ReactOS  0.4.15-dev-5462-g4d0d22a
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 1.2.12 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 
81 #ifndef FASTEST
83 #endif
86 local void lm_init OF((deflate_state *s));
88 local void flush_pending OF((z_streamp strm));
89 local unsigned read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
90 #ifdef ASMV
91 # pragma message("Assembler code may have bugs -- use at your own risk")
92  void match_init OF((void)); /* asm code initialization */
93  uInt longest_match OF((deflate_state *s, IPos cur_match));
94 #else
96 #endif
97 
98 #ifdef ZLIB_DEBUG
100  int length));
101 #endif
102 
103 /* ===========================================================================
104  * Local data
105  */
106 
107 #define NIL 0
108 /* Tail of hash chains */
109 
110 #ifndef TOO_FAR
111 # define TOO_FAR 4096
112 #endif
113 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
114 
115 /* Values for max_lazy_match, good_match and max_chain_length, depending on
116  * the desired pack level (0..9). The values given below have been tuned to
117  * exclude worst case performance for pathological files. Better values may be
118  * found for specific files.
119  */
120 typedef struct config_s {
121  ush good_length; /* reduce lazy search above this match length */
122  ush max_lazy; /* do not perform lazy search above this match length */
123  ush nice_length; /* quit search above this match length */
125  compress_func func;
126 } config;
127 
128 #ifdef FASTEST
129 local const config configuration_table[2] = {
130 /* good lazy nice chain */
131 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
132 /* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */
133 #else
135 /* good lazy nice chain */
136 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
137 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
138 /* 2 */ {4, 5, 16, 8, deflate_fast},
139 /* 3 */ {4, 6, 32, 32, deflate_fast},
140 
141 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
142 /* 5 */ {8, 16, 32, 32, deflate_slow},
143 /* 6 */ {8, 16, 128, 128, deflate_slow},
144 /* 7 */ {8, 32, 128, 256, deflate_slow},
145 /* 8 */ {32, 128, 258, 1024, deflate_slow},
146 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
147 #endif
148 
149 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
150  * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
151  * meaning.
152  */
153 
154 /* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
155 #define RANK(f) (((f) * 2) - ((f) > 4 ? 9 : 0))
156 
157 /* ===========================================================================
158  * Update a hash value with the given input byte
159  * IN assertion: all calls to UPDATE_HASH are made with consecutive input
160  * characters, so that a running hash key can be computed from the previous
161  * key instead of complete recalculation each time.
162  */
163 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
164 
165 
166 /* ===========================================================================
167  * Insert string str in the dictionary and set match_head to the previous head
168  * of the hash chain (the most recent string with same hash key). Return
169  * the previous length of the hash chain.
170  * If this file is compiled with -DFASTEST, the compression level is forced
171  * to 1, and no hash chains are maintained.
172  * IN assertion: all calls to INSERT_STRING are made with consecutive input
173  * characters and the first MIN_MATCH bytes of str are valid (except for
174  * the last MIN_MATCH-1 bytes of the input file).
175  */
176 #ifdef FASTEST
177 #define INSERT_STRING(s, str, match_head) \
178  (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
179  match_head = s->head[s->ins_h], \
180  s->head[s->ins_h] = (Pos)(str))
181 #else
182 #define INSERT_STRING(s, str, match_head) \
183  (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
184  match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
185  s->head[s->ins_h] = (Pos)(str))
186 #endif
187 
188 /* ===========================================================================
189  * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
190  * prev[] will be initialized on the fly.
191  */
192 #define CLEAR_HASH(s) \
193  do { \
194  s->head[s->hash_size-1] = NIL; \
195  zmemzero((Bytef *)s->head, \
196  (unsigned)(s->hash_size-1)*sizeof(*s->head)); \
197  } while (0)
198 
199 /* ===========================================================================
200  * Slide the hash table when sliding the window down (could be avoided with 32
201  * bit values at the expense of memory usage). We slide even when level == 0 to
202  * keep the hash table consistent if we switch back to level > 0 later.
203  */
205  deflate_state *s;
206 {
207  unsigned n, m;
208  Posf *p;
209  uInt wsize = s->w_size;
210 
211  n = s->hash_size;
212  p = &s->head[n];
213  do {
214  m = *--p;
215  *p = (Pos)(m >= wsize ? m - wsize : NIL);
216  } while (--n);
217  n = wsize;
218 #ifndef FASTEST
219  p = &s->prev[n];
220  do {
221  m = *--p;
222  *p = (Pos)(m >= wsize ? m - wsize : NIL);
223  /* If n is not on any hash chain, prev[n] is garbage but
224  * its value will never be used.
225  */
226  } while (--n);
227 #endif
228 }
229 
230 /* ========================================================================= */
232  z_streamp strm;
233  int level;
234  const char *version;
235  int stream_size;
236 {
239  /* To do: ignore strm->next_in if we use it as window */
240 }
241 
242 /* ========================================================================= */
243 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
245  z_streamp strm;
246  int level;
247  int method;
248  int windowBits;
249  int memLevel;
250  int strategy;
251  const char *version;
252  int stream_size;
253 {
254  deflate_state *s;
255  int wrap = 1;
256  static const char my_version[] = ZLIB_VERSION;
257 
258  if (version == Z_NULL || version[0] != my_version[0] ||
259  stream_size != sizeof(z_stream)) {
260  return Z_VERSION_ERROR;
261  }
262  if (strm == Z_NULL) return Z_STREAM_ERROR;
263 
264  strm->msg = Z_NULL;
265  if (strm->zalloc == (alloc_func)0) {
266 #ifdef Z_SOLO
267  return Z_STREAM_ERROR;
268 #else
269  strm->zalloc = zcalloc;
270  strm->opaque = (voidpf)0;
271 #endif
272  }
273  if (strm->zfree == (free_func)0)
274 #ifdef Z_SOLO
275  return Z_STREAM_ERROR;
276 #else
277  strm->zfree = zcfree;
278 #endif
279 
280 #ifdef FASTEST
281  if (level != 0) level = 1;
282 #else
283  if (level == Z_DEFAULT_COMPRESSION) level = 6;
284 #endif
285 
286  if (windowBits < 0) { /* suppress zlib wrapper */
287  wrap = 0;
289  }
290 #ifdef GZIP
291  else if (windowBits > 15) {
292  wrap = 2; /* write gzip wrapper instead */
293  windowBits -= 16;
294  }
295 #endif
296  if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
297  windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
298  strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
299  return Z_STREAM_ERROR;
300  }
301  if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */
302  s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
303  if (s == Z_NULL) return Z_MEM_ERROR;
304  strm->state = (struct internal_state FAR *)s;
305  s->strm = strm;
306  s->status = INIT_STATE; /* to pass state test in deflateReset() */
307 
308  s->wrap = wrap;
309  s->gzhead = Z_NULL;
310  s->w_bits = (uInt)windowBits;
311  s->w_size = 1 << s->w_bits;
312  s->w_mask = s->w_size - 1;
313 
314  s->hash_bits = (uInt)memLevel + 7;
315  s->hash_size = 1 << s->hash_bits;
316  s->hash_mask = s->hash_size - 1;
317  s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
318 
319  s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
320  s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
321  s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
322 
323  s->high_water = 0; /* nothing written to s->window yet */
324 
325  s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
326 
327  /* We overlay pending_buf and sym_buf. This works since the average size
328  * for length/distance pairs over any compressed block is assured to be 31
329  * bits or less.
330  *
331  * Analysis: The longest fixed codes are a length code of 8 bits plus 5
332  * extra bits, for lengths 131 to 257. The longest fixed distance codes are
333  * 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest
334  * possible fixed-codes length/distance pair is then 31 bits total.
335  *
336  * sym_buf starts one-fourth of the way into pending_buf. So there are
337  * three bytes in sym_buf for every four bytes in pending_buf. Each symbol
338  * in sym_buf is three bytes -- two for the distance and one for the
339  * literal/length. As each symbol is consumed, the pointer to the next
340  * sym_buf value to read moves forward three bytes. From that symbol, up to
341  * 31 bits are written to pending_buf. The closest the written pending_buf
342  * bits gets to the next sym_buf symbol to read is just before the last
343  * code is written. At that time, 31*(n-2) bits have been written, just
344  * after 24*(n-2) bits have been consumed from sym_buf. sym_buf starts at
345  * 8*n bits into pending_buf. (Note that the symbol buffer fills when n-1
346  * symbols are written.) The closest the writing gets to what is unread is
347  * then n+14 bits. Here n is lit_bufsize, which is 16384 by default, and
348  * can range from 128 to 32768.
349  *
350  * Therefore, at a minimum, there are 142 bits of space between what is
351  * written and what is read in the overlain buffers, so the symbols cannot
352  * be overwritten by the compressed data. That space is actually 139 bits,
353  * due to the three-bit fixed-code block header.
354  *
355  * That covers the case where either Z_FIXED is specified, forcing fixed
356  * codes, or when the use of fixed codes is chosen, because that choice
357  * results in a smaller compressed block than dynamic codes. That latter
358  * condition then assures that the above analysis also covers all dynamic
359  * blocks. A dynamic-code block will only be chosen to be emitted if it has
360  * fewer bits than a fixed-code block would for the same set of symbols.
361  * Therefore its average symbol length is assured to be less than 31. So
362  * the compressed data for a dynamic block also cannot overwrite the
363  * symbols from which it is being constructed.
364  */
365 
366  s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 4);
367  s->pending_buf_size = (ulg)s->lit_bufsize * 4;
368 
369  if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
370  s->pending_buf == Z_NULL) {
371  s->status = FINISH_STATE;
372  strm->msg = ERR_MSG(Z_MEM_ERROR);
373  deflateEnd (strm);
374  return Z_MEM_ERROR;
375  }
376  s->sym_buf = s->pending_buf + s->lit_bufsize;
377  s->sym_end = (s->lit_bufsize - 1) * 3;
378  /* We avoid equality with lit_bufsize*3 because of wraparound at 64K
379  * on 16 bit machines and because stored blocks are restricted to
380  * 64K-1 bytes.
381  */
382 
383  s->level = level;
384  s->strategy = strategy;
385  s->method = (Byte)method;
386 
387  return deflateReset(strm);
388 }
389 
390 /* =========================================================================
391  * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
392  */
394  z_streamp strm;
395 {
396  deflate_state *s;
397  if (strm == Z_NULL ||
398  strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
399  return 1;
400  s = strm->state;
401  if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
402 #ifdef GZIP
403  s->status != GZIP_STATE &&
404 #endif
405  s->status != EXTRA_STATE &&
406  s->status != NAME_STATE &&
407  s->status != COMMENT_STATE &&
408  s->status != HCRC_STATE &&
409  s->status != BUSY_STATE &&
410  s->status != FINISH_STATE))
411  return 1;
412  return 0;
413 }
414 
415 /* ========================================================================= */
417  z_streamp strm;
418  const Bytef *dictionary;
419  uInt dictLength;
420 {
421  deflate_state *s;
422  uInt str, n;
423  int wrap;
424  unsigned avail;
425  z_const unsigned char *next;
426 
428  return Z_STREAM_ERROR;
429  s = strm->state;
430  wrap = s->wrap;
431  if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
432  return Z_STREAM_ERROR;
433 
434  /* when using zlib wrappers, compute Adler-32 for provided dictionary */
435  if (wrap == 1)
436  strm->adler = adler32(strm->adler, dictionary, dictLength);
437  s->wrap = 0; /* avoid computing Adler-32 in read_buf */
438 
439  /* if dictionary would fill window, just replace the history */
440  if (dictLength >= s->w_size) {
441  if (wrap == 0) { /* already empty otherwise */
442  CLEAR_HASH(s);
443  s->strstart = 0;
444  s->block_start = 0L;
445  s->insert = 0;
446  }
447  dictionary += dictLength - s->w_size; /* use the tail */
448  dictLength = s->w_size;
449  }
450 
451  /* insert dictionary into window and hash */
452  avail = strm->avail_in;
453  next = strm->next_in;
454  strm->avail_in = dictLength;
455  strm->next_in = (z_const Bytef *)dictionary;
456  fill_window(s);
457  while (s->lookahead >= MIN_MATCH) {
458  str = s->strstart;
459  n = s->lookahead - (MIN_MATCH-1);
460  do {
461  UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
462 #ifndef FASTEST
463  s->prev[str & s->w_mask] = s->head[s->ins_h];
464 #endif
465  s->head[s->ins_h] = (Pos)str;
466  str++;
467  } while (--n);
468  s->strstart = str;
469  s->lookahead = MIN_MATCH-1;
470  fill_window(s);
471  }
472  s->strstart += s->lookahead;
473  s->block_start = (long)s->strstart;
474  s->insert = s->lookahead;
475  s->lookahead = 0;
476  s->match_length = s->prev_length = MIN_MATCH-1;
477  s->match_available = 0;
478  strm->next_in = next;
479  strm->avail_in = avail;
480  s->wrap = wrap;
481  return Z_OK;
482 }
483 
484 /* ========================================================================= */
486  z_streamp strm;
487  Bytef *dictionary;
488  uInt *dictLength;
489 {
490  deflate_state *s;
491  uInt len;
492 
493  if (deflateStateCheck(strm))
494  return Z_STREAM_ERROR;
495  s = strm->state;
496  len = s->strstart + s->lookahead;
497  if (len > s->w_size)
498  len = s->w_size;
499  if (dictionary != Z_NULL && len)
500  zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
501  if (dictLength != Z_NULL)
502  *dictLength = len;
503  return Z_OK;
504 }
505 
506 /* ========================================================================= */
508  z_streamp strm;
509 {
510  deflate_state *s;
511 
512  if (deflateStateCheck(strm)) {
513  return Z_STREAM_ERROR;
514  }
515 
516  strm->total_in = strm->total_out = 0;
517  strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
518  strm->data_type = Z_UNKNOWN;
519 
520  s = (deflate_state *)strm->state;
521  s->pending = 0;
522  s->pending_out = s->pending_buf;
523 
524  if (s->wrap < 0) {
525  s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
526  }
527  s->status =
528 #ifdef GZIP
529  s->wrap == 2 ? GZIP_STATE :
530 #endif
531  INIT_STATE;
532  strm->adler =
533 #ifdef GZIP
534  s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
535 #endif
536  adler32(0L, Z_NULL, 0);
537  s->last_flush = -2;
538 
539  _tr_init(s);
540 
541  return Z_OK;
542 }
543 
544 /* ========================================================================= */
546  z_streamp strm;
547 {
548  int ret;
549 
551  if (ret == Z_OK)
552  lm_init(strm->state);
553  return ret;
554 }
555 
556 /* ========================================================================= */
558  z_streamp strm;
560 {
561  if (deflateStateCheck(strm) || strm->state->wrap != 2)
562  return Z_STREAM_ERROR;
563  strm->state->gzhead = head;
564  return Z_OK;
565 }
566 
567 /* ========================================================================= */
569  unsigned *pending;
570  int *bits;
571  z_streamp strm;
572 {
574  if (pending != Z_NULL)
575  *pending = strm->state->pending;
576  if (bits != Z_NULL)
577  *bits = strm->state->bi_valid;
578  return Z_OK;
579 }
580 
581 /* ========================================================================= */
583  z_streamp strm;
584  int bits;
585  int value;
586 {
587  deflate_state *s;
588  int put;
589 
591  s = strm->state;
592  if (bits < 0 || bits > 16 ||
593  s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3))
594  return Z_BUF_ERROR;
595  do {
596  put = Buf_size - s->bi_valid;
597  if (put > bits)
598  put = bits;
599  s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
600  s->bi_valid += put;
601  _tr_flush_bits(s);
602  value >>= put;
603  bits -= put;
604  } while (bits);
605  return Z_OK;
606 }
607 
608 /* ========================================================================= */
610  z_streamp strm;
611  int level;
612  int strategy;
613 {
614  deflate_state *s;
615  compress_func func;
616 
618  s = strm->state;
619 
620 #ifdef FASTEST
621  if (level != 0) level = 1;
622 #else
623  if (level == Z_DEFAULT_COMPRESSION) level = 6;
624 #endif
625  if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
626  return Z_STREAM_ERROR;
627  }
628  func = configuration_table[s->level].func;
629 
630  if ((strategy != s->strategy || func != configuration_table[level].func) &&
631  s->last_flush != -2) {
632  /* Flush the last buffer: */
633  int err = deflate(strm, Z_BLOCK);
634  if (err == Z_STREAM_ERROR)
635  return err;
636  if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead)
637  return Z_BUF_ERROR;
638  }
639  if (s->level != level) {
640  if (s->level == 0 && s->matches != 0) {
641  if (s->matches == 1)
642  slide_hash(s);
643  else
644  CLEAR_HASH(s);
645  s->matches = 0;
646  }
647  s->level = level;
648  s->max_lazy_match = configuration_table[level].max_lazy;
649  s->good_match = configuration_table[level].good_length;
650  s->nice_match = configuration_table[level].nice_length;
651  s->max_chain_length = configuration_table[level].max_chain;
652  }
653  s->strategy = strategy;
654  return Z_OK;
655 }
656 
657 /* ========================================================================= */
658 int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
659  z_streamp strm;
660  int good_length;
661  int max_lazy;
662  int nice_length;
663  int max_chain;
664 {
665  deflate_state *s;
666 
668  s = strm->state;
669  s->good_match = (uInt)good_length;
670  s->max_lazy_match = (uInt)max_lazy;
671  s->nice_match = nice_length;
672  s->max_chain_length = (uInt)max_chain;
673  return Z_OK;
674 }
675 
676 /* =========================================================================
677  * For the default windowBits of 15 and memLevel of 8, this function returns
678  * a close to exact, as well as small, upper bound on the compressed size.
679  * They are coded as constants here for a reason--if the #define's are
680  * changed, then this function needs to be changed as well. The return
681  * value for 15 and 8 only works for those exact settings.
682  *
683  * For any setting other than those defaults for windowBits and memLevel,
684  * the value returned is a conservative worst case for the maximum expansion
685  * resulting from using fixed blocks instead of stored blocks, which deflate
686  * can emit on compressed data for some combinations of the parameters.
687  *
688  * This function could be more sophisticated to provide closer upper bounds for
689  * every combination of windowBits and memLevel. But even the conservative
690  * upper bound of about 14% expansion does not seem onerous for output buffer
691  * allocation.
692  */
694  z_streamp strm;
695  uLong sourceLen;
696 {
697  deflate_state *s;
698  uLong complen, wraplen;
699 
700  /* conservative upper bound for compressed data */
701  complen = sourceLen +
702  ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
703 
704  /* if can't get parameters, return conservative bound plus zlib wrapper */
705  if (deflateStateCheck(strm))
706  return complen + 6;
707 
708  /* compute wrapper length */
709  s = strm->state;
710  switch (s->wrap) {
711  case 0: /* raw deflate */
712  wraplen = 0;
713  break;
714  case 1: /* zlib wrapper */
715  wraplen = 6 + (s->strstart ? 4 : 0);
716  break;
717 #ifdef GZIP
718  case 2: /* gzip wrapper */
719  wraplen = 18;
720  if (s->gzhead != Z_NULL) { /* user-supplied gzip header */
721  Bytef *str;
722  if (s->gzhead->extra != Z_NULL)
723  wraplen += 2 + s->gzhead->extra_len;
724  str = s->gzhead->name;
725  if (str != Z_NULL)
726  do {
727  wraplen++;
728  } while (*str++);
729  str = s->gzhead->comment;
730  if (str != Z_NULL)
731  do {
732  wraplen++;
733  } while (*str++);
734  if (s->gzhead->hcrc)
735  wraplen += 2;
736  }
737  break;
738 #endif
739  default: /* for compiler happiness */
740  wraplen = 6;
741  }
742 
743  /* if not default parameters, return conservative bound */
744  if (s->w_bits != 15 || s->hash_bits != 8 + 7)
745  return complen + wraplen;
746 
747  /* default settings: return tight bound for that case */
748  return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
749  (sourceLen >> 25) + 13 - 6 + wraplen;
750 }
751 
752 /* =========================================================================
753  * Put a short in the pending buffer. The 16-bit value is put in MSB order.
754  * IN assertion: the stream state is correct and there is enough room in
755  * pending_buf.
756  */
758  deflate_state *s;
759  uInt b;
760 {
761  put_byte(s, (Byte)(b >> 8));
762  put_byte(s, (Byte)(b & 0xff));
763 }
764 
765 /* =========================================================================
766  * Flush as much pending output as possible. All deflate() output, except for
767  * some deflate_stored() output, goes through this function so some
768  * applications may wish to modify it to avoid allocating a large
769  * strm->next_out buffer and copying into it. (See also read_buf()).
770  */
772  z_streamp strm;
773 {
774  unsigned len;
775  deflate_state *s = strm->state;
776 
777  _tr_flush_bits(s);
778  len = s->pending;
779  if (len > strm->avail_out) len = strm->avail_out;
780  if (len == 0) return;
781 
782  zmemcpy(strm->next_out, s->pending_out, len);
783  strm->next_out += len;
784  s->pending_out += len;
785  strm->total_out += len;
786  strm->avail_out -= len;
787  s->pending -= len;
788  if (s->pending == 0) {
789  s->pending_out = s->pending_buf;
790  }
791 }
792 
793 /* ===========================================================================
794  * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
795  */
796 #define HCRC_UPDATE(beg) \
797  do { \
798  if (s->gzhead->hcrc && s->pending > (beg)) \
799  strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
800  s->pending - (beg)); \
801  } while (0)
802 
803 /* ========================================================================= */
805  z_streamp strm;
806  int flush;
807 {
808  int old_flush; /* value of flush param for previous deflate call */
809  deflate_state *s;
810 
811  if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
812  return Z_STREAM_ERROR;
813  }
814  s = strm->state;
815 
816  if (strm->next_out == Z_NULL ||
817  (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
818  (s->status == FINISH_STATE && flush != Z_FINISH)) {
820  }
821  if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
822 
823  old_flush = s->last_flush;
824  s->last_flush = flush;
825 
826  /* Flush as much pending output as possible */
827  if (s->pending != 0) {
829  if (strm->avail_out == 0) {
830  /* Since avail_out is 0, deflate will be called again with
831  * more output space, but possibly with both pending and
832  * avail_in equal to zero. There won't be anything to do,
833  * but this is not an error situation so make sure we
834  * return OK instead of BUF_ERROR at next call of deflate:
835  */
836  s->last_flush = -1;
837  return Z_OK;
838  }
839 
840  /* Make sure there is something to do and avoid duplicate consecutive
841  * flushes. For repeated and useless calls with Z_FINISH, we keep
842  * returning Z_STREAM_END instead of Z_BUF_ERROR.
843  */
844  } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
845  flush != Z_FINISH) {
847  }
848 
849  /* User must not provide more input after the first FINISH: */
850  if (s->status == FINISH_STATE && strm->avail_in != 0) {
852  }
853 
854  /* Write the header */
855  if (s->status == INIT_STATE && s->wrap == 0)
856  s->status = BUSY_STATE;
857  if (s->status == INIT_STATE) {
858  /* zlib header */
859  uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
860  uInt level_flags;
861 
862  if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
863  level_flags = 0;
864  else if (s->level < 6)
865  level_flags = 1;
866  else if (s->level == 6)
867  level_flags = 2;
868  else
869  level_flags = 3;
870  header |= (level_flags << 6);
871  if (s->strstart != 0) header |= PRESET_DICT;
872  header += 31 - (header % 31);
873 
874  putShortMSB(s, header);
875 
876  /* Save the adler32 of the preset dictionary: */
877  if (s->strstart != 0) {
878  putShortMSB(s, (uInt)(strm->adler >> 16));
879  putShortMSB(s, (uInt)(strm->adler & 0xffff));
880  }
881  strm->adler = adler32(0L, Z_NULL, 0);
882  s->status = BUSY_STATE;
883 
884  /* Compression must start with an empty pending buffer */
886  if (s->pending != 0) {
887  s->last_flush = -1;
888  return Z_OK;
889  }
890  }
891 #ifdef GZIP
892  if (s->status == GZIP_STATE) {
893  /* gzip header */
894  strm->adler = crc32(0L, Z_NULL, 0);
895  put_byte(s, 31);
896  put_byte(s, 139);
897  put_byte(s, 8);
898  if (s->gzhead == Z_NULL) {
899  put_byte(s, 0);
900  put_byte(s, 0);
901  put_byte(s, 0);
902  put_byte(s, 0);
903  put_byte(s, 0);
904  put_byte(s, s->level == 9 ? 2 :
905  (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
906  4 : 0));
907  put_byte(s, OS_CODE);
908  s->status = BUSY_STATE;
909 
910  /* Compression must start with an empty pending buffer */
912  if (s->pending != 0) {
913  s->last_flush = -1;
914  return Z_OK;
915  }
916  }
917  else {
918  put_byte(s, (s->gzhead->text ? 1 : 0) +
919  (s->gzhead->hcrc ? 2 : 0) +
920  (s->gzhead->extra == Z_NULL ? 0 : 4) +
921  (s->gzhead->name == Z_NULL ? 0 : 8) +
922  (s->gzhead->comment == Z_NULL ? 0 : 16)
923  );
924  put_byte(s, (Byte)(s->gzhead->time & 0xff));
925  put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
926  put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
927  put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
928  put_byte(s, s->level == 9 ? 2 :
929  (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
930  4 : 0));
931  put_byte(s, s->gzhead->os & 0xff);
932  if (s->gzhead->extra != Z_NULL) {
933  put_byte(s, s->gzhead->extra_len & 0xff);
934  put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
935  }
936  if (s->gzhead->hcrc)
937  strm->adler = crc32(strm->adler, s->pending_buf,
938  s->pending);
939  s->gzindex = 0;
940  s->status = EXTRA_STATE;
941  }
942  }
943  if (s->status == EXTRA_STATE) {
944  if (s->gzhead->extra != Z_NULL) {
945  ulg beg = s->pending; /* start of bytes to update crc */
946  uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
947  while (s->pending + left > s->pending_buf_size) {
948  uInt copy = s->pending_buf_size - s->pending;
949  zmemcpy(s->pending_buf + s->pending,
950  s->gzhead->extra + s->gzindex, copy);
951  s->pending = s->pending_buf_size;
952  HCRC_UPDATE(beg);
953  s->gzindex += copy;
955  if (s->pending != 0) {
956  s->last_flush = -1;
957  return Z_OK;
958  }
959  beg = 0;
960  left -= copy;
961  }
962  zmemcpy(s->pending_buf + s->pending,
963  s->gzhead->extra + s->gzindex, left);
964  s->pending += left;
965  HCRC_UPDATE(beg);
966  s->gzindex = 0;
967  }
968  s->status = NAME_STATE;
969  }
970  if (s->status == NAME_STATE) {
971  if (s->gzhead->name != Z_NULL) {
972  ulg beg = s->pending; /* start of bytes to update crc */
973  int val;
974  do {
975  if (s->pending == s->pending_buf_size) {
976  HCRC_UPDATE(beg);
978  if (s->pending != 0) {
979  s->last_flush = -1;
980  return Z_OK;
981  }
982  beg = 0;
983  }
984  val = s->gzhead->name[s->gzindex++];
985  put_byte(s, val);
986  } while (val != 0);
987  HCRC_UPDATE(beg);
988  s->gzindex = 0;
989  }
990  s->status = COMMENT_STATE;
991  }
992  if (s->status == COMMENT_STATE) {
993  if (s->gzhead->comment != Z_NULL) {
994  ulg beg = s->pending; /* start of bytes to update crc */
995  int val;
996  do {
997  if (s->pending == s->pending_buf_size) {
998  HCRC_UPDATE(beg);
1000  if (s->pending != 0) {
1001  s->last_flush = -1;
1002  return Z_OK;
1003  }
1004  beg = 0;
1005  }
1006  val = s->gzhead->comment[s->gzindex++];
1007  put_byte(s, val);
1008  } while (val != 0);
1009  HCRC_UPDATE(beg);
1010  }
1011  s->status = HCRC_STATE;
1012  }
1013  if (s->status == HCRC_STATE) {
1014  if (s->gzhead->hcrc) {
1015  if (s->pending + 2 > s->pending_buf_size) {
1017  if (s->pending != 0) {
1018  s->last_flush = -1;
1019  return Z_OK;
1020  }
1021  }
1022  put_byte(s, (Byte)(strm->adler & 0xff));
1023  put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
1024  strm->adler = crc32(0L, Z_NULL, 0);
1025  }
1026  s->status = BUSY_STATE;
1027 
1028  /* Compression must start with an empty pending buffer */
1030  if (s->pending != 0) {
1031  s->last_flush = -1;
1032  return Z_OK;
1033  }
1034  }
1035 #endif
1036 
1037  /* Start a new block or continue the current one.
1038  */
1039  if (strm->avail_in != 0 || s->lookahead != 0 ||
1040  (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1041  block_state bstate;
1042 
1043  bstate = s->level == 0 ? deflate_stored(s, flush) :
1044  s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
1045  s->strategy == Z_RLE ? deflate_rle(s, flush) :
1046  (*(configuration_table[s->level].func))(s, flush);
1047 
1048  if (bstate == finish_started || bstate == finish_done) {
1049  s->status = FINISH_STATE;
1050  }
1051  if (bstate == need_more || bstate == finish_started) {
1052  if (strm->avail_out == 0) {
1053  s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1054  }
1055  return Z_OK;
1056  /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1057  * of deflate should use the same flush parameter to make sure
1058  * that the flush is complete. So we don't have to output an
1059  * empty block here, this will be done at next call. This also
1060  * ensures that for a very small output buffer, we emit at most
1061  * one empty block.
1062  */
1063  }
1064  if (bstate == block_done) {
1065  if (flush == Z_PARTIAL_FLUSH) {
1066  _tr_align(s);
1067  } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
1068  _tr_stored_block(s, (char*)0, 0L, 0);
1069  /* For a full flush, this empty block will be recognized
1070  * as a special marker by inflate_sync().
1071  */
1072  if (flush == Z_FULL_FLUSH) {
1073  CLEAR_HASH(s); /* forget history */
1074  if (s->lookahead == 0) {
1075  s->strstart = 0;
1076  s->block_start = 0L;
1077  s->insert = 0;
1078  }
1079  }
1080  }
1082  if (strm->avail_out == 0) {
1083  s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1084  return Z_OK;
1085  }
1086  }
1087  }
1088 
1089  if (flush != Z_FINISH) return Z_OK;
1090  if (s->wrap <= 0) return Z_STREAM_END;
1091 
1092  /* Write the trailer */
1093 #ifdef GZIP
1094  if (s->wrap == 2) {
1095  put_byte(s, (Byte)(strm->adler & 0xff));
1096  put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
1097  put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
1098  put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
1099  put_byte(s, (Byte)(strm->total_in & 0xff));
1100  put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
1101  put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
1102  put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
1103  }
1104  else
1105 #endif
1106  {
1107  putShortMSB(s, (uInt)(strm->adler >> 16));
1108  putShortMSB(s, (uInt)(strm->adler & 0xffff));
1109  }
1111  /* If avail_out is zero, the application will call deflate again
1112  * to flush the rest.
1113  */
1114  if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
1115  return s->pending != 0 ? Z_OK : Z_STREAM_END;
1116 }
1117 
1118 /* ========================================================================= */
1120  z_streamp strm;
1121 {
1122  int status;
1123 
1124  if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
1125 
1126  status = strm->state->status;
1127 
1128  /* Deallocate in reverse order of allocations: */
1129  TRY_FREE(strm, strm->state->pending_buf);
1130  TRY_FREE(strm, strm->state->head);
1131  TRY_FREE(strm, strm->state->prev);
1132  TRY_FREE(strm, strm->state->window);
1133 
1134  ZFREE(strm, strm->state);
1135  strm->state = Z_NULL;
1136 
1137  return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1138 }
1139 
1140 /* =========================================================================
1141  * Copy the source state to the destination state.
1142  * To simplify the source, this is not supported for 16-bit MSDOS (which
1143  * doesn't have enough memory anyway to duplicate compression states).
1144  */
1146  z_streamp dest;
1147  z_streamp source;
1148 {
1149 #ifdef MAXSEG_64K
1150  return Z_STREAM_ERROR;
1151 #else
1152  deflate_state *ds;
1153  deflate_state *ss;
1154 
1155 
1156  if (deflateStateCheck(source) || dest == Z_NULL) {
1157  return Z_STREAM_ERROR;
1158  }
1159 
1160  ss = source->state;
1161 
1162  zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1163 
1164  ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1165  if (ds == Z_NULL) return Z_MEM_ERROR;
1166  dest->state = (struct internal_state FAR *) ds;
1167  zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
1168  ds->strm = dest;
1169 
1170  ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1171  ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1172  ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1173  ds->pending_buf = (uchf *) ZALLOC(dest, ds->lit_bufsize, 4);
1174 
1175  if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1176  ds->pending_buf == Z_NULL) {
1177  deflateEnd (dest);
1178  return Z_MEM_ERROR;
1179  }
1180  /* following zmemcpy do not work for 16-bit MSDOS */
1181  zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1182  zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
1183  zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
1184  zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1185 
1186  ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1187  ds->sym_buf = ds->pending_buf + ds->lit_bufsize;
1188 
1189  ds->l_desc.dyn_tree = ds->dyn_ltree;
1190  ds->d_desc.dyn_tree = ds->dyn_dtree;
1191  ds->bl_desc.dyn_tree = ds->bl_tree;
1192 
1193  return Z_OK;
1194 #endif /* MAXSEG_64K */
1195 }
1196 
1197 /* ===========================================================================
1198  * Read a new buffer from the current input stream, update the adler32
1199  * and total number of bytes read. All deflate() input goes through
1200  * this function so some applications may wish to modify it to avoid
1201  * allocating a large strm->next_in buffer and copying from it.
1202  * (See also flush_pending()).
1203  */
1205  z_streamp strm;
1206  Bytef *buf;
1207  unsigned size;
1208 {
1209  unsigned len = strm->avail_in;
1210 
1211  if (len > size) len = size;
1212  if (len == 0) return 0;
1213 
1214  strm->avail_in -= len;
1215 
1216  zmemcpy(buf, strm->next_in, len);
1217  if (strm->state->wrap == 1) {
1218  strm->adler = adler32(strm->adler, buf, len);
1219  }
1220 #ifdef GZIP
1221  else if (strm->state->wrap == 2) {
1222  strm->adler = crc32(strm->adler, buf, len);
1223  }
1224 #endif
1225  strm->next_in += len;
1226  strm->total_in += len;
1227 
1228  return len;
1229 }
1230 
1231 /* ===========================================================================
1232  * Initialize the "longest match" routines for a new zlib stream
1233  */
1235  deflate_state *s;
1236 {
1237  s->window_size = (ulg)2L*s->w_size;
1238 
1239  CLEAR_HASH(s);
1240 
1241  /* Set the default configuration parameters:
1242  */
1243  s->max_lazy_match = configuration_table[s->level].max_lazy;
1244  s->good_match = configuration_table[s->level].good_length;
1245  s->nice_match = configuration_table[s->level].nice_length;
1246  s->max_chain_length = configuration_table[s->level].max_chain;
1247 
1248  s->strstart = 0;
1249  s->block_start = 0L;
1250  s->lookahead = 0;
1251  s->insert = 0;
1252  s->match_length = s->prev_length = MIN_MATCH-1;
1253  s->match_available = 0;
1254  s->ins_h = 0;
1255 #ifndef FASTEST
1256 #ifdef ASMV
1257  match_init(); /* initialize the asm code */
1258 #endif
1259 #endif
1260 }
1261 
1262 #ifndef FASTEST
1263 /* ===========================================================================
1264  * Set match_start to the longest match starting at the given string and
1265  * return its length. Matches shorter or equal to prev_length are discarded,
1266  * in which case the result is equal to prev_length and match_start is
1267  * garbage.
1268  * IN assertions: cur_match is the head of the hash chain for the current
1269  * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1270  * OUT assertion: the match length is not greater than s->lookahead.
1271  */
1272 #ifndef ASMV
1273 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1274  * match.S. The code will be functionally equivalent.
1275  */
1277  deflate_state *s;
1278  IPos cur_match; /* current match */
1279 {
1280  unsigned chain_length = s->max_chain_length;/* max hash chain length */
1281  register Bytef *scan = s->window + s->strstart; /* current string */
1282  register Bytef *match; /* matched string */
1283  register int len; /* length of current match */
1284  int best_len = (int)s->prev_length; /* best match length so far */
1285  int nice_match = s->nice_match; /* stop if match long enough */
1286  IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1287  s->strstart - (IPos)MAX_DIST(s) : NIL;
1288  /* Stop when cur_match becomes <= limit. To simplify the code,
1289  * we prevent matches with the string of window index 0.
1290  */
1291  Posf *prev = s->prev;
1292  uInt wmask = s->w_mask;
1293 
1294 #ifdef UNALIGNED_OK
1295  /* Compare two bytes at a time. Note: this is not always beneficial.
1296  * Try with and without -DUNALIGNED_OK to check.
1297  */
1298  register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1299  register ush scan_start = *(ushf*)scan;
1300  register ush scan_end = *(ushf*)(scan+best_len-1);
1301 #else
1302  register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1303  register Byte scan_end1 = scan[best_len-1];
1304  register Byte scan_end = scan[best_len];
1305 #endif
1306 
1307  /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1308  * It is easy to get rid of this optimization if necessary.
1309  */
1310  Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1311 
1312  /* Do not waste too much time if we already have a good match: */
1313  if (s->prev_length >= s->good_match) {
1314  chain_length >>= 2;
1315  }
1316  /* Do not look for matches beyond the end of the input. This is necessary
1317  * to make deflate deterministic.
1318  */
1319  if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
1320 
1321  Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1322 
1323  do {
1324  Assert(cur_match < s->strstart, "no future");
1325  match = s->window + cur_match;
1326 
1327  /* Skip to next match if the match length cannot increase
1328  * or if the match length is less than 2. Note that the checks below
1329  * for insufficient lookahead only occur occasionally for performance
1330  * reasons. Therefore uninitialized memory will be accessed, and
1331  * conditional jumps will be made that depend on those values.
1332  * However the length of the match is limited to the lookahead, so
1333  * the output of deflate is not affected by the uninitialized values.
1334  */
1335 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1336  /* This code assumes sizeof(unsigned short) == 2. Do not use
1337  * UNALIGNED_OK if your compiler uses a different size.
1338  */
1339  if (*(ushf*)(match+best_len-1) != scan_end ||
1340  *(ushf*)match != scan_start) continue;
1341 
1342  /* It is not necessary to compare scan[2] and match[2] since they are
1343  * always equal when the other bytes match, given that the hash keys
1344  * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1345  * strstart+3, +5, ... up to strstart+257. We check for insufficient
1346  * lookahead only every 4th comparison; the 128th check will be made
1347  * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1348  * necessary to put more guard bytes at the end of the window, or
1349  * to check more often for insufficient lookahead.
1350  */
1351  Assert(scan[2] == match[2], "scan[2]?");
1352  scan++, match++;
1353  do {
1354  } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1355  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1356  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1357  *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1358  scan < strend);
1359  /* The funny "do {}" generates better code on most compilers */
1360 
1361  /* Here, scan <= window+strstart+257 */
1362  Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1363  if (*scan == *match) scan++;
1364 
1365  len = (MAX_MATCH - 1) - (int)(strend-scan);
1366  scan = strend - (MAX_MATCH-1);
1367 
1368 #else /* UNALIGNED_OK */
1369 
1370  if (match[best_len] != scan_end ||
1371  match[best_len-1] != scan_end1 ||
1372  *match != *scan ||
1373  *++match != scan[1]) continue;
1374 
1375  /* The check at best_len-1 can be removed because it will be made
1376  * again later. (This heuristic is not always a win.)
1377  * It is not necessary to compare scan[2] and match[2] since they
1378  * are always equal when the other bytes match, given that
1379  * the hash keys are equal and that HASH_BITS >= 8.
1380  */
1381  scan += 2, match++;
1382  Assert(*scan == *match, "match[2]?");
1383 
1384  /* We check for insufficient lookahead only every 8th comparison;
1385  * the 256th check will be made at strstart+258.
1386  */
1387  do {
1388  } while (*++scan == *++match && *++scan == *++match &&
1389  *++scan == *++match && *++scan == *++match &&
1390  *++scan == *++match && *++scan == *++match &&
1391  *++scan == *++match && *++scan == *++match &&
1392  scan < strend);
1393 
1394  Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1395 
1396  len = MAX_MATCH - (int)(strend - scan);
1397  scan = strend - MAX_MATCH;
1398 
1399 #endif /* UNALIGNED_OK */
1400 
1401  if (len > best_len) {
1402  s->match_start = cur_match;
1403  best_len = len;
1404  if (len >= nice_match) break;
1405 #ifdef UNALIGNED_OK
1406  scan_end = *(ushf*)(scan+best_len-1);
1407 #else
1408  scan_end1 = scan[best_len-1];
1409  scan_end = scan[best_len];
1410 #endif
1411  }
1412  } while ((cur_match = prev[cur_match & wmask]) > limit
1413  && --chain_length != 0);
1414 
1415  if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1416  return s->lookahead;
1417 }
1418 #endif /* ASMV */
1419 
1420 #else /* FASTEST */
1421 
1422 /* ---------------------------------------------------------------------------
1423  * Optimized version for FASTEST only
1424  */
1425 local uInt longest_match(s, cur_match)
1426  deflate_state *s;
1427  IPos cur_match; /* current match */
1428 {
1429  register Bytef *scan = s->window + s->strstart; /* current string */
1430  register Bytef *match; /* matched string */
1431  register int len; /* length of current match */
1432  register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1433 
1434  /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1435  * It is easy to get rid of this optimization if necessary.
1436  */
1437  Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1438 
1439  Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1440 
1441  Assert(cur_match < s->strstart, "no future");
1442 
1443  match = s->window + cur_match;
1444 
1445  /* Return failure if the match length is less than 2:
1446  */
1447  if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1448 
1449  /* The check at best_len-1 can be removed because it will be made
1450  * again later. (This heuristic is not always a win.)
1451  * It is not necessary to compare scan[2] and match[2] since they
1452  * are always equal when the other bytes match, given that
1453  * the hash keys are equal and that HASH_BITS >= 8.
1454  */
1455  scan += 2, match += 2;
1456  Assert(*scan == *match, "match[2]?");
1457 
1458  /* We check for insufficient lookahead only every 8th comparison;
1459  * the 256th check will be made at strstart+258.
1460  */
1461  do {
1462  } while (*++scan == *++match && *++scan == *++match &&
1463  *++scan == *++match && *++scan == *++match &&
1464  *++scan == *++match && *++scan == *++match &&
1465  *++scan == *++match && *++scan == *++match &&
1466  scan < strend);
1467 
1468  Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1469 
1470  len = MAX_MATCH - (int)(strend - scan);
1471 
1472  if (len < MIN_MATCH) return MIN_MATCH - 1;
1473 
1474  s->match_start = cur_match;
1475  return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
1476 }
1477 
1478 #endif /* FASTEST */
1479 
1480 #ifdef ZLIB_DEBUG
1481 
1482 #define EQUAL 0
1483 /* result of memcmp for equal strings */
1484 
1485 /* ===========================================================================
1486  * Check that the match at match_start is indeed a match.
1487  */
1489  deflate_state *s;
1490  IPos start, match;
1491  int length;
1492 {
1493  /* check that the match is indeed a match */
1494  if (zmemcmp(s->window + match,
1495  s->window + start, length) != EQUAL) {
1496  fprintf(stderr, " start %u, match %u, length %d\n",
1497  start, match, length);
1498  do {
1499  fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1500  } while (--length != 0);
1501  z_error("invalid match");
1502  }
1503  if (z_verbose > 1) {
1504  fprintf(stderr,"\\[%d,%d]", start-match, length);
1505  do { putc(s->window[start++], stderr); } while (--length != 0);
1506  }
1507 }
1508 #else
1509 # define check_match(s, start, match, length)
1510 #endif /* ZLIB_DEBUG */
1511 
1512 /* ===========================================================================
1513  * Fill the window when the lookahead becomes insufficient.
1514  * Updates strstart and lookahead.
1515  *
1516  * IN assertion: lookahead < MIN_LOOKAHEAD
1517  * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1518  * At least one byte has been read, or avail_in == 0; reads are
1519  * performed for at least two bytes (required for the zip translate_eol
1520  * option -- not supported here).
1521  */
1523  deflate_state *s;
1524 {
1525  unsigned n;
1526  unsigned more; /* Amount of free space at the end of the window. */
1527  uInt wsize = s->w_size;
1528 
1529  Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
1530 
1531  do {
1532  more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1533 
1534  /* Deal with !@#$% 64K limit: */
1535  if (sizeof(int) <= 2) {
1536  if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1537  more = wsize;
1538 
1539  } else if (more == (unsigned)(-1)) {
1540  /* Very unlikely, but possible on 16 bit machine if
1541  * strstart == 0 && lookahead == 1 (input done a byte at time)
1542  */
1543  more--;
1544  }
1545  }
1546 
1547  /* If the window is almost full and there is insufficient lookahead,
1548  * move the upper half to the lower one to make room in the upper half.
1549  */
1550  if (s->strstart >= wsize+MAX_DIST(s)) {
1551 
1552  zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
1553  s->match_start -= wsize;
1554  s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1555  s->block_start -= (long) wsize;
1556  if (s->insert > s->strstart)
1557  s->insert = s->strstart;
1558  slide_hash(s);
1559  more += wsize;
1560  }
1561  if (s->strm->avail_in == 0) break;
1562 
1563  /* If there was no sliding:
1564  * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1565  * more == window_size - lookahead - strstart
1566  * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1567  * => more >= window_size - 2*WSIZE + 2
1568  * In the BIG_MEM or MMAP case (not yet supported),
1569  * window_size == input_size + MIN_LOOKAHEAD &&
1570  * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1571  * Otherwise, window_size == 2*WSIZE so more >= 2.
1572  * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1573  */
1574  Assert(more >= 2, "more < 2");
1575 
1576  n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1577  s->lookahead += n;
1578 
1579  /* Initialize the hash value now that we have some input: */
1580  if (s->lookahead + s->insert >= MIN_MATCH) {
1581  uInt str = s->strstart - s->insert;
1582  s->ins_h = s->window[str];
1583  UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
1584 #if MIN_MATCH != 3
1585  Call UPDATE_HASH() MIN_MATCH-3 more times
1586 #endif
1587  while (s->insert) {
1588  UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
1589 #ifndef FASTEST
1590  s->prev[str & s->w_mask] = s->head[s->ins_h];
1591 #endif
1592  s->head[s->ins_h] = (Pos)str;
1593  str++;
1594  s->insert--;
1595  if (s->lookahead + s->insert < MIN_MATCH)
1596  break;
1597  }
1598  }
1599  /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1600  * but this is not important since only literal bytes will be emitted.
1601  */
1602 
1603  } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1604 
1605  /* If the WIN_INIT bytes after the end of the current data have never been
1606  * written, then zero those bytes in order to avoid memory check reports of
1607  * the use of uninitialized (or uninitialised as Julian writes) bytes by
1608  * the longest match routines. Update the high water mark for the next
1609  * time through here. WIN_INIT is set to MAX_MATCH since the longest match
1610  * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
1611  */
1612  if (s->high_water < s->window_size) {
1613  ulg curr = s->strstart + (ulg)(s->lookahead);
1614  ulg init;
1615 
1616  if (s->high_water < curr) {
1617  /* Previous high water mark below current data -- zero WIN_INIT
1618  * bytes or up to end of window, whichever is less.
1619  */
1620  init = s->window_size - curr;
1621  if (init > WIN_INIT)
1622  init = WIN_INIT;
1623  zmemzero(s->window + curr, (unsigned)init);
1624  s->high_water = curr + init;
1625  }
1626  else if (s->high_water < (ulg)curr + WIN_INIT) {
1627  /* High water mark at or above current data, but below current data
1628  * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
1629  * to end of window, whichever is less.
1630  */
1631  init = (ulg)curr + WIN_INIT - s->high_water;
1632  if (init > s->window_size - s->high_water)
1633  init = s->window_size - s->high_water;
1634  zmemzero(s->window + s->high_water, (unsigned)init);
1635  s->high_water += init;
1636  }
1637  }
1638 
1639  Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
1640  "not enough room for search");
1641 }
1642 
1643 /* ===========================================================================
1644  * Flush the current block, with given end-of-file flag.
1645  * IN assertion: strstart is set to the end of the current match.
1646  */
1647 #define FLUSH_BLOCK_ONLY(s, last) { \
1648  _tr_flush_block(s, (s->block_start >= 0L ? \
1649  (charf *)&s->window[(unsigned)s->block_start] : \
1650  (charf *)Z_NULL), \
1651  (ulg)((long)s->strstart - s->block_start), \
1652  (last)); \
1653  s->block_start = s->strstart; \
1654  flush_pending(s->strm); \
1655  Tracev((stderr,"[FLUSH]")); \
1656 }
1657 
1658 /* Same but force premature exit if necessary. */
1659 #define FLUSH_BLOCK(s, last) { \
1660  FLUSH_BLOCK_ONLY(s, last); \
1661  if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
1662 }
1663 
1664 /* Maximum stored block length in deflate format (not including header). */
1665 #define MAX_STORED 65535
1666 
1667 /* Minimum of a and b. */
1668 #define MIN(a, b) ((a) > (b) ? (b) : (a))
1669 
1670 /* ===========================================================================
1671  * Copy without compression as much as possible from the input stream, return
1672  * the current block state.
1673  *
1674  * In case deflateParams() is used to later switch to a non-zero compression
1675  * level, s->matches (otherwise unused when storing) keeps track of the number
1676  * of hash table slides to perform. If s->matches is 1, then one hash table
1677  * slide will be done when switching. If s->matches is 2, the maximum value
1678  * allowed here, then the hash table will be cleared, since two or more slides
1679  * is the same as a clear.
1680  *
1681  * deflate_stored() is written to minimize the number of times an input byte is
1682  * copied. It is most efficient with large input and output buffers, which
1683  * maximizes the opportunites to have a single copy from next_in to next_out.
1684  */
1686  deflate_state *s;
1687  int flush;
1688 {
1689  /* Smallest worthy block size when not flushing or finishing. By default
1690  * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
1691  * large input and output buffers, the stored block size will be larger.
1692  */
1693  unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
1694 
1695  /* Copy as many min_block or larger stored blocks directly to next_out as
1696  * possible. If flushing, copy the remaining available input to next_out as
1697  * stored blocks, if there is enough space.
1698  */
1699  unsigned len, left, have, last = 0;
1700  unsigned used = s->strm->avail_in;
1701  do {
1702  /* Set len to the maximum size block that we can copy directly with the
1703  * available input data and output space. Set left to how much of that
1704  * would be copied from what's left in the window.
1705  */
1706  len = MAX_STORED; /* maximum deflate stored block length */
1707  have = (s->bi_valid + 42) >> 3; /* number of header bytes */
1708  if (s->strm->avail_out < have) /* need room for header */
1709  break;
1710  /* maximum stored block length that will fit in avail_out: */
1711  have = s->strm->avail_out - have;
1712  left = s->strstart - s->block_start; /* bytes left in window */
1713  if (len > (ulg)left + s->strm->avail_in)
1714  len = left + s->strm->avail_in; /* limit len to the input */
1715  if (len > have)
1716  len = have; /* limit len to the output */
1717 
1718  /* If the stored block would be less than min_block in length, or if
1719  * unable to copy all of the available input when flushing, then try
1720  * copying to the window and the pending buffer instead. Also don't
1721  * write an empty block when flushing -- deflate() does that.
1722  */
1723  if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
1724  flush == Z_NO_FLUSH ||
1725  len != left + s->strm->avail_in))
1726  break;
1727 
1728  /* Make a dummy stored block in pending to get the header bytes,
1729  * including any pending bits. This also updates the debugging counts.
1730  */
1731  last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
1732  _tr_stored_block(s, (char *)0, 0L, last);
1733 
1734  /* Replace the lengths in the dummy stored block with len. */
1735  s->pending_buf[s->pending - 4] = len;
1736  s->pending_buf[s->pending - 3] = len >> 8;
1737  s->pending_buf[s->pending - 2] = ~len;
1738  s->pending_buf[s->pending - 1] = ~len >> 8;
1739 
1740  /* Write the stored block header bytes. */
1741  flush_pending(s->strm);
1742 
1743 #ifdef ZLIB_DEBUG
1744  /* Update debugging counts for the data about to be copied. */
1745  s->compressed_len += len << 3;
1746  s->bits_sent += len << 3;
1747 #endif
1748 
1749  /* Copy uncompressed bytes from the window to next_out. */
1750  if (left) {
1751  if (left > len)
1752  left = len;
1753  zmemcpy(s->strm->next_out, s->window + s->block_start, left);
1754  s->strm->next_out += left;
1755  s->strm->avail_out -= left;
1756  s->strm->total_out += left;
1757  s->block_start += left;
1758  len -= left;
1759  }
1760 
1761  /* Copy uncompressed bytes directly from next_in to next_out, updating
1762  * the check value.
1763  */
1764  if (len) {
1765  read_buf(s->strm, s->strm->next_out, len);
1766  s->strm->next_out += len;
1767  s->strm->avail_out -= len;
1768  s->strm->total_out += len;
1769  }
1770  } while (last == 0);
1771 
1772  /* Update the sliding window with the last s->w_size bytes of the copied
1773  * data, or append all of the copied data to the existing window if less
1774  * than s->w_size bytes were copied. Also update the number of bytes to
1775  * insert in the hash tables, in the event that deflateParams() switches to
1776  * a non-zero compression level.
1777  */
1778  used -= s->strm->avail_in; /* number of input bytes directly copied */
1779  if (used) {
1780  /* If any input was used, then no unused input remains in the window,
1781  * therefore s->block_start == s->strstart.
1782  */
1783  if (used >= s->w_size) { /* supplant the previous history */
1784  s->matches = 2; /* clear hash */
1785  zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
1786  s->strstart = s->w_size;
1787  s->insert = s->strstart;
1788  }
1789  else {
1790  if (s->window_size - s->strstart <= used) {
1791  /* Slide the window down. */
1792  s->strstart -= s->w_size;
1793  zmemcpy(s->window, s->window + s->w_size, s->strstart);
1794  if (s->matches < 2)
1795  s->matches++; /* add a pending slide_hash() */
1796  if (s->insert > s->strstart)
1797  s->insert = s->strstart;
1798  }
1799  zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
1800  s->strstart += used;
1801  s->insert += MIN(used, s->w_size - s->insert);
1802  }
1803  s->block_start = s->strstart;
1804  }
1805  if (s->high_water < s->strstart)
1806  s->high_water = s->strstart;
1807 
1808  /* If the last block was written to next_out, then done. */
1809  if (last)
1810  return finish_done;
1811 
1812  /* If flushing and all input has been consumed, then done. */
1813  if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
1814  s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
1815  return block_done;
1816 
1817  /* Fill the window with any remaining input. */
1818  have = s->window_size - s->strstart;
1819  if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
1820  /* Slide the window down. */
1821  s->block_start -= s->w_size;
1822  s->strstart -= s->w_size;
1823  zmemcpy(s->window, s->window + s->w_size, s->strstart);
1824  if (s->matches < 2)
1825  s->matches++; /* add a pending slide_hash() */
1826  have += s->w_size; /* more space now */
1827  if (s->insert > s->strstart)
1828  s->insert = s->strstart;
1829  }
1830  if (have > s->strm->avail_in)
1831  have = s->strm->avail_in;
1832  if (have) {
1833  read_buf(s->strm, s->window + s->strstart, have);
1834  s->strstart += have;
1835  s->insert += MIN(have, s->w_size - s->insert);
1836  }
1837  if (s->high_water < s->strstart)
1838  s->high_water = s->strstart;
1839 
1840  /* There was not enough avail_out to write a complete worthy or flushed
1841  * stored block to next_out. Write a stored block to pending instead, if we
1842  * have enough input for a worthy block, or if flushing and there is enough
1843  * room for the remaining input as a stored block in the pending buffer.
1844  */
1845  have = (s->bi_valid + 42) >> 3; /* number of header bytes */
1846  /* maximum stored block length that will fit in pending: */
1847  have = MIN(s->pending_buf_size - have, MAX_STORED);
1848  min_block = MIN(have, s->w_size);
1849  left = s->strstart - s->block_start;
1850  if (left >= min_block ||
1851  ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
1852  s->strm->avail_in == 0 && left <= have)) {
1853  len = MIN(left, have);
1854  last = flush == Z_FINISH && s->strm->avail_in == 0 &&
1855  len == left ? 1 : 0;
1856  _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
1857  s->block_start += len;
1858  flush_pending(s->strm);
1859  }
1860 
1861  /* We've done all we can with the available input and output. */
1862  return last ? finish_started : need_more;
1863 }
1864 
1865 /* ===========================================================================
1866  * Compress as much as possible from the input stream, return the current
1867  * block state.
1868  * This function does not perform lazy evaluation of matches and inserts
1869  * new strings in the dictionary only for unmatched strings or for short
1870  * matches. It is used only for the fast compression options.
1871  */
1873  deflate_state *s;
1874  int flush;
1875 {
1876  IPos hash_head; /* head of the hash chain */
1877  int bflush; /* set if current block must be flushed */
1878 
1879  for (;;) {
1880  /* Make sure that we always have enough lookahead, except
1881  * at the end of the input file. We need MAX_MATCH bytes
1882  * for the next match, plus MIN_MATCH bytes to insert the
1883  * string following the next match.
1884  */
1885  if (s->lookahead < MIN_LOOKAHEAD) {
1886  fill_window(s);
1887  if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1888  return need_more;
1889  }
1890  if (s->lookahead == 0) break; /* flush the current block */
1891  }
1892 
1893  /* Insert the string window[strstart .. strstart+2] in the
1894  * dictionary, and set hash_head to the head of the hash chain:
1895  */
1896  hash_head = NIL;
1897  if (s->lookahead >= MIN_MATCH) {
1898  INSERT_STRING(s, s->strstart, hash_head);
1899  }
1900 
1901  /* Find the longest match, discarding those <= prev_length.
1902  * At this point we have always match_length < MIN_MATCH
1903  */
1904  if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1905  /* To simplify the code, we prevent matches with the string
1906  * of window index 0 (in particular we have to avoid a match
1907  * of the string with itself at the start of the input file).
1908  */
1909  s->match_length = longest_match (s, hash_head);
1910  /* longest_match() sets match_start */
1911  }
1912  if (s->match_length >= MIN_MATCH) {
1913  check_match(s, s->strstart, s->match_start, s->match_length);
1914 
1915  _tr_tally_dist(s, s->strstart - s->match_start,
1916  s->match_length - MIN_MATCH, bflush);
1917 
1918  s->lookahead -= s->match_length;
1919 
1920  /* Insert new strings in the hash table only if the match length
1921  * is not too large. This saves time but degrades compression.
1922  */
1923 #ifndef FASTEST
1924  if (s->match_length <= s->max_insert_length &&
1925  s->lookahead >= MIN_MATCH) {
1926  s->match_length--; /* string at strstart already in table */
1927  do {
1928  s->strstart++;
1929  INSERT_STRING(s, s->strstart, hash_head);
1930  /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1931  * always MIN_MATCH bytes ahead.
1932  */
1933  } while (--s->match_length != 0);
1934  s->strstart++;
1935  } else
1936 #endif
1937  {
1938  s->strstart += s->match_length;
1939  s->match_length = 0;
1940  s->ins_h = s->window[s->strstart];
1941  UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1942 #if MIN_MATCH != 3
1943  Call UPDATE_HASH() MIN_MATCH-3 more times
1944 #endif
1945  /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1946  * matter since it will be recomputed at next deflate call.
1947  */
1948  }
1949  } else {
1950  /* No match, output a literal byte */
1951  Tracevv((stderr,"%c", s->window[s->strstart]));
1952  _tr_tally_lit (s, s->window[s->strstart], bflush);
1953  s->lookahead--;
1954  s->strstart++;
1955  }
1956  if (bflush) FLUSH_BLOCK(s, 0);
1957  }
1958  s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
1959  if (flush == Z_FINISH) {
1960  FLUSH_BLOCK(s, 1);
1961  return finish_done;
1962  }
1963  if (s->sym_next)
1964  FLUSH_BLOCK(s, 0);
1965  return block_done;
1966 }
1967 
1968 #ifndef FASTEST
1969 /* ===========================================================================
1970  * Same as above, but achieves better compression. We use a lazy
1971  * evaluation for matches: a match is finally adopted only if there is
1972  * no better match at the next window position.
1973  */
1975  deflate_state *s;
1976  int flush;
1977 {
1978  IPos hash_head; /* head of hash chain */
1979  int bflush; /* set if current block must be flushed */
1980 
1981  /* Process the input block. */
1982  for (;;) {
1983  /* Make sure that we always have enough lookahead, except
1984  * at the end of the input file. We need MAX_MATCH bytes
1985  * for the next match, plus MIN_MATCH bytes to insert the
1986  * string following the next match.
1987  */
1988  if (s->lookahead < MIN_LOOKAHEAD) {
1989  fill_window(s);
1990  if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1991  return need_more;
1992  }
1993  if (s->lookahead == 0) break; /* flush the current block */
1994  }
1995 
1996  /* Insert the string window[strstart .. strstart+2] in the
1997  * dictionary, and set hash_head to the head of the hash chain:
1998  */
1999  hash_head = NIL;
2000  if (s->lookahead >= MIN_MATCH) {
2001  INSERT_STRING(s, s->strstart, hash_head);
2002  }
2003 
2004  /* Find the longest match, discarding those <= prev_length.
2005  */
2006  s->prev_length = s->match_length, s->prev_match = s->match_start;
2007  s->match_length = MIN_MATCH-1;
2008 
2009  if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
2010  s->strstart - hash_head <= MAX_DIST(s)) {
2011  /* To simplify the code, we prevent matches with the string
2012  * of window index 0 (in particular we have to avoid a match
2013  * of the string with itself at the start of the input file).
2014  */
2015  s->match_length = longest_match (s, hash_head);
2016  /* longest_match() sets match_start */
2017 
2018  if (s->match_length <= 5 && (s->strategy == Z_FILTERED
2019 #if TOO_FAR <= 32767
2020  || (s->match_length == MIN_MATCH &&
2021  s->strstart - s->match_start > TOO_FAR)
2022 #endif
2023  )) {
2024 
2025  /* If prev_match is also MIN_MATCH, match_start is garbage
2026  * but we will ignore the current match anyway.
2027  */
2028  s->match_length = MIN_MATCH-1;
2029  }
2030  }
2031  /* If there was a match at the previous step and the current
2032  * match is not better, output the previous match:
2033  */
2034  if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
2035  uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
2036  /* Do not insert strings in hash table beyond this. */
2037 
2038  check_match(s, s->strstart-1, s->prev_match, s->prev_length);
2039 
2040  _tr_tally_dist(s, s->strstart -1 - s->prev_match,
2041  s->prev_length - MIN_MATCH, bflush);
2042 
2043  /* Insert in hash table all strings up to the end of the match.
2044  * strstart-1 and strstart are already inserted. If there is not
2045  * enough lookahead, the last two strings are not inserted in
2046  * the hash table.
2047  */
2048  s->lookahead -= s->prev_length-1;
2049  s->prev_length -= 2;
2050  do {
2051  if (++s->strstart <= max_insert) {
2052  INSERT_STRING(s, s->strstart, hash_head);
2053  }
2054  } while (--s->prev_length != 0);
2055  s->match_available = 0;
2056  s->match_length = MIN_MATCH-1;
2057  s->strstart++;
2058 
2059  if (bflush) FLUSH_BLOCK(s, 0);
2060 
2061  } else if (s->match_available) {
2062  /* If there was no match at the previous position, output a
2063  * single literal. If there was a match but the current match
2064  * is longer, truncate the previous match to a single literal.
2065  */
2066  Tracevv((stderr,"%c", s->window[s->strstart-1]));
2067  _tr_tally_lit(s, s->window[s->strstart-1], bflush);
2068  if (bflush) {
2069  FLUSH_BLOCK_ONLY(s, 0);
2070  }
2071  s->strstart++;
2072  s->lookahead--;
2073  if (s->strm->avail_out == 0) return need_more;
2074  } else {
2075  /* There is no previous match to compare with, wait for
2076  * the next step to decide.
2077  */
2078  s->match_available = 1;
2079  s->strstart++;
2080  s->lookahead--;
2081  }
2082  }
2083  Assert (flush != Z_NO_FLUSH, "no flush?");
2084  if (s->match_available) {
2085  Tracevv((stderr,"%c", s->window[s->strstart-1]));
2086  _tr_tally_lit(s, s->window[s->strstart-1], bflush);
2087  s->match_available = 0;
2088  }
2089  s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
2090  if (flush == Z_FINISH) {
2091  FLUSH_BLOCK(s, 1);
2092  return finish_done;
2093  }
2094  if (s->sym_next)
2095  FLUSH_BLOCK(s, 0);
2096  return block_done;
2097 }
2098 #endif /* FASTEST */
2099 
2100 /* ===========================================================================
2101  * For Z_RLE, simply look for runs of bytes, generate matches only of distance
2102  * one. Do not maintain a hash table. (It will be regenerated if this run of
2103  * deflate switches away from Z_RLE.)
2104  */
2106  deflate_state *s;
2107  int flush;
2108 {
2109  int bflush; /* set if current block must be flushed */
2110  uInt prev; /* byte at distance one to match */
2111  Bytef *scan, *strend; /* scan goes up to strend for length of run */
2112 
2113  for (;;) {
2114  /* Make sure that we always have enough lookahead, except
2115  * at the end of the input file. We need MAX_MATCH bytes
2116  * for the longest run, plus one for the unrolled loop.
2117  */
2118  if (s->lookahead <= MAX_MATCH) {
2119  fill_window(s);
2120  if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
2121  return need_more;
2122  }
2123  if (s->lookahead == 0) break; /* flush the current block */
2124  }
2125 
2126  /* See how many times the previous byte repeats */
2127  s->match_length = 0;
2128  if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
2129  scan = s->window + s->strstart - 1;
2130  prev = *scan;
2131  if (prev == *++scan && prev == *++scan && prev == *++scan) {
2132  strend = s->window + s->strstart + MAX_MATCH;
2133  do {
2134  } while (prev == *++scan && prev == *++scan &&
2135  prev == *++scan && prev == *++scan &&
2136  prev == *++scan && prev == *++scan &&
2137  prev == *++scan && prev == *++scan &&
2138  scan < strend);
2139  s->match_length = MAX_MATCH - (uInt)(strend - scan);
2140  if (s->match_length > s->lookahead)
2141  s->match_length = s->lookahead;
2142  }
2143  Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
2144  }
2145 
2146  /* Emit match if have run of MIN_MATCH or longer, else emit literal */
2147  if (s->match_length >= MIN_MATCH) {
2148  check_match(s, s->strstart, s->strstart - 1, s->match_length);
2149 
2150  _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
2151 
2152  s->lookahead -= s->match_length;
2153  s->strstart += s->match_length;
2154  s->match_length = 0;
2155  } else {
2156  /* No match, output a literal byte */
2157  Tracevv((stderr,"%c", s->window[s->strstart]));
2158  _tr_tally_lit (s, s->window[s->strstart], bflush);
2159  s->lookahead--;
2160  s->strstart++;
2161  }
2162  if (bflush) FLUSH_BLOCK(s, 0);
2163  }
2164  s->insert = 0;
2165  if (flush == Z_FINISH) {
2166  FLUSH_BLOCK(s, 1);
2167  return finish_done;
2168  }
2169  if (s->sym_next)
2170  FLUSH_BLOCK(s, 0);
2171  return block_done;
2172 }
2173 
2174 /* ===========================================================================
2175  * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
2176  * (It will be regenerated if this run of deflate switches away from Huffman.)
2177  */
2179  deflate_state *s;
2180  int flush;
2181 {
2182  int bflush; /* set if current block must be flushed */
2183 
2184  for (;;) {
2185  /* Make sure that we have a literal to write. */
2186  if (s->lookahead == 0) {
2187  fill_window(s);
2188  if (s->lookahead == 0) {
2189  if (flush == Z_NO_FLUSH)
2190  return need_more;
2191  break; /* flush the current block */
2192  }
2193  }
2194 
2195  /* Output a literal byte */
2196  s->match_length = 0;
2197  Tracevv((stderr,"%c", s->window[s->strstart]));
2198  _tr_tally_lit (s, s->window[s->strstart], bflush);
2199  s->lookahead--;
2200  s->strstart++;
2201  if (bflush) FLUSH_BLOCK(s, 0);
2202  }
2203  s->insert = 0;
2204  if (flush == Z_FINISH) {
2205  FLUSH_BLOCK(s, 1);
2206  return finish_done;
2207  }
2208  if (s->sym_next)
2209  FLUSH_BLOCK(s, 0);
2210  return block_done;
2211 }
#define Z_BLOCK
Definition: zlib.h:110
#define INIT_STATE
Definition: deflate.h:54
GLenum func
Definition: glext.h:6028
while(CdLookupNextInitialFileDirent(IrpContext, Fcb, FileContext))
int ZEXPORT deflateGetDictionary(z_streamp strm, Bytef *dictionary, uInt *dictLength)
Definition: deflate.c:485
#define MIN_MATCH
Definition: zutil.h:64
GLint level
Definition: gl.h:1546
#define RANK(f)
Definition: deflate.c:155
int ZEXPORT deflateParams(z_streamp strm, int level, int strategy)
Definition: deflate.c:609
Definition: pdh_main.c:93
#define Z_RLE
Definition: zlib.h:135
int windowBits
Definition: zlib.h:813
block_state compress_func OF((deflate_state *s, int flush))
Definition: deflate.c:73
block_state deflate_slow(deflate_state *s, int flush)
Definition: deflate.c:1974
struct config_s config
#define Z_VERSION_ERROR
Definition: zlib.h:122
#define INSERT_STRING(s, str, match_head)
Definition: deflate.c:182
void putShortMSB(deflate_state *s, uInt b)
Definition: deflate.c:757
#define check_match(s, start, match, length)
Definition: deflate.c:1509
void FAR * voidpf
Definition: zlib.h:42
#define HCRC_STATE
Definition: deflate.h:61
#define TOO_FAR
Definition: deflate.c:111
struct outqueuenode * head
Definition: adnsresfilter.c:66
POINT last
Definition: font.c:46
Definition: match.c:28
z_stream FAR * z_streamp
Definition: zlib.h:80
#define MAX_MATCH
Definition: zutil.h:65
#define Z_STREAM_ERROR
Definition: zlib.h:118
#define Z_FILTERED
Definition: zlib.h:133
#define Z_OK
Definition: zlib.h:114
#define PRESET_DICT
Definition: zutil.h:68
block_state deflate_fast(deflate_state *s, int flush)
Definition: deflate.c:1872
void ZLIB_INTERNAL _tr_align(deflate_state *s)
Definition: trees.c:897
block_state
Definition: deflate.c:66
ush Pos
Definition: deflate.h:92
GLdouble n
Definition: glext.h:7729
#define zmemzero(dest, len)
Definition: inflate.c:39
#define Z_DEFAULT_COMPRESSION
Definition: zlib.h:130
#define Tracevv(x)
Definition: inflate.c:44
#define OS_CODE
Definition: zutil.h:139
#define UPDATE_HASH(s, h, c)
Definition: deflate.c:163
#define ERR_MSG(err)
Definition: zutil.h:59
Posf * prev
Definition: deflate.h:134
#define MAX_WBITS
Definition: zlib.h:151
ush good_length
Definition: deflate.c:121
if(dx==0 &&dy==0)
Definition: linetemp.h:174
GLenum GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * bits
Definition: glext.h:10929
ush FAR ushf
Definition: zlib.h:50
#define Z_SOLO
Definition: cabinet.c:13
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:243
uLong ZEXPORT deflateBound(z_streamp strm, uLong sourceLen)
Definition: deflate.c:693
int ZEXPORT deflateEnd(z_streamp strm)
Definition: deflate.c:1119
static int init
Definition: wintirpc.c:33
static int avail
Definition: adh-main.c:39
const GLfloat * m
Definition: glext.h:10848
int ZEXPORT deflatePrime(z_streamp strm, int bits, int value)
Definition: deflate.c:582
unsigned read_buf(z_streamp strm, Bytef *buf, unsigned size)
Definition: deflate.c:1204
GLint limit
Definition: glext.h:10326
const char deflate_copyright[]
Definition: deflate.c:54
unsigned long uLong
Definition: zlib.h:39
#define put(ret, state, sp, n)
Definition: match.c:105
GLenum GLuint GLenum GLsizei const GLchar * buf
Definition: glext.h:7751
#define L(x)
Definition: ntvdm.h:50
#define _tr_tally_lit(s, c, flush)
Definition: deflate.h:321
const config configuration_table[10]
Definition: deflate.c:134
#define Z_STREAM_END
Definition: zlib.h:115
#define WIN_INIT
Definition: deflate.h:289
void fill_window(deflate_state *s)
Definition: deflate.c:1522
#define MAX_DIST(s)
Definition: deflate.h:284
#define BUSY_STATE
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_Check_return_opt_ _CRTIMP int __cdecl fprintf(_Inout_ FILE *_File, _In_z_ _Printf_format_string_ const char *_Format,...)
#define ZLIB_VERSION
Definition: zlib.h:40
#define ZFREE(strm, addr)
Definition: inflate.c:51
GLenum GLuint GLenum GLsizei length
Definition: glext.h:5579
const WCHAR * str
#define MIN_LOOKAHEAD
Definition: deflate.h:279
static const WCHAR version[]
Definition: asmname.c:66
#define Buf_size
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struct match match
Definition: match.c:33
z_streamp strm
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#define b
Definition: ke_i.h:79
GLuint GLfloat * val
Definition: glext.h:7180
int ZEXPORT deflateCopy(z_streamp dest, z_streamp source)
Definition: deflate.c:1145
static const struct encodedFiletime times[]
Definition: encode.c:556
int ZEXPORT deflateTune(z_streamp strm, int good_length, int max_lazy, int nice_length, int max_chain)
Definition: deflate.c:658
#define NIL
Definition: deflate.c:107
#define Z_UNKNOWN
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void ZLIB_INTERNAL _tr_init(deflate_state *s)
Definition: trees.c:379
_Check_return_opt_ _CRTIMP int __cdecl putc(_In_ int _Ch, _Inout_ FILE *_File)
int flush
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void(* free_func)(voidpf opaque, voidpf address)
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GLboolean GLboolean GLboolean b
Definition: glext.h:6204
static const unsigned char dictionary[][3]
Definition: decode.c:37
GLsizeiptr size
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compress_func func
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int const char int stream_size
Definition: zlib.h:813
#define zmemcpy
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ush max_chain
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Pos FAR Posf
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#define MIN(a, b)
Definition: deflate.c:1668
char * name
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int deflateStateCheck(z_streamp strm)
Definition: deflate.c:393
GLint left
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#define put_byte(s, c)
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void ZLIB_INTERNAL _tr_flush_bits(deflate_state *s)
Definition: trees.c:887
#define MAX_MEM_LEVEL
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method
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#define COMMENT_STATE
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uch FAR uchf
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int ret
#define CLEAR_HASH(s)
Definition: deflate.c:192
block_state deflate_rle(deflate_state *s, int flush)
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#define NAME_STATE
Definition: deflate.h:59
#define MAX_STORED
Definition: deflate.c:1665
#define _tr_tally_dist(s, distance, length, flush)
Definition: deflate.h:329
int ZEXPORT deflate(z_streamp strm, int flush)
Definition: deflate.c:804
GLenum GLsizei len
Definition: glext.h:6722
GLdouble s
Definition: gl.h:2039
GLsizei const GLfloat * value
Definition: glext.h:6069
void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int last)
Definition: trees.c:863
ush max_lazy
Definition: deflate.c:122
#define err(...)
static IHTMLWindow2 * window
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#define ZALLOC(strm, items, size)
Definition: inflate.c:49
unsigned short ush
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gz_header FAR * gz_headerp
Definition: zlib.h:103
static int used
Definition: adh-main.c:39
#define Z_DEFLATED
Definition: zlib.h:146
#define FINISH_STATE
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#define local
Definition: zutil.h:30
block_state deflate_stored(deflate_state *s, int flush)
Definition: deflate.c:1685
#define ds
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#define Z_FINISH
Definition: zlib.h:109
int nice_match
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unsigned int uInt
Definition: zlib.h:38
#define Z_NULL
Definition: zlib.h:149
static unsigned __int64 next
Definition: rand_nt.c:6
#define Z_PARTIAL_FLUSH
Definition: zlib.h:106
uInt longest_match(deflate_state *s, IPos cur_match)
Definition: deflate.c:1276
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Definition: zutil.c:173
GLuint start
Definition: gl.h:1545
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Definition: glext.h:6048
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void slide_hash(deflate_state *s)
Definition: deflate.c:204
#define long
Definition: qsort.c:33
#define Z_BUF_ERROR
Definition: zlib.h:121
int ZEXPORT deflateResetKeep(z_streamp strm)
Definition: deflate.c:507
INT copy(TCHAR source[MAX_PATH], TCHAR dest[MAX_PATH], INT append, DWORD lpdwFlags, BOOL bTouch)
Definition: copy.c:51
int ZEXPORT deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength)
Definition: deflate.c:416
uInt strstart
Definition: deflate.h:162
unsigned long ulg
Definition: zlib.h:51
voidpf zcalloc(voidpf opaque, unsigned items, unsigned size)
Definition: zutil.c:164
int ZEXPORT deflateSetHeader(z_streamp strm, gz_headerp head)
Definition: deflate.c:557
#define FLUSH_BLOCK(s, last)
Definition: deflate.c:1659
#define TRY_FREE(s, p)
Definition: inflate.c:52
#define Z_FULL_FLUSH
Definition: zlib.h:108
#define GZIP_STATE
Definition: deflate.h:56
Byte FAR Bytef
Definition: zlib.h:41
#define EXTRA_STATE
Definition: deflate.h:58
#define Z_MEM_ERROR
Definition: zlib.h:120
unsigned char Byte
Definition: zlib.h:37
#define crc32(crc, buf, len)
Definition: inflate.c:1081
int ZEXPORT deflateInit_(z_streamp strm, int level, const char *version, int stream_size)
Definition: deflate.c:231
#define z_const
Definition: zlib.h:35
voidpf(* alloc_func)(voidpf opaque, uInt items, uInt size)
Definition: zlib.h:53
#define Z_DATA_ERROR
Definition: zlib.h:119
#define Z_NO_FLUSH
Definition: zlib.h:105
void flush_pending(z_streamp strm)
Definition: deflate.c:771
FILE * stderr
#define HCRC_UPDATE(beg)
Definition: deflate.c:796
int ZEXPORT deflateReset(z_streamp strm)
Definition: deflate.c:545
int ZEXPORT deflatePending(z_streamp strm, unsigned *pending, int *bits)
Definition: deflate.c:568
#define wrap(journal, var)
Definition: recovery.c:207
static char * dest
Definition: rtl.c:135
#define ss
Definition: i386-dis.c:442
#define DEF_MEM_LEVEL
Definition: zutil.h:53
#define FAR
Definition: zlib.h:34
char FAR charf
Definition: zlib.h:44
GLfloat GLfloat p
Definition: glext.h:8902
#define Z_FIXED
Definition: zlib.h:136
block_state deflate_huff(deflate_state *s, int flush)
Definition: deflate.c:2178
void lm_init(deflate_state *s)
Definition: deflate.c:1234
static SERVICE_STATUS status
Definition: service.c:31
#define ZEXPORT
Definition: zconf.h:380
ush nice_length
Definition: deflate.c:123
uLong ZEXPORT adler32(uLong adler, const Bytef *buf, uInt len)
Definition: adler32.c:134
#define Assert(cond, msg)
Definition: inflate.c:41
#define Z_DEFAULT_STRATEGY
Definition: zlib.h:137
#define ERR_RETURN(strm, err)
Definition: zutil.h:41
#define GZIP
Definition: deflate.h:23
static unsigned(__cdecl *hash_bstr)(bstr_t s)
#define FLUSH_BLOCK_ONLY(s, last)
Definition: deflate.c:1647
unsigned int(__cdecl typeof(jpeg_read_scanlines))(struct jpeg_decompress_struct *
Definition: typeof.h:31
unsigned IPos
Definition: deflate.h:94
#define Z_HUFFMAN_ONLY
Definition: zlib.h:134
Definition: ps.c:97