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| 1 /* deflate.c -- compress data using the deflation algorithm |
| 2 * Copyright (C) 1995-2010 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://www.ietf.org/rfc/rfc1951.txt |
| 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 <assert.h> |
| 53 |
| 54 #include "deflate.h" |
| 55 #include "x86.h" |
| 56 |
| 57 const char deflate_copyright[] = |
| 58 " deflate 1.2.5 Copyright 1995-2010 Jean-loup Gailly and Mark Adler "; |
| 59 /* |
| 60 If you use the zlib library in a product, an acknowledgment is welcome |
| 61 in the documentation of your product. If for some reason you cannot |
| 62 include such an acknowledgment, I would appreciate that you keep this |
| 63 copyright string in the executable of your product. |
| 64 */ |
| 65 |
| 66 /* =========================================================================== |
| 67 * Function prototypes. |
| 68 */ |
| 69 typedef enum { |
| 70 need_more, /* block not completed, need more input or more output */ |
| 71 block_done, /* block flush performed */ |
| 72 finish_started, /* finish started, need only more output at next deflate */ |
| 73 finish_done /* finish done, accept no more input or output */ |
| 74 } block_state; |
| 75 |
| 76 typedef block_state (*compress_func) OF((deflate_state *s, int flush, |
| 77 int clas)); |
| 78 /* Compression function. Returns the block state after the call. */ |
| 79 |
| 80 local void fill_window OF((deflate_state *s)); |
| 81 local block_state deflate_stored OF((deflate_state *s, int flush, int clas)); |
| 82 local block_state deflate_fast OF((deflate_state *s, int flush, int clas)); |
| 83 #ifndef FASTEST |
| 84 local block_state deflate_slow OF((deflate_state *s, int flush, int clas)); |
| 85 #endif |
| 86 local block_state deflate_rle OF((deflate_state *s, int flush)); |
| 87 local block_state deflate_huff OF((deflate_state *s, int flush)); |
| 88 local void lm_init OF((deflate_state *s)); |
| 89 local void putShortMSB OF((deflate_state *s, uInt b)); |
| 90 local void flush_pending OF((z_streamp strm)); |
| 91 |
| 92 #ifdef ASMV |
| 93 void match_init OF((void)); /* asm code initialization */ |
| 94 uInt longest_match OF((deflate_state *s, IPos cur_match, int clas)); |
| 95 #else |
| 96 local uInt longest_match OF((deflate_state *s, IPos cur_match, int clas)); |
| 97 #endif |
| 98 |
| 99 #ifdef DEBUG |
| 100 local void check_match OF((deflate_state *s, IPos start, IPos match, |
| 101 int length)); |
| 102 #endif |
| 103 |
| 104 /* For fill_window_sse.c to use */ |
| 105 ZLIB_INTERNAL int read_buf OF((z_streamp strm, Bytef *buf, unsigned size)); |
| 106 |
| 107 /* From crc32.c */ |
| 108 extern void ZLIB_INTERNAL crc_reset(deflate_state *const s); |
| 109 extern void ZLIB_INTERNAL crc_finalize(deflate_state *const s); |
| 110 extern void ZLIB_INTERNAL copy_with_crc(z_streamp strm, Bytef *dst, long size); |
| 111 |
| 112 #ifdef _MSC_VER |
| 113 #define INLINE __inline |
| 114 #else |
| 115 #define INLINE inline |
| 116 #endif |
| 117 |
| 118 /* Inline optimisation */ |
| 119 local INLINE Pos insert_string_sse(deflate_state *const s, const Pos str); |
| 120 |
| 121 /* =========================================================================== |
| 122 * Local data |
| 123 */ |
| 124 |
| 125 #define NIL 0 |
| 126 /* Tail of hash chains */ |
| 127 |
| 128 #ifndef TOO_FAR |
| 129 # define TOO_FAR 4096 |
| 130 #endif |
| 131 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ |
| 132 |
| 133 /* Values for max_lazy_match, good_match and max_chain_length, depending on |
| 134 * the desired pack level (0..9). The values given below have been tuned to |
| 135 * exclude worst case performance for pathological files. Better values may be |
| 136 * found for specific files. |
| 137 */ |
| 138 typedef struct config_s { |
| 139 ush good_length; /* reduce lazy search above this match length */ |
| 140 ush max_lazy; /* do not perform lazy search above this match length */ |
| 141 ush nice_length; /* quit search above this match length */ |
| 142 ush max_chain; |
| 143 compress_func func; |
| 144 } config; |
| 145 |
| 146 #ifdef FASTEST |
| 147 local const config configuration_table[2] = { |
| 148 /* good lazy nice chain */ |
| 149 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ |
| 150 /* 1 */ {4, 4, 8, 4, deflate_fast}}; /* max speed, no lazy matches */ |
| 151 #else |
| 152 local const config configuration_table[10] = { |
| 153 /* good lazy nice chain */ |
| 154 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ |
| 155 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* max speed, no lazy matches */ |
| 156 /* 2 */ {4, 5, 16, 8, deflate_fast}, |
| 157 /* 3 */ {4, 6, 32, 32, deflate_fast}, |
| 158 |
| 159 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ |
| 160 /* 5 */ {8, 16, 32, 32, deflate_slow}, |
| 161 /* 6 */ {8, 16, 128, 128, deflate_slow}, |
| 162 /* 7 */ {8, 32, 128, 256, deflate_slow}, |
| 163 /* 8 */ {32, 128, 258, 1024, deflate_slow}, |
| 164 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* max compression */ |
| 165 #endif |
| 166 |
| 167 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 |
| 168 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different |
| 169 * meaning. |
| 170 */ |
| 171 |
| 172 #define EQUAL 0 |
| 173 /* result of memcmp for equal strings */ |
| 174 |
| 175 #ifndef NO_DUMMY_DECL |
| 176 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ |
| 177 #endif |
| 178 |
| 179 /* =========================================================================== |
| 180 * Update a hash value with the given input byte |
| 181 * IN assertion: all calls to to UPDATE_HASH are made with consecutive |
| 182 * input characters, so that a running hash key can be computed from the |
| 183 * previous key instead of complete recalculation each time. |
| 184 */ |
| 185 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) |
| 186 |
| 187 /* =========================================================================== |
| 188 * Insert string str in the dictionary and set match_head to the previous head |
| 189 * of the hash chain (the most recent string with same hash key). Return |
| 190 * the previous length of the hash chain. |
| 191 * If this file is compiled with -DFASTEST, the compression level is forced |
| 192 * to 1, and no hash chains are maintained. |
| 193 * IN assertion: all calls to to INSERT_STRING are made with consecutive |
| 194 * input characters and the first MIN_MATCH bytes of str are valid |
| 195 * (except for the last MIN_MATCH-1 bytes of the input file). |
| 196 */ |
| 197 local INLINE Pos insert_string_c(deflate_state *const s, const Pos str) |
| 198 { |
| 199 Pos ret; |
| 200 |
| 201 UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]); |
| 202 #ifdef FASTEST |
| 203 ret = s->head[s->ins_h]; |
| 204 #else |
| 205 ret = s->prev[str & s->w_mask] = s->head[s->ins_h]; |
| 206 #endif |
| 207 s->head[s->ins_h] = str; |
| 208 |
| 209 return ret; |
| 210 } |
| 211 |
| 212 local INLINE Pos insert_string(deflate_state *const s, const Pos str) |
| 213 { |
| 214 if (x86_cpu_enable_simd) |
| 215 return insert_string_sse(s, str); |
| 216 return insert_string_c(s, str); |
| 217 } |
| 218 |
| 219 |
| 220 /* =========================================================================== |
| 221 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). |
| 222 * prev[] will be initialized on the fly. |
| 223 */ |
| 224 #define CLEAR_HASH(s) \ |
| 225 s->head[s->hash_size-1] = NIL; \ |
| 226 zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); |
| 227 |
| 228 /* ========================================================================= */ |
| 229 int ZEXPORT deflateInit_(strm, level, version, stream_size) |
| 230 z_streamp strm; |
| 231 int level; |
| 232 const char *version; |
| 233 int stream_size; |
| 234 { |
| 235 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, |
| 236 Z_DEFAULT_STRATEGY, version, stream_size); |
| 237 /* To do: ignore strm->next_in if we use it as window */ |
| 238 } |
| 239 |
| 240 /* ========================================================================= */ |
| 241 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy, |
| 242 version, stream_size) |
| 243 z_streamp strm; |
| 244 int level; |
| 245 int method; |
| 246 int windowBits; |
| 247 int memLevel; |
| 248 int strategy; |
| 249 const char *version; |
| 250 int stream_size; |
| 251 { |
| 252 unsigned window_padding = 8; |
| 253 deflate_state *s; |
| 254 int wrap = 1; |
| 255 static const char my_version[] = ZLIB_VERSION; |
| 256 |
| 257 ushf *overlay; |
| 258 /* We overlay pending_buf and d_buf+l_buf. This works since the average |
| 259 * output size for (length,distance) codes is <= 24 bits. |
| 260 */ |
| 261 |
| 262 x86_check_features(); |
| 263 |
| 264 if (version == Z_NULL || version[0] != my_version[0] || |
| 265 stream_size != sizeof(z_stream)) { |
| 266 return Z_VERSION_ERROR; |
| 267 } |
| 268 if (strm == Z_NULL) return Z_STREAM_ERROR; |
| 269 |
| 270 strm->msg = Z_NULL; |
| 271 if (strm->zalloc == (alloc_func)0) { |
| 272 strm->zalloc = zcalloc; |
| 273 strm->opaque = (voidpf)0; |
| 274 } |
| 275 if (strm->zfree == (free_func)0) strm->zfree = zcfree; |
| 276 |
| 277 #ifdef FASTEST |
| 278 if (level != 0) level = 1; |
| 279 #else |
| 280 if (level == Z_DEFAULT_COMPRESSION) level = 6; |
| 281 #endif |
| 282 |
| 283 if (windowBits < 0) { /* suppress zlib wrapper */ |
| 284 wrap = 0; |
| 285 windowBits = -windowBits; |
| 286 } |
| 287 #ifdef GZIP |
| 288 else if (windowBits > 15) { |
| 289 wrap = 2; /* write gzip wrapper instead */ |
| 290 windowBits -= 16; |
| 291 } |
| 292 #endif |
| 293 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || |
| 294 windowBits < 8 || windowBits > 15 || level < 0 || level > 9 || |
| 295 strategy < 0 || strategy > Z_FIXED) { |
| 296 return Z_STREAM_ERROR; |
| 297 } |
| 298 if (windowBits == 8) windowBits = 9; /* until 256-byte window bug fixed */ |
| 299 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); |
| 300 if (s == Z_NULL) return Z_MEM_ERROR; |
| 301 strm->state = (struct internal_state FAR *)s; |
| 302 s->strm = strm; |
| 303 |
| 304 s->wrap = wrap; |
| 305 s->gzhead = Z_NULL; |
| 306 s->w_bits = windowBits; |
| 307 s->w_size = 1 << s->w_bits; |
| 308 s->w_mask = s->w_size - 1; |
| 309 |
| 310 if (x86_cpu_enable_simd) { |
| 311 s->hash_bits = 15; |
| 312 } else { |
| 313 s->hash_bits = memLevel + 7; |
| 314 } |
| 315 |
| 316 s->hash_size = 1 << s->hash_bits; |
| 317 s->hash_mask = s->hash_size - 1; |
| 318 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); |
| 319 |
| 320 s->window = (Bytef *) ZALLOC(strm, s->w_size + window_padding, 2*sizeof(Byte
)); |
| 321 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); |
| 322 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); |
| 323 s->class_bitmap = NULL; |
| 324 zmemzero(&s->cookie_locations, sizeof(s->cookie_locations)); |
| 325 strm->clas = 0; |
| 326 |
| 327 s->high_water = 0; /* nothing written to s->window yet */ |
| 328 |
| 329 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ |
| 330 |
| 331 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); |
| 332 s->pending_buf = (uchf *) overlay; |
| 333 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); |
| 334 |
| 335 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || |
| 336 s->pending_buf == Z_NULL) { |
| 337 s->status = FINISH_STATE; |
| 338 strm->msg = (char*)ERR_MSG(Z_MEM_ERROR); |
| 339 deflateEnd (strm); |
| 340 return Z_MEM_ERROR; |
| 341 } |
| 342 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); |
| 343 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; |
| 344 |
| 345 s->level = level; |
| 346 s->strategy = strategy; |
| 347 s->method = (Byte)method; |
| 348 |
| 349 return deflateReset(strm); |
| 350 } |
| 351 |
| 352 /* ========================================================================= */ |
| 353 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength) |
| 354 z_streamp strm; |
| 355 const Bytef *dictionary; |
| 356 uInt dictLength; |
| 357 { |
| 358 deflate_state *s; |
| 359 uInt length = dictLength; |
| 360 uInt n; |
| 361 IPos hash_head = 0; |
| 362 |
| 363 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL || |
| 364 strm->state->wrap == 2 || |
| 365 (strm->state->wrap == 1 && strm->state->status != INIT_STATE)) |
| 366 return Z_STREAM_ERROR; |
| 367 |
| 368 s = strm->state; |
| 369 if (s->wrap) |
| 370 strm->adler = adler32(strm->adler, dictionary, dictLength); |
| 371 |
| 372 if (length < MIN_MATCH) return Z_OK; |
| 373 if (length > s->w_size) { |
| 374 length = s->w_size; |
| 375 dictionary += dictLength - length; /* use the tail of the dictionary */ |
| 376 } |
| 377 zmemcpy(s->window, dictionary, length); |
| 378 s->strstart = length; |
| 379 s->block_start = (long)length; |
| 380 |
| 381 /* Insert all strings in the hash table (except for the last two bytes). |
| 382 * s->lookahead stays null, so s->ins_h will be recomputed at the next |
| 383 * call of fill_window. |
| 384 */ |
| 385 s->ins_h = s->window[0]; |
| 386 UPDATE_HASH(s, s->ins_h, s->window[1]); |
| 387 for (n = 0; n <= length - MIN_MATCH; n++) { |
| 388 insert_string(s, n); |
| 389 } |
| 390 if (hash_head) hash_head = 0; /* to make compiler happy */ |
| 391 return Z_OK; |
| 392 } |
| 393 |
| 394 /* ========================================================================= */ |
| 395 int ZEXPORT deflateReset (strm) |
| 396 z_streamp strm; |
| 397 { |
| 398 deflate_state *s; |
| 399 |
| 400 if (strm == Z_NULL || strm->state == Z_NULL || |
| 401 strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) { |
| 402 return Z_STREAM_ERROR; |
| 403 } |
| 404 |
| 405 strm->total_in = strm->total_out = 0; |
| 406 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ |
| 407 strm->data_type = Z_UNKNOWN; |
| 408 |
| 409 s = (deflate_state *)strm->state; |
| 410 s->pending = 0; |
| 411 s->pending_out = s->pending_buf; |
| 412 TRY_FREE(strm, s->class_bitmap); |
| 413 s->class_bitmap = NULL; |
| 414 |
| 415 if (s->wrap < 0) { |
| 416 s->wrap = -s->wrap; /* was made negative by deflate(..., Z_FINISH); */ |
| 417 } |
| 418 s->status = s->wrap ? INIT_STATE : BUSY_STATE; |
| 419 strm->adler = |
| 420 #ifdef GZIP |
| 421 s->wrap == 2 ? crc32(0L, Z_NULL, 0) : |
| 422 #endif |
| 423 adler32(0L, Z_NULL, 0); |
| 424 s->last_flush = Z_NO_FLUSH; |
| 425 |
| 426 _tr_init(s); |
| 427 lm_init(s); |
| 428 |
| 429 return Z_OK; |
| 430 } |
| 431 |
| 432 /* ========================================================================= */ |
| 433 int ZEXPORT deflateSetHeader (strm, head) |
| 434 z_streamp strm; |
| 435 gz_headerp head; |
| 436 { |
| 437 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| 438 if (strm->state->wrap != 2) return Z_STREAM_ERROR; |
| 439 strm->state->gzhead = head; |
| 440 return Z_OK; |
| 441 } |
| 442 |
| 443 /* ========================================================================= */ |
| 444 int ZEXPORT deflatePrime (strm, bits, value) |
| 445 z_streamp strm; |
| 446 int bits; |
| 447 int value; |
| 448 { |
| 449 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| 450 strm->state->bi_valid = bits; |
| 451 strm->state->bi_buf = (ush)(value & ((1 << bits) - 1)); |
| 452 return Z_OK; |
| 453 } |
| 454 |
| 455 /* ========================================================================= */ |
| 456 int ZEXPORT deflateParams(strm, level, strategy) |
| 457 z_streamp strm; |
| 458 int level; |
| 459 int strategy; |
| 460 { |
| 461 deflate_state *s; |
| 462 compress_func func; |
| 463 int err = Z_OK; |
| 464 |
| 465 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| 466 s = strm->state; |
| 467 |
| 468 #ifdef FASTEST |
| 469 if (level != 0) level = 1; |
| 470 #else |
| 471 if (level == Z_DEFAULT_COMPRESSION) level = 6; |
| 472 #endif |
| 473 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_FIXED) { |
| 474 return Z_STREAM_ERROR; |
| 475 } |
| 476 func = configuration_table[s->level].func; |
| 477 |
| 478 if ((strategy != s->strategy || func != configuration_table[level].func) && |
| 479 strm->total_in != 0) { |
| 480 /* Flush the last buffer: */ |
| 481 err = deflate(strm, Z_BLOCK); |
| 482 } |
| 483 if (s->level != level) { |
| 484 s->level = level; |
| 485 s->max_lazy_match = configuration_table[level].max_lazy; |
| 486 s->good_match = configuration_table[level].good_length; |
| 487 s->nice_match = configuration_table[level].nice_length; |
| 488 s->max_chain_length = configuration_table[level].max_chain; |
| 489 } |
| 490 s->strategy = strategy; |
| 491 return err; |
| 492 } |
| 493 |
| 494 /* ========================================================================= */ |
| 495 int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain) |
| 496 z_streamp strm; |
| 497 int good_length; |
| 498 int max_lazy; |
| 499 int nice_length; |
| 500 int max_chain; |
| 501 { |
| 502 deflate_state *s; |
| 503 |
| 504 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| 505 s = strm->state; |
| 506 s->good_match = good_length; |
| 507 s->max_lazy_match = max_lazy; |
| 508 s->nice_match = nice_length; |
| 509 s->max_chain_length = max_chain; |
| 510 return Z_OK; |
| 511 } |
| 512 |
| 513 /* ========================================================================= |
| 514 * For the default windowBits of 15 and memLevel of 8, this function returns |
| 515 * a close to exact, as well as small, upper bound on the compressed size. |
| 516 * They are coded as constants here for a reason--if the #define's are |
| 517 * changed, then this function needs to be changed as well. The return |
| 518 * value for 15 and 8 only works for those exact settings. |
| 519 * |
| 520 * For any setting other than those defaults for windowBits and memLevel, |
| 521 * the value returned is a conservative worst case for the maximum expansion |
| 522 * resulting from using fixed blocks instead of stored blocks, which deflate |
| 523 * can emit on compressed data for some combinations of the parameters. |
| 524 * |
| 525 * This function could be more sophisticated to provide closer upper bounds for |
| 526 * every combination of windowBits and memLevel. But even the conservative |
| 527 * upper bound of about 14% expansion does not seem onerous for output buffer |
| 528 * allocation. |
| 529 */ |
| 530 uLong ZEXPORT deflateBound(strm, sourceLen) |
| 531 z_streamp strm; |
| 532 uLong sourceLen; |
| 533 { |
| 534 deflate_state *s; |
| 535 uLong complen, wraplen; |
| 536 Bytef *str; |
| 537 |
| 538 /* conservative upper bound for compressed data */ |
| 539 complen = sourceLen + |
| 540 ((sourceLen + 7) >> 3) + ((sourceLen + 63) >> 6) + 5; |
| 541 |
| 542 /* if can't get parameters, return conservative bound plus zlib wrapper */ |
| 543 if (strm == Z_NULL || strm->state == Z_NULL) |
| 544 return complen + 6; |
| 545 |
| 546 /* compute wrapper length */ |
| 547 s = strm->state; |
| 548 switch (s->wrap) { |
| 549 case 0: /* raw deflate */ |
| 550 wraplen = 0; |
| 551 break; |
| 552 case 1: /* zlib wrapper */ |
| 553 wraplen = 6 + (s->strstart ? 4 : 0); |
| 554 break; |
| 555 case 2: /* gzip wrapper */ |
| 556 wraplen = 18; |
| 557 if (s->gzhead != Z_NULL) { /* user-supplied gzip header */ |
| 558 if (s->gzhead->extra != Z_NULL) |
| 559 wraplen += 2 + s->gzhead->extra_len; |
| 560 str = s->gzhead->name; |
| 561 if (str != Z_NULL) |
| 562 do { |
| 563 wraplen++; |
| 564 } while (*str++); |
| 565 str = s->gzhead->comment; |
| 566 if (str != Z_NULL) |
| 567 do { |
| 568 wraplen++; |
| 569 } while (*str++); |
| 570 if (s->gzhead->hcrc) |
| 571 wraplen += 2; |
| 572 } |
| 573 break; |
| 574 default: /* for compiler happiness */ |
| 575 wraplen = 6; |
| 576 } |
| 577 |
| 578 /* if not default parameters, return conservative bound */ |
| 579 if (s->w_bits != 15 || s->hash_bits != 8 + 7) |
| 580 return complen + wraplen; |
| 581 |
| 582 /* default settings: return tight bound for that case */ |
| 583 return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + |
| 584 (sourceLen >> 25) + 13 - 6 + wraplen; |
| 585 } |
| 586 |
| 587 /* ========================================================================= |
| 588 * Put a short in the pending buffer. The 16-bit value is put in MSB order. |
| 589 * IN assertion: the stream state is correct and there is enough room in |
| 590 * pending_buf. |
| 591 */ |
| 592 local void putShortMSB (s, b) |
| 593 deflate_state *s; |
| 594 uInt b; |
| 595 { |
| 596 put_byte(s, (Byte)(b >> 8)); |
| 597 put_byte(s, (Byte)(b & 0xff)); |
| 598 } |
| 599 |
| 600 /* ========================================================================= |
| 601 * Flush as much pending output as possible. All deflate() output goes |
| 602 * through this function so some applications may wish to modify it |
| 603 * to avoid allocating a large strm->next_out buffer and copying into it. |
| 604 * (See also read_buf()). |
| 605 */ |
| 606 local void flush_pending(strm) |
| 607 z_streamp strm; |
| 608 { |
| 609 unsigned len = strm->state->pending; |
| 610 |
| 611 if (len > strm->avail_out) len = strm->avail_out; |
| 612 if (len == 0) return; |
| 613 |
| 614 zmemcpy(strm->next_out, strm->state->pending_out, len); |
| 615 strm->next_out += len; |
| 616 strm->state->pending_out += len; |
| 617 strm->total_out += len; |
| 618 strm->avail_out -= len; |
| 619 strm->state->pending -= len; |
| 620 if (strm->state->pending == 0) { |
| 621 strm->state->pending_out = strm->state->pending_buf; |
| 622 } |
| 623 } |
| 624 |
| 625 /* ========================================================================= */ |
| 626 int ZEXPORT deflate (strm, flush) |
| 627 z_streamp strm; |
| 628 int flush; |
| 629 { |
| 630 int old_flush; /* value of flush param for previous deflate call */ |
| 631 deflate_state *s; |
| 632 |
| 633 if (strm == Z_NULL || strm->state == Z_NULL || |
| 634 flush > Z_BLOCK || flush < 0) { |
| 635 return Z_STREAM_ERROR; |
| 636 } |
| 637 s = strm->state; |
| 638 |
| 639 if (strm->next_out == Z_NULL || |
| 640 (strm->next_in == Z_NULL && strm->avail_in != 0) || |
| 641 (s->status == FINISH_STATE && flush != Z_FINISH)) { |
| 642 ERR_RETURN(strm, Z_STREAM_ERROR); |
| 643 } |
| 644 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); |
| 645 |
| 646 s->strm = strm; /* just in case */ |
| 647 old_flush = s->last_flush; |
| 648 s->last_flush = flush; |
| 649 |
| 650 /* Write the header */ |
| 651 if (s->status == INIT_STATE) { |
| 652 #ifdef GZIP |
| 653 if (s->wrap == 2) { |
| 654 crc_reset(s); |
| 655 put_byte(s, 31); |
| 656 put_byte(s, 139); |
| 657 put_byte(s, 8); |
| 658 if (s->gzhead == Z_NULL) { |
| 659 put_byte(s, 0); |
| 660 put_byte(s, 0); |
| 661 put_byte(s, 0); |
| 662 put_byte(s, 0); |
| 663 put_byte(s, 0); |
| 664 put_byte(s, s->level == 9 ? 2 : |
| 665 (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? |
| 666 4 : 0)); |
| 667 put_byte(s, OS_CODE); |
| 668 s->status = BUSY_STATE; |
| 669 } |
| 670 else { |
| 671 put_byte(s, (s->gzhead->text ? 1 : 0) + |
| 672 (s->gzhead->hcrc ? 2 : 0) + |
| 673 (s->gzhead->extra == Z_NULL ? 0 : 4) + |
| 674 (s->gzhead->name == Z_NULL ? 0 : 8) + |
| 675 (s->gzhead->comment == Z_NULL ? 0 : 16) |
| 676 ); |
| 677 put_byte(s, (Byte)(s->gzhead->time & 0xff)); |
| 678 put_byte(s, (Byte)((s->gzhead->time >> 8) & 0xff)); |
| 679 put_byte(s, (Byte)((s->gzhead->time >> 16) & 0xff)); |
| 680 put_byte(s, (Byte)((s->gzhead->time >> 24) & 0xff)); |
| 681 put_byte(s, s->level == 9 ? 2 : |
| 682 (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2 ? |
| 683 4 : 0)); |
| 684 put_byte(s, s->gzhead->os & 0xff); |
| 685 if (s->gzhead->extra != Z_NULL) { |
| 686 put_byte(s, s->gzhead->extra_len & 0xff); |
| 687 put_byte(s, (s->gzhead->extra_len >> 8) & 0xff); |
| 688 } |
| 689 if (s->gzhead->hcrc) |
| 690 strm->adler = crc32(strm->adler, s->pending_buf, |
| 691 s->pending); |
| 692 s->gzindex = 0; |
| 693 s->status = EXTRA_STATE; |
| 694 } |
| 695 } |
| 696 else |
| 697 #endif |
| 698 { |
| 699 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; |
| 700 uInt level_flags; |
| 701 |
| 702 if (s->strategy >= Z_HUFFMAN_ONLY || s->level < 2) |
| 703 level_flags = 0; |
| 704 else if (s->level < 6) |
| 705 level_flags = 1; |
| 706 else if (s->level == 6) |
| 707 level_flags = 2; |
| 708 else |
| 709 level_flags = 3; |
| 710 header |= (level_flags << 6); |
| 711 if (s->strstart != 0) header |= PRESET_DICT; |
| 712 header += 31 - (header % 31); |
| 713 |
| 714 s->status = BUSY_STATE; |
| 715 putShortMSB(s, header); |
| 716 |
| 717 /* Save the adler32 of the preset dictionary: */ |
| 718 if (s->strstart != 0) { |
| 719 putShortMSB(s, (uInt)(strm->adler >> 16)); |
| 720 putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
| 721 } |
| 722 strm->adler = adler32(0L, Z_NULL, 0); |
| 723 } |
| 724 } |
| 725 #ifdef GZIP |
| 726 if (s->status == EXTRA_STATE) { |
| 727 if (s->gzhead->extra != Z_NULL) { |
| 728 uInt beg = s->pending; /* start of bytes to update crc */ |
| 729 |
| 730 while (s->gzindex < (s->gzhead->extra_len & 0xffff)) { |
| 731 if (s->pending == s->pending_buf_size) { |
| 732 if (s->gzhead->hcrc && s->pending > beg) |
| 733 strm->adler = crc32(strm->adler, s->pending_buf + beg, |
| 734 s->pending - beg); |
| 735 flush_pending(strm); |
| 736 beg = s->pending; |
| 737 if (s->pending == s->pending_buf_size) |
| 738 break; |
| 739 } |
| 740 put_byte(s, s->gzhead->extra[s->gzindex]); |
| 741 s->gzindex++; |
| 742 } |
| 743 if (s->gzhead->hcrc && s->pending > beg) |
| 744 strm->adler = crc32(strm->adler, s->pending_buf + beg, |
| 745 s->pending - beg); |
| 746 if (s->gzindex == s->gzhead->extra_len) { |
| 747 s->gzindex = 0; |
| 748 s->status = NAME_STATE; |
| 749 } |
| 750 } |
| 751 else |
| 752 s->status = NAME_STATE; |
| 753 } |
| 754 if (s->status == NAME_STATE) { |
| 755 if (s->gzhead->name != Z_NULL) { |
| 756 uInt beg = s->pending; /* start of bytes to update crc */ |
| 757 int val; |
| 758 |
| 759 do { |
| 760 if (s->pending == s->pending_buf_size) { |
| 761 if (s->gzhead->hcrc && s->pending > beg) |
| 762 strm->adler = crc32(strm->adler, s->pending_buf + beg, |
| 763 s->pending - beg); |
| 764 flush_pending(strm); |
| 765 beg = s->pending; |
| 766 if (s->pending == s->pending_buf_size) { |
| 767 val = 1; |
| 768 break; |
| 769 } |
| 770 } |
| 771 val = s->gzhead->name[s->gzindex++]; |
| 772 put_byte(s, val); |
| 773 } while (val != 0); |
| 774 if (s->gzhead->hcrc && s->pending > beg) |
| 775 strm->adler = crc32(strm->adler, s->pending_buf + beg, |
| 776 s->pending - beg); |
| 777 if (val == 0) { |
| 778 s->gzindex = 0; |
| 779 s->status = COMMENT_STATE; |
| 780 } |
| 781 } |
| 782 else |
| 783 s->status = COMMENT_STATE; |
| 784 } |
| 785 if (s->status == COMMENT_STATE) { |
| 786 if (s->gzhead->comment != Z_NULL) { |
| 787 uInt beg = s->pending; /* start of bytes to update crc */ |
| 788 int val; |
| 789 |
| 790 do { |
| 791 if (s->pending == s->pending_buf_size) { |
| 792 if (s->gzhead->hcrc && s->pending > beg) |
| 793 strm->adler = crc32(strm->adler, s->pending_buf + beg, |
| 794 s->pending - beg); |
| 795 flush_pending(strm); |
| 796 beg = s->pending; |
| 797 if (s->pending == s->pending_buf_size) { |
| 798 val = 1; |
| 799 break; |
| 800 } |
| 801 } |
| 802 val = s->gzhead->comment[s->gzindex++]; |
| 803 put_byte(s, val); |
| 804 } while (val != 0); |
| 805 if (s->gzhead->hcrc && s->pending > beg) |
| 806 strm->adler = crc32(strm->adler, s->pending_buf + beg, |
| 807 s->pending - beg); |
| 808 if (val == 0) |
| 809 s->status = HCRC_STATE; |
| 810 } |
| 811 else |
| 812 s->status = HCRC_STATE; |
| 813 } |
| 814 if (s->status == HCRC_STATE) { |
| 815 if (s->gzhead->hcrc) { |
| 816 if (s->pending + 2 > s->pending_buf_size) |
| 817 flush_pending(strm); |
| 818 if (s->pending + 2 <= s->pending_buf_size) { |
| 819 put_byte(s, (Byte)(strm->adler & 0xff)); |
| 820 put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); |
| 821 strm->adler = crc32(0L, Z_NULL, 0); |
| 822 s->status = BUSY_STATE; |
| 823 } |
| 824 } |
| 825 else |
| 826 s->status = BUSY_STATE; |
| 827 } |
| 828 #endif |
| 829 |
| 830 /* Flush as much pending output as possible */ |
| 831 if (s->pending != 0) { |
| 832 flush_pending(strm); |
| 833 if (strm->avail_out == 0) { |
| 834 /* Since avail_out is 0, deflate will be called again with |
| 835 * more output space, but possibly with both pending and |
| 836 * avail_in equal to zero. There won't be anything to do, |
| 837 * but this is not an error situation so make sure we |
| 838 * return OK instead of BUF_ERROR at next call of deflate: |
| 839 */ |
| 840 s->last_flush = -1; |
| 841 return Z_OK; |
| 842 } |
| 843 |
| 844 /* Make sure there is something to do and avoid duplicate consecutive |
| 845 * flushes. For repeated and useless calls with Z_FINISH, we keep |
| 846 * returning Z_STREAM_END instead of Z_BUF_ERROR. |
| 847 */ |
| 848 } else if (strm->avail_in == 0 && flush <= old_flush && |
| 849 flush != Z_FINISH) { |
| 850 ERR_RETURN(strm, Z_BUF_ERROR); |
| 851 } |
| 852 |
| 853 /* User must not provide more input after the first FINISH: */ |
| 854 if (s->status == FINISH_STATE && strm->avail_in != 0) { |
| 855 ERR_RETURN(strm, Z_BUF_ERROR); |
| 856 } |
| 857 |
| 858 /* Start a new block or continue the current one. |
| 859 */ |
| 860 if (strm->avail_in != 0 || s->lookahead != 0 || |
| 861 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { |
| 862 block_state bstate; |
| 863 |
| 864 if (strm->clas && s->class_bitmap == NULL) { |
| 865 /* This is the first time that we have seen alternative class |
| 866 * data. All data up till this point has been standard class. */ |
| 867 s->class_bitmap = (Bytef*) ZALLOC(strm, s->w_size/4, sizeof(Byte)); |
| 868 zmemzero(s->class_bitmap, s->w_size/4); |
| 869 } |
| 870 |
| 871 if (strm->clas && s->strategy == Z_RLE) { |
| 872 /* We haven't patched deflate_rle. */ |
| 873 ERR_RETURN(strm, Z_BUF_ERROR); |
| 874 } |
| 875 |
| 876 if (s->strategy == Z_HUFFMAN_ONLY) { |
| 877 bstate = deflate_huff(s, flush); |
| 878 } else if (s->strategy == Z_RLE) { |
| 879 bstate = deflate_rle(s, flush); |
| 880 } else { |
| 881 bstate = (*(configuration_table[s->level].func)) |
| 882 (s, flush, strm->clas); |
| 883 } |
| 884 |
| 885 if (bstate == finish_started || bstate == finish_done) { |
| 886 s->status = FINISH_STATE; |
| 887 } |
| 888 if (bstate == need_more || bstate == finish_started) { |
| 889 if (strm->avail_out == 0) { |
| 890 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ |
| 891 } |
| 892 return Z_OK; |
| 893 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call |
| 894 * of deflate should use the same flush parameter to make sure |
| 895 * that the flush is complete. So we don't have to output an |
| 896 * empty block here, this will be done at next call. This also |
| 897 * ensures that for a very small output buffer, we emit at most |
| 898 * one empty block. |
| 899 */ |
| 900 } |
| 901 if (bstate == block_done) { |
| 902 if (flush == Z_PARTIAL_FLUSH) { |
| 903 _tr_align(s); |
| 904 } else if (flush != Z_BLOCK) { /* FULL_FLUSH or SYNC_FLUSH */ |
| 905 _tr_stored_block(s, (char*)0, 0L, 0); |
| 906 /* For a full flush, this empty block will be recognized |
| 907 * as a special marker by inflate_sync(). |
| 908 */ |
| 909 if (flush == Z_FULL_FLUSH) { |
| 910 CLEAR_HASH(s); /* forget history */ |
| 911 if (s->lookahead == 0) { |
| 912 s->strstart = 0; |
| 913 s->block_start = 0L; |
| 914 } |
| 915 } |
| 916 } |
| 917 flush_pending(strm); |
| 918 if (strm->avail_out == 0) { |
| 919 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ |
| 920 return Z_OK; |
| 921 } |
| 922 } |
| 923 } |
| 924 Assert(strm->avail_out > 0, "bug2"); |
| 925 |
| 926 if (flush != Z_FINISH) return Z_OK; |
| 927 if (s->wrap <= 0) return Z_STREAM_END; |
| 928 |
| 929 /* Write the trailer */ |
| 930 #ifdef GZIP |
| 931 if (s->wrap == 2) { |
| 932 crc_finalize(s); |
| 933 put_byte(s, (Byte)(strm->adler & 0xff)); |
| 934 put_byte(s, (Byte)((strm->adler >> 8) & 0xff)); |
| 935 put_byte(s, (Byte)((strm->adler >> 16) & 0xff)); |
| 936 put_byte(s, (Byte)((strm->adler >> 24) & 0xff)); |
| 937 put_byte(s, (Byte)(strm->total_in & 0xff)); |
| 938 put_byte(s, (Byte)((strm->total_in >> 8) & 0xff)); |
| 939 put_byte(s, (Byte)((strm->total_in >> 16) & 0xff)); |
| 940 put_byte(s, (Byte)((strm->total_in >> 24) & 0xff)); |
| 941 } |
| 942 else |
| 943 #endif |
| 944 { |
| 945 putShortMSB(s, (uInt)(strm->adler >> 16)); |
| 946 putShortMSB(s, (uInt)(strm->adler & 0xffff)); |
| 947 } |
| 948 flush_pending(strm); |
| 949 /* If avail_out is zero, the application will call deflate again |
| 950 * to flush the rest. |
| 951 */ |
| 952 if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */ |
| 953 return s->pending != 0 ? Z_OK : Z_STREAM_END; |
| 954 } |
| 955 |
| 956 /* ========================================================================= */ |
| 957 int ZEXPORT deflateEnd (strm) |
| 958 z_streamp strm; |
| 959 { |
| 960 int status; |
| 961 |
| 962 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| 963 |
| 964 status = strm->state->status; |
| 965 if (status != INIT_STATE && |
| 966 status != EXTRA_STATE && |
| 967 status != NAME_STATE && |
| 968 status != COMMENT_STATE && |
| 969 status != HCRC_STATE && |
| 970 status != BUSY_STATE && |
| 971 status != FINISH_STATE) { |
| 972 return Z_STREAM_ERROR; |
| 973 } |
| 974 |
| 975 /* Deallocate in reverse order of allocations: */ |
| 976 TRY_FREE(strm, strm->state->pending_buf); |
| 977 TRY_FREE(strm, strm->state->head); |
| 978 TRY_FREE(strm, strm->state->prev); |
| 979 TRY_FREE(strm, strm->state->window); |
| 980 TRY_FREE(strm, strm->state->class_bitmap); |
| 981 |
| 982 ZFREE(strm, strm->state); |
| 983 strm->state = Z_NULL; |
| 984 |
| 985 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; |
| 986 } |
| 987 |
| 988 /* ========================================================================= |
| 989 * Copy the source state to the destination state. |
| 990 * To simplify the source, this is not supported for 16-bit MSDOS (which |
| 991 * doesn't have enough memory anyway to duplicate compression states). |
| 992 */ |
| 993 int ZEXPORT deflateCopy (dest, source) |
| 994 z_streamp dest; |
| 995 z_streamp source; |
| 996 { |
| 997 #ifdef MAXSEG_64K |
| 998 return Z_STREAM_ERROR; |
| 999 #else |
| 1000 deflate_state *ds; |
| 1001 deflate_state *ss; |
| 1002 ushf *overlay; |
| 1003 |
| 1004 |
| 1005 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) { |
| 1006 return Z_STREAM_ERROR; |
| 1007 } |
| 1008 |
| 1009 ss = source->state; |
| 1010 |
| 1011 zmemcpy(dest, source, sizeof(z_stream)); |
| 1012 |
| 1013 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); |
| 1014 if (ds == Z_NULL) return Z_MEM_ERROR; |
| 1015 dest->state = (struct internal_state FAR *) ds; |
| 1016 zmemcpy(ds, ss, sizeof(deflate_state)); |
| 1017 ds->strm = dest; |
| 1018 |
| 1019 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); |
| 1020 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); |
| 1021 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); |
| 1022 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); |
| 1023 ds->pending_buf = (uchf *) overlay; |
| 1024 |
| 1025 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || |
| 1026 ds->pending_buf == Z_NULL) { |
| 1027 deflateEnd (dest); |
| 1028 return Z_MEM_ERROR; |
| 1029 } |
| 1030 /* following zmemcpy do not work for 16-bit MSDOS */ |
| 1031 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); |
| 1032 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); |
| 1033 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); |
| 1034 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); |
| 1035 |
| 1036 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); |
| 1037 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); |
| 1038 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; |
| 1039 |
| 1040 ds->l_desc.dyn_tree = ds->dyn_ltree; |
| 1041 ds->d_desc.dyn_tree = ds->dyn_dtree; |
| 1042 ds->bl_desc.dyn_tree = ds->bl_tree; |
| 1043 |
| 1044 return Z_OK; |
| 1045 #endif /* MAXSEG_64K */ |
| 1046 } |
| 1047 |
| 1048 /* =========================================================================== |
| 1049 * Read a new buffer from the current input stream, update the adler32 |
| 1050 * and total number of bytes read. All deflate() input goes through |
| 1051 * this function so some applications may wish to modify it to avoid |
| 1052 * allocating a large strm->next_in buffer and copying from it. |
| 1053 * (See also flush_pending()). |
| 1054 */ |
| 1055 ZLIB_INTERNAL int read_buf(strm, buf, size) |
| 1056 z_streamp strm; |
| 1057 Bytef *buf; |
| 1058 unsigned size; |
| 1059 { |
| 1060 unsigned len = strm->avail_in; |
| 1061 |
| 1062 if (len > size) len = size; |
| 1063 if (len == 0) return 0; |
| 1064 |
| 1065 strm->avail_in -= len; |
| 1066 |
| 1067 #ifdef GZIP |
| 1068 if (strm->state->wrap == 2) { |
| 1069 copy_with_crc(strm, buf, len); |
| 1070 } |
| 1071 else |
| 1072 #endif |
| 1073 { |
| 1074 zmemcpy(buf, strm->next_in, len); |
| 1075 if (strm->state->wrap == 1) |
| 1076 strm->adler = adler32(strm->adler, buf, len); |
| 1077 } |
| 1078 strm->next_in += len; |
| 1079 strm->total_in += len; |
| 1080 |
| 1081 return (int)len; |
| 1082 } |
| 1083 |
| 1084 /* =========================================================================== |
| 1085 * Initialize the "longest match" routines for a new zlib stream |
| 1086 */ |
| 1087 local void lm_init (s) |
| 1088 deflate_state *s; |
| 1089 { |
| 1090 s->window_size = (ulg)2L*s->w_size; |
| 1091 |
| 1092 CLEAR_HASH(s); |
| 1093 |
| 1094 /* Set the default configuration parameters: |
| 1095 */ |
| 1096 s->max_lazy_match = configuration_table[s->level].max_lazy; |
| 1097 s->good_match = configuration_table[s->level].good_length; |
| 1098 s->nice_match = configuration_table[s->level].nice_length; |
| 1099 s->max_chain_length = configuration_table[s->level].max_chain; |
| 1100 |
| 1101 s->strstart = 0; |
| 1102 s->block_start = 0L; |
| 1103 s->lookahead = 0; |
| 1104 s->match_length = s->prev_length = MIN_MATCH-1; |
| 1105 s->match_available = 0; |
| 1106 s->ins_h = 0; |
| 1107 #ifndef FASTEST |
| 1108 #ifdef ASMV |
| 1109 match_init(); /* initialize the asm code */ |
| 1110 #endif |
| 1111 #endif |
| 1112 } |
| 1113 |
| 1114 /* class_set sets bits [offset,offset+len) in s->class_bitmap to either 1 (if |
| 1115 * class != 0) or 0 (otherwise). */ |
| 1116 local void class_set(s, offset, len, clas) |
| 1117 deflate_state *s; |
| 1118 IPos offset; |
| 1119 uInt len; |
| 1120 int clas; |
| 1121 { |
| 1122 IPos byte = offset >> 3; |
| 1123 IPos bit = offset & 7; |
| 1124 Bytef class_byte_value = clas ? 0xff : 0x00; |
| 1125 Bytef class_bit_value = clas ? 1 : 0; |
| 1126 static const Bytef mask[8] = {0xfe, 0xfd, 0xfb, 0xf7, |
| 1127 0xef, 0xdf, 0xbf, 0x7f}; |
| 1128 |
| 1129 if (bit) { |
| 1130 while (len) { |
| 1131 s->class_bitmap[byte] &= mask[bit]; |
| 1132 s->class_bitmap[byte] |= class_bit_value << bit; |
| 1133 bit++; |
| 1134 len--; |
| 1135 if (bit == 8) { |
| 1136 bit = 0; |
| 1137 byte++; |
| 1138 break; |
| 1139 } |
| 1140 } |
| 1141 } |
| 1142 |
| 1143 while (len >= 8) { |
| 1144 s->class_bitmap[byte++] = class_byte_value; |
| 1145 len -= 8; |
| 1146 } |
| 1147 |
| 1148 while (len) { |
| 1149 s->class_bitmap[byte] &= mask[bit]; |
| 1150 s->class_bitmap[byte] |= class_bit_value << bit; |
| 1151 bit++; |
| 1152 len--; |
| 1153 } |
| 1154 } |
| 1155 |
| 1156 local int class_at(s, window_offset) |
| 1157 deflate_state *s; |
| 1158 IPos window_offset; |
| 1159 { |
| 1160 IPos byte = window_offset >> 3; |
| 1161 IPos bit = window_offset & 7; |
| 1162 return (s->class_bitmap[byte] >> bit) & 1; |
| 1163 } |
| 1164 |
| 1165 #ifndef FASTEST |
| 1166 /* =========================================================================== |
| 1167 * Set match_start to the longest match starting at the given string and |
| 1168 * return its length. Matches shorter or equal to prev_length are discarded, |
| 1169 * in which case the result is equal to prev_length and match_start is |
| 1170 * garbage. |
| 1171 * IN assertions: cur_match is the head of the hash chain for the current |
| 1172 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 |
| 1173 * OUT assertion: the match length is not greater than s->lookahead. |
| 1174 */ |
| 1175 #ifndef ASMV |
| 1176 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or |
| 1177 * match.S. The code will be functionally equivalent. |
| 1178 */ |
| 1179 local uInt longest_match(s, cur_match, clas) |
| 1180 deflate_state *s; |
| 1181 IPos cur_match; /* current match */ |
| 1182 int clas; |
| 1183 { |
| 1184 unsigned chain_length = s->max_chain_length;/* max hash chain length */ |
| 1185 register Bytef *scan = s->window + s->strstart; /* current string */ |
| 1186 register Bytef *match; /* matched string */ |
| 1187 register int len; /* length of current match */ |
| 1188 int best_len = s->prev_length; /* best match length so far */ |
| 1189 int nice_match = s->nice_match; /* stop if match long enough */ |
| 1190 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? |
| 1191 s->strstart - (IPos)MAX_DIST(s) : NIL; |
| 1192 /* Stop when cur_match becomes <= limit. To simplify the code, |
| 1193 * we prevent matches with the string of window index 0. |
| 1194 */ |
| 1195 Posf *prev = s->prev; |
| 1196 uInt wmask = s->w_mask; |
| 1197 |
| 1198 #ifdef UNALIGNED_OK |
| 1199 /* Compare two bytes at a time. Note: this is not always beneficial. |
| 1200 * Try with and without -DUNALIGNED_OK to check. |
| 1201 */ |
| 1202 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; |
| 1203 register ush scan_start = *(ushf*)scan; |
| 1204 register ush scan_end = *(ushf*)(scan+best_len-1); |
| 1205 #else |
| 1206 register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
| 1207 register Byte scan_end1 = scan[best_len-1]; |
| 1208 register Byte scan_end = scan[best_len]; |
| 1209 #endif |
| 1210 |
| 1211 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
| 1212 * It is easy to get rid of this optimization if necessary. |
| 1213 */ |
| 1214 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); |
| 1215 |
| 1216 /* Do not waste too much time if we already have a good match: */ |
| 1217 if (s->prev_length >= s->good_match) { |
| 1218 chain_length >>= 2; |
| 1219 } |
| 1220 /* Do not look for matches beyond the end of the input. This is necessary |
| 1221 * to make deflate deterministic. |
| 1222 */ |
| 1223 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; |
| 1224 |
| 1225 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); |
| 1226 |
| 1227 do { |
| 1228 Assert(cur_match < s->strstart, "no future"); |
| 1229 match = s->window + cur_match; |
| 1230 /* If the matched data is in the wrong class, skip it. */ |
| 1231 if (s->class_bitmap && class_at(s, cur_match) != clas) |
| 1232 continue; |
| 1233 |
| 1234 /* Skip to next match if the match length cannot increase |
| 1235 * or if the match length is less than 2. Note that the checks below |
| 1236 * for insufficient lookahead only occur occasionally for performance |
| 1237 * reasons. Therefore uninitialized memory will be accessed, and |
| 1238 * conditional jumps will be made that depend on those values. |
| 1239 * However the length of the match is limited to the lookahead, so |
| 1240 * the output of deflate is not affected by the uninitialized values. |
| 1241 */ |
| 1242 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) |
| 1243 /* This code assumes sizeof(unsigned short) == 2. Do not use |
| 1244 * UNALIGNED_OK if your compiler uses a different size. |
| 1245 */ |
| 1246 if (*(ushf*)(match+best_len-1) != scan_end || |
| 1247 *(ushf*)match != scan_start) continue; |
| 1248 |
| 1249 /* It is not necessary to compare scan[2] and match[2] since they are |
| 1250 * always equal when the other bytes match, given that the hash keys |
| 1251 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at |
| 1252 * strstart+3, +5, ... up to strstart+257. We check for insufficient |
| 1253 * lookahead only every 4th comparison; the 128th check will be made |
| 1254 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is |
| 1255 * necessary to put more guard bytes at the end of the window, or |
| 1256 * to check more often for insufficient lookahead. |
| 1257 */ |
| 1258 Assert(scan[2] == match[2], "scan[2]?"); |
| 1259 scan++, match++; |
| 1260 do { |
| 1261 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
| 1262 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
| 1263 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
| 1264 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && |
| 1265 scan < strend); |
| 1266 /* The funny "do {}" generates better code on most compilers */ |
| 1267 |
| 1268 /* Here, scan <= window+strstart+257 */ |
| 1269 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
| 1270 if (*scan == *match) scan++; |
| 1271 |
| 1272 len = (MAX_MATCH - 1) - (int)(strend-scan); |
| 1273 scan = strend - (MAX_MATCH-1); |
| 1274 |
| 1275 #error "UNALIGNED_OK hasn't been patched." |
| 1276 |
| 1277 #else /* UNALIGNED_OK */ |
| 1278 |
| 1279 if (match[best_len] != scan_end || |
| 1280 match[best_len-1] != scan_end1 || |
| 1281 *match != *scan || |
| 1282 *++match != scan[1]) continue; |
| 1283 |
| 1284 /* The check at best_len-1 can be removed because it will be made |
| 1285 * again later. (This heuristic is not always a win.) |
| 1286 * It is not necessary to compare scan[2] and match[2] since they |
| 1287 * are always equal when the other bytes match, given that |
| 1288 * the hash keys are equal and that HASH_BITS >= 8. |
| 1289 */ |
| 1290 scan += 2, match++; |
| 1291 Assert(*scan == *match, "match[2]?"); |
| 1292 |
| 1293 if (!s->class_bitmap) { |
| 1294 /* We check for insufficient lookahead only every 8th comparison; |
| 1295 * the 256th check will be made at strstart+258. |
| 1296 */ |
| 1297 do { |
| 1298 } while (*++scan == *++match && *++scan == *++match && |
| 1299 *++scan == *++match && *++scan == *++match && |
| 1300 *++scan == *++match && *++scan == *++match && |
| 1301 *++scan == *++match && *++scan == *++match && |
| 1302 scan < strend); |
| 1303 } else { |
| 1304 /* We have to be mindful of the class of the data and not stray. */ |
| 1305 do { |
| 1306 } while (*++scan == *++match && |
| 1307 class_at(s, match - s->window) == clas && |
| 1308 scan < strend); |
| 1309 } |
| 1310 |
| 1311 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
| 1312 |
| 1313 len = MAX_MATCH - (int)(strend - scan); |
| 1314 scan = strend - MAX_MATCH; |
| 1315 |
| 1316 #endif /* UNALIGNED_OK */ |
| 1317 |
| 1318 if (len > best_len) { |
| 1319 s->match_start = cur_match; |
| 1320 best_len = len; |
| 1321 if (len >= nice_match) break; |
| 1322 #ifdef UNALIGNED_OK |
| 1323 scan_end = *(ushf*)(scan+best_len-1); |
| 1324 #else |
| 1325 scan_end1 = scan[best_len-1]; |
| 1326 scan_end = scan[best_len]; |
| 1327 #endif |
| 1328 } |
| 1329 } while ((cur_match = prev[cur_match & wmask]) > limit |
| 1330 && --chain_length != 0); |
| 1331 |
| 1332 if ((uInt)best_len <= s->lookahead) return (uInt)best_len; |
| 1333 return s->lookahead; |
| 1334 } |
| 1335 #endif /* ASMV */ |
| 1336 |
| 1337 /* cookie_match is a replacement for longest_match in the case of cookie data. |
| 1338 * Here we only wish to match the entire value so trying the partial matches in |
| 1339 * longest_match is both wasteful and often fails to find the correct match. |
| 1340 * |
| 1341 * So we take the djb2 hash of the cookie and look up the last position for a |
| 1342 * match in a special hash table. */ |
| 1343 local uInt cookie_match(s, start, len) |
| 1344 deflate_state *s; |
| 1345 IPos start; |
| 1346 unsigned len; |
| 1347 { |
| 1348 unsigned hash = 5381; |
| 1349 Bytef *str = s->window + start; |
| 1350 unsigned i; |
| 1351 IPos cookie_location; |
| 1352 |
| 1353 if (len >= MAX_MATCH || len == 0) |
| 1354 return 0; |
| 1355 |
| 1356 for (i = 0; i < len; i++) |
| 1357 hash = ((hash << 5) + hash) + str[i]; |
| 1358 |
| 1359 hash &= Z_COOKIE_HASH_MASK; |
| 1360 cookie_location = s->cookie_locations[hash]; |
| 1361 s->cookie_locations[hash] = start; |
| 1362 s->match_start = 0; |
| 1363 if (cookie_location && |
| 1364 (start - cookie_location) > len && |
| 1365 (start - cookie_location) < MAX_DIST(s) && |
| 1366 len <= s->lookahead) { |
| 1367 for (i = 0; i < len; i++) { |
| 1368 if (s->window[start+i] != s->window[cookie_location+i] || |
| 1369 class_at(s, cookie_location+i) != 1) { |
| 1370 return 0; |
| 1371 } |
| 1372 } |
| 1373 /* Check that we aren't matching a prefix of another cookie by ensuring |
| 1374 * that the final byte is either a semicolon (which cannot appear in a |
| 1375 * cookie value), or the match is followed by non-cookie data. */ |
| 1376 if (s->window[cookie_location+len-1] != ';' && |
| 1377 class_at(s, cookie_location+len) != 0) { |
| 1378 return 0; |
| 1379 } |
| 1380 s->match_start = cookie_location; |
| 1381 return len; |
| 1382 } |
| 1383 |
| 1384 return 0; |
| 1385 } |
| 1386 |
| 1387 |
| 1388 #else /* FASTEST */ |
| 1389 |
| 1390 /* --------------------------------------------------------------------------- |
| 1391 * Optimized version for FASTEST only |
| 1392 */ |
| 1393 local uInt longest_match(s, cur_match, clas) |
| 1394 deflate_state *s; |
| 1395 IPos cur_match; /* current match */ |
| 1396 int clas; |
| 1397 { |
| 1398 register Bytef *scan = s->window + s->strstart; /* current string */ |
| 1399 register Bytef *match; /* matched string */ |
| 1400 register int len; /* length of current match */ |
| 1401 register Bytef *strend = s->window + s->strstart + MAX_MATCH; |
| 1402 |
| 1403 #error "This code not patched" |
| 1404 |
| 1405 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. |
| 1406 * It is easy to get rid of this optimization if necessary. |
| 1407 */ |
| 1408 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); |
| 1409 |
| 1410 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); |
| 1411 |
| 1412 Assert(cur_match < s->strstart, "no future"); |
| 1413 |
| 1414 match = s->window + cur_match; |
| 1415 |
| 1416 /* Return failure if the match length is less than 2: |
| 1417 */ |
| 1418 if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1; |
| 1419 |
| 1420 /* The check at best_len-1 can be removed because it will be made |
| 1421 * again later. (This heuristic is not always a win.) |
| 1422 * It is not necessary to compare scan[2] and match[2] since they |
| 1423 * are always equal when the other bytes match, given that |
| 1424 * the hash keys are equal and that HASH_BITS >= 8. |
| 1425 */ |
| 1426 scan += 2, match += 2; |
| 1427 Assert(*scan == *match, "match[2]?"); |
| 1428 |
| 1429 /* We check for insufficient lookahead only every 8th comparison; |
| 1430 * the 256th check will be made at strstart+258. |
| 1431 */ |
| 1432 do { |
| 1433 } while (*++scan == *++match && *++scan == *++match && |
| 1434 *++scan == *++match && *++scan == *++match && |
| 1435 *++scan == *++match && *++scan == *++match && |
| 1436 *++scan == *++match && *++scan == *++match && |
| 1437 scan < strend); |
| 1438 |
| 1439 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); |
| 1440 |
| 1441 len = MAX_MATCH - (int)(strend - scan); |
| 1442 |
| 1443 if (len < MIN_MATCH) return MIN_MATCH - 1; |
| 1444 |
| 1445 s->match_start = cur_match; |
| 1446 return (uInt)len <= s->lookahead ? (uInt)len : s->lookahead; |
| 1447 } |
| 1448 |
| 1449 #endif /* FASTEST */ |
| 1450 |
| 1451 #ifdef DEBUG |
| 1452 /* =========================================================================== |
| 1453 * Check that the match at match_start is indeed a match. |
| 1454 */ |
| 1455 local void check_match(s, start, match, length) |
| 1456 deflate_state *s; |
| 1457 IPos start, match; |
| 1458 int length; |
| 1459 { |
| 1460 /* check that the match is indeed a match */ |
| 1461 if (zmemcmp(s->window + match, |
| 1462 s->window + start, length) != EQUAL) { |
| 1463 fprintf(stderr, " start %u, match %u, length %d\n", |
| 1464 start, match, length); |
| 1465 do { |
| 1466 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); |
| 1467 } while (--length != 0); |
| 1468 z_error("invalid match"); |
| 1469 } |
| 1470 if (z_verbose > 1) { |
| 1471 fprintf(stderr,"\\[%d,%d]", start-match, length); |
| 1472 do { putc(s->window[start++], stderr); } while (--length != 0); |
| 1473 } |
| 1474 } |
| 1475 #else |
| 1476 # define check_match(s, start, match, length) |
| 1477 #endif /* DEBUG */ |
| 1478 |
| 1479 /* =========================================================================== |
| 1480 * Fill the window when the lookahead becomes insufficient. |
| 1481 * Updates strstart and lookahead. |
| 1482 * |
| 1483 * IN assertion: lookahead < MIN_LOOKAHEAD |
| 1484 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD |
| 1485 * At least one byte has been read, or avail_in == 0; reads are |
| 1486 * performed for at least two bytes (required for the zip translate_eol |
| 1487 * option -- not supported here). |
| 1488 */ |
| 1489 local void fill_window_c(deflate_state *s); |
| 1490 |
| 1491 local void fill_window(deflate_state *s) |
| 1492 { |
| 1493 if (x86_cpu_enable_simd) { |
| 1494 fill_window_sse(s); |
| 1495 return; |
| 1496 } |
| 1497 |
| 1498 fill_window_c(s); |
| 1499 } |
| 1500 |
| 1501 local void fill_window_c(s) |
| 1502 deflate_state *s; |
| 1503 { |
| 1504 register unsigned n, m; |
| 1505 register Posf *p; |
| 1506 unsigned more; /* Amount of free space at the end of the window. */ |
| 1507 uInt wsize = s->w_size; |
| 1508 |
| 1509 do { |
| 1510 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); |
| 1511 |
| 1512 /* Deal with !@#$% 64K limit: */ |
| 1513 if (sizeof(int) <= 2) { |
| 1514 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { |
| 1515 more = wsize; |
| 1516 |
| 1517 } else if (more == (unsigned)(-1)) { |
| 1518 /* Very unlikely, but possible on 16 bit machine if |
| 1519 * strstart == 0 && lookahead == 1 (input done a byte at time) |
| 1520 */ |
| 1521 more--; |
| 1522 } |
| 1523 } |
| 1524 |
| 1525 /* If the window is almost full and there is insufficient lookahead, |
| 1526 * move the upper half to the lower one to make room in the upper half. |
| 1527 */ |
| 1528 if (s->strstart >= wsize+MAX_DIST(s)) { |
| 1529 |
| 1530 zmemcpy(s->window, s->window+wsize, (unsigned)wsize); |
| 1531 s->match_start -= wsize; |
| 1532 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ |
| 1533 s->block_start -= (long) wsize; |
| 1534 |
| 1535 /* Slide the hash table (could be avoided with 32 bit values |
| 1536 at the expense of memory usage). We slide even when level == 0 |
| 1537 to keep the hash table consistent if we switch back to level > 0 |
| 1538 later. (Using level 0 permanently is not an optimal usage of |
| 1539 zlib, so we don't care about this pathological case.) |
| 1540 */ |
| 1541 n = s->hash_size; |
| 1542 p = &s->head[n]; |
| 1543 do { |
| 1544 m = *--p; |
| 1545 *p = (Pos)(m >= wsize ? m-wsize : NIL); |
| 1546 } while (--n); |
| 1547 |
| 1548 n = wsize; |
| 1549 #ifndef FASTEST |
| 1550 p = &s->prev[n]; |
| 1551 do { |
| 1552 m = *--p; |
| 1553 *p = (Pos)(m >= wsize ? m-wsize : NIL); |
| 1554 /* If n is not on any hash chain, prev[n] is garbage but |
| 1555 * its value will never be used. |
| 1556 */ |
| 1557 } while (--n); |
| 1558 #endif |
| 1559 |
| 1560 for (n = 0; n < Z_COOKIE_HASH_SIZE; n++) { |
| 1561 if (s->cookie_locations[n] > wsize) { |
| 1562 s->cookie_locations[n] -= wsize; |
| 1563 } else { |
| 1564 s->cookie_locations[n] = 0; |
| 1565 } |
| 1566 } |
| 1567 |
| 1568 if (s->class_bitmap) { |
| 1569 zmemcpy(s->class_bitmap, s->class_bitmap + s->w_size/8, |
| 1570 s->w_size/8); |
| 1571 zmemzero(s->class_bitmap + s->w_size/8, s->w_size/8); |
| 1572 } |
| 1573 |
| 1574 more += wsize; |
| 1575 } |
| 1576 if (s->strm->avail_in == 0) return; |
| 1577 |
| 1578 /* If there was no sliding: |
| 1579 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && |
| 1580 * more == window_size - lookahead - strstart |
| 1581 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) |
| 1582 * => more >= window_size - 2*WSIZE + 2 |
| 1583 * In the BIG_MEM or MMAP case (not yet supported), |
| 1584 * window_size == input_size + MIN_LOOKAHEAD && |
| 1585 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. |
| 1586 * Otherwise, window_size == 2*WSIZE so more >= 2. |
| 1587 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. |
| 1588 */ |
| 1589 Assert(more >= 2, "more < 2"); |
| 1590 |
| 1591 n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more); |
| 1592 if (s->class_bitmap != NULL) { |
| 1593 class_set(s, s->strstart + s->lookahead, n, s->strm->clas); |
| 1594 } |
| 1595 s->lookahead += n; |
| 1596 |
| 1597 /* Initialize the hash value now that we have some input: */ |
| 1598 if (s->lookahead >= MIN_MATCH) { |
| 1599 s->ins_h = s->window[s->strstart]; |
| 1600 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
| 1601 #if MIN_MATCH != 3 |
| 1602 Call UPDATE_HASH() MIN_MATCH-3 more times |
| 1603 #endif |
| 1604 } |
| 1605 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, |
| 1606 * but this is not important since only literal bytes will be emitted. |
| 1607 */ |
| 1608 |
| 1609 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); |
| 1610 |
| 1611 /* If the WIN_INIT bytes after the end of the current data have never been |
| 1612 * written, then zero those bytes in order to avoid memory check reports of |
| 1613 * the use of uninitialized (or uninitialised as Julian writes) bytes by |
| 1614 * the longest match routines. Update the high water mark for the next |
| 1615 * time through here. WIN_INIT is set to MAX_MATCH since the longest match |
| 1616 * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead. |
| 1617 */ |
| 1618 if (s->high_water < s->window_size) { |
| 1619 ulg curr = s->strstart + (ulg)(s->lookahead); |
| 1620 ulg init; |
| 1621 |
| 1622 if (s->high_water < curr) { |
| 1623 /* Previous high water mark below current data -- zero WIN_INIT |
| 1624 * bytes or up to end of window, whichever is less. |
| 1625 */ |
| 1626 init = s->window_size - curr; |
| 1627 if (init > WIN_INIT) |
| 1628 init = WIN_INIT; |
| 1629 zmemzero(s->window + curr, (unsigned)init); |
| 1630 s->high_water = curr + init; |
| 1631 } |
| 1632 else if (s->high_water < (ulg)curr + WIN_INIT) { |
| 1633 /* High water mark at or above current data, but below current data |
| 1634 * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up |
| 1635 * to end of window, whichever is less. |
| 1636 */ |
| 1637 init = (ulg)curr + WIN_INIT - s->high_water; |
| 1638 if (init > s->window_size - s->high_water) |
| 1639 init = s->window_size - s->high_water; |
| 1640 zmemzero(s->window + s->high_water, (unsigned)init); |
| 1641 s->high_water += init; |
| 1642 } |
| 1643 } |
| 1644 } |
| 1645 |
| 1646 /* =========================================================================== |
| 1647 * Flush the current block, with given end-of-file flag. |
| 1648 * IN assertion: strstart is set to the end of the current match. |
| 1649 */ |
| 1650 #define FLUSH_BLOCK_ONLY(s, last) { \ |
| 1651 _tr_flush_block(s, (s->block_start >= 0L ? \ |
| 1652 (charf *)&s->window[(unsigned)s->block_start] : \ |
| 1653 (charf *)Z_NULL), \ |
| 1654 (ulg)((long)s->strstart - s->block_start), \ |
| 1655 (last)); \ |
| 1656 s->block_start = s->strstart; \ |
| 1657 flush_pending(s->strm); \ |
| 1658 Tracev((stderr,"[FLUSH]")); \ |
| 1659 } |
| 1660 |
| 1661 /* Same but force premature exit if necessary. */ |
| 1662 #define FLUSH_BLOCK(s, last) { \ |
| 1663 FLUSH_BLOCK_ONLY(s, last); \ |
| 1664 if (s->strm->avail_out == 0) return (last) ? finish_started : need_more; \ |
| 1665 } |
| 1666 |
| 1667 /* =========================================================================== |
| 1668 * Copy without compression as much as possible from the input stream, return |
| 1669 * the current block state. |
| 1670 * This function does not insert new strings in the dictionary since |
| 1671 * uncompressible data is probably not useful. This function is used |
| 1672 * only for the level=0 compression option. |
| 1673 * NOTE: this function should be optimized to avoid extra copying from |
| 1674 * window to pending_buf. |
| 1675 */ |
| 1676 local block_state deflate_stored(s, flush, clas) |
| 1677 deflate_state *s; |
| 1678 int flush; |
| 1679 int clas; |
| 1680 { |
| 1681 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited |
| 1682 * to pending_buf_size, and each stored block has a 5 byte header: |
| 1683 */ |
| 1684 ulg max_block_size = 0xffff; |
| 1685 ulg max_start; |
| 1686 |
| 1687 if (max_block_size > s->pending_buf_size - 5) { |
| 1688 max_block_size = s->pending_buf_size - 5; |
| 1689 } |
| 1690 |
| 1691 /* Copy as much as possible from input to output: */ |
| 1692 for (;;) { |
| 1693 /* Fill the window as much as possible: */ |
| 1694 if (s->lookahead <= 1) { |
| 1695 |
| 1696 Assert(s->strstart < s->w_size+MAX_DIST(s) || |
| 1697 s->block_start >= (long)s->w_size, "slide too late"); |
| 1698 |
| 1699 fill_window(s); |
| 1700 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; |
| 1701 |
| 1702 if (s->lookahead == 0) break; /* flush the current block */ |
| 1703 } |
| 1704 Assert(s->block_start >= 0L, "block gone"); |
| 1705 |
| 1706 s->strstart += s->lookahead; |
| 1707 s->lookahead = 0; |
| 1708 |
| 1709 /* Emit a stored block if pending_buf will be full: */ |
| 1710 max_start = s->block_start + max_block_size; |
| 1711 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { |
| 1712 /* strstart == 0 is possible when wraparound on 16-bit machine */ |
| 1713 s->lookahead = (uInt)(s->strstart - max_start); |
| 1714 s->strstart = (uInt)max_start; |
| 1715 FLUSH_BLOCK(s, 0); |
| 1716 } |
| 1717 /* Flush if we may have to slide, otherwise block_start may become |
| 1718 * negative and the data will be gone: |
| 1719 */ |
| 1720 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { |
| 1721 FLUSH_BLOCK(s, 0); |
| 1722 } |
| 1723 } |
| 1724 FLUSH_BLOCK(s, flush == Z_FINISH); |
| 1725 return flush == Z_FINISH ? finish_done : block_done; |
| 1726 } |
| 1727 |
| 1728 /* =========================================================================== |
| 1729 * Compress as much as possible from the input stream, return the current |
| 1730 * block state. |
| 1731 * This function does not perform lazy evaluation of matches and inserts |
| 1732 * new strings in the dictionary only for unmatched strings or for short |
| 1733 * matches. It is used only for the fast compression options. |
| 1734 */ |
| 1735 local block_state deflate_fast(s, flush, clas) |
| 1736 deflate_state *s; |
| 1737 int flush; |
| 1738 int clas; |
| 1739 { |
| 1740 IPos hash_head; /* head of the hash chain */ |
| 1741 int bflush; /* set if current block must be flushed */ |
| 1742 |
| 1743 if (clas != 0) { |
| 1744 /* We haven't patched this code for alternative class data. */ |
| 1745 return Z_BUF_ERROR; |
| 1746 } |
| 1747 |
| 1748 for (;;) { |
| 1749 /* Make sure that we always have enough lookahead, except |
| 1750 * at the end of the input file. We need MAX_MATCH bytes |
| 1751 * for the next match, plus MIN_MATCH bytes to insert the |
| 1752 * string following the next match. |
| 1753 */ |
| 1754 if (s->lookahead < MIN_LOOKAHEAD) { |
| 1755 fill_window(s); |
| 1756 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
| 1757 return need_more; |
| 1758 } |
| 1759 if (s->lookahead == 0) break; /* flush the current block */ |
| 1760 } |
| 1761 |
| 1762 /* Insert the string window[strstart .. strstart+2] in the |
| 1763 * dictionary, and set hash_head to the head of the hash chain: |
| 1764 */ |
| 1765 hash_head = NIL; |
| 1766 if (s->lookahead >= MIN_MATCH) { |
| 1767 hash_head = insert_string(s, s->strstart); |
| 1768 } |
| 1769 |
| 1770 /* Find the longest match, discarding those <= prev_length. |
| 1771 * At this point we have always match_length < MIN_MATCH |
| 1772 */ |
| 1773 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { |
| 1774 /* To simplify the code, we prevent matches with the string |
| 1775 * of window index 0 (in particular we have to avoid a match |
| 1776 * of the string with itself at the start of the input file). |
| 1777 */ |
| 1778 s->match_length = longest_match (s, hash_head, clas); |
| 1779 /* longest_match() sets match_start */ |
| 1780 } |
| 1781 if (s->match_length >= MIN_MATCH) { |
| 1782 check_match(s, s->strstart, s->match_start, s->match_length); |
| 1783 |
| 1784 _tr_tally_dist(s, s->strstart - s->match_start, |
| 1785 s->match_length - MIN_MATCH, bflush); |
| 1786 |
| 1787 s->lookahead -= s->match_length; |
| 1788 |
| 1789 /* Insert new strings in the hash table only if the match length |
| 1790 * is not too large. This saves time but degrades compression. |
| 1791 */ |
| 1792 #ifndef FASTEST |
| 1793 if (s->match_length <= s->max_insert_length && |
| 1794 s->lookahead >= MIN_MATCH) { |
| 1795 s->match_length--; /* string at strstart already in table */ |
| 1796 do { |
| 1797 s->strstart++; |
| 1798 hash_head = insert_string(s, s->strstart); |
| 1799 /* strstart never exceeds WSIZE-MAX_MATCH, so there are |
| 1800 * always MIN_MATCH bytes ahead. |
| 1801 */ |
| 1802 } while (--s->match_length != 0); |
| 1803 s->strstart++; |
| 1804 } else |
| 1805 #endif |
| 1806 { |
| 1807 s->strstart += s->match_length; |
| 1808 s->match_length = 0; |
| 1809 s->ins_h = s->window[s->strstart]; |
| 1810 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); |
| 1811 #if MIN_MATCH != 3 |
| 1812 Call UPDATE_HASH() MIN_MATCH-3 more times |
| 1813 #endif |
| 1814 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not |
| 1815 * matter since it will be recomputed at next deflate call. |
| 1816 */ |
| 1817 } |
| 1818 } else { |
| 1819 /* No match, output a literal byte */ |
| 1820 Tracevv((stderr,"%c", s->window[s->strstart])); |
| 1821 _tr_tally_lit (s, s->window[s->strstart], bflush); |
| 1822 s->lookahead--; |
| 1823 s->strstart++; |
| 1824 } |
| 1825 if (bflush) FLUSH_BLOCK(s, 0); |
| 1826 } |
| 1827 FLUSH_BLOCK(s, flush == Z_FINISH); |
| 1828 return flush == Z_FINISH ? finish_done : block_done; |
| 1829 } |
| 1830 |
| 1831 #ifndef FASTEST |
| 1832 /* =========================================================================== |
| 1833 * Same as above, but achieves better compression. We use a lazy |
| 1834 * evaluation for matches: a match is finally adopted only if there is |
| 1835 * no better match at the next window position. |
| 1836 */ |
| 1837 local block_state deflate_slow(s, flush, clas) |
| 1838 deflate_state *s; |
| 1839 int flush; |
| 1840 int clas; |
| 1841 { |
| 1842 IPos hash_head; /* head of hash chain */ |
| 1843 int bflush; /* set if current block must be flushed */ |
| 1844 uInt input_length ; |
| 1845 int first = 1; /* first says whether this is the first iteration |
| 1846 of the loop, below. */ |
| 1847 |
| 1848 if (clas == Z_CLASS_COOKIE) { |
| 1849 if (s->lookahead) { |
| 1850 /* Alternative class data must always be presented at the beginning |
| 1851 * of a block. */ |
| 1852 return Z_BUF_ERROR; |
| 1853 } |
| 1854 input_length = s->strm->avail_in; |
| 1855 } |
| 1856 |
| 1857 /* Process the input block. */ |
| 1858 for (;;) { |
| 1859 /* Make sure that we always have enough lookahead, except |
| 1860 * at the end of the input file. We need MAX_MATCH bytes |
| 1861 * for the next match, plus MIN_MATCH bytes to insert the |
| 1862 * string following the next match. |
| 1863 */ |
| 1864 if (s->lookahead < MIN_LOOKAHEAD) { |
| 1865 fill_window(s); |
| 1866 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { |
| 1867 return need_more; |
| 1868 } |
| 1869 if (s->lookahead == 0) break; /* flush the current block */ |
| 1870 } |
| 1871 |
| 1872 /* Insert the string window[strstart .. strstart+2] in the |
| 1873 * dictionary, and set hash_head to the head of the hash chain: |
| 1874 */ |
| 1875 hash_head = NIL; |
| 1876 if (s->lookahead >= MIN_MATCH) { |
| 1877 hash_head = insert_string(s, s->strstart); |
| 1878 } |
| 1879 |
| 1880 /* Find the longest match, discarding those <= prev_length. |
| 1881 */ |
| 1882 s->prev_length = s->match_length, s->prev_match = s->match_start; |
| 1883 s->match_length = MIN_MATCH-1; |
| 1884 |
| 1885 if (clas == Z_CLASS_COOKIE && first) { |
| 1886 s->match_length = cookie_match(s, s->strstart, input_length); |
| 1887 } else if (clas == Z_CLASS_STANDARD && |
| 1888 hash_head != NIL && |
| 1889 s->prev_length < s->max_lazy_match && |
| 1890 s->strstart - hash_head <= MAX_DIST(s)) { |
| 1891 /* To simplify the code, we prevent matches with the string |
| 1892 * of window index 0 (in particular we have to avoid a match |
| 1893 * of the string with itself at the start of the input file). |
| 1894 */ |
| 1895 s->match_length = longest_match (s, hash_head, clas); |
| 1896 |
| 1897 /* longest_match() sets match_start */ |
| 1898 |
| 1899 if (s->match_length <= 5 && (s->strategy == Z_FILTERED |
| 1900 #if TOO_FAR <= 32767 |
| 1901 || (s->match_length == MIN_MATCH && |
| 1902 s->strstart - s->match_start > TOO_FAR) |
| 1903 #endif |
| 1904 )) { |
| 1905 |
| 1906 /* If prev_match is also MIN_MATCH, match_start is garbage |
| 1907 * but we will ignore the current match anyway. |
| 1908 */ |
| 1909 s->match_length = MIN_MATCH-1; |
| 1910 } |
| 1911 } |
| 1912 /* If there was a match at the previous step and the current |
| 1913 * match is not better, output the previous match: |
| 1914 */ |
| 1915 first = 0; |
| 1916 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length && |
| 1917 /* We will only accept an exact match for Z_CLASS_COOKIE data and |
| 1918 * we won't match Z_CLASS_HUFFMAN_ONLY data at all. */ |
| 1919 (clas == Z_CLASS_STANDARD || (clas == Z_CLASS_COOKIE && |
| 1920 s->prev_length == input_length && |
| 1921 s->prev_match > 0 && |
| 1922 /* We require that a Z_CLASS_COOKIE match be |
| 1923 * preceded by either a semicolon (which cannot be |
| 1924 * part of a cookie), or non-cookie data. This is |
| 1925 * to prevent a cookie from being a suffix of |
| 1926 * another. */ |
| 1927 (class_at(s, s->prev_match-1) == Z_CLASS_STANDARD || |
| 1928 *(s->window + s->prev_match-1) == ';')))) { |
| 1929 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; |
| 1930 /* Do not insert strings in hash table beyond this. */ |
| 1931 |
| 1932 check_match(s, s->strstart-1, s->prev_match, s->prev_length); |
| 1933 |
| 1934 _tr_tally_dist(s, s->strstart -1 - s->prev_match, |
| 1935 s->prev_length - MIN_MATCH, bflush); |
| 1936 |
| 1937 /* Insert in hash table all strings up to the end of the match. |
| 1938 * strstart-1 and strstart are already inserted. If there is not |
| 1939 * enough lookahead, the last two strings are not inserted in |
| 1940 * the hash table. |
| 1941 */ |
| 1942 s->lookahead -= s->prev_length-1; |
| 1943 s->prev_length -= 2; |
| 1944 do { |
| 1945 if (++s->strstart <= max_insert) { |
| 1946 hash_head = insert_string(s, s->strstart); |
| 1947 } |
| 1948 } while (--s->prev_length != 0); |
| 1949 s->match_available = 0; |
| 1950 s->match_length = MIN_MATCH-1; |
| 1951 s->strstart++; |
| 1952 |
| 1953 if (bflush) FLUSH_BLOCK(s, 0); |
| 1954 |
| 1955 } else if (s->match_available) { |
| 1956 /* If there was no match at the previous position, output a |
| 1957 * single literal. If there was a match but the current match |
| 1958 * is longer, truncate the previous match to a single literal. |
| 1959 */ |
| 1960 Tracevv((stderr,"%c", s->window[s->strstart-1])); |
| 1961 _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
| 1962 if (bflush) { |
| 1963 FLUSH_BLOCK_ONLY(s, 0); |
| 1964 } |
| 1965 s->strstart++; |
| 1966 s->lookahead--; |
| 1967 if (s->strm->avail_out == 0) return need_more; |
| 1968 } else { |
| 1969 /* There is no previous match to compare with, wait for |
| 1970 * the next step to decide. |
| 1971 */ |
| 1972 s->match_available = 1; |
| 1973 s->strstart++; |
| 1974 s->lookahead--; |
| 1975 } |
| 1976 } |
| 1977 Assert (flush != Z_NO_FLUSH, "no flush?"); |
| 1978 if (s->match_available) { |
| 1979 Tracevv((stderr,"%c", s->window[s->strstart-1])); |
| 1980 _tr_tally_lit(s, s->window[s->strstart-1], bflush); |
| 1981 s->match_available = 0; |
| 1982 } |
| 1983 FLUSH_BLOCK(s, flush == Z_FINISH); |
| 1984 return flush == Z_FINISH ? finish_done : block_done; |
| 1985 } |
| 1986 #endif /* FASTEST */ |
| 1987 |
| 1988 /* =========================================================================== |
| 1989 * For Z_RLE, simply look for runs of bytes, generate matches only of distance |
| 1990 * one. Do not maintain a hash table. (It will be regenerated if this run of |
| 1991 * deflate switches away from Z_RLE.) |
| 1992 */ |
| 1993 local block_state deflate_rle(s, flush) |
| 1994 deflate_state *s; |
| 1995 int flush; |
| 1996 { |
| 1997 int bflush; /* set if current block must be flushed */ |
| 1998 uInt prev; /* byte at distance one to match */ |
| 1999 Bytef *scan, *strend; /* scan goes up to strend for length of run */ |
| 2000 |
| 2001 for (;;) { |
| 2002 /* Make sure that we always have enough lookahead, except |
| 2003 * at the end of the input file. We need MAX_MATCH bytes |
| 2004 * for the longest encodable run. |
| 2005 */ |
| 2006 if (s->lookahead < MAX_MATCH) { |
| 2007 fill_window(s); |
| 2008 if (s->lookahead < MAX_MATCH && flush == Z_NO_FLUSH) { |
| 2009 return need_more; |
| 2010 } |
| 2011 if (s->lookahead == 0) break; /* flush the current block */ |
| 2012 } |
| 2013 |
| 2014 /* See how many times the previous byte repeats */ |
| 2015 s->match_length = 0; |
| 2016 if (s->lookahead >= MIN_MATCH && s->strstart > 0) { |
| 2017 scan = s->window + s->strstart - 1; |
| 2018 prev = *scan; |
| 2019 if (prev == *++scan && prev == *++scan && prev == *++scan) { |
| 2020 strend = s->window + s->strstart + MAX_MATCH; |
| 2021 do { |
| 2022 } while (prev == *++scan && prev == *++scan && |
| 2023 prev == *++scan && prev == *++scan && |
| 2024 prev == *++scan && prev == *++scan && |
| 2025 prev == *++scan && prev == *++scan && |
| 2026 scan < strend); |
| 2027 s->match_length = MAX_MATCH - (int)(strend - scan); |
| 2028 if (s->match_length > s->lookahead) |
| 2029 s->match_length = s->lookahead; |
| 2030 } |
| 2031 } |
| 2032 |
| 2033 /* Emit match if have run of MIN_MATCH or longer, else emit literal */ |
| 2034 if (s->match_length >= MIN_MATCH) { |
| 2035 check_match(s, s->strstart, s->strstart - 1, s->match_length); |
| 2036 |
| 2037 _tr_tally_dist(s, 1, s->match_length - MIN_MATCH, bflush); |
| 2038 |
| 2039 s->lookahead -= s->match_length; |
| 2040 s->strstart += s->match_length; |
| 2041 s->match_length = 0; |
| 2042 } else { |
| 2043 /* No match, output a literal byte */ |
| 2044 Tracevv((stderr,"%c", s->window[s->strstart])); |
| 2045 _tr_tally_lit (s, s->window[s->strstart], bflush); |
| 2046 s->lookahead--; |
| 2047 s->strstart++; |
| 2048 } |
| 2049 if (bflush) FLUSH_BLOCK(s, 0); |
| 2050 } |
| 2051 FLUSH_BLOCK(s, flush == Z_FINISH); |
| 2052 return flush == Z_FINISH ? finish_done : block_done; |
| 2053 } |
| 2054 |
| 2055 /* =========================================================================== |
| 2056 * For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table. |
| 2057 * (It will be regenerated if this run of deflate switches away from Huffman.) |
| 2058 */ |
| 2059 local block_state deflate_huff(s, flush) |
| 2060 deflate_state *s; |
| 2061 int flush; |
| 2062 { |
| 2063 int bflush; /* set if current block must be flushed */ |
| 2064 |
| 2065 for (;;) { |
| 2066 /* Make sure that we have a literal to write. */ |
| 2067 if (s->lookahead == 0) { |
| 2068 fill_window(s); |
| 2069 if (s->lookahead == 0) { |
| 2070 if (flush == Z_NO_FLUSH) |
| 2071 return need_more; |
| 2072 break; /* flush the current block */ |
| 2073 } |
| 2074 } |
| 2075 |
| 2076 /* Output a literal byte */ |
| 2077 s->match_length = 0; |
| 2078 Tracevv((stderr,"%c", s->window[s->strstart])); |
| 2079 _tr_tally_lit (s, s->window[s->strstart], bflush); |
| 2080 s->lookahead--; |
| 2081 s->strstart++; |
| 2082 if (bflush) FLUSH_BLOCK(s, 0); |
| 2083 } |
| 2084 FLUSH_BLOCK(s, flush == Z_FINISH); |
| 2085 return flush == Z_FINISH ? finish_done : block_done; |
| 2086 } |
| 2087 |
| 2088 /* Safe to inline this as GCC/clang will use inline asm and Visual Studio will |
| 2089 * use intrinsic without extra params |
| 2090 */ |
| 2091 local INLINE Pos insert_string_sse(deflate_state *const s, const Pos str) |
| 2092 { |
| 2093 Pos ret; |
| 2094 unsigned *ip, val, h = 0; |
| 2095 |
| 2096 ip = (unsigned *)&s->window[str]; |
| 2097 val = *ip; |
| 2098 |
| 2099 if (s->level >= 6) |
| 2100 val &= 0xFFFFFF; |
| 2101 |
| 2102 /* Windows clang should use inline asm */ |
| 2103 #if defined(_MSC_VER) && !defined(__clang__) |
| 2104 h = _mm_crc32_u32(h, val); |
| 2105 #elif defined(__i386__) || defined(__amd64__) |
| 2106 __asm__ __volatile__ ( |
| 2107 "crc32 %1,%0\n\t" |
| 2108 : "+r" (h) |
| 2109 : "r" (val) |
| 2110 ); |
| 2111 #else |
| 2112 /* This should never happen */ |
| 2113 assert(0); |
| 2114 #endif |
| 2115 |
| 2116 ret = s->head[h & s->hash_mask]; |
| 2117 s->head[h & s->hash_mask] = str; |
| 2118 s->prev[str & s->w_mask] = ret; |
| 2119 return ret; |
| 2120 } |
OLD | NEW |