1 | /* deflate.c -- compress data using the deflation algorithm |
2 | * Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler |
3 | * For conditions of distribution and use, see copyright notice in zlib.h |
4 | */ |
5 | |
6 | /* |
7 | * ALGORITHM |
8 | * |
9 | * The "deflation" process depends on being able to identify portions |
10 | * of the input text which are identical to earlier input (within a |
11 | * sliding window trailing behind the input currently being processed). |
12 | * |
13 | * The most straightforward technique turns out to be the fastest for |
14 | * most input files: try all possible matches and select the longest. |
15 | * The key feature of this algorithm is that insertions into the string |
16 | * dictionary are very simple and thus fast, and deletions are avoided |
17 | * completely. Insertions are performed at each input character, whereas |
18 | * string matches are performed only when the previous match ends. So it |
19 | * is preferable to spend more time in matches to allow very fast string |
20 | * insertions and avoid deletions. The matching algorithm for small |
21 | * strings is inspired from that of Rabin & Karp. A brute force approach |
22 | * is used to find longer strings when a small match has been found. |
23 | * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze |
24 | * (by Leonid Broukhis). |
25 | * A previous version of this file used a more sophisticated algorithm |
26 | * (by Fiala and Greene) which is guaranteed to run in linear amortized |
27 | * time, but has a larger average cost, uses more memory and is patented. |
28 | * However the F&G algorithm may be faster for some highly redundant |
29 | * files if the parameter max_chain_length (described below) is too large. |
30 | * |
31 | * ACKNOWLEDGEMENTS |
32 | * |
33 | * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and |
34 | * I found it in 'freeze' written by Leonid Broukhis. |
35 | * Thanks to many people for bug reports and testing. |
36 | * |
37 | * REFERENCES |
38 | * |
39 | * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". |
40 | * Available in http://tools.ietf.org/html/rfc1951 |
41 | * |
42 | * A description of the Rabin and Karp algorithm is given in the book |
43 | * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. |
44 | * |
45 | * Fiala,E.R., and Greene,D.H. |
46 | * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 |
47 | * |
48 | */ |
49 | |
50 | /* @(#) $Id$ */ |
51 | |
52 | #include "deflate.h" |
53 | |
54 | const char deflate_copyright[] = |
55 | " deflate 1.2.12 Copyright 1995-2022 Jean-loup Gailly and Mark Adler " ; |
56 | /* |
57 | If you use the zlib library in a product, an acknowledgment is welcome |
58 | in the documentation of your product. If for some reason you cannot |
59 | include such an acknowledgment, I would appreciate that you keep this |
60 | copyright string in the executable of your product. |
61 | */ |
62 | |
63 | /* =========================================================================== |
64 | * Function prototypes. |
65 | */ |
66 | typedef enum { |
67 | need_more, /* block not completed, need more input or more output */ |
68 | block_done, /* block flush performed */ |
69 | finish_started, /* finish started, need only more output at next deflate */ |
70 | finish_done /* finish done, accept no more input or output */ |
71 | } block_state; |
72 | |
73 | typedef block_state (*compress_func) OF((deflate_state *s, int flush)); |
74 | /* Compression function. Returns the block state after the call. */ |
75 | |
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 | do { \ |
194 | s->head[s->hash_size-1] = NIL; \ |
195 | zmemzero((Bytef *)s->head, \ |
196 | (unsigned)(s->hash_size-1)*sizeof(*s->head)); \ |
197 | } while (0) |
198 | |
199 | /* =========================================================================== |
200 | * Slide the hash table when sliding the window down (could be avoided with 32 |
201 | * bit values at the expense of memory usage). We slide even when level == 0 to |
202 | * keep the hash table consistent if we switch back to level > 0 later. |
203 | */ |
204 | local void slide_hash(s) |
205 | deflate_state *s; |
206 | { |
207 | unsigned n, m; |
208 | Posf *p; |
209 | uInt wsize = s->w_size; |
210 | |
211 | n = s->hash_size; |
212 | p = &s->head[n]; |
213 | do { |
214 | m = *--p; |
215 | *p = (Pos)(m >= wsize ? m - wsize : NIL); |
216 | } while (--n); |
217 | n = wsize; |
218 | #ifndef FASTEST |
219 | p = &s->prev[n]; |
220 | do { |
221 | m = *--p; |
222 | *p = (Pos)(m >= wsize ? m - wsize : NIL); |
223 | /* If n is not on any hash chain, prev[n] is garbage but |
224 | * its value will never be used. |
225 | */ |
226 | } while (--n); |
227 | #endif |
228 | } |
229 | |
230 | /* ========================================================================= */ |
231 | int ZEXPORT deflateInit_(strm, level, version, stream_size) |
232 | z_streamp strm; |
233 | int level; |
234 | const char *version; |
235 | int stream_size; |
236 | { |
237 | return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, |
238 | Z_DEFAULT_STRATEGY, version, stream_size); |
239 | /* To do: ignore strm->next_in if we use it as window */ |
240 | } |
241 | |
242 | /* ========================================================================= */ |
243 | int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, |
244 | version, stream_size) |
245 | z_streamp strm; |
246 | int level; |
247 | int method; |
248 | int windowBits; |
249 | int memLevel; |
250 | int strategy; |
251 | const char *version; |
252 | int stream_size; |
253 | { |
254 | deflate_state *s; |
255 | int wrap = 1; |
256 | static const char my_version[] = ZLIB_VERSION; |
257 | |
258 | if (version == Z_NULL || version[0] != my_version[0] || |
259 | stream_size != sizeof(z_stream)) { |
260 | return Z_VERSION_ERROR; |
261 | } |
262 | if (strm == Z_NULL) return Z_STREAM_ERROR; |
263 | |
264 | strm->msg = Z_NULL; |
265 | if (strm->zalloc == (alloc_func)0) { |
266 | #ifdef Z_SOLO |
267 | return Z_STREAM_ERROR; |
268 | #else |
269 | strm->zalloc = zcalloc; |
270 | strm->opaque = (voidpf)0; |
271 | #endif |
272 | } |
273 | if (strm->zfree == (free_func)0) |
274 | #ifdef Z_SOLO |
275 | return Z_STREAM_ERROR; |
276 | #else |
277 | strm->zfree = zcfree; |
278 | #endif |
279 | |
280 | #ifdef FASTEST |
281 | if (level != 0) level = 1; |
282 | #else |
283 | if (level == Z_DEFAULT_COMPRESSION) level = 6; |
284 | #endif |
285 | |
286 | if (windowBits < 0) { /* suppress zlib wrapper */ |
287 | wrap = 0; |
288 | windowBits = -windowBits; |
289 | } |
290 | #ifdef GZIP |
291 | else if (windowBits > 15) { |
292 | wrap = 2; /* write gzip wrapper instead */ |
293 | windowBits -= 16; |
294 | } |
295 | #endif |
296 | if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || |
297 | windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || |
298 | strategy < 0 || strategy > Z_FIXED || (windowBits == 8 && wrap != 1)) { |
299 | return Z_STREAM_ERROR; |
300 | } |
301 | if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ |
302 | s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); |
303 | if (s == Z_NULL) return Z_MEM_ERROR; |
304 | strm->state = (struct internal_state FAR *)s; |
305 | s->strm = strm; |
306 | s->status = INIT_STATE; /* to pass state test in deflateReset() */ |
307 | |
308 | s->wrap = wrap; |
309 | s->gzhead = Z_NULL; |
310 | s->w_bits = (uInt)windowBits; |
311 | s->w_size = 1 << s->w_bits; |
312 | s->w_mask = s->w_size - 1; |
313 | |
314 | s->hash_bits = (uInt)memLevel + 7; |
315 | s->hash_size = 1 << s->hash_bits; |
316 | s->hash_mask = s->hash_size - 1; |
317 | s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); |
318 | |
319 | s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); |
320 | s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); |
321 | s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); |
322 | |
323 | s->high_water = 0; /* nothing written to s->window yet */ |
324 | |
325 | s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ |
326 | |
327 | /* We overlay pending_buf and sym_buf. This works since the average size |
328 | * for length/distance pairs over any compressed block is assured to be 31 |
329 | * bits or less. |
330 | * |
331 | * Analysis: The longest fixed codes are a length code of 8 bits plus 5 |
332 | * extra bits, for lengths 131 to 257. The longest fixed distance codes are |
333 | * 5 bits plus 13 extra bits, for distances 16385 to 32768. The longest |
334 | * possible fixed-codes length/distance pair is then 31 bits total. |
335 | * |
336 | * sym_buf starts one-fourth of the way into pending_buf. So there are |
337 | * three bytes in sym_buf for every four bytes in pending_buf. Each symbol |
338 | * in sym_buf is three bytes -- two for the distance and one for the |
339 | * literal/length. As each symbol is consumed, the pointer to the next |
340 | * sym_buf value to read moves forward three bytes. From that symbol, up to |
341 | * 31 bits are written to pending_buf. The closest the written pending_buf |
342 | * bits gets to the next sym_buf symbol to read is just before the last |
343 | * code is written. At that time, 31*(n-2) bits have been written, just |
344 | * after 24*(n-2) bits have been consumed from sym_buf. sym_buf starts at |
345 | * 8*n bits into pending_buf. (Note that the symbol buffer fills when n-1 |
346 | * symbols are written.) The closest the writing gets to what is unread is |
347 | * then n+14 bits. Here n is lit_bufsize, which is 16384 by default, and |
348 | * can range from 128 to 32768. |
349 | * |
350 | * Therefore, at a minimum, there are 142 bits of space between what is |
351 | * written and what is read in the overlain buffers, so the symbols cannot |
352 | * be overwritten by the compressed data. That space is actually 139 bits, |
353 | * due to the three-bit fixed-code block header. |
354 | * |
355 | * That covers the case where either Z_FIXED is specified, forcing fixed |
356 | * codes, or when the use of fixed codes is chosen, because that choice |
357 | * results in a smaller compressed block than dynamic codes. That latter |
358 | * condition then assures that the above analysis also covers all dynamic |
359 | * blocks. A dynamic-code block will only be chosen to be emitted if it has |
360 | * fewer bits than a fixed-code block would for the same set of symbols. |
361 | * Therefore its average symbol length is assured to be less than 31. So |
362 | * the compressed data for a dynamic block also cannot overwrite the |
363 | * symbols from which it is being constructed. |
364 | */ |
365 | |
366 | s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 4); |
367 | s->pending_buf_size = (ulg)s->lit_bufsize * 4; |
368 | |
369 | if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || |
370 | s->pending_buf == Z_NULL) { |
371 | s->status = FINISH_STATE; |
372 | strm->msg = ERR_MSG(Z_MEM_ERROR); |
373 | deflateEnd (strm); |
374 | return Z_MEM_ERROR; |
375 | } |
376 | s->sym_buf = s->pending_buf + s->lit_bufsize; |
377 | s->sym_end = (s->lit_bufsize - 1) * 3; |
378 | /* We avoid equality with lit_bufsize*3 because of wraparound at 64K |
379 | * on 16 bit machines and because stored blocks are restricted to |
380 | * 64K-1 bytes. |
381 | */ |
382 | |
383 | s->level = level; |
384 | s->strategy = strategy; |
385 | s->method = (Byte)method; |
386 | |
387 | return deflateReset(strm); |
388 | } |
389 | |
390 | /* ========================================================================= |
391 | * Check for a valid deflate stream state. Return 0 if ok, 1 if not. |
392 | */ |
393 | local int deflateStateCheck (strm) |
394 | z_streamp strm; |
395 | { |
396 | deflate_state *s; |
397 | if (strm == Z_NULL || |
398 | strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) |
399 | return 1; |
400 | s = strm->state; |
401 | if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE && |
402 | #ifdef GZIP |
403 | s->status != GZIP_STATE && |
404 | #endif |
405 | s->status != EXTRA_STATE && |
406 | s->status != NAME_STATE && |
407 | s->status != COMMENT_STATE && |
408 | s->status != HCRC_STATE && |
409 | s->status != BUSY_STATE && |
410 | s->status != FINISH_STATE)) |
411 | return 1; |
412 | return 0; |
413 | } |
414 | |
415 | /* ========================================================================= */ |
416 | int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) |
417 | z_streamp strm; |
418 | const Bytef *dictionary; |
419 | uInt dictLength; |
420 | { |
421 | deflate_state *s; |
422 | uInt str, n; |
423 | int wrap; |
424 | unsigned avail; |
425 | z_const unsigned char *next; |
426 | |
427 | if (deflateStateCheck(strm) || dictionary == Z_NULL) |
428 | return Z_STREAM_ERROR; |
429 | s = strm->state; |
430 | wrap = s->wrap; |
431 | if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead) |
432 | return Z_STREAM_ERROR; |
433 | |
434 | /* when using zlib wrappers, compute Adler-32 for provided dictionary */ |
435 | if (wrap == 1) |
436 | strm->adler = adler32(strm->adler, dictionary, dictLength); |
437 | s->wrap = 0; /* avoid computing Adler-32 in read_buf */ |
438 | |
439 | /* if dictionary would fill window, just replace the history */ |
440 | if (dictLength >= s->w_size) { |
441 | if (wrap == 0) { /* already empty otherwise */ |
442 | CLEAR_HASH(s); |
443 | s->strstart = 0; |
444 | s->block_start = 0L; |
445 | s->insert = 0; |
446 | } |
447 | dictionary += dictLength - s->w_size; /* use the tail */ |
448 | dictLength = s->w_size; |
449 | } |
450 | |
451 | /* insert dictionary into window and hash */ |
452 | avail = strm->avail_in; |
453 | next = strm->next_in; |
454 | strm->avail_in = dictLength; |
455 | strm->next_in = (z_const Bytef *)dictionary; |
456 | fill_window(s); |
457 | while (s->lookahead >= MIN_MATCH) { |
458 | str = s->strstart; |
459 | n = s->lookahead - (MIN_MATCH-1); |
460 | do { |
461 | UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); |
462 | #ifndef FASTEST |
463 | s->prev[str & s->w_mask] = s->head[s->ins_h]; |
464 | #endif |
465 | s->head[s->ins_h] = (Pos)str; |
466 | str++; |
467 | } while (--n); |
468 | s->strstart = str; |
469 | s->lookahead = MIN_MATCH-1; |
470 | fill_window(s); |
471 | } |
472 | s->strstart += s->lookahead; |
473 | s->block_start = (long)s->strstart; |
474 | s->insert = s->lookahead; |
475 | s->lookahead = 0; |
476 | s->match_length = s->prev_length = MIN_MATCH-1; |
477 | s->match_available = 0; |
478 | strm->next_in = next; |
479 | strm->avail_in = avail; |
480 | s->wrap = wrap; |
481 | return Z_OK; |
482 | } |
483 | |
484 | /* ========================================================================= */ |
485 | int ZEXPORT deflateGetDictionary (strm, dictionary, dictLength) |
486 | z_streamp strm; |
487 | Bytef *dictionary; |
488 | uInt *dictLength; |
489 | { |
490 | deflate_state *s; |
491 | uInt len; |
492 | |
493 | if (deflateStateCheck(strm)) |
494 | return Z_STREAM_ERROR; |
495 | s = strm->state; |
496 | len = s->strstart + s->lookahead; |
497 | if (len > s->w_size) |
498 | len = s->w_size; |
499 | if (dictionary != Z_NULL && len) |
500 | zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len); |
501 | if (dictLength != Z_NULL) |
502 | *dictLength = len; |
503 | return Z_OK; |
504 | } |
505 | |
506 | /* ========================================================================= */ |
507 | int ZEXPORT deflateResetKeep (strm) |
508 | z_streamp strm; |
509 | { |
510 | deflate_state *s; |
511 | |
512 | if (deflateStateCheck(strm)) { |
513 | return Z_STREAM_ERROR; |
514 | } |
515 | |
516 | strm->total_in = strm->total_out = 0; |
517 | strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ |
518 | strm->data_type = Z_UNKNOWN; |
519 | |
520 | s = (deflate_state *)strm->state; |
521 | s->pending = 0; |
522 | s->pending_out = s->pending_buf; |
523 | |
524 | if (s->wrap < 0) { |
525 | s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ |
526 | } |
527 | s->status = |
528 | #ifdef GZIP |
529 | s->wrap == 2 ? GZIP_STATE : |
530 | #endif |
531 | INIT_STATE; |
532 | strm->adler = |
533 | #ifdef GZIP |
534 | s->wrap == 2 ? crc32(0L, Z_NULL, 0) : |
535 | #endif |
536 | adler32(0L, Z_NULL, 0); |
537 | s->last_flush = -2; |
538 | |
539 | _tr_init(s); |
540 | |
541 | return Z_OK; |
542 | } |
543 | |
544 | /* ========================================================================= */ |
545 | int ZEXPORT deflateReset (strm) |
546 | z_streamp strm; |
547 | { |
548 | int ret; |
549 | |
550 | ret = deflateResetKeep(strm); |
551 | if (ret == Z_OK) |
552 | lm_init(strm->state); |
553 | return ret; |
554 | } |
555 | |
556 | /* ========================================================================= */ |
557 | int ZEXPORT (strm, head) |
558 | z_streamp strm; |
559 | gz_headerp head; |
560 | { |
561 | if (deflateStateCheck(strm) || strm->state->wrap != 2) |
562 | return Z_STREAM_ERROR; |
563 | strm->state->gzhead = head; |
564 | return Z_OK; |
565 | } |
566 | |
567 | /* ========================================================================= */ |
568 | int ZEXPORT deflatePending (strm, pending, bits) |
569 | unsigned *pending; |
570 | int *bits; |
571 | z_streamp strm; |
572 | { |
573 | if (deflateStateCheck(strm)) return Z_STREAM_ERROR; |
574 | if (pending != Z_NULL) |
575 | *pending = strm->state->pending; |
576 | if (bits != Z_NULL) |
577 | *bits = strm->state->bi_valid; |
578 | return Z_OK; |
579 | } |
580 | |
581 | /* ========================================================================= */ |
582 | int ZEXPORT deflatePrime (strm, bits, value) |
583 | z_streamp strm; |
584 | int bits; |
585 | int value; |
586 | { |
587 | deflate_state *s; |
588 | int put; |
589 | |
590 | if (deflateStateCheck(strm)) return Z_STREAM_ERROR; |
591 | s = strm->state; |
592 | if (bits < 0 || bits > 16 || |
593 | s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3)) |
594 | return Z_BUF_ERROR; |
595 | do { |
596 | put = Buf_size - s->bi_valid; |
597 | if (put > bits) |
598 | put = bits; |
599 | s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid); |
600 | s->bi_valid += put; |
601 | _tr_flush_bits(s); |
602 | value >>= put; |
603 | bits -= put; |
604 | } while (bits); |
605 | return Z_OK; |
606 | } |
607 | |
608 | /* ========================================================================= */ |
609 | int ZEXPORT deflateParams(strm, level, strategy) |
610 | z_streamp strm; |
611 | int level; |
612 | int strategy; |
613 | { |
614 | deflate_state *s; |
615 | compress_func func; |
616 | |
617 | if (deflateStateCheck(strm)) return Z_STREAM_ERROR; |
618 | s = strm->state; |
619 | |
620 | #ifdef FASTEST |
621 | if (level != 0) level = 1; |
622 | #else |
623 | if (level == Z_DEFAULT_COMPRESSION) level = 6; |
624 | #endif |
625 | if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { |
626 | return Z_STREAM_ERROR; |
627 | } |
628 | func = configuration_table[s->level].func; |
629 | |
630 | if ((strategy != s->strategy || func != configuration_table[level].func) && |
631 | s->last_flush != -2) { |
632 | /* Flush the last buffer: */ |
633 | int err = deflate(strm, Z_BLOCK); |
634 | if (err == Z_STREAM_ERROR) |
635 | return err; |
636 | if (strm->avail_in || (s->strstart - s->block_start) + s->lookahead) |
637 | return Z_BUF_ERROR; |
638 | } |
639 | if (s->level != level) { |
640 | if (s->level == 0 && s->matches != 0) { |
641 | if (s->matches == 1) |
642 | slide_hash(s); |
643 | else |
644 | CLEAR_HASH(s); |
645 | s->matches = 0; |
646 | } |
647 | s->level = level; |
648 | s->max_lazy_match = configuration_table[level].max_lazy; |
649 | s->good_match = configuration_table[level].good_length; |
650 | s->nice_match = configuration_table[level].nice_length; |
651 | s->max_chain_length = configuration_table[level].max_chain; |
652 | } |
653 | s->strategy = strategy; |
654 | return Z_OK; |
655 | } |
656 | |
657 | /* ========================================================================= */ |
658 | int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain) |
659 | z_streamp strm; |
660 | int good_length; |
661 | int max_lazy; |
662 | int nice_length; |
663 | int max_chain; |
664 | { |
665 | deflate_state *s; |
666 | |
667 | if (deflateStateCheck(strm)) return Z_STREAM_ERROR; |
668 | s = strm->state; |
669 | s->good_match = (uInt)good_length; |
670 | s->max_lazy_match = (uInt)max_lazy; |
671 | s->nice_match = nice_length; |
672 | s->max_chain_length = (uInt)max_chain; |
673 | return Z_OK; |
674 | } |
675 | |
676 | /* ========================================================================= |
677 | * For the default windowBits of 15 and memLevel of 8, this function returns |
678 | * a close to exact, as well as small, upper bound on the compressed size. |
679 | * They are coded as constants here for a reason--if the #define's are |
680 | * changed, then this function needs to be changed as well. The return |
681 | * value for 15 and 8 only works for those exact settings. |
682 | * |
683 | * For any setting other than those defaults for windowBits and memLevel, |
684 | * the value returned is a conservative worst case for the maximum expansion |
685 | * resulting from using fixed blocks instead of stored blocks, which deflate |
686 | * can emit on compressed data for some combinations of the parameters. |
687 | * |
688 | * This function could be more sophisticated to provide closer upper bounds for |
689 | * every combination of windowBits and memLevel. But even the conservative |
690 | * upper bound of about 14% expansion does not seem onerous for output buffer |
691 | * allocation. |
692 | */ |
693 | uLong ZEXPORT deflateBound(strm, sourceLen) |
694 | z_streamp strm; |
695 | uLong sourceLen; |
696 | { |
697 | deflate_state *s; |
698 | uLong complen, wraplen; |
699 | |
700 | /* conservative upper bound for compressed data */ |
701 | complen = sourceLen + |
702 | ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; |
703 | |
704 | /* if can't get parameters, return conservative bound plus zlib wrapper */ |
705 | if (deflateStateCheck(strm)) |
706 | return complen + 6; |
707 | |
708 | /* compute wrapper length */ |
709 | s = strm->state; |
710 | switch (s->wrap) { |
711 | case 0: /* raw deflate */ |
712 | wraplen = 0; |
713 | break; |
714 | case 1: /* zlib wrapper */ |
715 | wraplen = 6 + (s->strstart ? 4 : 0); |
716 | break; |
717 | #ifdef GZIP |
718 | case 2: /* gzip wrapper */ |
719 | wraplen = 18; |
720 | if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ |
721 | Bytef *str; |
722 | if (s->gzhead->extra != Z_NULL) |
723 | wraplen += 2 + s->gzhead->extra_len; |
724 | str = s->gzhead->name; |
725 | if (str != Z_NULL) |
726 | do { |
727 | wraplen++; |
728 | } while (*str++); |
729 | str = s->gzhead->comment; |
730 | if (str != Z_NULL) |
731 | do { |
732 | wraplen++; |
733 | } while (*str++); |
734 | if (s->gzhead->hcrc) |
735 | wraplen += 2; |
736 | } |
737 | break; |
738 | #endif |
739 | default: /* for compiler happiness */ |
740 | wraplen = 6; |
741 | } |
742 | |
743 | /* if not default parameters, return conservative bound */ |
744 | if (s->w_bits != 15 || s->hash_bits != 8 + 7) |
745 | return complen + wraplen; |
746 | |
747 | /* default settings: return tight bound for that case */ |
748 | return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
749 | (sourceLen >> 25) + 13 - 6 + wraplen; |
750 | } |
751 | |
752 | /* ========================================================================= |
753 | * Put a short in the pending buffer. The 16-bit value is put in MSB order. |
754 | * IN assertion: the stream state is correct and there is enough room in |
755 | * pending_buf. |
756 | */ |
757 | local void putShortMSB (s, b) |
758 | deflate_state *s; |
759 | uInt b; |
760 | { |
761 | put_byte(s, (Byte)(b >> 8)); |
762 | put_byte(s, (Byte)(b & 0xff)); |
763 | } |
764 | |
765 | /* ========================================================================= |
766 | * Flush as much pending output as possible. All deflate() output, except for |
767 | * some deflate_stored() output, goes through this function so some |
768 | * applications may wish to modify it to avoid allocating a large |
769 | * strm->next_out buffer and copying into it. (See also read_buf()). |
770 | */ |
771 | local void flush_pending(strm) |
772 | z_streamp strm; |
773 | { |
774 | unsigned len; |
775 | deflate_state *s = strm->state; |
776 | |
777 | _tr_flush_bits(s); |
778 | len = s->pending; |
779 | if (len > strm->avail_out) len = strm->avail_out; |
780 | if (len == 0) return; |
781 | |
782 | zmemcpy(strm->next_out, s->pending_out, len); |
783 | strm->next_out += len; |
784 | s->pending_out += len; |
785 | strm->total_out += len; |
786 | strm->avail_out -= len; |
787 | s->pending -= len; |
788 | if (s->pending == 0) { |
789 | s->pending_out = s->pending_buf; |
790 | } |
791 | } |
792 | |
793 | /* =========================================================================== |
794 | * Update the header CRC with the bytes s->pending_buf[beg..s->pending - 1]. |
795 | */ |
796 | #define HCRC_UPDATE(beg) \ |
797 | do { \ |
798 | if (s->gzhead->hcrc && s->pending > (beg)) \ |
799 | strm->adler = crc32(strm->adler, s->pending_buf + (beg), \ |
800 | s->pending - (beg)); \ |
801 | } while (0) |
802 | |
803 | /* ========================================================================= */ |
804 | int ZEXPORT deflate (strm, flush) |
805 | z_streamp strm; |
806 | int flush; |
807 | { |
808 | int old_flush; /* value of flush param for previous deflate call */ |
809 | deflate_state *s; |
810 | |
811 | if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) { |
812 | return Z_STREAM_ERROR; |
813 | } |
814 | s = strm->state; |
815 | |
816 | if (strm->next_out == Z_NULL || |
817 | (strm->avail_in != 0 && strm->next_in == Z_NULL) || |
818 | (s->status == FINISH_STATE && flush != Z_FINISH)) { |
819 | ERR_RETURN(strm, Z_STREAM_ERROR); |
820 | } |
821 | if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); |
822 | |
823 | old_flush = s->last_flush; |
824 | s->last_flush = flush; |
825 | |
826 | /* Flush as much pending output as possible */ |
827 | if (s->pending != 0) { |
828 | flush_pending(strm); |
829 | if (strm->avail_out == 0) { |
830 | /* Since avail_out is 0, deflate will be called again with |
831 | * more output space, but possibly with both pending and |
832 | * avail_in equal to zero. There won't be anything to do, |
833 | * but this is not an error situation so make sure we |
834 | * return OK instead of BUF_ERROR at next call of deflate: |
835 | */ |
836 | s->last_flush = -1; |
837 | return Z_OK; |
838 | } |
839 | |
840 | /* Make sure there is something to do and avoid duplicate consecutive |
841 | * flushes. For repeated and useless calls with Z_FINISH, we keep |
842 | * returning Z_STREAM_END instead of Z_BUF_ERROR. |
843 | */ |
844 | } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) && |
845 | flush != Z_FINISH) { |
846 | ERR_RETURN(strm, Z_BUF_ERROR); |
847 | } |
848 | |
849 | /* User must not provide more input after the first FINISH: */ |
850 | if (s->status == FINISH_STATE && strm->avail_in != 0) { |
851 | ERR_RETURN(strm, Z_BUF_ERROR); |
852 | } |
853 | |
854 | /* Write the header */ |
855 | if (s->status == INIT_STATE && s->wrap == 0) |
856 | s->status = BUSY_STATE; |
857 | if (s->status == INIT_STATE) { |
858 | /* zlib header */ |
859 | uInt = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; |
860 | uInt level_flags; |
861 | |
862 | if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2) |
863 | level_flags = 0; |
864 | else if (s->level < 6) |
865 | level_flags = 1; |
866 | else if (s->level == 6) |
867 | level_flags = 2; |
868 | else |
869 | level_flags = 3; |
870 | header |= (level_flags << 6); |
871 | if (s->strstart != 0) header |= PRESET_DICT; |
872 | header += 31 - (header % 31); |
873 | |
874 | putShortMSB(s, header); |
875 | |
876 | /* Save the adler32 of the preset dictionary: */ |
877 | if (s->strstart != 0) { |
878 | putShortMSB(s, (uInt)(strm->adler >> 16)); |
879 | putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
880 | } |
881 | strm->adler = adler32(0L, Z_NULL, 0); |
882 | s->status = BUSY_STATE; |
883 | |
884 | /* Compression must start with an empty pending buffer */ |
885 | flush_pending(strm); |
886 | if (s->pending != 0) { |
887 | s->last_flush = -1; |
888 | return Z_OK; |
889 | } |
890 | } |
891 | #ifdef GZIP |
892 | if (s->status == GZIP_STATE) { |
893 | /* gzip header */ |
894 | strm->adler = crc32(0L, Z_NULL, 0); |
895 | put_byte(s, 31); |
896 | put_byte(s, 139); |
897 | put_byte(s, 8); |
898 | if (s->gzhead == Z_NULL) { |
899 | put_byte(s, 0); |
900 | put_byte(s, 0); |
901 | put_byte(s, 0); |
902 | put_byte(s, 0); |
903 | put_byte(s, 0); |
904 | put_byte(s, s->level == 9 ? 2 : |
905 | (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? |
906 | 4 : 0)); |
907 | put_byte(s, OS_CODE); |
908 | s->status = BUSY_STATE; |
909 | |
910 | /* Compression must start with an empty pending buffer */ |
911 | flush_pending(strm); |
912 | if (s->pending != 0) { |
913 | s->last_flush = -1; |
914 | return Z_OK; |
915 | } |
916 | } |
917 | else { |
918 | put_byte(s, (s->gzhead->text ? 1 : 0) + |
919 | (s->gzhead->hcrc ? 2 : 0) + |
920 | (s->gzhead->extra == Z_NULL ? 0 : 4) + |
921 | (s->gzhead->name == Z_NULL ? 0 : 8) + |
922 | (s->gzhead->comment == Z_NULL ? 0 : 16) |
923 | ); |
924 | put_byte(s, (Byte)(s->gzhead->time & 0xff)); |
925 | put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff)); |
926 | put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff)); |
927 | put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff)); |
928 | put_byte(s, s->level == 9 ? 2 : |
929 | (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? |
930 | 4 : 0)); |
931 | put_byte(s, s->gzhead->os & 0xff); |
932 | if (s->gzhead->extra != Z_NULL) { |
933 | put_byte(s, s->gzhead->extra_len & 0xff); |
934 | put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); |
935 | } |
936 | if (s->gzhead->hcrc) |
937 | strm->adler = crc32(strm->adler, s->pending_buf, |
938 | s->pending); |
939 | s->gzindex = 0; |
940 | s->status = EXTRA_STATE; |
941 | } |
942 | } |
943 | if (s->status == EXTRA_STATE) { |
944 | if (s->gzhead->extra != Z_NULL) { |
945 | ulg beg = s->pending; /* start of bytes to update crc */ |
946 | uInt left = (s->gzhead->extra_len & 0xffff) - s->gzindex; |
947 | while (s->pending + left > s->pending_buf_size) { |
948 | uInt copy = s->pending_buf_size - s->pending; |
949 | zmemcpy(s->pending_buf + s->pending, |
950 | s->gzhead->extra + s->gzindex, copy); |
951 | s->pending = s->pending_buf_size; |
952 | HCRC_UPDATE(beg); |
953 | s->gzindex += copy; |
954 | flush_pending(strm); |
955 | if (s->pending != 0) { |
956 | s->last_flush = -1; |
957 | return Z_OK; |
958 | } |
959 | beg = 0; |
960 | left -= copy; |
961 | } |
962 | zmemcpy(s->pending_buf + s->pending, |
963 | s->gzhead->extra + s->gzindex, left); |
964 | s->pending += left; |
965 | HCRC_UPDATE(beg); |
966 | s->gzindex = 0; |
967 | } |
968 | s->status = NAME_STATE; |
969 | } |
970 | if (s->status == NAME_STATE) { |
971 | if (s->gzhead->name != Z_NULL) { |
972 | ulg beg = s->pending; /* start of bytes to update crc */ |
973 | int val; |
974 | do { |
975 | if (s->pending == s->pending_buf_size) { |
976 | HCRC_UPDATE(beg); |
977 | flush_pending(strm); |
978 | if (s->pending != 0) { |
979 | s->last_flush = -1; |
980 | return Z_OK; |
981 | } |
982 | beg = 0; |
983 | } |
984 | val = s->gzhead->name[s->gzindex++]; |
985 | put_byte(s, val); |
986 | } while (val != 0); |
987 | HCRC_UPDATE(beg); |
988 | s->gzindex = 0; |
989 | } |
990 | s->status = COMMENT_STATE; |
991 | } |
992 | if (s->status == COMMENT_STATE) { |
993 | if (s->gzhead->comment != Z_NULL) { |
994 | ulg beg = s->pending; /* start of bytes to update crc */ |
995 | int val; |
996 | do { |
997 | if (s->pending == s->pending_buf_size) { |
998 | HCRC_UPDATE(beg); |
999 | flush_pending(strm); |
1000 | if (s->pending != 0) { |
1001 | s->last_flush = -1; |
1002 | return Z_OK; |
1003 | } |
1004 | beg = 0; |
1005 | } |
1006 | val = s->gzhead->comment[s->gzindex++]; |
1007 | put_byte(s, val); |
1008 | } while (val != 0); |
1009 | HCRC_UPDATE(beg); |
1010 | } |
1011 | s->status = HCRC_STATE; |
1012 | } |
1013 | if (s->status == HCRC_STATE) { |
1014 | if (s->gzhead->hcrc) { |
1015 | if (s->pending + 2 > s->pending_buf_size) { |
1016 | flush_pending(strm); |
1017 | if (s->pending != 0) { |
1018 | s->last_flush = -1; |
1019 | return Z_OK; |
1020 | } |
1021 | } |
1022 | put_byte(s, (Byte)(strm->adler & 0xff)); |
1023 | put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); |
1024 | strm->adler = crc32(0L, Z_NULL, 0); |
1025 | } |
1026 | s->status = BUSY_STATE; |
1027 | |
1028 | /* Compression must start with an empty pending buffer */ |
1029 | flush_pending(strm); |
1030 | if (s->pending != 0) { |
1031 | s->last_flush = -1; |
1032 | return Z_OK; |
1033 | } |
1034 | } |
1035 | #endif |
1036 | |
1037 | /* Start a new block or continue the current one. |
1038 | */ |
1039 | if (strm->avail_in != 0 || s->lookahead != 0 || |
1040 | (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { |
1041 | block_state bstate; |
1042 | |
1043 | bstate = s->level == 0 ? deflate_stored(s, flush) : |
1044 | s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) : |
1045 | s->strategy == Z_RLE ? deflate_rle(s, flush) : |
1046 | (*(configuration_table[s->level].func))(s, flush); |
1047 | |
1048 | if (bstate == finish_started || bstate == finish_done) { |
1049 | s->status = FINISH_STATE; |
1050 | } |
1051 | if (bstate == need_more || bstate == finish_started) { |
1052 | if (strm->avail_out == 0) { |
1053 | s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ |
1054 | } |
1055 | return Z_OK; |
1056 | /* If flush != Z_NO_FLUSH && avail_out == 0, the next call |
1057 | * of deflate should use the same flush parameter to make sure |
1058 | * that the flush is complete. So we don't have to output an |
1059 | * empty block here, this will be done at next call. This also |
1060 | * ensures that for a very small output buffer, we emit at most |
1061 | * one empty block. |
1062 | */ |
1063 | } |
1064 | if (bstate == block_done) { |
1065 | if (flush == Z_PARTIAL_FLUSH) { |
1066 | _tr_align(s); |
1067 | } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ |
1068 | _tr_stored_block(s, (char*)0, 0L, 0); |
1069 | /* For a full flush, this empty block will be recognized |
1070 | * as a special marker by inflate_sync(). |
1071 | */ |
1072 | if (flush == Z_FULL_FLUSH) { |
1073 | CLEAR_HASH(s); /* forget history */ |
1074 | if (s->lookahead == 0) { |
1075 | s->strstart = 0; |
1076 | s->block_start = 0L; |
1077 | s->insert = 0; |
1078 | } |
1079 | } |
1080 | } |
1081 | flush_pending(strm); |
1082 | if (strm->avail_out == 0) { |
1083 | s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ |
1084 | return Z_OK; |
1085 | } |
1086 | } |
1087 | } |
1088 | |
1089 | if (flush != Z_FINISH) return Z_OK; |
1090 | if (s->wrap <= 0) return Z_STREAM_END; |
1091 | |
1092 | /* Write the trailer */ |
1093 | #ifdef GZIP |
1094 | if (s->wrap == 2) { |
1095 | put_byte(s, (Byte)(strm->adler & 0xff)); |
1096 | put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); |
1097 | put_byte(s, (Byte)((strm->adler >> 16) & 0xff)); |
1098 | put_byte(s, (Byte)((strm->adler >> 24) & 0xff)); |
1099 | put_byte(s, (Byte)(strm->total_in & 0xff)); |
1100 | put_byte(s, (Byte)((strm->total_in >> 8) & 0xff)); |
1101 | put_byte(s, (Byte)((strm->total_in >> 16) & 0xff)); |
1102 | put_byte(s, (Byte)((strm->total_in >> 24) & 0xff)); |
1103 | } |
1104 | else |
1105 | #endif |
1106 | { |
1107 | putShortMSB(s, (uInt)(strm->adler >> 16)); |
1108 | putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
1109 | } |
1110 | flush_pending(strm); |
1111 | /* If avail_out is zero, the application will call deflate again |
1112 | * to flush the rest. |
1113 | */ |
1114 | if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ |
1115 | return s->pending != 0 ? Z_OK : Z_STREAM_END; |
1116 | } |
1117 | |
1118 | /* ========================================================================= */ |
1119 | int ZEXPORT deflateEnd (strm) |
1120 | z_streamp strm; |
1121 | { |
1122 | int status; |
1123 | |
1124 | if (deflateStateCheck(strm)) return Z_STREAM_ERROR; |
1125 | |
1126 | status = strm->state->status; |
1127 | |
1128 | /* Deallocate in reverse order of allocations: */ |
1129 | TRY_FREE(strm, strm->state->pending_buf); |
1130 | TRY_FREE(strm, strm->state->head); |
1131 | TRY_FREE(strm, strm->state->prev); |
1132 | TRY_FREE(strm, strm->state->window); |
1133 | |
1134 | ZFREE(strm, strm->state); |
1135 | strm->state = Z_NULL; |
1136 | |
1137 | return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; |
1138 | } |
1139 | |
1140 | /* ========================================================================= |
1141 | * Copy the source state to the destination state. |
1142 | * To simplify the source, this is not supported for 16-bit MSDOS (which |
1143 | * doesn't have enough memory anyway to duplicate compression states). |
1144 | */ |
1145 | int ZEXPORT deflateCopy (dest, source) |
1146 | z_streamp dest; |
1147 | z_streamp source; |
1148 | { |
1149 | #ifdef MAXSEG_64K |
1150 | return Z_STREAM_ERROR; |
1151 | #else |
1152 | deflate_state *ds; |
1153 | deflate_state *ss; |
1154 | |
1155 | |
1156 | if (deflateStateCheck(source) || dest == Z_NULL) { |
1157 | return Z_STREAM_ERROR; |
1158 | } |
1159 | |
1160 | ss = source->state; |
1161 | |
1162 | zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); |
1163 | |
1164 | ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); |
1165 | if (ds == Z_NULL) return Z_MEM_ERROR; |
1166 | dest->state = (struct internal_state FAR *) ds; |
1167 | zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state)); |
1168 | ds->strm = dest; |
1169 | |
1170 | ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); |
1171 | ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); |
1172 | ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); |
1173 | ds->pending_buf = (uchf *) ZALLOC(dest, ds->lit_bufsize, 4); |
1174 | |
1175 | if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || |
1176 | ds->pending_buf == Z_NULL) { |
1177 | deflateEnd (dest); |
1178 | return Z_MEM_ERROR; |
1179 | } |
1180 | /* following zmemcpy do not work for 16-bit MSDOS */ |
1181 | zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); |
1182 | zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos)); |
1183 | zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos)); |
1184 | zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); |
1185 | |
1186 | ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); |
1187 | ds->sym_buf = ds->pending_buf + ds->lit_bufsize; |
1188 | |
1189 | ds->l_desc.dyn_tree = ds->dyn_ltree; |
1190 | ds->d_desc.dyn_tree = ds->dyn_dtree; |
1191 | ds->bl_desc.dyn_tree = ds->bl_tree; |
1192 | |
1193 | return Z_OK; |
1194 | #endif /* MAXSEG_64K */ |
1195 | } |
1196 | |
1197 | /* =========================================================================== |
1198 | * Read a new buffer from the current input stream, update the adler32 |
1199 | * and total number of bytes read. All deflate() input goes through |
1200 | * this function so some applications may wish to modify it to avoid |
1201 | * allocating a large strm->next_in buffer and copying from it. |
1202 | * (See also flush_pending()). |
1203 | */ |
1204 | local unsigned read_buf(strm, buf, size) |
1205 | z_streamp strm; |
1206 | Bytef *buf; |
1207 | unsigned size; |
1208 | { |
1209 | unsigned len = strm->avail_in; |
1210 | |
1211 | if (len > size) len = size; |
1212 | if (len == 0) return 0; |
1213 | |
1214 | strm->avail_in -= len; |
1215 | |
1216 | zmemcpy(buf, strm->next_in, len); |
1217 | if (strm->state->wrap == 1) { |
1218 | strm->adler = adler32(strm->adler, buf, len); |
1219 | } |
1220 | #ifdef GZIP |
1221 | else if (strm->state->wrap == 2) { |
1222 | strm->adler = crc32(strm->adler, buf, len); |
1223 | } |
1224 | #endif |
1225 | strm->next_in += len; |
1226 | strm->total_in += len; |
1227 | |
1228 | return len; |
1229 | } |
1230 | |
1231 | /* =========================================================================== |
1232 | * Initialize the "longest match" routines for a new zlib stream |
1233 | */ |
1234 | local void lm_init (s) |
1235 | deflate_state *s; |
1236 | { |
1237 | s->window_size = (ulg)2L*s->w_size; |
1238 | |
1239 | CLEAR_HASH(s); |
1240 | |
1241 | /* Set the default configuration parameters: |
1242 | */ |
1243 | s->max_lazy_match = configuration_table[s->level].max_lazy; |
1244 | s->good_match = configuration_table[s->level].good_length; |
1245 | s->nice_match = configuration_table[s->level].nice_length; |
1246 | s->max_chain_length = configuration_table[s->level].max_chain; |
1247 | |
1248 | s->strstart = 0; |
1249 | s->block_start = 0L; |
1250 | s->lookahead = 0; |
1251 | s->insert = 0; |
1252 | s->match_length = s->prev_length = MIN_MATCH-1; |
1253 | s->match_available = 0; |
1254 | s->ins_h = 0; |
1255 | #ifndef FASTEST |
1256 | #ifdef ASMV |
1257 | match_init(); /* initialize the asm code */ |
1258 | #endif |
1259 | #endif |
1260 | } |
1261 | |
1262 | #ifndef FASTEST |
1263 | /* =========================================================================== |
1264 | * Set match_start to the longest match starting at the given string and |
1265 | * return its length. Matches shorter or equal to prev_length are discarded, |
1266 | * in which case the result is equal to prev_length and match_start is |
1267 | * garbage. |
1268 | * IN assertions: cur_match is the head of the hash chain for the current |
1269 | * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 |
1270 | * OUT assertion: the match length is not greater than s->lookahead. |
1271 | */ |
1272 | #ifndef ASMV |
1273 | /* For 80x86 and 680x0, an optimized version will be provided in match.asm or |
1274 | * match.S. The code will be functionally equivalent. |
1275 | */ |
1276 | local uInt longest_match(s, cur_match) |
1277 | deflate_state *s; |
1278 | IPos cur_match; /* current match */ |
1279 | { |
1280 | unsigned chain_length = s->max_chain_length;/* max hash chain length */ |
1281 | register Bytef *scan = s->window + s->strstart; /* current string */ |
1282 | register Bytef *match; /* matched string */ |
1283 | register int len; /* length of current match */ |
1284 | int best_len = (int)s->prev_length; /* best match length so far */ |
1285 | int nice_match = s->nice_match; /* stop if match long enough */ |
1286 | IPos limit = s->strstart > (IPos)MAX_DIST(s) ? |
1287 | s->strstart - (IPos)MAX_DIST(s) : NIL; |
1288 | /* Stop when cur_match becomes <= limit. To simplify the code, |
1289 | * we prevent matches with the string of window index 0. |
1290 | */ |
1291 | Posf *prev = s->prev; |
1292 | uInt wmask = s->w_mask; |
1293 | |
1294 | #ifdef UNALIGNED_OK |
1295 | /* Compare two bytes at a time. Note: this is not always beneficial. |
1296 | * Try with and without -DUNALIGNED_OK to check. |
1297 | */ |
1298 | register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; |
1299 | register ush scan_start = *(ushf*)scan; |
1300 | register ush scan_end = *(ushf*)(scan+best_len-1); |
1301 | #else |
1302 | register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
1303 | register Byte scan_end1 = scan[best_len-1]; |
1304 | register Byte scan_end = scan[best_len]; |
1305 | #endif |
1306 | |
1307 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
1308 | * It is easy to get rid of this optimization if necessary. |
1309 | */ |
1310 | Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever" ); |
1311 | |
1312 | /* Do not waste too much time if we already have a good match: */ |
1313 | if (s->prev_length >= s->good_match) { |
1314 | chain_length >>= 2; |
1315 | } |
1316 | /* Do not look for matches beyond the end of the input. This is necessary |
1317 | * to make deflate deterministic. |
1318 | */ |
1319 | if ((uInt)nice_match > s->lookahead) nice_match = (int)s->lookahead; |
1320 | |
1321 | Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead" ); |
1322 | |
1323 | do { |
1324 | Assert(cur_match < s->strstart, "no future" ); |
1325 | match = s->window + cur_match; |
1326 | |
1327 | /* Skip to next match if the match length cannot increase |
1328 | * or if the match length is less than 2. Note that the checks below |
1329 | * for insufficient lookahead only occur occasionally for performance |
1330 | * reasons. Therefore uninitialized memory will be accessed, and |
1331 | * conditional jumps will be made that depend on those values. |
1332 | * However the length of the match is limited to the lookahead, so |
1333 | * the output of deflate is not affected by the uninitialized values. |
1334 | */ |
1335 | #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) |
1336 | /* This code assumes sizeof(unsigned short) == 2. Do not use |
1337 | * UNALIGNED_OK if your compiler uses a different size. |
1338 | */ |
1339 | if (*(ushf*)(match+best_len-1) != scan_end || |
1340 | *(ushf*)match != scan_start) continue; |
1341 | |
1342 | /* It is not necessary to compare scan[2] and match[2] since they are |
1343 | * always equal when the other bytes match, given that the hash keys |
1344 | * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at |
1345 | * strstart+3, +5, ... up to strstart+257. We check for insufficient |
1346 | * lookahead only every 4th comparison; the 128th check will be made |
1347 | * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is |
1348 | * necessary to put more guard bytes at the end of the window, or |
1349 | * to check more often for insufficient lookahead. |
1350 | */ |
1351 | Assert(scan[2] == match[2], "scan[2]?" ); |
1352 | scan++, match++; |
1353 | do { |
1354 | } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
1355 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
1356 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
1357 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
1358 | scan < strend); |
1359 | /* The funny "do {}" generates better code on most compilers */ |
1360 | |
1361 | /* Here, scan <= window+strstart+257 */ |
1362 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan" ); |
1363 | if (*scan == *match) scan++; |
1364 | |
1365 | len = (MAX_MATCH - 1) - (int)(strend-scan); |
1366 | scan = strend - (MAX_MATCH-1); |
1367 | |
1368 | #else /* UNALIGNED_OK */ |
1369 | |
1370 | if (match[best_len] != scan_end || |
1371 | match[best_len-1] != scan_end1 || |
1372 | *match != *scan || |
1373 | *++match != scan[1]) continue; |
1374 | |
1375 | /* The check at best_len-1 can be removed because it will be made |
1376 | * again later. (This heuristic is not always a win.) |
1377 | * It is not necessary to compare scan[2] and match[2] since they |
1378 | * are always equal when the other bytes match, given that |
1379 | * the hash keys are equal and that HASH_BITS >= 8. |
1380 | */ |
1381 | scan += 2, match++; |
1382 | Assert(*scan == *match, "match[2]?" ); |
1383 | |
1384 | /* We check for insufficient lookahead only every 8th comparison; |
1385 | * the 256th check will be made at strstart+258. |
1386 | */ |
1387 | do { |
1388 | } while (*++scan == *++match && *++scan == *++match && |
1389 | *++scan == *++match && *++scan == *++match && |
1390 | *++scan == *++match && *++scan == *++match && |
1391 | *++scan == *++match && *++scan == *++match && |
1392 | scan < strend); |
1393 | |
1394 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan" ); |
1395 | |
1396 | len = MAX_MATCH - (int)(strend - scan); |
1397 | scan = strend - MAX_MATCH; |
1398 | |
1399 | #endif /* UNALIGNED_OK */ |
1400 | |
1401 | if (len > best_len) { |
1402 | s->match_start = cur_match; |
1403 | best_len = len; |
1404 | if (len >= nice_match) break; |
1405 | #ifdef UNALIGNED_OK |
1406 | scan_end = *(ushf*)(scan+best_len-1); |
1407 | #else |
1408 | scan_end1 = scan[best_len-1]; |
1409 | scan_end = scan[best_len]; |
1410 | #endif |
1411 | } |
1412 | } while ((cur_match = prev[cur_match & wmask]) > limit |
1413 | && --chain_length != 0); |
1414 | |
1415 | if ((uInt)best_len <= s->lookahead) return (uInt)best_len; |
1416 | return s->lookahead; |
1417 | } |
1418 | #endif /* ASMV */ |
1419 | |
1420 | #else /* FASTEST */ |
1421 | |
1422 | /* --------------------------------------------------------------------------- |
1423 | * Optimized version for FASTEST only |
1424 | */ |
1425 | local uInt longest_match(s, cur_match) |
1426 | deflate_state *s; |
1427 | IPos cur_match; /* current match */ |
1428 | { |
1429 | register Bytef *scan = s->window + s->strstart; /* current string */ |
1430 | register Bytef *match; /* matched string */ |
1431 | register int len; /* length of current match */ |
1432 | register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
1433 | |
1434 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
1435 | * It is easy to get rid of this optimization if necessary. |
1436 | */ |
1437 | Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever" ); |
1438 | |
1439 | Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead" ); |
1440 | |
1441 | Assert(cur_match < s->strstart, "no future" ); |
1442 | |
1443 | match = s->window + cur_match; |
1444 | |
1445 | /* Return failure if the match length is less than 2: |
1446 | */ |
1447 | if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1; |
1448 | |
1449 | /* The check at best_len-1 can be removed because it will be made |
1450 | * again later. (This heuristic is not always a win.) |
1451 | * It is not necessary to compare scan[2] and match[2] since they |
1452 | * are always equal when the other bytes match, given that |
1453 | * the hash keys are equal and that HASH_BITS >= 8. |
1454 | */ |
1455 | scan += 2, match += 2; |
1456 | Assert(*scan == *match, "match[2]?" ); |
1457 | |
1458 | /* We check for insufficient lookahead only every 8th comparison; |
1459 | * the 256th check will be made at strstart+258. |
1460 | */ |
1461 | do { |
1462 | } while (*++scan == *++match && *++scan == *++match && |
1463 | *++scan == *++match && *++scan == *++match && |
1464 | *++scan == *++match && *++scan == *++match && |
1465 | *++scan == *++match && *++scan == *++match && |
1466 | scan < strend); |
1467 | |
1468 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan" ); |
1469 | |
1470 | len = MAX_MATCH - (int)(strend - scan); |
1471 | |
1472 | if (len < MIN_MATCH) return MIN_MATCH - 1; |
1473 | |
1474 | s->match_start = cur_match; |
1475 | return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; |
1476 | } |
1477 | |
1478 | #endif /* FASTEST */ |
1479 | |
1480 | #ifdef ZLIB_DEBUG |
1481 | |
1482 | #define EQUAL 0 |
1483 | /* result of memcmp for equal strings */ |
1484 | |
1485 | /* =========================================================================== |
1486 | * Check that the match at match_start is indeed a match. |
1487 | */ |
1488 | local void check_match(s, start, match, length) |
1489 | deflate_state *s; |
1490 | IPos start, match; |
1491 | int length; |
1492 | { |
1493 | /* check that the match is indeed a match */ |
1494 | if (zmemcmp(s->window + match, |
1495 | s->window + start, length) != EQUAL) { |
1496 | fprintf(stderr, " start %u, match %u, length %d\n" , |
1497 | start, match, length); |
1498 | do { |
1499 | fprintf(stderr, "%c%c" , s->window[match++], s->window[start++]); |
1500 | } while (--length != 0); |
1501 | z_error("invalid match" ); |
1502 | } |
1503 | if (z_verbose > 1) { |
1504 | fprintf(stderr,"\\[%d,%d]" , start-match, length); |
1505 | do { putc(s->window[start++], stderr); } while (--length != 0); |
1506 | } |
1507 | } |
1508 | #else |
1509 | # define check_match(s, start, match, length) |
1510 | #endif /* ZLIB_DEBUG */ |
1511 | |
1512 | /* =========================================================================== |
1513 | * Fill the window when the lookahead becomes insufficient. |
1514 | * Updates strstart and lookahead. |
1515 | * |
1516 | * IN assertion: lookahead < MIN_LOOKAHEAD |
1517 | * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD |
1518 | * At least one byte has been read, or avail_in == 0; reads are |
1519 | * performed for at least two bytes (required for the zip translate_eol |
1520 | * option -- not supported here). |
1521 | */ |
1522 | local void fill_window(s) |
1523 | deflate_state *s; |
1524 | { |
1525 | unsigned n; |
1526 | unsigned more; /* Amount of free space at the end of the window. */ |
1527 | uInt wsize = s->w_size; |
1528 | |
1529 | Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead" ); |
1530 | |
1531 | do { |
1532 | more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); |
1533 | |
1534 | /* Deal with !@#$% 64K limit: */ |
1535 | if (sizeof(int) <= 2) { |
1536 | if (more == 0 && s->strstart == 0 && s->lookahead == 0) { |
1537 | more = wsize; |
1538 | |
1539 | } else if (more == (unsigned)(-1)) { |
1540 | /* Very unlikely, but possible on 16 bit machine if |
1541 | * strstart == 0 && lookahead == 1 (input done a byte at time) |
1542 | */ |
1543 | more--; |
1544 | } |
1545 | } |
1546 | |
1547 | /* If the window is almost full and there is insufficient lookahead, |
1548 | * move the upper half to the lower one to make room in the upper half. |
1549 | */ |
1550 | if (s->strstart >= wsize+MAX_DIST(s)) { |
1551 | |
1552 | zmemcpy(s->window, s->window+wsize, (unsigned)wsize - more); |
1553 | s->match_start -= wsize; |
1554 | s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ |
1555 | s->block_start -= (long) wsize; |
1556 | if (s->insert > s->strstart) |
1557 | s->insert = s->strstart; |
1558 | slide_hash(s); |
1559 | more += wsize; |
1560 | } |
1561 | if (s->strm->avail_in == 0) break; |
1562 | |
1563 | /* If there was no sliding: |
1564 | * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && |
1565 | * more == window_size - lookahead - strstart |
1566 | * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) |
1567 | * => more >= window_size - 2*WSIZE + 2 |
1568 | * In the BIG_MEM or MMAP case (not yet supported), |
1569 | * window_size == input_size + MIN_LOOKAHEAD && |
1570 | * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. |
1571 | * Otherwise, window_size == 2*WSIZE so more >= 2. |
1572 | * If there was sliding, more >= WSIZE. So in all cases, more >= 2. |
1573 | */ |
1574 | Assert(more >= 2, "more < 2" ); |
1575 | |
1576 | n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more); |
1577 | s->lookahead += n; |
1578 | |
1579 | /* Initialize the hash value now that we have some input: */ |
1580 | if (s->lookahead + s->insert >= MIN_MATCH) { |
1581 | uInt str = s->strstart - s->insert; |
1582 | s->ins_h = s->window[str]; |
1583 | UPDATE_HASH(s, s->ins_h, s->window[str + 1]); |
1584 | #if MIN_MATCH != 3 |
1585 | Call UPDATE_HASH() MIN_MATCH-3 more times |
1586 | #endif |
1587 | while (s->insert) { |
1588 | UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); |
1589 | #ifndef FASTEST |
1590 | s->prev[str & s->w_mask] = s->head[s->ins_h]; |
1591 | #endif |
1592 | s->head[s->ins_h] = (Pos)str; |
1593 | str++; |
1594 | s->insert--; |
1595 | if (s->lookahead + s->insert < MIN_MATCH) |
1596 | break; |
1597 | } |
1598 | } |
1599 | /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, |
1600 | * but this is not important since only literal bytes will be emitted. |
1601 | */ |
1602 | |
1603 | } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); |
1604 | |
1605 | /* If the WIN_INIT bytes after the end of the current data have never been |
1606 | * written, then zero those bytes in order to avoid memory check reports of |
1607 | * the use of uninitialized (or uninitialised as Julian writes) bytes by |
1608 | * the longest match routines. Update the high water mark for the next |
1609 | * time through here. WIN_INIT is set to MAX_MATCH since the longest match |
1610 | * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. |
1611 | */ |
1612 | if (s->high_water < s->window_size) { |
1613 | ulg curr = s->strstart + (ulg)(s->lookahead); |
1614 | ulg init; |
1615 | |
1616 | if (s->high_water < curr) { |
1617 | /* Previous high water mark below current data -- zero WIN_INIT |
1618 | * bytes or up to end of window, whichever is less. |
1619 | */ |
1620 | init = s->window_size - curr; |
1621 | if (init > WIN_INIT) |
1622 | init = WIN_INIT; |
1623 | zmemzero(s->window + curr, (unsigned)init); |
1624 | s->high_water = curr + init; |
1625 | } |
1626 | else if (s->high_water < (ulg)curr + WIN_INIT) { |
1627 | /* High water mark at or above current data, but below current data |
1628 | * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up |
1629 | * to end of window, whichever is less. |
1630 | */ |
1631 | init = (ulg)curr + WIN_INIT - s->high_water; |
1632 | if (init > s->window_size - s->high_water) |
1633 | init = s->window_size - s->high_water; |
1634 | zmemzero(s->window + s->high_water, (unsigned)init); |
1635 | s->high_water += init; |
1636 | } |
1637 | } |
1638 | |
1639 | Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD, |
1640 | "not enough room for search" ); |
1641 | } |
1642 | |
1643 | /* =========================================================================== |
1644 | * Flush the current block, with given end-of-file flag. |
1645 | * IN assertion: strstart is set to the end of the current match. |
1646 | */ |
1647 | #define FLUSH_BLOCK_ONLY(s, last) { \ |
1648 | _tr_flush_block(s, (s->block_start >= 0L ? \ |
1649 | (charf *)&s->window[(unsigned)s->block_start] : \ |
1650 | (charf *)Z_NULL), \ |
1651 | (ulg)((long)s->strstart - s->block_start), \ |
1652 | (last)); \ |
1653 | s->block_start = s->strstart; \ |
1654 | flush_pending(s->strm); \ |
1655 | Tracev((stderr,"[FLUSH]")); \ |
1656 | } |
1657 | |
1658 | /* Same but force premature exit if necessary. */ |
1659 | #define FLUSH_BLOCK(s, last) { \ |
1660 | FLUSH_BLOCK_ONLY(s, last); \ |
1661 | if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ |
1662 | } |
1663 | |
1664 | /* Maximum stored block length in deflate format (not including header). */ |
1665 | #define MAX_STORED 65535 |
1666 | |
1667 | /* Minimum of a and b. */ |
1668 | #define MIN(a, b) ((a) > (b) ? (b) : (a)) |
1669 | |
1670 | /* =========================================================================== |
1671 | * Copy without compression as much as possible from the input stream, return |
1672 | * the current block state. |
1673 | * |
1674 | * In case deflateParams() is used to later switch to a non-zero compression |
1675 | * level, s->matches (otherwise unused when storing) keeps track of the number |
1676 | * of hash table slides to perform. If s->matches is 1, then one hash table |
1677 | * slide will be done when switching. If s->matches is 2, the maximum value |
1678 | * allowed here, then the hash table will be cleared, since two or more slides |
1679 | * is the same as a clear. |
1680 | * |
1681 | * deflate_stored() is written to minimize the number of times an input byte is |
1682 | * copied. It is most efficient with large input and output buffers, which |
1683 | * maximizes the opportunites to have a single copy from next_in to next_out. |
1684 | */ |
1685 | local block_state deflate_stored(s, flush) |
1686 | deflate_state *s; |
1687 | int flush; |
1688 | { |
1689 | /* Smallest worthy block size when not flushing or finishing. By default |
1690 | * this is 32K. This can be as small as 507 bytes for memLevel == 1. For |
1691 | * large input and output buffers, the stored block size will be larger. |
1692 | */ |
1693 | unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size); |
1694 | |
1695 | /* Copy as many min_block or larger stored blocks directly to next_out as |
1696 | * possible. If flushing, copy the remaining available input to next_out as |
1697 | * stored blocks, if there is enough space. |
1698 | */ |
1699 | unsigned len, left, have, last = 0; |
1700 | unsigned used = s->strm->avail_in; |
1701 | do { |
1702 | /* Set len to the maximum size block that we can copy directly with the |
1703 | * available input data and output space. Set left to how much of that |
1704 | * would be copied from what's left in the window. |
1705 | */ |
1706 | len = MAX_STORED; /* maximum deflate stored block length */ |
1707 | have = (s->bi_valid + 42) >> 3; /* number of header bytes */ |
1708 | if (s->strm->avail_out < have) /* need room for header */ |
1709 | break; |
1710 | /* maximum stored block length that will fit in avail_out: */ |
1711 | have = s->strm->avail_out - have; |
1712 | left = s->strstart - s->block_start; /* bytes left in window */ |
1713 | if (len > (ulg)left + s->strm->avail_in) |
1714 | len = left + s->strm->avail_in; /* limit len to the input */ |
1715 | if (len > have) |
1716 | len = have; /* limit len to the output */ |
1717 | |
1718 | /* If the stored block would be less than min_block in length, or if |
1719 | * unable to copy all of the available input when flushing, then try |
1720 | * copying to the window and the pending buffer instead. Also don't |
1721 | * write an empty block when flushing -- deflate() does that. |
1722 | */ |
1723 | if (len < min_block && ((len == 0 && flush != Z_FINISH) || |
1724 | flush == Z_NO_FLUSH || |
1725 | len != left + s->strm->avail_in)) |
1726 | break; |
1727 | |
1728 | /* Make a dummy stored block in pending to get the header bytes, |
1729 | * including any pending bits. This also updates the debugging counts. |
1730 | */ |
1731 | last = flush == Z_FINISH && len == left + s->strm->avail_in ? 1 : 0; |
1732 | _tr_stored_block(s, (char *)0, 0L, last); |
1733 | |
1734 | /* Replace the lengths in the dummy stored block with len. */ |
1735 | s->pending_buf[s->pending - 4] = len; |
1736 | s->pending_buf[s->pending - 3] = len >> 8; |
1737 | s->pending_buf[s->pending - 2] = ~len; |
1738 | s->pending_buf[s->pending - 1] = ~len >> 8; |
1739 | |
1740 | /* Write the stored block header bytes. */ |
1741 | flush_pending(s->strm); |
1742 | |
1743 | #ifdef ZLIB_DEBUG |
1744 | /* Update debugging counts for the data about to be copied. */ |
1745 | s->compressed_len += len << 3; |
1746 | s->bits_sent += len << 3; |
1747 | #endif |
1748 | |
1749 | /* Copy uncompressed bytes from the window to next_out. */ |
1750 | if (left) { |
1751 | if (left > len) |
1752 | left = len; |
1753 | zmemcpy(s->strm->next_out, s->window + s->block_start, left); |
1754 | s->strm->next_out += left; |
1755 | s->strm->avail_out -= left; |
1756 | s->strm->total_out += left; |
1757 | s->block_start += left; |
1758 | len -= left; |
1759 | } |
1760 | |
1761 | /* Copy uncompressed bytes directly from next_in to next_out, updating |
1762 | * the check value. |
1763 | */ |
1764 | if (len) { |
1765 | read_buf(s->strm, s->strm->next_out, len); |
1766 | s->strm->next_out += len; |
1767 | s->strm->avail_out -= len; |
1768 | s->strm->total_out += len; |
1769 | } |
1770 | } while (last == 0); |
1771 | |
1772 | /* Update the sliding window with the last s->w_size bytes of the copied |
1773 | * data, or append all of the copied data to the existing window if less |
1774 | * than s->w_size bytes were copied. Also update the number of bytes to |
1775 | * insert in the hash tables, in the event that deflateParams() switches to |
1776 | * a non-zero compression level. |
1777 | */ |
1778 | used -= s->strm->avail_in; /* number of input bytes directly copied */ |
1779 | if (used) { |
1780 | /* If any input was used, then no unused input remains in the window, |
1781 | * therefore s->block_start == s->strstart. |
1782 | */ |
1783 | if (used >= s->w_size) { /* supplant the previous history */ |
1784 | s->matches = 2; /* clear hash */ |
1785 | zmemcpy(s->window, s->strm->next_in - s->w_size, s->w_size); |
1786 | s->strstart = s->w_size; |
1787 | s->insert = s->strstart; |
1788 | } |
1789 | else { |
1790 | if (s->window_size - s->strstart <= used) { |
1791 | /* Slide the window down. */ |
1792 | s->strstart -= s->w_size; |
1793 | zmemcpy(s->window, s->window + s->w_size, s->strstart); |
1794 | if (s->matches < 2) |
1795 | s->matches++; /* add a pending slide_hash() */ |
1796 | if (s->insert > s->strstart) |
1797 | s->insert = s->strstart; |
1798 | } |
1799 | zmemcpy(s->window + s->strstart, s->strm->next_in - used, used); |
1800 | s->strstart += used; |
1801 | s->insert += MIN(used, s->w_size - s->insert); |
1802 | } |
1803 | s->block_start = s->strstart; |
1804 | } |
1805 | if (s->high_water < s->strstart) |
1806 | s->high_water = s->strstart; |
1807 | |
1808 | /* If the last block was written to next_out, then done. */ |
1809 | if (last) |
1810 | return finish_done; |
1811 | |
1812 | /* If flushing and all input has been consumed, then done. */ |
1813 | if (flush != Z_NO_FLUSH && flush != Z_FINISH && |
1814 | s->strm->avail_in == 0 && (long)s->strstart == s->block_start) |
1815 | return block_done; |
1816 | |
1817 | /* Fill the window with any remaining input. */ |
1818 | have = s->window_size - s->strstart; |
1819 | if (s->strm->avail_in > have && s->block_start >= (long)s->w_size) { |
1820 | /* Slide the window down. */ |
1821 | s->block_start -= s->w_size; |
1822 | s->strstart -= s->w_size; |
1823 | zmemcpy(s->window, s->window + s->w_size, s->strstart); |
1824 | if (s->matches < 2) |
1825 | s->matches++; /* add a pending slide_hash() */ |
1826 | have += s->w_size; /* more space now */ |
1827 | if (s->insert > s->strstart) |
1828 | s->insert = s->strstart; |
1829 | } |
1830 | if (have > s->strm->avail_in) |
1831 | have = s->strm->avail_in; |
1832 | if (have) { |
1833 | read_buf(s->strm, s->window + s->strstart, have); |
1834 | s->strstart += have; |
1835 | s->insert += MIN(have, s->w_size - s->insert); |
1836 | } |
1837 | if (s->high_water < s->strstart) |
1838 | s->high_water = s->strstart; |
1839 | |
1840 | /* There was not enough avail_out to write a complete worthy or flushed |
1841 | * stored block to next_out. Write a stored block to pending instead, if we |
1842 | * have enough input for a worthy block, or if flushing and there is enough |
1843 | * room for the remaining input as a stored block in the pending buffer. |
1844 | */ |
1845 | have = (s->bi_valid + 42) >> 3; /* number of header bytes */ |
1846 | /* maximum stored block length that will fit in pending: */ |
1847 | have = MIN(s->pending_buf_size - have, MAX_STORED); |
1848 | min_block = MIN(have, s->w_size); |
1849 | left = s->strstart - s->block_start; |
1850 | if (left >= min_block || |
1851 | ((left || flush == Z_FINISH) && flush != Z_NO_FLUSH && |
1852 | s->strm->avail_in == 0 && left <= have)) { |
1853 | len = MIN(left, have); |
1854 | last = flush == Z_FINISH && s->strm->avail_in == 0 && |
1855 | len == left ? 1 : 0; |
1856 | _tr_stored_block(s, (charf *)s->window + s->block_start, len, last); |
1857 | s->block_start += len; |
1858 | flush_pending(s->strm); |
1859 | } |
1860 | |
1861 | /* We've done all we can with the available input and output. */ |
1862 | return last ? finish_started : need_more; |
1863 | } |
1864 | |
1865 | /* =========================================================================== |
1866 | * Compress as much as possible from the input stream, return the current |
1867 | * block state. |
1868 | * This function does not perform lazy evaluation of matches and inserts |
1869 | * new strings in the dictionary only for unmatched strings or for short |
1870 | * matches. It is used only for the fast compression options. |
1871 | */ |
1872 | local block_state deflate_fast(s, flush) |
1873 | deflate_state *s; |
1874 | int flush; |
1875 | { |
1876 | IPos hash_head; /* head of the hash chain */ |
1877 | int bflush; /* set if current block must be flushed */ |
1878 | |
1879 | for (;;) { |
1880 | /* Make sure that we always have enough lookahead, except |
1881 | * at the end of the input file. We need MAX_MATCH bytes |
1882 | * for the next match, plus MIN_MATCH bytes to insert the |
1883 | * string following the next match. |
1884 | */ |
1885 | if (s->lookahead < MIN_LOOKAHEAD) { |
1886 | fill_window(s); |
1887 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
1888 | return need_more; |
1889 | } |
1890 | if (s->lookahead == 0) break; /* flush the current block */ |
1891 | } |
1892 | |
1893 | /* Insert the string window[strstart .. strstart+2] in the |
1894 | * dictionary, and set hash_head to the head of the hash chain: |
1895 | */ |
1896 | hash_head = NIL; |
1897 | if (s->lookahead >= MIN_MATCH) { |
1898 | INSERT_STRING(s, s->strstart, hash_head); |
1899 | } |
1900 | |
1901 | /* Find the longest match, discarding those <= prev_length. |
1902 | * At this point we have always match_length < MIN_MATCH |
1903 | */ |
1904 | if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { |
1905 | /* To simplify the code, we prevent matches with the string |
1906 | * of window index 0 (in particular we have to avoid a match |
1907 | * of the string with itself at the start of the input file). |
1908 | */ |
1909 | s->match_length = longest_match (s, hash_head); |
1910 | /* longest_match() sets match_start */ |
1911 | } |
1912 | if (s->match_length >= MIN_MATCH) { |
1913 | check_match(s, s->strstart, s->match_start, s->match_length); |
1914 | |
1915 | _tr_tally_dist(s, s->strstart - s->match_start, |
1916 | s->match_length - MIN_MATCH, bflush); |
1917 | |
1918 | s->lookahead -= s->match_length; |
1919 | |
1920 | /* Insert new strings in the hash table only if the match length |
1921 | * is not too large. This saves time but degrades compression. |
1922 | */ |
1923 | #ifndef FASTEST |
1924 | if (s->match_length <= s->max_insert_length && |
1925 | s->lookahead >= MIN_MATCH) { |
1926 | s->match_length--; /* string at strstart already in table */ |
1927 | do { |
1928 | s->strstart++; |
1929 | INSERT_STRING(s, s->strstart, hash_head); |
1930 | /* strstart never exceeds WSIZE-MAX_MATCH, so there are |
1931 | * always MIN_MATCH bytes ahead. |
1932 | */ |
1933 | } while (--s->match_length != 0); |
1934 | s->strstart++; |
1935 | } else |
1936 | #endif |
1937 | { |
1938 | s->strstart += s->match_length; |
1939 | s->match_length = 0; |
1940 | s->ins_h = s->window[s->strstart]; |
1941 | UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
1942 | #if MIN_MATCH != 3 |
1943 | Call UPDATE_HASH() MIN_MATCH-3 more times |
1944 | #endif |
1945 | /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not |
1946 | * matter since it will be recomputed at next deflate call. |
1947 | */ |
1948 | } |
1949 | } else { |
1950 | /* No match, output a literal byte */ |
1951 | Tracevv((stderr,"%c" , s->window[s->strstart])); |
1952 | _tr_tally_lit (s, s->window[s->strstart], bflush); |
1953 | s->lookahead--; |
1954 | s->strstart++; |
1955 | } |
1956 | if (bflush) FLUSH_BLOCK(s, 0); |
1957 | } |
1958 | s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1; |
1959 | if (flush == Z_FINISH) { |
1960 | FLUSH_BLOCK(s, 1); |
1961 | return finish_done; |
1962 | } |
1963 | if (s->sym_next) |
1964 | FLUSH_BLOCK(s, 0); |
1965 | return block_done; |
1966 | } |
1967 | |
1968 | #ifndef FASTEST |
1969 | /* =========================================================================== |
1970 | * Same as above, but achieves better compression. We use a lazy |
1971 | * evaluation for matches: a match is finally adopted only if there is |
1972 | * no better match at the next window position. |
1973 | */ |
1974 | local block_state deflate_slow(s, flush) |
1975 | deflate_state *s; |
1976 | int flush; |
1977 | { |
1978 | IPos hash_head; /* head of hash chain */ |
1979 | int bflush; /* set if current block must be flushed */ |
1980 | |
1981 | /* Process the input block. */ |
1982 | for (;;) { |
1983 | /* Make sure that we always have enough lookahead, except |
1984 | * at the end of the input file. We need MAX_MATCH bytes |
1985 | * for the next match, plus MIN_MATCH bytes to insert the |
1986 | * string following the next match. |
1987 | */ |
1988 | if (s->lookahead < MIN_LOOKAHEAD) { |
1989 | fill_window(s); |
1990 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
1991 | return need_more; |
1992 | } |
1993 | if (s->lookahead == 0) break; /* flush the current block */ |
1994 | } |
1995 | |
1996 | /* Insert the string window[strstart .. strstart+2] in the |
1997 | * dictionary, and set hash_head to the head of the hash chain: |
1998 | */ |
1999 | hash_head = NIL; |
2000 | if (s->lookahead >= MIN_MATCH) { |
2001 | INSERT_STRING(s, s->strstart, hash_head); |
2002 | } |
2003 | |
2004 | /* Find the longest match, discarding those <= prev_length. |
2005 | */ |
2006 | s->prev_length = s->match_length, s->prev_match = s->match_start; |
2007 | s->match_length = MIN_MATCH-1; |
2008 | |
2009 | if (hash_head != NIL && s->prev_length < s->max_lazy_match && |
2010 | s->strstart - hash_head <= MAX_DIST(s)) { |
2011 | /* To simplify the code, we prevent matches with the string |
2012 | * of window index 0 (in particular we have to avoid a match |
2013 | * of the string with itself at the start of the input file). |
2014 | */ |
2015 | s->match_length = longest_match (s, hash_head); |
2016 | /* longest_match() sets match_start */ |
2017 | |
2018 | if (s->match_length <= 5 && (s->strategy == Z_FILTERED |
2019 | #if TOO_FAR <= 32767 |
2020 | || (s->match_length == MIN_MATCH && |
2021 | s->strstart - s->match_start > TOO_FAR) |
2022 | #endif |
2023 | )) { |
2024 | |
2025 | /* If prev_match is also MIN_MATCH, match_start is garbage |
2026 | * but we will ignore the current match anyway. |
2027 | */ |
2028 | s->match_length = MIN_MATCH-1; |
2029 | } |
2030 | } |
2031 | /* If there was a match at the previous step and the current |
2032 | * match is not better, output the previous match: |
2033 | */ |
2034 | if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { |
2035 | uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; |
2036 | /* Do not insert strings in hash table beyond this. */ |
2037 | |
2038 | check_match(s, s->strstart-1, s->prev_match, s->prev_length); |
2039 | |
2040 | _tr_tally_dist(s, s->strstart -1 - s->prev_match, |
2041 | s->prev_length - MIN_MATCH, bflush); |
2042 | |
2043 | /* Insert in hash table all strings up to the end of the match. |
2044 | * strstart-1 and strstart are already inserted. If there is not |
2045 | * enough lookahead, the last two strings are not inserted in |
2046 | * the hash table. |
2047 | */ |
2048 | s->lookahead -= s->prev_length-1; |
2049 | s->prev_length -= 2; |
2050 | do { |
2051 | if (++s->strstart <= max_insert) { |
2052 | INSERT_STRING(s, s->strstart, hash_head); |
2053 | } |
2054 | } while (--s->prev_length != 0); |
2055 | s->match_available = 0; |
2056 | s->match_length = MIN_MATCH-1; |
2057 | s->strstart++; |
2058 | |
2059 | if (bflush) FLUSH_BLOCK(s, 0); |
2060 | |
2061 | } else if (s->match_available) { |
2062 | /* If there was no match at the previous position, output a |
2063 | * single literal. If there was a match but the current match |
2064 | * is longer, truncate the previous match to a single literal. |
2065 | */ |
2066 | Tracevv((stderr,"%c" , s->window[s->strstart-1])); |
2067 | _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
2068 | if (bflush) { |
2069 | FLUSH_BLOCK_ONLY(s, 0); |
2070 | } |
2071 | s->strstart++; |
2072 | s->lookahead--; |
2073 | if (s->strm->avail_out == 0) return need_more; |
2074 | } else { |
2075 | /* There is no previous match to compare with, wait for |
2076 | * the next step to decide. |
2077 | */ |
2078 | s->match_available = 1; |
2079 | s->strstart++; |
2080 | s->lookahead--; |
2081 | } |
2082 | } |
2083 | Assert (flush != Z_NO_FLUSH, "no flush?" ); |
2084 | if (s->match_available) { |
2085 | Tracevv((stderr,"%c" , s->window[s->strstart-1])); |
2086 | _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
2087 | s->match_available = 0; |
2088 | } |
2089 | s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1; |
2090 | if (flush == Z_FINISH) { |
2091 | FLUSH_BLOCK(s, 1); |
2092 | return finish_done; |
2093 | } |
2094 | if (s->sym_next) |
2095 | FLUSH_BLOCK(s, 0); |
2096 | return block_done; |
2097 | } |
2098 | #endif /* FASTEST */ |
2099 | |
2100 | /* =========================================================================== |
2101 | * For Z_RLE, simply look for runs of bytes, generate matches only of distance |
2102 | * one. Do not maintain a hash table. (It will be regenerated if this run of |
2103 | * deflate switches away from Z_RLE.) |
2104 | */ |
2105 | local block_state deflate_rle(s, flush) |
2106 | deflate_state *s; |
2107 | int flush; |
2108 | { |
2109 | int bflush; /* set if current block must be flushed */ |
2110 | uInt prev; /* byte at distance one to match */ |
2111 | Bytef *scan, *strend; /* scan goes up to strend for length of run */ |
2112 | |
2113 | for (;;) { |
2114 | /* Make sure that we always have enough lookahead, except |
2115 | * at the end of the input file. We need MAX_MATCH bytes |
2116 | * for the longest run, plus one for the unrolled loop. |
2117 | */ |
2118 | if (s->lookahead <= MAX_MATCH) { |
2119 | fill_window(s); |
2120 | if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) { |
2121 | return need_more; |
2122 | } |
2123 | if (s->lookahead == 0) break; /* flush the current block */ |
2124 | } |
2125 | |
2126 | /* See how many times the previous byte repeats */ |
2127 | s->match_length = 0; |
2128 | if (s->lookahead >= MIN_MATCH && s->strstart > 0) { |
2129 | scan = s->window + s->strstart - 1; |
2130 | prev = *scan; |
2131 | if (prev == *++scan && prev == *++scan && prev == *++scan) { |
2132 | strend = s->window + s->strstart + MAX_MATCH; |
2133 | do { |
2134 | } while (prev == *++scan && prev == *++scan && |
2135 | prev == *++scan && prev == *++scan && |
2136 | prev == *++scan && prev == *++scan && |
2137 | prev == *++scan && prev == *++scan && |
2138 | scan < strend); |
2139 | s->match_length = MAX_MATCH - (uInt)(strend - scan); |
2140 | if (s->match_length > s->lookahead) |
2141 | s->match_length = s->lookahead; |
2142 | } |
2143 | Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan" ); |
2144 | } |
2145 | |
2146 | /* Emit match if have run of MIN_MATCH or longer, else emit literal */ |
2147 | if (s->match_length >= MIN_MATCH) { |
2148 | check_match(s, s->strstart, s->strstart - 1, s->match_length); |
2149 | |
2150 | _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush); |
2151 | |
2152 | s->lookahead -= s->match_length; |
2153 | s->strstart += s->match_length; |
2154 | s->match_length = 0; |
2155 | } else { |
2156 | /* No match, output a literal byte */ |
2157 | Tracevv((stderr,"%c" , s->window[s->strstart])); |
2158 | _tr_tally_lit (s, s->window[s->strstart], bflush); |
2159 | s->lookahead--; |
2160 | s->strstart++; |
2161 | } |
2162 | if (bflush) FLUSH_BLOCK(s, 0); |
2163 | } |
2164 | s->insert = 0; |
2165 | if (flush == Z_FINISH) { |
2166 | FLUSH_BLOCK(s, 1); |
2167 | return finish_done; |
2168 | } |
2169 | if (s->sym_next) |
2170 | FLUSH_BLOCK(s, 0); |
2171 | return block_done; |
2172 | } |
2173 | |
2174 | /* =========================================================================== |
2175 | * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. |
2176 | * (It will be regenerated if this run of deflate switches away from Huffman.) |
2177 | */ |
2178 | local block_state deflate_huff(s, flush) |
2179 | deflate_state *s; |
2180 | int flush; |
2181 | { |
2182 | int bflush; /* set if current block must be flushed */ |
2183 | |
2184 | for (;;) { |
2185 | /* Make sure that we have a literal to write. */ |
2186 | if (s->lookahead == 0) { |
2187 | fill_window(s); |
2188 | if (s->lookahead == 0) { |
2189 | if (flush == Z_NO_FLUSH) |
2190 | return need_more; |
2191 | break; /* flush the current block */ |
2192 | } |
2193 | } |
2194 | |
2195 | /* Output a literal byte */ |
2196 | s->match_length = 0; |
2197 | Tracevv((stderr,"%c" , s->window[s->strstart])); |
2198 | _tr_tally_lit (s, s->window[s->strstart], bflush); |
2199 | s->lookahead--; |
2200 | s->strstart++; |
2201 | if (bflush) FLUSH_BLOCK(s, 0); |
2202 | } |
2203 | s->insert = 0; |
2204 | if (flush == Z_FINISH) { |
2205 | FLUSH_BLOCK(s, 1); |
2206 | return finish_done; |
2207 | } |
2208 | if (s->sym_next) |
2209 | FLUSH_BLOCK(s, 0); |
2210 | return block_done; |
2211 | } |
2212 | |