
1107 put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
1108 put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
1109 put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
1110 put_byte(s, (Byte)(strm->total_in & 0xff));
1111 put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
1112 put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
1113 put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
1114 }
1115 else
1116#endif
1117 {
1118 putShortMSB(s, (uInt)(strm->adler >> 16));
1119 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1120 }
1121 flush_pending(strm);
1122 /* If avail_out is zero, the application will call deflate again
1123 * to flush the rest.
1124 */
1125 if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
1126 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1127}
1128
1129/* ========================================================================= */
1130 int ZEXPORT deflateEnd(strm)
1131 z_streamp strm;
1132{
1133 int status;
1134
1135 if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
1136
1137 status = strm->state->status;
1138
1139 /* Deallocate in reverse order of allocations: */
1140 TRY_FREE(strm, strm->state->pending_buf);
1141 TRY_FREE(strm, strm->state->head);
1142 TRY_FREE(strm, strm->state->prev);
1143 TRY_FREE(strm, strm->state->window);
1144
1145 ZFREE(strm, strm->state);
1146 strm->state = Z_NULL;
1147
1148 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1149}
1150
1151/* =========================================================================
1152 * Copy the source state to the destination state.
1153 * To simplify the source, this is not supported for 16-bit MSDOS (which
1154 * doesn't have enough memory anyway to duplicate compression states).
1155 */
1156 int ZEXPORT deflateCopy(dest, source)
1157 z_streamp dest;
1158 z_streamp source;
1159{
1160#ifdef MAXSEG_64K
1161 return Z_STREAM_ERROR;
1162#else
1163 deflate_state *ds;
1164 deflate_state *ss;
1165
1166
1167 if (deflateStateCheck(source) || dest == Z_NULL) {
1168 return Z_STREAM_ERROR;
1169 }
1170
1171 ss = source->state;
1172
1173 zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1174
1175 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1176 if (ds == Z_NULL) return Z_MEM_ERROR;
1177 dest->state = (struct internal_state FAR *) ds;
1178 zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
1179 ds->strm = dest;
1180
1181 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1182 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1183 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1184 ds->pending_buf = (uchf *) ZALLOC(dest, ds->lit_bufsize, 4);
1185
1186 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1187 ds->pending_buf == Z_NULL) {
1188 deflateEnd (dest);
1189 return Z_MEM_ERROR;
1190 }
1191 /* following zmemcpy do not work for 16-bit MSDOS */
1192 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1193 zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
1194 zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
1195 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1196
1197 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1198 ds->sym_buf = ds->pending_buf + ds->lit_bufsize;
1199
1200 ds->l_desc.dyn_tree = ds->dyn_ltree;
1201 ds->d_desc.dyn_tree = ds->dyn_dtree;
1202 ds->bl_desc.dyn_tree = ds->bl_tree;
1203
1204 return Z_OK;
1205#endif /* MAXSEG_64K */
1206}
1207
1208/* ===========================================================================
1209 * Read a new buffer from the current input stream, update the adler32
1210 * and total number of bytes read. All deflate() input goes through
1211 * this function so some applications may wish to modify it to avoid
1212 * allocating a large strm->next_in buffer and copying from it.
1213 * (See also flush_pending()).
1214 */
1215 local unsigned read_buf(strm, buf, size)
1216 z_streamp strm;
1217 Bytef *buf;
1218 unsigned size;
1219{
1220 unsigned len = strm->avail_in;
1221
1222 if (len > size) len = size;
1223 if (len == 0) return 0;
1224
1225 strm->avail_in -= len;
1226
1227 zmemcpy(buf, strm->next_in, len);
1228 if (strm->state->wrap == 1) {
1229 strm->adler = adler32(strm->adler, buf, len);
1230 }
1231#ifdef GZIP
1232 else if (strm->state->wrap == 2) {
1233 strm->adler = crc32(strm->adler, buf, len);
1234 }
1235#endif
1236 strm->next_in += len;
1237 strm->total_in += len;
1238
1239 return len;
1240}
1241
1242/* ===========================================================================
1243 * Initialize the "longest match" routines for a new zlib stream
1244 */
1245 local void lm_init(s)
1246 deflate_state *s;
1247{
1248 s->window_size = (ulg)2L*s->w_size;
1249
1250 CLEAR_HASH(s);
1251
1252 /* Set the default configuration parameters:
1253 */
1254 s->max_lazy_match = configuration_table[s->level].max_lazy;
1255 s->good_match = configuration_table[s->level].good_length;
1256 s->nice_match = configuration_table[s->level].nice_length;
1257 s->max_chain_length = configuration_table[s->level].max_chain;
1258
1259 s->strstart = 0;
1260 s->block_start = 0L;
1261 s->lookahead = 0;
1262 s->insert = 0;
1263 s->match_length = s->prev_length = MIN_MATCH-1;
1264 s->match_available = 0;
1265 s->ins_h = 0;
1266}
1267
1268#ifndef FASTEST
1269/* ===========================================================================
1270 * Set match_start to the longest match starting at the given string and
1271 * return its length. Matches shorter or equal to prev_length are discarded,
1272 * in which case the result is equal to prev_length and match_start is
1273 * garbage.
1274 * IN assertions: cur_match is the head of the hash chain for the current
1275 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1276 * OUT assertion: the match length is not greater than s->lookahead.
1277 */
1278 local uInt longest_match(s, cur_match)
1279 deflate_state *s;
1280 IPos cur_match; /* current match */
1281{
1282 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1283 register Bytef *scan = s->window + s->strstart; /* current string */
1284 register Bytef *match; /* matched string */
1285 register int len; /* length of current match */
1286 int best_len = (int)s->prev_length; /* best match length so far */
1287 int nice_match = s->nice_match; /* stop if match long enough */
1288 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1289 s->strstart - (IPos)MAX_DIST(s) : NIL;
1290 /* Stop when cur_match becomes <= limit. To simplify the code,
1291 * we prevent matches with the string of window index 0.
1292 */
1293 Posf *prev = s->prev;
1294 uInt wmask = s->w_mask;
1295
1296#ifdef UNALIGNED_OK
1297 /* Compare two bytes at a time. Note: this is not always beneficial.
1298 * Try with and without -DUNALIGNED_OK to check.
1299 */
1300 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1301 register ush scan_start = *(ushf*)scan;
1302 register ush scan_end = *(ushf*)(scan + best_len - 1);
1303#else
1304 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1305 register Byte scan_end1 = scan[best_len - 1];
1306 register Byte scan_end = scan[best_len];
1307#endif
1308
1309 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1310 * It is easy to get rid of this optimization if necessary.
1311 */
1312 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1313
1314 /* Do not waste too much time if we already have a good match: */
1315 if (s->prev_length >= s->good_match) {
1316 chain_length >>= 2;
1317 }
1318 /* Do not look for matches beyond the end of the input. This is necessary
1319 * to make deflate deterministic.
1320 */
1321 if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
1322
1323 Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
1324 "need lookahead");
1325
1326 do {
1327 Assert(cur_match < s->strstart, "no future");
1328 match = s->window + cur_match;
1329
1330 /* Skip to next match if the match length cannot increase
1331 * or if the match length is less than 2. Note that the checks below
1332 * for insufficient lookahead only occur occasionally for performance
1333 * reasons. Therefore uninitialized memory will be accessed, and
1334 * conditional jumps will be made that depend on those values.
1335 * However the length of the match is limited to the lookahead, so
1336 * the output of deflate is not affected by the uninitialized values.
1337 */
1338#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1339 /* This code assumes sizeof(unsigned short) == 2. Do not use
1340 * UNALIGNED_OK if your compiler uses a different size.
1341 */
1342 if (*(ushf*)(match + best_len - 1) != scan_end ||
1343 *(ushf*)match != scan_start) continue;
1344
1345 /* It is not necessary to compare scan[2] and match[2] since they are
1346 * always equal when the other bytes match, given that the hash keys
1347 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1348 * strstart + 3, + 5, up to strstart + 257. We check for insufficient
1349 * lookahead only every 4th comparison; the 128th check will be made
1350 * at strstart + 257. If MAX_MATCH-2 is not a multiple of 8, it is
1351 * necessary to put more guard bytes at the end of the window, or
1352 * to check more often for insufficient lookahead.
1353 */
1354 Assert(scan[2] == match[2], "scan[2]?");
1355 scan++, match++;
1356 do {
1357 } while (*(ushf*)(scan += 2) == *(ushf*)(match += 2) &&
1358 *(ushf*)(scan += 2) == *(ushf*)(match += 2) &&
1359 *(ushf*)(scan += 2) == *(ushf*)(match += 2) &&
1360 *(ushf*)(scan += 2) == *(ushf*)(match += 2) &&
1361 scan < strend);
1362 /* The funny "do {}" generates better code on most compilers */
1363
1364 /* Here, scan <= window + strstart + 257 */
1365 Assert(scan <= s->window + (unsigned)(s->window_size - 1),
1366 "wild scan");
1367 if (*scan == *match) scan++;
1368
1369 len = (MAX_MATCH - 1) - (int)(strend - scan);
1370 scan = strend - (MAX_MATCH-1);
1371
1372#else /* UNALIGNED_OK */
1373
1374 if (match[best_len] != scan_end ||
1375 match[best_len - 1] != scan_end1 ||
1376 *match != *scan ||
1377 *++match != scan[1]) continue;
1378
1379 /* The check at best_len - 1 can be removed because it will be made
1380 * again later. (This heuristic is not always a win.)
1381 * It is not necessary to compare scan[2] and match[2] since they
1382 * are always equal when the other bytes match, given that
1383 * the hash keys are equal and that HASH_BITS >= 8.
1384 */
1385 scan += 2, match++;
1386 Assert(*scan == *match, "match[2]?");
1387
1388 /* We check for insufficient lookahead only every 8th comparison;
1389 * the 256th check will be made at strstart + 258.
1390 */
1391 do {
1392 } while (*++scan == *++match && *++scan == *++match &&
1393 *++scan == *++match && *++scan == *++match &&
1394 *++scan == *++match && *++scan == *++match &&
1395 *++scan == *++match && *++scan == *++match &&
1396 scan < strend);
1397
1398 Assert(scan <= s->window + (unsigned)(s->window_size - 1),
1399 "wild scan");
1400
1401 len = MAX_MATCH - (int)(strend - scan);
1402 scan = strend - MAX_MATCH;
1403
1404#endif /* UNALIGNED_OK */
1405
1406 if (len > best_len) {
1407 s->match_start = cur_match;
1408 best_len = len;
1409 if (len >= nice_match) break;
1410#ifdef UNALIGNED_OK
1411 scan_end = *(ushf*)(scan + best_len - 1);
1412#else
1413 scan_end1 = scan[best_len - 1];
1414 scan_end = scan[best_len];
1415#endif
1416 }
1417 } while ((cur_match = prev[cur_match & wmask]) > limit
1418 && --chain_length != 0);
1419
1420 if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1421 return s->lookahead;
1422}
1423
1424#else /* FASTEST */
1425
1426/* ---------------------------------------------------------------------------
1427 * Optimized version for FASTEST only
1428 */
1429 local uInt longest_match(s, cur_match)
1430 deflate_state *s;
1431 IPos cur_match; /* current match */
1432{
1433 register Bytef *scan = s->window + s->strstart; /* current string */
1434 register Bytef *match; /* matched string */
1435 register int len; /* length of current match */
1436 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1437
1438 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1439 * It is easy to get rid of this optimization if necessary.
1440 */
1441 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1442
1443 Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
1444 "need lookahead");
1445
1446 Assert(cur_match < s->strstart, "no future");
1447
1448 match = s->window + cur_match;
1449
1450 /* Return failure if the match length is less than 2:
1451 */
1452 if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1453
1454 /* The check at best_len - 1 can be removed because it will be made
1455 * again later. (This heuristic is not always a win.)
1456 * It is not necessary to compare scan[2] and match[2] since they
1457 * are always equal when the other bytes match, given that
1458 * the hash keys are equal and that HASH_BITS >= 8.
1459 */
1460 scan += 2, match += 2;
1461 Assert(*scan == *match, "match[2]?");
1462
1463 /* We check for insufficient lookahead only every 8th comparison;
1464 * the 256th check will be made at strstart + 258.
1465 */
1466 do {
1467 } while (*++scan == *++match && *++scan == *++match &&
1468 *++scan == *++match && *++scan == *++match &&
1469 *++scan == *++match && *++scan == *++match &&
1470 *++scan == *++match && *++scan == *++match &&
1471 scan < strend);
1472
1473 Assert(scan <= s->window + (unsigned)(s->window_size - 1), "wild scan");
1474
1475 len = MAX_MATCH - (int)(strend - scan);
1476
1477 if (len < MIN_MATCH) return MIN_MATCH - 1;
1478
1479 s->match_start = cur_match;
1480 return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
1481}
1482
1483#endif /* FASTEST */
1484
1485#ifdef ZLIB_DEBUG
1486
1487#define EQUAL 0
1488/* result of memcmp for equal strings */
1489
1490/* ===========================================================================
1491 * Check that the match at match_start is indeed a match.
1492 */
1493 local void check_match(s, start, match, length)
1494 deflate_state *s;
1495 IPos start, match;
1496 int length;
1497{
1498 /* check that the match is indeed a match */
1499 if (zmemcmp(s->window + match,
1500 s->window + start, length) != EQUAL) {
1501 fprintf(stderr, " start %u, match %u, length %d\n",
1502 start, match, length);
1503 do {
1504 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1505 } while (--length != 0);
1506 z_error("invalid match");
1507 }
1508 if (z_verbose > 1) {
1509 fprintf(stderr,"\\[%d,%d]", start - match, length);
1510 do { putc(s->window[start++], stderr); } while (--length != 0);
1511 }
1512}
1513#else
1514# define check_match(s, start, match, length)
1515#endif /* ZLIB_DEBUG */
1516
1517/* ===========================================================================
1518 * Fill the window when the lookahead becomes insufficient.
1519 * Updates strstart and lookahead.
1520 *
1521 * IN assertion: lookahead < MIN_LOOKAHEAD
1522 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1523 * At least one byte has been read, or avail_in == 0; reads are
1524 * performed for at least two bytes (required for the zip translate_eol
1525 * option -- not supported here).
1526 */
1527 local void fill_window(s)
1528 deflate_state *s;
1529{
1530 unsigned n;
1531 unsigned more; /* Amount of free space at the end of the window. */
1532 uInt wsize = s->w_size;
1533
1534 Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
1535
1536 do {
1537 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1538
1539 /* Deal with !@#$% 64K limit: */
1540 if (sizeof(int) <= 2) {
1541 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1542 more = wsize;
1543
1544 } else if (more == (unsigned)(-1)) {
1545 /* Very unlikely, but possible on 16 bit machine if
1546 * strstart == 0 && lookahead == 1 (input done a byte at time)
1547 */
1548 more--;
1549 }
1550 }
1551
1552 /* If the window is almost full and there is insufficient lookahead,
1553 * move the upper half to the lower one to make room in the upper half.
1554 */
1555 if (s->strstart >= wsize + MAX_DIST(s)) {
1556
1557 zmemcpy(s->window, s->window + wsize, (unsigned)wsize - more);
1558 s->match_start -= wsize;
1559 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1560 s->block_start -= (long) wsize;
1561 if (s->insert > s->strstart)
1562 s->insert = s->strstart;
1563 slide_hash(s);
1564 more += wsize;
1565 }
1566 if (s->strm->avail_in == 0) break;
1567
1568 /* If there was no sliding:
1569 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1570 * more == window_size - lookahead - strstart
1571 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1572 * => more >= window_size - 2*WSIZE + 2
1573 * In the BIG_MEM or MMAP case (not yet supported),
1574 * window_size == input_size + MIN_LOOKAHEAD &&
1575 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1576 * Otherwise, window_size == 2*WSIZE so more >= 2.
1577 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1578 */
1579 Assert(more >= 2, "more < 2");
1580
1581 n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1582 s->lookahead += n;
1583
1584 /* Initialize the hash value now that we have some input: */
1585 if (s->lookahead + s->insert >= MIN_MATCH) {
1586 uInt str = s->strstart - s->insert;
1587 s->ins_h = s->window[str];
1588 UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
1589#if MIN_MATCH != 3
1590 Call UPDATE_HASH() MIN_MATCH-3 more times
1591#endif
1592 while (s->insert) {
1593 UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
1594#ifndef FASTEST
1595 s->prev[str & s->w_mask] = s->head[s->ins_h];
1596#endif
1597 s->head[s->ins_h] = (Pos)str;
1598 str++;
1599 s->insert--;
1600 if (s->lookahead + s->insert < MIN_MATCH)
1601 break;
1602 }
1603 }
1604 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1605 * but this is not important since only literal bytes will be emitted.
1606 */
1607
1608 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1609
1610 /* If the WIN_INIT bytes after the end of the current data have never been
1611 * written, then zero those bytes in order to avoid memory check reports of
1612 * the use of uninitialized (or uninitialised as Julian writes) bytes by
1613 * the longest match routines. Update the high water mark for the next
1614 * time through here. WIN_INIT is set to MAX_MATCH since the longest match
1615 * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
1616 */
1617 if (s->high_water < s->window_size) {
1618 ulg curr = s->strstart + (ulg)(s->lookahead);
1619 ulg init;
1620
1621 if (s->high_water < curr) {
1622 /* Previous high water mark below current data -- zero WIN_INIT
1623 * bytes or up to end of window, whichever is less.
1624 */
1625 init = s->window_size - curr;
1626 if (init > WIN_INIT)
1627 init = WIN_INIT;
1628 zmemzero(s->window + curr, (unsigned)init);
1629 s->high_water = curr + init;
1630 }
1631 else if (s->high_water < (ulg)curr + WIN_INIT) {
1632 /* High water mark at or above current data, but below current data
1633 * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
1634 * to end of window, whichever is less.
1635 */
1636 init = (ulg)curr + WIN_INIT - s->high_water;
1637 if (init > s->window_size - s->high_water)
1638 init = s->window_size - s->high_water;
1639 zmemzero(s->window + s->high_water, (unsigned)init);
1640 s->high_water += init;
1641 }
1642 }
1643
1644 Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
1645 "not enough room for search");
1646}
1647
1648/* ===========================================================================
1649 * Flush the current block, with given end-of-file flag.
1650 * IN assertion: strstart is set to the end of the current match.
1651 */
1652#define FLUSH_BLOCK_ONLY(s, last) { \
1653 _tr_flush_block(s, (s->block_start >= 0L ? \
1654 (charf *)&s->window[(unsigned)s->block_start] : \
1655 (charf *)Z_NULL), \
1656 (ulg)((long)s->strstart - s->block_start), \
1657 (last)); \
1658 s->block_start = s->strstart; \
1659 flush_pending(s->strm); \
1660 Tracev((stderr,"[FLUSH]")); \
1661}
1662
1663/* Same but force premature exit if necessary. */
1664#define FLUSH_BLOCK(s, last) { \
1665 FLUSH_BLOCK_ONLY(s, last); \
1666 if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
1667}
1668
1669/* Maximum stored block length in deflate format (not including header). */
1670#define MAX_STORED 65535
1671
1672/* Minimum of a and b. */
1673#define MIN(a, b) ((a) > (b) ? (b) : (a))
1674
1675/* ===========================================================================
1676 * Copy without compression as much as possible from the input stream, return
1677 * the current block state.
1678 *
1679 * In case deflateParams() is used to later switch to a non-zero compression
1680 * level, s->matches (otherwise unused when storing) keeps track of the number
1681 * of hash table slides to perform. If s->matches is 1, then one hash table
1682 * slide will be done when switching. If s->matches is 2, the maximum value
1683 * allowed here, then the hash table will be cleared, since two or more slides
1684 * is the same as a clear.
1685 *
1686 * deflate_stored() is written to minimize the number of times an input byte is
1687 * copied. It is most efficient with large input and output buffers, which
1688 * maximizes the opportunities to have a single copy from next_in to next_out.
1689 */
1690 local block_state deflate_stored(s, flush)
1691 deflate_state *s;
1692 int flush;
1693{
1694 /* Smallest worthy block size when not flushing or finishing. By default
1695 * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
1696 * large input and output buffers, the stored block size will be larger.
1697 */
1698 unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
1699
1700 /* Copy as many min_block or larger stored blocks directly to next_out as
1701 * possible. If flushing, copy the remaining available input to next_out as
1702 * stored blocks, if there is enough space.
1703 */
1704 unsigned len, left, have, last = 0;
1705 unsigned used = s->strm->avail_in;
1706 do {
1707 /* Set len to the maximum size block that we can copy directly with the
1708 * available input data and output space. Set left to how much of that
1709 * would be copied from what's left in the window.
1710 */
1711 len = MAX_STORED; /* maximum deflate stored block length */
1712 have = (s->bi_valid + 42) >> 3; /* number of header bytes */
1713 if (s->strm->avail_out < have) /* need room for header */
1714 break;
1715 /* maximum stored block length that will fit in avail_out: */
1716 have = s->strm->avail_out - have;
1717 left = s->strstart - s->block_start; /* bytes left in window */
1718 if (len > (ulg)left + s->strm->avail_in)
1719 len = left + s->strm->avail_in; /* limit len to the input */
1720 if (len > have)
1721 len = have; /* limit len to the output */
1722
1723 /* If the stored block would be less than min_block in length, or if
1724 * unable to copy all of the available input when flushing, then try
1725 * copying to the window and the pending buffer instead. Also don't
1726 * write an empty block when flushing -- deflate() does that.
1727 */
1728 if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
1729 flush == Z_NO_FLUSH ||
1730 len != left + s->strm->avail_in))
1731 break;
1732
1733 /* Make a dummy stored block in pending to get the header bytes,
1734 * including any pending bits. This also updates the debugging counts.
1735 */
1736 last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
1737 _tr_stored_block(s, (char *)0, 0L, last);
1738
1739 /* Replace the lengths in the dummy stored block with len. */
1740 s->pending_buf[s->pending - 4] = len;
1741 s->pending_buf[s->pending - 3] = len >> 8;
1742 s->pending_buf[s->pending - 2] = ~len;
1743 s->pending_buf[s->pending - 1] = ~len >> 8;
1744
1745 /* Write the stored block header bytes. */
1746 flush_pending(s->strm);
1747
1748#ifdef ZLIB_DEBUG
1749 /* Update debugging counts for the data about to be copied. */
1750 s->compressed_len += len << 3;
1751 s->bits_sent += len << 3;
1752#endif
1753
1754 /* Copy uncompressed bytes from the window to next_out. */
1755 if (left) {
1756 if (left > len)
1757 left = len;
1758 zmemcpy(s->strm->next_out, s->window + s->block_start, left);
1759 s->strm->next_out += left;
1760 s->strm->avail_out -= left;
1761 s->strm->total_out += left;
1762 s->block_start += left;
1763 len -= left;
1764 }
1765
1766 /* Copy uncompressed bytes directly from next_in to next_out, updating
1767 * the check value.
1768 */
1769 if (len) {
1770 read_buf(s->strm, s->strm->next_out, len);
1771 s->strm->next_out += len;
1772 s->strm->avail_out -= len;
1773 s->strm->total_out += len;
1774 }
1775 } while (last == 0);
1776
1777 /* Update the sliding window with the last s->w_size bytes of the copied
1778 * data, or append all of the copied data to the existing window if less
1779 * than s->w_size bytes were copied. Also update the number of bytes to
1780 * insert in the hash tables, in the event that deflateParams() switches to
1781 * a non-zero compression level.
1782 */
1783 used -= s->strm->avail_in; /* number of input bytes directly copied */
1784 if (used) {
1785 /* If any input was used, then no unused input remains in the window,
1786 * therefore s->block_start == s->strstart.
1787 */
1788 if (used >= s->w_size) { /* supplant the previous history */
1789 s->matches = 2; /* clear hash */
1790 zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
1791 s->strstart = s->w_size;
1792 s->insert = s->strstart;
1793 }
1794 else {
1795 if (s->window_size - s->strstart <= used) {
1796 /* Slide the window down. */
1797 s->strstart -= s->w_size;
1798 zmemcpy(s->window, s->window + s->w_size, s->strstart);
1799 if (s->matches < 2)
1800 s->matches++; /* add a pending slide_hash() */
1801 if (s->insert > s->strstart)
1802 s->insert = s->strstart;
1803 }
1804 zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
1805 s->strstart += used;
1806 s->insert += MIN(used, s->w_size - s->insert);
1807 }
1808 s->block_start = s->strstart;
1809 }
1810 if (s->high_water < s->strstart)
1811 s->high_water = s->strstart;
1812
1813 /* If the last block was written to next_out, then done. */
1814 if (last)
1815 return finish_done;
1816
1817 /* If flushing and all input has been consumed, then done. */
1818 if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
1819 s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
1820 return block_done;
1821
1822 /* Fill the window with any remaining input. */
1823 have = s->window_size - s->strstart;
1824 if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
1825 /* Slide the window down. */
1826 s->block_start -= s->w_size;
1827 s->strstart -= s->w_size;
1828 zmemcpy(s->window, s->window + s->w_size, s->strstart);
1829 if (s->matches < 2)
1830 s->matches++; /* add a pending slide_hash() */
1831 have += s->w_size; /* more space now */
1832 if (s->insert > s->strstart)
1833 s->insert = s->strstart;
1834 }
1835 if (have > s->strm->avail_in)
1836 have = s->strm->avail_in;
1837 if (have) {
1838 read_buf(s->strm, s->window + s->strstart, have);
1839 s->strstart += have;
1840 s->insert += MIN(have, s->w_size - s->insert);
1841 }
1842 if (s->high_water < s->strstart)
1843 s->high_water = s->strstart;
1844
1845 /* There was not enough avail_out to write a complete worthy or flushed
1846 * stored block to next_out. Write a stored block to pending instead, if we
1847 * have enough input for a worthy block, or if flushing and there is enough
1848 * room for the remaining input as a stored block in the pending buffer.
1849 */
1850 have = (s->bi_valid + 42) >> 3; /* number of header bytes */
1851 /* maximum stored block length that will fit in pending: */
1852 have = MIN(s->pending_buf_size - have, MAX_STORED);
1853 min_block = MIN(have, s->w_size);
1854 left = s->strstart - s->block_start;
1855 if (left >= min_block ||
1856 ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
1857 s->strm->avail_in == 0 && left <= have)) {
1858 len = MIN(left, have);
1859 last = flush == Z_FINISH && s->strm->avail_in == 0 &&
1860 len == left ? 1 : 0;
1861 _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
1862 s->block_start += len;
1863 flush_pending(s->strm);
1864 }
1865
1866 /* We've done all we can with the available input and output. */
1867 return last ? finish_started : need_more;
1868}
1869
1870/* ===========================================================================
1871 * Compress as much as possible from the input stream, return the current
1872 * block state.
1873 * This function does not perform lazy evaluation of matches and inserts
1874 * new strings in the dictionary only for unmatched strings or for short
1875 * matches. It is used only for the fast compression options.
1876 */
1877 local block_state deflate_fast(s, flush)
1878 deflate_state *s;
1879 int flush;
1880{
1881 IPos hash_head; /* head of the hash chain */
1882 int bflush; /* set if current block must be flushed */
1883
1884 for (;;) {
1885 /* Make sure that we always have enough lookahead, except
1886 * at the end of the input file. We need MAX_MATCH bytes
1887 * for the next match, plus MIN_MATCH bytes to insert the
1888 * string following the next match.
1889 */
1890 if (s->lookahead < MIN_LOOKAHEAD) {
1891 fill_window(s);
1892 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1893 return need_more;
1894 }
1895 if (s->lookahead == 0) break; /* flush the current block */
1896 }
1897
1898 /* Insert the string window[strstart .. strstart + 2] in the
1899 * dictionary, and set hash_head to the head of the hash chain:
1900 */
1901 hash_head = NIL;
1902 if (s->lookahead >= MIN_MATCH) {
1903 INSERT_STRING(s, s->strstart, hash_head);
1904 }
1905
1906 /* Find the longest match, discarding those <= prev_length.
1907 * At this point we have always match_length < MIN_MATCH
1908 */
1909 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1910 /* To simplify the code, we prevent matches with the string
1911 * of window index 0 (in particular we have to avoid a match
1912 * of the string with itself at the start of the input file).
1913 */
1914 s->match_length = longest_match (s, hash_head);
1915 /* longest_match() sets match_start */
1916 }
1917 if (s->match_length >= MIN_MATCH) {
1918 check_match(s, s->strstart, s->match_start, s->match_length);
1919
1920 _tr_tally_dist(s, s->strstart - s->match_start,
1921 s->match_length - MIN_MATCH, bflush);
1922
1923 s->lookahead -= s->match_length;
1924
1925 /* Insert new strings in the hash table only if the match length
1926 * is not too large. This saves time but degrades compression.
1927 */
1928#ifndef FASTEST
1929 if (s->match_length <= s->max_insert_length &&
1930 s->lookahead >= MIN_MATCH) {
1931 s->match_length--; /* string at strstart already in table */
1932 do {
1933 s->strstart++;
1934 INSERT_STRING(s, s->strstart, hash_head);
1935 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1936 * always MIN_MATCH bytes ahead.
1937 */
1938 } while (--s->match_length != 0);
1939 s->strstart++;
1940 } else
1941#endif
1942 {
1943 s->strstart += s->match_length;
1944 s->match_length = 0;
1945 s->ins_h = s->window[s->strstart];
1946 UPDATE_HASH(s, s->ins_h, s->window[s->strstart + 1]);
1947#if MIN_MATCH != 3
1948 Call UPDATE_HASH() MIN_MATCH-3 more times
1949#endif
1950 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1951 * matter since it will be recomputed at next deflate call.
1952 */
1953 }
1954 } else {
1955 /* No match, output a literal byte */
1956 Tracevv((stderr,"%c", s->window[s->strstart]));
1957 _tr_tally_lit(s, s->window[s->strstart], bflush);
1958 s->lookahead--;
1959 s->strstart++;
1960 }
1961 if (bflush) FLUSH_BLOCK(s, 0);
1962 }
1963 s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
1964 if (flush == Z_FINISH) {
1965 FLUSH_BLOCK(s, 1);
1966 return finish_done;
1967 }
1968 if (s->sym_next)
1969 FLUSH_BLOCK(s, 0);
1970 return block_done;
1971}
1972
1973#ifndef FASTEST
1974/* ===========================================================================
1975 * Same as above, but achieves better compression. We use a lazy
1976 * evaluation for matches: a match is finally adopted only if there is
1977 * no better match at the next window position.
1978 */
1979 local block_state deflate_slow(s, flush)
1980 deflate_state *s;
1981 int flush;
1982{
1983 IPos hash_head; /* head of hash chain */
1984 int bflush; /* set if current block must be flushed */
1985
1986 /* Process the input block. */
1987 for (;;) {
1988 /* Make sure that we always have enough lookahead, except
1989 * at the end of the input file. We need MAX_MATCH bytes
1990 * for the next match, plus MIN_MATCH bytes to insert the
1991 * string following the next match.
1992 */
1993 if (s->lookahead < MIN_LOOKAHEAD) {
1994 fill_window(s);
1995 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1996 return need_more;
1997 }
1998 if (s->lookahead == 0) break; /* flush the current block */
1999 }
2000
2001 /* Insert the string window[strstart .. strstart + 2] in the
2002 * dictionary, and set hash_head to the head of the hash chain:
2003 */
2004 hash_head = NIL;
2005 if (s->lookahead >= MIN_MATCH) {
2006 INSERT_STRING(s, s->strstart, hash_head);
2007 }
2008
2009 /* Find the longest match, discarding those <= prev_length.
2010 */
2011 s->prev_length = s->match_length, s->prev_match = s->match_start;
2012 s->match_length = MIN_MATCH-1;
2013
2014 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
2015 s->strstart - hash_head <= MAX_DIST(s)) {
2016 /* To simplify the code, we prevent matches with the string
2017 * of window index 0 (in particular we have to avoid a match
2018 * of the string with itself at the start of the input file).
2019 */
2020 s->match_length = longest_match (s, hash_head);
2021 /* longest_match() sets match_start */
2022
2023 if (s->match_length <= 5 && (s->strategy == Z_FILTERED
2024#if TOO_FAR <= 32767
2025 || (s->match_length == MIN_MATCH &&
2026 s->strstart - s->match_start > TOO_FAR)
2027#endif
2028 )) {
2029
2030 /* If prev_match is also MIN_MATCH, match_start is garbage
2031 * but we will ignore the current match anyway.
2032 */
2033 s->match_length = MIN_MATCH-1;
2034 }
2035 }
2036 /* If there was a match at the previous step and the current
2037 * match is not better, output the previous match:
2038 */
2039 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
2040 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
2041 /* Do not insert strings in hash table beyond this. */
2042
2043 check_match(s, s->strstart - 1, s->prev_match, s->prev_length);
2044
2045 _tr_tally_dist(s, s->strstart - 1 - s->prev_match,
2046 s->prev_length - MIN_MATCH, bflush);
2047
2048 /* Insert in hash table all strings up to the end of the match.
2049 * strstart - 1 and strstart are already inserted. If there is not
2050 * enough lookahead, the last two strings are not inserted in
2051 * the hash table.
2052 */
2053 s->lookahead -= s->prev_length - 1;
2054 s->prev_length -= 2;
2055 do {
2056 if (++s->strstart <= max_insert) {
2057 INSERT_STRING(s, s->strstart, hash_head);
2058 }
2059 } while (--s->prev_length != 0);
2060 s->match_available = 0;
2061 s->match_length = MIN_MATCH-1;
2062 s->strstart++;
2063
2064 if (bflush) FLUSH_BLOCK(s, 0);
2065
2066 } else if (s->match_available) {
2067 /* If there was no match at the previous position, output a
2068 * single literal. If there was a match but the current match
2069 * is longer, truncate the previous match to a single literal.
2070 */
2071 Tracevv((stderr,"%c", s->window[s->strstart - 1]));
2072 _tr_tally_lit(s, s->window[s->strstart - 1], bflush);
2073 if (bflush) {
2074 FLUSH_BLOCK_ONLY(s, 0);
2075 }
2076 s->strstart++;
2077 s->lookahead--;
2078 if (s->strm->avail_out == 0) return need_more;
2079 } else {
2080 /* There is no previous match to compare with, wait for
2081 * the next step to decide.
2082 */
2083 s->match_available = 1;
2084 s->strstart++;
2085 s->lookahead--;
2086 }
2087 }
2088 Assert (flush != Z_NO_FLUSH, "no flush?");
2089 if (s->match_available) {
2090 Tracevv((stderr,"%c", s->window[s->strstart - 1]));
2091 _tr_tally_lit(s, s->window[s->strstart - 1], bflush);
2092 s->match_available = 0;
2093 }
2094 s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
2095 if (flush == Z_FINISH) {
2096 FLUSH_BLOCK(s, 1);
2097 return finish_done;
2098 }
2099 if (s->sym_next)
2100 FLUSH_BLOCK(s, 0);
2101 return block_done;
2102}
2103#endif /* FASTEST */
2104
2105/* ===========================================================================
2106 * For Z_RLE, simply look for runs of bytes, generate matches only of distance
2107 * one. Do not maintain a hash table. (It will be regenerated if this run of
2108 * deflate switches away from Z_RLE.)
2109 */
2110 local block_state deflate_rle(s, flush)
2111 deflate_state *s;
2112 int flush;
2113{
2114 int bflush; /* set if current block must be flushed */
2115 uInt prev; /* byte at distance one to match */
2116 Bytef *scan, *strend; /* scan goes up to strend for length of run */
2117
2118 for (;;) {
2119 /* Make sure that we always have enough lookahead, except
2120 * at the end of the input file. We need MAX_MATCH bytes
2121 * for the longest run, plus one for the unrolled loop.
2122 */
2123 if (s->lookahead <= MAX_MATCH) {
2124 fill_window(s);
2125 if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
2126 return need_more;
2127 }
2128 if (s->lookahead == 0) break; /* flush the current block */
2129 }
2130
2131 /* See how many times the previous byte repeats */
2132 s->match_length = 0;
2133 if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
2134 scan = s->window + s->strstart - 1;
2135 prev = *scan;
2136 if (prev == *++scan && prev == *++scan && prev == *++scan) {
2137 strend = s->window + s->strstart + MAX_MATCH;
2138 do {
2139 } while (prev == *++scan && prev == *++scan &&
2140 prev == *++scan && prev == *++scan &&
2141 prev == *++scan && prev == *++scan &&
2142 prev == *++scan && prev == *++scan &&
2143 scan < strend);
2144 s->match_length = MAX_MATCH - (uInt)(strend - scan);
2145 if (s->match_length > s->lookahead)
2146 s->match_length = s->lookahead;
2147 }
2148 Assert(scan <= s->window + (uInt)(s->window_size - 1),
2149 "wild scan");
2150 }
2151
2152 /* Emit match if have run of MIN_MATCH or longer, else emit literal */
2153 if (s->match_length >= MIN_MATCH) {
2154 check_match(s, s->strstart, s->strstart - 1, s->match_length);
2155
2156 _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
2157
2158 s->lookahead -= s->match_length;
2159 s->strstart += s->match_length;
2160 s->match_length = 0;
2161 } else {
2162 /* No match, output a literal byte */
2163 Tracevv((stderr,"%c", s->window[s->strstart]));
2164 _tr_tally_lit(s, s->window[s->strstart], bflush);
2165 s->lookahead--;
2166 s->strstart++;
2167 }
2168 if (bflush) FLUSH_BLOCK(s, 0);
2169 }
2170 s->insert = 0;
2171 if (flush == Z_FINISH) {
2172 FLUSH_BLOCK(s, 1);
2173 return finish_done;
2174 }
2175 if (s->sym_next)
2176 FLUSH_BLOCK(s, 0);
2177 return block_done;
2178}
2179
2180/* ===========================================================================
2181 * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
2182 * (It will be regenerated if this run of deflate switches away from Huffman.)
2183 */
2184 local block_state deflate_huff(s, flush)
2185 deflate_state *s;
2186 int flush;
2187{
2188 int bflush; /* set if current block must be flushed */
2189
2190 for (;;) {
2191 /* Make sure that we have a literal to write. */
2192 if (s->lookahead == 0) {
2193 fill_window(s);
2194 if (s->lookahead == 0) {
2195 if (flush == Z_NO_FLUSH)
2196 return need_more;
2197 break; /* flush the current block */
2198 }
2199 }
2200
2201 /* Output a literal byte */
2202 s->match_length = 0;
2203 Tracevv((stderr,"%c", s->window[s->strstart]));
2204 _tr_tally_lit(s, s->window[s->strstart], bflush);
2205 s->lookahead--;
2206 s->strstart++;
2207 if (bflush) FLUSH_BLOCK(s, 0);
2208 }
2209 s->insert = 0;
2210 if (flush == Z_FINISH) {
2211 FLUSH_BLOCK(s, 1);
2212 return finish_done;
2213 }
2214 if (s->sym_next)
2215 FLUSH_BLOCK(s, 0);
2216 return block_done;
2217}
adler32
uLong ZEXPORT adler32(uLong adler, const Bytef *buf, uInt len)
Definition: adler32.c:134
L
#define L(x)
Definition: asm.h:125
local
#define local
Definition: blast.c:36
bits
int bits(struct state *s, int need)
Definition: blast.c:72
crc32
unsigned long ZEXPORT crc32(unsigned long crc, const unsigned char FAR *buf, uInt len)
Definition: crc32.c:1072
configuration_table
const config configuration_table[10]
Definition: deflate.c:128
deflateSetHeader
int ZEXPORT deflateSetHeader(z_streamp strm, gz_headerp head)
Definition: deflate.c:553
deflateInit_
int ZEXPORT deflateInit_(z_streamp strm, int level, const char *version, int stream_size)
Definition: deflate.c:225
block_state
block_state
Definition: deflate.c:66
finish_started
@ finish_started
Definition: deflate.c:69
block_done
@ block_done
Definition: deflate.c:68
need_more
@ need_more
Definition: deflate.c:67
finish_done
@ finish_done
Definition: deflate.c:70
FLUSH_BLOCK_ONLY
#define FLUSH_BLOCK_ONLY(s, last)
Definition: deflate.c:1652
HCRC_UPDATE
#define HCRC_UPDATE(beg)
Definition: deflate.c:807
NIL
#define NIL
Definition: deflate.c:101
deflatePending
int ZEXPORT deflatePending(z_streamp strm, unsigned *pending, int *bits)
Definition: deflate.c:564
config
struct config_s config
deflate_stored
block_state deflate_stored(deflate_state *s, int flush)
Definition: deflate.c:1690
MIN
#define MIN(a, b)
Definition: deflate.c:1673
check_match
#define check_match(s, start, match, length)
Definition: deflate.c:1514
putShortMSB
void putShortMSB(deflate_state *s, uInt b)
Definition: deflate.c:768
UPDATE_HASH
#define UPDATE_HASH(s, h, c)
Definition: deflate.c:157
deflateCopy
int ZEXPORT deflateCopy(z_streamp dest, z_streamp source)
Definition: deflate.c:1156
deflateSetDictionary
int ZEXPORT deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength)
Definition: deflate.c:412
flush_pending
void flush_pending(z_streamp strm)
Definition: deflate.c:782
deflateReset
int ZEXPORT deflateReset(z_streamp strm)
Definition: deflate.c:541
INSERT_STRING
#define INSERT_STRING(s, str, match_head)
Definition: deflate.c:176
deflateParams
int ZEXPORT deflateParams(z_streamp strm, int level, int strategy)
Definition: deflate.c:605
OF
block_state compress_func OF((deflate_state *s, int flush))
Addition for GDAL : START.
Definition: deflate.c:73
deflateBound
uLong ZEXPORT deflateBound(z_streamp strm, uLong sourceLen)
Definition: deflate.c:696
read_buf
unsigned read_buf(z_streamp strm, Bytef *buf, unsigned size)
Definition: deflate.c:1215
deflate_copyright
const char deflate_copyright[]
Definition: deflate.c:54
deflate_fast
block_state deflate_fast(deflate_state *s, int flush)
Definition: deflate.c:1877
deflate_slow
block_state deflate_slow(deflate_state *s, int flush)
Definition: deflate.c:1979
FLUSH_BLOCK
#define FLUSH_BLOCK(s, last)
Definition: deflate.c:1664
deflateTune
int ZEXPORT deflateTune(z_streamp strm, int good_length, int max_lazy, int nice_length, int max_chain)
Definition: deflate.c:654
longest_match
uInt longest_match(deflate_state *s, IPos cur_match)
Definition: deflate.c:1278
deflatePrime
int ZEXPORT deflatePrime(z_streamp strm, int bits, int value)
Definition: deflate.c:578
deflateGetDictionary
int ZEXPORT deflateGetDictionary(z_streamp strm, Bytef *dictionary, uInt *dictLength)
Definition: deflate.c:481
TOO_FAR
#define TOO_FAR
Definition: deflate.c:105
deflate_huff
block_state deflate_huff(deflate_state *s, int flush)
Definition: deflate.c:2184
deflateStateCheck
int deflateStateCheck(z_streamp strm)
Definition: deflate.c:389
MAX_STORED
#define MAX_STORED
Definition: deflate.c:1670
deflateResetKeep
int ZEXPORT deflateResetKeep(z_streamp strm)
Definition: deflate.c:503
deflateEnd
int ZEXPORT deflateEnd(z_streamp strm)
Definition: deflate.c:1130
fill_window
void fill_window(deflate_state *s)
Definition: deflate.c:1527
deflateInit2_
int ZEXPORT deflateInit2_(z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy, const char *version, int stream_size)
Definition: deflate.c:237
RANK
#define RANK(f)
Definition: deflate.c:149
lm_init
void lm_init(deflate_state *s)
Definition: deflate.c:1245
deflate
int ZEXPORT deflate(z_streamp strm, int flush)
Definition: deflate.c:815
slide_hash
void slide_hash(deflate_state *s)
Definition: deflate.c:198
CLEAR_HASH
#define CLEAR_HASH(s)
Definition: deflate.c:186
deflate_rle
block_state deflate_rle(deflate_state *s, int flush)
Definition: deflate.c:2110
deflate.h
FINISH_STATE
#define FINISH_STATE
Definition: deflate.h:63
COMMENT_STATE
#define COMMENT_STATE
Definition: deflate.h:60
HCRC_STATE
#define HCRC_STATE
Definition: deflate.h:61
Buf_size
#define Buf_size
Definition: deflate.h:51
GZIP_STATE
#define GZIP_STATE
Definition: deflate.h:56
MAX_DIST
#define MAX_DIST(s)
Definition: deflate.h:284
BUSY_STATE
#define BUSY_STATE
Definition: deflate.h:62
put_byte
#define put_byte(s, c)
Definition: deflate.h:276
_tr_tally_dist
#define _tr_tally_dist(s, distance, length, flush)
Definition: deflate.h:329
Posf
Pos FAR Posf
Definition: deflate.h:93
Pos
ush Pos
Definition: deflate.h:92
GZIP
#define GZIP
Definition: deflate.h:23
INIT_STATE
#define INIT_STATE
Definition: deflate.h:54
MIN_LOOKAHEAD
#define MIN_LOOKAHEAD
Definition: deflate.h:279
WIN_INIT
#define WIN_INIT
Definition: deflate.h:289
NAME_STATE
#define NAME_STATE
Definition: deflate.h:59
IPos
unsigned IPos
Definition: deflate.h:94
_tr_tally_lit
#define _tr_tally_lit(s, c, flush)
Definition: deflate.h:321
EXTRA_STATE
#define EXTRA_STATE
Definition: deflate.h:58
len
uint8_t len
Definition: escape.c:17
str
char str[HTML_ESCAPE_MAX_LEN+1]
Definition: escape.c:18
match
unsigned char match[65280+2]
Definition: gun.c:165
size
voidpf void uLong size
Definition: ioapi.h:138
long
typedef long(ZCALLBACK *tell_file_func) OF((voidpf opaque
int
typedef int(ZCALLBACK *close_file_func) OF((voidpf opaque
buf
voidpf void * buf
Definition: ioapi.h:138
strstart
#define strstart(s, n)
Definition: langinfo.c:57
last
unsigned int last
Definition: nkf.c:4324
EQUAL
#define EQUAL(tab, x, y)
Definition: st.c:176
config_s
Definition: deflate.c:114
config_s::good_length
ush good_length
Definition: deflate.c:115
config_s::max_chain
ush max_chain
Definition: deflate.c:118
config_s::func
compress_func func
Definition: deflate.c:119
config_s::nice_length
ush nice_length
Definition: deflate.c:117
config_s::max_lazy
ush max_lazy
Definition: deflate.c:116
internal_state
Definition: deflate.h:100
internal_state::w_bits
uInt w_bits
Definition: deflate.h:116
internal_state::l_desc
struct tree_desc_s l_desc
Definition: deflate.h:202
internal_state::w_mask
uInt w_mask
Definition: deflate.h:117
internal_state::bi_valid
int bi_valid
Definition: deflate.h:259
internal_state::lit_bufsize
uInt lit_bufsize
Definition: deflate.h:222
internal_state::insert
uInt insert
Definition: deflate.h:248
internal_state::nice_match
int nice_match
Definition: deflate.h:194
internal_state::lookahead
uInt lookahead
Definition: deflate.h:164
internal_state::dyn_dtree
struct ct_data_s dyn_dtree[2 *D_CODES+1]
Definition: deflate.h:199
internal_state::pending
ulg pending
Definition: deflate.h:106
internal_state::block_start
long block_start
Definition: deflate.h:154
internal_state::window_size
ulg window_size
Definition: deflate.h:129
internal_state::sym_end
uInt sym_end
Definition: deflate.h:243
internal_state::hash_bits
uInt hash_bits
Definition: deflate.h:144
internal_state::strategy
int strategy
Definition: deflate.h:189
internal_state::bi_buf
ush bi_buf
Definition: deflate.h:255
internal_state::good_match
uInt good_match
Definition: deflate.h:191
internal_state::pending_out
Bytef * pending_out
Definition: deflate.h:105
internal_state::prev_length
uInt prev_length
Definition: deflate.h:166
internal_state::level
int level
Definition: deflate.h:188
internal_state::hash_mask
uInt hash_mask
Definition: deflate.h:145
internal_state::high_water
ulg high_water
Definition: deflate.h:264
internal_state::w_size
uInt w_size
Definition: deflate.h:115
internal_state::status
int status
Definition: deflate.h:102
internal_state::ins_h
uInt ins_h
Definition: deflate.h:142
internal_state::window
Bytef * window
Definition: deflate.h:119
internal_state::pending_buf_size
ulg pending_buf_size
Definition: deflate.h:104
internal_state::prev
Posf * prev
Definition: deflate.h:134
internal_state::strstart
uInt strstart
Definition: deflate.h:162
internal_state::bl_tree
struct ct_data_s bl_tree[2 *BL_CODES+1]
Definition: deflate.h:200
internal_state::bl_desc
struct tree_desc_s bl_desc
Definition: deflate.h:204
internal_state::match_length
uInt match_length
Definition: deflate.h:159
internal_state::last_flush
int last_flush
Definition: deflate.h:111
internal_state::hash_size
uInt hash_size
Definition: deflate.h:143
internal_state::strm
z_streamp strm
Definition: deflate.h:101
internal_state::head
Posf * head
Definition: deflate.h:140
internal_state::max_chain_length
uInt max_chain_length
Definition: deflate.h:171
internal_state::d_desc
struct tree_desc_s d_desc
Definition: deflate.h:203
internal_state::max_lazy_match
uInt max_lazy_match
Definition: deflate.h:177
internal_state::gzhead
gz_headerp gzhead
Definition: deflate.h:108
internal_state::matches
uInt matches
Definition: deflate.h:247
internal_state::match_available
int match_available
Definition: deflate.h:161
internal_state::gzindex
ulg gzindex
Definition: deflate.h:109
internal_state::dyn_ltree
struct ct_data_s dyn_ltree[HEAP_SIZE]
Definition: deflate.h:198
internal_state::pending_buf
Bytef * pending_buf
Definition: deflate.h:103
internal_state::wrap
int wrap
Definition: deflate.h:107
internal_state::method
Byte method
Definition: deflate.h:110
internal_state::hash_shift
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Definition: trees.c:887
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Definition: zconf.h:400
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Definition: zconf.h:386
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Definition: zlib.h:108
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Definition: zlib.h:173
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Definition: zlib.h:177
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Definition: zutil.h:43
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Definition: zutil.h:255