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