Line data Source code
1 : /* deflate.c -- compress data using the deflation algorithm
2 : * Copyright (C) 1995-2017 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 1.2.11 Copyright 1995-2017 Jean-loup Gailly and Mark Adler ";
56 : /*
57 : If you use the zlib library in a product, an acknowledgment is welcome
58 : in the documentation of your product. If for some reason you cannot
59 : include such an acknowledgment, I would appreciate that you keep this
60 : copyright string in the executable of your product.
61 : */
62 :
63 : /* ===========================================================================
64 : * Function prototypes.
65 : */
66 : typedef enum {
67 : need_more, /* block not completed, need more input or more output */
68 : block_done, /* block flush performed */
69 : finish_started, /* finish started, need only more output at next deflate */
70 : finish_done /* finish done, accept no more input or output */
71 : } block_state;
72 :
73 : typedef block_state (*compress_func) OF((deflate_state *s, int flush));
74 : /* Compression function. Returns the block state after the call. */
75 :
76 : local int deflateStateCheck OF((z_streamp strm));
77 : local void slide_hash OF((deflate_state *s));
78 : local void fill_window OF((deflate_state *s));
79 : local block_state deflate_stored OF((deflate_state *s, int flush));
80 : local block_state deflate_fast OF((deflate_state *s, int flush));
81 : #ifndef FASTEST
82 : local block_state deflate_slow OF((deflate_state *s, int flush));
83 : #endif
84 : local block_state deflate_rle OF((deflate_state *s, int flush));
85 : local block_state deflate_huff OF((deflate_state *s, int flush));
86 : local void lm_init OF((deflate_state *s));
87 : local void putShortMSB OF((deflate_state *s, uInt b));
88 : local void flush_pending OF((z_streamp strm));
89 : local unsigned read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
90 : #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
95 : local uInt longest_match OF((deflate_state *s, IPos cur_match));
96 : #endif
97 :
98 : #ifdef ZLIB_DEBUG
99 : local void check_match OF((deflate_state *s, IPos start, IPos match,
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 */
124 : ush max_chain;
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
134 : local const config configuration_table[10] = {
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 : s->head[s->hash_size-1] = NIL; \
194 : zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
195 :
196 : /* ===========================================================================
197 : * Slide the hash table when sliding the window down (could be avoided with 32
198 : * bit values at the expense of memory usage). We slide even when level == 0 to
199 : * keep the hash table consistent if we switch back to level > 0 later.
200 : */
201 0 : local void slide_hash(s)
202 : deflate_state *s;
203 : {
204 : unsigned n, m;
205 : Posf *p;
206 0 : uInt wsize = s->w_size;
207 :
208 0 : n = s->hash_size;
209 0 : p = &s->head[n];
210 : do {
211 0 : m = *--p;
212 0 : *p = (Pos)(m >= wsize ? m - wsize : NIL);
213 0 : } while (--n);
214 0 : n = wsize;
215 : #ifndef FASTEST
216 0 : p = &s->prev[n];
217 : do {
218 0 : m = *--p;
219 0 : *p = (Pos)(m >= wsize ? m - wsize : NIL);
220 : /* If n is not on any hash chain, prev[n] is garbage but
221 : * its value will never be used.
222 : */
223 0 : } while (--n);
224 : #endif
225 0 : }
226 :
227 : /* ========================================================================= */
228 72 : int ZEXPORT deflateInit_(strm, level, version, stream_size)
229 : z_streamp strm;
230 : int level;
231 : const char *version;
232 : int stream_size;
233 : {
234 72 : return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
235 : Z_DEFAULT_STRATEGY, version, stream_size);
236 : /* To do: ignore strm->next_in if we use it as window */
237 : }
238 :
239 : /* ========================================================================= */
240 72 : int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
241 : version, stream_size)
242 : z_streamp strm;
243 : int level;
244 : int method;
245 : int windowBits;
246 : int memLevel;
247 : int strategy;
248 : const char *version;
249 : int stream_size;
250 : {
251 : deflate_state *s;
252 72 : int wrap = 1;
253 : static const char my_version[] = ZLIB_VERSION;
254 :
255 : ushf *overlay;
256 : /* We overlay pending_buf and d_buf+l_buf. This works since the average
257 : * output size for (length,distance) codes is <= 24 bits.
258 : */
259 :
260 72 : if (version == Z_NULL || version[0] != my_version[0] ||
261 : stream_size != sizeof(z_stream)) {
262 0 : return Z_VERSION_ERROR;
263 : }
264 72 : if (strm == Z_NULL) return Z_STREAM_ERROR;
265 :
266 72 : strm->msg = Z_NULL;
267 72 : if (strm->zalloc == (alloc_func)0) {
268 : #ifdef Z_SOLO
269 : return Z_STREAM_ERROR;
270 : #else
271 72 : strm->zalloc = zcalloc;
272 72 : strm->opaque = (voidpf)0;
273 : #endif
274 : }
275 72 : if (strm->zfree == (free_func)0)
276 : #ifdef Z_SOLO
277 : return Z_STREAM_ERROR;
278 : #else
279 72 : strm->zfree = zcfree;
280 : #endif
281 :
282 : #ifdef FASTEST
283 : if (level != 0) level = 1;
284 : #else
285 72 : if (level == Z_DEFAULT_COMPRESSION) level = 6;
286 : #endif
287 :
288 72 : if (windowBits < 0) { /* suppress zlib wrapper */
289 0 : wrap = 0;
290 0 : windowBits = -windowBits;
291 : }
292 : #ifdef GZIP
293 72 : else if (windowBits > 15) {
294 0 : wrap = 2; /* write gzip wrapper instead */
295 0 : windowBits -= 16;
296 : }
297 : #endif
298 72 : if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
299 72 : windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
300 72 : strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) {
301 0 : return Z_STREAM_ERROR;
302 : }
303 72 : if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */
304 72 : s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
305 72 : if (s == Z_NULL) return Z_MEM_ERROR;
306 72 : strm->state = (struct internal_state FAR *)s;
307 72 : s->strm = strm;
308 72 : s->status = INIT_STATE; /* to pass state test in deflateReset() */
309 :
310 72 : s->wrap = wrap;
311 72 : s->gzhead = Z_NULL;
312 72 : s->w_bits = (uInt)windowBits;
313 72 : s->w_size = 1 << s->w_bits;
314 72 : s->w_mask = s->w_size - 1;
315 :
316 72 : s->hash_bits = (uInt)memLevel + 7;
317 72 : s->hash_size = 1 << s->hash_bits;
318 72 : s->hash_mask = s->hash_size - 1;
319 72 : s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
320 :
321 72 : s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
322 72 : s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
323 72 : s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
324 :
325 72 : s->high_water = 0; /* nothing written to s->window yet */
326 :
327 72 : s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
328 :
329 72 : overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
330 72 : s->pending_buf = (uchf *) overlay;
331 72 : s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
332 :
333 144 : if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
334 72 : s->pending_buf == Z_NULL) {
335 0 : s->status = FINISH_STATE;
336 0 : strm->msg = ERR_MSG(Z_MEM_ERROR);
337 0 : deflateEnd (strm);
338 0 : return Z_MEM_ERROR;
339 : }
340 72 : s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
341 72 : s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
342 :
343 72 : s->level = level;
344 72 : s->strategy = strategy;
345 72 : s->method = (Byte)method;
346 :
347 72 : return deflateReset(strm);
348 : }
349 :
350 : /* =========================================================================
351 : * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
352 : */
353 216 : local int deflateStateCheck (strm)
354 : z_streamp strm;
355 : {
356 : deflate_state *s;
357 432 : if (strm == Z_NULL ||
358 432 : strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
359 0 : return 1;
360 216 : s = strm->state;
361 288 : if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
362 : #ifdef GZIP
363 144 : s->status != GZIP_STATE &&
364 : #endif
365 144 : s->status != EXTRA_STATE &&
366 144 : s->status != NAME_STATE &&
367 144 : s->status != COMMENT_STATE &&
368 144 : s->status != HCRC_STATE &&
369 144 : s->status != BUSY_STATE &&
370 72 : s->status != FINISH_STATE))
371 0 : return 1;
372 216 : return 0;
373 : }
374 :
375 : /* ========================================================================= */
376 0 : int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
377 : z_streamp strm;
378 : const Bytef *dictionary;
379 : uInt dictLength;
380 : {
381 : deflate_state *s;
382 : uInt str, n;
383 : int wrap;
384 : unsigned avail;
385 : z_const unsigned char *next;
386 :
387 0 : if (deflateStateCheck(strm) || dictionary == Z_NULL)
388 0 : return Z_STREAM_ERROR;
389 0 : s = strm->state;
390 0 : wrap = s->wrap;
391 0 : if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead)
392 0 : return Z_STREAM_ERROR;
393 :
394 : /* when using zlib wrappers, compute Adler-32 for provided dictionary */
395 0 : if (wrap == 1)
396 0 : strm->adler = adler32(strm->adler, dictionary, dictLength);
397 0 : s->wrap = 0; /* avoid computing Adler-32 in read_buf */
398 :
399 : /* if dictionary would fill window, just replace the history */
400 0 : if (dictLength >= s->w_size) {
401 0 : if (wrap == 0) { /* already empty otherwise */
402 0 : CLEAR_HASH(s);
403 0 : s->strstart = 0;
404 0 : s->block_start = 0L;
405 0 : s->insert = 0;
406 : }
407 0 : dictionary += dictLength - s->w_size; /* use the tail */
408 0 : dictLength = s->w_size;
409 : }
410 :
411 : /* insert dictionary into window and hash */
412 0 : avail = strm->avail_in;
413 0 : next = strm->next_in;
414 0 : strm->avail_in = dictLength;
415 0 : strm->next_in = (z_const Bytef *)dictionary;
416 0 : fill_window(s);
417 0 : while (s->lookahead >= MIN_MATCH) {
418 0 : str = s->strstart;
419 0 : n = s->lookahead - (MIN_MATCH-1);
420 : do {
421 0 : UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
422 : #ifndef FASTEST
423 0 : s->prev[str & s->w_mask] = s->head[s->ins_h];
424 : #endif
425 0 : s->head[s->ins_h] = (Pos)str;
426 0 : str++;
427 0 : } while (--n);
428 0 : s->strstart = str;
429 0 : s->lookahead = MIN_MATCH-1;
430 0 : fill_window(s);
431 : }
432 0 : s->strstart += s->lookahead;
433 0 : s->block_start = (long)s->strstart;
434 0 : s->insert = s->lookahead;
435 0 : s->lookahead = 0;
436 0 : s->match_length = s->prev_length = MIN_MATCH-1;
437 0 : s->match_available = 0;
438 0 : strm->next_in = next;
439 0 : strm->avail_in = avail;
440 0 : s->wrap = wrap;
441 0 : return Z_OK;
442 : }
443 :
444 : /* ========================================================================= */
445 0 : int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength)
446 : z_streamp strm;
447 : Bytef *dictionary;
448 : uInt *dictLength;
449 : {
450 : deflate_state *s;
451 : uInt len;
452 :
453 0 : if (deflateStateCheck(strm))
454 0 : return Z_STREAM_ERROR;
455 0 : s = strm->state;
456 0 : len = s->strstart + s->lookahead;
457 0 : if (len > s->w_size)
458 0 : len = s->w_size;
459 0 : if (dictionary != Z_NULL && len)
460 0 : zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
461 0 : if (dictLength != Z_NULL)
462 0 : *dictLength = len;
463 0 : return Z_OK;
464 : }
465 :
466 : /* ========================================================================= */
467 72 : int ZEXPORT deflateResetKeep (strm)
468 : z_streamp strm;
469 : {
470 : deflate_state *s;
471 :
472 72 : if (deflateStateCheck(strm)) {
473 0 : return Z_STREAM_ERROR;
474 : }
475 :
476 72 : strm->total_in = strm->total_out = 0;
477 72 : strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
478 72 : strm->data_type = Z_UNKNOWN;
479 :
480 72 : s = (deflate_state *)strm->state;
481 72 : s->pending = 0;
482 72 : s->pending_out = s->pending_buf;
483 :
484 72 : if (s->wrap < 0) {
485 0 : s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */
486 : }
487 72 : s->status =
488 : #ifdef GZIP
489 144 : s->wrap == 2 ? GZIP_STATE :
490 : #endif
491 72 : s->wrap ? INIT_STATE : BUSY_STATE;
492 72 : strm->adler =
493 : #ifdef GZIP
494 72 : s->wrap == 2 ? crc32(0L, Z_NULL, 0) :
495 : #endif
496 : adler32(0L, Z_NULL, 0);
497 72 : s->last_flush = Z_NO_FLUSH;
498 :
499 72 : _tr_init(s);
500 :
501 72 : return Z_OK;
502 : }
503 :
504 : /* ========================================================================= */
505 72 : int ZEXPORT deflateReset (strm)
506 : z_streamp strm;
507 : {
508 : int ret;
509 :
510 72 : ret = deflateResetKeep(strm);
511 72 : if (ret == Z_OK)
512 72 : lm_init(strm->state);
513 72 : return ret;
514 : }
515 :
516 : /* ========================================================================= */
517 0 : int ZEXPORT deflateSetHeader (strm, head)
518 : z_streamp strm;
519 : gz_headerp head;
520 : {
521 0 : if (deflateStateCheck(strm) || strm->state->wrap != 2)
522 0 : return Z_STREAM_ERROR;
523 0 : strm->state->gzhead = head;
524 0 : return Z_OK;
525 : }
526 :
527 : /* ========================================================================= */
528 0 : int ZEXPORT deflatePending (strm, pending, bits)
529 : unsigned *pending;
530 : int *bits;
531 : z_streamp strm;
532 : {
533 0 : if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
534 0 : if (pending != Z_NULL)
535 0 : *pending = strm->state->pending;
536 0 : if (bits != Z_NULL)
537 0 : *bits = strm->state->bi_valid;
538 0 : return Z_OK;
539 : }
540 :
541 : /* ========================================================================= */
542 0 : int ZEXPORT deflatePrime (strm, bits, value)
543 : z_streamp strm;
544 : int bits;
545 : int value;
546 : {
547 : deflate_state *s;
548 : int put;
549 :
550 0 : if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
551 0 : s = strm->state;
552 0 : if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3))
553 0 : return Z_BUF_ERROR;
554 : do {
555 0 : put = Buf_size - s->bi_valid;
556 0 : if (put > bits)
557 0 : put = bits;
558 0 : s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid);
559 0 : s->bi_valid += put;
560 0 : _tr_flush_bits(s);
561 0 : value >>= put;
562 0 : bits -= put;
563 0 : } while (bits);
564 0 : return Z_OK;
565 : }
566 :
567 : /* ========================================================================= */
568 0 : int ZEXPORT deflateParams(strm, level, strategy)
569 : z_streamp strm;
570 : int level;
571 : int strategy;
572 : {
573 : deflate_state *s;
574 : compress_func func;
575 :
576 0 : if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
577 0 : s = strm->state;
578 :
579 : #ifdef FASTEST
580 : if (level != 0) level = 1;
581 : #else
582 0 : if (level == Z_DEFAULT_COMPRESSION) level = 6;
583 : #endif
584 0 : if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) {
585 0 : return Z_STREAM_ERROR;
586 : }
587 0 : func = configuration_table[s->level].func;
588 :
589 0 : if ((strategy != s->strategy || func != configuration_table[level].func) &&
590 0 : s->high_water) {
591 : /* Flush the last buffer: */
592 0 : int err = deflate(strm, Z_BLOCK);
593 0 : if (err == Z_STREAM_ERROR)
594 0 : return err;
595 0 : if (strm->avail_out == 0)
596 0 : return Z_BUF_ERROR;
597 : }
598 0 : if (s->level != level) {
599 0 : if (s->level == 0 && s->matches != 0) {
600 0 : if (s->matches == 1)
601 0 : slide_hash(s);
602 : else
603 0 : CLEAR_HASH(s);
604 0 : s->matches = 0;
605 : }
606 0 : s->level = level;
607 0 : s->max_lazy_match = configuration_table[level].max_lazy;
608 0 : s->good_match = configuration_table[level].good_length;
609 0 : s->nice_match = configuration_table[level].nice_length;
610 0 : s->max_chain_length = configuration_table[level].max_chain;
611 : }
612 0 : s->strategy = strategy;
613 0 : return Z_OK;
614 : }
615 :
616 : /* ========================================================================= */
617 0 : int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
618 : z_streamp strm;
619 : int good_length;
620 : int max_lazy;
621 : int nice_length;
622 : int max_chain;
623 : {
624 : deflate_state *s;
625 :
626 0 : if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
627 0 : s = strm->state;
628 0 : s->good_match = (uInt)good_length;
629 0 : s->max_lazy_match = (uInt)max_lazy;
630 0 : s->nice_match = nice_length;
631 0 : s->max_chain_length = (uInt)max_chain;
632 0 : return Z_OK;
633 : }
634 :
635 : /* =========================================================================
636 : * For the default windowBits of 15 and memLevel of 8, this function returns
637 : * a close to exact, as well as small, upper bound on the compressed size.
638 : * They are coded as constants here for a reason--if the #define's are
639 : * changed, then this function needs to be changed as well. The return
640 : * value for 15 and 8 only works for those exact settings.
641 : *
642 : * For any setting other than those defaults for windowBits and memLevel,
643 : * the value returned is a conservative worst case for the maximum expansion
644 : * resulting from using fixed blocks instead of stored blocks, which deflate
645 : * can emit on compressed data for some combinations of the parameters.
646 : *
647 : * This function could be more sophisticated to provide closer upper bounds for
648 : * every combination of windowBits and memLevel. But even the conservative
649 : * upper bound of about 14% expansion does not seem onerous for output buffer
650 : * allocation.
651 : */
652 0 : uLong ZEXPORT deflateBound(strm, sourceLen)
653 : z_streamp strm;
654 : uLong sourceLen;
655 : {
656 : deflate_state *s;
657 : uLong complen, wraplen;
658 :
659 : /* conservative upper bound for compressed data */
660 0 : complen = sourceLen +
661 0 : ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5;
662 :
663 : /* if can't get parameters, return conservative bound plus zlib wrapper */
664 0 : if (deflateStateCheck(strm))
665 0 : return complen + 6;
666 :
667 : /* compute wrapper length */
668 0 : s = strm->state;
669 0 : switch (s->wrap) {
670 : case 0: /* raw deflate */
671 0 : wraplen = 0;
672 0 : break;
673 : case 1: /* zlib wrapper */
674 0 : wraplen = 6 + (s->strstart ? 4 : 0);
675 0 : break;
676 : #ifdef GZIP
677 : case 2: /* gzip wrapper */
678 0 : wraplen = 18;
679 0 : if (s->gzhead != Z_NULL) { /* user-supplied gzip header */
680 : Bytef *str;
681 0 : if (s->gzhead->extra != Z_NULL)
682 0 : wraplen += 2 + s->gzhead->extra_len;
683 0 : str = s->gzhead->name;
684 0 : if (str != Z_NULL)
685 : do {
686 0 : wraplen++;
687 0 : } while (*str++);
688 0 : str = s->gzhead->comment;
689 0 : if (str != Z_NULL)
690 : do {
691 0 : wraplen++;
692 0 : } while (*str++);
693 0 : if (s->gzhead->hcrc)
694 0 : wraplen += 2;
695 : }
696 0 : break;
697 : #endif
698 : default: /* for compiler happiness */
699 0 : wraplen = 6;
700 : }
701 :
702 : /* if not default parameters, return conservative bound */
703 0 : if (s->w_bits != 15 || s->hash_bits != 8 + 7)
704 0 : return complen + wraplen;
705 :
706 : /* default settings: return tight bound for that case */
707 0 : return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
708 0 : (sourceLen >> 25) + 13 - 6 + wraplen;
709 : }
710 :
711 : /* =========================================================================
712 : * Put a short in the pending buffer. The 16-bit value is put in MSB order.
713 : * IN assertion: the stream state is correct and there is enough room in
714 : * pending_buf.
715 : */
716 216 : local void putShortMSB (s, b)
717 : deflate_state *s;
718 : uInt b;
719 : {
720 216 : put_byte(s, (Byte)(b >> 8));
721 216 : put_byte(s, (Byte)(b & 0xff));
722 216 : }
723 :
724 : /* =========================================================================
725 : * Flush as much pending output as possible. All deflate() output, except for
726 : * some deflate_stored() output, goes through this function so some
727 : * applications may wish to modify it to avoid allocating a large
728 : * strm->next_out buffer and copying into it. (See also read_buf()).
729 : */
730 216 : local void flush_pending(strm)
731 : z_streamp strm;
732 : {
733 : unsigned len;
734 216 : deflate_state *s = strm->state;
735 :
736 216 : _tr_flush_bits(s);
737 216 : len = s->pending;
738 216 : if (len > strm->avail_out) len = strm->avail_out;
739 216 : if (len == 0) return;
740 :
741 216 : zmemcpy(strm->next_out, s->pending_out, len);
742 216 : strm->next_out += len;
743 216 : s->pending_out += len;
744 216 : strm->total_out += len;
745 216 : strm->avail_out -= len;
746 216 : s->pending -= len;
747 216 : if (s->pending == 0) {
748 216 : s->pending_out = s->pending_buf;
749 : }
750 : }
751 :
752 : /* ===========================================================================
753 : * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1].
754 : */
755 : #define HCRC_UPDATE(beg) \
756 : do { \
757 : if (s->gzhead->hcrc && s->pending > (beg)) \
758 : strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
759 : s->pending - (beg)); \
760 : } while (0)
761 :
762 : /* ========================================================================= */
763 72 : int ZEXPORT deflate (strm, flush)
764 : z_streamp strm;
765 : int flush;
766 : {
767 : int old_flush; /* value of flush param for previous deflate call */
768 : deflate_state *s;
769 :
770 72 : if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
771 0 : return Z_STREAM_ERROR;
772 : }
773 72 : s = strm->state;
774 :
775 144 : if (strm->next_out == Z_NULL ||
776 144 : (strm->avail_in != 0 && strm->next_in == Z_NULL) ||
777 72 : (s->status == FINISH_STATE && flush != Z_FINISH)) {
778 0 : ERR_RETURN(strm, Z_STREAM_ERROR);
779 : }
780 72 : if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
781 :
782 72 : old_flush = s->last_flush;
783 72 : s->last_flush = flush;
784 :
785 : /* Flush as much pending output as possible */
786 72 : if (s->pending != 0) {
787 0 : flush_pending(strm);
788 0 : if (strm->avail_out == 0) {
789 : /* Since avail_out is 0, deflate will be called again with
790 : * more output space, but possibly with both pending and
791 : * avail_in equal to zero. There won't be anything to do,
792 : * but this is not an error situation so make sure we
793 : * return OK instead of BUF_ERROR at next call of deflate:
794 : */
795 0 : s->last_flush = -1;
796 0 : return Z_OK;
797 : }
798 :
799 : /* Make sure there is something to do and avoid duplicate consecutive
800 : * flushes. For repeated and useless calls with Z_FINISH, we keep
801 : * returning Z_STREAM_END instead of Z_BUF_ERROR.
802 : */
803 72 : } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) &&
804 : flush != Z_FINISH) {
805 0 : ERR_RETURN(strm, Z_BUF_ERROR);
806 : }
807 :
808 : /* User must not provide more input after the first FINISH: */
809 72 : if (s->status == FINISH_STATE && strm->avail_in != 0) {
810 0 : ERR_RETURN(strm, Z_BUF_ERROR);
811 : }
812 :
813 : /* Write the header */
814 72 : if (s->status == INIT_STATE) {
815 : /* zlib header */
816 72 : uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
817 : uInt level_flags;
818 :
819 72 : if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2)
820 0 : level_flags = 0;
821 72 : else if (s->level < 6)
822 0 : level_flags = 1;
823 72 : else if (s->level == 6)
824 72 : level_flags = 2;
825 : else
826 0 : level_flags = 3;
827 72 : header |= (level_flags << 6);
828 72 : if (s->strstart != 0) header |= PRESET_DICT;
829 72 : header += 31 - (header % 31);
830 :
831 72 : putShortMSB(s, header);
832 :
833 : /* Save the adler32 of the preset dictionary: */
834 72 : if (s->strstart != 0) {
835 0 : putShortMSB(s, (uInt)(strm->adler >> 16));
836 0 : putShortMSB(s, (uInt)(strm->adler & 0xffff));
837 : }
838 72 : strm->adler = adler32(0L, Z_NULL, 0);
839 72 : s->status = BUSY_STATE;
840 :
841 : /* Compression must start with an empty pending buffer */
842 72 : flush_pending(strm);
843 72 : if (s->pending != 0) {
844 0 : s->last_flush = -1;
845 0 : return Z_OK;
846 : }
847 : }
848 : #ifdef GZIP
849 72 : if (s->status == GZIP_STATE) {
850 : /* gzip header */
851 0 : strm->adler = crc32(0L, Z_NULL, 0);
852 0 : put_byte(s, 31);
853 0 : put_byte(s, 139);
854 0 : put_byte(s, 8);
855 0 : if (s->gzhead == Z_NULL) {
856 0 : put_byte(s, 0);
857 0 : put_byte(s, 0);
858 0 : put_byte(s, 0);
859 0 : put_byte(s, 0);
860 0 : put_byte(s, 0);
861 0 : put_byte(s, s->level == 9 ? 2 :
862 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
863 : 4 : 0));
864 0 : put_byte(s, OS_CODE);
865 0 : s->status = BUSY_STATE;
866 :
867 : /* Compression must start with an empty pending buffer */
868 0 : flush_pending(strm);
869 0 : if (s->pending != 0) {
870 0 : s->last_flush = -1;
871 0 : return Z_OK;
872 : }
873 : }
874 : else {
875 0 : put_byte(s, (s->gzhead->text ? 1 : 0) +
876 : (s->gzhead->hcrc ? 2 : 0) +
877 : (s->gzhead->extra == Z_NULL ? 0 : 4) +
878 : (s->gzhead->name == Z_NULL ? 0 : 8) +
879 : (s->gzhead->comment == Z_NULL ? 0 : 16)
880 : );
881 0 : put_byte(s, (Byte)(s->gzhead->time & 0xff));
882 0 : put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff));
883 0 : put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff));
884 0 : put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff));
885 0 : put_byte(s, s->level == 9 ? 2 :
886 : (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ?
887 : 4 : 0));
888 0 : put_byte(s, s->gzhead->os & 0xff);
889 0 : if (s->gzhead->extra != Z_NULL) {
890 0 : put_byte(s, s->gzhead->extra_len & 0xff);
891 0 : put_byte(s, (s->gzhead->extra_len >> 8) & 0xff);
892 : }
893 0 : if (s->gzhead->hcrc)
894 0 : strm->adler = crc32(strm->adler, s->pending_buf,
895 0 : s->pending);
896 0 : s->gzindex = 0;
897 0 : s->status = EXTRA_STATE;
898 : }
899 : }
900 72 : if (s->status == EXTRA_STATE) {
901 0 : if (s->gzhead->extra != Z_NULL) {
902 0 : ulg beg = s->pending; /* start of bytes to update crc */
903 0 : uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex;
904 0 : while (s->pending + left > s->pending_buf_size) {
905 0 : uInt copy = s->pending_buf_size - s->pending;
906 0 : zmemcpy(s->pending_buf + s->pending,
907 0 : s->gzhead->extra + s->gzindex, copy);
908 0 : s->pending = s->pending_buf_size;
909 0 : HCRC_UPDATE(beg);
910 0 : s->gzindex += copy;
911 0 : flush_pending(strm);
912 0 : if (s->pending != 0) {
913 0 : s->last_flush = -1;
914 0 : return Z_OK;
915 : }
916 0 : beg = 0;
917 0 : left -= copy;
918 : }
919 0 : zmemcpy(s->pending_buf + s->pending,
920 0 : s->gzhead->extra + s->gzindex, left);
921 0 : s->pending += left;
922 0 : HCRC_UPDATE(beg);
923 0 : s->gzindex = 0;
924 : }
925 0 : s->status = NAME_STATE;
926 : }
927 72 : if (s->status == NAME_STATE) {
928 0 : if (s->gzhead->name != Z_NULL) {
929 0 : ulg beg = s->pending; /* start of bytes to update crc */
930 : int val;
931 : do {
932 0 : if (s->pending == s->pending_buf_size) {
933 0 : HCRC_UPDATE(beg);
934 0 : flush_pending(strm);
935 0 : if (s->pending != 0) {
936 0 : s->last_flush = -1;
937 0 : return Z_OK;
938 : }
939 0 : beg = 0;
940 : }
941 0 : val = s->gzhead->name[s->gzindex++];
942 0 : put_byte(s, val);
943 0 : } while (val != 0);
944 0 : HCRC_UPDATE(beg);
945 0 : s->gzindex = 0;
946 : }
947 0 : s->status = COMMENT_STATE;
948 : }
949 72 : if (s->status == COMMENT_STATE) {
950 0 : if (s->gzhead->comment != Z_NULL) {
951 0 : ulg beg = s->pending; /* start of bytes to update crc */
952 : int val;
953 : do {
954 0 : if (s->pending == s->pending_buf_size) {
955 0 : HCRC_UPDATE(beg);
956 0 : flush_pending(strm);
957 0 : if (s->pending != 0) {
958 0 : s->last_flush = -1;
959 0 : return Z_OK;
960 : }
961 0 : beg = 0;
962 : }
963 0 : val = s->gzhead->comment[s->gzindex++];
964 0 : put_byte(s, val);
965 0 : } while (val != 0);
966 0 : HCRC_UPDATE(beg);
967 : }
968 0 : s->status = HCRC_STATE;
969 : }
970 72 : if (s->status == HCRC_STATE) {
971 0 : if (s->gzhead->hcrc) {
972 0 : if (s->pending + 2 > s->pending_buf_size) {
973 0 : flush_pending(strm);
974 0 : if (s->pending != 0) {
975 0 : s->last_flush = -1;
976 0 : return Z_OK;
977 : }
978 : }
979 0 : put_byte(s, (Byte)(strm->adler & 0xff));
980 0 : put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
981 0 : strm->adler = crc32(0L, Z_NULL, 0);
982 : }
983 0 : s->status = BUSY_STATE;
984 :
985 : /* Compression must start with an empty pending buffer */
986 0 : flush_pending(strm);
987 0 : if (s->pending != 0) {
988 0 : s->last_flush = -1;
989 0 : return Z_OK;
990 : }
991 : }
992 : #endif
993 :
994 : /* Start a new block or continue the current one.
995 : */
996 72 : if (strm->avail_in != 0 || s->lookahead != 0 ||
997 72 : (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
998 : block_state bstate;
999 :
1000 288 : bstate = s->level == 0 ? deflate_stored(s, flush) :
1001 72 : s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) :
1002 72 : s->strategy == Z_RLE ? deflate_rle(s, flush) :
1003 72 : (*(configuration_table[s->level].func))(s, flush);
1004 :
1005 72 : if (bstate == finish_started || bstate == finish_done) {
1006 72 : s->status = FINISH_STATE;
1007 : }
1008 72 : if (bstate == need_more || bstate == finish_started) {
1009 0 : if (strm->avail_out == 0) {
1010 0 : s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1011 : }
1012 0 : return Z_OK;
1013 : /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1014 : * of deflate should use the same flush parameter to make sure
1015 : * that the flush is complete. So we don't have to output an
1016 : * empty block here, this will be done at next call. This also
1017 : * ensures that for a very small output buffer, we emit at most
1018 : * one empty block.
1019 : */
1020 : }
1021 72 : if (bstate == block_done) {
1022 0 : if (flush == Z_PARTIAL_FLUSH) {
1023 0 : _tr_align(s);
1024 0 : } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */
1025 0 : _tr_stored_block(s, (char*)0, 0L, 0);
1026 : /* For a full flush, this empty block will be recognized
1027 : * as a special marker by inflate_sync().
1028 : */
1029 0 : if (flush == Z_FULL_FLUSH) {
1030 0 : CLEAR_HASH(s); /* forget history */
1031 0 : if (s->lookahead == 0) {
1032 0 : s->strstart = 0;
1033 0 : s->block_start = 0L;
1034 0 : s->insert = 0;
1035 : }
1036 : }
1037 : }
1038 0 : flush_pending(strm);
1039 0 : if (strm->avail_out == 0) {
1040 0 : s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1041 0 : return Z_OK;
1042 : }
1043 : }
1044 : }
1045 :
1046 72 : if (flush != Z_FINISH) return Z_OK;
1047 72 : if (s->wrap <= 0) return Z_STREAM_END;
1048 :
1049 : /* Write the trailer */
1050 : #ifdef GZIP
1051 72 : if (s->wrap == 2) {
1052 0 : put_byte(s, (Byte)(strm->adler & 0xff));
1053 0 : put_byte(s, (Byte)((strm->adler >> 8) & 0xff));
1054 0 : put_byte(s, (Byte)((strm->adler >> 16) & 0xff));
1055 0 : put_byte(s, (Byte)((strm->adler >> 24) & 0xff));
1056 0 : put_byte(s, (Byte)(strm->total_in & 0xff));
1057 0 : put_byte(s, (Byte)((strm->total_in >> 8) & 0xff));
1058 0 : put_byte(s, (Byte)((strm->total_in >> 16) & 0xff));
1059 0 : put_byte(s, (Byte)((strm->total_in >> 24) & 0xff));
1060 : }
1061 : else
1062 : #endif
1063 : {
1064 72 : putShortMSB(s, (uInt)(strm->adler >> 16));
1065 72 : putShortMSB(s, (uInt)(strm->adler & 0xffff));
1066 : }
1067 72 : flush_pending(strm);
1068 : /* If avail_out is zero, the application will call deflate again
1069 : * to flush the rest.
1070 : */
1071 72 : if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
1072 72 : return s->pending != 0 ? Z_OK : Z_STREAM_END;
1073 : }
1074 :
1075 : /* ========================================================================= */
1076 72 : int ZEXPORT deflateEnd (strm)
1077 : z_streamp strm;
1078 : {
1079 : int status;
1080 :
1081 72 : if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
1082 :
1083 72 : status = strm->state->status;
1084 :
1085 : /* Deallocate in reverse order of allocations: */
1086 72 : TRY_FREE(strm, strm->state->pending_buf);
1087 72 : TRY_FREE(strm, strm->state->head);
1088 72 : TRY_FREE(strm, strm->state->prev);
1089 72 : TRY_FREE(strm, strm->state->window);
1090 :
1091 72 : ZFREE(strm, strm->state);
1092 72 : strm->state = Z_NULL;
1093 :
1094 72 : return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1095 : }
1096 :
1097 : /* =========================================================================
1098 : * Copy the source state to the destination state.
1099 : * To simplify the source, this is not supported for 16-bit MSDOS (which
1100 : * doesn't have enough memory anyway to duplicate compression states).
1101 : */
1102 0 : int ZEXPORT deflateCopy (dest, source)
1103 : z_streamp dest;
1104 : z_streamp source;
1105 : {
1106 : #ifdef MAXSEG_64K
1107 : return Z_STREAM_ERROR;
1108 : #else
1109 : deflate_state *ds;
1110 : deflate_state *ss;
1111 : ushf *overlay;
1112 :
1113 :
1114 0 : if (deflateStateCheck(source) || dest == Z_NULL) {
1115 0 : return Z_STREAM_ERROR;
1116 : }
1117 :
1118 0 : ss = source->state;
1119 :
1120 0 : zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1121 :
1122 0 : ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1123 0 : if (ds == Z_NULL) return Z_MEM_ERROR;
1124 0 : dest->state = (struct internal_state FAR *) ds;
1125 0 : zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state));
1126 0 : ds->strm = dest;
1127 :
1128 0 : ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1129 0 : ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1130 0 : ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1131 0 : overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1132 0 : ds->pending_buf = (uchf *) overlay;
1133 :
1134 0 : if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1135 0 : ds->pending_buf == Z_NULL) {
1136 0 : deflateEnd (dest);
1137 0 : return Z_MEM_ERROR;
1138 : }
1139 : /* following zmemcpy do not work for 16-bit MSDOS */
1140 0 : zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1141 0 : zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos));
1142 0 : zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos));
1143 0 : zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1144 :
1145 0 : ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1146 0 : ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1147 0 : ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1148 :
1149 0 : ds->l_desc.dyn_tree = ds->dyn_ltree;
1150 0 : ds->d_desc.dyn_tree = ds->dyn_dtree;
1151 0 : ds->bl_desc.dyn_tree = ds->bl_tree;
1152 :
1153 0 : return Z_OK;
1154 : #endif /* MAXSEG_64K */
1155 : }
1156 :
1157 : /* ===========================================================================
1158 : * Read a new buffer from the current input stream, update the adler32
1159 : * and total number of bytes read. All deflate() input goes through
1160 : * this function so some applications may wish to modify it to avoid
1161 : * allocating a large strm->next_in buffer and copying from it.
1162 : * (See also flush_pending()).
1163 : */
1164 0 : local unsigned read_buf(strm, buf, size)
1165 : z_streamp strm;
1166 : Bytef *buf;
1167 : unsigned size;
1168 : {
1169 0 : unsigned len = strm->avail_in;
1170 :
1171 0 : if (len > size) len = size;
1172 0 : if (len == 0) return 0;
1173 :
1174 0 : strm->avail_in -= len;
1175 :
1176 0 : zmemcpy(buf, strm->next_in, len);
1177 0 : if (strm->state->wrap == 1) {
1178 0 : strm->adler = adler32(strm->adler, buf, len);
1179 : }
1180 : #ifdef GZIP
1181 0 : else if (strm->state->wrap == 2) {
1182 0 : strm->adler = crc32(strm->adler, buf, len);
1183 : }
1184 : #endif
1185 0 : strm->next_in += len;
1186 0 : strm->total_in += len;
1187 :
1188 0 : return len;
1189 : }
1190 :
1191 : /* ===========================================================================
1192 : * Initialize the "longest match" routines for a new zlib stream
1193 : */
1194 72 : local void lm_init (s)
1195 : deflate_state *s;
1196 : {
1197 72 : s->window_size = (ulg)2L*s->w_size;
1198 :
1199 72 : CLEAR_HASH(s);
1200 :
1201 : /* Set the default configuration parameters:
1202 : */
1203 72 : s->max_lazy_match = configuration_table[s->level].max_lazy;
1204 72 : s->good_match = configuration_table[s->level].good_length;
1205 72 : s->nice_match = configuration_table[s->level].nice_length;
1206 72 : s->max_chain_length = configuration_table[s->level].max_chain;
1207 :
1208 72 : s->strstart = 0;
1209 72 : s->block_start = 0L;
1210 72 : s->lookahead = 0;
1211 72 : s->insert = 0;
1212 72 : s->match_length = s->prev_length = MIN_MATCH-1;
1213 72 : s->match_available = 0;
1214 72 : s->ins_h = 0;
1215 : #ifndef FASTEST
1216 : #ifdef ASMV
1217 : match_init(); /* initialize the asm code */
1218 : #endif
1219 : #endif
1220 72 : }
1221 :
1222 : #ifndef FASTEST
1223 : /* ===========================================================================
1224 : * Set match_start to the longest match starting at the given string and
1225 : * return its length. Matches shorter or equal to prev_length are discarded,
1226 : * in which case the result is equal to prev_length and match_start is
1227 : * garbage.
1228 : * IN assertions: cur_match is the head of the hash chain for the current
1229 : * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1230 : * OUT assertion: the match length is not greater than s->lookahead.
1231 : */
1232 : #ifndef ASMV
1233 : /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1234 : * match.S. The code will be functionally equivalent.
1235 : */
1236 0 : local uInt longest_match(s, cur_match)
1237 : deflate_state *s;
1238 : IPos cur_match; /* current match */
1239 : {
1240 0 : unsigned chain_length = s->max_chain_length;/* max hash chain length */
1241 0 : register Bytef *scan = s->window + s->strstart; /* current string */
1242 : register Bytef *match; /* matched string */
1243 : register int len; /* length of current match */
1244 0 : int best_len = (int)s->prev_length; /* best match length so far */
1245 0 : int nice_match = s->nice_match; /* stop if match long enough */
1246 0 : IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1247 0 : s->strstart - (IPos)MAX_DIST(s) : NIL;
1248 : /* Stop when cur_match becomes <= limit. To simplify the code,
1249 : * we prevent matches with the string of window index 0.
1250 : */
1251 0 : Posf *prev = s->prev;
1252 0 : uInt wmask = s->w_mask;
1253 :
1254 : #ifdef UNALIGNED_OK
1255 : /* Compare two bytes at a time. Note: this is not always beneficial.
1256 : * Try with and without -DUNALIGNED_OK to check.
1257 : */
1258 : register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1259 : register ush scan_start = *(ushf*)scan;
1260 : register ush scan_end = *(ushf*)(scan+best_len-1);
1261 : #else
1262 0 : register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1263 0 : register Byte scan_end1 = scan[best_len-1];
1264 0 : register Byte scan_end = scan[best_len];
1265 : #endif
1266 :
1267 : /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1268 : * It is easy to get rid of this optimization if necessary.
1269 : */
1270 : Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1271 :
1272 : /* Do not waste too much time if we already have a good match: */
1273 0 : if (s->prev_length >= s->good_match) {
1274 0 : chain_length >>= 2;
1275 : }
1276 : /* Do not look for matches beyond the end of the input. This is necessary
1277 : * to make deflate deterministic.
1278 : */
1279 0 : if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead;
1280 :
1281 : Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1282 :
1283 : do {
1284 : Assert(cur_match < s->strstart, "no future");
1285 0 : match = s->window + cur_match;
1286 :
1287 : /* Skip to next match if the match length cannot increase
1288 : * or if the match length is less than 2. Note that the checks below
1289 : * for insufficient lookahead only occur occasionally for performance
1290 : * reasons. Therefore uninitialized memory will be accessed, and
1291 : * conditional jumps will be made that depend on those values.
1292 : * However the length of the match is limited to the lookahead, so
1293 : * the output of deflate is not affected by the uninitialized values.
1294 : */
1295 : #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1296 : /* This code assumes sizeof(unsigned short) == 2. Do not use
1297 : * UNALIGNED_OK if your compiler uses a different size.
1298 : */
1299 : if (*(ushf*)(match+best_len-1) != scan_end ||
1300 : *(ushf*)match != scan_start) continue;
1301 :
1302 : /* It is not necessary to compare scan[2] and match[2] since they are
1303 : * always equal when the other bytes match, given that the hash keys
1304 : * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1305 : * strstart+3, +5, ... up to strstart+257. We check for insufficient
1306 : * lookahead only every 4th comparison; the 128th check will be made
1307 : * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1308 : * necessary to put more guard bytes at the end of the window, or
1309 : * to check more often for insufficient lookahead.
1310 : */
1311 : Assert(scan[2] == match[2], "scan[2]?");
1312 : scan++, match++;
1313 : do {
1314 : } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1315 : *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1316 : *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1317 : *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1318 : scan < strend);
1319 : /* The funny "do {}" generates better code on most compilers */
1320 :
1321 : /* Here, scan <= window+strstart+257 */
1322 : Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1323 : if (*scan == *match) scan++;
1324 :
1325 : len = (MAX_MATCH - 1) - (int)(strend-scan);
1326 : scan = strend - (MAX_MATCH-1);
1327 :
1328 : #else /* UNALIGNED_OK */
1329 :
1330 0 : if (match[best_len] != scan_end ||
1331 0 : match[best_len-1] != scan_end1 ||
1332 0 : *match != *scan ||
1333 0 : *++match != scan[1]) continue;
1334 :
1335 : /* The check at best_len-1 can be removed because it will be made
1336 : * again later. (This heuristic is not always a win.)
1337 : * It is not necessary to compare scan[2] and match[2] since they
1338 : * are always equal when the other bytes match, given that
1339 : * the hash keys are equal and that HASH_BITS >= 8.
1340 : */
1341 0 : scan += 2, match++;
1342 : Assert(*scan == *match, "match[2]?");
1343 :
1344 : /* We check for insufficient lookahead only every 8th comparison;
1345 : * the 256th check will be made at strstart+258.
1346 : */
1347 : do {
1348 0 : } while (*++scan == *++match && *++scan == *++match &&
1349 0 : *++scan == *++match && *++scan == *++match &&
1350 0 : *++scan == *++match && *++scan == *++match &&
1351 0 : *++scan == *++match && *++scan == *++match &&
1352 0 : scan < strend);
1353 :
1354 : Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1355 :
1356 0 : len = MAX_MATCH - (int)(strend - scan);
1357 0 : scan = strend - MAX_MATCH;
1358 :
1359 : #endif /* UNALIGNED_OK */
1360 :
1361 0 : if (len > best_len) {
1362 0 : s->match_start = cur_match;
1363 0 : best_len = len;
1364 0 : if (len >= nice_match) break;
1365 : #ifdef UNALIGNED_OK
1366 : scan_end = *(ushf*)(scan+best_len-1);
1367 : #else
1368 0 : scan_end1 = scan[best_len-1];
1369 0 : scan_end = scan[best_len];
1370 : #endif
1371 : }
1372 0 : } while ((cur_match = prev[cur_match & wmask]) > limit
1373 0 : && --chain_length != 0);
1374 :
1375 0 : if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1376 0 : return s->lookahead;
1377 : }
1378 : #endif /* ASMV */
1379 :
1380 : #else /* FASTEST */
1381 :
1382 : /* ---------------------------------------------------------------------------
1383 : * Optimized version for FASTEST only
1384 : */
1385 : local uInt longest_match(s, cur_match)
1386 : deflate_state *s;
1387 : IPos cur_match; /* current match */
1388 : {
1389 : register Bytef *scan = s->window + s->strstart; /* current string */
1390 : register Bytef *match; /* matched string */
1391 : register int len; /* length of current match */
1392 : register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1393 :
1394 : /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1395 : * It is easy to get rid of this optimization if necessary.
1396 : */
1397 : Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1398 :
1399 : Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1400 :
1401 : Assert(cur_match < s->strstart, "no future");
1402 :
1403 : match = s->window + cur_match;
1404 :
1405 : /* Return failure if the match length is less than 2:
1406 : */
1407 : if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1408 :
1409 : /* The check at best_len-1 can be removed because it will be made
1410 : * again later. (This heuristic is not always a win.)
1411 : * It is not necessary to compare scan[2] and match[2] since they
1412 : * are always equal when the other bytes match, given that
1413 : * the hash keys are equal and that HASH_BITS >= 8.
1414 : */
1415 : scan += 2, match += 2;
1416 : Assert(*scan == *match, "match[2]?");
1417 :
1418 : /* We check for insufficient lookahead only every 8th comparison;
1419 : * the 256th check will be made at strstart+258.
1420 : */
1421 : do {
1422 : } while (*++scan == *++match && *++scan == *++match &&
1423 : *++scan == *++match && *++scan == *++match &&
1424 : *++scan == *++match && *++scan == *++match &&
1425 : *++scan == *++match && *++scan == *++match &&
1426 : scan < strend);
1427 :
1428 : Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1429 :
1430 : len = MAX_MATCH - (int)(strend - scan);
1431 :
1432 : if (len < MIN_MATCH) return MIN_MATCH - 1;
1433 :
1434 : s->match_start = cur_match;
1435 : return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead;
1436 : }
1437 :
1438 : #endif /* FASTEST */
1439 :
1440 : #ifdef ZLIB_DEBUG
1441 :
1442 : #define EQUAL 0
1443 : /* result of memcmp for equal strings */
1444 :
1445 : /* ===========================================================================
1446 : * Check that the match at match_start is indeed a match.
1447 : */
1448 : local void check_match(s, start, match, length)
1449 : deflate_state *s;
1450 : IPos start, match;
1451 : int length;
1452 : {
1453 : /* check that the match is indeed a match */
1454 : if (zmemcmp(s->window + match,
1455 : s->window + start, length) != EQUAL) {
1456 : fprintf(stderr, " start %u, match %u, length %d\n",
1457 : start, match, length);
1458 : do {
1459 : fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1460 : } while (--length != 0);
1461 : z_error("invalid match");
1462 : }
1463 : if (z_verbose > 1) {
1464 : fprintf(stderr,"\\[%d,%d]", start-match, length);
1465 : do { putc(s->window[start++], stderr); } while (--length != 0);
1466 : }
1467 : }
1468 : #else
1469 : # define check_match(s, start, match, length)
1470 : #endif /* ZLIB_DEBUG */
1471 :
1472 : /* ===========================================================================
1473 : * Fill the window when the lookahead becomes insufficient.
1474 : * Updates strstart and lookahead.
1475 : *
1476 : * IN assertion: lookahead < MIN_LOOKAHEAD
1477 : * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1478 : * At least one byte has been read, or avail_in == 0; reads are
1479 : * performed for at least two bytes (required for the zip translate_eol
1480 : * option -- not supported here).
1481 : */
1482 72 : local void fill_window(s)
1483 : deflate_state *s;
1484 : {
1485 : unsigned n;
1486 : unsigned more; /* Amount of free space at the end of the window. */
1487 72 : uInt wsize = s->w_size;
1488 :
1489 : Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");
1490 :
1491 : do {
1492 72 : more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1493 :
1494 : /* Deal with !@#$% 64K limit: */
1495 : if (sizeof(int) <= 2) {
1496 : if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1497 : more = wsize;
1498 :
1499 : } else if (more == (unsigned)(-1)) {
1500 : /* Very unlikely, but possible on 16 bit machine if
1501 : * strstart == 0 && lookahead == 1 (input done a byte at time)
1502 : */
1503 : more--;
1504 : }
1505 : }
1506 :
1507 : /* If the window is almost full and there is insufficient lookahead,
1508 : * move the upper half to the lower one to make room in the upper half.
1509 : */
1510 72 : if (s->strstart >= wsize+MAX_DIST(s)) {
1511 :
1512 0 : zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more);
1513 0 : s->match_start -= wsize;
1514 0 : s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1515 0 : s->block_start -= (long) wsize;
1516 0 : slide_hash(s);
1517 0 : more += wsize;
1518 : }
1519 72 : if (s->strm->avail_in == 0) break;
1520 :
1521 : /* If there was no sliding:
1522 : * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1523 : * more == window_size - lookahead - strstart
1524 : * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1525 : * => more >= window_size - 2*WSIZE + 2
1526 : * In the BIG_MEM or MMAP case (not yet supported),
1527 : * window_size == input_size + MIN_LOOKAHEAD &&
1528 : * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1529 : * Otherwise, window_size == 2*WSIZE so more >= 2.
1530 : * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1531 : */
1532 : Assert(more >= 2, "more < 2");
1533 :
1534 0 : n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1535 0 : s->lookahead += n;
1536 :
1537 : /* Initialize the hash value now that we have some input: */
1538 0 : if (s->lookahead + s->insert >= MIN_MATCH) {
1539 0 : uInt str = s->strstart - s->insert;
1540 0 : s->ins_h = s->window[str];
1541 0 : UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
1542 : #if MIN_MATCH != 3
1543 : Call UPDATE_HASH() MIN_MATCH-3 more times
1544 : #endif
1545 0 : while (s->insert) {
1546 0 : UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
1547 : #ifndef FASTEST
1548 0 : s->prev[str & s->w_mask] = s->head[s->ins_h];
1549 : #endif
1550 0 : s->head[s->ins_h] = (Pos)str;
1551 0 : str++;
1552 0 : s->insert--;
1553 0 : if (s->lookahead + s->insert < MIN_MATCH)
1554 0 : break;
1555 : }
1556 : }
1557 : /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1558 : * but this is not important since only literal bytes will be emitted.
1559 : */
1560 :
1561 0 : } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1562 :
1563 : /* If the WIN_INIT bytes after the end of the current data have never been
1564 : * written, then zero those bytes in order to avoid memory check reports of
1565 : * the use of uninitialized (or uninitialised as Julian writes) bytes by
1566 : * the longest match routines. Update the high water mark for the next
1567 : * time through here. WIN_INIT is set to MAX_MATCH since the longest match
1568 : * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
1569 : */
1570 72 : if (s->high_water < s->window_size) {
1571 72 : ulg curr = s->strstart + (ulg)(s->lookahead);
1572 : ulg init;
1573 :
1574 72 : if (s->high_water < curr) {
1575 : /* Previous high water mark below current data -- zero WIN_INIT
1576 : * bytes or up to end of window, whichever is less.
1577 : */
1578 0 : init = s->window_size - curr;
1579 0 : if (init > WIN_INIT)
1580 0 : init = WIN_INIT;
1581 0 : zmemzero(s->window + curr, (unsigned)init);
1582 0 : s->high_water = curr + init;
1583 : }
1584 72 : else if (s->high_water < (ulg)curr + WIN_INIT) {
1585 : /* High water mark at or above current data, but below current data
1586 : * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
1587 : * to end of window, whichever is less.
1588 : */
1589 72 : init = (ulg)curr + WIN_INIT - s->high_water;
1590 72 : if (init > s->window_size - s->high_water)
1591 0 : init = s->window_size - s->high_water;
1592 72 : zmemzero(s->window + s->high_water, (unsigned)init);
1593 72 : s->high_water += init;
1594 : }
1595 : }
1596 :
1597 : Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
1598 : "not enough room for search");
1599 72 : }
1600 :
1601 : /* ===========================================================================
1602 : * Flush the current block, with given end-of-file flag.
1603 : * IN assertion: strstart is set to the end of the current match.
1604 : */
1605 : #define FLUSH_BLOCK_ONLY(s, last) { \
1606 : _tr_flush_block(s, (s->block_start >= 0L ? \
1607 : (charf *)&s->window[(unsigned)s->block_start] : \
1608 : (charf *)Z_NULL), \
1609 : (ulg)((long)s->strstart - s->block_start), \
1610 : (last)); \
1611 : s->block_start = s->strstart; \
1612 : flush_pending(s->strm); \
1613 : Tracev((stderr,"[FLUSH]")); \
1614 : }
1615 :
1616 : /* Same but force premature exit if necessary. */
1617 : #define FLUSH_BLOCK(s, last) { \
1618 : FLUSH_BLOCK_ONLY(s, last); \
1619 : if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \
1620 : }
1621 :
1622 : /* Maximum stored block length in deflate format (not including header). */
1623 : #define MAX_STORED 65535
1624 :
1625 : /* Minimum of a and b. */
1626 : #define MIN(a, b) ((a) > (b) ? (b) : (a))
1627 :
1628 : /* ===========================================================================
1629 : * Copy without compression as much as possible from the input stream, return
1630 : * the current block state.
1631 : *
1632 : * In case deflateParams() is used to later switch to a non-zero compression
1633 : * level, s->matches (otherwise unused when storing) keeps track of the number
1634 : * of hash table slides to perform. If s->matches is 1, then one hash table
1635 : * slide will be done when switching. If s->matches is 2, the maximum value
1636 : * allowed here, then the hash table will be cleared, since two or more slides
1637 : * is the same as a clear.
1638 : *
1639 : * deflate_stored() is written to minimize the number of times an input byte is
1640 : * copied. It is most efficient with large input and output buffers, which
1641 : * maximizes the opportunites to have a single copy from next_in to next_out.
1642 : */
1643 0 : local block_state deflate_stored(s, flush)
1644 : deflate_state *s;
1645 : int flush;
1646 : {
1647 : /* Smallest worthy block size when not flushing or finishing. By default
1648 : * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
1649 : * large input and output buffers, the stored block size will be larger.
1650 : */
1651 0 : unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);
1652 :
1653 : /* Copy as many min_block or larger stored blocks directly to next_out as
1654 : * possible. If flushing, copy the remaining available input to next_out as
1655 : * stored blocks, if there is enough space.
1656 : */
1657 0 : unsigned len, left, have, last = 0;
1658 0 : unsigned used = s->strm->avail_in;
1659 : do {
1660 : /* Set len to the maximum size block that we can copy directly with the
1661 : * available input data and output space. Set left to how much of that
1662 : * would be copied from what's left in the window.
1663 : */
1664 0 : len = MAX_STORED; /* maximum deflate stored block length */
1665 0 : have = (s->bi_valid + 42) >> 3; /* number of header bytes */
1666 0 : if (s->strm->avail_out < have) /* need room for header */
1667 0 : break;
1668 : /* maximum stored block length that will fit in avail_out: */
1669 0 : have = s->strm->avail_out - have;
1670 0 : left = s->strstart - s->block_start; /* bytes left in window */
1671 0 : if (len > (ulg)left + s->strm->avail_in)
1672 0 : len = left + s->strm->avail_in; /* limit len to the input */
1673 0 : if (len > have)
1674 0 : len = have; /* limit len to the output */
1675 :
1676 : /* If the stored block would be less than min_block in length, or if
1677 : * unable to copy all of the available input when flushing, then try
1678 : * copying to the window and the pending buffer instead. Also don't
1679 : * write an empty block when flushing -- deflate() does that.
1680 : */
1681 0 : if (len < min_block && ((len == 0 && flush != Z_FINISH) ||
1682 0 : flush == Z_NO_FLUSH ||
1683 0 : len != left + s->strm->avail_in))
1684 : break;
1685 :
1686 : /* Make a dummy stored block in pending to get the header bytes,
1687 : * including any pending bits. This also updates the debugging counts.
1688 : */
1689 0 : last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0;
1690 0 : _tr_stored_block(s, (char *)0, 0L, last);
1691 :
1692 : /* Replace the lengths in the dummy stored block with len. */
1693 0 : s->pending_buf[s->pending - 4] = len;
1694 0 : s->pending_buf[s->pending - 3] = len >> 8;
1695 0 : s->pending_buf[s->pending - 2] = ~len;
1696 0 : s->pending_buf[s->pending - 1] = ~len >> 8;
1697 :
1698 : /* Write the stored block header bytes. */
1699 0 : flush_pending(s->strm);
1700 :
1701 : #ifdef ZLIB_DEBUG
1702 : /* Update debugging counts for the data about to be copied. */
1703 : s->compressed_len += len << 3;
1704 : s->bits_sent += len << 3;
1705 : #endif
1706 :
1707 : /* Copy uncompressed bytes from the window to next_out. */
1708 0 : if (left) {
1709 0 : if (left > len)
1710 0 : left = len;
1711 0 : zmemcpy(s->strm->next_out, s->window + s->block_start, left);
1712 0 : s->strm->next_out += left;
1713 0 : s->strm->avail_out -= left;
1714 0 : s->strm->total_out += left;
1715 0 : s->block_start += left;
1716 0 : len -= left;
1717 : }
1718 :
1719 : /* Copy uncompressed bytes directly from next_in to next_out, updating
1720 : * the check value.
1721 : */
1722 0 : if (len) {
1723 0 : read_buf(s->strm, s->strm->next_out, len);
1724 0 : s->strm->next_out += len;
1725 0 : s->strm->avail_out -= len;
1726 0 : s->strm->total_out += len;
1727 : }
1728 0 : } while (last == 0);
1729 :
1730 : /* Update the sliding window with the last s->w_size bytes of the copied
1731 : * data, or append all of the copied data to the existing window if less
1732 : * than s->w_size bytes were copied. Also update the number of bytes to
1733 : * insert in the hash tables, in the event that deflateParams() switches to
1734 : * a non-zero compression level.
1735 : */
1736 0 : used -= s->strm->avail_in; /* number of input bytes directly copied */
1737 0 : if (used) {
1738 : /* If any input was used, then no unused input remains in the window,
1739 : * therefore s->block_start == s->strstart.
1740 : */
1741 0 : if (used >= s->w_size) { /* supplant the previous history */
1742 0 : s->matches = 2; /* clear hash */
1743 0 : zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size);
1744 0 : s->strstart = s->w_size;
1745 : }
1746 : else {
1747 0 : if (s->window_size - s->strstart <= used) {
1748 : /* Slide the window down. */
1749 0 : s->strstart -= s->w_size;
1750 0 : zmemcpy(s->window, s->window + s->w_size, s->strstart);
1751 0 : if (s->matches < 2)
1752 0 : s->matches++; /* add a pending slide_hash() */
1753 : }
1754 0 : zmemcpy(s->window + s->strstart, s->strm->next_in - used, used);
1755 0 : s->strstart += used;
1756 : }
1757 0 : s->block_start = s->strstart;
1758 0 : s->insert += MIN(used, s->w_size - s->insert);
1759 : }
1760 0 : if (s->high_water < s->strstart)
1761 0 : s->high_water = s->strstart;
1762 :
1763 : /* If the last block was written to next_out, then done. */
1764 0 : if (last)
1765 0 : return finish_done;
1766 :
1767 : /* If flushing and all input has been consumed, then done. */
1768 0 : if (flush != Z_NO_FLUSH && flush != Z_FINISH &&
1769 0 : s->strm->avail_in == 0 && (long)s->strstart == s->block_start)
1770 0 : return block_done;
1771 :
1772 : /* Fill the window with any remaining input. */
1773 0 : have = s->window_size - s->strstart - 1;
1774 0 : if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) {
1775 : /* Slide the window down. */
1776 0 : s->block_start -= s->w_size;
1777 0 : s->strstart -= s->w_size;
1778 0 : zmemcpy(s->window, s->window + s->w_size, s->strstart);
1779 0 : if (s->matches < 2)
1780 0 : s->matches++; /* add a pending slide_hash() */
1781 0 : have += s->w_size; /* more space now */
1782 : }
1783 0 : if (have > s->strm->avail_in)
1784 0 : have = s->strm->avail_in;
1785 0 : if (have) {
1786 0 : read_buf(s->strm, s->window + s->strstart, have);
1787 0 : s->strstart += have;
1788 : }
1789 0 : if (s->high_water < s->strstart)
1790 0 : s->high_water = s->strstart;
1791 :
1792 : /* There was not enough avail_out to write a complete worthy or flushed
1793 : * stored block to next_out. Write a stored block to pending instead, if we
1794 : * have enough input for a worthy block, or if flushing and there is enough
1795 : * room for the remaining input as a stored block in the pending buffer.
1796 : */
1797 0 : have = (s->bi_valid + 42) >> 3; /* number of header bytes */
1798 : /* maximum stored block length that will fit in pending: */
1799 0 : have = MIN(s->pending_buf_size - have, MAX_STORED);
1800 0 : min_block = MIN(have, s->w_size);
1801 0 : left = s->strstart - s->block_start;
1802 0 : if (left >= min_block ||
1803 0 : ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH &&
1804 0 : s->strm->avail_in == 0 && left <= have)) {
1805 0 : len = MIN(left, have);
1806 0 : last = flush == Z_FINISH && s->strm->avail_in == 0 &&
1807 0 : len == left ? 1 : 0;
1808 0 : _tr_stored_block(s, (charf *)s->window + s->block_start, len, last);
1809 0 : s->block_start += len;
1810 0 : flush_pending(s->strm);
1811 : }
1812 :
1813 : /* We've done all we can with the available input and output. */
1814 0 : return last ? finish_started : need_more;
1815 : }
1816 :
1817 : /* ===========================================================================
1818 : * Compress as much as possible from the input stream, return the current
1819 : * block state.
1820 : * This function does not perform lazy evaluation of matches and inserts
1821 : * new strings in the dictionary only for unmatched strings or for short
1822 : * matches. It is used only for the fast compression options.
1823 : */
1824 0 : local block_state deflate_fast(s, flush)
1825 : deflate_state *s;
1826 : int flush;
1827 : {
1828 : IPos hash_head; /* head of the hash chain */
1829 : int bflush; /* set if current block must be flushed */
1830 :
1831 : for (;;) {
1832 : /* Make sure that we always have enough lookahead, except
1833 : * at the end of the input file. We need MAX_MATCH bytes
1834 : * for the next match, plus MIN_MATCH bytes to insert the
1835 : * string following the next match.
1836 : */
1837 0 : if (s->lookahead < MIN_LOOKAHEAD) {
1838 0 : fill_window(s);
1839 0 : if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1840 0 : return need_more;
1841 : }
1842 0 : if (s->lookahead == 0) break; /* flush the current block */
1843 : }
1844 :
1845 : /* Insert the string window[strstart .. strstart+2] in the
1846 : * dictionary, and set hash_head to the head of the hash chain:
1847 : */
1848 0 : hash_head = NIL;
1849 0 : if (s->lookahead >= MIN_MATCH) {
1850 0 : INSERT_STRING(s, s->strstart, hash_head);
1851 : }
1852 :
1853 : /* Find the longest match, discarding those <= prev_length.
1854 : * At this point we have always match_length < MIN_MATCH
1855 : */
1856 0 : if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1857 : /* To simplify the code, we prevent matches with the string
1858 : * of window index 0 (in particular we have to avoid a match
1859 : * of the string with itself at the start of the input file).
1860 : */
1861 0 : s->match_length = longest_match (s, hash_head);
1862 : /* longest_match() sets match_start */
1863 : }
1864 0 : if (s->match_length >= MIN_MATCH) {
1865 : check_match(s, s->strstart, s->match_start, s->match_length);
1866 :
1867 0 : _tr_tally_dist(s, s->strstart - s->match_start,
1868 : s->match_length - MIN_MATCH, bflush);
1869 :
1870 0 : s->lookahead -= s->match_length;
1871 :
1872 : /* Insert new strings in the hash table only if the match length
1873 : * is not too large. This saves time but degrades compression.
1874 : */
1875 : #ifndef FASTEST
1876 0 : if (s->match_length <= s->max_insert_length &&
1877 0 : s->lookahead >= MIN_MATCH) {
1878 0 : s->match_length--; /* string at strstart already in table */
1879 : do {
1880 0 : s->strstart++;
1881 0 : INSERT_STRING(s, s->strstart, hash_head);
1882 : /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1883 : * always MIN_MATCH bytes ahead.
1884 : */
1885 0 : } while (--s->match_length != 0);
1886 0 : s->strstart++;
1887 : } else
1888 : #endif
1889 : {
1890 0 : s->strstart += s->match_length;
1891 0 : s->match_length = 0;
1892 0 : s->ins_h = s->window[s->strstart];
1893 0 : UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1894 : #if MIN_MATCH != 3
1895 : Call UPDATE_HASH() MIN_MATCH-3 more times
1896 : #endif
1897 : /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1898 : * matter since it will be recomputed at next deflate call.
1899 : */
1900 : }
1901 : } else {
1902 : /* No match, output a literal byte */
1903 : Tracevv((stderr,"%c", s->window[s->strstart]));
1904 0 : _tr_tally_lit (s, s->window[s->strstart], bflush);
1905 0 : s->lookahead--;
1906 0 : s->strstart++;
1907 : }
1908 0 : if (bflush) FLUSH_BLOCK(s, 0);
1909 : }
1910 0 : s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
1911 0 : if (flush == Z_FINISH) {
1912 0 : FLUSH_BLOCK(s, 1);
1913 0 : return finish_done;
1914 : }
1915 0 : if (s->last_lit)
1916 0 : FLUSH_BLOCK(s, 0);
1917 0 : return block_done;
1918 : }
1919 :
1920 : #ifndef FASTEST
1921 : /* ===========================================================================
1922 : * Same as above, but achieves better compression. We use a lazy
1923 : * evaluation for matches: a match is finally adopted only if there is
1924 : * no better match at the next window position.
1925 : */
1926 72 : local block_state deflate_slow(s, flush)
1927 : deflate_state *s;
1928 : int flush;
1929 : {
1930 : IPos hash_head; /* head of hash chain */
1931 : int bflush; /* set if current block must be flushed */
1932 :
1933 : /* Process the input block. */
1934 : for (;;) {
1935 : /* Make sure that we always have enough lookahead, except
1936 : * at the end of the input file. We need MAX_MATCH bytes
1937 : * for the next match, plus MIN_MATCH bytes to insert the
1938 : * string following the next match.
1939 : */
1940 72 : if (s->lookahead < MIN_LOOKAHEAD) {
1941 72 : fill_window(s);
1942 72 : if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1943 0 : return need_more;
1944 : }
1945 72 : if (s->lookahead == 0) break; /* flush the current block */
1946 : }
1947 :
1948 : /* Insert the string window[strstart .. strstart+2] in the
1949 : * dictionary, and set hash_head to the head of the hash chain:
1950 : */
1951 0 : hash_head = NIL;
1952 0 : if (s->lookahead >= MIN_MATCH) {
1953 0 : INSERT_STRING(s, s->strstart, hash_head);
1954 : }
1955 :
1956 : /* Find the longest match, discarding those <= prev_length.
1957 : */
1958 0 : s->prev_length = s->match_length, s->prev_match = s->match_start;
1959 0 : s->match_length = MIN_MATCH-1;
1960 :
1961 0 : if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1962 0 : s->strstart - hash_head <= MAX_DIST(s)) {
1963 : /* To simplify the code, we prevent matches with the string
1964 : * of window index 0 (in particular we have to avoid a match
1965 : * of the string with itself at the start of the input file).
1966 : */
1967 0 : s->match_length = longest_match (s, hash_head);
1968 : /* longest_match() sets match_start */
1969 :
1970 0 : if (s->match_length <= 5 && (s->strategy == Z_FILTERED
1971 : #if TOO_FAR <= 32767
1972 0 : || (s->match_length == MIN_MATCH &&
1973 0 : s->strstart - s->match_start > TOO_FAR)
1974 : #endif
1975 : )) {
1976 :
1977 : /* If prev_match is also MIN_MATCH, match_start is garbage
1978 : * but we will ignore the current match anyway.
1979 : */
1980 0 : s->match_length = MIN_MATCH-1;
1981 : }
1982 : }
1983 : /* If there was a match at the previous step and the current
1984 : * match is not better, output the previous match:
1985 : */
1986 0 : if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1987 0 : uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1988 : /* Do not insert strings in hash table beyond this. */
1989 :
1990 : check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1991 :
1992 0 : _tr_tally_dist(s, s->strstart -1 - s->prev_match,
1993 : s->prev_length - MIN_MATCH, bflush);
1994 :
1995 : /* Insert in hash table all strings up to the end of the match.
1996 : * strstart-1 and strstart are already inserted. If there is not
1997 : * enough lookahead, the last two strings are not inserted in
1998 : * the hash table.
1999 : */
2000 0 : s->lookahead -= s->prev_length-1;
2001 0 : s->prev_length -= 2;
2002 : do {
2003 0 : if (++s->strstart <= max_insert) {
2004 0 : INSERT_STRING(s, s->strstart, hash_head);
2005 : }
2006 0 : } while (--s->prev_length != 0);
2007 0 : s->match_available = 0;
2008 0 : s->match_length = MIN_MATCH-1;
2009 0 : s->strstart++;
2010 :
2011 0 : if (bflush) FLUSH_BLOCK(s, 0);
2012 :
2013 0 : } else if (s->match_available) {
2014 : /* If there was no match at the previous position, output a
2015 : * single literal. If there was a match but the current match
2016 : * is longer, truncate the previous match to a single literal.
2017 : */
2018 : Tracevv((stderr,"%c", s->window[s->strstart-1]));
2019 0 : _tr_tally_lit(s, s->window[s->strstart-1], bflush);
2020 0 : if (bflush) {
2021 0 : FLUSH_BLOCK_ONLY(s, 0);
2022 : }
2023 0 : s->strstart++;
2024 0 : s->lookahead--;
2025 0 : if (s->strm->avail_out == 0) return need_more;
2026 : } else {
2027 : /* There is no previous match to compare with, wait for
2028 : * the next step to decide.
2029 : */
2030 0 : s->match_available = 1;
2031 0 : s->strstart++;
2032 0 : s->lookahead--;
2033 : }
2034 : }
2035 : Assert (flush != Z_NO_FLUSH, "no flush?");
2036 72 : if (s->match_available) {
2037 : Tracevv((stderr,"%c", s->window[s->strstart-1]));
2038 0 : _tr_tally_lit(s, s->window[s->strstart-1], bflush);
2039 0 : s->match_available = 0;
2040 : }
2041 72 : s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1;
2042 72 : if (flush == Z_FINISH) {
2043 72 : FLUSH_BLOCK(s, 1);
2044 72 : return finish_done;
2045 : }
2046 0 : if (s->last_lit)
2047 0 : FLUSH_BLOCK(s, 0);
2048 0 : return block_done;
2049 : }
2050 : #endif /* FASTEST */
2051 :
2052 : /* ===========================================================================
2053 : * For Z_RLE, simply look for runs of bytes, generate matches only of distance
2054 : * one. Do not maintain a hash table. (It will be regenerated if this run of
2055 : * deflate switches away from Z_RLE.)
2056 : */
2057 0 : local block_state deflate_rle(s, flush)
2058 : deflate_state *s;
2059 : int flush;
2060 : {
2061 : int bflush; /* set if current block must be flushed */
2062 : uInt prev; /* byte at distance one to match */
2063 : Bytef *scan, *strend; /* scan goes up to strend for length of run */
2064 :
2065 : for (;;) {
2066 : /* Make sure that we always have enough lookahead, except
2067 : * at the end of the input file. We need MAX_MATCH bytes
2068 : * for the longest run, plus one for the unrolled loop.
2069 : */
2070 0 : if (s->lookahead <= MAX_MATCH) {
2071 0 : fill_window(s);
2072 0 : if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) {
2073 0 : return need_more;
2074 : }
2075 0 : if (s->lookahead == 0) break; /* flush the current block */
2076 : }
2077 :
2078 : /* See how many times the previous byte repeats */
2079 0 : s->match_length = 0;
2080 0 : if (s->lookahead >= MIN_MATCH && s->strstart > 0) {
2081 0 : scan = s->window + s->strstart - 1;
2082 0 : prev = *scan;
2083 0 : if (prev == *++scan && prev == *++scan && prev == *++scan) {
2084 0 : strend = s->window + s->strstart + MAX_MATCH;
2085 : do {
2086 0 : } while (prev == *++scan && prev == *++scan &&
2087 0 : prev == *++scan && prev == *++scan &&
2088 0 : prev == *++scan && prev == *++scan &&
2089 0 : prev == *++scan && prev == *++scan &&
2090 0 : scan < strend);
2091 0 : s->match_length = MAX_MATCH - (uInt)(strend - scan);
2092 0 : if (s->match_length > s->lookahead)
2093 0 : s->match_length = s->lookahead;
2094 : }
2095 : Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan");
2096 : }
2097 :
2098 : /* Emit match if have run of MIN_MATCH or longer, else emit literal */
2099 0 : if (s->match_length >= MIN_MATCH) {
2100 : check_match(s, s->strstart, s->strstart - 1, s->match_length);
2101 :
2102 0 : _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush);
2103 :
2104 0 : s->lookahead -= s->match_length;
2105 0 : s->strstart += s->match_length;
2106 0 : s->match_length = 0;
2107 : } else {
2108 : /* No match, output a literal byte */
2109 : Tracevv((stderr,"%c", s->window[s->strstart]));
2110 0 : _tr_tally_lit (s, s->window[s->strstart], bflush);
2111 0 : s->lookahead--;
2112 0 : s->strstart++;
2113 : }
2114 0 : if (bflush) FLUSH_BLOCK(s, 0);
2115 : }
2116 0 : s->insert = 0;
2117 0 : if (flush == Z_FINISH) {
2118 0 : FLUSH_BLOCK(s, 1);
2119 0 : return finish_done;
2120 : }
2121 0 : if (s->last_lit)
2122 0 : FLUSH_BLOCK(s, 0);
2123 0 : return block_done;
2124 : }
2125 :
2126 : /* ===========================================================================
2127 : * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
2128 : * (It will be regenerated if this run of deflate switches away from Huffman.)
2129 : */
2130 0 : local block_state deflate_huff(s, flush)
2131 : deflate_state *s;
2132 : int flush;
2133 : {
2134 : int bflush; /* set if current block must be flushed */
2135 :
2136 : for (;;) {
2137 : /* Make sure that we have a literal to write. */
2138 0 : if (s->lookahead == 0) {
2139 0 : fill_window(s);
2140 0 : if (s->lookahead == 0) {
2141 0 : if (flush == Z_NO_FLUSH)
2142 0 : return need_more;
2143 0 : break; /* flush the current block */
2144 : }
2145 : }
2146 :
2147 : /* Output a literal byte */
2148 0 : s->match_length = 0;
2149 : Tracevv((stderr,"%c", s->window[s->strstart]));
2150 0 : _tr_tally_lit (s, s->window[s->strstart], bflush);
2151 0 : s->lookahead--;
2152 0 : s->strstart++;
2153 0 : if (bflush) FLUSH_BLOCK(s, 0);
2154 : }
2155 0 : s->insert = 0;
2156 0 : if (flush == Z_FINISH) {
2157 0 : FLUSH_BLOCK(s, 1);
2158 0 : return finish_done;
2159 : }
2160 0 : if (s->last_lit)
2161 0 : FLUSH_BLOCK(s, 0);
2162 0 : return block_done;
2163 : }
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