zlib.c revision 106696
1/* 2 * This file is derived from various .h and .c files from the zlib-1.0.4 3 * distribution by Jean-loup Gailly and Mark Adler, with some additions 4 * by Paul Mackerras to aid in implementing Deflate compression and 5 * decompression for PPP packets. See zlib.h for conditions of 6 * distribution and use. 7 * 8 * Changes that have been made include: 9 * - added Z_PACKET_FLUSH (see zlib.h for details) 10 * - added inflateIncomp and deflateOutputPending 11 * - allow strm->next_out to be NULL, meaning discard the output 12 * 13 * $FreeBSD: head/sys/net/zlib.c 106696 2002-11-09 12:55:07Z alfred $ 14 */ 15 16/* 17 * ==FILEVERSION 971210== 18 * 19 * This marker is used by the Linux installation script to determine 20 * whether an up-to-date version of this file is already installed. 21 */ 22 23#define NO_DUMMY_DECL 24#define NO_ZCFUNCS 25#define MY_ZCALLOC 26 27#if defined(__FreeBSD__) && defined(_KERNEL) 28#define inflate inflate_ppp /* FreeBSD already has an inflate :-( */ 29#endif 30 31 32/* +++ zutil.h */ 33/* zutil.h -- internal interface and configuration of the compression library 34 * Copyright (C) 1995-1996 Jean-loup Gailly. 35 * For conditions of distribution and use, see copyright notice in zlib.h 36 */ 37 38/* WARNING: this file should *not* be used by applications. It is 39 part of the implementation of the compression library and is 40 subject to change. Applications should only use zlib.h. 41 */ 42 43/* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */ 44 45#ifndef _Z_UTIL_H 46#define _Z_UTIL_H 47 48#ifdef _KERNEL 49#include <net/zlib.h> 50#else 51#include "zlib.h" 52#endif 53 54#ifdef _KERNEL 55/* Assume this is a *BSD or SVR4 kernel */ 56#include <sys/types.h> 57#include <sys/time.h> 58#include <sys/systm.h> 59# define HAVE_MEMCPY 60 61#else 62#if defined(__KERNEL__) 63/* Assume this is a Linux kernel */ 64#include <linux/string.h> 65#define HAVE_MEMCPY 66 67#else /* not kernel */ 68 69#if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS) 70# include <stddef.h> 71# include <errno.h> 72#else 73 extern int errno; 74#endif 75#ifdef STDC 76# include <string.h> 77# include <stdlib.h> 78#endif 79#endif /* __KERNEL__ */ 80#endif /* _KERNEL */ 81 82#ifndef local 83# define local static 84#endif 85/* compile with -Dlocal if your debugger can't find static symbols */ 86 87typedef unsigned char uch; 88typedef uch FAR uchf; 89typedef unsigned short ush; 90typedef ush FAR ushf; 91typedef unsigned long ulg; 92 93extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */ 94/* (size given to avoid silly warnings with Visual C++) */ 95 96#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] 97 98#define ERR_RETURN(strm,err) \ 99 return (strm->msg = (const char*)ERR_MSG(err), (err)) 100/* To be used only when the state is known to be valid */ 101 102 /* common constants */ 103 104#ifndef DEF_WBITS 105# define DEF_WBITS MAX_WBITS 106#endif 107/* default windowBits for decompression. MAX_WBITS is for compression only */ 108 109#if MAX_MEM_LEVEL >= 8 110# define DEF_MEM_LEVEL 8 111#else 112# define DEF_MEM_LEVEL MAX_MEM_LEVEL 113#endif 114/* default memLevel */ 115 116#define STORED_BLOCK 0 117#define STATIC_TREES 1 118#define DYN_TREES 2 119/* The three kinds of block type */ 120 121#define MIN_MATCH 3 122#define MAX_MATCH 258 123/* The minimum and maximum match lengths */ 124 125#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */ 126 127 /* target dependencies */ 128 129#ifdef MSDOS 130# define OS_CODE 0x00 131# ifdef __TURBOC__ 132# include <alloc.h> 133# else /* MSC or DJGPP */ 134# include <malloc.h> 135# endif 136#endif 137 138#ifdef OS2 139# define OS_CODE 0x06 140#endif 141 142#ifdef WIN32 /* Window 95 & Windows NT */ 143# define OS_CODE 0x0b 144#endif 145 146#if defined(VAXC) || defined(VMS) 147# define OS_CODE 0x02 148# define FOPEN(name, mode) \ 149 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") 150#endif 151 152#ifdef AMIGA 153# define OS_CODE 0x01 154#endif 155 156#if defined(ATARI) || defined(atarist) 157# define OS_CODE 0x05 158#endif 159 160#ifdef MACOS 161# define OS_CODE 0x07 162#endif 163 164#ifdef __50SERIES /* Prime/PRIMOS */ 165# define OS_CODE 0x0F 166#endif 167 168#ifdef TOPS20 169# define OS_CODE 0x0a 170#endif 171 172#if defined(_BEOS_) || defined(RISCOS) 173# define fdopen(fd,mode) NULL /* No fdopen() */ 174#endif 175 176 /* Common defaults */ 177 178#ifndef OS_CODE 179# define OS_CODE 0x03 /* assume Unix */ 180#endif 181 182#ifndef FOPEN 183# define FOPEN(name, mode) fopen((name), (mode)) 184#endif 185 186 /* functions */ 187 188#ifdef HAVE_STRERROR 189 extern char *strerror OF((int)); 190# define zstrerror(errnum) strerror(errnum) 191#else 192# define zstrerror(errnum) "" 193#endif 194 195#if defined(pyr) 196# define NO_MEMCPY 197#endif 198#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER) 199 /* Use our own functions for small and medium model with MSC <= 5.0. 200 * You may have to use the same strategy for Borland C (untested). 201 */ 202# define NO_MEMCPY 203#endif 204#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 205# define HAVE_MEMCPY 206#endif 207#ifdef HAVE_MEMCPY 208# ifdef SMALL_MEDIUM /* MSDOS small or medium model */ 209# define zmemcpy _fmemcpy 210# define zmemcmp _fmemcmp 211# define zmemzero(dest, len) _fmemset(dest, 0, len) 212# else 213# define zmemcpy memcpy 214# define zmemcmp memcmp 215# define zmemzero(dest, len) memset(dest, 0, len) 216# endif 217#else 218 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); 219 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len)); 220 extern void zmemzero OF((Bytef* dest, uInt len)); 221#endif 222 223/* Diagnostic functions */ 224#ifdef DEBUG_ZLIB 225# include <stdio.h> 226# ifndef verbose 227# define verbose 0 228# endif 229 extern void z_error OF((char *m)); 230# define Assert(cond,msg) {if(!(cond)) z_error(msg);} 231# define Trace(x) fprintf x 232# define Tracev(x) {if (verbose) fprintf x ;} 233# define Tracevv(x) {if (verbose>1) fprintf x ;} 234# define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 235# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 236#else 237# define Assert(cond,msg) 238# define Trace(x) 239# define Tracev(x) 240# define Tracevv(x) 241# define Tracec(c,x) 242# define Tracecv(c,x) 243#endif 244 245 246typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len)); 247 248voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); 249void zcfree OF((voidpf opaque, voidpf ptr)); 250 251#define ZALLOC(strm, items, size) \ 252 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 253#define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr)) 254#define TRY_FREE(s, p) {if (p) ZFREE(s, p);} 255 256#endif /* _Z_UTIL_H */ 257/* --- zutil.h */ 258 259/* +++ deflate.h */ 260/* deflate.h -- internal compression state 261 * Copyright (C) 1995-1996 Jean-loup Gailly 262 * For conditions of distribution and use, see copyright notice in zlib.h 263 */ 264 265/* WARNING: this file should *not* be used by applications. It is 266 part of the implementation of the compression library and is 267 subject to change. Applications should only use zlib.h. 268 */ 269 270/* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */ 271 272#ifndef _DEFLATE_H 273#define _DEFLATE_H 274 275/* #include "zutil.h" */ 276 277/* =========================================================================== 278 * Internal compression state. 279 */ 280 281#define LENGTH_CODES 29 282/* number of length codes, not counting the special END_BLOCK code */ 283 284#define LITERALS 256 285/* number of literal bytes 0..255 */ 286 287#define L_CODES (LITERALS+1+LENGTH_CODES) 288/* number of Literal or Length codes, including the END_BLOCK code */ 289 290#define D_CODES 30 291/* number of distance codes */ 292 293#define BL_CODES 19 294/* number of codes used to transfer the bit lengths */ 295 296#define HEAP_SIZE (2*L_CODES+1) 297/* maximum heap size */ 298 299#define MAX_BITS 15 300/* All codes must not exceed MAX_BITS bits */ 301 302#define INIT_STATE 42 303#define BUSY_STATE 113 304#define FINISH_STATE 666 305/* Stream status */ 306 307 308/* Data structure describing a single value and its code string. */ 309typedef struct ct_data_s { 310 union { 311 ush freq; /* frequency count */ 312 ush code; /* bit string */ 313 } fc; 314 union { 315 ush dad; /* father node in Huffman tree */ 316 ush len; /* length of bit string */ 317 } dl; 318} FAR ct_data; 319 320#define Freq fc.freq 321#define Code fc.code 322#define Dad dl.dad 323#define Len dl.len 324 325typedef struct static_tree_desc_s static_tree_desc; 326 327typedef struct tree_desc_s { 328 ct_data *dyn_tree; /* the dynamic tree */ 329 int max_code; /* largest code with non zero frequency */ 330 static_tree_desc *stat_desc; /* the corresponding static tree */ 331} FAR tree_desc; 332 333typedef ush Pos; 334typedef Pos FAR Posf; 335typedef unsigned IPos; 336 337/* A Pos is an index in the character window. We use short instead of int to 338 * save space in the various tables. IPos is used only for parameter passing. 339 */ 340 341typedef struct deflate_state { 342 z_streamp strm; /* pointer back to this zlib stream */ 343 int status; /* as the name implies */ 344 Bytef *pending_buf; /* output still pending */ 345 ulg pending_buf_size; /* size of pending_buf */ 346 Bytef *pending_out; /* next pending byte to output to the stream */ 347 int pending; /* nb of bytes in the pending buffer */ 348 int noheader; /* suppress zlib header and adler32 */ 349 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 350 Byte method; /* STORED (for zip only) or DEFLATED */ 351 int last_flush; /* value of flush param for previous deflate call */ 352 353 /* used by deflate.c: */ 354 355 uInt w_size; /* LZ77 window size (32K by default) */ 356 uInt w_bits; /* log2(w_size) (8..16) */ 357 uInt w_mask; /* w_size - 1 */ 358 359 Bytef *window; 360 /* Sliding window. Input bytes are read into the second half of the window, 361 * and move to the first half later to keep a dictionary of at least wSize 362 * bytes. With this organization, matches are limited to a distance of 363 * wSize-MAX_MATCH bytes, but this ensures that IO is always 364 * performed with a length multiple of the block size. Also, it limits 365 * the window size to 64K, which is quite useful on MSDOS. 366 * To do: use the user input buffer as sliding window. 367 */ 368 369 ulg window_size; 370 /* Actual size of window: 2*wSize, except when the user input buffer 371 * is directly used as sliding window. 372 */ 373 374 Posf *prev; 375 /* Link to older string with same hash index. To limit the size of this 376 * array to 64K, this link is maintained only for the last 32K strings. 377 * An index in this array is thus a window index modulo 32K. 378 */ 379 380 Posf *head; /* Heads of the hash chains or NIL. */ 381 382 uInt ins_h; /* hash index of string to be inserted */ 383 uInt hash_size; /* number of elements in hash table */ 384 uInt hash_bits; /* log2(hash_size) */ 385 uInt hash_mask; /* hash_size-1 */ 386 387 uInt hash_shift; 388 /* Number of bits by which ins_h must be shifted at each input 389 * step. It must be such that after MIN_MATCH steps, the oldest 390 * byte no longer takes part in the hash key, that is: 391 * hash_shift * MIN_MATCH >= hash_bits 392 */ 393 394 long block_start; 395 /* Window position at the beginning of the current output block. Gets 396 * negative when the window is moved backwards. 397 */ 398 399 uInt match_length; /* length of best match */ 400 IPos prev_match; /* previous match */ 401 int match_available; /* set if previous match exists */ 402 uInt strstart; /* start of string to insert */ 403 uInt match_start; /* start of matching string */ 404 uInt lookahead; /* number of valid bytes ahead in window */ 405 406 uInt prev_length; 407 /* Length of the best match at previous step. Matches not greater than this 408 * are discarded. This is used in the lazy match evaluation. 409 */ 410 411 uInt max_chain_length; 412 /* To speed up deflation, hash chains are never searched beyond this 413 * length. A higher limit improves compression ratio but degrades the 414 * speed. 415 */ 416 417 uInt max_lazy_match; 418 /* Attempt to find a better match only when the current match is strictly 419 * smaller than this value. This mechanism is used only for compression 420 * levels >= 4. 421 */ 422# define max_insert_length max_lazy_match 423 /* Insert new strings in the hash table only if the match length is not 424 * greater than this length. This saves time but degrades compression. 425 * max_insert_length is used only for compression levels <= 3. 426 */ 427 428 int level; /* compression level (1..9) */ 429 int strategy; /* favor or force Huffman coding*/ 430 431 uInt good_match; 432 /* Use a faster search when the previous match is longer than this */ 433 434 int nice_match; /* Stop searching when current match exceeds this */ 435 436 /* used by trees.c: */ 437 /* Didn't use ct_data typedef below to supress compiler warning */ 438 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 439 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 440 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 441 442 struct tree_desc_s l_desc; /* desc. for literal tree */ 443 struct tree_desc_s d_desc; /* desc. for distance tree */ 444 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 445 446 ush bl_count[MAX_BITS+1]; 447 /* number of codes at each bit length for an optimal tree */ 448 449 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 450 int heap_len; /* number of elements in the heap */ 451 int heap_max; /* element of largest frequency */ 452 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 453 * The same heap array is used to build all trees. 454 */ 455 456 uch depth[2*L_CODES+1]; 457 /* Depth of each subtree used as tie breaker for trees of equal frequency 458 */ 459 460 uchf *l_buf; /* buffer for literals or lengths */ 461 462 uInt lit_bufsize; 463 /* Size of match buffer for literals/lengths. There are 4 reasons for 464 * limiting lit_bufsize to 64K: 465 * - frequencies can be kept in 16 bit counters 466 * - if compression is not successful for the first block, all input 467 * data is still in the window so we can still emit a stored block even 468 * when input comes from standard input. (This can also be done for 469 * all blocks if lit_bufsize is not greater than 32K.) 470 * - if compression is not successful for a file smaller than 64K, we can 471 * even emit a stored file instead of a stored block (saving 5 bytes). 472 * This is applicable only for zip (not gzip or zlib). 473 * - creating new Huffman trees less frequently may not provide fast 474 * adaptation to changes in the input data statistics. (Take for 475 * example a binary file with poorly compressible code followed by 476 * a highly compressible string table.) Smaller buffer sizes give 477 * fast adaptation but have of course the overhead of transmitting 478 * trees more frequently. 479 * - I can't count above 4 480 */ 481 482 uInt last_lit; /* running index in l_buf */ 483 484 ushf *d_buf; 485 /* Buffer for distances. To simplify the code, d_buf and l_buf have 486 * the same number of elements. To use different lengths, an extra flag 487 * array would be necessary. 488 */ 489 490 ulg opt_len; /* bit length of current block with optimal trees */ 491 ulg static_len; /* bit length of current block with static trees */ 492 ulg compressed_len; /* total bit length of compressed file */ 493 uInt matches; /* number of string matches in current block */ 494 int last_eob_len; /* bit length of EOB code for last block */ 495 496#ifdef DEBUG_ZLIB 497 ulg bits_sent; /* bit length of the compressed data */ 498#endif 499 500 ush bi_buf; 501 /* Output buffer. bits are inserted starting at the bottom (least 502 * significant bits). 503 */ 504 int bi_valid; 505 /* Number of valid bits in bi_buf. All bits above the last valid bit 506 * are always zero. 507 */ 508 509} FAR deflate_state; 510 511/* Output a byte on the stream. 512 * IN assertion: there is enough room in pending_buf. 513 */ 514#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 515 516 517#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 518/* Minimum amount of lookahead, except at the end of the input file. 519 * See deflate.c for comments about the MIN_MATCH+1. 520 */ 521 522#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 523/* In order to simplify the code, particularly on 16 bit machines, match 524 * distances are limited to MAX_DIST instead of WSIZE. 525 */ 526 527 /* in trees.c */ 528void _tr_init OF((deflate_state *s)); 529int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); 530ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 531 int eof)); 532void _tr_align OF((deflate_state *s)); 533void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 534 int eof)); 535void _tr_stored_type_only OF((deflate_state *)); 536 537#endif 538/* --- deflate.h */ 539 540/* +++ deflate.c */ 541/* deflate.c -- compress data using the deflation algorithm 542 * Copyright (C) 1995-1996 Jean-loup Gailly. 543 * For conditions of distribution and use, see copyright notice in zlib.h 544 */ 545 546/* 547 * ALGORITHM 548 * 549 * The "deflation" process depends on being able to identify portions 550 * of the input text which are identical to earlier input (within a 551 * sliding window trailing behind the input currently being processed). 552 * 553 * The most straightforward technique turns out to be the fastest for 554 * most input files: try all possible matches and select the longest. 555 * The key feature of this algorithm is that insertions into the string 556 * dictionary are very simple and thus fast, and deletions are avoided 557 * completely. Insertions are performed at each input character, whereas 558 * string matches are performed only when the previous match ends. So it 559 * is preferable to spend more time in matches to allow very fast string 560 * insertions and avoid deletions. The matching algorithm for small 561 * strings is inspired from that of Rabin & Karp. A brute force approach 562 * is used to find longer strings when a small match has been found. 563 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 564 * (by Leonid Broukhis). 565 * A previous version of this file used a more sophisticated algorithm 566 * (by Fiala and Greene) which is guaranteed to run in linear amortized 567 * time, but has a larger average cost, uses more memory and is patented. 568 * However the F&G algorithm may be faster for some highly redundant 569 * files if the parameter max_chain_length (described below) is too large. 570 * 571 * ACKNOWLEDGEMENTS 572 * 573 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 574 * I found it in 'freeze' written by Leonid Broukhis. 575 * Thanks to many people for bug reports and testing. 576 * 577 * REFERENCES 578 * 579 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". 580 * Available in ftp://ds.internic.net/rfc/rfc1951.txt 581 * 582 * A description of the Rabin and Karp algorithm is given in the book 583 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 584 * 585 * Fiala,E.R., and Greene,D.H. 586 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 587 * 588 */ 589 590/* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */ 591 592/* #include "deflate.h" */ 593 594char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly "; 595/* 596 If you use the zlib library in a product, an acknowledgment is welcome 597 in the documentation of your product. If for some reason you cannot 598 include such an acknowledgment, I would appreciate that you keep this 599 copyright string in the executable of your product. 600 */ 601 602/* =========================================================================== 603 * Function prototypes. 604 */ 605typedef enum { 606 need_more, /* block not completed, need more input or more output */ 607 block_done, /* block flush performed */ 608 finish_started, /* finish started, need only more output at next deflate */ 609 finish_done /* finish done, accept no more input or output */ 610} block_state; 611 612typedef block_state (*compress_func) OF((deflate_state *s, int flush)); 613/* Compression function. Returns the block state after the call. */ 614 615local void fill_window OF((deflate_state *s)); 616local block_state deflate_stored OF((deflate_state *s, int flush)); 617local block_state deflate_fast OF((deflate_state *s, int flush)); 618local block_state deflate_slow OF((deflate_state *s, int flush)); 619local void lm_init OF((deflate_state *s)); 620local void putShortMSB OF((deflate_state *s, uInt b)); 621local void flush_pending OF((z_streamp strm)); 622local int read_buf OF((z_streamp strm, charf *buf, unsigned size)); 623#ifdef ASMV 624 void match_init OF((void)); /* asm code initialization */ 625 uInt longest_match OF((deflate_state *s, IPos cur_match)); 626#else 627local uInt longest_match OF((deflate_state *s, IPos cur_match)); 628#endif 629 630#ifdef DEBUG_ZLIB 631local void check_match OF((deflate_state *s, IPos start, IPos match, 632 int length)); 633#endif 634 635/* =========================================================================== 636 * Local data 637 */ 638 639#define NIL 0 640/* Tail of hash chains */ 641 642#ifndef TOO_FAR 643# define TOO_FAR 4096 644#endif 645/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 646 647#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 648/* Minimum amount of lookahead, except at the end of the input file. 649 * See deflate.c for comments about the MIN_MATCH+1. 650 */ 651 652/* Values for max_lazy_match, good_match and max_chain_length, depending on 653 * the desired pack level (0..9). The values given below have been tuned to 654 * exclude worst case performance for pathological files. Better values may be 655 * found for specific files. 656 */ 657typedef struct config_s { 658 ush good_length; /* reduce lazy search above this match length */ 659 ush max_lazy; /* do not perform lazy search above this match length */ 660 ush nice_length; /* quit search above this match length */ 661 ush max_chain; 662 compress_func func; 663} config; 664 665local config configuration_table[10] = { 666/* good lazy nice chain */ 667/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ 668/* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */ 669/* 2 */ {4, 5, 16, 8, deflate_fast}, 670/* 3 */ {4, 6, 32, 32, deflate_fast}, 671 672/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ 673/* 5 */ {8, 16, 32, 32, deflate_slow}, 674/* 6 */ {8, 16, 128, 128, deflate_slow}, 675/* 7 */ {8, 32, 128, 256, deflate_slow}, 676/* 8 */ {32, 128, 258, 1024, deflate_slow}, 677/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */ 678 679/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 680 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 681 * meaning. 682 */ 683 684#define EQUAL 0 685/* result of memcmp for equal strings */ 686 687#ifndef NO_DUMMY_DECL 688struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ 689#endif 690 691/* =========================================================================== 692 * Update a hash value with the given input byte 693 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 694 * input characters, so that a running hash key can be computed from the 695 * previous key instead of complete recalculation each time. 696 */ 697#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 698 699 700/* =========================================================================== 701 * Insert string str in the dictionary and set match_head to the previous head 702 * of the hash chain (the most recent string with same hash key). Return 703 * the previous length of the hash chain. 704 * IN assertion: all calls to to INSERT_STRING are made with consecutive 705 * input characters and the first MIN_MATCH bytes of str are valid 706 * (except for the last MIN_MATCH-1 bytes of the input file). 707 */ 708#define INSERT_STRING(s, str, match_head) \ 709 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 710 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 711 s->head[s->ins_h] = (Pos)(str)) 712 713/* =========================================================================== 714 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 715 * prev[] will be initialized on the fly. 716 */ 717#define CLEAR_HASH(s) \ 718 s->head[s->hash_size-1] = NIL; \ 719 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 720 721/* ========================================================================= */ 722int deflateInit_(strm, level, version, stream_size) 723 z_streamp strm; 724 int level; 725 const char *version; 726 int stream_size; 727{ 728 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 729 Z_DEFAULT_STRATEGY, version, stream_size); 730 /* To do: ignore strm->next_in if we use it as window */ 731} 732 733/* ========================================================================= */ 734int deflateInit2_(strm, level, method, windowBits, memLevel, strategy, 735 version, stream_size) 736 z_streamp strm; 737 int level; 738 int method; 739 int windowBits; 740 int memLevel; 741 int strategy; 742 const char *version; 743 int stream_size; 744{ 745 deflate_state *s; 746 int noheader = 0; 747 static char* my_version = ZLIB_VERSION; 748 749 ushf *overlay; 750 /* We overlay pending_buf and d_buf+l_buf. This works since the average 751 * output size for (length,distance) codes is <= 24 bits. 752 */ 753 754 if (version == Z_NULL || version[0] != my_version[0] || 755 stream_size != sizeof(z_stream)) { 756 return Z_VERSION_ERROR; 757 } 758 if (strm == Z_NULL) return Z_STREAM_ERROR; 759 760 strm->msg = Z_NULL; 761#ifndef NO_ZCFUNCS 762 if (strm->zalloc == Z_NULL) { 763 strm->zalloc = zcalloc; 764 strm->opaque = (voidpf)0; 765 } 766 if (strm->zfree == Z_NULL) strm->zfree = zcfree; 767#endif 768 769 if (level == Z_DEFAULT_COMPRESSION) level = 6; 770 771 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 772 noheader = 1; 773 windowBits = -windowBits; 774 } 775 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || 776 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 || 777 strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 778 return Z_STREAM_ERROR; 779 } 780 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 781 if (s == Z_NULL) return Z_MEM_ERROR; 782 strm->state = (struct internal_state FAR *)s; 783 s->strm = strm; 784 785 s->noheader = noheader; 786 s->w_bits = windowBits; 787 s->w_size = 1 << s->w_bits; 788 s->w_mask = s->w_size - 1; 789 790 s->hash_bits = memLevel + 7; 791 s->hash_size = 1 << s->hash_bits; 792 s->hash_mask = s->hash_size - 1; 793 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 794 795 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 796 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 797 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 798 799 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 800 801 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); 802 s->pending_buf = (uchf *) overlay; 803 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); 804 805 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 806 s->pending_buf == Z_NULL) { 807 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR); 808 deflateEnd (strm); 809 return Z_MEM_ERROR; 810 } 811 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); 812 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; 813 814 s->level = level; 815 s->strategy = strategy; 816 s->method = (Byte)method; 817 818 return deflateReset(strm); 819} 820 821/* ========================================================================= */ 822int deflateSetDictionary (strm, dictionary, dictLength) 823 z_streamp strm; 824 const Bytef *dictionary; 825 uInt dictLength; 826{ 827 deflate_state *s; 828 uInt length = dictLength; 829 uInt n; 830 IPos hash_head = 0; 831 832 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) 833 return Z_STREAM_ERROR; 834 835 s = (deflate_state *) strm->state; 836 if (s->status != INIT_STATE) return Z_STREAM_ERROR; 837 838 strm->adler = adler32(strm->adler, dictionary, dictLength); 839 840 if (length < MIN_MATCH) return Z_OK; 841 if (length > MAX_DIST(s)) { 842 length = MAX_DIST(s); 843#ifndef USE_DICT_HEAD 844 dictionary += dictLength - length; /* use the tail of the dictionary */ 845#endif 846 } 847 zmemcpy((charf *)s->window, dictionary, length); 848 s->strstart = length; 849 s->block_start = (long)length; 850 851 /* Insert all strings in the hash table (except for the last two bytes). 852 * s->lookahead stays null, so s->ins_h will be recomputed at the next 853 * call of fill_window. 854 */ 855 s->ins_h = s->window[0]; 856 UPDATE_HASH(s, s->ins_h, s->window[1]); 857 for (n = 0; n <= length - MIN_MATCH; n++) { 858 INSERT_STRING(s, n, hash_head); 859 } 860 if (hash_head) hash_head = 0; /* to make compiler happy */ 861 return Z_OK; 862} 863 864/* ========================================================================= */ 865int deflateReset (strm) 866 z_streamp strm; 867{ 868 deflate_state *s; 869 870 if (strm == Z_NULL || strm->state == Z_NULL || 871 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 872 873 strm->total_in = strm->total_out = 0; 874 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 875 strm->data_type = Z_UNKNOWN; 876 877 s = (deflate_state *)strm->state; 878 s->pending = 0; 879 s->pending_out = s->pending_buf; 880 881 if (s->noheader < 0) { 882 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 883 } 884 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 885 strm->adler = 1; 886 s->last_flush = Z_NO_FLUSH; 887 888 _tr_init(s); 889 lm_init(s); 890 891 return Z_OK; 892} 893 894/* ========================================================================= */ 895int deflateParams(strm, level, strategy) 896 z_streamp strm; 897 int level; 898 int strategy; 899{ 900 deflate_state *s; 901 compress_func func; 902 int err = Z_OK; 903 904 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 905 s = (deflate_state *) strm->state; 906 907 if (level == Z_DEFAULT_COMPRESSION) { 908 level = 6; 909 } 910 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 911 return Z_STREAM_ERROR; 912 } 913 func = configuration_table[s->level].func; 914 915 if (func != configuration_table[level].func && strm->total_in != 0) { 916 /* Flush the last buffer: */ 917 err = deflate(strm, Z_PARTIAL_FLUSH); 918 } 919 if (s->level != level) { 920 s->level = level; 921 s->max_lazy_match = configuration_table[level].max_lazy; 922 s->good_match = configuration_table[level].good_length; 923 s->nice_match = configuration_table[level].nice_length; 924 s->max_chain_length = configuration_table[level].max_chain; 925 } 926 s->strategy = strategy; 927 return err; 928} 929 930/* ========================================================================= 931 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 932 * IN assertion: the stream state is correct and there is enough room in 933 * pending_buf. 934 */ 935local void putShortMSB (s, b) 936 deflate_state *s; 937 uInt b; 938{ 939 put_byte(s, (Byte)(b >> 8)); 940 put_byte(s, (Byte)(b & 0xff)); 941} 942 943/* ========================================================================= 944 * Flush as much pending output as possible. All deflate() output goes 945 * through this function so some applications may wish to modify it 946 * to avoid allocating a large strm->next_out buffer and copying into it. 947 * (See also read_buf()). 948 */ 949local void flush_pending(strm) 950 z_streamp strm; 951{ 952 deflate_state *s = (deflate_state *) strm->state; 953 unsigned len = s->pending; 954 955 if (len > strm->avail_out) len = strm->avail_out; 956 if (len == 0) return; 957 958 if (strm->next_out != Z_NULL) { 959 zmemcpy(strm->next_out, s->pending_out, len); 960 strm->next_out += len; 961 } 962 s->pending_out += len; 963 strm->total_out += len; 964 strm->avail_out -= len; 965 s->pending -= len; 966 if (s->pending == 0) { 967 s->pending_out = s->pending_buf; 968 } 969} 970 971/* ========================================================================= */ 972int deflate (strm, flush) 973 z_streamp strm; 974 int flush; 975{ 976 int old_flush; /* value of flush param for previous deflate call */ 977 deflate_state *s; 978 979 if (strm == Z_NULL || strm->state == Z_NULL || 980 flush > Z_FINISH || flush < 0) { 981 return Z_STREAM_ERROR; 982 } 983 s = (deflate_state *) strm->state; 984 985 if ((strm->next_in == Z_NULL && strm->avail_in != 0) || 986 (s->status == FINISH_STATE && flush != Z_FINISH)) { 987 ERR_RETURN(strm, Z_STREAM_ERROR); 988 } 989 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 990 991 s->strm = strm; /* just in case */ 992 old_flush = s->last_flush; 993 s->last_flush = flush; 994 995 /* Write the zlib header */ 996 if (s->status == INIT_STATE) { 997 998 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; 999 uInt level_flags = (s->level-1) >> 1; 1000 1001 if (level_flags > 3) level_flags = 3; 1002 header |= (level_flags << 6); 1003 if (s->strstart != 0) header |= PRESET_DICT; 1004 header += 31 - (header % 31); 1005 1006 s->status = BUSY_STATE; 1007 putShortMSB(s, header); 1008 1009 /* Save the adler32 of the preset dictionary: */ 1010 if (s->strstart != 0) { 1011 putShortMSB(s, (uInt)(strm->adler >> 16)); 1012 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1013 } 1014 strm->adler = 1L; 1015 } 1016 1017 /* Flush as much pending output as possible */ 1018 if (s->pending != 0) { 1019 flush_pending(strm); 1020 if (strm->avail_out == 0) { 1021 /* Since avail_out is 0, deflate will be called again with 1022 * more output space, but possibly with both pending and 1023 * avail_in equal to zero. There won't be anything to do, 1024 * but this is not an error situation so make sure we 1025 * return OK instead of BUF_ERROR at next call of deflate: 1026 */ 1027 s->last_flush = -1; 1028 return Z_OK; 1029 } 1030 1031 /* Make sure there is something to do and avoid duplicate consecutive 1032 * flushes. For repeated and useless calls with Z_FINISH, we keep 1033 * returning Z_STREAM_END instead of Z_BUFF_ERROR. 1034 */ 1035 } else if (strm->avail_in == 0 && flush <= old_flush && 1036 flush != Z_FINISH) { 1037 ERR_RETURN(strm, Z_BUF_ERROR); 1038 } 1039 1040 /* User must not provide more input after the first FINISH: */ 1041 if (s->status == FINISH_STATE && strm->avail_in != 0) { 1042 ERR_RETURN(strm, Z_BUF_ERROR); 1043 } 1044 1045 /* Start a new block or continue the current one. 1046 */ 1047 if (strm->avail_in != 0 || s->lookahead != 0 || 1048 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { 1049 block_state bstate; 1050 1051 bstate = (*(configuration_table[s->level].func))(s, flush); 1052 1053 if (bstate == finish_started || bstate == finish_done) { 1054 s->status = FINISH_STATE; 1055 } 1056 if (bstate == need_more || bstate == finish_started) { 1057 if (strm->avail_out == 0) { 1058 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ 1059 } 1060 return Z_OK; 1061 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 1062 * of deflate should use the same flush parameter to make sure 1063 * that the flush is complete. So we don't have to output an 1064 * empty block here, this will be done at next call. This also 1065 * ensures that for a very small output buffer, we emit at most 1066 * one empty block. 1067 */ 1068 } 1069 if (bstate == block_done) { 1070 if (flush == Z_PARTIAL_FLUSH) { 1071 _tr_align(s); 1072 } else if (flush == Z_PACKET_FLUSH) { 1073 /* Output just the 3-bit `stored' block type value, 1074 but not a zero length. */ 1075 _tr_stored_type_only(s); 1076 } else { /* FULL_FLUSH or SYNC_FLUSH */ 1077 _tr_stored_block(s, (char*)0, 0L, 0); 1078 /* For a full flush, this empty block will be recognized 1079 * as a special marker by inflate_sync(). 1080 */ 1081 if (flush == Z_FULL_FLUSH) { 1082 CLEAR_HASH(s); /* forget history */ 1083 } 1084 } 1085 flush_pending(strm); 1086 if (strm->avail_out == 0) { 1087 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ 1088 return Z_OK; 1089 } 1090 } 1091 } 1092 Assert(strm->avail_out > 0, "bug2"); 1093 1094 if (flush != Z_FINISH) return Z_OK; 1095 if (s->noheader) return Z_STREAM_END; 1096 1097 /* Write the zlib trailer (adler32) */ 1098 putShortMSB(s, (uInt)(strm->adler >> 16)); 1099 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1100 flush_pending(strm); 1101 /* If avail_out is zero, the application will call deflate again 1102 * to flush the rest. 1103 */ 1104 s->noheader = -1; /* write the trailer only once! */ 1105 return s->pending != 0 ? Z_OK : Z_STREAM_END; 1106} 1107 1108/* ========================================================================= */ 1109int deflateEnd (strm) 1110 z_streamp strm; 1111{ 1112 int status; 1113 deflate_state *s; 1114 1115 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 1116 s = (deflate_state *) strm->state; 1117 1118 status = s->status; 1119 if (status != INIT_STATE && status != BUSY_STATE && 1120 status != FINISH_STATE) { 1121 return Z_STREAM_ERROR; 1122 } 1123 1124 /* Deallocate in reverse order of allocations: */ 1125 TRY_FREE(strm, s->pending_buf); 1126 TRY_FREE(strm, s->head); 1127 TRY_FREE(strm, s->prev); 1128 TRY_FREE(strm, s->window); 1129 1130 ZFREE(strm, s); 1131 strm->state = Z_NULL; 1132 1133 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; 1134} 1135 1136/* ========================================================================= 1137 * Copy the source state to the destination state. 1138 */ 1139int deflateCopy (dest, source) 1140 z_streamp dest; 1141 z_streamp source; 1142{ 1143 deflate_state *ds; 1144 deflate_state *ss; 1145 ushf *overlay; 1146 1147 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) 1148 return Z_STREAM_ERROR; 1149 ss = (deflate_state *) source->state; 1150 1151 zmemcpy(dest, source, sizeof(*dest)); 1152 1153 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); 1154 if (ds == Z_NULL) return Z_MEM_ERROR; 1155 dest->state = (struct internal_state FAR *) ds; 1156 zmemcpy(ds, ss, sizeof(*ds)); 1157 ds->strm = dest; 1158 1159 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); 1160 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); 1161 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); 1162 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); 1163 ds->pending_buf = (uchf *) overlay; 1164 1165 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || 1166 ds->pending_buf == Z_NULL) { 1167 deflateEnd (dest); 1168 return Z_MEM_ERROR; 1169 } 1170 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ 1171 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); 1172 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); 1173 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); 1174 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); 1175 1176 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); 1177 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); 1178 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; 1179 1180 ds->l_desc.dyn_tree = ds->dyn_ltree; 1181 ds->d_desc.dyn_tree = ds->dyn_dtree; 1182 ds->bl_desc.dyn_tree = ds->bl_tree; 1183 1184 return Z_OK; 1185} 1186 1187/* =========================================================================== 1188 * Return the number of bytes of output which are immediately available 1189 * for output from the decompressor. 1190 */ 1191int deflateOutputPending (strm) 1192 z_streamp strm; 1193{ 1194 if (strm == Z_NULL || strm->state == Z_NULL) return 0; 1195 1196 return ((deflate_state *)(strm->state))->pending; 1197} 1198 1199/* =========================================================================== 1200 * Read a new buffer from the current input stream, update the adler32 1201 * and total number of bytes read. All deflate() input goes through 1202 * this function so some applications may wish to modify it to avoid 1203 * allocating a large strm->next_in buffer and copying from it. 1204 * (See also flush_pending()). 1205 */ 1206local int read_buf(strm, buf, size) 1207 z_streamp strm; 1208 charf *buf; 1209 unsigned size; 1210{ 1211 unsigned len = strm->avail_in; 1212 1213 if (len > size) len = size; 1214 if (len == 0) return 0; 1215 1216 strm->avail_in -= len; 1217 1218 if (!((deflate_state *)(strm->state))->noheader) { 1219 strm->adler = adler32(strm->adler, strm->next_in, len); 1220 } 1221 zmemcpy(buf, strm->next_in, len); 1222 strm->next_in += len; 1223 strm->total_in += len; 1224 1225 return (int)len; 1226} 1227 1228/* =========================================================================== 1229 * Initialize the "longest match" routines for a new zlib stream 1230 */ 1231local void lm_init (s) 1232 deflate_state *s; 1233{ 1234 s->window_size = (ulg)2L*s->w_size; 1235 1236 CLEAR_HASH(s); 1237 1238 /* Set the default configuration parameters: 1239 */ 1240 s->max_lazy_match = configuration_table[s->level].max_lazy; 1241 s->good_match = configuration_table[s->level].good_length; 1242 s->nice_match = configuration_table[s->level].nice_length; 1243 s->max_chain_length = configuration_table[s->level].max_chain; 1244 1245 s->strstart = 0; 1246 s->block_start = 0L; 1247 s->lookahead = 0; 1248 s->match_length = s->prev_length = MIN_MATCH-1; 1249 s->match_available = 0; 1250 s->ins_h = 0; 1251#ifdef ASMV 1252 match_init(); /* initialize the asm code */ 1253#endif 1254} 1255 1256/* =========================================================================== 1257 * Set match_start to the longest match starting at the given string and 1258 * return its length. Matches shorter or equal to prev_length are discarded, 1259 * in which case the result is equal to prev_length and match_start is 1260 * garbage. 1261 * IN assertions: cur_match is the head of the hash chain for the current 1262 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 1263 * OUT assertion: the match length is not greater than s->lookahead. 1264 */ 1265#ifndef ASMV 1266/* For 80x86 and 680x0, an optimized version will be provided in match.asm or 1267 * match.S. The code will be functionally equivalent. 1268 */ 1269local uInt longest_match(s, cur_match) 1270 deflate_state *s; 1271 IPos cur_match; /* current match */ 1272{ 1273 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 1274 register Bytef *scan = s->window + s->strstart; /* current string */ 1275 register Bytef *match; /* matched string */ 1276 register int len; /* length of current match */ 1277 int best_len = s->prev_length; /* best match length so far */ 1278 int nice_match = s->nice_match; /* stop if match long enough */ 1279 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 1280 s->strstart - (IPos)MAX_DIST(s) : NIL; 1281 /* Stop when cur_match becomes <= limit. To simplify the code, 1282 * we prevent matches with the string of window index 0. 1283 */ 1284 Posf *prev = s->prev; 1285 uInt wmask = s->w_mask; 1286 1287#ifdef UNALIGNED_OK 1288 /* Compare two bytes at a time. Note: this is not always beneficial. 1289 * Try with and without -DUNALIGNED_OK to check. 1290 */ 1291 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 1292 register ush scan_start = *(ushf*)scan; 1293 register ush scan_end = *(ushf*)(scan+best_len-1); 1294#else 1295 register Bytef *strend = s->window + s->strstart + MAX_MATCH; 1296 register Byte scan_end1 = scan[best_len-1]; 1297 register Byte scan_end = scan[best_len]; 1298#endif 1299 1300 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 1301 * It is easy to get rid of this optimization if necessary. 1302 */ 1303 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 1304 1305 /* Do not waste too much time if we already have a good match: */ 1306 if (s->prev_length >= s->good_match) { 1307 chain_length >>= 2; 1308 } 1309 /* Do not look for matches beyond the end of the input. This is necessary 1310 * to make deflate deterministic. 1311 */ 1312 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; 1313 1314 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1315 1316 do { 1317 Assert(cur_match < s->strstart, "no future"); 1318 match = s->window + cur_match; 1319 1320 /* Skip to next match if the match length cannot increase 1321 * or if the match length is less than 2: 1322 */ 1323#if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1324 /* This code assumes sizeof(unsigned short) == 2. Do not use 1325 * UNALIGNED_OK if your compiler uses a different size. 1326 */ 1327 if (*(ushf*)(match+best_len-1) != scan_end || 1328 *(ushf*)match != scan_start) continue; 1329 1330 /* It is not necessary to compare scan[2] and match[2] since they are 1331 * always equal when the other bytes match, given that the hash keys 1332 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1333 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1334 * lookahead only every 4th comparison; the 128th check will be made 1335 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1336 * necessary to put more guard bytes at the end of the window, or 1337 * to check more often for insufficient lookahead. 1338 */ 1339 Assert(scan[2] == match[2], "scan[2]?"); 1340 scan++, match++; 1341 do { 1342 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1343 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1344 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1345 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1346 scan < strend); 1347 /* The funny "do {}" generates better code on most compilers */ 1348 1349 /* Here, scan <= window+strstart+257 */ 1350 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1351 if (*scan == *match) scan++; 1352 1353 len = (MAX_MATCH - 1) - (int)(strend-scan); 1354 scan = strend - (MAX_MATCH-1); 1355 1356#else /* UNALIGNED_OK */ 1357 1358 if (match[best_len] != scan_end || 1359 match[best_len-1] != scan_end1 || 1360 *match != *scan || 1361 *++match != scan[1]) continue; 1362 1363 /* The check at best_len-1 can be removed because it will be made 1364 * again later. (This heuristic is not always a win.) 1365 * It is not necessary to compare scan[2] and match[2] since they 1366 * are always equal when the other bytes match, given that 1367 * the hash keys are equal and that HASH_BITS >= 8. 1368 */ 1369 scan += 2, match++; 1370 Assert(*scan == *match, "match[2]?"); 1371 1372 /* We check for insufficient lookahead only every 8th comparison; 1373 * the 256th check will be made at strstart+258. 1374 */ 1375 do { 1376 } while (*++scan == *++match && *++scan == *++match && 1377 *++scan == *++match && *++scan == *++match && 1378 *++scan == *++match && *++scan == *++match && 1379 *++scan == *++match && *++scan == *++match && 1380 scan < strend); 1381 1382 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1383 1384 len = MAX_MATCH - (int)(strend - scan); 1385 scan = strend - MAX_MATCH; 1386 1387#endif /* UNALIGNED_OK */ 1388 1389 if (len > best_len) { 1390 s->match_start = cur_match; 1391 best_len = len; 1392 if (len >= nice_match) break; 1393#ifdef UNALIGNED_OK 1394 scan_end = *(ushf*)(scan+best_len-1); 1395#else 1396 scan_end1 = scan[best_len-1]; 1397 scan_end = scan[best_len]; 1398#endif 1399 } 1400 } while ((cur_match = prev[cur_match & wmask]) > limit 1401 && --chain_length != 0); 1402 1403 if ((uInt)best_len <= s->lookahead) return best_len; 1404 return s->lookahead; 1405} 1406#endif /* ASMV */ 1407 1408#ifdef DEBUG_ZLIB 1409/* =========================================================================== 1410 * Check that the match at match_start is indeed a match. 1411 */ 1412local void check_match(s, start, match, length) 1413 deflate_state *s; 1414 IPos start, match; 1415 int length; 1416{ 1417 /* check that the match is indeed a match */ 1418 if (zmemcmp((charf *)s->window + match, 1419 (charf *)s->window + start, length) != EQUAL) { 1420 fprintf(stderr, " start %u, match %u, length %d\n", 1421 start, match, length); 1422 do { 1423 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); 1424 } while (--length != 0); 1425 z_error("invalid match"); 1426 } 1427 if (z_verbose > 1) { 1428 fprintf(stderr,"\\[%d,%d]", start-match, length); 1429 do { putc(s->window[start++], stderr); } while (--length != 0); 1430 } 1431} 1432#else 1433# define check_match(s, start, match, length) 1434#endif 1435 1436/* =========================================================================== 1437 * Fill the window when the lookahead becomes insufficient. 1438 * Updates strstart and lookahead. 1439 * 1440 * IN assertion: lookahead < MIN_LOOKAHEAD 1441 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1442 * At least one byte has been read, or avail_in == 0; reads are 1443 * performed for at least two bytes (required for the zip translate_eol 1444 * option -- not supported here). 1445 */ 1446local void fill_window(s) 1447 deflate_state *s; 1448{ 1449 register unsigned n, m; 1450 register Posf *p; 1451 unsigned more; /* Amount of free space at the end of the window. */ 1452 uInt wsize = s->w_size; 1453 1454 do { 1455 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1456 1457 /* Deal with !@#$% 64K limit: */ 1458 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1459 more = wsize; 1460 1461 } else if (more == (unsigned)(-1)) { 1462 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1463 * and lookahead == 1 (input done one byte at time) 1464 */ 1465 more--; 1466 1467 /* If the window is almost full and there is insufficient lookahead, 1468 * move the upper half to the lower one to make room in the upper half. 1469 */ 1470 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1471 1472 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1473 (unsigned)wsize); 1474 s->match_start -= wsize; 1475 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1476 s->block_start -= (long) wsize; 1477 1478 /* Slide the hash table (could be avoided with 32 bit values 1479 at the expense of memory usage). We slide even when level == 0 1480 to keep the hash table consistent if we switch back to level > 0 1481 later. (Using level 0 permanently is not an optimal usage of 1482 zlib, so we don't care about this pathological case.) 1483 */ 1484 n = s->hash_size; 1485 p = &s->head[n]; 1486 do { 1487 m = *--p; 1488 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1489 } while (--n); 1490 1491 n = wsize; 1492 p = &s->prev[n]; 1493 do { 1494 m = *--p; 1495 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1496 /* If n is not on any hash chain, prev[n] is garbage but 1497 * its value will never be used. 1498 */ 1499 } while (--n); 1500 more += wsize; 1501 } 1502 if (s->strm->avail_in == 0) return; 1503 1504 /* If there was no sliding: 1505 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1506 * more == window_size - lookahead - strstart 1507 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1508 * => more >= window_size - 2*WSIZE + 2 1509 * In the BIG_MEM or MMAP case (not yet supported), 1510 * window_size == input_size + MIN_LOOKAHEAD && 1511 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1512 * Otherwise, window_size == 2*WSIZE so more >= 2. 1513 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1514 */ 1515 Assert(more >= 2, "more < 2"); 1516 1517 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1518 more); 1519 s->lookahead += n; 1520 1521 /* Initialize the hash value now that we have some input: */ 1522 if (s->lookahead >= MIN_MATCH) { 1523 s->ins_h = s->window[s->strstart]; 1524 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1525#if MIN_MATCH != 3 1526 Call UPDATE_HASH() MIN_MATCH-3 more times 1527#endif 1528 } 1529 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1530 * but this is not important since only literal bytes will be emitted. 1531 */ 1532 1533 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1534} 1535 1536/* =========================================================================== 1537 * Flush the current block, with given end-of-file flag. 1538 * IN assertion: strstart is set to the end of the current match. 1539 */ 1540#define FLUSH_BLOCK_ONLY(s, eof) { \ 1541 _tr_flush_block(s, (s->block_start >= 0L ? \ 1542 (charf *)&s->window[(unsigned)s->block_start] : \ 1543 (charf *)Z_NULL), \ 1544 (ulg)((long)s->strstart - s->block_start), \ 1545 (eof)); \ 1546 s->block_start = s->strstart; \ 1547 flush_pending(s->strm); \ 1548 Tracev((stderr,"[FLUSH]")); \ 1549} 1550 1551/* Same but force premature exit if necessary. */ 1552#define FLUSH_BLOCK(s, eof) { \ 1553 FLUSH_BLOCK_ONLY(s, eof); \ 1554 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ 1555} 1556 1557/* =========================================================================== 1558 * Copy without compression as much as possible from the input stream, return 1559 * the current block state. 1560 * This function does not insert new strings in the dictionary since 1561 * uncompressible data is probably not useful. This function is used 1562 * only for the level=0 compression option. 1563 * NOTE: this function should be optimized to avoid extra copying from 1564 * window to pending_buf. 1565 */ 1566local block_state deflate_stored(s, flush) 1567 deflate_state *s; 1568 int flush; 1569{ 1570 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited 1571 * to pending_buf_size, and each stored block has a 5 byte header: 1572 */ 1573 ulg max_block_size = 0xffff; 1574 ulg max_start; 1575 1576 if (max_block_size > s->pending_buf_size - 5) { 1577 max_block_size = s->pending_buf_size - 5; 1578 } 1579 1580 /* Copy as much as possible from input to output: */ 1581 for (;;) { 1582 /* Fill the window as much as possible: */ 1583 if (s->lookahead <= 1) { 1584 1585 Assert(s->strstart < s->w_size+MAX_DIST(s) || 1586 s->block_start >= (long)s->w_size, "slide too late"); 1587 1588 fill_window(s); 1589 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; 1590 1591 if (s->lookahead == 0) break; /* flush the current block */ 1592 } 1593 Assert(s->block_start >= 0L, "block gone"); 1594 1595 s->strstart += s->lookahead; 1596 s->lookahead = 0; 1597 1598 /* Emit a stored block if pending_buf will be full: */ 1599 max_start = s->block_start + max_block_size; 1600 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { 1601 /* strstart == 0 is possible when wraparound on 16-bit machine */ 1602 s->lookahead = (uInt)(s->strstart - max_start); 1603 s->strstart = (uInt)max_start; 1604 FLUSH_BLOCK(s, 0); 1605 } 1606 /* Flush if we may have to slide, otherwise block_start may become 1607 * negative and the data will be gone: 1608 */ 1609 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { 1610 FLUSH_BLOCK(s, 0); 1611 } 1612 } 1613 FLUSH_BLOCK(s, flush == Z_FINISH); 1614 return flush == Z_FINISH ? finish_done : block_done; 1615} 1616 1617/* =========================================================================== 1618 * Compress as much as possible from the input stream, return the current 1619 * block state. 1620 * This function does not perform lazy evaluation of matches and inserts 1621 * new strings in the dictionary only for unmatched strings or for short 1622 * matches. It is used only for the fast compression options. 1623 */ 1624local block_state deflate_fast(s, flush) 1625 deflate_state *s; 1626 int flush; 1627{ 1628 IPos hash_head = NIL; /* head of the hash chain */ 1629 int bflush; /* set if current block must be flushed */ 1630 1631 for (;;) { 1632 /* Make sure that we always have enough lookahead, except 1633 * at the end of the input file. We need MAX_MATCH bytes 1634 * for the next match, plus MIN_MATCH bytes to insert the 1635 * string following the next match. 1636 */ 1637 if (s->lookahead < MIN_LOOKAHEAD) { 1638 fill_window(s); 1639 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1640 return need_more; 1641 } 1642 if (s->lookahead == 0) break; /* flush the current block */ 1643 } 1644 1645 /* Insert the string window[strstart .. strstart+2] in the 1646 * dictionary, and set hash_head to the head of the hash chain: 1647 */ 1648 if (s->lookahead >= MIN_MATCH) { 1649 INSERT_STRING(s, s->strstart, hash_head); 1650 } 1651 1652 /* Find the longest match, discarding those <= prev_length. 1653 * At this point we have always match_length < MIN_MATCH 1654 */ 1655 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1656 /* To simplify the code, we prevent matches with the string 1657 * of window index 0 (in particular we have to avoid a match 1658 * of the string with itself at the start of the input file). 1659 */ 1660 if (s->strategy != Z_HUFFMAN_ONLY) { 1661 s->match_length = longest_match (s, hash_head); 1662 } 1663 /* longest_match() sets match_start */ 1664 } 1665 if (s->match_length >= MIN_MATCH) { 1666 check_match(s, s->strstart, s->match_start, s->match_length); 1667 1668 bflush = _tr_tally(s, s->strstart - s->match_start, 1669 s->match_length - MIN_MATCH); 1670 1671 s->lookahead -= s->match_length; 1672 1673 /* Insert new strings in the hash table only if the match length 1674 * is not too large. This saves time but degrades compression. 1675 */ 1676 if (s->match_length <= s->max_insert_length && 1677 s->lookahead >= MIN_MATCH) { 1678 s->match_length--; /* string at strstart already in hash table */ 1679 do { 1680 s->strstart++; 1681 INSERT_STRING(s, s->strstart, hash_head); 1682 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1683 * always MIN_MATCH bytes ahead. 1684 */ 1685 } while (--s->match_length != 0); 1686 s->strstart++; 1687 } else { 1688 s->strstart += s->match_length; 1689 s->match_length = 0; 1690 s->ins_h = s->window[s->strstart]; 1691 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1692#if MIN_MATCH != 3 1693 Call UPDATE_HASH() MIN_MATCH-3 more times 1694#endif 1695 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1696 * matter since it will be recomputed at next deflate call. 1697 */ 1698 } 1699 } else { 1700 /* No match, output a literal byte */ 1701 Tracevv((stderr,"%c", s->window[s->strstart])); 1702 bflush = _tr_tally (s, 0, s->window[s->strstart]); 1703 s->lookahead--; 1704 s->strstart++; 1705 } 1706 if (bflush) FLUSH_BLOCK(s, 0); 1707 } 1708 FLUSH_BLOCK(s, flush == Z_FINISH); 1709 return flush == Z_FINISH ? finish_done : block_done; 1710} 1711 1712/* =========================================================================== 1713 * Same as above, but achieves better compression. We use a lazy 1714 * evaluation for matches: a match is finally adopted only if there is 1715 * no better match at the next window position. 1716 */ 1717local block_state deflate_slow(s, flush) 1718 deflate_state *s; 1719 int flush; 1720{ 1721 IPos hash_head = NIL; /* head of hash chain */ 1722 int bflush; /* set if current block must be flushed */ 1723 1724 /* Process the input block. */ 1725 for (;;) { 1726 /* Make sure that we always have enough lookahead, except 1727 * at the end of the input file. We need MAX_MATCH bytes 1728 * for the next match, plus MIN_MATCH bytes to insert the 1729 * string following the next match. 1730 */ 1731 if (s->lookahead < MIN_LOOKAHEAD) { 1732 fill_window(s); 1733 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1734 return need_more; 1735 } 1736 if (s->lookahead == 0) break; /* flush the current block */ 1737 } 1738 1739 /* Insert the string window[strstart .. strstart+2] in the 1740 * dictionary, and set hash_head to the head of the hash chain: 1741 */ 1742 if (s->lookahead >= MIN_MATCH) { 1743 INSERT_STRING(s, s->strstart, hash_head); 1744 } 1745 1746 /* Find the longest match, discarding those <= prev_length. 1747 */ 1748 s->prev_length = s->match_length, s->prev_match = s->match_start; 1749 s->match_length = MIN_MATCH-1; 1750 1751 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1752 s->strstart - hash_head <= MAX_DIST(s)) { 1753 /* To simplify the code, we prevent matches with the string 1754 * of window index 0 (in particular we have to avoid a match 1755 * of the string with itself at the start of the input file). 1756 */ 1757 if (s->strategy != Z_HUFFMAN_ONLY) { 1758 s->match_length = longest_match (s, hash_head); 1759 } 1760 /* longest_match() sets match_start */ 1761 1762 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1763 (s->match_length == MIN_MATCH && 1764 s->strstart - s->match_start > TOO_FAR))) { 1765 1766 /* If prev_match is also MIN_MATCH, match_start is garbage 1767 * but we will ignore the current match anyway. 1768 */ 1769 s->match_length = MIN_MATCH-1; 1770 } 1771 } 1772 /* If there was a match at the previous step and the current 1773 * match is not better, output the previous match: 1774 */ 1775 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1776 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1777 /* Do not insert strings in hash table beyond this. */ 1778 1779 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1780 1781 bflush = _tr_tally(s, s->strstart -1 - s->prev_match, 1782 s->prev_length - MIN_MATCH); 1783 1784 /* Insert in hash table all strings up to the end of the match. 1785 * strstart-1 and strstart are already inserted. If there is not 1786 * enough lookahead, the last two strings are not inserted in 1787 * the hash table. 1788 */ 1789 s->lookahead -= s->prev_length-1; 1790 s->prev_length -= 2; 1791 do { 1792 if (++s->strstart <= max_insert) { 1793 INSERT_STRING(s, s->strstart, hash_head); 1794 } 1795 } while (--s->prev_length != 0); 1796 s->match_available = 0; 1797 s->match_length = MIN_MATCH-1; 1798 s->strstart++; 1799 1800 if (bflush) FLUSH_BLOCK(s, 0); 1801 1802 } else if (s->match_available) { 1803 /* If there was no match at the previous position, output a 1804 * single literal. If there was a match but the current match 1805 * is longer, truncate the previous match to a single literal. 1806 */ 1807 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1808 if (_tr_tally (s, 0, s->window[s->strstart-1])) { 1809 FLUSH_BLOCK_ONLY(s, 0); 1810 } 1811 s->strstart++; 1812 s->lookahead--; 1813 if (s->strm->avail_out == 0) return need_more; 1814 } else { 1815 /* There is no previous match to compare with, wait for 1816 * the next step to decide. 1817 */ 1818 s->match_available = 1; 1819 s->strstart++; 1820 s->lookahead--; 1821 } 1822 } 1823 Assert (flush != Z_NO_FLUSH, "no flush?"); 1824 if (s->match_available) { 1825 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1826 _tr_tally (s, 0, s->window[s->strstart-1]); 1827 s->match_available = 0; 1828 } 1829 FLUSH_BLOCK(s, flush == Z_FINISH); 1830 return flush == Z_FINISH ? finish_done : block_done; 1831} 1832/* --- deflate.c */ 1833 1834/* +++ trees.c */ 1835/* trees.c -- output deflated data using Huffman coding 1836 * Copyright (C) 1995-1996 Jean-loup Gailly 1837 * For conditions of distribution and use, see copyright notice in zlib.h 1838 */ 1839 1840/* 1841 * ALGORITHM 1842 * 1843 * The "deflation" process uses several Huffman trees. The more 1844 * common source values are represented by shorter bit sequences. 1845 * 1846 * Each code tree is stored in a compressed form which is itself 1847 * a Huffman encoding of the lengths of all the code strings (in 1848 * ascending order by source values). The actual code strings are 1849 * reconstructed from the lengths in the inflate process, as described 1850 * in the deflate specification. 1851 * 1852 * REFERENCES 1853 * 1854 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1855 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1856 * 1857 * Storer, James A. 1858 * Data Compression: Methods and Theory, pp. 49-50. 1859 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1860 * 1861 * Sedgewick, R. 1862 * Algorithms, p290. 1863 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1864 */ 1865 1866/* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ 1867 1868/* #include "deflate.h" */ 1869 1870#ifdef DEBUG_ZLIB 1871# include <ctype.h> 1872#endif 1873 1874/* =========================================================================== 1875 * Constants 1876 */ 1877 1878#define MAX_BL_BITS 7 1879/* Bit length codes must not exceed MAX_BL_BITS bits */ 1880 1881#define END_BLOCK 256 1882/* end of block literal code */ 1883 1884#define REP_3_6 16 1885/* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1886 1887#define REPZ_3_10 17 1888/* repeat a zero length 3-10 times (3 bits of repeat count) */ 1889 1890#define REPZ_11_138 18 1891/* repeat a zero length 11-138 times (7 bits of repeat count) */ 1892 1893local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1894 = {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}; 1895 1896local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1897 = {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}; 1898 1899local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1900 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1901 1902local uch bl_order[BL_CODES] 1903 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1904/* The lengths of the bit length codes are sent in order of decreasing 1905 * probability, to avoid transmitting the lengths for unused bit length codes. 1906 */ 1907 1908#define Buf_size (8 * 2*sizeof(char)) 1909/* Number of bits used within bi_buf. (bi_buf might be implemented on 1910 * more than 16 bits on some systems.) 1911 */ 1912 1913/* =========================================================================== 1914 * Local data. These are initialized only once. 1915 */ 1916 1917local ct_data static_ltree[L_CODES+2]; 1918/* The static literal tree. Since the bit lengths are imposed, there is no 1919 * need for the L_CODES extra codes used during heap construction. However 1920 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 1921 * below). 1922 */ 1923 1924local ct_data static_dtree[D_CODES]; 1925/* The static distance tree. (Actually a trivial tree since all codes use 1926 * 5 bits.) 1927 */ 1928 1929local uch dist_code[512]; 1930/* distance codes. The first 256 values correspond to the distances 1931 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1932 * the 15 bit distances. 1933 */ 1934 1935local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1936/* length code for each normalized match length (0 == MIN_MATCH) */ 1937 1938local int base_length[LENGTH_CODES]; 1939/* First normalized length for each code (0 = MIN_MATCH) */ 1940 1941local int base_dist[D_CODES]; 1942/* First normalized distance for each code (0 = distance of 1) */ 1943 1944struct static_tree_desc_s { 1945 ct_data *static_tree; /* static tree or NULL */ 1946 intf *extra_bits; /* extra bits for each code or NULL */ 1947 int extra_base; /* base index for extra_bits */ 1948 int elems; /* max number of elements in the tree */ 1949 int max_length; /* max bit length for the codes */ 1950}; 1951 1952local static_tree_desc static_l_desc = 1953{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1954 1955local static_tree_desc static_d_desc = 1956{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1957 1958local static_tree_desc static_bl_desc = 1959{(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1960 1961/* =========================================================================== 1962 * Local (static) routines in this file. 1963 */ 1964 1965local void tr_static_init OF((void)); 1966local void init_block OF((deflate_state *s)); 1967local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1968local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1969local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1970local void build_tree OF((deflate_state *s, tree_desc *desc)); 1971local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1972local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1973local int build_bl_tree OF((deflate_state *s)); 1974local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1975 int blcodes)); 1976local void compress_block OF((deflate_state *s, ct_data *ltree, 1977 ct_data *dtree)); 1978local void set_data_type OF((deflate_state *s)); 1979local unsigned bi_reverse OF((unsigned value, int length)); 1980local void bi_windup OF((deflate_state *s)); 1981local void bi_flush OF((deflate_state *s)); 1982local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1983 int header)); 1984 1985#ifndef DEBUG_ZLIB 1986# define send_code(s, c, tree) send_bits(s, tree[(c)].Code, tree[(c)].Len) 1987 /* Send a code of the given tree. c and tree must not have side effects */ 1988 1989#else /* DEBUG_ZLIB */ 1990# define send_code(s, c, tree) \ 1991 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 1992 send_bits(s, tree[c].Code, tree[c].Len); } 1993#endif 1994 1995#define d_code(dist) \ 1996 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 1997/* Mapping from a distance to a distance code. dist is the distance - 1 and 1998 * must not have side effects. dist_code[256] and dist_code[257] are never 1999 * used. 2000 */ 2001 2002/* =========================================================================== 2003 * Output a short LSB first on the stream. 2004 * IN assertion: there is enough room in pendingBuf. 2005 */ 2006#define put_short(s, w) { \ 2007 put_byte(s, (uch)((w) & 0xff)); \ 2008 put_byte(s, (uch)((ush)(w) >> 8)); \ 2009} 2010 2011/* =========================================================================== 2012 * Send a value on a given number of bits. 2013 * IN assertion: length <= 16 and value fits in length bits. 2014 */ 2015#ifdef DEBUG_ZLIB 2016local void send_bits OF((deflate_state *s, int value, int length)); 2017 2018local void send_bits(s, value, length) 2019 deflate_state *s; 2020 int value; /* value to send */ 2021 int length; /* number of bits */ 2022{ 2023 Tracevv((stderr," l %2d v %4x ", length, value)); 2024 Assert(length > 0 && length <= 15, "invalid length"); 2025 s->bits_sent += (ulg)length; 2026 2027 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 2028 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 2029 * unused bits in value. 2030 */ 2031 if (s->bi_valid > (int)Buf_size - length) { 2032 s->bi_buf |= (value << s->bi_valid); 2033 put_short(s, s->bi_buf); 2034 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 2035 s->bi_valid += length - Buf_size; 2036 } else { 2037 s->bi_buf |= value << s->bi_valid; 2038 s->bi_valid += length; 2039 } 2040} 2041#else /* !DEBUG_ZLIB */ 2042 2043#define send_bits(s, value, length) \ 2044{ int len = (length);\ 2045 if ((s)->bi_valid > (int)Buf_size - len) {\ 2046 int val = (value);\ 2047 (s)->bi_buf |= (val << (s)->bi_valid);\ 2048 put_short((s), (s)->bi_buf);\ 2049 (s)->bi_buf = (ush)val >> (Buf_size - (s)->bi_valid);\ 2050 (s)->bi_valid += len - Buf_size;\ 2051 } else {\ 2052 (s)->bi_buf |= (value) << (s)->bi_valid;\ 2053 (s)->bi_valid += len;\ 2054 }\ 2055} 2056#endif /* DEBUG_ZLIB */ 2057 2058 2059#define MAX(a,b) (a >= b ? a : b) 2060/* the arguments must not have side effects */ 2061 2062/* =========================================================================== 2063 * Initialize the various 'constant' tables. In a multi-threaded environment, 2064 * this function may be called by two threads concurrently, but this is 2065 * harmless since both invocations do exactly the same thing. 2066 */ 2067local void tr_static_init() 2068{ 2069 static int static_init_done = 0; 2070 int n; /* iterates over tree elements */ 2071 int bits; /* bit counter */ 2072 int length; /* length value */ 2073 int code; /* code value */ 2074 int dist; /* distance index */ 2075 ush bl_count[MAX_BITS+1]; 2076 /* number of codes at each bit length for an optimal tree */ 2077 2078 if (static_init_done) return; 2079 2080 /* Initialize the mapping length (0..255) -> length code (0..28) */ 2081 length = 0; 2082 for (code = 0; code < LENGTH_CODES-1; code++) { 2083 base_length[code] = length; 2084 for (n = 0; n < (1<<extra_lbits[code]); n++) { 2085 length_code[length++] = (uch)code; 2086 } 2087 } 2088 Assert (length == 256, "tr_static_init: length != 256"); 2089 /* Note that the length 255 (match length 258) can be represented 2090 * in two different ways: code 284 + 5 bits or code 285, so we 2091 * overwrite length_code[255] to use the best encoding: 2092 */ 2093 length_code[length-1] = (uch)code; 2094 2095 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 2096 dist = 0; 2097 for (code = 0 ; code < 16; code++) { 2098 base_dist[code] = dist; 2099 for (n = 0; n < (1<<extra_dbits[code]); n++) { 2100 dist_code[dist++] = (uch)code; 2101 } 2102 } 2103 Assert (dist == 256, "tr_static_init: dist != 256"); 2104 dist >>= 7; /* from now on, all distances are divided by 128 */ 2105 for ( ; code < D_CODES; code++) { 2106 base_dist[code] = dist << 7; 2107 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 2108 dist_code[256 + dist++] = (uch)code; 2109 } 2110 } 2111 Assert (dist == 256, "tr_static_init: 256+dist != 512"); 2112 2113 /* Construct the codes of the static literal tree */ 2114 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 2115 n = 0; 2116 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 2117 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 2118 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 2119 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 2120 /* Codes 286 and 287 do not exist, but we must include them in the 2121 * tree construction to get a canonical Huffman tree (longest code 2122 * all ones) 2123 */ 2124 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 2125 2126 /* The static distance tree is trivial: */ 2127 for (n = 0; n < D_CODES; n++) { 2128 static_dtree[n].Len = 5; 2129 static_dtree[n].Code = bi_reverse((unsigned)n, 5); 2130 } 2131 static_init_done = 1; 2132} 2133 2134/* =========================================================================== 2135 * Initialize the tree data structures for a new zlib stream. 2136 */ 2137void _tr_init(s) 2138 deflate_state *s; 2139{ 2140 tr_static_init(); 2141 2142 s->compressed_len = 0L; 2143 2144 s->l_desc.dyn_tree = s->dyn_ltree; 2145 s->l_desc.stat_desc = &static_l_desc; 2146 2147 s->d_desc.dyn_tree = s->dyn_dtree; 2148 s->d_desc.stat_desc = &static_d_desc; 2149 2150 s->bl_desc.dyn_tree = s->bl_tree; 2151 s->bl_desc.stat_desc = &static_bl_desc; 2152 2153 s->bi_buf = 0; 2154 s->bi_valid = 0; 2155 s->last_eob_len = 8; /* enough lookahead for inflate */ 2156#ifdef DEBUG_ZLIB 2157 s->bits_sent = 0L; 2158#endif 2159 2160 /* Initialize the first block of the first file: */ 2161 init_block(s); 2162} 2163 2164/* =========================================================================== 2165 * Initialize a new block. 2166 */ 2167local void init_block(s) 2168 deflate_state *s; 2169{ 2170 int n; /* iterates over tree elements */ 2171 2172 /* Initialize the trees. */ 2173 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 2174 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 2175 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 2176 2177 s->dyn_ltree[END_BLOCK].Freq = 1; 2178 s->opt_len = s->static_len = 0L; 2179 s->last_lit = s->matches = 0; 2180} 2181 2182#define SMALLEST 1 2183/* Index within the heap array of least frequent node in the Huffman tree */ 2184 2185 2186/* =========================================================================== 2187 * Remove the smallest element from the heap and recreate the heap with 2188 * one less element. Updates heap and heap_len. 2189 */ 2190#define pqremove(s, tree, top) \ 2191{\ 2192 top = s->heap[SMALLEST]; \ 2193 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 2194 pqdownheap(s, tree, SMALLEST); \ 2195} 2196 2197/* =========================================================================== 2198 * Compares to subtrees, using the tree depth as tie breaker when 2199 * the subtrees have equal frequency. This minimizes the worst case length. 2200 */ 2201#define smaller(tree, n, m, depth) \ 2202 (tree[n].Freq < tree[m].Freq || \ 2203 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 2204 2205/* =========================================================================== 2206 * Restore the heap property by moving down the tree starting at node k, 2207 * exchanging a node with the smallest of its two sons if necessary, stopping 2208 * when the heap property is re-established (each father smaller than its 2209 * two sons). 2210 */ 2211local void pqdownheap(s, tree, k) 2212 deflate_state *s; 2213 ct_data *tree; /* the tree to restore */ 2214 int k; /* node to move down */ 2215{ 2216 int v = s->heap[k]; 2217 int j = k << 1; /* left son of k */ 2218 while (j <= s->heap_len) { 2219 /* Set j to the smallest of the two sons: */ 2220 if (j < s->heap_len && 2221 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 2222 j++; 2223 } 2224 /* Exit if v is smaller than both sons */ 2225 if (smaller(tree, v, s->heap[j], s->depth)) break; 2226 2227 /* Exchange v with the smallest son */ 2228 s->heap[k] = s->heap[j]; k = j; 2229 2230 /* And continue down the tree, setting j to the left son of k */ 2231 j <<= 1; 2232 } 2233 s->heap[k] = v; 2234} 2235 2236/* =========================================================================== 2237 * Compute the optimal bit lengths for a tree and update the total bit length 2238 * for the current block. 2239 * IN assertion: the fields freq and dad are set, heap[heap_max] and 2240 * above are the tree nodes sorted by increasing frequency. 2241 * OUT assertions: the field len is set to the optimal bit length, the 2242 * array bl_count contains the frequencies for each bit length. 2243 * The length opt_len is updated; static_len is also updated if stree is 2244 * not null. 2245 */ 2246local void gen_bitlen(s, desc) 2247 deflate_state *s; 2248 tree_desc *desc; /* the tree descriptor */ 2249{ 2250 ct_data *tree = desc->dyn_tree; 2251 int max_code = desc->max_code; 2252 ct_data *stree = desc->stat_desc->static_tree; 2253 intf *extra = desc->stat_desc->extra_bits; 2254 int base = desc->stat_desc->extra_base; 2255 int max_length = desc->stat_desc->max_length; 2256 int h; /* heap index */ 2257 int n, m; /* iterate over the tree elements */ 2258 int bits; /* bit length */ 2259 int xbits; /* extra bits */ 2260 ush f; /* frequency */ 2261 int overflow = 0; /* number of elements with bit length too large */ 2262 2263 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 2264 2265 /* In a first pass, compute the optimal bit lengths (which may 2266 * overflow in the case of the bit length tree). 2267 */ 2268 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 2269 2270 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 2271 n = s->heap[h]; 2272 bits = tree[tree[n].Dad].Len + 1; 2273 if (bits > max_length) bits = max_length, overflow++; 2274 tree[n].Len = (ush)bits; 2275 /* We overwrite tree[n].Dad which is no longer needed */ 2276 2277 if (n > max_code) continue; /* not a leaf node */ 2278 2279 s->bl_count[bits]++; 2280 xbits = 0; 2281 if (n >= base) xbits = extra[n-base]; 2282 f = tree[n].Freq; 2283 s->opt_len += (ulg)f * (bits + xbits); 2284 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 2285 } 2286 if (overflow == 0) return; 2287 2288 Trace((stderr,"\nbit length overflow\n")); 2289 /* This happens for example on obj2 and pic of the Calgary corpus */ 2290 2291 /* Find the first bit length which could increase: */ 2292 do { 2293 bits = max_length-1; 2294 while (s->bl_count[bits] == 0) bits--; 2295 s->bl_count[bits]--; /* move one leaf down the tree */ 2296 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 2297 s->bl_count[max_length]--; 2298 /* The brother of the overflow item also moves one step up, 2299 * but this does not affect bl_count[max_length] 2300 */ 2301 overflow -= 2; 2302 } while (overflow > 0); 2303 2304 /* Now recompute all bit lengths, scanning in increasing frequency. 2305 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 2306 * lengths instead of fixing only the wrong ones. This idea is taken 2307 * from 'ar' written by Haruhiko Okumura.) 2308 */ 2309 for (bits = max_length; bits != 0; bits--) { 2310 n = s->bl_count[bits]; 2311 while (n != 0) { 2312 m = s->heap[--h]; 2313 if (m > max_code) continue; 2314 if (tree[m].Len != (unsigned) bits) { 2315 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 2316 s->opt_len += ((long)bits - (long)tree[m].Len) 2317 *(long)tree[m].Freq; 2318 tree[m].Len = (ush)bits; 2319 } 2320 n--; 2321 } 2322 } 2323} 2324 2325/* =========================================================================== 2326 * Generate the codes for a given tree and bit counts (which need not be 2327 * optimal). 2328 * IN assertion: the array bl_count contains the bit length statistics for 2329 * the given tree and the field len is set for all tree elements. 2330 * OUT assertion: the field code is set for all tree elements of non 2331 * zero code length. 2332 */ 2333local void gen_codes (tree, max_code, bl_count) 2334 ct_data *tree; /* the tree to decorate */ 2335 int max_code; /* largest code with non zero frequency */ 2336 ushf *bl_count; /* number of codes at each bit length */ 2337{ 2338 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 2339 ush code = 0; /* running code value */ 2340 int bits; /* bit index */ 2341 int n; /* code index */ 2342 2343 /* The distribution counts are first used to generate the code values 2344 * without bit reversal. 2345 */ 2346 for (bits = 1; bits <= MAX_BITS; bits++) { 2347 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 2348 } 2349 /* Check that the bit counts in bl_count are consistent. The last code 2350 * must be all ones. 2351 */ 2352 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 2353 "inconsistent bit counts"); 2354 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 2355 2356 for (n = 0; n <= max_code; n++) { 2357 int len = tree[n].Len; 2358 if (len == 0) continue; 2359 /* Now reverse the bits */ 2360 tree[n].Code = bi_reverse(next_code[len]++, len); 2361 2362 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 2363 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 2364 } 2365} 2366 2367/* =========================================================================== 2368 * Construct one Huffman tree and assigns the code bit strings and lengths. 2369 * Update the total bit length for the current block. 2370 * IN assertion: the field freq is set for all tree elements. 2371 * OUT assertions: the fields len and code are set to the optimal bit length 2372 * and corresponding code. The length opt_len is updated; static_len is 2373 * also updated if stree is not null. The field max_code is set. 2374 */ 2375local void build_tree(s, desc) 2376 deflate_state *s; 2377 tree_desc *desc; /* the tree descriptor */ 2378{ 2379 ct_data *tree = desc->dyn_tree; 2380 ct_data *stree = desc->stat_desc->static_tree; 2381 int elems = desc->stat_desc->elems; 2382 int n, m; /* iterate over heap elements */ 2383 int max_code = -1; /* largest code with non zero frequency */ 2384 int node; /* new node being created */ 2385 2386 /* Construct the initial heap, with least frequent element in 2387 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2388 * heap[0] is not used. 2389 */ 2390 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2391 2392 for (n = 0; n < elems; n++) { 2393 if (tree[n].Freq != 0) { 2394 s->heap[++(s->heap_len)] = max_code = n; 2395 s->depth[n] = 0; 2396 } else { 2397 tree[n].Len = 0; 2398 } 2399 } 2400 2401 /* The pkzip format requires that at least one distance code exists, 2402 * and that at least one bit should be sent even if there is only one 2403 * possible code. So to avoid special checks later on we force at least 2404 * two codes of non zero frequency. 2405 */ 2406 while (s->heap_len < 2) { 2407 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2408 tree[node].Freq = 1; 2409 s->depth[node] = 0; 2410 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2411 /* node is 0 or 1 so it does not have extra bits */ 2412 } 2413 desc->max_code = max_code; 2414 2415 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2416 * establish sub-heaps of increasing lengths: 2417 */ 2418 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2419 2420 /* Construct the Huffman tree by repeatedly combining the least two 2421 * frequent nodes. 2422 */ 2423 node = elems; /* next internal node of the tree */ 2424 do { 2425 pqremove(s, tree, n); /* n = node of least frequency */ 2426 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2427 2428 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2429 s->heap[--(s->heap_max)] = m; 2430 2431 /* Create a new node father of n and m */ 2432 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2433 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2434 tree[n].Dad = tree[m].Dad = (ush)node; 2435#ifdef DUMP_BL_TREE 2436 if (tree == s->bl_tree) { 2437 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2438 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2439 } 2440#endif 2441 /* and insert the new node in the heap */ 2442 s->heap[SMALLEST] = node++; 2443 pqdownheap(s, tree, SMALLEST); 2444 2445 } while (s->heap_len >= 2); 2446 2447 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2448 2449 /* At this point, the fields freq and dad are set. We can now 2450 * generate the bit lengths. 2451 */ 2452 gen_bitlen(s, (tree_desc *)desc); 2453 2454 /* The field len is now set, we can generate the bit codes */ 2455 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2456} 2457 2458/* =========================================================================== 2459 * Scan a literal or distance tree to determine the frequencies of the codes 2460 * in the bit length tree. 2461 */ 2462local void scan_tree (s, tree, max_code) 2463 deflate_state *s; 2464 ct_data *tree; /* the tree to be scanned */ 2465 int max_code; /* and its largest code of non zero frequency */ 2466{ 2467 int n; /* iterates over all tree elements */ 2468 int prevlen = -1; /* last emitted length */ 2469 int curlen; /* length of current code */ 2470 int nextlen = tree[0].Len; /* length of next code */ 2471 int count = 0; /* repeat count of the current code */ 2472 int max_count = 7; /* max repeat count */ 2473 int min_count = 4; /* min repeat count */ 2474 2475 if (nextlen == 0) max_count = 138, min_count = 3; 2476 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2477 2478 for (n = 0; n <= max_code; n++) { 2479 curlen = nextlen; nextlen = tree[n+1].Len; 2480 if (++count < max_count && curlen == nextlen) { 2481 continue; 2482 } else if (count < min_count) { 2483 s->bl_tree[curlen].Freq += count; 2484 } else if (curlen != 0) { 2485 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2486 s->bl_tree[REP_3_6].Freq++; 2487 } else if (count <= 10) { 2488 s->bl_tree[REPZ_3_10].Freq++; 2489 } else { 2490 s->bl_tree[REPZ_11_138].Freq++; 2491 } 2492 count = 0; prevlen = curlen; 2493 if (nextlen == 0) { 2494 max_count = 138, min_count = 3; 2495 } else if (curlen == nextlen) { 2496 max_count = 6, min_count = 3; 2497 } else { 2498 max_count = 7, min_count = 4; 2499 } 2500 } 2501} 2502 2503/* =========================================================================== 2504 * Send a literal or distance tree in compressed form, using the codes in 2505 * bl_tree. 2506 */ 2507local void send_tree (s, tree, max_code) 2508 deflate_state *s; 2509 ct_data *tree; /* the tree to be scanned */ 2510 int max_code; /* and its largest code of non zero frequency */ 2511{ 2512 int n; /* iterates over all tree elements */ 2513 int prevlen = -1; /* last emitted length */ 2514 int curlen; /* length of current code */ 2515 int nextlen = tree[0].Len; /* length of next code */ 2516 int count = 0; /* repeat count of the current code */ 2517 int max_count = 7; /* max repeat count */ 2518 int min_count = 4; /* min repeat count */ 2519 2520 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2521 if (nextlen == 0) max_count = 138, min_count = 3; 2522 2523 for (n = 0; n <= max_code; n++) { 2524 curlen = nextlen; nextlen = tree[n+1].Len; 2525 if (++count < max_count && curlen == nextlen) { 2526 continue; 2527 } else if (count < min_count) { 2528 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2529 2530 } else if (curlen != 0) { 2531 if (curlen != prevlen) { 2532 send_code(s, curlen, s->bl_tree); count--; 2533 } 2534 Assert(count >= 3 && count <= 6, " 3_6?"); 2535 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2536 2537 } else if (count <= 10) { 2538 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2539 2540 } else { 2541 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2542 } 2543 count = 0; prevlen = curlen; 2544 if (nextlen == 0) { 2545 max_count = 138, min_count = 3; 2546 } else if (curlen == nextlen) { 2547 max_count = 6, min_count = 3; 2548 } else { 2549 max_count = 7, min_count = 4; 2550 } 2551 } 2552} 2553 2554/* =========================================================================== 2555 * Construct the Huffman tree for the bit lengths and return the index in 2556 * bl_order of the last bit length code to send. 2557 */ 2558local int build_bl_tree(s) 2559 deflate_state *s; 2560{ 2561 int max_blindex; /* index of last bit length code of non zero freq */ 2562 2563 /* Determine the bit length frequencies for literal and distance trees */ 2564 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2565 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2566 2567 /* Build the bit length tree: */ 2568 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2569 /* opt_len now includes the length of the tree representations, except 2570 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2571 */ 2572 2573 /* Determine the number of bit length codes to send. The pkzip format 2574 * requires that at least 4 bit length codes be sent. (appnote.txt says 2575 * 3 but the actual value used is 4.) 2576 */ 2577 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2578 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2579 } 2580 /* Update opt_len to include the bit length tree and counts */ 2581 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2582 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2583 s->opt_len, s->static_len)); 2584 2585 return max_blindex; 2586} 2587 2588/* =========================================================================== 2589 * Send the header for a block using dynamic Huffman trees: the counts, the 2590 * lengths of the bit length codes, the literal tree and the distance tree. 2591 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2592 */ 2593local void send_all_trees(s, lcodes, dcodes, blcodes) 2594 deflate_state *s; 2595 int lcodes, dcodes, blcodes; /* number of codes for each tree */ 2596{ 2597 int rank; /* index in bl_order */ 2598 2599 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2600 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2601 "too many codes"); 2602 Tracev((stderr, "\nbl counts: ")); 2603 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2604 send_bits(s, dcodes-1, 5); 2605 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2606 for (rank = 0; rank < blcodes; rank++) { 2607 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2608 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2609 } 2610 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2611 2612 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2613 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2614 2615 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2616 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2617} 2618 2619/* =========================================================================== 2620 * Send a stored block 2621 */ 2622void _tr_stored_block(s, buf, stored_len, eof) 2623 deflate_state *s; 2624 charf *buf; /* input block */ 2625 ulg stored_len; /* length of input block */ 2626 int eof; /* true if this is the last block for a file */ 2627{ 2628 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2629 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; 2630 s->compressed_len += (stored_len + 4) << 3; 2631 2632 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2633} 2634 2635/* Send just the `stored block' type code without any length bytes or data. 2636 */ 2637void _tr_stored_type_only(s) 2638 deflate_state *s; 2639{ 2640 send_bits(s, (STORED_BLOCK << 1), 3); 2641 bi_windup(s); 2642 s->compressed_len = (s->compressed_len + 3) & ~7L; 2643} 2644 2645 2646/* =========================================================================== 2647 * Send one empty static block to give enough lookahead for inflate. 2648 * This takes 10 bits, of which 7 may remain in the bit buffer. 2649 * The current inflate code requires 9 bits of lookahead. If the 2650 * last two codes for the previous block (real code plus EOB) were coded 2651 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode 2652 * the last real code. In this case we send two empty static blocks instead 2653 * of one. (There are no problems if the previous block is stored or fixed.) 2654 * To simplify the code, we assume the worst case of last real code encoded 2655 * on one bit only. 2656 */ 2657void _tr_align(s) 2658 deflate_state *s; 2659{ 2660 send_bits(s, STATIC_TREES<<1, 3); 2661 send_code(s, END_BLOCK, static_ltree); 2662 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2663 bi_flush(s); 2664 /* Of the 10 bits for the empty block, we have already sent 2665 * (10 - bi_valid) bits. The lookahead for the last real code (before 2666 * the EOB of the previous block) was thus at least one plus the length 2667 * of the EOB plus what we have just sent of the empty static block. 2668 */ 2669 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { 2670 send_bits(s, STATIC_TREES<<1, 3); 2671 send_code(s, END_BLOCK, static_ltree); 2672 s->compressed_len += 10L; 2673 bi_flush(s); 2674 } 2675 s->last_eob_len = 7; 2676} 2677 2678/* =========================================================================== 2679 * Determine the best encoding for the current block: dynamic trees, static 2680 * trees or store, and output the encoded block to the zip file. This function 2681 * returns the total compressed length for the file so far. 2682 */ 2683ulg _tr_flush_block(s, buf, stored_len, eof) 2684 deflate_state *s; 2685 charf *buf; /* input block, or NULL if too old */ 2686 ulg stored_len; /* length of input block */ 2687 int eof; /* true if this is the last block for a file */ 2688{ 2689 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2690 int max_blindex = 0; /* index of last bit length code of non zero freq */ 2691 2692 /* Build the Huffman trees unless a stored block is forced */ 2693 if (s->level > 0) { 2694 2695 /* Check if the file is ascii or binary */ 2696 if (s->data_type == Z_UNKNOWN) set_data_type(s); 2697 2698 /* Construct the literal and distance trees */ 2699 build_tree(s, (tree_desc *)(&(s->l_desc))); 2700 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2701 s->static_len)); 2702 2703 build_tree(s, (tree_desc *)(&(s->d_desc))); 2704 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2705 s->static_len)); 2706 /* At this point, opt_len and static_len are the total bit lengths of 2707 * the compressed block data, excluding the tree representations. 2708 */ 2709 2710 /* Build the bit length tree for the above two trees, and get the index 2711 * in bl_order of the last bit length code to send. 2712 */ 2713 max_blindex = build_bl_tree(s); 2714 2715 /* Determine the best encoding. Compute first the block length in bytes*/ 2716 opt_lenb = (s->opt_len+3+7)>>3; 2717 static_lenb = (s->static_len+3+7)>>3; 2718 2719 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2720 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2721 s->last_lit)); 2722 2723 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2724 2725 } else { 2726 Assert(buf != (char*)0, "lost buf"); 2727 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 2728 } 2729 2730 /* If compression failed and this is the first and last block, 2731 * and if the .zip file can be seeked (to rewrite the local header), 2732 * the whole file is transformed into a stored file: 2733 */ 2734#ifdef STORED_FILE_OK 2735# ifdef FORCE_STORED_FILE 2736 if (eof && s->compressed_len == 0L) { /* force stored file */ 2737# else 2738 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { 2739# endif 2740 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2741 if (buf == (charf*)0) error ("block vanished"); 2742 2743 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ 2744 s->compressed_len = stored_len << 3; 2745 s->method = STORED; 2746 } else 2747#endif /* STORED_FILE_OK */ 2748 2749#ifdef FORCE_STORED 2750 if (buf != (char*)0) { /* force stored block */ 2751#else 2752 if (stored_len+4 <= opt_lenb && buf != (char*)0) { 2753 /* 4: two words for the lengths */ 2754#endif 2755 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2756 * Otherwise we can't have processed more than WSIZE input bytes since 2757 * the last block flush, because compression would have been 2758 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2759 * transform a block into a stored block. 2760 */ 2761 _tr_stored_block(s, buf, stored_len, eof); 2762 2763#ifdef FORCE_STATIC 2764 } else if (static_lenb >= 0) { /* force static trees */ 2765#else 2766 } else if (static_lenb == opt_lenb) { 2767#endif 2768 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2769 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2770 s->compressed_len += 3 + s->static_len; 2771 } else { 2772 send_bits(s, (DYN_TREES<<1)+eof, 3); 2773 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2774 max_blindex+1); 2775 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2776 s->compressed_len += 3 + s->opt_len; 2777 } 2778 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2779 init_block(s); 2780 2781 if (eof) { 2782 bi_windup(s); 2783 s->compressed_len += 7; /* align on byte boundary */ 2784 } 2785 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2786 s->compressed_len-7*eof)); 2787 2788 return s->compressed_len >> 3; 2789} 2790 2791/* =========================================================================== 2792 * Save the match info and tally the frequency counts. Return true if 2793 * the current block must be flushed. 2794 */ 2795int _tr_tally (s, dist, lc) 2796 deflate_state *s; 2797 unsigned dist; /* distance of matched string */ 2798 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 2799{ 2800 s->d_buf[s->last_lit] = (ush)dist; 2801 s->l_buf[s->last_lit++] = (uch)lc; 2802 if (dist == 0) { 2803 /* lc is the unmatched char */ 2804 s->dyn_ltree[lc].Freq++; 2805 } else { 2806 s->matches++; 2807 /* Here, lc is the match length - MIN_MATCH */ 2808 dist--; /* dist = match distance - 1 */ 2809 Assert((ush)dist < (ush)MAX_DIST(s) && 2810 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2811 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 2812 2813 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2814 s->dyn_dtree[d_code(dist)].Freq++; 2815 } 2816 2817 /* Try to guess if it is profitable to stop the current block here */ 2818 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2819 /* Compute an upper bound for the compressed length */ 2820 ulg out_length = (ulg)s->last_lit*8L; 2821 ulg in_length = (ulg)((long)s->strstart - s->block_start); 2822 int dcode; 2823 for (dcode = 0; dcode < D_CODES; dcode++) { 2824 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2825 (5L+extra_dbits[dcode]); 2826 } 2827 out_length >>= 3; 2828 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2829 s->last_lit, in_length, out_length, 2830 100L - out_length*100L/in_length)); 2831 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2832 } 2833 return (s->last_lit == s->lit_bufsize-1); 2834 /* We avoid equality with lit_bufsize because of wraparound at 64K 2835 * on 16 bit machines and because stored blocks are restricted to 2836 * 64K-1 bytes. 2837 */ 2838} 2839 2840/* =========================================================================== 2841 * Send the block data compressed using the given Huffman trees 2842 */ 2843local void compress_block(s, ltree, dtree) 2844 deflate_state *s; 2845 ct_data *ltree; /* literal tree */ 2846 ct_data *dtree; /* distance tree */ 2847{ 2848 unsigned dist; /* distance of matched string */ 2849 int lc; /* match length or unmatched char (if dist == 0) */ 2850 unsigned lx = 0; /* running index in l_buf */ 2851 unsigned code; /* the code to send */ 2852 int extra; /* number of extra bits to send */ 2853 2854 if (s->last_lit != 0) do { 2855 dist = s->d_buf[lx]; 2856 lc = s->l_buf[lx++]; 2857 if (dist == 0) { 2858 send_code(s, lc, ltree); /* send a literal byte */ 2859 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2860 } else { 2861 /* Here, lc is the match length - MIN_MATCH */ 2862 code = length_code[lc]; 2863 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2864 extra = extra_lbits[code]; 2865 if (extra != 0) { 2866 lc -= base_length[code]; 2867 send_bits(s, lc, extra); /* send the extra length bits */ 2868 } 2869 dist--; /* dist is now the match distance - 1 */ 2870 code = d_code(dist); 2871 Assert (code < D_CODES, "bad d_code"); 2872 2873 send_code(s, code, dtree); /* send the distance code */ 2874 extra = extra_dbits[code]; 2875 if (extra != 0) { 2876 dist -= base_dist[code]; 2877 send_bits(s, dist, extra); /* send the extra distance bits */ 2878 } 2879 } /* literal or match pair ? */ 2880 2881 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2882 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2883 2884 } while (lx < s->last_lit); 2885 2886 send_code(s, END_BLOCK, ltree); 2887 s->last_eob_len = ltree[END_BLOCK].Len; 2888} 2889 2890/* =========================================================================== 2891 * Set the data type to ASCII or BINARY, using a crude approximation: 2892 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2893 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2894 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2895 */ 2896local void set_data_type(s) 2897 deflate_state *s; 2898{ 2899 int n = 0; 2900 unsigned ascii_freq = 0; 2901 unsigned bin_freq = 0; 2902 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2903 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2904 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2905 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 2906} 2907 2908/* =========================================================================== 2909 * Reverse the first len bits of a code, using straightforward code (a faster 2910 * method would use a table) 2911 * IN assertion: 1 <= len <= 15 2912 */ 2913local unsigned bi_reverse(code, len) 2914 unsigned code; /* the value to invert */ 2915 int len; /* its bit length */ 2916{ 2917 register unsigned res = 0; 2918 do { 2919 res |= code & 1; 2920 code >>= 1, res <<= 1; 2921 } while (--len > 0); 2922 return res >> 1; 2923} 2924 2925/* =========================================================================== 2926 * Flush the bit buffer, keeping at most 7 bits in it. 2927 */ 2928local void bi_flush(s) 2929 deflate_state *s; 2930{ 2931 if (s->bi_valid == 16) { 2932 put_short(s, s->bi_buf); 2933 s->bi_buf = 0; 2934 s->bi_valid = 0; 2935 } else if (s->bi_valid >= 8) { 2936 put_byte(s, (Byte)s->bi_buf); 2937 s->bi_buf >>= 8; 2938 s->bi_valid -= 8; 2939 } 2940} 2941 2942/* =========================================================================== 2943 * Flush the bit buffer and align the output on a byte boundary 2944 */ 2945local void bi_windup(s) 2946 deflate_state *s; 2947{ 2948 if (s->bi_valid > 8) { 2949 put_short(s, s->bi_buf); 2950 } else if (s->bi_valid > 0) { 2951 put_byte(s, (Byte)s->bi_buf); 2952 } 2953 s->bi_buf = 0; 2954 s->bi_valid = 0; 2955#ifdef DEBUG_ZLIB 2956 s->bits_sent = (s->bits_sent+7) & ~7; 2957#endif 2958} 2959 2960/* =========================================================================== 2961 * Copy a stored block, storing first the length and its 2962 * one's complement if requested. 2963 */ 2964local void copy_block(s, buf, len, header) 2965 deflate_state *s; 2966 charf *buf; /* the input data */ 2967 unsigned len; /* its length */ 2968 int header; /* true if block header must be written */ 2969{ 2970 bi_windup(s); /* align on byte boundary */ 2971 s->last_eob_len = 8; /* enough lookahead for inflate */ 2972 2973 if (header) { 2974 put_short(s, (ush)len); 2975 put_short(s, (ush)~len); 2976#ifdef DEBUG_ZLIB 2977 s->bits_sent += 2*16; 2978#endif 2979 } 2980#ifdef DEBUG_ZLIB 2981 s->bits_sent += (ulg)len<<3; 2982#endif 2983 /* bundle up the put_byte(s, *buf++) calls */ 2984 zmemcpy(&s->pending_buf[s->pending], buf, len); 2985 s->pending += len; 2986} 2987/* --- trees.c */ 2988 2989/* +++ inflate.c */ 2990/* inflate.c -- zlib interface to inflate modules 2991 * Copyright (C) 1995-1996 Mark Adler 2992 * For conditions of distribution and use, see copyright notice in zlib.h 2993 */ 2994 2995/* #include "zutil.h" */ 2996 2997/* +++ infblock.h */ 2998/* infblock.h -- header to use infblock.c 2999 * Copyright (C) 1995-1996 Mark Adler 3000 * For conditions of distribution and use, see copyright notice in zlib.h 3001 */ 3002 3003/* WARNING: this file should *not* be used by applications. It is 3004 part of the implementation of the compression library and is 3005 subject to change. Applications should only use zlib.h. 3006 */ 3007 3008struct inflate_blocks_state; 3009typedef struct inflate_blocks_state FAR inflate_blocks_statef; 3010 3011extern inflate_blocks_statef * inflate_blocks_new OF(( 3012 z_streamp z, 3013 check_func c, /* check function */ 3014 uInt w)); /* window size */ 3015 3016extern int inflate_blocks OF(( 3017 inflate_blocks_statef *, 3018 z_streamp , 3019 int)); /* initial return code */ 3020 3021extern void inflate_blocks_reset OF(( 3022 inflate_blocks_statef *, 3023 z_streamp , 3024 uLongf *)); /* check value on output */ 3025 3026extern int inflate_blocks_free OF(( 3027 inflate_blocks_statef *, 3028 z_streamp , 3029 uLongf *)); /* check value on output */ 3030 3031extern void inflate_set_dictionary OF(( 3032 inflate_blocks_statef *s, 3033 const Bytef *d, /* dictionary */ 3034 uInt n)); /* dictionary length */ 3035 3036extern int inflate_addhistory OF(( 3037 inflate_blocks_statef *, 3038 z_streamp)); 3039 3040extern int inflate_packet_flush OF(( 3041 inflate_blocks_statef *)); 3042/* --- infblock.h */ 3043 3044#ifndef NO_DUMMY_DECL 3045struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ 3046#endif 3047 3048/* inflate private state */ 3049struct internal_state { 3050 3051 /* mode */ 3052 enum { 3053 METHOD, /* waiting for method byte */ 3054 FLAG, /* waiting for flag byte */ 3055 DICT4, /* four dictionary check bytes to go */ 3056 DICT3, /* three dictionary check bytes to go */ 3057 DICT2, /* two dictionary check bytes to go */ 3058 DICT1, /* one dictionary check byte to go */ 3059 DICT0, /* waiting for inflateSetDictionary */ 3060 BLOCKS, /* decompressing blocks */ 3061 CHECK4, /* four check bytes to go */ 3062 CHECK3, /* three check bytes to go */ 3063 CHECK2, /* two check bytes to go */ 3064 CHECK1, /* one check byte to go */ 3065 DONE, /* finished check, done */ 3066 BAD} /* got an error--stay here */ 3067 mode; /* current inflate mode */ 3068 3069 /* mode dependent information */ 3070 union { 3071 uInt method; /* if FLAGS, method byte */ 3072 struct { 3073 uLong was; /* computed check value */ 3074 uLong need; /* stream check value */ 3075 } check; /* if CHECK, check values to compare */ 3076 uInt marker; /* if BAD, inflateSync's marker bytes count */ 3077 } sub; /* submode */ 3078 3079 /* mode independent information */ 3080 int nowrap; /* flag for no wrapper */ 3081 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 3082 inflate_blocks_statef 3083 *blocks; /* current inflate_blocks state */ 3084 3085}; 3086 3087 3088int inflateReset(z) 3089z_streamp z; 3090{ 3091 uLong c; 3092 3093 if (z == Z_NULL || z->state == Z_NULL) 3094 return Z_STREAM_ERROR; 3095 z->total_in = z->total_out = 0; 3096 z->msg = Z_NULL; 3097 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 3098 inflate_blocks_reset(z->state->blocks, z, &c); 3099 Trace((stderr, "inflate: reset\n")); 3100 return Z_OK; 3101} 3102 3103 3104int inflateEnd(z) 3105z_streamp z; 3106{ 3107 uLong c; 3108 3109 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 3110 return Z_STREAM_ERROR; 3111 if (z->state->blocks != Z_NULL) 3112 inflate_blocks_free(z->state->blocks, z, &c); 3113 ZFREE(z, z->state); 3114 z->state = Z_NULL; 3115 Trace((stderr, "inflate: end\n")); 3116 return Z_OK; 3117} 3118 3119 3120int inflateInit2_(z, w, version, stream_size) 3121z_streamp z; 3122int w; 3123const char *version; 3124int stream_size; 3125{ 3126 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || 3127 stream_size != sizeof(z_stream)) 3128 return Z_VERSION_ERROR; 3129 3130 /* initialize state */ 3131 if (z == Z_NULL) 3132 return Z_STREAM_ERROR; 3133 z->msg = Z_NULL; 3134#ifndef NO_ZCFUNCS 3135 if (z->zalloc == Z_NULL) 3136 { 3137 z->zalloc = zcalloc; 3138 z->opaque = (voidpf)0; 3139 } 3140 if (z->zfree == Z_NULL) z->zfree = zcfree; 3141#endif 3142 if ((z->state = (struct internal_state FAR *) 3143 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 3144 return Z_MEM_ERROR; 3145 z->state->blocks = Z_NULL; 3146 3147 /* handle undocumented nowrap option (no zlib header or check) */ 3148 z->state->nowrap = 0; 3149 if (w < 0) 3150 { 3151 w = - w; 3152 z->state->nowrap = 1; 3153 } 3154 3155 /* set window size */ 3156 if (w < 8 || w > 15) 3157 { 3158 inflateEnd(z); 3159 return Z_STREAM_ERROR; 3160 } 3161 z->state->wbits = (uInt)w; 3162 3163 /* create inflate_blocks state */ 3164 if ((z->state->blocks = 3165 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) 3166 == Z_NULL) 3167 { 3168 inflateEnd(z); 3169 return Z_MEM_ERROR; 3170 } 3171 Trace((stderr, "inflate: allocated\n")); 3172 3173 /* reset state */ 3174 inflateReset(z); 3175 return Z_OK; 3176} 3177 3178 3179int inflateInit_(z, version, stream_size) 3180z_streamp z; 3181const char *version; 3182int stream_size; 3183{ 3184 return inflateInit2_(z, DEF_WBITS, version, stream_size); 3185} 3186 3187 3188#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 3189#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 3190 3191int inflate(z, f) 3192z_streamp z; 3193int f; 3194{ 3195 int r; 3196 uInt b; 3197 3198 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) 3199 return Z_STREAM_ERROR; 3200 r = Z_BUF_ERROR; 3201 while (1) switch (z->state->mode) 3202 { 3203 case METHOD: 3204 NEEDBYTE 3205 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) 3206 { 3207 z->state->mode = BAD; 3208 z->msg = (char*)"unknown compression method"; 3209 z->state->sub.marker = 5; /* can't try inflateSync */ 3210 break; 3211 } 3212 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 3213 { 3214 z->state->mode = BAD; 3215 z->msg = (char*)"invalid window size"; 3216 z->state->sub.marker = 5; /* can't try inflateSync */ 3217 break; 3218 } 3219 z->state->mode = FLAG; 3220 case FLAG: 3221 NEEDBYTE 3222 b = NEXTBYTE; 3223 if (((z->state->sub.method << 8) + b) % 31) 3224 { 3225 z->state->mode = BAD; 3226 z->msg = (char*)"incorrect header check"; 3227 z->state->sub.marker = 5; /* can't try inflateSync */ 3228 break; 3229 } 3230 Trace((stderr, "inflate: zlib header ok\n")); 3231 if (!(b & PRESET_DICT)) 3232 { 3233 z->state->mode = BLOCKS; 3234 break; 3235 } 3236 z->state->mode = DICT4; 3237 case DICT4: 3238 NEEDBYTE 3239 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3240 z->state->mode = DICT3; 3241 case DICT3: 3242 NEEDBYTE 3243 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3244 z->state->mode = DICT2; 3245 case DICT2: 3246 NEEDBYTE 3247 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3248 z->state->mode = DICT1; 3249 case DICT1: 3250 NEEDBYTE 3251 z->state->sub.check.need += (uLong)NEXTBYTE; 3252 z->adler = z->state->sub.check.need; 3253 z->state->mode = DICT0; 3254 return Z_NEED_DICT; 3255 case DICT0: 3256 z->state->mode = BAD; 3257 z->msg = (char*)"need dictionary"; 3258 z->state->sub.marker = 0; /* can try inflateSync */ 3259 return Z_STREAM_ERROR; 3260 case BLOCKS: 3261 r = inflate_blocks(z->state->blocks, z, r); 3262 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 3263 r = inflate_packet_flush(z->state->blocks); 3264 if (r == Z_DATA_ERROR) 3265 { 3266 z->state->mode = BAD; 3267 z->state->sub.marker = 0; /* can try inflateSync */ 3268 break; 3269 } 3270 if (r != Z_STREAM_END) 3271 return r; 3272 r = Z_OK; 3273 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 3274 if (z->state->nowrap) 3275 { 3276 z->state->mode = DONE; 3277 break; 3278 } 3279 z->state->mode = CHECK4; 3280 case CHECK4: 3281 NEEDBYTE 3282 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3283 z->state->mode = CHECK3; 3284 case CHECK3: 3285 NEEDBYTE 3286 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3287 z->state->mode = CHECK2; 3288 case CHECK2: 3289 NEEDBYTE 3290 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3291 z->state->mode = CHECK1; 3292 case CHECK1: 3293 NEEDBYTE 3294 z->state->sub.check.need += (uLong)NEXTBYTE; 3295 3296 if (z->state->sub.check.was != z->state->sub.check.need) 3297 { 3298 z->state->mode = BAD; 3299 z->msg = (char*)"incorrect data check"; 3300 z->state->sub.marker = 5; /* can't try inflateSync */ 3301 break; 3302 } 3303 Trace((stderr, "inflate: zlib check ok\n")); 3304 z->state->mode = DONE; 3305 case DONE: 3306 return Z_STREAM_END; 3307 case BAD: 3308 return Z_DATA_ERROR; 3309 default: 3310 return Z_STREAM_ERROR; 3311 } 3312 3313 empty: 3314 if (f != Z_PACKET_FLUSH) 3315 return r; 3316 z->state->mode = BAD; 3317 z->msg = (char *)"need more for packet flush"; 3318 z->state->sub.marker = 0; /* can try inflateSync */ 3319 return Z_DATA_ERROR; 3320} 3321 3322 3323int inflateSetDictionary(z, dictionary, dictLength) 3324z_streamp z; 3325const Bytef *dictionary; 3326uInt dictLength; 3327{ 3328 uInt length = dictLength; 3329 3330 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) 3331 return Z_STREAM_ERROR; 3332 3333 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; 3334 z->adler = 1L; 3335 3336 if (length >= ((uInt)1<<z->state->wbits)) 3337 { 3338 length = (1<<z->state->wbits)-1; 3339 dictionary += dictLength - length; 3340 } 3341 inflate_set_dictionary(z->state->blocks, dictionary, length); 3342 z->state->mode = BLOCKS; 3343 return Z_OK; 3344} 3345 3346/* 3347 * This subroutine adds the data at next_in/avail_in to the output history 3348 * without performing any output. The output buffer must be "caught up"; 3349 * i.e. no pending output (hence s->read equals s->write), and the state must 3350 * be BLOCKS (i.e. we should be willing to see the start of a series of 3351 * BLOCKS). On exit, the output will also be caught up, and the checksum 3352 * will have been updated if need be. 3353 */ 3354 3355int inflateIncomp(z) 3356z_stream *z; 3357{ 3358 if (z->state->mode != BLOCKS) 3359 return Z_DATA_ERROR; 3360 return inflate_addhistory(z->state->blocks, z); 3361} 3362 3363 3364int inflateSync(z) 3365z_streamp z; 3366{ 3367 uInt n; /* number of bytes to look at */ 3368 Bytef *p; /* pointer to bytes */ 3369 uInt m; /* number of marker bytes found in a row */ 3370 uLong r, w; /* temporaries to save total_in and total_out */ 3371 3372 /* set up */ 3373 if (z == Z_NULL || z->state == Z_NULL) 3374 return Z_STREAM_ERROR; 3375 if (z->state->mode != BAD) 3376 { 3377 z->state->mode = BAD; 3378 z->state->sub.marker = 0; 3379 } 3380 if ((n = z->avail_in) == 0) 3381 return Z_BUF_ERROR; 3382 p = z->next_in; 3383 m = z->state->sub.marker; 3384 3385 /* search */ 3386 while (n && m < 4) 3387 { 3388 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3389 m++; 3390 else if (*p) 3391 m = 0; 3392 else 3393 m = 4 - m; 3394 p++, n--; 3395 } 3396 3397 /* restore */ 3398 z->total_in += p - z->next_in; 3399 z->next_in = p; 3400 z->avail_in = n; 3401 z->state->sub.marker = m; 3402 3403 /* return no joy or set up to restart on a new block */ 3404 if (m != 4) 3405 return Z_DATA_ERROR; 3406 r = z->total_in; w = z->total_out; 3407 inflateReset(z); 3408 z->total_in = r; z->total_out = w; 3409 z->state->mode = BLOCKS; 3410 return Z_OK; 3411} 3412 3413#undef NEEDBYTE 3414#undef NEXTBYTE 3415/* --- inflate.c */ 3416 3417/* +++ infblock.c */ 3418/* infblock.c -- interpret and process block types to last block 3419 * Copyright (C) 1995-1996 Mark Adler 3420 * For conditions of distribution and use, see copyright notice in zlib.h 3421 */ 3422 3423/* #include "zutil.h" */ 3424/* #include "infblock.h" */ 3425 3426/* +++ inftrees.h */ 3427/* inftrees.h -- header to use inftrees.c 3428 * Copyright (C) 1995-1996 Mark Adler 3429 * For conditions of distribution and use, see copyright notice in zlib.h 3430 */ 3431 3432/* WARNING: this file should *not* be used by applications. It is 3433 part of the implementation of the compression library and is 3434 subject to change. Applications should only use zlib.h. 3435 */ 3436 3437/* Huffman code lookup table entry--this entry is four bytes for machines 3438 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 3439 3440typedef struct inflate_huft_s FAR inflate_huft; 3441 3442struct inflate_huft_s { 3443 union { 3444 struct { 3445 Byte Exop; /* number of extra bits or operation */ 3446 Byte Bits; /* number of bits in this code or subcode */ 3447 } what; 3448 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 3449 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 3450 union { 3451 uInt Base; /* literal, length base, or distance base */ 3452 inflate_huft *Next; /* pointer to next level of table */ 3453 } more; 3454}; 3455 3456#ifdef DEBUG_ZLIB 3457 extern uInt inflate_hufts; 3458#endif 3459 3460extern int inflate_trees_bits OF(( 3461 uIntf *, /* 19 code lengths */ 3462 uIntf *, /* bits tree desired/actual depth */ 3463 inflate_huft * FAR *, /* bits tree result */ 3464 z_streamp )); /* for zalloc, zfree functions */ 3465 3466extern int inflate_trees_dynamic OF(( 3467 uInt, /* number of literal/length codes */ 3468 uInt, /* number of distance codes */ 3469 uIntf *, /* that many (total) code lengths */ 3470 uIntf *, /* literal desired/actual bit depth */ 3471 uIntf *, /* distance desired/actual bit depth */ 3472 inflate_huft * FAR *, /* literal/length tree result */ 3473 inflate_huft * FAR *, /* distance tree result */ 3474 z_streamp )); /* for zalloc, zfree functions */ 3475 3476extern int inflate_trees_fixed OF(( 3477 uIntf *, /* literal desired/actual bit depth */ 3478 uIntf *, /* distance desired/actual bit depth */ 3479 inflate_huft * FAR *, /* literal/length tree result */ 3480 inflate_huft * FAR *)); /* distance tree result */ 3481 3482extern int inflate_trees_free OF(( 3483 inflate_huft *, /* tables to free */ 3484 z_streamp )); /* for zfree function */ 3485 3486/* --- inftrees.h */ 3487 3488/* +++ infcodes.h */ 3489/* infcodes.h -- header to use infcodes.c 3490 * Copyright (C) 1995-1996 Mark Adler 3491 * For conditions of distribution and use, see copyright notice in zlib.h 3492 */ 3493 3494/* WARNING: this file should *not* be used by applications. It is 3495 part of the implementation of the compression library and is 3496 subject to change. Applications should only use zlib.h. 3497 */ 3498 3499struct inflate_codes_state; 3500typedef struct inflate_codes_state FAR inflate_codes_statef; 3501 3502extern inflate_codes_statef *inflate_codes_new OF(( 3503 uInt, uInt, 3504 inflate_huft *, inflate_huft *, 3505 z_streamp )); 3506 3507extern int inflate_codes OF(( 3508 inflate_blocks_statef *, 3509 z_streamp , 3510 int)); 3511 3512extern void inflate_codes_free OF(( 3513 inflate_codes_statef *, 3514 z_streamp )); 3515 3516/* --- infcodes.h */ 3517 3518/* +++ infutil.h */ 3519/* infutil.h -- types and macros common to blocks and codes 3520 * Copyright (C) 1995-1996 Mark Adler 3521 * For conditions of distribution and use, see copyright notice in zlib.h 3522 */ 3523 3524/* WARNING: this file should *not* be used by applications. It is 3525 part of the implementation of the compression library and is 3526 subject to change. Applications should only use zlib.h. 3527 */ 3528 3529#ifndef _INFUTIL_H 3530#define _INFUTIL_H 3531 3532typedef enum { 3533 TYPE, /* get type bits (3, including end bit) */ 3534 LENS, /* get lengths for stored */ 3535 STORED, /* processing stored block */ 3536 TABLE, /* get table lengths */ 3537 BTREE, /* get bit lengths tree for a dynamic block */ 3538 DTREE, /* get length, distance trees for a dynamic block */ 3539 CODES, /* processing fixed or dynamic block */ 3540 DRY, /* output remaining window bytes */ 3541 DONEB, /* finished last block, done */ 3542 BADB} /* got a data error--stuck here */ 3543inflate_block_mode; 3544 3545/* inflate blocks semi-private state */ 3546struct inflate_blocks_state { 3547 3548 /* mode */ 3549 inflate_block_mode mode; /* current inflate_block mode */ 3550 3551 /* mode dependent information */ 3552 union { 3553 uInt left; /* if STORED, bytes left to copy */ 3554 struct { 3555 uInt table; /* table lengths (14 bits) */ 3556 uInt index; /* index into blens (or border) */ 3557 uIntf *blens; /* bit lengths of codes */ 3558 uInt bb; /* bit length tree depth */ 3559 inflate_huft *tb; /* bit length decoding tree */ 3560 } trees; /* if DTREE, decoding info for trees */ 3561 struct { 3562 inflate_huft *tl; 3563 inflate_huft *td; /* trees to free */ 3564 inflate_codes_statef 3565 *codes; 3566 } decode; /* if CODES, current state */ 3567 } sub; /* submode */ 3568 uInt last; /* true if this block is the last block */ 3569 3570 /* mode independent information */ 3571 uInt bitk; /* bits in bit buffer */ 3572 uLong bitb; /* bit buffer */ 3573 Bytef *window; /* sliding window */ 3574 Bytef *end; /* one byte after sliding window */ 3575 Bytef *read; /* window read pointer */ 3576 Bytef *write; /* window write pointer */ 3577 check_func checkfn; /* check function */ 3578 uLong check; /* check on output */ 3579 3580}; 3581 3582 3583/* defines for inflate input/output */ 3584/* update pointers and return */ 3585#define UPDBITS {s->bitb=b;s->bitk=k;} 3586#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3587#define UPDOUT {s->write=q;} 3588#define UPDATE {UPDBITS UPDIN UPDOUT} 3589#define LEAVE {UPDATE return inflate_flush(s,z,r);} 3590/* get bytes and bits */ 3591#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3592#define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3593#define NEXTBYTE (n--,*p++) 3594#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3595#define DUMPBITS(j) {b>>=(j);k-=(j);} 3596/* output bytes */ 3597#define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) 3598#define LOADOUT {q=s->write;m=(uInt)WAVAIL;} 3599#define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} 3600#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3601#define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} 3602#define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3603/* load local pointers */ 3604#define LOAD {LOADIN LOADOUT} 3605 3606/* masks for lower bits (size given to avoid silly warnings with Visual C++) */ 3607extern uInt inflate_mask[17]; 3608 3609/* copy as much as possible from the sliding window to the output area */ 3610extern int inflate_flush OF(( 3611 inflate_blocks_statef *, 3612 z_streamp , 3613 int)); 3614 3615#ifndef NO_DUMMY_DECL 3616struct internal_state {int dummy;}; /* for buggy compilers */ 3617#endif 3618 3619#endif 3620/* --- infutil.h */ 3621 3622#ifndef NO_DUMMY_DECL 3623struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 3624#endif 3625 3626/* Table for deflate from PKZIP's appnote.txt. */ 3627local const uInt border[] = { /* Order of the bit length code lengths */ 3628 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3629 3630/* 3631 Notes beyond the 1.93a appnote.txt: 3632 3633 1. Distance pointers never point before the beginning of the output 3634 stream. 3635 2. Distance pointers can point back across blocks, up to 32k away. 3636 3. There is an implied maximum of 7 bits for the bit length table and 3637 15 bits for the actual data. 3638 4. If only one code exists, then it is encoded using one bit. (Zero 3639 would be more efficient, but perhaps a little confusing.) If two 3640 codes exist, they are coded using one bit each (0 and 1). 3641 5. There is no way of sending zero distance codes--a dummy must be 3642 sent if there are none. (History: a pre 2.0 version of PKZIP would 3643 store blocks with no distance codes, but this was discovered to be 3644 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3645 zero distance codes, which is sent as one code of zero bits in 3646 length. 3647 6. There are up to 286 literal/length codes. Code 256 represents the 3648 end-of-block. Note however that the static length tree defines 3649 288 codes just to fill out the Huffman codes. Codes 286 and 287 3650 cannot be used though, since there is no length base or extra bits 3651 defined for them. Similarily, there are up to 30 distance codes. 3652 However, static trees define 32 codes (all 5 bits) to fill out the 3653 Huffman codes, but the last two had better not show up in the data. 3654 7. Unzip can check dynamic Huffman blocks for complete code sets. 3655 The exception is that a single code would not be complete (see #4). 3656 8. The five bits following the block type is really the number of 3657 literal codes sent minus 257. 3658 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3659 (1+6+6). Therefore, to output three times the length, you output 3660 three codes (1+1+1), whereas to output four times the same length, 3661 you only need two codes (1+3). Hmm. 3662 10. In the tree reconstruction algorithm, Code = Code + Increment 3663 only if BitLength(i) is not zero. (Pretty obvious.) 3664 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3665 12. Note: length code 284 can represent 227-258, but length code 285 3666 really is 258. The last length deserves its own, short code 3667 since it gets used a lot in very redundant files. The length 3668 258 is special since 258 - 3 (the min match length) is 255. 3669 13. The literal/length and distance code bit lengths are read as a 3670 single stream of lengths. It is possible (and advantageous) for 3671 a repeat code (16, 17, or 18) to go across the boundary between 3672 the two sets of lengths. 3673 */ 3674 3675 3676void inflate_blocks_reset(s, z, c) 3677inflate_blocks_statef *s; 3678z_streamp z; 3679uLongf *c; 3680{ 3681 if (s->checkfn != Z_NULL) 3682 *c = s->check; 3683 if (s->mode == BTREE || s->mode == DTREE) 3684 ZFREE(z, s->sub.trees.blens); 3685 if (s->mode == CODES) 3686 { 3687 inflate_codes_free(s->sub.decode.codes, z); 3688 inflate_trees_free(s->sub.decode.td, z); 3689 inflate_trees_free(s->sub.decode.tl, z); 3690 } 3691 s->mode = TYPE; 3692 s->bitk = 0; 3693 s->bitb = 0; 3694 s->read = s->write = s->window; 3695 if (s->checkfn != Z_NULL) 3696 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); 3697 Trace((stderr, "inflate: blocks reset\n")); 3698} 3699 3700 3701inflate_blocks_statef *inflate_blocks_new(z, c, w) 3702z_streamp z; 3703check_func c; 3704uInt w; 3705{ 3706 inflate_blocks_statef *s; 3707 3708 if ((s = (inflate_blocks_statef *)ZALLOC 3709 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3710 return s; 3711 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3712 { 3713 ZFREE(z, s); 3714 return Z_NULL; 3715 } 3716 s->end = s->window + w; 3717 s->checkfn = c; 3718 s->mode = TYPE; 3719 Trace((stderr, "inflate: blocks allocated\n")); 3720 inflate_blocks_reset(s, z, &s->check); 3721 return s; 3722} 3723 3724 3725#ifdef DEBUG_ZLIB 3726 extern uInt inflate_hufts; 3727#endif 3728int inflate_blocks(s, z, r) 3729inflate_blocks_statef *s; 3730z_streamp z; 3731int r; 3732{ 3733 uInt t; /* temporary storage */ 3734 uLong b; /* bit buffer */ 3735 uInt k; /* bits in bit buffer */ 3736 Bytef *p; /* input data pointer */ 3737 uInt n; /* bytes available there */ 3738 Bytef *q; /* output window write pointer */ 3739 uInt m; /* bytes to end of window or read pointer */ 3740 3741 /* copy input/output information to locals (UPDATE macro restores) */ 3742 LOAD 3743 3744 /* process input based on current state */ 3745 while (1) switch (s->mode) 3746 { 3747 case TYPE: 3748 NEEDBITS(3) 3749 t = (uInt)b & 7; 3750 s->last = t & 1; 3751 switch (t >> 1) 3752 { 3753 case 0: /* stored */ 3754 Trace((stderr, "inflate: stored block%s\n", 3755 s->last ? " (last)" : "")); 3756 DUMPBITS(3) 3757 t = k & 7; /* go to byte boundary */ 3758 DUMPBITS(t) 3759 s->mode = LENS; /* get length of stored block */ 3760 break; 3761 case 1: /* fixed */ 3762 Trace((stderr, "inflate: fixed codes block%s\n", 3763 s->last ? " (last)" : "")); 3764 { 3765 uInt bl, bd; 3766 inflate_huft *tl, *td; 3767 3768 inflate_trees_fixed(&bl, &bd, &tl, &td); 3769 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3770 if (s->sub.decode.codes == Z_NULL) 3771 { 3772 r = Z_MEM_ERROR; 3773 LEAVE 3774 } 3775 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3776 s->sub.decode.td = Z_NULL; 3777 } 3778 DUMPBITS(3) 3779 s->mode = CODES; 3780 break; 3781 case 2: /* dynamic */ 3782 Trace((stderr, "inflate: dynamic codes block%s\n", 3783 s->last ? " (last)" : "")); 3784 DUMPBITS(3) 3785 s->mode = TABLE; 3786 break; 3787 case 3: /* illegal */ 3788 DUMPBITS(3) 3789 s->mode = BADB; 3790 z->msg = (char*)"invalid block type"; 3791 r = Z_DATA_ERROR; 3792 LEAVE 3793 } 3794 break; 3795 case LENS: 3796 NEEDBITS(32) 3797 if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) 3798 { 3799 s->mode = BADB; 3800 z->msg = (char*)"invalid stored block lengths"; 3801 r = Z_DATA_ERROR; 3802 LEAVE 3803 } 3804 s->sub.left = (uInt)b & 0xffff; 3805 b = k = 0; /* dump bits */ 3806 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3807 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); 3808 break; 3809 case STORED: 3810 if (n == 0) 3811 LEAVE 3812 NEEDOUT 3813 t = s->sub.left; 3814 if (t > n) t = n; 3815 if (t > m) t = m; 3816 zmemcpy(q, p, t); 3817 p += t; n -= t; 3818 q += t; m -= t; 3819 if ((s->sub.left -= t) != 0) 3820 break; 3821 Tracev((stderr, "inflate: stored end, %lu total out\n", 3822 z->total_out + (q >= s->read ? q - s->read : 3823 (s->end - s->read) + (q - s->window)))); 3824 s->mode = s->last ? DRY : TYPE; 3825 break; 3826 case TABLE: 3827 NEEDBITS(14) 3828 s->sub.trees.table = t = (uInt)b & 0x3fff; 3829#ifndef PKZIP_BUG_WORKAROUND 3830 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3831 { 3832 s->mode = BADB; 3833 z->msg = (char*)"too many length or distance symbols"; 3834 r = Z_DATA_ERROR; 3835 LEAVE 3836 } 3837#endif 3838 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3839 if (t < 19) 3840 t = 19; 3841 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3842 { 3843 r = Z_MEM_ERROR; 3844 LEAVE 3845 } 3846 DUMPBITS(14) 3847 s->sub.trees.index = 0; 3848 Tracev((stderr, "inflate: table sizes ok\n")); 3849 s->mode = BTREE; 3850 case BTREE: 3851 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3852 { 3853 NEEDBITS(3) 3854 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3855 DUMPBITS(3) 3856 } 3857 while (s->sub.trees.index < 19) 3858 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3859 s->sub.trees.bb = 7; 3860 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3861 &s->sub.trees.tb, z); 3862 if (t != Z_OK) 3863 { 3864 r = t; 3865 if (r == Z_DATA_ERROR) { 3866 ZFREE(z, s->sub.trees.blens); 3867 s->mode = BADB; 3868 } 3869 LEAVE 3870 } 3871 s->sub.trees.index = 0; 3872 Tracev((stderr, "inflate: bits tree ok\n")); 3873 s->mode = DTREE; 3874 case DTREE: 3875 while (t = s->sub.trees.table, 3876 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3877 { 3878 inflate_huft *h; 3879 uInt i, j, c; 3880 3881 t = s->sub.trees.bb; 3882 NEEDBITS(t) 3883 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3884 t = h->word.what.Bits; 3885 c = h->more.Base; 3886 if (c < 16) 3887 { 3888 DUMPBITS(t) 3889 s->sub.trees.blens[s->sub.trees.index++] = c; 3890 } 3891 else /* c == 16..18 */ 3892 { 3893 i = c == 18 ? 7 : c - 14; 3894 j = c == 18 ? 11 : 3; 3895 NEEDBITS(t + i) 3896 DUMPBITS(t) 3897 j += (uInt)b & inflate_mask[i]; 3898 DUMPBITS(i) 3899 i = s->sub.trees.index; 3900 t = s->sub.trees.table; 3901 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3902 (c == 16 && i < 1)) 3903 { 3904 inflate_trees_free(s->sub.trees.tb, z); 3905 ZFREE(z, s->sub.trees.blens); 3906 s->mode = BADB; 3907 z->msg = (char*)"invalid bit length repeat"; 3908 r = Z_DATA_ERROR; 3909 LEAVE 3910 } 3911 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3912 do { 3913 s->sub.trees.blens[i++] = c; 3914 } while (--j); 3915 s->sub.trees.index = i; 3916 } 3917 } 3918 inflate_trees_free(s->sub.trees.tb, z); 3919 s->sub.trees.tb = Z_NULL; 3920 { 3921 uInt bl, bd; 3922 inflate_huft *tl, *td; 3923 inflate_codes_statef *c; 3924 3925 bl = 9; /* must be <= 9 for lookahead assumptions */ 3926 bd = 6; /* must be <= 9 for lookahead assumptions */ 3927 t = s->sub.trees.table; 3928#ifdef DEBUG_ZLIB 3929 inflate_hufts = 0; 3930#endif 3931 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3932 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3933 if (t != Z_OK) 3934 { 3935 if (t == (uInt)Z_DATA_ERROR) { 3936 ZFREE(z, s->sub.trees.blens); 3937 s->mode = BADB; 3938 } 3939 r = t; 3940 LEAVE 3941 } 3942 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", 3943 inflate_hufts, sizeof(inflate_huft))); 3944 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3945 { 3946 inflate_trees_free(td, z); 3947 inflate_trees_free(tl, z); 3948 r = Z_MEM_ERROR; 3949 LEAVE 3950 } 3951 /* 3952 * this ZFREE must occur *BEFORE* we mess with sub.decode, because 3953 * sub.trees is union'd with sub.decode. 3954 */ 3955 ZFREE(z, s->sub.trees.blens); 3956 s->sub.decode.codes = c; 3957 s->sub.decode.tl = tl; 3958 s->sub.decode.td = td; 3959 } 3960 s->mode = CODES; 3961 case CODES: 3962 UPDATE 3963 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3964 return inflate_flush(s, z, r); 3965 r = Z_OK; 3966 inflate_codes_free(s->sub.decode.codes, z); 3967 inflate_trees_free(s->sub.decode.td, z); 3968 inflate_trees_free(s->sub.decode.tl, z); 3969 LOAD 3970 Tracev((stderr, "inflate: codes end, %lu total out\n", 3971 z->total_out + (q >= s->read ? q - s->read : 3972 (s->end - s->read) + (q - s->window)))); 3973 if (!s->last) 3974 { 3975 s->mode = TYPE; 3976 break; 3977 } 3978 if (k > 7) /* return unused byte, if any */ 3979 { 3980 Assert(k < 16, "inflate_codes grabbed too many bytes") 3981 k -= 8; 3982 n++; 3983 p--; /* can always return one */ 3984 } 3985 s->mode = DRY; 3986 case DRY: 3987 FLUSH 3988 if (s->read != s->write) 3989 LEAVE 3990 s->mode = DONEB; 3991 case DONEB: 3992 r = Z_STREAM_END; 3993 LEAVE 3994 case BADB: 3995 r = Z_DATA_ERROR; 3996 LEAVE 3997 default: 3998 r = Z_STREAM_ERROR; 3999 LEAVE 4000 } 4001} 4002 4003 4004int inflate_blocks_free(s, z, c) 4005inflate_blocks_statef *s; 4006z_streamp z; 4007uLongf *c; 4008{ 4009 inflate_blocks_reset(s, z, c); 4010 ZFREE(z, s->window); 4011 ZFREE(z, s); 4012 Trace((stderr, "inflate: blocks freed\n")); 4013 return Z_OK; 4014} 4015 4016 4017void inflate_set_dictionary(s, d, n) 4018inflate_blocks_statef *s; 4019const Bytef *d; 4020uInt n; 4021{ 4022 zmemcpy((charf *)s->window, d, n); 4023 s->read = s->write = s->window + n; 4024} 4025 4026/* 4027 * This subroutine adds the data at next_in/avail_in to the output history 4028 * without performing any output. The output buffer must be "caught up"; 4029 * i.e. no pending output (hence s->read equals s->write), and the state must 4030 * be BLOCKS (i.e. we should be willing to see the start of a series of 4031 * BLOCKS). On exit, the output will also be caught up, and the checksum 4032 * will have been updated if need be. 4033 */ 4034int inflate_addhistory(s, z) 4035inflate_blocks_statef *s; 4036z_stream *z; 4037{ 4038 uLong b; /* bit buffer */ /* NOT USED HERE */ 4039 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 4040 uInt t; /* temporary storage */ 4041 Bytef *p; /* input data pointer */ 4042 uInt n; /* bytes available there */ 4043 Bytef *q; /* output window write pointer */ 4044 uInt m; /* bytes to end of window or read pointer */ 4045 4046 if (s->read != s->write) 4047 return Z_STREAM_ERROR; 4048 if (s->mode != TYPE) 4049 return Z_DATA_ERROR; 4050 4051 /* we're ready to rock */ 4052 LOAD 4053 /* while there is input ready, copy to output buffer, moving 4054 * pointers as needed. 4055 */ 4056 while (n) { 4057 t = n; /* how many to do */ 4058 /* is there room until end of buffer? */ 4059 if (t > m) t = m; 4060 /* update check information */ 4061 if (s->checkfn != Z_NULL) 4062 s->check = (*s->checkfn)(s->check, q, t); 4063 zmemcpy(q, p, t); 4064 q += t; 4065 p += t; 4066 n -= t; 4067 z->total_out += t; 4068 s->read = q; /* drag read pointer forward */ 4069/* WWRAP */ /* expand WWRAP macro by hand to handle s->read */ 4070 if (q == s->end) { 4071 s->read = q = s->window; 4072 m = WAVAIL; 4073 } 4074 } 4075 UPDATE 4076 return Z_OK; 4077} 4078 4079 4080/* 4081 * At the end of a Deflate-compressed PPP packet, we expect to have seen 4082 * a `stored' block type value but not the (zero) length bytes. 4083 */ 4084int inflate_packet_flush(s) 4085 inflate_blocks_statef *s; 4086{ 4087 if (s->mode != LENS) 4088 return Z_DATA_ERROR; 4089 s->mode = TYPE; 4090 return Z_OK; 4091} 4092/* --- infblock.c */ 4093 4094/* +++ inftrees.c */ 4095/* inftrees.c -- generate Huffman trees for efficient decoding 4096 * Copyright (C) 1995-1996 Mark Adler 4097 * For conditions of distribution and use, see copyright notice in zlib.h 4098 */ 4099 4100/* #include "zutil.h" */ 4101/* #include "inftrees.h" */ 4102 4103char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler "; 4104/* 4105 If you use the zlib library in a product, an acknowledgment is welcome 4106 in the documentation of your product. If for some reason you cannot 4107 include such an acknowledgment, I would appreciate that you keep this 4108 copyright string in the executable of your product. 4109 */ 4110 4111#ifndef NO_DUMMY_DECL 4112struct internal_state {int dummy;}; /* for buggy compilers */ 4113#endif 4114 4115/* simplify the use of the inflate_huft type with some defines */ 4116#define base more.Base 4117#define next more.Next 4118#define exop word.what.Exop 4119#define bits word.what.Bits 4120 4121 4122local int huft_build OF(( 4123 uIntf *, /* code lengths in bits */ 4124 uInt, /* number of codes */ 4125 uInt, /* number of "simple" codes */ 4126 const uIntf *, /* list of base values for non-simple codes */ 4127 const uIntf *, /* list of extra bits for non-simple codes */ 4128 inflate_huft * FAR*,/* result: starting table */ 4129 uIntf *, /* maximum lookup bits (returns actual) */ 4130 z_streamp )); /* for zalloc function */ 4131 4132local voidpf falloc OF(( 4133 voidpf, /* opaque pointer (not used) */ 4134 uInt, /* number of items */ 4135 uInt)); /* size of item */ 4136 4137/* Tables for deflate from PKZIP's appnote.txt. */ 4138local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */ 4139 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 4140 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 4141 /* see note #13 above about 258 */ 4142local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */ 4143 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 4144 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */ 4145local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */ 4146 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 4147 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 4148 8193, 12289, 16385, 24577}; 4149local const uInt cpdext[30] = { /* Extra bits for distance codes */ 4150 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 4151 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 4152 12, 12, 13, 13}; 4153 4154/* 4155 Huffman code decoding is performed using a multi-level table lookup. 4156 The fastest way to decode is to simply build a lookup table whose 4157 size is determined by the longest code. However, the time it takes 4158 to build this table can also be a factor if the data being decoded 4159 is not very long. The most common codes are necessarily the 4160 shortest codes, so those codes dominate the decoding time, and hence 4161 the speed. The idea is you can have a shorter table that decodes the 4162 shorter, more probable codes, and then point to subsidiary tables for 4163 the longer codes. The time it costs to decode the longer codes is 4164 then traded against the time it takes to make longer tables. 4165 4166 This results of this trade are in the variables lbits and dbits 4167 below. lbits is the number of bits the first level table for literal/ 4168 length codes can decode in one step, and dbits is the same thing for 4169 the distance codes. Subsequent tables are also less than or equal to 4170 those sizes. These values may be adjusted either when all of the 4171 codes are shorter than that, in which case the longest code length in 4172 bits is used, or when the shortest code is *longer* than the requested 4173 table size, in which case the length of the shortest code in bits is 4174 used. 4175 4176 There are two different values for the two tables, since they code a 4177 different number of possibilities each. The literal/length table 4178 codes 286 possible values, or in a flat code, a little over eight 4179 bits. The distance table codes 30 possible values, or a little less 4180 than five bits, flat. The optimum values for speed end up being 4181 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 4182 The optimum values may differ though from machine to machine, and 4183 possibly even between compilers. Your mileage may vary. 4184 */ 4185 4186 4187/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 4188#define BMAX 15 /* maximum bit length of any code */ 4189#define N_MAX 288 /* maximum number of codes in any set */ 4190 4191#ifdef DEBUG_ZLIB 4192 uInt inflate_hufts; 4193#endif 4194 4195local int huft_build(b, n, s, d, e, t, m, zs) 4196uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ 4197uInt n; /* number of codes (assumed <= N_MAX) */ 4198uInt s; /* number of simple-valued codes (0..s-1) */ 4199const uIntf *d; /* list of base values for non-simple codes */ 4200const uIntf *e; /* list of extra bits for non-simple codes */ 4201inflate_huft * FAR *t; /* result: starting table */ 4202uIntf *m; /* maximum lookup bits, returns actual */ 4203z_streamp zs; /* for zalloc function */ 4204/* Given a list of code lengths and a maximum table size, make a set of 4205 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 4206 if the given code set is incomplete (the tables are still built in this 4207 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of 4208 lengths), or Z_MEM_ERROR if not enough memory. */ 4209{ 4210 4211 uInt a; /* counter for codes of length k */ 4212 uInt c[BMAX+1]; /* bit length count table */ 4213 uInt f; /* i repeats in table every f entries */ 4214 int g; /* maximum code length */ 4215 int h; /* table level */ 4216 register uInt i; /* counter, current code */ 4217 register uInt j; /* counter */ 4218 register int k; /* number of bits in current code */ 4219 int l; /* bits per table (returned in m) */ 4220 register uIntf *p; /* pointer into c[], b[], or v[] */ 4221 inflate_huft *q; /* points to current table */ 4222 struct inflate_huft_s r; /* table entry for structure assignment */ 4223 inflate_huft *u[BMAX]; /* table stack */ 4224 uInt v[N_MAX]; /* values in order of bit length */ 4225 register int w; /* bits before this table == (l * h) */ 4226 uInt x[BMAX+1]; /* bit offsets, then code stack */ 4227 uIntf *xp; /* pointer into x */ 4228 int y; /* number of dummy codes added */ 4229 uInt z; /* number of entries in current table */ 4230 4231 4232 /* Generate counts for each bit length */ 4233 p = c; 4234#define C0 *p++ = 0; 4235#define C2 C0 C0 C0 C0 4236#define C4 C2 C2 C2 C2 4237 C4 /* clear c[]--assume BMAX+1 is 16 */ 4238 p = b; i = n; 4239 do { 4240 c[*p++]++; /* assume all entries <= BMAX */ 4241 } while (--i); 4242 if (c[0] == n) /* null input--all zero length codes */ 4243 { 4244 *t = (inflate_huft *)Z_NULL; 4245 *m = 0; 4246 return Z_OK; 4247 } 4248 4249 4250 /* Find minimum and maximum length, bound *m by those */ 4251 l = *m; 4252 for (j = 1; j <= BMAX; j++) 4253 if (c[j]) 4254 break; 4255 k = j; /* minimum code length */ 4256 if ((uInt)l < j) 4257 l = j; 4258 for (i = BMAX; i; i--) 4259 if (c[i]) 4260 break; 4261 g = i; /* maximum code length */ 4262 if ((uInt)l > i) 4263 l = i; 4264 *m = l; 4265 4266 4267 /* Adjust last length count to fill out codes, if needed */ 4268 for (y = 1 << j; j < i; j++, y <<= 1) 4269 if ((y -= c[j]) < 0) 4270 return Z_DATA_ERROR; 4271 if ((y -= c[i]) < 0) 4272 return Z_DATA_ERROR; 4273 c[i] += y; 4274 4275 4276 /* Generate starting offsets into the value table for each length */ 4277 x[1] = j = 0; 4278 p = c + 1; xp = x + 2; 4279 while (--i) { /* note that i == g from above */ 4280 *xp++ = (j += *p++); 4281 } 4282 4283 4284 /* Make a table of values in order of bit lengths */ 4285 p = b; i = 0; 4286 do { 4287 if ((j = *p++) != 0) 4288 v[x[j]++] = i; 4289 } while (++i < n); 4290 n = x[g]; /* set n to length of v */ 4291 4292 4293 /* Generate the Huffman codes and for each, make the table entries */ 4294 x[0] = i = 0; /* first Huffman code is zero */ 4295 p = v; /* grab values in bit order */ 4296 h = -1; /* no tables yet--level -1 */ 4297 w = -l; /* bits decoded == (l * h) */ 4298 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 4299 q = (inflate_huft *)Z_NULL; /* ditto */ 4300 z = 0; /* ditto */ 4301 4302 /* go through the bit lengths (k already is bits in shortest code) */ 4303 for (; k <= g; k++) 4304 { 4305 a = c[k]; 4306 while (a--) 4307 { 4308 /* here i is the Huffman code of length k bits for value *p */ 4309 /* make tables up to required level */ 4310 while (k > w + l) 4311 { 4312 h++; 4313 w += l; /* previous table always l bits */ 4314 4315 /* compute minimum size table less than or equal to l bits */ 4316 z = g - w; 4317 z = z > (uInt)l ? l : z; /* table size upper limit */ 4318 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 4319 { /* too few codes for k-w bit table */ 4320 f -= a + 1; /* deduct codes from patterns left */ 4321 xp = c + k; 4322 if (j < z) 4323 while (++j < z) /* try smaller tables up to z bits */ 4324 { 4325 if ((f <<= 1) <= *++xp) 4326 break; /* enough codes to use up j bits */ 4327 f -= *xp; /* else deduct codes from patterns */ 4328 } 4329 } 4330 z = 1 << j; /* table entries for j-bit table */ 4331 4332 /* allocate and link in new table */ 4333 if ((q = (inflate_huft *)ZALLOC 4334 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 4335 { 4336 if (h) 4337 inflate_trees_free(u[0], zs); 4338 return Z_MEM_ERROR; /* not enough memory */ 4339 } 4340#ifdef DEBUG_ZLIB 4341 inflate_hufts += z + 1; 4342#endif 4343 *t = q + 1; /* link to list for huft_free() */ 4344 *(t = &(q->next)) = Z_NULL; 4345 u[h] = ++q; /* table starts after link */ 4346 4347 /* connect to last table, if there is one */ 4348 if (h) 4349 { 4350 x[h] = i; /* save pattern for backing up */ 4351 r.bits = (Byte)l; /* bits to dump before this table */ 4352 r.exop = (Byte)j; /* bits in this table */ 4353 r.next = q; /* pointer to this table */ 4354 j = i >> (w - l); /* (get around Turbo C bug) */ 4355 u[h-1][j] = r; /* connect to last table */ 4356 } 4357 } 4358 4359 /* set up table entry in r */ 4360 r.bits = (Byte)(k - w); 4361 if (p >= v + n) 4362 r.exop = 128 + 64; /* out of values--invalid code */ 4363 else if (*p < s) 4364 { 4365 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 4366 r.base = *p++; /* simple code is just the value */ 4367 } 4368 else 4369 { 4370 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ 4371 r.base = d[*p++ - s]; 4372 } 4373 4374 /* fill code-like entries with r */ 4375 f = 1 << (k - w); 4376 for (j = i >> w; j < z; j += f) 4377 q[j] = r; 4378 4379 /* backwards increment the k-bit code i */ 4380 for (j = 1 << (k - 1); i & j; j >>= 1) 4381 i ^= j; 4382 i ^= j; 4383 4384 /* backup over finished tables */ 4385 while ((i & ((1 << w) - 1)) != x[h]) 4386 { 4387 h--; /* don't need to update q */ 4388 w -= l; 4389 } 4390 } 4391 } 4392 4393 4394 /* Return Z_BUF_ERROR if we were given an incomplete table */ 4395 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 4396} 4397 4398 4399int inflate_trees_bits(c, bb, tb, z) 4400uIntf *c; /* 19 code lengths */ 4401uIntf *bb; /* bits tree desired/actual depth */ 4402inflate_huft * FAR *tb; /* bits tree result */ 4403z_streamp z; /* for zfree function */ 4404{ 4405 int r; 4406 4407 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 4408 if (r == Z_DATA_ERROR) 4409 z->msg = (char*)"oversubscribed dynamic bit lengths tree"; 4410 else if (r == Z_BUF_ERROR || *bb == 0) 4411 { 4412 inflate_trees_free(*tb, z); 4413 z->msg = (char*)"incomplete dynamic bit lengths tree"; 4414 r = Z_DATA_ERROR; 4415 } 4416 return r; 4417} 4418 4419 4420int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) 4421uInt nl; /* number of literal/length codes */ 4422uInt nd; /* number of distance codes */ 4423uIntf *c; /* that many (total) code lengths */ 4424uIntf *bl; /* literal desired/actual bit depth */ 4425uIntf *bd; /* distance desired/actual bit depth */ 4426inflate_huft * FAR *tl; /* literal/length tree result */ 4427inflate_huft * FAR *td; /* distance tree result */ 4428z_streamp z; /* for zfree function */ 4429{ 4430 int r; 4431 4432 /* build literal/length tree */ 4433 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); 4434 if (r != Z_OK || *bl == 0) 4435 { 4436 if (r == Z_DATA_ERROR) 4437 z->msg = (char*)"oversubscribed literal/length tree"; 4438 else if (r != Z_MEM_ERROR) 4439 { 4440 inflate_trees_free(*tl, z); 4441 z->msg = (char*)"incomplete literal/length tree"; 4442 r = Z_DATA_ERROR; 4443 } 4444 return r; 4445 } 4446 4447 /* build distance tree */ 4448 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); 4449 if (r != Z_OK || (*bd == 0 && nl > 257)) 4450 { 4451 if (r == Z_DATA_ERROR) 4452 z->msg = (char*)"oversubscribed distance tree"; 4453 else if (r == Z_BUF_ERROR) { 4454#ifdef PKZIP_BUG_WORKAROUND 4455 r = Z_OK; 4456 } 4457#else 4458 inflate_trees_free(*td, z); 4459 z->msg = (char*)"incomplete distance tree"; 4460 r = Z_DATA_ERROR; 4461 } 4462 else if (r != Z_MEM_ERROR) 4463 { 4464 z->msg = (char*)"empty distance tree with lengths"; 4465 r = Z_DATA_ERROR; 4466 } 4467 inflate_trees_free(*tl, z); 4468 return r; 4469#endif 4470 } 4471 4472 /* done */ 4473 return Z_OK; 4474} 4475 4476 4477/* build fixed tables only once--keep them here */ 4478local int fixed_built = 0; 4479#define FIXEDH 530 /* number of hufts used by fixed tables */ 4480local inflate_huft fixed_mem[FIXEDH]; 4481local uInt fixed_bl; 4482local uInt fixed_bd; 4483local inflate_huft *fixed_tl; 4484local inflate_huft *fixed_td; 4485 4486 4487local voidpf falloc(q, n, s) 4488voidpf q; /* opaque pointer */ 4489uInt n; /* number of items */ 4490uInt s; /* size of item */ 4491{ 4492 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, 4493 "inflate_trees falloc overflow"); 4494 *(intf *)q -= n+s-s; /* s-s to avoid warning */ 4495 return (voidpf)(fixed_mem + *(intf *)q); 4496} 4497 4498 4499int inflate_trees_fixed(bl, bd, tl, td) 4500uIntf *bl; /* literal desired/actual bit depth */ 4501uIntf *bd; /* distance desired/actual bit depth */ 4502inflate_huft * FAR *tl; /* literal/length tree result */ 4503inflate_huft * FAR *td; /* distance tree result */ 4504{ 4505 /* build fixed tables if not already (multiple overlapped executions ok) */ 4506 if (!fixed_built) 4507 { 4508 int k; /* temporary variable */ 4509 unsigned c[288]; /* length list for huft_build */ 4510 z_stream z; /* for falloc function */ 4511 int f = FIXEDH; /* number of hufts left in fixed_mem */ 4512 4513 /* set up fake z_stream for memory routines */ 4514 z.zalloc = falloc; 4515 z.zfree = Z_NULL; 4516 z.opaque = (voidpf)&f; 4517 4518 /* literal table */ 4519 for (k = 0; k < 144; k++) 4520 c[k] = 8; 4521 for (; k < 256; k++) 4522 c[k] = 9; 4523 for (; k < 280; k++) 4524 c[k] = 7; 4525 for (; k < 288; k++) 4526 c[k] = 8; 4527 fixed_bl = 7; 4528 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4529 4530 /* distance table */ 4531 for (k = 0; k < 30; k++) 4532 c[k] = 5; 4533 fixed_bd = 5; 4534 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4535 4536 /* done */ 4537 Assert(f == 0, "invalid build of fixed tables"); 4538 fixed_built = 1; 4539 } 4540 *bl = fixed_bl; 4541 *bd = fixed_bd; 4542 *tl = fixed_tl; 4543 *td = fixed_td; 4544 return Z_OK; 4545} 4546 4547 4548int inflate_trees_free(t, z) 4549inflate_huft *t; /* table to free */ 4550z_streamp z; /* for zfree function */ 4551/* Free the malloc'ed tables built by huft_build(), which makes a linked 4552 list of the tables it made, with the links in a dummy first entry of 4553 each table. */ 4554{ 4555 register inflate_huft *p, *q, *r; 4556 4557 /* Reverse linked list */ 4558 p = Z_NULL; 4559 q = t; 4560 while (q != Z_NULL) 4561 { 4562 r = (q - 1)->next; 4563 (q - 1)->next = p; 4564 p = q; 4565 q = r; 4566 } 4567 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4568 while (p != Z_NULL) 4569 { 4570 q = (--p)->next; 4571 ZFREE(z,p); 4572 p = q; 4573 } 4574 return Z_OK; 4575} 4576/* --- inftrees.c */ 4577 4578/* +++ infcodes.c */ 4579/* infcodes.c -- process literals and length/distance pairs 4580 * Copyright (C) 1995-1996 Mark Adler 4581 * For conditions of distribution and use, see copyright notice in zlib.h 4582 */ 4583 4584/* #include "zutil.h" */ 4585/* #include "inftrees.h" */ 4586/* #include "infblock.h" */ 4587/* #include "infcodes.h" */ 4588/* #include "infutil.h" */ 4589 4590/* +++ inffast.h */ 4591/* inffast.h -- header to use inffast.c 4592 * Copyright (C) 1995-1996 Mark Adler 4593 * For conditions of distribution and use, see copyright notice in zlib.h 4594 */ 4595 4596/* WARNING: this file should *not* be used by applications. It is 4597 part of the implementation of the compression library and is 4598 subject to change. Applications should only use zlib.h. 4599 */ 4600 4601extern int inflate_fast OF(( 4602 uInt, 4603 uInt, 4604 inflate_huft *, 4605 inflate_huft *, 4606 inflate_blocks_statef *, 4607 z_streamp )); 4608/* --- inffast.h */ 4609 4610/* simplify the use of the inflate_huft type with some defines */ 4611#define base more.Base 4612#define next more.Next 4613#define exop word.what.Exop 4614#define bits word.what.Bits 4615 4616/* inflate codes private state */ 4617struct inflate_codes_state { 4618 4619 /* mode */ 4620 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4621 START, /* x: set up for LEN */ 4622 LEN, /* i: get length/literal/eob next */ 4623 LENEXT, /* i: getting length extra (have base) */ 4624 DIST, /* i: get distance next */ 4625 DISTEXT, /* i: getting distance extra */ 4626 COPY, /* o: copying bytes in window, waiting for space */ 4627 LIT, /* o: got literal, waiting for output space */ 4628 WASH, /* o: got eob, possibly still output waiting */ 4629 END, /* x: got eob and all data flushed */ 4630 BADCODE} /* x: got error */ 4631 mode; /* current inflate_codes mode */ 4632 4633 /* mode dependent information */ 4634 uInt len; 4635 union { 4636 struct { 4637 inflate_huft *tree; /* pointer into tree */ 4638 uInt need; /* bits needed */ 4639 } code; /* if LEN or DIST, where in tree */ 4640 uInt lit; /* if LIT, literal */ 4641 struct { 4642 uInt get; /* bits to get for extra */ 4643 uInt dist; /* distance back to copy from */ 4644 } copy; /* if EXT or COPY, where and how much */ 4645 } sub; /* submode */ 4646 4647 /* mode independent information */ 4648 Byte lbits; /* ltree bits decoded per branch */ 4649 Byte dbits; /* dtree bits decoder per branch */ 4650 inflate_huft *ltree; /* literal/length/eob tree */ 4651 inflate_huft *dtree; /* distance tree */ 4652 4653}; 4654 4655 4656inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) 4657uInt bl, bd; 4658inflate_huft *tl; 4659inflate_huft *td; /* need separate declaration for Borland C++ */ 4660z_streamp z; 4661{ 4662 inflate_codes_statef *c; 4663 4664 if ((c = (inflate_codes_statef *) 4665 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4666 { 4667 c->mode = START; 4668 c->lbits = (Byte)bl; 4669 c->dbits = (Byte)bd; 4670 c->ltree = tl; 4671 c->dtree = td; 4672 Tracev((stderr, "inflate: codes new\n")); 4673 } 4674 return c; 4675} 4676 4677 4678int inflate_codes(s, z, r) 4679inflate_blocks_statef *s; 4680z_streamp z; 4681int r; 4682{ 4683 uInt j; /* temporary storage */ 4684 inflate_huft *t; /* temporary pointer */ 4685 uInt e; /* extra bits or operation */ 4686 uLong b; /* bit buffer */ 4687 uInt k; /* bits in bit buffer */ 4688 Bytef *p; /* input data pointer */ 4689 uInt n; /* bytes available there */ 4690 Bytef *q; /* output window write pointer */ 4691 uInt m; /* bytes to end of window or read pointer */ 4692 Bytef *f; /* pointer to copy strings from */ 4693 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4694 4695 /* copy input/output information to locals (UPDATE macro restores) */ 4696 LOAD 4697 4698 /* process input and output based on current state */ 4699 while (1) switch (c->mode) 4700 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4701 case START: /* x: set up for LEN */ 4702#ifndef SLOW 4703 if (m >= 258 && n >= 10) 4704 { 4705 UPDATE 4706 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4707 LOAD 4708 if (r != Z_OK) 4709 { 4710 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4711 break; 4712 } 4713 } 4714#endif /* !SLOW */ 4715 c->sub.code.need = c->lbits; 4716 c->sub.code.tree = c->ltree; 4717 c->mode = LEN; 4718 case LEN: /* i: get length/literal/eob next */ 4719 j = c->sub.code.need; 4720 NEEDBITS(j) 4721 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4722 DUMPBITS(t->bits) 4723 e = (uInt)(t->exop); 4724 if (e == 0) /* literal */ 4725 { 4726 c->sub.lit = t->base; 4727 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4728 "inflate: literal '%c'\n" : 4729 "inflate: literal 0x%02x\n", t->base)); 4730 c->mode = LIT; 4731 break; 4732 } 4733 if (e & 16) /* length */ 4734 { 4735 c->sub.copy.get = e & 15; 4736 c->len = t->base; 4737 c->mode = LENEXT; 4738 break; 4739 } 4740 if ((e & 64) == 0) /* next table */ 4741 { 4742 c->sub.code.need = e; 4743 c->sub.code.tree = t->next; 4744 break; 4745 } 4746 if (e & 32) /* end of block */ 4747 { 4748 Tracevv((stderr, "inflate: end of block\n")); 4749 c->mode = WASH; 4750 break; 4751 } 4752 c->mode = BADCODE; /* invalid code */ 4753 z->msg = (char*)"invalid literal/length code"; 4754 r = Z_DATA_ERROR; 4755 LEAVE 4756 case LENEXT: /* i: getting length extra (have base) */ 4757 j = c->sub.copy.get; 4758 NEEDBITS(j) 4759 c->len += (uInt)b & inflate_mask[j]; 4760 DUMPBITS(j) 4761 c->sub.code.need = c->dbits; 4762 c->sub.code.tree = c->dtree; 4763 Tracevv((stderr, "inflate: length %u\n", c->len)); 4764 c->mode = DIST; 4765 case DIST: /* i: get distance next */ 4766 j = c->sub.code.need; 4767 NEEDBITS(j) 4768 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4769 DUMPBITS(t->bits) 4770 e = (uInt)(t->exop); 4771 if (e & 16) /* distance */ 4772 { 4773 c->sub.copy.get = e & 15; 4774 c->sub.copy.dist = t->base; 4775 c->mode = DISTEXT; 4776 break; 4777 } 4778 if ((e & 64) == 0) /* next table */ 4779 { 4780 c->sub.code.need = e; 4781 c->sub.code.tree = t->next; 4782 break; 4783 } 4784 c->mode = BADCODE; /* invalid code */ 4785 z->msg = (char*)"invalid distance code"; 4786 r = Z_DATA_ERROR; 4787 LEAVE 4788 case DISTEXT: /* i: getting distance extra */ 4789 j = c->sub.copy.get; 4790 NEEDBITS(j) 4791 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4792 DUMPBITS(j) 4793 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4794 c->mode = COPY; 4795 case COPY: /* o: copying bytes in window, waiting for space */ 4796#ifndef __TURBOC__ /* Turbo C bug for following expression */ 4797 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4798 s->end - (c->sub.copy.dist - (q - s->window)) : 4799 q - c->sub.copy.dist; 4800#else 4801 f = q - c->sub.copy.dist; 4802 if ((uInt)(q - s->window) < c->sub.copy.dist) 4803 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); 4804#endif 4805 while (c->len) 4806 { 4807 NEEDOUT 4808 OUTBYTE(*f++) 4809 if (f == s->end) 4810 f = s->window; 4811 c->len--; 4812 } 4813 c->mode = START; 4814 break; 4815 case LIT: /* o: got literal, waiting for output space */ 4816 NEEDOUT 4817 OUTBYTE(c->sub.lit) 4818 c->mode = START; 4819 break; 4820 case WASH: /* o: got eob, possibly more output */ 4821 FLUSH 4822 if (s->read != s->write) 4823 LEAVE 4824 c->mode = END; 4825 case END: 4826 r = Z_STREAM_END; 4827 LEAVE 4828 case BADCODE: /* x: got error */ 4829 r = Z_DATA_ERROR; 4830 LEAVE 4831 default: 4832 r = Z_STREAM_ERROR; 4833 LEAVE 4834 } 4835} 4836 4837 4838void inflate_codes_free(c, z) 4839inflate_codes_statef *c; 4840z_streamp z; 4841{ 4842 ZFREE(z, c); 4843 Tracev((stderr, "inflate: codes free\n")); 4844} 4845/* --- infcodes.c */ 4846 4847/* +++ infutil.c */ 4848/* inflate_util.c -- data and routines common to blocks and codes 4849 * Copyright (C) 1995-1996 Mark Adler 4850 * For conditions of distribution and use, see copyright notice in zlib.h 4851 */ 4852 4853/* #include "zutil.h" */ 4854/* #include "infblock.h" */ 4855/* #include "inftrees.h" */ 4856/* #include "infcodes.h" */ 4857/* #include "infutil.h" */ 4858 4859#ifndef NO_DUMMY_DECL 4860struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4861#endif 4862 4863/* And'ing with mask[n] masks the lower n bits */ 4864uInt inflate_mask[17] = { 4865 0x0000, 4866 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 4867 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 4868}; 4869 4870 4871/* copy as much as possible from the sliding window to the output area */ 4872int inflate_flush(s, z, r) 4873inflate_blocks_statef *s; 4874z_streamp z; 4875int r; 4876{ 4877 uInt n; 4878 Bytef *p; 4879 Bytef *q; 4880 4881 /* local copies of source and destination pointers */ 4882 p = z->next_out; 4883 q = s->read; 4884 4885 /* compute number of bytes to copy as far as end of window */ 4886 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4887 if (n > z->avail_out) n = z->avail_out; 4888 if (n && r == Z_BUF_ERROR) r = Z_OK; 4889 4890 /* update counters */ 4891 z->avail_out -= n; 4892 z->total_out += n; 4893 4894 /* update check information */ 4895 if (s->checkfn != Z_NULL) 4896 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4897 4898 /* copy as far as end of window */ 4899 if (p != Z_NULL) { 4900 zmemcpy(p, q, n); 4901 p += n; 4902 } 4903 q += n; 4904 4905 /* see if more to copy at beginning of window */ 4906 if (q == s->end) 4907 { 4908 /* wrap pointers */ 4909 q = s->window; 4910 if (s->write == s->end) 4911 s->write = s->window; 4912 4913 /* compute bytes to copy */ 4914 n = (uInt)(s->write - q); 4915 if (n > z->avail_out) n = z->avail_out; 4916 if (n && r == Z_BUF_ERROR) r = Z_OK; 4917 4918 /* update counters */ 4919 z->avail_out -= n; 4920 z->total_out += n; 4921 4922 /* update check information */ 4923 if (s->checkfn != Z_NULL) 4924 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4925 4926 /* copy */ 4927 if (p != Z_NULL) { 4928 zmemcpy(p, q, n); 4929 p += n; 4930 } 4931 q += n; 4932 } 4933 4934 /* update pointers */ 4935 z->next_out = p; 4936 s->read = q; 4937 4938 /* done */ 4939 return r; 4940} 4941/* --- infutil.c */ 4942 4943/* +++ inffast.c */ 4944/* inffast.c -- process literals and length/distance pairs fast 4945 * Copyright (C) 1995-1996 Mark Adler 4946 * For conditions of distribution and use, see copyright notice in zlib.h 4947 */ 4948 4949/* #include "zutil.h" */ 4950/* #include "inftrees.h" */ 4951/* #include "infblock.h" */ 4952/* #include "infcodes.h" */ 4953/* #include "infutil.h" */ 4954/* #include "inffast.h" */ 4955 4956#ifndef NO_DUMMY_DECL 4957struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4958#endif 4959 4960/* simplify the use of the inflate_huft type with some defines */ 4961#define base more.Base 4962#define next more.Next 4963#define exop word.what.Exop 4964#define bits word.what.Bits 4965 4966/* macros for bit input with no checking and for returning unused bytes */ 4967#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4968#define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4969 4970/* Called with number of bytes left to write in window at least 258 4971 (the maximum string length) and number of input bytes available 4972 at least ten. The ten bytes are six bytes for the longest length/ 4973 distance pair plus four bytes for overloading the bit buffer. */ 4974 4975int inflate_fast(bl, bd, tl, td, s, z) 4976uInt bl, bd; 4977inflate_huft *tl; 4978inflate_huft *td; /* need separate declaration for Borland C++ */ 4979inflate_blocks_statef *s; 4980z_streamp z; 4981{ 4982 inflate_huft *t; /* temporary pointer */ 4983 uInt e; /* extra bits or operation */ 4984 uLong b; /* bit buffer */ 4985 uInt k; /* bits in bit buffer */ 4986 Bytef *p; /* input data pointer */ 4987 uInt n; /* bytes available there */ 4988 Bytef *q; /* output window write pointer */ 4989 uInt m; /* bytes to end of window or read pointer */ 4990 uInt ml; /* mask for literal/length tree */ 4991 uInt md; /* mask for distance tree */ 4992 uInt c; /* bytes to copy */ 4993 uInt d; /* distance back to copy from */ 4994 Bytef *r; /* copy source pointer */ 4995 4996 /* load input, output, bit values */ 4997 LOAD 4998 4999 /* initialize masks */ 5000 ml = inflate_mask[bl]; 5001 md = inflate_mask[bd]; 5002 5003 /* do until not enough input or output space for fast loop */ 5004 do { /* assume called with m >= 258 && n >= 10 */ 5005 /* get literal/length code */ 5006 GRABBITS(20) /* max bits for literal/length code */ 5007 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 5008 { 5009 DUMPBITS(t->bits) 5010 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5011 "inflate: * literal '%c'\n" : 5012 "inflate: * literal 0x%02x\n", t->base)); 5013 *q++ = (Byte)t->base; 5014 m--; 5015 continue; 5016 } 5017 do { 5018 DUMPBITS(t->bits) 5019 if (e & 16) 5020 { 5021 /* get extra bits for length */ 5022 e &= 15; 5023 c = t->base + ((uInt)b & inflate_mask[e]); 5024 DUMPBITS(e) 5025 Tracevv((stderr, "inflate: * length %u\n", c)); 5026 5027 /* decode distance base of block to copy */ 5028 GRABBITS(15); /* max bits for distance code */ 5029 e = (t = td + ((uInt)b & md))->exop; 5030 do { 5031 DUMPBITS(t->bits) 5032 if (e & 16) 5033 { 5034 /* get extra bits to add to distance base */ 5035 e &= 15; 5036 GRABBITS(e) /* get extra bits (up to 13) */ 5037 d = t->base + ((uInt)b & inflate_mask[e]); 5038 DUMPBITS(e) 5039 Tracevv((stderr, "inflate: * distance %u\n", d)); 5040 5041 /* do the copy */ 5042 m -= c; 5043 if ((uInt)(q - s->window) >= d) /* offset before dest */ 5044 { /* just copy */ 5045 r = q - d; 5046 *q++ = *r++; c--; /* minimum count is three, */ 5047 *q++ = *r++; c--; /* so unroll loop a little */ 5048 } 5049 else /* else offset after destination */ 5050 { 5051 e = d - (uInt)(q - s->window); /* bytes from offset to end */ 5052 r = s->end - e; /* pointer to offset */ 5053 if (c > e) /* if source crosses, */ 5054 { 5055 c -= e; /* copy to end of window */ 5056 do { 5057 *q++ = *r++; 5058 } while (--e); 5059 r = s->window; /* copy rest from start of window */ 5060 } 5061 } 5062 do { /* copy all or what's left */ 5063 *q++ = *r++; 5064 } while (--c); 5065 break; 5066 } 5067 else if ((e & 64) == 0) 5068 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 5069 else 5070 { 5071 z->msg = (char*)"invalid distance code"; 5072 UNGRAB 5073 UPDATE 5074 return Z_DATA_ERROR; 5075 } 5076 } while (1); 5077 break; 5078 } 5079 if ((e & 64) == 0) 5080 { 5081 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 5082 { 5083 DUMPBITS(t->bits) 5084 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5085 "inflate: * literal '%c'\n" : 5086 "inflate: * literal 0x%02x\n", t->base)); 5087 *q++ = (Byte)t->base; 5088 m--; 5089 break; 5090 } 5091 } 5092 else if (e & 32) 5093 { 5094 Tracevv((stderr, "inflate: * end of block\n")); 5095 UNGRAB 5096 UPDATE 5097 return Z_STREAM_END; 5098 } 5099 else 5100 { 5101 z->msg = (char*)"invalid literal/length code"; 5102 UNGRAB 5103 UPDATE 5104 return Z_DATA_ERROR; 5105 } 5106 } while (1); 5107 } while (m >= 258 && n >= 10); 5108 5109 /* not enough input or output--restore pointers and return */ 5110 UNGRAB 5111 UPDATE 5112 return Z_OK; 5113} 5114/* --- inffast.c */ 5115 5116/* +++ zutil.c */ 5117/* zutil.c -- target dependent utility functions for the compression library 5118 * Copyright (C) 1995-1996 Jean-loup Gailly. 5119 * For conditions of distribution and use, see copyright notice in zlib.h 5120 */ 5121 5122/* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ 5123 5124#ifdef DEBUG_ZLIB 5125#include <stdio.h> 5126#endif 5127 5128/* #include "zutil.h" */ 5129 5130#ifndef NO_DUMMY_DECL 5131struct internal_state {int dummy;}; /* for buggy compilers */ 5132#endif 5133 5134#ifndef STDC 5135extern void exit OF((int)); 5136#endif 5137 5138static const char *z_errmsg[10] = { 5139"need dictionary", /* Z_NEED_DICT 2 */ 5140"stream end", /* Z_STREAM_END 1 */ 5141"", /* Z_OK 0 */ 5142"file error", /* Z_ERRNO (-1) */ 5143"stream error", /* Z_STREAM_ERROR (-2) */ 5144"data error", /* Z_DATA_ERROR (-3) */ 5145"insufficient memory", /* Z_MEM_ERROR (-4) */ 5146"buffer error", /* Z_BUF_ERROR (-5) */ 5147"incompatible version",/* Z_VERSION_ERROR (-6) */ 5148""}; 5149 5150 5151const char *zlibVersion() 5152{ 5153 return ZLIB_VERSION; 5154} 5155 5156#ifdef DEBUG_ZLIB 5157void z_error (m) 5158 char *m; 5159{ 5160 fprintf(stderr, "%s\n", m); 5161 exit(1); 5162} 5163#endif 5164 5165#ifndef HAVE_MEMCPY 5166 5167void zmemcpy(dest, source, len) 5168 Bytef* dest; 5169 Bytef* source; 5170 uInt len; 5171{ 5172 if (len == 0) return; 5173 do { 5174 *dest++ = *source++; /* ??? to be unrolled */ 5175 } while (--len != 0); 5176} 5177 5178int zmemcmp(s1, s2, len) 5179 Bytef* s1; 5180 Bytef* s2; 5181 uInt len; 5182{ 5183 uInt j; 5184 5185 for (j = 0; j < len; j++) { 5186 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 5187 } 5188 return 0; 5189} 5190 5191void zmemzero(dest, len) 5192 Bytef* dest; 5193 uInt len; 5194{ 5195 if (len == 0) return; 5196 do { 5197 *dest++ = 0; /* ??? to be unrolled */ 5198 } while (--len != 0); 5199} 5200#endif 5201 5202#ifdef __TURBOC__ 5203#if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 5204/* Small and medium model in Turbo C are for now limited to near allocation 5205 * with reduced MAX_WBITS and MAX_MEM_LEVEL 5206 */ 5207# define MY_ZCALLOC 5208 5209/* Turbo C malloc() does not allow dynamic allocation of 64K bytes 5210 * and farmalloc(64K) returns a pointer with an offset of 8, so we 5211 * must fix the pointer. Warning: the pointer must be put back to its 5212 * original form in order to free it, use zcfree(). 5213 */ 5214 5215#define MAX_PTR 10 5216/* 10*64K = 640K */ 5217 5218local int next_ptr = 0; 5219 5220typedef struct ptr_table_s { 5221 voidpf org_ptr; 5222 voidpf new_ptr; 5223} ptr_table; 5224 5225local ptr_table table[MAX_PTR]; 5226/* This table is used to remember the original form of pointers 5227 * to large buffers (64K). Such pointers are normalized with a zero offset. 5228 * Since MSDOS is not a preemptive multitasking OS, this table is not 5229 * protected from concurrent access. This hack doesn't work anyway on 5230 * a protected system like OS/2. Use Microsoft C instead. 5231 */ 5232 5233voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5234{ 5235 voidpf buf = opaque; /* just to make some compilers happy */ 5236 ulg bsize = (ulg)items*size; 5237 5238 /* If we allocate less than 65520 bytes, we assume that farmalloc 5239 * will return a usable pointer which doesn't have to be normalized. 5240 */ 5241 if (bsize < 65520L) { 5242 buf = farmalloc(bsize); 5243 if (*(ush*)&buf != 0) return buf; 5244 } else { 5245 buf = farmalloc(bsize + 16L); 5246 } 5247 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 5248 table[next_ptr].org_ptr = buf; 5249 5250 /* Normalize the pointer to seg:0 */ 5251 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 5252 *(ush*)&buf = 0; 5253 table[next_ptr++].new_ptr = buf; 5254 return buf; 5255} 5256 5257void zcfree (voidpf opaque, voidpf ptr) 5258{ 5259 int n; 5260 if (*(ush*)&ptr != 0) { /* object < 64K */ 5261 farfree(ptr); 5262 return; 5263 } 5264 /* Find the original pointer */ 5265 for (n = 0; n < next_ptr; n++) { 5266 if (ptr != table[n].new_ptr) continue; 5267 5268 farfree(table[n].org_ptr); 5269 while (++n < next_ptr) { 5270 table[n-1] = table[n]; 5271 } 5272 next_ptr--; 5273 return; 5274 } 5275 ptr = opaque; /* just to make some compilers happy */ 5276 Assert(0, "zcfree: ptr not found"); 5277} 5278#endif 5279#endif /* __TURBOC__ */ 5280 5281 5282#if defined(M_I86) && !defined(__32BIT__) 5283/* Microsoft C in 16-bit mode */ 5284 5285# define MY_ZCALLOC 5286 5287#if (!defined(_MSC_VER) || (_MSC_VER < 600)) 5288# define _halloc halloc 5289# define _hfree hfree 5290#endif 5291 5292voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5293{ 5294 if (opaque) opaque = 0; /* to make compiler happy */ 5295 return _halloc((long)items, size); 5296} 5297 5298void zcfree (voidpf opaque, voidpf ptr) 5299{ 5300 if (opaque) opaque = 0; /* to make compiler happy */ 5301 _hfree(ptr); 5302} 5303 5304#endif /* MSC */ 5305 5306 5307#ifndef MY_ZCALLOC /* Any system without a special alloc function */ 5308 5309#ifndef STDC 5310extern voidp calloc OF((uInt items, uInt size)); 5311extern void free OF((voidpf ptr)); 5312#endif 5313 5314voidpf zcalloc (opaque, items, size) 5315 voidpf opaque; 5316 unsigned items; 5317 unsigned size; 5318{ 5319 if (opaque) items += size - size; /* make compiler happy */ 5320 return (voidpf)calloc(items, size); 5321} 5322 5323void zcfree (opaque, ptr) 5324 voidpf opaque; 5325 voidpf ptr; 5326{ 5327 free(ptr); 5328 if (opaque) return; /* make compiler happy */ 5329} 5330 5331#endif /* MY_ZCALLOC */ 5332/* --- zutil.c */ 5333 5334/* +++ adler32.c */ 5335/* adler32.c -- compute the Adler-32 checksum of a data stream 5336 * Copyright (C) 1995-1996 Mark Adler 5337 * For conditions of distribution and use, see copyright notice in zlib.h 5338 */ 5339 5340/* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ 5341 5342/* #include "zlib.h" */ 5343 5344#define BASE 65521L /* largest prime smaller than 65536 */ 5345#define NMAX 5552 5346/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 5347 5348#define DO1(buf,i) {s1 += buf[(i)]; s2 += s1;} 5349#define DO2(buf,i) DO1(buf,i); DO1(buf,(i)+1); 5350#define DO4(buf,i) DO2(buf,i); DO2(buf,(i)+2); 5351#define DO8(buf,i) DO4(buf,i); DO4(buf,(i)+4); 5352#define DO16(buf) DO8(buf,0); DO8(buf,8); 5353 5354/* ========================================================================= */ 5355uLong adler32(adler, buf, len) 5356 uLong adler; 5357 const Bytef *buf; 5358 uInt len; 5359{ 5360 unsigned long s1 = adler & 0xffff; 5361 unsigned long s2 = (adler >> 16) & 0xffff; 5362 int k; 5363 5364 if (buf == Z_NULL) return 1L; 5365 5366 while (len > 0) { 5367 k = len < NMAX ? len : NMAX; 5368 len -= k; 5369 while (k >= 16) { 5370 DO16(buf); 5371 buf += 16; 5372 k -= 16; 5373 } 5374 if (k != 0) do { 5375 s1 += *buf++; 5376 s2 += s1; 5377 } while (--k); 5378 s1 %= BASE; 5379 s2 %= BASE; 5380 } 5381 return (s2 << 16) | s1; 5382} 5383/* --- adler32.c */ 5384