File Coverage

cpan/Compress-Raw-Zlib/deflate.c
Criterion Covered Total %
statement 473 695 68.1
branch n/a
condition n/a
subroutine n/a
total 473 695 68.1


line stmt bran cond sub time code
1           /* deflate.c -- compress data using the deflation algorithm
2           * Copyright (C) 1995-2013 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 1.2.8 Copyright 1995-2013 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 void fill_window OF((deflate_state *s));
77           local block_state deflate_stored OF((deflate_state *s, int flush));
78           local block_state deflate_fast OF((deflate_state *s, int flush));
79           #ifndef FASTEST
80           local block_state deflate_slow OF((deflate_state *s, int flush));
81           #endif
82           local block_state deflate_rle OF((deflate_state *s, int flush));
83           local block_state deflate_huff OF((deflate_state *s, int flush));
84           local void lm_init OF((deflate_state *s));
85           local void putShortMSB OF((deflate_state *s, uInt b));
86           local void flush_pending OF((z_streamp strm));
87           local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
88           #ifdef ASMV
89           void match_init OF((void)); /* asm code initialization */
90           uInt longest_match OF((deflate_state *s, IPos cur_match));
91           #else
92           local uInt longest_match OF((deflate_state *s, IPos cur_match));
93           #endif
94            
95           #ifdef DEBUG
96           local void check_match OF((deflate_state *s, IPos start, IPos match,
97           int length));
98           #endif
99            
100           /* ===========================================================================
101           * Local data
102           */
103            
104           #define NIL 0
105           /* Tail of hash chains */
106            
107           #ifndef TOO_FAR
108           # define TOO_FAR 4096
109           #endif
110           /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
111            
112           /* Values for max_lazy_match, good_match and max_chain_length, depending on
113           * the desired pack level (0..9). The values given below have been tuned to
114           * exclude worst case performance for pathological files. Better values may be
115           * found for specific files.
116           */
117           typedef struct config_s {
118           ush good_length; /* reduce lazy search above this match length */
119           ush max_lazy; /* do not perform lazy search above this match length */
120           ush nice_length; /* quit search above this match length */
121           ush max_chain;
122           compress_func func;
123           } config;
124            
125           #ifdef FASTEST
126           local const config configuration_table[2] = {
127           /* good lazy nice chain */
128           /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
129           /* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */
130           #else
131           local const config configuration_table[10] = {
132           /* good lazy nice chain */
133           /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
134           /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */
135           /* 2 */ {4, 5, 16, 8, deflate_fast},
136           /* 3 */ {4, 6, 32, 32, deflate_fast},
137            
138           /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
139           /* 5 */ {8, 16, 32, 32, deflate_slow},
140           /* 6 */ {8, 16, 128, 128, deflate_slow},
141           /* 7 */ {8, 32, 128, 256, deflate_slow},
142           /* 8 */ {32, 128, 258, 1024, deflate_slow},
143           /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */
144           #endif
145            
146           /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
147           * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
148           * meaning.
149           */
150            
151           #define EQUAL 0
152           /* result of memcmp for equal strings */
153            
154           #ifndef NO_DUMMY_DECL
155           struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
156           #endif
157            
158           /* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */
159           #define RANK(f) (((f) << 1) - ((f) > 4 ? 9 : 0))
160            
161           /* ===========================================================================
162           * Update a hash value with the given input byte
163           * IN assertion: all calls to to UPDATE_HASH are made with consecutive
164           * input characters, so that a running hash key can be computed from the
165           * previous key instead of complete recalculation each time.
166           */
167           #define UPDATE_HASH(s,h,c) (h = (((h)<hash_shift) ^ (c)) & s->hash_mask)
168            
169            
170           /* ===========================================================================
171           * Insert string str in the dictionary and set match_head to the previous head
172           * of the hash chain (the most recent string with same hash key). Return
173           * the previous length of the hash chain.
174           * If this file is compiled with -DFASTEST, the compression level is forced
175           * to 1, and no hash chains are maintained.
176           * IN assertion: all calls to to INSERT_STRING are made with consecutive
177           * input characters and the first MIN_MATCH bytes of str are valid
178           * (except for the last MIN_MATCH-1 bytes of the input file).
179           */
180           #ifdef FASTEST
181           #define INSERT_STRING(s, str, match_head) \
182           (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
183           match_head = s->head[s->ins_h], \
184           s->head[s->ins_h] = (Pos)(str))
185           #else
186           #define INSERT_STRING(s, str, match_head) \
187           (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
188           match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \
189           s->head[s->ins_h] = (Pos)(str))
190           #endif
191            
192           /* ===========================================================================
193           * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
194           * prev[] will be initialized on the fly.
195           */
196           #define CLEAR_HASH(s) \
197           s->head[s->hash_size-1] = NIL; \
198           zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
199            
200           /* ========================================================================= */
201 0         int ZEXPORT deflateInit_(
202           z_streamp strm,
203           int level,
204           const char *version,
205           int stream_size)
206           {
207 0         return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
208           Z_DEFAULT_STRATEGY, version, stream_size);
209           /* To do: ignore strm->next_in if we use it as window */
210           }
211            
212           /* ========================================================================= */
213 3052         int ZEXPORT deflateInit2_(
214           z_streamp strm,
215           int level,
216           int method,
217           int windowBits,
218           int memLevel,
219           int strategy,
220           const char *version,
221           int stream_size)
222           {
223           deflate_state *s;
224           int wrap = 1;
225           static const char my_version[] = ZLIB_VERSION;
226            
227           ushf *overlay;
228           /* We overlay pending_buf and d_buf+l_buf. This works since the average
229           * output size for (length,distance) codes is <= 24 bits.
230           */
231            
232 6104         if (version == Z_NULL || version[0] != my_version[0] ||
233 3052         stream_size != sizeof(z_stream)) {
234           return Z_VERSION_ERROR;
235           }
236 3052         if (strm == Z_NULL) return Z_STREAM_ERROR;
237            
238 3052         strm->msg = Z_NULL;
239 3052         if (strm->zalloc == (alloc_func)0) {
240           #ifdef Z_SOLO
241           return Z_STREAM_ERROR;
242           #else
243           strm->zalloc = zcalloc;
244           strm->opaque = (voidpf)0;
245           #endif
246           }
247 3052         if (strm->zfree == (free_func)0)
248           #ifdef Z_SOLO
249           return Z_STREAM_ERROR;
250           #else
251           strm->zfree = zcfree;
252           #endif
253            
254           #ifdef FASTEST
255           if (level != 0) level = 1;
256           #else
257 3052         if (level == Z_DEFAULT_COMPRESSION) level = 6;
258           #endif
259            
260 3052         if (windowBits < 0) { /* suppress zlib wrapper */
261           wrap = 0;
262 2852         windowBits = -windowBits;
263           }
264           #ifdef GZIP
265 200         else if (windowBits > 15) {
266           wrap = 2; /* write gzip wrapper instead */
267 4         windowBits -= 16;
268           }
269           #endif
270 3052         if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
271 3052         windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
272 3050         strategy < 0 || strategy > Z_FIXED) {
273           return Z_STREAM_ERROR;
274           }
275 3050         if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */
276 3050         s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
277 3050         if (s == Z_NULL) return Z_MEM_ERROR;
278 3050         strm->state = (struct internal_state FAR *)s;
279 3050         s->strm = strm;
280            
281 3050         s->wrap = wrap;
282 3050         s->gzhead = Z_NULL;
283 3050         s->w_bits = windowBits;
284 3050         s->w_size = 1 << s->w_bits;
285 3050         s->w_mask = s->w_size - 1;
286            
287 3050         s->hash_bits = memLevel + 7;
288 3050         s->hash_size = 1 << s->hash_bits;
289 3050         s->hash_mask = s->hash_size - 1;
290 3050         s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
291            
292 3050         s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
293 3050         s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
294 3050         s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
295            
296 3050         s->high_water = 0; /* nothing written to s->window yet */
297            
298 3050         s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
299            
300 3050         overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
301 3050         s->pending_buf = (uchf *) overlay;
302 3050         s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
303            
304 6100         if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
305 3050         s->pending_buf == Z_NULL) {
306 0         s->status = FINISH_STATE;
307 0         strm->msg = ERR_MSG(Z_MEM_ERROR);
308 0         deflateEnd (strm);
309 0         return Z_MEM_ERROR;
310           }
311 3050         s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
312 3050         s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
313            
314 3050         s->level = level;
315 3050         s->strategy = strategy;
316 3050         s->method = (Byte)method;
317            
318 3050         return deflateReset(strm);
319           }
320            
321           /* ========================================================================= */
322 124         int ZEXPORT deflateSetDictionary (
323           z_streamp strm,
324           const Bytef *dictionary,
325           uInt dictLength)
326           {
327           deflate_state *s;
328           uInt str, n;
329           int wrap;
330           unsigned avail;
331           z_const unsigned char *next;
332            
333 124         if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
334           return Z_STREAM_ERROR;
335 124         s = strm->state;
336 124         wrap = s->wrap;
337 124         if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
338           return Z_STREAM_ERROR;
339            
340           /* when using zlib wrappers, compute Adler-32 for provided dictionary */
341 124         if (wrap == 1)
342 4         strm->adler = adler32(strm->adler, dictionary, dictLength);
343 124         s->wrap = 0; /* avoid computing Adler-32 in read_buf */
344            
345           /* if dictionary would fill window, just replace the history */
346 124         if (dictLength >= s->w_size) {
347 0         if (wrap == 0) { /* already empty otherwise */
348 0         CLEAR_HASH(s);
349 0         s->strstart = 0;
350 0         s->block_start = 0L;
351 0         s->insert = 0;
352           }
353 0         dictionary += dictLength - s->w_size; /* use the tail */
354 0         dictLength = s->w_size;
355           }
356            
357           /* insert dictionary into window and hash */
358 124         avail = strm->avail_in;
359 124         next = strm->next_in;
360 124         strm->avail_in = dictLength;
361 124         strm->next_in = (z_const Bytef *)dictionary;
362 124         fill_window(s);
363 282         while (s->lookahead >= MIN_MATCH) {
364 34         str = s->strstart;
365 34         n = s->lookahead - (MIN_MATCH-1);
366           do {
367 102         UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
368           #ifndef FASTEST
369 102         s->prev[str & s->w_mask] = s->head[s->ins_h];
370           #endif
371 102         s->head[s->ins_h] = (Pos)str;
372 102         str++;
373 102         } while (--n);
374 34         s->strstart = str;
375 34         s->lookahead = MIN_MATCH-1;
376 34         fill_window(s);
377           }
378 124         s->strstart += s->lookahead;
379 124         s->block_start = (long)s->strstart;
380 124         s->insert = s->lookahead;
381 124         s->lookahead = 0;
382 124         s->match_length = s->prev_length = MIN_MATCH-1;
383 124         s->match_available = 0;
384 124         strm->next_in = next;
385 124         strm->avail_in = avail;
386 124         s->wrap = wrap;
387 124         return Z_OK;
388           }
389            
390           /* ========================================================================= */
391 3050         int ZEXPORT deflateResetKeep (
392           z_streamp strm)
393           {
394           deflate_state *s;
395            
396 6100         if (strm == Z_NULL || strm->state == Z_NULL ||
397 6100         strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) {
398           return Z_STREAM_ERROR;
399           }
400            
401 3050         strm->total_in = strm->total_out = 0;
402 3050         strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
403 3050         strm->data_type = Z_UNKNOWN;
404            
405 3050         s = (deflate_state *)strm->state;
406 3050         s->pending = 0;
407 3050         s->pending_out = s->pending_buf;
408            
409 3050         if (s->wrap < 0) {
410 0         s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
411           }
412 3050         s->status = s->wrap ? INIT_STATE : BUSY_STATE;
413 3050         strm->adler =
414           #ifdef GZIP
415 3050         s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
416           #endif
417           adler32(0L, Z_NULL, 0);
418 3050         s->last_flush = Z_NO_FLUSH;
419            
420 3050         _tr_init(s);
421            
422 3050         return Z_OK;
423           }
424            
425           /* ========================================================================= */
426 3050         int ZEXPORT deflateReset (
427           z_streamp strm)
428           {
429           int ret;
430            
431 3050         ret = deflateResetKeep(strm);
432 3050         if (ret == Z_OK)
433 3050         lm_init(strm->state);
434 3050         return ret;
435           }
436            
437           /* ========================================================================= */
438 0         int ZEXPORT deflateSetHeader (
439           z_streamp strm,
440           gz_headerp head)
441           {
442 0         if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
443 0         if (strm->state->wrap != 2) return Z_STREAM_ERROR;
444 0         strm->state->gzhead = head;
445 0         return Z_OK;
446           }
447            
448           /* ========================================================================= */
449 0         int ZEXPORT deflatePending (
450           z_streamp strm,
451           unsigned *pending,
452           int *bits)
453           {
454 0         if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
455 0         if (pending != Z_NULL)
456 0         *pending = strm->state->pending;
457 0         if (bits != Z_NULL)
458 0         *bits = strm->state->bi_valid;
459           return Z_OK;
460           }
461            
462           /* ========================================================================= */
463 120         int ZEXPORT deflatePrime (
464           z_streamp strm,
465           int bits,
466           int value)
467           {
468           deflate_state *s;
469           int put;
470            
471 120         if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
472 120         s = strm->state;
473 120         if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
474           return Z_BUF_ERROR;
475           do {
476 120         put = Buf_size - s->bi_valid;
477 120         if (put > bits)
478           put = bits;
479 120         s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
480 120         s->bi_valid += put;
481 120         _tr_flush_bits(s);
482 120         value >>= put;
483 120         bits -= put;
484 120         } while (bits);
485           return Z_OK;
486           }
487            
488           /* ========================================================================= */
489 20         int ZEXPORT deflateParams(
490           z_streamp strm,
491           int level,
492           int strategy)
493           {
494           deflate_state *s;
495           compress_func func;
496           int err = Z_OK;
497            
498 20         if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
499 20         s = strm->state;
500            
501           #ifdef FASTEST
502           if (level != 0) level = 1;
503           #else
504 20         if (level == Z_DEFAULT_COMPRESSION) level = 6;
505           #endif
506 20         if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
507           return Z_STREAM_ERROR;
508           }
509 20         func = configuration_table[s->level].func;
510            
511 40         if ((strategy != s->strategy || func != configuration_table[level].func) &&
512 20         strm->total_in != 0) {
513           /* Flush the last buffer: */
514 20         err = deflate(strm, Z_BLOCK);
515 20         if (err == Z_BUF_ERROR && s->pending == 0)
516           err = Z_OK;
517           }
518 20         if (s->level != level) {
519 16         s->level = level;
520 16         s->max_lazy_match = configuration_table[level].max_lazy;
521 16         s->good_match = configuration_table[level].good_length;
522 16         s->nice_match = configuration_table[level].nice_length;
523 16         s->max_chain_length = configuration_table[level].max_chain;
524           }
525 20         s->strategy = strategy;
526 20         return err;
527           }
528            
529           /* ========================================================================= */
530 0         int ZEXPORT deflateTune(
531           z_streamp strm,
532           int good_length,
533           int max_lazy,
534           int nice_length,
535           int max_chain)
536           {
537           deflate_state *s;
538            
539 0         if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
540 0         s = strm->state;
541 0         s->good_match = good_length;
542 0         s->max_lazy_match = max_lazy;
543 0         s->nice_match = nice_length;
544 0         s->max_chain_length = max_chain;
545 0         return Z_OK;
546           }
547            
548           /* =========================================================================
549           * For the default windowBits of 15 and memLevel of 8, this function returns
550           * a close to exact, as well as small, upper bound on the compressed size.
551           * They are coded as constants here for a reason--if the #define's are
552           * changed, then this function needs to be changed as well. The return
553           * value for 15 and 8 only works for those exact settings.
554           *
555           * For any setting other than those defaults for windowBits and memLevel,
556           * the value returned is a conservative worst case for the maximum expansion
557           * resulting from using fixed blocks instead of stored blocks, which deflate
558           * can emit on compressed data for some combinations of the parameters.
559           *
560           * This function could be more sophisticated to provide closer upper bounds for
561           * every combination of windowBits and memLevel. But even the conservative
562           * upper bound of about 14% expansion does not seem onerous for output buffer
563           * allocation.
564           */
565 0         uLong ZEXPORT deflateBound(
566           z_streamp strm,
567           uLong sourceLen)
568           {
569           deflate_state *s;
570           uLong complen, wraplen;
571           Bytef *str;
572            
573           /* conservative upper bound for compressed data */
574 0         complen = sourceLen +
575 0         ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
576            
577           /* if can't get parameters, return conservative bound plus zlib wrapper */
578 0         if (strm == Z_NULL || strm->state == Z_NULL)
579 0         return complen + 6;
580            
581           /* compute wrapper length */
582 0         s = strm->state;
583 0         switch (s->wrap) {
584           case 0: /* raw deflate */
585           wraplen = 0;
586           break;
587           case 1: /* zlib wrapper */
588 0         wraplen = 6 + (s->strstart ? 4 : 0);
589 0         break;
590           case 2: /* gzip wrapper */
591           wraplen = 18;
592 0         if (s->gzhead != Z_NULL) { /* user-supplied gzip header */
593 0         if (s->gzhead->extra != Z_NULL)
594 0         wraplen += 2 + s->gzhead->extra_len;
595 0         str = s->gzhead->name;
596 0         if (str != Z_NULL)
597           do {
598 0         wraplen++;
599 0         } while (*str++);
600 0         str = s->gzhead->comment;
601 0         if (str != Z_NULL)
602           do {
603 0         wraplen++;
604 0         } while (*str++);
605 0         if (s->gzhead->hcrc)
606 0         wraplen += 2;
607           }
608           break;
609           default: /* for compiler happiness */
610           wraplen = 6;
611           }
612            
613           /* if not default parameters, return conservative bound */
614 0         if (s->w_bits != 15 || s->hash_bits != 8 + 7)
615 0         return complen + wraplen;
616            
617           /* default settings: return tight bound for that case */
618 0         return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
619 0         (sourceLen >> 25) + 13 - 6 + wraplen;
620           }
621            
622           /* =========================================================================
623           * Put a short in the pending buffer. The 16-bit value is put in MSB order.
624           * IN assertion: the stream state is correct and there is enough room in
625           * pending_buf.
626           */
627 0         local void putShortMSB (
628           deflate_state *s,
629           uInt b)
630           {
631 574         put_byte(s, (Byte)(b >> 8));
632 574         put_byte(s, (Byte)(b & 0xff));
633 0         }
634            
635           /* =========================================================================
636           * Flush as much pending output as possible. All deflate() output goes
637           * through this function so some applications may wish to modify it
638           * to avoid allocating a large strm->next_out buffer and copying into it.
639           * (See also read_buf()).
640           */
641 3846         local void flush_pending(
642           z_streamp strm)
643           {
644           unsigned len;
645 3846         deflate_state *s = strm->state;
646            
647 3846         _tr_flush_bits(s);
648 3846         len = s->pending;
649 3846         if (len > strm->avail_out) len = strm->avail_out;
650 7692         if (len == 0) return;
651            
652 3846         zmemcpy(strm->next_out, s->pending_out, len);
653 3846         strm->next_out += len;
654 3846         s->pending_out += len;
655 3846         strm->total_out += len;
656 3846         strm->avail_out -= len;
657 3846         s->pending -= len;
658 3846         if (s->pending == 0) {
659 3482         s->pending_out = s->pending_buf;
660           }
661           }
662            
663           /* ========================================================================= */
664 312642         int ZEXPORT deflate (
665           z_streamp strm,
666           int flush)
667           {
668           int old_flush; /* value of flush param for previous deflate call */
669           deflate_state *s;
670            
671 625284         if (strm == Z_NULL || strm->state == Z_NULL ||
672 625282         flush > Z_BLOCK || flush < 0) {
673           return Z_STREAM_ERROR;
674           }
675 312640         s = strm->state;
676            
677 625280         if (strm->next_out == Z_NULL ||
678 626006         (strm->next_in == Z_NULL && strm->avail_in != 0) ||
679 312640         (s->status == FINISH_STATE && flush != Z_FINISH)) {
680 0         ERR_RETURN(strm, Z_STREAM_ERROR);
681           }
682 312640         if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
683            
684 312640         s->strm = strm; /* just in case */
685 312640         old_flush = s->last_flush;
686 312640         s->last_flush = flush;
687            
688           /* Write the header */
689 312640         if (s->status == INIT_STATE) {
690           #ifdef GZIP
691 198         if (s->wrap == 2) {
692 4         strm->adler = crc32(0L, Z_NULL, 0);
693 4         put_byte(s, 31);
694 4         put_byte(s, 139);
695 4         put_byte(s, 8);
696 4         if (s->gzhead == Z_NULL) {
697 4         put_byte(s, 0);
698 4         put_byte(s, 0);
699 4         put_byte(s, 0);
700 4         put_byte(s, 0);
701 4         put_byte(s, 0);
702 4         put_byte(s, s->level == 9 ? 2 :
703           (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
704           4 : 0));
705 4         put_byte(s, OS_CODE);
706 4         s->status = BUSY_STATE;
707           }
708           else {
709 0         put_byte(s, (s->gzhead->text ? 1 : 0) +
710           (s->gzhead->hcrc ? 2 : 0) +
711           (s->gzhead->extra == Z_NULL ? 0 : 4) +
712           (s->gzhead->name == Z_NULL ? 0 : 8) +
713           (s->gzhead->comment == Z_NULL ? 0 : 16)
714           );
715 0         put_byte(s, (Byte)(s->gzhead->time & 0xff));
716 0         put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
717 0         put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
718 0         put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
719 0         put_byte(s, s->level == 9 ? 2 :
720           (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
721           4 : 0));
722 0         put_byte(s, s->gzhead->os & 0xff);
723 0         if (s->gzhead->extra != Z_NULL) {
724 0         put_byte(s, s->gzhead->extra_len & 0xff);
725 0         put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
726           }
727 0         if (s->gzhead->hcrc)
728 0         strm->adler = crc32(strm->adler, s->pending_buf,
729           s->pending);
730 0         s->gzindex = 0;
731 0         s->status = EXTRA_STATE;
732           }
733           }
734           else
735           #endif
736           {
737 194         uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
738           uInt level_flags;
739            
740 194         if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
741           level_flags = 0;
742 182         else if (s->level < 6)
743           level_flags = 1;
744 174         else if (s->level == 6)
745           level_flags = 2;
746           else
747           level_flags = 3;
748 194         header |= (level_flags << 6);
749 194         if (s->strstart != 0) header |= PRESET_DICT;
750 194         header += 31 - (header % 31);
751            
752 194         s->status = BUSY_STATE;
753           putShortMSB(s, header);
754            
755           /* Save the adler32 of the preset dictionary: */
756 194         if (s->strstart != 0) {
757 4         putShortMSB(s, (uInt)(strm->adler >> 16));
758 4         putShortMSB(s, (uInt)(strm->adler & 0xffff));
759           }
760 194         strm->adler = adler32(0L, Z_NULL, 0);
761           }
762           }
763           #ifdef GZIP
764 312640         if (s->status == EXTRA_STATE) {
765 0         if (s->gzhead->extra != Z_NULL) {
766 0         uInt beg = s->pending; /* start of bytes to update crc */
767            
768 0         while (s->gzindex < (s->gzhead->extra_len & 0xffff)) {
769 0         if (s->pending == s->pending_buf_size) {
770 0         if (s->gzhead->hcrc && s->pending > beg)
771 0         strm->adler = crc32(strm->adler, s->pending_buf + beg,
772 0         s->pending - beg);
773 0         flush_pending(strm);
774 0         beg = s->pending;
775 0         if (s->pending == s->pending_buf_size)
776           break;
777           }
778 0         put_byte(s, s->gzhead->extra[s->gzindex]);
779 0         s->gzindex++;
780           }
781 0         if (s->gzhead->hcrc && s->pending > beg)
782 0         strm->adler = crc32(strm->adler, s->pending_buf + beg,
783 0         s->pending - beg);
784 0         if (s->gzindex == s->gzhead->extra_len) {
785 0         s->gzindex = 0;
786 0         s->status = NAME_STATE;
787           }
788           }
789           else
790 0         s->status = NAME_STATE;
791           }
792 312640         if (s->status == NAME_STATE) {
793 0         if (s->gzhead->name != Z_NULL) {
794 0         uInt beg = s->pending; /* start of bytes to update crc */
795           int val;
796            
797           do {
798 0         if (s->pending == s->pending_buf_size) {
799 0         if (s->gzhead->hcrc && s->pending > beg)
800 0         strm->adler = crc32(strm->adler, s->pending_buf + beg,
801 0         s->pending - beg);
802 0         flush_pending(strm);
803 0         beg = s->pending;
804 0         if (s->pending == s->pending_buf_size) {
805           val = 1;
806           break;
807           }
808           }
809 0         val = s->gzhead->name[s->gzindex++];
810 0         put_byte(s, val);
811 0         } while (val != 0);
812 0         if (s->gzhead->hcrc && s->pending > beg)
813 0         strm->adler = crc32(strm->adler, s->pending_buf + beg,
814 0         s->pending - beg);
815 0         if (val == 0) {
816 0         s->gzindex = 0;
817 0         s->status = COMMENT_STATE;
818           }
819           }
820           else
821 0         s->status = COMMENT_STATE;
822           }
823 312640         if (s->status == COMMENT_STATE) {
824 0         if (s->gzhead->comment != Z_NULL) {
825 0         uInt beg = s->pending; /* start of bytes to update crc */
826           int val;
827            
828           do {
829 0         if (s->pending == s->pending_buf_size) {
830 0         if (s->gzhead->hcrc && s->pending > beg)
831 0         strm->adler = crc32(strm->adler, s->pending_buf + beg,
832 0         s->pending - beg);
833 0         flush_pending(strm);
834 0         beg = s->pending;
835 0         if (s->pending == s->pending_buf_size) {
836           val = 1;
837           break;
838           }
839           }
840 0         val = s->gzhead->comment[s->gzindex++];
841 0         put_byte(s, val);
842 0         } while (val != 0);
843 0         if (s->gzhead->hcrc && s->pending > beg)
844 0         strm->adler = crc32(strm->adler, s->pending_buf + beg,
845 0         s->pending - beg);
846 0         if (val == 0)
847 0         s->status = HCRC_STATE;
848           }
849           else
850 0         s->status = HCRC_STATE;
851           }
852 312640         if (s->status == HCRC_STATE) {
853 0         if (s->gzhead->hcrc) {
854 0         if (s->pending + 2 > s->pending_buf_size)
855 0         flush_pending(strm);
856 0         if (s->pending + 2 <= s->pending_buf_size) {
857 0         put_byte(s, (Byte)(strm->adler & 0xff));
858 0         put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
859 0         strm->adler = crc32(0L, Z_NULL, 0);
860 0         s->status = BUSY_STATE;
861           }
862           }
863           else
864 0         s->status = BUSY_STATE;
865           }
866           #endif
867            
868           /* Flush as much pending output as possible */
869 312640         if (s->pending != 0) {
870 562         flush_pending(strm);
871 562         if (strm->avail_out == 0) {
872           /* Since avail_out is 0, deflate will be called again with
873           * more output space, but possibly with both pending and
874           * avail_in equal to zero. There won't be anything to do,
875           * but this is not an error situation so make sure we
876           * return OK instead of BUF_ERROR at next call of deflate:
877           */
878 118         s->last_flush = -1;
879 118         return Z_OK;
880           }
881            
882           /* Make sure there is something to do and avoid duplicate consecutive
883           * flushes. For repeated and useless calls with Z_FINISH, we keep
884           * returning Z_STREAM_END instead of Z_BUF_ERROR.
885           */
886 315194         } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
887 3116         flush != Z_FINISH) {
888 12         ERR_RETURN(strm, Z_BUF_ERROR);
889           }
890            
891           /* User must not provide more input after the first FINISH: */
892 312510         if (s->status == FINISH_STATE && strm->avail_in != 0) {
893 0         ERR_RETURN(strm, Z_BUF_ERROR);
894           }
895            
896           /* Start a new block or continue the current one.
897           */
898 312510         if (strm->avail_in != 0 || s->lookahead != 0 ||
899 1034         (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
900           block_state bstate;
901            
902 936650         bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
903 312200         (s->strategy == Z_RLE ? deflate_rle(s, flush) :
904 312200         (*(configuration_table[s->level].func))(s, flush));
905            
906 312250         if (bstate == finish_started || bstate == finish_done) {
907 3030         s->status = FINISH_STATE;
908           }
909 312250         if (bstate == need_more || bstate == finish_started) {
910 309404         if (strm->avail_out == 0) {
911 238         s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
912           }
913           return Z_OK;
914           /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
915           * of deflate should use the same flush parameter to make sure
916           * that the flush is complete. So we don't have to output an
917           * empty block here, this will be done at next call. This also
918           * ensures that for a very small output buffer, we emit at most
919           * one empty block.
920           */
921           }
922 2846         if (bstate == block_done) {
923 24         if (flush == Z_PARTIAL_FLUSH) {
924 0         _tr_align(s);
925 24         } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
926 24         _tr_stored_block(s, (char*)0, 0L, 0);
927           /* For a full flush, this empty block will be recognized
928           * as a special marker by inflate_sync().
929           */
930 24         if (flush == Z_FULL_FLUSH) {
931 12         CLEAR_HASH(s); /* forget history */
932 12         if (s->lookahead == 0) {
933 12         s->strstart = 0;
934 12         s->block_start = 0L;
935 12         s->insert = 0;
936           }
937           }
938           }
939 24         flush_pending(strm);
940 24         if (strm->avail_out == 0) {
941 0         s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
942 0         return Z_OK;
943           }
944           }
945           }
946           Assert(strm->avail_out > 0, "bug2");
947            
948 3106         if (flush != Z_FINISH) return Z_OK;
949 3082         if (s->wrap <= 0) return Z_STREAM_END;
950            
951           /* Write the trailer */
952           #ifdef GZIP
953 190         if (s->wrap == 2) {
954 4         put_byte(s, (Byte)(strm->adler & 0xff));
955 4         put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
956 4         put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
957 4         put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
958 4         put_byte(s, (Byte)(strm->total_in & 0xff));
959 4         put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
960 4         put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
961 4         put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
962           }
963           else
964           #endif
965           {
966 186         putShortMSB(s, (uInt)(strm->adler >> 16));
967 186         putShortMSB(s, (uInt)(strm->adler & 0xffff));
968           }
969 190         flush_pending(strm);
970           /* If avail_out is zero, the application will call deflate again
971           * to flush the rest.
972           */
973 190         if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
974 190         return s->pending != 0 ? Z_OK : Z_STREAM_END;
975           }
976            
977           /* ========================================================================= */
978 3050         int ZEXPORT deflateEnd (
979           z_streamp strm)
980           {
981           int status;
982            
983 3050         if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
984            
985 3050         status = strm->state->status;
986 6100         if (status != INIT_STATE &&
987 3050         status != EXTRA_STATE &&
988 6100         status != NAME_STATE &&
989 3050         status != COMMENT_STATE &&
990 6100         status != HCRC_STATE &&
991 6080         status != BUSY_STATE &&
992           status != FINISH_STATE) {
993           return Z_STREAM_ERROR;
994           }
995            
996           /* Deallocate in reverse order of allocations: */
997 3050         TRY_FREE(strm, strm->state->pending_buf);
998 3050         TRY_FREE(strm, strm->state->head);
999 3050         TRY_FREE(strm, strm->state->prev);
1000 3050         TRY_FREE(strm, strm->state->window);
1001            
1002 3050         ZFREE(strm, strm->state);
1003 3050         strm->state = Z_NULL;
1004            
1005 3050         return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1006           }
1007            
1008           /* =========================================================================
1009           * Copy the source state to the destination state.
1010           * To simplify the source, this is not supported for 16-bit MSDOS (which
1011           * doesn't have enough memory anyway to duplicate compression states).
1012           */
1013 0         int ZEXPORT deflateCopy (
1014           z_streamp dest,
1015           z_streamp source)
1016           {
1017           #ifdef MAXSEG_64K
1018           return Z_STREAM_ERROR;
1019           #else
1020           deflate_state *ds;
1021           deflate_state *ss;
1022           ushf *overlay;
1023            
1024            
1025 0         if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
1026           return Z_STREAM_ERROR;
1027           }
1028            
1029 0         ss = source->state;
1030            
1031 0         zmemcpy((Bytef*)dest, (Bytef*)source, sizeof(z_stream));
1032            
1033 0         ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1034 0         if (ds == Z_NULL) return Z_MEM_ERROR;
1035 0         dest->state = (struct internal_state FAR *) ds;
1036 0         zmemcpy((Bytef*)ds, (Bytef*)ss, sizeof(deflate_state));
1037 0         ds->strm = dest;
1038            
1039 0         ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1040 0         ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1041 0         ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1042 0         overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1043 0         ds->pending_buf = (uchf *) overlay;
1044            
1045 0         if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1046 0         ds->pending_buf == Z_NULL) {
1047 0         deflateEnd (dest);
1048 0         return Z_MEM_ERROR;
1049           }
1050           /* following zmemcpy do not work for 16-bit MSDOS */
1051 0         zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1052 0         zmemcpy((Bytef*)ds->prev, (Bytef*)ss->prev, ds->w_size * sizeof(Pos));
1053 0         zmemcpy((Bytef*)ds->head, (Bytef*)ss->head, ds->hash_size * sizeof(Pos));
1054 0         zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1055            
1056 0         ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1057 0         ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1058 0         ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1059            
1060 0         ds->l_desc.dyn_tree = ds->dyn_ltree;
1061 0         ds->d_desc.dyn_tree = ds->dyn_dtree;
1062 0         ds->bl_desc.dyn_tree = ds->bl_tree;
1063            
1064 0         return Z_OK;
1065           #endif /* MAXSEG_64K */
1066           }
1067            
1068           /* ===========================================================================
1069           * Read a new buffer from the current input stream, update the adler32
1070           * and total number of bytes read. All deflate() input goes through
1071           * this function so some applications may wish to modify it to avoid
1072           * allocating a large strm->next_in buffer and copying from it.
1073           * (See also flush_pending()).
1074           */
1075 309344         local int read_buf(
1076           z_streamp strm,
1077           Bytef *buf,
1078           unsigned size)
1079           {
1080 309344         unsigned len = strm->avail_in;
1081            
1082 309344         if (len > size) len = size;
1083 309344         if (len == 0) return 0;
1084            
1085 309344         strm->avail_in -= len;
1086            
1087 309344         zmemcpy(buf, strm->next_in, len);
1088 309344         if (strm->state->wrap == 1) {
1089 306100         strm->adler = adler32(strm->adler, buf, len);
1090           }
1091           #ifdef GZIP
1092 3244         else if (strm->state->wrap == 2) {
1093 4         strm->adler = crc32(strm->adler, buf, len);
1094           }
1095           #endif
1096 309344         strm->next_in += len;
1097 309344         strm->total_in += len;
1098            
1099 309344         return (int)len;
1100           }
1101            
1102           /* ===========================================================================
1103           * Initialize the "longest match" routines for a new zlib stream
1104           */
1105 3050         local void lm_init (
1106           deflate_state *s)
1107           {
1108 3050         s->window_size = (ulg)2L*s->w_size;
1109            
1110 3050         CLEAR_HASH(s);
1111            
1112           /* Set the default configuration parameters:
1113           */
1114 3050         s->max_lazy_match = configuration_table[s->level].max_lazy;
1115 3050         s->good_match = configuration_table[s->level].good_length;
1116 3050         s->nice_match = configuration_table[s->level].nice_length;
1117 3050         s->max_chain_length = configuration_table[s->level].max_chain;
1118            
1119 3050         s->strstart = 0;
1120 3050         s->block_start = 0L;
1121 3050         s->lookahead = 0;
1122 3050         s->insert = 0;
1123 3050         s->match_length = s->prev_length = MIN_MATCH-1;
1124 3050         s->match_available = 0;
1125 3050         s->ins_h = 0;
1126           #ifndef FASTEST
1127           #ifdef ASMV
1128           match_init(); /* initialize the asm code */
1129           #endif
1130           #endif
1131 3050         }
1132            
1133           #ifndef FASTEST
1134           /* ===========================================================================
1135           * Set match_start to the longest match starting at the given string and
1136           * return its length. Matches shorter or equal to prev_length are discarded,
1137           * in which case the result is equal to prev_length and match_start is
1138           * garbage.
1139           * IN assertions: cur_match is the head of the hash chain for the current
1140           * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1141           * OUT assertion: the match length is not greater than s->lookahead.
1142           */
1143           #ifndef ASMV
1144           /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1145           * match.S. The code will be functionally equivalent.
1146           */
1147 117978         local uInt longest_match(
1148           deflate_state *s,
1149           IPos cur_match)
1150           {
1151 117978         unsigned chain_length = s->max_chain_length;/* max hash chain length */
1152 117978         register Bytef *scan = s->window + s->strstart; /* current string */
1153           register Bytef *match; /* matched string */
1154           register int len; /* length of current match */
1155 117978         int best_len = s->prev_length; /* best match length so far */
1156 117978         int nice_match = s->nice_match; /* stop if match long enough */
1157 117978         IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1158 117978         s->strstart - (IPos)MAX_DIST(s) : NIL;
1159           /* Stop when cur_match becomes <= limit. To simplify the code,
1160           * we prevent matches with the string of window index 0.
1161           */
1162 117978         Posf *prev = s->prev;
1163 117978         uInt wmask = s->w_mask;
1164            
1165           #ifdef UNALIGNED_OK
1166           /* Compare two bytes at a time. Note: this is not always beneficial.
1167           * Try with and without -DUNALIGNED_OK to check.
1168           */
1169           register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1170           register ush scan_start = *(ushf*)scan;
1171           register ush scan_end = *(ushf*)(scan+best_len-1);
1172           #else
1173 117978         register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1174 117978         register Byte scan_end1 = scan[best_len-1];
1175 117978         register Byte scan_end = scan[best_len];
1176           #endif
1177            
1178           /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1179           * It is easy to get rid of this optimization if necessary.
1180           */
1181           Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1182            
1183           /* Do not waste too much time if we already have a good match: */
1184 117978         if (s->prev_length >= s->good_match) {
1185 124         chain_length >>= 2;
1186           }
1187           /* Do not look for matches beyond the end of the input. This is necessary
1188           * to make deflate deterministic.
1189           */
1190 117978         if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1191            
1192           Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1193            
1194           do {
1195           Assert(cur_match < s->strstart, "no future");
1196 219874         match = s->window + cur_match;
1197            
1198           /* Skip to next match if the match length cannot increase
1199           * or if the match length is less than 2. Note that the checks below
1200           * for insufficient lookahead only occur occasionally for performance
1201           * reasons. Therefore uninitialized memory will be accessed, and
1202           * conditional jumps will be made that depend on those values.
1203           * However the length of the match is limited to the lookahead, so
1204           * the output of deflate is not affected by the uninitialized values.
1205           */
1206           #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1207           /* This code assumes sizeof(unsigned short) == 2. Do not use
1208           * UNALIGNED_OK if your compiler uses a different size.
1209           */
1210           if (*(ushf*)(match+best_len-1) != scan_end ||
1211           *(ushf*)match != scan_start) continue;
1212            
1213           /* It is not necessary to compare scan[2] and match[2] since they are
1214           * always equal when the other bytes match, given that the hash keys
1215           * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1216           * strstart+3, +5, ... up to strstart+257. We check for insufficient
1217           * lookahead only every 4th comparison; the 128th check will be made
1218           * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1219           * necessary to put more guard bytes at the end of the window, or
1220           * to check more often for insufficient lookahead.
1221           */
1222           Assert(scan[2] == match[2], "scan[2]?");
1223           scan++, match++;
1224           do {
1225           } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1226           *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1227           *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1228           *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1229           scan < strend);
1230           /* The funny "do {}" generates better code on most compilers */
1231            
1232           /* Here, scan <= window+strstart+257 */
1233           Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1234           if (*scan == *match) scan++;
1235            
1236           len = (MAX_MATCH - 1) - (int)(strend-scan);
1237           scan = strend - (MAX_MATCH-1);
1238            
1239           #else /* UNALIGNED_OK */
1240            
1241 334240         if (match[best_len] != scan_end ||
1242 217772         match[best_len-1] != scan_end1 ||
1243 181968         *match != *scan ||
1244 219874         *++match != scan[1]) continue;
1245            
1246           /* The check at best_len-1 can be removed because it will be made
1247           * again later. (This heuristic is not always a win.)
1248           * It is not necessary to compare scan[2] and match[2] since they
1249           * are always equal when the other bytes match, given that
1250           * the hash keys are equal and that HASH_BITS >= 8.
1251           */
1252 78562         scan += 2, match++;
1253           Assert(*scan == *match, "match[2]?");
1254            
1255           /* We check for insufficient lookahead only every 8th comparison;
1256           * the 256th check will be made at strstart+258.
1257           */
1258           do {
1259 3452600         } while (*++scan == *++match && *++scan == *++match &&
1260 3402632         *++scan == *++match && *++scan == *++match &&
1261 3380010         *++scan == *++match && *++scan == *++match &&
1262 2245260         *++scan == *++match && *++scan == *++match &&
1263 2329044         scan < strend);
1264            
1265           Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1266            
1267 78562         len = MAX_MATCH - (int)(strend - scan);
1268 78562         scan = strend - MAX_MATCH;
1269            
1270           #endif /* UNALIGNED_OK */
1271            
1272 78562         if (len > best_len) {
1273 78414         s->match_start = cur_match;
1274           best_len = len;
1275 78414         if (len >= nice_match) break;
1276           #ifdef UNALIGNED_OK
1277           scan_end = *(ushf*)(scan+best_len-1);
1278           #else
1279 32744         scan_end1 = scan[best_len-1];
1280 32744         scan_end = scan[best_len];
1281           #endif
1282           }
1283 174204         } while ((cur_match = prev[cur_match & wmask]) > limit
1284 174204         && --chain_length != 0);
1285            
1286 117978         if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1287 334         return s->lookahead;
1288           }
1289           #endif /* ASMV */
1290            
1291           #else /* FASTEST */
1292            
1293           /* ---------------------------------------------------------------------------
1294           * Optimized version for FASTEST only
1295           */
1296           local uInt longest_match(
1297           deflate_state *s,
1298           IPos cur_match)
1299           {
1300           register Bytef *scan = s->window + s->strstart; /* current string */
1301           register Bytef *match; /* matched string */
1302           register int len; /* length of current match */
1303           register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1304            
1305           /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1306           * It is easy to get rid of this optimization if necessary.
1307           */
1308           Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1309            
1310           Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1311            
1312           Assert(cur_match < s->strstart, "no future");
1313            
1314           match = s->window + cur_match;
1315            
1316           /* Return failure if the match length is less than 2:
1317           */
1318           if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1319            
1320           /* The check at best_len-1 can be removed because it will be made
1321           * again later. (This heuristic is not always a win.)
1322           * It is not necessary to compare scan[2] and match[2] since they
1323           * are always equal when the other bytes match, given that
1324           * the hash keys are equal and that HASH_BITS >= 8.
1325           */
1326           scan += 2, match += 2;
1327           Assert(*scan == *match, "match[2]?");
1328            
1329           /* We check for insufficient lookahead only every 8th comparison;
1330           * the 256th check will be made at strstart+258.
1331           */
1332           do {
1333           } while (*++scan == *++match && *++scan == *++match &&
1334           *++scan == *++match && *++scan == *++match &&
1335           *++scan == *++match && *++scan == *++match &&
1336           *++scan == *++match && *++scan == *++match &&
1337           scan < strend);
1338            
1339           Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1340            
1341           len = MAX_MATCH - (int)(strend - scan);
1342            
1343           if (len < MIN_MATCH) return MIN_MATCH - 1;
1344            
1345           s->match_start = cur_match;
1346           return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
1347           }
1348            
1349           #endif /* FASTEST */
1350            
1351           #ifdef DEBUG
1352           /* ===========================================================================
1353           * Check that the match at match_start is indeed a match.
1354           */
1355           local void check_match(
1356           deflate_state *s,
1357           IPos start,
1358           IPos match,
1359           int length)
1360           {
1361           /* check that the match is indeed a match */
1362           if (zmemcmp(s->window + match,
1363           s->window + start, length) != EQUAL) {
1364           fprintf(stderr, " start %u, match %u, length %d\n",
1365           start, match, length);
1366           do {
1367           fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1368           } while (--length != 0);
1369           z_error("invalid match");
1370           }
1371           if (z_verbose > 1) {
1372           fprintf(stderr,"\\[%d,%d]", start-match, length);
1373           do { putc(s->window[start++], stderr); } while (--length != 0);
1374           }
1375           }
1376           #else
1377           # define check_match(s, start, match, length)
1378           #endif /* DEBUG */
1379            
1380           /* ===========================================================================
1381           * Fill the window when the lookahead becomes insufficient.
1382           * Updates strstart and lookahead.
1383           *
1384           * IN assertion: lookahead < MIN_LOOKAHEAD
1385           * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1386           * At least one byte has been read, or avail_in == 0; reads are
1387           * performed for at least two bytes (required for the zip translate_eol
1388           * option -- not supported here).
1389           */
1390 356464         local void fill_window(
1391           deflate_state *s)
1392           {
1393           register unsigned n, m;
1394           register Posf *p;
1395           unsigned more; /* Amount of free space at the end of the window. */
1396 356464         uInt wsize = s->w_size;
1397            
1398           Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
1399            
1400           do {
1401 356464         more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1402            
1403           /* Deal with !@#$% 64K limit: */
1404           if (sizeof(int) <= 2) {
1405           if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1406           more = wsize;
1407            
1408           } else if (more == (unsigned)(-1)) {
1409           /* Very unlikely, but possible on 16 bit machine if
1410           * strstart == 0 && lookahead == 1 (input done a byte at time)
1411           */
1412           more--;
1413           }
1414           }
1415            
1416           /* If the window is almost full and there is insufficient lookahead,
1417           * move the upper half to the lower one to make room in the upper half.
1418           */
1419 356464         if (s->strstart >= wsize+MAX_DIST(s)) {
1420            
1421 112         zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
1422 112         s->match_start -= wsize;
1423 112         s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1424 112         s->block_start -= (long) wsize;
1425            
1426           /* Slide the hash table (could be avoided with 32 bit values
1427           at the expense of memory usage). We slide even when level == 0
1428           to keep the hash table consistent if we switch back to level > 0
1429           later. (Using level 0 permanently is not an optimal usage of
1430           zlib, so we don't care about this pathological case.)
1431           */
1432 112         n = s->hash_size;
1433 112         p = &s->head[n];
1434           do {
1435 7340032         m = *--p;
1436 7340032         *p = (Pos)(m >= wsize ? m-wsize : NIL);
1437 7340032         } while (--n);
1438            
1439           n = wsize;
1440           #ifndef FASTEST
1441 112         p = &s->prev[n];
1442           do {
1443 3670016         m = *--p;
1444 3670016         *p = (Pos)(m >= wsize ? m-wsize : NIL);
1445           /* If n is not on any hash chain, prev[n] is garbage but
1446           * its value will never be used.
1447           */
1448 3670016         } while (--n);
1449           #endif
1450 112         more += wsize;
1451           }
1452 356464         if (s->strm->avail_in == 0) break;
1453            
1454           /* If there was no sliding:
1455           * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1456           * more == window_size - lookahead - strstart
1457           * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1458           * => more >= window_size - 2*WSIZE + 2
1459           * In the BIG_MEM or MMAP case (not yet supported),
1460           * window_size == input_size + MIN_LOOKAHEAD &&
1461           * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1462           * Otherwise, window_size == 2*WSIZE so more >= 2.
1463           * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1464           */
1465           Assert(more >= 2, "more < 2");
1466            
1467 309344         n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1468 309344         s->lookahead += n;
1469            
1470           /* Initialize the hash value now that we have some input: */
1471 309344         if (s->lookahead + s->insert >= MIN_MATCH) {
1472 309210         uInt str = s->strstart - s->insert;
1473 309210         s->ins_h = s->window[str];
1474 309210         UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
1475           #if MIN_MATCH != 3
1476           Call UPDATE_HASH() MIN_MATCH-3 more times
1477           #endif
1478 618542         while (s->insert) {
1479 122         UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
1480           #ifndef FASTEST
1481 122         s->prev[str & s->w_mask] = s->head[s->ins_h];
1482           #endif
1483 122         s->head[s->ins_h] = (Pos)str;
1484 122         str++;
1485 122         s->insert--;
1486 122         if (s->lookahead + s->insert < MIN_MATCH)
1487           break;
1488           }
1489           }
1490           /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1491           * but this is not important since only literal bytes will be emitted.
1492           */
1493            
1494 309344         } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1495            
1496           /* If the WIN_INIT bytes after the end of the current data have never been
1497           * written, then zero those bytes in order to avoid memory check reports of
1498           * the use of uninitialized (or uninitialised as Julian writes) bytes by
1499           * the longest match routines. Update the high water mark for the next
1500           * time through here. WIN_INIT is set to MAX_MATCH since the longest match
1501           * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
1502           */
1503 356464         if (s->high_water < s->window_size) {
1504 356240         ulg curr = s->strstart + (ulg)(s->lookahead);
1505           ulg init;
1506            
1507 356240         if (s->high_water < curr) {
1508           /* Previous high water mark below current data -- zero WIN_INIT
1509           * bytes or up to end of window, whichever is less.
1510           */
1511 2512         init = s->window_size - curr;
1512 2512         if (init > WIN_INIT)
1513           init = WIN_INIT;
1514 2512         zmemzero(s->window + curr, (unsigned)init);
1515 2512         s->high_water = curr + init;
1516           }
1517 353728         else if (s->high_water < (ulg)curr + WIN_INIT) {
1518           /* High water mark at or above current data, but below current data
1519           * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
1520           * to end of window, whichever is less.
1521           */
1522 307486         init = (ulg)curr + WIN_INIT - s->high_water;
1523 307486         if (init > s->window_size - s->high_water)
1524 0         init = s->window_size - s->high_water;
1525 307486         zmemzero(s->window + s->high_water, (unsigned)init);
1526 307486         s->high_water += init;
1527           }
1528           }
1529            
1530           Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
1531           "not enough room for search");
1532 356464         }
1533            
1534           /* ===========================================================================
1535           * Flush the current block, with given end-of-file flag.
1536           * IN assertion: strstart is set to the end of the current match.
1537           */
1538           #define FLUSH_BLOCK_ONLY(s, last) { \
1539           _tr_flush_block(s, (s->block_start >= 0L ? \
1540           (charf *)&s->window[(unsigned)s->block_start] : \
1541           (charf *)Z_NULL), \
1542           (ulg)((long)s->strstart - s->block_start), \
1543           (last)); \
1544           s->block_start = s->strstart; \
1545           flush_pending(s->strm); \
1546           Tracev((stderr,"[FLUSH]")); \
1547           }
1548            
1549           /* Same but force premature exit if necessary. */
1550           #define FLUSH_BLOCK(s, last) { \
1551           FLUSH_BLOCK_ONLY(s, last); \
1552           if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
1553           }
1554            
1555           /* ===========================================================================
1556           * Copy without compression as much as possible from the input stream, return
1557           * the current block state.
1558           * This function does not insert new strings in the dictionary since
1559           * uncompressible data is probably not useful. This function is used
1560           * only for the level=0 compression option.
1561           * NOTE: this function should be optimized to avoid extra copying from
1562           * window to pending_buf.
1563           */
1564 24         local block_state deflate_stored(
1565           deflate_state *s,
1566           int flush)
1567           {
1568           /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1569           * to pending_buf_size, and each stored block has a 5 byte header:
1570           */
1571           ulg max_block_size = 0xffff;
1572           ulg max_start;
1573            
1574 24         if (max_block_size > s->pending_buf_size - 5) {
1575 0         max_block_size = s->pending_buf_size - 5;
1576           }
1577            
1578           /* Copy as much as possible from input to output: */
1579           for (;;) {
1580           /* Fill the window as much as possible: */
1581 36         if (s->lookahead <= 1) {
1582            
1583           Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1584           s->block_start >= (long)s->w_size, "slide too late");
1585            
1586 36         fill_window(s);
1587 36         if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1588            
1589 24         if (s->lookahead == 0) break; /* flush the current block */
1590           }
1591           Assert(s->block_start >= 0L, "block gone");
1592            
1593 12         s->strstart += s->lookahead;
1594 12         s->lookahead = 0;
1595            
1596           /* Emit a stored block if pending_buf will be full: */
1597 12         max_start = s->block_start + max_block_size;
1598 12         if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1599           /* strstart == 0 is possible when wraparound on 16-bit machine */
1600 0         s->lookahead = (uInt)(s->strstart - max_start);
1601 0         s->strstart = (uInt)max_start;
1602 0         FLUSH_BLOCK(s, 0);
1603           }
1604           /* Flush if we may have to slide, otherwise block_start may become
1605           * negative and the data will be gone:
1606           */
1607 12         if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1608 0         FLUSH_BLOCK(s, 0);
1609           }
1610           }
1611 12         s->insert = 0;
1612 12         if (flush == Z_FINISH) {
1613 12         FLUSH_BLOCK(s, 1);
1614 6         return finish_done;
1615           }
1616 0         if ((long)s->strstart > s->block_start)
1617 0         FLUSH_BLOCK(s, 0);
1618 0         return block_done;
1619           }
1620            
1621           /* ===========================================================================
1622           * Compress as much as possible from the input stream, return the current
1623           * block state.
1624           * This function does not perform lazy evaluation of matches and inserts
1625           * new strings in the dictionary only for unmatched strings or for short
1626           * matches. It is used only for the fast compression options.
1627           */
1628 360         local block_state deflate_fast(
1629           deflate_state *s,
1630           int flush)
1631           {
1632           IPos hash_head; /* head of the hash chain */
1633           int bflush; /* set if current block must be flushed */
1634            
1635           for (;;) {
1636           /* Make sure that we always have enough lookahead, except
1637           * at the end of the input file. We need MAX_MATCH bytes
1638           * for the next match, plus MIN_MATCH bytes to insert the
1639           * string following the next match.
1640           */
1641 73954         if (s->lookahead < MIN_LOOKAHEAD) {
1642 836         fill_window(s);
1643 836         if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1644           return need_more;
1645           }
1646 512         if (s->lookahead == 0) break; /* flush the current block */
1647           }
1648            
1649           /* Insert the string window[strstart .. strstart+2] in the
1650           * dictionary, and set hash_head to the head of the hash chain:
1651           */
1652           hash_head = NIL;
1653 73594         if (s->lookahead >= MIN_MATCH) {
1654 73558         INSERT_STRING(s, s->strstart, hash_head);
1655           }
1656            
1657           /* Find the longest match, discarding those <= prev_length.
1658           * At this point we have always match_length < MIN_MATCH
1659           */
1660 73594         if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1661           /* To simplify the code, we prevent matches with the string
1662           * of window index 0 (in particular we have to avoid a match
1663           * of the string with itself at the start of the input file).
1664           */
1665 43862         s->match_length = longest_match (s, hash_head);
1666           /* longest_match() sets match_start */
1667           }
1668 73594         if (s->match_length >= MIN_MATCH) {
1669           check_match(s, s->strstart, s->match_start, s->match_length);
1670            
1671 35332         _tr_tally_dist(s, s->strstart - s->match_start,
1672           s->match_length - MIN_MATCH, bflush);
1673            
1674 35332         s->lookahead -= s->match_length;
1675            
1676           /* Insert new strings in the hash table only if the match length
1677           * is not too large. This saves time but degrades compression.
1678           */
1679           #ifndef FASTEST
1680 51244         if (s->match_length <= s->max_insert_length &&
1681 15912         s->lookahead >= MIN_MATCH) {
1682 15912         s->match_length--; /* string at strstart already in table */
1683           do {
1684 38724         s->strstart++;
1685 38724         INSERT_STRING(s, s->strstart, hash_head);
1686           /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1687           * always MIN_MATCH bytes ahead.
1688           */
1689 38724         } while (--s->match_length != 0);
1690 15912         s->strstart++;
1691           } else
1692           #endif
1693           {
1694 19420         s->strstart += s->match_length;
1695 19420         s->match_length = 0;
1696 19420         s->ins_h = s->window[s->strstart];
1697 19420         UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1698           #if MIN_MATCH != 3
1699           Call UPDATE_HASH() MIN_MATCH-3 more times
1700           #endif
1701           /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1702           * matter since it will be recomputed at next deflate call.
1703           */
1704           }
1705           } else {
1706           /* No match, output a literal byte */
1707           Tracevv((stderr,"%c", s->window[s->strstart]));
1708 38262         _tr_tally_lit (s, s->window[s->strstart], bflush);
1709 38262         s->lookahead--;
1710 38262         s->strstart++;
1711           }
1712 73594         if (bflush) FLUSH_BLOCK(s, 0);
1713           }
1714 36         s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
1715 36         if (flush == Z_FINISH) {
1716 36         FLUSH_BLOCK(s, 1);
1717 28         return finish_done;
1718           }
1719 0         if (s->last_lit)
1720 0         FLUSH_BLOCK(s, 0);
1721 0         return block_done;
1722           }
1723            
1724           #ifndef FASTEST
1725           /* ===========================================================================
1726           * Same as above, but achieves better compression. We use a lazy
1727           * evaluation for matches: a match is finally adopted only if there is
1728           * no better match at the next window position.
1729           */
1730 311816         local block_state deflate_slow(
1731           deflate_state *s,
1732           int flush)
1733           {
1734           IPos hash_head; /* head of hash chain */
1735           int bflush; /* set if current block must be flushed */
1736            
1737           /* Process the input block. */
1738           for (;;) {
1739           /* Make sure that we always have enough lookahead, except
1740           * at the end of the input file. We need MAX_MATCH bytes
1741           * for the next match, plus MIN_MATCH bytes to insert the
1742           * string following the next match.
1743           */
1744 688148         if (s->lookahead < MIN_LOOKAHEAD) {
1745 355344         fill_window(s);
1746 355344         if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1747           return need_more;
1748           }
1749 46538         if (s->lookahead == 0) break; /* flush the current block */
1750           }
1751            
1752           /* Insert the string window[strstart .. strstart+2] in the
1753           * dictionary, and set hash_head to the head of the hash chain:
1754           */
1755           hash_head = NIL;
1756 376334         if (s->lookahead >= MIN_MATCH) {
1757 372780         INSERT_STRING(s, s->strstart, hash_head);
1758           }
1759            
1760           /* Find the longest match, discarding those <= prev_length.
1761           */
1762 376334         s->prev_length = s->match_length, s->prev_match = s->match_start;
1763 376334         s->match_length = MIN_MATCH-1;
1764            
1765 453162         if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1766 76828         s->strstart - hash_head <= MAX_DIST(s)) {
1767           /* To simplify the code, we prevent matches with the string
1768           * of window index 0 (in particular we have to avoid a match
1769           * of the string with itself at the start of the input file).
1770           */
1771 74116         s->match_length = longest_match (s, hash_head);
1772           /* longest_match() sets match_start */
1773            
1774 74116         if (s->match_length <= 5 && (s->strategy == Z_FILTERED
1775           #if TOO_FAR <= 32767
1776 41018         || (s->match_length == MIN_MATCH &&
1777 1430         s->strstart - s->match_start > TOO_FAR)
1778           #endif
1779           )) {
1780            
1781           /* If prev_match is also MIN_MATCH, match_start is garbage
1782           * but we will ignore the current match anyway.
1783           */
1784 98         s->match_length = MIN_MATCH-1;
1785           }
1786           }
1787           /* If there was a match at the previous step and the current
1788           * match is not better, output the previous match:
1789           */
1790 376334         if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1791 35924         uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1792           /* Do not insert strings in hash table beyond this. */
1793            
1794           check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1795            
1796 35924         _tr_tally_dist(s, s->strstart -1 - s->prev_match,
1797           s->prev_length - MIN_MATCH, bflush);
1798            
1799           /* Insert in hash table all strings up to the end of the match.
1800           * strstart-1 and strstart are already inserted. If there is not
1801           * enough lookahead, the last two strings are not inserted in
1802           * the hash table.
1803           */
1804 35924         s->lookahead -= s->prev_length-1;
1805 35924         s->prev_length -= 2;
1806           do {
1807 8742594         if (++s->strstart <= max_insert) {
1808 8741650         INSERT_STRING(s, s->strstart, hash_head);
1809           }
1810 8742594         } while (--s->prev_length != 0);
1811 35924         s->match_available = 0;
1812 35924         s->match_length = MIN_MATCH-1;
1813 35924         s->strstart++;
1814            
1815 35924         if (bflush) FLUSH_BLOCK(s, 0);
1816            
1817 340410         } else if (s->match_available) {
1818           /* If there was no match at the previous position, output a
1819           * single literal. If there was a match but the current match
1820           * is longer, truncate the previous match to a single literal.
1821           */
1822           Tracevv((stderr,"%c", s->window[s->strstart-1]));
1823 302676         _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1824 302676         if (bflush) {
1825 2         FLUSH_BLOCK_ONLY(s, 0);
1826           }
1827 302676         s->strstart++;
1828 302676         s->lookahead--;
1829 302676         if (s->strm->avail_out == 0) return need_more;
1830           } else {
1831           /* There is no previous match to compare with, wait for
1832           * the next step to decide.
1833           */
1834 37734         s->match_available = 1;
1835 37734         s->strstart++;
1836 37734         s->lookahead--;
1837           }
1838           }
1839           Assert (flush != Z_NO_FLUSH, "no flush?");
1840 3008         if (s->match_available) {
1841           Tracevv((stderr,"%c", s->window[s->strstart-1]));
1842 1810         _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1843 1810         s->match_available = 0;
1844           }
1845 3008         s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
1846 3008         if (flush == Z_FINISH) {
1847 2964         FLUSH_BLOCK(s, 1);
1848 2772         return finish_done;
1849           }
1850 44         if (s->last_lit)
1851 30         FLUSH_BLOCK(s, 0);
1852 24         return block_done;
1853           }
1854           #endif /* FASTEST */
1855            
1856           /* ===========================================================================
1857           * For Z_RLE, simply look for runs of bytes, generate matches only of distance
1858           * one. Do not maintain a hash table. (It will be regenerated if this run of
1859           * deflate switches away from Z_RLE.)
1860           */
1861 0         local block_state deflate_rle(
1862           deflate_state *s,
1863           int flush)
1864           {
1865           int bflush; /* set if current block must be flushed */
1866           uInt prev; /* byte at distance one to match */
1867           Bytef *scan, *strend; /* scan goes up to strend for length of run */
1868            
1869           for (;;) {
1870           /* Make sure that we always have enough lookahead, except
1871           * at the end of the input file. We need MAX_MATCH bytes
1872           * for the longest run, plus one for the unrolled loop.
1873           */
1874 0         if (s->lookahead <= MAX_MATCH) {
1875 0         fill_window(s);
1876 0         if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
1877           return need_more;
1878           }
1879 0         if (s->lookahead == 0) break; /* flush the current block */
1880           }
1881            
1882           /* See how many times the previous byte repeats */
1883 0         s->match_length = 0;
1884 0         if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
1885 0         scan = s->window + s->strstart - 1;
1886 0         prev = *scan;
1887 0         if (prev == *++scan && prev == *++scan && prev == *++scan) {
1888 0         strend = s->window + s->strstart + MAX_MATCH;
1889           do {
1890 0         } while (prev == *++scan && prev == *++scan &&
1891 0         prev == *++scan && prev == *++scan &&
1892 0         prev == *++scan && prev == *++scan &&
1893 0         prev == *++scan && prev == *++scan &&
1894 0         scan < strend);
1895 0         s->match_length = MAX_MATCH - (int)(strend - scan);
1896 0         if (s->match_length > s->lookahead)
1897 0         s->match_length = s->lookahead;
1898           }
1899           Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
1900           }
1901            
1902           /* Emit match if have run of MIN_MATCH or longer, else emit literal */
1903 0         if (s->match_length >= MIN_MATCH) {
1904           check_match(s, s->strstart, s->strstart - 1, s->match_length);
1905            
1906 0         _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
1907            
1908 0         s->lookahead -= s->match_length;
1909 0         s->strstart += s->match_length;
1910 0         s->match_length = 0;
1911           } else {
1912           /* No match, output a literal byte */
1913           Tracevv((stderr,"%c", s->window[s->strstart]));
1914 0         _tr_tally_lit (s, s->window[s->strstart], bflush);
1915 0         s->lookahead--;
1916 0         s->strstart++;
1917           }
1918 0         if (bflush) FLUSH_BLOCK(s, 0);
1919           }
1920 0         s->insert = 0;
1921 0         if (flush == Z_FINISH) {
1922 0         FLUSH_BLOCK(s, 1);
1923 0         return finish_done;
1924           }
1925 0         if (s->last_lit)
1926 0         FLUSH_BLOCK(s, 0);
1927 0         return block_done;
1928           }
1929            
1930           /* ===========================================================================
1931           * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
1932           * (It will be regenerated if this run of deflate switches away from Huffman.)
1933           */
1934 50         local block_state deflate_huff(
1935           deflate_state *s,
1936           int flush)
1937           {
1938           int bflush; /* set if current block must be flushed */
1939            
1940           for (;;) {
1941           /* Make sure that we have a literal to write. */
1942 418210         if (s->lookahead == 0) {
1943 90         fill_window(s);
1944 90         if (s->lookahead == 0) {
1945 50         if (flush == Z_NO_FLUSH)
1946           return need_more;
1947           break; /* flush the current block */
1948           }
1949           }
1950            
1951           /* Output a literal byte */
1952 418160         s->match_length = 0;
1953           Tracevv((stderr,"%c", s->window[s->strstart]));
1954 418160         _tr_tally_lit (s, s->window[s->strstart], bflush);
1955 418160         s->lookahead--;
1956 418160         s->strstart++;
1957 418160         if (bflush) FLUSH_BLOCK(s, 0);
1958           }
1959 26         s->insert = 0;
1960 26         if (flush == Z_FINISH) {
1961 18         FLUSH_BLOCK(s, 1);
1962 16         return finish_done;
1963           }
1964 8         if (s->last_lit)
1965 8         FLUSH_BLOCK(s, 0);
1966 0         return block_done;
1967           }