]>
Commit | Line | Data |
---|---|---|
d4286ec4 | 1 | /* deflate.c -- compress data using the deflation algorithm |
f0da8242 | 2 | * Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler |
1e1cf689 | 3 | * For conditions of distribution and use, see copyright notice in zlib.h |
d4286ec4 PM |
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". | |
f0da8242 | 40 | * Available in http://tools.ietf.org/html/rfc1951 |
d4286ec4 PM |
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 | ||
12febd80 WD |
54 | #define read_buf dread_buf |
55 | ||
d4286ec4 | 56 | const char deflate_copyright[] = |
f0da8242 | 57 | " deflate 1.2.8 Copyright 1995-2013 Jean-loup Gailly and Mark Adler "; |
d4286ec4 PM |
58 | /* |
59 | If you use the zlib library in a product, an acknowledgment is welcome | |
60 | in the documentation of your product. If for some reason you cannot | |
61 | include such an acknowledgment, I would appreciate that you keep this | |
62 | copyright string in the executable of your product. | |
63 | */ | |
64 | ||
65 | /* =========================================================================== | |
66 | * Function prototypes. | |
67 | */ | |
68 | typedef enum { | |
69 | need_more, /* block not completed, need more input or more output */ | |
70 | block_done, /* block flush performed */ | |
71 | finish_started, /* finish started, need only more output at next deflate */ | |
72 | finish_done /* finish done, accept no more input or output */ | |
73 | } block_state; | |
74 | ||
75 | typedef block_state (*compress_func) OF((deflate_state *s, int flush)); | |
76 | /* Compression function. Returns the block state after the call. */ | |
77 | ||
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)); | |
1e1cf689 | 81 | #ifndef FASTEST |
d4286ec4 | 82 | local block_state deflate_slow OF((deflate_state *s, int flush)); |
1e1cf689 | 83 | #endif |
f0da8242 WD |
84 | local block_state deflate_rle OF((deflate_state *s, int flush)); |
85 | local block_state deflate_huff OF((deflate_state *s, int flush)); | |
d4286ec4 PM |
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)); | |
12febd80 | 89 | local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size)); |
d4286ec4 PM |
90 | #ifdef ASMV |
91 | void match_init OF((void)); /* asm code initialization */ | |
92 | uInt longest_match OF((deflate_state *s, IPos cur_match)); | |
93 | #else | |
94 | local uInt longest_match OF((deflate_state *s, IPos cur_match)); | |
95 | #endif | |
96 | ||
97 | #ifdef DEBUG | |
98 | local void check_match OF((deflate_state *s, IPos start, IPos match, | |
99 | int length)); | |
100 | #endif | |
101 | ||
102 | /* =========================================================================== | |
103 | * Local data | |
104 | */ | |
105 | ||
106 | #define NIL 0 | |
107 | /* Tail of hash chains */ | |
108 | ||
109 | #ifndef TOO_FAR | |
110 | # define TOO_FAR 4096 | |
111 | #endif | |
112 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ | |
113 | ||
d4286ec4 PM |
114 | /* Values for max_lazy_match, good_match and max_chain_length, depending on |
115 | * the desired pack level (0..9). The values given below have been tuned to | |
116 | * exclude worst case performance for pathological files. Better values may be | |
117 | * found for specific files. | |
118 | */ | |
119 | typedef struct config_s { | |
120 | ush good_length; /* reduce lazy search above this match length */ | |
121 | ush max_lazy; /* do not perform lazy search above this match length */ | |
122 | ush nice_length; /* quit search above this match length */ | |
123 | ush max_chain; | |
124 | compress_func func; | |
125 | } config; | |
126 | ||
1e1cf689 WD |
127 | #ifdef FASTEST |
128 | local const config configuration_table[2] = { | |
129 | /* good lazy nice chain */ | |
130 | /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ | |
131 | /* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */ | |
132 | #else | |
d4286ec4 PM |
133 | local const config configuration_table[10] = { |
134 | /* good lazy nice chain */ | |
135 | /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ | |
1e1cf689 | 136 | /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ |
d4286ec4 PM |
137 | /* 2 */ {4, 5, 16, 8, deflate_fast}, |
138 | /* 3 */ {4, 6, 32, 32, deflate_fast}, | |
139 | ||
140 | /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ | |
141 | /* 5 */ {8, 16, 32, 32, deflate_slow}, | |
142 | /* 6 */ {8, 16, 128, 128, deflate_slow}, | |
143 | /* 7 */ {8, 32, 128, 256, deflate_slow}, | |
144 | /* 8 */ {32, 128, 258, 1024, deflate_slow}, | |
1e1cf689 WD |
145 | /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */ |
146 | #endif | |
d4286ec4 PM |
147 | |
148 | /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 | |
149 | * For deflate_fast() (levels <= 3) good is ignored and lazy has a different | |
150 | * meaning. | |
151 | */ | |
152 | ||
153 | #define EQUAL 0 | |
154 | /* result of memcmp for equal strings */ | |
155 | ||
1e1cf689 | 156 | #ifndef NO_DUMMY_DECL |
d4286ec4 | 157 | struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ |
1e1cf689 | 158 | #endif |
d4286ec4 | 159 | |
f0da8242 WD |
160 | /* rank Z_BLOCK between Z_NO_FLUSH and Z_PARTIAL_FLUSH */ |
161 | #define RANK(f) (((f) << 1) - ((f) > 4 ? 9 : 0)) | |
162 | ||
d4286ec4 PM |
163 | /* =========================================================================== |
164 | * Update a hash value with the given input byte | |
165 | * IN assertion: all calls to to UPDATE_HASH are made with consecutive | |
166 | * input characters, so that a running hash key can be computed from the | |
167 | * previous key instead of complete recalculation each time. | |
168 | */ | |
169 | #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) | |
170 | ||
171 | ||
172 | /* =========================================================================== | |
173 | * Insert string str in the dictionary and set match_head to the previous head | |
174 | * of the hash chain (the most recent string with same hash key). Return | |
175 | * the previous length of the hash chain. | |
176 | * If this file is compiled with -DFASTEST, the compression level is forced | |
177 | * to 1, and no hash chains are maintained. | |
178 | * IN assertion: all calls to to INSERT_STRING are made with consecutive | |
179 | * input characters and the first MIN_MATCH bytes of str are valid | |
180 | * (except for the last MIN_MATCH-1 bytes of the input file). | |
181 | */ | |
182 | #ifdef FASTEST | |
183 | #define INSERT_STRING(s, str, match_head) \ | |
184 | (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ | |
185 | match_head = s->head[s->ins_h], \ | |
186 | s->head[s->ins_h] = (Pos)(str)) | |
187 | #else | |
188 | #define INSERT_STRING(s, str, match_head) \ | |
189 | (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ | |
1e1cf689 | 190 | match_head = s->prev[(str) & s->w_mask] = s->head[s->ins_h], \ |
d4286ec4 PM |
191 | s->head[s->ins_h] = (Pos)(str)) |
192 | #endif | |
193 | ||
194 | /* =========================================================================== | |
195 | * Initialize the hash table (avoiding 64K overflow for 16 bit systems). | |
196 | * prev[] will be initialized on the fly. | |
197 | */ | |
198 | #define CLEAR_HASH(s) \ | |
199 | s->head[s->hash_size-1] = NIL; \ | |
200 | zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); | |
201 | ||
202 | /* ========================================================================= */ | |
203 | int ZEXPORT deflateInit_(strm, level, version, stream_size) | |
204 | z_streamp strm; | |
205 | int level; | |
206 | const char *version; | |
207 | int stream_size; | |
208 | { | |
209 | return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, | |
1e1cf689 | 210 | Z_DEFAULT_STRATEGY, version, stream_size); |
d4286ec4 PM |
211 | /* To do: ignore strm->next_in if we use it as window */ |
212 | } | |
213 | ||
214 | /* ========================================================================= */ | |
215 | int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, | |
1e1cf689 | 216 | version, stream_size) |
d4286ec4 PM |
217 | z_streamp strm; |
218 | int level; | |
219 | int method; | |
220 | int windowBits; | |
221 | int memLevel; | |
222 | int strategy; | |
223 | const char *version; | |
224 | int stream_size; | |
225 | { | |
226 | deflate_state *s; | |
1e1cf689 WD |
227 | int wrap = 1; |
228 | static const char my_version[] = ZLIB_VERSION; | |
d4286ec4 PM |
229 | |
230 | ushf *overlay; | |
231 | /* We overlay pending_buf and d_buf+l_buf. This works since the average | |
232 | * output size for (length,distance) codes is <= 24 bits. | |
233 | */ | |
234 | ||
235 | if (version == Z_NULL || version[0] != my_version[0] || | |
236 | stream_size != sizeof(z_stream)) { | |
1e1cf689 | 237 | return Z_VERSION_ERROR; |
d4286ec4 PM |
238 | } |
239 | if (strm == Z_NULL) return Z_STREAM_ERROR; | |
240 | ||
241 | strm->msg = Z_NULL; | |
1e1cf689 | 242 | if (strm->zalloc == (alloc_func)0) { |
f0da8242 WD |
243 | #ifdef Z_SOLO |
244 | return Z_STREAM_ERROR; | |
245 | #else | |
1e1cf689 WD |
246 | strm->zalloc = zcalloc; |
247 | strm->opaque = (voidpf)0; | |
f0da8242 | 248 | #endif |
d4286ec4 | 249 | } |
f0da8242 WD |
250 | if (strm->zfree == (free_func)0) |
251 | #ifdef Z_SOLO | |
252 | return Z_STREAM_ERROR; | |
253 | #else | |
254 | strm->zfree = zcfree; | |
255 | #endif | |
d4286ec4 | 256 | |
d4286ec4 | 257 | #ifdef FASTEST |
1e1cf689 WD |
258 | if (level != 0) level = 1; |
259 | #else | |
260 | if (level == Z_DEFAULT_COMPRESSION) level = 6; | |
d4286ec4 PM |
261 | #endif |
262 | ||
1e1cf689 WD |
263 | if (windowBits < 0) { /* suppress zlib wrapper */ |
264 | wrap = 0; | |
d4286ec4 PM |
265 | windowBits = -windowBits; |
266 | } | |
1e1cf689 WD |
267 | #ifdef GZIP |
268 | else if (windowBits > 15) { | |
269 | wrap = 2; /* write gzip wrapper instead */ | |
270 | windowBits -= 16; | |
271 | } | |
272 | #endif | |
d4286ec4 | 273 | if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || |
1e1cf689 | 274 | windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || |
cd426074 | 275 | strategy < 0 || strategy > Z_FIXED) { |
d4286ec4 PM |
276 | return Z_STREAM_ERROR; |
277 | } | |
1e1cf689 | 278 | if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ |
d4286ec4 PM |
279 | s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); |
280 | if (s == Z_NULL) return Z_MEM_ERROR; | |
281 | strm->state = (struct internal_state FAR *)s; | |
282 | s->strm = strm; | |
283 | ||
1e1cf689 | 284 | s->wrap = wrap; |
cd426074 | 285 | s->gzhead = Z_NULL; |
d4286ec4 PM |
286 | s->w_bits = windowBits; |
287 | s->w_size = 1 << s->w_bits; | |
288 | s->w_mask = s->w_size - 1; | |
289 | ||
290 | s->hash_bits = memLevel + 7; | |
291 | s->hash_size = 1 << s->hash_bits; | |
292 | s->hash_mask = s->hash_size - 1; | |
293 | s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); | |
294 | ||
295 | s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); | |
296 | s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); | |
297 | s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); | |
298 | ||
f0da8242 WD |
299 | s->high_water = 0; /* nothing written to s->window yet */ |
300 | ||
d4286ec4 PM |
301 | s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ |
302 | ||
303 | overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); | |
304 | s->pending_buf = (uchf *) overlay; | |
305 | s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); | |
306 | ||
307 | if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || | |
308 | s->pending_buf == Z_NULL) { | |
1e1cf689 | 309 | s->status = FINISH_STATE; |
f0da8242 | 310 | strm->msg = ERR_MSG(Z_MEM_ERROR); |
d4286ec4 PM |
311 | deflateEnd (strm); |
312 | return Z_MEM_ERROR; | |
313 | } | |
314 | s->d_buf = overlay + s->lit_bufsize/sizeof(ush); | |
315 | s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; | |
316 | ||
317 | s->level = level; | |
318 | s->strategy = strategy; | |
319 | s->method = (Byte)method; | |
320 | ||
321 | return deflateReset(strm); | |
322 | } | |
323 | ||
324 | /* ========================================================================= */ | |
325 | int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) | |
326 | z_streamp strm; | |
327 | const Bytef *dictionary; | |
328 | uInt dictLength; | |
329 | { | |
330 | deflate_state *s; | |
f0da8242 WD |
331 | uInt str, n; |
332 | int wrap; | |
333 | unsigned avail; | |
334 | z_const unsigned char *next; | |
d4286ec4 | 335 | |
f0da8242 | 336 | if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) |
1e1cf689 | 337 | return Z_STREAM_ERROR; |
d4286ec4 | 338 | s = strm->state; |
f0da8242 WD |
339 | wrap = s->wrap; |
340 | if (wrap == 2 || (wrap == 1 && s->status != INIT_STATE) || s->lookahead) | |
341 | return Z_STREAM_ERROR; | |
d4286ec4 | 342 | |
f0da8242 WD |
343 | /* when using zlib wrappers, compute Adler-32 for provided dictionary */ |
344 | if (wrap == 1) | |
345 | strm->adler = adler32(strm->adler, dictionary, dictLength); | |
346 | s->wrap = 0; /* avoid computing Adler-32 in read_buf */ | |
347 | ||
348 | /* if dictionary would fill window, just replace the history */ | |
349 | if (dictLength >= s->w_size) { | |
350 | if (wrap == 0) { /* already empty otherwise */ | |
351 | CLEAR_HASH(s); | |
352 | s->strstart = 0; | |
353 | s->block_start = 0L; | |
354 | s->insert = 0; | |
355 | } | |
356 | dictionary += dictLength - s->w_size; /* use the tail */ | |
357 | dictLength = s->w_size; | |
d4286ec4 | 358 | } |
d4286ec4 | 359 | |
f0da8242 WD |
360 | /* insert dictionary into window and hash */ |
361 | avail = strm->avail_in; | |
362 | next = strm->next_in; | |
363 | strm->avail_in = dictLength; | |
364 | strm->next_in = (z_const Bytef *)dictionary; | |
365 | fill_window(s); | |
366 | while (s->lookahead >= MIN_MATCH) { | |
367 | str = s->strstart; | |
368 | n = s->lookahead - (MIN_MATCH-1); | |
369 | do { | |
370 | UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); | |
371 | #ifndef FASTEST | |
372 | s->prev[str & s->w_mask] = s->head[s->ins_h]; | |
373 | #endif | |
374 | s->head[s->ins_h] = (Pos)str; | |
375 | str++; | |
376 | } while (--n); | |
377 | s->strstart = str; | |
378 | s->lookahead = MIN_MATCH-1; | |
379 | fill_window(s); | |
d4286ec4 | 380 | } |
f0da8242 WD |
381 | s->strstart += s->lookahead; |
382 | s->block_start = (long)s->strstart; | |
383 | s->insert = s->lookahead; | |
384 | s->lookahead = 0; | |
385 | s->match_length = s->prev_length = MIN_MATCH-1; | |
386 | s->match_available = 0; | |
387 | strm->next_in = next; | |
388 | strm->avail_in = avail; | |
389 | s->wrap = wrap; | |
d4286ec4 PM |
390 | return Z_OK; |
391 | } | |
392 | ||
393 | /* ========================================================================= */ | |
f0da8242 | 394 | int ZEXPORT deflateResetKeep (strm) |
d4286ec4 PM |
395 | z_streamp strm; |
396 | { | |
397 | deflate_state *s; | |
1e1cf689 | 398 | |
d4286ec4 | 399 | if (strm == Z_NULL || strm->state == Z_NULL || |
1e1cf689 WD |
400 | strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) { |
401 | return Z_STREAM_ERROR; | |
402 | } | |
d4286ec4 PM |
403 | |
404 | strm->total_in = strm->total_out = 0; | |
405 | strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ | |
406 | strm->data_type = Z_UNKNOWN; | |
407 | ||
408 | s = (deflate_state *)strm->state; | |
409 | s->pending = 0; | |
410 | s->pending_out = s->pending_buf; | |
411 | ||
1e1cf689 WD |
412 | if (s->wrap < 0) { |
413 | s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ | |
d4286ec4 | 414 | } |
1e1cf689 WD |
415 | s->status = s->wrap ? INIT_STATE : BUSY_STATE; |
416 | strm->adler = | |
417 | #ifdef GZIP | |
418 | s->wrap == 2 ? crc32(0L, Z_NULL, 0) : | |
419 | #endif | |
420 | adler32(0L, Z_NULL, 0); | |
d4286ec4 PM |
421 | s->last_flush = Z_NO_FLUSH; |
422 | ||
423 | _tr_init(s); | |
d4286ec4 PM |
424 | |
425 | return Z_OK; | |
426 | } | |
427 | ||
f0da8242 WD |
428 | /* ========================================================================= */ |
429 | int ZEXPORT deflateReset (strm) | |
430 | z_streamp strm; | |
431 | { | |
432 | int ret; | |
433 | ||
434 | ret = deflateResetKeep(strm); | |
435 | if (ret == Z_OK) | |
436 | lm_init(strm->state); | |
437 | return ret; | |
438 | } | |
439 | ||
cd426074 WD |
440 | /* ========================================================================= */ |
441 | int ZEXPORT deflateSetHeader (strm, head) | |
442 | z_streamp strm; | |
443 | gz_headerp head; | |
444 | { | |
445 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; | |
446 | if (strm->state->wrap != 2) return Z_STREAM_ERROR; | |
447 | strm->state->gzhead = head; | |
448 | return Z_OK; | |
449 | } | |
450 | ||
f0da8242 WD |
451 | /* ========================================================================= */ |
452 | int ZEXPORT deflatePending (strm, pending, bits) | |
453 | unsigned *pending; | |
454 | int *bits; | |
455 | z_streamp strm; | |
456 | { | |
457 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; | |
458 | if (pending != Z_NULL) | |
459 | *pending = strm->state->pending; | |
460 | if (bits != Z_NULL) | |
461 | *bits = strm->state->bi_valid; | |
462 | return Z_OK; | |
463 | } | |
464 | ||
1e1cf689 WD |
465 | /* ========================================================================= */ |
466 | int ZEXPORT deflatePrime (strm, bits, value) | |
467 | z_streamp strm; | |
468 | int bits; | |
469 | int value; | |
470 | { | |
f0da8242 WD |
471 | deflate_state *s; |
472 | int put; | |
473 | ||
1e1cf689 | 474 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
f0da8242 WD |
475 | s = strm->state; |
476 | if ((Bytef *)(s->d_buf) < s->pending_out + ((Buf_size + 7) >> 3)) | |
477 | return Z_BUF_ERROR; | |
478 | do { | |
479 | put = Buf_size - s->bi_valid; | |
480 | if (put > bits) | |
481 | put = bits; | |
482 | s->bi_buf |= (ush)((value & ((1 << put) - 1)) << s->bi_valid); | |
483 | s->bi_valid += put; | |
484 | _tr_flush_bits(s); | |
485 | value >>= put; | |
486 | bits -= put; | |
487 | } while (bits); | |
1e1cf689 WD |
488 | return Z_OK; |
489 | } | |
490 | ||
d4286ec4 PM |
491 | /* ========================================================================= */ |
492 | int ZEXPORT deflateParams(strm, level, strategy) | |
493 | z_streamp strm; | |
494 | int level; | |
495 | int strategy; | |
496 | { | |
497 | deflate_state *s; | |
498 | compress_func func; | |
499 | int err = Z_OK; | |
500 | ||
501 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; | |
502 | s = strm->state; | |
503 | ||
1e1cf689 WD |
504 | #ifdef FASTEST |
505 | if (level != 0) level = 1; | |
506 | #else | |
507 | if (level == Z_DEFAULT_COMPRESSION) level = 6; | |
508 | #endif | |
cd426074 | 509 | if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { |
1e1cf689 | 510 | return Z_STREAM_ERROR; |
d4286ec4 PM |
511 | } |
512 | func = configuration_table[s->level].func; | |
513 | ||
f0da8242 WD |
514 | if ((strategy != s->strategy || func != configuration_table[level].func) && |
515 | strm->total_in != 0) { | |
1e1cf689 | 516 | /* Flush the last buffer: */ |
f0da8242 WD |
517 | err = deflate(strm, Z_BLOCK); |
518 | if (err == Z_BUF_ERROR && s->pending == 0) | |
519 | err = Z_OK; | |
d4286ec4 PM |
520 | } |
521 | if (s->level != level) { | |
1e1cf689 WD |
522 | s->level = level; |
523 | s->max_lazy_match = configuration_table[level].max_lazy; | |
524 | s->good_match = configuration_table[level].good_length; | |
525 | s->nice_match = configuration_table[level].nice_length; | |
526 | s->max_chain_length = configuration_table[level].max_chain; | |
d4286ec4 PM |
527 | } |
528 | s->strategy = strategy; | |
529 | return err; | |
530 | } | |
531 | ||
cd426074 WD |
532 | /* ========================================================================= */ |
533 | int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain) | |
534 | z_streamp strm; | |
535 | int good_length; | |
536 | int max_lazy; | |
537 | int nice_length; | |
538 | int max_chain; | |
539 | { | |
540 | deflate_state *s; | |
541 | ||
542 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; | |
543 | s = strm->state; | |
544 | s->good_match = good_length; | |
545 | s->max_lazy_match = max_lazy; | |
546 | s->nice_match = nice_length; | |
547 | s->max_chain_length = max_chain; | |
548 | return Z_OK; | |
549 | } | |
550 | ||
1e1cf689 WD |
551 | /* ========================================================================= |
552 | * For the default windowBits of 15 and memLevel of 8, this function returns | |
553 | * a close to exact, as well as small, upper bound on the compressed size. | |
554 | * They are coded as constants here for a reason--if the #define's are | |
555 | * changed, then this function needs to be changed as well. The return | |
556 | * value for 15 and 8 only works for those exact settings. | |
557 | * | |
558 | * For any setting other than those defaults for windowBits and memLevel, | |
559 | * the value returned is a conservative worst case for the maximum expansion | |
560 | * resulting from using fixed blocks instead of stored blocks, which deflate | |
561 | * can emit on compressed data for some combinations of the parameters. | |
562 | * | |
f0da8242 WD |
563 | * This function could be more sophisticated to provide closer upper bounds for |
564 | * every combination of windowBits and memLevel. But even the conservative | |
565 | * upper bound of about 14% expansion does not seem onerous for output buffer | |
566 | * allocation. | |
1e1cf689 WD |
567 | */ |
568 | uLong ZEXPORT deflateBound(strm, sourceLen) | |
569 | z_streamp strm; | |
570 | uLong sourceLen; | |
571 | { | |
572 | deflate_state *s; | |
f0da8242 WD |
573 | uLong complen, wraplen; |
574 | Bytef *str; | |
1e1cf689 | 575 | |
f0da8242 WD |
576 | /* conservative upper bound for compressed data */ |
577 | complen = sourceLen + | |
578 | ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; | |
1e1cf689 | 579 | |
f0da8242 | 580 | /* if can't get parameters, return conservative bound plus zlib wrapper */ |
1e1cf689 | 581 | if (strm == Z_NULL || strm->state == Z_NULL) |
f0da8242 | 582 | return complen + 6; |
1e1cf689 | 583 | |
f0da8242 | 584 | /* compute wrapper length */ |
1e1cf689 | 585 | s = strm->state; |
f0da8242 WD |
586 | switch (s->wrap) { |
587 | case 0: /* raw deflate */ | |
588 | wraplen = 0; | |
589 | break; | |
590 | case 1: /* zlib wrapper */ | |
591 | wraplen = 6 + (s->strstart ? 4 : 0); | |
592 | break; | |
593 | case 2: /* gzip wrapper */ | |
594 | wraplen = 18; | |
595 | if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ | |
596 | if (s->gzhead->extra != Z_NULL) | |
597 | wraplen += 2 + s->gzhead->extra_len; | |
598 | str = s->gzhead->name; | |
599 | if (str != Z_NULL) | |
600 | do { | |
601 | wraplen++; | |
602 | } while (*str++); | |
603 | str = s->gzhead->comment; | |
604 | if (str != Z_NULL) | |
605 | do { | |
606 | wraplen++; | |
607 | } while (*str++); | |
608 | if (s->gzhead->hcrc) | |
609 | wraplen += 2; | |
610 | } | |
611 | break; | |
612 | default: /* for compiler happiness */ | |
613 | wraplen = 6; | |
614 | } | |
615 | ||
616 | /* if not default parameters, return conservative bound */ | |
1e1cf689 | 617 | if (s->w_bits != 15 || s->hash_bits != 8 + 7) |
f0da8242 | 618 | return complen + wraplen; |
1e1cf689 WD |
619 | |
620 | /* default settings: return tight bound for that case */ | |
f0da8242 WD |
621 | return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
622 | (sourceLen >> 25) + 13 - 6 + wraplen; | |
1e1cf689 WD |
623 | } |
624 | ||
d4286ec4 PM |
625 | /* ========================================================================= |
626 | * Put a short in the pending buffer. The 16-bit value is put in MSB order. | |
627 | * IN assertion: the stream state is correct and there is enough room in | |
628 | * pending_buf. | |
629 | */ | |
630 | local void putShortMSB (s, b) | |
631 | deflate_state *s; | |
632 | uInt b; | |
633 | { | |
634 | put_byte(s, (Byte)(b >> 8)); | |
635 | put_byte(s, (Byte)(b & 0xff)); | |
1e1cf689 | 636 | } |
d4286ec4 PM |
637 | |
638 | /* ========================================================================= | |
639 | * Flush as much pending output as possible. All deflate() output goes | |
640 | * through this function so some applications may wish to modify it | |
641 | * to avoid allocating a large strm->next_out buffer and copying into it. | |
12febd80 | 642 | * (See also read_buf()). |
d4286ec4 PM |
643 | */ |
644 | local void flush_pending(strm) | |
645 | z_streamp strm; | |
646 | { | |
f0da8242 WD |
647 | unsigned len; |
648 | deflate_state *s = strm->state; | |
d4286ec4 | 649 | |
f0da8242 WD |
650 | _tr_flush_bits(s); |
651 | len = s->pending; | |
d4286ec4 PM |
652 | if (len > strm->avail_out) len = strm->avail_out; |
653 | if (len == 0) return; | |
654 | ||
f0da8242 | 655 | zmemcpy(strm->next_out, s->pending_out, len); |
d4286ec4 | 656 | strm->next_out += len; |
f0da8242 | 657 | s->pending_out += len; |
d4286ec4 PM |
658 | strm->total_out += len; |
659 | strm->avail_out -= len; | |
f0da8242 WD |
660 | s->pending -= len; |
661 | if (s->pending == 0) { | |
662 | s->pending_out = s->pending_buf; | |
d4286ec4 PM |
663 | } |
664 | } | |
665 | ||
666 | /* ========================================================================= */ | |
667 | int ZEXPORT deflate (strm, flush) | |
668 | z_streamp strm; | |
669 | int flush; | |
670 | { | |
671 | int old_flush; /* value of flush param for previous deflate call */ | |
672 | deflate_state *s; | |
673 | ||
674 | if (strm == Z_NULL || strm->state == Z_NULL || | |
f0da8242 | 675 | (flush > Z_BLOCK && flush != Z_INSERT_ONLY) || flush < 0) { |
d4286ec4 PM |
676 | return Z_STREAM_ERROR; |
677 | } | |
678 | s = strm->state; | |
679 | ||
680 | if (strm->next_out == Z_NULL || | |
681 | (strm->next_in == Z_NULL && strm->avail_in != 0) || | |
1e1cf689 | 682 | (s->status == FINISH_STATE && flush != Z_FINISH)) { |
d4286ec4 PM |
683 | ERR_RETURN(strm, Z_STREAM_ERROR); |
684 | } | |
685 | if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); | |
686 | ||
687 | s->strm = strm; /* just in case */ | |
688 | old_flush = s->last_flush; | |
689 | s->last_flush = flush; | |
690 | ||
1e1cf689 | 691 | /* Write the header */ |
d4286ec4 | 692 | if (s->status == INIT_STATE) { |
1e1cf689 WD |
693 | #ifdef GZIP |
694 | if (s->wrap == 2) { | |
cd426074 | 695 | strm->adler = crc32(0L, Z_NULL, 0); |
1e1cf689 WD |
696 | put_byte(s, 31); |
697 | put_byte(s, 139); | |
698 | put_byte(s, 8); | |
f0da8242 | 699 | if (s->gzhead == Z_NULL) { |
cd426074 WD |
700 | put_byte(s, 0); |
701 | put_byte(s, 0); | |
702 | put_byte(s, 0); | |
703 | put_byte(s, 0); | |
704 | put_byte(s, 0); | |
705 | put_byte(s, s->level == 9 ? 2 : | |
706 | (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? | |
707 | 4 : 0)); | |
708 | put_byte(s, OS_CODE); | |
709 | s->status = BUSY_STATE; | |
710 | } | |
711 | else { | |
712 | put_byte(s, (s->gzhead->text ? 1 : 0) + | |
713 | (s->gzhead->hcrc ? 2 : 0) + | |
714 | (s->gzhead->extra == Z_NULL ? 0 : 4) + | |
715 | (s->gzhead->name == Z_NULL ? 0 : 8) + | |
716 | (s->gzhead->comment == Z_NULL ? 0 : 16) | |
717 | ); | |
718 | put_byte(s, (Byte)(s->gzhead->time & 0xff)); | |
719 | put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff)); | |
720 | put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff)); | |
721 | put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff)); | |
722 | put_byte(s, s->level == 9 ? 2 : | |
723 | (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? | |
724 | 4 : 0)); | |
725 | put_byte(s, s->gzhead->os & 0xff); | |
f0da8242 | 726 | if (s->gzhead->extra != Z_NULL) { |
cd426074 WD |
727 | put_byte(s, s->gzhead->extra_len & 0xff); |
728 | put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); | |
729 | } | |
730 | if (s->gzhead->hcrc) | |
731 | strm->adler = crc32(strm->adler, s->pending_buf, | |
732 | s->pending); | |
733 | s->gzindex = 0; | |
734 | s->status = EXTRA_STATE; | |
735 | } | |
1e1cf689 WD |
736 | } |
737 | else | |
738 | #endif | |
739 | { | |
740 | uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; | |
741 | uInt level_flags; | |
742 | ||
743 | if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2) | |
744 | level_flags = 0; | |
745 | else if (s->level < 6) | |
746 | level_flags = 1; | |
747 | else if (s->level == 6) | |
748 | level_flags = 2; | |
749 | else | |
750 | level_flags = 3; | |
751 | header |= (level_flags << 6); | |
752 | if (s->strstart != 0) header |= PRESET_DICT; | |
753 | header += 31 - (header % 31); | |
754 | ||
755 | s->status = BUSY_STATE; | |
756 | putShortMSB(s, header); | |
757 | ||
758 | /* Save the adler32 of the preset dictionary: */ | |
759 | if (s->strstart != 0) { | |
760 | putShortMSB(s, (uInt)(strm->adler >> 16)); | |
761 | putShortMSB(s, (uInt)(strm->adler & 0xffff)); | |
762 | } | |
763 | strm->adler = adler32(0L, Z_NULL, 0); | |
764 | } | |
d4286ec4 | 765 | } |
cd426074 WD |
766 | #ifdef GZIP |
767 | if (s->status == EXTRA_STATE) { | |
f0da8242 | 768 | if (s->gzhead->extra != Z_NULL) { |
cd426074 WD |
769 | uInt beg = s->pending; /* start of bytes to update crc */ |
770 | ||
771 | while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { | |
772 | if (s->pending == s->pending_buf_size) { | |
773 | if (s->gzhead->hcrc && s->pending > beg) | |
774 | strm->adler = crc32(strm->adler, s->pending_buf + beg, | |
775 | s->pending - beg); | |
776 | flush_pending(strm); | |
777 | beg = s->pending; | |
778 | if (s->pending == s->pending_buf_size) | |
779 | break; | |
780 | } | |
781 | put_byte(s, s->gzhead->extra[s->gzindex]); | |
782 | s->gzindex++; | |
783 | } | |
784 | if (s->gzhead->hcrc && s->pending > beg) | |
785 | strm->adler = crc32(strm->adler, s->pending_buf + beg, | |
786 | s->pending - beg); | |
787 | if (s->gzindex == s->gzhead->extra_len) { | |
788 | s->gzindex = 0; | |
789 | s->status = NAME_STATE; | |
790 | } | |
791 | } | |
792 | else | |
793 | s->status = NAME_STATE; | |
794 | } | |
795 | if (s->status == NAME_STATE) { | |
f0da8242 | 796 | if (s->gzhead->name != Z_NULL) { |
cd426074 WD |
797 | uInt beg = s->pending; /* start of bytes to update crc */ |
798 | int val; | |
799 | ||
800 | do { | |
801 | if (s->pending == s->pending_buf_size) { | |
802 | if (s->gzhead->hcrc && s->pending > beg) | |
803 | strm->adler = crc32(strm->adler, s->pending_buf + beg, | |
804 | s->pending - beg); | |
805 | flush_pending(strm); | |
806 | beg = s->pending; | |
807 | if (s->pending == s->pending_buf_size) { | |
808 | val = 1; | |
809 | break; | |
810 | } | |
811 | } | |
812 | val = s->gzhead->name[s->gzindex++]; | |
813 | put_byte(s, val); | |
814 | } while (val != 0); | |
815 | if (s->gzhead->hcrc && s->pending > beg) | |
816 | strm->adler = crc32(strm->adler, s->pending_buf + beg, | |
817 | s->pending - beg); | |
818 | if (val == 0) { | |
819 | s->gzindex = 0; | |
820 | s->status = COMMENT_STATE; | |
821 | } | |
822 | } | |
823 | else | |
824 | s->status = COMMENT_STATE; | |
825 | } | |
826 | if (s->status == COMMENT_STATE) { | |
f0da8242 | 827 | if (s->gzhead->comment != Z_NULL) { |
cd426074 WD |
828 | uInt beg = s->pending; /* start of bytes to update crc */ |
829 | int val; | |
830 | ||
831 | do { | |
832 | if (s->pending == s->pending_buf_size) { | |
833 | if (s->gzhead->hcrc && s->pending > beg) | |
834 | strm->adler = crc32(strm->adler, s->pending_buf + beg, | |
835 | s->pending - beg); | |
836 | flush_pending(strm); | |
837 | beg = s->pending; | |
838 | if (s->pending == s->pending_buf_size) { | |
839 | val = 1; | |
840 | break; | |
841 | } | |
842 | } | |
843 | val = s->gzhead->comment[s->gzindex++]; | |
844 | put_byte(s, val); | |
845 | } while (val != 0); | |
846 | if (s->gzhead->hcrc && s->pending > beg) | |
847 | strm->adler = crc32(strm->adler, s->pending_buf + beg, | |
848 | s->pending - beg); | |
849 | if (val == 0) | |
850 | s->status = HCRC_STATE; | |
851 | } | |
852 | else | |
853 | s->status = HCRC_STATE; | |
854 | } | |
855 | if (s->status == HCRC_STATE) { | |
856 | if (s->gzhead->hcrc) { | |
857 | if (s->pending + 2 > s->pending_buf_size) | |
858 | flush_pending(strm); | |
859 | if (s->pending + 2 <= s->pending_buf_size) { | |
860 | put_byte(s, (Byte)(strm->adler & 0xff)); | |
861 | put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); | |
862 | strm->adler = crc32(0L, Z_NULL, 0); | |
863 | s->status = BUSY_STATE; | |
864 | } | |
865 | } | |
866 | else | |
867 | s->status = BUSY_STATE; | |
868 | } | |
869 | #endif | |
d4286ec4 PM |
870 | |
871 | /* Flush as much pending output as possible */ | |
872 | if (s->pending != 0) { | |
873 | flush_pending(strm); | |
874 | if (strm->avail_out == 0) { | |
1e1cf689 WD |
875 | /* Since avail_out is 0, deflate will be called again with |
876 | * more output space, but possibly with both pending and | |
877 | * avail_in equal to zero. There won't be anything to do, | |
878 | * but this is not an error situation so make sure we | |
879 | * return OK instead of BUF_ERROR at next call of deflate: | |
d4286ec4 | 880 | */ |
1e1cf689 WD |
881 | s->last_flush = -1; |
882 | return Z_OK; | |
883 | } | |
d4286ec4 PM |
884 | |
885 | /* Make sure there is something to do and avoid duplicate consecutive | |
886 | * flushes. For repeated and useless calls with Z_FINISH, we keep | |
1e1cf689 | 887 | * returning Z_STREAM_END instead of Z_BUF_ERROR. |
d4286ec4 | 888 | */ |
f0da8242 | 889 | } else if (strm->avail_in == 0 && RANK(flush) <= RANK(old_flush) && |
1e1cf689 | 890 | flush != Z_FINISH) { |
d4286ec4 PM |
891 | ERR_RETURN(strm, Z_BUF_ERROR); |
892 | } | |
893 | ||
894 | /* User must not provide more input after the first FINISH: */ | |
895 | if (s->status == FINISH_STATE && strm->avail_in != 0) { | |
896 | ERR_RETURN(strm, Z_BUF_ERROR); | |
897 | } | |
898 | ||
899 | /* Start a new block or continue the current one. | |
900 | */ | |
901 | if (strm->avail_in != 0 || s->lookahead != 0 || | |
902 | (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { | |
903 | block_state bstate; | |
904 | ||
f0da8242 WD |
905 | bstate = s->strategy == Z_HUFFMAN_ONLY ? deflate_huff(s, flush) : |
906 | (s->strategy == Z_RLE ? deflate_rle(s, flush) : | |
907 | (*(configuration_table[s->level].func))(s, flush)); | |
d4286ec4 PM |
908 | |
909 | if (bstate == finish_started || bstate == finish_done) { | |
910 | s->status = FINISH_STATE; | |
911 | } | |
912 | if (bstate == need_more || bstate == finish_started) { | |
1e1cf689 WD |
913 | if (strm->avail_out == 0) { |
914 | s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ | |
915 | } | |
916 | return Z_OK; | |
917 | /* If flush != Z_NO_FLUSH && avail_out == 0, the next call | |
918 | * of deflate should use the same flush parameter to make sure | |
919 | * that the flush is complete. So we don't have to output an | |
920 | * empty block here, this will be done at next call. This also | |
921 | * ensures that for a very small output buffer, we emit at most | |
922 | * one empty block. | |
923 | */ | |
924 | } | |
d4286ec4 PM |
925 | if (bstate == block_done) { |
926 | if (flush == Z_PARTIAL_FLUSH) { | |
927 | _tr_align(s); | |
f0da8242 | 928 | } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ |
d4286ec4 PM |
929 | _tr_stored_block(s, (char*)0, 0L, 0); |
930 | /* For a full flush, this empty block will be recognized | |
931 | * as a special marker by inflate_sync(). | |
932 | */ | |
933 | if (flush == Z_FULL_FLUSH) { | |
934 | CLEAR_HASH(s); /* forget history */ | |
f0da8242 WD |
935 | if (s->lookahead == 0) { |
936 | s->strstart = 0; | |
937 | s->block_start = 0L; | |
938 | s->insert = 0; | |
939 | } | |
d4286ec4 PM |
940 | } |
941 | } | |
942 | flush_pending(strm); | |
1e1cf689 WD |
943 | if (strm->avail_out == 0) { |
944 | s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ | |
945 | return Z_OK; | |
946 | } | |
d4286ec4 PM |
947 | } |
948 | } | |
949 | Assert(strm->avail_out > 0, "bug2"); | |
950 | ||
951 | if (flush != Z_FINISH) return Z_OK; | |
1e1cf689 WD |
952 | if (s->wrap <= 0) return Z_STREAM_END; |
953 | ||
954 | /* Write the trailer */ | |
955 | #ifdef GZIP | |
956 | if (s->wrap == 2) { | |
957 | put_byte(s, (Byte)(strm->adler & 0xff)); | |
958 | put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); | |
959 | put_byte(s, (Byte)((strm->adler >> 16) & 0xff)); | |
960 | put_byte(s, (Byte)((strm->adler >> 24) & 0xff)); | |
961 | put_byte(s, (Byte)(strm->total_in & 0xff)); | |
962 | put_byte(s, (Byte)((strm->total_in >> 8) & 0xff)); | |
963 | put_byte(s, (Byte)((strm->total_in >> 16) & 0xff)); | |
964 | put_byte(s, (Byte)((strm->total_in >> 24) & 0xff)); | |
965 | } | |
966 | else | |
967 | #endif | |
968 | { | |
969 | putShortMSB(s, (uInt)(strm->adler >> 16)); | |
970 | putShortMSB(s, (uInt)(strm->adler & 0xffff)); | |
971 | } | |
d4286ec4 PM |
972 | flush_pending(strm); |
973 | /* If avail_out is zero, the application will call deflate again | |
974 | * to flush the rest. | |
975 | */ | |
1e1cf689 | 976 | if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ |
d4286ec4 PM |
977 | return s->pending != 0 ? Z_OK : Z_STREAM_END; |
978 | } | |
979 | ||
980 | /* ========================================================================= */ | |
981 | int ZEXPORT deflateEnd (strm) | |
982 | z_streamp strm; | |
983 | { | |
984 | int status; | |
985 | ||
986 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; | |
987 | ||
988 | status = strm->state->status; | |
cd426074 WD |
989 | if (status != INIT_STATE && |
990 | status != EXTRA_STATE && | |
991 | status != NAME_STATE && | |
992 | status != COMMENT_STATE && | |
993 | status != HCRC_STATE && | |
994 | status != BUSY_STATE && | |
1e1cf689 | 995 | status != FINISH_STATE) { |
d4286ec4 PM |
996 | return Z_STREAM_ERROR; |
997 | } | |
998 | ||
999 | /* Deallocate in reverse order of allocations: */ | |
1000 | TRY_FREE(strm, strm->state->pending_buf); | |
1001 | TRY_FREE(strm, strm->state->head); | |
1002 | TRY_FREE(strm, strm->state->prev); | |
1003 | TRY_FREE(strm, strm->state->window); | |
1004 | ||
1005 | ZFREE(strm, strm->state); | |
1006 | strm->state = Z_NULL; | |
1007 | ||
1008 | return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; | |
1009 | } | |
1010 | ||
1011 | /* ========================================================================= | |
1012 | * Copy the source state to the destination state. | |
1013 | * To simplify the source, this is not supported for 16-bit MSDOS (which | |
1014 | * doesn't have enough memory anyway to duplicate compression states). | |
1015 | */ | |
1016 | int ZEXPORT deflateCopy (dest, source) | |
1017 | z_streamp dest; | |
1018 | z_streamp source; | |
1019 | { | |
1020 | #ifdef MAXSEG_64K | |
1021 | return Z_STREAM_ERROR; | |
1022 | #else | |
1023 | deflate_state *ds; | |
1024 | deflate_state *ss; | |
1025 | ushf *overlay; | |
1026 | ||
d4286ec4 | 1027 | |
06b91d8e | 1028 | if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) { |
d4286ec4 PM |
1029 | return Z_STREAM_ERROR; |
1030 | } | |
06b91d8e MP |
1031 | |
1032 | ss = source->state; | |
1033 | ||
f0da8242 | 1034 | zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); |
d4286ec4 PM |
1035 | |
1036 | ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); | |
1037 | if (ds == Z_NULL) return Z_MEM_ERROR; | |
1038 | dest->state = (struct internal_state FAR *) ds; | |
f0da8242 | 1039 | zmemcpy((voidpf)ds, (voidpf)ss, sizeof(deflate_state)); |
d4286ec4 PM |
1040 | ds->strm = dest; |
1041 | ||
1042 | ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); | |
1043 | ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); | |
1044 | ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); | |
1045 | overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); | |
1046 | ds->pending_buf = (uchf *) overlay; | |
1047 | ||
1048 | if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || | |
1049 | ds->pending_buf == Z_NULL) { | |
1050 | deflateEnd (dest); | |
1051 | return Z_MEM_ERROR; | |
1052 | } | |
1053 | /* following zmemcpy do not work for 16-bit MSDOS */ | |
1054 | zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); | |
f0da8242 WD |
1055 | zmemcpy((voidpf)ds->prev, (voidpf)ss->prev, ds->w_size * sizeof(Pos)); |
1056 | zmemcpy((voidpf)ds->head, (voidpf)ss->head, ds->hash_size * sizeof(Pos)); | |
d4286ec4 PM |
1057 | zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); |
1058 | ||
1059 | ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); | |
1060 | ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); | |
1061 | ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; | |
1062 | ||
1063 | ds->l_desc.dyn_tree = ds->dyn_ltree; | |
1064 | ds->d_desc.dyn_tree = ds->dyn_dtree; | |
1065 | ds->bl_desc.dyn_tree = ds->bl_tree; | |
1066 | ||
1067 | return Z_OK; | |
1e1cf689 | 1068 | #endif /* MAXSEG_64K */ |
d4286ec4 PM |
1069 | } |
1070 | ||
1071 | /* =========================================================================== | |
1072 | * Read a new buffer from the current input stream, update the adler32 | |
1073 | * and total number of bytes read. All deflate() input goes through | |
1074 | * this function so some applications may wish to modify it to avoid | |
1075 | * allocating a large strm->next_in buffer and copying from it. | |
1076 | * (See also flush_pending()). | |
1077 | */ | |
12febd80 | 1078 | local int read_buf(strm, buf, size) |
d4286ec4 PM |
1079 | z_streamp strm; |
1080 | Bytef *buf; | |
1081 | unsigned size; | |
1082 | { | |
1083 | unsigned len = strm->avail_in; | |
1084 | ||
1085 | if (len > size) len = size; | |
1086 | if (len == 0) return 0; | |
1087 | ||
1088 | strm->avail_in -= len; | |
1089 | ||
f0da8242 | 1090 | zmemcpy(buf, strm->next_in, len); |
1e1cf689 | 1091 | if (strm->state->wrap == 1) { |
f0da8242 | 1092 | strm->adler = adler32(strm->adler, buf, len); |
d4286ec4 | 1093 | } |
1e1cf689 WD |
1094 | #ifdef GZIP |
1095 | else if (strm->state->wrap == 2) { | |
f0da8242 | 1096 | strm->adler = crc32(strm->adler, buf, len); |
1e1cf689 WD |
1097 | } |
1098 | #endif | |
d4286ec4 PM |
1099 | strm->next_in += len; |
1100 | strm->total_in += len; | |
1101 | ||
1102 | return (int)len; | |
1103 | } | |
1104 | ||
1105 | /* =========================================================================== | |
1106 | * Initialize the "longest match" routines for a new zlib stream | |
1107 | */ | |
1108 | local void lm_init (s) | |
1109 | deflate_state *s; | |
1110 | { | |
1111 | s->window_size = (ulg)2L*s->w_size; | |
1112 | ||
1113 | CLEAR_HASH(s); | |
1114 | ||
1115 | /* Set the default configuration parameters: | |
1116 | */ | |
1117 | s->max_lazy_match = configuration_table[s->level].max_lazy; | |
1118 | s->good_match = configuration_table[s->level].good_length; | |
1119 | s->nice_match = configuration_table[s->level].nice_length; | |
1120 | s->max_chain_length = configuration_table[s->level].max_chain; | |
1121 | ||
1122 | s->strstart = 0; | |
1123 | s->block_start = 0L; | |
1124 | s->lookahead = 0; | |
f0da8242 | 1125 | s->insert = 0; |
d4286ec4 PM |
1126 | s->match_length = s->prev_length = MIN_MATCH-1; |
1127 | s->match_available = 0; | |
1128 | s->ins_h = 0; | |
cd426074 | 1129 | #ifndef FASTEST |
d4286ec4 PM |
1130 | #ifdef ASMV |
1131 | match_init(); /* initialize the asm code */ | |
1132 | #endif | |
cd426074 | 1133 | #endif |
d4286ec4 PM |
1134 | } |
1135 | ||
1e1cf689 | 1136 | #ifndef FASTEST |
d4286ec4 PM |
1137 | /* =========================================================================== |
1138 | * Set match_start to the longest match starting at the given string and | |
1139 | * return its length. Matches shorter or equal to prev_length are discarded, | |
1140 | * in which case the result is equal to prev_length and match_start is | |
1141 | * garbage. | |
1142 | * IN assertions: cur_match is the head of the hash chain for the current | |
1143 | * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 | |
1144 | * OUT assertion: the match length is not greater than s->lookahead. | |
1145 | */ | |
1146 | #ifndef ASMV | |
1147 | /* For 80x86 and 680x0, an optimized version will be provided in match.asm or | |
1148 | * match.S. The code will be functionally equivalent. | |
1149 | */ | |
d4286ec4 PM |
1150 | local uInt longest_match(s, cur_match) |
1151 | deflate_state *s; | |
1152 | IPos cur_match; /* current match */ | |
1153 | { | |
1154 | unsigned chain_length = s->max_chain_length;/* max hash chain length */ | |
1155 | register Bytef *scan = s->window + s->strstart; /* current string */ | |
1156 | register Bytef *match; /* matched string */ | |
1157 | register int len; /* length of current match */ | |
1158 | int best_len = s->prev_length; /* best match length so far */ | |
1159 | int nice_match = s->nice_match; /* stop if match long enough */ | |
1160 | IPos limit = s->strstart > (IPos)MAX_DIST(s) ? | |
1161 | s->strstart - (IPos)MAX_DIST(s) : NIL; | |
1162 | /* Stop when cur_match becomes <= limit. To simplify the code, | |
1163 | * we prevent matches with the string of window index 0. | |
1164 | */ | |
1165 | Posf *prev = s->prev; | |
1166 | uInt wmask = s->w_mask; | |
1167 | ||
1168 | #ifdef UNALIGNED_OK | |
1169 | /* Compare two bytes at a time. Note: this is not always beneficial. | |
1170 | * Try with and without -DUNALIGNED_OK to check. | |
1171 | */ | |
1172 | register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; | |
1173 | register ush scan_start = *(ushf*)scan; | |
1174 | register ush scan_end = *(ushf*)(scan+best_len-1); | |
1175 | #else | |
1176 | register Bytef *strend = s->window + s->strstart + MAX_MATCH; | |
1177 | register Byte scan_end1 = scan[best_len-1]; | |
1178 | register Byte scan_end = scan[best_len]; | |
1179 | #endif | |
1180 | ||
1181 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. | |
1182 | * It is easy to get rid of this optimization if necessary. | |
1183 | */ | |
1184 | Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); | |
1185 | ||
1186 | /* Do not waste too much time if we already have a good match: */ | |
1187 | if (s->prev_length >= s->good_match) { | |
1188 | chain_length >>= 2; | |
1189 | } | |
1190 | /* Do not look for matches beyond the end of the input. This is necessary | |
1191 | * to make deflate deterministic. | |
1192 | */ | |
1193 | if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; | |
1194 | ||
1195 | Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); | |
1196 | ||
1197 | do { | |
1198 | Assert(cur_match < s->strstart, "no future"); | |
1199 | match = s->window + cur_match; | |
1200 | ||
1201 | /* Skip to next match if the match length cannot increase | |
cd426074 WD |
1202 | * or if the match length is less than 2. Note that the checks below |
1203 | * for insufficient lookahead only occur occasionally for performance | |
1204 | * reasons. Therefore uninitialized memory will be accessed, and | |
1205 | * conditional jumps will be made that depend on those values. | |
1206 | * However the length of the match is limited to the lookahead, so | |
1207 | * the output of deflate is not affected by the uninitialized values. | |
d4286ec4 PM |
1208 | */ |
1209 | #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) | |
1210 | /* This code assumes sizeof(unsigned short) == 2. Do not use | |
1211 | * UNALIGNED_OK if your compiler uses a different size. | |
1212 | */ | |
1213 | if (*(ushf*)(match+best_len-1) != scan_end || | |
1214 | *(ushf*)match != scan_start) continue; | |
1215 | ||
1216 | /* It is not necessary to compare scan[2] and match[2] since they are | |
1217 | * always equal when the other bytes match, given that the hash keys | |
1218 | * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at | |
1219 | * strstart+3, +5, ... up to strstart+257. We check for insufficient | |
1220 | * lookahead only every 4th comparison; the 128th check will be made | |
1221 | * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is | |
1222 | * necessary to put more guard bytes at the end of the window, or | |
1223 | * to check more often for insufficient lookahead. | |
1224 | */ | |
1225 | Assert(scan[2] == match[2], "scan[2]?"); | |
1226 | scan++, match++; | |
1227 | do { | |
1228 | } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
1229 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
1230 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
1231 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
1232 | scan < strend); | |
1233 | /* The funny "do {}" generates better code on most compilers */ | |
1234 | ||
1235 | /* Here, scan <= window+strstart+257 */ | |
1236 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); | |
1237 | if (*scan == *match) scan++; | |
1238 | ||
1239 | len = (MAX_MATCH - 1) - (int)(strend-scan); | |
1240 | scan = strend - (MAX_MATCH-1); | |
1241 | ||
1242 | #else /* UNALIGNED_OK */ | |
1243 | ||
1244 | if (match[best_len] != scan_end || | |
1245 | match[best_len-1] != scan_end1 || | |
1246 | *match != *scan || | |
1247 | *++match != scan[1]) continue; | |
1248 | ||
1249 | /* The check at best_len-1 can be removed because it will be made | |
1250 | * again later. (This heuristic is not always a win.) | |
1251 | * It is not necessary to compare scan[2] and match[2] since they | |
1252 | * are always equal when the other bytes match, given that | |
1253 | * the hash keys are equal and that HASH_BITS >= 8. | |
1254 | */ | |
1255 | scan += 2, match++; | |
1256 | Assert(*scan == *match, "match[2]?"); | |
1257 | ||
1258 | /* We check for insufficient lookahead only every 8th comparison; | |
1259 | * the 256th check will be made at strstart+258. | |
1260 | */ | |
1261 | do { | |
1262 | } while (*++scan == *++match && *++scan == *++match && | |
1263 | *++scan == *++match && *++scan == *++match && | |
1264 | *++scan == *++match && *++scan == *++match && | |
1265 | *++scan == *++match && *++scan == *++match && | |
1266 | scan < strend); | |
1267 | ||
1268 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); | |
1269 | ||
1270 | len = MAX_MATCH - (int)(strend - scan); | |
1271 | scan = strend - MAX_MATCH; | |
1272 | ||
1273 | #endif /* UNALIGNED_OK */ | |
1274 | ||
1275 | if (len > best_len) { | |
1276 | s->match_start = cur_match; | |
1277 | best_len = len; | |
1278 | if (len >= nice_match) break; | |
1279 | #ifdef UNALIGNED_OK | |
1280 | scan_end = *(ushf*)(scan+best_len-1); | |
1281 | #else | |
1282 | scan_end1 = scan[best_len-1]; | |
1283 | scan_end = scan[best_len]; | |
1284 | #endif | |
1285 | } | |
1286 | } while ((cur_match = prev[cur_match & wmask]) > limit | |
1287 | && --chain_length != 0); | |
1288 | ||
1289 | if ((uInt)best_len <= s->lookahead) return (uInt)best_len; | |
1290 | return s->lookahead; | |
1291 | } | |
1e1cf689 | 1292 | #endif /* ASMV */ |
f0da8242 WD |
1293 | |
1294 | #else /* FASTEST */ | |
d4286ec4 | 1295 | |
d4286ec4 | 1296 | /* --------------------------------------------------------------------------- |
f0da8242 | 1297 | * Optimized version for FASTEST only |
d4286ec4 | 1298 | */ |
f0da8242 | 1299 | local uInt longest_match(s, cur_match) |
d4286ec4 PM |
1300 | deflate_state *s; |
1301 | IPos cur_match; /* current match */ | |
1302 | { | |
1303 | register Bytef *scan = s->window + s->strstart; /* current string */ | |
1304 | register Bytef *match; /* matched string */ | |
1305 | register int len; /* length of current match */ | |
1306 | register Bytef *strend = s->window + s->strstart + MAX_MATCH; | |
1307 | ||
1308 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. | |
1309 | * It is easy to get rid of this optimization if necessary. | |
1310 | */ | |
1311 | Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); | |
1312 | ||
1313 | Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); | |
1314 | ||
1315 | Assert(cur_match < s->strstart, "no future"); | |
1316 | ||
1317 | match = s->window + cur_match; | |
1318 | ||
1319 | /* Return failure if the match length is less than 2: | |
1320 | */ | |
1321 | if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1; | |
1322 | ||
1323 | /* The check at best_len-1 can be removed because it will be made | |
1324 | * again later. (This heuristic is not always a win.) | |
1325 | * It is not necessary to compare scan[2] and match[2] since they | |
1326 | * are always equal when the other bytes match, given that | |
1327 | * the hash keys are equal and that HASH_BITS >= 8. | |
1328 | */ | |
1329 | scan += 2, match += 2; | |
1330 | Assert(*scan == *match, "match[2]?"); | |
1331 | ||
1332 | /* We check for insufficient lookahead only every 8th comparison; | |
1333 | * the 256th check will be made at strstart+258. | |
1334 | */ | |
1335 | do { | |
1336 | } while (*++scan == *++match && *++scan == *++match && | |
1e1cf689 WD |
1337 | *++scan == *++match && *++scan == *++match && |
1338 | *++scan == *++match && *++scan == *++match && | |
1339 | *++scan == *++match && *++scan == *++match && | |
1340 | scan < strend); | |
d4286ec4 PM |
1341 | |
1342 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); | |
1343 | ||
1344 | len = MAX_MATCH - (int)(strend - scan); | |
1345 | ||
1346 | if (len < MIN_MATCH) return MIN_MATCH - 1; | |
1347 | ||
1348 | s->match_start = cur_match; | |
1e1cf689 | 1349 | return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; |
d4286ec4 | 1350 | } |
d4286ec4 | 1351 | |
f0da8242 WD |
1352 | #endif /* FASTEST */ |
1353 | ||
d4286ec4 PM |
1354 | #ifdef DEBUG |
1355 | /* =========================================================================== | |
1356 | * Check that the match at match_start is indeed a match. | |
1357 | */ | |
1358 | local void check_match(s, start, match, length) | |
1359 | deflate_state *s; | |
1360 | IPos start, match; | |
1361 | int length; | |
1362 | { | |
1363 | /* check that the match is indeed a match */ | |
1364 | if (zmemcmp(s->window + match, | |
1365 | s->window + start, length) != EQUAL) { | |
1366 | fprintf(stderr, " start %u, match %u, length %d\n", | |
1e1cf689 | 1367 | start, match, length); |
d4286ec4 | 1368 | do { |
1e1cf689 WD |
1369 | fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); |
1370 | } while (--length != 0); | |
d4286ec4 PM |
1371 | z_error("invalid match"); |
1372 | } | |
1373 | if (z_verbose > 1) { | |
1374 | fprintf(stderr,"\\[%d,%d]", start-match, length); | |
1375 | do { putc(s->window[start++], stderr); } while (--length != 0); | |
1376 | } | |
1377 | } | |
1378 | #else | |
1379 | # define check_match(s, start, match, length) | |
1e1cf689 | 1380 | #endif /* DEBUG */ |
d4286ec4 PM |
1381 | |
1382 | /* =========================================================================== | |
1383 | * Fill the window when the lookahead becomes insufficient. | |
1384 | * Updates strstart and lookahead. | |
1385 | * | |
1386 | * IN assertion: lookahead < MIN_LOOKAHEAD | |
1387 | * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD | |
1388 | * At least one byte has been read, or avail_in == 0; reads are | |
1389 | * performed for at least two bytes (required for the zip translate_eol | |
1390 | * option -- not supported here). | |
1391 | */ | |
1392 | local void fill_window(s) | |
1393 | deflate_state *s; | |
1394 | { | |
1395 | register unsigned n, m; | |
1396 | register Posf *p; | |
1397 | unsigned more; /* Amount of free space at the end of the window. */ | |
1398 | uInt wsize = s->w_size; | |
1399 | ||
f0da8242 WD |
1400 | Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead"); |
1401 | ||
d4286ec4 PM |
1402 | do { |
1403 | more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); | |
1404 | ||
1405 | /* Deal with !@#$% 64K limit: */ | |
1e1cf689 WD |
1406 | if (sizeof(int) <= 2) { |
1407 | if (more == 0 && s->strstart == 0 && s->lookahead == 0) { | |
1408 | more = wsize; | |
d4286ec4 | 1409 | |
1e1cf689 WD |
1410 | } else if (more == (unsigned)(-1)) { |
1411 | /* Very unlikely, but possible on 16 bit machine if | |
1412 | * strstart == 0 && lookahead == 1 (input done a byte at time) | |
1413 | */ | |
1414 | more--; | |
1415 | } | |
1416 | } | |
d4286ec4 PM |
1417 | |
1418 | /* If the window is almost full and there is insufficient lookahead, | |
1419 | * move the upper half to the lower one to make room in the upper half. | |
1420 | */ | |
1e1cf689 | 1421 | if (s->strstart >= wsize+MAX_DIST(s)) { |
d4286ec4 PM |
1422 | |
1423 | zmemcpy(s->window, s->window+wsize, (unsigned)wsize); | |
1424 | s->match_start -= wsize; | |
1425 | s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ | |
1426 | s->block_start -= (long) wsize; | |
1427 | ||
1428 | /* Slide the hash table (could be avoided with 32 bit values | |
1429 | at the expense of memory usage). We slide even when level == 0 | |
1430 | to keep the hash table consistent if we switch back to level > 0 | |
1431 | later. (Using level 0 permanently is not an optimal usage of | |
1432 | zlib, so we don't care about this pathological case.) | |
1433 | */ | |
1e1cf689 WD |
1434 | n = s->hash_size; |
1435 | p = &s->head[n]; | |
1436 | do { | |
1437 | m = *--p; | |
1438 | *p = (Pos)(m >= wsize ? m-wsize : NIL); | |
1439 | } while (--n); | |
1440 | ||
1441 | n = wsize; | |
d4286ec4 | 1442 | #ifndef FASTEST |
1e1cf689 WD |
1443 | p = &s->prev[n]; |
1444 | do { | |
1445 | m = *--p; | |
1446 | *p = (Pos)(m >= wsize ? m-wsize : NIL); | |
1447 | /* If n is not on any hash chain, prev[n] is garbage but | |
1448 | * its value will never be used. | |
1449 | */ | |
1450 | } while (--n); | |
d4286ec4 PM |
1451 | #endif |
1452 | more += wsize; | |
1453 | } | |
f0da8242 | 1454 | if (s->strm->avail_in == 0) break; |
d4286ec4 PM |
1455 | |
1456 | /* If there was no sliding: | |
1457 | * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && | |
1458 | * more == window_size - lookahead - strstart | |
1459 | * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) | |
1460 | * => more >= window_size - 2*WSIZE + 2 | |
1461 | * In the BIG_MEM or MMAP case (not yet supported), | |
1462 | * window_size == input_size + MIN_LOOKAHEAD && | |
1463 | * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. | |
1464 | * Otherwise, window_size == 2*WSIZE so more >= 2. | |
1465 | * If there was sliding, more >= WSIZE. So in all cases, more >= 2. | |
1466 | */ | |
1467 | Assert(more >= 2, "more < 2"); | |
1468 | ||
12febd80 | 1469 | n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more); |
d4286ec4 PM |
1470 | s->lookahead += n; |
1471 | ||
1472 | /* Initialize the hash value now that we have some input: */ | |
f0da8242 WD |
1473 | if (s->lookahead + s->insert >= MIN_MATCH) { |
1474 | uInt str = s->strstart - s->insert; | |
1475 | s->ins_h = s->window[str]; | |
1476 | UPDATE_HASH(s, s->ins_h, s->window[str + 1]); | |
d4286ec4 PM |
1477 | #if MIN_MATCH != 3 |
1478 | Call UPDATE_HASH() MIN_MATCH-3 more times | |
1479 | #endif | |
f0da8242 WD |
1480 | while (s->insert) { |
1481 | UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]); | |
1482 | #ifndef FASTEST | |
1483 | s->prev[str & s->w_mask] = s->head[s->ins_h]; | |
1484 | #endif | |
1485 | s->head[s->ins_h] = (Pos)str; | |
1486 | str++; | |
1487 | s->insert--; | |
1488 | if (s->lookahead + s->insert < MIN_MATCH) | |
1489 | break; | |
1490 | } | |
d4286ec4 PM |
1491 | } |
1492 | /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, | |
1493 | * but this is not important since only literal bytes will be emitted. | |
1494 | */ | |
1495 | ||
1496 | } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); | |
f0da8242 WD |
1497 | |
1498 | /* If the WIN_INIT bytes after the end of the current data have never been | |
1499 | * written, then zero those bytes in order to avoid memory check reports of | |
1500 | * the use of uninitialized (or uninitialised as Julian writes) bytes by | |
1501 | * the longest match routines. Update the high water mark for the next | |
1502 | * time through here. WIN_INIT is set to MAX_MATCH since the longest match | |
1503 | * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. | |
1504 | */ | |
1505 | if (s->high_water < s->window_size) { | |
1506 | ulg curr = s->strstart + (ulg)(s->lookahead); | |
1507 | ulg init; | |
1508 | ||
1509 | if (s->high_water < curr) { | |
1510 | /* Previous high water mark below current data -- zero WIN_INIT | |
1511 | * bytes or up to end of window, whichever is less. | |
1512 | */ | |
1513 | init = s->window_size - curr; | |
1514 | if (init > WIN_INIT) | |
1515 | init = WIN_INIT; | |
1516 | zmemzero(s->window + curr, (unsigned)init); | |
1517 | s->high_water = curr + init; | |
1518 | } | |
1519 | else if (s->high_water < (ulg)curr + WIN_INIT) { | |
1520 | /* High water mark at or above current data, but below current data | |
1521 | * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up | |
1522 | * to end of window, whichever is less. | |
1523 | */ | |
1524 | init = (ulg)curr + WIN_INIT - s->high_water; | |
1525 | if (init > s->window_size - s->high_water) | |
1526 | init = s->window_size - s->high_water; | |
1527 | zmemzero(s->window + s->high_water, (unsigned)init); | |
1528 | s->high_water += init; | |
1529 | } | |
1530 | } | |
1531 | ||
1532 | Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD, | |
1533 | "not enough room for search"); | |
d4286ec4 PM |
1534 | } |
1535 | ||
1536 | /* =========================================================================== | |
1537 | * Flush the current block, with given end-of-file flag. | |
1538 | * IN assertion: strstart is set to the end of the current match. | |
1539 | */ | |
f0da8242 | 1540 | #define FLUSH_BLOCK_ONLY(s, last) { \ |
d4286ec4 PM |
1541 | _tr_flush_block(s, (s->block_start >= 0L ? \ |
1542 | (charf *)&s->window[(unsigned)s->block_start] : \ | |
1543 | (charf *)Z_NULL), \ | |
1e1cf689 | 1544 | (ulg)((long)s->strstart - s->block_start), \ |
f0da8242 | 1545 | (last)); \ |
d4286ec4 PM |
1546 | s->block_start = s->strstart; \ |
1547 | flush_pending(s->strm); \ | |
1548 | Tracev((stderr,"[FLUSH]")); \ | |
1549 | } | |
1550 | ||
1551 | /* Same but force premature exit if necessary. */ | |
f0da8242 WD |
1552 | #define FLUSH_BLOCK(s, last) { \ |
1553 | FLUSH_BLOCK_ONLY(s, last); \ | |
1554 | if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ | |
d4286ec4 PM |
1555 | } |
1556 | ||
1557 | /* =========================================================================== | |
1558 | * Copy without compression as much as possible from the input stream, return | |
1559 | * the current block state. | |
1560 | * This function does not insert new strings in the dictionary since | |
1561 | * uncompressible data is probably not useful. This function is used | |
1562 | * only for the level=0 compression option. | |
1563 | * NOTE: this function should be optimized to avoid extra copying from | |
1564 | * window to pending_buf. | |
1565 | */ | |
1566 | local block_state deflate_stored(s, flush) | |
1567 | deflate_state *s; | |
1568 | int flush; | |
1569 | { | |
1570 | /* Stored blocks are limited to 0xffff bytes, pending_buf is limited | |
1571 | * to pending_buf_size, and each stored block has a 5 byte header: | |
1572 | */ | |
1573 | ulg max_block_size = 0xffff; | |
1574 | ulg max_start; | |
1575 | ||
1576 | if (max_block_size > s->pending_buf_size - 5) { | |
1577 | max_block_size = s->pending_buf_size - 5; | |
1578 | } | |
1579 | ||
1580 | /* Copy as much as possible from input to output: */ | |
1581 | for (;;) { | |
1582 | /* Fill the window as much as possible: */ | |
1583 | if (s->lookahead <= 1) { | |
1584 | ||
1585 | Assert(s->strstart < s->w_size+MAX_DIST(s) || | |
1e1cf689 | 1586 | s->block_start >= (long)s->w_size, "slide too late"); |
d4286ec4 PM |
1587 | |
1588 | fill_window(s); | |
1589 | if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; | |
1590 | ||
1591 | if (s->lookahead == 0) break; /* flush the current block */ | |
1592 | } | |
1e1cf689 | 1593 | Assert(s->block_start >= 0L, "block gone"); |
d4286ec4 | 1594 | |
1e1cf689 WD |
1595 | s->strstart += s->lookahead; |
1596 | s->lookahead = 0; | |
d4286ec4 | 1597 | |
0301b334 WD |
1598 | if (flush == Z_INSERT_ONLY) { |
1599 | s->block_start = s->strstart; | |
1600 | continue; | |
1601 | } | |
1602 | ||
1e1cf689 WD |
1603 | /* Emit a stored block if pending_buf will be full: */ |
1604 | max_start = s->block_start + max_block_size; | |
d4286ec4 | 1605 | if (s->strstart == 0 || (ulg)s->strstart >= max_start) { |
1e1cf689 WD |
1606 | /* strstart == 0 is possible when wraparound on 16-bit machine */ |
1607 | s->lookahead = (uInt)(s->strstart - max_start); | |
1608 | s->strstart = (uInt)max_start; | |
d4286ec4 | 1609 | FLUSH_BLOCK(s, 0); |
1e1cf689 WD |
1610 | } |
1611 | /* Flush if we may have to slide, otherwise block_start may become | |
d4286ec4 PM |
1612 | * negative and the data will be gone: |
1613 | */ | |
1614 | if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { | |
1615 | FLUSH_BLOCK(s, 0); | |
1e1cf689 | 1616 | } |
d4286ec4 | 1617 | } |
f0da8242 | 1618 | s->insert = 0; |
0301b334 WD |
1619 | if (flush == Z_INSERT_ONLY) { |
1620 | s->block_start = s->strstart; | |
1621 | return need_more; | |
1622 | } | |
f0da8242 WD |
1623 | if (flush == Z_FINISH) { |
1624 | FLUSH_BLOCK(s, 1); | |
1625 | return finish_done; | |
1626 | } | |
1627 | if ((long)s->strstart > s->block_start) | |
1628 | FLUSH_BLOCK(s, 0); | |
1629 | return block_done; | |
d4286ec4 PM |
1630 | } |
1631 | ||
1632 | /* =========================================================================== | |
1633 | * Compress as much as possible from the input stream, return the current | |
1634 | * block state. | |
1635 | * This function does not perform lazy evaluation of matches and inserts | |
1636 | * new strings in the dictionary only for unmatched strings or for short | |
1637 | * matches. It is used only for the fast compression options. | |
1638 | */ | |
1639 | local block_state deflate_fast(s, flush) | |
1640 | deflate_state *s; | |
1641 | int flush; | |
1642 | { | |
f0da8242 | 1643 | IPos hash_head; /* head of the hash chain */ |
d4286ec4 PM |
1644 | int bflush; /* set if current block must be flushed */ |
1645 | ||
1646 | for (;;) { | |
1647 | /* Make sure that we always have enough lookahead, except | |
1648 | * at the end of the input file. We need MAX_MATCH bytes | |
1649 | * for the next match, plus MIN_MATCH bytes to insert the | |
1650 | * string following the next match. | |
1651 | */ | |
1652 | if (s->lookahead < MIN_LOOKAHEAD) { | |
1653 | fill_window(s); | |
1654 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { | |
1e1cf689 WD |
1655 | return need_more; |
1656 | } | |
d4286ec4 PM |
1657 | if (s->lookahead == 0) break; /* flush the current block */ |
1658 | } | |
1659 | ||
1660 | /* Insert the string window[strstart .. strstart+2] in the | |
1661 | * dictionary, and set hash_head to the head of the hash chain: | |
1662 | */ | |
f0da8242 | 1663 | hash_head = NIL; |
d4286ec4 PM |
1664 | if (s->lookahead >= MIN_MATCH) { |
1665 | INSERT_STRING(s, s->strstart, hash_head); | |
1666 | } | |
1667 | ||
5914bf15 PM |
1668 | if (flush == Z_INSERT_ONLY) { |
1669 | s->strstart++; | |
1670 | s->lookahead--; | |
1671 | continue; | |
1672 | } | |
1673 | ||
d4286ec4 PM |
1674 | /* Find the longest match, discarding those <= prev_length. |
1675 | * At this point we have always match_length < MIN_MATCH | |
1676 | */ | |
1677 | if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { | |
1678 | /* To simplify the code, we prevent matches with the string | |
1679 | * of window index 0 (in particular we have to avoid a match | |
1680 | * of the string with itself at the start of the input file). | |
1681 | */ | |
f0da8242 WD |
1682 | s->match_length = longest_match (s, hash_head); |
1683 | /* longest_match() sets match_start */ | |
d4286ec4 PM |
1684 | } |
1685 | if (s->match_length >= MIN_MATCH) { | |
1686 | check_match(s, s->strstart, s->match_start, s->match_length); | |
1687 | ||
1688 | _tr_tally_dist(s, s->strstart - s->match_start, | |
1689 | s->match_length - MIN_MATCH, bflush); | |
1690 | ||
1691 | s->lookahead -= s->match_length; | |
1692 | ||
1693 | /* Insert new strings in the hash table only if the match length | |
1694 | * is not too large. This saves time but degrades compression. | |
1695 | */ | |
1696 | #ifndef FASTEST | |
1697 | if (s->match_length <= s->max_insert_length && | |
1698 | s->lookahead >= MIN_MATCH) { | |
1e1cf689 | 1699 | s->match_length--; /* string at strstart already in table */ |
d4286ec4 PM |
1700 | do { |
1701 | s->strstart++; | |
1702 | INSERT_STRING(s, s->strstart, hash_head); | |
1703 | /* strstart never exceeds WSIZE-MAX_MATCH, so there are | |
1704 | * always MIN_MATCH bytes ahead. | |
1705 | */ | |
1706 | } while (--s->match_length != 0); | |
1e1cf689 | 1707 | s->strstart++; |
d4286ec4 PM |
1708 | } else |
1709 | #endif | |
1e1cf689 | 1710 | { |
d4286ec4 PM |
1711 | s->strstart += s->match_length; |
1712 | s->match_length = 0; | |
1713 | s->ins_h = s->window[s->strstart]; | |
1714 | UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); | |
1715 | #if MIN_MATCH != 3 | |
1716 | Call UPDATE_HASH() MIN_MATCH-3 more times | |
1717 | #endif | |
1718 | /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not | |
1719 | * matter since it will be recomputed at next deflate call. | |
1720 | */ | |
1721 | } | |
1722 | } else { | |
1723 | /* No match, output a literal byte */ | |
1724 | Tracevv((stderr,"%c", s->window[s->strstart])); | |
1725 | _tr_tally_lit (s, s->window[s->strstart], bflush); | |
1726 | s->lookahead--; | |
1e1cf689 | 1727 | s->strstart++; |
d4286ec4 PM |
1728 | } |
1729 | if (bflush) FLUSH_BLOCK(s, 0); | |
1730 | } | |
5914bf15 PM |
1731 | if (flush == Z_INSERT_ONLY) { |
1732 | s->block_start = s->strstart; | |
1733 | return need_more; | |
1734 | } | |
f0da8242 WD |
1735 | s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1; |
1736 | if (flush == Z_FINISH) { | |
1737 | FLUSH_BLOCK(s, 1); | |
1738 | return finish_done; | |
1739 | } | |
1740 | if (s->last_lit) | |
1741 | FLUSH_BLOCK(s, 0); | |
1742 | return block_done; | |
d4286ec4 PM |
1743 | } |
1744 | ||
1e1cf689 | 1745 | #ifndef FASTEST |
d4286ec4 PM |
1746 | /* =========================================================================== |
1747 | * Same as above, but achieves better compression. We use a lazy | |
1748 | * evaluation for matches: a match is finally adopted only if there is | |
1749 | * no better match at the next window position. | |
1750 | */ | |
1751 | local block_state deflate_slow(s, flush) | |
1752 | deflate_state *s; | |
1753 | int flush; | |
1754 | { | |
f0da8242 | 1755 | IPos hash_head; /* head of hash chain */ |
d4286ec4 PM |
1756 | int bflush; /* set if current block must be flushed */ |
1757 | ||
1758 | /* Process the input block. */ | |
1759 | for (;;) { | |
1760 | /* Make sure that we always have enough lookahead, except | |
1761 | * at the end of the input file. We need MAX_MATCH bytes | |
1762 | * for the next match, plus MIN_MATCH bytes to insert the | |
1763 | * string following the next match. | |
1764 | */ | |
1765 | if (s->lookahead < MIN_LOOKAHEAD) { | |
1766 | fill_window(s); | |
1767 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { | |
1e1cf689 WD |
1768 | return need_more; |
1769 | } | |
d4286ec4 PM |
1770 | if (s->lookahead == 0) break; /* flush the current block */ |
1771 | } | |
1772 | ||
1773 | /* Insert the string window[strstart .. strstart+2] in the | |
1774 | * dictionary, and set hash_head to the head of the hash chain: | |
1775 | */ | |
f0da8242 | 1776 | hash_head = NIL; |
d4286ec4 PM |
1777 | if (s->lookahead >= MIN_MATCH) { |
1778 | INSERT_STRING(s, s->strstart, hash_head); | |
1779 | } | |
1780 | ||
5914bf15 PM |
1781 | if (flush == Z_INSERT_ONLY) { |
1782 | s->strstart++; | |
1783 | s->lookahead--; | |
1784 | continue; | |
1785 | } | |
1786 | ||
d4286ec4 PM |
1787 | /* Find the longest match, discarding those <= prev_length. |
1788 | */ | |
1789 | s->prev_length = s->match_length, s->prev_match = s->match_start; | |
1790 | s->match_length = MIN_MATCH-1; | |
1791 | ||
1792 | if (hash_head != NIL && s->prev_length < s->max_lazy_match && | |
1793 | s->strstart - hash_head <= MAX_DIST(s)) { | |
1794 | /* To simplify the code, we prevent matches with the string | |
1795 | * of window index 0 (in particular we have to avoid a match | |
1796 | * of the string with itself at the start of the input file). | |
1797 | */ | |
f0da8242 WD |
1798 | s->match_length = longest_match (s, hash_head); |
1799 | /* longest_match() sets match_start */ | |
d4286ec4 | 1800 | |
1e1cf689 WD |
1801 | if (s->match_length <= 5 && (s->strategy == Z_FILTERED |
1802 | #if TOO_FAR <= 32767 | |
1803 | || (s->match_length == MIN_MATCH && | |
1804 | s->strstart - s->match_start > TOO_FAR) | |
1805 | #endif | |
1806 | )) { | |
d4286ec4 PM |
1807 | |
1808 | /* If prev_match is also MIN_MATCH, match_start is garbage | |
1809 | * but we will ignore the current match anyway. | |
1810 | */ | |
1811 | s->match_length = MIN_MATCH-1; | |
1812 | } | |
1813 | } | |
1814 | /* If there was a match at the previous step and the current | |
1815 | * match is not better, output the previous match: | |
1816 | */ | |
1817 | if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { | |
1818 | uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; | |
1819 | /* Do not insert strings in hash table beyond this. */ | |
1820 | ||
1821 | check_match(s, s->strstart-1, s->prev_match, s->prev_length); | |
1822 | ||
1823 | _tr_tally_dist(s, s->strstart -1 - s->prev_match, | |
1e1cf689 | 1824 | s->prev_length - MIN_MATCH, bflush); |
d4286ec4 PM |
1825 | |
1826 | /* Insert in hash table all strings up to the end of the match. | |
1827 | * strstart-1 and strstart are already inserted. If there is not | |
1828 | * enough lookahead, the last two strings are not inserted in | |
1829 | * the hash table. | |
1830 | */ | |
1831 | s->lookahead -= s->prev_length-1; | |
1832 | s->prev_length -= 2; | |
1833 | do { | |
1834 | if (++s->strstart <= max_insert) { | |
1835 | INSERT_STRING(s, s->strstart, hash_head); | |
1836 | } | |
1837 | } while (--s->prev_length != 0); | |
1838 | s->match_available = 0; | |
1839 | s->match_length = MIN_MATCH-1; | |
1840 | s->strstart++; | |
1841 | ||
1842 | if (bflush) FLUSH_BLOCK(s, 0); | |
1843 | ||
1844 | } else if (s->match_available) { | |
1845 | /* If there was no match at the previous position, output a | |
1846 | * single literal. If there was a match but the current match | |
1847 | * is longer, truncate the previous match to a single literal. | |
1848 | */ | |
1849 | Tracevv((stderr,"%c", s->window[s->strstart-1])); | |
1e1cf689 WD |
1850 | _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
1851 | if (bflush) { | |
d4286ec4 PM |
1852 | FLUSH_BLOCK_ONLY(s, 0); |
1853 | } | |
1854 | s->strstart++; | |
1855 | s->lookahead--; | |
1856 | if (s->strm->avail_out == 0) return need_more; | |
1857 | } else { | |
1858 | /* There is no previous match to compare with, wait for | |
1859 | * the next step to decide. | |
1860 | */ | |
1861 | s->match_available = 1; | |
1862 | s->strstart++; | |
1863 | s->lookahead--; | |
1864 | } | |
1865 | } | |
5914bf15 PM |
1866 | if (flush == Z_INSERT_ONLY) { |
1867 | s->block_start = s->strstart; | |
1868 | return need_more; | |
1869 | } | |
d4286ec4 PM |
1870 | Assert (flush != Z_NO_FLUSH, "no flush?"); |
1871 | if (s->match_available) { | |
1872 | Tracevv((stderr,"%c", s->window[s->strstart-1])); | |
1873 | _tr_tally_lit(s, s->window[s->strstart-1], bflush); | |
1874 | s->match_available = 0; | |
1875 | } | |
f0da8242 WD |
1876 | s->insert = s->strstart < MIN_MATCH-1 ? s->strstart : MIN_MATCH-1; |
1877 | if (flush == Z_FINISH) { | |
1878 | FLUSH_BLOCK(s, 1); | |
1879 | return finish_done; | |
1880 | } | |
1881 | if (s->last_lit) | |
1882 | FLUSH_BLOCK(s, 0); | |
1883 | return block_done; | |
d4286ec4 | 1884 | } |
1e1cf689 | 1885 | #endif /* FASTEST */ |
cd426074 | 1886 | |
cd426074 WD |
1887 | /* =========================================================================== |
1888 | * For Z_RLE, simply look for runs of bytes, generate matches only of distance | |
1889 | * one. Do not maintain a hash table. (It will be regenerated if this run of | |
1890 | * deflate switches away from Z_RLE.) | |
1891 | */ | |
1892 | local block_state deflate_rle(s, flush) | |
1893 | deflate_state *s; | |
1894 | int flush; | |
1895 | { | |
f0da8242 WD |
1896 | int bflush; /* set if current block must be flushed */ |
1897 | uInt prev; /* byte at distance one to match */ | |
1898 | Bytef *scan, *strend; /* scan goes up to strend for length of run */ | |
cd426074 WD |
1899 | |
1900 | for (;;) { | |
1901 | /* Make sure that we always have enough lookahead, except | |
1902 | * at the end of the input file. We need MAX_MATCH bytes | |
f0da8242 | 1903 | * for the longest run, plus one for the unrolled loop. |
cd426074 | 1904 | */ |
f0da8242 | 1905 | if (s->lookahead <= MAX_MATCH) { |
cd426074 | 1906 | fill_window(s); |
f0da8242 | 1907 | if (s->lookahead <= MAX_MATCH && flush == Z_NO_FLUSH) { |
cd426074 WD |
1908 | return need_more; |
1909 | } | |
1910 | if (s->lookahead == 0) break; /* flush the current block */ | |
1911 | } | |
1912 | ||
1913 | /* See how many times the previous byte repeats */ | |
f0da8242 WD |
1914 | s->match_length = 0; |
1915 | if (s->lookahead >= MIN_MATCH && s->strstart > 0) { | |
cd426074 | 1916 | scan = s->window + s->strstart - 1; |
f0da8242 WD |
1917 | prev = *scan; |
1918 | if (prev == *++scan && prev == *++scan && prev == *++scan) { | |
1919 | strend = s->window + s->strstart + MAX_MATCH; | |
1920 | do { | |
1921 | } while (prev == *++scan && prev == *++scan && | |
1922 | prev == *++scan && prev == *++scan && | |
1923 | prev == *++scan && prev == *++scan && | |
1924 | prev == *++scan && prev == *++scan && | |
1925 | scan < strend); | |
1926 | s->match_length = MAX_MATCH - (int)(strend - scan); | |
1927 | if (s->match_length > s->lookahead) | |
1928 | s->match_length = s->lookahead; | |
1929 | } | |
1930 | Assert(scan <= s->window+(uInt)(s->window_size-1), "wild scan"); | |
cd426074 WD |
1931 | } |
1932 | ||
1933 | /* Emit match if have run of MIN_MATCH or longer, else emit literal */ | |
f0da8242 WD |
1934 | if (s->match_length >= MIN_MATCH) { |
1935 | check_match(s, s->strstart, s->strstart - 1, s->match_length); | |
1936 | ||
1937 | _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush); | |
1938 | ||
1939 | s->lookahead -= s->match_length; | |
1940 | s->strstart += s->match_length; | |
1941 | s->match_length = 0; | |
cd426074 WD |
1942 | } else { |
1943 | /* No match, output a literal byte */ | |
1944 | Tracevv((stderr,"%c", s->window[s->strstart])); | |
1945 | _tr_tally_lit (s, s->window[s->strstart], bflush); | |
1946 | s->lookahead--; | |
1947 | s->strstart++; | |
1948 | } | |
1949 | if (bflush) FLUSH_BLOCK(s, 0); | |
1950 | } | |
f0da8242 WD |
1951 | s->insert = 0; |
1952 | if (flush == Z_FINISH) { | |
1953 | FLUSH_BLOCK(s, 1); | |
1954 | return finish_done; | |
1955 | } | |
1956 | if (s->last_lit) | |
1957 | FLUSH_BLOCK(s, 0); | |
1958 | return block_done; | |
1959 | } | |
1960 | ||
1961 | /* =========================================================================== | |
1962 | * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. | |
1963 | * (It will be regenerated if this run of deflate switches away from Huffman.) | |
1964 | */ | |
1965 | local block_state deflate_huff(s, flush) | |
1966 | deflate_state *s; | |
1967 | int flush; | |
1968 | { | |
1969 | int bflush; /* set if current block must be flushed */ | |
1970 | ||
1971 | for (;;) { | |
1972 | /* Make sure that we have a literal to write. */ | |
1973 | if (s->lookahead == 0) { | |
1974 | fill_window(s); | |
1975 | if (s->lookahead == 0) { | |
1976 | if (flush == Z_NO_FLUSH) | |
1977 | return need_more; | |
1978 | break; /* flush the current block */ | |
1979 | } | |
1980 | } | |
1981 | ||
1982 | /* Output a literal byte */ | |
1983 | s->match_length = 0; | |
1984 | Tracevv((stderr,"%c", s->window[s->strstart])); | |
1985 | _tr_tally_lit (s, s->window[s->strstart], bflush); | |
1986 | s->lookahead--; | |
1987 | s->strstart++; | |
1988 | if (bflush) FLUSH_BLOCK(s, 0); | |
1989 | } | |
1990 | s->insert = 0; | |
1991 | if (flush == Z_FINISH) { | |
1992 | FLUSH_BLOCK(s, 1); | |
1993 | return finish_done; | |
1994 | } | |
1995 | if (s->last_lit) | |
1996 | FLUSH_BLOCK(s, 0); | |
1997 | return block_done; | |
cd426074 | 1998 | } |