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: src/sys/net/zlib.c,v 1.10.2.3 2002/03/24 23:12:48 jedgar Exp $ 14 * $DragonFly: src/sys/net/zlib.c,v 1.11 2007/01/07 00:41:29 dillon Exp $ 15 */ 16 17 /* 18 * ==FILEVERSION 971210== 19 * 20 * This marker is used by the Linux installation script to determine 21 * whether an up-to-date version of this file is already installed. 22 */ 23 24 #define NO_DUMMY_DECL 25 #define NO_ZCFUNCS 26 #define MY_ZCALLOC 27 28 #if (defined(__DragonFly__) || defined(__FreeBSD__)) && defined(_KERNEL) 29 #define inflate inflate_ppp /* FreeBSD already has an inflate :-( */ 30 #endif 31 32 33 /* +++ zutil.h */ 34 /* zutil.h -- internal interface and configuration of the compression library 35 * Copyright (C) 1995-1996 Jean-loup Gailly. 36 * For conditions of distribution and use, see copyright notice in zlib.h 37 */ 38 39 /* WARNING: this file should *not* be used by applications. It is 40 part of the implementation of the compression library and is 41 subject to change. Applications should only use zlib.h. 42 */ 43 44 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */ 45 46 #ifndef _Z_UTIL_H 47 #define _Z_UTIL_H 48 49 #ifdef _KERNEL 50 #include <net/zlib.h> 51 #else 52 #include "zlib.h" 53 #endif 54 55 #ifdef _KERNEL 56 /* Assume this is a *BSD or SVR4 kernel */ 57 #include <sys/param.h> 58 #include <sys/types.h> 59 #include <sys/time.h> 60 #include <sys/systm.h> 61 #include <sys/module.h> 62 # define HAVE_MEMCPY 63 # define memcpy(d, s, n) bcopy((s), (d), (n)) 64 # define memset(d, v, n) bzero((d), (n)) 65 # define memcmp bcmp 66 67 #else 68 #if defined(__KERNEL__) 69 /* Assume this is a Linux kernel */ 70 #include <linux/string.h> 71 #define HAVE_MEMCPY 72 73 #else /* not kernel */ 74 75 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS) 76 # include <stddef.h> 77 # include <errno.h> 78 #else 79 extern int errno; 80 #endif 81 #ifdef STDC 82 # include <string.h> 83 # include <stdlib.h> 84 #endif 85 #endif /* __KERNEL__ */ 86 #endif /* _KERNEL */ 87 88 #ifndef local 89 # define local static 90 #endif 91 /* compile with -Dlocal if your debugger can't find static symbols */ 92 93 typedef unsigned char uch; 94 typedef uch FAR uchf; 95 typedef unsigned short ush; 96 typedef ush FAR ushf; 97 typedef unsigned long ulg; 98 99 static const char *z_errmsg[10] = { 100 "need dictionary", /* Z_NEED_DICT 2 */ 101 "stream end", /* Z_STREAM_END 1 */ 102 "", /* Z_OK 0 */ 103 "file error", /* Z_ERRNO (-1) */ 104 "stream error", /* Z_STREAM_ERROR (-2) */ 105 "data error", /* Z_DATA_ERROR (-3) */ 106 "insufficient memory", /* Z_MEM_ERROR (-4) */ 107 "buffer error", /* Z_BUF_ERROR (-5) */ 108 "incompatible version",/* Z_VERSION_ERROR (-6) */ 109 ""}; 110 111 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] 112 113 #define ERR_RETURN(strm,err) \ 114 return (strm->msg = (const char*)ERR_MSG(err), (err)) 115 /* To be used only when the state is known to be valid */ 116 117 /* common constants */ 118 119 #ifndef DEF_WBITS 120 # define DEF_WBITS MAX_WBITS 121 #endif 122 /* default windowBits for decompression. MAX_WBITS is for compression only */ 123 124 #if MAX_MEM_LEVEL >= 8 125 # define DEF_MEM_LEVEL 8 126 #else 127 # define DEF_MEM_LEVEL MAX_MEM_LEVEL 128 #endif 129 /* default memLevel */ 130 131 #define STORED_BLOCK 0 132 #define STATIC_TREES 1 133 #define DYN_TREES 2 134 /* The three kinds of block type */ 135 136 #define MIN_MATCH 3 137 #define MAX_MATCH 258 138 /* The minimum and maximum match lengths */ 139 140 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */ 141 142 /* target dependencies */ 143 144 #ifdef MSDOS 145 # define OS_CODE 0x00 146 # ifdef __TURBOC__ 147 # include <alloc.h> 148 # else /* MSC or DJGPP */ 149 # include <malloc.h> 150 # endif 151 #endif 152 153 #ifdef OS2 154 # define OS_CODE 0x06 155 #endif 156 157 #ifdef WIN32 /* Window 95 & Windows NT */ 158 # define OS_CODE 0x0b 159 #endif 160 161 #if defined(VAXC) || defined(VMS) 162 # define OS_CODE 0x02 163 # define FOPEN(name, mode) \ 164 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") 165 #endif 166 167 #ifdef AMIGA 168 # define OS_CODE 0x01 169 #endif 170 171 #if defined(ATARI) || defined(atarist) 172 # define OS_CODE 0x05 173 #endif 174 175 #ifdef MACOS 176 # define OS_CODE 0x07 177 #endif 178 179 #ifdef __50SERIES /* Prime/PRIMOS */ 180 # define OS_CODE 0x0F 181 #endif 182 183 #ifdef TOPS20 184 # define OS_CODE 0x0a 185 #endif 186 187 #if defined(_BEOS_) || defined(RISCOS) 188 # define fdopen(fd,mode) NULL /* No fdopen() */ 189 #endif 190 191 /* Common defaults */ 192 193 #ifndef OS_CODE 194 # define OS_CODE 0x03 /* assume Unix */ 195 #endif 196 197 #ifndef FOPEN 198 # define FOPEN(name, mode) fopen((name), (mode)) 199 #endif 200 201 /* functions */ 202 203 #ifdef HAVE_STRERROR 204 extern char *strerror OF((int)); 205 # define zstrerror(errnum) strerror(errnum) 206 #else 207 # define zstrerror(errnum) "" 208 #endif 209 210 #if defined(pyr) 211 # define NO_MEMCPY 212 #endif 213 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER) 214 /* Use our own functions for small and medium model with MSC <= 5.0. 215 * You may have to use the same strategy for Borland C (untested). 216 */ 217 # define NO_MEMCPY 218 #endif 219 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 220 # define HAVE_MEMCPY 221 #endif 222 #ifdef HAVE_MEMCPY 223 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */ 224 # define zmemcpy _fmemcpy 225 # define zmemcmp _fmemcmp 226 # define zmemzero(dest, len) _fmemset(dest, 0, len) 227 # else 228 # define zmemcpy memcpy 229 # define zmemcmp memcmp 230 # define zmemzero(dest, len) memset(dest, 0, len) 231 # endif 232 #else 233 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); 234 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len)); 235 extern void zmemzero OF((Bytef* dest, uInt len)); 236 #endif 237 238 /* Diagnostic functions */ 239 #ifdef DEBUG_ZLIB 240 # include <stdio.h> 241 # ifndef verbose 242 # define verbose 0 243 # endif 244 extern void z_error OF((char *m)); 245 # define Assert(cond,msg) {if(!(cond)) z_error(msg);} 246 # define Trace(x) fprintf x 247 # define Tracev(x) {if (verbose) fprintf x ;} 248 # define Tracevv(x) {if (verbose>1) fprintf x ;} 249 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 250 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 251 #else 252 # define Assert(cond,msg) 253 # define Trace(x) 254 # define Tracev(x) 255 # define Tracevv(x) 256 # define Tracec(c,x) 257 # define Tracecv(c,x) 258 #endif 259 260 261 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len)); 262 263 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); 264 void zcfree OF((voidpf opaque, voidpf ptr)); 265 266 #define ZALLOC(strm, items, size) \ 267 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 268 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr)) 269 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);} 270 271 #endif /* _Z_UTIL_H */ 272 /* --- zutil.h */ 273 274 /* +++ deflate.h */ 275 /* deflate.h -- internal compression state 276 * Copyright (C) 1995-1996 Jean-loup Gailly 277 * For conditions of distribution and use, see copyright notice in zlib.h 278 */ 279 280 /* WARNING: this file should *not* be used by applications. It is 281 part of the implementation of the compression library and is 282 subject to change. Applications should only use zlib.h. 283 */ 284 285 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */ 286 287 #ifndef _DEFLATE_H 288 #define _DEFLATE_H 289 290 /* #include "zutil.h" */ 291 292 /* =========================================================================== 293 * Internal compression state. 294 */ 295 296 #define LENGTH_CODES 29 297 /* number of length codes, not counting the special END_BLOCK code */ 298 299 #define LITERALS 256 300 /* number of literal bytes 0..255 */ 301 302 #define L_CODES (LITERALS+1+LENGTH_CODES) 303 /* number of Literal or Length codes, including the END_BLOCK code */ 304 305 #define D_CODES 30 306 /* number of distance codes */ 307 308 #define BL_CODES 19 309 /* number of codes used to transfer the bit lengths */ 310 311 #define HEAP_SIZE (2*L_CODES+1) 312 /* maximum heap size */ 313 314 #define MAX_BITS 15 315 /* All codes must not exceed MAX_BITS bits */ 316 317 #define INIT_STATE 42 318 #define BUSY_STATE 113 319 #define FINISH_STATE 666 320 /* Stream status */ 321 322 323 /* Data structure describing a single value and its code string. */ 324 typedef struct ct_data_s { 325 union { 326 ush freq; /* frequency count */ 327 ush code; /* bit string */ 328 } fc; 329 union { 330 ush dad; /* father node in Huffman tree */ 331 ush len; /* length of bit string */ 332 } dl; 333 } FAR ct_data; 334 335 #define Freq fc.freq 336 #define Code fc.code 337 #define Dad dl.dad 338 #define Len dl.len 339 340 typedef struct static_tree_desc_s static_tree_desc; 341 342 typedef struct tree_desc_s { 343 ct_data *dyn_tree; /* the dynamic tree */ 344 int max_code; /* largest code with non zero frequency */ 345 static_tree_desc *stat_desc; /* the corresponding static tree */ 346 } FAR tree_desc; 347 348 typedef ush Pos; 349 typedef Pos FAR Posf; 350 typedef unsigned IPos; 351 352 /* A Pos is an index in the character window. We use short instead of int to 353 * save space in the various tables. IPos is used only for parameter passing. 354 */ 355 356 typedef struct deflate_state { 357 z_streamp strm; /* pointer back to this zlib stream */ 358 int status; /* as the name implies */ 359 Bytef *pending_buf; /* output still pending */ 360 ulg pending_buf_size; /* size of pending_buf */ 361 Bytef *pending_out; /* next pending byte to output to the stream */ 362 int pending; /* nb of bytes in the pending buffer */ 363 int noheader; /* suppress zlib header and adler32 */ 364 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 365 Byte method; /* STORED (for zip only) or DEFLATED */ 366 int last_flush; /* value of flush param for previous deflate call */ 367 368 /* used by deflate.c: */ 369 370 uInt w_size; /* LZ77 window size (32K by default) */ 371 uInt w_bits; /* log2(w_size) (8..16) */ 372 uInt w_mask; /* w_size - 1 */ 373 374 Bytef *window; 375 /* Sliding window. Input bytes are read into the second half of the window, 376 * and move to the first half later to keep a dictionary of at least wSize 377 * bytes. With this organization, matches are limited to a distance of 378 * wSize-MAX_MATCH bytes, but this ensures that IO is always 379 * performed with a length multiple of the block size. Also, it limits 380 * the window size to 64K, which is quite useful on MSDOS. 381 * To do: use the user input buffer as sliding window. 382 */ 383 384 ulg window_size; 385 /* Actual size of window: 2*wSize, except when the user input buffer 386 * is directly used as sliding window. 387 */ 388 389 Posf *prev; 390 /* Link to older string with same hash index. To limit the size of this 391 * array to 64K, this link is maintained only for the last 32K strings. 392 * An index in this array is thus a window index modulo 32K. 393 */ 394 395 Posf *head; /* Heads of the hash chains or NIL. */ 396 397 uInt ins_h; /* hash index of string to be inserted */ 398 uInt hash_size; /* number of elements in hash table */ 399 uInt hash_bits; /* log2(hash_size) */ 400 uInt hash_mask; /* hash_size-1 */ 401 402 uInt hash_shift; 403 /* Number of bits by which ins_h must be shifted at each input 404 * step. It must be such that after MIN_MATCH steps, the oldest 405 * byte no longer takes part in the hash key, that is: 406 * hash_shift * MIN_MATCH >= hash_bits 407 */ 408 409 long block_start; 410 /* Window position at the beginning of the current output block. Gets 411 * negative when the window is moved backwards. 412 */ 413 414 uInt match_length; /* length of best match */ 415 IPos prev_match; /* previous match */ 416 int match_available; /* set if previous match exists */ 417 uInt strstart; /* start of string to insert */ 418 uInt match_start; /* start of matching string */ 419 uInt lookahead; /* number of valid bytes ahead in window */ 420 421 uInt prev_length; 422 /* Length of the best match at previous step. Matches not greater than this 423 * are discarded. This is used in the lazy match evaluation. 424 */ 425 426 uInt max_chain_length; 427 /* To speed up deflation, hash chains are never searched beyond this 428 * length. A higher limit improves compression ratio but degrades the 429 * speed. 430 */ 431 432 uInt max_lazy_match; 433 /* Attempt to find a better match only when the current match is strictly 434 * smaller than this value. This mechanism is used only for compression 435 * levels >= 4. 436 */ 437 # define max_insert_length max_lazy_match 438 /* Insert new strings in the hash table only if the match length is not 439 * greater than this length. This saves time but degrades compression. 440 * max_insert_length is used only for compression levels <= 3. 441 */ 442 443 int level; /* compression level (1..9) */ 444 int strategy; /* favor or force Huffman coding*/ 445 446 uInt good_match; 447 /* Use a faster search when the previous match is longer than this */ 448 449 int nice_match; /* Stop searching when current match exceeds this */ 450 451 /* used by trees.c: */ 452 /* Didn't use ct_data typedef below to supress compiler warning */ 453 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 454 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 455 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 456 457 struct tree_desc_s l_desc; /* desc. for literal tree */ 458 struct tree_desc_s d_desc; /* desc. for distance tree */ 459 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 460 461 ush bl_count[MAX_BITS+1]; 462 /* number of codes at each bit length for an optimal tree */ 463 464 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 465 int heap_len; /* number of elements in the heap */ 466 int heap_max; /* element of largest frequency */ 467 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 468 * The same heap array is used to build all trees. 469 */ 470 471 uch depth[2*L_CODES+1]; 472 /* Depth of each subtree used as tie breaker for trees of equal frequency 473 */ 474 475 uchf *l_buf; /* buffer for literals or lengths */ 476 477 uInt lit_bufsize; 478 /* Size of match buffer for literals/lengths. There are 4 reasons for 479 * limiting lit_bufsize to 64K: 480 * - frequencies can be kept in 16 bit counters 481 * - if compression is not successful for the first block, all input 482 * data is still in the window so we can still emit a stored block even 483 * when input comes from standard input. (This can also be done for 484 * all blocks if lit_bufsize is not greater than 32K.) 485 * - if compression is not successful for a file smaller than 64K, we can 486 * even emit a stored file instead of a stored block (saving 5 bytes). 487 * This is applicable only for zip (not gzip or zlib). 488 * - creating new Huffman trees less frequently may not provide fast 489 * adaptation to changes in the input data statistics. (Take for 490 * example a binary file with poorly compressible code followed by 491 * a highly compressible string table.) Smaller buffer sizes give 492 * fast adaptation but have of course the overhead of transmitting 493 * trees more frequently. 494 * - I can't count above 4 495 */ 496 497 uInt last_lit; /* running index in l_buf */ 498 499 ushf *d_buf; 500 /* Buffer for distances. To simplify the code, d_buf and l_buf have 501 * the same number of elements. To use different lengths, an extra flag 502 * array would be necessary. 503 */ 504 505 ulg opt_len; /* bit length of current block with optimal trees */ 506 ulg static_len; /* bit length of current block with static trees */ 507 ulg compressed_len; /* total bit length of compressed file */ 508 uInt matches; /* number of string matches in current block */ 509 int last_eob_len; /* bit length of EOB code for last block */ 510 511 #ifdef DEBUG_ZLIB 512 ulg bits_sent; /* bit length of the compressed data */ 513 #endif 514 515 ush bi_buf; 516 /* Output buffer. bits are inserted starting at the bottom (least 517 * significant bits). 518 */ 519 int bi_valid; 520 /* Number of valid bits in bi_buf. All bits above the last valid bit 521 * are always zero. 522 */ 523 524 } FAR deflate_state; 525 526 /* Output a byte on the stream. 527 * IN assertion: there is enough room in pending_buf. 528 */ 529 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 530 531 532 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 533 /* Minimum amount of lookahead, except at the end of the input file. 534 * See deflate.c for comments about the MIN_MATCH+1. 535 */ 536 537 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 538 /* In order to simplify the code, particularly on 16 bit machines, match 539 * distances are limited to MAX_DIST instead of WSIZE. 540 */ 541 542 /* in trees.c */ 543 void _tr_init OF((deflate_state *s)); 544 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); 545 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 546 int eof)); 547 void _tr_align OF((deflate_state *s)); 548 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 549 int eof)); 550 void _tr_stored_type_only OF((deflate_state *)); 551 552 #endif 553 /* --- deflate.h */ 554 555 /* +++ deflate.c */ 556 /* deflate.c -- compress data using the deflation algorithm 557 * Copyright (C) 1995-1996 Jean-loup Gailly. 558 * For conditions of distribution and use, see copyright notice in zlib.h 559 */ 560 561 /* 562 * ALGORITHM 563 * 564 * The "deflation" process depends on being able to identify portions 565 * of the input text which are identical to earlier input (within a 566 * sliding window trailing behind the input currently being processed). 567 * 568 * The most straightforward technique turns out to be the fastest for 569 * most input files: try all possible matches and select the longest. 570 * The key feature of this algorithm is that insertions into the string 571 * dictionary are very simple and thus fast, and deletions are avoided 572 * completely. Insertions are performed at each input character, whereas 573 * string matches are performed only when the previous match ends. So it 574 * is preferable to spend more time in matches to allow very fast string 575 * insertions and avoid deletions. The matching algorithm for small 576 * strings is inspired from that of Rabin & Karp. A brute force approach 577 * is used to find longer strings when a small match has been found. 578 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 579 * (by Leonid Broukhis). 580 * A previous version of this file used a more sophisticated algorithm 581 * (by Fiala and Greene) which is guaranteed to run in linear amortized 582 * time, but has a larger average cost, uses more memory and is patented. 583 * However the F&G algorithm may be faster for some highly redundant 584 * files if the parameter max_chain_length (described below) is too large. 585 * 586 * ACKNOWLEDGEMENTS 587 * 588 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 589 * I found it in 'freeze' written by Leonid Broukhis. 590 * Thanks to many people for bug reports and testing. 591 * 592 * REFERENCES 593 * 594 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". 595 * Available in ftp://ds.internic.net/rfc/rfc1951.txt 596 * 597 * A description of the Rabin and Karp algorithm is given in the book 598 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 599 * 600 * Fiala,E.R., and Greene,D.H. 601 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 602 * 603 */ 604 605 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */ 606 607 /* #include "deflate.h" */ 608 609 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly "; 610 /* 611 If you use the zlib library in a product, an acknowledgment is welcome 612 in the documentation of your product. If for some reason you cannot 613 include such an acknowledgment, I would appreciate that you keep this 614 copyright string in the executable of your product. 615 */ 616 617 /* =========================================================================== 618 * Function prototypes. 619 */ 620 typedef enum { 621 need_more, /* block not completed, need more input or more output */ 622 block_done, /* block flush performed */ 623 finish_started, /* finish started, need only more output at next deflate */ 624 finish_done /* finish done, accept no more input or output */ 625 } block_state; 626 627 typedef block_state (*compress_func) OF((deflate_state *s, int flush)); 628 /* Compression function. Returns the block state after the call. */ 629 630 local void fill_window OF((deflate_state *s)); 631 local block_state deflate_stored OF((deflate_state *s, int flush)); 632 local block_state deflate_fast OF((deflate_state *s, int flush)); 633 local block_state deflate_slow OF((deflate_state *s, int flush)); 634 local void lm_init OF((deflate_state *s)); 635 local void putShortMSB OF((deflate_state *s, uInt b)); 636 local void flush_pending OF((z_streamp strm)); 637 local int read_buf OF((z_streamp strm, charf *buf, unsigned size)); 638 #ifdef ASMV 639 void match_init OF((void)); /* asm code initialization */ 640 uInt longest_match OF((deflate_state *s, IPos cur_match)); 641 #else 642 local uInt longest_match OF((deflate_state *s, IPos cur_match)); 643 #endif 644 645 #ifdef DEBUG_ZLIB 646 local void check_match OF((deflate_state *s, IPos start, IPos match, 647 int length)); 648 #endif 649 650 /* =========================================================================== 651 * Local data 652 */ 653 654 #define NIL 0 655 /* Tail of hash chains */ 656 657 #ifndef TOO_FAR 658 # define TOO_FAR 4096 659 #endif 660 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 661 662 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 663 /* Minimum amount of lookahead, except at the end of the input file. 664 * See deflate.c for comments about the MIN_MATCH+1. 665 */ 666 667 /* Values for max_lazy_match, good_match and max_chain_length, depending on 668 * the desired pack level (0..9). The values given below have been tuned to 669 * exclude worst case performance for pathological files. Better values may be 670 * found for specific files. 671 */ 672 typedef struct config_s { 673 ush good_length; /* reduce lazy search above this match length */ 674 ush max_lazy; /* do not perform lazy search above this match length */ 675 ush nice_length; /* quit search above this match length */ 676 ush max_chain; 677 compress_func func; 678 } config; 679 680 local config configuration_table[10] = { 681 /* good lazy nice chain */ 682 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ 683 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */ 684 /* 2 */ {4, 5, 16, 8, deflate_fast}, 685 /* 3 */ {4, 6, 32, 32, deflate_fast}, 686 687 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ 688 /* 5 */ {8, 16, 32, 32, deflate_slow}, 689 /* 6 */ {8, 16, 128, 128, deflate_slow}, 690 /* 7 */ {8, 32, 128, 256, deflate_slow}, 691 /* 8 */ {32, 128, 258, 1024, deflate_slow}, 692 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */ 693 694 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 695 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 696 * meaning. 697 */ 698 699 #define EQUAL 0 700 /* result of memcmp for equal strings */ 701 702 #ifndef NO_DUMMY_DECL 703 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ 704 #endif 705 706 /* =========================================================================== 707 * Update a hash value with the given input byte 708 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 709 * input characters, so that a running hash key can be computed from the 710 * previous key instead of complete recalculation each time. 711 */ 712 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 713 714 715 /* =========================================================================== 716 * Insert string str in the dictionary and set match_head to the previous head 717 * of the hash chain (the most recent string with same hash key). Return 718 * the previous length of the hash chain. 719 * IN assertion: all calls to to INSERT_STRING are made with consecutive 720 * input characters and the first MIN_MATCH bytes of str are valid 721 * (except for the last MIN_MATCH-1 bytes of the input file). 722 */ 723 #define INSERT_STRING(s, str, match_head) \ 724 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 725 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 726 s->head[s->ins_h] = (Pos)(str)) 727 728 /* =========================================================================== 729 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 730 * prev[] will be initialized on the fly. 731 */ 732 #define CLEAR_HASH(s) \ 733 s->head[s->hash_size-1] = NIL; \ 734 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 735 736 /* ========================================================================= */ 737 int 738 deflateInit_(z_streamp strm, int level, const char * version, 739 int stream_size) 740 { 741 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 742 Z_DEFAULT_STRATEGY, version, stream_size); 743 /* To do: ignore strm->next_in if we use it as window */ 744 } 745 746 /* ========================================================================= */ 747 int 748 deflateInit2_(z_streamp strm, int level, int method, int windowBits, 749 int memLevel, int strategy, const char *version, 750 int stream_size) 751 { 752 deflate_state *s; 753 int noheader = 0; 754 static char* my_version = ZLIB_VERSION; 755 756 ushf *overlay; 757 /* We overlay pending_buf and d_buf+l_buf. This works since the average 758 * output size for (length,distance) codes is <= 24 bits. 759 */ 760 761 if (version == Z_NULL || version[0] != my_version[0] || 762 stream_size != sizeof(z_stream)) { 763 return Z_VERSION_ERROR; 764 } 765 if (strm == Z_NULL) return Z_STREAM_ERROR; 766 767 strm->msg = Z_NULL; 768 #ifndef NO_ZCFUNCS 769 if (strm->zalloc == Z_NULL) { 770 strm->zalloc = zcalloc; 771 strm->opaque = (voidpf)0; 772 } 773 if (strm->zfree == Z_NULL) strm->zfree = zcfree; 774 #endif 775 776 if (level == Z_DEFAULT_COMPRESSION) level = 6; 777 778 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 779 noheader = 1; 780 windowBits = -windowBits; 781 } 782 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || 783 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 || 784 strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 785 return Z_STREAM_ERROR; 786 } 787 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 788 if (s == Z_NULL) return Z_MEM_ERROR; 789 strm->state = (struct internal_state FAR *)s; 790 s->strm = strm; 791 792 s->noheader = noheader; 793 s->w_bits = windowBits; 794 s->w_size = 1 << s->w_bits; 795 s->w_mask = s->w_size - 1; 796 797 s->hash_bits = memLevel + 7; 798 s->hash_size = 1 << s->hash_bits; 799 s->hash_mask = s->hash_size - 1; 800 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 801 802 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 803 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 804 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 805 806 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 807 808 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); 809 s->pending_buf = (uchf *) overlay; 810 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); 811 812 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 813 s->pending_buf == Z_NULL) { 814 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR); 815 deflateEnd (strm); 816 return Z_MEM_ERROR; 817 } 818 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); 819 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; 820 821 s->level = level; 822 s->strategy = strategy; 823 s->method = (Byte)method; 824 825 return deflateReset(strm); 826 } 827 828 /* ========================================================================= */ 829 int 830 deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength) 831 { 832 deflate_state *s; 833 uInt length = dictLength; 834 uInt n; 835 IPos hash_head = 0; 836 837 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) 838 return Z_STREAM_ERROR; 839 840 s = (deflate_state *) strm->state; 841 if (s->status != INIT_STATE) return Z_STREAM_ERROR; 842 843 strm->adler = adler32(strm->adler, dictionary, dictLength); 844 845 if (length < MIN_MATCH) return Z_OK; 846 if (length > MAX_DIST(s)) { 847 length = MAX_DIST(s); 848 #ifndef USE_DICT_HEAD 849 dictionary += dictLength - length; /* use the tail of the dictionary */ 850 #endif 851 } 852 zmemcpy((charf *)s->window, dictionary, length); 853 s->strstart = length; 854 s->block_start = (long)length; 855 856 /* Insert all strings in the hash table (except for the last two bytes). 857 * s->lookahead stays null, so s->ins_h will be recomputed at the next 858 * call of fill_window. 859 */ 860 s->ins_h = s->window[0]; 861 UPDATE_HASH(s, s->ins_h, s->window[1]); 862 for (n = 0; n <= length - MIN_MATCH; n++) { 863 INSERT_STRING(s, n, hash_head); 864 } 865 if (hash_head) hash_head = 0; /* to make compiler happy */ 866 return Z_OK; 867 } 868 869 /* ========================================================================= */ 870 int 871 deflateReset(z_streamp strm) 872 { 873 deflate_state *s; 874 875 if (strm == Z_NULL || strm->state == Z_NULL || 876 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 877 878 strm->total_in = strm->total_out = 0; 879 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 880 strm->data_type = Z_UNKNOWN; 881 882 s = (deflate_state *)strm->state; 883 s->pending = 0; 884 s->pending_out = s->pending_buf; 885 886 if (s->noheader < 0) { 887 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 888 } 889 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 890 strm->adler = 1; 891 s->last_flush = Z_NO_FLUSH; 892 893 _tr_init(s); 894 lm_init(s); 895 896 return Z_OK; 897 } 898 899 /* ========================================================================= */ 900 int 901 deflateParams(z_streamp strm, int level, 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 */ 938 local void 939 putShortMSB(deflate_state *s, uInt b) 940 { 941 put_byte(s, (Byte)(b >> 8)); 942 put_byte(s, (Byte)(b & 0xff)); 943 } 944 945 /* ========================================================================= 946 * Flush as much pending output as possible. All deflate() output goes 947 * through this function so some applications may wish to modify it 948 * to avoid allocating a large strm->next_out buffer and copying into it. 949 * (See also read_buf()). 950 */ 951 local void 952 flush_pending(z_streamp strm) 953 { 954 deflate_state *s = (deflate_state *) strm->state; 955 unsigned len = s->pending; 956 957 if (len > strm->avail_out) len = strm->avail_out; 958 if (len == 0) return; 959 960 if (strm->next_out != Z_NULL) { 961 zmemcpy(strm->next_out, s->pending_out, len); 962 strm->next_out += len; 963 } 964 s->pending_out += len; 965 strm->total_out += len; 966 strm->avail_out -= len; 967 s->pending -= len; 968 if (s->pending == 0) { 969 s->pending_out = s->pending_buf; 970 } 971 } 972 973 /* ========================================================================= */ 974 int 975 deflate(z_streamp strm, int flush) 976 { 977 int old_flush; /* value of flush param for previous deflate call */ 978 deflate_state *s; 979 980 if (strm == Z_NULL || strm->state == Z_NULL || 981 flush > Z_FINISH || flush < 0) { 982 return Z_STREAM_ERROR; 983 } 984 s = (deflate_state *) strm->state; 985 986 if ((strm->next_in == Z_NULL && strm->avail_in != 0) || 987 (s->status == FINISH_STATE && flush != Z_FINISH)) { 988 ERR_RETURN(strm, Z_STREAM_ERROR); 989 } 990 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 991 992 s->strm = strm; /* just in case */ 993 old_flush = s->last_flush; 994 s->last_flush = flush; 995 996 /* Write the zlib header */ 997 if (s->status == INIT_STATE) { 998 999 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; 1000 uInt level_flags = (s->level-1) >> 1; 1001 1002 if (level_flags > 3) level_flags = 3; 1003 header |= (level_flags << 6); 1004 if (s->strstart != 0) header |= PRESET_DICT; 1005 header += 31 - (header % 31); 1006 1007 s->status = BUSY_STATE; 1008 putShortMSB(s, header); 1009 1010 /* Save the adler32 of the preset dictionary: */ 1011 if (s->strstart != 0) { 1012 putShortMSB(s, (uInt)(strm->adler >> 16)); 1013 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1014 } 1015 strm->adler = 1L; 1016 } 1017 1018 /* Flush as much pending output as possible */ 1019 if (s->pending != 0) { 1020 flush_pending(strm); 1021 if (strm->avail_out == 0) { 1022 /* Since avail_out is 0, deflate will be called again with 1023 * more output space, but possibly with both pending and 1024 * avail_in equal to zero. There won't be anything to do, 1025 * but this is not an error situation so make sure we 1026 * return OK instead of BUF_ERROR at next call of deflate: 1027 */ 1028 s->last_flush = -1; 1029 return Z_OK; 1030 } 1031 1032 /* Make sure there is something to do and avoid duplicate consecutive 1033 * flushes. For repeated and useless calls with Z_FINISH, we keep 1034 * returning Z_STREAM_END instead of Z_BUFF_ERROR. 1035 */ 1036 } else if (strm->avail_in == 0 && flush <= old_flush && 1037 flush != Z_FINISH) { 1038 ERR_RETURN(strm, Z_BUF_ERROR); 1039 } 1040 1041 /* User must not provide more input after the first FINISH: */ 1042 if (s->status == FINISH_STATE && strm->avail_in != 0) { 1043 ERR_RETURN(strm, Z_BUF_ERROR); 1044 } 1045 1046 /* Start a new block or continue the current one. 1047 */ 1048 if (strm->avail_in != 0 || s->lookahead != 0 || 1049 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { 1050 block_state bstate; 1051 1052 bstate = (*(configuration_table[s->level].func))(s, flush); 1053 1054 if (bstate == finish_started || bstate == finish_done) { 1055 s->status = FINISH_STATE; 1056 } 1057 if (bstate == need_more || bstate == finish_started) { 1058 if (strm->avail_out == 0) { 1059 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ 1060 } 1061 return Z_OK; 1062 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 1063 * of deflate should use the same flush parameter to make sure 1064 * that the flush is complete. So we don't have to output an 1065 * empty block here, this will be done at next call. This also 1066 * ensures that for a very small output buffer, we emit at most 1067 * one empty block. 1068 */ 1069 } 1070 if (bstate == block_done) { 1071 if (flush == Z_PARTIAL_FLUSH) { 1072 _tr_align(s); 1073 } else if (flush == Z_PACKET_FLUSH) { 1074 /* Output just the 3-bit `stored' block type value, 1075 but not a zero length. */ 1076 _tr_stored_type_only(s); 1077 } else { /* FULL_FLUSH or SYNC_FLUSH */ 1078 _tr_stored_block(s, NULL, 0L, 0); 1079 /* For a full flush, this empty block will be recognized 1080 * as a special marker by inflate_sync(). 1081 */ 1082 if (flush == Z_FULL_FLUSH) { 1083 CLEAR_HASH(s); /* forget history */ 1084 } 1085 } 1086 flush_pending(strm); 1087 if (strm->avail_out == 0) { 1088 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ 1089 return Z_OK; 1090 } 1091 } 1092 } 1093 Assert(strm->avail_out > 0, "bug2"); 1094 1095 if (flush != Z_FINISH) return Z_OK; 1096 if (s->noheader) return Z_STREAM_END; 1097 1098 /* Write the zlib trailer (adler32) */ 1099 putShortMSB(s, (uInt)(strm->adler >> 16)); 1100 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1101 flush_pending(strm); 1102 /* If avail_out is zero, the application will call deflate again 1103 * to flush the rest. 1104 */ 1105 s->noheader = -1; /* write the trailer only once! */ 1106 return s->pending != 0 ? Z_OK : Z_STREAM_END; 1107 } 1108 1109 /* ========================================================================= */ 1110 int 1111 deflateEnd(z_streamp strm) 1112 { 1113 int status; 1114 deflate_state *s; 1115 1116 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 1117 s = (deflate_state *) strm->state; 1118 1119 status = s->status; 1120 if (status != INIT_STATE && status != BUSY_STATE && 1121 status != FINISH_STATE) { 1122 return Z_STREAM_ERROR; 1123 } 1124 1125 /* Deallocate in reverse order of allocations: */ 1126 TRY_FREE(strm, s->pending_buf); 1127 TRY_FREE(strm, s->head); 1128 TRY_FREE(strm, s->prev); 1129 TRY_FREE(strm, s->window); 1130 1131 ZFREE(strm, s); 1132 strm->state = Z_NULL; 1133 1134 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; 1135 } 1136 1137 /* ========================================================================= 1138 * Copy the source state to the destination state. 1139 */ 1140 int 1141 deflateCopy(z_streamp dest, z_streamp source) 1142 { 1143 deflate_state *ds; 1144 deflate_state *ss; 1145 ushf *overlay; 1146 1147 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) 1148 return Z_STREAM_ERROR; 1149 ss = (deflate_state *) source->state; 1150 1151 zmemcpy(dest, source, sizeof(*dest)); 1152 1153 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); 1154 if (ds == Z_NULL) return Z_MEM_ERROR; 1155 dest->state = (struct internal_state FAR *) ds; 1156 zmemcpy(ds, ss, sizeof(*ds)); 1157 ds->strm = dest; 1158 1159 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); 1160 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); 1161 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); 1162 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); 1163 ds->pending_buf = (uchf *) overlay; 1164 1165 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || 1166 ds->pending_buf == Z_NULL) { 1167 deflateEnd (dest); 1168 return Z_MEM_ERROR; 1169 } 1170 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ 1171 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); 1172 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); 1173 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); 1174 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); 1175 1176 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); 1177 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); 1178 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; 1179 1180 ds->l_desc.dyn_tree = ds->dyn_ltree; 1181 ds->d_desc.dyn_tree = ds->dyn_dtree; 1182 ds->bl_desc.dyn_tree = ds->bl_tree; 1183 1184 return Z_OK; 1185 } 1186 1187 /* =========================================================================== 1188 * Return the number of bytes of output which are immediately available 1189 * for output from the decompressor. 1190 */ 1191 int 1192 deflateOutputPending(z_streamp strm) 1193 { 1194 if (strm == Z_NULL || strm->state == Z_NULL) return 0; 1195 1196 return ((deflate_state *)(strm->state))->pending; 1197 } 1198 1199 /* =========================================================================== 1200 * Read a new buffer from the current input stream, update the adler32 1201 * and total number of bytes read. All deflate() input goes through 1202 * this function so some applications may wish to modify it to avoid 1203 * allocating a large strm->next_in buffer and copying from it. 1204 * (See also flush_pending()). 1205 */ 1206 local int 1207 read_buf(z_streamp strm, charf *buf, unsigned size) 1208 { 1209 unsigned len = strm->avail_in; 1210 1211 if (len > size) len = size; 1212 if (len == 0) return 0; 1213 1214 strm->avail_in -= len; 1215 1216 if (!((deflate_state *)(strm->state))->noheader) { 1217 strm->adler = adler32(strm->adler, strm->next_in, len); 1218 } 1219 zmemcpy(buf, strm->next_in, len); 1220 strm->next_in += len; 1221 strm->total_in += len; 1222 1223 return (int)len; 1224 } 1225 1226 /* =========================================================================== 1227 * Initialize the "longest match" routines for a new zlib stream 1228 */ 1229 local void 1230 lm_init(deflate_state *s) 1231 { 1232 s->window_size = (ulg)2L*s->w_size; 1233 1234 CLEAR_HASH(s); 1235 1236 /* Set the default configuration parameters: 1237 */ 1238 s->max_lazy_match = configuration_table[s->level].max_lazy; 1239 s->good_match = configuration_table[s->level].good_length; 1240 s->nice_match = configuration_table[s->level].nice_length; 1241 s->max_chain_length = configuration_table[s->level].max_chain; 1242 1243 s->strstart = 0; 1244 s->block_start = 0L; 1245 s->lookahead = 0; 1246 s->match_length = s->prev_length = MIN_MATCH-1; 1247 s->match_available = 0; 1248 s->ins_h = 0; 1249 #ifdef ASMV 1250 match_init(); /* initialize the asm code */ 1251 #endif 1252 } 1253 1254 /* =========================================================================== 1255 * Set match_start to the longest match starting at the given string and 1256 * return its length. Matches shorter or equal to prev_length are discarded, 1257 * in which case the result is equal to prev_length and match_start is 1258 * garbage. 1259 * IN assertions: cur_match is the head of the hash chain for the current 1260 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 1261 * OUT assertion: the match length is not greater than s->lookahead. 1262 * 1263 * Parameters: 1264 * cur_match: current match 1265 */ 1266 #ifndef ASMV 1267 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or 1268 * match.S. The code will be functionally equivalent. 1269 */ 1270 local uInt 1271 longest_match(deflate_state *s, IPos cur_match) 1272 { 1273 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 1274 Bytef *scan = s->window + s->strstart; /* current string */ 1275 Bytef *match; /* matched string */ 1276 int len; /* length of current match */ 1277 int best_len = s->prev_length; /* best match length so far */ 1278 int nice_match = s->nice_match; /* stop if match long enough */ 1279 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 1280 s->strstart - (IPos)MAX_DIST(s) : NIL; 1281 /* Stop when cur_match becomes <= limit. To simplify the code, 1282 * we prevent matches with the string of window index 0. 1283 */ 1284 Posf *prev = s->prev; 1285 uInt wmask = s->w_mask; 1286 1287 #ifdef UNALIGNED_OK 1288 /* Compare two bytes at a time. Note: this is not always beneficial. 1289 * Try with and without -DUNALIGNED_OK to check. 1290 */ 1291 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 1292 ush scan_start = *(ushf*)scan; 1293 ush scan_end = *(ushf*)(scan+best_len-1); 1294 #else 1295 Bytef *strend = s->window + s->strstart + MAX_MATCH; 1296 Byte scan_end1 = scan[best_len-1]; 1297 Byte scan_end = scan[best_len]; 1298 #endif 1299 1300 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 1301 * It is easy to get rid of this optimization if necessary. 1302 */ 1303 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 1304 1305 /* Do not waste too much time if we already have a good match: */ 1306 if (s->prev_length >= s->good_match) { 1307 chain_length >>= 2; 1308 } 1309 /* Do not look for matches beyond the end of the input. This is necessary 1310 * to make deflate deterministic. 1311 */ 1312 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; 1313 1314 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1315 1316 do { 1317 Assert(cur_match < s->strstart, "no future"); 1318 match = s->window + cur_match; 1319 1320 /* Skip to next match if the match length cannot increase 1321 * or if the match length is less than 2: 1322 */ 1323 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1324 /* This code assumes sizeof(unsigned short) == 2. Do not use 1325 * UNALIGNED_OK if your compiler uses a different size. 1326 */ 1327 if (*(ushf*)(match+best_len-1) != scan_end || 1328 *(ushf*)match != scan_start) continue; 1329 1330 /* It is not necessary to compare scan[2] and match[2] since they are 1331 * always equal when the other bytes match, given that the hash keys 1332 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1333 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1334 * lookahead only every 4th comparison; the 128th check will be made 1335 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1336 * necessary to put more guard bytes at the end of the window, or 1337 * to check more often for insufficient lookahead. 1338 */ 1339 Assert(scan[2] == match[2], "scan[2]?"); 1340 scan++, match++; 1341 do { 1342 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1343 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1344 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1345 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1346 scan < strend); 1347 /* The funny "do {}" generates better code on most compilers */ 1348 1349 /* Here, scan <= window+strstart+257 */ 1350 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1351 if (*scan == *match) scan++; 1352 1353 len = (MAX_MATCH - 1) - (int)(strend-scan); 1354 scan = strend - (MAX_MATCH-1); 1355 1356 #else /* UNALIGNED_OK */ 1357 1358 if (match[best_len] != scan_end || 1359 match[best_len-1] != scan_end1 || 1360 *match != *scan || 1361 *++match != scan[1]) continue; 1362 1363 /* The check at best_len-1 can be removed because it will be made 1364 * again later. (This heuristic is not always a win.) 1365 * It is not necessary to compare scan[2] and match[2] since they 1366 * are always equal when the other bytes match, given that 1367 * the hash keys are equal and that HASH_BITS >= 8. 1368 */ 1369 scan += 2, match++; 1370 Assert(*scan == *match, "match[2]?"); 1371 1372 /* We check for insufficient lookahead only every 8th comparison; 1373 * the 256th check will be made at strstart+258. 1374 */ 1375 do { 1376 } while (*++scan == *++match && *++scan == *++match && 1377 *++scan == *++match && *++scan == *++match && 1378 *++scan == *++match && *++scan == *++match && 1379 *++scan == *++match && *++scan == *++match && 1380 scan < strend); 1381 1382 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1383 1384 len = MAX_MATCH - (int)(strend - scan); 1385 scan = strend - MAX_MATCH; 1386 1387 #endif /* UNALIGNED_OK */ 1388 1389 if (len > best_len) { 1390 s->match_start = cur_match; 1391 best_len = len; 1392 if (len >= nice_match) break; 1393 #ifdef UNALIGNED_OK 1394 scan_end = *(ushf*)(scan+best_len-1); 1395 #else 1396 scan_end1 = scan[best_len-1]; 1397 scan_end = scan[best_len]; 1398 #endif 1399 } 1400 } while ((cur_match = prev[cur_match & wmask]) > limit 1401 && --chain_length != 0); 1402 1403 if ((uInt)best_len <= s->lookahead) return best_len; 1404 return s->lookahead; 1405 } 1406 #endif /* ASMV */ 1407 1408 #ifdef DEBUG_ZLIB 1409 /* =========================================================================== 1410 * Check that the match at match_start is indeed a match. 1411 */ 1412 local void 1413 check_match(deflate_state *s, IPos start, IPos match, int length) 1414 { 1415 /* check that the match is indeed a match */ 1416 if (zmemcmp((charf *)s->window + match, 1417 (charf *)s->window + start, length) != EQUAL) { 1418 fprintf(stderr, " start %u, match %u, length %d\n", 1419 start, match, length); 1420 do { 1421 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); 1422 } while (--length != 0); 1423 z_error("invalid match"); 1424 } 1425 if (z_verbose > 1) { 1426 fprintf(stderr,"\\[%d,%d]", start-match, length); 1427 do { putc(s->window[start++], stderr); } while (--length != 0); 1428 } 1429 } 1430 #else 1431 # define check_match(s, start, match, length) 1432 #endif 1433 1434 /* =========================================================================== 1435 * Fill the window when the lookahead becomes insufficient. 1436 * Updates strstart and lookahead. 1437 * 1438 * IN assertion: lookahead < MIN_LOOKAHEAD 1439 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1440 * At least one byte has been read, or avail_in == 0; reads are 1441 * performed for at least two bytes (required for the zip translate_eol 1442 * option -- not supported here). 1443 */ 1444 local void 1445 fill_window(deflate_state *s) 1446 { 1447 unsigned n, m; 1448 Posf *p; 1449 unsigned more; /* Amount of free space at the end of the window. */ 1450 uInt wsize = s->w_size; 1451 1452 do { 1453 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1454 1455 /* Deal with !@#$% 64K limit: */ 1456 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1457 more = wsize; 1458 1459 } else if (more == (unsigned)(-1)) { 1460 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1461 * and lookahead == 1 (input done one byte at time) 1462 */ 1463 more--; 1464 1465 /* If the window is almost full and there is insufficient lookahead, 1466 * move the upper half to the lower one to make room in the upper half. 1467 */ 1468 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1469 1470 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1471 (unsigned)wsize); 1472 s->match_start -= wsize; 1473 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1474 s->block_start -= (long) wsize; 1475 1476 /* Slide the hash table (could be avoided with 32 bit values 1477 at the expense of memory usage). We slide even when level == 0 1478 to keep the hash table consistent if we switch back to level > 0 1479 later. (Using level 0 permanently is not an optimal usage of 1480 zlib, so we don't care about this pathological case.) 1481 */ 1482 n = s->hash_size; 1483 p = &s->head[n]; 1484 do { 1485 m = *--p; 1486 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1487 } while (--n); 1488 1489 n = wsize; 1490 p = &s->prev[n]; 1491 do { 1492 m = *--p; 1493 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1494 /* If n is not on any hash chain, prev[n] is garbage but 1495 * its value will never be used. 1496 */ 1497 } while (--n); 1498 more += wsize; 1499 } 1500 if (s->strm->avail_in == 0) return; 1501 1502 /* If there was no sliding: 1503 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1504 * more == window_size - lookahead - strstart 1505 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1506 * => more >= window_size - 2*WSIZE + 2 1507 * In the BIG_MEM or MMAP case (not yet supported), 1508 * window_size == input_size + MIN_LOOKAHEAD && 1509 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1510 * Otherwise, window_size == 2*WSIZE so more >= 2. 1511 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1512 */ 1513 Assert(more >= 2, "more < 2"); 1514 1515 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1516 more); 1517 s->lookahead += n; 1518 1519 /* Initialize the hash value now that we have some input: */ 1520 if (s->lookahead >= MIN_MATCH) { 1521 s->ins_h = s->window[s->strstart]; 1522 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1523 #if MIN_MATCH != 3 1524 Call UPDATE_HASH() MIN_MATCH-3 more times 1525 #endif 1526 } 1527 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1528 * but this is not important since only literal bytes will be emitted. 1529 */ 1530 1531 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1532 } 1533 1534 /* =========================================================================== 1535 * Flush the current block, with given end-of-file flag. 1536 * IN assertion: strstart is set to the end of the current match. 1537 */ 1538 #define FLUSH_BLOCK_ONLY(s, eof) { \ 1539 _tr_flush_block(s, (s->block_start >= 0L ? \ 1540 (charf *)&s->window[(unsigned)s->block_start] : \ 1541 (charf *)Z_NULL), \ 1542 (ulg)((long)s->strstart - s->block_start), \ 1543 (eof)); \ 1544 s->block_start = s->strstart; \ 1545 flush_pending(s->strm); \ 1546 Tracev((stderr,"[FLUSH]")); \ 1547 } 1548 1549 /* Same but force premature exit if necessary. */ 1550 #define FLUSH_BLOCK(s, eof) { \ 1551 FLUSH_BLOCK_ONLY(s, eof); \ 1552 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ 1553 } 1554 1555 /* =========================================================================== 1556 * Copy without compression as much as possible from the input stream, return 1557 * the current block state. 1558 * This function does not insert new strings in the dictionary since 1559 * uncompressible data is probably not useful. This function is used 1560 * only for the level=0 compression option. 1561 * NOTE: this function should be optimized to avoid extra copying from 1562 * window to pending_buf. 1563 */ 1564 local block_state 1565 deflate_stored(deflate_state *s, int flush) 1566 { 1567 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited 1568 * to pending_buf_size, and each stored block has a 5 byte header: 1569 */ 1570 ulg max_block_size = 0xffff; 1571 ulg max_start; 1572 1573 if (max_block_size > s->pending_buf_size - 5) { 1574 max_block_size = s->pending_buf_size - 5; 1575 } 1576 1577 /* Copy as much as possible from input to output: */ 1578 for (;;) { 1579 /* Fill the window as much as possible: */ 1580 if (s->lookahead <= 1) { 1581 1582 Assert(s->strstart < s->w_size+MAX_DIST(s) || 1583 s->block_start >= (long)s->w_size, "slide too late"); 1584 1585 fill_window(s); 1586 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; 1587 1588 if (s->lookahead == 0) break; /* flush the current block */ 1589 } 1590 Assert(s->block_start >= 0L, "block gone"); 1591 1592 s->strstart += s->lookahead; 1593 s->lookahead = 0; 1594 1595 /* Emit a stored block if pending_buf will be full: */ 1596 max_start = s->block_start + max_block_size; 1597 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { 1598 /* strstart == 0 is possible when wraparound on 16-bit machine */ 1599 s->lookahead = (uInt)(s->strstart - max_start); 1600 s->strstart = (uInt)max_start; 1601 FLUSH_BLOCK(s, 0); 1602 } 1603 /* Flush if we may have to slide, otherwise block_start may become 1604 * negative and the data will be gone: 1605 */ 1606 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { 1607 FLUSH_BLOCK(s, 0); 1608 } 1609 } 1610 FLUSH_BLOCK(s, flush == Z_FINISH); 1611 return flush == Z_FINISH ? finish_done : block_done; 1612 } 1613 1614 /* =========================================================================== 1615 * Compress as much as possible from the input stream, return the current 1616 * block state. 1617 * This function does not perform lazy evaluation of matches and inserts 1618 * new strings in the dictionary only for unmatched strings or for short 1619 * matches. It is used only for the fast compression options. 1620 */ 1621 local block_state 1622 deflate_fast(deflate_state *s, int flush) 1623 { 1624 IPos hash_head = NIL; /* head of the hash chain */ 1625 int bflush; /* set if current block must be flushed */ 1626 1627 for (;;) { 1628 /* Make sure that we always have enough lookahead, except 1629 * at the end of the input file. We need MAX_MATCH bytes 1630 * for the next match, plus MIN_MATCH bytes to insert the 1631 * string following the next match. 1632 */ 1633 if (s->lookahead < MIN_LOOKAHEAD) { 1634 fill_window(s); 1635 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1636 return need_more; 1637 } 1638 if (s->lookahead == 0) break; /* flush the current block */ 1639 } 1640 1641 /* Insert the string window[strstart .. strstart+2] in the 1642 * dictionary, and set hash_head to the head of the hash chain: 1643 */ 1644 if (s->lookahead >= MIN_MATCH) { 1645 INSERT_STRING(s, s->strstart, hash_head); 1646 } 1647 1648 /* Find the longest match, discarding those <= prev_length. 1649 * At this point we have always match_length < MIN_MATCH 1650 */ 1651 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1652 /* To simplify the code, we prevent matches with the string 1653 * of window index 0 (in particular we have to avoid a match 1654 * of the string with itself at the start of the input file). 1655 */ 1656 if (s->strategy != Z_HUFFMAN_ONLY) { 1657 s->match_length = longest_match (s, hash_head); 1658 } 1659 /* longest_match() sets match_start */ 1660 } 1661 if (s->match_length >= MIN_MATCH) { 1662 check_match(s, s->strstart, s->match_start, s->match_length); 1663 1664 bflush = _tr_tally(s, s->strstart - s->match_start, 1665 s->match_length - MIN_MATCH); 1666 1667 s->lookahead -= s->match_length; 1668 1669 /* Insert new strings in the hash table only if the match length 1670 * is not too large. This saves time but degrades compression. 1671 */ 1672 if (s->match_length <= s->max_insert_length && 1673 s->lookahead >= MIN_MATCH) { 1674 s->match_length--; /* string at strstart already in hash table */ 1675 do { 1676 s->strstart++; 1677 INSERT_STRING(s, s->strstart, hash_head); 1678 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1679 * always MIN_MATCH bytes ahead. 1680 */ 1681 } while (--s->match_length != 0); 1682 s->strstart++; 1683 } else { 1684 s->strstart += s->match_length; 1685 s->match_length = 0; 1686 s->ins_h = s->window[s->strstart]; 1687 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1688 #if MIN_MATCH != 3 1689 Call UPDATE_HASH() MIN_MATCH-3 more times 1690 #endif 1691 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1692 * matter since it will be recomputed at next deflate call. 1693 */ 1694 } 1695 } else { 1696 /* No match, output a literal byte */ 1697 Tracevv((stderr,"%c", s->window[s->strstart])); 1698 bflush = _tr_tally (s, 0, s->window[s->strstart]); 1699 s->lookahead--; 1700 s->strstart++; 1701 } 1702 if (bflush) FLUSH_BLOCK(s, 0); 1703 } 1704 FLUSH_BLOCK(s, flush == Z_FINISH); 1705 return flush == Z_FINISH ? finish_done : block_done; 1706 } 1707 1708 /* =========================================================================== 1709 * Same as above, but achieves better compression. We use a lazy 1710 * evaluation for matches: a match is finally adopted only if there is 1711 * no better match at the next window position. 1712 */ 1713 local block_state 1714 deflate_slow(deflate_state *s, int flush) 1715 { 1716 IPos hash_head = NIL; /* head of hash chain */ 1717 int bflush; /* set if current block must be flushed */ 1718 1719 /* Process the input block. */ 1720 for (;;) { 1721 /* Make sure that we always have enough lookahead, except 1722 * at the end of the input file. We need MAX_MATCH bytes 1723 * for the next match, plus MIN_MATCH bytes to insert the 1724 * string following the next match. 1725 */ 1726 if (s->lookahead < MIN_LOOKAHEAD) { 1727 fill_window(s); 1728 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1729 return need_more; 1730 } 1731 if (s->lookahead == 0) break; /* flush the current block */ 1732 } 1733 1734 /* Insert the string window[strstart .. strstart+2] in the 1735 * dictionary, and set hash_head to the head of the hash chain: 1736 */ 1737 if (s->lookahead >= MIN_MATCH) { 1738 INSERT_STRING(s, s->strstart, hash_head); 1739 } 1740 1741 /* Find the longest match, discarding those <= prev_length. 1742 */ 1743 s->prev_length = s->match_length, s->prev_match = s->match_start; 1744 s->match_length = MIN_MATCH-1; 1745 1746 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1747 s->strstart - hash_head <= MAX_DIST(s)) { 1748 /* To simplify the code, we prevent matches with the string 1749 * of window index 0 (in particular we have to avoid a match 1750 * of the string with itself at the start of the input file). 1751 */ 1752 if (s->strategy != Z_HUFFMAN_ONLY) { 1753 s->match_length = longest_match (s, hash_head); 1754 } 1755 /* longest_match() sets match_start */ 1756 1757 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1758 (s->match_length == MIN_MATCH && 1759 s->strstart - s->match_start > TOO_FAR))) { 1760 1761 /* If prev_match is also MIN_MATCH, match_start is garbage 1762 * but we will ignore the current match anyway. 1763 */ 1764 s->match_length = MIN_MATCH-1; 1765 } 1766 } 1767 /* If there was a match at the previous step and the current 1768 * match is not better, output the previous match: 1769 */ 1770 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1771 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1772 /* Do not insert strings in hash table beyond this. */ 1773 1774 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1775 1776 bflush = _tr_tally(s, s->strstart -1 - s->prev_match, 1777 s->prev_length - MIN_MATCH); 1778 1779 /* Insert in hash table all strings up to the end of the match. 1780 * strstart-1 and strstart are already inserted. If there is not 1781 * enough lookahead, the last two strings are not inserted in 1782 * the hash table. 1783 */ 1784 s->lookahead -= s->prev_length-1; 1785 s->prev_length -= 2; 1786 do { 1787 if (++s->strstart <= max_insert) { 1788 INSERT_STRING(s, s->strstart, hash_head); 1789 } 1790 } while (--s->prev_length != 0); 1791 s->match_available = 0; 1792 s->match_length = MIN_MATCH-1; 1793 s->strstart++; 1794 1795 if (bflush) FLUSH_BLOCK(s, 0); 1796 1797 } else if (s->match_available) { 1798 /* If there was no match at the previous position, output a 1799 * single literal. If there was a match but the current match 1800 * is longer, truncate the previous match to a single literal. 1801 */ 1802 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1803 if (_tr_tally (s, 0, s->window[s->strstart-1])) { 1804 FLUSH_BLOCK_ONLY(s, 0); 1805 } 1806 s->strstart++; 1807 s->lookahead--; 1808 if (s->strm->avail_out == 0) return need_more; 1809 } else { 1810 /* There is no previous match to compare with, wait for 1811 * the next step to decide. 1812 */ 1813 s->match_available = 1; 1814 s->strstart++; 1815 s->lookahead--; 1816 } 1817 } 1818 Assert (flush != Z_NO_FLUSH, "no flush?"); 1819 if (s->match_available) { 1820 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1821 _tr_tally (s, 0, s->window[s->strstart-1]); 1822 s->match_available = 0; 1823 } 1824 FLUSH_BLOCK(s, flush == Z_FINISH); 1825 return flush == Z_FINISH ? finish_done : block_done; 1826 } 1827 /* --- deflate.c */ 1828 1829 /* +++ trees.c */ 1830 /* trees.c -- output deflated data using Huffman coding 1831 * Copyright (C) 1995-1996 Jean-loup Gailly 1832 * For conditions of distribution and use, see copyright notice in zlib.h 1833 */ 1834 1835 /* 1836 * ALGORITHM 1837 * 1838 * The "deflation" process uses several Huffman trees. The more 1839 * common source values are represented by shorter bit sequences. 1840 * 1841 * Each code tree is stored in a compressed form which is itself 1842 * a Huffman encoding of the lengths of all the code strings (in 1843 * ascending order by source values). The actual code strings are 1844 * reconstructed from the lengths in the inflate process, as described 1845 * in the deflate specification. 1846 * 1847 * REFERENCES 1848 * 1849 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1850 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1851 * 1852 * Storer, James A. 1853 * Data Compression: Methods and Theory, pp. 49-50. 1854 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1855 * 1856 * Sedgewick, R. 1857 * Algorithms, p290. 1858 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1859 */ 1860 1861 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ 1862 1863 /* #include "deflate.h" */ 1864 1865 #ifdef DEBUG_ZLIB 1866 # include <ctype.h> 1867 #endif 1868 1869 /* =========================================================================== 1870 * Constants 1871 */ 1872 1873 #define MAX_BL_BITS 7 1874 /* Bit length codes must not exceed MAX_BL_BITS bits */ 1875 1876 #define END_BLOCK 256 1877 /* end of block literal code */ 1878 1879 #define REP_3_6 16 1880 /* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1881 1882 #define REPZ_3_10 17 1883 /* repeat a zero length 3-10 times (3 bits of repeat count) */ 1884 1885 #define REPZ_11_138 18 1886 /* repeat a zero length 11-138 times (7 bits of repeat count) */ 1887 1888 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1889 = {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}; 1890 1891 local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1892 = {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}; 1893 1894 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1895 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1896 1897 local uch bl_order[BL_CODES] 1898 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1899 /* The lengths of the bit length codes are sent in order of decreasing 1900 * probability, to avoid transmitting the lengths for unused bit length codes. 1901 */ 1902 1903 #define Buf_size (8 * 2*sizeof(char)) 1904 /* Number of bits used within bi_buf. (bi_buf might be implemented on 1905 * more than 16 bits on some systems.) 1906 */ 1907 1908 /* =========================================================================== 1909 * Local data. These are initialized only once. 1910 */ 1911 1912 local ct_data static_ltree[L_CODES+2]; 1913 /* The static literal tree. Since the bit lengths are imposed, there is no 1914 * need for the L_CODES extra codes used during heap construction. However 1915 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 1916 * below). 1917 */ 1918 1919 local ct_data static_dtree[D_CODES]; 1920 /* The static distance tree. (Actually a trivial tree since all codes use 1921 * 5 bits.) 1922 */ 1923 1924 local uch dist_code[512]; 1925 /* distance codes. The first 256 values correspond to the distances 1926 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1927 * the 15 bit distances. 1928 */ 1929 1930 local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1931 /* length code for each normalized match length (0 == MIN_MATCH) */ 1932 1933 local int base_length[LENGTH_CODES]; 1934 /* First normalized length for each code (0 = MIN_MATCH) */ 1935 1936 local int base_dist[D_CODES]; 1937 /* First normalized distance for each code (0 = distance of 1) */ 1938 1939 struct static_tree_desc_s { 1940 ct_data *static_tree; /* static tree or NULL */ 1941 intf *extra_bits; /* extra bits for each code or NULL */ 1942 int extra_base; /* base index for extra_bits */ 1943 int elems; /* max number of elements in the tree */ 1944 int max_length; /* max bit length for the codes */ 1945 }; 1946 1947 local static_tree_desc static_l_desc = 1948 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1949 1950 local static_tree_desc static_d_desc = 1951 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1952 1953 local static_tree_desc static_bl_desc = 1954 {NULL, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1955 1956 /* =========================================================================== 1957 * Local (static) routines in this file. 1958 */ 1959 1960 local void tr_static_init OF((void)); 1961 local void init_block OF((deflate_state *s)); 1962 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1963 local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1964 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1965 local void build_tree OF((deflate_state *s, tree_desc *desc)); 1966 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1967 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1968 local int build_bl_tree OF((deflate_state *s)); 1969 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1970 int blcodes)); 1971 local void compress_block OF((deflate_state *s, ct_data *ltree, 1972 ct_data *dtree)); 1973 local void set_data_type OF((deflate_state *s)); 1974 local unsigned bi_reverse OF((unsigned value, int length)); 1975 local void bi_windup OF((deflate_state *s)); 1976 local void bi_flush OF((deflate_state *s)); 1977 local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1978 int header)); 1979 1980 #ifndef DEBUG_ZLIB 1981 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 1982 /* Send a code of the given tree. c and tree must not have side effects */ 1983 1984 #else /* DEBUG_ZLIB */ 1985 # define send_code(s, c, tree) \ 1986 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 1987 send_bits(s, tree[c].Code, tree[c].Len); } 1988 #endif 1989 1990 #define d_code(dist) \ 1991 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 1992 /* Mapping from a distance to a distance code. dist is the distance - 1 and 1993 * must not have side effects. dist_code[256] and dist_code[257] are never 1994 * used. 1995 */ 1996 1997 /* =========================================================================== 1998 * Output a short LSB first on the stream. 1999 * IN assertion: there is enough room in pendingBuf. 2000 */ 2001 #define put_short(s, w) { \ 2002 put_byte(s, (uch)((w) & 0xff)); \ 2003 put_byte(s, (uch)((ush)(w) >> 8)); \ 2004 } 2005 2006 /* =========================================================================== 2007 * Send a value on a given number of bits. 2008 * IN assertion: length <= 16 and value fits in length bits. 2009 * 2010 * Parameters: 2011 * value: value to send 2012 * length: number of bits 2013 */ 2014 #ifdef DEBUG_ZLIB 2015 local void send_bits OF((deflate_state *s, int value, int length)); 2016 2017 local void 2018 send_bits(deflate_state *s, int value, int length) 2019 { 2020 Tracevv((stderr," l %2d v %4x ", length, value)); 2021 Assert(length > 0 && length <= 15, "invalid length"); 2022 s->bits_sent += (ulg)length; 2023 2024 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 2025 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 2026 * unused bits in value. 2027 */ 2028 if (s->bi_valid > (int)Buf_size - length) { 2029 s->bi_buf |= (value << s->bi_valid); 2030 put_short(s, s->bi_buf); 2031 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 2032 s->bi_valid += length - Buf_size; 2033 } else { 2034 s->bi_buf |= value << s->bi_valid; 2035 s->bi_valid += length; 2036 } 2037 } 2038 #else /* !DEBUG_ZLIB */ 2039 2040 #define send_bits(s, value, length) \ 2041 { int len = length;\ 2042 if (s->bi_valid > (int)Buf_size - len) {\ 2043 int val = value;\ 2044 s->bi_buf |= (val << s->bi_valid);\ 2045 put_short(s, s->bi_buf);\ 2046 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 2047 s->bi_valid += len - Buf_size;\ 2048 } else {\ 2049 s->bi_buf |= (value) << s->bi_valid;\ 2050 s->bi_valid += len;\ 2051 }\ 2052 } 2053 #endif /* DEBUG_ZLIB */ 2054 2055 /* the arguments must not have side effects */ 2056 2057 /* =========================================================================== 2058 * Initialize the various 'constant' tables. In a multi-threaded environment, 2059 * this function may be called by two threads concurrently, but this is 2060 * harmless since both invocations do exactly the same thing. 2061 */ 2062 local void 2063 tr_static_init(void) 2064 { 2065 static int static_init_done = 0; 2066 int n; /* iterates over tree elements */ 2067 int bits; /* bit counter */ 2068 int length; /* length value */ 2069 int code; /* code value */ 2070 int dist; /* distance index */ 2071 ush bl_count[MAX_BITS+1]; 2072 /* number of codes at each bit length for an optimal tree */ 2073 2074 if (static_init_done) return; 2075 2076 /* Initialize the mapping length (0..255) -> length code (0..28) */ 2077 length = 0; 2078 for (code = 0; code < LENGTH_CODES-1; code++) { 2079 base_length[code] = length; 2080 for (n = 0; n < (1<<extra_lbits[code]); n++) { 2081 length_code[length++] = (uch)code; 2082 } 2083 } 2084 Assert (length == 256, "tr_static_init: length != 256"); 2085 /* Note that the length 255 (match length 258) can be represented 2086 * in two different ways: code 284 + 5 bits or code 285, so we 2087 * overwrite length_code[255] to use the best encoding: 2088 */ 2089 length_code[length-1] = (uch)code; 2090 2091 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 2092 dist = 0; 2093 for (code = 0 ; code < 16; code++) { 2094 base_dist[code] = dist; 2095 for (n = 0; n < (1<<extra_dbits[code]); n++) { 2096 dist_code[dist++] = (uch)code; 2097 } 2098 } 2099 Assert (dist == 256, "tr_static_init: dist != 256"); 2100 dist >>= 7; /* from now on, all distances are divided by 128 */ 2101 for ( ; code < D_CODES; code++) { 2102 base_dist[code] = dist << 7; 2103 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 2104 dist_code[256 + dist++] = (uch)code; 2105 } 2106 } 2107 Assert (dist == 256, "tr_static_init: 256+dist != 512"); 2108 2109 /* Construct the codes of the static literal tree */ 2110 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 2111 n = 0; 2112 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 2113 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 2114 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 2115 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 2116 /* Codes 286 and 287 do not exist, but we must include them in the 2117 * tree construction to get a canonical Huffman tree (longest code 2118 * all ones) 2119 */ 2120 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 2121 2122 /* The static distance tree is trivial: */ 2123 for (n = 0; n < D_CODES; n++) { 2124 static_dtree[n].Len = 5; 2125 static_dtree[n].Code = bi_reverse((unsigned)n, 5); 2126 } 2127 static_init_done = 1; 2128 } 2129 2130 /* =========================================================================== 2131 * Initialize the tree data structures for a new zlib stream. 2132 */ 2133 void 2134 _tr_init(deflate_state *s) 2135 { 2136 tr_static_init(); 2137 2138 s->compressed_len = 0L; 2139 2140 s->l_desc.dyn_tree = s->dyn_ltree; 2141 s->l_desc.stat_desc = &static_l_desc; 2142 2143 s->d_desc.dyn_tree = s->dyn_dtree; 2144 s->d_desc.stat_desc = &static_d_desc; 2145 2146 s->bl_desc.dyn_tree = s->bl_tree; 2147 s->bl_desc.stat_desc = &static_bl_desc; 2148 2149 s->bi_buf = 0; 2150 s->bi_valid = 0; 2151 s->last_eob_len = 8; /* enough lookahead for inflate */ 2152 #ifdef DEBUG_ZLIB 2153 s->bits_sent = 0L; 2154 #endif 2155 2156 /* Initialize the first block of the first file: */ 2157 init_block(s); 2158 } 2159 2160 /* =========================================================================== 2161 * Initialize a new block. 2162 */ 2163 local void 2164 init_block(deflate_state *s) 2165 { 2166 int n; /* iterates over tree elements */ 2167 2168 /* Initialize the trees. */ 2169 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 2170 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 2171 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 2172 2173 s->dyn_ltree[END_BLOCK].Freq = 1; 2174 s->opt_len = s->static_len = 0L; 2175 s->last_lit = s->matches = 0; 2176 } 2177 2178 #define SMALLEST 1 2179 /* Index within the heap array of least frequent node in the Huffman tree */ 2180 2181 2182 /* =========================================================================== 2183 * Remove the smallest element from the heap and recreate the heap with 2184 * one less element. Updates heap and heap_len. 2185 */ 2186 #define pqremove(s, tree, top) \ 2187 {\ 2188 top = s->heap[SMALLEST]; \ 2189 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 2190 pqdownheap(s, tree, SMALLEST); \ 2191 } 2192 2193 /* =========================================================================== 2194 * Compares to subtrees, using the tree depth as tie breaker when 2195 * the subtrees have equal frequency. This minimizes the worst case length. 2196 */ 2197 #define smaller(tree, n, m, depth) \ 2198 (tree[n].Freq < tree[m].Freq || \ 2199 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 2200 2201 /* =========================================================================== 2202 * Restore the heap property by moving down the tree starting at node k, 2203 * exchanging a node with the smallest of its two sons if necessary, stopping 2204 * when the heap property is re-established (each father smaller than its 2205 * two sons). 2206 * 2207 * Parameters: 2208 * tree: the tree to restore 2209 * k: node to move down 2210 */ 2211 local void 2212 pqdownheap(deflate_state *s, ct_data *tree, int k) 2213 { 2214 int v = s->heap[k]; 2215 int j = k << 1; /* left son of k */ 2216 while (j <= s->heap_len) { 2217 /* Set j to the smallest of the two sons: */ 2218 if (j < s->heap_len && 2219 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 2220 j++; 2221 } 2222 /* Exit if v is smaller than both sons */ 2223 if (smaller(tree, v, s->heap[j], s->depth)) break; 2224 2225 /* Exchange v with the smallest son */ 2226 s->heap[k] = s->heap[j]; k = j; 2227 2228 /* And continue down the tree, setting j to the left son of k */ 2229 j <<= 1; 2230 } 2231 s->heap[k] = v; 2232 } 2233 2234 /* =========================================================================== 2235 * Compute the optimal bit lengths for a tree and update the total bit length 2236 * for the current block. 2237 * IN assertion: the fields freq and dad are set, heap[heap_max] and 2238 * above are the tree nodes sorted by increasing frequency. 2239 * OUT assertions: the field len is set to the optimal bit length, the 2240 * array bl_count contains the frequencies for each bit length. 2241 * The length opt_len is updated; static_len is also updated if stree is 2242 * not null. 2243 * 2244 * Parameters: 2245 * desc: the tree descriptor 2246 */ 2247 local void 2248 gen_bitlen(deflate_state *s, tree_desc *desc) 2249 { 2250 ct_data *tree = desc->dyn_tree; 2251 int max_code = desc->max_code; 2252 ct_data *stree = desc->stat_desc->static_tree; 2253 intf *extra = desc->stat_desc->extra_bits; 2254 int base = desc->stat_desc->extra_base; 2255 int max_length = desc->stat_desc->max_length; 2256 int h; /* heap index */ 2257 int n, m; /* iterate over the tree elements */ 2258 int bits; /* bit length */ 2259 int xbits; /* extra bits */ 2260 ush f; /* frequency */ 2261 int overflow = 0; /* number of elements with bit length too large */ 2262 2263 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 2264 2265 /* In a first pass, compute the optimal bit lengths (which may 2266 * overflow in the case of the bit length tree). 2267 */ 2268 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 2269 2270 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 2271 n = s->heap[h]; 2272 bits = tree[tree[n].Dad].Len + 1; 2273 if (bits > max_length) bits = max_length, overflow++; 2274 tree[n].Len = (ush)bits; 2275 /* We overwrite tree[n].Dad which is no longer needed */ 2276 2277 if (n > max_code) continue; /* not a leaf node */ 2278 2279 s->bl_count[bits]++; 2280 xbits = 0; 2281 if (n >= base) xbits = extra[n-base]; 2282 f = tree[n].Freq; 2283 s->opt_len += (ulg)f * (bits + xbits); 2284 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 2285 } 2286 if (overflow == 0) return; 2287 2288 Trace((stderr,"\nbit length overflow\n")); 2289 /* This happens for example on obj2 and pic of the Calgary corpus */ 2290 2291 /* Find the first bit length which could increase: */ 2292 do { 2293 bits = max_length-1; 2294 while (s->bl_count[bits] == 0) bits--; 2295 s->bl_count[bits]--; /* move one leaf down the tree */ 2296 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 2297 s->bl_count[max_length]--; 2298 /* The brother of the overflow item also moves one step up, 2299 * but this does not affect bl_count[max_length] 2300 */ 2301 overflow -= 2; 2302 } while (overflow > 0); 2303 2304 /* Now recompute all bit lengths, scanning in increasing frequency. 2305 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 2306 * lengths instead of fixing only the wrong ones. This idea is taken 2307 * from 'ar' written by Haruhiko Okumura.) 2308 */ 2309 for (bits = max_length; bits != 0; bits--) { 2310 n = s->bl_count[bits]; 2311 while (n != 0) { 2312 m = s->heap[--h]; 2313 if (m > max_code) continue; 2314 if (tree[m].Len != (unsigned) bits) { 2315 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 2316 s->opt_len += ((long)bits - (long)tree[m].Len) 2317 *(long)tree[m].Freq; 2318 tree[m].Len = (ush)bits; 2319 } 2320 n--; 2321 } 2322 } 2323 } 2324 2325 /* =========================================================================== 2326 * Generate the codes for a given tree and bit counts (which need not be 2327 * optimal). 2328 * IN assertion: the array bl_count contains the bit length statistics for 2329 * the given tree and the field len is set for all tree elements. 2330 * OUT assertion: the field code is set for all tree elements of non 2331 * zero code length. 2332 * 2333 * Parameters: 2334 * tree: the tree to decorate 2335 * max_code: largest code with non zero frequency 2336 * bl_count: number of codes at each bit length 2337 */ 2338 local void 2339 gen_codes(ct_data *tree, int max_code, ushf *bl_count) 2340 { 2341 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 2342 ush code = 0; /* running code value */ 2343 int bits; /* bit index */ 2344 int n; /* code index */ 2345 2346 /* The distribution counts are first used to generate the code values 2347 * without bit reversal. 2348 */ 2349 for (bits = 1; bits <= MAX_BITS; bits++) { 2350 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 2351 } 2352 /* Check that the bit counts in bl_count are consistent. The last code 2353 * must be all ones. 2354 */ 2355 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 2356 "inconsistent bit counts"); 2357 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 2358 2359 for (n = 0; n <= max_code; n++) { 2360 int len = tree[n].Len; 2361 if (len == 0) continue; 2362 /* Now reverse the bits */ 2363 tree[n].Code = bi_reverse(next_code[len]++, len); 2364 2365 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 2366 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 2367 } 2368 } 2369 2370 /* =========================================================================== 2371 * Construct one Huffman tree and assigns the code bit strings and lengths. 2372 * Update the total bit length for the current block. 2373 * IN assertion: the field freq is set for all tree elements. 2374 * OUT assertions: the fields len and code are set to the optimal bit length 2375 * and corresponding code. The length opt_len is updated; static_len is 2376 * also updated if stree is not null. The field max_code is set. 2377 * 2378 * Parameters: 2379 * desc: the tree descriptor 2380 */ 2381 local void 2382 build_tree(deflate_state *s, tree_desc *desc) 2383 { 2384 ct_data *tree = desc->dyn_tree; 2385 ct_data *stree = desc->stat_desc->static_tree; 2386 int elems = desc->stat_desc->elems; 2387 int n, m; /* iterate over heap elements */ 2388 int max_code = -1; /* largest code with non zero frequency */ 2389 int node; /* new node being created */ 2390 2391 /* Construct the initial heap, with least frequent element in 2392 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2393 * heap[0] is not used. 2394 */ 2395 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2396 2397 for (n = 0; n < elems; n++) { 2398 if (tree[n].Freq != 0) { 2399 s->heap[++(s->heap_len)] = max_code = n; 2400 s->depth[n] = 0; 2401 } else { 2402 tree[n].Len = 0; 2403 } 2404 } 2405 2406 /* The pkzip format requires that at least one distance code exists, 2407 * and that at least one bit should be sent even if there is only one 2408 * possible code. So to avoid special checks later on we force at least 2409 * two codes of non zero frequency. 2410 */ 2411 while (s->heap_len < 2) { 2412 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2413 tree[node].Freq = 1; 2414 s->depth[node] = 0; 2415 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2416 /* node is 0 or 1 so it does not have extra bits */ 2417 } 2418 desc->max_code = max_code; 2419 2420 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2421 * establish sub-heaps of increasing lengths: 2422 */ 2423 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2424 2425 /* Construct the Huffman tree by repeatedly combining the least two 2426 * frequent nodes. 2427 */ 2428 node = elems; /* next internal node of the tree */ 2429 do { 2430 pqremove(s, tree, n); /* n = node of least frequency */ 2431 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2432 2433 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2434 s->heap[--(s->heap_max)] = m; 2435 2436 /* Create a new node father of n and m */ 2437 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2438 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2439 tree[n].Dad = tree[m].Dad = (ush)node; 2440 #ifdef DUMP_BL_TREE 2441 if (tree == s->bl_tree) { 2442 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2443 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2444 } 2445 #endif 2446 /* and insert the new node in the heap */ 2447 s->heap[SMALLEST] = node++; 2448 pqdownheap(s, tree, SMALLEST); 2449 2450 } while (s->heap_len >= 2); 2451 2452 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2453 2454 /* At this point, the fields freq and dad are set. We can now 2455 * generate the bit lengths. 2456 */ 2457 gen_bitlen(s, (tree_desc *)desc); 2458 2459 /* The field len is now set, we can generate the bit codes */ 2460 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2461 } 2462 2463 /* =========================================================================== 2464 * Scan a literal or distance tree to determine the frequencies of the codes 2465 * in the bit length tree. 2466 * 2467 * Parameters: 2468 * tree: the tree to be scanned 2469 * max_code: and its largest code of non zero frequency 2470 */ 2471 local void 2472 scan_tree (deflate_state *s, ct_data *tree, int max_code) 2473 { 2474 int n; /* iterates over all tree elements */ 2475 int prevlen = -1; /* last emitted length */ 2476 int curlen; /* length of current code */ 2477 int nextlen = tree[0].Len; /* length of next code */ 2478 int count = 0; /* repeat count of the current code */ 2479 int max_count = 7; /* max repeat count */ 2480 int min_count = 4; /* min repeat count */ 2481 2482 if (nextlen == 0) max_count = 138, min_count = 3; 2483 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2484 2485 for (n = 0; n <= max_code; n++) { 2486 curlen = nextlen; nextlen = tree[n+1].Len; 2487 if (++count < max_count && curlen == nextlen) { 2488 continue; 2489 } else if (count < min_count) { 2490 s->bl_tree[curlen].Freq += count; 2491 } else if (curlen != 0) { 2492 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2493 s->bl_tree[REP_3_6].Freq++; 2494 } else if (count <= 10) { 2495 s->bl_tree[REPZ_3_10].Freq++; 2496 } else { 2497 s->bl_tree[REPZ_11_138].Freq++; 2498 } 2499 count = 0; prevlen = curlen; 2500 if (nextlen == 0) { 2501 max_count = 138, min_count = 3; 2502 } else if (curlen == nextlen) { 2503 max_count = 6, min_count = 3; 2504 } else { 2505 max_count = 7, min_count = 4; 2506 } 2507 } 2508 } 2509 2510 /* =========================================================================== 2511 * Send a literal or distance tree in compressed form, using the codes in 2512 * bl_tree. 2513 * 2514 * Parameters: 2515 * tree: the tree to be scanned 2516 * max_code: and its largest code of non zero frequency 2517 */ 2518 local void 2519 send_tree(deflate_state *s, ct_data *tree, int max_code) 2520 { 2521 int n; /* iterates over all tree elements */ 2522 int prevlen = -1; /* last emitted length */ 2523 int curlen; /* length of current code */ 2524 int nextlen = tree[0].Len; /* length of next code */ 2525 int count = 0; /* repeat count of the current code */ 2526 int max_count = 7; /* max repeat count */ 2527 int min_count = 4; /* min repeat count */ 2528 2529 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2530 if (nextlen == 0) max_count = 138, min_count = 3; 2531 2532 for (n = 0; n <= max_code; n++) { 2533 curlen = nextlen; nextlen = tree[n+1].Len; 2534 if (++count < max_count && curlen == nextlen) { 2535 continue; 2536 } else if (count < min_count) { 2537 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2538 2539 } else if (curlen != 0) { 2540 if (curlen != prevlen) { 2541 send_code(s, curlen, s->bl_tree); count--; 2542 } 2543 Assert(count >= 3 && count <= 6, " 3_6?"); 2544 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2545 2546 } else if (count <= 10) { 2547 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2548 2549 } else { 2550 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2551 } 2552 count = 0; prevlen = curlen; 2553 if (nextlen == 0) { 2554 max_count = 138, min_count = 3; 2555 } else if (curlen == nextlen) { 2556 max_count = 6, min_count = 3; 2557 } else { 2558 max_count = 7, min_count = 4; 2559 } 2560 } 2561 } 2562 2563 /* =========================================================================== 2564 * Construct the Huffman tree for the bit lengths and return the index in 2565 * bl_order of the last bit length code to send. 2566 */ 2567 local int 2568 build_bl_tree(deflate_state *s) 2569 { 2570 int max_blindex; /* index of last bit length code of non zero freq */ 2571 2572 /* Determine the bit length frequencies for literal and distance trees */ 2573 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2574 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2575 2576 /* Build the bit length tree: */ 2577 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2578 /* opt_len now includes the length of the tree representations, except 2579 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2580 */ 2581 2582 /* Determine the number of bit length codes to send. The pkzip format 2583 * requires that at least 4 bit length codes be sent. (appnote.txt says 2584 * 3 but the actual value used is 4.) 2585 */ 2586 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2587 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2588 } 2589 /* Update opt_len to include the bit length tree and counts */ 2590 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2591 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2592 s->opt_len, s->static_len)); 2593 2594 return max_blindex; 2595 } 2596 2597 /* =========================================================================== 2598 * Send the header for a block using dynamic Huffman trees: the counts, the 2599 * lengths of the bit length codes, the literal tree and the distance tree. 2600 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2601 * 2602 * Parameters: 2603 * lcodes, dcodes, blcodes: number of codes for each tree 2604 */ 2605 local void 2606 send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes) 2607 { 2608 int rank; /* index in bl_order */ 2609 2610 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2611 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2612 "too many codes"); 2613 Tracev((stderr, "\nbl counts: ")); 2614 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2615 send_bits(s, dcodes-1, 5); 2616 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2617 for (rank = 0; rank < blcodes; rank++) { 2618 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2619 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2620 } 2621 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2622 2623 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2624 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2625 2626 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2627 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2628 } 2629 2630 /* =========================================================================== 2631 * Send a stored block 2632 * 2633 * Parameters: 2634 * buf: input block 2635 * stored_len: length of input block 2636 * eof: true if this is the last block for a file 2637 */ 2638 void 2639 _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof) 2640 { 2641 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2642 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; 2643 s->compressed_len += (stored_len + 4) << 3; 2644 2645 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2646 } 2647 2648 /* Send just the `stored block' type code without any length bytes or data. 2649 */ 2650 void 2651 _tr_stored_type_only(deflate_state *s) 2652 { 2653 send_bits(s, (STORED_BLOCK << 1), 3); 2654 bi_windup(s); 2655 s->compressed_len = (s->compressed_len + 3) & ~7L; 2656 } 2657 2658 2659 /* =========================================================================== 2660 * Send one empty static block to give enough lookahead for inflate. 2661 * This takes 10 bits, of which 7 may remain in the bit buffer. 2662 * The current inflate code requires 9 bits of lookahead. If the 2663 * last two codes for the previous block (real code plus EOB) were coded 2664 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode 2665 * the last real code. In this case we send two empty static blocks instead 2666 * of one. (There are no problems if the previous block is stored or fixed.) 2667 * To simplify the code, we assume the worst case of last real code encoded 2668 * on one bit only. 2669 */ 2670 void 2671 _tr_align(deflate_state *s) 2672 { 2673 send_bits(s, STATIC_TREES<<1, 3); 2674 send_code(s, END_BLOCK, static_ltree); 2675 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2676 bi_flush(s); 2677 /* Of the 10 bits for the empty block, we have already sent 2678 * (10 - bi_valid) bits. The lookahead for the last real code (before 2679 * the EOB of the previous block) was thus at least one plus the length 2680 * of the EOB plus what we have just sent of the empty static block. 2681 */ 2682 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { 2683 send_bits(s, STATIC_TREES<<1, 3); 2684 send_code(s, END_BLOCK, static_ltree); 2685 s->compressed_len += 10L; 2686 bi_flush(s); 2687 } 2688 s->last_eob_len = 7; 2689 } 2690 2691 /* =========================================================================== 2692 * Determine the best encoding for the current block: dynamic trees, static 2693 * trees or store, and output the encoded block to the zip file. This function 2694 * returns the total compressed length for the file so far. 2695 * 2696 * Parameters: 2697 * buf: input block, or NULL if too old 2698 * stored_len: length of input block 2699 * eof: true if this is the last block for a file 2700 */ 2701 ulg 2702 _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) 2703 { 2704 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2705 int max_blindex = 0; /* index of last bit length code of non zero freq */ 2706 2707 /* Build the Huffman trees unless a stored block is forced */ 2708 if (s->level > 0) { 2709 2710 /* Check if the file is ascii or binary */ 2711 if (s->data_type == Z_UNKNOWN) set_data_type(s); 2712 2713 /* Construct the literal and distance trees */ 2714 build_tree(s, (tree_desc *)(&(s->l_desc))); 2715 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2716 s->static_len)); 2717 2718 build_tree(s, (tree_desc *)(&(s->d_desc))); 2719 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2720 s->static_len)); 2721 /* At this point, opt_len and static_len are the total bit lengths of 2722 * the compressed block data, excluding the tree representations. 2723 */ 2724 2725 /* Build the bit length tree for the above two trees, and get the index 2726 * in bl_order of the last bit length code to send. 2727 */ 2728 max_blindex = build_bl_tree(s); 2729 2730 /* Determine the best encoding. Compute first the block length in bytes*/ 2731 opt_lenb = (s->opt_len+3+7)>>3; 2732 static_lenb = (s->static_len+3+7)>>3; 2733 2734 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2735 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2736 s->last_lit)); 2737 2738 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2739 2740 } else { 2741 Assert(buf != NULL, "lost buf"); 2742 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 2743 } 2744 2745 /* If compression failed and this is the first and last block, 2746 * and if the .zip file can be seeked (to rewrite the local header), 2747 * the whole file is transformed into a stored file: 2748 */ 2749 #ifdef STORED_FILE_OK 2750 # ifdef FORCE_STORED_FILE 2751 if (eof && s->compressed_len == 0L) { /* force stored file */ 2752 # else 2753 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { 2754 # endif 2755 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2756 if (buf == NULL) error ("block vanished"); 2757 2758 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ 2759 s->compressed_len = stored_len << 3; 2760 s->method = STORED; 2761 } else 2762 #endif /* STORED_FILE_OK */ 2763 2764 #ifdef FORCE_STORED 2765 if (buf != NULL) { /* force stored block */ 2766 #else 2767 if (stored_len+4 <= opt_lenb && buf != NULL) { 2768 /* 4: two words for the lengths */ 2769 #endif 2770 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2771 * Otherwise we can't have processed more than WSIZE input bytes since 2772 * the last block flush, because compression would have been 2773 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2774 * transform a block into a stored block. 2775 */ 2776 _tr_stored_block(s, buf, stored_len, eof); 2777 2778 #ifdef FORCE_STATIC 2779 } else if (static_lenb >= 0) { /* force static trees */ 2780 #else 2781 } else if (static_lenb == opt_lenb) { 2782 #endif 2783 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2784 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2785 s->compressed_len += 3 + s->static_len; 2786 } else { 2787 send_bits(s, (DYN_TREES<<1)+eof, 3); 2788 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2789 max_blindex+1); 2790 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2791 s->compressed_len += 3 + s->opt_len; 2792 } 2793 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2794 init_block(s); 2795 2796 if (eof) { 2797 bi_windup(s); 2798 s->compressed_len += 7; /* align on byte boundary */ 2799 } 2800 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2801 s->compressed_len-7*eof)); 2802 2803 return s->compressed_len >> 3; 2804 } 2805 2806 /* =========================================================================== 2807 * Save the match info and tally the frequency counts. Return true if 2808 * the current block must be flushed. 2809 * 2810 * Parameters: 2811 * dist: distance of matched string 2812 * lc: match length-MIN_MATCH or unmatched char (if dist==0) 2813 */ 2814 int 2815 _tr_tally(deflate_state *s, unsigned dist, unsigned lc) 2816 { 2817 s->d_buf[s->last_lit] = (ush)dist; 2818 s->l_buf[s->last_lit++] = (uch)lc; 2819 if (dist == 0) { 2820 /* lc is the unmatched char */ 2821 s->dyn_ltree[lc].Freq++; 2822 } else { 2823 s->matches++; 2824 /* Here, lc is the match length - MIN_MATCH */ 2825 dist--; /* dist = match distance - 1 */ 2826 Assert((ush)dist < (ush)MAX_DIST(s) && 2827 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2828 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 2829 2830 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2831 s->dyn_dtree[d_code(dist)].Freq++; 2832 } 2833 2834 /* Try to guess if it is profitable to stop the current block here */ 2835 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2836 /* Compute an upper bound for the compressed length */ 2837 ulg out_length = (ulg)s->last_lit*8L; 2838 ulg in_length = (ulg)((long)s->strstart - s->block_start); 2839 int dcode; 2840 for (dcode = 0; dcode < D_CODES; dcode++) { 2841 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2842 (5L+extra_dbits[dcode]); 2843 } 2844 out_length >>= 3; 2845 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2846 s->last_lit, in_length, out_length, 2847 100L - out_length*100L/in_length)); 2848 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2849 } 2850 return (s->last_lit == s->lit_bufsize-1); 2851 /* We avoid equality with lit_bufsize because of wraparound at 64K 2852 * on 16 bit machines and because stored blocks are restricted to 2853 * 64K-1 bytes. 2854 */ 2855 } 2856 2857 /* =========================================================================== 2858 * Send the block data compressed using the given Huffman trees 2859 * 2860 * Parameters: 2861 * ltree: literal tree 2862 * dtree: distance tree 2863 */ 2864 local void 2865 compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) 2866 { 2867 unsigned dist; /* distance of matched string */ 2868 int lc; /* match length or unmatched char (if dist == 0) */ 2869 unsigned lx = 0; /* running index in l_buf */ 2870 unsigned code; /* the code to send */ 2871 int extra; /* number of extra bits to send */ 2872 2873 if (s->last_lit != 0) do { 2874 dist = s->d_buf[lx]; 2875 lc = s->l_buf[lx++]; 2876 if (dist == 0) { 2877 send_code(s, lc, ltree); /* send a literal byte */ 2878 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2879 } else { 2880 /* Here, lc is the match length - MIN_MATCH */ 2881 code = length_code[lc]; 2882 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2883 extra = extra_lbits[code]; 2884 if (extra != 0) { 2885 lc -= base_length[code]; 2886 send_bits(s, lc, extra); /* send the extra length bits */ 2887 } 2888 dist--; /* dist is now the match distance - 1 */ 2889 code = d_code(dist); 2890 Assert (code < D_CODES, "bad d_code"); 2891 2892 send_code(s, code, dtree); /* send the distance code */ 2893 extra = extra_dbits[code]; 2894 if (extra != 0) { 2895 dist -= base_dist[code]; 2896 send_bits(s, dist, extra); /* send the extra distance bits */ 2897 } 2898 } /* literal or match pair ? */ 2899 2900 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2901 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2902 2903 } while (lx < s->last_lit); 2904 2905 send_code(s, END_BLOCK, ltree); 2906 s->last_eob_len = ltree[END_BLOCK].Len; 2907 } 2908 2909 /* =========================================================================== 2910 * Set the data type to ASCII or BINARY, using a crude approximation: 2911 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2912 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2913 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2914 */ 2915 local void 2916 set_data_type(deflate_state *s) 2917 { 2918 int n = 0; 2919 unsigned ascii_freq = 0; 2920 unsigned bin_freq = 0; 2921 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2922 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2923 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2924 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 2925 } 2926 2927 /* =========================================================================== 2928 * Reverse the first len bits of a code, using straightforward code (a faster 2929 * method would use a table) 2930 * IN assertion: 1 <= len <= 15 2931 * 2932 * Parameters: 2933 * code: the value to invert 2934 * len: its bit length 2935 */ 2936 local unsigned 2937 bi_reverse(unsigned code, int len) 2938 { 2939 unsigned res = 0; 2940 do { 2941 res |= code & 1; 2942 code >>= 1, res <<= 1; 2943 } while (--len > 0); 2944 return res >> 1; 2945 } 2946 2947 /* =========================================================================== 2948 * Flush the bit buffer, keeping at most 7 bits in it. 2949 */ 2950 local void 2951 bi_flush(deflate_state *s) 2952 { 2953 if (s->bi_valid == 16) { 2954 put_short(s, s->bi_buf); 2955 s->bi_buf = 0; 2956 s->bi_valid = 0; 2957 } else if (s->bi_valid >= 8) { 2958 put_byte(s, (Byte)s->bi_buf); 2959 s->bi_buf >>= 8; 2960 s->bi_valid -= 8; 2961 } 2962 } 2963 2964 /* =========================================================================== 2965 * Flush the bit buffer and align the output on a byte boundary 2966 */ 2967 local void 2968 bi_windup(deflate_state *s) 2969 { 2970 if (s->bi_valid > 8) { 2971 put_short(s, s->bi_buf); 2972 } else if (s->bi_valid > 0) { 2973 put_byte(s, (Byte)s->bi_buf); 2974 } 2975 s->bi_buf = 0; 2976 s->bi_valid = 0; 2977 #ifdef DEBUG_ZLIB 2978 s->bits_sent = (s->bits_sent+7) & ~7; 2979 #endif 2980 } 2981 2982 /* =========================================================================== 2983 * Copy a stored block, storing first the length and its 2984 * one's complement if requested. 2985 * 2986 * Parameters: 2987 * buf: the input data 2988 * len: its length 2989 * header: true if block header must be written 2990 */ 2991 local void 2992 copy_block(deflate_state *s, charf *buf, unsigned len, int header) 2993 { 2994 bi_windup(s); /* align on byte boundary */ 2995 s->last_eob_len = 8; /* enough lookahead for inflate */ 2996 2997 if (header) { 2998 put_short(s, (ush)len); 2999 put_short(s, (ush)~len); 3000 #ifdef DEBUG_ZLIB 3001 s->bits_sent += 2*16; 3002 #endif 3003 } 3004 #ifdef DEBUG_ZLIB 3005 s->bits_sent += (ulg)len<<3; 3006 #endif 3007 /* bundle up the put_byte(s, *buf++) calls */ 3008 zmemcpy(&s->pending_buf[s->pending], buf, len); 3009 s->pending += len; 3010 } 3011 /* --- trees.c */ 3012 3013 /* +++ inflate.c */ 3014 /* inflate.c -- zlib interface to inflate modules 3015 * Copyright (C) 1995-1996 Mark Adler 3016 * For conditions of distribution and use, see copyright notice in zlib.h 3017 */ 3018 3019 /* #include "zutil.h" */ 3020 3021 /* +++ infblock.h */ 3022 /* infblock.h -- header to use infblock.c 3023 * Copyright (C) 1995-1996 Mark Adler 3024 * For conditions of distribution and use, see copyright notice in zlib.h 3025 */ 3026 3027 /* WARNING: this file should *not* be used by applications. It is 3028 part of the implementation of the compression library and is 3029 subject to change. Applications should only use zlib.h. 3030 */ 3031 3032 struct inflate_blocks_state; 3033 typedef struct inflate_blocks_state FAR inflate_blocks_statef; 3034 3035 extern inflate_blocks_statef * inflate_blocks_new OF(( 3036 z_streamp z, 3037 check_func c, /* check function */ 3038 uInt w)); /* window size */ 3039 3040 extern int inflate_blocks OF(( 3041 inflate_blocks_statef *, 3042 z_streamp , 3043 int)); /* initial return code */ 3044 3045 extern void inflate_blocks_reset OF(( 3046 inflate_blocks_statef *, 3047 z_streamp , 3048 uLongf *)); /* check value on output */ 3049 3050 extern int inflate_blocks_free OF(( 3051 inflate_blocks_statef *, 3052 z_streamp , 3053 uLongf *)); /* check value on output */ 3054 3055 extern void inflate_set_dictionary OF(( 3056 inflate_blocks_statef *s, 3057 const Bytef *d, /* dictionary */ 3058 uInt n)); /* dictionary length */ 3059 3060 extern int inflate_addhistory OF(( 3061 inflate_blocks_statef *, 3062 z_streamp)); 3063 3064 extern int inflate_packet_flush OF(( 3065 inflate_blocks_statef *)); 3066 /* --- infblock.h */ 3067 3068 #ifndef NO_DUMMY_DECL 3069 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ 3070 #endif 3071 3072 /* inflate private state */ 3073 struct internal_state { 3074 3075 /* mode */ 3076 enum { 3077 METHOD, /* waiting for method byte */ 3078 FLAG, /* waiting for flag byte */ 3079 DICT4, /* four dictionary check bytes to go */ 3080 DICT3, /* three dictionary check bytes to go */ 3081 DICT2, /* two dictionary check bytes to go */ 3082 DICT1, /* one dictionary check byte to go */ 3083 DICT0, /* waiting for inflateSetDictionary */ 3084 BLOCKS, /* decompressing blocks */ 3085 CHECK4, /* four check bytes to go */ 3086 CHECK3, /* three check bytes to go */ 3087 CHECK2, /* two check bytes to go */ 3088 CHECK1, /* one check byte to go */ 3089 DONE, /* finished check, done */ 3090 BAD} /* got an error--stay here */ 3091 mode; /* current inflate mode */ 3092 3093 /* mode dependent information */ 3094 union { 3095 uInt method; /* if FLAGS, method byte */ 3096 struct { 3097 uLong was; /* computed check value */ 3098 uLong need; /* stream check value */ 3099 } check; /* if CHECK, check values to compare */ 3100 uInt marker; /* if BAD, inflateSync's marker bytes count */ 3101 } sub; /* submode */ 3102 3103 /* mode independent information */ 3104 int nowrap; /* flag for no wrapper */ 3105 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 3106 inflate_blocks_statef 3107 *blocks; /* current inflate_blocks state */ 3108 3109 }; 3110 3111 3112 int 3113 inflateReset(z_streamp z) 3114 { 3115 uLong c; 3116 3117 if (z == Z_NULL || z->state == Z_NULL) 3118 return Z_STREAM_ERROR; 3119 z->total_in = z->total_out = 0; 3120 z->msg = Z_NULL; 3121 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 3122 inflate_blocks_reset(z->state->blocks, z, &c); 3123 Trace((stderr, "inflate: reset\n")); 3124 return Z_OK; 3125 } 3126 3127 3128 int 3129 inflateEnd(z_streamp z) 3130 { 3131 uLong c; 3132 3133 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 3134 return Z_STREAM_ERROR; 3135 if (z->state->blocks != Z_NULL) 3136 inflate_blocks_free(z->state->blocks, z, &c); 3137 ZFREE(z, z->state); 3138 z->state = Z_NULL; 3139 Trace((stderr, "inflate: end\n")); 3140 return Z_OK; 3141 } 3142 3143 3144 int 3145 inflateInit2_(z_streamp z, int w, const char *version, int stream_size) 3146 { 3147 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || 3148 stream_size != sizeof(z_stream)) 3149 return Z_VERSION_ERROR; 3150 3151 /* initialize state */ 3152 if (z == Z_NULL) 3153 return Z_STREAM_ERROR; 3154 z->msg = Z_NULL; 3155 #ifndef NO_ZCFUNCS 3156 if (z->zalloc == Z_NULL) 3157 { 3158 z->zalloc = zcalloc; 3159 z->opaque = (voidpf)0; 3160 } 3161 if (z->zfree == Z_NULL) z->zfree = zcfree; 3162 #endif 3163 if ((z->state = (struct internal_state FAR *) 3164 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 3165 return Z_MEM_ERROR; 3166 z->state->blocks = Z_NULL; 3167 3168 /* handle undocumented nowrap option (no zlib header or check) */ 3169 z->state->nowrap = 0; 3170 if (w < 0) 3171 { 3172 w = - w; 3173 z->state->nowrap = 1; 3174 } 3175 3176 /* set window size */ 3177 if (w < 8 || w > 15) 3178 { 3179 inflateEnd(z); 3180 return Z_STREAM_ERROR; 3181 } 3182 z->state->wbits = (uInt)w; 3183 3184 /* create inflate_blocks state */ 3185 if ((z->state->blocks = 3186 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) 3187 == Z_NULL) 3188 { 3189 inflateEnd(z); 3190 return Z_MEM_ERROR; 3191 } 3192 Trace((stderr, "inflate: allocated\n")); 3193 3194 /* reset state */ 3195 inflateReset(z); 3196 return Z_OK; 3197 } 3198 3199 3200 int 3201 inflateInit_(z_streamp z, const char *version, int stream_size) 3202 { 3203 return inflateInit2_(z, DEF_WBITS, version, stream_size); 3204 } 3205 3206 3207 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 3208 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 3209 3210 int 3211 inflate(z_streamp z, int f) 3212 { 3213 int r; 3214 uInt b; 3215 3216 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) 3217 return Z_STREAM_ERROR; 3218 r = Z_BUF_ERROR; 3219 while (1) switch (z->state->mode) 3220 { 3221 case METHOD: 3222 NEEDBYTE 3223 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) 3224 { 3225 z->state->mode = BAD; 3226 z->msg = (char*)"unknown compression method"; 3227 z->state->sub.marker = 5; /* can't try inflateSync */ 3228 break; 3229 } 3230 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 3231 { 3232 z->state->mode = BAD; 3233 z->msg = (char*)"invalid window size"; 3234 z->state->sub.marker = 5; /* can't try inflateSync */ 3235 break; 3236 } 3237 z->state->mode = FLAG; 3238 case FLAG: 3239 NEEDBYTE 3240 b = NEXTBYTE; 3241 if (((z->state->sub.method << 8) + b) % 31) 3242 { 3243 z->state->mode = BAD; 3244 z->msg = (char*)"incorrect header check"; 3245 z->state->sub.marker = 5; /* can't try inflateSync */ 3246 break; 3247 } 3248 Trace((stderr, "inflate: zlib header ok\n")); 3249 if (!(b & PRESET_DICT)) 3250 { 3251 z->state->mode = BLOCKS; 3252 break; 3253 } 3254 z->state->mode = DICT4; 3255 case DICT4: 3256 NEEDBYTE 3257 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3258 z->state->mode = DICT3; 3259 case DICT3: 3260 NEEDBYTE 3261 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3262 z->state->mode = DICT2; 3263 case DICT2: 3264 NEEDBYTE 3265 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3266 z->state->mode = DICT1; 3267 case DICT1: 3268 NEEDBYTE 3269 z->state->sub.check.need += (uLong)NEXTBYTE; 3270 z->adler = z->state->sub.check.need; 3271 z->state->mode = DICT0; 3272 return Z_NEED_DICT; 3273 case DICT0: 3274 z->state->mode = BAD; 3275 z->msg = (char*)"need dictionary"; 3276 z->state->sub.marker = 0; /* can try inflateSync */ 3277 return Z_STREAM_ERROR; 3278 case BLOCKS: 3279 r = inflate_blocks(z->state->blocks, z, r); 3280 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 3281 r = inflate_packet_flush(z->state->blocks); 3282 if (r == Z_DATA_ERROR) 3283 { 3284 z->state->mode = BAD; 3285 z->state->sub.marker = 0; /* can try inflateSync */ 3286 break; 3287 } 3288 if (r != Z_STREAM_END) 3289 return r; 3290 r = Z_OK; 3291 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 3292 if (z->state->nowrap) 3293 { 3294 z->state->mode = DONE; 3295 break; 3296 } 3297 z->state->mode = CHECK4; 3298 case CHECK4: 3299 NEEDBYTE 3300 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3301 z->state->mode = CHECK3; 3302 case CHECK3: 3303 NEEDBYTE 3304 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3305 z->state->mode = CHECK2; 3306 case CHECK2: 3307 NEEDBYTE 3308 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3309 z->state->mode = CHECK1; 3310 case CHECK1: 3311 NEEDBYTE 3312 z->state->sub.check.need += (uLong)NEXTBYTE; 3313 3314 if (z->state->sub.check.was != z->state->sub.check.need) 3315 { 3316 z->state->mode = BAD; 3317 z->msg = (char*)"incorrect data check"; 3318 z->state->sub.marker = 5; /* can't try inflateSync */ 3319 break; 3320 } 3321 Trace((stderr, "inflate: zlib check ok\n")); 3322 z->state->mode = DONE; 3323 case DONE: 3324 return Z_STREAM_END; 3325 case BAD: 3326 return Z_DATA_ERROR; 3327 default: 3328 return Z_STREAM_ERROR; 3329 } 3330 3331 empty: 3332 if (f != Z_PACKET_FLUSH) 3333 return r; 3334 z->state->mode = BAD; 3335 z->msg = (char *)"need more for packet flush"; 3336 z->state->sub.marker = 0; /* can try inflateSync */ 3337 return Z_DATA_ERROR; 3338 } 3339 3340 3341 int 3342 inflateSetDictionary(z_streamp z, const Bytef *dictionary, uInt dictLength) 3343 { 3344 uInt length = dictLength; 3345 3346 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) 3347 return Z_STREAM_ERROR; 3348 3349 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; 3350 z->adler = 1L; 3351 3352 if (length >= ((uInt)1<<z->state->wbits)) 3353 { 3354 length = (1<<z->state->wbits)-1; 3355 dictionary += dictLength - length; 3356 } 3357 inflate_set_dictionary(z->state->blocks, dictionary, length); 3358 z->state->mode = BLOCKS; 3359 return Z_OK; 3360 } 3361 3362 /* 3363 * This subroutine adds the data at next_in/avail_in to the output history 3364 * without performing any output. The output buffer must be "caught up"; 3365 * i.e. no pending output (hence s->read equals s->write), and the state must 3366 * be BLOCKS (i.e. we should be willing to see the start of a series of 3367 * BLOCKS). On exit, the output will also be caught up, and the checksum 3368 * will have been updated if need be. 3369 */ 3370 3371 int 3372 inflateIncomp(z_stream *z) 3373 { 3374 if (z->state->mode != BLOCKS) 3375 return Z_DATA_ERROR; 3376 return inflate_addhistory(z->state->blocks, z); 3377 } 3378 3379 3380 int 3381 inflateSync(z_streamp z) 3382 { 3383 uInt n; /* number of bytes to look at */ 3384 Bytef *p; /* pointer to bytes */ 3385 uInt m; /* number of marker bytes found in a row */ 3386 uLong r, w; /* temporaries to save total_in and total_out */ 3387 3388 /* set up */ 3389 if (z == Z_NULL || z->state == Z_NULL) 3390 return Z_STREAM_ERROR; 3391 if (z->state->mode != BAD) 3392 { 3393 z->state->mode = BAD; 3394 z->state->sub.marker = 0; 3395 } 3396 if ((n = z->avail_in) == 0) 3397 return Z_BUF_ERROR; 3398 p = z->next_in; 3399 m = z->state->sub.marker; 3400 3401 /* search */ 3402 while (n && m < 4) 3403 { 3404 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3405 m++; 3406 else if (*p) 3407 m = 0; 3408 else 3409 m = 4 - m; 3410 p++, n--; 3411 } 3412 3413 /* restore */ 3414 z->total_in += p - z->next_in; 3415 z->next_in = p; 3416 z->avail_in = n; 3417 z->state->sub.marker = m; 3418 3419 /* return no joy or set up to restart on a new block */ 3420 if (m != 4) 3421 return Z_DATA_ERROR; 3422 r = z->total_in; w = z->total_out; 3423 inflateReset(z); 3424 z->total_in = r; z->total_out = w; 3425 z->state->mode = BLOCKS; 3426 return Z_OK; 3427 } 3428 3429 #undef NEEDBYTE 3430 #undef NEXTBYTE 3431 /* --- inflate.c */ 3432 3433 /* +++ infblock.c */ 3434 /* infblock.c -- interpret and process block types to last block 3435 * Copyright (C) 1995-1996 Mark Adler 3436 * For conditions of distribution and use, see copyright notice in zlib.h 3437 */ 3438 3439 /* #include "zutil.h" */ 3440 /* #include "infblock.h" */ 3441 3442 /* +++ inftrees.h */ 3443 /* inftrees.h -- header to use inftrees.c 3444 * Copyright (C) 1995-1996 Mark Adler 3445 * For conditions of distribution and use, see copyright notice in zlib.h 3446 */ 3447 3448 /* WARNING: this file should *not* be used by applications. It is 3449 part of the implementation of the compression library and is 3450 subject to change. Applications should only use zlib.h. 3451 */ 3452 3453 /* Huffman code lookup table entry--this entry is four bytes for machines 3454 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 3455 3456 typedef struct inflate_huft_s FAR inflate_huft; 3457 3458 struct inflate_huft_s { 3459 union { 3460 struct { 3461 Byte Exop; /* number of extra bits or operation */ 3462 Byte Bits; /* number of bits in this code or subcode */ 3463 } what; 3464 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 3465 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 3466 union { 3467 uInt Base; /* literal, length base, or distance base */ 3468 inflate_huft *Next; /* pointer to next level of table */ 3469 } more; 3470 }; 3471 3472 #ifdef DEBUG_ZLIB 3473 extern uInt inflate_hufts; 3474 #endif 3475 3476 extern int inflate_trees_bits OF(( 3477 uIntf *, /* 19 code lengths */ 3478 uIntf *, /* bits tree desired/actual depth */ 3479 inflate_huft * FAR *, /* bits tree result */ 3480 z_streamp )); /* for zalloc, zfree functions */ 3481 3482 extern int inflate_trees_dynamic OF(( 3483 uInt, /* number of literal/length codes */ 3484 uInt, /* number of distance codes */ 3485 uIntf *, /* that many (total) code lengths */ 3486 uIntf *, /* literal desired/actual bit depth */ 3487 uIntf *, /* distance desired/actual bit depth */ 3488 inflate_huft * FAR *, /* literal/length tree result */ 3489 inflate_huft * FAR *, /* distance tree result */ 3490 z_streamp )); /* for zalloc, zfree functions */ 3491 3492 extern int inflate_trees_fixed OF(( 3493 uIntf *, /* literal desired/actual bit depth */ 3494 uIntf *, /* distance desired/actual bit depth */ 3495 inflate_huft * FAR *, /* literal/length tree result */ 3496 inflate_huft * FAR *)); /* distance tree result */ 3497 3498 extern int inflate_trees_free OF(( 3499 inflate_huft *, /* tables to free */ 3500 z_streamp )); /* for zfree function */ 3501 3502 /* --- inftrees.h */ 3503 3504 /* +++ infcodes.h */ 3505 /* infcodes.h -- header to use infcodes.c 3506 * Copyright (C) 1995-1996 Mark Adler 3507 * For conditions of distribution and use, see copyright notice in zlib.h 3508 */ 3509 3510 /* WARNING: this file should *not* be used by applications. It is 3511 part of the implementation of the compression library and is 3512 subject to change. Applications should only use zlib.h. 3513 */ 3514 3515 struct inflate_codes_state; 3516 typedef struct inflate_codes_state FAR inflate_codes_statef; 3517 3518 extern inflate_codes_statef *inflate_codes_new OF(( 3519 uInt, uInt, 3520 inflate_huft *, inflate_huft *, 3521 z_streamp )); 3522 3523 extern int inflate_codes OF(( 3524 inflate_blocks_statef *, 3525 z_streamp , 3526 int)); 3527 3528 extern void inflate_codes_free OF(( 3529 inflate_codes_statef *, 3530 z_streamp )); 3531 3532 /* --- infcodes.h */ 3533 3534 /* +++ infutil.h */ 3535 /* infutil.h -- types and macros common to blocks and codes 3536 * Copyright (C) 1995-1996 Mark Adler 3537 * For conditions of distribution and use, see copyright notice in zlib.h 3538 */ 3539 3540 /* WARNING: this file should *not* be used by applications. It is 3541 part of the implementation of the compression library and is 3542 subject to change. Applications should only use zlib.h. 3543 */ 3544 3545 #ifndef _INFUTIL_H 3546 #define _INFUTIL_H 3547 3548 typedef enum { 3549 TYPE, /* get type bits (3, including end bit) */ 3550 LENS, /* get lengths for stored */ 3551 STORED, /* processing stored block */ 3552 TABLE, /* get table lengths */ 3553 BTREE, /* get bit lengths tree for a dynamic block */ 3554 DTREE, /* get length, distance trees for a dynamic block */ 3555 CODES, /* processing fixed or dynamic block */ 3556 DRY, /* output remaining window bytes */ 3557 DONEB, /* finished last block, done */ 3558 BADB} /* got a data error--stuck here */ 3559 inflate_block_mode; 3560 3561 /* inflate blocks semi-private state */ 3562 struct inflate_blocks_state { 3563 3564 /* mode */ 3565 inflate_block_mode mode; /* current inflate_block mode */ 3566 3567 /* mode dependent information */ 3568 union { 3569 uInt left; /* if STORED, bytes left to copy */ 3570 struct { 3571 uInt table; /* table lengths (14 bits) */ 3572 uInt index; /* index into blens (or border) */ 3573 uIntf *blens; /* bit lengths of codes */ 3574 uInt bb; /* bit length tree depth */ 3575 inflate_huft *tb; /* bit length decoding tree */ 3576 } trees; /* if DTREE, decoding info for trees */ 3577 struct { 3578 inflate_huft *tl; 3579 inflate_huft *td; /* trees to free */ 3580 inflate_codes_statef 3581 *codes; 3582 } decode; /* if CODES, current state */ 3583 } sub; /* submode */ 3584 uInt last; /* true if this block is the last block */ 3585 3586 /* mode independent information */ 3587 uInt bitk; /* bits in bit buffer */ 3588 uLong bitb; /* bit buffer */ 3589 Bytef *window; /* sliding window */ 3590 Bytef *end; /* one byte after sliding window */ 3591 Bytef *read; /* window read pointer */ 3592 Bytef *write; /* window write pointer */ 3593 check_func checkfn; /* check function */ 3594 uLong check; /* check on output */ 3595 3596 }; 3597 3598 3599 /* defines for inflate input/output */ 3600 /* update pointers and return */ 3601 #define UPDBITS {s->bitb=b;s->bitk=k;} 3602 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3603 #define UPDOUT {s->write=q;} 3604 #define UPDATE {UPDBITS UPDIN UPDOUT} 3605 #define LEAVE {UPDATE return inflate_flush(s,z,r);} 3606 /* get bytes and bits */ 3607 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3608 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3609 #define NEXTBYTE (n--,*p++) 3610 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3611 #define DUMPBITS(j) {b>>=(j);k-=(j);} 3612 /* output bytes */ 3613 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) 3614 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} 3615 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} 3616 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3617 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} 3618 #define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3619 /* load local pointers */ 3620 #define LOAD {LOADIN LOADOUT} 3621 3622 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ 3623 extern uInt inflate_mask[17]; 3624 3625 /* copy as much as possible from the sliding window to the output area */ 3626 extern int inflate_flush OF(( 3627 inflate_blocks_statef *, 3628 z_streamp , 3629 int)); 3630 3631 #ifndef NO_DUMMY_DECL 3632 struct internal_state {int dummy;}; /* for buggy compilers */ 3633 #endif 3634 3635 #endif 3636 /* --- infutil.h */ 3637 3638 #ifndef NO_DUMMY_DECL 3639 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 3640 #endif 3641 3642 /* Table for deflate from PKZIP's appnote.txt. */ 3643 local const uInt border[] = { /* Order of the bit length code lengths */ 3644 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3645 3646 /* 3647 Notes beyond the 1.93a appnote.txt: 3648 3649 1. Distance pointers never point before the beginning of the output 3650 stream. 3651 2. Distance pointers can point back across blocks, up to 32k away. 3652 3. There is an implied maximum of 7 bits for the bit length table and 3653 15 bits for the actual data. 3654 4. If only one code exists, then it is encoded using one bit. (Zero 3655 would be more efficient, but perhaps a little confusing.) If two 3656 codes exist, they are coded using one bit each (0 and 1). 3657 5. There is no way of sending zero distance codes--a dummy must be 3658 sent if there are none. (History: a pre 2.0 version of PKZIP would 3659 store blocks with no distance codes, but this was discovered to be 3660 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3661 zero distance codes, which is sent as one code of zero bits in 3662 length. 3663 6. There are up to 286 literal/length codes. Code 256 represents the 3664 end-of-block. Note however that the static length tree defines 3665 288 codes just to fill out the Huffman codes. Codes 286 and 287 3666 cannot be used though, since there is no length base or extra bits 3667 defined for them. Similarily, there are up to 30 distance codes. 3668 However, static trees define 32 codes (all 5 bits) to fill out the 3669 Huffman codes, but the last two had better not show up in the data. 3670 7. Unzip can check dynamic Huffman blocks for complete code sets. 3671 The exception is that a single code would not be complete (see #4). 3672 8. The five bits following the block type is really the number of 3673 literal codes sent minus 257. 3674 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3675 (1+6+6). Therefore, to output three times the length, you output 3676 three codes (1+1+1), whereas to output four times the same length, 3677 you only need two codes (1+3). Hmm. 3678 10. In the tree reconstruction algorithm, Code = Code + Increment 3679 only if BitLength(i) is not zero. (Pretty obvious.) 3680 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3681 12. Note: length code 284 can represent 227-258, but length code 285 3682 really is 258. The last length deserves its own, short code 3683 since it gets used a lot in very redundant files. The length 3684 258 is special since 258 - 3 (the min match length) is 255. 3685 13. The literal/length and distance code bit lengths are read as a 3686 single stream of lengths. It is possible (and advantageous) for 3687 a repeat code (16, 17, or 18) to go across the boundary between 3688 the two sets of lengths. 3689 */ 3690 3691 3692 void 3693 inflate_blocks_reset(inflate_blocks_statef *s, z_streamp z, uLongf *c) 3694 { 3695 if (s->checkfn != Z_NULL) 3696 *c = s->check; 3697 if (s->mode == BTREE || s->mode == DTREE) 3698 ZFREE(z, s->sub.trees.blens); 3699 if (s->mode == CODES) 3700 { 3701 inflate_codes_free(s->sub.decode.codes, z); 3702 inflate_trees_free(s->sub.decode.td, z); 3703 inflate_trees_free(s->sub.decode.tl, z); 3704 } 3705 s->mode = TYPE; 3706 s->bitk = 0; 3707 s->bitb = 0; 3708 s->read = s->write = s->window; 3709 if (s->checkfn != Z_NULL) 3710 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); 3711 Trace((stderr, "inflate: blocks reset\n")); 3712 } 3713 3714 3715 inflate_blocks_statef * 3716 inflate_blocks_new(z_streamp z, check_func c, uInt w) 3717 { 3718 inflate_blocks_statef *s; 3719 3720 if ((s = (inflate_blocks_statef *)ZALLOC 3721 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3722 return s; 3723 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3724 { 3725 ZFREE(z, s); 3726 return Z_NULL; 3727 } 3728 s->end = s->window + w; 3729 s->checkfn = c; 3730 s->mode = TYPE; 3731 Trace((stderr, "inflate: blocks allocated\n")); 3732 inflate_blocks_reset(s, z, &s->check); 3733 return s; 3734 } 3735 3736 3737 #ifdef DEBUG_ZLIB 3738 extern uInt inflate_hufts; 3739 #endif 3740 3741 int 3742 inflate_blocks(inflate_blocks_statef *s, z_streamp z, int r) 3743 { 3744 uInt t; /* temporary storage */ 3745 uLong b; /* bit buffer */ 3746 uInt k; /* bits in bit buffer */ 3747 Bytef *p; /* input data pointer */ 3748 uInt n; /* bytes available there */ 3749 Bytef *q; /* output window write pointer */ 3750 uInt m; /* bytes to end of window or read pointer */ 3751 3752 /* copy input/output information to locals (UPDATE macro restores) */ 3753 LOAD 3754 3755 /* process input based on current state */ 3756 while (1) switch (s->mode) 3757 { 3758 case TYPE: 3759 NEEDBITS(3) 3760 t = (uInt)b & 7; 3761 s->last = t & 1; 3762 switch (t >> 1) 3763 { 3764 case 0: /* stored */ 3765 Trace((stderr, "inflate: stored block%s\n", 3766 s->last ? " (last)" : "")); 3767 DUMPBITS(3) 3768 t = k & 7; /* go to byte boundary */ 3769 DUMPBITS(t) 3770 s->mode = LENS; /* get length of stored block */ 3771 break; 3772 case 1: /* fixed */ 3773 Trace((stderr, "inflate: fixed codes block%s\n", 3774 s->last ? " (last)" : "")); 3775 { 3776 uInt bl, bd; 3777 inflate_huft *tl, *td; 3778 3779 inflate_trees_fixed(&bl, &bd, &tl, &td); 3780 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3781 if (s->sub.decode.codes == Z_NULL) 3782 { 3783 r = Z_MEM_ERROR; 3784 LEAVE 3785 } 3786 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3787 s->sub.decode.td = Z_NULL; 3788 } 3789 DUMPBITS(3) 3790 s->mode = CODES; 3791 break; 3792 case 2: /* dynamic */ 3793 Trace((stderr, "inflate: dynamic codes block%s\n", 3794 s->last ? " (last)" : "")); 3795 DUMPBITS(3) 3796 s->mode = TABLE; 3797 break; 3798 case 3: /* illegal */ 3799 DUMPBITS(3) 3800 s->mode = BADB; 3801 z->msg = (char*)"invalid block type"; 3802 r = Z_DATA_ERROR; 3803 LEAVE 3804 } 3805 break; 3806 case LENS: 3807 NEEDBITS(32) 3808 if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) 3809 { 3810 s->mode = BADB; 3811 z->msg = (char*)"invalid stored block lengths"; 3812 r = Z_DATA_ERROR; 3813 LEAVE 3814 } 3815 s->sub.left = (uInt)b & 0xffff; 3816 b = k = 0; /* dump bits */ 3817 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3818 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); 3819 break; 3820 case STORED: 3821 if (n == 0) 3822 LEAVE 3823 NEEDOUT 3824 t = s->sub.left; 3825 if (t > n) t = n; 3826 if (t > m) t = m; 3827 zmemcpy(q, p, t); 3828 p += t; n -= t; 3829 q += t; m -= t; 3830 if ((s->sub.left -= t) != 0) 3831 break; 3832 Tracev((stderr, "inflate: stored end, %lu total out\n", 3833 z->total_out + (q >= s->read ? q - s->read : 3834 (s->end - s->read) + (q - s->window)))); 3835 s->mode = s->last ? DRY : TYPE; 3836 break; 3837 case TABLE: 3838 NEEDBITS(14) 3839 s->sub.trees.table = t = (uInt)b & 0x3fff; 3840 #ifndef PKZIP_BUG_WORKAROUND 3841 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3842 { 3843 s->mode = BADB; 3844 z->msg = (char*)"too many length or distance symbols"; 3845 r = Z_DATA_ERROR; 3846 LEAVE 3847 } 3848 #endif 3849 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3850 if (t < 19) 3851 t = 19; 3852 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3853 { 3854 r = Z_MEM_ERROR; 3855 LEAVE 3856 } 3857 DUMPBITS(14) 3858 s->sub.trees.index = 0; 3859 Tracev((stderr, "inflate: table sizes ok\n")); 3860 s->mode = BTREE; 3861 case BTREE: 3862 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3863 { 3864 NEEDBITS(3) 3865 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3866 DUMPBITS(3) 3867 } 3868 while (s->sub.trees.index < 19) 3869 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3870 s->sub.trees.bb = 7; 3871 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3872 &s->sub.trees.tb, z); 3873 if (t != Z_OK) 3874 { 3875 r = t; 3876 if (r == Z_DATA_ERROR) { 3877 ZFREE(z, s->sub.trees.blens); 3878 s->mode = BADB; 3879 } 3880 LEAVE 3881 } 3882 s->sub.trees.index = 0; 3883 Tracev((stderr, "inflate: bits tree ok\n")); 3884 s->mode = DTREE; 3885 case DTREE: 3886 while (t = s->sub.trees.table, 3887 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3888 { 3889 inflate_huft *h; 3890 uInt i, j, c; 3891 3892 t = s->sub.trees.bb; 3893 NEEDBITS(t) 3894 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3895 t = h->word.what.Bits; 3896 c = h->more.Base; 3897 if (c < 16) 3898 { 3899 DUMPBITS(t) 3900 s->sub.trees.blens[s->sub.trees.index++] = c; 3901 } 3902 else /* c == 16..18 */ 3903 { 3904 i = c == 18 ? 7 : c - 14; 3905 j = c == 18 ? 11 : 3; 3906 NEEDBITS(t + i) 3907 DUMPBITS(t) 3908 j += (uInt)b & inflate_mask[i]; 3909 DUMPBITS(i) 3910 i = s->sub.trees.index; 3911 t = s->sub.trees.table; 3912 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3913 (c == 16 && i < 1)) 3914 { 3915 inflate_trees_free(s->sub.trees.tb, z); 3916 ZFREE(z, s->sub.trees.blens); 3917 s->mode = BADB; 3918 z->msg = (char*)"invalid bit length repeat"; 3919 r = Z_DATA_ERROR; 3920 LEAVE 3921 } 3922 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3923 do { 3924 s->sub.trees.blens[i++] = c; 3925 } while (--j); 3926 s->sub.trees.index = i; 3927 } 3928 } 3929 inflate_trees_free(s->sub.trees.tb, z); 3930 s->sub.trees.tb = Z_NULL; 3931 { 3932 uInt bl, bd; 3933 inflate_huft *tl, *td; 3934 inflate_codes_statef *c; 3935 3936 bl = 9; /* must be <= 9 for lookahead assumptions */ 3937 bd = 6; /* must be <= 9 for lookahead assumptions */ 3938 t = s->sub.trees.table; 3939 #ifdef DEBUG_ZLIB 3940 inflate_hufts = 0; 3941 #endif 3942 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3943 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3944 if (t != Z_OK) 3945 { 3946 if (t == (uInt)Z_DATA_ERROR) { 3947 ZFREE(z, s->sub.trees.blens); 3948 s->mode = BADB; 3949 } 3950 r = t; 3951 LEAVE 3952 } 3953 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", 3954 inflate_hufts, sizeof(inflate_huft))); 3955 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3956 { 3957 inflate_trees_free(td, z); 3958 inflate_trees_free(tl, z); 3959 r = Z_MEM_ERROR; 3960 LEAVE 3961 } 3962 /* 3963 * this ZFREE must occur *BEFORE* we mess with sub.decode, because 3964 * sub.trees is union'd with sub.decode. 3965 */ 3966 ZFREE(z, s->sub.trees.blens); 3967 s->sub.decode.codes = c; 3968 s->sub.decode.tl = tl; 3969 s->sub.decode.td = td; 3970 } 3971 s->mode = CODES; 3972 case CODES: 3973 UPDATE 3974 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3975 return inflate_flush(s, z, r); 3976 r = Z_OK; 3977 inflate_codes_free(s->sub.decode.codes, z); 3978 inflate_trees_free(s->sub.decode.td, z); 3979 inflate_trees_free(s->sub.decode.tl, z); 3980 LOAD 3981 Tracev((stderr, "inflate: codes end, %lu total out\n", 3982 z->total_out + (q >= s->read ? q - s->read : 3983 (s->end - s->read) + (q - s->window)))); 3984 if (!s->last) 3985 { 3986 s->mode = TYPE; 3987 break; 3988 } 3989 if (k > 7) /* return unused byte, if any */ 3990 { 3991 Assert(k < 16, "inflate_codes grabbed too many bytes") 3992 k -= 8; 3993 n++; 3994 p--; /* can always return one */ 3995 } 3996 s->mode = DRY; 3997 case DRY: 3998 FLUSH 3999 if (s->read != s->write) 4000 LEAVE 4001 s->mode = DONEB; 4002 case DONEB: 4003 r = Z_STREAM_END; 4004 LEAVE 4005 case BADB: 4006 r = Z_DATA_ERROR; 4007 LEAVE 4008 default: 4009 r = Z_STREAM_ERROR; 4010 LEAVE 4011 } 4012 } 4013 4014 4015 int 4016 inflate_blocks_free(inflate_blocks_statef *s, z_streamp z, uLongf *c) 4017 { 4018 inflate_blocks_reset(s, z, c); 4019 ZFREE(z, s->window); 4020 ZFREE(z, s); 4021 Trace((stderr, "inflate: blocks freed\n")); 4022 return Z_OK; 4023 } 4024 4025 4026 void 4027 inflate_set_dictionary(inflate_blocks_statef *s, const Bytef *d, uInt n) 4028 { 4029 zmemcpy((charf *)s->window, d, n); 4030 s->read = s->write = s->window + n; 4031 } 4032 4033 /* 4034 * This subroutine adds the data at next_in/avail_in to the output history 4035 * without performing any output. The output buffer must be "caught up"; 4036 * i.e. no pending output (hence s->read equals s->write), and the state must 4037 * be BLOCKS (i.e. we should be willing to see the start of a series of 4038 * BLOCKS). On exit, the output will also be caught up, and the checksum 4039 * will have been updated if need be. 4040 */ 4041 int 4042 inflate_addhistory(inflate_blocks_statef *s, z_stream *z) 4043 { 4044 uLong b; /* bit buffer */ /* NOT USED HERE */ 4045 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 4046 uInt t; /* temporary storage */ 4047 Bytef *p; /* input data pointer */ 4048 uInt n; /* bytes available there */ 4049 Bytef *q; /* output window write pointer */ 4050 uInt m; /* bytes to end of window or read pointer */ 4051 4052 if (s->read != s->write) 4053 return Z_STREAM_ERROR; 4054 if (s->mode != TYPE) 4055 return Z_DATA_ERROR; 4056 4057 /* we're ready to rock */ 4058 LOAD 4059 /* while there is input ready, copy to output buffer, moving 4060 * pointers as needed. 4061 */ 4062 while (n) { 4063 t = n; /* how many to do */ 4064 /* is there room until end of buffer? */ 4065 if (t > m) t = m; 4066 /* update check information */ 4067 if (s->checkfn != Z_NULL) 4068 s->check = (*s->checkfn)(s->check, q, t); 4069 zmemcpy(q, p, t); 4070 q += t; 4071 p += t; 4072 n -= t; 4073 z->total_out += t; 4074 s->read = q; /* drag read pointer forward */ 4075 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */ 4076 if (q == s->end) { 4077 s->read = q = s->window; 4078 m = WAVAIL; 4079 } 4080 } 4081 UPDATE 4082 return Z_OK; 4083 } 4084 4085 4086 /* 4087 * At the end of a Deflate-compressed PPP packet, we expect to have seen 4088 * a `stored' block type value but not the (zero) length bytes. 4089 */ 4090 int 4091 inflate_packet_flush(inflate_blocks_statef *s) 4092 { 4093 if (s->mode != LENS) 4094 return Z_DATA_ERROR; 4095 s->mode = TYPE; 4096 return Z_OK; 4097 } 4098 /* --- infblock.c */ 4099 4100 /* +++ inftrees.c */ 4101 /* inftrees.c -- generate Huffman trees for efficient decoding 4102 * Copyright (C) 1995-1996 Mark Adler 4103 * For conditions of distribution and use, see copyright notice in zlib.h 4104 */ 4105 4106 /* #include "zutil.h" */ 4107 /* #include "inftrees.h" */ 4108 4109 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler "; 4110 /* 4111 If you use the zlib library in a product, an acknowledgment is welcome 4112 in the documentation of your product. If for some reason you cannot 4113 include such an acknowledgment, I would appreciate that you keep this 4114 copyright string in the executable of your product. 4115 */ 4116 4117 #ifndef NO_DUMMY_DECL 4118 struct internal_state {int dummy;}; /* for buggy compilers */ 4119 #endif 4120 4121 /* simplify the use of the inflate_huft type with some defines */ 4122 #define base more.Base 4123 #define next more.Next 4124 #define exop word.what.Exop 4125 #define bits word.what.Bits 4126 4127 4128 local int huft_build OF(( 4129 uIntf *, /* code lengths in bits */ 4130 uInt, /* number of codes */ 4131 uInt, /* number of "simple" codes */ 4132 const uIntf *, /* list of base values for non-simple codes */ 4133 const uIntf *, /* list of extra bits for non-simple codes */ 4134 inflate_huft * FAR*,/* result: starting table */ 4135 uIntf *, /* maximum lookup bits (returns actual) */ 4136 z_streamp )); /* for zalloc function */ 4137 4138 local voidpf zfalloc OF(( 4139 voidpf, /* opaque pointer (not used) */ 4140 uInt, /* number of items */ 4141 uInt)); /* size of item */ 4142 4143 /* Tables for deflate from PKZIP's appnote.txt. */ 4144 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */ 4145 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 4146 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 4147 /* see note #13 above about 258 */ 4148 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */ 4149 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 4150 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */ 4151 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */ 4152 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 4153 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 4154 8193, 12289, 16385, 24577}; 4155 local const uInt cpdext[30] = { /* Extra bits for distance codes */ 4156 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 4157 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 4158 12, 12, 13, 13}; 4159 4160 /* 4161 Huffman code decoding is performed using a multi-level table lookup. 4162 The fastest way to decode is to simply build a lookup table whose 4163 size is determined by the longest code. However, the time it takes 4164 to build this table can also be a factor if the data being decoded 4165 is not very long. The most common codes are necessarily the 4166 shortest codes, so those codes dominate the decoding time, and hence 4167 the speed. The idea is you can have a shorter table that decodes the 4168 shorter, more probable codes, and then point to subsidiary tables for 4169 the longer codes. The time it costs to decode the longer codes is 4170 then traded against the time it takes to make longer tables. 4171 4172 This results of this trade are in the variables lbits and dbits 4173 below. lbits is the number of bits the first level table for literal/ 4174 length codes can decode in one step, and dbits is the same thing for 4175 the distance codes. Subsequent tables are also less than or equal to 4176 those sizes. These values may be adjusted either when all of the 4177 codes are shorter than that, in which case the longest code length in 4178 bits is used, or when the shortest code is *longer* than the requested 4179 table size, in which case the length of the shortest code in bits is 4180 used. 4181 4182 There are two different values for the two tables, since they code a 4183 different number of possibilities each. The literal/length table 4184 codes 286 possible values, or in a flat code, a little over eight 4185 bits. The distance table codes 30 possible values, or a little less 4186 than five bits, flat. The optimum values for speed end up being 4187 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 4188 The optimum values may differ though from machine to machine, and 4189 possibly even between compilers. Your mileage may vary. 4190 */ 4191 4192 4193 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 4194 #define BMAX 15 /* maximum bit length of any code */ 4195 #define N_MAX 288 /* maximum number of codes in any set */ 4196 4197 #ifdef DEBUG_ZLIB 4198 uInt inflate_hufts; 4199 #endif 4200 4201 /* 4202 * Parameters: 4203 * b: code lengths in bits (all assumed <= BMAX) 4204 * n: number of codes (assumed <= N_MAX) 4205 * s: number of simple-valued codes (0..s-1) 4206 * d: list of base values for non-simple codes 4207 * e: list of extra bits for non-simple codes 4208 * t: result: starting table 4209 * m: maximum lookup bits, returns actual 4210 * zs: for zalloc function 4211 * 4212 * Given a list of code lengths and a maximum table size, make a set of 4213 * tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 4214 * if the given code set is incomplete (the tables are still built in this 4215 * case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of 4216 * lengths), or Z_MEM_ERROR if not enough memory. 4217 */ 4218 local int 4219 huft_build(uIntf *b, uInt n, uInt s, const uIntf *d, const uIntf *e, 4220 inflate_huft * FAR *t, uIntf *m, z_streamp zs) 4221 { 4222 4223 uInt a; /* counter for codes of length k */ 4224 uInt c[BMAX+1]; /* bit length count table */ 4225 uInt f; /* i repeats in table every f entries */ 4226 int g; /* maximum code length */ 4227 int h; /* table level */ 4228 uInt i; /* counter, current code */ 4229 uInt j; /* counter */ 4230 int k; /* number of bits in current code */ 4231 int l; /* bits per table (returned in m) */ 4232 uIntf *p; /* pointer into c[], b[], or v[] */ 4233 inflate_huft *q; /* points to current table */ 4234 struct inflate_huft_s r; /* table entry for structure assignment */ 4235 inflate_huft *u[BMAX]; /* table stack */ 4236 uInt v[N_MAX]; /* values in order of bit length */ 4237 int w; /* bits before this table == (l * h) */ 4238 uInt x[BMAX+1]; /* bit offsets, then code stack */ 4239 uIntf *xp; /* pointer into x */ 4240 int y; /* number of dummy codes added */ 4241 uInt z; /* number of entries in current table */ 4242 4243 4244 /* Generate counts for each bit length */ 4245 p = c; 4246 #define C0 *p++ = 0; 4247 #define C2 C0 C0 C0 C0 4248 #define C4 C2 C2 C2 C2 4249 C4 /* clear c[]--assume BMAX+1 is 16 */ 4250 p = b; i = n; 4251 do { 4252 c[*p++]++; /* assume all entries <= BMAX */ 4253 } while (--i); 4254 if (c[0] == n) /* null input--all zero length codes */ 4255 { 4256 *t = (inflate_huft *)Z_NULL; 4257 *m = 0; 4258 return Z_OK; 4259 } 4260 4261 4262 /* Find minimum and maximum length, bound *m by those */ 4263 l = *m; 4264 for (j = 1; j <= BMAX; j++) 4265 if (c[j]) 4266 break; 4267 k = j; /* minimum code length */ 4268 if ((uInt)l < j) 4269 l = j; 4270 for (i = BMAX; i; i--) 4271 if (c[i]) 4272 break; 4273 g = i; /* maximum code length */ 4274 if ((uInt)l > i) 4275 l = i; 4276 *m = l; 4277 4278 4279 /* Adjust last length count to fill out codes, if needed */ 4280 for (y = 1 << j; j < i; j++, y <<= 1) 4281 if ((y -= c[j]) < 0) 4282 return Z_DATA_ERROR; 4283 if ((y -= c[i]) < 0) 4284 return Z_DATA_ERROR; 4285 c[i] += y; 4286 4287 4288 /* Generate starting offsets into the value table for each length */ 4289 x[1] = j = 0; 4290 p = c + 1; xp = x + 2; 4291 while (--i) { /* note that i == g from above */ 4292 *xp++ = (j += *p++); 4293 } 4294 4295 4296 /* Make a table of values in order of bit lengths */ 4297 p = b; i = 0; 4298 do { 4299 if ((j = *p++) != 0) 4300 v[x[j]++] = i; 4301 } while (++i < n); 4302 n = x[g]; /* set n to length of v */ 4303 4304 4305 /* Generate the Huffman codes and for each, make the table entries */ 4306 x[0] = i = 0; /* first Huffman code is zero */ 4307 p = v; /* grab values in bit order */ 4308 h = -1; /* no tables yet--level -1 */ 4309 w = -l; /* bits decoded == (l * h) */ 4310 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 4311 q = (inflate_huft *)Z_NULL; /* ditto */ 4312 z = 0; /* ditto */ 4313 4314 /* go through the bit lengths (k already is bits in shortest code) */ 4315 for (; k <= g; k++) 4316 { 4317 a = c[k]; 4318 while (a--) 4319 { 4320 /* here i is the Huffman code of length k bits for value *p */ 4321 /* make tables up to required level */ 4322 while (k > w + l) 4323 { 4324 h++; 4325 w += l; /* previous table always l bits */ 4326 4327 /* compute minimum size table less than or equal to l bits */ 4328 z = g - w; 4329 z = z > (uInt)l ? l : z; /* table size upper limit */ 4330 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 4331 { /* too few codes for k-w bit table */ 4332 f -= a + 1; /* deduct codes from patterns left */ 4333 xp = c + k; 4334 if (j < z) 4335 while (++j < z) /* try smaller tables up to z bits */ 4336 { 4337 if ((f <<= 1) <= *++xp) 4338 break; /* enough codes to use up j bits */ 4339 f -= *xp; /* else deduct codes from patterns */ 4340 } 4341 } 4342 z = 1 << j; /* table entries for j-bit table */ 4343 4344 /* allocate and link in new table */ 4345 if ((q = (inflate_huft *)ZALLOC 4346 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 4347 { 4348 if (h) 4349 inflate_trees_free(u[0], zs); 4350 return Z_MEM_ERROR; /* not enough memory */ 4351 } 4352 #ifdef DEBUG_ZLIB 4353 inflate_hufts += z + 1; 4354 #endif 4355 *t = q + 1; /* link to list for huft_free() */ 4356 *(t = &(q->next)) = Z_NULL; 4357 u[h] = ++q; /* table starts after link */ 4358 4359 /* connect to last table, if there is one */ 4360 if (h) 4361 { 4362 x[h] = i; /* save pattern for backing up */ 4363 r.bits = (Byte)l; /* bits to dump before this table */ 4364 r.exop = (Byte)j; /* bits in this table */ 4365 r.next = q; /* pointer to this table */ 4366 j = i >> (w - l); /* (get around Turbo C bug) */ 4367 u[h-1][j] = r; /* connect to last table */ 4368 } 4369 } 4370 4371 /* set up table entry in r */ 4372 r.bits = (Byte)(k - w); 4373 if (p >= v + n) 4374 r.exop = 128 + 64; /* out of values--invalid code */ 4375 else if (*p < s) 4376 { 4377 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 4378 r.base = *p++; /* simple code is just the value */ 4379 } 4380 else 4381 { 4382 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ 4383 r.base = d[*p++ - s]; 4384 } 4385 4386 /* fill code-like entries with r */ 4387 f = 1 << (k - w); 4388 for (j = i >> w; j < z; j += f) 4389 q[j] = r; 4390 4391 /* backwards increment the k-bit code i */ 4392 for (j = 1 << (k - 1); i & j; j >>= 1) 4393 i ^= j; 4394 i ^= j; 4395 4396 /* backup over finished tables */ 4397 while ((i & ((1 << w) - 1)) != x[h]) 4398 { 4399 h--; /* don't need to update q */ 4400 w -= l; 4401 } 4402 } 4403 } 4404 4405 4406 /* Return Z_BUF_ERROR if we were given an incomplete table */ 4407 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 4408 } 4409 4410 /* 4411 * Parameters: 4412 * c: 19 code lengths 4413 * bb: bits tree desired/actual depth 4414 * tb: bits tree result 4415 * z: for zfree function 4416 */ 4417 int 4418 inflate_trees_bits(uIntf *c, uIntf *bb, inflate_huft * FAR *tb, z_streamp z) 4419 { 4420 int r; 4421 4422 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 4423 if (r == Z_DATA_ERROR) 4424 z->msg = (char*)"oversubscribed dynamic bit lengths tree"; 4425 else if (r == Z_BUF_ERROR || *bb == 0) 4426 { 4427 inflate_trees_free(*tb, z); 4428 z->msg = (char*)"incomplete dynamic bit lengths tree"; 4429 r = Z_DATA_ERROR; 4430 } 4431 return r; 4432 } 4433 4434 /* 4435 * Parameters: 4436 * nl: number of literal/length codes 4437 * nd: number of distance codes 4438 * c: that many (total) code lengths 4439 * bl: literal desired/actual bit depth 4440 * bd: distance desired/actual bit depth 4441 * tl: literal/length tree result 4442 * td: distance tree result 4443 * z: for zfree function 4444 */ 4445 int 4446 inflate_trees_dynamic(uInt nl, uInt nd, uIntf *c, uIntf *bl, uIntf *bd, 4447 inflate_huft * FAR *tl, inflate_huft * FAR *td, 4448 z_streamp z) 4449 { 4450 int r; 4451 4452 /* build literal/length tree */ 4453 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); 4454 if (r != Z_OK || *bl == 0) 4455 { 4456 if (r == Z_DATA_ERROR) 4457 z->msg = (char*)"oversubscribed literal/length tree"; 4458 else if (r != Z_MEM_ERROR) 4459 { 4460 inflate_trees_free(*tl, z); 4461 z->msg = (char*)"incomplete literal/length tree"; 4462 r = Z_DATA_ERROR; 4463 } 4464 return r; 4465 } 4466 4467 /* build distance tree */ 4468 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); 4469 if (r != Z_OK || (*bd == 0 && nl > 257)) 4470 { 4471 if (r == Z_DATA_ERROR) 4472 z->msg = (char*)"oversubscribed distance tree"; 4473 else if (r == Z_BUF_ERROR) { 4474 #ifdef PKZIP_BUG_WORKAROUND 4475 r = Z_OK; 4476 } 4477 #else 4478 inflate_trees_free(*td, z); 4479 z->msg = (char*)"incomplete distance tree"; 4480 r = Z_DATA_ERROR; 4481 } 4482 else if (r != Z_MEM_ERROR) 4483 { 4484 z->msg = (char*)"empty distance tree with lengths"; 4485 r = Z_DATA_ERROR; 4486 } 4487 inflate_trees_free(*tl, z); 4488 return r; 4489 #endif 4490 } 4491 4492 /* done */ 4493 return Z_OK; 4494 } 4495 4496 4497 /* build fixed tables only once--keep them here */ 4498 local int fixed_built = 0; 4499 #define FIXEDH 530 /* number of hufts used by fixed tables */ 4500 local inflate_huft fixed_mem[FIXEDH]; 4501 local uInt fixed_bl; 4502 local uInt fixed_bd; 4503 local inflate_huft *fixed_tl; 4504 local inflate_huft *fixed_td; 4505 4506 /* 4507 * Parameters: 4508 * q: opaque pointer 4509 * n: number of items 4510 * s: size of item 4511 */ 4512 local voidpf 4513 zfalloc(voidpf q, uInt n, uInt s) 4514 { 4515 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, 4516 "inflate_trees zfalloc overflow"); 4517 *(intf *)q -= n+s-s; /* s-s to avoid warning */ 4518 return (voidpf)(fixed_mem + *(intf *)q); 4519 } 4520 4521 /* 4522 * Parameters: 4523 * bl: literal desired/actual bit depth 4524 * bd: distance desired/actual bit depth 4525 * tl: literal/length tree result 4526 * td: distance tree result 4527 */ 4528 int 4529 inflate_trees_fixed(uIntf *bl, uIntf *bd, inflate_huft * FAR *tl, 4530 inflate_huft * FAR *td) 4531 { 4532 /* build fixed tables if not already (multiple overlapped executions ok) */ 4533 if (!fixed_built) 4534 { 4535 int k; /* temporary variable */ 4536 unsigned c[288]; /* length list for huft_build */ 4537 z_stream z; /* for zfalloc function */ 4538 int f = FIXEDH; /* number of hufts left in fixed_mem */ 4539 4540 /* set up fake z_stream for memory routines */ 4541 z.zalloc = zfalloc; 4542 z.zfree = Z_NULL; 4543 z.opaque = (voidpf)&f; 4544 4545 /* literal table */ 4546 for (k = 0; k < 144; k++) 4547 c[k] = 8; 4548 for (; k < 256; k++) 4549 c[k] = 9; 4550 for (; k < 280; k++) 4551 c[k] = 7; 4552 for (; k < 288; k++) 4553 c[k] = 8; 4554 fixed_bl = 7; 4555 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4556 4557 /* distance table */ 4558 for (k = 0; k < 30; k++) 4559 c[k] = 5; 4560 fixed_bd = 5; 4561 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4562 4563 /* done */ 4564 Assert(f == 0, "invalid build of fixed tables"); 4565 fixed_built = 1; 4566 } 4567 *bl = fixed_bl; 4568 *bd = fixed_bd; 4569 *tl = fixed_tl; 4570 *td = fixed_td; 4571 return Z_OK; 4572 } 4573 4574 /* 4575 * Parameters: 4576 * t: table to free 4577 * z: for zfree function 4578 * Free the malloc'ed tables built by huft_build(), which makes a linked 4579 * list of the tables it made, with the links in a dummy first entry of 4580 * each table. 4581 */ 4582 int 4583 inflate_trees_free(inflate_huft *t, z_streamp z) 4584 { 4585 inflate_huft *p, *q, *r; 4586 4587 /* Reverse linked list */ 4588 p = Z_NULL; 4589 q = t; 4590 while (q != Z_NULL) 4591 { 4592 r = (q - 1)->next; 4593 (q - 1)->next = p; 4594 p = q; 4595 q = r; 4596 } 4597 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4598 while (p != Z_NULL) 4599 { 4600 q = (--p)->next; 4601 ZFREE(z,p); 4602 p = q; 4603 } 4604 return Z_OK; 4605 } 4606 /* --- inftrees.c */ 4607 4608 /* +++ infcodes.c */ 4609 /* infcodes.c -- process literals and length/distance pairs 4610 * Copyright (C) 1995-1996 Mark Adler 4611 * For conditions of distribution and use, see copyright notice in zlib.h 4612 */ 4613 4614 /* #include "zutil.h" */ 4615 /* #include "inftrees.h" */ 4616 /* #include "infblock.h" */ 4617 /* #include "infcodes.h" */ 4618 /* #include "infutil.h" */ 4619 4620 /* +++ inffast.h */ 4621 /* inffast.h -- header to use inffast.c 4622 * Copyright (C) 1995-1996 Mark Adler 4623 * For conditions of distribution and use, see copyright notice in zlib.h 4624 */ 4625 4626 /* WARNING: this file should *not* be used by applications. It is 4627 part of the implementation of the compression library and is 4628 subject to change. Applications should only use zlib.h. 4629 */ 4630 4631 extern int inflate_fast OF(( 4632 uInt, 4633 uInt, 4634 inflate_huft *, 4635 inflate_huft *, 4636 inflate_blocks_statef *, 4637 z_streamp )); 4638 /* --- inffast.h */ 4639 4640 /* simplify the use of the inflate_huft type with some defines */ 4641 #define base more.Base 4642 #define next more.Next 4643 #define exop word.what.Exop 4644 #define bits word.what.Bits 4645 4646 /* inflate codes private state */ 4647 struct inflate_codes_state { 4648 4649 /* mode */ 4650 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4651 START, /* x: set up for LEN */ 4652 LEN, /* i: get length/literal/eob next */ 4653 LENEXT, /* i: getting length extra (have base) */ 4654 DIST, /* i: get distance next */ 4655 DISTEXT, /* i: getting distance extra */ 4656 COPY, /* o: copying bytes in window, waiting for space */ 4657 LIT, /* o: got literal, waiting for output space */ 4658 WASH, /* o: got eob, possibly still output waiting */ 4659 END, /* x: got eob and all data flushed */ 4660 BADCODE} /* x: got error */ 4661 mode; /* current inflate_codes mode */ 4662 4663 /* mode dependent information */ 4664 uInt len; 4665 union { 4666 struct { 4667 inflate_huft *tree; /* pointer into tree */ 4668 uInt need; /* bits needed */ 4669 } code; /* if LEN or DIST, where in tree */ 4670 uInt lit; /* if LIT, literal */ 4671 struct { 4672 uInt get; /* bits to get for extra */ 4673 uInt dist; /* distance back to copy from */ 4674 } copy; /* if EXT or COPY, where and how much */ 4675 } sub; /* submode */ 4676 4677 /* mode independent information */ 4678 Byte lbits; /* ltree bits decoded per branch */ 4679 Byte dbits; /* dtree bits decoder per branch */ 4680 inflate_huft *ltree; /* literal/length/eob tree */ 4681 inflate_huft *dtree; /* distance tree */ 4682 4683 }; 4684 4685 /* 4686 * Parameters: 4687 * td: need separate declaration for Borland C++ 4688 */ 4689 inflate_codes_statef * 4690 inflate_codes_new(uInt bl, uInt bd, inflate_huft *tl, inflate_huft *td, 4691 z_streamp z) 4692 { 4693 inflate_codes_statef *c; 4694 4695 if ((c = (inflate_codes_statef *) 4696 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4697 { 4698 c->mode = START; 4699 c->lbits = (Byte)bl; 4700 c->dbits = (Byte)bd; 4701 c->ltree = tl; 4702 c->dtree = td; 4703 Tracev((stderr, "inflate: codes new\n")); 4704 } 4705 return c; 4706 } 4707 4708 4709 int 4710 inflate_codes(inflate_blocks_statef *s, z_streamp z, int r) 4711 { 4712 uInt j; /* temporary storage */ 4713 inflate_huft *t; /* temporary pointer */ 4714 uInt e; /* extra bits or operation */ 4715 uLong b; /* bit buffer */ 4716 uInt k; /* bits in bit buffer */ 4717 Bytef *p; /* input data pointer */ 4718 uInt n; /* bytes available there */ 4719 Bytef *q; /* output window write pointer */ 4720 uInt m; /* bytes to end of window or read pointer */ 4721 Bytef *f; /* pointer to copy strings from */ 4722 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4723 4724 /* copy input/output information to locals (UPDATE macro restores) */ 4725 LOAD 4726 4727 /* process input and output based on current state */ 4728 while (1) switch (c->mode) 4729 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4730 case START: /* x: set up for LEN */ 4731 #ifndef SLOW 4732 if (m >= 258 && n >= 10) 4733 { 4734 UPDATE 4735 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4736 LOAD 4737 if (r != Z_OK) 4738 { 4739 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4740 break; 4741 } 4742 } 4743 #endif /* !SLOW */ 4744 c->sub.code.need = c->lbits; 4745 c->sub.code.tree = c->ltree; 4746 c->mode = LEN; 4747 case LEN: /* i: get length/literal/eob next */ 4748 j = c->sub.code.need; 4749 NEEDBITS(j) 4750 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4751 DUMPBITS(t->bits) 4752 e = (uInt)(t->exop); 4753 if (e == 0) /* literal */ 4754 { 4755 c->sub.lit = t->base; 4756 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4757 "inflate: literal '%c'\n" : 4758 "inflate: literal 0x%02x\n", t->base)); 4759 c->mode = LIT; 4760 break; 4761 } 4762 if (e & 16) /* length */ 4763 { 4764 c->sub.copy.get = e & 15; 4765 c->len = t->base; 4766 c->mode = LENEXT; 4767 break; 4768 } 4769 if ((e & 64) == 0) /* next table */ 4770 { 4771 c->sub.code.need = e; 4772 c->sub.code.tree = t->next; 4773 break; 4774 } 4775 if (e & 32) /* end of block */ 4776 { 4777 Tracevv((stderr, "inflate: end of block\n")); 4778 c->mode = WASH; 4779 break; 4780 } 4781 c->mode = BADCODE; /* invalid code */ 4782 z->msg = (char*)"invalid literal/length code"; 4783 r = Z_DATA_ERROR; 4784 LEAVE 4785 case LENEXT: /* i: getting length extra (have base) */ 4786 j = c->sub.copy.get; 4787 NEEDBITS(j) 4788 c->len += (uInt)b & inflate_mask[j]; 4789 DUMPBITS(j) 4790 c->sub.code.need = c->dbits; 4791 c->sub.code.tree = c->dtree; 4792 Tracevv((stderr, "inflate: length %u\n", c->len)); 4793 c->mode = DIST; 4794 case DIST: /* i: get distance next */ 4795 j = c->sub.code.need; 4796 NEEDBITS(j) 4797 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4798 DUMPBITS(t->bits) 4799 e = (uInt)(t->exop); 4800 if (e & 16) /* distance */ 4801 { 4802 c->sub.copy.get = e & 15; 4803 c->sub.copy.dist = t->base; 4804 c->mode = DISTEXT; 4805 break; 4806 } 4807 if ((e & 64) == 0) /* next table */ 4808 { 4809 c->sub.code.need = e; 4810 c->sub.code.tree = t->next; 4811 break; 4812 } 4813 c->mode = BADCODE; /* invalid code */ 4814 z->msg = (char*)"invalid distance code"; 4815 r = Z_DATA_ERROR; 4816 LEAVE 4817 case DISTEXT: /* i: getting distance extra */ 4818 j = c->sub.copy.get; 4819 NEEDBITS(j) 4820 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4821 DUMPBITS(j) 4822 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4823 c->mode = COPY; 4824 case COPY: /* o: copying bytes in window, waiting for space */ 4825 #ifndef __TURBOC__ /* Turbo C bug for following expression */ 4826 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4827 s->end - (c->sub.copy.dist - (q - s->window)) : 4828 q - c->sub.copy.dist; 4829 #else 4830 f = q - c->sub.copy.dist; 4831 if ((uInt)(q - s->window) < c->sub.copy.dist) 4832 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); 4833 #endif 4834 while (c->len) 4835 { 4836 NEEDOUT 4837 OUTBYTE(*f++) 4838 if (f == s->end) 4839 f = s->window; 4840 c->len--; 4841 } 4842 c->mode = START; 4843 break; 4844 case LIT: /* o: got literal, waiting for output space */ 4845 NEEDOUT 4846 OUTBYTE(c->sub.lit) 4847 c->mode = START; 4848 break; 4849 case WASH: /* o: got eob, possibly more output */ 4850 FLUSH 4851 if (s->read != s->write) 4852 LEAVE 4853 c->mode = END; 4854 case END: 4855 r = Z_STREAM_END; 4856 LEAVE 4857 case BADCODE: /* x: got error */ 4858 r = Z_DATA_ERROR; 4859 LEAVE 4860 default: 4861 r = Z_STREAM_ERROR; 4862 LEAVE 4863 } 4864 } 4865 4866 4867 void 4868 inflate_codes_free(inflate_codes_statef *c, z_streamp z) 4869 { 4870 ZFREE(z, c); 4871 Tracev((stderr, "inflate: codes free\n")); 4872 } 4873 /* --- infcodes.c */ 4874 4875 /* +++ infutil.c */ 4876 /* inflate_util.c -- data and routines common to blocks and codes 4877 * Copyright (C) 1995-1996 Mark Adler 4878 * For conditions of distribution and use, see copyright notice in zlib.h 4879 */ 4880 4881 /* #include "zutil.h" */ 4882 /* #include "infblock.h" */ 4883 /* #include "inftrees.h" */ 4884 /* #include "infcodes.h" */ 4885 /* #include "infutil.h" */ 4886 4887 #ifndef NO_DUMMY_DECL 4888 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4889 #endif 4890 4891 /* And'ing with mask[n] masks the lower n bits */ 4892 uInt inflate_mask[17] = { 4893 0x0000, 4894 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 4895 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 4896 }; 4897 4898 4899 /* copy as much as possible from the sliding window to the output area */ 4900 int 4901 inflate_flush(inflate_blocks_statef *s, z_streamp z, int r) 4902 { 4903 uInt n; 4904 Bytef *p; 4905 Bytef *q; 4906 4907 /* local copies of source and destination pointers */ 4908 p = z->next_out; 4909 q = s->read; 4910 4911 /* compute number of bytes to copy as far as end of window */ 4912 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4913 if (n > z->avail_out) n = z->avail_out; 4914 if (n && r == Z_BUF_ERROR) r = Z_OK; 4915 4916 /* update counters */ 4917 z->avail_out -= n; 4918 z->total_out += n; 4919 4920 /* update check information */ 4921 if (s->checkfn != Z_NULL) 4922 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4923 4924 /* copy as far as end of window */ 4925 if (p != Z_NULL) { 4926 zmemcpy(p, q, n); 4927 p += n; 4928 } 4929 q += n; 4930 4931 /* see if more to copy at beginning of window */ 4932 if (q == s->end) 4933 { 4934 /* wrap pointers */ 4935 q = s->window; 4936 if (s->write == s->end) 4937 s->write = s->window; 4938 4939 /* compute bytes to copy */ 4940 n = (uInt)(s->write - q); 4941 if (n > z->avail_out) n = z->avail_out; 4942 if (n && r == Z_BUF_ERROR) r = Z_OK; 4943 4944 /* update counters */ 4945 z->avail_out -= n; 4946 z->total_out += n; 4947 4948 /* update check information */ 4949 if (s->checkfn != Z_NULL) 4950 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4951 4952 /* copy */ 4953 if (p != Z_NULL) { 4954 zmemcpy(p, q, n); 4955 p += n; 4956 } 4957 q += n; 4958 } 4959 4960 /* update pointers */ 4961 z->next_out = p; 4962 s->read = q; 4963 4964 /* done */ 4965 return r; 4966 } 4967 /* --- infutil.c */ 4968 4969 /* +++ inffast.c */ 4970 /* inffast.c -- process literals and length/distance pairs fast 4971 * Copyright (C) 1995-1996 Mark Adler 4972 * For conditions of distribution and use, see copyright notice in zlib.h 4973 */ 4974 4975 /* #include "zutil.h" */ 4976 /* #include "inftrees.h" */ 4977 /* #include "infblock.h" */ 4978 /* #include "infcodes.h" */ 4979 /* #include "infutil.h" */ 4980 /* #include "inffast.h" */ 4981 4982 #ifndef NO_DUMMY_DECL 4983 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4984 #endif 4985 4986 /* simplify the use of the inflate_huft type with some defines */ 4987 #define base more.Base 4988 #define next more.Next 4989 #define exop word.what.Exop 4990 #define bits word.what.Bits 4991 4992 /* macros for bit input with no checking and for returning unused bytes */ 4993 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4994 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4995 4996 /* Called with number of bytes left to write in window at least 258 4997 * (the maximum string length) and number of input bytes available 4998 * at least ten. The ten bytes are six bytes for the longest length/ 4999 * distance pair plus four bytes for overloading the bit buffer. 5000 * 5001 * Parameters: 5002 * td: need separate declaration for Borland C++ 5003 */ 5004 int 5005 inflate_fast(uInt bl, uInt bd, inflate_huft *tl, inflate_huft *td, 5006 inflate_blocks_statef *s, z_streamp z) 5007 { 5008 inflate_huft *t; /* temporary pointer */ 5009 uInt e; /* extra bits or operation */ 5010 uLong b; /* bit buffer */ 5011 uInt k; /* bits in bit buffer */ 5012 Bytef *p; /* input data pointer */ 5013 uInt n; /* bytes available there */ 5014 Bytef *q; /* output window write pointer */ 5015 uInt m; /* bytes to end of window or read pointer */ 5016 uInt ml; /* mask for literal/length tree */ 5017 uInt md; /* mask for distance tree */ 5018 uInt c; /* bytes to copy */ 5019 uInt d; /* distance back to copy from */ 5020 Bytef *r; /* copy source pointer */ 5021 5022 /* load input, output, bit values */ 5023 LOAD 5024 5025 /* initialize masks */ 5026 ml = inflate_mask[bl]; 5027 md = inflate_mask[bd]; 5028 5029 /* do until not enough input or output space for fast loop */ 5030 do { /* assume called with m >= 258 && n >= 10 */ 5031 /* get literal/length code */ 5032 GRABBITS(20) /* max bits for literal/length code */ 5033 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 5034 { 5035 DUMPBITS(t->bits) 5036 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5037 "inflate: * literal '%c'\n" : 5038 "inflate: * literal 0x%02x\n", t->base)); 5039 *q++ = (Byte)t->base; 5040 m--; 5041 continue; 5042 } 5043 do { 5044 DUMPBITS(t->bits) 5045 if (e & 16) 5046 { 5047 /* get extra bits for length */ 5048 e &= 15; 5049 c = t->base + ((uInt)b & inflate_mask[e]); 5050 DUMPBITS(e) 5051 Tracevv((stderr, "inflate: * length %u\n", c)); 5052 5053 /* decode distance base of block to copy */ 5054 GRABBITS(15); /* max bits for distance code */ 5055 e = (t = td + ((uInt)b & md))->exop; 5056 do { 5057 DUMPBITS(t->bits) 5058 if (e & 16) 5059 { 5060 /* get extra bits to add to distance base */ 5061 e &= 15; 5062 GRABBITS(e) /* get extra bits (up to 13) */ 5063 d = t->base + ((uInt)b & inflate_mask[e]); 5064 DUMPBITS(e) 5065 Tracevv((stderr, "inflate: * distance %u\n", d)); 5066 5067 /* do the copy */ 5068 m -= c; 5069 if ((uInt)(q - s->window) >= d) /* offset before dest */ 5070 { /* just copy */ 5071 r = q - d; 5072 *q++ = *r++; c--; /* minimum count is three, */ 5073 *q++ = *r++; c--; /* so unroll loop a little */ 5074 } 5075 else /* else offset after destination */ 5076 { 5077 e = d - (uInt)(q - s->window); /* bytes from offset to end */ 5078 r = s->end - e; /* pointer to offset */ 5079 if (c > e) /* if source crosses, */ 5080 { 5081 c -= e; /* copy to end of window */ 5082 do { 5083 *q++ = *r++; 5084 } while (--e); 5085 r = s->window; /* copy rest from start of window */ 5086 } 5087 } 5088 do { /* copy all or what's left */ 5089 *q++ = *r++; 5090 } while (--c); 5091 break; 5092 } 5093 else if ((e & 64) == 0) 5094 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 5095 else 5096 { 5097 z->msg = (char*)"invalid distance code"; 5098 UNGRAB 5099 UPDATE 5100 return Z_DATA_ERROR; 5101 } 5102 } while (1); 5103 break; 5104 } 5105 if ((e & 64) == 0) 5106 { 5107 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 5108 { 5109 DUMPBITS(t->bits) 5110 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5111 "inflate: * literal '%c'\n" : 5112 "inflate: * literal 0x%02x\n", t->base)); 5113 *q++ = (Byte)t->base; 5114 m--; 5115 break; 5116 } 5117 } 5118 else if (e & 32) 5119 { 5120 Tracevv((stderr, "inflate: * end of block\n")); 5121 UNGRAB 5122 UPDATE 5123 return Z_STREAM_END; 5124 } 5125 else 5126 { 5127 z->msg = (char*)"invalid literal/length code"; 5128 UNGRAB 5129 UPDATE 5130 return Z_DATA_ERROR; 5131 } 5132 } while (1); 5133 } while (m >= 258 && n >= 10); 5134 5135 /* not enough input or output--restore pointers and return */ 5136 UNGRAB 5137 UPDATE 5138 return Z_OK; 5139 } 5140 /* --- inffast.c */ 5141 5142 /* +++ zutil.c */ 5143 /* zutil.c -- target dependent utility functions for the compression library 5144 * Copyright (C) 1995-1996 Jean-loup Gailly. 5145 * For conditions of distribution and use, see copyright notice in zlib.h 5146 */ 5147 5148 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ 5149 5150 #ifdef DEBUG_ZLIB 5151 #include <stdio.h> 5152 #endif 5153 5154 /* #include "zutil.h" */ 5155 5156 #ifndef NO_DUMMY_DECL 5157 struct internal_state {int dummy;}; /* for buggy compilers */ 5158 #endif 5159 5160 #ifndef STDC 5161 extern void exit OF((int)); 5162 #endif 5163 5164 const char 5165 *zlibVersion(void) 5166 { 5167 return ZLIB_VERSION; 5168 } 5169 5170 #ifdef DEBUG_ZLIB 5171 void 5172 z_error(char *m) 5173 { 5174 fprintf(stderr, "%s\n", m); 5175 exit(1); 5176 } 5177 #endif 5178 5179 #ifndef HAVE_MEMCPY 5180 5181 void 5182 zmemcpy(Bytef *dest, Bytef *source, uInt len) 5183 { 5184 if (len == 0) return; 5185 do { 5186 *dest++ = *source++; /* ??? to be unrolled */ 5187 } while (--len != 0); 5188 } 5189 5190 int 5191 zmemcmp(Bytef *s1, Bytef *s2, uInt len) 5192 { 5193 uInt j; 5194 5195 for (j = 0; j < len; j++) { 5196 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 5197 } 5198 return 0; 5199 } 5200 5201 void 5202 zmemzero(Bytef *dest, uInt len) 5203 { 5204 if (len == 0) return; 5205 do { 5206 *dest++ = 0; /* ??? to be unrolled */ 5207 } while (--len != 0); 5208 } 5209 #endif 5210 5211 #ifdef __TURBOC__ 5212 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 5213 /* Small and medium model in Turbo C are for now limited to near allocation 5214 * with reduced MAX_WBITS and MAX_MEM_LEVEL 5215 */ 5216 # define MY_ZCALLOC 5217 5218 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes 5219 * and farmalloc(64K) returns a pointer with an offset of 8, so we 5220 * must fix the pointer. Warning: the pointer must be put back to its 5221 * original form in order to free it, use zcfree(). 5222 */ 5223 5224 #define MAX_PTR 10 5225 /* 10*64K = 640K */ 5226 5227 local int next_ptr = 0; 5228 5229 typedef struct ptr_table_s { 5230 voidpf org_ptr; 5231 voidpf new_ptr; 5232 } ptr_table; 5233 5234 local ptr_table table[MAX_PTR]; 5235 /* This table is used to remember the original form of pointers 5236 * to large buffers (64K). Such pointers are normalized with a zero offset. 5237 * Since MSDOS is not a preemptive multitasking OS, this table is not 5238 * protected from concurrent access. This hack doesn't work anyway on 5239 * a protected system like OS/2. Use Microsoft C instead. 5240 */ 5241 5242 voidpf 5243 zcalloc(voidpf opaque, unsigned items, unsigned size) 5244 { 5245 voidpf buf = opaque; /* just to make some compilers happy */ 5246 ulg bsize = (ulg)items*size; 5247 5248 /* If we allocate less than 65520 bytes, we assume that farmalloc 5249 * will return a usable pointer which doesn't have to be normalized. 5250 */ 5251 if (bsize < 65520L) { 5252 buf = farmalloc(bsize); 5253 if (*(ush*)&buf != 0) return buf; 5254 } else { 5255 buf = farmalloc(bsize + 16L); 5256 } 5257 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 5258 table[next_ptr].org_ptr = buf; 5259 5260 /* Normalize the pointer to seg:0 */ 5261 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 5262 *(ush*)&buf = 0; 5263 table[next_ptr++].new_ptr = buf; 5264 return buf; 5265 } 5266 5267 void 5268 zcfree(voidpf opaque, voidpf ptr) 5269 { 5270 int n; 5271 if (*(ush*)&ptr != 0) { /* object < 64K */ 5272 farfree(ptr); 5273 return; 5274 } 5275 /* Find the original pointer */ 5276 for (n = 0; n < next_ptr; n++) { 5277 if (ptr != table[n].new_ptr) continue; 5278 5279 farfree(table[n].org_ptr); 5280 while (++n < next_ptr) { 5281 table[n-1] = table[n]; 5282 } 5283 next_ptr--; 5284 return; 5285 } 5286 ptr = opaque; /* just to make some compilers happy */ 5287 Assert(0, "zcfree: ptr not found"); 5288 } 5289 #endif 5290 #endif /* __TURBOC__ */ 5291 5292 5293 #if defined(M_I86) && !defined(__32BIT__) 5294 /* Microsoft C in 16-bit mode */ 5295 5296 # define MY_ZCALLOC 5297 5298 #if (!defined(_MSC_VER) || (_MSC_VER < 600)) 5299 # define _halloc halloc 5300 # define _hfree hfree 5301 #endif 5302 5303 voidpf 5304 zcalloc(voidpf opaque, unsigned items, unsigned size) 5305 { 5306 if (opaque) opaque = 0; /* to make compiler happy */ 5307 return _halloc((long)items, size); 5308 } 5309 5310 void 5311 zcfree(voidpf opaque, voidpf ptr) 5312 { 5313 if (opaque) opaque = 0; /* to make compiler happy */ 5314 _hfree(ptr); 5315 } 5316 5317 #endif /* MSC */ 5318 5319 5320 #ifndef MY_ZCALLOC /* Any system without a special alloc function */ 5321 5322 #ifndef STDC 5323 extern voidp calloc OF((uInt items, uInt size)); 5324 extern void free OF((voidpf ptr)); 5325 #endif 5326 5327 voidpf 5328 zcalloc(voidpf opaque, unsigned items, unsigned size) 5329 { 5330 if (opaque) items += size - size; /* make compiler happy */ 5331 return (voidpf)calloc(items, size); 5332 } 5333 5334 void 5335 zcfree(voidpf opaque, voidpf ptr) 5336 { 5337 free(ptr); 5338 if (opaque) return; /* make compiler happy */ 5339 } 5340 5341 #endif /* MY_ZCALLOC */ 5342 /* --- zutil.c */ 5343 5344 /* +++ adler32.c */ 5345 /* adler32.c -- compute the Adler-32 checksum of a data stream 5346 * Copyright (C) 1995-1996 Mark Adler 5347 * For conditions of distribution and use, see copyright notice in zlib.h 5348 */ 5349 5350 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ 5351 5352 /* #include "zlib.h" */ 5353 5354 #define BASE 65521L /* largest prime smaller than 65536 */ 5355 #define NMAX 5552 5356 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 5357 5358 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;} 5359 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1); 5360 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2); 5361 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); 5362 #define DO16(buf) DO8(buf,0); DO8(buf,8); 5363 5364 /* ========================================================================= */ 5365 uLong 5366 adler32(uLong adler, const Bytef *buf, uInt len) 5367 { 5368 unsigned long s1 = adler & 0xffff; 5369 unsigned long s2 = (adler >> 16) & 0xffff; 5370 int k; 5371 5372 if (buf == Z_NULL) return 1L; 5373 5374 while (len > 0) { 5375 k = len < NMAX ? len : NMAX; 5376 len -= k; 5377 while (k >= 16) { 5378 DO16(buf); 5379 buf += 16; 5380 k -= 16; 5381 } 5382 if (k != 0) do { 5383 s1 += *buf++; 5384 s2 += s1; 5385 } while (--k); 5386 s1 %= BASE; 5387 s2 %= BASE; 5388 } 5389 return (s2 << 16) | s1; 5390 } 5391 /* --- adler32.c */ 5392 5393 MODULE_VERSION(zlib, 1); 5394