zlib.c revision 130799
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 130799 2004-06-20 17:42:35Z markm $ 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#include <sys/param.h> 60#include <sys/kernel.h> 61#include <sys/module.h> 62# define HAVE_MEMCPY 63 64#else 65#if defined(__KERNEL__) 66/* Assume this is a Linux kernel */ 67#include <linux/string.h> 68#define HAVE_MEMCPY 69 70#else /* not kernel */ 71 72#if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS) 73# include <stddef.h> 74# include <errno.h> 75#else 76 extern int errno; 77#endif 78#ifdef STDC 79# include <string.h> 80# include <stdlib.h> 81#endif 82#endif /* __KERNEL__ */ 83#endif /* _KERNEL */ 84 85#ifndef local 86# define local static 87#endif 88/* compile with -Dlocal if your debugger can't find static symbols */ 89 90typedef unsigned char uch; 91typedef uch FAR uchf; 92typedef unsigned short ush; 93typedef ush FAR ushf; 94typedef unsigned long ulg; 95 96extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */ 97/* (size given to avoid silly warnings with Visual C++) */ 98 99#define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] 100 101#define ERR_RETURN(strm,err) \ 102 return (strm->msg = (const char*)ERR_MSG(err), (err)) 103/* To be used only when the state is known to be valid */ 104 105 /* common constants */ 106 107#ifndef DEF_WBITS 108# define DEF_WBITS MAX_WBITS 109#endif 110/* default windowBits for decompression. MAX_WBITS is for compression only */ 111 112#if MAX_MEM_LEVEL >= 8 113# define DEF_MEM_LEVEL 8 114#else 115# define DEF_MEM_LEVEL MAX_MEM_LEVEL 116#endif 117/* default memLevel */ 118 119#define STORED_BLOCK 0 120#define STATIC_TREES 1 121#define DYN_TREES 2 122/* The three kinds of block type */ 123 124#define MIN_MATCH 3 125#define MAX_MATCH 258 126/* The minimum and maximum match lengths */ 127 128#define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */ 129 130 /* target dependencies */ 131 132#ifdef MSDOS 133# define OS_CODE 0x00 134# ifdef __TURBOC__ 135# include <alloc.h> 136# else /* MSC or DJGPP */ 137# include <malloc.h> 138# endif 139#endif 140 141#ifdef OS2 142# define OS_CODE 0x06 143#endif 144 145#ifdef WIN32 /* Window 95 & Windows NT */ 146# define OS_CODE 0x0b 147#endif 148 149#if defined(VAXC) || defined(VMS) 150# define OS_CODE 0x02 151# define FOPEN(name, mode) \ 152 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") 153#endif 154 155#ifdef AMIGA 156# define OS_CODE 0x01 157#endif 158 159#if defined(ATARI) || defined(atarist) 160# define OS_CODE 0x05 161#endif 162 163#ifdef MACOS 164# define OS_CODE 0x07 165#endif 166 167#ifdef __50SERIES /* Prime/PRIMOS */ 168# define OS_CODE 0x0F 169#endif 170 171#ifdef TOPS20 172# define OS_CODE 0x0a 173#endif 174 175#if defined(_BEOS_) || defined(RISCOS) 176# define fdopen(fd,mode) NULL /* No fdopen() */ 177#endif 178 179 /* Common defaults */ 180 181#ifndef OS_CODE 182# define OS_CODE 0x03 /* assume Unix */ 183#endif 184 185#ifndef FOPEN 186# define FOPEN(name, mode) fopen((name), (mode)) 187#endif 188 189 /* functions */ 190 191#ifdef HAVE_STRERROR 192 extern char *strerror OF((int)); 193# define zstrerror(errnum) strerror(errnum) 194#else 195# define zstrerror(errnum) "" 196#endif 197 198#if defined(pyr) 199# define NO_MEMCPY 200#endif 201#if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER) 202 /* Use our own functions for small and medium model with MSC <= 5.0. 203 * You may have to use the same strategy for Borland C (untested). 204 */ 205# define NO_MEMCPY 206#endif 207#if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 208# define HAVE_MEMCPY 209#endif 210#ifdef HAVE_MEMCPY 211# ifdef SMALL_MEDIUM /* MSDOS small or medium model */ 212# define zmemcpy _fmemcpy 213# define zmemcmp _fmemcmp 214# define zmemzero(dest, len) _fmemset(dest, 0, len) 215# else 216# define zmemcpy memcpy 217# define zmemcmp memcmp 218# define zmemzero(dest, len) memset(dest, 0, len) 219# endif 220#else 221 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); 222 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len)); 223 extern void zmemzero OF((Bytef* dest, uInt len)); 224#endif 225 226/* Diagnostic functions */ 227#ifdef DEBUG_ZLIB 228# include <stdio.h> 229# ifndef verbose 230# define verbose 0 231# endif 232 extern void z_error OF((char *m)); 233# define Assert(cond,msg) {if(!(cond)) z_error(msg);} 234# define Trace(x) fprintf x 235# define Tracev(x) {if (verbose) fprintf x ;} 236# define Tracevv(x) {if (verbose>1) fprintf x ;} 237# define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 238# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 239#else 240# define Assert(cond,msg) 241# define Trace(x) 242# define Tracev(x) 243# define Tracevv(x) 244# define Tracec(c,x) 245# define Tracecv(c,x) 246#endif 247 248 249typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len)); 250 251voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); 252void zcfree OF((voidpf opaque, voidpf ptr)); 253 254#define ZALLOC(strm, items, size) \ 255 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 256#define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr)) 257#define TRY_FREE(s, p) {if (p) ZFREE(s, p);} 258 259#endif /* _Z_UTIL_H */ 260/* --- zutil.h */ 261 262/* +++ deflate.h */ 263/* deflate.h -- internal compression state 264 * Copyright (C) 1995-1996 Jean-loup Gailly 265 * For conditions of distribution and use, see copyright notice in zlib.h 266 */ 267 268/* WARNING: this file should *not* be used by applications. It is 269 part of the implementation of the compression library and is 270 subject to change. Applications should only use zlib.h. 271 */ 272 273/* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */ 274 275#ifndef _DEFLATE_H 276#define _DEFLATE_H 277 278/* #include "zutil.h" */ 279 280/* =========================================================================== 281 * Internal compression state. 282 */ 283 284#define LENGTH_CODES 29 285/* number of length codes, not counting the special END_BLOCK code */ 286 287#define LITERALS 256 288/* number of literal bytes 0..255 */ 289 290#define L_CODES (LITERALS+1+LENGTH_CODES) 291/* number of Literal or Length codes, including the END_BLOCK code */ 292 293#define D_CODES 30 294/* number of distance codes */ 295 296#define BL_CODES 19 297/* number of codes used to transfer the bit lengths */ 298 299#define HEAP_SIZE (2*L_CODES+1) 300/* maximum heap size */ 301 302#define MAX_BITS 15 303/* All codes must not exceed MAX_BITS bits */ 304 305#define INIT_STATE 42 306#define BUSY_STATE 113 307#define FINISH_STATE 666 308/* Stream status */ 309 310 311/* Data structure describing a single value and its code string. */ 312typedef struct ct_data_s { 313 union { 314 ush freq; /* frequency count */ 315 ush code; /* bit string */ 316 } fc; 317 union { 318 ush dad; /* father node in Huffman tree */ 319 ush len; /* length of bit string */ 320 } dl; 321} FAR ct_data; 322 323#define Freq fc.freq 324#define Code fc.code 325#define Dad dl.dad 326#define Len dl.len 327 328typedef struct static_tree_desc_s static_tree_desc; 329 330typedef struct tree_desc_s { 331 ct_data *dyn_tree; /* the dynamic tree */ 332 int max_code; /* largest code with non zero frequency */ 333 static_tree_desc *stat_desc; /* the corresponding static tree */ 334} FAR tree_desc; 335 336typedef ush Pos; 337typedef Pos FAR Posf; 338typedef unsigned IPos; 339 340/* A Pos is an index in the character window. We use short instead of int to 341 * save space in the various tables. IPos is used only for parameter passing. 342 */ 343 344typedef struct deflate_state { 345 z_streamp strm; /* pointer back to this zlib stream */ 346 int status; /* as the name implies */ 347 Bytef *pending_buf; /* output still pending */ 348 ulg pending_buf_size; /* size of pending_buf */ 349 Bytef *pending_out; /* next pending byte to output to the stream */ 350 int pending; /* nb of bytes in the pending buffer */ 351 int noheader; /* suppress zlib header and adler32 */ 352 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 353 Byte method; /* STORED (for zip only) or DEFLATED */ 354 int last_flush; /* value of flush param for previous deflate call */ 355 356 /* used by deflate.c: */ 357 358 uInt w_size; /* LZ77 window size (32K by default) */ 359 uInt w_bits; /* log2(w_size) (8..16) */ 360 uInt w_mask; /* w_size - 1 */ 361 362 Bytef *window; 363 /* Sliding window. Input bytes are read into the second half of the window, 364 * and move to the first half later to keep a dictionary of at least wSize 365 * bytes. With this organization, matches are limited to a distance of 366 * wSize-MAX_MATCH bytes, but this ensures that IO is always 367 * performed with a length multiple of the block size. Also, it limits 368 * the window size to 64K, which is quite useful on MSDOS. 369 * To do: use the user input buffer as sliding window. 370 */ 371 372 ulg window_size; 373 /* Actual size of window: 2*wSize, except when the user input buffer 374 * is directly used as sliding window. 375 */ 376 377 Posf *prev; 378 /* Link to older string with same hash index. To limit the size of this 379 * array to 64K, this link is maintained only for the last 32K strings. 380 * An index in this array is thus a window index modulo 32K. 381 */ 382 383 Posf *head; /* Heads of the hash chains or NIL. */ 384 385 uInt ins_h; /* hash index of string to be inserted */ 386 uInt hash_size; /* number of elements in hash table */ 387 uInt hash_bits; /* log2(hash_size) */ 388 uInt hash_mask; /* hash_size-1 */ 389 390 uInt hash_shift; 391 /* Number of bits by which ins_h must be shifted at each input 392 * step. It must be such that after MIN_MATCH steps, the oldest 393 * byte no longer takes part in the hash key, that is: 394 * hash_shift * MIN_MATCH >= hash_bits 395 */ 396 397 long block_start; 398 /* Window position at the beginning of the current output block. Gets 399 * negative when the window is moved backwards. 400 */ 401 402 uInt match_length; /* length of best match */ 403 IPos prev_match; /* previous match */ 404 int match_available; /* set if previous match exists */ 405 uInt strstart; /* start of string to insert */ 406 uInt match_start; /* start of matching string */ 407 uInt lookahead; /* number of valid bytes ahead in window */ 408 409 uInt prev_length; 410 /* Length of the best match at previous step. Matches not greater than this 411 * are discarded. This is used in the lazy match evaluation. 412 */ 413 414 uInt max_chain_length; 415 /* To speed up deflation, hash chains are never searched beyond this 416 * length. A higher limit improves compression ratio but degrades the 417 * speed. 418 */ 419 420 uInt max_lazy_match; 421 /* Attempt to find a better match only when the current match is strictly 422 * smaller than this value. This mechanism is used only for compression 423 * levels >= 4. 424 */ 425# define max_insert_length max_lazy_match 426 /* Insert new strings in the hash table only if the match length is not 427 * greater than this length. This saves time but degrades compression. 428 * max_insert_length is used only for compression levels <= 3. 429 */ 430 431 int level; /* compression level (1..9) */ 432 int strategy; /* favor or force Huffman coding*/ 433 434 uInt good_match; 435 /* Use a faster search when the previous match is longer than this */ 436 437 int nice_match; /* Stop searching when current match exceeds this */ 438 439 /* used by trees.c: */ 440 /* Didn't use ct_data typedef below to supress compiler warning */ 441 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 442 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 443 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 444 445 struct tree_desc_s l_desc; /* desc. for literal tree */ 446 struct tree_desc_s d_desc; /* desc. for distance tree */ 447 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 448 449 ush bl_count[MAX_BITS+1]; 450 /* number of codes at each bit length for an optimal tree */ 451 452 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 453 int heap_len; /* number of elements in the heap */ 454 int heap_max; /* element of largest frequency */ 455 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 456 * The same heap array is used to build all trees. 457 */ 458 459 uch depth[2*L_CODES+1]; 460 /* Depth of each subtree used as tie breaker for trees of equal frequency 461 */ 462 463 uchf *l_buf; /* buffer for literals or lengths */ 464 465 uInt lit_bufsize; 466 /* Size of match buffer for literals/lengths. There are 4 reasons for 467 * limiting lit_bufsize to 64K: 468 * - frequencies can be kept in 16 bit counters 469 * - if compression is not successful for the first block, all input 470 * data is still in the window so we can still emit a stored block even 471 * when input comes from standard input. (This can also be done for 472 * all blocks if lit_bufsize is not greater than 32K.) 473 * - if compression is not successful for a file smaller than 64K, we can 474 * even emit a stored file instead of a stored block (saving 5 bytes). 475 * This is applicable only for zip (not gzip or zlib). 476 * - creating new Huffman trees less frequently may not provide fast 477 * adaptation to changes in the input data statistics. (Take for 478 * example a binary file with poorly compressible code followed by 479 * a highly compressible string table.) Smaller buffer sizes give 480 * fast adaptation but have of course the overhead of transmitting 481 * trees more frequently. 482 * - I can't count above 4 483 */ 484 485 uInt last_lit; /* running index in l_buf */ 486 487 ushf *d_buf; 488 /* Buffer for distances. To simplify the code, d_buf and l_buf have 489 * the same number of elements. To use different lengths, an extra flag 490 * array would be necessary. 491 */ 492 493 ulg opt_len; /* bit length of current block with optimal trees */ 494 ulg static_len; /* bit length of current block with static trees */ 495 ulg compressed_len; /* total bit length of compressed file */ 496 uInt matches; /* number of string matches in current block */ 497 int last_eob_len; /* bit length of EOB code for last block */ 498 499#ifdef DEBUG_ZLIB 500 ulg bits_sent; /* bit length of the compressed data */ 501#endif 502 503 ush bi_buf; 504 /* Output buffer. bits are inserted starting at the bottom (least 505 * significant bits). 506 */ 507 int bi_valid; 508 /* Number of valid bits in bi_buf. All bits above the last valid bit 509 * are always zero. 510 */ 511 512} FAR deflate_state; 513 514/* Output a byte on the stream. 515 * IN assertion: there is enough room in pending_buf. 516 */ 517#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 518 519 520#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 521/* Minimum amount of lookahead, except at the end of the input file. 522 * See deflate.c for comments about the MIN_MATCH+1. 523 */ 524 525#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 526/* In order to simplify the code, particularly on 16 bit machines, match 527 * distances are limited to MAX_DIST instead of WSIZE. 528 */ 529 530 /* in trees.c */ 531void _tr_init OF((deflate_state *s)); 532int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); 533ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 534 int eof)); 535void _tr_align OF((deflate_state *s)); 536void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 537 int eof)); 538void _tr_stored_type_only OF((deflate_state *)); 539 540#endif 541/* --- deflate.h */ 542 543/* +++ deflate.c */ 544/* deflate.c -- compress data using the deflation algorithm 545 * Copyright (C) 1995-1996 Jean-loup Gailly. 546 * For conditions of distribution and use, see copyright notice in zlib.h 547 */ 548 549/* 550 * ALGORITHM 551 * 552 * The "deflation" process depends on being able to identify portions 553 * of the input text which are identical to earlier input (within a 554 * sliding window trailing behind the input currently being processed). 555 * 556 * The most straightforward technique turns out to be the fastest for 557 * most input files: try all possible matches and select the longest. 558 * The key feature of this algorithm is that insertions into the string 559 * dictionary are very simple and thus fast, and deletions are avoided 560 * completely. Insertions are performed at each input character, whereas 561 * string matches are performed only when the previous match ends. So it 562 * is preferable to spend more time in matches to allow very fast string 563 * insertions and avoid deletions. The matching algorithm for small 564 * strings is inspired from that of Rabin & Karp. A brute force approach 565 * is used to find longer strings when a small match has been found. 566 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 567 * (by Leonid Broukhis). 568 * A previous version of this file used a more sophisticated algorithm 569 * (by Fiala and Greene) which is guaranteed to run in linear amortized 570 * time, but has a larger average cost, uses more memory and is patented. 571 * However the F&G algorithm may be faster for some highly redundant 572 * files if the parameter max_chain_length (described below) is too large. 573 * 574 * ACKNOWLEDGEMENTS 575 * 576 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 577 * I found it in 'freeze' written by Leonid Broukhis. 578 * Thanks to many people for bug reports and testing. 579 * 580 * REFERENCES 581 * 582 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". 583 * Available in ftp://ds.internic.net/rfc/rfc1951.txt 584 * 585 * A description of the Rabin and Karp algorithm is given in the book 586 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 587 * 588 * Fiala,E.R., and Greene,D.H. 589 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 590 * 591 */ 592 593/* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */ 594 595/* #include "deflate.h" */ 596 597char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly "; 598/* 599 If you use the zlib library in a product, an acknowledgment is welcome 600 in the documentation of your product. If for some reason you cannot 601 include such an acknowledgment, I would appreciate that you keep this 602 copyright string in the executable of your product. 603 */ 604 605/* =========================================================================== 606 * Function prototypes. 607 */ 608typedef enum { 609 need_more, /* block not completed, need more input or more output */ 610 block_done, /* block flush performed */ 611 finish_started, /* finish started, need only more output at next deflate */ 612 finish_done /* finish done, accept no more input or output */ 613} block_state; 614 615typedef block_state (*compress_func) OF((deflate_state *s, int flush)); 616/* Compression function. Returns the block state after the call. */ 617 618local void fill_window OF((deflate_state *s)); 619local block_state deflate_stored OF((deflate_state *s, int flush)); 620local block_state deflate_fast OF((deflate_state *s, int flush)); 621local block_state deflate_slow OF((deflate_state *s, int flush)); 622local void lm_init OF((deflate_state *s)); 623local void putShortMSB OF((deflate_state *s, uInt b)); 624local void flush_pending OF((z_streamp strm)); 625local int read_buf OF((z_streamp strm, charf *buf, unsigned size)); 626#ifdef ASMV 627 void match_init OF((void)); /* asm code initialization */ 628 uInt longest_match OF((deflate_state *s, IPos cur_match)); 629#else 630local uInt longest_match OF((deflate_state *s, IPos cur_match)); 631#endif 632 633#ifdef DEBUG_ZLIB 634local void check_match OF((deflate_state *s, IPos start, IPos match, 635 int length)); 636#endif 637 638/* =========================================================================== 639 * Local data 640 */ 641 642#define NIL 0 643/* Tail of hash chains */ 644 645#ifndef TOO_FAR 646# define TOO_FAR 4096 647#endif 648/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 649 650#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 651/* Minimum amount of lookahead, except at the end of the input file. 652 * See deflate.c for comments about the MIN_MATCH+1. 653 */ 654 655/* Values for max_lazy_match, good_match and max_chain_length, depending on 656 * the desired pack level (0..9). The values given below have been tuned to 657 * exclude worst case performance for pathological files. Better values may be 658 * found for specific files. 659 */ 660typedef struct config_s { 661 ush good_length; /* reduce lazy search above this match length */ 662 ush max_lazy; /* do not perform lazy search above this match length */ 663 ush nice_length; /* quit search above this match length */ 664 ush max_chain; 665 compress_func func; 666} config; 667 668local config configuration_table[10] = { 669/* good lazy nice chain */ 670/* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ 671/* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */ 672/* 2 */ {4, 5, 16, 8, deflate_fast}, 673/* 3 */ {4, 6, 32, 32, deflate_fast}, 674 675/* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ 676/* 5 */ {8, 16, 32, 32, deflate_slow}, 677/* 6 */ {8, 16, 128, 128, deflate_slow}, 678/* 7 */ {8, 32, 128, 256, deflate_slow}, 679/* 8 */ {32, 128, 258, 1024, deflate_slow}, 680/* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */ 681 682/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 683 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 684 * meaning. 685 */ 686 687#define EQUAL 0 688/* result of memcmp for equal strings */ 689 690#ifndef NO_DUMMY_DECL 691struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ 692#endif 693 694/* =========================================================================== 695 * Update a hash value with the given input byte 696 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 697 * input characters, so that a running hash key can be computed from the 698 * previous key instead of complete recalculation each time. 699 */ 700#define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 701 702 703/* =========================================================================== 704 * Insert string str in the dictionary and set match_head to the previous head 705 * of the hash chain (the most recent string with same hash key). Return 706 * the previous length of the hash chain. 707 * IN assertion: all calls to to INSERT_STRING are made with consecutive 708 * input characters and the first MIN_MATCH bytes of str are valid 709 * (except for the last MIN_MATCH-1 bytes of the input file). 710 */ 711#define INSERT_STRING(s, str, match_head) \ 712 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 713 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 714 s->head[s->ins_h] = (Pos)(str)) 715 716/* =========================================================================== 717 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 718 * prev[] will be initialized on the fly. 719 */ 720#define CLEAR_HASH(s) \ 721 s->head[s->hash_size-1] = NIL; \ 722 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 723 724/* ========================================================================= */ 725int deflateInit_(strm, level, version, stream_size) 726 z_streamp strm; 727 int level; 728 const char *version; 729 int stream_size; 730{ 731 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 732 Z_DEFAULT_STRATEGY, version, stream_size); 733 /* To do: ignore strm->next_in if we use it as window */ 734} 735 736/* ========================================================================= */ 737int deflateInit2_(strm, level, method, windowBits, memLevel, strategy, 738 version, stream_size) 739 z_streamp strm; 740 int level; 741 int method; 742 int windowBits; 743 int memLevel; 744 int strategy; 745 const char *version; 746 int stream_size; 747{ 748 deflate_state *s; 749 int noheader = 0; 750 static char* my_version = ZLIB_VERSION; 751 752 ushf *overlay; 753 /* We overlay pending_buf and d_buf+l_buf. This works since the average 754 * output size for (length,distance) codes is <= 24 bits. 755 */ 756 757 if (version == Z_NULL || version[0] != my_version[0] || 758 stream_size != sizeof(z_stream)) { 759 return Z_VERSION_ERROR; 760 } 761 if (strm == Z_NULL) return Z_STREAM_ERROR; 762 763 strm->msg = Z_NULL; 764#ifndef NO_ZCFUNCS 765 if (strm->zalloc == Z_NULL) { 766 strm->zalloc = zcalloc; 767 strm->opaque = (voidpf)0; 768 } 769 if (strm->zfree == Z_NULL) strm->zfree = zcfree; 770#endif 771 772 if (level == Z_DEFAULT_COMPRESSION) level = 6; 773 774 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 775 noheader = 1; 776 windowBits = -windowBits; 777 } 778 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || 779 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 || 780 strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 781 return Z_STREAM_ERROR; 782 } 783 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 784 if (s == Z_NULL) return Z_MEM_ERROR; 785 strm->state = (struct internal_state FAR *)s; 786 s->strm = strm; 787 788 s->noheader = noheader; 789 s->w_bits = windowBits; 790 s->w_size = 1 << s->w_bits; 791 s->w_mask = s->w_size - 1; 792 793 s->hash_bits = memLevel + 7; 794 s->hash_size = 1 << s->hash_bits; 795 s->hash_mask = s->hash_size - 1; 796 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 797 798 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 799 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 800 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 801 802 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 803 804 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); 805 s->pending_buf = (uchf *) overlay; 806 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); 807 808 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 809 s->pending_buf == Z_NULL) { 810 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR); 811 deflateEnd (strm); 812 return Z_MEM_ERROR; 813 } 814 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); 815 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; 816 817 s->level = level; 818 s->strategy = strategy; 819 s->method = (Byte)method; 820 821 return deflateReset(strm); 822} 823 824/* ========================================================================= */ 825int deflateSetDictionary (strm, dictionary, dictLength) 826 z_streamp strm; 827 const Bytef *dictionary; 828 uInt dictLength; 829{ 830 deflate_state *s; 831 uInt length = dictLength; 832 uInt n; 833 IPos hash_head = 0; 834 835 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) 836 return Z_STREAM_ERROR; 837 838 s = (deflate_state *) strm->state; 839 if (s->status != INIT_STATE) return Z_STREAM_ERROR; 840 841 strm->adler = adler32(strm->adler, dictionary, dictLength); 842 843 if (length < MIN_MATCH) return Z_OK; 844 if (length > MAX_DIST(s)) { 845 length = MAX_DIST(s); 846#ifndef USE_DICT_HEAD 847 dictionary += dictLength - length; /* use the tail of the dictionary */ 848#endif 849 } 850 zmemcpy((charf *)s->window, dictionary, length); 851 s->strstart = length; 852 s->block_start = (long)length; 853 854 /* Insert all strings in the hash table (except for the last two bytes). 855 * s->lookahead stays null, so s->ins_h will be recomputed at the next 856 * call of fill_window. 857 */ 858 s->ins_h = s->window[0]; 859 UPDATE_HASH(s, s->ins_h, s->window[1]); 860 for (n = 0; n <= length - MIN_MATCH; n++) { 861 INSERT_STRING(s, n, hash_head); 862 } 863 if (hash_head) hash_head = 0; /* to make compiler happy */ 864 return Z_OK; 865} 866 867/* ========================================================================= */ 868int deflateReset (strm) 869 z_streamp strm; 870{ 871 deflate_state *s; 872 873 if (strm == Z_NULL || strm->state == Z_NULL || 874 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 875 876 strm->total_in = strm->total_out = 0; 877 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 878 strm->data_type = Z_UNKNOWN; 879 880 s = (deflate_state *)strm->state; 881 s->pending = 0; 882 s->pending_out = s->pending_buf; 883 884 if (s->noheader < 0) { 885 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 886 } 887 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 888 strm->adler = 1; 889 s->last_flush = Z_NO_FLUSH; 890 891 _tr_init(s); 892 lm_init(s); 893 894 return Z_OK; 895} 896 897/* ========================================================================= */ 898int deflateParams(strm, level, strategy) 899 z_streamp strm; 900 int level; 901 int strategy; 902{ 903 deflate_state *s; 904 compress_func func; 905 int err = Z_OK; 906 907 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 908 s = (deflate_state *) strm->state; 909 910 if (level == Z_DEFAULT_COMPRESSION) { 911 level = 6; 912 } 913 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 914 return Z_STREAM_ERROR; 915 } 916 func = configuration_table[s->level].func; 917 918 if (func != configuration_table[level].func && strm->total_in != 0) { 919 /* Flush the last buffer: */ 920 err = deflate(strm, Z_PARTIAL_FLUSH); 921 } 922 if (s->level != level) { 923 s->level = level; 924 s->max_lazy_match = configuration_table[level].max_lazy; 925 s->good_match = configuration_table[level].good_length; 926 s->nice_match = configuration_table[level].nice_length; 927 s->max_chain_length = configuration_table[level].max_chain; 928 } 929 s->strategy = strategy; 930 return err; 931} 932 933/* ========================================================================= 934 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 935 * IN assertion: the stream state is correct and there is enough room in 936 * pending_buf. 937 */ 938local void putShortMSB (s, b) 939 deflate_state *s; 940 uInt b; 941{ 942 put_byte(s, (Byte)(b >> 8)); 943 put_byte(s, (Byte)(b & 0xff)); 944} 945 946/* ========================================================================= 947 * Flush as much pending output as possible. All deflate() output goes 948 * through this function so some applications may wish to modify it 949 * to avoid allocating a large strm->next_out buffer and copying into it. 950 * (See also read_buf()). 951 */ 952local void flush_pending(strm) 953 z_streamp strm; 954{ 955 deflate_state *s = (deflate_state *) strm->state; 956 unsigned len = s->pending; 957 958 if (len > strm->avail_out) len = strm->avail_out; 959 if (len == 0) return; 960 961 if (strm->next_out != Z_NULL) { 962 zmemcpy(strm->next_out, s->pending_out, len); 963 strm->next_out += len; 964 } 965 s->pending_out += len; 966 strm->total_out += len; 967 strm->avail_out -= len; 968 s->pending -= len; 969 if (s->pending == 0) { 970 s->pending_out = s->pending_buf; 971 } 972} 973 974/* ========================================================================= */ 975int deflate (strm, flush) 976 z_streamp strm; 977 int flush; 978{ 979 int old_flush; /* value of flush param for previous deflate call */ 980 deflate_state *s; 981 982 if (strm == Z_NULL || strm->state == Z_NULL || 983 flush > Z_FINISH || flush < 0) { 984 return Z_STREAM_ERROR; 985 } 986 s = (deflate_state *) strm->state; 987 988 if ((strm->next_in == Z_NULL && strm->avail_in != 0) || 989 (s->status == FINISH_STATE && flush != Z_FINISH)) { 990 ERR_RETURN(strm, Z_STREAM_ERROR); 991 } 992 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 993 994 s->strm = strm; /* just in case */ 995 old_flush = s->last_flush; 996 s->last_flush = flush; 997 998 /* Write the zlib header */ 999 if (s->status == INIT_STATE) { 1000 1001 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; 1002 uInt level_flags = (s->level-1) >> 1; 1003 1004 if (level_flags > 3) level_flags = 3; 1005 header |= (level_flags << 6); 1006 if (s->strstart != 0) header |= PRESET_DICT; 1007 header += 31 - (header % 31); 1008 1009 s->status = BUSY_STATE; 1010 putShortMSB(s, header); 1011 1012 /* Save the adler32 of the preset dictionary: */ 1013 if (s->strstart != 0) { 1014 putShortMSB(s, (uInt)(strm->adler >> 16)); 1015 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1016 } 1017 strm->adler = 1L; 1018 } 1019 1020 /* Flush as much pending output as possible */ 1021 if (s->pending != 0) { 1022 flush_pending(strm); 1023 if (strm->avail_out == 0) { 1024 /* Since avail_out is 0, deflate will be called again with 1025 * more output space, but possibly with both pending and 1026 * avail_in equal to zero. There won't be anything to do, 1027 * but this is not an error situation so make sure we 1028 * return OK instead of BUF_ERROR at next call of deflate: 1029 */ 1030 s->last_flush = -1; 1031 return Z_OK; 1032 } 1033 1034 /* Make sure there is something to do and avoid duplicate consecutive 1035 * flushes. For repeated and useless calls with Z_FINISH, we keep 1036 * returning Z_STREAM_END instead of Z_BUFF_ERROR. 1037 */ 1038 } else if (strm->avail_in == 0 && flush <= old_flush && 1039 flush != Z_FINISH) { 1040 ERR_RETURN(strm, Z_BUF_ERROR); 1041 } 1042 1043 /* User must not provide more input after the first FINISH: */ 1044 if (s->status == FINISH_STATE && strm->avail_in != 0) { 1045 ERR_RETURN(strm, Z_BUF_ERROR); 1046 } 1047 1048 /* Start a new block or continue the current one. 1049 */ 1050 if (strm->avail_in != 0 || s->lookahead != 0 || 1051 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { 1052 block_state bstate; 1053 1054 bstate = (*(configuration_table[s->level].func))(s, flush); 1055 1056 if (bstate == finish_started || bstate == finish_done) { 1057 s->status = FINISH_STATE; 1058 } 1059 if (bstate == need_more || bstate == finish_started) { 1060 if (strm->avail_out == 0) { 1061 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ 1062 } 1063 return Z_OK; 1064 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 1065 * of deflate should use the same flush parameter to make sure 1066 * that the flush is complete. So we don't have to output an 1067 * empty block here, this will be done at next call. This also 1068 * ensures that for a very small output buffer, we emit at most 1069 * one empty block. 1070 */ 1071 } 1072 if (bstate == block_done) { 1073 if (flush == Z_PARTIAL_FLUSH) { 1074 _tr_align(s); 1075 } else if (flush == Z_PACKET_FLUSH) { 1076 /* Output just the 3-bit `stored' block type value, 1077 but not a zero length. */ 1078 _tr_stored_type_only(s); 1079 } else { /* FULL_FLUSH or SYNC_FLUSH */ 1080 _tr_stored_block(s, (char*)0, 0L, 0); 1081 /* For a full flush, this empty block will be recognized 1082 * as a special marker by inflate_sync(). 1083 */ 1084 if (flush == Z_FULL_FLUSH) { 1085 CLEAR_HASH(s); /* forget history */ 1086 } 1087 } 1088 flush_pending(strm); 1089 if (strm->avail_out == 0) { 1090 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ 1091 return Z_OK; 1092 } 1093 } 1094 } 1095 Assert(strm->avail_out > 0, "bug2"); 1096 1097 if (flush != Z_FINISH) return Z_OK; 1098 if (s->noheader) return Z_STREAM_END; 1099 1100 /* Write the zlib trailer (adler32) */ 1101 putShortMSB(s, (uInt)(strm->adler >> 16)); 1102 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1103 flush_pending(strm); 1104 /* If avail_out is zero, the application will call deflate again 1105 * to flush the rest. 1106 */ 1107 s->noheader = -1; /* write the trailer only once! */ 1108 return s->pending != 0 ? Z_OK : Z_STREAM_END; 1109} 1110 1111/* ========================================================================= */ 1112int deflateEnd (strm) 1113 z_streamp strm; 1114{ 1115 int status; 1116 deflate_state *s; 1117 1118 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 1119 s = (deflate_state *) strm->state; 1120 1121 status = s->status; 1122 if (status != INIT_STATE && status != BUSY_STATE && 1123 status != FINISH_STATE) { 1124 return Z_STREAM_ERROR; 1125 } 1126 1127 /* Deallocate in reverse order of allocations: */ 1128 TRY_FREE(strm, s->pending_buf); 1129 TRY_FREE(strm, s->head); 1130 TRY_FREE(strm, s->prev); 1131 TRY_FREE(strm, s->window); 1132 1133 ZFREE(strm, s); 1134 strm->state = Z_NULL; 1135 1136 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; 1137} 1138 1139/* ========================================================================= 1140 * Copy the source state to the destination state. 1141 */ 1142int deflateCopy (dest, source) 1143 z_streamp dest; 1144 z_streamp source; 1145{ 1146 deflate_state *ds; 1147 deflate_state *ss; 1148 ushf *overlay; 1149 1150 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) 1151 return Z_STREAM_ERROR; 1152 ss = (deflate_state *) source->state; 1153 1154 zmemcpy(dest, source, sizeof(*dest)); 1155 1156 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); 1157 if (ds == Z_NULL) return Z_MEM_ERROR; 1158 dest->state = (struct internal_state FAR *) ds; 1159 zmemcpy(ds, ss, sizeof(*ds)); 1160 ds->strm = dest; 1161 1162 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); 1163 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); 1164 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); 1165 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); 1166 ds->pending_buf = (uchf *) overlay; 1167 1168 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || 1169 ds->pending_buf == Z_NULL) { 1170 deflateEnd (dest); 1171 return Z_MEM_ERROR; 1172 } 1173 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ 1174 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); 1175 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); 1176 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); 1177 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); 1178 1179 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); 1180 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); 1181 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; 1182 1183 ds->l_desc.dyn_tree = ds->dyn_ltree; 1184 ds->d_desc.dyn_tree = ds->dyn_dtree; 1185 ds->bl_desc.dyn_tree = ds->bl_tree; 1186 1187 return Z_OK; 1188} 1189 1190/* =========================================================================== 1191 * Return the number of bytes of output which are immediately available 1192 * for output from the decompressor. 1193 */ 1194int deflateOutputPending (strm) 1195 z_streamp strm; 1196{ 1197 if (strm == Z_NULL || strm->state == Z_NULL) return 0; 1198 1199 return ((deflate_state *)(strm->state))->pending; 1200} 1201 1202/* =========================================================================== 1203 * Read a new buffer from the current input stream, update the adler32 1204 * and total number of bytes read. All deflate() input goes through 1205 * this function so some applications may wish to modify it to avoid 1206 * allocating a large strm->next_in buffer and copying from it. 1207 * (See also flush_pending()). 1208 */ 1209local int read_buf(strm, buf, size) 1210 z_streamp strm; 1211 charf *buf; 1212 unsigned size; 1213{ 1214 unsigned len = strm->avail_in; 1215 1216 if (len > size) len = size; 1217 if (len == 0) return 0; 1218 1219 strm->avail_in -= len; 1220 1221 if (!((deflate_state *)(strm->state))->noheader) { 1222 strm->adler = adler32(strm->adler, strm->next_in, len); 1223 } 1224 zmemcpy(buf, strm->next_in, len); 1225 strm->next_in += len; 1226 strm->total_in += len; 1227 1228 return (int)len; 1229} 1230 1231/* =========================================================================== 1232 * Initialize the "longest match" routines for a new zlib stream 1233 */ 1234local void lm_init (s) 1235 deflate_state *s; 1236{ 1237 s->window_size = (ulg)2L*s->w_size; 1238 1239 CLEAR_HASH(s); 1240 1241 /* Set the default configuration parameters: 1242 */ 1243 s->max_lazy_match = configuration_table[s->level].max_lazy; 1244 s->good_match = configuration_table[s->level].good_length; 1245 s->nice_match = configuration_table[s->level].nice_length; 1246 s->max_chain_length = configuration_table[s->level].max_chain; 1247 1248 s->strstart = 0; 1249 s->block_start = 0L; 1250 s->lookahead = 0; 1251 s->match_length = s->prev_length = MIN_MATCH-1; 1252 s->match_available = 0; 1253 s->ins_h = 0; 1254#ifdef ASMV 1255 match_init(); /* initialize the asm code */ 1256#endif 1257} 1258 1259/* =========================================================================== 1260 * Set match_start to the longest match starting at the given string and 1261 * return its length. Matches shorter or equal to prev_length are discarded, 1262 * in which case the result is equal to prev_length and match_start is 1263 * garbage. 1264 * IN assertions: cur_match is the head of the hash chain for the current 1265 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 1266 * OUT assertion: the match length is not greater than s->lookahead. 1267 */ 1268#ifndef ASMV 1269/* For 80x86 and 680x0, an optimized version will be provided in match.asm or 1270 * match.S. The code will be functionally equivalent. 1271 */ 1272local uInt longest_match(s, cur_match) 1273 deflate_state *s; 1274 IPos cur_match; /* current match */ 1275{ 1276 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 1277 register Bytef *scan = s->window + s->strstart; /* current string */ 1278 register Bytef *match; /* matched string */ 1279 register int len; /* length of current match */ 1280 int best_len = s->prev_length; /* best match length so far */ 1281 int nice_match = s->nice_match; /* stop if match long enough */ 1282 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 1283 s->strstart - (IPos)MAX_DIST(s) : NIL; 1284 /* Stop when cur_match becomes <= limit. To simplify the code, 1285 * we prevent matches with the string of window index 0. 1286 */ 1287 Posf *prev = s->prev; 1288 uInt wmask = s->w_mask; 1289 1290#ifdef UNALIGNED_OK 1291 /* Compare two bytes at a time. Note: this is not always beneficial. 1292 * Try with and without -DUNALIGNED_OK to check. 1293 */ 1294 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 1295 register ush scan_start = *(ushf*)scan; 1296 register ush scan_end = *(ushf*)(scan+best_len-1); 1297#else 1298 register Bytef *strend = s->window + s->strstart + MAX_MATCH; 1299 register Byte scan_end1 = scan[best_len-1]; 1300 register Byte scan_end = scan[best_len]; 1301#endif 1302 1303 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 1304 * It is easy to get rid of this optimization if necessary. 1305 */ 1306 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 1307 1308 /* Do not waste too much time if we already have a good match: */ 1309 if (s->prev_length >= s->good_match) { 1310 chain_length >>= 2; 1311 } 1312 /* Do not look for matches beyond the end of the input. This is necessary 1313 * to make deflate deterministic. 1314 */ 1315 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; 1316 1317 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1318 1319 do { 1320 Assert(cur_match < s->strstart, "no future"); 1321 match = s->window + cur_match; 1322 1323 /* Skip to next match if the match length cannot increase 1324 * or if the match length is less than 2: 1325 */ 1326#if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1327 /* This code assumes sizeof(unsigned short) == 2. Do not use 1328 * UNALIGNED_OK if your compiler uses a different size. 1329 */ 1330 if (*(ushf*)(match+best_len-1) != scan_end || 1331 *(ushf*)match != scan_start) continue; 1332 1333 /* It is not necessary to compare scan[2] and match[2] since they are 1334 * always equal when the other bytes match, given that the hash keys 1335 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1336 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1337 * lookahead only every 4th comparison; the 128th check will be made 1338 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1339 * necessary to put more guard bytes at the end of the window, or 1340 * to check more often for insufficient lookahead. 1341 */ 1342 Assert(scan[2] == match[2], "scan[2]?"); 1343 scan++, match++; 1344 do { 1345 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1346 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1347 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1348 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1349 scan < strend); 1350 /* The funny "do {}" generates better code on most compilers */ 1351 1352 /* Here, scan <= window+strstart+257 */ 1353 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1354 if (*scan == *match) scan++; 1355 1356 len = (MAX_MATCH - 1) - (int)(strend-scan); 1357 scan = strend - (MAX_MATCH-1); 1358 1359#else /* UNALIGNED_OK */ 1360 1361 if (match[best_len] != scan_end || 1362 match[best_len-1] != scan_end1 || 1363 *match != *scan || 1364 *++match != scan[1]) continue; 1365 1366 /* The check at best_len-1 can be removed because it will be made 1367 * again later. (This heuristic is not always a win.) 1368 * It is not necessary to compare scan[2] and match[2] since they 1369 * are always equal when the other bytes match, given that 1370 * the hash keys are equal and that HASH_BITS >= 8. 1371 */ 1372 scan += 2, match++; 1373 Assert(*scan == *match, "match[2]?"); 1374 1375 /* We check for insufficient lookahead only every 8th comparison; 1376 * the 256th check will be made at strstart+258. 1377 */ 1378 do { 1379 } while (*++scan == *++match && *++scan == *++match && 1380 *++scan == *++match && *++scan == *++match && 1381 *++scan == *++match && *++scan == *++match && 1382 *++scan == *++match && *++scan == *++match && 1383 scan < strend); 1384 1385 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1386 1387 len = MAX_MATCH - (int)(strend - scan); 1388 scan = strend - MAX_MATCH; 1389 1390#endif /* UNALIGNED_OK */ 1391 1392 if (len > best_len) { 1393 s->match_start = cur_match; 1394 best_len = len; 1395 if (len >= nice_match) break; 1396#ifdef UNALIGNED_OK 1397 scan_end = *(ushf*)(scan+best_len-1); 1398#else 1399 scan_end1 = scan[best_len-1]; 1400 scan_end = scan[best_len]; 1401#endif 1402 } 1403 } while ((cur_match = prev[cur_match & wmask]) > limit 1404 && --chain_length != 0); 1405 1406 if ((uInt)best_len <= s->lookahead) return best_len; 1407 return s->lookahead; 1408} 1409#endif /* ASMV */ 1410 1411#ifdef DEBUG_ZLIB 1412/* =========================================================================== 1413 * Check that the match at match_start is indeed a match. 1414 */ 1415local void check_match(s, start, match, length) 1416 deflate_state *s; 1417 IPos start, match; 1418 int length; 1419{ 1420 /* check that the match is indeed a match */ 1421 if (zmemcmp((charf *)s->window + match, 1422 (charf *)s->window + start, length) != EQUAL) { 1423 fprintf(stderr, " start %u, match %u, length %d\n", 1424 start, match, length); 1425 do { 1426 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); 1427 } while (--length != 0); 1428 z_error("invalid match"); 1429 } 1430 if (z_verbose > 1) { 1431 fprintf(stderr,"\\[%d,%d]", start-match, length); 1432 do { putc(s->window[start++], stderr); } while (--length != 0); 1433 } 1434} 1435#else 1436# define check_match(s, start, match, length) 1437#endif 1438 1439/* =========================================================================== 1440 * Fill the window when the lookahead becomes insufficient. 1441 * Updates strstart and lookahead. 1442 * 1443 * IN assertion: lookahead < MIN_LOOKAHEAD 1444 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1445 * At least one byte has been read, or avail_in == 0; reads are 1446 * performed for at least two bytes (required for the zip translate_eol 1447 * option -- not supported here). 1448 */ 1449local void fill_window(s) 1450 deflate_state *s; 1451{ 1452 register unsigned n, m; 1453 register Posf *p; 1454 unsigned more; /* Amount of free space at the end of the window. */ 1455 uInt wsize = s->w_size; 1456 1457 do { 1458 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1459 1460 /* Deal with !@#$% 64K limit: */ 1461 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1462 more = wsize; 1463 1464 } else if (more == (unsigned)(-1)) { 1465 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1466 * and lookahead == 1 (input done one byte at time) 1467 */ 1468 more--; 1469 1470 /* If the window is almost full and there is insufficient lookahead, 1471 * move the upper half to the lower one to make room in the upper half. 1472 */ 1473 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1474 1475 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1476 (unsigned)wsize); 1477 s->match_start -= wsize; 1478 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1479 s->block_start -= (long) wsize; 1480 1481 /* Slide the hash table (could be avoided with 32 bit values 1482 at the expense of memory usage). We slide even when level == 0 1483 to keep the hash table consistent if we switch back to level > 0 1484 later. (Using level 0 permanently is not an optimal usage of 1485 zlib, so we don't care about this pathological case.) 1486 */ 1487 n = s->hash_size; 1488 p = &s->head[n]; 1489 do { 1490 m = *--p; 1491 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1492 } while (--n); 1493 1494 n = wsize; 1495 p = &s->prev[n]; 1496 do { 1497 m = *--p; 1498 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1499 /* If n is not on any hash chain, prev[n] is garbage but 1500 * its value will never be used. 1501 */ 1502 } while (--n); 1503 more += wsize; 1504 } 1505 if (s->strm->avail_in == 0) return; 1506 1507 /* If there was no sliding: 1508 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1509 * more == window_size - lookahead - strstart 1510 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1511 * => more >= window_size - 2*WSIZE + 2 1512 * In the BIG_MEM or MMAP case (not yet supported), 1513 * window_size == input_size + MIN_LOOKAHEAD && 1514 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1515 * Otherwise, window_size == 2*WSIZE so more >= 2. 1516 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1517 */ 1518 Assert(more >= 2, "more < 2"); 1519 1520 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1521 more); 1522 s->lookahead += n; 1523 1524 /* Initialize the hash value now that we have some input: */ 1525 if (s->lookahead >= MIN_MATCH) { 1526 s->ins_h = s->window[s->strstart]; 1527 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1528#if MIN_MATCH != 3 1529 Call UPDATE_HASH() MIN_MATCH-3 more times 1530#endif 1531 } 1532 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1533 * but this is not important since only literal bytes will be emitted. 1534 */ 1535 1536 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1537} 1538 1539/* =========================================================================== 1540 * Flush the current block, with given end-of-file flag. 1541 * IN assertion: strstart is set to the end of the current match. 1542 */ 1543#define FLUSH_BLOCK_ONLY(s, eof) { \ 1544 _tr_flush_block(s, (s->block_start >= 0L ? \ 1545 (charf *)&s->window[(unsigned)s->block_start] : \ 1546 (charf *)Z_NULL), \ 1547 (ulg)((long)s->strstart - s->block_start), \ 1548 (eof)); \ 1549 s->block_start = s->strstart; \ 1550 flush_pending(s->strm); \ 1551 Tracev((stderr,"[FLUSH]")); \ 1552} 1553 1554/* Same but force premature exit if necessary. */ 1555#define FLUSH_BLOCK(s, eof) { \ 1556 FLUSH_BLOCK_ONLY(s, eof); \ 1557 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ 1558} 1559 1560/* =========================================================================== 1561 * Copy without compression as much as possible from the input stream, return 1562 * the current block state. 1563 * This function does not insert new strings in the dictionary since 1564 * uncompressible data is probably not useful. This function is used 1565 * only for the level=0 compression option. 1566 * NOTE: this function should be optimized to avoid extra copying from 1567 * window to pending_buf. 1568 */ 1569local block_state deflate_stored(s, flush) 1570 deflate_state *s; 1571 int flush; 1572{ 1573 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited 1574 * to pending_buf_size, and each stored block has a 5 byte header: 1575 */ 1576 ulg max_block_size = 0xffff; 1577 ulg max_start; 1578 1579 if (max_block_size > s->pending_buf_size - 5) { 1580 max_block_size = s->pending_buf_size - 5; 1581 } 1582 1583 /* Copy as much as possible from input to output: */ 1584 for (;;) { 1585 /* Fill the window as much as possible: */ 1586 if (s->lookahead <= 1) { 1587 1588 Assert(s->strstart < s->w_size+MAX_DIST(s) || 1589 s->block_start >= (long)s->w_size, "slide too late"); 1590 1591 fill_window(s); 1592 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; 1593 1594 if (s->lookahead == 0) break; /* flush the current block */ 1595 } 1596 Assert(s->block_start >= 0L, "block gone"); 1597 1598 s->strstart += s->lookahead; 1599 s->lookahead = 0; 1600 1601 /* Emit a stored block if pending_buf will be full: */ 1602 max_start = s->block_start + max_block_size; 1603 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { 1604 /* strstart == 0 is possible when wraparound on 16-bit machine */ 1605 s->lookahead = (uInt)(s->strstart - max_start); 1606 s->strstart = (uInt)max_start; 1607 FLUSH_BLOCK(s, 0); 1608 } 1609 /* Flush if we may have to slide, otherwise block_start may become 1610 * negative and the data will be gone: 1611 */ 1612 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { 1613 FLUSH_BLOCK(s, 0); 1614 } 1615 } 1616 FLUSH_BLOCK(s, flush == Z_FINISH); 1617 return flush == Z_FINISH ? finish_done : block_done; 1618} 1619 1620/* =========================================================================== 1621 * Compress as much as possible from the input stream, return the current 1622 * block state. 1623 * This function does not perform lazy evaluation of matches and inserts 1624 * new strings in the dictionary only for unmatched strings or for short 1625 * matches. It is used only for the fast compression options. 1626 */ 1627local block_state deflate_fast(s, flush) 1628 deflate_state *s; 1629 int flush; 1630{ 1631 IPos hash_head = NIL; /* head of the hash chain */ 1632 int bflush; /* set if current block must be flushed */ 1633 1634 for (;;) { 1635 /* Make sure that we always have enough lookahead, except 1636 * at the end of the input file. We need MAX_MATCH bytes 1637 * for the next match, plus MIN_MATCH bytes to insert the 1638 * string following the next match. 1639 */ 1640 if (s->lookahead < MIN_LOOKAHEAD) { 1641 fill_window(s); 1642 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1643 return need_more; 1644 } 1645 if (s->lookahead == 0) break; /* flush the current block */ 1646 } 1647 1648 /* Insert the string window[strstart .. strstart+2] in the 1649 * dictionary, and set hash_head to the head of the hash chain: 1650 */ 1651 if (s->lookahead >= MIN_MATCH) { 1652 INSERT_STRING(s, s->strstart, hash_head); 1653 } 1654 1655 /* Find the longest match, discarding those <= prev_length. 1656 * At this point we have always match_length < MIN_MATCH 1657 */ 1658 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1659 /* To simplify the code, we prevent matches with the string 1660 * of window index 0 (in particular we have to avoid a match 1661 * of the string with itself at the start of the input file). 1662 */ 1663 if (s->strategy != Z_HUFFMAN_ONLY) { 1664 s->match_length = longest_match (s, hash_head); 1665 } 1666 /* longest_match() sets match_start */ 1667 } 1668 if (s->match_length >= MIN_MATCH) { 1669 check_match(s, s->strstart, s->match_start, s->match_length); 1670 1671 bflush = _tr_tally(s, s->strstart - s->match_start, 1672 s->match_length - MIN_MATCH); 1673 1674 s->lookahead -= s->match_length; 1675 1676 /* Insert new strings in the hash table only if the match length 1677 * is not too large. This saves time but degrades compression. 1678 */ 1679 if (s->match_length <= s->max_insert_length && 1680 s->lookahead >= MIN_MATCH) { 1681 s->match_length--; /* string at strstart already in hash table */ 1682 do { 1683 s->strstart++; 1684 INSERT_STRING(s, s->strstart, hash_head); 1685 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1686 * always MIN_MATCH bytes ahead. 1687 */ 1688 } while (--s->match_length != 0); 1689 s->strstart++; 1690 } else { 1691 s->strstart += s->match_length; 1692 s->match_length = 0; 1693 s->ins_h = s->window[s->strstart]; 1694 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1695#if MIN_MATCH != 3 1696 Call UPDATE_HASH() MIN_MATCH-3 more times 1697#endif 1698 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1699 * matter since it will be recomputed at next deflate call. 1700 */ 1701 } 1702 } else { 1703 /* No match, output a literal byte */ 1704 Tracevv((stderr,"%c", s->window[s->strstart])); 1705 bflush = _tr_tally (s, 0, s->window[s->strstart]); 1706 s->lookahead--; 1707 s->strstart++; 1708 } 1709 if (bflush) FLUSH_BLOCK(s, 0); 1710 } 1711 FLUSH_BLOCK(s, flush == Z_FINISH); 1712 return flush == Z_FINISH ? finish_done : block_done; 1713} 1714 1715/* =========================================================================== 1716 * Same as above, but achieves better compression. We use a lazy 1717 * evaluation for matches: a match is finally adopted only if there is 1718 * no better match at the next window position. 1719 */ 1720local block_state deflate_slow(s, flush) 1721 deflate_state *s; 1722 int flush; 1723{ 1724 IPos hash_head = NIL; /* head of hash chain */ 1725 int bflush; /* set if current block must be flushed */ 1726 1727 /* Process the input block. */ 1728 for (;;) { 1729 /* Make sure that we always have enough lookahead, except 1730 * at the end of the input file. We need MAX_MATCH bytes 1731 * for the next match, plus MIN_MATCH bytes to insert the 1732 * string following the next match. 1733 */ 1734 if (s->lookahead < MIN_LOOKAHEAD) { 1735 fill_window(s); 1736 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1737 return need_more; 1738 } 1739 if (s->lookahead == 0) break; /* flush the current block */ 1740 } 1741 1742 /* Insert the string window[strstart .. strstart+2] in the 1743 * dictionary, and set hash_head to the head of the hash chain: 1744 */ 1745 if (s->lookahead >= MIN_MATCH) { 1746 INSERT_STRING(s, s->strstart, hash_head); 1747 } 1748 1749 /* Find the longest match, discarding those <= prev_length. 1750 */ 1751 s->prev_length = s->match_length, s->prev_match = s->match_start; 1752 s->match_length = MIN_MATCH-1; 1753 1754 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1755 s->strstart - hash_head <= MAX_DIST(s)) { 1756 /* To simplify the code, we prevent matches with the string 1757 * of window index 0 (in particular we have to avoid a match 1758 * of the string with itself at the start of the input file). 1759 */ 1760 if (s->strategy != Z_HUFFMAN_ONLY) { 1761 s->match_length = longest_match (s, hash_head); 1762 } 1763 /* longest_match() sets match_start */ 1764 1765 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1766 (s->match_length == MIN_MATCH && 1767 s->strstart - s->match_start > TOO_FAR))) { 1768 1769 /* If prev_match is also MIN_MATCH, match_start is garbage 1770 * but we will ignore the current match anyway. 1771 */ 1772 s->match_length = MIN_MATCH-1; 1773 } 1774 } 1775 /* If there was a match at the previous step and the current 1776 * match is not better, output the previous match: 1777 */ 1778 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1779 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1780 /* Do not insert strings in hash table beyond this. */ 1781 1782 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1783 1784 bflush = _tr_tally(s, s->strstart -1 - s->prev_match, 1785 s->prev_length - MIN_MATCH); 1786 1787 /* Insert in hash table all strings up to the end of the match. 1788 * strstart-1 and strstart are already inserted. If there is not 1789 * enough lookahead, the last two strings are not inserted in 1790 * the hash table. 1791 */ 1792 s->lookahead -= s->prev_length-1; 1793 s->prev_length -= 2; 1794 do { 1795 if (++s->strstart <= max_insert) { 1796 INSERT_STRING(s, s->strstart, hash_head); 1797 } 1798 } while (--s->prev_length != 0); 1799 s->match_available = 0; 1800 s->match_length = MIN_MATCH-1; 1801 s->strstart++; 1802 1803 if (bflush) FLUSH_BLOCK(s, 0); 1804 1805 } else if (s->match_available) { 1806 /* If there was no match at the previous position, output a 1807 * single literal. If there was a match but the current match 1808 * is longer, truncate the previous match to a single literal. 1809 */ 1810 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1811 if (_tr_tally (s, 0, s->window[s->strstart-1])) { 1812 FLUSH_BLOCK_ONLY(s, 0); 1813 } 1814 s->strstart++; 1815 s->lookahead--; 1816 if (s->strm->avail_out == 0) return need_more; 1817 } else { 1818 /* There is no previous match to compare with, wait for 1819 * the next step to decide. 1820 */ 1821 s->match_available = 1; 1822 s->strstart++; 1823 s->lookahead--; 1824 } 1825 } 1826 Assert (flush != Z_NO_FLUSH, "no flush?"); 1827 if (s->match_available) { 1828 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1829 _tr_tally (s, 0, s->window[s->strstart-1]); 1830 s->match_available = 0; 1831 } 1832 FLUSH_BLOCK(s, flush == Z_FINISH); 1833 return flush == Z_FINISH ? finish_done : block_done; 1834} 1835/* --- deflate.c */ 1836 1837/* +++ trees.c */ 1838/* trees.c -- output deflated data using Huffman coding 1839 * Copyright (C) 1995-1996 Jean-loup Gailly 1840 * For conditions of distribution and use, see copyright notice in zlib.h 1841 */ 1842 1843/* 1844 * ALGORITHM 1845 * 1846 * The "deflation" process uses several Huffman trees. The more 1847 * common source values are represented by shorter bit sequences. 1848 * 1849 * Each code tree is stored in a compressed form which is itself 1850 * a Huffman encoding of the lengths of all the code strings (in 1851 * ascending order by source values). The actual code strings are 1852 * reconstructed from the lengths in the inflate process, as described 1853 * in the deflate specification. 1854 * 1855 * REFERENCES 1856 * 1857 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1858 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1859 * 1860 * Storer, James A. 1861 * Data Compression: Methods and Theory, pp. 49-50. 1862 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1863 * 1864 * Sedgewick, R. 1865 * Algorithms, p290. 1866 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1867 */ 1868 1869/* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ 1870 1871/* #include "deflate.h" */ 1872 1873#ifdef DEBUG_ZLIB 1874# include <ctype.h> 1875#endif 1876 1877/* =========================================================================== 1878 * Constants 1879 */ 1880 1881#define MAX_BL_BITS 7 1882/* Bit length codes must not exceed MAX_BL_BITS bits */ 1883 1884#define END_BLOCK 256 1885/* end of block literal code */ 1886 1887#define REP_3_6 16 1888/* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1889 1890#define REPZ_3_10 17 1891/* repeat a zero length 3-10 times (3 bits of repeat count) */ 1892 1893#define REPZ_11_138 18 1894/* repeat a zero length 11-138 times (7 bits of repeat count) */ 1895 1896local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1897 = {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}; 1898 1899local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1900 = {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}; 1901 1902local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1903 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1904 1905local uch bl_order[BL_CODES] 1906 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1907/* The lengths of the bit length codes are sent in order of decreasing 1908 * probability, to avoid transmitting the lengths for unused bit length codes. 1909 */ 1910 1911#define Buf_size (8 * 2*sizeof(char)) 1912/* Number of bits used within bi_buf. (bi_buf might be implemented on 1913 * more than 16 bits on some systems.) 1914 */ 1915 1916/* =========================================================================== 1917 * Local data. These are initialized only once. 1918 */ 1919 1920local ct_data static_ltree[L_CODES+2]; 1921/* The static literal tree. Since the bit lengths are imposed, there is no 1922 * need for the L_CODES extra codes used during heap construction. However 1923 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 1924 * below). 1925 */ 1926 1927local ct_data static_dtree[D_CODES]; 1928/* The static distance tree. (Actually a trivial tree since all codes use 1929 * 5 bits.) 1930 */ 1931 1932local uch dist_code[512]; 1933/* distance codes. The first 256 values correspond to the distances 1934 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1935 * the 15 bit distances. 1936 */ 1937 1938local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1939/* length code for each normalized match length (0 == MIN_MATCH) */ 1940 1941local int base_length[LENGTH_CODES]; 1942/* First normalized length for each code (0 = MIN_MATCH) */ 1943 1944local int base_dist[D_CODES]; 1945/* First normalized distance for each code (0 = distance of 1) */ 1946 1947struct static_tree_desc_s { 1948 ct_data *static_tree; /* static tree or NULL */ 1949 intf *extra_bits; /* extra bits for each code or NULL */ 1950 int extra_base; /* base index for extra_bits */ 1951 int elems; /* max number of elements in the tree */ 1952 int max_length; /* max bit length for the codes */ 1953}; 1954 1955local static_tree_desc static_l_desc = 1956{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1957 1958local static_tree_desc static_d_desc = 1959{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1960 1961local static_tree_desc static_bl_desc = 1962{(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1963 1964/* =========================================================================== 1965 * Local (static) routines in this file. 1966 */ 1967 1968local void tr_static_init OF((void)); 1969local void init_block OF((deflate_state *s)); 1970local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1971local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1972local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1973local void build_tree OF((deflate_state *s, tree_desc *desc)); 1974local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1975local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1976local int build_bl_tree OF((deflate_state *s)); 1977local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1978 int blcodes)); 1979local void compress_block OF((deflate_state *s, ct_data *ltree, 1980 ct_data *dtree)); 1981local void set_data_type OF((deflate_state *s)); 1982local unsigned bi_reverse OF((unsigned value, int length)); 1983local void bi_windup OF((deflate_state *s)); 1984local void bi_flush OF((deflate_state *s)); 1985local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1986 int header)); 1987 1988#ifndef DEBUG_ZLIB 1989# define send_code(s, c, tree) send_bits(s, tree[(c)].Code, tree[(c)].Len) 1990 /* Send a code of the given tree. c and tree must not have side effects */ 1991 1992#else /* DEBUG_ZLIB */ 1993# define send_code(s, c, tree) \ 1994 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 1995 send_bits(s, tree[c].Code, tree[c].Len); } 1996#endif 1997 1998#define d_code(dist) \ 1999 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 2000/* Mapping from a distance to a distance code. dist is the distance - 1 and 2001 * must not have side effects. dist_code[256] and dist_code[257] are never 2002 * used. 2003 */ 2004 2005/* =========================================================================== 2006 * Output a short LSB first on the stream. 2007 * IN assertion: there is enough room in pendingBuf. 2008 */ 2009#define put_short(s, w) { \ 2010 put_byte(s, (uch)((w) & 0xff)); \ 2011 put_byte(s, (uch)((ush)(w) >> 8)); \ 2012} 2013 2014/* =========================================================================== 2015 * Send a value on a given number of bits. 2016 * IN assertion: length <= 16 and value fits in length bits. 2017 */ 2018#ifdef DEBUG_ZLIB 2019local void send_bits OF((deflate_state *s, int value, int length)); 2020 2021local void send_bits(s, value, length) 2022 deflate_state *s; 2023 int value; /* value to send */ 2024 int length; /* number of bits */ 2025{ 2026 Tracevv((stderr," l %2d v %4x ", length, value)); 2027 Assert(length > 0 && length <= 15, "invalid length"); 2028 s->bits_sent += (ulg)length; 2029 2030 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 2031 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 2032 * unused bits in value. 2033 */ 2034 if (s->bi_valid > (int)Buf_size - length) { 2035 s->bi_buf |= (value << s->bi_valid); 2036 put_short(s, s->bi_buf); 2037 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 2038 s->bi_valid += length - Buf_size; 2039 } else { 2040 s->bi_buf |= value << s->bi_valid; 2041 s->bi_valid += length; 2042 } 2043} 2044#else /* !DEBUG_ZLIB */ 2045 2046#define send_bits(s, value, length) \ 2047{ int len = (length);\ 2048 if ((s)->bi_valid > (int)Buf_size - len) {\ 2049 int val = (value);\ 2050 (s)->bi_buf |= (val << (s)->bi_valid);\ 2051 put_short((s), (s)->bi_buf);\ 2052 (s)->bi_buf = (ush)val >> (Buf_size - (s)->bi_valid);\ 2053 (s)->bi_valid += len - Buf_size;\ 2054 } else {\ 2055 (s)->bi_buf |= (value) << (s)->bi_valid;\ 2056 (s)->bi_valid += len;\ 2057 }\ 2058} 2059#endif /* DEBUG_ZLIB */ 2060 2061/* the arguments must not have side effects */ 2062 2063/* =========================================================================== 2064 * Initialize the various 'constant' tables. In a multi-threaded environment, 2065 * this function may be called by two threads concurrently, but this is 2066 * harmless since both invocations do exactly the same thing. 2067 */ 2068local void tr_static_init() 2069{ 2070 static int static_init_done = 0; 2071 int n; /* iterates over tree elements */ 2072 int bits; /* bit counter */ 2073 int length; /* length value */ 2074 int code; /* code value */ 2075 int dist; /* distance index */ 2076 ush bl_count[MAX_BITS+1]; 2077 /* number of codes at each bit length for an optimal tree */ 2078 2079 if (static_init_done) return; 2080 2081 /* Initialize the mapping length (0..255) -> length code (0..28) */ 2082 length = 0; 2083 for (code = 0; code < LENGTH_CODES-1; code++) { 2084 base_length[code] = length; 2085 for (n = 0; n < (1<<extra_lbits[code]); n++) { 2086 length_code[length++] = (uch)code; 2087 } 2088 } 2089 Assert (length == 256, "tr_static_init: length != 256"); 2090 /* Note that the length 255 (match length 258) can be represented 2091 * in two different ways: code 284 + 5 bits or code 285, so we 2092 * overwrite length_code[255] to use the best encoding: 2093 */ 2094 length_code[length-1] = (uch)code; 2095 2096 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 2097 dist = 0; 2098 for (code = 0 ; code < 16; code++) { 2099 base_dist[code] = dist; 2100 for (n = 0; n < (1<<extra_dbits[code]); n++) { 2101 dist_code[dist++] = (uch)code; 2102 } 2103 } 2104 Assert (dist == 256, "tr_static_init: dist != 256"); 2105 dist >>= 7; /* from now on, all distances are divided by 128 */ 2106 for ( ; code < D_CODES; code++) { 2107 base_dist[code] = dist << 7; 2108 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 2109 dist_code[256 + dist++] = (uch)code; 2110 } 2111 } 2112 Assert (dist == 256, "tr_static_init: 256+dist != 512"); 2113 2114 /* Construct the codes of the static literal tree */ 2115 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 2116 n = 0; 2117 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 2118 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 2119 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 2120 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 2121 /* Codes 286 and 287 do not exist, but we must include them in the 2122 * tree construction to get a canonical Huffman tree (longest code 2123 * all ones) 2124 */ 2125 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 2126 2127 /* The static distance tree is trivial: */ 2128 for (n = 0; n < D_CODES; n++) { 2129 static_dtree[n].Len = 5; 2130 static_dtree[n].Code = bi_reverse((unsigned)n, 5); 2131 } 2132 static_init_done = 1; 2133} 2134 2135/* =========================================================================== 2136 * Initialize the tree data structures for a new zlib stream. 2137 */ 2138void _tr_init(s) 2139 deflate_state *s; 2140{ 2141 tr_static_init(); 2142 2143 s->compressed_len = 0L; 2144 2145 s->l_desc.dyn_tree = s->dyn_ltree; 2146 s->l_desc.stat_desc = &static_l_desc; 2147 2148 s->d_desc.dyn_tree = s->dyn_dtree; 2149 s->d_desc.stat_desc = &static_d_desc; 2150 2151 s->bl_desc.dyn_tree = s->bl_tree; 2152 s->bl_desc.stat_desc = &static_bl_desc; 2153 2154 s->bi_buf = 0; 2155 s->bi_valid = 0; 2156 s->last_eob_len = 8; /* enough lookahead for inflate */ 2157#ifdef DEBUG_ZLIB 2158 s->bits_sent = 0L; 2159#endif 2160 2161 /* Initialize the first block of the first file: */ 2162 init_block(s); 2163} 2164 2165/* =========================================================================== 2166 * Initialize a new block. 2167 */ 2168local void init_block(s) 2169 deflate_state *s; 2170{ 2171 int n; /* iterates over tree elements */ 2172 2173 /* Initialize the trees. */ 2174 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 2175 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 2176 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 2177 2178 s->dyn_ltree[END_BLOCK].Freq = 1; 2179 s->opt_len = s->static_len = 0L; 2180 s->last_lit = s->matches = 0; 2181} 2182 2183#define SMALLEST 1 2184/* Index within the heap array of least frequent node in the Huffman tree */ 2185 2186 2187/* =========================================================================== 2188 * Remove the smallest element from the heap and recreate the heap with 2189 * one less element. Updates heap and heap_len. 2190 */ 2191#define pqremove(s, tree, top) \ 2192{\ 2193 top = s->heap[SMALLEST]; \ 2194 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 2195 pqdownheap(s, tree, SMALLEST); \ 2196} 2197 2198/* =========================================================================== 2199 * Compares to subtrees, using the tree depth as tie breaker when 2200 * the subtrees have equal frequency. This minimizes the worst case length. 2201 */ 2202#define smaller(tree, n, m, depth) \ 2203 (tree[n].Freq < tree[m].Freq || \ 2204 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 2205 2206/* =========================================================================== 2207 * Restore the heap property by moving down the tree starting at node k, 2208 * exchanging a node with the smallest of its two sons if necessary, stopping 2209 * when the heap property is re-established (each father smaller than its 2210 * two sons). 2211 */ 2212local void pqdownheap(s, tree, k) 2213 deflate_state *s; 2214 ct_data *tree; /* the tree to restore */ 2215 int k; /* node to move down */ 2216{ 2217 int v = s->heap[k]; 2218 int j = k << 1; /* left son of k */ 2219 while (j <= s->heap_len) { 2220 /* Set j to the smallest of the two sons: */ 2221 if (j < s->heap_len && 2222 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 2223 j++; 2224 } 2225 /* Exit if v is smaller than both sons */ 2226 if (smaller(tree, v, s->heap[j], s->depth)) break; 2227 2228 /* Exchange v with the smallest son */ 2229 s->heap[k] = s->heap[j]; k = j; 2230 2231 /* And continue down the tree, setting j to the left son of k */ 2232 j <<= 1; 2233 } 2234 s->heap[k] = v; 2235} 2236 2237/* =========================================================================== 2238 * Compute the optimal bit lengths for a tree and update the total bit length 2239 * for the current block. 2240 * IN assertion: the fields freq and dad are set, heap[heap_max] and 2241 * above are the tree nodes sorted by increasing frequency. 2242 * OUT assertions: the field len is set to the optimal bit length, the 2243 * array bl_count contains the frequencies for each bit length. 2244 * The length opt_len is updated; static_len is also updated if stree is 2245 * not null. 2246 */ 2247local void gen_bitlen(s, desc) 2248 deflate_state *s; 2249 tree_desc *desc; /* the tree descriptor */ 2250{ 2251 ct_data *tree = desc->dyn_tree; 2252 int max_code = desc->max_code; 2253 ct_data *stree = desc->stat_desc->static_tree; 2254 intf *extra = desc->stat_desc->extra_bits; 2255 int base = desc->stat_desc->extra_base; 2256 int max_length = desc->stat_desc->max_length; 2257 int h; /* heap index */ 2258 int n, m; /* iterate over the tree elements */ 2259 int bits; /* bit length */ 2260 int xbits; /* extra bits */ 2261 ush f; /* frequency */ 2262 int overflow = 0; /* number of elements with bit length too large */ 2263 2264 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 2265 2266 /* In a first pass, compute the optimal bit lengths (which may 2267 * overflow in the case of the bit length tree). 2268 */ 2269 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 2270 2271 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 2272 n = s->heap[h]; 2273 bits = tree[tree[n].Dad].Len + 1; 2274 if (bits > max_length) bits = max_length, overflow++; 2275 tree[n].Len = (ush)bits; 2276 /* We overwrite tree[n].Dad which is no longer needed */ 2277 2278 if (n > max_code) continue; /* not a leaf node */ 2279 2280 s->bl_count[bits]++; 2281 xbits = 0; 2282 if (n >= base) xbits = extra[n-base]; 2283 f = tree[n].Freq; 2284 s->opt_len += (ulg)f * (bits + xbits); 2285 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 2286 } 2287 if (overflow == 0) return; 2288 2289 Trace((stderr,"\nbit length overflow\n")); 2290 /* This happens for example on obj2 and pic of the Calgary corpus */ 2291 2292 /* Find the first bit length which could increase: */ 2293 do { 2294 bits = max_length-1; 2295 while (s->bl_count[bits] == 0) bits--; 2296 s->bl_count[bits]--; /* move one leaf down the tree */ 2297 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 2298 s->bl_count[max_length]--; 2299 /* The brother of the overflow item also moves one step up, 2300 * but this does not affect bl_count[max_length] 2301 */ 2302 overflow -= 2; 2303 } while (overflow > 0); 2304 2305 /* Now recompute all bit lengths, scanning in increasing frequency. 2306 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 2307 * lengths instead of fixing only the wrong ones. This idea is taken 2308 * from 'ar' written by Haruhiko Okumura.) 2309 */ 2310 for (bits = max_length; bits != 0; bits--) { 2311 n = s->bl_count[bits]; 2312 while (n != 0) { 2313 m = s->heap[--h]; 2314 if (m > max_code) continue; 2315 if (tree[m].Len != (unsigned) bits) { 2316 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 2317 s->opt_len += ((long)bits - (long)tree[m].Len) 2318 *(long)tree[m].Freq; 2319 tree[m].Len = (ush)bits; 2320 } 2321 n--; 2322 } 2323 } 2324} 2325 2326/* =========================================================================== 2327 * Generate the codes for a given tree and bit counts (which need not be 2328 * optimal). 2329 * IN assertion: the array bl_count contains the bit length statistics for 2330 * the given tree and the field len is set for all tree elements. 2331 * OUT assertion: the field code is set for all tree elements of non 2332 * zero code length. 2333 */ 2334local void gen_codes (tree, max_code, bl_count) 2335 ct_data *tree; /* the tree to decorate */ 2336 int max_code; /* largest code with non zero frequency */ 2337 ushf *bl_count; /* number of codes at each bit length */ 2338{ 2339 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 2340 ush code = 0; /* running code value */ 2341 int bits; /* bit index */ 2342 int n; /* code index */ 2343 2344 /* The distribution counts are first used to generate the code values 2345 * without bit reversal. 2346 */ 2347 for (bits = 1; bits <= MAX_BITS; bits++) { 2348 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 2349 } 2350 /* Check that the bit counts in bl_count are consistent. The last code 2351 * must be all ones. 2352 */ 2353 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 2354 "inconsistent bit counts"); 2355 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 2356 2357 for (n = 0; n <= max_code; n++) { 2358 int len = tree[n].Len; 2359 if (len == 0) continue; 2360 /* Now reverse the bits */ 2361 tree[n].Code = bi_reverse(next_code[len]++, len); 2362 2363 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 2364 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 2365 } 2366} 2367 2368/* =========================================================================== 2369 * Construct one Huffman tree and assigns the code bit strings and lengths. 2370 * Update the total bit length for the current block. 2371 * IN assertion: the field freq is set for all tree elements. 2372 * OUT assertions: the fields len and code are set to the optimal bit length 2373 * and corresponding code. The length opt_len is updated; static_len is 2374 * also updated if stree is not null. The field max_code is set. 2375 */ 2376local void build_tree(s, desc) 2377 deflate_state *s; 2378 tree_desc *desc; /* the tree descriptor */ 2379{ 2380 ct_data *tree = desc->dyn_tree; 2381 ct_data *stree = desc->stat_desc->static_tree; 2382 int elems = desc->stat_desc->elems; 2383 int n, m; /* iterate over heap elements */ 2384 int max_code = -1; /* largest code with non zero frequency */ 2385 int node; /* new node being created */ 2386 2387 /* Construct the initial heap, with least frequent element in 2388 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2389 * heap[0] is not used. 2390 */ 2391 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2392 2393 for (n = 0; n < elems; n++) { 2394 if (tree[n].Freq != 0) { 2395 s->heap[++(s->heap_len)] = max_code = n; 2396 s->depth[n] = 0; 2397 } else { 2398 tree[n].Len = 0; 2399 } 2400 } 2401 2402 /* The pkzip format requires that at least one distance code exists, 2403 * and that at least one bit should be sent even if there is only one 2404 * possible code. So to avoid special checks later on we force at least 2405 * two codes of non zero frequency. 2406 */ 2407 while (s->heap_len < 2) { 2408 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2409 tree[node].Freq = 1; 2410 s->depth[node] = 0; 2411 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2412 /* node is 0 or 1 so it does not have extra bits */ 2413 } 2414 desc->max_code = max_code; 2415 2416 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2417 * establish sub-heaps of increasing lengths: 2418 */ 2419 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2420 2421 /* Construct the Huffman tree by repeatedly combining the least two 2422 * frequent nodes. 2423 */ 2424 node = elems; /* next internal node of the tree */ 2425 do { 2426 pqremove(s, tree, n); /* n = node of least frequency */ 2427 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2428 2429 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2430 s->heap[--(s->heap_max)] = m; 2431 2432 /* Create a new node father of n and m */ 2433 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2434 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2435 tree[n].Dad = tree[m].Dad = (ush)node; 2436#ifdef DUMP_BL_TREE 2437 if (tree == s->bl_tree) { 2438 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2439 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2440 } 2441#endif 2442 /* and insert the new node in the heap */ 2443 s->heap[SMALLEST] = node++; 2444 pqdownheap(s, tree, SMALLEST); 2445 2446 } while (s->heap_len >= 2); 2447 2448 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2449 2450 /* At this point, the fields freq and dad are set. We can now 2451 * generate the bit lengths. 2452 */ 2453 gen_bitlen(s, (tree_desc *)desc); 2454 2455 /* The field len is now set, we can generate the bit codes */ 2456 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2457} 2458 2459/* =========================================================================== 2460 * Scan a literal or distance tree to determine the frequencies of the codes 2461 * in the bit length tree. 2462 */ 2463local void scan_tree (s, tree, max_code) 2464 deflate_state *s; 2465 ct_data *tree; /* the tree to be scanned */ 2466 int max_code; /* and its largest code of non zero frequency */ 2467{ 2468 int n; /* iterates over all tree elements */ 2469 int prevlen = -1; /* last emitted length */ 2470 int curlen; /* length of current code */ 2471 int nextlen = tree[0].Len; /* length of next code */ 2472 int count = 0; /* repeat count of the current code */ 2473 int max_count = 7; /* max repeat count */ 2474 int min_count = 4; /* min repeat count */ 2475 2476 if (nextlen == 0) max_count = 138, min_count = 3; 2477 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2478 2479 for (n = 0; n <= max_code; n++) { 2480 curlen = nextlen; nextlen = tree[n+1].Len; 2481 if (++count < max_count && curlen == nextlen) { 2482 continue; 2483 } else if (count < min_count) { 2484 s->bl_tree[curlen].Freq += count; 2485 } else if (curlen != 0) { 2486 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2487 s->bl_tree[REP_3_6].Freq++; 2488 } else if (count <= 10) { 2489 s->bl_tree[REPZ_3_10].Freq++; 2490 } else { 2491 s->bl_tree[REPZ_11_138].Freq++; 2492 } 2493 count = 0; prevlen = curlen; 2494 if (nextlen == 0) { 2495 max_count = 138, min_count = 3; 2496 } else if (curlen == nextlen) { 2497 max_count = 6, min_count = 3; 2498 } else { 2499 max_count = 7, min_count = 4; 2500 } 2501 } 2502} 2503 2504/* =========================================================================== 2505 * Send a literal or distance tree in compressed form, using the codes in 2506 * bl_tree. 2507 */ 2508local void send_tree (s, tree, max_code) 2509 deflate_state *s; 2510 ct_data *tree; /* the tree to be scanned */ 2511 int max_code; /* and its largest code of non zero frequency */ 2512{ 2513 int n; /* iterates over all tree elements */ 2514 int prevlen = -1; /* last emitted length */ 2515 int curlen; /* length of current code */ 2516 int nextlen = tree[0].Len; /* length of next code */ 2517 int count = 0; /* repeat count of the current code */ 2518 int max_count = 7; /* max repeat count */ 2519 int min_count = 4; /* min repeat count */ 2520 2521 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2522 if (nextlen == 0) max_count = 138, min_count = 3; 2523 2524 for (n = 0; n <= max_code; n++) { 2525 curlen = nextlen; nextlen = tree[n+1].Len; 2526 if (++count < max_count && curlen == nextlen) { 2527 continue; 2528 } else if (count < min_count) { 2529 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2530 2531 } else if (curlen != 0) { 2532 if (curlen != prevlen) { 2533 send_code(s, curlen, s->bl_tree); count--; 2534 } 2535 Assert(count >= 3 && count <= 6, " 3_6?"); 2536 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2537 2538 } else if (count <= 10) { 2539 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2540 2541 } else { 2542 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2543 } 2544 count = 0; prevlen = curlen; 2545 if (nextlen == 0) { 2546 max_count = 138, min_count = 3; 2547 } else if (curlen == nextlen) { 2548 max_count = 6, min_count = 3; 2549 } else { 2550 max_count = 7, min_count = 4; 2551 } 2552 } 2553} 2554 2555/* =========================================================================== 2556 * Construct the Huffman tree for the bit lengths and return the index in 2557 * bl_order of the last bit length code to send. 2558 */ 2559local int build_bl_tree(s) 2560 deflate_state *s; 2561{ 2562 int max_blindex; /* index of last bit length code of non zero freq */ 2563 2564 /* Determine the bit length frequencies for literal and distance trees */ 2565 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2566 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2567 2568 /* Build the bit length tree: */ 2569 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2570 /* opt_len now includes the length of the tree representations, except 2571 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2572 */ 2573 2574 /* Determine the number of bit length codes to send. The pkzip format 2575 * requires that at least 4 bit length codes be sent. (appnote.txt says 2576 * 3 but the actual value used is 4.) 2577 */ 2578 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2579 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2580 } 2581 /* Update opt_len to include the bit length tree and counts */ 2582 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2583 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2584 s->opt_len, s->static_len)); 2585 2586 return max_blindex; 2587} 2588 2589/* =========================================================================== 2590 * Send the header for a block using dynamic Huffman trees: the counts, the 2591 * lengths of the bit length codes, the literal tree and the distance tree. 2592 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2593 */ 2594local void send_all_trees(s, lcodes, dcodes, blcodes) 2595 deflate_state *s; 2596 int lcodes, dcodes, blcodes; /* number of codes for each tree */ 2597{ 2598 int rank; /* index in bl_order */ 2599 2600 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2601 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2602 "too many codes"); 2603 Tracev((stderr, "\nbl counts: ")); 2604 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2605 send_bits(s, dcodes-1, 5); 2606 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2607 for (rank = 0; rank < blcodes; rank++) { 2608 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2609 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2610 } 2611 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2612 2613 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2614 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2615 2616 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2617 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2618} 2619 2620/* =========================================================================== 2621 * Send a stored block 2622 */ 2623void _tr_stored_block(s, buf, stored_len, eof) 2624 deflate_state *s; 2625 charf *buf; /* input block */ 2626 ulg stored_len; /* length of input block */ 2627 int eof; /* true if this is the last block for a file */ 2628{ 2629 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2630 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; 2631 s->compressed_len += (stored_len + 4) << 3; 2632 2633 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2634} 2635 2636/* Send just the `stored block' type code without any length bytes or data. 2637 */ 2638void _tr_stored_type_only(s) 2639 deflate_state *s; 2640{ 2641 send_bits(s, (STORED_BLOCK << 1), 3); 2642 bi_windup(s); 2643 s->compressed_len = (s->compressed_len + 3) & ~7L; 2644} 2645 2646 2647/* =========================================================================== 2648 * Send one empty static block to give enough lookahead for inflate. 2649 * This takes 10 bits, of which 7 may remain in the bit buffer. 2650 * The current inflate code requires 9 bits of lookahead. If the 2651 * last two codes for the previous block (real code plus EOB) were coded 2652 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode 2653 * the last real code. In this case we send two empty static blocks instead 2654 * of one. (There are no problems if the previous block is stored or fixed.) 2655 * To simplify the code, we assume the worst case of last real code encoded 2656 * on one bit only. 2657 */ 2658void _tr_align(s) 2659 deflate_state *s; 2660{ 2661 send_bits(s, STATIC_TREES<<1, 3); 2662 send_code(s, END_BLOCK, static_ltree); 2663 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2664 bi_flush(s); 2665 /* Of the 10 bits for the empty block, we have already sent 2666 * (10 - bi_valid) bits. The lookahead for the last real code (before 2667 * the EOB of the previous block) was thus at least one plus the length 2668 * of the EOB plus what we have just sent of the empty static block. 2669 */ 2670 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { 2671 send_bits(s, STATIC_TREES<<1, 3); 2672 send_code(s, END_BLOCK, static_ltree); 2673 s->compressed_len += 10L; 2674 bi_flush(s); 2675 } 2676 s->last_eob_len = 7; 2677} 2678 2679/* =========================================================================== 2680 * Determine the best encoding for the current block: dynamic trees, static 2681 * trees or store, and output the encoded block to the zip file. This function 2682 * returns the total compressed length for the file so far. 2683 */ 2684ulg _tr_flush_block(s, buf, stored_len, eof) 2685 deflate_state *s; 2686 charf *buf; /* input block, or NULL if too old */ 2687 ulg stored_len; /* length of input block */ 2688 int eof; /* true if this is the last block for a file */ 2689{ 2690 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2691 int max_blindex = 0; /* index of last bit length code of non zero freq */ 2692 2693 /* Build the Huffman trees unless a stored block is forced */ 2694 if (s->level > 0) { 2695 2696 /* Check if the file is ascii or binary */ 2697 if (s->data_type == Z_UNKNOWN) set_data_type(s); 2698 2699 /* Construct the literal and distance trees */ 2700 build_tree(s, (tree_desc *)(&(s->l_desc))); 2701 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2702 s->static_len)); 2703 2704 build_tree(s, (tree_desc *)(&(s->d_desc))); 2705 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2706 s->static_len)); 2707 /* At this point, opt_len and static_len are the total bit lengths of 2708 * the compressed block data, excluding the tree representations. 2709 */ 2710 2711 /* Build the bit length tree for the above two trees, and get the index 2712 * in bl_order of the last bit length code to send. 2713 */ 2714 max_blindex = build_bl_tree(s); 2715 2716 /* Determine the best encoding. Compute first the block length in bytes*/ 2717 opt_lenb = (s->opt_len+3+7)>>3; 2718 static_lenb = (s->static_len+3+7)>>3; 2719 2720 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2721 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2722 s->last_lit)); 2723 2724 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2725 2726 } else { 2727 Assert(buf != (char*)0, "lost buf"); 2728 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 2729 } 2730 2731 /* If compression failed and this is the first and last block, 2732 * and if the .zip file can be seeked (to rewrite the local header), 2733 * the whole file is transformed into a stored file: 2734 */ 2735#ifdef STORED_FILE_OK 2736# ifdef FORCE_STORED_FILE 2737 if (eof && s->compressed_len == 0L) { /* force stored file */ 2738# else 2739 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { 2740# endif 2741 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2742 if (buf == (charf*)0) error ("block vanished"); 2743 2744 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ 2745 s->compressed_len = stored_len << 3; 2746 s->method = STORED; 2747 } else 2748#endif /* STORED_FILE_OK */ 2749 2750#ifdef FORCE_STORED 2751 if (buf != (char*)0) { /* force stored block */ 2752#else 2753 if (stored_len+4 <= opt_lenb && buf != (char*)0) { 2754 /* 4: two words for the lengths */ 2755#endif 2756 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2757 * Otherwise we can't have processed more than WSIZE input bytes since 2758 * the last block flush, because compression would have been 2759 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2760 * transform a block into a stored block. 2761 */ 2762 _tr_stored_block(s, buf, stored_len, eof); 2763 2764#ifdef FORCE_STATIC 2765 } else if (static_lenb >= 0) { /* force static trees */ 2766#else 2767 } else if (static_lenb == opt_lenb) { 2768#endif 2769 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2770 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2771 s->compressed_len += 3 + s->static_len; 2772 } else { 2773 send_bits(s, (DYN_TREES<<1)+eof, 3); 2774 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2775 max_blindex+1); 2776 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2777 s->compressed_len += 3 + s->opt_len; 2778 } 2779 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2780 init_block(s); 2781 2782 if (eof) { 2783 bi_windup(s); 2784 s->compressed_len += 7; /* align on byte boundary */ 2785 } 2786 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2787 s->compressed_len-7*eof)); 2788 2789 return s->compressed_len >> 3; 2790} 2791 2792/* =========================================================================== 2793 * Save the match info and tally the frequency counts. Return true if 2794 * the current block must be flushed. 2795 */ 2796int _tr_tally (s, dist, lc) 2797 deflate_state *s; 2798 unsigned dist; /* distance of matched string */ 2799 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 2800{ 2801 s->d_buf[s->last_lit] = (ush)dist; 2802 s->l_buf[s->last_lit++] = (uch)lc; 2803 if (dist == 0) { 2804 /* lc is the unmatched char */ 2805 s->dyn_ltree[lc].Freq++; 2806 } else { 2807 s->matches++; 2808 /* Here, lc is the match length - MIN_MATCH */ 2809 dist--; /* dist = match distance - 1 */ 2810 Assert((ush)dist < (ush)MAX_DIST(s) && 2811 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2812 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 2813 2814 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2815 s->dyn_dtree[d_code(dist)].Freq++; 2816 } 2817 2818 /* Try to guess if it is profitable to stop the current block here */ 2819 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2820 /* Compute an upper bound for the compressed length */ 2821 ulg out_length = (ulg)s->last_lit*8L; 2822 ulg in_length = (ulg)((long)s->strstart - s->block_start); 2823 int dcode; 2824 for (dcode = 0; dcode < D_CODES; dcode++) { 2825 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2826 (5L+extra_dbits[dcode]); 2827 } 2828 out_length >>= 3; 2829 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2830 s->last_lit, in_length, out_length, 2831 100L - out_length*100L/in_length)); 2832 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2833 } 2834 return (s->last_lit == s->lit_bufsize-1); 2835 /* We avoid equality with lit_bufsize because of wraparound at 64K 2836 * on 16 bit machines and because stored blocks are restricted to 2837 * 64K-1 bytes. 2838 */ 2839} 2840 2841/* =========================================================================== 2842 * Send the block data compressed using the given Huffman trees 2843 */ 2844local void compress_block(s, ltree, dtree) 2845 deflate_state *s; 2846 ct_data *ltree; /* literal tree */ 2847 ct_data *dtree; /* distance tree */ 2848{ 2849 unsigned dist; /* distance of matched string */ 2850 int lc; /* match length or unmatched char (if dist == 0) */ 2851 unsigned lx = 0; /* running index in l_buf */ 2852 unsigned code; /* the code to send */ 2853 int extra; /* number of extra bits to send */ 2854 2855 if (s->last_lit != 0) do { 2856 dist = s->d_buf[lx]; 2857 lc = s->l_buf[lx++]; 2858 if (dist == 0) { 2859 send_code(s, lc, ltree); /* send a literal byte */ 2860 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2861 } else { 2862 /* Here, lc is the match length - MIN_MATCH */ 2863 code = length_code[lc]; 2864 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2865 extra = extra_lbits[code]; 2866 if (extra != 0) { 2867 lc -= base_length[code]; 2868 send_bits(s, lc, extra); /* send the extra length bits */ 2869 } 2870 dist--; /* dist is now the match distance - 1 */ 2871 code = d_code(dist); 2872 Assert (code < D_CODES, "bad d_code"); 2873 2874 send_code(s, code, dtree); /* send the distance code */ 2875 extra = extra_dbits[code]; 2876 if (extra != 0) { 2877 dist -= base_dist[code]; 2878 send_bits(s, dist, extra); /* send the extra distance bits */ 2879 } 2880 } /* literal or match pair ? */ 2881 2882 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2883 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2884 2885 } while (lx < s->last_lit); 2886 2887 send_code(s, END_BLOCK, ltree); 2888 s->last_eob_len = ltree[END_BLOCK].Len; 2889} 2890 2891/* =========================================================================== 2892 * Set the data type to ASCII or BINARY, using a crude approximation: 2893 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2894 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2895 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2896 */ 2897local void set_data_type(s) 2898 deflate_state *s; 2899{ 2900 int n = 0; 2901 unsigned ascii_freq = 0; 2902 unsigned bin_freq = 0; 2903 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2904 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2905 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2906 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 2907} 2908 2909/* =========================================================================== 2910 * Reverse the first len bits of a code, using straightforward code (a faster 2911 * method would use a table) 2912 * IN assertion: 1 <= len <= 15 2913 */ 2914local unsigned bi_reverse(code, len) 2915 unsigned code; /* the value to invert */ 2916 int len; /* its bit length */ 2917{ 2918 register unsigned res = 0; 2919 do { 2920 res |= code & 1; 2921 code >>= 1, res <<= 1; 2922 } while (--len > 0); 2923 return res >> 1; 2924} 2925 2926/* =========================================================================== 2927 * Flush the bit buffer, keeping at most 7 bits in it. 2928 */ 2929local void bi_flush(s) 2930 deflate_state *s; 2931{ 2932 if (s->bi_valid == 16) { 2933 put_short(s, s->bi_buf); 2934 s->bi_buf = 0; 2935 s->bi_valid = 0; 2936 } else if (s->bi_valid >= 8) { 2937 put_byte(s, (Byte)s->bi_buf); 2938 s->bi_buf >>= 8; 2939 s->bi_valid -= 8; 2940 } 2941} 2942 2943/* =========================================================================== 2944 * Flush the bit buffer and align the output on a byte boundary 2945 */ 2946local void bi_windup(s) 2947 deflate_state *s; 2948{ 2949 if (s->bi_valid > 8) { 2950 put_short(s, s->bi_buf); 2951 } else if (s->bi_valid > 0) { 2952 put_byte(s, (Byte)s->bi_buf); 2953 } 2954 s->bi_buf = 0; 2955 s->bi_valid = 0; 2956#ifdef DEBUG_ZLIB 2957 s->bits_sent = (s->bits_sent+7) & ~7; 2958#endif 2959} 2960 2961/* =========================================================================== 2962 * Copy a stored block, storing first the length and its 2963 * one's complement if requested. 2964 */ 2965local void copy_block(s, buf, len, header) 2966 deflate_state *s; 2967 charf *buf; /* the input data */ 2968 unsigned len; /* its length */ 2969 int header; /* true if block header must be written */ 2970{ 2971 bi_windup(s); /* align on byte boundary */ 2972 s->last_eob_len = 8; /* enough lookahead for inflate */ 2973 2974 if (header) { 2975 put_short(s, (ush)len); 2976 put_short(s, (ush)~len); 2977#ifdef DEBUG_ZLIB 2978 s->bits_sent += 2*16; 2979#endif 2980 } 2981#ifdef DEBUG_ZLIB 2982 s->bits_sent += (ulg)len<<3; 2983#endif 2984 /* bundle up the put_byte(s, *buf++) calls */ 2985 zmemcpy(&s->pending_buf[s->pending], buf, len); 2986 s->pending += len; 2987} 2988/* --- trees.c */ 2989 2990/* +++ inflate.c */ 2991/* inflate.c -- zlib interface to inflate modules 2992 * Copyright (C) 1995-1996 Mark Adler 2993 * For conditions of distribution and use, see copyright notice in zlib.h 2994 */ 2995 2996/* #include "zutil.h" */ 2997 2998/* +++ infblock.h */ 2999/* infblock.h -- header to use infblock.c 3000 * Copyright (C) 1995-1996 Mark Adler 3001 * For conditions of distribution and use, see copyright notice in zlib.h 3002 */ 3003 3004/* WARNING: this file should *not* be used by applications. It is 3005 part of the implementation of the compression library and is 3006 subject to change. Applications should only use zlib.h. 3007 */ 3008 3009struct inflate_blocks_state; 3010typedef struct inflate_blocks_state FAR inflate_blocks_statef; 3011 3012extern inflate_blocks_statef * inflate_blocks_new OF(( 3013 z_streamp z, 3014 check_func c, /* check function */ 3015 uInt w)); /* window size */ 3016 3017extern int inflate_blocks OF(( 3018 inflate_blocks_statef *, 3019 z_streamp , 3020 int)); /* initial return code */ 3021 3022extern void inflate_blocks_reset OF(( 3023 inflate_blocks_statef *, 3024 z_streamp , 3025 uLongf *)); /* check value on output */ 3026 3027extern int inflate_blocks_free OF(( 3028 inflate_blocks_statef *, 3029 z_streamp , 3030 uLongf *)); /* check value on output */ 3031 3032extern void inflate_set_dictionary OF(( 3033 inflate_blocks_statef *s, 3034 const Bytef *d, /* dictionary */ 3035 uInt n)); /* dictionary length */ 3036 3037extern int inflate_addhistory OF(( 3038 inflate_blocks_statef *, 3039 z_streamp)); 3040 3041extern int inflate_packet_flush OF(( 3042 inflate_blocks_statef *)); 3043/* --- infblock.h */ 3044 3045#ifndef NO_DUMMY_DECL 3046struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ 3047#endif 3048 3049/* inflate private state */ 3050struct internal_state { 3051 3052 /* mode */ 3053 enum { 3054 METHOD, /* waiting for method byte */ 3055 FLAG, /* waiting for flag byte */ 3056 DICT4, /* four dictionary check bytes to go */ 3057 DICT3, /* three dictionary check bytes to go */ 3058 DICT2, /* two dictionary check bytes to go */ 3059 DICT1, /* one dictionary check byte to go */ 3060 DICT0, /* waiting for inflateSetDictionary */ 3061 BLOCKS, /* decompressing blocks */ 3062 CHECK4, /* four check bytes to go */ 3063 CHECK3, /* three check bytes to go */ 3064 CHECK2, /* two check bytes to go */ 3065 CHECK1, /* one check byte to go */ 3066 DONE, /* finished check, done */ 3067 BAD} /* got an error--stay here */ 3068 mode; /* current inflate mode */ 3069 3070 /* mode dependent information */ 3071 union { 3072 uInt method; /* if FLAGS, method byte */ 3073 struct { 3074 uLong was; /* computed check value */ 3075 uLong need; /* stream check value */ 3076 } check; /* if CHECK, check values to compare */ 3077 uInt marker; /* if BAD, inflateSync's marker bytes count */ 3078 } sub; /* submode */ 3079 3080 /* mode independent information */ 3081 int nowrap; /* flag for no wrapper */ 3082 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 3083 inflate_blocks_statef 3084 *blocks; /* current inflate_blocks state */ 3085 3086}; 3087 3088 3089int inflateReset(z) 3090z_streamp z; 3091{ 3092 uLong c; 3093 3094 if (z == Z_NULL || z->state == Z_NULL) 3095 return Z_STREAM_ERROR; 3096 z->total_in = z->total_out = 0; 3097 z->msg = Z_NULL; 3098 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 3099 inflate_blocks_reset(z->state->blocks, z, &c); 3100 Trace((stderr, "inflate: reset\n")); 3101 return Z_OK; 3102} 3103 3104 3105int inflateEnd(z) 3106z_streamp z; 3107{ 3108 uLong c; 3109 3110 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 3111 return Z_STREAM_ERROR; 3112 if (z->state->blocks != Z_NULL) 3113 inflate_blocks_free(z->state->blocks, z, &c); 3114 ZFREE(z, z->state); 3115 z->state = Z_NULL; 3116 Trace((stderr, "inflate: end\n")); 3117 return Z_OK; 3118} 3119 3120 3121int inflateInit2_(z, w, version, stream_size) 3122z_streamp z; 3123int w; 3124const char *version; 3125int stream_size; 3126{ 3127 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || 3128 stream_size != sizeof(z_stream)) 3129 return Z_VERSION_ERROR; 3130 3131 /* initialize state */ 3132 if (z == Z_NULL) 3133 return Z_STREAM_ERROR; 3134 z->msg = Z_NULL; 3135#ifndef NO_ZCFUNCS 3136 if (z->zalloc == Z_NULL) 3137 { 3138 z->zalloc = zcalloc; 3139 z->opaque = (voidpf)0; 3140 } 3141 if (z->zfree == Z_NULL) z->zfree = zcfree; 3142#endif 3143 if ((z->state = (struct internal_state FAR *) 3144 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 3145 return Z_MEM_ERROR; 3146 z->state->blocks = Z_NULL; 3147 3148 /* handle undocumented nowrap option (no zlib header or check) */ 3149 z->state->nowrap = 0; 3150 if (w < 0) 3151 { 3152 w = - w; 3153 z->state->nowrap = 1; 3154 } 3155 3156 /* set window size */ 3157 if (w < 8 || w > 15) 3158 { 3159 inflateEnd(z); 3160 return Z_STREAM_ERROR; 3161 } 3162 z->state->wbits = (uInt)w; 3163 3164 /* create inflate_blocks state */ 3165 if ((z->state->blocks = 3166 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) 3167 == Z_NULL) 3168 { 3169 inflateEnd(z); 3170 return Z_MEM_ERROR; 3171 } 3172 Trace((stderr, "inflate: allocated\n")); 3173 3174 /* reset state */ 3175 inflateReset(z); 3176 return Z_OK; 3177} 3178 3179 3180int inflateInit_(z, version, stream_size) 3181z_streamp z; 3182const char *version; 3183int stream_size; 3184{ 3185 return inflateInit2_(z, DEF_WBITS, version, stream_size); 3186} 3187 3188 3189#define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 3190#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 3191 3192int inflate(z, f) 3193z_streamp z; 3194int f; 3195{ 3196 int r; 3197 uInt b; 3198 3199 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) 3200 return Z_STREAM_ERROR; 3201 r = Z_BUF_ERROR; 3202 while (1) switch (z->state->mode) 3203 { 3204 case METHOD: 3205 NEEDBYTE 3206 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) 3207 { 3208 z->state->mode = BAD; 3209 z->msg = (char*)"unknown compression method"; 3210 z->state->sub.marker = 5; /* can't try inflateSync */ 3211 break; 3212 } 3213 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 3214 { 3215 z->state->mode = BAD; 3216 z->msg = (char*)"invalid window size"; 3217 z->state->sub.marker = 5; /* can't try inflateSync */ 3218 break; 3219 } 3220 z->state->mode = FLAG; 3221 case FLAG: 3222 NEEDBYTE 3223 b = NEXTBYTE; 3224 if (((z->state->sub.method << 8) + b) % 31) 3225 { 3226 z->state->mode = BAD; 3227 z->msg = (char*)"incorrect header check"; 3228 z->state->sub.marker = 5; /* can't try inflateSync */ 3229 break; 3230 } 3231 Trace((stderr, "inflate: zlib header ok\n")); 3232 if (!(b & PRESET_DICT)) 3233 { 3234 z->state->mode = BLOCKS; 3235 break; 3236 } 3237 z->state->mode = DICT4; 3238 case DICT4: 3239 NEEDBYTE 3240 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3241 z->state->mode = DICT3; 3242 case DICT3: 3243 NEEDBYTE 3244 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3245 z->state->mode = DICT2; 3246 case DICT2: 3247 NEEDBYTE 3248 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3249 z->state->mode = DICT1; 3250 case DICT1: 3251 NEEDBYTE 3252 z->state->sub.check.need += (uLong)NEXTBYTE; 3253 z->adler = z->state->sub.check.need; 3254 z->state->mode = DICT0; 3255 return Z_NEED_DICT; 3256 case DICT0: 3257 z->state->mode = BAD; 3258 z->msg = (char*)"need dictionary"; 3259 z->state->sub.marker = 0; /* can try inflateSync */ 3260 return Z_STREAM_ERROR; 3261 case BLOCKS: 3262 r = inflate_blocks(z->state->blocks, z, r); 3263 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 3264 r = inflate_packet_flush(z->state->blocks); 3265 if (r == Z_DATA_ERROR) 3266 { 3267 z->state->mode = BAD; 3268 z->state->sub.marker = 0; /* can try inflateSync */ 3269 break; 3270 } 3271 if (r != Z_STREAM_END) 3272 return r; 3273 r = Z_OK; 3274 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 3275 if (z->state->nowrap) 3276 { 3277 z->state->mode = DONE; 3278 break; 3279 } 3280 z->state->mode = CHECK4; 3281 case CHECK4: 3282 NEEDBYTE 3283 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3284 z->state->mode = CHECK3; 3285 case CHECK3: 3286 NEEDBYTE 3287 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3288 z->state->mode = CHECK2; 3289 case CHECK2: 3290 NEEDBYTE 3291 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3292 z->state->mode = CHECK1; 3293 case CHECK1: 3294 NEEDBYTE 3295 z->state->sub.check.need += (uLong)NEXTBYTE; 3296 3297 if (z->state->sub.check.was != z->state->sub.check.need) 3298 { 3299 z->state->mode = BAD; 3300 z->msg = (char*)"incorrect data check"; 3301 z->state->sub.marker = 5; /* can't try inflateSync */ 3302 break; 3303 } 3304 Trace((stderr, "inflate: zlib check ok\n")); 3305 z->state->mode = DONE; 3306 case DONE: 3307 return Z_STREAM_END; 3308 case BAD: 3309 return Z_DATA_ERROR; 3310 default: 3311 return Z_STREAM_ERROR; 3312 } 3313 3314 empty: 3315 if (f != Z_PACKET_FLUSH) 3316 return r; 3317 z->state->mode = BAD; 3318 z->msg = (char *)"need more for packet flush"; 3319 z->state->sub.marker = 0; /* can try inflateSync */ 3320 return Z_DATA_ERROR; 3321} 3322 3323 3324int inflateSetDictionary(z, dictionary, dictLength) 3325z_streamp z; 3326const Bytef *dictionary; 3327uInt dictLength; 3328{ 3329 uInt length = dictLength; 3330 3331 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) 3332 return Z_STREAM_ERROR; 3333 3334 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; 3335 z->adler = 1L; 3336 3337 if (length >= ((uInt)1<<z->state->wbits)) 3338 { 3339 length = (1<<z->state->wbits)-1; 3340 dictionary += dictLength - length; 3341 } 3342 inflate_set_dictionary(z->state->blocks, dictionary, length); 3343 z->state->mode = BLOCKS; 3344 return Z_OK; 3345} 3346 3347/* 3348 * This subroutine adds the data at next_in/avail_in to the output history 3349 * without performing any output. The output buffer must be "caught up"; 3350 * i.e. no pending output (hence s->read equals s->write), and the state must 3351 * be BLOCKS (i.e. we should be willing to see the start of a series of 3352 * BLOCKS). On exit, the output will also be caught up, and the checksum 3353 * will have been updated if need be. 3354 */ 3355 3356int inflateIncomp(z) 3357z_stream *z; 3358{ 3359 if (z->state->mode != BLOCKS) 3360 return Z_DATA_ERROR; 3361 return inflate_addhistory(z->state->blocks, z); 3362} 3363 3364 3365int inflateSync(z) 3366z_streamp z; 3367{ 3368 uInt n; /* number of bytes to look at */ 3369 Bytef *p; /* pointer to bytes */ 3370 uInt m; /* number of marker bytes found in a row */ 3371 uLong r, w; /* temporaries to save total_in and total_out */ 3372 3373 /* set up */ 3374 if (z == Z_NULL || z->state == Z_NULL) 3375 return Z_STREAM_ERROR; 3376 if (z->state->mode != BAD) 3377 { 3378 z->state->mode = BAD; 3379 z->state->sub.marker = 0; 3380 } 3381 if ((n = z->avail_in) == 0) 3382 return Z_BUF_ERROR; 3383 p = z->next_in; 3384 m = z->state->sub.marker; 3385 3386 /* search */ 3387 while (n && m < 4) 3388 { 3389 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3390 m++; 3391 else if (*p) 3392 m = 0; 3393 else 3394 m = 4 - m; 3395 p++, n--; 3396 } 3397 3398 /* restore */ 3399 z->total_in += p - z->next_in; 3400 z->next_in = p; 3401 z->avail_in = n; 3402 z->state->sub.marker = m; 3403 3404 /* return no joy or set up to restart on a new block */ 3405 if (m != 4) 3406 return Z_DATA_ERROR; 3407 r = z->total_in; w = z->total_out; 3408 inflateReset(z); 3409 z->total_in = r; z->total_out = w; 3410 z->state->mode = BLOCKS; 3411 return Z_OK; 3412} 3413 3414#undef NEEDBYTE 3415#undef NEXTBYTE 3416/* --- inflate.c */ 3417 3418/* +++ infblock.c */ 3419/* infblock.c -- interpret and process block types to last block 3420 * Copyright (C) 1995-1996 Mark Adler 3421 * For conditions of distribution and use, see copyright notice in zlib.h 3422 */ 3423 3424/* #include "zutil.h" */ 3425/* #include "infblock.h" */ 3426 3427/* +++ inftrees.h */ 3428/* inftrees.h -- header to use inftrees.c 3429 * Copyright (C) 1995-1996 Mark Adler 3430 * For conditions of distribution and use, see copyright notice in zlib.h 3431 */ 3432 3433/* WARNING: this file should *not* be used by applications. It is 3434 part of the implementation of the compression library and is 3435 subject to change. Applications should only use zlib.h. 3436 */ 3437 3438/* Huffman code lookup table entry--this entry is four bytes for machines 3439 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 3440 3441typedef struct inflate_huft_s FAR inflate_huft; 3442 3443struct inflate_huft_s { 3444 union { 3445 struct { 3446 Byte Exop; /* number of extra bits or operation */ 3447 Byte Bits; /* number of bits in this code or subcode */ 3448 } what; 3449 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 3450 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 3451 union { 3452 uInt Base; /* literal, length base, or distance base */ 3453 inflate_huft *Next; /* pointer to next level of table */ 3454 } more; 3455}; 3456 3457#ifdef DEBUG_ZLIB 3458 extern uInt inflate_hufts; 3459#endif 3460 3461extern int inflate_trees_bits OF(( 3462 uIntf *, /* 19 code lengths */ 3463 uIntf *, /* bits tree desired/actual depth */ 3464 inflate_huft * FAR *, /* bits tree result */ 3465 z_streamp )); /* for zalloc, zfree functions */ 3466 3467extern int inflate_trees_dynamic OF(( 3468 uInt, /* number of literal/length codes */ 3469 uInt, /* number of distance codes */ 3470 uIntf *, /* that many (total) code lengths */ 3471 uIntf *, /* literal desired/actual bit depth */ 3472 uIntf *, /* distance desired/actual bit depth */ 3473 inflate_huft * FAR *, /* literal/length tree result */ 3474 inflate_huft * FAR *, /* distance tree result */ 3475 z_streamp )); /* for zalloc, zfree functions */ 3476 3477extern int inflate_trees_fixed OF(( 3478 uIntf *, /* literal desired/actual bit depth */ 3479 uIntf *, /* distance desired/actual bit depth */ 3480 inflate_huft * FAR *, /* literal/length tree result */ 3481 inflate_huft * FAR *)); /* distance tree result */ 3482 3483extern int inflate_trees_free OF(( 3484 inflate_huft *, /* tables to free */ 3485 z_streamp )); /* for zfree function */ 3486 3487/* --- inftrees.h */ 3488 3489/* +++ infcodes.h */ 3490/* infcodes.h -- header to use infcodes.c 3491 * Copyright (C) 1995-1996 Mark Adler 3492 * For conditions of distribution and use, see copyright notice in zlib.h 3493 */ 3494 3495/* WARNING: this file should *not* be used by applications. It is 3496 part of the implementation of the compression library and is 3497 subject to change. Applications should only use zlib.h. 3498 */ 3499 3500struct inflate_codes_state; 3501typedef struct inflate_codes_state FAR inflate_codes_statef; 3502 3503extern inflate_codes_statef *inflate_codes_new OF(( 3504 uInt, uInt, 3505 inflate_huft *, inflate_huft *, 3506 z_streamp )); 3507 3508extern int inflate_codes OF(( 3509 inflate_blocks_statef *, 3510 z_streamp , 3511 int)); 3512 3513extern void inflate_codes_free OF(( 3514 inflate_codes_statef *, 3515 z_streamp )); 3516 3517/* --- infcodes.h */ 3518 3519/* +++ infutil.h */ 3520/* infutil.h -- types and macros common to blocks and codes 3521 * Copyright (C) 1995-1996 Mark Adler 3522 * For conditions of distribution and use, see copyright notice in zlib.h 3523 */ 3524 3525/* WARNING: this file should *not* be used by applications. It is 3526 part of the implementation of the compression library and is 3527 subject to change. Applications should only use zlib.h. 3528 */ 3529 3530#ifndef _INFUTIL_H 3531#define _INFUTIL_H 3532 3533typedef enum { 3534 TYPE, /* get type bits (3, including end bit) */ 3535 LENS, /* get lengths for stored */ 3536 STORED, /* processing stored block */ 3537 TABLE, /* get table lengths */ 3538 BTREE, /* get bit lengths tree for a dynamic block */ 3539 DTREE, /* get length, distance trees for a dynamic block */ 3540 CODES, /* processing fixed or dynamic block */ 3541 DRY, /* output remaining window bytes */ 3542 DONEB, /* finished last block, done */ 3543 BADB} /* got a data error--stuck here */ 3544inflate_block_mode; 3545 3546/* inflate blocks semi-private state */ 3547struct inflate_blocks_state { 3548 3549 /* mode */ 3550 inflate_block_mode mode; /* current inflate_block mode */ 3551 3552 /* mode dependent information */ 3553 union { 3554 uInt left; /* if STORED, bytes left to copy */ 3555 struct { 3556 uInt table; /* table lengths (14 bits) */ 3557 uInt index; /* index into blens (or border) */ 3558 uIntf *blens; /* bit lengths of codes */ 3559 uInt bb; /* bit length tree depth */ 3560 inflate_huft *tb; /* bit length decoding tree */ 3561 } trees; /* if DTREE, decoding info for trees */ 3562 struct { 3563 inflate_huft *tl; 3564 inflate_huft *td; /* trees to free */ 3565 inflate_codes_statef 3566 *codes; 3567 } decode; /* if CODES, current state */ 3568 } sub; /* submode */ 3569 uInt last; /* true if this block is the last block */ 3570 3571 /* mode independent information */ 3572 uInt bitk; /* bits in bit buffer */ 3573 uLong bitb; /* bit buffer */ 3574 Bytef *window; /* sliding window */ 3575 Bytef *end; /* one byte after sliding window */ 3576 Bytef *read; /* window read pointer */ 3577 Bytef *write; /* window write pointer */ 3578 check_func checkfn; /* check function */ 3579 uLong check; /* check on output */ 3580 3581}; 3582 3583 3584/* defines for inflate input/output */ 3585/* update pointers and return */ 3586#define UPDBITS {s->bitb=b;s->bitk=k;} 3587#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3588#define UPDOUT {s->write=q;} 3589#define UPDATE {UPDBITS UPDIN UPDOUT} 3590#define LEAVE {UPDATE return inflate_flush(s,z,r);} 3591/* get bytes and bits */ 3592#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3593#define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3594#define NEXTBYTE (n--,*p++) 3595#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3596#define DUMPBITS(j) {b>>=(j);k-=(j);} 3597/* output bytes */ 3598#define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) 3599#define LOADOUT {q=s->write;m=(uInt)WAVAIL;} 3600#define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} 3601#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3602#define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} 3603#define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3604/* load local pointers */ 3605#define LOAD {LOADIN LOADOUT} 3606 3607/* masks for lower bits (size given to avoid silly warnings with Visual C++) */ 3608extern uInt inflate_mask[17]; 3609 3610/* copy as much as possible from the sliding window to the output area */ 3611extern int inflate_flush OF(( 3612 inflate_blocks_statef *, 3613 z_streamp , 3614 int)); 3615 3616#ifndef NO_DUMMY_DECL 3617struct internal_state {int dummy;}; /* for buggy compilers */ 3618#endif 3619 3620#endif 3621/* --- infutil.h */ 3622 3623#ifndef NO_DUMMY_DECL 3624struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 3625#endif 3626 3627/* Table for deflate from PKZIP's appnote.txt. */ 3628local const uInt border[] = { /* Order of the bit length code lengths */ 3629 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3630 3631/* 3632 Notes beyond the 1.93a appnote.txt: 3633 3634 1. Distance pointers never point before the beginning of the output 3635 stream. 3636 2. Distance pointers can point back across blocks, up to 32k away. 3637 3. There is an implied maximum of 7 bits for the bit length table and 3638 15 bits for the actual data. 3639 4. If only one code exists, then it is encoded using one bit. (Zero 3640 would be more efficient, but perhaps a little confusing.) If two 3641 codes exist, they are coded using one bit each (0 and 1). 3642 5. There is no way of sending zero distance codes--a dummy must be 3643 sent if there are none. (History: a pre 2.0 version of PKZIP would 3644 store blocks with no distance codes, but this was discovered to be 3645 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3646 zero distance codes, which is sent as one code of zero bits in 3647 length. 3648 6. There are up to 286 literal/length codes. Code 256 represents the 3649 end-of-block. Note however that the static length tree defines 3650 288 codes just to fill out the Huffman codes. Codes 286 and 287 3651 cannot be used though, since there is no length base or extra bits 3652 defined for them. Similarily, there are up to 30 distance codes. 3653 However, static trees define 32 codes (all 5 bits) to fill out the 3654 Huffman codes, but the last two had better not show up in the data. 3655 7. Unzip can check dynamic Huffman blocks for complete code sets. 3656 The exception is that a single code would not be complete (see #4). 3657 8. The five bits following the block type is really the number of 3658 literal codes sent minus 257. 3659 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3660 (1+6+6). Therefore, to output three times the length, you output 3661 three codes (1+1+1), whereas to output four times the same length, 3662 you only need two codes (1+3). Hmm. 3663 10. In the tree reconstruction algorithm, Code = Code + Increment 3664 only if BitLength(i) is not zero. (Pretty obvious.) 3665 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3666 12. Note: length code 284 can represent 227-258, but length code 285 3667 really is 258. The last length deserves its own, short code 3668 since it gets used a lot in very redundant files. The length 3669 258 is special since 258 - 3 (the min match length) is 255. 3670 13. The literal/length and distance code bit lengths are read as a 3671 single stream of lengths. It is possible (and advantageous) for 3672 a repeat code (16, 17, or 18) to go across the boundary between 3673 the two sets of lengths. 3674 */ 3675 3676 3677void inflate_blocks_reset(s, z, c) 3678inflate_blocks_statef *s; 3679z_streamp z; 3680uLongf *c; 3681{ 3682 if (s->checkfn != Z_NULL) 3683 *c = s->check; 3684 if (s->mode == BTREE || s->mode == DTREE) 3685 ZFREE(z, s->sub.trees.blens); 3686 if (s->mode == CODES) 3687 { 3688 inflate_codes_free(s->sub.decode.codes, z); 3689 inflate_trees_free(s->sub.decode.td, z); 3690 inflate_trees_free(s->sub.decode.tl, z); 3691 } 3692 s->mode = TYPE; 3693 s->bitk = 0; 3694 s->bitb = 0; 3695 s->read = s->write = s->window; 3696 if (s->checkfn != Z_NULL) 3697 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); 3698 Trace((stderr, "inflate: blocks reset\n")); 3699} 3700 3701 3702inflate_blocks_statef *inflate_blocks_new(z, c, w) 3703z_streamp z; 3704check_func c; 3705uInt w; 3706{ 3707 inflate_blocks_statef *s; 3708 3709 if ((s = (inflate_blocks_statef *)ZALLOC 3710 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3711 return s; 3712 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3713 { 3714 ZFREE(z, s); 3715 return Z_NULL; 3716 } 3717 s->end = s->window + w; 3718 s->checkfn = c; 3719 s->mode = TYPE; 3720 Trace((stderr, "inflate: blocks allocated\n")); 3721 inflate_blocks_reset(s, z, &s->check); 3722 return s; 3723} 3724 3725 3726#ifdef DEBUG_ZLIB 3727 extern uInt inflate_hufts; 3728#endif 3729int inflate_blocks(s, z, r) 3730inflate_blocks_statef *s; 3731z_streamp z; 3732int r; 3733{ 3734 uInt t; /* temporary storage */ 3735 uLong b; /* bit buffer */ 3736 uInt k; /* bits in bit buffer */ 3737 Bytef *p; /* input data pointer */ 3738 uInt n; /* bytes available there */ 3739 Bytef *q; /* output window write pointer */ 3740 uInt m; /* bytes to end of window or read pointer */ 3741 3742 /* copy input/output information to locals (UPDATE macro restores) */ 3743 LOAD 3744 3745 /* process input based on current state */ 3746 while (1) switch (s->mode) 3747 { 3748 case TYPE: 3749 NEEDBITS(3) 3750 t = (uInt)b & 7; 3751 s->last = t & 1; 3752 switch (t >> 1) 3753 { 3754 case 0: /* stored */ 3755 Trace((stderr, "inflate: stored block%s\n", 3756 s->last ? " (last)" : "")); 3757 DUMPBITS(3) 3758 t = k & 7; /* go to byte boundary */ 3759 DUMPBITS(t) 3760 s->mode = LENS; /* get length of stored block */ 3761 break; 3762 case 1: /* fixed */ 3763 Trace((stderr, "inflate: fixed codes block%s\n", 3764 s->last ? " (last)" : "")); 3765 { 3766 uInt bl, bd; 3767 inflate_huft *tl, *td; 3768 3769 inflate_trees_fixed(&bl, &bd, &tl, &td); 3770 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3771 if (s->sub.decode.codes == Z_NULL) 3772 { 3773 r = Z_MEM_ERROR; 3774 LEAVE 3775 } 3776 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3777 s->sub.decode.td = Z_NULL; 3778 } 3779 DUMPBITS(3) 3780 s->mode = CODES; 3781 break; 3782 case 2: /* dynamic */ 3783 Trace((stderr, "inflate: dynamic codes block%s\n", 3784 s->last ? " (last)" : "")); 3785 DUMPBITS(3) 3786 s->mode = TABLE; 3787 break; 3788 case 3: /* illegal */ 3789 DUMPBITS(3) 3790 s->mode = BADB; 3791 z->msg = (char*)"invalid block type"; 3792 r = Z_DATA_ERROR; 3793 LEAVE 3794 } 3795 break; 3796 case LENS: 3797 NEEDBITS(32) 3798 if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) 3799 { 3800 s->mode = BADB; 3801 z->msg = (char*)"invalid stored block lengths"; 3802 r = Z_DATA_ERROR; 3803 LEAVE 3804 } 3805 s->sub.left = (uInt)b & 0xffff; 3806 b = k = 0; /* dump bits */ 3807 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3808 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); 3809 break; 3810 case STORED: 3811 if (n == 0) 3812 LEAVE 3813 NEEDOUT 3814 t = s->sub.left; 3815 if (t > n) t = n; 3816 if (t > m) t = m; 3817 zmemcpy(q, p, t); 3818 p += t; n -= t; 3819 q += t; m -= t; 3820 if ((s->sub.left -= t) != 0) 3821 break; 3822 Tracev((stderr, "inflate: stored end, %lu total out\n", 3823 z->total_out + (q >= s->read ? q - s->read : 3824 (s->end - s->read) + (q - s->window)))); 3825 s->mode = s->last ? DRY : TYPE; 3826 break; 3827 case TABLE: 3828 NEEDBITS(14) 3829 s->sub.trees.table = t = (uInt)b & 0x3fff; 3830#ifndef PKZIP_BUG_WORKAROUND 3831 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3832 { 3833 s->mode = BADB; 3834 z->msg = (char*)"too many length or distance symbols"; 3835 r = Z_DATA_ERROR; 3836 LEAVE 3837 } 3838#endif 3839 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3840 if (t < 19) 3841 t = 19; 3842 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3843 { 3844 r = Z_MEM_ERROR; 3845 LEAVE 3846 } 3847 DUMPBITS(14) 3848 s->sub.trees.index = 0; 3849 Tracev((stderr, "inflate: table sizes ok\n")); 3850 s->mode = BTREE; 3851 case BTREE: 3852 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3853 { 3854 NEEDBITS(3) 3855 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3856 DUMPBITS(3) 3857 } 3858 while (s->sub.trees.index < 19) 3859 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3860 s->sub.trees.bb = 7; 3861 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3862 &s->sub.trees.tb, z); 3863 if (t != Z_OK) 3864 { 3865 r = t; 3866 if (r == Z_DATA_ERROR) { 3867 ZFREE(z, s->sub.trees.blens); 3868 s->mode = BADB; 3869 } 3870 LEAVE 3871 } 3872 s->sub.trees.index = 0; 3873 Tracev((stderr, "inflate: bits tree ok\n")); 3874 s->mode = DTREE; 3875 case DTREE: 3876 while (t = s->sub.trees.table, 3877 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3878 { 3879 inflate_huft *h; 3880 uInt i, j, c; 3881 3882 t = s->sub.trees.bb; 3883 NEEDBITS(t) 3884 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3885 t = h->word.what.Bits; 3886 c = h->more.Base; 3887 if (c < 16) 3888 { 3889 DUMPBITS(t) 3890 s->sub.trees.blens[s->sub.trees.index++] = c; 3891 } 3892 else /* c == 16..18 */ 3893 { 3894 i = c == 18 ? 7 : c - 14; 3895 j = c == 18 ? 11 : 3; 3896 NEEDBITS(t + i) 3897 DUMPBITS(t) 3898 j += (uInt)b & inflate_mask[i]; 3899 DUMPBITS(i) 3900 i = s->sub.trees.index; 3901 t = s->sub.trees.table; 3902 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3903 (c == 16 && i < 1)) 3904 { 3905 inflate_trees_free(s->sub.trees.tb, z); 3906 ZFREE(z, s->sub.trees.blens); 3907 s->mode = BADB; 3908 z->msg = (char*)"invalid bit length repeat"; 3909 r = Z_DATA_ERROR; 3910 LEAVE 3911 } 3912 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3913 do { 3914 s->sub.trees.blens[i++] = c; 3915 } while (--j); 3916 s->sub.trees.index = i; 3917 } 3918 } 3919 inflate_trees_free(s->sub.trees.tb, z); 3920 s->sub.trees.tb = Z_NULL; 3921 { 3922 uInt bl, bd; 3923 inflate_huft *tl, *td; 3924 inflate_codes_statef *c; 3925 3926 bl = 9; /* must be <= 9 for lookahead assumptions */ 3927 bd = 6; /* must be <= 9 for lookahead assumptions */ 3928 t = s->sub.trees.table; 3929#ifdef DEBUG_ZLIB 3930 inflate_hufts = 0; 3931#endif 3932 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3933 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3934 if (t != Z_OK) 3935 { 3936 if (t == (uInt)Z_DATA_ERROR) { 3937 ZFREE(z, s->sub.trees.blens); 3938 s->mode = BADB; 3939 } 3940 r = t; 3941 LEAVE 3942 } 3943 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", 3944 inflate_hufts, sizeof(inflate_huft))); 3945 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3946 { 3947 inflate_trees_free(td, z); 3948 inflate_trees_free(tl, z); 3949 r = Z_MEM_ERROR; 3950 LEAVE 3951 } 3952 /* 3953 * this ZFREE must occur *BEFORE* we mess with sub.decode, because 3954 * sub.trees is union'd with sub.decode. 3955 */ 3956 ZFREE(z, s->sub.trees.blens); 3957 s->sub.decode.codes = c; 3958 s->sub.decode.tl = tl; 3959 s->sub.decode.td = td; 3960 } 3961 s->mode = CODES; 3962 case CODES: 3963 UPDATE 3964 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3965 return inflate_flush(s, z, r); 3966 r = Z_OK; 3967 inflate_codes_free(s->sub.decode.codes, z); 3968 inflate_trees_free(s->sub.decode.td, z); 3969 inflate_trees_free(s->sub.decode.tl, z); 3970 LOAD 3971 Tracev((stderr, "inflate: codes end, %lu total out\n", 3972 z->total_out + (q >= s->read ? q - s->read : 3973 (s->end - s->read) + (q - s->window)))); 3974 if (!s->last) 3975 { 3976 s->mode = TYPE; 3977 break; 3978 } 3979 if (k > 7) /* return unused byte, if any */ 3980 { 3981 Assert(k < 16, "inflate_codes grabbed too many bytes") 3982 k -= 8; 3983 n++; 3984 p--; /* can always return one */ 3985 } 3986 s->mode = DRY; 3987 case DRY: 3988 FLUSH 3989 if (s->read != s->write) 3990 LEAVE 3991 s->mode = DONEB; 3992 case DONEB: 3993 r = Z_STREAM_END; 3994 LEAVE 3995 case BADB: 3996 r = Z_DATA_ERROR; 3997 LEAVE 3998 default: 3999 r = Z_STREAM_ERROR; 4000 LEAVE 4001 } 4002} 4003 4004 4005int inflate_blocks_free(s, z, c) 4006inflate_blocks_statef *s; 4007z_streamp z; 4008uLongf *c; 4009{ 4010 inflate_blocks_reset(s, z, c); 4011 ZFREE(z, s->window); 4012 ZFREE(z, s); 4013 Trace((stderr, "inflate: blocks freed\n")); 4014 return Z_OK; 4015} 4016 4017 4018void inflate_set_dictionary(s, d, n) 4019inflate_blocks_statef *s; 4020const Bytef *d; 4021uInt n; 4022{ 4023 zmemcpy((charf *)s->window, d, n); 4024 s->read = s->write = s->window + n; 4025} 4026 4027/* 4028 * This subroutine adds the data at next_in/avail_in to the output history 4029 * without performing any output. The output buffer must be "caught up"; 4030 * i.e. no pending output (hence s->read equals s->write), and the state must 4031 * be BLOCKS (i.e. we should be willing to see the start of a series of 4032 * BLOCKS). On exit, the output will also be caught up, and the checksum 4033 * will have been updated if need be. 4034 */ 4035int inflate_addhistory(s, z) 4036inflate_blocks_statef *s; 4037z_stream *z; 4038{ 4039 uLong b; /* bit buffer */ /* NOT USED HERE */ 4040 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 4041 uInt t; /* temporary storage */ 4042 Bytef *p; /* input data pointer */ 4043 uInt n; /* bytes available there */ 4044 Bytef *q; /* output window write pointer */ 4045 uInt m; /* bytes to end of window or read pointer */ 4046 4047 if (s->read != s->write) 4048 return Z_STREAM_ERROR; 4049 if (s->mode != TYPE) 4050 return Z_DATA_ERROR; 4051 4052 /* we're ready to rock */ 4053 LOAD 4054 /* while there is input ready, copy to output buffer, moving 4055 * pointers as needed. 4056 */ 4057 while (n) { 4058 t = n; /* how many to do */ 4059 /* is there room until end of buffer? */ 4060 if (t > m) t = m; 4061 /* update check information */ 4062 if (s->checkfn != Z_NULL) 4063 s->check = (*s->checkfn)(s->check, q, t); 4064 zmemcpy(q, p, t); 4065 q += t; 4066 p += t; 4067 n -= t; 4068 z->total_out += t; 4069 s->read = q; /* drag read pointer forward */ 4070/* WWRAP */ /* expand WWRAP macro by hand to handle s->read */ 4071 if (q == s->end) { 4072 s->read = q = s->window; 4073 m = WAVAIL; 4074 } 4075 } 4076 UPDATE 4077 return Z_OK; 4078} 4079 4080 4081/* 4082 * At the end of a Deflate-compressed PPP packet, we expect to have seen 4083 * a `stored' block type value but not the (zero) length bytes. 4084 */ 4085int inflate_packet_flush(s) 4086 inflate_blocks_statef *s; 4087{ 4088 if (s->mode != LENS) 4089 return Z_DATA_ERROR; 4090 s->mode = TYPE; 4091 return Z_OK; 4092} 4093/* --- infblock.c */ 4094 4095/* +++ inftrees.c */ 4096/* inftrees.c -- generate Huffman trees for efficient decoding 4097 * Copyright (C) 1995-1996 Mark Adler 4098 * For conditions of distribution and use, see copyright notice in zlib.h 4099 */ 4100 4101/* #include "zutil.h" */ 4102/* #include "inftrees.h" */ 4103 4104char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler "; 4105/* 4106 If you use the zlib library in a product, an acknowledgment is welcome 4107 in the documentation of your product. If for some reason you cannot 4108 include such an acknowledgment, I would appreciate that you keep this 4109 copyright string in the executable of your product. 4110 */ 4111 4112#ifndef NO_DUMMY_DECL 4113struct internal_state {int dummy;}; /* for buggy compilers */ 4114#endif 4115 4116/* simplify the use of the inflate_huft type with some defines */ 4117#define base more.Base 4118#define next more.Next 4119#define exop word.what.Exop 4120#define bits word.what.Bits 4121 4122 4123local int huft_build OF(( 4124 uIntf *, /* code lengths in bits */ 4125 uInt, /* number of codes */ 4126 uInt, /* number of "simple" codes */ 4127 const uIntf *, /* list of base values for non-simple codes */ 4128 const uIntf *, /* list of extra bits for non-simple codes */ 4129 inflate_huft * FAR*,/* result: starting table */ 4130 uIntf *, /* maximum lookup bits (returns actual) */ 4131 z_streamp )); /* for zalloc function */ 4132 4133local voidpf falloc OF(( 4134 voidpf, /* opaque pointer (not used) */ 4135 uInt, /* number of items */ 4136 uInt)); /* size of item */ 4137 4138/* Tables for deflate from PKZIP's appnote.txt. */ 4139local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */ 4140 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 4141 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 4142 /* see note #13 above about 258 */ 4143local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */ 4144 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 4145 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */ 4146local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */ 4147 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 4148 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 4149 8193, 12289, 16385, 24577}; 4150local const uInt cpdext[30] = { /* Extra bits for distance codes */ 4151 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 4152 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 4153 12, 12, 13, 13}; 4154 4155/* 4156 Huffman code decoding is performed using a multi-level table lookup. 4157 The fastest way to decode is to simply build a lookup table whose 4158 size is determined by the longest code. However, the time it takes 4159 to build this table can also be a factor if the data being decoded 4160 is not very long. The most common codes are necessarily the 4161 shortest codes, so those codes dominate the decoding time, and hence 4162 the speed. The idea is you can have a shorter table that decodes the 4163 shorter, more probable codes, and then point to subsidiary tables for 4164 the longer codes. The time it costs to decode the longer codes is 4165 then traded against the time it takes to make longer tables. 4166 4167 This results of this trade are in the variables lbits and dbits 4168 below. lbits is the number of bits the first level table for literal/ 4169 length codes can decode in one step, and dbits is the same thing for 4170 the distance codes. Subsequent tables are also less than or equal to 4171 those sizes. These values may be adjusted either when all of the 4172 codes are shorter than that, in which case the longest code length in 4173 bits is used, or when the shortest code is *longer* than the requested 4174 table size, in which case the length of the shortest code in bits is 4175 used. 4176 4177 There are two different values for the two tables, since they code a 4178 different number of possibilities each. The literal/length table 4179 codes 286 possible values, or in a flat code, a little over eight 4180 bits. The distance table codes 30 possible values, or a little less 4181 than five bits, flat. The optimum values for speed end up being 4182 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 4183 The optimum values may differ though from machine to machine, and 4184 possibly even between compilers. Your mileage may vary. 4185 */ 4186 4187 4188/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 4189#define BMAX 15 /* maximum bit length of any code */ 4190#define N_MAX 288 /* maximum number of codes in any set */ 4191 4192#ifdef DEBUG_ZLIB 4193 uInt inflate_hufts; 4194#endif 4195 4196local int huft_build(b, n, s, d, e, t, m, zs) 4197uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ 4198uInt n; /* number of codes (assumed <= N_MAX) */ 4199uInt s; /* number of simple-valued codes (0..s-1) */ 4200const uIntf *d; /* list of base values for non-simple codes */ 4201const uIntf *e; /* list of extra bits for non-simple codes */ 4202inflate_huft * FAR *t; /* result: starting table */ 4203uIntf *m; /* maximum lookup bits, returns actual */ 4204z_streamp zs; /* for zalloc function */ 4205/* Given a list of code lengths and a maximum table size, make a set of 4206 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 4207 if the given code set is incomplete (the tables are still built in this 4208 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of 4209 lengths), or Z_MEM_ERROR if not enough memory. */ 4210{ 4211 4212 uInt a; /* counter for codes of length k */ 4213 uInt c[BMAX+1]; /* bit length count table */ 4214 uInt f; /* i repeats in table every f entries */ 4215 int g; /* maximum code length */ 4216 int h; /* table level */ 4217 register uInt i; /* counter, current code */ 4218 register uInt j; /* counter */ 4219 register int k; /* number of bits in current code */ 4220 int l; /* bits per table (returned in m) */ 4221 register uIntf *p; /* pointer into c[], b[], or v[] */ 4222 inflate_huft *q; /* points to current table */ 4223 struct inflate_huft_s r; /* table entry for structure assignment */ 4224 inflate_huft *u[BMAX]; /* table stack */ 4225 uInt v[N_MAX]; /* values in order of bit length */ 4226 register int w; /* bits before this table == (l * h) */ 4227 uInt x[BMAX+1]; /* bit offsets, then code stack */ 4228 uIntf *xp; /* pointer into x */ 4229 int y; /* number of dummy codes added */ 4230 uInt z; /* number of entries in current table */ 4231 4232 4233 /* Generate counts for each bit length */ 4234 p = c; 4235#define C0 *p++ = 0; 4236#define C2 C0 C0 C0 C0 4237#define C4 C2 C2 C2 C2 4238 C4 /* clear c[]--assume BMAX+1 is 16 */ 4239 p = b; i = n; 4240 do { 4241 c[*p++]++; /* assume all entries <= BMAX */ 4242 } while (--i); 4243 if (c[0] == n) /* null input--all zero length codes */ 4244 { 4245 *t = (inflate_huft *)Z_NULL; 4246 *m = 0; 4247 return Z_OK; 4248 } 4249 4250 4251 /* Find minimum and maximum length, bound *m by those */ 4252 l = *m; 4253 for (j = 1; j <= BMAX; j++) 4254 if (c[j]) 4255 break; 4256 k = j; /* minimum code length */ 4257 if ((uInt)l < j) 4258 l = j; 4259 for (i = BMAX; i; i--) 4260 if (c[i]) 4261 break; 4262 g = i; /* maximum code length */ 4263 if ((uInt)l > i) 4264 l = i; 4265 *m = l; 4266 4267 4268 /* Adjust last length count to fill out codes, if needed */ 4269 for (y = 1 << j; j < i; j++, y <<= 1) 4270 if ((y -= c[j]) < 0) 4271 return Z_DATA_ERROR; 4272 if ((y -= c[i]) < 0) 4273 return Z_DATA_ERROR; 4274 c[i] += y; 4275 4276 4277 /* Generate starting offsets into the value table for each length */ 4278 x[1] = j = 0; 4279 p = c + 1; xp = x + 2; 4280 while (--i) { /* note that i == g from above */ 4281 *xp++ = (j += *p++); 4282 } 4283 4284 4285 /* Make a table of values in order of bit lengths */ 4286 p = b; i = 0; 4287 do { 4288 if ((j = *p++) != 0) 4289 v[x[j]++] = i; 4290 } while (++i < n); 4291 n = x[g]; /* set n to length of v */ 4292 4293 4294 /* Generate the Huffman codes and for each, make the table entries */ 4295 x[0] = i = 0; /* first Huffman code is zero */ 4296 p = v; /* grab values in bit order */ 4297 h = -1; /* no tables yet--level -1 */ 4298 w = -l; /* bits decoded == (l * h) */ 4299 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 4300 q = (inflate_huft *)Z_NULL; /* ditto */ 4301 z = 0; /* ditto */ 4302 4303 /* go through the bit lengths (k already is bits in shortest code) */ 4304 for (; k <= g; k++) 4305 { 4306 a = c[k]; 4307 while (a--) 4308 { 4309 /* here i is the Huffman code of length k bits for value *p */ 4310 /* make tables up to required level */ 4311 while (k > w + l) 4312 { 4313 h++; 4314 w += l; /* previous table always l bits */ 4315 4316 /* compute minimum size table less than or equal to l bits */ 4317 z = g - w; 4318 z = z > (uInt)l ? l : z; /* table size upper limit */ 4319 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 4320 { /* too few codes for k-w bit table */ 4321 f -= a + 1; /* deduct codes from patterns left */ 4322 xp = c + k; 4323 if (j < z) 4324 while (++j < z) /* try smaller tables up to z bits */ 4325 { 4326 if ((f <<= 1) <= *++xp) 4327 break; /* enough codes to use up j bits */ 4328 f -= *xp; /* else deduct codes from patterns */ 4329 } 4330 } 4331 z = 1 << j; /* table entries for j-bit table */ 4332 4333 /* allocate and link in new table */ 4334 if ((q = (inflate_huft *)ZALLOC 4335 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 4336 { 4337 if (h) 4338 inflate_trees_free(u[0], zs); 4339 return Z_MEM_ERROR; /* not enough memory */ 4340 } 4341#ifdef DEBUG_ZLIB 4342 inflate_hufts += z + 1; 4343#endif 4344 *t = q + 1; /* link to list for huft_free() */ 4345 *(t = &(q->next)) = Z_NULL; 4346 u[h] = ++q; /* table starts after link */ 4347 4348 /* connect to last table, if there is one */ 4349 if (h) 4350 { 4351 x[h] = i; /* save pattern for backing up */ 4352 r.bits = (Byte)l; /* bits to dump before this table */ 4353 r.exop = (Byte)j; /* bits in this table */ 4354 r.next = q; /* pointer to this table */ 4355 j = i >> (w - l); /* (get around Turbo C bug) */ 4356 u[h-1][j] = r; /* connect to last table */ 4357 } 4358 } 4359 4360 /* set up table entry in r */ 4361 r.bits = (Byte)(k - w); 4362 if (p >= v + n) 4363 r.exop = 128 + 64; /* out of values--invalid code */ 4364 else if (*p < s) 4365 { 4366 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 4367 r.base = *p++; /* simple code is just the value */ 4368 } 4369 else 4370 { 4371 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ 4372 r.base = d[*p++ - s]; 4373 } 4374 4375 /* fill code-like entries with r */ 4376 f = 1 << (k - w); 4377 for (j = i >> w; j < z; j += f) 4378 q[j] = r; 4379 4380 /* backwards increment the k-bit code i */ 4381 for (j = 1 << (k - 1); i & j; j >>= 1) 4382 i ^= j; 4383 i ^= j; 4384 4385 /* backup over finished tables */ 4386 while ((i & ((1 << w) - 1)) != x[h]) 4387 { 4388 h--; /* don't need to update q */ 4389 w -= l; 4390 } 4391 } 4392 } 4393 4394 4395 /* Return Z_BUF_ERROR if we were given an incomplete table */ 4396 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 4397} 4398 4399 4400int inflate_trees_bits(c, bb, tb, z) 4401uIntf *c; /* 19 code lengths */ 4402uIntf *bb; /* bits tree desired/actual depth */ 4403inflate_huft * FAR *tb; /* bits tree result */ 4404z_streamp z; /* for zfree function */ 4405{ 4406 int r; 4407 4408 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 4409 if (r == Z_DATA_ERROR) 4410 z->msg = (char*)"oversubscribed dynamic bit lengths tree"; 4411 else if (r == Z_BUF_ERROR || *bb == 0) 4412 { 4413 inflate_trees_free(*tb, z); 4414 z->msg = (char*)"incomplete dynamic bit lengths tree"; 4415 r = Z_DATA_ERROR; 4416 } 4417 return r; 4418} 4419 4420 4421int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) 4422uInt nl; /* number of literal/length codes */ 4423uInt nd; /* number of distance codes */ 4424uIntf *c; /* that many (total) code lengths */ 4425uIntf *bl; /* literal desired/actual bit depth */ 4426uIntf *bd; /* distance desired/actual bit depth */ 4427inflate_huft * FAR *tl; /* literal/length tree result */ 4428inflate_huft * FAR *td; /* distance tree result */ 4429z_streamp z; /* for zfree function */ 4430{ 4431 int r; 4432 4433 /* build literal/length tree */ 4434 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); 4435 if (r != Z_OK || *bl == 0) 4436 { 4437 if (r == Z_DATA_ERROR) 4438 z->msg = (char*)"oversubscribed literal/length tree"; 4439 else if (r != Z_MEM_ERROR) 4440 { 4441 inflate_trees_free(*tl, z); 4442 z->msg = (char*)"incomplete literal/length tree"; 4443 r = Z_DATA_ERROR; 4444 } 4445 return r; 4446 } 4447 4448 /* build distance tree */ 4449 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); 4450 if (r != Z_OK || (*bd == 0 && nl > 257)) 4451 { 4452 if (r == Z_DATA_ERROR) 4453 z->msg = (char*)"oversubscribed distance tree"; 4454 else if (r == Z_BUF_ERROR) { 4455#ifdef PKZIP_BUG_WORKAROUND 4456 r = Z_OK; 4457 } 4458#else 4459 inflate_trees_free(*td, z); 4460 z->msg = (char*)"incomplete distance tree"; 4461 r = Z_DATA_ERROR; 4462 } 4463 else if (r != Z_MEM_ERROR) 4464 { 4465 z->msg = (char*)"empty distance tree with lengths"; 4466 r = Z_DATA_ERROR; 4467 } 4468 inflate_trees_free(*tl, z); 4469 return r; 4470#endif 4471 } 4472 4473 /* done */ 4474 return Z_OK; 4475} 4476 4477 4478/* build fixed tables only once--keep them here */ 4479local int fixed_built = 0; 4480#define FIXEDH 530 /* number of hufts used by fixed tables */ 4481local inflate_huft fixed_mem[FIXEDH]; 4482local uInt fixed_bl; 4483local uInt fixed_bd; 4484local inflate_huft *fixed_tl; 4485local inflate_huft *fixed_td; 4486 4487 4488local voidpf falloc(q, n, s) 4489voidpf q; /* opaque pointer */ 4490uInt n; /* number of items */ 4491uInt s; /* size of item */ 4492{ 4493 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, 4494 "inflate_trees falloc overflow"); 4495 *(intf *)q -= n+s-s; /* s-s to avoid warning */ 4496 return (voidpf)(fixed_mem + *(intf *)q); 4497} 4498 4499 4500int inflate_trees_fixed(bl, bd, tl, td) 4501uIntf *bl; /* literal desired/actual bit depth */ 4502uIntf *bd; /* distance desired/actual bit depth */ 4503inflate_huft * FAR *tl; /* literal/length tree result */ 4504inflate_huft * FAR *td; /* distance tree result */ 4505{ 4506 /* build fixed tables if not already (multiple overlapped executions ok) */ 4507 if (!fixed_built) 4508 { 4509 int k; /* temporary variable */ 4510 unsigned c[288]; /* length list for huft_build */ 4511 z_stream z; /* for falloc function */ 4512 int f = FIXEDH; /* number of hufts left in fixed_mem */ 4513 4514 /* set up fake z_stream for memory routines */ 4515 z.zalloc = falloc; 4516 z.zfree = Z_NULL; 4517 z.opaque = (voidpf)&f; 4518 4519 /* literal table */ 4520 for (k = 0; k < 144; k++) 4521 c[k] = 8; 4522 for (; k < 256; k++) 4523 c[k] = 9; 4524 for (; k < 280; k++) 4525 c[k] = 7; 4526 for (; k < 288; k++) 4527 c[k] = 8; 4528 fixed_bl = 7; 4529 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4530 4531 /* distance table */ 4532 for (k = 0; k < 30; k++) 4533 c[k] = 5; 4534 fixed_bd = 5; 4535 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4536 4537 /* done */ 4538 Assert(f == 0, "invalid build of fixed tables"); 4539 fixed_built = 1; 4540 } 4541 *bl = fixed_bl; 4542 *bd = fixed_bd; 4543 *tl = fixed_tl; 4544 *td = fixed_td; 4545 return Z_OK; 4546} 4547 4548 4549int inflate_trees_free(t, z) 4550inflate_huft *t; /* table to free */ 4551z_streamp z; /* for zfree function */ 4552/* Free the malloc'ed tables built by huft_build(), which makes a linked 4553 list of the tables it made, with the links in a dummy first entry of 4554 each table. */ 4555{ 4556 register inflate_huft *p, *q, *r; 4557 4558 /* Reverse linked list */ 4559 p = Z_NULL; 4560 q = t; 4561 while (q != Z_NULL) 4562 { 4563 r = (q - 1)->next; 4564 (q - 1)->next = p; 4565 p = q; 4566 q = r; 4567 } 4568 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4569 while (p != Z_NULL) 4570 { 4571 q = (--p)->next; 4572 ZFREE(z,p); 4573 p = q; 4574 } 4575 return Z_OK; 4576} 4577/* --- inftrees.c */ 4578 4579/* +++ infcodes.c */ 4580/* infcodes.c -- process literals and length/distance pairs 4581 * Copyright (C) 1995-1996 Mark Adler 4582 * For conditions of distribution and use, see copyright notice in zlib.h 4583 */ 4584 4585/* #include "zutil.h" */ 4586/* #include "inftrees.h" */ 4587/* #include "infblock.h" */ 4588/* #include "infcodes.h" */ 4589/* #include "infutil.h" */ 4590 4591/* +++ inffast.h */ 4592/* inffast.h -- header to use inffast.c 4593 * Copyright (C) 1995-1996 Mark Adler 4594 * For conditions of distribution and use, see copyright notice in zlib.h 4595 */ 4596 4597/* WARNING: this file should *not* be used by applications. It is 4598 part of the implementation of the compression library and is 4599 subject to change. Applications should only use zlib.h. 4600 */ 4601 4602extern int inflate_fast OF(( 4603 uInt, 4604 uInt, 4605 inflate_huft *, 4606 inflate_huft *, 4607 inflate_blocks_statef *, 4608 z_streamp )); 4609/* --- inffast.h */ 4610 4611/* simplify the use of the inflate_huft type with some defines */ 4612#define base more.Base 4613#define next more.Next 4614#define exop word.what.Exop 4615#define bits word.what.Bits 4616 4617/* inflate codes private state */ 4618struct inflate_codes_state { 4619 4620 /* mode */ 4621 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4622 START, /* x: set up for LEN */ 4623 LEN, /* i: get length/literal/eob next */ 4624 LENEXT, /* i: getting length extra (have base) */ 4625 DIST, /* i: get distance next */ 4626 DISTEXT, /* i: getting distance extra */ 4627 COPY, /* o: copying bytes in window, waiting for space */ 4628 LIT, /* o: got literal, waiting for output space */ 4629 WASH, /* o: got eob, possibly still output waiting */ 4630 END, /* x: got eob and all data flushed */ 4631 BADCODE} /* x: got error */ 4632 mode; /* current inflate_codes mode */ 4633 4634 /* mode dependent information */ 4635 uInt len; 4636 union { 4637 struct { 4638 inflate_huft *tree; /* pointer into tree */ 4639 uInt need; /* bits needed */ 4640 } code; /* if LEN or DIST, where in tree */ 4641 uInt lit; /* if LIT, literal */ 4642 struct { 4643 uInt get; /* bits to get for extra */ 4644 uInt dist; /* distance back to copy from */ 4645 } copy; /* if EXT or COPY, where and how much */ 4646 } sub; /* submode */ 4647 4648 /* mode independent information */ 4649 Byte lbits; /* ltree bits decoded per branch */ 4650 Byte dbits; /* dtree bits decoder per branch */ 4651 inflate_huft *ltree; /* literal/length/eob tree */ 4652 inflate_huft *dtree; /* distance tree */ 4653 4654}; 4655 4656 4657inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) 4658uInt bl, bd; 4659inflate_huft *tl; 4660inflate_huft *td; /* need separate declaration for Borland C++ */ 4661z_streamp z; 4662{ 4663 inflate_codes_statef *c; 4664 4665 if ((c = (inflate_codes_statef *) 4666 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4667 { 4668 c->mode = START; 4669 c->lbits = (Byte)bl; 4670 c->dbits = (Byte)bd; 4671 c->ltree = tl; 4672 c->dtree = td; 4673 Tracev((stderr, "inflate: codes new\n")); 4674 } 4675 return c; 4676} 4677 4678 4679int inflate_codes(s, z, r) 4680inflate_blocks_statef *s; 4681z_streamp z; 4682int r; 4683{ 4684 uInt j; /* temporary storage */ 4685 inflate_huft *t; /* temporary pointer */ 4686 uInt e; /* extra bits or operation */ 4687 uLong b; /* bit buffer */ 4688 uInt k; /* bits in bit buffer */ 4689 Bytef *p; /* input data pointer */ 4690 uInt n; /* bytes available there */ 4691 Bytef *q; /* output window write pointer */ 4692 uInt m; /* bytes to end of window or read pointer */ 4693 Bytef *f; /* pointer to copy strings from */ 4694 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4695 4696 /* copy input/output information to locals (UPDATE macro restores) */ 4697 LOAD 4698 4699 /* process input and output based on current state */ 4700 while (1) switch (c->mode) 4701 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4702 case START: /* x: set up for LEN */ 4703#ifndef SLOW 4704 if (m >= 258 && n >= 10) 4705 { 4706 UPDATE 4707 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4708 LOAD 4709 if (r != Z_OK) 4710 { 4711 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4712 break; 4713 } 4714 } 4715#endif /* !SLOW */ 4716 c->sub.code.need = c->lbits; 4717 c->sub.code.tree = c->ltree; 4718 c->mode = LEN; 4719 case LEN: /* i: get length/literal/eob next */ 4720 j = c->sub.code.need; 4721 NEEDBITS(j) 4722 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4723 DUMPBITS(t->bits) 4724 e = (uInt)(t->exop); 4725 if (e == 0) /* literal */ 4726 { 4727 c->sub.lit = t->base; 4728 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4729 "inflate: literal '%c'\n" : 4730 "inflate: literal 0x%02x\n", t->base)); 4731 c->mode = LIT; 4732 break; 4733 } 4734 if (e & 16) /* length */ 4735 { 4736 c->sub.copy.get = e & 15; 4737 c->len = t->base; 4738 c->mode = LENEXT; 4739 break; 4740 } 4741 if ((e & 64) == 0) /* next table */ 4742 { 4743 c->sub.code.need = e; 4744 c->sub.code.tree = t->next; 4745 break; 4746 } 4747 if (e & 32) /* end of block */ 4748 { 4749 Tracevv((stderr, "inflate: end of block\n")); 4750 c->mode = WASH; 4751 break; 4752 } 4753 c->mode = BADCODE; /* invalid code */ 4754 z->msg = (char*)"invalid literal/length code"; 4755 r = Z_DATA_ERROR; 4756 LEAVE 4757 case LENEXT: /* i: getting length extra (have base) */ 4758 j = c->sub.copy.get; 4759 NEEDBITS(j) 4760 c->len += (uInt)b & inflate_mask[j]; 4761 DUMPBITS(j) 4762 c->sub.code.need = c->dbits; 4763 c->sub.code.tree = c->dtree; 4764 Tracevv((stderr, "inflate: length %u\n", c->len)); 4765 c->mode = DIST; 4766 case DIST: /* i: get distance next */ 4767 j = c->sub.code.need; 4768 NEEDBITS(j) 4769 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4770 DUMPBITS(t->bits) 4771 e = (uInt)(t->exop); 4772 if (e & 16) /* distance */ 4773 { 4774 c->sub.copy.get = e & 15; 4775 c->sub.copy.dist = t->base; 4776 c->mode = DISTEXT; 4777 break; 4778 } 4779 if ((e & 64) == 0) /* next table */ 4780 { 4781 c->sub.code.need = e; 4782 c->sub.code.tree = t->next; 4783 break; 4784 } 4785 c->mode = BADCODE; /* invalid code */ 4786 z->msg = (char*)"invalid distance code"; 4787 r = Z_DATA_ERROR; 4788 LEAVE 4789 case DISTEXT: /* i: getting distance extra */ 4790 j = c->sub.copy.get; 4791 NEEDBITS(j) 4792 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4793 DUMPBITS(j) 4794 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4795 c->mode = COPY; 4796 case COPY: /* o: copying bytes in window, waiting for space */ 4797#ifndef __TURBOC__ /* Turbo C bug for following expression */ 4798 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4799 s->end - (c->sub.copy.dist - (q - s->window)) : 4800 q - c->sub.copy.dist; 4801#else 4802 f = q - c->sub.copy.dist; 4803 if ((uInt)(q - s->window) < c->sub.copy.dist) 4804 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); 4805#endif 4806 while (c->len) 4807 { 4808 NEEDOUT 4809 OUTBYTE(*f++) 4810 if (f == s->end) 4811 f = s->window; 4812 c->len--; 4813 } 4814 c->mode = START; 4815 break; 4816 case LIT: /* o: got literal, waiting for output space */ 4817 NEEDOUT 4818 OUTBYTE(c->sub.lit) 4819 c->mode = START; 4820 break; 4821 case WASH: /* o: got eob, possibly more output */ 4822 FLUSH 4823 if (s->read != s->write) 4824 LEAVE 4825 c->mode = END; 4826 case END: 4827 r = Z_STREAM_END; 4828 LEAVE 4829 case BADCODE: /* x: got error */ 4830 r = Z_DATA_ERROR; 4831 LEAVE 4832 default: 4833 r = Z_STREAM_ERROR; 4834 LEAVE 4835 } 4836} 4837 4838 4839void inflate_codes_free(c, z) 4840inflate_codes_statef *c; 4841z_streamp z; 4842{ 4843 ZFREE(z, c); 4844 Tracev((stderr, "inflate: codes free\n")); 4845} 4846/* --- infcodes.c */ 4847 4848/* +++ infutil.c */ 4849/* inflate_util.c -- data and routines common to blocks and codes 4850 * Copyright (C) 1995-1996 Mark Adler 4851 * For conditions of distribution and use, see copyright notice in zlib.h 4852 */ 4853 4854/* #include "zutil.h" */ 4855/* #include "infblock.h" */ 4856/* #include "inftrees.h" */ 4857/* #include "infcodes.h" */ 4858/* #include "infutil.h" */ 4859 4860#ifndef NO_DUMMY_DECL 4861struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4862#endif 4863 4864/* And'ing with mask[n] masks the lower n bits */ 4865uInt inflate_mask[17] = { 4866 0x0000, 4867 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 4868 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 4869}; 4870 4871 4872/* copy as much as possible from the sliding window to the output area */ 4873int inflate_flush(s, z, r) 4874inflate_blocks_statef *s; 4875z_streamp z; 4876int r; 4877{ 4878 uInt n; 4879 Bytef *p; 4880 Bytef *q; 4881 4882 /* local copies of source and destination pointers */ 4883 p = z->next_out; 4884 q = s->read; 4885 4886 /* compute number of bytes to copy as far as end of window */ 4887 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4888 if (n > z->avail_out) n = z->avail_out; 4889 if (n && r == Z_BUF_ERROR) r = Z_OK; 4890 4891 /* update counters */ 4892 z->avail_out -= n; 4893 z->total_out += n; 4894 4895 /* update check information */ 4896 if (s->checkfn != Z_NULL) 4897 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4898 4899 /* copy as far as end of window */ 4900 if (p != Z_NULL) { 4901 zmemcpy(p, q, n); 4902 p += n; 4903 } 4904 q += n; 4905 4906 /* see if more to copy at beginning of window */ 4907 if (q == s->end) 4908 { 4909 /* wrap pointers */ 4910 q = s->window; 4911 if (s->write == s->end) 4912 s->write = s->window; 4913 4914 /* compute bytes to copy */ 4915 n = (uInt)(s->write - q); 4916 if (n > z->avail_out) n = z->avail_out; 4917 if (n && r == Z_BUF_ERROR) r = Z_OK; 4918 4919 /* update counters */ 4920 z->avail_out -= n; 4921 z->total_out += n; 4922 4923 /* update check information */ 4924 if (s->checkfn != Z_NULL) 4925 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4926 4927 /* copy */ 4928 if (p != Z_NULL) { 4929 zmemcpy(p, q, n); 4930 p += n; 4931 } 4932 q += n; 4933 } 4934 4935 /* update pointers */ 4936 z->next_out = p; 4937 s->read = q; 4938 4939 /* done */ 4940 return r; 4941} 4942/* --- infutil.c */ 4943 4944/* +++ inffast.c */ 4945/* inffast.c -- process literals and length/distance pairs fast 4946 * Copyright (C) 1995-1996 Mark Adler 4947 * For conditions of distribution and use, see copyright notice in zlib.h 4948 */ 4949 4950/* #include "zutil.h" */ 4951/* #include "inftrees.h" */ 4952/* #include "infblock.h" */ 4953/* #include "infcodes.h" */ 4954/* #include "infutil.h" */ 4955/* #include "inffast.h" */ 4956 4957#ifndef NO_DUMMY_DECL 4958struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4959#endif 4960 4961/* simplify the use of the inflate_huft type with some defines */ 4962#define base more.Base 4963#define next more.Next 4964#define exop word.what.Exop 4965#define bits word.what.Bits 4966 4967/* macros for bit input with no checking and for returning unused bytes */ 4968#define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4969#define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4970 4971/* Called with number of bytes left to write in window at least 258 4972 (the maximum string length) and number of input bytes available 4973 at least ten. The ten bytes are six bytes for the longest length/ 4974 distance pair plus four bytes for overloading the bit buffer. */ 4975 4976int inflate_fast(bl, bd, tl, td, s, z) 4977uInt bl, bd; 4978inflate_huft *tl; 4979inflate_huft *td; /* need separate declaration for Borland C++ */ 4980inflate_blocks_statef *s; 4981z_streamp z; 4982{ 4983 inflate_huft *t; /* temporary pointer */ 4984 uInt e; /* extra bits or operation */ 4985 uLong b; /* bit buffer */ 4986 uInt k; /* bits in bit buffer */ 4987 Bytef *p; /* input data pointer */ 4988 uInt n; /* bytes available there */ 4989 Bytef *q; /* output window write pointer */ 4990 uInt m; /* bytes to end of window or read pointer */ 4991 uInt ml; /* mask for literal/length tree */ 4992 uInt md; /* mask for distance tree */ 4993 uInt c; /* bytes to copy */ 4994 uInt d; /* distance back to copy from */ 4995 Bytef *r; /* copy source pointer */ 4996 4997 /* load input, output, bit values */ 4998 LOAD 4999 5000 /* initialize masks */ 5001 ml = inflate_mask[bl]; 5002 md = inflate_mask[bd]; 5003 5004 /* do until not enough input or output space for fast loop */ 5005 do { /* assume called with m >= 258 && n >= 10 */ 5006 /* get literal/length code */ 5007 GRABBITS(20) /* max bits for literal/length code */ 5008 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 5009 { 5010 DUMPBITS(t->bits) 5011 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5012 "inflate: * literal '%c'\n" : 5013 "inflate: * literal 0x%02x\n", t->base)); 5014 *q++ = (Byte)t->base; 5015 m--; 5016 continue; 5017 } 5018 do { 5019 DUMPBITS(t->bits) 5020 if (e & 16) 5021 { 5022 /* get extra bits for length */ 5023 e &= 15; 5024 c = t->base + ((uInt)b & inflate_mask[e]); 5025 DUMPBITS(e) 5026 Tracevv((stderr, "inflate: * length %u\n", c)); 5027 5028 /* decode distance base of block to copy */ 5029 GRABBITS(15); /* max bits for distance code */ 5030 e = (t = td + ((uInt)b & md))->exop; 5031 do { 5032 DUMPBITS(t->bits) 5033 if (e & 16) 5034 { 5035 /* get extra bits to add to distance base */ 5036 e &= 15; 5037 GRABBITS(e) /* get extra bits (up to 13) */ 5038 d = t->base + ((uInt)b & inflate_mask[e]); 5039 DUMPBITS(e) 5040 Tracevv((stderr, "inflate: * distance %u\n", d)); 5041 5042 /* do the copy */ 5043 m -= c; 5044 if ((uInt)(q - s->window) >= d) /* offset before dest */ 5045 { /* just copy */ 5046 r = q - d; 5047 *q++ = *r++; c--; /* minimum count is three, */ 5048 *q++ = *r++; c--; /* so unroll loop a little */ 5049 } 5050 else /* else offset after destination */ 5051 { 5052 e = d - (uInt)(q - s->window); /* bytes from offset to end */ 5053 r = s->end - e; /* pointer to offset */ 5054 if (c > e) /* if source crosses, */ 5055 { 5056 c -= e; /* copy to end of window */ 5057 do { 5058 *q++ = *r++; 5059 } while (--e); 5060 r = s->window; /* copy rest from start of window */ 5061 } 5062 } 5063 do { /* copy all or what's left */ 5064 *q++ = *r++; 5065 } while (--c); 5066 break; 5067 } 5068 else if ((e & 64) == 0) 5069 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 5070 else 5071 { 5072 z->msg = (char*)"invalid distance code"; 5073 UNGRAB 5074 UPDATE 5075 return Z_DATA_ERROR; 5076 } 5077 } while (1); 5078 break; 5079 } 5080 if ((e & 64) == 0) 5081 { 5082 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 5083 { 5084 DUMPBITS(t->bits) 5085 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5086 "inflate: * literal '%c'\n" : 5087 "inflate: * literal 0x%02x\n", t->base)); 5088 *q++ = (Byte)t->base; 5089 m--; 5090 break; 5091 } 5092 } 5093 else if (e & 32) 5094 { 5095 Tracevv((stderr, "inflate: * end of block\n")); 5096 UNGRAB 5097 UPDATE 5098 return Z_STREAM_END; 5099 } 5100 else 5101 { 5102 z->msg = (char*)"invalid literal/length code"; 5103 UNGRAB 5104 UPDATE 5105 return Z_DATA_ERROR; 5106 } 5107 } while (1); 5108 } while (m >= 258 && n >= 10); 5109 5110 /* not enough input or output--restore pointers and return */ 5111 UNGRAB 5112 UPDATE 5113 return Z_OK; 5114} 5115/* --- inffast.c */ 5116 5117/* +++ zutil.c */ 5118/* zutil.c -- target dependent utility functions for the compression library 5119 * Copyright (C) 1995-1996 Jean-loup Gailly. 5120 * For conditions of distribution and use, see copyright notice in zlib.h 5121 */ 5122 5123/* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ 5124 5125#ifdef DEBUG_ZLIB 5126#include <stdio.h> 5127#endif 5128 5129/* #include "zutil.h" */ 5130 5131#ifndef NO_DUMMY_DECL 5132struct internal_state {int dummy;}; /* for buggy compilers */ 5133#endif 5134 5135#ifndef STDC 5136extern void exit OF((int)); 5137#endif 5138 5139static const char *z_errmsg[10] = { 5140"need dictionary", /* Z_NEED_DICT 2 */ 5141"stream end", /* Z_STREAM_END 1 */ 5142"", /* Z_OK 0 */ 5143"file error", /* Z_ERRNO (-1) */ 5144"stream error", /* Z_STREAM_ERROR (-2) */ 5145"data error", /* Z_DATA_ERROR (-3) */ 5146"insufficient memory", /* Z_MEM_ERROR (-4) */ 5147"buffer error", /* Z_BUF_ERROR (-5) */ 5148"incompatible version",/* Z_VERSION_ERROR (-6) */ 5149""}; 5150 5151 5152const char *zlibVersion() 5153{ 5154 return ZLIB_VERSION; 5155} 5156 5157#ifdef DEBUG_ZLIB 5158void z_error (m) 5159 char *m; 5160{ 5161 fprintf(stderr, "%s\n", m); 5162 exit(1); 5163} 5164#endif 5165 5166#ifndef HAVE_MEMCPY 5167 5168void zmemcpy(dest, source, len) 5169 Bytef* dest; 5170 Bytef* source; 5171 uInt len; 5172{ 5173 if (len == 0) return; 5174 do { 5175 *dest++ = *source++; /* ??? to be unrolled */ 5176 } while (--len != 0); 5177} 5178 5179int zmemcmp(s1, s2, len) 5180 Bytef* s1; 5181 Bytef* s2; 5182 uInt len; 5183{ 5184 uInt j; 5185 5186 for (j = 0; j < len; j++) { 5187 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 5188 } 5189 return 0; 5190} 5191 5192void zmemzero(dest, len) 5193 Bytef* dest; 5194 uInt len; 5195{ 5196 if (len == 0) return; 5197 do { 5198 *dest++ = 0; /* ??? to be unrolled */ 5199 } while (--len != 0); 5200} 5201#endif 5202 5203#ifdef __TURBOC__ 5204#if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 5205/* Small and medium model in Turbo C are for now limited to near allocation 5206 * with reduced MAX_WBITS and MAX_MEM_LEVEL 5207 */ 5208# define MY_ZCALLOC 5209 5210/* Turbo C malloc() does not allow dynamic allocation of 64K bytes 5211 * and farmalloc(64K) returns a pointer with an offset of 8, so we 5212 * must fix the pointer. Warning: the pointer must be put back to its 5213 * original form in order to free it, use zcfree(). 5214 */ 5215 5216#define MAX_PTR 10 5217/* 10*64K = 640K */ 5218 5219local int next_ptr = 0; 5220 5221typedef struct ptr_table_s { 5222 voidpf org_ptr; 5223 voidpf new_ptr; 5224} ptr_table; 5225 5226local ptr_table table[MAX_PTR]; 5227/* This table is used to remember the original form of pointers 5228 * to large buffers (64K). Such pointers are normalized with a zero offset. 5229 * Since MSDOS is not a preemptive multitasking OS, this table is not 5230 * protected from concurrent access. This hack doesn't work anyway on 5231 * a protected system like OS/2. Use Microsoft C instead. 5232 */ 5233 5234voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5235{ 5236 voidpf buf = opaque; /* just to make some compilers happy */ 5237 ulg bsize = (ulg)items*size; 5238 5239 /* If we allocate less than 65520 bytes, we assume that farmalloc 5240 * will return a usable pointer which doesn't have to be normalized. 5241 */ 5242 if (bsize < 65520L) { 5243 buf = farmalloc(bsize); 5244 if (*(ush*)&buf != 0) return buf; 5245 } else { 5246 buf = farmalloc(bsize + 16L); 5247 } 5248 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 5249 table[next_ptr].org_ptr = buf; 5250 5251 /* Normalize the pointer to seg:0 */ 5252 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 5253 *(ush*)&buf = 0; 5254 table[next_ptr++].new_ptr = buf; 5255 return buf; 5256} 5257 5258void zcfree (voidpf opaque, voidpf ptr) 5259{ 5260 int n; 5261 if (*(ush*)&ptr != 0) { /* object < 64K */ 5262 farfree(ptr); 5263 return; 5264 } 5265 /* Find the original pointer */ 5266 for (n = 0; n < next_ptr; n++) { 5267 if (ptr != table[n].new_ptr) continue; 5268 5269 farfree(table[n].org_ptr); 5270 while (++n < next_ptr) { 5271 table[n-1] = table[n]; 5272 } 5273 next_ptr--; 5274 return; 5275 } 5276 ptr = opaque; /* just to make some compilers happy */ 5277 Assert(0, "zcfree: ptr not found"); 5278} 5279#endif 5280#endif /* __TURBOC__ */ 5281 5282 5283#if defined(M_I86) && !defined(__32BIT__) 5284/* Microsoft C in 16-bit mode */ 5285 5286# define MY_ZCALLOC 5287 5288#if (!defined(_MSC_VER) || (_MSC_VER < 600)) 5289# define _halloc halloc 5290# define _hfree hfree 5291#endif 5292 5293voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5294{ 5295 if (opaque) opaque = 0; /* to make compiler happy */ 5296 return _halloc((long)items, size); 5297} 5298 5299void zcfree (voidpf opaque, voidpf ptr) 5300{ 5301 if (opaque) opaque = 0; /* to make compiler happy */ 5302 _hfree(ptr); 5303} 5304 5305#endif /* MSC */ 5306 5307 5308#ifndef MY_ZCALLOC /* Any system without a special alloc function */ 5309 5310#ifndef STDC 5311extern voidp calloc OF((uInt items, uInt size)); 5312extern void free OF((voidpf ptr)); 5313#endif 5314 5315voidpf zcalloc (opaque, items, size) 5316 voidpf opaque; 5317 unsigned items; 5318 unsigned size; 5319{ 5320 if (opaque) items += size - size; /* make compiler happy */ 5321 return (voidpf)calloc(items, size); 5322} 5323 5324void zcfree (opaque, ptr) 5325 voidpf opaque; 5326 voidpf ptr; 5327{ 5328 free(ptr); 5329 if (opaque) return; /* make compiler happy */ 5330} 5331 5332#endif /* MY_ZCALLOC */ 5333/* --- zutil.c */ 5334 5335/* +++ adler32.c */ 5336/* adler32.c -- compute the Adler-32 checksum of a data stream 5337 * Copyright (C) 1995-1996 Mark Adler 5338 * For conditions of distribution and use, see copyright notice in zlib.h 5339 */ 5340 5341/* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ 5342 5343/* #include "zlib.h" */ 5344 5345#define BASE 65521L /* largest prime smaller than 65536 */ 5346#define NMAX 5552 5347/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 5348 5349#define DO1(buf,i) {s1 += buf[(i)]; s2 += s1;} 5350#define DO2(buf,i) DO1(buf,i); DO1(buf,(i)+1); 5351#define DO4(buf,i) DO2(buf,i); DO2(buf,(i)+2); 5352#define DO8(buf,i) DO4(buf,i); DO4(buf,(i)+4); 5353#define DO16(buf) DO8(buf,0); DO8(buf,8); 5354 5355/* ========================================================================= */ 5356uLong adler32(adler, buf, len) 5357 uLong adler; 5358 const Bytef *buf; 5359 uInt len; 5360{ 5361 unsigned long s1 = adler & 0xffff; 5362 unsigned long s2 = (adler >> 16) & 0xffff; 5363 int k; 5364 5365 if (buf == Z_NULL) return 1L; 5366 5367 while (len > 0) { 5368 k = len < NMAX ? len : NMAX; 5369 len -= k; 5370 while (k >= 16) { 5371 DO16(buf); 5372 buf += 16; 5373 k -= 16; 5374 } 5375 if (k != 0) do { 5376 s1 += *buf++; 5377 s2 += s1; 5378 } while (--k); 5379 s1 %= BASE; 5380 s2 %= BASE; 5381 } 5382 return (s2 << 16) | s1; 5383} 5384/* --- adler32.c */ 5385 5386#ifdef _KERNEL 5387static int 5388zlib_modevent(module_t mod, int type, void *unused) 5389{ 5390 switch (type) { 5391 case MOD_LOAD: 5392 return 0; 5393 case MOD_UNLOAD: 5394 return 0; 5395 } 5396 return EINVAL; 5397} 5398 5399static moduledata_t zlib_mod = { 5400 "zlib", 5401 zlib_modevent, 5402 0 5403}; 5404DECLARE_MODULE(zlib, zlib_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 5405MODULE_VERSION(zlib, 1); 5406#endif /* _KERNEL */ 5407