1 /* $NetBSD: zlib.c,v 1.3 1996/09/18 03:11:03 scottr Exp $ */ 2 3 /* 4 * This file is derived from various .h and .c files from the zlib-0.95 5 * distribution by Jean-loup Gailly and Mark Adler, with some additions 6 * by Paul Mackerras to aid in implementing Deflate compression and 7 * decompression for PPP packets. See zlib.h for conditions of 8 * distribution and use. 9 * 10 * Changes that have been made include: 11 * - changed functions not used outside this file to "local" 12 * - added minCompression parameter to deflateInit2 13 * - added Z_PACKET_FLUSH (see zlib.h for details) 14 * - added inflateIncomp 15 */ 16 17 18 /*+++++*/ 19 /* zutil.h -- internal interface and configuration of the compression library 20 * Copyright (C) 1995 Jean-loup Gailly. 21 * For conditions of distribution and use, see copyright notice in zlib.h 22 */ 23 24 /* WARNING: this file should *not* be used by applications. It is 25 part of the implementation of the compression library and is 26 subject to change. Applications should only use zlib.h. 27 */ 28 29 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */ 30 31 #define _Z_UTIL_H 32 33 #include "zlib.h" 34 35 #ifndef __NetBSD__ 36 # ifdef STDC 37 # include <string.h> 38 # endif 39 #endif 40 41 #ifndef local 42 # define local static 43 #endif 44 /* compile with -Dlocal if your debugger can't find static symbols */ 45 46 #define FAR 47 48 typedef unsigned char uch; 49 typedef uch FAR uchf; 50 typedef unsigned short ush; 51 typedef ush FAR ushf; 52 typedef unsigned long ulg; 53 54 extern char *z_errmsg[]; /* indexed by 1-zlib_error */ 55 56 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err) 57 /* To be used only when the state is known to be valid */ 58 59 #ifndef NULL 60 #define NULL ((void *) 0) 61 #endif 62 63 /* common constants */ 64 65 #define DEFLATED 8 66 67 #ifndef DEF_WBITS 68 # define DEF_WBITS MAX_WBITS 69 #endif 70 /* default windowBits for decompression. MAX_WBITS is for compression only */ 71 72 #if MAX_MEM_LEVEL >= 8 73 # define DEF_MEM_LEVEL 8 74 #else 75 # define DEF_MEM_LEVEL MAX_MEM_LEVEL 76 #endif 77 /* default memLevel */ 78 79 #define STORED_BLOCK 0 80 #define STATIC_TREES 1 81 #define DYN_TREES 2 82 /* The three kinds of block type */ 83 84 #define MIN_MATCH 3 85 #define MAX_MATCH 258 86 /* The minimum and maximum match lengths */ 87 88 /* functions */ 89 90 #if defined(KERNEL) || defined(_KERNEL) 91 # ifdef __NetBSD__ 92 # include <sys/types.h> 93 # include <sys/systm.h> 94 # endif 95 # define zmemcpy(d, s, n) bcopy((s), (d), (n)) 96 # define zmemzero bzero 97 #else 98 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 99 # define HAVE_MEMCPY 100 #endif 101 #ifdef HAVE_MEMCPY 102 # define zmemcpy memcpy 103 # define zmemzero(dest, len) memset(dest, 0, len) 104 #else 105 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); 106 extern void zmemzero OF((Bytef* dest, uInt len)); 107 #endif 108 #endif 109 110 /* Diagnostic functions */ 111 #ifdef DEBUG_ZLIB 112 # include <stdio.h> 113 # ifndef verbose 114 # define verbose 0 115 # endif 116 # define Assert(cond,msg) {if(!(cond)) z_error(msg);} 117 # define Trace(x) fprintf x 118 # define Tracev(x) {if (verbose) fprintf x ;} 119 # define Tracevv(x) {if (verbose>1) fprintf x ;} 120 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 121 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 122 #else 123 # define Assert(cond,msg) 124 # define Trace(x) 125 # define Tracev(x) 126 # define Tracevv(x) 127 # define Tracec(c,x) 128 # define Tracecv(c,x) 129 #endif 130 131 132 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len)); 133 134 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */ 135 /* void zcfree OF((voidpf opaque, voidpf ptr)); */ 136 137 #define ZALLOC(strm, items, size) \ 138 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 139 #define ZFREE(strm, addr, size) \ 140 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size)) 141 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);} 142 143 /* deflate.h -- internal compression state 144 * Copyright (C) 1995 Jean-loup Gailly 145 * For conditions of distribution and use, see copyright notice in zlib.h 146 */ 147 148 /* WARNING: this file should *not* be used by applications. It is 149 part of the implementation of the compression library and is 150 subject to change. Applications should only use zlib.h. 151 */ 152 153 154 /*+++++*/ 155 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */ 156 157 /* =========================================================================== 158 * Internal compression state. 159 */ 160 161 /* Data type */ 162 #define BINARY 0 163 #define ASCII 1 164 #define UNKNOWN 2 165 166 #define LENGTH_CODES 29 167 /* number of length codes, not counting the special END_BLOCK code */ 168 169 #define LITERALS 256 170 /* number of literal bytes 0..255 */ 171 172 #define L_CODES (LITERALS+1+LENGTH_CODES) 173 /* number of Literal or Length codes, including the END_BLOCK code */ 174 175 #define D_CODES 30 176 /* number of distance codes */ 177 178 #define BL_CODES 19 179 /* number of codes used to transfer the bit lengths */ 180 181 #define HEAP_SIZE (2*L_CODES+1) 182 /* maximum heap size */ 183 184 #define MAX_BITS 15 185 /* All codes must not exceed MAX_BITS bits */ 186 187 #define INIT_STATE 42 188 #define BUSY_STATE 113 189 #define FLUSH_STATE 124 190 #define FINISH_STATE 666 191 /* Stream status */ 192 193 194 /* Data structure describing a single value and its code string. */ 195 typedef struct ct_data_s { 196 union { 197 ush freq; /* frequency count */ 198 ush code; /* bit string */ 199 } fc; 200 union { 201 ush dad; /* father node in Huffman tree */ 202 ush len; /* length of bit string */ 203 } dl; 204 } FAR ct_data; 205 206 #define Freq fc.freq 207 #define Code fc.code 208 #define Dad dl.dad 209 #define Len dl.len 210 211 typedef struct static_tree_desc_s static_tree_desc; 212 213 typedef struct tree_desc_s { 214 ct_data *dyn_tree; /* the dynamic tree */ 215 int max_code; /* largest code with non zero frequency */ 216 static_tree_desc *stat_desc; /* the corresponding static tree */ 217 } FAR tree_desc; 218 219 typedef ush Pos; 220 typedef Pos FAR Posf; 221 typedef unsigned IPos; 222 223 /* A Pos is an index in the character window. We use short instead of int to 224 * save space in the various tables. IPos is used only for parameter passing. 225 */ 226 227 typedef struct deflate_state { 228 z_stream *strm; /* pointer back to this zlib stream */ 229 int status; /* as the name implies */ 230 Bytef *pending_buf; /* output still pending */ 231 Bytef *pending_out; /* next pending byte to output to the stream */ 232 int pending; /* nb of bytes in the pending buffer */ 233 uLong adler; /* adler32 of uncompressed data */ 234 int noheader; /* suppress zlib header and adler32 */ 235 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 236 Byte method; /* STORED (for zip only) or DEFLATED */ 237 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */ 238 239 /* used by deflate.c: */ 240 241 uInt w_size; /* LZ77 window size (32K by default) */ 242 uInt w_bits; /* log2(w_size) (8..16) */ 243 uInt w_mask; /* w_size - 1 */ 244 245 Bytef *window; 246 /* Sliding window. Input bytes are read into the second half of the window, 247 * and move to the first half later to keep a dictionary of at least wSize 248 * bytes. With this organization, matches are limited to a distance of 249 * wSize-MAX_MATCH bytes, but this ensures that IO is always 250 * performed with a length multiple of the block size. Also, it limits 251 * the window size to 64K, which is quite useful on MSDOS. 252 * To do: use the user input buffer as sliding window. 253 */ 254 255 ulg window_size; 256 /* Actual size of window: 2*wSize, except when the user input buffer 257 * is directly used as sliding window. 258 */ 259 260 Posf *prev; 261 /* Link to older string with same hash index. To limit the size of this 262 * array to 64K, this link is maintained only for the last 32K strings. 263 * An index in this array is thus a window index modulo 32K. 264 */ 265 266 Posf *head; /* Heads of the hash chains or NIL. */ 267 268 uInt ins_h; /* hash index of string to be inserted */ 269 uInt hash_size; /* number of elements in hash table */ 270 uInt hash_bits; /* log2(hash_size) */ 271 uInt hash_mask; /* hash_size-1 */ 272 273 uInt hash_shift; 274 /* Number of bits by which ins_h must be shifted at each input 275 * step. It must be such that after MIN_MATCH steps, the oldest 276 * byte no longer takes part in the hash key, that is: 277 * hash_shift * MIN_MATCH >= hash_bits 278 */ 279 280 long block_start; 281 /* Window position at the beginning of the current output block. Gets 282 * negative when the window is moved backwards. 283 */ 284 285 uInt match_length; /* length of best match */ 286 IPos prev_match; /* previous match */ 287 int match_available; /* set if previous match exists */ 288 uInt strstart; /* start of string to insert */ 289 uInt match_start; /* start of matching string */ 290 uInt lookahead; /* number of valid bytes ahead in window */ 291 292 uInt prev_length; 293 /* Length of the best match at previous step. Matches not greater than this 294 * are discarded. This is used in the lazy match evaluation. 295 */ 296 297 uInt max_chain_length; 298 /* To speed up deflation, hash chains are never searched beyond this 299 * length. A higher limit improves compression ratio but degrades the 300 * speed. 301 */ 302 303 uInt max_lazy_match; 304 /* Attempt to find a better match only when the current match is strictly 305 * smaller than this value. This mechanism is used only for compression 306 * levels >= 4. 307 */ 308 # define max_insert_length max_lazy_match 309 /* Insert new strings in the hash table only if the match length is not 310 * greater than this length. This saves time but degrades compression. 311 * max_insert_length is used only for compression levels <= 3. 312 */ 313 314 int level; /* compression level (1..9) */ 315 int strategy; /* favor or force Huffman coding*/ 316 317 uInt good_match; 318 /* Use a faster search when the previous match is longer than this */ 319 320 int nice_match; /* Stop searching when current match exceeds this */ 321 322 /* used by trees.c: */ 323 /* Didn't use ct_data typedef below to supress compiler warning */ 324 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 325 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 326 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 327 328 struct tree_desc_s l_desc; /* desc. for literal tree */ 329 struct tree_desc_s d_desc; /* desc. for distance tree */ 330 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 331 332 ush bl_count[MAX_BITS+1]; 333 /* number of codes at each bit length for an optimal tree */ 334 335 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 336 int heap_len; /* number of elements in the heap */ 337 int heap_max; /* element of largest frequency */ 338 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 339 * The same heap array is used to build all trees. 340 */ 341 342 uch depth[2*L_CODES+1]; 343 /* Depth of each subtree used as tie breaker for trees of equal frequency 344 */ 345 346 uchf *l_buf; /* buffer for literals or lengths */ 347 348 uInt lit_bufsize; 349 /* Size of match buffer for literals/lengths. There are 4 reasons for 350 * limiting lit_bufsize to 64K: 351 * - frequencies can be kept in 16 bit counters 352 * - if compression is not successful for the first block, all input 353 * data is still in the window so we can still emit a stored block even 354 * when input comes from standard input. (This can also be done for 355 * all blocks if lit_bufsize is not greater than 32K.) 356 * - if compression is not successful for a file smaller than 64K, we can 357 * even emit a stored file instead of a stored block (saving 5 bytes). 358 * This is applicable only for zip (not gzip or zlib). 359 * - creating new Huffman trees less frequently may not provide fast 360 * adaptation to changes in the input data statistics. (Take for 361 * example a binary file with poorly compressible code followed by 362 * a highly compressible string table.) Smaller buffer sizes give 363 * fast adaptation but have of course the overhead of transmitting 364 * trees more frequently. 365 * - I can't count above 4 366 */ 367 368 uInt last_lit; /* running index in l_buf */ 369 370 ushf *d_buf; 371 /* Buffer for distances. To simplify the code, d_buf and l_buf have 372 * the same number of elements. To use different lengths, an extra flag 373 * array would be necessary. 374 */ 375 376 ulg opt_len; /* bit length of current block with optimal trees */ 377 ulg static_len; /* bit length of current block with static trees */ 378 ulg compressed_len; /* total bit length of compressed file */ 379 uInt matches; /* number of string matches in current block */ 380 int last_eob_len; /* bit length of EOB code for last block */ 381 382 #ifdef DEBUG_ZLIB 383 ulg bits_sent; /* bit length of the compressed data */ 384 #endif 385 386 ush bi_buf; 387 /* Output buffer. bits are inserted starting at the bottom (least 388 * significant bits). 389 */ 390 int bi_valid; 391 /* Number of valid bits in bi_buf. All bits above the last valid bit 392 * are always zero. 393 */ 394 395 uInt blocks_in_packet; 396 /* Number of blocks produced since the last time Z_PACKET_FLUSH 397 * was used. 398 */ 399 400 } FAR deflate_state; 401 402 /* Output a byte on the stream. 403 * IN assertion: there is enough room in pending_buf. 404 */ 405 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 406 407 408 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 409 /* Minimum amount of lookahead, except at the end of the input file. 410 * See deflate.c for comments about the MIN_MATCH+1. 411 */ 412 413 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 414 /* In order to simplify the code, particularly on 16 bit machines, match 415 * distances are limited to MAX_DIST instead of WSIZE. 416 */ 417 418 /* in trees.c */ 419 local void ct_init OF((deflate_state *s)); 420 local int ct_tally OF((deflate_state *s, int dist, int lc)); 421 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 422 int flush)); 423 local void ct_align OF((deflate_state *s)); 424 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 425 int eof)); 426 local void ct_stored_type_only OF((deflate_state *s)); 427 428 429 /*+++++*/ 430 /* deflate.c -- compress data using the deflation algorithm 431 * Copyright (C) 1995 Jean-loup Gailly. 432 * For conditions of distribution and use, see copyright notice in zlib.h 433 */ 434 435 /* 436 * ALGORITHM 437 * 438 * The "deflation" process depends on being able to identify portions 439 * of the input text which are identical to earlier input (within a 440 * sliding window trailing behind the input currently being processed). 441 * 442 * The most straightforward technique turns out to be the fastest for 443 * most input files: try all possible matches and select the longest. 444 * The key feature of this algorithm is that insertions into the string 445 * dictionary are very simple and thus fast, and deletions are avoided 446 * completely. Insertions are performed at each input character, whereas 447 * string matches are performed only when the previous match ends. So it 448 * is preferable to spend more time in matches to allow very fast string 449 * insertions and avoid deletions. The matching algorithm for small 450 * strings is inspired from that of Rabin & Karp. A brute force approach 451 * is used to find longer strings when a small match has been found. 452 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 453 * (by Leonid Broukhis). 454 * A previous version of this file used a more sophisticated algorithm 455 * (by Fiala and Greene) which is guaranteed to run in linear amortized 456 * time, but has a larger average cost, uses more memory and is patented. 457 * However the F&G algorithm may be faster for some highly redundant 458 * files if the parameter max_chain_length (described below) is too large. 459 * 460 * ACKNOWLEDGEMENTS 461 * 462 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 463 * I found it in 'freeze' written by Leonid Broukhis. 464 * Thanks to many people for bug reports and testing. 465 * 466 * REFERENCES 467 * 468 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 469 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 470 * 471 * A description of the Rabin and Karp algorithm is given in the book 472 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 473 * 474 * Fiala,E.R., and Greene,D.H. 475 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 476 * 477 */ 478 479 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */ 480 481 #if 0 482 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly "; 483 #endif 484 /* 485 If you use the zlib library in a product, an acknowledgment is welcome 486 in the documentation of your product. If for some reason you cannot 487 include such an acknowledgment, I would appreciate that you keep this 488 copyright string in the executable of your product. 489 */ 490 491 #define NIL 0 492 /* Tail of hash chains */ 493 494 #ifndef TOO_FAR 495 # define TOO_FAR 4096 496 #endif 497 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 498 499 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 500 /* Minimum amount of lookahead, except at the end of the input file. 501 * See deflate.c for comments about the MIN_MATCH+1. 502 */ 503 504 /* Values for max_lazy_match, good_match and max_chain_length, depending on 505 * the desired pack level (0..9). The values given below have been tuned to 506 * exclude worst case performance for pathological files. Better values may be 507 * found for specific files. 508 */ 509 510 typedef struct config_s { 511 ush good_length; /* reduce lazy search above this match length */ 512 ush max_lazy; /* do not perform lazy search above this match length */ 513 ush nice_length; /* quit search above this match length */ 514 ush max_chain; 515 } config; 516 517 local config configuration_table[10] = { 518 /* good lazy nice chain */ 519 /* 0 */ {0, 0, 0, 0}, /* store only */ 520 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */ 521 /* 2 */ {4, 5, 16, 8}, 522 /* 3 */ {4, 6, 32, 32}, 523 524 /* 4 */ {4, 4, 16, 16}, /* lazy matches */ 525 /* 5 */ {8, 16, 32, 32}, 526 /* 6 */ {8, 16, 128, 128}, 527 /* 7 */ {8, 32, 128, 256}, 528 /* 8 */ {32, 128, 258, 1024}, 529 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ 530 531 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 532 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 533 * meaning. 534 */ 535 536 #define EQUAL 0 537 /* result of memcmp for equal strings */ 538 539 /* =========================================================================== 540 * Prototypes for local functions. 541 */ 542 543 local void fill_window OF((deflate_state *s)); 544 local int deflate_fast OF((deflate_state *s, int flush)); 545 local int deflate_slow OF((deflate_state *s, int flush)); 546 local void lm_init OF((deflate_state *s)); 547 local int longest_match OF((deflate_state *s, IPos cur_match)); 548 local void putShortMSB OF((deflate_state *s, uInt b)); 549 local void flush_pending OF((z_stream *strm)); 550 local int read_buf OF((z_stream *strm, charf *buf, unsigned size)); 551 #ifdef ASMV 552 void match_init OF((void)); /* asm code initialization */ 553 #endif 554 555 #ifdef DEBUG_ZLIB 556 local void check_match OF((deflate_state *s, IPos start, IPos match, 557 int length)); 558 #endif 559 560 561 /* =========================================================================== 562 * Update a hash value with the given input byte 563 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 564 * input characters, so that a running hash key can be computed from the 565 * previous key instead of complete recalculation each time. 566 */ 567 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 568 569 570 /* =========================================================================== 571 * Insert string str in the dictionary and set match_head to the previous head 572 * of the hash chain (the most recent string with same hash key). Return 573 * the previous length of the hash chain. 574 * IN assertion: all calls to to INSERT_STRING are made with consecutive 575 * input characters and the first MIN_MATCH bytes of str are valid 576 * (except for the last MIN_MATCH-1 bytes of the input file). 577 */ 578 #define INSERT_STRING(s, str, match_head) \ 579 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 580 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 581 s->head[s->ins_h] = (str)) 582 583 /* =========================================================================== 584 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 585 * prev[] will be initialized on the fly. 586 */ 587 #define CLEAR_HASH(s) \ 588 s->head[s->hash_size-1] = NIL; \ 589 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 590 591 /* ========================================================================= */ 592 int deflateInit (strm, level) 593 z_stream *strm; 594 int level; 595 { 596 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 597 0, 0); 598 /* To do: ignore strm->next_in if we use it as window */ 599 } 600 601 /* ========================================================================= */ 602 int deflateInit2 (strm, level, method, windowBits, memLevel, 603 strategy, minCompression) 604 z_stream *strm; 605 int level; 606 int method; 607 int windowBits; 608 int memLevel; 609 int strategy; 610 int minCompression; 611 { 612 deflate_state *s; 613 int noheader = 0; 614 615 if (strm == Z_NULL) return Z_STREAM_ERROR; 616 617 strm->msg = Z_NULL; 618 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */ 619 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */ 620 621 if (level == Z_DEFAULT_COMPRESSION) level = 6; 622 623 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 624 noheader = 1; 625 windowBits = -windowBits; 626 } 627 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED || 628 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) { 629 return Z_STREAM_ERROR; 630 } 631 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 632 if (s == Z_NULL) return Z_MEM_ERROR; 633 strm->state = (struct internal_state FAR *)s; 634 s->strm = strm; 635 636 s->noheader = noheader; 637 s->w_bits = windowBits; 638 s->w_size = 1 << s->w_bits; 639 s->w_mask = s->w_size - 1; 640 641 s->hash_bits = memLevel + 7; 642 s->hash_size = 1 << s->hash_bits; 643 s->hash_mask = s->hash_size - 1; 644 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 645 646 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 647 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 648 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 649 650 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 651 652 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush)); 653 654 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 655 s->pending_buf == Z_NULL) { 656 strm->msg = z_errmsg[1-Z_MEM_ERROR]; 657 deflateEnd (strm); 658 return Z_MEM_ERROR; 659 } 660 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]); 661 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]); 662 /* We overlay pending_buf and d_buf+l_buf. This works since the average 663 * output size for (length,distance) codes is <= 32 bits (worst case 664 * is 15+15+13=33). 665 */ 666 667 s->level = level; 668 s->strategy = strategy; 669 s->method = (Byte)method; 670 s->minCompr = minCompression; 671 s->blocks_in_packet = 0; 672 673 return deflateReset(strm); 674 } 675 676 /* ========================================================================= */ 677 int deflateReset (strm) 678 z_stream *strm; 679 { 680 deflate_state *s; 681 682 if (strm == Z_NULL || strm->state == Z_NULL || 683 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 684 685 strm->total_in = strm->total_out = 0; 686 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 687 strm->data_type = Z_UNKNOWN; 688 689 s = (deflate_state *)strm->state; 690 s->pending = 0; 691 s->pending_out = s->pending_buf; 692 693 if (s->noheader < 0) { 694 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 695 } 696 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 697 s->adler = 1; 698 699 ct_init(s); 700 lm_init(s); 701 702 return Z_OK; 703 } 704 705 /* ========================================================================= 706 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 707 * IN assertion: the stream state is correct and there is enough room in 708 * pending_buf. 709 */ 710 local void putShortMSB (s, b) 711 deflate_state *s; 712 uInt b; 713 { 714 put_byte(s, (Byte)(b >> 8)); 715 put_byte(s, (Byte)(b & 0xff)); 716 } 717 718 /* ========================================================================= 719 * Flush as much pending output as possible. 720 */ 721 local void flush_pending(strm) 722 z_stream *strm; 723 { 724 deflate_state *state = (deflate_state *) strm->state; 725 unsigned len = state->pending; 726 727 if (len > strm->avail_out) len = strm->avail_out; 728 if (len == 0) return; 729 730 if (strm->next_out != NULL) { 731 zmemcpy(strm->next_out, state->pending_out, len); 732 strm->next_out += len; 733 } 734 state->pending_out += len; 735 strm->total_out += len; 736 strm->avail_out -= len; 737 state->pending -= len; 738 if (state->pending == 0) { 739 state->pending_out = state->pending_buf; 740 } 741 } 742 743 /* ========================================================================= */ 744 int deflate (strm, flush) 745 z_stream *strm; 746 int flush; 747 { 748 deflate_state *state = (deflate_state *) strm->state; 749 750 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; 751 752 if (strm->next_in == Z_NULL && strm->avail_in != 0) { 753 ERR_RETURN(strm, Z_STREAM_ERROR); 754 } 755 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 756 757 state->strm = strm; /* just in case */ 758 759 /* Write the zlib header */ 760 if (state->status == INIT_STATE) { 761 762 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8; 763 uInt level_flags = (state->level-1) >> 1; 764 765 if (level_flags > 3) level_flags = 3; 766 header |= (level_flags << 6); 767 header += 31 - (header % 31); 768 769 state->status = BUSY_STATE; 770 putShortMSB(state, header); 771 } 772 773 /* Flush as much pending output as possible */ 774 if (state->pending != 0) { 775 flush_pending(strm); 776 if (strm->avail_out == 0) return Z_OK; 777 } 778 779 /* If we came back in here to get the last output from 780 * a previous flush, we're done for now. 781 */ 782 if (state->status == FLUSH_STATE) { 783 state->status = BUSY_STATE; 784 if (flush != Z_NO_FLUSH && flush != Z_FINISH) 785 return Z_OK; 786 } 787 788 /* User must not provide more input after the first FINISH: */ 789 if (state->status == FINISH_STATE && strm->avail_in != 0) { 790 ERR_RETURN(strm, Z_BUF_ERROR); 791 } 792 793 /* Start a new block or continue the current one. 794 */ 795 if (strm->avail_in != 0 || state->lookahead != 0 || 796 (flush == Z_FINISH && state->status != FINISH_STATE)) { 797 int quit; 798 799 if (flush == Z_FINISH) { 800 state->status = FINISH_STATE; 801 } 802 if (state->level <= 3) { 803 quit = deflate_fast(state, flush); 804 } else { 805 quit = deflate_slow(state, flush); 806 } 807 if (quit || strm->avail_out == 0) 808 return Z_OK; 809 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 810 * of deflate should use the same flush parameter to make sure 811 * that the flush is complete. So we don't have to output an 812 * empty block here, this will be done at next call. This also 813 * ensures that for a very small output buffer, we emit at most 814 * one empty block. 815 */ 816 } 817 818 /* If a flush was requested, we have a little more to output now. */ 819 if (flush != Z_NO_FLUSH && flush != Z_FINISH 820 && state->status != FINISH_STATE) { 821 switch (flush) { 822 case Z_PARTIAL_FLUSH: 823 ct_align(state); 824 break; 825 case Z_PACKET_FLUSH: 826 /* Output just the 3-bit `stored' block type value, 827 but not a zero length. */ 828 ct_stored_type_only(state); 829 break; 830 default: 831 ct_stored_block(state, (char*)0, 0L, 0); 832 /* For a full flush, this empty block will be recognized 833 * as a special marker by inflate_sync(). 834 */ 835 if (flush == Z_FULL_FLUSH) { 836 CLEAR_HASH(state); /* forget history */ 837 } 838 } 839 flush_pending(strm); 840 if (strm->avail_out == 0) { 841 /* We'll have to come back to get the rest of the output; 842 * this ensures we don't output a second zero-length stored 843 * block (or whatever). 844 */ 845 state->status = FLUSH_STATE; 846 return Z_OK; 847 } 848 } 849 850 Assert(strm->avail_out > 0, "bug2"); 851 852 if (flush != Z_FINISH) return Z_OK; 853 if (state->noheader) return Z_STREAM_END; 854 855 /* Write the zlib trailer (adler32) */ 856 putShortMSB(state, (uInt)(state->adler >> 16)); 857 putShortMSB(state, (uInt)(state->adler & 0xffff)); 858 flush_pending(strm); 859 /* If avail_out is zero, the application will call deflate again 860 * to flush the rest. 861 */ 862 state->noheader = -1; /* write the trailer only once! */ 863 return state->pending != 0 ? Z_OK : Z_STREAM_END; 864 } 865 866 /* ========================================================================= */ 867 int deflateEnd (strm) 868 z_stream *strm; 869 { 870 deflate_state *state = (deflate_state *) strm->state; 871 872 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; 873 874 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte)); 875 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos)); 876 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos)); 877 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush)); 878 879 ZFREE(strm, state, sizeof(deflate_state)); 880 strm->state = Z_NULL; 881 882 return Z_OK; 883 } 884 885 /* =========================================================================== 886 * Read a new buffer from the current input stream, update the adler32 887 * and total number of bytes read. 888 */ 889 local int read_buf(strm, buf, size) 890 z_stream *strm; 891 charf *buf; 892 unsigned size; 893 { 894 unsigned len = strm->avail_in; 895 deflate_state *state = (deflate_state *) strm->state; 896 897 if (len > size) len = size; 898 if (len == 0) return 0; 899 900 strm->avail_in -= len; 901 902 if (!state->noheader) { 903 state->adler = adler32(state->adler, strm->next_in, len); 904 } 905 zmemcpy(buf, strm->next_in, len); 906 strm->next_in += len; 907 strm->total_in += len; 908 909 return (int)len; 910 } 911 912 /* =========================================================================== 913 * Initialize the "longest match" routines for a new zlib stream 914 */ 915 local void lm_init (s) 916 deflate_state *s; 917 { 918 s->window_size = (ulg)2L*s->w_size; 919 920 CLEAR_HASH(s); 921 922 /* Set the default configuration parameters: 923 */ 924 s->max_lazy_match = configuration_table[s->level].max_lazy; 925 s->good_match = configuration_table[s->level].good_length; 926 s->nice_match = configuration_table[s->level].nice_length; 927 s->max_chain_length = configuration_table[s->level].max_chain; 928 929 s->strstart = 0; 930 s->block_start = 0L; 931 s->lookahead = 0; 932 s->match_length = MIN_MATCH-1; 933 s->match_available = 0; 934 s->ins_h = 0; 935 #ifdef ASMV 936 match_init(); /* initialize the asm code */ 937 #endif 938 } 939 940 /* =========================================================================== 941 * Set match_start to the longest match starting at the given string and 942 * return its length. Matches shorter or equal to prev_length are discarded, 943 * in which case the result is equal to prev_length and match_start is 944 * garbage. 945 * IN assertions: cur_match is the head of the hash chain for the current 946 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 947 */ 948 #ifndef ASMV 949 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or 950 * match.S. The code will be functionally equivalent. 951 */ 952 local int longest_match(s, cur_match) 953 deflate_state *s; 954 IPos cur_match; /* current match */ 955 { 956 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 957 register Bytef *scan = s->window + s->strstart; /* current string */ 958 register Bytef *match; /* matched string */ 959 register int len; /* length of current match */ 960 int best_len = s->prev_length; /* best match length so far */ 961 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 962 s->strstart - (IPos)MAX_DIST(s) : NIL; 963 /* Stop when cur_match becomes <= limit. To simplify the code, 964 * we prevent matches with the string of window index 0. 965 */ 966 Posf *prev = s->prev; 967 uInt wmask = s->w_mask; 968 969 #ifdef UNALIGNED_OK 970 /* Compare two bytes at a time. Note: this is not always beneficial. 971 * Try with and without -DUNALIGNED_OK to check. 972 */ 973 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 974 register ush scan_start = *(ushf*)scan; 975 register ush scan_end = *(ushf*)(scan+best_len-1); 976 #else 977 register Bytef *strend = s->window + s->strstart + MAX_MATCH; 978 register Byte scan_end1 = scan[best_len-1]; 979 register Byte scan_end = scan[best_len]; 980 #endif 981 982 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 983 * It is easy to get rid of this optimization if necessary. 984 */ 985 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 986 987 /* Do not waste too much time if we already have a good match: */ 988 if (s->prev_length >= s->good_match) { 989 chain_length >>= 2; 990 } 991 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 992 993 do { 994 Assert(cur_match < s->strstart, "no future"); 995 match = s->window + cur_match; 996 997 /* Skip to next match if the match length cannot increase 998 * or if the match length is less than 2: 999 */ 1000 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1001 /* This code assumes sizeof(unsigned short) == 2. Do not use 1002 * UNALIGNED_OK if your compiler uses a different size. 1003 */ 1004 if (*(ushf*)(match+best_len-1) != scan_end || 1005 *(ushf*)match != scan_start) continue; 1006 1007 /* It is not necessary to compare scan[2] and match[2] since they are 1008 * always equal when the other bytes match, given that the hash keys 1009 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1010 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1011 * lookahead only every 4th comparison; the 128th check will be made 1012 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1013 * necessary to put more guard bytes at the end of the window, or 1014 * to check more often for insufficient lookahead. 1015 */ 1016 Assert(scan[2] == match[2], "scan[2]?"); 1017 scan++, match++; 1018 do { 1019 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1020 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1021 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1022 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1023 scan < strend); 1024 /* The funny "do {}" generates better code on most compilers */ 1025 1026 /* Here, scan <= window+strstart+257 */ 1027 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1028 if (*scan == *match) scan++; 1029 1030 len = (MAX_MATCH - 1) - (int)(strend-scan); 1031 scan = strend - (MAX_MATCH-1); 1032 1033 #else /* UNALIGNED_OK */ 1034 1035 if (match[best_len] != scan_end || 1036 match[best_len-1] != scan_end1 || 1037 *match != *scan || 1038 *++match != scan[1]) continue; 1039 1040 /* The check at best_len-1 can be removed because it will be made 1041 * again later. (This heuristic is not always a win.) 1042 * It is not necessary to compare scan[2] and match[2] since they 1043 * are always equal when the other bytes match, given that 1044 * the hash keys are equal and that HASH_BITS >= 8. 1045 */ 1046 scan += 2, match++; 1047 Assert(*scan == *match, "match[2]?"); 1048 1049 /* We check for insufficient lookahead only every 8th comparison; 1050 * the 256th check will be made at strstart+258. 1051 */ 1052 do { 1053 } while (*++scan == *++match && *++scan == *++match && 1054 *++scan == *++match && *++scan == *++match && 1055 *++scan == *++match && *++scan == *++match && 1056 *++scan == *++match && *++scan == *++match && 1057 scan < strend); 1058 1059 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1060 1061 len = MAX_MATCH - (int)(strend - scan); 1062 scan = strend - MAX_MATCH; 1063 1064 #endif /* UNALIGNED_OK */ 1065 1066 if (len > best_len) { 1067 s->match_start = cur_match; 1068 best_len = len; 1069 if (len >= s->nice_match) break; 1070 #ifdef UNALIGNED_OK 1071 scan_end = *(ushf*)(scan+best_len-1); 1072 #else 1073 scan_end1 = scan[best_len-1]; 1074 scan_end = scan[best_len]; 1075 #endif 1076 } 1077 } while ((cur_match = prev[cur_match & wmask]) > limit 1078 && --chain_length != 0); 1079 1080 return best_len; 1081 } 1082 #endif /* ASMV */ 1083 1084 #ifdef DEBUG_ZLIB 1085 /* =========================================================================== 1086 * Check that the match at match_start is indeed a match. 1087 */ 1088 local void check_match(s, start, match, length) 1089 deflate_state *s; 1090 IPos start, match; 1091 int length; 1092 { 1093 /* check that the match is indeed a match */ 1094 if (memcmp((charf *)s->window + match, 1095 (charf *)s->window + start, length) != EQUAL) { 1096 fprintf(stderr, 1097 " start %u, match %u, length %d\n", 1098 start, match, length); 1099 do { fprintf(stderr, "%c%c", s->window[match++], 1100 s->window[start++]); } while (--length != 0); 1101 z_error("invalid match"); 1102 } 1103 if (verbose > 1) { 1104 fprintf(stderr,"\\[%d,%d]", start-match, length); 1105 do { putc(s->window[start++], stderr); } while (--length != 0); 1106 } 1107 } 1108 #else 1109 # define check_match(s, start, match, length) 1110 #endif 1111 1112 /* =========================================================================== 1113 * Fill the window when the lookahead becomes insufficient. 1114 * Updates strstart and lookahead. 1115 * 1116 * IN assertion: lookahead < MIN_LOOKAHEAD 1117 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1118 * At least one byte has been read, or avail_in == 0; reads are 1119 * performed for at least two bytes (required for the zip translate_eol 1120 * option -- not supported here). 1121 */ 1122 local void fill_window(s) 1123 deflate_state *s; 1124 { 1125 register unsigned n, m; 1126 register Posf *p; 1127 unsigned more; /* Amount of free space at the end of the window. */ 1128 uInt wsize = s->w_size; 1129 1130 do { 1131 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1132 1133 /* Deal with !@#$% 64K limit: */ 1134 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1135 more = wsize; 1136 } else if (more == (unsigned)(-1)) { 1137 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1138 * and lookahead == 1 (input done one byte at time) 1139 */ 1140 more--; 1141 1142 /* If the window is almost full and there is insufficient lookahead, 1143 * move the upper half to the lower one to make room in the upper half. 1144 */ 1145 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1146 1147 /* By the IN assertion, the window is not empty so we can't confuse 1148 * more == 0 with more == 64K on a 16 bit machine. 1149 */ 1150 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1151 (unsigned)wsize); 1152 s->match_start -= wsize; 1153 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1154 1155 s->block_start -= (long) wsize; 1156 1157 /* Slide the hash table (could be avoided with 32 bit values 1158 at the expense of memory usage): 1159 */ 1160 n = s->hash_size; 1161 p = &s->head[n]; 1162 do { 1163 m = *--p; 1164 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1165 } while (--n); 1166 1167 n = wsize; 1168 p = &s->prev[n]; 1169 do { 1170 m = *--p; 1171 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1172 /* If n is not on any hash chain, prev[n] is garbage but 1173 * its value will never be used. 1174 */ 1175 } while (--n); 1176 1177 more += wsize; 1178 } 1179 if (s->strm->avail_in == 0) return; 1180 1181 /* If there was no sliding: 1182 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1183 * more == window_size - lookahead - strstart 1184 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1185 * => more >= window_size - 2*WSIZE + 2 1186 * In the BIG_MEM or MMAP case (not yet supported), 1187 * window_size == input_size + MIN_LOOKAHEAD && 1188 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1189 * Otherwise, window_size == 2*WSIZE so more >= 2. 1190 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1191 */ 1192 Assert(more >= 2, "more < 2"); 1193 1194 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1195 more); 1196 s->lookahead += n; 1197 1198 /* Initialize the hash value now that we have some input: */ 1199 if (s->lookahead >= MIN_MATCH) { 1200 s->ins_h = s->window[s->strstart]; 1201 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1202 #if MIN_MATCH != 3 1203 Call UPDATE_HASH() MIN_MATCH-3 more times 1204 #endif 1205 } 1206 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1207 * but this is not important since only literal bytes will be emitted. 1208 */ 1209 1210 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1211 } 1212 1213 /* =========================================================================== 1214 * Flush the current block, with given end-of-file flag. 1215 * IN assertion: strstart is set to the end of the current match. 1216 */ 1217 #define FLUSH_BLOCK_ONLY(s, flush) { \ 1218 ct_flush_block(s, (s->block_start >= 0L ? \ 1219 (charf *)&s->window[(unsigned)s->block_start] : \ 1220 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \ 1221 s->block_start = s->strstart; \ 1222 flush_pending(s->strm); \ 1223 Tracev((stderr,"[FLUSH]")); \ 1224 } 1225 1226 /* Same but force premature exit if necessary. */ 1227 #define FLUSH_BLOCK(s, flush) { \ 1228 FLUSH_BLOCK_ONLY(s, flush); \ 1229 if (s->strm->avail_out == 0) return 1; \ 1230 } 1231 1232 /* =========================================================================== 1233 * Compress as much as possible from the input stream, return true if 1234 * processing was terminated prematurely (no more input or output space). 1235 * This function does not perform lazy evaluationof matches and inserts 1236 * new strings in the dictionary only for unmatched strings or for short 1237 * matches. It is used only for the fast compression options. 1238 */ 1239 local int deflate_fast(s, flush) 1240 deflate_state *s; 1241 int flush; 1242 { 1243 IPos hash_head = NIL; /* head of the hash chain */ 1244 int bflush; /* set if current block must be flushed */ 1245 1246 s->prev_length = MIN_MATCH-1; 1247 1248 for (;;) { 1249 /* Make sure that we always have enough lookahead, except 1250 * at the end of the input file. We need MAX_MATCH bytes 1251 * for the next match, plus MIN_MATCH bytes to insert the 1252 * string following the next match. 1253 */ 1254 if (s->lookahead < MIN_LOOKAHEAD) { 1255 fill_window(s); 1256 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; 1257 1258 if (s->lookahead == 0) break; /* flush the current block */ 1259 } 1260 1261 /* Insert the string window[strstart .. strstart+2] in the 1262 * dictionary, and set hash_head to the head of the hash chain: 1263 */ 1264 if (s->lookahead >= MIN_MATCH) { 1265 INSERT_STRING(s, s->strstart, hash_head); 1266 } 1267 1268 /* Find the longest match, discarding those <= prev_length. 1269 * At this point we have always match_length < MIN_MATCH 1270 */ 1271 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1272 /* To simplify the code, we prevent matches with the string 1273 * of window index 0 (in particular we have to avoid a match 1274 * of the string with itself at the start of the input file). 1275 */ 1276 if (s->strategy != Z_HUFFMAN_ONLY) { 1277 s->match_length = longest_match (s, hash_head); 1278 } 1279 /* longest_match() sets match_start */ 1280 1281 if (s->match_length > s->lookahead) s->match_length = s->lookahead; 1282 } 1283 if (s->match_length >= MIN_MATCH) { 1284 check_match(s, s->strstart, s->match_start, s->match_length); 1285 1286 bflush = ct_tally(s, s->strstart - s->match_start, 1287 s->match_length - MIN_MATCH); 1288 1289 s->lookahead -= s->match_length; 1290 1291 /* Insert new strings in the hash table only if the match length 1292 * is not too large. This saves time but degrades compression. 1293 */ 1294 if (s->match_length <= s->max_insert_length && 1295 s->lookahead >= MIN_MATCH) { 1296 s->match_length--; /* string at strstart already in hash table */ 1297 do { 1298 s->strstart++; 1299 INSERT_STRING(s, s->strstart, hash_head); 1300 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1301 * always MIN_MATCH bytes ahead. 1302 */ 1303 } while (--s->match_length != 0); 1304 s->strstart++; 1305 } else { 1306 s->strstart += s->match_length; 1307 s->match_length = 0; 1308 s->ins_h = s->window[s->strstart]; 1309 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1310 #if MIN_MATCH != 3 1311 Call UPDATE_HASH() MIN_MATCH-3 more times 1312 #endif 1313 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1314 * matter since it will be recomputed at next deflate call. 1315 */ 1316 } 1317 } else { 1318 /* No match, output a literal byte */ 1319 Tracevv((stderr,"%c", s->window[s->strstart])); 1320 bflush = ct_tally (s, 0, s->window[s->strstart]); 1321 s->lookahead--; 1322 s->strstart++; 1323 } 1324 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); 1325 } 1326 FLUSH_BLOCK(s, flush); 1327 return 0; /* normal exit */ 1328 } 1329 1330 /* =========================================================================== 1331 * Same as above, but achieves better compression. We use a lazy 1332 * evaluation for matches: a match is finally adopted only if there is 1333 * no better match at the next window position. 1334 */ 1335 local int deflate_slow(s, flush) 1336 deflate_state *s; 1337 int flush; 1338 { 1339 IPos hash_head = NIL; /* head of hash chain */ 1340 int bflush; /* set if current block must be flushed */ 1341 1342 /* Process the input block. */ 1343 for (;;) { 1344 /* Make sure that we always have enough lookahead, except 1345 * at the end of the input file. We need MAX_MATCH bytes 1346 * for the next match, plus MIN_MATCH bytes to insert the 1347 * string following the next match. 1348 */ 1349 if (s->lookahead < MIN_LOOKAHEAD) { 1350 fill_window(s); 1351 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; 1352 1353 if (s->lookahead == 0) break; /* flush the current block */ 1354 } 1355 1356 /* Insert the string window[strstart .. strstart+2] in the 1357 * dictionary, and set hash_head to the head of the hash chain: 1358 */ 1359 if (s->lookahead >= MIN_MATCH) { 1360 INSERT_STRING(s, s->strstart, hash_head); 1361 } 1362 1363 /* Find the longest match, discarding those <= prev_length. 1364 */ 1365 s->prev_length = s->match_length, s->prev_match = s->match_start; 1366 s->match_length = MIN_MATCH-1; 1367 1368 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1369 s->strstart - hash_head <= MAX_DIST(s)) { 1370 /* To simplify the code, we prevent matches with the string 1371 * of window index 0 (in particular we have to avoid a match 1372 * of the string with itself at the start of the input file). 1373 */ 1374 if (s->strategy != Z_HUFFMAN_ONLY) { 1375 s->match_length = longest_match (s, hash_head); 1376 } 1377 /* longest_match() sets match_start */ 1378 if (s->match_length > s->lookahead) s->match_length = s->lookahead; 1379 1380 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1381 (s->match_length == MIN_MATCH && 1382 s->strstart - s->match_start > TOO_FAR))) { 1383 1384 /* If prev_match is also MIN_MATCH, match_start is garbage 1385 * but we will ignore the current match anyway. 1386 */ 1387 s->match_length = MIN_MATCH-1; 1388 } 1389 } 1390 /* If there was a match at the previous step and the current 1391 * match is not better, output the previous match: 1392 */ 1393 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1394 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1395 /* Do not insert strings in hash table beyond this. */ 1396 1397 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1398 1399 bflush = ct_tally(s, s->strstart -1 - s->prev_match, 1400 s->prev_length - MIN_MATCH); 1401 1402 /* Insert in hash table all strings up to the end of the match. 1403 * strstart-1 and strstart are already inserted. If there is not 1404 * enough lookahead, the last two strings are not inserted in 1405 * the hash table. 1406 */ 1407 s->lookahead -= s->prev_length-1; 1408 s->prev_length -= 2; 1409 do { 1410 if (++s->strstart <= max_insert) { 1411 INSERT_STRING(s, s->strstart, hash_head); 1412 } 1413 } while (--s->prev_length != 0); 1414 s->match_available = 0; 1415 s->match_length = MIN_MATCH-1; 1416 s->strstart++; 1417 1418 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); 1419 1420 } else if (s->match_available) { 1421 /* If there was no match at the previous position, output a 1422 * single literal. If there was a match but the current match 1423 * is longer, truncate the previous match to a single literal. 1424 */ 1425 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1426 if (ct_tally (s, 0, s->window[s->strstart-1])) { 1427 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH); 1428 } 1429 s->strstart++; 1430 s->lookahead--; 1431 if (s->strm->avail_out == 0) return 1; 1432 } else { 1433 /* There is no previous match to compare with, wait for 1434 * the next step to decide. 1435 */ 1436 s->match_available = 1; 1437 s->strstart++; 1438 s->lookahead--; 1439 } 1440 } 1441 Assert (flush != Z_NO_FLUSH, "no flush?"); 1442 if (s->match_available) { 1443 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1444 ct_tally (s, 0, s->window[s->strstart-1]); 1445 s->match_available = 0; 1446 } 1447 FLUSH_BLOCK(s, flush); 1448 return 0; 1449 } 1450 1451 1452 /*+++++*/ 1453 /* trees.c -- output deflated data using Huffman coding 1454 * Copyright (C) 1995 Jean-loup Gailly 1455 * For conditions of distribution and use, see copyright notice in zlib.h 1456 */ 1457 1458 /* 1459 * ALGORITHM 1460 * 1461 * The "deflation" process uses several Huffman trees. The more 1462 * common source values are represented by shorter bit sequences. 1463 * 1464 * Each code tree is stored in a compressed form which is itself 1465 * a Huffman encoding of the lengths of all the code strings (in 1466 * ascending order by source values). The actual code strings are 1467 * reconstructed from the lengths in the inflate process, as described 1468 * in the deflate specification. 1469 * 1470 * REFERENCES 1471 * 1472 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1473 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1474 * 1475 * Storer, James A. 1476 * Data Compression: Methods and Theory, pp. 49-50. 1477 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1478 * 1479 * Sedgewick, R. 1480 * Algorithms, p290. 1481 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1482 */ 1483 1484 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */ 1485 1486 #ifdef DEBUG_ZLIB 1487 # include <ctype.h> 1488 #endif 1489 1490 /* =========================================================================== 1491 * Constants 1492 */ 1493 1494 #define MAX_BL_BITS 7 1495 /* Bit length codes must not exceed MAX_BL_BITS bits */ 1496 1497 #define END_BLOCK 256 1498 /* end of block literal code */ 1499 1500 #define REP_3_6 16 1501 /* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1502 1503 #define REPZ_3_10 17 1504 /* repeat a zero length 3-10 times (3 bits of repeat count) */ 1505 1506 #define REPZ_11_138 18 1507 /* repeat a zero length 11-138 times (7 bits of repeat count) */ 1508 1509 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1510 = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0}; 1511 1512 local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1513 = {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13}; 1514 1515 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1516 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1517 1518 local uch bl_order[BL_CODES] 1519 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1520 /* The lengths of the bit length codes are sent in order of decreasing 1521 * probability, to avoid transmitting the lengths for unused bit length codes. 1522 */ 1523 1524 #define Buf_size (8 * 2*sizeof(char)) 1525 /* Number of bits used within bi_buf. (bi_buf might be implemented on 1526 * more than 16 bits on some systems.) 1527 */ 1528 1529 /* =========================================================================== 1530 * Local data. These are initialized only once. 1531 * To do: initialize at compile time to be completely reentrant. ??? 1532 */ 1533 1534 local ct_data static_ltree[L_CODES+2]; 1535 /* The static literal tree. Since the bit lengths are imposed, there is no 1536 * need for the L_CODES extra codes used during heap construction. However 1537 * The codes 286 and 287 are needed to build a canonical tree (see ct_init 1538 * below). 1539 */ 1540 1541 local ct_data static_dtree[D_CODES]; 1542 /* The static distance tree. (Actually a trivial tree since all codes use 1543 * 5 bits.) 1544 */ 1545 1546 local uch dist_code[512]; 1547 /* distance codes. The first 256 values correspond to the distances 1548 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1549 * the 15 bit distances. 1550 */ 1551 1552 local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1553 /* length code for each normalized match length (0 == MIN_MATCH) */ 1554 1555 local int base_length[LENGTH_CODES]; 1556 /* First normalized length for each code (0 = MIN_MATCH) */ 1557 1558 local int base_dist[D_CODES]; 1559 /* First normalized distance for each code (0 = distance of 1) */ 1560 1561 struct static_tree_desc_s { 1562 ct_data *static_tree; /* static tree or NULL */ 1563 intf *extra_bits; /* extra bits for each code or NULL */ 1564 int extra_base; /* base index for extra_bits */ 1565 int elems; /* max number of elements in the tree */ 1566 int max_length; /* max bit length for the codes */ 1567 }; 1568 1569 local static_tree_desc static_l_desc = 1570 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1571 1572 local static_tree_desc static_d_desc = 1573 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1574 1575 local static_tree_desc static_bl_desc = 1576 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1577 1578 /* =========================================================================== 1579 * Local (static) routines in this file. 1580 */ 1581 1582 local void ct_static_init OF((void)); 1583 local void init_block OF((deflate_state *s)); 1584 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1585 local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1586 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1587 local void build_tree OF((deflate_state *s, tree_desc *desc)); 1588 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1589 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1590 local int build_bl_tree OF((deflate_state *s)); 1591 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1592 int blcodes)); 1593 local void compress_block OF((deflate_state *s, ct_data *ltree, 1594 ct_data *dtree)); 1595 local void set_data_type OF((deflate_state *s)); 1596 local unsigned bi_reverse OF((unsigned value, int length)); 1597 local void bi_windup OF((deflate_state *s)); 1598 local void bi_flush OF((deflate_state *s)); 1599 local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1600 int header)); 1601 1602 #ifndef DEBUG_ZLIB 1603 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 1604 /* Send a code of the given tree. c and tree must not have side effects */ 1605 1606 #else /* DEBUG_ZLIB */ 1607 # define send_code(s, c, tree) \ 1608 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ 1609 send_bits(s, tree[c].Code, tree[c].Len); } 1610 #endif 1611 1612 #define d_code(dist) \ 1613 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 1614 /* Mapping from a distance to a distance code. dist is the distance - 1 and 1615 * must not have side effects. dist_code[256] and dist_code[257] are never 1616 * used. 1617 */ 1618 1619 /* =========================================================================== 1620 * Output a short LSB first on the stream. 1621 * IN assertion: there is enough room in pendingBuf. 1622 */ 1623 #define put_short(s, w) { \ 1624 put_byte(s, (uch)((w) & 0xff)); \ 1625 put_byte(s, (uch)((ush)(w) >> 8)); \ 1626 } 1627 1628 /* =========================================================================== 1629 * Send a value on a given number of bits. 1630 * IN assertion: length <= 16 and value fits in length bits. 1631 */ 1632 #ifdef DEBUG_ZLIB 1633 local void send_bits OF((deflate_state *s, int value, int length)); 1634 1635 local void send_bits(s, value, length) 1636 deflate_state *s; 1637 int value; /* value to send */ 1638 int length; /* number of bits */ 1639 { 1640 Tracev((stderr," l %2d v %4x ", length, value)); 1641 Assert(length > 0 && length <= 15, "invalid length"); 1642 s->bits_sent += (ulg)length; 1643 1644 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 1645 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 1646 * unused bits in value. 1647 */ 1648 if (s->bi_valid > (int)Buf_size - length) { 1649 s->bi_buf |= (value << s->bi_valid); 1650 put_short(s, s->bi_buf); 1651 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 1652 s->bi_valid += length - Buf_size; 1653 } else { 1654 s->bi_buf |= value << s->bi_valid; 1655 s->bi_valid += length; 1656 } 1657 } 1658 #else /* !DEBUG_ZLIB */ 1659 1660 #define send_bits(s, value, length) \ 1661 { int len = length;\ 1662 if (s->bi_valid > (int)Buf_size - len) {\ 1663 int val = value;\ 1664 s->bi_buf |= (val << s->bi_valid);\ 1665 put_short(s, s->bi_buf);\ 1666 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 1667 s->bi_valid += len - Buf_size;\ 1668 } else {\ 1669 s->bi_buf |= (value) << s->bi_valid;\ 1670 s->bi_valid += len;\ 1671 }\ 1672 } 1673 #endif /* DEBUG_ZLIB */ 1674 1675 1676 #define MAX(a,b) (a >= b ? a : b) 1677 /* the arguments must not have side effects */ 1678 1679 /* =========================================================================== 1680 * Initialize the various 'constant' tables. 1681 * To do: do this at compile time. 1682 */ 1683 local void ct_static_init() 1684 { 1685 int n; /* iterates over tree elements */ 1686 int bits; /* bit counter */ 1687 int length; /* length value */ 1688 int code; /* code value */ 1689 int dist; /* distance index */ 1690 ush bl_count[MAX_BITS+1]; 1691 /* number of codes at each bit length for an optimal tree */ 1692 1693 /* Initialize the mapping length (0..255) -> length code (0..28) */ 1694 length = 0; 1695 for (code = 0; code < LENGTH_CODES-1; code++) { 1696 base_length[code] = length; 1697 for (n = 0; n < (1<<extra_lbits[code]); n++) { 1698 length_code[length++] = (uch)code; 1699 } 1700 } 1701 Assert (length == 256, "ct_static_init: length != 256"); 1702 /* Note that the length 255 (match length 258) can be represented 1703 * in two different ways: code 284 + 5 bits or code 285, so we 1704 * overwrite length_code[255] to use the best encoding: 1705 */ 1706 length_code[length-1] = (uch)code; 1707 1708 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 1709 dist = 0; 1710 for (code = 0 ; code < 16; code++) { 1711 base_dist[code] = dist; 1712 for (n = 0; n < (1<<extra_dbits[code]); n++) { 1713 dist_code[dist++] = (uch)code; 1714 } 1715 } 1716 Assert (dist == 256, "ct_static_init: dist != 256"); 1717 dist >>= 7; /* from now on, all distances are divided by 128 */ 1718 for ( ; code < D_CODES; code++) { 1719 base_dist[code] = dist << 7; 1720 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 1721 dist_code[256 + dist++] = (uch)code; 1722 } 1723 } 1724 Assert (dist == 256, "ct_static_init: 256+dist != 512"); 1725 1726 /* Construct the codes of the static literal tree */ 1727 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 1728 n = 0; 1729 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 1730 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 1731 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 1732 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 1733 /* Codes 286 and 287 do not exist, but we must include them in the 1734 * tree construction to get a canonical Huffman tree (longest code 1735 * all ones) 1736 */ 1737 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 1738 1739 /* The static distance tree is trivial: */ 1740 for (n = 0; n < D_CODES; n++) { 1741 static_dtree[n].Len = 5; 1742 static_dtree[n].Code = bi_reverse(n, 5); 1743 } 1744 } 1745 1746 /* =========================================================================== 1747 * Initialize the tree data structures for a new zlib stream. 1748 */ 1749 local void ct_init(s) 1750 deflate_state *s; 1751 { 1752 if (static_dtree[0].Len == 0) { 1753 ct_static_init(); /* To do: at compile time */ 1754 } 1755 1756 s->compressed_len = 0L; 1757 1758 s->l_desc.dyn_tree = s->dyn_ltree; 1759 s->l_desc.stat_desc = &static_l_desc; 1760 1761 s->d_desc.dyn_tree = s->dyn_dtree; 1762 s->d_desc.stat_desc = &static_d_desc; 1763 1764 s->bl_desc.dyn_tree = s->bl_tree; 1765 s->bl_desc.stat_desc = &static_bl_desc; 1766 1767 s->bi_buf = 0; 1768 s->bi_valid = 0; 1769 s->last_eob_len = 8; /* enough lookahead for inflate */ 1770 #ifdef DEBUG_ZLIB 1771 s->bits_sent = 0L; 1772 #endif 1773 s->blocks_in_packet = 0; 1774 1775 /* Initialize the first block of the first file: */ 1776 init_block(s); 1777 } 1778 1779 /* =========================================================================== 1780 * Initialize a new block. 1781 */ 1782 local void init_block(s) 1783 deflate_state *s; 1784 { 1785 int n; /* iterates over tree elements */ 1786 1787 /* Initialize the trees. */ 1788 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 1789 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 1790 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 1791 1792 s->dyn_ltree[END_BLOCK].Freq = 1; 1793 s->opt_len = s->static_len = 0L; 1794 s->last_lit = s->matches = 0; 1795 } 1796 1797 #define SMALLEST 1 1798 /* Index within the heap array of least frequent node in the Huffman tree */ 1799 1800 1801 /* =========================================================================== 1802 * Remove the smallest element from the heap and recreate the heap with 1803 * one less element. Updates heap and heap_len. 1804 */ 1805 #define pqremove(s, tree, top) \ 1806 {\ 1807 top = s->heap[SMALLEST]; \ 1808 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 1809 pqdownheap(s, tree, SMALLEST); \ 1810 } 1811 1812 /* =========================================================================== 1813 * Compares to subtrees, using the tree depth as tie breaker when 1814 * the subtrees have equal frequency. This minimizes the worst case length. 1815 */ 1816 #define smaller(tree, n, m, depth) \ 1817 (tree[n].Freq < tree[m].Freq || \ 1818 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 1819 1820 /* =========================================================================== 1821 * Restore the heap property by moving down the tree starting at node k, 1822 * exchanging a node with the smallest of its two sons if necessary, stopping 1823 * when the heap property is re-established (each father smaller than its 1824 * two sons). 1825 */ 1826 local void pqdownheap(s, tree, k) 1827 deflate_state *s; 1828 ct_data *tree; /* the tree to restore */ 1829 int k; /* node to move down */ 1830 { 1831 int v = s->heap[k]; 1832 int j = k << 1; /* left son of k */ 1833 while (j <= s->heap_len) { 1834 /* Set j to the smallest of the two sons: */ 1835 if (j < s->heap_len && 1836 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 1837 j++; 1838 } 1839 /* Exit if v is smaller than both sons */ 1840 if (smaller(tree, v, s->heap[j], s->depth)) break; 1841 1842 /* Exchange v with the smallest son */ 1843 s->heap[k] = s->heap[j]; k = j; 1844 1845 /* And continue down the tree, setting j to the left son of k */ 1846 j <<= 1; 1847 } 1848 s->heap[k] = v; 1849 } 1850 1851 /* =========================================================================== 1852 * Compute the optimal bit lengths for a tree and update the total bit length 1853 * for the current block. 1854 * IN assertion: the fields freq and dad are set, heap[heap_max] and 1855 * above are the tree nodes sorted by increasing frequency. 1856 * OUT assertions: the field len is set to the optimal bit length, the 1857 * array bl_count contains the frequencies for each bit length. 1858 * The length opt_len is updated; static_len is also updated if stree is 1859 * not null. 1860 */ 1861 local void gen_bitlen(s, desc) 1862 deflate_state *s; 1863 tree_desc *desc; /* the tree descriptor */ 1864 { 1865 ct_data *tree = desc->dyn_tree; 1866 int max_code = desc->max_code; 1867 ct_data *stree = desc->stat_desc->static_tree; 1868 intf *extra = desc->stat_desc->extra_bits; 1869 int base = desc->stat_desc->extra_base; 1870 int max_length = desc->stat_desc->max_length; 1871 int h; /* heap index */ 1872 int n, m; /* iterate over the tree elements */ 1873 int bits; /* bit length */ 1874 int xbits; /* extra bits */ 1875 ush f; /* frequency */ 1876 int overflow = 0; /* number of elements with bit length too large */ 1877 1878 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 1879 1880 /* In a first pass, compute the optimal bit lengths (which may 1881 * overflow in the case of the bit length tree). 1882 */ 1883 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 1884 1885 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 1886 n = s->heap[h]; 1887 bits = tree[tree[n].Dad].Len + 1; 1888 if (bits > max_length) bits = max_length, overflow++; 1889 tree[n].Len = (ush)bits; 1890 /* We overwrite tree[n].Dad which is no longer needed */ 1891 1892 if (n > max_code) continue; /* not a leaf node */ 1893 1894 s->bl_count[bits]++; 1895 xbits = 0; 1896 if (n >= base) xbits = extra[n-base]; 1897 f = tree[n].Freq; 1898 s->opt_len += (ulg)f * (bits + xbits); 1899 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 1900 } 1901 if (overflow == 0) return; 1902 1903 Trace((stderr,"\nbit length overflow\n")); 1904 /* This happens for example on obj2 and pic of the Calgary corpus */ 1905 1906 /* Find the first bit length which could increase: */ 1907 do { 1908 bits = max_length-1; 1909 while (s->bl_count[bits] == 0) bits--; 1910 s->bl_count[bits]--; /* move one leaf down the tree */ 1911 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 1912 s->bl_count[max_length]--; 1913 /* The brother of the overflow item also moves one step up, 1914 * but this does not affect bl_count[max_length] 1915 */ 1916 overflow -= 2; 1917 } while (overflow > 0); 1918 1919 /* Now recompute all bit lengths, scanning in increasing frequency. 1920 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 1921 * lengths instead of fixing only the wrong ones. This idea is taken 1922 * from 'ar' written by Haruhiko Okumura.) 1923 */ 1924 for (bits = max_length; bits != 0; bits--) { 1925 n = s->bl_count[bits]; 1926 while (n != 0) { 1927 m = s->heap[--h]; 1928 if (m > max_code) continue; 1929 if (tree[m].Len != (unsigned) bits) { 1930 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 1931 s->opt_len += ((long)bits - (long)tree[m].Len) 1932 *(long)tree[m].Freq; 1933 tree[m].Len = (ush)bits; 1934 } 1935 n--; 1936 } 1937 } 1938 } 1939 1940 /* =========================================================================== 1941 * Generate the codes for a given tree and bit counts (which need not be 1942 * optimal). 1943 * IN assertion: the array bl_count contains the bit length statistics for 1944 * the given tree and the field len is set for all tree elements. 1945 * OUT assertion: the field code is set for all tree elements of non 1946 * zero code length. 1947 */ 1948 local void gen_codes (tree, max_code, bl_count) 1949 ct_data *tree; /* the tree to decorate */ 1950 int max_code; /* largest code with non zero frequency */ 1951 ushf *bl_count; /* number of codes at each bit length */ 1952 { 1953 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 1954 ush code = 0; /* running code value */ 1955 int bits; /* bit index */ 1956 int n; /* code index */ 1957 1958 /* The distribution counts are first used to generate the code values 1959 * without bit reversal. 1960 */ 1961 for (bits = 1; bits <= MAX_BITS; bits++) { 1962 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 1963 } 1964 /* Check that the bit counts in bl_count are consistent. The last code 1965 * must be all ones. 1966 */ 1967 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 1968 "inconsistent bit counts"); 1969 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 1970 1971 for (n = 0; n <= max_code; n++) { 1972 int len = tree[n].Len; 1973 if (len == 0) continue; 1974 /* Now reverse the bits */ 1975 tree[n].Code = bi_reverse(next_code[len]++, len); 1976 1977 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 1978 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 1979 } 1980 } 1981 1982 /* =========================================================================== 1983 * Construct one Huffman tree and assigns the code bit strings and lengths. 1984 * Update the total bit length for the current block. 1985 * IN assertion: the field freq is set for all tree elements. 1986 * OUT assertions: the fields len and code are set to the optimal bit length 1987 * and corresponding code. The length opt_len is updated; static_len is 1988 * also updated if stree is not null. The field max_code is set. 1989 */ 1990 local void build_tree(s, desc) 1991 deflate_state *s; 1992 tree_desc *desc; /* the tree descriptor */ 1993 { 1994 ct_data *tree = desc->dyn_tree; 1995 ct_data *stree = desc->stat_desc->static_tree; 1996 int elems = desc->stat_desc->elems; 1997 int n, m; /* iterate over heap elements */ 1998 int max_code = -1; /* largest code with non zero frequency */ 1999 int node; /* new node being created */ 2000 2001 /* Construct the initial heap, with least frequent element in 2002 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2003 * heap[0] is not used. 2004 */ 2005 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2006 2007 for (n = 0; n < elems; n++) { 2008 if (tree[n].Freq != 0) { 2009 s->heap[++(s->heap_len)] = max_code = n; 2010 s->depth[n] = 0; 2011 } else { 2012 tree[n].Len = 0; 2013 } 2014 } 2015 2016 /* The pkzip format requires that at least one distance code exists, 2017 * and that at least one bit should be sent even if there is only one 2018 * possible code. So to avoid special checks later on we force at least 2019 * two codes of non zero frequency. 2020 */ 2021 while (s->heap_len < 2) { 2022 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2023 tree[node].Freq = 1; 2024 s->depth[node] = 0; 2025 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2026 /* node is 0 or 1 so it does not have extra bits */ 2027 } 2028 desc->max_code = max_code; 2029 2030 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2031 * establish sub-heaps of increasing lengths: 2032 */ 2033 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2034 2035 /* Construct the Huffman tree by repeatedly combining the least two 2036 * frequent nodes. 2037 */ 2038 node = elems; /* next internal node of the tree */ 2039 do { 2040 pqremove(s, tree, n); /* n = node of least frequency */ 2041 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2042 2043 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2044 s->heap[--(s->heap_max)] = m; 2045 2046 /* Create a new node father of n and m */ 2047 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2048 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2049 tree[n].Dad = tree[m].Dad = (ush)node; 2050 #ifdef DUMP_BL_TREE 2051 if (tree == s->bl_tree) { 2052 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2053 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2054 } 2055 #endif 2056 /* and insert the new node in the heap */ 2057 s->heap[SMALLEST] = node++; 2058 pqdownheap(s, tree, SMALLEST); 2059 2060 } while (s->heap_len >= 2); 2061 2062 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2063 2064 /* At this point, the fields freq and dad are set. We can now 2065 * generate the bit lengths. 2066 */ 2067 gen_bitlen(s, (tree_desc *)desc); 2068 2069 /* The field len is now set, we can generate the bit codes */ 2070 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2071 } 2072 2073 /* =========================================================================== 2074 * Scan a literal or distance tree to determine the frequencies of the codes 2075 * in the bit length tree. 2076 */ 2077 local void scan_tree (s, tree, max_code) 2078 deflate_state *s; 2079 ct_data *tree; /* the tree to be scanned */ 2080 int max_code; /* and its largest code of non zero frequency */ 2081 { 2082 int n; /* iterates over all tree elements */ 2083 int prevlen = -1; /* last emitted length */ 2084 int curlen; /* length of current code */ 2085 int nextlen = tree[0].Len; /* length of next code */ 2086 int count = 0; /* repeat count of the current code */ 2087 int max_count = 7; /* max repeat count */ 2088 int min_count = 4; /* min repeat count */ 2089 2090 if (nextlen == 0) max_count = 138, min_count = 3; 2091 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2092 2093 for (n = 0; n <= max_code; n++) { 2094 curlen = nextlen; nextlen = tree[n+1].Len; 2095 if (++count < max_count && curlen == nextlen) { 2096 continue; 2097 } else if (count < min_count) { 2098 s->bl_tree[curlen].Freq += count; 2099 } else if (curlen != 0) { 2100 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2101 s->bl_tree[REP_3_6].Freq++; 2102 } else if (count <= 10) { 2103 s->bl_tree[REPZ_3_10].Freq++; 2104 } else { 2105 s->bl_tree[REPZ_11_138].Freq++; 2106 } 2107 count = 0; prevlen = curlen; 2108 if (nextlen == 0) { 2109 max_count = 138, min_count = 3; 2110 } else if (curlen == nextlen) { 2111 max_count = 6, min_count = 3; 2112 } else { 2113 max_count = 7, min_count = 4; 2114 } 2115 } 2116 } 2117 2118 /* =========================================================================== 2119 * Send a literal or distance tree in compressed form, using the codes in 2120 * bl_tree. 2121 */ 2122 local void send_tree (s, tree, max_code) 2123 deflate_state *s; 2124 ct_data *tree; /* the tree to be scanned */ 2125 int max_code; /* and its largest code of non zero frequency */ 2126 { 2127 int n; /* iterates over all tree elements */ 2128 int prevlen = -1; /* last emitted length */ 2129 int curlen; /* length of current code */ 2130 int nextlen = tree[0].Len; /* length of next code */ 2131 int count = 0; /* repeat count of the current code */ 2132 int max_count = 7; /* max repeat count */ 2133 int min_count = 4; /* min repeat count */ 2134 2135 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2136 if (nextlen == 0) max_count = 138, min_count = 3; 2137 2138 for (n = 0; n <= max_code; n++) { 2139 curlen = nextlen; nextlen = tree[n+1].Len; 2140 if (++count < max_count && curlen == nextlen) { 2141 continue; 2142 } else if (count < min_count) { 2143 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2144 2145 } else if (curlen != 0) { 2146 if (curlen != prevlen) { 2147 send_code(s, curlen, s->bl_tree); count--; 2148 } 2149 Assert(count >= 3 && count <= 6, " 3_6?"); 2150 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2151 2152 } else if (count <= 10) { 2153 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2154 2155 } else { 2156 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2157 } 2158 count = 0; prevlen = curlen; 2159 if (nextlen == 0) { 2160 max_count = 138, min_count = 3; 2161 } else if (curlen == nextlen) { 2162 max_count = 6, min_count = 3; 2163 } else { 2164 max_count = 7, min_count = 4; 2165 } 2166 } 2167 } 2168 2169 /* =========================================================================== 2170 * Construct the Huffman tree for the bit lengths and return the index in 2171 * bl_order of the last bit length code to send. 2172 */ 2173 local int build_bl_tree(s) 2174 deflate_state *s; 2175 { 2176 int max_blindex; /* index of last bit length code of non zero freq */ 2177 2178 /* Determine the bit length frequencies for literal and distance trees */ 2179 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2180 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2181 2182 /* Build the bit length tree: */ 2183 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2184 /* opt_len now includes the length of the tree representations, except 2185 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2186 */ 2187 2188 /* Determine the number of bit length codes to send. The pkzip format 2189 * requires that at least 4 bit length codes be sent. (appnote.txt says 2190 * 3 but the actual value used is 4.) 2191 */ 2192 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2193 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2194 } 2195 /* Update opt_len to include the bit length tree and counts */ 2196 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2197 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2198 s->opt_len, s->static_len)); 2199 2200 return max_blindex; 2201 } 2202 2203 /* =========================================================================== 2204 * Send the header for a block using dynamic Huffman trees: the counts, the 2205 * lengths of the bit length codes, the literal tree and the distance tree. 2206 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2207 */ 2208 local void send_all_trees(s, lcodes, dcodes, blcodes) 2209 deflate_state *s; 2210 int lcodes, dcodes, blcodes; /* number of codes for each tree */ 2211 { 2212 int rank; /* index in bl_order */ 2213 2214 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2215 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2216 "too many codes"); 2217 Tracev((stderr, "\nbl counts: ")); 2218 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2219 send_bits(s, dcodes-1, 5); 2220 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2221 for (rank = 0; rank < blcodes; rank++) { 2222 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2223 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2224 } 2225 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2226 2227 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2228 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2229 2230 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2231 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2232 } 2233 2234 /* =========================================================================== 2235 * Send a stored block 2236 */ 2237 local void ct_stored_block(s, buf, stored_len, eof) 2238 deflate_state *s; 2239 charf *buf; /* input block */ 2240 ulg stored_len; /* length of input block */ 2241 int eof; /* true if this is the last block for a file */ 2242 { 2243 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2244 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L; 2245 s->compressed_len += (stored_len + 4) << 3; 2246 2247 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2248 } 2249 2250 /* Send just the `stored block' type code without any length bytes or data. 2251 */ 2252 local void ct_stored_type_only(s) 2253 deflate_state *s; 2254 { 2255 send_bits(s, (STORED_BLOCK << 1), 3); 2256 bi_windup(s); 2257 s->compressed_len = (s->compressed_len + 3) & ~7L; 2258 } 2259 2260 2261 /* =========================================================================== 2262 * Send one empty static block to give enough lookahead for inflate. 2263 * This takes 10 bits, of which 7 may remain in the bit buffer. 2264 * The current inflate code requires 9 bits of lookahead. If the EOB 2265 * code for the previous block was coded on 5 bits or less, inflate 2266 * may have only 5+3 bits of lookahead to decode this EOB. 2267 * (There are no problems if the previous block is stored or fixed.) 2268 */ 2269 local void ct_align(s) 2270 deflate_state *s; 2271 { 2272 send_bits(s, STATIC_TREES<<1, 3); 2273 send_code(s, END_BLOCK, static_ltree); 2274 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2275 bi_flush(s); 2276 /* Of the 10 bits for the empty block, we have already sent 2277 * (10 - bi_valid) bits. The lookahead for the EOB of the previous 2278 * block was thus its length plus what we have just sent. 2279 */ 2280 if (s->last_eob_len + 10 - s->bi_valid < 9) { 2281 send_bits(s, STATIC_TREES<<1, 3); 2282 send_code(s, END_BLOCK, static_ltree); 2283 s->compressed_len += 10L; 2284 bi_flush(s); 2285 } 2286 s->last_eob_len = 7; 2287 } 2288 2289 /* =========================================================================== 2290 * Determine the best encoding for the current block: dynamic trees, static 2291 * trees or store, and output the encoded block to the zip file. This function 2292 * returns the total compressed length for the file so far. 2293 */ 2294 local ulg ct_flush_block(s, buf, stored_len, flush) 2295 deflate_state *s; 2296 charf *buf; /* input block, or NULL if too old */ 2297 ulg stored_len; /* length of input block */ 2298 int flush; /* Z_FINISH if this is the last block for a file */ 2299 { 2300 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2301 int max_blindex; /* index of last bit length code of non zero freq */ 2302 int eof = flush == Z_FINISH; 2303 2304 ++s->blocks_in_packet; 2305 2306 /* Check if the file is ascii or binary */ 2307 if (s->data_type == UNKNOWN) set_data_type(s); 2308 2309 /* Construct the literal and distance trees */ 2310 build_tree(s, (tree_desc *)(&(s->l_desc))); 2311 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2312 s->static_len)); 2313 2314 build_tree(s, (tree_desc *)(&(s->d_desc))); 2315 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2316 s->static_len)); 2317 /* At this point, opt_len and static_len are the total bit lengths of 2318 * the compressed block data, excluding the tree representations. 2319 */ 2320 2321 /* Build the bit length tree for the above two trees, and get the index 2322 * in bl_order of the last bit length code to send. 2323 */ 2324 max_blindex = build_bl_tree(s); 2325 2326 /* Determine the best encoding. Compute first the block length in bytes */ 2327 opt_lenb = (s->opt_len+3+7)>>3; 2328 static_lenb = (s->static_len+3+7)>>3; 2329 2330 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2331 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2332 s->last_lit)); 2333 2334 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2335 2336 /* If compression failed and this is the first and last block, 2337 * and if the .zip file can be seeked (to rewrite the local header), 2338 * the whole file is transformed into a stored file: 2339 */ 2340 #ifdef STORED_FILE_OK 2341 # ifdef FORCE_STORED_FILE 2342 if (eof && compressed_len == 0L) /* force stored file */ 2343 # else 2344 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) 2345 # endif 2346 { 2347 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2348 if (buf == (charf*)0) error ("block vanished"); 2349 2350 copy_block(buf, (unsigned)stored_len, 0); /* without header */ 2351 s->compressed_len = stored_len << 3; 2352 s->method = STORED; 2353 } else 2354 #endif /* STORED_FILE_OK */ 2355 2356 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum 2357 * compression, and this block contains all the data since the last 2358 * time we used Z_PACKET_FLUSH, then just omit this block completely 2359 * from the output. 2360 */ 2361 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1 2362 && opt_lenb > stored_len - s->minCompr) { 2363 s->blocks_in_packet = 0; 2364 /* output nothing */ 2365 } else 2366 2367 #ifdef FORCE_STORED 2368 if (buf != (char*)0) /* force stored block */ 2369 #else 2370 if (stored_len+4 <= opt_lenb && buf != (char*)0) 2371 /* 4: two words for the lengths */ 2372 #endif 2373 { 2374 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2375 * Otherwise we can't have processed more than WSIZE input bytes since 2376 * the last block flush, because compression would have been 2377 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2378 * transform a block into a stored block. 2379 */ 2380 ct_stored_block(s, buf, stored_len, eof); 2381 } else 2382 2383 #ifdef FORCE_STATIC 2384 if (static_lenb >= 0) /* force static trees */ 2385 #else 2386 if (static_lenb == opt_lenb) 2387 #endif 2388 { 2389 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2390 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2391 s->compressed_len += 3 + s->static_len; 2392 } else { 2393 send_bits(s, (DYN_TREES<<1)+eof, 3); 2394 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2395 max_blindex+1); 2396 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2397 s->compressed_len += 3 + s->opt_len; 2398 } 2399 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2400 init_block(s); 2401 2402 if (eof) { 2403 bi_windup(s); 2404 s->compressed_len += 7; /* align on byte boundary */ 2405 } 2406 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2407 s->compressed_len-7*eof)); 2408 2409 return s->compressed_len >> 3; 2410 } 2411 2412 /* =========================================================================== 2413 * Save the match info and tally the frequency counts. Return true if 2414 * the current block must be flushed. 2415 */ 2416 local int ct_tally (s, dist, lc) 2417 deflate_state *s; 2418 int dist; /* distance of matched string */ 2419 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 2420 { 2421 s->d_buf[s->last_lit] = (ush)dist; 2422 s->l_buf[s->last_lit++] = (uch)lc; 2423 if (dist == 0) { 2424 /* lc is the unmatched char */ 2425 s->dyn_ltree[lc].Freq++; 2426 } else { 2427 s->matches++; 2428 /* Here, lc is the match length - MIN_MATCH */ 2429 dist--; /* dist = match distance - 1 */ 2430 Assert((ush)dist < (ush)MAX_DIST(s) && 2431 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2432 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match"); 2433 2434 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2435 s->dyn_dtree[d_code(dist)].Freq++; 2436 } 2437 2438 /* Try to guess if it is profitable to stop the current block here */ 2439 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2440 /* Compute an upper bound for the compressed length */ 2441 ulg out_length = (ulg)s->last_lit*8L; 2442 ulg in_length = (ulg)s->strstart - s->block_start; 2443 int dcode; 2444 for (dcode = 0; dcode < D_CODES; dcode++) { 2445 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2446 (5L+extra_dbits[dcode]); 2447 } 2448 out_length >>= 3; 2449 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2450 s->last_lit, in_length, out_length, 2451 100L - out_length*100L/in_length)); 2452 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2453 } 2454 return (s->last_lit == s->lit_bufsize-1); 2455 /* We avoid equality with lit_bufsize because of wraparound at 64K 2456 * on 16 bit machines and because stored blocks are restricted to 2457 * 64K-1 bytes. 2458 */ 2459 } 2460 2461 /* =========================================================================== 2462 * Send the block data compressed using the given Huffman trees 2463 */ 2464 local void compress_block(s, ltree, dtree) 2465 deflate_state *s; 2466 ct_data *ltree; /* literal tree */ 2467 ct_data *dtree; /* distance tree */ 2468 { 2469 unsigned dist; /* distance of matched string */ 2470 int lc; /* match length or unmatched char (if dist == 0) */ 2471 unsigned lx = 0; /* running index in l_buf */ 2472 unsigned code; /* the code to send */ 2473 int extra; /* number of extra bits to send */ 2474 2475 if (s->last_lit != 0) do { 2476 dist = s->d_buf[lx]; 2477 lc = s->l_buf[lx++]; 2478 if (dist == 0) { 2479 send_code(s, lc, ltree); /* send a literal byte */ 2480 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2481 } else { 2482 /* Here, lc is the match length - MIN_MATCH */ 2483 code = length_code[lc]; 2484 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2485 extra = extra_lbits[code]; 2486 if (extra != 0) { 2487 lc -= base_length[code]; 2488 send_bits(s, lc, extra); /* send the extra length bits */ 2489 } 2490 dist--; /* dist is now the match distance - 1 */ 2491 code = d_code(dist); 2492 Assert (code < D_CODES, "bad d_code"); 2493 2494 send_code(s, code, dtree); /* send the distance code */ 2495 extra = extra_dbits[code]; 2496 if (extra != 0) { 2497 dist -= base_dist[code]; 2498 send_bits(s, dist, extra); /* send the extra distance bits */ 2499 } 2500 } /* literal or match pair ? */ 2501 2502 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2503 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2504 2505 } while (lx < s->last_lit); 2506 2507 send_code(s, END_BLOCK, ltree); 2508 s->last_eob_len = ltree[END_BLOCK].Len; 2509 } 2510 2511 /* =========================================================================== 2512 * Set the data type to ASCII or BINARY, using a crude approximation: 2513 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2514 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2515 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2516 */ 2517 local void set_data_type(s) 2518 deflate_state *s; 2519 { 2520 int n = 0; 2521 unsigned ascii_freq = 0; 2522 unsigned bin_freq = 0; 2523 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2524 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2525 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2526 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII); 2527 } 2528 2529 /* =========================================================================== 2530 * Reverse the first len bits of a code, using straightforward code (a faster 2531 * method would use a table) 2532 * IN assertion: 1 <= len <= 15 2533 */ 2534 local unsigned bi_reverse(code, len) 2535 unsigned code; /* the value to invert */ 2536 int len; /* its bit length */ 2537 { 2538 register unsigned res = 0; 2539 do { 2540 res |= code & 1; 2541 code >>= 1, res <<= 1; 2542 } while (--len > 0); 2543 return res >> 1; 2544 } 2545 2546 /* =========================================================================== 2547 * Flush the bit buffer, keeping at most 7 bits in it. 2548 */ 2549 local void bi_flush(s) 2550 deflate_state *s; 2551 { 2552 if (s->bi_valid == 16) { 2553 put_short(s, s->bi_buf); 2554 s->bi_buf = 0; 2555 s->bi_valid = 0; 2556 } else if (s->bi_valid >= 8) { 2557 put_byte(s, (Byte)s->bi_buf); 2558 s->bi_buf >>= 8; 2559 s->bi_valid -= 8; 2560 } 2561 } 2562 2563 /* =========================================================================== 2564 * Flush the bit buffer and align the output on a byte boundary 2565 */ 2566 local void bi_windup(s) 2567 deflate_state *s; 2568 { 2569 if (s->bi_valid > 8) { 2570 put_short(s, s->bi_buf); 2571 } else if (s->bi_valid > 0) { 2572 put_byte(s, (Byte)s->bi_buf); 2573 } 2574 s->bi_buf = 0; 2575 s->bi_valid = 0; 2576 #ifdef DEBUG_ZLIB 2577 s->bits_sent = (s->bits_sent+7) & ~7; 2578 #endif 2579 } 2580 2581 /* =========================================================================== 2582 * Copy a stored block, storing first the length and its 2583 * one's complement if requested. 2584 */ 2585 local void copy_block(s, buf, len, header) 2586 deflate_state *s; 2587 charf *buf; /* the input data */ 2588 unsigned len; /* its length */ 2589 int header; /* true if block header must be written */ 2590 { 2591 bi_windup(s); /* align on byte boundary */ 2592 s->last_eob_len = 8; /* enough lookahead for inflate */ 2593 2594 if (header) { 2595 put_short(s, (ush)len); 2596 put_short(s, (ush)~len); 2597 #ifdef DEBUG_ZLIB 2598 s->bits_sent += 2*16; 2599 #endif 2600 } 2601 #ifdef DEBUG_ZLIB 2602 s->bits_sent += (ulg)len<<3; 2603 #endif 2604 while (len--) { 2605 put_byte(s, *buf++); 2606 } 2607 } 2608 2609 2610 /*+++++*/ 2611 /* infblock.h -- header to use infblock.c 2612 * Copyright (C) 1995 Mark Adler 2613 * For conditions of distribution and use, see copyright notice in zlib.h 2614 */ 2615 2616 /* WARNING: this file should *not* be used by applications. It is 2617 part of the implementation of the compression library and is 2618 subject to change. Applications should only use zlib.h. 2619 */ 2620 2621 struct inflate_blocks_state; 2622 typedef struct inflate_blocks_state FAR inflate_blocks_statef; 2623 2624 local inflate_blocks_statef * inflate_blocks_new OF(( 2625 z_stream *z, 2626 check_func c, /* check function */ 2627 uInt w)); /* window size */ 2628 2629 local int inflate_blocks OF(( 2630 inflate_blocks_statef *, 2631 z_stream *, 2632 int)); /* initial return code */ 2633 2634 local void inflate_blocks_reset OF(( 2635 inflate_blocks_statef *, 2636 z_stream *, 2637 uLongf *)); /* check value on output */ 2638 2639 local int inflate_blocks_free OF(( 2640 inflate_blocks_statef *, 2641 z_stream *, 2642 uLongf *)); /* check value on output */ 2643 2644 local int inflate_addhistory OF(( 2645 inflate_blocks_statef *, 2646 z_stream *)); 2647 2648 local int inflate_packet_flush OF(( 2649 inflate_blocks_statef *)); 2650 2651 /*+++++*/ 2652 /* inftrees.h -- header to use inftrees.c 2653 * Copyright (C) 1995 Mark Adler 2654 * For conditions of distribution and use, see copyright notice in zlib.h 2655 */ 2656 2657 /* WARNING: this file should *not* be used by applications. It is 2658 part of the implementation of the compression library and is 2659 subject to change. Applications should only use zlib.h. 2660 */ 2661 2662 /* Huffman code lookup table entry--this entry is four bytes for machines 2663 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 2664 2665 typedef struct inflate_huft_s FAR inflate_huft; 2666 2667 struct inflate_huft_s { 2668 union { 2669 struct { 2670 Byte Exop; /* number of extra bits or operation */ 2671 Byte Bits; /* number of bits in this code or subcode */ 2672 } what; 2673 uInt Nalloc; /* number of these allocated here */ 2674 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 2675 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 2676 union { 2677 uInt Base; /* literal, length base, or distance base */ 2678 inflate_huft *Next; /* pointer to next level of table */ 2679 } more; 2680 }; 2681 2682 #ifdef DEBUG_ZLIB 2683 local uInt inflate_hufts; 2684 #endif 2685 2686 local int inflate_trees_bits OF(( 2687 uIntf *, /* 19 code lengths */ 2688 uIntf *, /* bits tree desired/actual depth */ 2689 inflate_huft * FAR *, /* bits tree result */ 2690 z_stream *)); /* for zalloc, zfree functions */ 2691 2692 local int inflate_trees_dynamic OF(( 2693 uInt, /* number of literal/length codes */ 2694 uInt, /* number of distance codes */ 2695 uIntf *, /* that many (total) code lengths */ 2696 uIntf *, /* literal desired/actual bit depth */ 2697 uIntf *, /* distance desired/actual bit depth */ 2698 inflate_huft * FAR *, /* literal/length tree result */ 2699 inflate_huft * FAR *, /* distance tree result */ 2700 z_stream *)); /* for zalloc, zfree functions */ 2701 2702 local int inflate_trees_fixed OF(( 2703 uIntf *, /* literal desired/actual bit depth */ 2704 uIntf *, /* distance desired/actual bit depth */ 2705 inflate_huft * FAR *, /* literal/length tree result */ 2706 inflate_huft * FAR *)); /* distance tree result */ 2707 2708 local int inflate_trees_free OF(( 2709 inflate_huft *, /* tables to free */ 2710 z_stream *)); /* for zfree function */ 2711 2712 2713 /*+++++*/ 2714 /* infcodes.h -- header to use infcodes.c 2715 * Copyright (C) 1995 Mark Adler 2716 * For conditions of distribution and use, see copyright notice in zlib.h 2717 */ 2718 2719 /* WARNING: this file should *not* be used by applications. It is 2720 part of the implementation of the compression library and is 2721 subject to change. Applications should only use zlib.h. 2722 */ 2723 2724 struct inflate_codes_state; 2725 typedef struct inflate_codes_state FAR inflate_codes_statef; 2726 2727 local inflate_codes_statef *inflate_codes_new OF(( 2728 uInt, uInt, 2729 inflate_huft *, inflate_huft *, 2730 z_stream *)); 2731 2732 local int inflate_codes OF(( 2733 inflate_blocks_statef *, 2734 z_stream *, 2735 int)); 2736 2737 local void inflate_codes_free OF(( 2738 inflate_codes_statef *, 2739 z_stream *)); 2740 2741 2742 /*+++++*/ 2743 /* inflate.c -- zlib interface to inflate modules 2744 * Copyright (C) 1995 Mark Adler 2745 * For conditions of distribution and use, see copyright notice in zlib.h 2746 */ 2747 2748 /* inflate private state */ 2749 struct internal_state { 2750 2751 /* mode */ 2752 enum { 2753 METHOD, /* waiting for method byte */ 2754 FLAG, /* waiting for flag byte */ 2755 BLOCKS, /* decompressing blocks */ 2756 CHECK4, /* four check bytes to go */ 2757 CHECK3, /* three check bytes to go */ 2758 CHECK2, /* two check bytes to go */ 2759 CHECK1, /* one check byte to go */ 2760 DONE, /* finished check, done */ 2761 BAD} /* got an error--stay here */ 2762 mode; /* current inflate mode */ 2763 2764 /* mode dependent information */ 2765 union { 2766 uInt method; /* if FLAGS, method byte */ 2767 struct { 2768 uLong was; /* computed check value */ 2769 uLong need; /* stream check value */ 2770 } check; /* if CHECK, check values to compare */ 2771 uInt marker; /* if BAD, inflateSync's marker bytes count */ 2772 } sub; /* submode */ 2773 2774 /* mode independent information */ 2775 int nowrap; /* flag for no wrapper */ 2776 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 2777 inflate_blocks_statef 2778 *blocks; /* current inflate_blocks state */ 2779 2780 }; 2781 2782 2783 int inflateReset(z) 2784 z_stream *z; 2785 { 2786 uLong c; 2787 2788 if (z == Z_NULL || z->state == Z_NULL) 2789 return Z_STREAM_ERROR; 2790 z->total_in = z->total_out = 0; 2791 z->msg = Z_NULL; 2792 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 2793 inflate_blocks_reset(z->state->blocks, z, &c); 2794 Trace((stderr, "inflate: reset\n")); 2795 return Z_OK; 2796 } 2797 2798 2799 int inflateEnd(z) 2800 z_stream *z; 2801 { 2802 uLong c; 2803 2804 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 2805 return Z_STREAM_ERROR; 2806 if (z->state->blocks != Z_NULL) 2807 inflate_blocks_free(z->state->blocks, z, &c); 2808 ZFREE(z, z->state, sizeof(struct internal_state)); 2809 z->state = Z_NULL; 2810 Trace((stderr, "inflate: end\n")); 2811 return Z_OK; 2812 } 2813 2814 2815 int inflateInit2(z, w) 2816 z_stream *z; 2817 int w; 2818 { 2819 /* initialize state */ 2820 if (z == Z_NULL) 2821 return Z_STREAM_ERROR; 2822 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */ 2823 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */ 2824 if ((z->state = (struct internal_state FAR *) 2825 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 2826 return Z_MEM_ERROR; 2827 z->state->blocks = Z_NULL; 2828 2829 /* handle undocumented nowrap option (no zlib header or check) */ 2830 z->state->nowrap = 0; 2831 if (w < 0) 2832 { 2833 w = - w; 2834 z->state->nowrap = 1; 2835 } 2836 2837 /* set window size */ 2838 if (w < 8 || w > 15) 2839 { 2840 inflateEnd(z); 2841 return Z_STREAM_ERROR; 2842 } 2843 z->state->wbits = (uInt)w; 2844 2845 /* create inflate_blocks state */ 2846 if ((z->state->blocks = 2847 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w)) 2848 == Z_NULL) 2849 { 2850 inflateEnd(z); 2851 return Z_MEM_ERROR; 2852 } 2853 Trace((stderr, "inflate: allocated\n")); 2854 2855 /* reset state */ 2856 inflateReset(z); 2857 return Z_OK; 2858 } 2859 2860 2861 int inflateInit(z) 2862 z_stream *z; 2863 { 2864 return inflateInit2(z, DEF_WBITS); 2865 } 2866 2867 2868 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 2869 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 2870 2871 int inflate(z, f) 2872 z_stream *z; 2873 int f; 2874 { 2875 int r; 2876 uInt b; 2877 2878 if (z == Z_NULL || z->next_in == Z_NULL) 2879 return Z_STREAM_ERROR; 2880 r = Z_BUF_ERROR; 2881 while (1) switch (z->state->mode) 2882 { 2883 case METHOD: 2884 NEEDBYTE 2885 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED) 2886 { 2887 z->state->mode = BAD; 2888 z->msg = "unknown compression method"; 2889 z->state->sub.marker = 5; /* can't try inflateSync */ 2890 break; 2891 } 2892 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 2893 { 2894 z->state->mode = BAD; 2895 z->msg = "invalid window size"; 2896 z->state->sub.marker = 5; /* can't try inflateSync */ 2897 break; 2898 } 2899 z->state->mode = FLAG; 2900 case FLAG: 2901 NEEDBYTE 2902 if ((b = NEXTBYTE) & 0x20) 2903 { 2904 z->state->mode = BAD; 2905 z->msg = "invalid reserved bit"; 2906 z->state->sub.marker = 5; /* can't try inflateSync */ 2907 break; 2908 } 2909 if (((z->state->sub.method << 8) + b) % 31) 2910 { 2911 z->state->mode = BAD; 2912 z->msg = "incorrect header check"; 2913 z->state->sub.marker = 5; /* can't try inflateSync */ 2914 break; 2915 } 2916 Trace((stderr, "inflate: zlib header ok\n")); 2917 z->state->mode = BLOCKS; 2918 case BLOCKS: 2919 r = inflate_blocks(z->state->blocks, z, r); 2920 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 2921 r = inflate_packet_flush(z->state->blocks); 2922 if (r == Z_DATA_ERROR) 2923 { 2924 z->state->mode = BAD; 2925 z->state->sub.marker = 0; /* can try inflateSync */ 2926 break; 2927 } 2928 if (r != Z_STREAM_END) 2929 return r; 2930 r = Z_OK; 2931 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 2932 if (z->state->nowrap) 2933 { 2934 z->state->mode = DONE; 2935 break; 2936 } 2937 z->state->mode = CHECK4; 2938 case CHECK4: 2939 NEEDBYTE 2940 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 2941 z->state->mode = CHECK3; 2942 case CHECK3: 2943 NEEDBYTE 2944 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 2945 z->state->mode = CHECK2; 2946 case CHECK2: 2947 NEEDBYTE 2948 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 2949 z->state->mode = CHECK1; 2950 case CHECK1: 2951 NEEDBYTE 2952 z->state->sub.check.need += (uLong)NEXTBYTE; 2953 2954 if (z->state->sub.check.was != z->state->sub.check.need) 2955 { 2956 z->state->mode = BAD; 2957 z->msg = "incorrect data check"; 2958 z->state->sub.marker = 5; /* can't try inflateSync */ 2959 break; 2960 } 2961 Trace((stderr, "inflate: zlib check ok\n")); 2962 z->state->mode = DONE; 2963 case DONE: 2964 return Z_STREAM_END; 2965 case BAD: 2966 return Z_DATA_ERROR; 2967 default: 2968 return Z_STREAM_ERROR; 2969 } 2970 2971 empty: 2972 if (f != Z_PACKET_FLUSH) 2973 return r; 2974 z->state->mode = BAD; 2975 z->state->sub.marker = 0; /* can try inflateSync */ 2976 return Z_DATA_ERROR; 2977 } 2978 2979 /* 2980 * This subroutine adds the data at next_in/avail_in to the output history 2981 * without performing any output. The output buffer must be "caught up"; 2982 * i.e. no pending output (hence s->read equals s->write), and the state must 2983 * be BLOCKS (i.e. we should be willing to see the start of a series of 2984 * BLOCKS). On exit, the output will also be caught up, and the checksum 2985 * will have been updated if need be. 2986 */ 2987 2988 int inflateIncomp(z) 2989 z_stream *z; 2990 { 2991 if (z->state->mode != BLOCKS) 2992 return Z_DATA_ERROR; 2993 return inflate_addhistory(z->state->blocks, z); 2994 } 2995 2996 2997 int inflateSync(z) 2998 z_stream *z; 2999 { 3000 uInt n; /* number of bytes to look at */ 3001 Bytef *p; /* pointer to bytes */ 3002 uInt m; /* number of marker bytes found in a row */ 3003 uLong r, w; /* temporaries to save total_in and total_out */ 3004 3005 /* set up */ 3006 if (z == Z_NULL || z->state == Z_NULL) 3007 return Z_STREAM_ERROR; 3008 if (z->state->mode != BAD) 3009 { 3010 z->state->mode = BAD; 3011 z->state->sub.marker = 0; 3012 } 3013 if ((n = z->avail_in) == 0) 3014 return Z_BUF_ERROR; 3015 p = z->next_in; 3016 m = z->state->sub.marker; 3017 3018 /* search */ 3019 while (n && m < 4) 3020 { 3021 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3022 m++; 3023 else if (*p) 3024 m = 0; 3025 else 3026 m = 4 - m; 3027 p++, n--; 3028 } 3029 3030 /* restore */ 3031 z->total_in += p - z->next_in; 3032 z->next_in = p; 3033 z->avail_in = n; 3034 z->state->sub.marker = m; 3035 3036 /* return no joy or set up to restart on a new block */ 3037 if (m != 4) 3038 return Z_DATA_ERROR; 3039 r = z->total_in; w = z->total_out; 3040 inflateReset(z); 3041 z->total_in = r; z->total_out = w; 3042 z->state->mode = BLOCKS; 3043 return Z_OK; 3044 } 3045 3046 #undef NEEDBYTE 3047 #undef NEXTBYTE 3048 3049 /*+++++*/ 3050 /* infutil.h -- types and macros common to blocks and codes 3051 * Copyright (C) 1995 Mark Adler 3052 * For conditions of distribution and use, see copyright notice in zlib.h 3053 */ 3054 3055 /* WARNING: this file should *not* be used by applications. It is 3056 part of the implementation of the compression library and is 3057 subject to change. Applications should only use zlib.h. 3058 */ 3059 3060 /* inflate blocks semi-private state */ 3061 struct inflate_blocks_state { 3062 3063 /* mode */ 3064 enum { 3065 TYPE, /* get type bits (3, including end bit) */ 3066 LENS, /* get lengths for stored */ 3067 STORED, /* processing stored block */ 3068 TABLE, /* get table lengths */ 3069 BTREE, /* get bit lengths tree for a dynamic block */ 3070 DTREE, /* get length, distance trees for a dynamic block */ 3071 CODES, /* processing fixed or dynamic block */ 3072 DRY, /* output remaining window bytes */ 3073 DONEB, /* finished last block, done */ 3074 BADB} /* got a data error--stuck here */ 3075 mode; /* current inflate_block mode */ 3076 3077 /* mode dependent information */ 3078 union { 3079 uInt left; /* if STORED, bytes left to copy */ 3080 struct { 3081 uInt table; /* table lengths (14 bits) */ 3082 uInt index; /* index into blens (or border) */ 3083 uIntf *blens; /* bit lengths of codes */ 3084 uInt bb; /* bit length tree depth */ 3085 inflate_huft *tb; /* bit length decoding tree */ 3086 int nblens; /* # elements allocated at blens */ 3087 } trees; /* if DTREE, decoding info for trees */ 3088 struct { 3089 inflate_huft *tl, *td; /* trees to free */ 3090 inflate_codes_statef 3091 *codes; 3092 } decode; /* if CODES, current state */ 3093 } sub; /* submode */ 3094 uInt last; /* true if this block is the last block */ 3095 3096 /* mode independent information */ 3097 uInt bitk; /* bits in bit buffer */ 3098 uLong bitb; /* bit buffer */ 3099 Bytef *window; /* sliding window */ 3100 Bytef *end; /* one byte after sliding window */ 3101 Bytef *read; /* window read pointer */ 3102 Bytef *write; /* window write pointer */ 3103 check_func checkfn; /* check function */ 3104 uLong check; /* check on output */ 3105 3106 }; 3107 3108 3109 /* defines for inflate input/output */ 3110 /* update pointers and return */ 3111 #define UPDBITS {s->bitb=b;s->bitk=k;} 3112 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3113 #define UPDOUT {s->write=q;} 3114 #define UPDATE {UPDBITS UPDIN UPDOUT} 3115 #define LEAVE {UPDATE return inflate_flush(s,z,r);} 3116 /* get bytes and bits */ 3117 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3118 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3119 #define NEXTBYTE (n--,*p++) 3120 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3121 #define DUMPBITS(j) {b>>=(j);k-=(j);} 3122 /* output bytes */ 3123 #define WAVAIL (q<s->read?s->read-q-1:s->end-q) 3124 #define LOADOUT {q=s->write;m=WAVAIL;} 3125 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}} 3126 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3127 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} 3128 #define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3129 /* load local pointers */ 3130 #define LOAD {LOADIN LOADOUT} 3131 3132 /* And'ing with mask[n] masks the lower n bits */ 3133 local uInt inflate_mask[] = { 3134 0x0000, 3135 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 3136 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 3137 }; 3138 3139 /* copy as much as possible from the sliding window to the output area */ 3140 local int inflate_flush OF(( 3141 inflate_blocks_statef *, 3142 z_stream *, 3143 int)); 3144 3145 /*+++++*/ 3146 /* inffast.h -- header to use inffast.c 3147 * Copyright (C) 1995 Mark Adler 3148 * For conditions of distribution and use, see copyright notice in zlib.h 3149 */ 3150 3151 /* WARNING: this file should *not* be used by applications. It is 3152 part of the implementation of the compression library and is 3153 subject to change. Applications should only use zlib.h. 3154 */ 3155 3156 local int inflate_fast OF(( 3157 uInt, 3158 uInt, 3159 inflate_huft *, 3160 inflate_huft *, 3161 inflate_blocks_statef *, 3162 z_stream *)); 3163 3164 3165 /*+++++*/ 3166 /* infblock.c -- interpret and process block types to last block 3167 * Copyright (C) 1995 Mark Adler 3168 * For conditions of distribution and use, see copyright notice in zlib.h 3169 */ 3170 3171 /* Table for deflate from PKZIP's appnote.txt. */ 3172 local uInt border[] = { /* Order of the bit length code lengths */ 3173 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3174 3175 /* 3176 Notes beyond the 1.93a appnote.txt: 3177 3178 1. Distance pointers never point before the beginning of the output 3179 stream. 3180 2. Distance pointers can point back across blocks, up to 32k away. 3181 3. There is an implied maximum of 7 bits for the bit length table and 3182 15 bits for the actual data. 3183 4. If only one code exists, then it is encoded using one bit. (Zero 3184 would be more efficient, but perhaps a little confusing.) If two 3185 codes exist, they are coded using one bit each (0 and 1). 3186 5. There is no way of sending zero distance codes--a dummy must be 3187 sent if there are none. (History: a pre 2.0 version of PKZIP would 3188 store blocks with no distance codes, but this was discovered to be 3189 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3190 zero distance codes, which is sent as one code of zero bits in 3191 length. 3192 6. There are up to 286 literal/length codes. Code 256 represents the 3193 end-of-block. Note however that the static length tree defines 3194 288 codes just to fill out the Huffman codes. Codes 286 and 287 3195 cannot be used though, since there is no length base or extra bits 3196 defined for them. Similarily, there are up to 30 distance codes. 3197 However, static trees define 32 codes (all 5 bits) to fill out the 3198 Huffman codes, but the last two had better not show up in the data. 3199 7. Unzip can check dynamic Huffman blocks for complete code sets. 3200 The exception is that a single code would not be complete (see #4). 3201 8. The five bits following the block type is really the number of 3202 literal codes sent minus 257. 3203 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3204 (1+6+6). Therefore, to output three times the length, you output 3205 three codes (1+1+1), whereas to output four times the same length, 3206 you only need two codes (1+3). Hmm. 3207 10. In the tree reconstruction algorithm, Code = Code + Increment 3208 only if BitLength(i) is not zero. (Pretty obvious.) 3209 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3210 12. Note: length code 284 can represent 227-258, but length code 285 3211 really is 258. The last length deserves its own, short code 3212 since it gets used a lot in very redundant files. The length 3213 258 is special since 258 - 3 (the min match length) is 255. 3214 13. The literal/length and distance code bit lengths are read as a 3215 single stream of lengths. It is possible (and advantageous) for 3216 a repeat code (16, 17, or 18) to go across the boundary between 3217 the two sets of lengths. 3218 */ 3219 3220 3221 local void inflate_blocks_reset(s, z, c) 3222 inflate_blocks_statef *s; 3223 z_stream *z; 3224 uLongf *c; 3225 { 3226 if (s->checkfn != Z_NULL) 3227 *c = s->check; 3228 if (s->mode == BTREE || s->mode == DTREE) 3229 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt)); 3230 if (s->mode == CODES) 3231 { 3232 inflate_codes_free(s->sub.decode.codes, z); 3233 inflate_trees_free(s->sub.decode.td, z); 3234 inflate_trees_free(s->sub.decode.tl, z); 3235 } 3236 s->mode = TYPE; 3237 s->bitk = 0; 3238 s->bitb = 0; 3239 s->read = s->write = s->window; 3240 if (s->checkfn != Z_NULL) 3241 s->check = (*s->checkfn)(0L, Z_NULL, 0); 3242 Trace((stderr, "inflate: blocks reset\n")); 3243 } 3244 3245 3246 local inflate_blocks_statef *inflate_blocks_new(z, c, w) 3247 z_stream *z; 3248 check_func c; 3249 uInt w; 3250 { 3251 inflate_blocks_statef *s; 3252 3253 if ((s = (inflate_blocks_statef *)ZALLOC 3254 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3255 return s; 3256 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3257 { 3258 ZFREE(z, s, sizeof(struct inflate_blocks_state)); 3259 return Z_NULL; 3260 } 3261 s->end = s->window + w; 3262 s->checkfn = c; 3263 s->mode = TYPE; 3264 Trace((stderr, "inflate: blocks allocated\n")); 3265 inflate_blocks_reset(s, z, &s->check); 3266 return s; 3267 } 3268 3269 3270 local int inflate_blocks(s, z, r) 3271 inflate_blocks_statef *s; 3272 z_stream *z; 3273 int r; 3274 { 3275 uInt t; /* temporary storage */ 3276 uLong b; /* bit buffer */ 3277 uInt k; /* bits in bit buffer */ 3278 Bytef *p; /* input data pointer */ 3279 uInt n; /* bytes available there */ 3280 Bytef *q; /* output window write pointer */ 3281 uInt m; /* bytes to end of window or read pointer */ 3282 3283 /* copy input/output information to locals (UPDATE macro restores) */ 3284 LOAD 3285 3286 /* process input based on current state */ 3287 while (1) switch (s->mode) 3288 { 3289 case TYPE: 3290 NEEDBITS(3) 3291 t = (uInt)b & 7; 3292 s->last = t & 1; 3293 switch (t >> 1) 3294 { 3295 case 0: /* stored */ 3296 Trace((stderr, "inflate: stored block%s\n", 3297 s->last ? " (last)" : "")); 3298 DUMPBITS(3) 3299 t = k & 7; /* go to byte boundary */ 3300 DUMPBITS(t) 3301 s->mode = LENS; /* get length of stored block */ 3302 break; 3303 case 1: /* fixed */ 3304 Trace((stderr, "inflate: fixed codes block%s\n", 3305 s->last ? " (last)" : "")); 3306 { 3307 uInt bl, bd; 3308 inflate_huft *tl, *td; 3309 3310 inflate_trees_fixed(&bl, &bd, &tl, &td); 3311 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3312 if (s->sub.decode.codes == Z_NULL) 3313 { 3314 r = Z_MEM_ERROR; 3315 LEAVE 3316 } 3317 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3318 s->sub.decode.td = Z_NULL; 3319 } 3320 DUMPBITS(3) 3321 s->mode = CODES; 3322 break; 3323 case 2: /* dynamic */ 3324 Trace((stderr, "inflate: dynamic codes block%s\n", 3325 s->last ? " (last)" : "")); 3326 DUMPBITS(3) 3327 s->mode = TABLE; 3328 break; 3329 case 3: /* illegal */ 3330 DUMPBITS(3) 3331 s->mode = BADB; 3332 z->msg = "invalid block type"; 3333 r = Z_DATA_ERROR; 3334 LEAVE 3335 } 3336 break; 3337 case LENS: 3338 NEEDBITS(32) 3339 if (((~b) >> 16) != (b & 0xffff)) 3340 { 3341 s->mode = BADB; 3342 z->msg = "invalid stored block lengths"; 3343 r = Z_DATA_ERROR; 3344 LEAVE 3345 } 3346 s->sub.left = (uInt)b & 0xffff; 3347 b = k = 0; /* dump bits */ 3348 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3349 s->mode = s->sub.left ? STORED : TYPE; 3350 break; 3351 case STORED: 3352 if (n == 0) 3353 LEAVE 3354 NEEDOUT 3355 t = s->sub.left; 3356 if (t > n) t = n; 3357 if (t > m) t = m; 3358 zmemcpy(q, p, t); 3359 p += t; n -= t; 3360 q += t; m -= t; 3361 if ((s->sub.left -= t) != 0) 3362 break; 3363 Tracev((stderr, "inflate: stored end, %lu total out\n", 3364 z->total_out + (q >= s->read ? q - s->read : 3365 (s->end - s->read) + (q - s->window)))); 3366 s->mode = s->last ? DRY : TYPE; 3367 break; 3368 case TABLE: 3369 NEEDBITS(14) 3370 s->sub.trees.table = t = (uInt)b & 0x3fff; 3371 #ifndef PKZIP_BUG_WORKAROUND 3372 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3373 { 3374 s->mode = BADB; 3375 z->msg = "too many length or distance symbols"; 3376 r = Z_DATA_ERROR; 3377 LEAVE 3378 } 3379 #endif 3380 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3381 if (t < 19) 3382 t = 19; 3383 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3384 { 3385 r = Z_MEM_ERROR; 3386 LEAVE 3387 } 3388 s->sub.trees.nblens = t; 3389 DUMPBITS(14) 3390 s->sub.trees.index = 0; 3391 Tracev((stderr, "inflate: table sizes ok\n")); 3392 s->mode = BTREE; 3393 case BTREE: 3394 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3395 { 3396 NEEDBITS(3) 3397 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3398 DUMPBITS(3) 3399 } 3400 while (s->sub.trees.index < 19) 3401 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3402 s->sub.trees.bb = 7; 3403 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3404 &s->sub.trees.tb, z); 3405 if (t != Z_OK) 3406 { 3407 r = t; 3408 if (r == Z_DATA_ERROR) 3409 s->mode = BADB; 3410 LEAVE 3411 } 3412 s->sub.trees.index = 0; 3413 Tracev((stderr, "inflate: bits tree ok\n")); 3414 s->mode = DTREE; 3415 case DTREE: 3416 while (t = s->sub.trees.table, 3417 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3418 { 3419 inflate_huft *h; 3420 uInt i, j, c; 3421 3422 t = s->sub.trees.bb; 3423 NEEDBITS(t) 3424 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3425 t = h->word.what.Bits; 3426 c = h->more.Base; 3427 if (c < 16) 3428 { 3429 DUMPBITS(t) 3430 s->sub.trees.blens[s->sub.trees.index++] = c; 3431 } 3432 else /* c == 16..18 */ 3433 { 3434 i = c == 18 ? 7 : c - 14; 3435 j = c == 18 ? 11 : 3; 3436 NEEDBITS(t + i) 3437 DUMPBITS(t) 3438 j += (uInt)b & inflate_mask[i]; 3439 DUMPBITS(i) 3440 i = s->sub.trees.index; 3441 t = s->sub.trees.table; 3442 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3443 (c == 16 && i < 1)) 3444 { 3445 s->mode = BADB; 3446 z->msg = "invalid bit length repeat"; 3447 r = Z_DATA_ERROR; 3448 LEAVE 3449 } 3450 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3451 do { 3452 s->sub.trees.blens[i++] = c; 3453 } while (--j); 3454 s->sub.trees.index = i; 3455 } 3456 } 3457 inflate_trees_free(s->sub.trees.tb, z); 3458 s->sub.trees.tb = Z_NULL; 3459 { 3460 uInt bl, bd; 3461 inflate_huft *tl, *td; 3462 inflate_codes_statef *c; 3463 3464 bl = 9; /* must be <= 9 for lookahead assumptions */ 3465 bd = 6; /* must be <= 9 for lookahead assumptions */ 3466 t = s->sub.trees.table; 3467 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3468 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3469 if (t != Z_OK) 3470 { 3471 if (t == (uInt)Z_DATA_ERROR) 3472 s->mode = BADB; 3473 r = t; 3474 LEAVE 3475 } 3476 Tracev((stderr, "inflate: trees ok\n")); 3477 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3478 { 3479 inflate_trees_free(td, z); 3480 inflate_trees_free(tl, z); 3481 r = Z_MEM_ERROR; 3482 LEAVE 3483 } 3484 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt)); 3485 s->sub.decode.codes = c; 3486 s->sub.decode.tl = tl; 3487 s->sub.decode.td = td; 3488 } 3489 s->mode = CODES; 3490 case CODES: 3491 UPDATE 3492 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3493 return inflate_flush(s, z, r); 3494 r = Z_OK; 3495 inflate_codes_free(s->sub.decode.codes, z); 3496 inflate_trees_free(s->sub.decode.td, z); 3497 inflate_trees_free(s->sub.decode.tl, z); 3498 LOAD 3499 Tracev((stderr, "inflate: codes end, %lu total out\n", 3500 z->total_out + (q >= s->read ? q - s->read : 3501 (s->end - s->read) + (q - s->window)))); 3502 if (!s->last) 3503 { 3504 s->mode = TYPE; 3505 break; 3506 } 3507 if (k > 7) /* return unused byte, if any */ 3508 { 3509 Assert(k < 16, "inflate_codes grabbed too many bytes") 3510 k -= 8; 3511 n++; 3512 p--; /* can always return one */ 3513 } 3514 s->mode = DRY; 3515 case DRY: 3516 FLUSH 3517 if (s->read != s->write) 3518 LEAVE 3519 s->mode = DONEB; 3520 case DONEB: 3521 r = Z_STREAM_END; 3522 LEAVE 3523 case BADB: 3524 r = Z_DATA_ERROR; 3525 LEAVE 3526 default: 3527 r = Z_STREAM_ERROR; 3528 LEAVE 3529 } 3530 } 3531 3532 3533 local int inflate_blocks_free(s, z, c) 3534 inflate_blocks_statef *s; 3535 z_stream *z; 3536 uLongf *c; 3537 { 3538 inflate_blocks_reset(s, z, c); 3539 ZFREE(z, s->window, s->end - s->window); 3540 ZFREE(z, s, sizeof(struct inflate_blocks_state)); 3541 Trace((stderr, "inflate: blocks freed\n")); 3542 return Z_OK; 3543 } 3544 3545 /* 3546 * This subroutine adds the data at next_in/avail_in to the output history 3547 * without performing any output. The output buffer must be "caught up"; 3548 * i.e. no pending output (hence s->read equals s->write), and the state must 3549 * be BLOCKS (i.e. we should be willing to see the start of a series of 3550 * BLOCKS). On exit, the output will also be caught up, and the checksum 3551 * will have been updated if need be. 3552 */ 3553 local int inflate_addhistory(s, z) 3554 inflate_blocks_statef *s; 3555 z_stream *z; 3556 { 3557 uLong b; /* bit buffer */ /* NOT USED HERE */ 3558 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 3559 uInt t; /* temporary storage */ 3560 Bytef *p; /* input data pointer */ 3561 uInt n; /* bytes available there */ 3562 Bytef *q; /* output window write pointer */ 3563 uInt m; /* bytes to end of window or read pointer */ 3564 3565 if (s->read != s->write) 3566 return Z_STREAM_ERROR; 3567 if (s->mode != TYPE) 3568 return Z_DATA_ERROR; 3569 3570 /* we're ready to rock */ 3571 LOAD 3572 /* while there is input ready, copy to output buffer, moving 3573 * pointers as needed. 3574 */ 3575 while (n) { 3576 t = n; /* how many to do */ 3577 /* is there room until end of buffer? */ 3578 if (t > m) t = m; 3579 /* update check information */ 3580 if (s->checkfn != Z_NULL) 3581 s->check = (*s->checkfn)(s->check, q, t); 3582 zmemcpy(q, p, t); 3583 q += t; 3584 p += t; 3585 n -= t; 3586 z->total_out += t; 3587 s->read = q; /* drag read pointer forward */ 3588 /* WRAP */ /* expand WRAP macro by hand to handle s->read */ 3589 if (q == s->end) { 3590 s->read = q = s->window; 3591 m = WAVAIL; 3592 } 3593 } 3594 UPDATE 3595 return Z_OK; 3596 } 3597 3598 3599 /* 3600 * At the end of a Deflate-compressed PPP packet, we expect to have seen 3601 * a `stored' block type value but not the (zero) length bytes. 3602 */ 3603 local int inflate_packet_flush(s) 3604 inflate_blocks_statef *s; 3605 { 3606 if (s->mode != LENS) 3607 return Z_DATA_ERROR; 3608 s->mode = TYPE; 3609 return Z_OK; 3610 } 3611 3612 3613 /*+++++*/ 3614 /* inftrees.c -- generate Huffman trees for efficient decoding 3615 * Copyright (C) 1995 Mark Adler 3616 * For conditions of distribution and use, see copyright notice in zlib.h 3617 */ 3618 3619 /* simplify the use of the inflate_huft type with some defines */ 3620 #define base more.Base 3621 #define next more.Next 3622 #define exop word.what.Exop 3623 #define bits word.what.Bits 3624 3625 3626 local int huft_build OF(( 3627 uIntf *, /* code lengths in bits */ 3628 uInt, /* number of codes */ 3629 uInt, /* number of "simple" codes */ 3630 uIntf *, /* list of base values for non-simple codes */ 3631 uIntf *, /* list of extra bits for non-simple codes */ 3632 inflate_huft * FAR*,/* result: starting table */ 3633 uIntf *, /* maximum lookup bits (returns actual) */ 3634 z_stream *)); /* for zalloc function */ 3635 3636 local voidpf falloc OF(( 3637 voidpf, /* opaque pointer (not used) */ 3638 uInt, /* number of items */ 3639 uInt)); /* size of item */ 3640 3641 local void ffree OF(( 3642 voidpf q, /* opaque pointer (not used) */ 3643 voidpf p, /* what to free (not used) */ 3644 uInt n)); /* number of bytes (not used) */ 3645 3646 /* Tables for deflate from PKZIP's appnote.txt. */ 3647 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */ 3648 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 3649 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 3650 /* actually lengths - 2; also see note #13 above about 258 */ 3651 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */ 3652 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3653 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */ 3654 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */ 3655 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 3656 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 3657 8193, 12289, 16385, 24577}; 3658 local uInt cpdext[] = { /* Extra bits for distance codes */ 3659 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 3660 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 3661 12, 12, 13, 13}; 3662 3663 /* 3664 Huffman code decoding is performed using a multi-level table lookup. 3665 The fastest way to decode is to simply build a lookup table whose 3666 size is determined by the longest code. However, the time it takes 3667 to build this table can also be a factor if the data being decoded 3668 is not very long. The most common codes are necessarily the 3669 shortest codes, so those codes dominate the decoding time, and hence 3670 the speed. The idea is you can have a shorter table that decodes the 3671 shorter, more probable codes, and then point to subsidiary tables for 3672 the longer codes. The time it costs to decode the longer codes is 3673 then traded against the time it takes to make longer tables. 3674 3675 This results of this trade are in the variables lbits and dbits 3676 below. lbits is the number of bits the first level table for literal/ 3677 length codes can decode in one step, and dbits is the same thing for 3678 the distance codes. Subsequent tables are also less than or equal to 3679 those sizes. These values may be adjusted either when all of the 3680 codes are shorter than that, in which case the longest code length in 3681 bits is used, or when the shortest code is *longer* than the requested 3682 table size, in which case the length of the shortest code in bits is 3683 used. 3684 3685 There are two different values for the two tables, since they code a 3686 different number of possibilities each. The literal/length table 3687 codes 286 possible values, or in a flat code, a little over eight 3688 bits. The distance table codes 30 possible values, or a little less 3689 than five bits, flat. The optimum values for speed end up being 3690 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 3691 The optimum values may differ though from machine to machine, and 3692 possibly even between compilers. Your mileage may vary. 3693 */ 3694 3695 3696 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 3697 #define BMAX 15 /* maximum bit length of any code */ 3698 #define N_MAX 288 /* maximum number of codes in any set */ 3699 3700 #ifdef DEBUG_ZLIB 3701 uInt inflate_hufts; 3702 #endif 3703 3704 local int huft_build(b, n, s, d, e, t, m, zs) 3705 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ 3706 uInt n; /* number of codes (assumed <= N_MAX) */ 3707 uInt s; /* number of simple-valued codes (0..s-1) */ 3708 uIntf *d; /* list of base values for non-simple codes */ 3709 uIntf *e; /* list of extra bits for non-simple codes */ 3710 inflate_huft * FAR *t; /* result: starting table */ 3711 uIntf *m; /* maximum lookup bits, returns actual */ 3712 z_stream *zs; /* for zalloc function */ 3713 /* Given a list of code lengths and a maximum table size, make a set of 3714 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 3715 if the given code set is incomplete (the tables are still built in this 3716 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an 3717 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */ 3718 { 3719 3720 uInt a; /* counter for codes of length k */ 3721 uInt c[BMAX+1]; /* bit length count table */ 3722 uInt f; /* i repeats in table every f entries */ 3723 int g; /* maximum code length */ 3724 int h; /* table level */ 3725 register uInt i; /* counter, current code */ 3726 register uInt j; /* counter */ 3727 register int k; /* number of bits in current code */ 3728 int l; /* bits per table (returned in m) */ 3729 register uIntf *p; /* pointer into c[], b[], or v[] */ 3730 inflate_huft *q; /* points to current table */ 3731 struct inflate_huft_s r; /* table entry for structure assignment */ 3732 inflate_huft *u[BMAX]; /* table stack */ 3733 uInt v[N_MAX]; /* values in order of bit length */ 3734 register int w; /* bits before this table == (l * h) */ 3735 uInt x[BMAX+1]; /* bit offsets, then code stack */ 3736 uIntf *xp; /* pointer into x */ 3737 int y; /* number of dummy codes added */ 3738 uInt z; /* number of entries in current table */ 3739 3740 3741 /* Generate counts for each bit length */ 3742 p = c; 3743 #define C0 *p++ = 0; 3744 #define C2 C0 C0 C0 C0 3745 #define C4 C2 C2 C2 C2 3746 C4 /* clear c[]--assume BMAX+1 is 16 */ 3747 p = b; i = n; 3748 do { 3749 c[*p++]++; /* assume all entries <= BMAX */ 3750 } while (--i); 3751 if (c[0] == n) /* null input--all zero length codes */ 3752 { 3753 *t = (inflate_huft *)Z_NULL; 3754 *m = 0; 3755 return Z_OK; 3756 } 3757 3758 3759 /* Find minimum and maximum length, bound *m by those */ 3760 l = *m; 3761 for (j = 1; j <= BMAX; j++) 3762 if (c[j]) 3763 break; 3764 k = j; /* minimum code length */ 3765 if ((uInt)l < j) 3766 l = j; 3767 for (i = BMAX; i; i--) 3768 if (c[i]) 3769 break; 3770 g = i; /* maximum code length */ 3771 if ((uInt)l > i) 3772 l = i; 3773 *m = l; 3774 3775 3776 /* Adjust last length count to fill out codes, if needed */ 3777 for (y = 1 << j; j < i; j++, y <<= 1) 3778 if ((y -= c[j]) < 0) 3779 return Z_DATA_ERROR; 3780 if ((y -= c[i]) < 0) 3781 return Z_DATA_ERROR; 3782 c[i] += y; 3783 3784 3785 /* Generate starting offsets into the value table for each length */ 3786 x[1] = j = 0; 3787 p = c + 1; xp = x + 2; 3788 while (--i) { /* note that i == g from above */ 3789 *xp++ = (j += *p++); 3790 } 3791 3792 3793 /* Make a table of values in order of bit lengths */ 3794 p = b; i = 0; 3795 do { 3796 if ((j = *p++) != 0) 3797 v[x[j]++] = i; 3798 } while (++i < n); 3799 3800 3801 /* Generate the Huffman codes and for each, make the table entries */ 3802 x[0] = i = 0; /* first Huffman code is zero */ 3803 p = v; /* grab values in bit order */ 3804 h = -1; /* no tables yet--level -1 */ 3805 w = -l; /* bits decoded == (l * h) */ 3806 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 3807 q = (inflate_huft *)Z_NULL; /* ditto */ 3808 z = 0; /* ditto */ 3809 3810 /* go through the bit lengths (k already is bits in shortest code) */ 3811 for (; k <= g; k++) 3812 { 3813 a = c[k]; 3814 while (a--) 3815 { 3816 /* here i is the Huffman code of length k bits for value *p */ 3817 /* make tables up to required level */ 3818 while (k > w + l) 3819 { 3820 h++; 3821 w += l; /* previous table always l bits */ 3822 3823 /* compute minimum size table less than or equal to l bits */ 3824 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */ 3825 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 3826 { /* too few codes for k-w bit table */ 3827 f -= a + 1; /* deduct codes from patterns left */ 3828 xp = c + k; 3829 if (j < z) 3830 while (++j < z) /* try smaller tables up to z bits */ 3831 { 3832 if ((f <<= 1) <= *++xp) 3833 break; /* enough codes to use up j bits */ 3834 f -= *xp; /* else deduct codes from patterns */ 3835 } 3836 } 3837 z = 1 << j; /* table entries for j-bit table */ 3838 3839 /* allocate and link in new table */ 3840 if ((q = (inflate_huft *)ZALLOC 3841 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 3842 { 3843 if (h) 3844 inflate_trees_free(u[0], zs); 3845 return Z_MEM_ERROR; /* not enough memory */ 3846 } 3847 q->word.Nalloc = z + 1; 3848 #ifdef DEBUG_ZLIB 3849 inflate_hufts += z + 1; 3850 #endif 3851 *t = q + 1; /* link to list for huft_free() */ 3852 *(t = &(q->next)) = Z_NULL; 3853 u[h] = ++q; /* table starts after link */ 3854 3855 /* connect to last table, if there is one */ 3856 if (h) 3857 { 3858 x[h] = i; /* save pattern for backing up */ 3859 r.bits = (Byte)l; /* bits to dump before this table */ 3860 r.exop = (Byte)j; /* bits in this table */ 3861 r.next = q; /* pointer to this table */ 3862 j = i >> (w - l); /* (get around Turbo C bug) */ 3863 u[h-1][j] = r; /* connect to last table */ 3864 } 3865 } 3866 3867 /* set up table entry in r */ 3868 r.bits = (Byte)(k - w); 3869 if (p >= v + n) 3870 r.exop = 128 + 64; /* out of values--invalid code */ 3871 else if (*p < s) 3872 { 3873 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 3874 r.base = *p++; /* simple code is just the value */ 3875 } 3876 else 3877 { 3878 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */ 3879 r.base = d[*p++ - s]; 3880 } 3881 3882 /* fill code-like entries with r */ 3883 f = 1 << (k - w); 3884 for (j = i >> w; j < z; j += f) 3885 q[j] = r; 3886 3887 /* backwards increment the k-bit code i */ 3888 for (j = 1 << (k - 1); i & j; j >>= 1) 3889 i ^= j; 3890 i ^= j; 3891 3892 /* backup over finished tables */ 3893 while ((i & ((1 << w) - 1)) != x[h]) 3894 { 3895 h--; /* don't need to update q */ 3896 w -= l; 3897 } 3898 } 3899 } 3900 3901 3902 /* Return Z_BUF_ERROR if we were given an incomplete table */ 3903 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 3904 } 3905 3906 3907 local int inflate_trees_bits(c, bb, tb, z) 3908 uIntf *c; /* 19 code lengths */ 3909 uIntf *bb; /* bits tree desired/actual depth */ 3910 inflate_huft * FAR *tb; /* bits tree result */ 3911 z_stream *z; /* for zfree function */ 3912 { 3913 int r; 3914 3915 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 3916 if (r == Z_DATA_ERROR) 3917 z->msg = "oversubscribed dynamic bit lengths tree"; 3918 else if (r == Z_BUF_ERROR) 3919 { 3920 inflate_trees_free(*tb, z); 3921 z->msg = "incomplete dynamic bit lengths tree"; 3922 r = Z_DATA_ERROR; 3923 } 3924 return r; 3925 } 3926 3927 3928 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) 3929 uInt nl; /* number of literal/length codes */ 3930 uInt nd; /* number of distance codes */ 3931 uIntf *c; /* that many (total) code lengths */ 3932 uIntf *bl; /* literal desired/actual bit depth */ 3933 uIntf *bd; /* distance desired/actual bit depth */ 3934 inflate_huft * FAR *tl; /* literal/length tree result */ 3935 inflate_huft * FAR *td; /* distance tree result */ 3936 z_stream *z; /* for zfree function */ 3937 { 3938 int r; 3939 3940 /* build literal/length tree */ 3941 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK) 3942 { 3943 if (r == Z_DATA_ERROR) 3944 z->msg = "oversubscribed literal/length tree"; 3945 else if (r == Z_BUF_ERROR) 3946 { 3947 inflate_trees_free(*tl, z); 3948 z->msg = "incomplete literal/length tree"; 3949 r = Z_DATA_ERROR; 3950 } 3951 return r; 3952 } 3953 3954 /* build distance tree */ 3955 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK) 3956 { 3957 if (r == Z_DATA_ERROR) 3958 z->msg = "oversubscribed literal/length tree"; 3959 else if (r == Z_BUF_ERROR) { 3960 #ifdef PKZIP_BUG_WORKAROUND 3961 r = Z_OK; 3962 } 3963 #else 3964 inflate_trees_free(*td, z); 3965 z->msg = "incomplete literal/length tree"; 3966 r = Z_DATA_ERROR; 3967 } 3968 inflate_trees_free(*tl, z); 3969 return r; 3970 #endif 3971 } 3972 3973 /* done */ 3974 return Z_OK; 3975 } 3976 3977 3978 /* build fixed tables only once--keep them here */ 3979 local int fixed_lock = 0; 3980 local int fixed_built = 0; 3981 #define FIXEDH 530 /* number of hufts used by fixed tables */ 3982 local uInt fixed_left = FIXEDH; 3983 local inflate_huft fixed_mem[FIXEDH]; 3984 local uInt fixed_bl; 3985 local uInt fixed_bd; 3986 local inflate_huft *fixed_tl; 3987 local inflate_huft *fixed_td; 3988 3989 3990 local voidpf falloc(q, n, s) 3991 voidpf q; /* opaque pointer (not used) */ 3992 uInt n; /* number of items */ 3993 uInt s; /* size of item */ 3994 { 3995 Assert(s == sizeof(inflate_huft) && n <= fixed_left, 3996 "inflate_trees falloc overflow"); 3997 if (q) s++; /* to make some compilers happy */ 3998 fixed_left -= n; 3999 return (voidpf)(fixed_mem + fixed_left); 4000 } 4001 4002 4003 local void ffree(q, p, n) 4004 voidpf q; 4005 voidpf p; 4006 uInt n; 4007 { 4008 Assert(0, "inflate_trees ffree called!"); 4009 if (q) q = p; /* to make some compilers happy */ 4010 } 4011 4012 4013 local int inflate_trees_fixed(bl, bd, tl, td) 4014 uIntf *bl; /* literal desired/actual bit depth */ 4015 uIntf *bd; /* distance desired/actual bit depth */ 4016 inflate_huft * FAR *tl; /* literal/length tree result */ 4017 inflate_huft * FAR *td; /* distance tree result */ 4018 { 4019 /* build fixed tables if not built already--lock out other instances */ 4020 while (++fixed_lock > 1) 4021 fixed_lock--; 4022 if (!fixed_built) 4023 { 4024 int k; /* temporary variable */ 4025 unsigned c[288]; /* length list for huft_build */ 4026 z_stream z; /* for falloc function */ 4027 4028 /* set up fake z_stream for memory routines */ 4029 z.zalloc = falloc; 4030 z.zfree = ffree; 4031 z.opaque = Z_NULL; 4032 4033 /* literal table */ 4034 for (k = 0; k < 144; k++) 4035 c[k] = 8; 4036 for (; k < 256; k++) 4037 c[k] = 9; 4038 for (; k < 280; k++) 4039 c[k] = 7; 4040 for (; k < 288; k++) 4041 c[k] = 8; 4042 fixed_bl = 7; 4043 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4044 4045 /* distance table */ 4046 for (k = 0; k < 30; k++) 4047 c[k] = 5; 4048 fixed_bd = 5; 4049 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4050 4051 /* done */ 4052 fixed_built = 1; 4053 } 4054 fixed_lock--; 4055 *bl = fixed_bl; 4056 *bd = fixed_bd; 4057 *tl = fixed_tl; 4058 *td = fixed_td; 4059 return Z_OK; 4060 } 4061 4062 4063 local int inflate_trees_free(t, z) 4064 inflate_huft *t; /* table to free */ 4065 z_stream *z; /* for zfree function */ 4066 /* Free the malloc'ed tables built by huft_build(), which makes a linked 4067 list of the tables it made, with the links in a dummy first entry of 4068 each table. */ 4069 { 4070 register inflate_huft *p, *q; 4071 4072 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4073 p = t; 4074 while (p != Z_NULL) 4075 { 4076 q = (--p)->next; 4077 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft)); 4078 p = q; 4079 } 4080 return Z_OK; 4081 } 4082 4083 /*+++++*/ 4084 /* infcodes.c -- process literals and length/distance pairs 4085 * Copyright (C) 1995 Mark Adler 4086 * For conditions of distribution and use, see copyright notice in zlib.h 4087 */ 4088 4089 /* simplify the use of the inflate_huft type with some defines */ 4090 #define base more.Base 4091 #define next more.Next 4092 #define exop word.what.Exop 4093 #define bits word.what.Bits 4094 4095 /* inflate codes private state */ 4096 struct inflate_codes_state { 4097 4098 /* mode */ 4099 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4100 START, /* x: set up for LEN */ 4101 LEN, /* i: get length/literal/eob next */ 4102 LENEXT, /* i: getting length extra (have base) */ 4103 DIST, /* i: get distance next */ 4104 DISTEXT, /* i: getting distance extra */ 4105 COPY, /* o: copying bytes in window, waiting for space */ 4106 LIT, /* o: got literal, waiting for output space */ 4107 WASH, /* o: got eob, possibly still output waiting */ 4108 END, /* x: got eob and all data flushed */ 4109 BADCODE} /* x: got error */ 4110 mode; /* current inflate_codes mode */ 4111 4112 /* mode dependent information */ 4113 uInt len; 4114 union { 4115 struct { 4116 inflate_huft *tree; /* pointer into tree */ 4117 uInt need; /* bits needed */ 4118 } code; /* if LEN or DIST, where in tree */ 4119 uInt lit; /* if LIT, literal */ 4120 struct { 4121 uInt get; /* bits to get for extra */ 4122 uInt dist; /* distance back to copy from */ 4123 } copy; /* if EXT or COPY, where and how much */ 4124 } sub; /* submode */ 4125 4126 /* mode independent information */ 4127 Byte lbits; /* ltree bits decoded per branch */ 4128 Byte dbits; /* dtree bits decoder per branch */ 4129 inflate_huft *ltree; /* literal/length/eob tree */ 4130 inflate_huft *dtree; /* distance tree */ 4131 4132 }; 4133 4134 4135 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) 4136 uInt bl, bd; 4137 inflate_huft *tl, *td; 4138 z_stream *z; 4139 { 4140 inflate_codes_statef *c; 4141 4142 if ((c = (inflate_codes_statef *) 4143 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4144 { 4145 c->mode = START; 4146 c->lbits = (Byte)bl; 4147 c->dbits = (Byte)bd; 4148 c->ltree = tl; 4149 c->dtree = td; 4150 Tracev((stderr, "inflate: codes new\n")); 4151 } 4152 return c; 4153 } 4154 4155 4156 local int inflate_codes(s, z, r) 4157 inflate_blocks_statef *s; 4158 z_stream *z; 4159 int r; 4160 { 4161 uInt j; /* temporary storage */ 4162 inflate_huft *t; /* temporary pointer */ 4163 uInt e; /* extra bits or operation */ 4164 uLong b; /* bit buffer */ 4165 uInt k; /* bits in bit buffer */ 4166 Bytef *p; /* input data pointer */ 4167 uInt n; /* bytes available there */ 4168 Bytef *q; /* output window write pointer */ 4169 uInt m; /* bytes to end of window or read pointer */ 4170 Bytef *f; /* pointer to copy strings from */ 4171 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4172 4173 /* copy input/output information to locals (UPDATE macro restores) */ 4174 LOAD 4175 4176 /* process input and output based on current state */ 4177 while (1) switch (c->mode) 4178 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4179 case START: /* x: set up for LEN */ 4180 #ifndef SLOW 4181 if (m >= 258 && n >= 10) 4182 { 4183 UPDATE 4184 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4185 LOAD 4186 if (r != Z_OK) 4187 { 4188 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4189 break; 4190 } 4191 } 4192 #endif /* !SLOW */ 4193 c->sub.code.need = c->lbits; 4194 c->sub.code.tree = c->ltree; 4195 c->mode = LEN; 4196 case LEN: /* i: get length/literal/eob next */ 4197 j = c->sub.code.need; 4198 NEEDBITS(j) 4199 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4200 DUMPBITS(t->bits) 4201 e = (uInt)(t->exop); 4202 if (e == 0) /* literal */ 4203 { 4204 c->sub.lit = t->base; 4205 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4206 "inflate: literal '%c'\n" : 4207 "inflate: literal 0x%02x\n", t->base)); 4208 c->mode = LIT; 4209 break; 4210 } 4211 if (e & 16) /* length */ 4212 { 4213 c->sub.copy.get = e & 15; 4214 c->len = t->base; 4215 c->mode = LENEXT; 4216 break; 4217 } 4218 if ((e & 64) == 0) /* next table */ 4219 { 4220 c->sub.code.need = e; 4221 c->sub.code.tree = t->next; 4222 break; 4223 } 4224 if (e & 32) /* end of block */ 4225 { 4226 Tracevv((stderr, "inflate: end of block\n")); 4227 c->mode = WASH; 4228 break; 4229 } 4230 c->mode = BADCODE; /* invalid code */ 4231 z->msg = "invalid literal/length code"; 4232 r = Z_DATA_ERROR; 4233 LEAVE 4234 case LENEXT: /* i: getting length extra (have base) */ 4235 j = c->sub.copy.get; 4236 NEEDBITS(j) 4237 c->len += (uInt)b & inflate_mask[j]; 4238 DUMPBITS(j) 4239 c->sub.code.need = c->dbits; 4240 c->sub.code.tree = c->dtree; 4241 Tracevv((stderr, "inflate: length %u\n", c->len)); 4242 c->mode = DIST; 4243 case DIST: /* i: get distance next */ 4244 j = c->sub.code.need; 4245 NEEDBITS(j) 4246 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4247 DUMPBITS(t->bits) 4248 e = (uInt)(t->exop); 4249 if (e & 16) /* distance */ 4250 { 4251 c->sub.copy.get = e & 15; 4252 c->sub.copy.dist = t->base; 4253 c->mode = DISTEXT; 4254 break; 4255 } 4256 if ((e & 64) == 0) /* next table */ 4257 { 4258 c->sub.code.need = e; 4259 c->sub.code.tree = t->next; 4260 break; 4261 } 4262 c->mode = BADCODE; /* invalid code */ 4263 z->msg = "invalid distance code"; 4264 r = Z_DATA_ERROR; 4265 LEAVE 4266 case DISTEXT: /* i: getting distance extra */ 4267 j = c->sub.copy.get; 4268 NEEDBITS(j) 4269 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4270 DUMPBITS(j) 4271 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4272 c->mode = COPY; 4273 case COPY: /* o: copying bytes in window, waiting for space */ 4274 #ifndef __TURBOC__ /* Turbo C bug for following expression */ 4275 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4276 s->end - (c->sub.copy.dist - (q - s->window)) : 4277 q - c->sub.copy.dist; 4278 #else 4279 f = q - c->sub.copy.dist; 4280 if ((uInt)(q - s->window) < c->sub.copy.dist) 4281 f = s->end - (c->sub.copy.dist - (q - s->window)); 4282 #endif 4283 while (c->len) 4284 { 4285 NEEDOUT 4286 OUTBYTE(*f++) 4287 if (f == s->end) 4288 f = s->window; 4289 c->len--; 4290 } 4291 c->mode = START; 4292 break; 4293 case LIT: /* o: got literal, waiting for output space */ 4294 NEEDOUT 4295 OUTBYTE(c->sub.lit) 4296 c->mode = START; 4297 break; 4298 case WASH: /* o: got eob, possibly more output */ 4299 FLUSH 4300 if (s->read != s->write) 4301 LEAVE 4302 c->mode = END; 4303 case END: 4304 r = Z_STREAM_END; 4305 LEAVE 4306 case BADCODE: /* x: got error */ 4307 r = Z_DATA_ERROR; 4308 LEAVE 4309 default: 4310 r = Z_STREAM_ERROR; 4311 LEAVE 4312 } 4313 } 4314 4315 4316 local void inflate_codes_free(c, z) 4317 inflate_codes_statef *c; 4318 z_stream *z; 4319 { 4320 ZFREE(z, c, sizeof(struct inflate_codes_state)); 4321 Tracev((stderr, "inflate: codes free\n")); 4322 } 4323 4324 /*+++++*/ 4325 /* inflate_util.c -- data and routines common to blocks and codes 4326 * Copyright (C) 1995 Mark Adler 4327 * For conditions of distribution and use, see copyright notice in zlib.h 4328 */ 4329 4330 /* copy as much as possible from the sliding window to the output area */ 4331 local int inflate_flush(s, z, r) 4332 inflate_blocks_statef *s; 4333 z_stream *z; 4334 int r; 4335 { 4336 uInt n; 4337 Bytef *p, *q; 4338 4339 /* local copies of source and destination pointers */ 4340 p = z->next_out; 4341 q = s->read; 4342 4343 /* compute number of bytes to copy as far as end of window */ 4344 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4345 if (n > z->avail_out) n = z->avail_out; 4346 if (n && r == Z_BUF_ERROR) r = Z_OK; 4347 4348 /* update counters */ 4349 z->avail_out -= n; 4350 z->total_out += n; 4351 4352 /* update check information */ 4353 if (s->checkfn != Z_NULL) 4354 s->check = (*s->checkfn)(s->check, q, n); 4355 4356 /* copy as far as end of window */ 4357 if (p != NULL) { 4358 zmemcpy(p, q, n); 4359 p += n; 4360 } 4361 q += n; 4362 4363 /* see if more to copy at beginning of window */ 4364 if (q == s->end) 4365 { 4366 /* wrap pointers */ 4367 q = s->window; 4368 if (s->write == s->end) 4369 s->write = s->window; 4370 4371 /* compute bytes to copy */ 4372 n = (uInt)(s->write - q); 4373 if (n > z->avail_out) n = z->avail_out; 4374 if (n && r == Z_BUF_ERROR) r = Z_OK; 4375 4376 /* update counters */ 4377 z->avail_out -= n; 4378 z->total_out += n; 4379 4380 /* update check information */ 4381 if (s->checkfn != Z_NULL) 4382 s->check = (*s->checkfn)(s->check, q, n); 4383 4384 /* copy */ 4385 if (p != NULL) { 4386 zmemcpy(p, q, n); 4387 p += n; 4388 } 4389 q += n; 4390 } 4391 4392 /* update pointers */ 4393 z->next_out = p; 4394 s->read = q; 4395 4396 /* done */ 4397 return r; 4398 } 4399 4400 4401 /*+++++*/ 4402 /* inffast.c -- process literals and length/distance pairs fast 4403 * Copyright (C) 1995 Mark Adler 4404 * For conditions of distribution and use, see copyright notice in zlib.h 4405 */ 4406 4407 /* simplify the use of the inflate_huft type with some defines */ 4408 #define base more.Base 4409 #define next more.Next 4410 #define exop word.what.Exop 4411 #define bits word.what.Bits 4412 4413 /* macros for bit input with no checking and for returning unused bytes */ 4414 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4415 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4416 4417 /* Called with number of bytes left to write in window at least 258 4418 (the maximum string length) and number of input bytes available 4419 at least ten. The ten bytes are six bytes for the longest length/ 4420 distance pair plus four bytes for overloading the bit buffer. */ 4421 4422 local int inflate_fast(bl, bd, tl, td, s, z) 4423 uInt bl, bd; 4424 inflate_huft *tl, *td; 4425 inflate_blocks_statef *s; 4426 z_stream *z; 4427 { 4428 inflate_huft *t; /* temporary pointer */ 4429 uInt e; /* extra bits or operation */ 4430 uLong b; /* bit buffer */ 4431 uInt k; /* bits in bit buffer */ 4432 Bytef *p; /* input data pointer */ 4433 uInt n; /* bytes available there */ 4434 Bytef *q; /* output window write pointer */ 4435 uInt m; /* bytes to end of window or read pointer */ 4436 uInt ml; /* mask for literal/length tree */ 4437 uInt md; /* mask for distance tree */ 4438 uInt c; /* bytes to copy */ 4439 uInt d; /* distance back to copy from */ 4440 Bytef *r; /* copy source pointer */ 4441 4442 /* load input, output, bit values */ 4443 LOAD 4444 4445 /* initialize masks */ 4446 ml = inflate_mask[bl]; 4447 md = inflate_mask[bd]; 4448 4449 /* do until not enough input or output space for fast loop */ 4450 do { /* assume called with m >= 258 && n >= 10 */ 4451 /* get literal/length code */ 4452 GRABBITS(20) /* max bits for literal/length code */ 4453 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 4454 { 4455 DUMPBITS(t->bits) 4456 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4457 "inflate: * literal '%c'\n" : 4458 "inflate: * literal 0x%02x\n", t->base)); 4459 *q++ = (Byte)t->base; 4460 m--; 4461 continue; 4462 } 4463 do { 4464 DUMPBITS(t->bits) 4465 if (e & 16) 4466 { 4467 /* get extra bits for length */ 4468 e &= 15; 4469 c = t->base + ((uInt)b & inflate_mask[e]); 4470 DUMPBITS(e) 4471 Tracevv((stderr, "inflate: * length %u\n", c)); 4472 4473 /* decode distance base of block to copy */ 4474 GRABBITS(15); /* max bits for distance code */ 4475 e = (t = td + ((uInt)b & md))->exop; 4476 do { 4477 DUMPBITS(t->bits) 4478 if (e & 16) 4479 { 4480 /* get extra bits to add to distance base */ 4481 e &= 15; 4482 GRABBITS(e) /* get extra bits (up to 13) */ 4483 d = t->base + ((uInt)b & inflate_mask[e]); 4484 DUMPBITS(e) 4485 Tracevv((stderr, "inflate: * distance %u\n", d)); 4486 4487 /* do the copy */ 4488 m -= c; 4489 if ((uInt)(q - s->window) >= d) /* offset before dest */ 4490 { /* just copy */ 4491 r = q - d; 4492 *q++ = *r++; c--; /* minimum count is three, */ 4493 *q++ = *r++; c--; /* so unroll loop a little */ 4494 } 4495 else /* else offset after destination */ 4496 { 4497 e = d - (q - s->window); /* bytes from offset to end */ 4498 r = s->end - e; /* pointer to offset */ 4499 if (c > e) /* if source crosses, */ 4500 { 4501 c -= e; /* copy to end of window */ 4502 do { 4503 *q++ = *r++; 4504 } while (--e); 4505 r = s->window; /* copy rest from start of window */ 4506 } 4507 } 4508 do { /* copy all or what's left */ 4509 *q++ = *r++; 4510 } while (--c); 4511 break; 4512 } 4513 else if ((e & 64) == 0) 4514 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 4515 else 4516 { 4517 z->msg = "invalid distance code"; 4518 UNGRAB 4519 UPDATE 4520 return Z_DATA_ERROR; 4521 } 4522 } while (1); 4523 break; 4524 } 4525 if ((e & 64) == 0) 4526 { 4527 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 4528 { 4529 DUMPBITS(t->bits) 4530 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4531 "inflate: * literal '%c'\n" : 4532 "inflate: * literal 0x%02x\n", t->base)); 4533 *q++ = (Byte)t->base; 4534 m--; 4535 break; 4536 } 4537 } 4538 else if (e & 32) 4539 { 4540 Tracevv((stderr, "inflate: * end of block\n")); 4541 UNGRAB 4542 UPDATE 4543 return Z_STREAM_END; 4544 } 4545 else 4546 { 4547 z->msg = "invalid literal/length code"; 4548 UNGRAB 4549 UPDATE 4550 return Z_DATA_ERROR; 4551 } 4552 } while (1); 4553 } while (m >= 258 && n >= 10); 4554 4555 /* not enough input or output--restore pointers and return */ 4556 UNGRAB 4557 UPDATE 4558 return Z_OK; 4559 } 4560 4561 4562 /*+++++*/ 4563 /* zutil.c -- target dependent utility functions for the compression library 4564 * Copyright (C) 1995 Jean-loup Gailly. 4565 * For conditions of distribution and use, see copyright notice in zlib.h 4566 */ 4567 4568 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */ 4569 4570 char *zlib_version = ZLIB_VERSION; 4571 4572 char *z_errmsg[] = { 4573 "stream end", /* Z_STREAM_END 1 */ 4574 "", /* Z_OK 0 */ 4575 "file error", /* Z_ERRNO (-1) */ 4576 "stream error", /* Z_STREAM_ERROR (-2) */ 4577 "data error", /* Z_DATA_ERROR (-3) */ 4578 "insufficient memory", /* Z_MEM_ERROR (-4) */ 4579 "buffer error", /* Z_BUF_ERROR (-5) */ 4580 ""}; 4581 4582 4583 /*+++++*/ 4584 /* adler32.c -- compute the Adler-32 checksum of a data stream 4585 * Copyright (C) 1995 Mark Adler 4586 * For conditions of distribution and use, see copyright notice in zlib.h 4587 */ 4588 4589 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */ 4590 4591 #define BASE 65521L /* largest prime smaller than 65536 */ 4592 #define NMAX 5552 4593 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 4594 4595 #define DO1(buf) {s1 += *buf++; s2 += s1;} 4596 #define DO2(buf) DO1(buf); DO1(buf); 4597 #define DO4(buf) DO2(buf); DO2(buf); 4598 #define DO8(buf) DO4(buf); DO4(buf); 4599 #define DO16(buf) DO8(buf); DO8(buf); 4600 4601 /* ========================================================================= */ 4602 uLong adler32(adler, buf, len) 4603 uLong adler; 4604 Bytef *buf; 4605 uInt len; 4606 { 4607 unsigned long s1 = adler & 0xffff; 4608 unsigned long s2 = (adler >> 16) & 0xffff; 4609 int k; 4610 4611 if (buf == Z_NULL) return 1L; 4612 4613 while (len > 0) { 4614 k = len < NMAX ? len : NMAX; 4615 len -= k; 4616 while (k >= 16) { 4617 DO16(buf); 4618 k -= 16; 4619 } 4620 if (k != 0) do { 4621 DO1(buf); 4622 } while (--k); 4623 s1 %= BASE; 4624 s2 %= BASE; 4625 } 4626 return (s2 << 16) | s1; 4627 } 4628