1/* 2 * Copyright (c) 2003 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23/* 24 * This file is derived from various .h and .c files from the zlib-0.95 25 * distribution by Jean-loup Gailly and Mark Adler, with some additions 26 * by Paul Mackerras to aid in implementing Deflate compression and 27 * decompression for PPP packets. See zlib.h for conditions of 28 * distribution and use. 29 * 30 * Changes that have been made include: 31 * - changed functions not used outside this file to "local" 32 * - added minCompression parameter to deflateInit2 33 * - added Z_PACKET_FLUSH (see zlib.h for details) 34 * - added inflateIncomp 35 * 36 * $Id: zlib.c,v 1.3 2003/08/14 00:00:39 callie Exp $ 37 */ 38 39 40/*+++++*/ 41/* zutil.h -- internal interface and configuration of the compression library 42 * Copyright (C) 1995 Jean-loup Gailly. 43 * For conditions of distribution and use, see copyright notice in zlib.h 44 */ 45 46/* WARNING: this file should *not* be used by applications. It is 47 part of the implementation of the compression library and is 48 subject to change. Applications should only use zlib.h. 49 */ 50 51/* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */ 52 53#define _Z_UTIL_H 54 55#include "zlib.h" 56 57#ifdef STDC 58# include <string.h> 59#endif 60 61#ifndef local 62# define local static 63#endif 64/* compile with -Dlocal if your debugger can't find static symbols */ 65 66#define FAR 67 68typedef unsigned char uch; 69typedef uch FAR uchf; 70typedef unsigned short ush; 71typedef ush FAR ushf; 72typedef unsigned long ulg; 73 74extern char *z_errmsg[]; /* indexed by 1-zlib_error */ 75 76#define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err) 77/* To be used only when the state is known to be valid */ 78 79#ifndef NULL 80#define NULL ((void *) 0) 81#endif 82 83 /* common constants */ 84 85#define DEFLATED 8 86 87#ifndef DEF_WBITS 88# define DEF_WBITS MAX_WBITS 89#endif 90/* default windowBits for decompression. MAX_WBITS is for compression only */ 91 92#if MAX_MEM_LEVEL >= 8 93# define DEF_MEM_LEVEL 8 94#else 95# define DEF_MEM_LEVEL MAX_MEM_LEVEL 96#endif 97/* default memLevel */ 98 99#define STORED_BLOCK 0 100#define STATIC_TREES 1 101#define DYN_TREES 2 102/* The three kinds of block type */ 103 104#define MIN_MATCH 3 105#define MAX_MATCH 258 106/* The minimum and maximum match lengths */ 107 108 /* functions */ 109 110#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 111# define HAVE_MEMCPY 112#endif 113#ifdef HAVE_MEMCPY 114# define zmemcpy memcpy 115# define zmemzero(dest, len) memset(dest, 0, len) 116#else 117# define zmemcpy(d, s, n) bcopy((s), (d), (n)) 118# define zmemzero bzero 119#endif 120 121/* Diagnostic functions */ 122#ifdef DEBUG_ZLIB 123# include <stdio.h> 124# ifndef verbose 125# define verbose 0 126# endif 127# define Assert(cond,msg) {if(!(cond)) z_error(msg);} 128# define Trace(x) fprintf x 129# define Tracev(x) {if (verbose) fprintf x ;} 130# define Tracevv(x) {if (verbose>1) fprintf x ;} 131# define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 132# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 133#else 134# define Assert(cond,msg) 135# define Trace(x) 136# define Tracev(x) 137# define Tracevv(x) 138# define Tracec(c,x) 139# define Tracecv(c,x) 140#endif 141 142 143typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len)); 144 145/* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */ 146/* void zcfree OF((voidpf opaque, voidpf ptr)); */ 147 148#define ZALLOC(strm, items, size) \ 149 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 150#define ZFREE(strm, addr, size) \ 151 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size)) 152#define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);} 153 154/* deflate.h -- internal compression state 155 * Copyright (C) 1995 Jean-loup Gailly 156 * For conditions of distribution and use, see copyright notice in zlib.h 157 */ 158 159/* WARNING: this file should *not* be used by applications. It is 160 part of the implementation of the compression library and is 161 subject to change. Applications should only use zlib.h. 162 */ 163 164 165/*+++++*/ 166/* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */ 167 168/* =========================================================================== 169 * Internal compression state. 170 */ 171 172/* Data type */ 173#define BINARY 0 174#define ASCII 1 175#define UNKNOWN 2 176 177#define LENGTH_CODES 29 178/* number of length codes, not counting the special END_BLOCK code */ 179 180#define LITERALS 256 181/* number of literal bytes 0..255 */ 182 183#define L_CODES (LITERALS+1+LENGTH_CODES) 184/* number of Literal or Length codes, including the END_BLOCK code */ 185 186#define D_CODES 30 187/* number of distance codes */ 188 189#define BL_CODES 19 190/* number of codes used to transfer the bit lengths */ 191 192#define HEAP_SIZE (2*L_CODES+1) 193/* maximum heap size */ 194 195#define MAX_BITS 15 196/* All codes must not exceed MAX_BITS bits */ 197 198#define INIT_STATE 42 199#define BUSY_STATE 113 200#define FLUSH_STATE 124 201#define FINISH_STATE 666 202/* Stream status */ 203 204 205/* Data structure describing a single value and its code string. */ 206typedef struct ct_data_s { 207 union { 208 ush freq; /* frequency count */ 209 ush code; /* bit string */ 210 } fc; 211 union { 212 ush dad; /* father node in Huffman tree */ 213 ush len; /* length of bit string */ 214 } dl; 215} FAR ct_data; 216 217#define Freq fc.freq 218#define Code fc.code 219#define Dad dl.dad 220#define Len dl.len 221 222typedef struct static_tree_desc_s static_tree_desc; 223 224typedef struct tree_desc_s { 225 ct_data *dyn_tree; /* the dynamic tree */ 226 int max_code; /* largest code with non zero frequency */ 227 static_tree_desc *stat_desc; /* the corresponding static tree */ 228} FAR tree_desc; 229 230typedef ush Pos; 231typedef Pos FAR Posf; 232typedef unsigned IPos; 233 234/* A Pos is an index in the character window. We use short instead of int to 235 * save space in the various tables. IPos is used only for parameter passing. 236 */ 237 238typedef struct deflate_state { 239 z_stream *strm; /* pointer back to this zlib stream */ 240 int status; /* as the name implies */ 241 Bytef *pending_buf; /* output still pending */ 242 Bytef *pending_out; /* next pending byte to output to the stream */ 243 int pending; /* nb of bytes in the pending buffer */ 244 uLong adler; /* adler32 of uncompressed data */ 245 int noheader; /* suppress zlib header and adler32 */ 246 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 247 Byte method; /* STORED (for zip only) or DEFLATED */ 248 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */ 249 250 /* used by deflate.c: */ 251 252 uInt w_size; /* LZ77 window size (32K by default) */ 253 uInt w_bits; /* log2(w_size) (8..16) */ 254 uInt w_mask; /* w_size - 1 */ 255 256 Bytef *window; 257 /* Sliding window. Input bytes are read into the second half of the window, 258 * and move to the first half later to keep a dictionary of at least wSize 259 * bytes. With this organization, matches are limited to a distance of 260 * wSize-MAX_MATCH bytes, but this ensures that IO is always 261 * performed with a length multiple of the block size. Also, it limits 262 * the window size to 64K, which is quite useful on MSDOS. 263 * To do: use the user input buffer as sliding window. 264 */ 265 266 ulg window_size; 267 /* Actual size of window: 2*wSize, except when the user input buffer 268 * is directly used as sliding window. 269 */ 270 271 Posf *prev; 272 /* Link to older string with same hash index. To limit the size of this 273 * array to 64K, this link is maintained only for the last 32K strings. 274 * An index in this array is thus a window index modulo 32K. 275 */ 276 277 Posf *head; /* Heads of the hash chains or NIL. */ 278 279 uInt ins_h; /* hash index of string to be inserted */ 280 uInt hash_size; /* number of elements in hash table */ 281 uInt hash_bits; /* log2(hash_size) */ 282 uInt hash_mask; /* hash_size-1 */ 283 284 uInt hash_shift; 285 /* Number of bits by which ins_h must be shifted at each input 286 * step. It must be such that after MIN_MATCH steps, the oldest 287 * byte no longer takes part in the hash key, that is: 288 * hash_shift * MIN_MATCH >= hash_bits 289 */ 290 291 long block_start; 292 /* Window position at the beginning of the current output block. Gets 293 * negative when the window is moved backwards. 294 */ 295 296 uInt match_length; /* length of best match */ 297 IPos prev_match; /* previous match */ 298 int match_available; /* set if previous match exists */ 299 uInt strstart; /* start of string to insert */ 300 uInt match_start; /* start of matching string */ 301 uInt lookahead; /* number of valid bytes ahead in window */ 302 303 uInt prev_length; 304 /* Length of the best match at previous step. Matches not greater than this 305 * are discarded. This is used in the lazy match evaluation. 306 */ 307 308 uInt max_chain_length; 309 /* To speed up deflation, hash chains are never searched beyond this 310 * length. A higher limit improves compression ratio but degrades the 311 * speed. 312 */ 313 314 uInt max_lazy_match; 315 /* Attempt to find a better match only when the current match is strictly 316 * smaller than this value. This mechanism is used only for compression 317 * levels >= 4. 318 */ 319# define max_insert_length max_lazy_match 320 /* Insert new strings in the hash table only if the match length is not 321 * greater than this length. This saves time but degrades compression. 322 * max_insert_length is used only for compression levels <= 3. 323 */ 324 325 int level; /* compression level (1..9) */ 326 int strategy; /* favor or force Huffman coding*/ 327 328 uInt good_match; 329 /* Use a faster search when the previous match is longer than this */ 330 331 int nice_match; /* Stop searching when current match exceeds this */ 332 333 /* used by trees.c: */ 334 /* Didn't use ct_data typedef below to supress compiler warning */ 335 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 336 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 337 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 338 339 struct tree_desc_s l_desc; /* desc. for literal tree */ 340 struct tree_desc_s d_desc; /* desc. for distance tree */ 341 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 342 343 ush bl_count[MAX_BITS+1]; 344 /* number of codes at each bit length for an optimal tree */ 345 346 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 347 int heap_len; /* number of elements in the heap */ 348 int heap_max; /* element of largest frequency */ 349 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 350 * The same heap array is used to build all trees. 351 */ 352 353 uch depth[2*L_CODES+1]; 354 /* Depth of each subtree used as tie breaker for trees of equal frequency 355 */ 356 357 uchf *l_buf; /* buffer for literals or lengths */ 358 359 uInt lit_bufsize; 360 /* Size of match buffer for literals/lengths. There are 4 reasons for 361 * limiting lit_bufsize to 64K: 362 * - frequencies can be kept in 16 bit counters 363 * - if compression is not successful for the first block, all input 364 * data is still in the window so we can still emit a stored block even 365 * when input comes from standard input. (This can also be done for 366 * all blocks if lit_bufsize is not greater than 32K.) 367 * - if compression is not successful for a file smaller than 64K, we can 368 * even emit a stored file instead of a stored block (saving 5 bytes). 369 * This is applicable only for zip (not gzip or zlib). 370 * - creating new Huffman trees less frequently may not provide fast 371 * adaptation to changes in the input data statistics. (Take for 372 * example a binary file with poorly compressible code followed by 373 * a highly compressible string table.) Smaller buffer sizes give 374 * fast adaptation but have of course the overhead of transmitting 375 * trees more frequently. 376 * - I can't count above 4 377 */ 378 379 uInt last_lit; /* running index in l_buf */ 380 381 ushf *d_buf; 382 /* Buffer for distances. To simplify the code, d_buf and l_buf have 383 * the same number of elements. To use different lengths, an extra flag 384 * array would be necessary. 385 */ 386 387 ulg opt_len; /* bit length of current block with optimal trees */ 388 ulg static_len; /* bit length of current block with static trees */ 389 ulg compressed_len; /* total bit length of compressed file */ 390 uInt matches; /* number of string matches in current block */ 391 int last_eob_len; /* bit length of EOB code for last block */ 392 393#ifdef DEBUG_ZLIB 394 ulg bits_sent; /* bit length of the compressed data */ 395#endif 396 397 ush bi_buf; 398 /* Output buffer. bits are inserted starting at the bottom (least 399 * significant bits). 400 */ 401 int bi_valid; 402 /* Number of valid bits in bi_buf. All bits above the last valid bit 403 * are always zero. 404 */ 405 406 uInt blocks_in_packet; 407 /* Number of blocks produced since the last time Z_PACKET_FLUSH 408 * was used. 409 */ 410 411} FAR deflate_state; 412 413/* Output a byte on the stream. 414 * IN assertion: there is enough room in pending_buf. 415 */ 416#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 417 418 419#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 420/* Minimum amount of lookahead, except at the end of the input file. 421 * See deflate.c for comments about the MIN_MATCH+1. 422 */ 423 424#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 425/* In order to simplify the code, particularly on 16 bit machines, match 426 * distances are limited to MAX_DIST instead of WSIZE. 427 */ 428 429 /* in trees.c */ 430local void ct_init OF((deflate_state *s)); 431local int ct_tally OF((deflate_state *s, int dist, int lc)); 432local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 433 int flush)); 434local void ct_align OF((deflate_state *s)); 435local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 436 int eof)); 437local void ct_stored_type_only OF((deflate_state *s)); 438 439 440/*+++++*/ 441/* deflate.c -- compress data using the deflation algorithm 442 * Copyright (C) 1995 Jean-loup Gailly. 443 * For conditions of distribution and use, see copyright notice in zlib.h 444 */ 445 446/* 447 * ALGORITHM 448 * 449 * The "deflation" process depends on being able to identify portions 450 * of the input text which are identical to earlier input (within a 451 * sliding window trailing behind the input currently being processed). 452 * 453 * The most straightforward technique turns out to be the fastest for 454 * most input files: try all possible matches and select the longest. 455 * The key feature of this algorithm is that insertions into the string 456 * dictionary are very simple and thus fast, and deletions are avoided 457 * completely. Insertions are performed at each input character, whereas 458 * string matches are performed only when the previous match ends. So it 459 * is preferable to spend more time in matches to allow very fast string 460 * insertions and avoid deletions. The matching algorithm for small 461 * strings is inspired from that of Rabin & Karp. A brute force approach 462 * is used to find longer strings when a small match has been found. 463 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 464 * (by Leonid Broukhis). 465 * A previous version of this file used a more sophisticated algorithm 466 * (by Fiala and Greene) which is guaranteed to run in linear amortized 467 * time, but has a larger average cost, uses more memory and is patented. 468 * However the F&G algorithm may be faster for some highly redundant 469 * files if the parameter max_chain_length (described below) is too large. 470 * 471 * ACKNOWLEDGEMENTS 472 * 473 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 474 * I found it in 'freeze' written by Leonid Broukhis. 475 * Thanks to many people for bug reports and testing. 476 * 477 * REFERENCES 478 * 479 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 480 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 481 * 482 * A description of the Rabin and Karp algorithm is given in the book 483 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 484 * 485 * Fiala,E.R., and Greene,D.H. 486 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 487 * 488 */ 489 490/* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */ 491 492local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly "; 493/* 494 If you use the zlib library in a product, an acknowledgment is welcome 495 in the documentation of your product. If for some reason you cannot 496 include such an acknowledgment, I would appreciate that you keep this 497 copyright string in the executable of your product. 498 */ 499 500#define NIL 0 501/* Tail of hash chains */ 502 503#ifndef TOO_FAR 504# define TOO_FAR 4096 505#endif 506/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 507 508#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 509/* Minimum amount of lookahead, except at the end of the input file. 510 * See deflate.c for comments about the MIN_MATCH+1. 511 */ 512 513/* Values for max_lazy_match, good_match and max_chain_length, depending on 514 * the desired pack level (0..9). The values given below have been tuned to 515 * exclude worst case performance for pathological files. Better values may be 516 * found for specific files. 517 */ 518 519typedef struct config_s { 520 ush good_length; /* reduce lazy search above this match length */ 521 ush max_lazy; /* do not perform lazy search above this match length */ 522 ush nice_length; /* quit search above this match length */ 523 ush max_chain; 524} config; 525 526local config configuration_table[10] = { 527/* good lazy nice chain */ 528/* 0 */ {0, 0, 0, 0}, /* store only */ 529/* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */ 530/* 2 */ {4, 5, 16, 8}, 531/* 3 */ {4, 6, 32, 32}, 532 533/* 4 */ {4, 4, 16, 16}, /* lazy matches */ 534/* 5 */ {8, 16, 32, 32}, 535/* 6 */ {8, 16, 128, 128}, 536/* 7 */ {8, 32, 128, 256}, 537/* 8 */ {32, 128, 258, 1024}, 538/* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ 539 540/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 541 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 542 * meaning. 543 */ 544 545#define EQUAL 0 546/* result of memcmp for equal strings */ 547 548/* =========================================================================== 549 * Prototypes for local functions. 550 */ 551 552local void fill_window OF((deflate_state *s)); 553local int deflate_fast OF((deflate_state *s, int flush)); 554local int deflate_slow OF((deflate_state *s, int flush)); 555local void lm_init OF((deflate_state *s)); 556local int longest_match OF((deflate_state *s, IPos cur_match)); 557local void putShortMSB OF((deflate_state *s, uInt b)); 558local void flush_pending OF((z_stream *strm)); 559local int read_buf OF((z_stream *strm, charf *buf, unsigned size)); 560#ifdef ASMV 561 void match_init OF((void)); /* asm code initialization */ 562#endif 563 564#ifdef DEBUG_ZLIB 565local void check_match OF((deflate_state *s, IPos start, IPos match, 566 int length)); 567#endif 568 569 570/* =========================================================================== 571 * Update a hash value with the given input byte 572 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 573 * input characters, so that a running hash key can be computed from the 574 * previous key instead of complete recalculation each time. 575 */ 576#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 577 578 579/* =========================================================================== 580 * Insert string str in the dictionary and set match_head to the previous head 581 * of the hash chain (the most recent string with same hash key). Return 582 * the previous length of the hash chain. 583 * IN assertion: all calls to to INSERT_STRING are made with consecutive 584 * input characters and the first MIN_MATCH bytes of str are valid 585 * (except for the last MIN_MATCH-1 bytes of the input file). 586 */ 587#define INSERT_STRING(s, str, match_head) \ 588 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 589 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 590 s->head[s->ins_h] = (str)) 591 592/* =========================================================================== 593 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 594 * prev[] will be initialized on the fly. 595 */ 596#define CLEAR_HASH(s) \ 597 s->head[s->hash_size-1] = NIL; \ 598 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 599 600/* ========================================================================= */ 601int deflateInit (strm, level) 602 z_stream *strm; 603 int level; 604{ 605 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 606 0, 0); 607 /* To do: ignore strm->next_in if we use it as window */ 608} 609 610/* ========================================================================= */ 611int deflateInit2 (strm, level, method, windowBits, memLevel, 612 strategy, minCompression) 613 z_stream *strm; 614 int level; 615 int method; 616 int windowBits; 617 int memLevel; 618 int strategy; 619 int minCompression; 620{ 621 deflate_state *s; 622 int noheader = 0; 623 624 if (strm == Z_NULL) return Z_STREAM_ERROR; 625 626 strm->msg = Z_NULL; 627/* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */ 628/* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */ 629 630 if (level == Z_DEFAULT_COMPRESSION) level = 6; 631 632 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 633 noheader = 1; 634 windowBits = -windowBits; 635 } 636 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED || 637 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) { 638 return Z_STREAM_ERROR; 639 } 640 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 641 if (s == Z_NULL) return Z_MEM_ERROR; 642 strm->state = (struct internal_state FAR *)s; 643 s->strm = strm; 644 645 s->noheader = noheader; 646 s->w_bits = windowBits; 647 s->w_size = 1 << s->w_bits; 648 s->w_mask = s->w_size - 1; 649 650 s->hash_bits = memLevel + 7; 651 s->hash_size = 1 << s->hash_bits; 652 s->hash_mask = s->hash_size - 1; 653 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 654 655 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 656 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 657 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 658 659 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 660 661 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush)); 662 663 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 664 s->pending_buf == Z_NULL) { 665 strm->msg = z_errmsg[1-Z_MEM_ERROR]; 666 deflateEnd (strm); 667 return Z_MEM_ERROR; 668 } 669 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]); 670 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]); 671 /* We overlay pending_buf and d_buf+l_buf. This works since the average 672 * output size for (length,distance) codes is <= 32 bits (worst case 673 * is 15+15+13=33). 674 */ 675 676 s->level = level; 677 s->strategy = strategy; 678 s->method = (Byte)method; 679 s->minCompr = minCompression; 680 s->blocks_in_packet = 0; 681 682 return deflateReset(strm); 683} 684 685/* ========================================================================= */ 686int deflateReset (strm) 687 z_stream *strm; 688{ 689 deflate_state *s; 690 691 if (strm == Z_NULL || strm->state == Z_NULL || 692 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 693 694 strm->total_in = strm->total_out = 0; 695 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 696 strm->data_type = Z_UNKNOWN; 697 698 s = (deflate_state *)strm->state; 699 s->pending = 0; 700 s->pending_out = s->pending_buf; 701 702 if (s->noheader < 0) { 703 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 704 } 705 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 706 s->adler = 1; 707 708 ct_init(s); 709 lm_init(s); 710 711 return Z_OK; 712} 713 714/* ========================================================================= 715 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 716 * IN assertion: the stream state is correct and there is enough room in 717 * pending_buf. 718 */ 719local void putShortMSB (s, b) 720 deflate_state *s; 721 uInt b; 722{ 723 put_byte(s, (Byte)(b >> 8)); 724 put_byte(s, (Byte)(b & 0xff)); 725} 726 727/* ========================================================================= 728 * Flush as much pending output as possible. 729 */ 730local void flush_pending(strm) 731 z_stream *strm; 732{ 733 deflate_state *state = (deflate_state *) strm->state; 734 unsigned len = state->pending; 735 736 if (len > strm->avail_out) len = strm->avail_out; 737 if (len == 0) return; 738 739 if (strm->next_out != NULL) { 740 zmemcpy(strm->next_out, state->pending_out, len); 741 strm->next_out += len; 742 } 743 state->pending_out += len; 744 strm->total_out += len; 745 strm->avail_out -= len; 746 state->pending -= len; 747 if (state->pending == 0) { 748 state->pending_out = state->pending_buf; 749 } 750} 751 752/* ========================================================================= */ 753int deflate (strm, flush) 754 z_stream *strm; 755 int flush; 756{ 757 deflate_state *state = (deflate_state *) strm->state; 758 759 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; 760 761 if (strm->next_in == Z_NULL && strm->avail_in != 0) { 762 ERR_RETURN(strm, Z_STREAM_ERROR); 763 } 764 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 765 766 state->strm = strm; /* just in case */ 767 768 /* Write the zlib header */ 769 if (state->status == INIT_STATE) { 770 771 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8; 772 uInt level_flags = (state->level-1) >> 1; 773 774 if (level_flags > 3) level_flags = 3; 775 header |= (level_flags << 6); 776 header += 31 - (header % 31); 777 778 state->status = BUSY_STATE; 779 putShortMSB(state, header); 780 } 781 782 /* Flush as much pending output as possible */ 783 if (state->pending != 0) { 784 flush_pending(strm); 785 if (strm->avail_out == 0) return Z_OK; 786 } 787 788 /* If we came back in here to get the last output from 789 * a previous flush, we're done for now. 790 */ 791 if (state->status == FLUSH_STATE) { 792 state->status = BUSY_STATE; 793 if (flush != Z_NO_FLUSH && flush != Z_FINISH) 794 return Z_OK; 795 } 796 797 /* User must not provide more input after the first FINISH: */ 798 if (state->status == FINISH_STATE && strm->avail_in != 0) { 799 ERR_RETURN(strm, Z_BUF_ERROR); 800 } 801 802 /* Start a new block or continue the current one. 803 */ 804 if (strm->avail_in != 0 || state->lookahead != 0 || 805 (flush == Z_FINISH && state->status != FINISH_STATE)) { 806 int quit; 807 808 if (flush == Z_FINISH) { 809 state->status = FINISH_STATE; 810 } 811 if (state->level <= 3) { 812 quit = deflate_fast(state, flush); 813 } else { 814 quit = deflate_slow(state, flush); 815 } 816 if (quit || strm->avail_out == 0) 817 return Z_OK; 818 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 819 * of deflate should use the same flush parameter to make sure 820 * that the flush is complete. So we don't have to output an 821 * empty block here, this will be done at next call. This also 822 * ensures that for a very small output buffer, we emit at most 823 * one empty block. 824 */ 825 } 826 827 /* If a flush was requested, we have a little more to output now. */ 828 if (flush != Z_NO_FLUSH && flush != Z_FINISH 829 && state->status != FINISH_STATE) { 830 switch (flush) { 831 case Z_PARTIAL_FLUSH: 832 ct_align(state); 833 break; 834 case Z_PACKET_FLUSH: 835 /* Output just the 3-bit `stored' block type value, 836 but not a zero length. */ 837 ct_stored_type_only(state); 838 break; 839 default: 840 ct_stored_block(state, (char*)0, 0L, 0); 841 /* For a full flush, this empty block will be recognized 842 * as a special marker by inflate_sync(). 843 */ 844 if (flush == Z_FULL_FLUSH) { 845 CLEAR_HASH(state); /* forget history */ 846 } 847 } 848 flush_pending(strm); 849 if (strm->avail_out == 0) { 850 /* We'll have to come back to get the rest of the output; 851 * this ensures we don't output a second zero-length stored 852 * block (or whatever). 853 */ 854 state->status = FLUSH_STATE; 855 return Z_OK; 856 } 857 } 858 859 Assert(strm->avail_out > 0, "bug2"); 860 861 if (flush != Z_FINISH) return Z_OK; 862 if (state->noheader) return Z_STREAM_END; 863 864 /* Write the zlib trailer (adler32) */ 865 putShortMSB(state, (uInt)(state->adler >> 16)); 866 putShortMSB(state, (uInt)(state->adler & 0xffff)); 867 flush_pending(strm); 868 /* If avail_out is zero, the application will call deflate again 869 * to flush the rest. 870 */ 871 state->noheader = -1; /* write the trailer only once! */ 872 return state->pending != 0 ? Z_OK : Z_STREAM_END; 873} 874 875/* ========================================================================= */ 876int deflateEnd (strm) 877 z_stream *strm; 878{ 879 deflate_state *state = (deflate_state *) strm->state; 880 881 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; 882 883 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte)); 884 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos)); 885 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos)); 886 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush)); 887 888 ZFREE(strm, state, sizeof(deflate_state)); 889 strm->state = Z_NULL; 890 891 return Z_OK; 892} 893 894/* =========================================================================== 895 * Read a new buffer from the current input stream, update the adler32 896 * and total number of bytes read. 897 */ 898local int read_buf(strm, buf, size) 899 z_stream *strm; 900 charf *buf; 901 unsigned size; 902{ 903 unsigned len = strm->avail_in; 904 deflate_state *state = (deflate_state *) strm->state; 905 906 if (len > size) len = size; 907 if (len == 0) return 0; 908 909 strm->avail_in -= len; 910 911 if (!state->noheader) { 912 state->adler = adler32(state->adler, strm->next_in, len); 913 } 914 zmemcpy(buf, strm->next_in, len); 915 strm->next_in += len; 916 strm->total_in += len; 917 918 return (int)len; 919} 920 921/* =========================================================================== 922 * Initialize the "longest match" routines for a new zlib stream 923 */ 924local void lm_init (s) 925 deflate_state *s; 926{ 927 s->window_size = (ulg)2L*s->w_size; 928 929 CLEAR_HASH(s); 930 931 /* Set the default configuration parameters: 932 */ 933 s->max_lazy_match = configuration_table[s->level].max_lazy; 934 s->good_match = configuration_table[s->level].good_length; 935 s->nice_match = configuration_table[s->level].nice_length; 936 s->max_chain_length = configuration_table[s->level].max_chain; 937 938 s->strstart = 0; 939 s->block_start = 0L; 940 s->lookahead = 0; 941 s->match_length = MIN_MATCH-1; 942 s->match_available = 0; 943 s->ins_h = 0; 944#ifdef ASMV 945 match_init(); /* initialize the asm code */ 946#endif 947} 948 949/* =========================================================================== 950 * Set match_start to the longest match starting at the given string and 951 * return its length. Matches shorter or equal to prev_length are discarded, 952 * in which case the result is equal to prev_length and match_start is 953 * garbage. 954 * IN assertions: cur_match is the head of the hash chain for the current 955 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 956 */ 957#ifndef ASMV 958/* For 80x86 and 680x0, an optimized version will be provided in match.asm or 959 * match.S. The code will be functionally equivalent. 960 */ 961local int longest_match(s, cur_match) 962 deflate_state *s; 963 IPos cur_match; /* current match */ 964{ 965 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 966 register Bytef *scan = s->window + s->strstart; /* current string */ 967 register Bytef *match; /* matched string */ 968 register int len; /* length of current match */ 969 int best_len = s->prev_length; /* best match length so far */ 970 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 971 s->strstart - (IPos)MAX_DIST(s) : NIL; 972 /* Stop when cur_match becomes <= limit. To simplify the code, 973 * we prevent matches with the string of window index 0. 974 */ 975 Posf *prev = s->prev; 976 uInt wmask = s->w_mask; 977 978#ifdef UNALIGNED_OK 979 /* Compare two bytes at a time. Note: this is not always beneficial. 980 * Try with and without -DUNALIGNED_OK to check. 981 */ 982 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 983 register ush scan_start = *(ushf*)scan; 984 register ush scan_end = *(ushf*)(scan+best_len-1); 985#else 986 register Bytef *strend = s->window + s->strstart + MAX_MATCH; 987 register Byte scan_end1 = scan[best_len-1]; 988 register Byte scan_end = scan[best_len]; 989#endif 990 991 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 992 * It is easy to get rid of this optimization if necessary. 993 */ 994 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 995 996 /* Do not waste too much time if we already have a good match: */ 997 if (s->prev_length >= s->good_match) { 998 chain_length >>= 2; 999 } 1000 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1001 1002 do { 1003 Assert(cur_match < s->strstart, "no future"); 1004 match = s->window + cur_match; 1005 1006 /* Skip to next match if the match length cannot increase 1007 * or if the match length is less than 2: 1008 */ 1009#if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1010 /* This code assumes sizeof(unsigned short) == 2. Do not use 1011 * UNALIGNED_OK if your compiler uses a different size. 1012 */ 1013 if (*(ushf*)(match+best_len-1) != scan_end || 1014 *(ushf*)match != scan_start) continue; 1015 1016 /* It is not necessary to compare scan[2] and match[2] since they are 1017 * always equal when the other bytes match, given that the hash keys 1018 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1019 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1020 * lookahead only every 4th comparison; the 128th check will be made 1021 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1022 * necessary to put more guard bytes at the end of the window, or 1023 * to check more often for insufficient lookahead. 1024 */ 1025 Assert(scan[2] == match[2], "scan[2]?"); 1026 scan++, match++; 1027 do { 1028 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1029 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1030 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1031 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1032 scan < strend); 1033 /* The funny "do {}" generates better code on most compilers */ 1034 1035 /* Here, scan <= window+strstart+257 */ 1036 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1037 if (*scan == *match) scan++; 1038 1039 len = (MAX_MATCH - 1) - (int)(strend-scan); 1040 scan = strend - (MAX_MATCH-1); 1041 1042#else /* UNALIGNED_OK */ 1043 1044 if (match[best_len] != scan_end || 1045 match[best_len-1] != scan_end1 || 1046 *match != *scan || 1047 *++match != scan[1]) continue; 1048 1049 /* The check at best_len-1 can be removed because it will be made 1050 * again later. (This heuristic is not always a win.) 1051 * It is not necessary to compare scan[2] and match[2] since they 1052 * are always equal when the other bytes match, given that 1053 * the hash keys are equal and that HASH_BITS >= 8. 1054 */ 1055 scan += 2, match++; 1056 Assert(*scan == *match, "match[2]?"); 1057 1058 /* We check for insufficient lookahead only every 8th comparison; 1059 * the 256th check will be made at strstart+258. 1060 */ 1061 do { 1062 } while (*++scan == *++match && *++scan == *++match && 1063 *++scan == *++match && *++scan == *++match && 1064 *++scan == *++match && *++scan == *++match && 1065 *++scan == *++match && *++scan == *++match && 1066 scan < strend); 1067 1068 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1069 1070 len = MAX_MATCH - (int)(strend - scan); 1071 scan = strend - MAX_MATCH; 1072 1073#endif /* UNALIGNED_OK */ 1074 1075 if (len > best_len) { 1076 s->match_start = cur_match; 1077 best_len = len; 1078 if (len >= s->nice_match) break; 1079#ifdef UNALIGNED_OK 1080 scan_end = *(ushf*)(scan+best_len-1); 1081#else 1082 scan_end1 = scan[best_len-1]; 1083 scan_end = scan[best_len]; 1084#endif 1085 } 1086 } while ((cur_match = prev[cur_match & wmask]) > limit 1087 && --chain_length != 0); 1088 1089 return best_len; 1090} 1091#endif /* ASMV */ 1092 1093#ifdef DEBUG_ZLIB 1094/* =========================================================================== 1095 * Check that the match at match_start is indeed a match. 1096 */ 1097local void check_match(s, start, match, length) 1098 deflate_state *s; 1099 IPos start, match; 1100 int length; 1101{ 1102 /* check that the match is indeed a match */ 1103 if (memcmp((charf *)s->window + match, 1104 (charf *)s->window + start, length) != EQUAL) { 1105 fprintf(stderr, 1106 " start %u, match %u, length %d\n", 1107 start, match, length); 1108 do { fprintf(stderr, "%c%c", s->window[match++], 1109 s->window[start++]); } while (--length != 0); 1110 z_error("invalid match"); 1111 } 1112 if (verbose > 1) { 1113 fprintf(stderr,"\\[%d,%d]", start-match, length); 1114 do { putc(s->window[start++], stderr); } while (--length != 0); 1115 } 1116} 1117#else 1118# define check_match(s, start, match, length) 1119#endif 1120 1121/* =========================================================================== 1122 * Fill the window when the lookahead becomes insufficient. 1123 * Updates strstart and lookahead. 1124 * 1125 * IN assertion: lookahead < MIN_LOOKAHEAD 1126 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1127 * At least one byte has been read, or avail_in == 0; reads are 1128 * performed for at least two bytes (required for the zip translate_eol 1129 * option -- not supported here). 1130 */ 1131local void fill_window(s) 1132 deflate_state *s; 1133{ 1134 register unsigned n, m; 1135 register Posf *p; 1136 unsigned more; /* Amount of free space at the end of the window. */ 1137 uInt wsize = s->w_size; 1138 1139 do { 1140 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1141 1142 /* Deal with !@#$% 64K limit: */ 1143 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1144 more = wsize; 1145 } else if (more == (unsigned)(-1)) { 1146 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1147 * and lookahead == 1 (input done one byte at time) 1148 */ 1149 more--; 1150 1151 /* If the window is almost full and there is insufficient lookahead, 1152 * move the upper half to the lower one to make room in the upper half. 1153 */ 1154 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1155 1156 /* By the IN assertion, the window is not empty so we can't confuse 1157 * more == 0 with more == 64K on a 16 bit machine. 1158 */ 1159 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1160 (unsigned)wsize); 1161 s->match_start -= wsize; 1162 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1163 1164 s->block_start -= (long) wsize; 1165 1166 /* Slide the hash table (could be avoided with 32 bit values 1167 at the expense of memory usage): 1168 */ 1169 n = s->hash_size; 1170 p = &s->head[n]; 1171 do { 1172 m = *--p; 1173 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1174 } while (--n); 1175 1176 n = wsize; 1177 p = &s->prev[n]; 1178 do { 1179 m = *--p; 1180 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1181 /* If n is not on any hash chain, prev[n] is garbage but 1182 * its value will never be used. 1183 */ 1184 } while (--n); 1185 1186 more += wsize; 1187 } 1188 if (s->strm->avail_in == 0) return; 1189 1190 /* If there was no sliding: 1191 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1192 * more == window_size - lookahead - strstart 1193 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1194 * => more >= window_size - 2*WSIZE + 2 1195 * In the BIG_MEM or MMAP case (not yet supported), 1196 * window_size == input_size + MIN_LOOKAHEAD && 1197 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1198 * Otherwise, window_size == 2*WSIZE so more >= 2. 1199 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1200 */ 1201 Assert(more >= 2, "more < 2"); 1202 1203 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1204 more); 1205 s->lookahead += n; 1206 1207 /* Initialize the hash value now that we have some input: */ 1208 if (s->lookahead >= MIN_MATCH) { 1209 s->ins_h = s->window[s->strstart]; 1210 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1211#if MIN_MATCH != 3 1212 Call UPDATE_HASH() MIN_MATCH-3 more times 1213#endif 1214 } 1215 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1216 * but this is not important since only literal bytes will be emitted. 1217 */ 1218 1219 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1220} 1221 1222/* =========================================================================== 1223 * Flush the current block, with given end-of-file flag. 1224 * IN assertion: strstart is set to the end of the current match. 1225 */ 1226#define FLUSH_BLOCK_ONLY(s, flush) { \ 1227 ct_flush_block(s, (s->block_start >= 0L ? \ 1228 (charf *)&s->window[(unsigned)s->block_start] : \ 1229 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \ 1230 s->block_start = s->strstart; \ 1231 flush_pending(s->strm); \ 1232 Tracev((stderr,"[FLUSH]")); \ 1233} 1234 1235/* Same but force premature exit if necessary. */ 1236#define FLUSH_BLOCK(s, flush) { \ 1237 FLUSH_BLOCK_ONLY(s, flush); \ 1238 if (s->strm->avail_out == 0) return 1; \ 1239} 1240 1241/* =========================================================================== 1242 * Compress as much as possible from the input stream, return true if 1243 * processing was terminated prematurely (no more input or output space). 1244 * This function does not perform lazy evaluationof matches and inserts 1245 * new strings in the dictionary only for unmatched strings or for short 1246 * matches. It is used only for the fast compression options. 1247 */ 1248local int deflate_fast(s, flush) 1249 deflate_state *s; 1250 int flush; 1251{ 1252 IPos hash_head = NIL; /* head of the hash chain */ 1253 int bflush; /* set if current block must be flushed */ 1254 1255 s->prev_length = MIN_MATCH-1; 1256 1257 for (;;) { 1258 /* Make sure that we always have enough lookahead, except 1259 * at the end of the input file. We need MAX_MATCH bytes 1260 * for the next match, plus MIN_MATCH bytes to insert the 1261 * string following the next match. 1262 */ 1263 if (s->lookahead < MIN_LOOKAHEAD) { 1264 fill_window(s); 1265 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; 1266 1267 if (s->lookahead == 0) break; /* flush the current block */ 1268 } 1269 1270 /* Insert the string window[strstart .. strstart+2] in the 1271 * dictionary, and set hash_head to the head of the hash chain: 1272 */ 1273 if (s->lookahead >= MIN_MATCH) { 1274 INSERT_STRING(s, s->strstart, hash_head); 1275 } 1276 1277 /* Find the longest match, discarding those <= prev_length. 1278 * At this point we have always match_length < MIN_MATCH 1279 */ 1280 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1281 /* To simplify the code, we prevent matches with the string 1282 * of window index 0 (in particular we have to avoid a match 1283 * of the string with itself at the start of the input file). 1284 */ 1285 if (s->strategy != Z_HUFFMAN_ONLY) { 1286 s->match_length = longest_match (s, hash_head); 1287 } 1288 /* longest_match() sets match_start */ 1289 1290 if (s->match_length > s->lookahead) s->match_length = s->lookahead; 1291 } 1292 if (s->match_length >= MIN_MATCH) { 1293 check_match(s, s->strstart, s->match_start, s->match_length); 1294 1295 bflush = ct_tally(s, s->strstart - s->match_start, 1296 s->match_length - MIN_MATCH); 1297 1298 s->lookahead -= s->match_length; 1299 1300 /* Insert new strings in the hash table only if the match length 1301 * is not too large. This saves time but degrades compression. 1302 */ 1303 if (s->match_length <= s->max_insert_length && 1304 s->lookahead >= MIN_MATCH) { 1305 s->match_length--; /* string at strstart already in hash table */ 1306 do { 1307 s->strstart++; 1308 INSERT_STRING(s, s->strstart, hash_head); 1309 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1310 * always MIN_MATCH bytes ahead. 1311 */ 1312 } while (--s->match_length != 0); 1313 s->strstart++; 1314 } else { 1315 s->strstart += s->match_length; 1316 s->match_length = 0; 1317 s->ins_h = s->window[s->strstart]; 1318 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1319#if MIN_MATCH != 3 1320 Call UPDATE_HASH() MIN_MATCH-3 more times 1321#endif 1322 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1323 * matter since it will be recomputed at next deflate call. 1324 */ 1325 } 1326 } else { 1327 /* No match, output a literal byte */ 1328 Tracevv((stderr,"%c", s->window[s->strstart])); 1329 bflush = ct_tally (s, 0, s->window[s->strstart]); 1330 s->lookahead--; 1331 s->strstart++; 1332 } 1333 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); 1334 } 1335 FLUSH_BLOCK(s, flush); 1336 return 0; /* normal exit */ 1337} 1338 1339/* =========================================================================== 1340 * Same as above, but achieves better compression. We use a lazy 1341 * evaluation for matches: a match is finally adopted only if there is 1342 * no better match at the next window position. 1343 */ 1344local int deflate_slow(s, flush) 1345 deflate_state *s; 1346 int flush; 1347{ 1348 IPos hash_head = NIL; /* head of hash chain */ 1349 int bflush; /* set if current block must be flushed */ 1350 1351 /* Process the input block. */ 1352 for (;;) { 1353 /* Make sure that we always have enough lookahead, except 1354 * at the end of the input file. We need MAX_MATCH bytes 1355 * for the next match, plus MIN_MATCH bytes to insert the 1356 * string following the next match. 1357 */ 1358 if (s->lookahead < MIN_LOOKAHEAD) { 1359 fill_window(s); 1360 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; 1361 1362 if (s->lookahead == 0) break; /* flush the current block */ 1363 } 1364 1365 /* Insert the string window[strstart .. strstart+2] in the 1366 * dictionary, and set hash_head to the head of the hash chain: 1367 */ 1368 if (s->lookahead >= MIN_MATCH) { 1369 INSERT_STRING(s, s->strstart, hash_head); 1370 } 1371 1372 /* Find the longest match, discarding those <= prev_length. 1373 */ 1374 s->prev_length = s->match_length, s->prev_match = s->match_start; 1375 s->match_length = MIN_MATCH-1; 1376 1377 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1378 s->strstart - hash_head <= MAX_DIST(s)) { 1379 /* To simplify the code, we prevent matches with the string 1380 * of window index 0 (in particular we have to avoid a match 1381 * of the string with itself at the start of the input file). 1382 */ 1383 if (s->strategy != Z_HUFFMAN_ONLY) { 1384 s->match_length = longest_match (s, hash_head); 1385 } 1386 /* longest_match() sets match_start */ 1387 if (s->match_length > s->lookahead) s->match_length = s->lookahead; 1388 1389 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1390 (s->match_length == MIN_MATCH && 1391 s->strstart - s->match_start > TOO_FAR))) { 1392 1393 /* If prev_match is also MIN_MATCH, match_start is garbage 1394 * but we will ignore the current match anyway. 1395 */ 1396 s->match_length = MIN_MATCH-1; 1397 } 1398 } 1399 /* If there was a match at the previous step and the current 1400 * match is not better, output the previous match: 1401 */ 1402 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1403 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1404 /* Do not insert strings in hash table beyond this. */ 1405 1406 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1407 1408 bflush = ct_tally(s, s->strstart -1 - s->prev_match, 1409 s->prev_length - MIN_MATCH); 1410 1411 /* Insert in hash table all strings up to the end of the match. 1412 * strstart-1 and strstart are already inserted. If there is not 1413 * enough lookahead, the last two strings are not inserted in 1414 * the hash table. 1415 */ 1416 s->lookahead -= s->prev_length-1; 1417 s->prev_length -= 2; 1418 do { 1419 if (++s->strstart <= max_insert) { 1420 INSERT_STRING(s, s->strstart, hash_head); 1421 } 1422 } while (--s->prev_length != 0); 1423 s->match_available = 0; 1424 s->match_length = MIN_MATCH-1; 1425 s->strstart++; 1426 1427 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); 1428 1429 } else if (s->match_available) { 1430 /* If there was no match at the previous position, output a 1431 * single literal. If there was a match but the current match 1432 * is longer, truncate the previous match to a single literal. 1433 */ 1434 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1435 if (ct_tally (s, 0, s->window[s->strstart-1])) { 1436 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH); 1437 } 1438 s->strstart++; 1439 s->lookahead--; 1440 if (s->strm->avail_out == 0) return 1; 1441 } else { 1442 /* There is no previous match to compare with, wait for 1443 * the next step to decide. 1444 */ 1445 s->match_available = 1; 1446 s->strstart++; 1447 s->lookahead--; 1448 } 1449 } 1450 Assert (flush != Z_NO_FLUSH, "no flush?"); 1451 if (s->match_available) { 1452 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1453 ct_tally (s, 0, s->window[s->strstart-1]); 1454 s->match_available = 0; 1455 } 1456 FLUSH_BLOCK(s, flush); 1457 return 0; 1458} 1459 1460 1461/*+++++*/ 1462/* trees.c -- output deflated data using Huffman coding 1463 * Copyright (C) 1995 Jean-loup Gailly 1464 * For conditions of distribution and use, see copyright notice in zlib.h 1465 */ 1466 1467/* 1468 * ALGORITHM 1469 * 1470 * The "deflation" process uses several Huffman trees. The more 1471 * common source values are represented by shorter bit sequences. 1472 * 1473 * Each code tree is stored in a compressed form which is itself 1474 * a Huffman encoding of the lengths of all the code strings (in 1475 * ascending order by source values). The actual code strings are 1476 * reconstructed from the lengths in the inflate process, as described 1477 * in the deflate specification. 1478 * 1479 * REFERENCES 1480 * 1481 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1482 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1483 * 1484 * Storer, James A. 1485 * Data Compression: Methods and Theory, pp. 49-50. 1486 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1487 * 1488 * Sedgewick, R. 1489 * Algorithms, p290. 1490 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1491 */ 1492 1493/* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */ 1494 1495#ifdef DEBUG_ZLIB 1496# include <ctype.h> 1497#endif 1498 1499/* =========================================================================== 1500 * Constants 1501 */ 1502 1503#define MAX_BL_BITS 7 1504/* Bit length codes must not exceed MAX_BL_BITS bits */ 1505 1506#define END_BLOCK 256 1507/* end of block literal code */ 1508 1509#define REP_3_6 16 1510/* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1511 1512#define REPZ_3_10 17 1513/* repeat a zero length 3-10 times (3 bits of repeat count) */ 1514 1515#define REPZ_11_138 18 1516/* repeat a zero length 11-138 times (7 bits of repeat count) */ 1517 1518local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1519 = {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}; 1520 1521local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1522 = {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}; 1523 1524local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1525 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1526 1527local uch bl_order[BL_CODES] 1528 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1529/* The lengths of the bit length codes are sent in order of decreasing 1530 * probability, to avoid transmitting the lengths for unused bit length codes. 1531 */ 1532 1533#define Buf_size (8 * 2*sizeof(char)) 1534/* Number of bits used within bi_buf. (bi_buf might be implemented on 1535 * more than 16 bits on some systems.) 1536 */ 1537 1538/* =========================================================================== 1539 * Local data. These are initialized only once. 1540 * To do: initialize at compile time to be completely reentrant. ??? 1541 */ 1542 1543local ct_data static_ltree[L_CODES+2]; 1544/* The static literal tree. Since the bit lengths are imposed, there is no 1545 * need for the L_CODES extra codes used during heap construction. However 1546 * The codes 286 and 287 are needed to build a canonical tree (see ct_init 1547 * below). 1548 */ 1549 1550local ct_data static_dtree[D_CODES]; 1551/* The static distance tree. (Actually a trivial tree since all codes use 1552 * 5 bits.) 1553 */ 1554 1555local uch dist_code[512]; 1556/* distance codes. The first 256 values correspond to the distances 1557 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1558 * the 15 bit distances. 1559 */ 1560 1561local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1562/* length code for each normalized match length (0 == MIN_MATCH) */ 1563 1564local int base_length[LENGTH_CODES]; 1565/* First normalized length for each code (0 = MIN_MATCH) */ 1566 1567local int base_dist[D_CODES]; 1568/* First normalized distance for each code (0 = distance of 1) */ 1569 1570struct static_tree_desc_s { 1571 ct_data *static_tree; /* static tree or NULL */ 1572 intf *extra_bits; /* extra bits for each code or NULL */ 1573 int extra_base; /* base index for extra_bits */ 1574 int elems; /* max number of elements in the tree */ 1575 int max_length; /* max bit length for the codes */ 1576}; 1577 1578local static_tree_desc static_l_desc = 1579{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1580 1581local static_tree_desc static_d_desc = 1582{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1583 1584local static_tree_desc static_bl_desc = 1585{(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1586 1587/* =========================================================================== 1588 * Local (static) routines in this file. 1589 */ 1590 1591local void ct_static_init OF((void)); 1592local void init_block OF((deflate_state *s)); 1593local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1594local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1595local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1596local void build_tree OF((deflate_state *s, tree_desc *desc)); 1597local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1598local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1599local int build_bl_tree OF((deflate_state *s)); 1600local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1601 int blcodes)); 1602local void compress_block OF((deflate_state *s, ct_data *ltree, 1603 ct_data *dtree)); 1604local void set_data_type OF((deflate_state *s)); 1605local unsigned bi_reverse OF((unsigned value, int length)); 1606local void bi_windup OF((deflate_state *s)); 1607local void bi_flush OF((deflate_state *s)); 1608local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1609 int header)); 1610 1611#ifndef DEBUG_ZLIB 1612# define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 1613 /* Send a code of the given tree. c and tree must not have side effects */ 1614 1615#else /* DEBUG_ZLIB */ 1616# define send_code(s, c, tree) \ 1617 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ 1618 send_bits(s, tree[c].Code, tree[c].Len); } 1619#endif 1620 1621#define d_code(dist) \ 1622 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 1623/* Mapping from a distance to a distance code. dist is the distance - 1 and 1624 * must not have side effects. dist_code[256] and dist_code[257] are never 1625 * used. 1626 */ 1627 1628/* =========================================================================== 1629 * Output a short LSB first on the stream. 1630 * IN assertion: there is enough room in pendingBuf. 1631 */ 1632#define put_short(s, w) { \ 1633 put_byte(s, (uch)((w) & 0xff)); \ 1634 put_byte(s, (uch)((ush)(w) >> 8)); \ 1635} 1636 1637/* =========================================================================== 1638 * Send a value on a given number of bits. 1639 * IN assertion: length <= 16 and value fits in length bits. 1640 */ 1641#ifdef DEBUG_ZLIB 1642local void send_bits OF((deflate_state *s, int value, int length)); 1643 1644local void send_bits(s, value, length) 1645 deflate_state *s; 1646 int value; /* value to send */ 1647 int length; /* number of bits */ 1648{ 1649 Tracev((stderr," l %2d v %4x ", length, value)); 1650 Assert(length > 0 && length <= 15, "invalid length"); 1651 s->bits_sent += (ulg)length; 1652 1653 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 1654 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 1655 * unused bits in value. 1656 */ 1657 if (s->bi_valid > (int)Buf_size - length) { 1658 s->bi_buf |= (value << s->bi_valid); 1659 put_short(s, s->bi_buf); 1660 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 1661 s->bi_valid += length - Buf_size; 1662 } else { 1663 s->bi_buf |= value << s->bi_valid; 1664 s->bi_valid += length; 1665 } 1666} 1667#else /* !DEBUG_ZLIB */ 1668 1669#define send_bits(s, value, length) \ 1670{ int len = length;\ 1671 if (s->bi_valid > (int)Buf_size - len) {\ 1672 int val = value;\ 1673 s->bi_buf |= (val << s->bi_valid);\ 1674 put_short(s, s->bi_buf);\ 1675 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 1676 s->bi_valid += len - Buf_size;\ 1677 } else {\ 1678 s->bi_buf |= (value) << s->bi_valid;\ 1679 s->bi_valid += len;\ 1680 }\ 1681} 1682#endif /* DEBUG_ZLIB */ 1683 1684 1685#define MAX(a,b) (a >= b ? a : b) 1686/* the arguments must not have side effects */ 1687 1688/* =========================================================================== 1689 * Initialize the various 'constant' tables. 1690 * To do: do this at compile time. 1691 */ 1692local void ct_static_init() 1693{ 1694 int n; /* iterates over tree elements */ 1695 int bits; /* bit counter */ 1696 int length; /* length value */ 1697 int code; /* code value */ 1698 int dist; /* distance index */ 1699 ush bl_count[MAX_BITS+1]; 1700 /* number of codes at each bit length for an optimal tree */ 1701 1702 /* Initialize the mapping length (0..255) -> length code (0..28) */ 1703 length = 0; 1704 for (code = 0; code < LENGTH_CODES-1; code++) { 1705 base_length[code] = length; 1706 for (n = 0; n < (1<<extra_lbits[code]); n++) { 1707 length_code[length++] = (uch)code; 1708 } 1709 } 1710 Assert (length == 256, "ct_static_init: length != 256"); 1711 /* Note that the length 255 (match length 258) can be represented 1712 * in two different ways: code 284 + 5 bits or code 285, so we 1713 * overwrite length_code[255] to use the best encoding: 1714 */ 1715 length_code[length-1] = (uch)code; 1716 1717 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 1718 dist = 0; 1719 for (code = 0 ; code < 16; code++) { 1720 base_dist[code] = dist; 1721 for (n = 0; n < (1<<extra_dbits[code]); n++) { 1722 dist_code[dist++] = (uch)code; 1723 } 1724 } 1725 Assert (dist == 256, "ct_static_init: dist != 256"); 1726 dist >>= 7; /* from now on, all distances are divided by 128 */ 1727 for ( ; code < D_CODES; code++) { 1728 base_dist[code] = dist << 7; 1729 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 1730 dist_code[256 + dist++] = (uch)code; 1731 } 1732 } 1733 Assert (dist == 256, "ct_static_init: 256+dist != 512"); 1734 1735 /* Construct the codes of the static literal tree */ 1736 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 1737 n = 0; 1738 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 1739 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 1740 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 1741 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 1742 /* Codes 286 and 287 do not exist, but we must include them in the 1743 * tree construction to get a canonical Huffman tree (longest code 1744 * all ones) 1745 */ 1746 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 1747 1748 /* The static distance tree is trivial: */ 1749 for (n = 0; n < D_CODES; n++) { 1750 static_dtree[n].Len = 5; 1751 static_dtree[n].Code = bi_reverse(n, 5); 1752 } 1753} 1754 1755/* =========================================================================== 1756 * Initialize the tree data structures for a new zlib stream. 1757 */ 1758local void ct_init(s) 1759 deflate_state *s; 1760{ 1761 if (static_dtree[0].Len == 0) { 1762 ct_static_init(); /* To do: at compile time */ 1763 } 1764 1765 s->compressed_len = 0L; 1766 1767 s->l_desc.dyn_tree = s->dyn_ltree; 1768 s->l_desc.stat_desc = &static_l_desc; 1769 1770 s->d_desc.dyn_tree = s->dyn_dtree; 1771 s->d_desc.stat_desc = &static_d_desc; 1772 1773 s->bl_desc.dyn_tree = s->bl_tree; 1774 s->bl_desc.stat_desc = &static_bl_desc; 1775 1776 s->bi_buf = 0; 1777 s->bi_valid = 0; 1778 s->last_eob_len = 8; /* enough lookahead for inflate */ 1779#ifdef DEBUG_ZLIB 1780 s->bits_sent = 0L; 1781#endif 1782 s->blocks_in_packet = 0; 1783 1784 /* Initialize the first block of the first file: */ 1785 init_block(s); 1786} 1787 1788/* =========================================================================== 1789 * Initialize a new block. 1790 */ 1791local void init_block(s) 1792 deflate_state *s; 1793{ 1794 int n; /* iterates over tree elements */ 1795 1796 /* Initialize the trees. */ 1797 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 1798 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 1799 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 1800 1801 s->dyn_ltree[END_BLOCK].Freq = 1; 1802 s->opt_len = s->static_len = 0L; 1803 s->last_lit = s->matches = 0; 1804} 1805 1806#define SMALLEST 1 1807/* Index within the heap array of least frequent node in the Huffman tree */ 1808 1809 1810/* =========================================================================== 1811 * Remove the smallest element from the heap and recreate the heap with 1812 * one less element. Updates heap and heap_len. 1813 */ 1814#define pqremove(s, tree, top) \ 1815{\ 1816 top = s->heap[SMALLEST]; \ 1817 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 1818 pqdownheap(s, tree, SMALLEST); \ 1819} 1820 1821/* =========================================================================== 1822 * Compares to subtrees, using the tree depth as tie breaker when 1823 * the subtrees have equal frequency. This minimizes the worst case length. 1824 */ 1825#define smaller(tree, n, m, depth) \ 1826 (tree[n].Freq < tree[m].Freq || \ 1827 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 1828 1829/* =========================================================================== 1830 * Restore the heap property by moving down the tree starting at node k, 1831 * exchanging a node with the smallest of its two sons if necessary, stopping 1832 * when the heap property is re-established (each father smaller than its 1833 * two sons). 1834 */ 1835local void pqdownheap(s, tree, k) 1836 deflate_state *s; 1837 ct_data *tree; /* the tree to restore */ 1838 int k; /* node to move down */ 1839{ 1840 int v = s->heap[k]; 1841 int j = k << 1; /* left son of k */ 1842 while (j <= s->heap_len) { 1843 /* Set j to the smallest of the two sons: */ 1844 if (j < s->heap_len && 1845 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 1846 j++; 1847 } 1848 /* Exit if v is smaller than both sons */ 1849 if (smaller(tree, v, s->heap[j], s->depth)) break; 1850 1851 /* Exchange v with the smallest son */ 1852 s->heap[k] = s->heap[j]; k = j; 1853 1854 /* And continue down the tree, setting j to the left son of k */ 1855 j <<= 1; 1856 } 1857 s->heap[k] = v; 1858} 1859 1860/* =========================================================================== 1861 * Compute the optimal bit lengths for a tree and update the total bit length 1862 * for the current block. 1863 * IN assertion: the fields freq and dad are set, heap[heap_max] and 1864 * above are the tree nodes sorted by increasing frequency. 1865 * OUT assertions: the field len is set to the optimal bit length, the 1866 * array bl_count contains the frequencies for each bit length. 1867 * The length opt_len is updated; static_len is also updated if stree is 1868 * not null. 1869 */ 1870local void gen_bitlen(s, desc) 1871 deflate_state *s; 1872 tree_desc *desc; /* the tree descriptor */ 1873{ 1874 ct_data *tree = desc->dyn_tree; 1875 int max_code = desc->max_code; 1876 ct_data *stree = desc->stat_desc->static_tree; 1877 intf *extra = desc->stat_desc->extra_bits; 1878 int base = desc->stat_desc->extra_base; 1879 int max_length = desc->stat_desc->max_length; 1880 int h; /* heap index */ 1881 int n, m; /* iterate over the tree elements */ 1882 int bits; /* bit length */ 1883 int xbits; /* extra bits */ 1884 ush f; /* frequency */ 1885 int overflow = 0; /* number of elements with bit length too large */ 1886 1887 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 1888 1889 /* In a first pass, compute the optimal bit lengths (which may 1890 * overflow in the case of the bit length tree). 1891 */ 1892 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 1893 1894 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 1895 n = s->heap[h]; 1896 bits = tree[tree[n].Dad].Len + 1; 1897 if (bits > max_length) bits = max_length, overflow++; 1898 tree[n].Len = (ush)bits; 1899 /* We overwrite tree[n].Dad which is no longer needed */ 1900 1901 if (n > max_code) continue; /* not a leaf node */ 1902 1903 s->bl_count[bits]++; 1904 xbits = 0; 1905 if (n >= base) xbits = extra[n-base]; 1906 f = tree[n].Freq; 1907 s->opt_len += (ulg)f * (bits + xbits); 1908 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 1909 } 1910 if (overflow == 0) return; 1911 1912 Trace((stderr,"\nbit length overflow\n")); 1913 /* This happens for example on obj2 and pic of the Calgary corpus */ 1914 1915 /* Find the first bit length which could increase: */ 1916 do { 1917 bits = max_length-1; 1918 while (s->bl_count[bits] == 0) bits--; 1919 s->bl_count[bits]--; /* move one leaf down the tree */ 1920 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 1921 s->bl_count[max_length]--; 1922 /* The brother of the overflow item also moves one step up, 1923 * but this does not affect bl_count[max_length] 1924 */ 1925 overflow -= 2; 1926 } while (overflow > 0); 1927 1928 /* Now recompute all bit lengths, scanning in increasing frequency. 1929 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 1930 * lengths instead of fixing only the wrong ones. This idea is taken 1931 * from 'ar' written by Haruhiko Okumura.) 1932 */ 1933 for (bits = max_length; bits != 0; bits--) { 1934 n = s->bl_count[bits]; 1935 while (n != 0) { 1936 m = s->heap[--h]; 1937 if (m > max_code) continue; 1938 if (tree[m].Len != (unsigned) bits) { 1939 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 1940 s->opt_len += ((long)bits - (long)tree[m].Len) 1941 *(long)tree[m].Freq; 1942 tree[m].Len = (ush)bits; 1943 } 1944 n--; 1945 } 1946 } 1947} 1948 1949/* =========================================================================== 1950 * Generate the codes for a given tree and bit counts (which need not be 1951 * optimal). 1952 * IN assertion: the array bl_count contains the bit length statistics for 1953 * the given tree and the field len is set for all tree elements. 1954 * OUT assertion: the field code is set for all tree elements of non 1955 * zero code length. 1956 */ 1957local void gen_codes (tree, max_code, bl_count) 1958 ct_data *tree; /* the tree to decorate */ 1959 int max_code; /* largest code with non zero frequency */ 1960 ushf *bl_count; /* number of codes at each bit length */ 1961{ 1962 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 1963 ush code = 0; /* running code value */ 1964 int bits; /* bit index */ 1965 int n; /* code index */ 1966 1967 /* The distribution counts are first used to generate the code values 1968 * without bit reversal. 1969 */ 1970 for (bits = 1; bits <= MAX_BITS; bits++) { 1971 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 1972 } 1973 /* Check that the bit counts in bl_count are consistent. The last code 1974 * must be all ones. 1975 */ 1976 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 1977 "inconsistent bit counts"); 1978 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 1979 1980 for (n = 0; n <= max_code; n++) { 1981 int len = tree[n].Len; 1982 if (len == 0) continue; 1983 /* Now reverse the bits */ 1984 tree[n].Code = bi_reverse(next_code[len]++, len); 1985 1986 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 1987 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 1988 } 1989} 1990 1991/* =========================================================================== 1992 * Construct one Huffman tree and assigns the code bit strings and lengths. 1993 * Update the total bit length for the current block. 1994 * IN assertion: the field freq is set for all tree elements. 1995 * OUT assertions: the fields len and code are set to the optimal bit length 1996 * and corresponding code. The length opt_len is updated; static_len is 1997 * also updated if stree is not null. The field max_code is set. 1998 */ 1999local void build_tree(s, desc) 2000 deflate_state *s; 2001 tree_desc *desc; /* the tree descriptor */ 2002{ 2003 ct_data *tree = desc->dyn_tree; 2004 ct_data *stree = desc->stat_desc->static_tree; 2005 int elems = desc->stat_desc->elems; 2006 int n, m; /* iterate over heap elements */ 2007 int max_code = -1; /* largest code with non zero frequency */ 2008 int node; /* new node being created */ 2009 2010 /* Construct the initial heap, with least frequent element in 2011 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2012 * heap[0] is not used. 2013 */ 2014 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2015 2016 for (n = 0; n < elems; n++) { 2017 if (tree[n].Freq != 0) { 2018 s->heap[++(s->heap_len)] = max_code = n; 2019 s->depth[n] = 0; 2020 } else { 2021 tree[n].Len = 0; 2022 } 2023 } 2024 2025 /* The pkzip format requires that at least one distance code exists, 2026 * and that at least one bit should be sent even if there is only one 2027 * possible code. So to avoid special checks later on we force at least 2028 * two codes of non zero frequency. 2029 */ 2030 while (s->heap_len < 2) { 2031 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2032 tree[node].Freq = 1; 2033 s->depth[node] = 0; 2034 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2035 /* node is 0 or 1 so it does not have extra bits */ 2036 } 2037 desc->max_code = max_code; 2038 2039 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2040 * establish sub-heaps of increasing lengths: 2041 */ 2042 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2043 2044 /* Construct the Huffman tree by repeatedly combining the least two 2045 * frequent nodes. 2046 */ 2047 node = elems; /* next internal node of the tree */ 2048 do { 2049 pqremove(s, tree, n); /* n = node of least frequency */ 2050 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2051 2052 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2053 s->heap[--(s->heap_max)] = m; 2054 2055 /* Create a new node father of n and m */ 2056 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2057 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2058 tree[n].Dad = tree[m].Dad = (ush)node; 2059#ifdef DUMP_BL_TREE 2060 if (tree == s->bl_tree) { 2061 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2062 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2063 } 2064#endif 2065 /* and insert the new node in the heap */ 2066 s->heap[SMALLEST] = node++; 2067 pqdownheap(s, tree, SMALLEST); 2068 2069 } while (s->heap_len >= 2); 2070 2071 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2072 2073 /* At this point, the fields freq and dad are set. We can now 2074 * generate the bit lengths. 2075 */ 2076 gen_bitlen(s, (tree_desc *)desc); 2077 2078 /* The field len is now set, we can generate the bit codes */ 2079 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2080} 2081 2082/* =========================================================================== 2083 * Scan a literal or distance tree to determine the frequencies of the codes 2084 * in the bit length tree. 2085 */ 2086local void scan_tree (s, tree, max_code) 2087 deflate_state *s; 2088 ct_data *tree; /* the tree to be scanned */ 2089 int max_code; /* and its largest code of non zero frequency */ 2090{ 2091 int n; /* iterates over all tree elements */ 2092 int prevlen = -1; /* last emitted length */ 2093 int curlen; /* length of current code */ 2094 int nextlen = tree[0].Len; /* length of next code */ 2095 int count = 0; /* repeat count of the current code */ 2096 int max_count = 7; /* max repeat count */ 2097 int min_count = 4; /* min repeat count */ 2098 2099 if (nextlen == 0) max_count = 138, min_count = 3; 2100 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2101 2102 for (n = 0; n <= max_code; n++) { 2103 curlen = nextlen; nextlen = tree[n+1].Len; 2104 if (++count < max_count && curlen == nextlen) { 2105 continue; 2106 } else if (count < min_count) { 2107 s->bl_tree[curlen].Freq += count; 2108 } else if (curlen != 0) { 2109 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2110 s->bl_tree[REP_3_6].Freq++; 2111 } else if (count <= 10) { 2112 s->bl_tree[REPZ_3_10].Freq++; 2113 } else { 2114 s->bl_tree[REPZ_11_138].Freq++; 2115 } 2116 count = 0; prevlen = curlen; 2117 if (nextlen == 0) { 2118 max_count = 138, min_count = 3; 2119 } else if (curlen == nextlen) { 2120 max_count = 6, min_count = 3; 2121 } else { 2122 max_count = 7, min_count = 4; 2123 } 2124 } 2125} 2126 2127/* =========================================================================== 2128 * Send a literal or distance tree in compressed form, using the codes in 2129 * bl_tree. 2130 */ 2131local void send_tree (s, tree, max_code) 2132 deflate_state *s; 2133 ct_data *tree; /* the tree to be scanned */ 2134 int max_code; /* and its largest code of non zero frequency */ 2135{ 2136 int n; /* iterates over all tree elements */ 2137 int prevlen = -1; /* last emitted length */ 2138 int curlen; /* length of current code */ 2139 int nextlen = tree[0].Len; /* length of next code */ 2140 int count = 0; /* repeat count of the current code */ 2141 int max_count = 7; /* max repeat count */ 2142 int min_count = 4; /* min repeat count */ 2143 2144 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2145 if (nextlen == 0) max_count = 138, min_count = 3; 2146 2147 for (n = 0; n <= max_code; n++) { 2148 curlen = nextlen; nextlen = tree[n+1].Len; 2149 if (++count < max_count && curlen == nextlen) { 2150 continue; 2151 } else if (count < min_count) { 2152 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2153 2154 } else if (curlen != 0) { 2155 if (curlen != prevlen) { 2156 send_code(s, curlen, s->bl_tree); count--; 2157 } 2158 Assert(count >= 3 && count <= 6, " 3_6?"); 2159 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2160 2161 } else if (count <= 10) { 2162 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2163 2164 } else { 2165 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2166 } 2167 count = 0; prevlen = curlen; 2168 if (nextlen == 0) { 2169 max_count = 138, min_count = 3; 2170 } else if (curlen == nextlen) { 2171 max_count = 6, min_count = 3; 2172 } else { 2173 max_count = 7, min_count = 4; 2174 } 2175 } 2176} 2177 2178/* =========================================================================== 2179 * Construct the Huffman tree for the bit lengths and return the index in 2180 * bl_order of the last bit length code to send. 2181 */ 2182local int build_bl_tree(s) 2183 deflate_state *s; 2184{ 2185 int max_blindex; /* index of last bit length code of non zero freq */ 2186 2187 /* Determine the bit length frequencies for literal and distance trees */ 2188 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2189 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2190 2191 /* Build the bit length tree: */ 2192 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2193 /* opt_len now includes the length of the tree representations, except 2194 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2195 */ 2196 2197 /* Determine the number of bit length codes to send. The pkzip format 2198 * requires that at least 4 bit length codes be sent. (appnote.txt says 2199 * 3 but the actual value used is 4.) 2200 */ 2201 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2202 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2203 } 2204 /* Update opt_len to include the bit length tree and counts */ 2205 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2206 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2207 s->opt_len, s->static_len)); 2208 2209 return max_blindex; 2210} 2211 2212/* =========================================================================== 2213 * Send the header for a block using dynamic Huffman trees: the counts, the 2214 * lengths of the bit length codes, the literal tree and the distance tree. 2215 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2216 */ 2217local void send_all_trees(s, lcodes, dcodes, blcodes) 2218 deflate_state *s; 2219 int lcodes, dcodes, blcodes; /* number of codes for each tree */ 2220{ 2221 int rank; /* index in bl_order */ 2222 2223 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2224 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2225 "too many codes"); 2226 Tracev((stderr, "\nbl counts: ")); 2227 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2228 send_bits(s, dcodes-1, 5); 2229 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2230 for (rank = 0; rank < blcodes; rank++) { 2231 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2232 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2233 } 2234 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2235 2236 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2237 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2238 2239 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2240 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2241} 2242 2243/* =========================================================================== 2244 * Send a stored block 2245 */ 2246local void ct_stored_block(s, buf, stored_len, eof) 2247 deflate_state *s; 2248 charf *buf; /* input block */ 2249 ulg stored_len; /* length of input block */ 2250 int eof; /* true if this is the last block for a file */ 2251{ 2252 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2253 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L; 2254 s->compressed_len += (stored_len + 4) << 3; 2255 2256 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2257} 2258 2259/* Send just the `stored block' type code without any length bytes or data. 2260 */ 2261local void ct_stored_type_only(s) 2262 deflate_state *s; 2263{ 2264 send_bits(s, (STORED_BLOCK << 1), 3); 2265 bi_windup(s); 2266 s->compressed_len = (s->compressed_len + 3) & ~7L; 2267} 2268 2269 2270/* =========================================================================== 2271 * Send one empty static block to give enough lookahead for inflate. 2272 * This takes 10 bits, of which 7 may remain in the bit buffer. 2273 * The current inflate code requires 9 bits of lookahead. If the EOB 2274 * code for the previous block was coded on 5 bits or less, inflate 2275 * may have only 5+3 bits of lookahead to decode this EOB. 2276 * (There are no problems if the previous block is stored or fixed.) 2277 */ 2278local void ct_align(s) 2279 deflate_state *s; 2280{ 2281 send_bits(s, STATIC_TREES<<1, 3); 2282 send_code(s, END_BLOCK, static_ltree); 2283 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2284 bi_flush(s); 2285 /* Of the 10 bits for the empty block, we have already sent 2286 * (10 - bi_valid) bits. The lookahead for the EOB of the previous 2287 * block was thus its length plus what we have just sent. 2288 */ 2289 if (s->last_eob_len + 10 - s->bi_valid < 9) { 2290 send_bits(s, STATIC_TREES<<1, 3); 2291 send_code(s, END_BLOCK, static_ltree); 2292 s->compressed_len += 10L; 2293 bi_flush(s); 2294 } 2295 s->last_eob_len = 7; 2296} 2297 2298/* =========================================================================== 2299 * Determine the best encoding for the current block: dynamic trees, static 2300 * trees or store, and output the encoded block to the zip file. This function 2301 * returns the total compressed length for the file so far. 2302 */ 2303local ulg ct_flush_block(s, buf, stored_len, flush) 2304 deflate_state *s; 2305 charf *buf; /* input block, or NULL if too old */ 2306 ulg stored_len; /* length of input block */ 2307 int flush; /* Z_FINISH if this is the last block for a file */ 2308{ 2309 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2310 int max_blindex; /* index of last bit length code of non zero freq */ 2311 int eof = flush == Z_FINISH; 2312 2313 ++s->blocks_in_packet; 2314 2315 /* Check if the file is ascii or binary */ 2316 if (s->data_type == UNKNOWN) set_data_type(s); 2317 2318 /* Construct the literal and distance trees */ 2319 build_tree(s, (tree_desc *)(&(s->l_desc))); 2320 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2321 s->static_len)); 2322 2323 build_tree(s, (tree_desc *)(&(s->d_desc))); 2324 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2325 s->static_len)); 2326 /* At this point, opt_len and static_len are the total bit lengths of 2327 * the compressed block data, excluding the tree representations. 2328 */ 2329 2330 /* Build the bit length tree for the above two trees, and get the index 2331 * in bl_order of the last bit length code to send. 2332 */ 2333 max_blindex = build_bl_tree(s); 2334 2335 /* Determine the best encoding. Compute first the block length in bytes */ 2336 opt_lenb = (s->opt_len+3+7)>>3; 2337 static_lenb = (s->static_len+3+7)>>3; 2338 2339 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2340 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2341 s->last_lit)); 2342 2343 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2344 2345 /* If compression failed and this is the first and last block, 2346 * and if the .zip file can be seeked (to rewrite the local header), 2347 * the whole file is transformed into a stored file: 2348 */ 2349#ifdef STORED_FILE_OK 2350# ifdef FORCE_STORED_FILE 2351 if (eof && compressed_len == 0L) /* force stored file */ 2352# else 2353 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) 2354# endif 2355 { 2356 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2357 if (buf == (charf*)0) error ("block vanished"); 2358 2359 copy_block(buf, (unsigned)stored_len, 0); /* without header */ 2360 s->compressed_len = stored_len << 3; 2361 s->method = STORED; 2362 } else 2363#endif /* STORED_FILE_OK */ 2364 2365 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum 2366 * compression, and this block contains all the data since the last 2367 * time we used Z_PACKET_FLUSH, then just omit this block completely 2368 * from the output. 2369 */ 2370 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1 2371 && opt_lenb > stored_len - s->minCompr) { 2372 s->blocks_in_packet = 0; 2373 /* output nothing */ 2374 } else 2375 2376#ifdef FORCE_STORED 2377 if (buf != (char*)0) /* force stored block */ 2378#else 2379 if (stored_len+4 <= opt_lenb && buf != (char*)0) 2380 /* 4: two words for the lengths */ 2381#endif 2382 { 2383 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2384 * Otherwise we can't have processed more than WSIZE input bytes since 2385 * the last block flush, because compression would have been 2386 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2387 * transform a block into a stored block. 2388 */ 2389 ct_stored_block(s, buf, stored_len, eof); 2390 } else 2391 2392#ifdef FORCE_STATIC 2393 if (static_lenb >= 0) /* force static trees */ 2394#else 2395 if (static_lenb == opt_lenb) 2396#endif 2397 { 2398 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2399 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2400 s->compressed_len += 3 + s->static_len; 2401 } else { 2402 send_bits(s, (DYN_TREES<<1)+eof, 3); 2403 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2404 max_blindex+1); 2405 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2406 s->compressed_len += 3 + s->opt_len; 2407 } 2408 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2409 init_block(s); 2410 2411 if (eof) { 2412 bi_windup(s); 2413 s->compressed_len += 7; /* align on byte boundary */ 2414 } 2415 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2416 s->compressed_len-7*eof)); 2417 2418 return s->compressed_len >> 3; 2419} 2420 2421/* =========================================================================== 2422 * Save the match info and tally the frequency counts. Return true if 2423 * the current block must be flushed. 2424 */ 2425local int ct_tally (s, dist, lc) 2426 deflate_state *s; 2427 int dist; /* distance of matched string */ 2428 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 2429{ 2430 s->d_buf[s->last_lit] = (ush)dist; 2431 s->l_buf[s->last_lit++] = (uch)lc; 2432 if (dist == 0) { 2433 /* lc is the unmatched char */ 2434 s->dyn_ltree[lc].Freq++; 2435 } else { 2436 s->matches++; 2437 /* Here, lc is the match length - MIN_MATCH */ 2438 dist--; /* dist = match distance - 1 */ 2439 Assert((ush)dist < (ush)MAX_DIST(s) && 2440 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2441 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match"); 2442 2443 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2444 s->dyn_dtree[d_code(dist)].Freq++; 2445 } 2446 2447 /* Try to guess if it is profitable to stop the current block here */ 2448 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2449 /* Compute an upper bound for the compressed length */ 2450 ulg out_length = (ulg)s->last_lit*8L; 2451 ulg in_length = (ulg)s->strstart - s->block_start; 2452 int dcode; 2453 for (dcode = 0; dcode < D_CODES; dcode++) { 2454 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2455 (5L+extra_dbits[dcode]); 2456 } 2457 out_length >>= 3; 2458 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2459 s->last_lit, in_length, out_length, 2460 100L - out_length*100L/in_length)); 2461 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2462 } 2463 return (s->last_lit == s->lit_bufsize-1); 2464 /* We avoid equality with lit_bufsize because of wraparound at 64K 2465 * on 16 bit machines and because stored blocks are restricted to 2466 * 64K-1 bytes. 2467 */ 2468} 2469 2470/* =========================================================================== 2471 * Send the block data compressed using the given Huffman trees 2472 */ 2473local void compress_block(s, ltree, dtree) 2474 deflate_state *s; 2475 ct_data *ltree; /* literal tree */ 2476 ct_data *dtree; /* distance tree */ 2477{ 2478 unsigned dist; /* distance of matched string */ 2479 int lc; /* match length or unmatched char (if dist == 0) */ 2480 unsigned lx = 0; /* running index in l_buf */ 2481 unsigned code; /* the code to send */ 2482 int extra; /* number of extra bits to send */ 2483 2484 if (s->last_lit != 0) do { 2485 dist = s->d_buf[lx]; 2486 lc = s->l_buf[lx++]; 2487 if (dist == 0) { 2488 send_code(s, lc, ltree); /* send a literal byte */ 2489 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2490 } else { 2491 /* Here, lc is the match length - MIN_MATCH */ 2492 code = length_code[lc]; 2493 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2494 extra = extra_lbits[code]; 2495 if (extra != 0) { 2496 lc -= base_length[code]; 2497 send_bits(s, lc, extra); /* send the extra length bits */ 2498 } 2499 dist--; /* dist is now the match distance - 1 */ 2500 code = d_code(dist); 2501 Assert (code < D_CODES, "bad d_code"); 2502 2503 send_code(s, code, dtree); /* send the distance code */ 2504 extra = extra_dbits[code]; 2505 if (extra != 0) { 2506 dist -= base_dist[code]; 2507 send_bits(s, dist, extra); /* send the extra distance bits */ 2508 } 2509 } /* literal or match pair ? */ 2510 2511 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2512 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2513 2514 } while (lx < s->last_lit); 2515 2516 send_code(s, END_BLOCK, ltree); 2517 s->last_eob_len = ltree[END_BLOCK].Len; 2518} 2519 2520/* =========================================================================== 2521 * Set the data type to ASCII or BINARY, using a crude approximation: 2522 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2523 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2524 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2525 */ 2526local void set_data_type(s) 2527 deflate_state *s; 2528{ 2529 int n = 0; 2530 unsigned ascii_freq = 0; 2531 unsigned bin_freq = 0; 2532 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2533 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2534 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2535 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII); 2536} 2537 2538/* =========================================================================== 2539 * Reverse the first len bits of a code, using straightforward code (a faster 2540 * method would use a table) 2541 * IN assertion: 1 <= len <= 15 2542 */ 2543local unsigned bi_reverse(code, len) 2544 unsigned code; /* the value to invert */ 2545 int len; /* its bit length */ 2546{ 2547 register unsigned res = 0; 2548 do { 2549 res |= code & 1; 2550 code >>= 1, res <<= 1; 2551 } while (--len > 0); 2552 return res >> 1; 2553} 2554 2555/* =========================================================================== 2556 * Flush the bit buffer, keeping at most 7 bits in it. 2557 */ 2558local void bi_flush(s) 2559 deflate_state *s; 2560{ 2561 if (s->bi_valid == 16) { 2562 put_short(s, s->bi_buf); 2563 s->bi_buf = 0; 2564 s->bi_valid = 0; 2565 } else if (s->bi_valid >= 8) { 2566 put_byte(s, (Byte)s->bi_buf); 2567 s->bi_buf >>= 8; 2568 s->bi_valid -= 8; 2569 } 2570} 2571 2572/* =========================================================================== 2573 * Flush the bit buffer and align the output on a byte boundary 2574 */ 2575local void bi_windup(s) 2576 deflate_state *s; 2577{ 2578 if (s->bi_valid > 8) { 2579 put_short(s, s->bi_buf); 2580 } else if (s->bi_valid > 0) { 2581 put_byte(s, (Byte)s->bi_buf); 2582 } 2583 s->bi_buf = 0; 2584 s->bi_valid = 0; 2585#ifdef DEBUG_ZLIB 2586 s->bits_sent = (s->bits_sent+7) & ~7; 2587#endif 2588} 2589 2590/* =========================================================================== 2591 * Copy a stored block, storing first the length and its 2592 * one's complement if requested. 2593 */ 2594local void copy_block(s, buf, len, header) 2595 deflate_state *s; 2596 charf *buf; /* the input data */ 2597 unsigned len; /* its length */ 2598 int header; /* true if block header must be written */ 2599{ 2600 bi_windup(s); /* align on byte boundary */ 2601 s->last_eob_len = 8; /* enough lookahead for inflate */ 2602 2603 if (header) { 2604 put_short(s, (ush)len); 2605 put_short(s, (ush)~len); 2606#ifdef DEBUG_ZLIB 2607 s->bits_sent += 2*16; 2608#endif 2609 } 2610#ifdef DEBUG_ZLIB 2611 s->bits_sent += (ulg)len<<3; 2612#endif 2613 while (len--) { 2614 put_byte(s, *buf++); 2615 } 2616} 2617 2618 2619/*+++++*/ 2620/* infblock.h -- header to use infblock.c 2621 * Copyright (C) 1995 Mark Adler 2622 * For conditions of distribution and use, see copyright notice in zlib.h 2623 */ 2624 2625/* WARNING: this file should *not* be used by applications. It is 2626 part of the implementation of the compression library and is 2627 subject to change. Applications should only use zlib.h. 2628 */ 2629 2630struct inflate_blocks_state; 2631typedef struct inflate_blocks_state FAR inflate_blocks_statef; 2632 2633local inflate_blocks_statef * inflate_blocks_new OF(( 2634 z_stream *z, 2635 check_func c, /* check function */ 2636 uInt w)); /* window size */ 2637 2638local int inflate_blocks OF(( 2639 inflate_blocks_statef *, 2640 z_stream *, 2641 int)); /* initial return code */ 2642 2643local void inflate_blocks_reset OF(( 2644 inflate_blocks_statef *, 2645 z_stream *, 2646 uLongf *)); /* check value on output */ 2647 2648local int inflate_blocks_free OF(( 2649 inflate_blocks_statef *, 2650 z_stream *, 2651 uLongf *)); /* check value on output */ 2652 2653local int inflate_addhistory OF(( 2654 inflate_blocks_statef *, 2655 z_stream *)); 2656 2657local int inflate_packet_flush OF(( 2658 inflate_blocks_statef *)); 2659 2660/*+++++*/ 2661/* inftrees.h -- header to use inftrees.c 2662 * Copyright (C) 1995 Mark Adler 2663 * For conditions of distribution and use, see copyright notice in zlib.h 2664 */ 2665 2666/* WARNING: this file should *not* be used by applications. It is 2667 part of the implementation of the compression library and is 2668 subject to change. Applications should only use zlib.h. 2669 */ 2670 2671/* Huffman code lookup table entry--this entry is four bytes for machines 2672 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 2673 2674typedef struct inflate_huft_s FAR inflate_huft; 2675 2676struct inflate_huft_s { 2677 union { 2678 struct { 2679 Byte Exop; /* number of extra bits or operation */ 2680 Byte Bits; /* number of bits in this code or subcode */ 2681 } what; 2682 uInt Nalloc; /* number of these allocated here */ 2683 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 2684 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 2685 union { 2686 uInt Base; /* literal, length base, or distance base */ 2687 inflate_huft *Next; /* pointer to next level of table */ 2688 } more; 2689}; 2690 2691#ifdef DEBUG_ZLIB 2692 local uInt inflate_hufts; 2693#endif 2694 2695local int inflate_trees_bits OF(( 2696 uIntf *, /* 19 code lengths */ 2697 uIntf *, /* bits tree desired/actual depth */ 2698 inflate_huft * FAR *, /* bits tree result */ 2699 z_stream *)); /* for zalloc, zfree functions */ 2700 2701local int inflate_trees_dynamic OF(( 2702 uInt, /* number of literal/length codes */ 2703 uInt, /* number of distance codes */ 2704 uIntf *, /* that many (total) code lengths */ 2705 uIntf *, /* literal desired/actual bit depth */ 2706 uIntf *, /* distance desired/actual bit depth */ 2707 inflate_huft * FAR *, /* literal/length tree result */ 2708 inflate_huft * FAR *, /* distance tree result */ 2709 z_stream *)); /* for zalloc, zfree functions */ 2710 2711local int inflate_trees_fixed OF(( 2712 uIntf *, /* literal desired/actual bit depth */ 2713 uIntf *, /* distance desired/actual bit depth */ 2714 inflate_huft * FAR *, /* literal/length tree result */ 2715 inflate_huft * FAR *)); /* distance tree result */ 2716 2717local int inflate_trees_free OF(( 2718 inflate_huft *, /* tables to free */ 2719 z_stream *)); /* for zfree function */ 2720 2721 2722/*+++++*/ 2723/* infcodes.h -- header to use infcodes.c 2724 * Copyright (C) 1995 Mark Adler 2725 * For conditions of distribution and use, see copyright notice in zlib.h 2726 */ 2727 2728/* WARNING: this file should *not* be used by applications. It is 2729 part of the implementation of the compression library and is 2730 subject to change. Applications should only use zlib.h. 2731 */ 2732 2733struct inflate_codes_state; 2734typedef struct inflate_codes_state FAR inflate_codes_statef; 2735 2736local inflate_codes_statef *inflate_codes_new OF(( 2737 uInt, uInt, 2738 inflate_huft *, inflate_huft *, 2739 z_stream *)); 2740 2741local int inflate_codes OF(( 2742 inflate_blocks_statef *, 2743 z_stream *, 2744 int)); 2745 2746local void inflate_codes_free OF(( 2747 inflate_codes_statef *, 2748 z_stream *)); 2749 2750 2751/*+++++*/ 2752/* inflate.c -- zlib interface to inflate modules 2753 * Copyright (C) 1995 Mark Adler 2754 * For conditions of distribution and use, see copyright notice in zlib.h 2755 */ 2756 2757/* inflate private state */ 2758struct internal_state { 2759 2760 /* mode */ 2761 enum { 2762 METHOD, /* waiting for method byte */ 2763 FLAG, /* waiting for flag byte */ 2764 BLOCKS, /* decompressing blocks */ 2765 CHECK4, /* four check bytes to go */ 2766 CHECK3, /* three check bytes to go */ 2767 CHECK2, /* two check bytes to go */ 2768 CHECK1, /* one check byte to go */ 2769 DONE, /* finished check, done */ 2770 BAD} /* got an error--stay here */ 2771 mode; /* current inflate mode */ 2772 2773 /* mode dependent information */ 2774 union { 2775 uInt method; /* if FLAGS, method byte */ 2776 struct { 2777 uLong was; /* computed check value */ 2778 uLong need; /* stream check value */ 2779 } check; /* if CHECK, check values to compare */ 2780 uInt marker; /* if BAD, inflateSync's marker bytes count */ 2781 } sub; /* submode */ 2782 2783 /* mode independent information */ 2784 int nowrap; /* flag for no wrapper */ 2785 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 2786 inflate_blocks_statef 2787 *blocks; /* current inflate_blocks state */ 2788 2789}; 2790 2791 2792int inflateReset(z) 2793z_stream *z; 2794{ 2795 uLong c; 2796 2797 if (z == Z_NULL || z->state == Z_NULL) 2798 return Z_STREAM_ERROR; 2799 z->total_in = z->total_out = 0; 2800 z->msg = Z_NULL; 2801 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 2802 inflate_blocks_reset(z->state->blocks, z, &c); 2803 Trace((stderr, "inflate: reset\n")); 2804 return Z_OK; 2805} 2806 2807 2808int inflateEnd(z) 2809z_stream *z; 2810{ 2811 uLong c; 2812 2813 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 2814 return Z_STREAM_ERROR; 2815 if (z->state->blocks != Z_NULL) 2816 inflate_blocks_free(z->state->blocks, z, &c); 2817 ZFREE(z, z->state, sizeof(struct internal_state)); 2818 z->state = Z_NULL; 2819 Trace((stderr, "inflate: end\n")); 2820 return Z_OK; 2821} 2822 2823 2824int inflateInit2(z, w) 2825z_stream *z; 2826int w; 2827{ 2828 /* initialize state */ 2829 if (z == Z_NULL) 2830 return Z_STREAM_ERROR; 2831/* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */ 2832/* if (z->zfree == Z_NULL) z->zfree = zcfree; */ 2833 if ((z->state = (struct internal_state FAR *) 2834 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 2835 return Z_MEM_ERROR; 2836 z->state->blocks = Z_NULL; 2837 2838 /* handle undocumented nowrap option (no zlib header or check) */ 2839 z->state->nowrap = 0; 2840 if (w < 0) 2841 { 2842 w = - w; 2843 z->state->nowrap = 1; 2844 } 2845 2846 /* set window size */ 2847 if (w < 8 || w > 15) 2848 { 2849 inflateEnd(z); 2850 return Z_STREAM_ERROR; 2851 } 2852 z->state->wbits = (uInt)w; 2853 2854 /* create inflate_blocks state */ 2855 if ((z->state->blocks = 2856 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w)) 2857 == Z_NULL) 2858 { 2859 inflateEnd(z); 2860 return Z_MEM_ERROR; 2861 } 2862 Trace((stderr, "inflate: allocated\n")); 2863 2864 /* reset state */ 2865 inflateReset(z); 2866 return Z_OK; 2867} 2868 2869 2870int inflateInit(z) 2871z_stream *z; 2872{ 2873 return inflateInit2(z, DEF_WBITS); 2874} 2875 2876 2877#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 2878#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 2879 2880int inflate(z, f) 2881z_stream *z; 2882int f; 2883{ 2884 int r; 2885 uInt b; 2886 2887 if (z == Z_NULL || z->next_in == Z_NULL) 2888 return Z_STREAM_ERROR; 2889 r = Z_BUF_ERROR; 2890 while (1) switch (z->state->mode) 2891 { 2892 case METHOD: 2893 NEEDBYTE 2894 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED) 2895 { 2896 z->state->mode = BAD; 2897 z->msg = "unknown compression method"; 2898 z->state->sub.marker = 5; /* can't try inflateSync */ 2899 break; 2900 } 2901 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 2902 { 2903 z->state->mode = BAD; 2904 z->msg = "invalid window size"; 2905 z->state->sub.marker = 5; /* can't try inflateSync */ 2906 break; 2907 } 2908 z->state->mode = FLAG; 2909 case FLAG: 2910 NEEDBYTE 2911 if ((b = NEXTBYTE) & 0x20) 2912 { 2913 z->state->mode = BAD; 2914 z->msg = "invalid reserved bit"; 2915 z->state->sub.marker = 5; /* can't try inflateSync */ 2916 break; 2917 } 2918 if (((z->state->sub.method << 8) + b) % 31) 2919 { 2920 z->state->mode = BAD; 2921 z->msg = "incorrect header check"; 2922 z->state->sub.marker = 5; /* can't try inflateSync */ 2923 break; 2924 } 2925 Trace((stderr, "inflate: zlib header ok\n")); 2926 z->state->mode = BLOCKS; 2927 case BLOCKS: 2928 r = inflate_blocks(z->state->blocks, z, r); 2929 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 2930 r = inflate_packet_flush(z->state->blocks); 2931 if (r == Z_DATA_ERROR) 2932 { 2933 z->state->mode = BAD; 2934 z->state->sub.marker = 0; /* can try inflateSync */ 2935 break; 2936 } 2937 if (r != Z_STREAM_END) 2938 return r; 2939 r = Z_OK; 2940 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 2941 if (z->state->nowrap) 2942 { 2943 z->state->mode = DONE; 2944 break; 2945 } 2946 z->state->mode = CHECK4; 2947 case CHECK4: 2948 NEEDBYTE 2949 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 2950 z->state->mode = CHECK3; 2951 case CHECK3: 2952 NEEDBYTE 2953 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 2954 z->state->mode = CHECK2; 2955 case CHECK2: 2956 NEEDBYTE 2957 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 2958 z->state->mode = CHECK1; 2959 case CHECK1: 2960 NEEDBYTE 2961 z->state->sub.check.need += (uLong)NEXTBYTE; 2962 2963 if (z->state->sub.check.was != z->state->sub.check.need) 2964 { 2965 z->state->mode = BAD; 2966 z->msg = "incorrect data check"; 2967 z->state->sub.marker = 5; /* can't try inflateSync */ 2968 break; 2969 } 2970 Trace((stderr, "inflate: zlib check ok\n")); 2971 z->state->mode = DONE; 2972 case DONE: 2973 return Z_STREAM_END; 2974 case BAD: 2975 return Z_DATA_ERROR; 2976 default: 2977 return Z_STREAM_ERROR; 2978 } 2979 2980 empty: 2981 if (f != Z_PACKET_FLUSH) 2982 return r; 2983 z->state->mode = BAD; 2984 z->state->sub.marker = 0; /* can try inflateSync */ 2985 return Z_DATA_ERROR; 2986} 2987 2988/* 2989 * This subroutine adds the data at next_in/avail_in to the output history 2990 * without performing any output. The output buffer must be "caught up"; 2991 * i.e. no pending output (hence s->read equals s->write), and the state must 2992 * be BLOCKS (i.e. we should be willing to see the start of a series of 2993 * BLOCKS). On exit, the output will also be caught up, and the checksum 2994 * will have been updated if need be. 2995 */ 2996 2997int inflateIncomp(z) 2998z_stream *z; 2999{ 3000 if (z->state->mode != BLOCKS) 3001 return Z_DATA_ERROR; 3002 return inflate_addhistory(z->state->blocks, z); 3003} 3004 3005 3006int inflateSync(z) 3007z_stream *z; 3008{ 3009 uInt n; /* number of bytes to look at */ 3010 Bytef *p; /* pointer to bytes */ 3011 uInt m; /* number of marker bytes found in a row */ 3012 uLong r, w; /* temporaries to save total_in and total_out */ 3013 3014 /* set up */ 3015 if (z == Z_NULL || z->state == Z_NULL) 3016 return Z_STREAM_ERROR; 3017 if (z->state->mode != BAD) 3018 { 3019 z->state->mode = BAD; 3020 z->state->sub.marker = 0; 3021 } 3022 if ((n = z->avail_in) == 0) 3023 return Z_BUF_ERROR; 3024 p = z->next_in; 3025 m = z->state->sub.marker; 3026 3027 /* search */ 3028 while (n && m < 4) 3029 { 3030 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3031 m++; 3032 else if (*p) 3033 m = 0; 3034 else 3035 m = 4 - m; 3036 p++, n--; 3037 } 3038 3039 /* restore */ 3040 z->total_in += p - z->next_in; 3041 z->next_in = p; 3042 z->avail_in = n; 3043 z->state->sub.marker = m; 3044 3045 /* return no joy or set up to restart on a new block */ 3046 if (m != 4) 3047 return Z_DATA_ERROR; 3048 r = z->total_in; w = z->total_out; 3049 inflateReset(z); 3050 z->total_in = r; z->total_out = w; 3051 z->state->mode = BLOCKS; 3052 return Z_OK; 3053} 3054 3055#undef NEEDBYTE 3056#undef NEXTBYTE 3057 3058/*+++++*/ 3059/* infutil.h -- types and macros common to blocks and codes 3060 * Copyright (C) 1995 Mark Adler 3061 * For conditions of distribution and use, see copyright notice in zlib.h 3062 */ 3063 3064/* WARNING: this file should *not* be used by applications. It is 3065 part of the implementation of the compression library and is 3066 subject to change. Applications should only use zlib.h. 3067 */ 3068 3069/* inflate blocks semi-private state */ 3070struct inflate_blocks_state { 3071 3072 /* mode */ 3073 enum { 3074 TYPE, /* get type bits (3, including end bit) */ 3075 LENS, /* get lengths for stored */ 3076 STORED, /* processing stored block */ 3077 TABLE, /* get table lengths */ 3078 BTREE, /* get bit lengths tree for a dynamic block */ 3079 DTREE, /* get length, distance trees for a dynamic block */ 3080 CODES, /* processing fixed or dynamic block */ 3081 DRY, /* output remaining window bytes */ 3082 DONEB, /* finished last block, done */ 3083 BADB} /* got a data error--stuck here */ 3084 mode; /* current inflate_block mode */ 3085 3086 /* mode dependent information */ 3087 union { 3088 uInt left; /* if STORED, bytes left to copy */ 3089 struct { 3090 uInt table; /* table lengths (14 bits) */ 3091 uInt index; /* index into blens (or border) */ 3092 uIntf *blens; /* bit lengths of codes */ 3093 uInt bb; /* bit length tree depth */ 3094 inflate_huft *tb; /* bit length decoding tree */ 3095 int nblens; /* # elements allocated at blens */ 3096 } trees; /* if DTREE, decoding info for trees */ 3097 struct { 3098 inflate_huft *tl, *td; /* trees to free */ 3099 inflate_codes_statef 3100 *codes; 3101 } decode; /* if CODES, current state */ 3102 } sub; /* submode */ 3103 uInt last; /* true if this block is the last block */ 3104 3105 /* mode independent information */ 3106 uInt bitk; /* bits in bit buffer */ 3107 uLong bitb; /* bit buffer */ 3108 Bytef *window; /* sliding window */ 3109 Bytef *end; /* one byte after sliding window */ 3110 Bytef *read; /* window read pointer */ 3111 Bytef *write; /* window write pointer */ 3112 check_func checkfn; /* check function */ 3113 uLong check; /* check on output */ 3114 3115}; 3116 3117 3118/* defines for inflate input/output */ 3119/* update pointers and return */ 3120#define UPDBITS {s->bitb=b;s->bitk=k;} 3121#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3122#define UPDOUT {s->write=q;} 3123#define UPDATE {UPDBITS UPDIN UPDOUT} 3124#define LEAVE {UPDATE return inflate_flush(s,z,r);} 3125/* get bytes and bits */ 3126#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3127#define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3128#define NEXTBYTE (n--,*p++) 3129#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3130#define DUMPBITS(j) {b>>=(j);k-=(j);} 3131/* output bytes */ 3132#define WAVAIL (q<s->read?s->read-q-1:s->end-q) 3133#define LOADOUT {q=s->write;m=WAVAIL;} 3134#define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}} 3135#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3136#define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} 3137#define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3138/* load local pointers */ 3139#define LOAD {LOADIN LOADOUT} 3140 3141/* And'ing with mask[n] masks the lower n bits */ 3142local uInt inflate_mask[] = { 3143 0x0000, 3144 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 3145 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 3146}; 3147 3148/* copy as much as possible from the sliding window to the output area */ 3149local int inflate_flush OF(( 3150 inflate_blocks_statef *, 3151 z_stream *, 3152 int)); 3153 3154/*+++++*/ 3155/* inffast.h -- header to use inffast.c 3156 * Copyright (C) 1995 Mark Adler 3157 * For conditions of distribution and use, see copyright notice in zlib.h 3158 */ 3159 3160/* WARNING: this file should *not* be used by applications. It is 3161 part of the implementation of the compression library and is 3162 subject to change. Applications should only use zlib.h. 3163 */ 3164 3165local int inflate_fast OF(( 3166 uInt, 3167 uInt, 3168 inflate_huft *, 3169 inflate_huft *, 3170 inflate_blocks_statef *, 3171 z_stream *)); 3172 3173 3174/*+++++*/ 3175/* infblock.c -- interpret and process block types to last block 3176 * Copyright (C) 1995 Mark Adler 3177 * For conditions of distribution and use, see copyright notice in zlib.h 3178 */ 3179 3180/* Table for deflate from PKZIP's appnote.txt. */ 3181local uInt border[] = { /* Order of the bit length code lengths */ 3182 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3183 3184/* 3185 Notes beyond the 1.93a appnote.txt: 3186 3187 1. Distance pointers never point before the beginning of the output 3188 stream. 3189 2. Distance pointers can point back across blocks, up to 32k away. 3190 3. There is an implied maximum of 7 bits for the bit length table and 3191 15 bits for the actual data. 3192 4. If only one code exists, then it is encoded using one bit. (Zero 3193 would be more efficient, but perhaps a little confusing.) If two 3194 codes exist, they are coded using one bit each (0 and 1). 3195 5. There is no way of sending zero distance codes--a dummy must be 3196 sent if there are none. (History: a pre 2.0 version of PKZIP would 3197 store blocks with no distance codes, but this was discovered to be 3198 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3199 zero distance codes, which is sent as one code of zero bits in 3200 length. 3201 6. There are up to 286 literal/length codes. Code 256 represents the 3202 end-of-block. Note however that the static length tree defines 3203 288 codes just to fill out the Huffman codes. Codes 286 and 287 3204 cannot be used though, since there is no length base or extra bits 3205 defined for them. Similarily, there are up to 30 distance codes. 3206 However, static trees define 32 codes (all 5 bits) to fill out the 3207 Huffman codes, but the last two had better not show up in the data. 3208 7. Unzip can check dynamic Huffman blocks for complete code sets. 3209 The exception is that a single code would not be complete (see #4). 3210 8. The five bits following the block type is really the number of 3211 literal codes sent minus 257. 3212 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3213 (1+6+6). Therefore, to output three times the length, you output 3214 three codes (1+1+1), whereas to output four times the same length, 3215 you only need two codes (1+3). Hmm. 3216 10. In the tree reconstruction algorithm, Code = Code + Increment 3217 only if BitLength(i) is not zero. (Pretty obvious.) 3218 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3219 12. Note: length code 284 can represent 227-258, but length code 285 3220 really is 258. The last length deserves its own, short code 3221 since it gets used a lot in very redundant files. The length 3222 258 is special since 258 - 3 (the min match length) is 255. 3223 13. The literal/length and distance code bit lengths are read as a 3224 single stream of lengths. It is possible (and advantageous) for 3225 a repeat code (16, 17, or 18) to go across the boundary between 3226 the two sets of lengths. 3227 */ 3228 3229 3230local void inflate_blocks_reset(s, z, c) 3231inflate_blocks_statef *s; 3232z_stream *z; 3233uLongf *c; 3234{ 3235 if (s->checkfn != Z_NULL) 3236 *c = s->check; 3237 if (s->mode == BTREE || s->mode == DTREE) 3238 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt)); 3239 if (s->mode == CODES) 3240 { 3241 inflate_codes_free(s->sub.decode.codes, z); 3242 inflate_trees_free(s->sub.decode.td, z); 3243 inflate_trees_free(s->sub.decode.tl, z); 3244 } 3245 s->mode = TYPE; 3246 s->bitk = 0; 3247 s->bitb = 0; 3248 s->read = s->write = s->window; 3249 if (s->checkfn != Z_NULL) 3250 s->check = (*s->checkfn)(0L, Z_NULL, 0); 3251 Trace((stderr, "inflate: blocks reset\n")); 3252} 3253 3254 3255local inflate_blocks_statef *inflate_blocks_new(z, c, w) 3256z_stream *z; 3257check_func c; 3258uInt w; 3259{ 3260 inflate_blocks_statef *s; 3261 3262 if ((s = (inflate_blocks_statef *)ZALLOC 3263 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3264 return s; 3265 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3266 { 3267 ZFREE(z, s, sizeof(struct inflate_blocks_state)); 3268 return Z_NULL; 3269 } 3270 s->end = s->window + w; 3271 s->checkfn = c; 3272 s->mode = TYPE; 3273 Trace((stderr, "inflate: blocks allocated\n")); 3274 inflate_blocks_reset(s, z, &s->check); 3275 return s; 3276} 3277 3278 3279local int inflate_blocks(s, z, r) 3280inflate_blocks_statef *s; 3281z_stream *z; 3282int r; 3283{ 3284 uInt t; /* temporary storage */ 3285 uLong b; /* bit buffer */ 3286 uInt k; /* bits in bit buffer */ 3287 Bytef *p; /* input data pointer */ 3288 uInt n; /* bytes available there */ 3289 Bytef *q; /* output window write pointer */ 3290 uInt m; /* bytes to end of window or read pointer */ 3291 3292 /* copy input/output information to locals (UPDATE macro restores) */ 3293 LOAD 3294 3295 /* process input based on current state */ 3296 while (1) switch (s->mode) 3297 { 3298 case TYPE: 3299 NEEDBITS(3) 3300 t = (uInt)b & 7; 3301 s->last = t & 1; 3302 switch (t >> 1) 3303 { 3304 case 0: /* stored */ 3305 Trace((stderr, "inflate: stored block%s\n", 3306 s->last ? " (last)" : "")); 3307 DUMPBITS(3) 3308 t = k & 7; /* go to byte boundary */ 3309 DUMPBITS(t) 3310 s->mode = LENS; /* get length of stored block */ 3311 break; 3312 case 1: /* fixed */ 3313 Trace((stderr, "inflate: fixed codes block%s\n", 3314 s->last ? " (last)" : "")); 3315 { 3316 uInt bl, bd; 3317 inflate_huft *tl, *td; 3318 3319 inflate_trees_fixed(&bl, &bd, &tl, &td); 3320 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3321 if (s->sub.decode.codes == Z_NULL) 3322 { 3323 r = Z_MEM_ERROR; 3324 LEAVE 3325 } 3326 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3327 s->sub.decode.td = Z_NULL; 3328 } 3329 DUMPBITS(3) 3330 s->mode = CODES; 3331 break; 3332 case 2: /* dynamic */ 3333 Trace((stderr, "inflate: dynamic codes block%s\n", 3334 s->last ? " (last)" : "")); 3335 DUMPBITS(3) 3336 s->mode = TABLE; 3337 break; 3338 case 3: /* illegal */ 3339 DUMPBITS(3) 3340 s->mode = BADB; 3341 z->msg = "invalid block type"; 3342 r = Z_DATA_ERROR; 3343 LEAVE 3344 } 3345 break; 3346 case LENS: 3347 NEEDBITS(32) 3348 if (((~b) >> 16) != (b & 0xffff)) 3349 { 3350 s->mode = BADB; 3351 z->msg = "invalid stored block lengths"; 3352 r = Z_DATA_ERROR; 3353 LEAVE 3354 } 3355 s->sub.left = (uInt)b & 0xffff; 3356 b = k = 0; /* dump bits */ 3357 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3358 s->mode = s->sub.left ? STORED : TYPE; 3359 break; 3360 case STORED: 3361 if (n == 0) 3362 LEAVE 3363 NEEDOUT 3364 t = s->sub.left; 3365 if (t > n) t = n; 3366 if (t > m) t = m; 3367 zmemcpy(q, p, t); 3368 p += t; n -= t; 3369 q += t; m -= t; 3370 if ((s->sub.left -= t) != 0) 3371 break; 3372 Tracev((stderr, "inflate: stored end, %lu total out\n", 3373 z->total_out + (q >= s->read ? q - s->read : 3374 (s->end - s->read) + (q - s->window)))); 3375 s->mode = s->last ? DRY : TYPE; 3376 break; 3377 case TABLE: 3378 NEEDBITS(14) 3379 s->sub.trees.table = t = (uInt)b & 0x3fff; 3380#ifndef PKZIP_BUG_WORKAROUND 3381 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3382 { 3383 s->mode = BADB; 3384 z->msg = "too many length or distance symbols"; 3385 r = Z_DATA_ERROR; 3386 LEAVE 3387 } 3388#endif 3389 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3390 if (t < 19) 3391 t = 19; 3392 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3393 { 3394 r = Z_MEM_ERROR; 3395 LEAVE 3396 } 3397 s->sub.trees.nblens = t; 3398 DUMPBITS(14) 3399 s->sub.trees.index = 0; 3400 Tracev((stderr, "inflate: table sizes ok\n")); 3401 s->mode = BTREE; 3402 case BTREE: 3403 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3404 { 3405 NEEDBITS(3) 3406 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3407 DUMPBITS(3) 3408 } 3409 while (s->sub.trees.index < 19) 3410 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3411 s->sub.trees.bb = 7; 3412 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3413 &s->sub.trees.tb, z); 3414 if (t != Z_OK) 3415 { 3416 r = t; 3417 if (r == Z_DATA_ERROR) 3418 s->mode = BADB; 3419 LEAVE 3420 } 3421 s->sub.trees.index = 0; 3422 Tracev((stderr, "inflate: bits tree ok\n")); 3423 s->mode = DTREE; 3424 case DTREE: 3425 while (t = s->sub.trees.table, 3426 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3427 { 3428 inflate_huft *h; 3429 uInt i, j, c; 3430 3431 t = s->sub.trees.bb; 3432 NEEDBITS(t) 3433 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3434 t = h->word.what.Bits; 3435 c = h->more.Base; 3436 if (c < 16) 3437 { 3438 DUMPBITS(t) 3439 s->sub.trees.blens[s->sub.trees.index++] = c; 3440 } 3441 else /* c == 16..18 */ 3442 { 3443 i = c == 18 ? 7 : c - 14; 3444 j = c == 18 ? 11 : 3; 3445 NEEDBITS(t + i) 3446 DUMPBITS(t) 3447 j += (uInt)b & inflate_mask[i]; 3448 DUMPBITS(i) 3449 i = s->sub.trees.index; 3450 t = s->sub.trees.table; 3451 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3452 (c == 16 && i < 1)) 3453 { 3454 s->mode = BADB; 3455 z->msg = "invalid bit length repeat"; 3456 r = Z_DATA_ERROR; 3457 LEAVE 3458 } 3459 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3460 do { 3461 s->sub.trees.blens[i++] = c; 3462 } while (--j); 3463 s->sub.trees.index = i; 3464 } 3465 } 3466 inflate_trees_free(s->sub.trees.tb, z); 3467 s->sub.trees.tb = Z_NULL; 3468 { 3469 uInt bl, bd; 3470 inflate_huft *tl, *td; 3471 inflate_codes_statef *c; 3472 3473 bl = 9; /* must be <= 9 for lookahead assumptions */ 3474 bd = 6; /* must be <= 9 for lookahead assumptions */ 3475 t = s->sub.trees.table; 3476 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3477 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3478 if (t != Z_OK) 3479 { 3480 if (t == (uInt)Z_DATA_ERROR) 3481 s->mode = BADB; 3482 r = t; 3483 LEAVE 3484 } 3485 Tracev((stderr, "inflate: trees ok\n")); 3486 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3487 { 3488 inflate_trees_free(td, z); 3489 inflate_trees_free(tl, z); 3490 r = Z_MEM_ERROR; 3491 LEAVE 3492 } 3493 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt)); 3494 s->sub.decode.codes = c; 3495 s->sub.decode.tl = tl; 3496 s->sub.decode.td = td; 3497 } 3498 s->mode = CODES; 3499 case CODES: 3500 UPDATE 3501 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3502 return inflate_flush(s, z, r); 3503 r = Z_OK; 3504 inflate_codes_free(s->sub.decode.codes, z); 3505 inflate_trees_free(s->sub.decode.td, z); 3506 inflate_trees_free(s->sub.decode.tl, z); 3507 LOAD 3508 Tracev((stderr, "inflate: codes end, %lu total out\n", 3509 z->total_out + (q >= s->read ? q - s->read : 3510 (s->end - s->read) + (q - s->window)))); 3511 if (!s->last) 3512 { 3513 s->mode = TYPE; 3514 break; 3515 } 3516 if (k > 7) /* return unused byte, if any */ 3517 { 3518 Assert(k < 16, "inflate_codes grabbed too many bytes") 3519 k -= 8; 3520 n++; 3521 p--; /* can always return one */ 3522 } 3523 s->mode = DRY; 3524 case DRY: 3525 FLUSH 3526 if (s->read != s->write) 3527 LEAVE 3528 s->mode = DONEB; 3529 case DONEB: 3530 r = Z_STREAM_END; 3531 LEAVE 3532 case BADB: 3533 r = Z_DATA_ERROR; 3534 LEAVE 3535 default: 3536 r = Z_STREAM_ERROR; 3537 LEAVE 3538 } 3539} 3540 3541 3542local int inflate_blocks_free(s, z, c) 3543inflate_blocks_statef *s; 3544z_stream *z; 3545uLongf *c; 3546{ 3547 inflate_blocks_reset(s, z, c); 3548 ZFREE(z, s->window, s->end - s->window); 3549 ZFREE(z, s, sizeof(struct inflate_blocks_state)); 3550 Trace((stderr, "inflate: blocks freed\n")); 3551 return Z_OK; 3552} 3553 3554/* 3555 * This subroutine adds the data at next_in/avail_in to the output history 3556 * without performing any output. The output buffer must be "caught up"; 3557 * i.e. no pending output (hence s->read equals s->write), and the state must 3558 * be BLOCKS (i.e. we should be willing to see the start of a series of 3559 * BLOCKS). On exit, the output will also be caught up, and the checksum 3560 * will have been updated if need be. 3561 */ 3562local int inflate_addhistory(s, z) 3563inflate_blocks_statef *s; 3564z_stream *z; 3565{ 3566 uLong b; /* bit buffer */ /* NOT USED HERE */ 3567 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 3568 uInt t; /* temporary storage */ 3569 Bytef *p; /* input data pointer */ 3570 uInt n; /* bytes available there */ 3571 Bytef *q; /* output window write pointer */ 3572 uInt m; /* bytes to end of window or read pointer */ 3573 3574 if (s->read != s->write) 3575 return Z_STREAM_ERROR; 3576 if (s->mode != TYPE) 3577 return Z_DATA_ERROR; 3578 3579 /* we're ready to rock */ 3580 LOAD 3581 /* while there is input ready, copy to output buffer, moving 3582 * pointers as needed. 3583 */ 3584 while (n) { 3585 t = n; /* how many to do */ 3586 /* is there room until end of buffer? */ 3587 if (t > m) t = m; 3588 /* update check information */ 3589 if (s->checkfn != Z_NULL) 3590 s->check = (*s->checkfn)(s->check, q, t); 3591 zmemcpy(q, p, t); 3592 q += t; 3593 p += t; 3594 n -= t; 3595 z->total_out += t; 3596 s->read = q; /* drag read pointer forward */ 3597/* WRAP */ /* expand WRAP macro by hand to handle s->read */ 3598 if (q == s->end) { 3599 s->read = q = s->window; 3600 m = WAVAIL; 3601 } 3602 } 3603 UPDATE 3604 return Z_OK; 3605} 3606 3607 3608/* 3609 * At the end of a Deflate-compressed PPP packet, we expect to have seen 3610 * a `stored' block type value but not the (zero) length bytes. 3611 */ 3612local int inflate_packet_flush(s) 3613 inflate_blocks_statef *s; 3614{ 3615 if (s->mode != LENS) 3616 return Z_DATA_ERROR; 3617 s->mode = TYPE; 3618 return Z_OK; 3619} 3620 3621 3622/*+++++*/ 3623/* inftrees.c -- generate Huffman trees for efficient decoding 3624 * Copyright (C) 1995 Mark Adler 3625 * For conditions of distribution and use, see copyright notice in zlib.h 3626 */ 3627 3628/* simplify the use of the inflate_huft type with some defines */ 3629#define base more.Base 3630#define next more.Next 3631#define exop word.what.Exop 3632#define bits word.what.Bits 3633 3634 3635local int huft_build OF(( 3636 uIntf *, /* code lengths in bits */ 3637 uInt, /* number of codes */ 3638 uInt, /* number of "simple" codes */ 3639 uIntf *, /* list of base values for non-simple codes */ 3640 uIntf *, /* list of extra bits for non-simple codes */ 3641 inflate_huft * FAR*,/* result: starting table */ 3642 uIntf *, /* maximum lookup bits (returns actual) */ 3643 z_stream *)); /* for zalloc function */ 3644 3645local voidpf falloc OF(( 3646 voidpf, /* opaque pointer (not used) */ 3647 uInt, /* number of items */ 3648 uInt)); /* size of item */ 3649 3650local void ffree OF(( 3651 voidpf q, /* opaque pointer (not used) */ 3652 voidpf p, /* what to free (not used) */ 3653 uInt n)); /* number of bytes (not used) */ 3654 3655/* Tables for deflate from PKZIP's appnote.txt. */ 3656local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */ 3657 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 3658 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 3659 /* actually lengths - 2; also see note #13 above about 258 */ 3660local uInt cplext[] = { /* Extra bits for literal codes 257..285 */ 3661 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3662 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */ 3663local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */ 3664 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 3665 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 3666 8193, 12289, 16385, 24577}; 3667local uInt cpdext[] = { /* Extra bits for distance codes */ 3668 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 3669 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 3670 12, 12, 13, 13}; 3671 3672/* 3673 Huffman code decoding is performed using a multi-level table lookup. 3674 The fastest way to decode is to simply build a lookup table whose 3675 size is determined by the longest code. However, the time it takes 3676 to build this table can also be a factor if the data being decoded 3677 is not very long. The most common codes are necessarily the 3678 shortest codes, so those codes dominate the decoding time, and hence 3679 the speed. The idea is you can have a shorter table that decodes the 3680 shorter, more probable codes, and then point to subsidiary tables for 3681 the longer codes. The time it costs to decode the longer codes is 3682 then traded against the time it takes to make longer tables. 3683 3684 This results of this trade are in the variables lbits and dbits 3685 below. lbits is the number of bits the first level table for literal/ 3686 length codes can decode in one step, and dbits is the same thing for 3687 the distance codes. Subsequent tables are also less than or equal to 3688 those sizes. These values may be adjusted either when all of the 3689 codes are shorter than that, in which case the longest code length in 3690 bits is used, or when the shortest code is *longer* than the requested 3691 table size, in which case the length of the shortest code in bits is 3692 used. 3693 3694 There are two different values for the two tables, since they code a 3695 different number of possibilities each. The literal/length table 3696 codes 286 possible values, or in a flat code, a little over eight 3697 bits. The distance table codes 30 possible values, or a little less 3698 than five bits, flat. The optimum values for speed end up being 3699 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 3700 The optimum values may differ though from machine to machine, and 3701 possibly even between compilers. Your mileage may vary. 3702 */ 3703 3704 3705/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 3706#define BMAX 15 /* maximum bit length of any code */ 3707#define N_MAX 288 /* maximum number of codes in any set */ 3708 3709#ifdef DEBUG_ZLIB 3710 uInt inflate_hufts; 3711#endif 3712 3713local int huft_build(b, n, s, d, e, t, m, zs) 3714uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ 3715uInt n; /* number of codes (assumed <= N_MAX) */ 3716uInt s; /* number of simple-valued codes (0..s-1) */ 3717uIntf *d; /* list of base values for non-simple codes */ 3718uIntf *e; /* list of extra bits for non-simple codes */ 3719inflate_huft * FAR *t; /* result: starting table */ 3720uIntf *m; /* maximum lookup bits, returns actual */ 3721z_stream *zs; /* for zalloc function */ 3722/* Given a list of code lengths and a maximum table size, make a set of 3723 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 3724 if the given code set is incomplete (the tables are still built in this 3725 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an 3726 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */ 3727{ 3728 3729 uInt a; /* counter for codes of length k */ 3730 uInt c[BMAX+1]; /* bit length count table */ 3731 uInt f; /* i repeats in table every f entries */ 3732 int g; /* maximum code length */ 3733 int h; /* table level */ 3734 register uInt i; /* counter, current code */ 3735 register uInt j; /* counter */ 3736 register int k; /* number of bits in current code */ 3737 int l; /* bits per table (returned in m) */ 3738 register uIntf *p; /* pointer into c[], b[], or v[] */ 3739 inflate_huft *q; /* points to current table */ 3740 struct inflate_huft_s r; /* table entry for structure assignment */ 3741 inflate_huft *u[BMAX]; /* table stack */ 3742 uInt v[N_MAX]; /* values in order of bit length */ 3743 register int w; /* bits before this table == (l * h) */ 3744 uInt x[BMAX+1]; /* bit offsets, then code stack */ 3745 uIntf *xp; /* pointer into x */ 3746 int y; /* number of dummy codes added */ 3747 uInt z; /* number of entries in current table */ 3748 3749 3750 /* Generate counts for each bit length */ 3751 p = c; 3752#define C0 *p++ = 0; 3753#define C2 C0 C0 C0 C0 3754#define C4 C2 C2 C2 C2 3755 C4 /* clear c[]--assume BMAX+1 is 16 */ 3756 p = b; i = n; 3757 do { 3758 c[*p++]++; /* assume all entries <= BMAX */ 3759 } while (--i); 3760 if (c[0] == n) /* null input--all zero length codes */ 3761 { 3762 *t = (inflate_huft *)Z_NULL; 3763 *m = 0; 3764 return Z_OK; 3765 } 3766 3767 3768 /* Find minimum and maximum length, bound *m by those */ 3769 l = *m; 3770 for (j = 1; j <= BMAX; j++) 3771 if (c[j]) 3772 break; 3773 k = j; /* minimum code length */ 3774 if ((uInt)l < j) 3775 l = j; 3776 for (i = BMAX; i; i--) 3777 if (c[i]) 3778 break; 3779 g = i; /* maximum code length */ 3780 if ((uInt)l > i) 3781 l = i; 3782 *m = l; 3783 3784 3785 /* Adjust last length count to fill out codes, if needed */ 3786 for (y = 1 << j; j < i; j++, y <<= 1) 3787 if ((y -= c[j]) < 0) 3788 return Z_DATA_ERROR; 3789 if ((y -= c[i]) < 0) 3790 return Z_DATA_ERROR; 3791 c[i] += y; 3792 3793 3794 /* Generate starting offsets into the value table for each length */ 3795 x[1] = j = 0; 3796 p = c + 1; xp = x + 2; 3797 while (--i) { /* note that i == g from above */ 3798 *xp++ = (j += *p++); 3799 } 3800 3801 3802 /* Make a table of values in order of bit lengths */ 3803 p = b; i = 0; 3804 do { 3805 if ((j = *p++) != 0) 3806 v[x[j]++] = i; 3807 } while (++i < n); 3808 3809 3810 /* Generate the Huffman codes and for each, make the table entries */ 3811 x[0] = i = 0; /* first Huffman code is zero */ 3812 p = v; /* grab values in bit order */ 3813 h = -1; /* no tables yet--level -1 */ 3814 w = -l; /* bits decoded == (l * h) */ 3815 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 3816 q = (inflate_huft *)Z_NULL; /* ditto */ 3817 z = 0; /* ditto */ 3818 3819 /* go through the bit lengths (k already is bits in shortest code) */ 3820 for (; k <= g; k++) 3821 { 3822 a = c[k]; 3823 while (a--) 3824 { 3825 /* here i is the Huffman code of length k bits for value *p */ 3826 /* make tables up to required level */ 3827 while (k > w + l) 3828 { 3829 h++; 3830 w += l; /* previous table always l bits */ 3831 3832 /* compute minimum size table less than or equal to l bits */ 3833 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */ 3834 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 3835 { /* too few codes for k-w bit table */ 3836 f -= a + 1; /* deduct codes from patterns left */ 3837 xp = c + k; 3838 if (j < z) 3839 while (++j < z) /* try smaller tables up to z bits */ 3840 { 3841 if ((f <<= 1) <= *++xp) 3842 break; /* enough codes to use up j bits */ 3843 f -= *xp; /* else deduct codes from patterns */ 3844 } 3845 } 3846 z = 1 << j; /* table entries for j-bit table */ 3847 3848 /* allocate and link in new table */ 3849 if ((q = (inflate_huft *)ZALLOC 3850 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 3851 { 3852 if (h) 3853 inflate_trees_free(u[0], zs); 3854 return Z_MEM_ERROR; /* not enough memory */ 3855 } 3856 q->word.Nalloc = z + 1; 3857#ifdef DEBUG_ZLIB 3858 inflate_hufts += z + 1; 3859#endif 3860 *t = q + 1; /* link to list for huft_free() */ 3861 *(t = &(q->next)) = Z_NULL; 3862 u[h] = ++q; /* table starts after link */ 3863 3864 /* connect to last table, if there is one */ 3865 if (h) 3866 { 3867 x[h] = i; /* save pattern for backing up */ 3868 r.bits = (Byte)l; /* bits to dump before this table */ 3869 r.exop = (Byte)j; /* bits in this table */ 3870 r.next = q; /* pointer to this table */ 3871 j = i >> (w - l); /* (get around Turbo C bug) */ 3872 u[h-1][j] = r; /* connect to last table */ 3873 } 3874 } 3875 3876 /* set up table entry in r */ 3877 r.bits = (Byte)(k - w); 3878 if (p >= v + n) 3879 r.exop = 128 + 64; /* out of values--invalid code */ 3880 else if (*p < s) 3881 { 3882 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 3883 r.base = *p++; /* simple code is just the value */ 3884 } 3885 else 3886 { 3887 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */ 3888 r.base = d[*p++ - s]; 3889 } 3890 3891 /* fill code-like entries with r */ 3892 f = 1 << (k - w); 3893 for (j = i >> w; j < z; j += f) 3894 q[j] = r; 3895 3896 /* backwards increment the k-bit code i */ 3897 for (j = 1 << (k - 1); i & j; j >>= 1) 3898 i ^= j; 3899 i ^= j; 3900 3901 /* backup over finished tables */ 3902 while ((i & ((1 << w) - 1)) != x[h]) 3903 { 3904 h--; /* don't need to update q */ 3905 w -= l; 3906 } 3907 } 3908 } 3909 3910 3911 /* Return Z_BUF_ERROR if we were given an incomplete table */ 3912 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 3913} 3914 3915 3916local int inflate_trees_bits(c, bb, tb, z) 3917uIntf *c; /* 19 code lengths */ 3918uIntf *bb; /* bits tree desired/actual depth */ 3919inflate_huft * FAR *tb; /* bits tree result */ 3920z_stream *z; /* for zfree function */ 3921{ 3922 int r; 3923 3924 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 3925 if (r == Z_DATA_ERROR) 3926 z->msg = "oversubscribed dynamic bit lengths tree"; 3927 else if (r == Z_BUF_ERROR) 3928 { 3929 inflate_trees_free(*tb, z); 3930 z->msg = "incomplete dynamic bit lengths tree"; 3931 r = Z_DATA_ERROR; 3932 } 3933 return r; 3934} 3935 3936 3937local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) 3938uInt nl; /* number of literal/length codes */ 3939uInt nd; /* number of distance codes */ 3940uIntf *c; /* that many (total) code lengths */ 3941uIntf *bl; /* literal desired/actual bit depth */ 3942uIntf *bd; /* distance desired/actual bit depth */ 3943inflate_huft * FAR *tl; /* literal/length tree result */ 3944inflate_huft * FAR *td; /* distance tree result */ 3945z_stream *z; /* for zfree function */ 3946{ 3947 int r; 3948 3949 /* build literal/length tree */ 3950 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK) 3951 { 3952 if (r == Z_DATA_ERROR) 3953 z->msg = "oversubscribed literal/length tree"; 3954 else if (r == Z_BUF_ERROR) 3955 { 3956 inflate_trees_free(*tl, z); 3957 z->msg = "incomplete literal/length tree"; 3958 r = Z_DATA_ERROR; 3959 } 3960 return r; 3961 } 3962 3963 /* build distance tree */ 3964 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK) 3965 { 3966 if (r == Z_DATA_ERROR) 3967 z->msg = "oversubscribed literal/length tree"; 3968 else if (r == Z_BUF_ERROR) { 3969#ifdef PKZIP_BUG_WORKAROUND 3970 r = Z_OK; 3971 } 3972#else 3973 inflate_trees_free(*td, z); 3974 z->msg = "incomplete literal/length tree"; 3975 r = Z_DATA_ERROR; 3976 } 3977 inflate_trees_free(*tl, z); 3978 return r; 3979#endif 3980 } 3981 3982 /* done */ 3983 return Z_OK; 3984} 3985 3986 3987/* build fixed tables only once--keep them here */ 3988local int fixed_lock = 0; 3989local int fixed_built = 0; 3990#define FIXEDH 530 /* number of hufts used by fixed tables */ 3991local uInt fixed_left = FIXEDH; 3992local inflate_huft fixed_mem[FIXEDH]; 3993local uInt fixed_bl; 3994local uInt fixed_bd; 3995local inflate_huft *fixed_tl; 3996local inflate_huft *fixed_td; 3997 3998 3999local voidpf falloc(q, n, s) 4000voidpf q; /* opaque pointer (not used) */ 4001uInt n; /* number of items */ 4002uInt s; /* size of item */ 4003{ 4004 Assert(s == sizeof(inflate_huft) && n <= fixed_left, 4005 "inflate_trees falloc overflow"); 4006 if (q) s++; /* to make some compilers happy */ 4007 fixed_left -= n; 4008 return (voidpf)(fixed_mem + fixed_left); 4009} 4010 4011 4012local void ffree(q, p, n) 4013voidpf q; 4014voidpf p; 4015uInt n; 4016{ 4017 Assert(0, "inflate_trees ffree called!"); 4018 if (q) q = p; /* to make some compilers happy */ 4019} 4020 4021 4022local int inflate_trees_fixed(bl, bd, tl, td) 4023uIntf *bl; /* literal desired/actual bit depth */ 4024uIntf *bd; /* distance desired/actual bit depth */ 4025inflate_huft * FAR *tl; /* literal/length tree result */ 4026inflate_huft * FAR *td; /* distance tree result */ 4027{ 4028 /* build fixed tables if not built already--lock out other instances */ 4029 while (++fixed_lock > 1) 4030 fixed_lock--; 4031 if (!fixed_built) 4032 { 4033 int k; /* temporary variable */ 4034 unsigned c[288]; /* length list for huft_build */ 4035 z_stream z; /* for falloc function */ 4036 4037 /* set up fake z_stream for memory routines */ 4038 z.zalloc = falloc; 4039 z.zfree = ffree; 4040 z.opaque = Z_NULL; 4041 4042 /* literal table */ 4043 for (k = 0; k < 144; k++) 4044 c[k] = 8; 4045 for (; k < 256; k++) 4046 c[k] = 9; 4047 for (; k < 280; k++) 4048 c[k] = 7; 4049 for (; k < 288; k++) 4050 c[k] = 8; 4051 fixed_bl = 7; 4052 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4053 4054 /* distance table */ 4055 for (k = 0; k < 30; k++) 4056 c[k] = 5; 4057 fixed_bd = 5; 4058 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4059 4060 /* done */ 4061 fixed_built = 1; 4062 } 4063 fixed_lock--; 4064 *bl = fixed_bl; 4065 *bd = fixed_bd; 4066 *tl = fixed_tl; 4067 *td = fixed_td; 4068 return Z_OK; 4069} 4070 4071 4072local int inflate_trees_free(t, z) 4073inflate_huft *t; /* table to free */ 4074z_stream *z; /* for zfree function */ 4075/* Free the malloc'ed tables built by huft_build(), which makes a linked 4076 list of the tables it made, with the links in a dummy first entry of 4077 each table. */ 4078{ 4079 register inflate_huft *p, *q; 4080 4081 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4082 p = t; 4083 while (p != Z_NULL) 4084 { 4085 q = (--p)->next; 4086 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft)); 4087 p = q; 4088 } 4089 return Z_OK; 4090} 4091 4092/*+++++*/ 4093/* infcodes.c -- process literals and length/distance pairs 4094 * Copyright (C) 1995 Mark Adler 4095 * For conditions of distribution and use, see copyright notice in zlib.h 4096 */ 4097 4098/* simplify the use of the inflate_huft type with some defines */ 4099#define base more.Base 4100#define next more.Next 4101#define exop word.what.Exop 4102#define bits word.what.Bits 4103 4104/* inflate codes private state */ 4105struct inflate_codes_state { 4106 4107 /* mode */ 4108 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4109 START, /* x: set up for LEN */ 4110 LEN, /* i: get length/literal/eob next */ 4111 LENEXT, /* i: getting length extra (have base) */ 4112 DIST, /* i: get distance next */ 4113 DISTEXT, /* i: getting distance extra */ 4114 COPY, /* o: copying bytes in window, waiting for space */ 4115 LIT, /* o: got literal, waiting for output space */ 4116 WASH, /* o: got eob, possibly still output waiting */ 4117 END, /* x: got eob and all data flushed */ 4118 BADCODE} /* x: got error */ 4119 mode; /* current inflate_codes mode */ 4120 4121 /* mode dependent information */ 4122 uInt len; 4123 union { 4124 struct { 4125 inflate_huft *tree; /* pointer into tree */ 4126 uInt need; /* bits needed */ 4127 } code; /* if LEN or DIST, where in tree */ 4128 uInt lit; /* if LIT, literal */ 4129 struct { 4130 uInt get; /* bits to get for extra */ 4131 uInt dist; /* distance back to copy from */ 4132 } copy; /* if EXT or COPY, where and how much */ 4133 } sub; /* submode */ 4134 4135 /* mode independent information */ 4136 Byte lbits; /* ltree bits decoded per branch */ 4137 Byte dbits; /* dtree bits decoder per branch */ 4138 inflate_huft *ltree; /* literal/length/eob tree */ 4139 inflate_huft *dtree; /* distance tree */ 4140 4141}; 4142 4143 4144local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) 4145uInt bl, bd; 4146inflate_huft *tl, *td; 4147z_stream *z; 4148{ 4149 inflate_codes_statef *c; 4150 4151 if ((c = (inflate_codes_statef *) 4152 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4153 { 4154 c->mode = START; 4155 c->lbits = (Byte)bl; 4156 c->dbits = (Byte)bd; 4157 c->ltree = tl; 4158 c->dtree = td; 4159 Tracev((stderr, "inflate: codes new\n")); 4160 } 4161 return c; 4162} 4163 4164 4165local int inflate_codes(s, z, r) 4166inflate_blocks_statef *s; 4167z_stream *z; 4168int r; 4169{ 4170 uInt j; /* temporary storage */ 4171 inflate_huft *t; /* temporary pointer */ 4172 uInt e; /* extra bits or operation */ 4173 uLong b; /* bit buffer */ 4174 uInt k; /* bits in bit buffer */ 4175 Bytef *p; /* input data pointer */ 4176 uInt n; /* bytes available there */ 4177 Bytef *q; /* output window write pointer */ 4178 uInt m; /* bytes to end of window or read pointer */ 4179 Bytef *f; /* pointer to copy strings from */ 4180 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4181 4182 /* copy input/output information to locals (UPDATE macro restores) */ 4183 LOAD 4184 4185 /* process input and output based on current state */ 4186 while (1) switch (c->mode) 4187 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4188 case START: /* x: set up for LEN */ 4189#ifndef SLOW 4190 if (m >= 258 && n >= 10) 4191 { 4192 UPDATE 4193 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4194 LOAD 4195 if (r != Z_OK) 4196 { 4197 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4198 break; 4199 } 4200 } 4201#endif /* !SLOW */ 4202 c->sub.code.need = c->lbits; 4203 c->sub.code.tree = c->ltree; 4204 c->mode = LEN; 4205 case LEN: /* i: get length/literal/eob next */ 4206 j = c->sub.code.need; 4207 NEEDBITS(j) 4208 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4209 DUMPBITS(t->bits) 4210 e = (uInt)(t->exop); 4211 if (e == 0) /* literal */ 4212 { 4213 c->sub.lit = t->base; 4214 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4215 "inflate: literal '%c'\n" : 4216 "inflate: literal 0x%02x\n", t->base)); 4217 c->mode = LIT; 4218 break; 4219 } 4220 if (e & 16) /* length */ 4221 { 4222 c->sub.copy.get = e & 15; 4223 c->len = t->base; 4224 c->mode = LENEXT; 4225 break; 4226 } 4227 if ((e & 64) == 0) /* next table */ 4228 { 4229 c->sub.code.need = e; 4230 c->sub.code.tree = t->next; 4231 break; 4232 } 4233 if (e & 32) /* end of block */ 4234 { 4235 Tracevv((stderr, "inflate: end of block\n")); 4236 c->mode = WASH; 4237 break; 4238 } 4239 c->mode = BADCODE; /* invalid code */ 4240 z->msg = "invalid literal/length code"; 4241 r = Z_DATA_ERROR; 4242 LEAVE 4243 case LENEXT: /* i: getting length extra (have base) */ 4244 j = c->sub.copy.get; 4245 NEEDBITS(j) 4246 c->len += (uInt)b & inflate_mask[j]; 4247 DUMPBITS(j) 4248 c->sub.code.need = c->dbits; 4249 c->sub.code.tree = c->dtree; 4250 Tracevv((stderr, "inflate: length %u\n", c->len)); 4251 c->mode = DIST; 4252 case DIST: /* i: get distance next */ 4253 j = c->sub.code.need; 4254 NEEDBITS(j) 4255 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4256 DUMPBITS(t->bits) 4257 e = (uInt)(t->exop); 4258 if (e & 16) /* distance */ 4259 { 4260 c->sub.copy.get = e & 15; 4261 c->sub.copy.dist = t->base; 4262 c->mode = DISTEXT; 4263 break; 4264 } 4265 if ((e & 64) == 0) /* next table */ 4266 { 4267 c->sub.code.need = e; 4268 c->sub.code.tree = t->next; 4269 break; 4270 } 4271 c->mode = BADCODE; /* invalid code */ 4272 z->msg = "invalid distance code"; 4273 r = Z_DATA_ERROR; 4274 LEAVE 4275 case DISTEXT: /* i: getting distance extra */ 4276 j = c->sub.copy.get; 4277 NEEDBITS(j) 4278 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4279 DUMPBITS(j) 4280 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4281 c->mode = COPY; 4282 case COPY: /* o: copying bytes in window, waiting for space */ 4283#ifndef __TURBOC__ /* Turbo C bug for following expression */ 4284 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4285 s->end - (c->sub.copy.dist - (q - s->window)) : 4286 q - c->sub.copy.dist; 4287#else 4288 f = q - c->sub.copy.dist; 4289 if ((uInt)(q - s->window) < c->sub.copy.dist) 4290 f = s->end - (c->sub.copy.dist - (q - s->window)); 4291#endif 4292 while (c->len) 4293 { 4294 NEEDOUT 4295 OUTBYTE(*f++) 4296 if (f == s->end) 4297 f = s->window; 4298 c->len--; 4299 } 4300 c->mode = START; 4301 break; 4302 case LIT: /* o: got literal, waiting for output space */ 4303 NEEDOUT 4304 OUTBYTE(c->sub.lit) 4305 c->mode = START; 4306 break; 4307 case WASH: /* o: got eob, possibly more output */ 4308 FLUSH 4309 if (s->read != s->write) 4310 LEAVE 4311 c->mode = END; 4312 case END: 4313 r = Z_STREAM_END; 4314 LEAVE 4315 case BADCODE: /* x: got error */ 4316 r = Z_DATA_ERROR; 4317 LEAVE 4318 default: 4319 r = Z_STREAM_ERROR; 4320 LEAVE 4321 } 4322} 4323 4324 4325local void inflate_codes_free(c, z) 4326inflate_codes_statef *c; 4327z_stream *z; 4328{ 4329 ZFREE(z, c, sizeof(struct inflate_codes_state)); 4330 Tracev((stderr, "inflate: codes free\n")); 4331} 4332 4333/*+++++*/ 4334/* inflate_util.c -- data and routines common to blocks and codes 4335 * Copyright (C) 1995 Mark Adler 4336 * For conditions of distribution and use, see copyright notice in zlib.h 4337 */ 4338 4339/* copy as much as possible from the sliding window to the output area */ 4340local int inflate_flush(s, z, r) 4341inflate_blocks_statef *s; 4342z_stream *z; 4343int r; 4344{ 4345 uInt n; 4346 Bytef *p, *q; 4347 4348 /* local copies of source and destination pointers */ 4349 p = z->next_out; 4350 q = s->read; 4351 4352 /* compute number of bytes to copy as far as end of window */ 4353 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4354 if (n > z->avail_out) n = z->avail_out; 4355 if (n && r == Z_BUF_ERROR) r = Z_OK; 4356 4357 /* update counters */ 4358 z->avail_out -= n; 4359 z->total_out += n; 4360 4361 /* update check information */ 4362 if (s->checkfn != Z_NULL) 4363 s->check = (*s->checkfn)(s->check, q, n); 4364 4365 /* copy as far as end of window */ 4366 if (p != NULL) { 4367 zmemcpy(p, q, n); 4368 p += n; 4369 } 4370 q += n; 4371 4372 /* see if more to copy at beginning of window */ 4373 if (q == s->end) 4374 { 4375 /* wrap pointers */ 4376 q = s->window; 4377 if (s->write == s->end) 4378 s->write = s->window; 4379 4380 /* compute bytes to copy */ 4381 n = (uInt)(s->write - q); 4382 if (n > z->avail_out) n = z->avail_out; 4383 if (n && r == Z_BUF_ERROR) r = Z_OK; 4384 4385 /* update counters */ 4386 z->avail_out -= n; 4387 z->total_out += n; 4388 4389 /* update check information */ 4390 if (s->checkfn != Z_NULL) 4391 s->check = (*s->checkfn)(s->check, q, n); 4392 4393 /* copy */ 4394 if (p != NULL) { 4395 zmemcpy(p, q, n); 4396 p += n; 4397 } 4398 q += n; 4399 } 4400 4401 /* update pointers */ 4402 z->next_out = p; 4403 s->read = q; 4404 4405 /* done */ 4406 return r; 4407} 4408 4409 4410/*+++++*/ 4411/* inffast.c -- process literals and length/distance pairs fast 4412 * Copyright (C) 1995 Mark Adler 4413 * For conditions of distribution and use, see copyright notice in zlib.h 4414 */ 4415 4416/* simplify the use of the inflate_huft type with some defines */ 4417#define base more.Base 4418#define next more.Next 4419#define exop word.what.Exop 4420#define bits word.what.Bits 4421 4422/* macros for bit input with no checking and for returning unused bytes */ 4423#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4424#define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4425 4426/* Called with number of bytes left to write in window at least 258 4427 (the maximum string length) and number of input bytes available 4428 at least ten. The ten bytes are six bytes for the longest length/ 4429 distance pair plus four bytes for overloading the bit buffer. */ 4430 4431local int inflate_fast(bl, bd, tl, td, s, z) 4432uInt bl, bd; 4433inflate_huft *tl, *td; 4434inflate_blocks_statef *s; 4435z_stream *z; 4436{ 4437 inflate_huft *t; /* temporary pointer */ 4438 uInt e; /* extra bits or operation */ 4439 uLong b; /* bit buffer */ 4440 uInt k; /* bits in bit buffer */ 4441 Bytef *p; /* input data pointer */ 4442 uInt n; /* bytes available there */ 4443 Bytef *q; /* output window write pointer */ 4444 uInt m; /* bytes to end of window or read pointer */ 4445 uInt ml; /* mask for literal/length tree */ 4446 uInt md; /* mask for distance tree */ 4447 uInt c; /* bytes to copy */ 4448 uInt d; /* distance back to copy from */ 4449 Bytef *r; /* copy source pointer */ 4450 4451 /* load input, output, bit values */ 4452 LOAD 4453 4454 /* initialize masks */ 4455 ml = inflate_mask[bl]; 4456 md = inflate_mask[bd]; 4457 4458 /* do until not enough input or output space for fast loop */ 4459 do { /* assume called with m >= 258 && n >= 10 */ 4460 /* get literal/length code */ 4461 GRABBITS(20) /* max bits for literal/length code */ 4462 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 4463 { 4464 DUMPBITS(t->bits) 4465 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4466 "inflate: * literal '%c'\n" : 4467 "inflate: * literal 0x%02x\n", t->base)); 4468 *q++ = (Byte)t->base; 4469 m--; 4470 continue; 4471 } 4472 do { 4473 DUMPBITS(t->bits) 4474 if (e & 16) 4475 { 4476 /* get extra bits for length */ 4477 e &= 15; 4478 c = t->base + ((uInt)b & inflate_mask[e]); 4479 DUMPBITS(e) 4480 Tracevv((stderr, "inflate: * length %u\n", c)); 4481 4482 /* decode distance base of block to copy */ 4483 GRABBITS(15); /* max bits for distance code */ 4484 e = (t = td + ((uInt)b & md))->exop; 4485 do { 4486 DUMPBITS(t->bits) 4487 if (e & 16) 4488 { 4489 /* get extra bits to add to distance base */ 4490 e &= 15; 4491 GRABBITS(e) /* get extra bits (up to 13) */ 4492 d = t->base + ((uInt)b & inflate_mask[e]); 4493 DUMPBITS(e) 4494 Tracevv((stderr, "inflate: * distance %u\n", d)); 4495 4496 /* do the copy */ 4497 m -= c; 4498 if ((uInt)(q - s->window) >= d) /* offset before dest */ 4499 { /* just copy */ 4500 r = q - d; 4501 *q++ = *r++; c--; /* minimum count is three, */ 4502 *q++ = *r++; c--; /* so unroll loop a little */ 4503 } 4504 else /* else offset after destination */ 4505 { 4506 e = d - (q - s->window); /* bytes from offset to end */ 4507 r = s->end - e; /* pointer to offset */ 4508 if (c > e) /* if source crosses, */ 4509 { 4510 c -= e; /* copy to end of window */ 4511 do { 4512 *q++ = *r++; 4513 } while (--e); 4514 r = s->window; /* copy rest from start of window */ 4515 } 4516 } 4517 do { /* copy all or what's left */ 4518 *q++ = *r++; 4519 } while (--c); 4520 break; 4521 } 4522 else if ((e & 64) == 0) 4523 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 4524 else 4525 { 4526 z->msg = "invalid distance code"; 4527 UNGRAB 4528 UPDATE 4529 return Z_DATA_ERROR; 4530 } 4531 } while (1); 4532 break; 4533 } 4534 if ((e & 64) == 0) 4535 { 4536 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 4537 { 4538 DUMPBITS(t->bits) 4539 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4540 "inflate: * literal '%c'\n" : 4541 "inflate: * literal 0x%02x\n", t->base)); 4542 *q++ = (Byte)t->base; 4543 m--; 4544 break; 4545 } 4546 } 4547 else if (e & 32) 4548 { 4549 Tracevv((stderr, "inflate: * end of block\n")); 4550 UNGRAB 4551 UPDATE 4552 return Z_STREAM_END; 4553 } 4554 else 4555 { 4556 z->msg = "invalid literal/length code"; 4557 UNGRAB 4558 UPDATE 4559 return Z_DATA_ERROR; 4560 } 4561 } while (1); 4562 } while (m >= 258 && n >= 10); 4563 4564 /* not enough input or output--restore pointers and return */ 4565 UNGRAB 4566 UPDATE 4567 return Z_OK; 4568} 4569 4570 4571/*+++++*/ 4572/* zutil.c -- target dependent utility functions for the compression library 4573 * Copyright (C) 1995 Jean-loup Gailly. 4574 * For conditions of distribution and use, see copyright notice in zlib.h 4575 */ 4576 4577/* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */ 4578 4579char *zlib_version = ZLIB_VERSION; 4580 4581char *z_errmsg[] = { 4582"stream end", /* Z_STREAM_END 1 */ 4583"", /* Z_OK 0 */ 4584"file error", /* Z_ERRNO (-1) */ 4585"stream error", /* Z_STREAM_ERROR (-2) */ 4586"data error", /* Z_DATA_ERROR (-3) */ 4587"insufficient memory", /* Z_MEM_ERROR (-4) */ 4588"buffer error", /* Z_BUF_ERROR (-5) */ 4589""}; 4590 4591 4592/*+++++*/ 4593/* adler32.c -- compute the Adler-32 checksum of a data stream 4594 * Copyright (C) 1995 Mark Adler 4595 * For conditions of distribution and use, see copyright notice in zlib.h 4596 */ 4597 4598/* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */ 4599 4600#define BASE 65521L /* largest prime smaller than 65536 */ 4601#define NMAX 5552 4602/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 4603 4604#define DO1(buf) {s1 += *buf++; s2 += s1;} 4605#define DO2(buf) DO1(buf); DO1(buf); 4606#define DO4(buf) DO2(buf); DO2(buf); 4607#define DO8(buf) DO4(buf); DO4(buf); 4608#define DO16(buf) DO8(buf); DO8(buf); 4609 4610/* ========================================================================= */ 4611uLong adler32(adler, buf, len) 4612 uLong adler; 4613 Bytef *buf; 4614 uInt len; 4615{ 4616 unsigned long s1 = adler & 0xffff; 4617 unsigned long s2 = (adler >> 16) & 0xffff; 4618 int k; 4619 4620 if (buf == Z_NULL) return 1L; 4621 4622 while (len > 0) { 4623 k = len < NMAX ? len : NMAX; 4624 len -= k; 4625 while (k >= 16) { 4626 DO16(buf); 4627 k -= 16; 4628 } 4629 if (k != 0) do { 4630 DO1(buf); 4631 } while (--k); 4632 s1 %= BASE; 4633 s2 %= BASE; 4634 } 4635 return (s2 << 16) | s1; 4636} 4637