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 1.2 2003/06/17 04:28:48 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(__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/types.h> 58 #include <sys/time.h> 59 #include <sys/systm.h> 60 # define HAVE_MEMCPY 61 # define memcpy(d, s, n) bcopy((s), (d), (n)) 62 # define memset(d, v, n) bzero((d), (n)) 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 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */ 98 /* (size given to avoid silly warnings with Visual C++) */ 99 100 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] 101 102 #define ERR_RETURN(strm,err) \ 103 return (strm->msg = (const char*)ERR_MSG(err), (err)) 104 /* To be used only when the state is known to be valid */ 105 106 /* common constants */ 107 108 #ifndef DEF_WBITS 109 # define DEF_WBITS MAX_WBITS 110 #endif 111 /* default windowBits for decompression. MAX_WBITS is for compression only */ 112 113 #if MAX_MEM_LEVEL >= 8 114 # define DEF_MEM_LEVEL 8 115 #else 116 # define DEF_MEM_LEVEL MAX_MEM_LEVEL 117 #endif 118 /* default memLevel */ 119 120 #define STORED_BLOCK 0 121 #define STATIC_TREES 1 122 #define DYN_TREES 2 123 /* The three kinds of block type */ 124 125 #define MIN_MATCH 3 126 #define MAX_MATCH 258 127 /* The minimum and maximum match lengths */ 128 129 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */ 130 131 /* target dependencies */ 132 133 #ifdef MSDOS 134 # define OS_CODE 0x00 135 # ifdef __TURBOC__ 136 # include <alloc.h> 137 # else /* MSC or DJGPP */ 138 # include <malloc.h> 139 # endif 140 #endif 141 142 #ifdef OS2 143 # define OS_CODE 0x06 144 #endif 145 146 #ifdef WIN32 /* Window 95 & Windows NT */ 147 # define OS_CODE 0x0b 148 #endif 149 150 #if defined(VAXC) || defined(VMS) 151 # define OS_CODE 0x02 152 # define FOPEN(name, mode) \ 153 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") 154 #endif 155 156 #ifdef AMIGA 157 # define OS_CODE 0x01 158 #endif 159 160 #if defined(ATARI) || defined(atarist) 161 # define OS_CODE 0x05 162 #endif 163 164 #ifdef MACOS 165 # define OS_CODE 0x07 166 #endif 167 168 #ifdef __50SERIES /* Prime/PRIMOS */ 169 # define OS_CODE 0x0F 170 #endif 171 172 #ifdef TOPS20 173 # define OS_CODE 0x0a 174 #endif 175 176 #if defined(_BEOS_) || defined(RISCOS) 177 # define fdopen(fd,mode) NULL /* No fdopen() */ 178 #endif 179 180 /* Common defaults */ 181 182 #ifndef OS_CODE 183 # define OS_CODE 0x03 /* assume Unix */ 184 #endif 185 186 #ifndef FOPEN 187 # define FOPEN(name, mode) fopen((name), (mode)) 188 #endif 189 190 /* functions */ 191 192 #ifdef HAVE_STRERROR 193 extern char *strerror OF((int)); 194 # define zstrerror(errnum) strerror(errnum) 195 #else 196 # define zstrerror(errnum) "" 197 #endif 198 199 #if defined(pyr) 200 # define NO_MEMCPY 201 #endif 202 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER) 203 /* Use our own functions for small and medium model with MSC <= 5.0. 204 * You may have to use the same strategy for Borland C (untested). 205 */ 206 # define NO_MEMCPY 207 #endif 208 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 209 # define HAVE_MEMCPY 210 #endif 211 #ifdef HAVE_MEMCPY 212 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */ 213 # define zmemcpy _fmemcpy 214 # define zmemcmp _fmemcmp 215 # define zmemzero(dest, len) _fmemset(dest, 0, len) 216 # else 217 # define zmemcpy memcpy 218 # define zmemcmp memcmp 219 # define zmemzero(dest, len) memset(dest, 0, len) 220 # endif 221 #else 222 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); 223 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len)); 224 extern void zmemzero OF((Bytef* dest, uInt len)); 225 #endif 226 227 /* Diagnostic functions */ 228 #ifdef DEBUG_ZLIB 229 # include <stdio.h> 230 # ifndef verbose 231 # define verbose 0 232 # endif 233 extern void z_error OF((char *m)); 234 # define Assert(cond,msg) {if(!(cond)) z_error(msg);} 235 # define Trace(x) fprintf x 236 # define Tracev(x) {if (verbose) fprintf x ;} 237 # define Tracevv(x) {if (verbose>1) fprintf x ;} 238 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 239 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 240 #else 241 # define Assert(cond,msg) 242 # define Trace(x) 243 # define Tracev(x) 244 # define Tracevv(x) 245 # define Tracec(c,x) 246 # define Tracecv(c,x) 247 #endif 248 249 250 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len)); 251 252 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); 253 void zcfree OF((voidpf opaque, voidpf ptr)); 254 255 #define ZALLOC(strm, items, size) \ 256 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 257 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr)) 258 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);} 259 260 #endif /* _Z_UTIL_H */ 261 /* --- zutil.h */ 262 263 /* +++ deflate.h */ 264 /* deflate.h -- internal compression state 265 * Copyright (C) 1995-1996 Jean-loup Gailly 266 * For conditions of distribution and use, see copyright notice in zlib.h 267 */ 268 269 /* WARNING: this file should *not* be used by applications. It is 270 part of the implementation of the compression library and is 271 subject to change. Applications should only use zlib.h. 272 */ 273 274 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */ 275 276 #ifndef _DEFLATE_H 277 #define _DEFLATE_H 278 279 /* #include "zutil.h" */ 280 281 /* =========================================================================== 282 * Internal compression state. 283 */ 284 285 #define LENGTH_CODES 29 286 /* number of length codes, not counting the special END_BLOCK code */ 287 288 #define LITERALS 256 289 /* number of literal bytes 0..255 */ 290 291 #define L_CODES (LITERALS+1+LENGTH_CODES) 292 /* number of Literal or Length codes, including the END_BLOCK code */ 293 294 #define D_CODES 30 295 /* number of distance codes */ 296 297 #define BL_CODES 19 298 /* number of codes used to transfer the bit lengths */ 299 300 #define HEAP_SIZE (2*L_CODES+1) 301 /* maximum heap size */ 302 303 #define MAX_BITS 15 304 /* All codes must not exceed MAX_BITS bits */ 305 306 #define INIT_STATE 42 307 #define BUSY_STATE 113 308 #define FINISH_STATE 666 309 /* Stream status */ 310 311 312 /* Data structure describing a single value and its code string. */ 313 typedef struct ct_data_s { 314 union { 315 ush freq; /* frequency count */ 316 ush code; /* bit string */ 317 } fc; 318 union { 319 ush dad; /* father node in Huffman tree */ 320 ush len; /* length of bit string */ 321 } dl; 322 } FAR ct_data; 323 324 #define Freq fc.freq 325 #define Code fc.code 326 #define Dad dl.dad 327 #define Len dl.len 328 329 typedef struct static_tree_desc_s static_tree_desc; 330 331 typedef struct tree_desc_s { 332 ct_data *dyn_tree; /* the dynamic tree */ 333 int max_code; /* largest code with non zero frequency */ 334 static_tree_desc *stat_desc; /* the corresponding static tree */ 335 } FAR tree_desc; 336 337 typedef ush Pos; 338 typedef Pos FAR Posf; 339 typedef unsigned IPos; 340 341 /* A Pos is an index in the character window. We use short instead of int to 342 * save space in the various tables. IPos is used only for parameter passing. 343 */ 344 345 typedef struct deflate_state { 346 z_streamp strm; /* pointer back to this zlib stream */ 347 int status; /* as the name implies */ 348 Bytef *pending_buf; /* output still pending */ 349 ulg pending_buf_size; /* size of pending_buf */ 350 Bytef *pending_out; /* next pending byte to output to the stream */ 351 int pending; /* nb of bytes in the pending buffer */ 352 int noheader; /* suppress zlib header and adler32 */ 353 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 354 Byte method; /* STORED (for zip only) or DEFLATED */ 355 int last_flush; /* value of flush param for previous deflate call */ 356 357 /* used by deflate.c: */ 358 359 uInt w_size; /* LZ77 window size (32K by default) */ 360 uInt w_bits; /* log2(w_size) (8..16) */ 361 uInt w_mask; /* w_size - 1 */ 362 363 Bytef *window; 364 /* Sliding window. Input bytes are read into the second half of the window, 365 * and move to the first half later to keep a dictionary of at least wSize 366 * bytes. With this organization, matches are limited to a distance of 367 * wSize-MAX_MATCH bytes, but this ensures that IO is always 368 * performed with a length multiple of the block size. Also, it limits 369 * the window size to 64K, which is quite useful on MSDOS. 370 * To do: use the user input buffer as sliding window. 371 */ 372 373 ulg window_size; 374 /* Actual size of window: 2*wSize, except when the user input buffer 375 * is directly used as sliding window. 376 */ 377 378 Posf *prev; 379 /* Link to older string with same hash index. To limit the size of this 380 * array to 64K, this link is maintained only for the last 32K strings. 381 * An index in this array is thus a window index modulo 32K. 382 */ 383 384 Posf *head; /* Heads of the hash chains or NIL. */ 385 386 uInt ins_h; /* hash index of string to be inserted */ 387 uInt hash_size; /* number of elements in hash table */ 388 uInt hash_bits; /* log2(hash_size) */ 389 uInt hash_mask; /* hash_size-1 */ 390 391 uInt hash_shift; 392 /* Number of bits by which ins_h must be shifted at each input 393 * step. It must be such that after MIN_MATCH steps, the oldest 394 * byte no longer takes part in the hash key, that is: 395 * hash_shift * MIN_MATCH >= hash_bits 396 */ 397 398 long block_start; 399 /* Window position at the beginning of the current output block. Gets 400 * negative when the window is moved backwards. 401 */ 402 403 uInt match_length; /* length of best match */ 404 IPos prev_match; /* previous match */ 405 int match_available; /* set if previous match exists */ 406 uInt strstart; /* start of string to insert */ 407 uInt match_start; /* start of matching string */ 408 uInt lookahead; /* number of valid bytes ahead in window */ 409 410 uInt prev_length; 411 /* Length of the best match at previous step. Matches not greater than this 412 * are discarded. This is used in the lazy match evaluation. 413 */ 414 415 uInt max_chain_length; 416 /* To speed up deflation, hash chains are never searched beyond this 417 * length. A higher limit improves compression ratio but degrades the 418 * speed. 419 */ 420 421 uInt max_lazy_match; 422 /* Attempt to find a better match only when the current match is strictly 423 * smaller than this value. This mechanism is used only for compression 424 * levels >= 4. 425 */ 426 # define max_insert_length max_lazy_match 427 /* Insert new strings in the hash table only if the match length is not 428 * greater than this length. This saves time but degrades compression. 429 * max_insert_length is used only for compression levels <= 3. 430 */ 431 432 int level; /* compression level (1..9) */ 433 int strategy; /* favor or force Huffman coding*/ 434 435 uInt good_match; 436 /* Use a faster search when the previous match is longer than this */ 437 438 int nice_match; /* Stop searching when current match exceeds this */ 439 440 /* used by trees.c: */ 441 /* Didn't use ct_data typedef below to supress compiler warning */ 442 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 443 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 444 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 445 446 struct tree_desc_s l_desc; /* desc. for literal tree */ 447 struct tree_desc_s d_desc; /* desc. for distance tree */ 448 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 449 450 ush bl_count[MAX_BITS+1]; 451 /* number of codes at each bit length for an optimal tree */ 452 453 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 454 int heap_len; /* number of elements in the heap */ 455 int heap_max; /* element of largest frequency */ 456 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 457 * The same heap array is used to build all trees. 458 */ 459 460 uch depth[2*L_CODES+1]; 461 /* Depth of each subtree used as tie breaker for trees of equal frequency 462 */ 463 464 uchf *l_buf; /* buffer for literals or lengths */ 465 466 uInt lit_bufsize; 467 /* Size of match buffer for literals/lengths. There are 4 reasons for 468 * limiting lit_bufsize to 64K: 469 * - frequencies can be kept in 16 bit counters 470 * - if compression is not successful for the first block, all input 471 * data is still in the window so we can still emit a stored block even 472 * when input comes from standard input. (This can also be done for 473 * all blocks if lit_bufsize is not greater than 32K.) 474 * - if compression is not successful for a file smaller than 64K, we can 475 * even emit a stored file instead of a stored block (saving 5 bytes). 476 * This is applicable only for zip (not gzip or zlib). 477 * - creating new Huffman trees less frequently may not provide fast 478 * adaptation to changes in the input data statistics. (Take for 479 * example a binary file with poorly compressible code followed by 480 * a highly compressible string table.) Smaller buffer sizes give 481 * fast adaptation but have of course the overhead of transmitting 482 * trees more frequently. 483 * - I can't count above 4 484 */ 485 486 uInt last_lit; /* running index in l_buf */ 487 488 ushf *d_buf; 489 /* Buffer for distances. To simplify the code, d_buf and l_buf have 490 * the same number of elements. To use different lengths, an extra flag 491 * array would be necessary. 492 */ 493 494 ulg opt_len; /* bit length of current block with optimal trees */ 495 ulg static_len; /* bit length of current block with static trees */ 496 ulg compressed_len; /* total bit length of compressed file */ 497 uInt matches; /* number of string matches in current block */ 498 int last_eob_len; /* bit length of EOB code for last block */ 499 500 #ifdef DEBUG_ZLIB 501 ulg bits_sent; /* bit length of the compressed data */ 502 #endif 503 504 ush bi_buf; 505 /* Output buffer. bits are inserted starting at the bottom (least 506 * significant bits). 507 */ 508 int bi_valid; 509 /* Number of valid bits in bi_buf. All bits above the last valid bit 510 * are always zero. 511 */ 512 513 } FAR deflate_state; 514 515 /* Output a byte on the stream. 516 * IN assertion: there is enough room in pending_buf. 517 */ 518 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 519 520 521 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 522 /* Minimum amount of lookahead, except at the end of the input file. 523 * See deflate.c for comments about the MIN_MATCH+1. 524 */ 525 526 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 527 /* In order to simplify the code, particularly on 16 bit machines, match 528 * distances are limited to MAX_DIST instead of WSIZE. 529 */ 530 531 /* in trees.c */ 532 void _tr_init OF((deflate_state *s)); 533 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); 534 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 535 int eof)); 536 void _tr_align OF((deflate_state *s)); 537 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 538 int eof)); 539 void _tr_stored_type_only OF((deflate_state *)); 540 541 #endif 542 /* --- deflate.h */ 543 544 /* +++ deflate.c */ 545 /* deflate.c -- compress data using the deflation algorithm 546 * Copyright (C) 1995-1996 Jean-loup Gailly. 547 * For conditions of distribution and use, see copyright notice in zlib.h 548 */ 549 550 /* 551 * ALGORITHM 552 * 553 * The "deflation" process depends on being able to identify portions 554 * of the input text which are identical to earlier input (within a 555 * sliding window trailing behind the input currently being processed). 556 * 557 * The most straightforward technique turns out to be the fastest for 558 * most input files: try all possible matches and select the longest. 559 * The key feature of this algorithm is that insertions into the string 560 * dictionary are very simple and thus fast, and deletions are avoided 561 * completely. Insertions are performed at each input character, whereas 562 * string matches are performed only when the previous match ends. So it 563 * is preferable to spend more time in matches to allow very fast string 564 * insertions and avoid deletions. The matching algorithm for small 565 * strings is inspired from that of Rabin & Karp. A brute force approach 566 * is used to find longer strings when a small match has been found. 567 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 568 * (by Leonid Broukhis). 569 * A previous version of this file used a more sophisticated algorithm 570 * (by Fiala and Greene) which is guaranteed to run in linear amortized 571 * time, but has a larger average cost, uses more memory and is patented. 572 * However the F&G algorithm may be faster for some highly redundant 573 * files if the parameter max_chain_length (described below) is too large. 574 * 575 * ACKNOWLEDGEMENTS 576 * 577 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 578 * I found it in 'freeze' written by Leonid Broukhis. 579 * Thanks to many people for bug reports and testing. 580 * 581 * REFERENCES 582 * 583 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". 584 * Available in ftp://ds.internic.net/rfc/rfc1951.txt 585 * 586 * A description of the Rabin and Karp algorithm is given in the book 587 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 588 * 589 * Fiala,E.R., and Greene,D.H. 590 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 591 * 592 */ 593 594 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */ 595 596 /* #include "deflate.h" */ 597 598 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly "; 599 /* 600 If you use the zlib library in a product, an acknowledgment is welcome 601 in the documentation of your product. If for some reason you cannot 602 include such an acknowledgment, I would appreciate that you keep this 603 copyright string in the executable of your product. 604 */ 605 606 /* =========================================================================== 607 * Function prototypes. 608 */ 609 typedef enum { 610 need_more, /* block not completed, need more input or more output */ 611 block_done, /* block flush performed */ 612 finish_started, /* finish started, need only more output at next deflate */ 613 finish_done /* finish done, accept no more input or output */ 614 } block_state; 615 616 typedef block_state (*compress_func) OF((deflate_state *s, int flush)); 617 /* Compression function. Returns the block state after the call. */ 618 619 local void fill_window OF((deflate_state *s)); 620 local block_state deflate_stored OF((deflate_state *s, int flush)); 621 local block_state deflate_fast OF((deflate_state *s, int flush)); 622 local block_state deflate_slow OF((deflate_state *s, int flush)); 623 local void lm_init OF((deflate_state *s)); 624 local void putShortMSB OF((deflate_state *s, uInt b)); 625 local void flush_pending OF((z_streamp strm)); 626 local int read_buf OF((z_streamp strm, charf *buf, unsigned size)); 627 #ifdef ASMV 628 void match_init OF((void)); /* asm code initialization */ 629 uInt longest_match OF((deflate_state *s, IPos cur_match)); 630 #else 631 local uInt longest_match OF((deflate_state *s, IPos cur_match)); 632 #endif 633 634 #ifdef DEBUG_ZLIB 635 local void check_match OF((deflate_state *s, IPos start, IPos match, 636 int length)); 637 #endif 638 639 /* =========================================================================== 640 * Local data 641 */ 642 643 #define NIL 0 644 /* Tail of hash chains */ 645 646 #ifndef TOO_FAR 647 # define TOO_FAR 4096 648 #endif 649 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 650 651 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 652 /* Minimum amount of lookahead, except at the end of the input file. 653 * See deflate.c for comments about the MIN_MATCH+1. 654 */ 655 656 /* Values for max_lazy_match, good_match and max_chain_length, depending on 657 * the desired pack level (0..9). The values given below have been tuned to 658 * exclude worst case performance for pathological files. Better values may be 659 * found for specific files. 660 */ 661 typedef struct config_s { 662 ush good_length; /* reduce lazy search above this match length */ 663 ush max_lazy; /* do not perform lazy search above this match length */ 664 ush nice_length; /* quit search above this match length */ 665 ush max_chain; 666 compress_func func; 667 } config; 668 669 local config configuration_table[10] = { 670 /* good lazy nice chain */ 671 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ 672 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */ 673 /* 2 */ {4, 5, 16, 8, deflate_fast}, 674 /* 3 */ {4, 6, 32, 32, deflate_fast}, 675 676 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ 677 /* 5 */ {8, 16, 32, 32, deflate_slow}, 678 /* 6 */ {8, 16, 128, 128, deflate_slow}, 679 /* 7 */ {8, 32, 128, 256, deflate_slow}, 680 /* 8 */ {32, 128, 258, 1024, deflate_slow}, 681 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */ 682 683 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 684 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 685 * meaning. 686 */ 687 688 #define EQUAL 0 689 /* result of memcmp for equal strings */ 690 691 #ifndef NO_DUMMY_DECL 692 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ 693 #endif 694 695 /* =========================================================================== 696 * Update a hash value with the given input byte 697 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 698 * input characters, so that a running hash key can be computed from the 699 * previous key instead of complete recalculation each time. 700 */ 701 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 702 703 704 /* =========================================================================== 705 * Insert string str in the dictionary and set match_head to the previous head 706 * of the hash chain (the most recent string with same hash key). Return 707 * the previous length of the hash chain. 708 * IN assertion: all calls to to INSERT_STRING are made with consecutive 709 * input characters and the first MIN_MATCH bytes of str are valid 710 * (except for the last MIN_MATCH-1 bytes of the input file). 711 */ 712 #define INSERT_STRING(s, str, match_head) \ 713 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 714 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 715 s->head[s->ins_h] = (Pos)(str)) 716 717 /* =========================================================================== 718 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 719 * prev[] will be initialized on the fly. 720 */ 721 #define CLEAR_HASH(s) \ 722 s->head[s->hash_size-1] = NIL; \ 723 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 724 725 /* ========================================================================= */ 726 int deflateInit_(strm, level, version, stream_size) 727 z_streamp strm; 728 int level; 729 const char *version; 730 int stream_size; 731 { 732 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 733 Z_DEFAULT_STRATEGY, version, stream_size); 734 /* To do: ignore strm->next_in if we use it as window */ 735 } 736 737 /* ========================================================================= */ 738 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy, 739 version, stream_size) 740 z_streamp strm; 741 int level; 742 int method; 743 int windowBits; 744 int memLevel; 745 int strategy; 746 const char *version; 747 int stream_size; 748 { 749 deflate_state *s; 750 int noheader = 0; 751 static char* my_version = ZLIB_VERSION; 752 753 ushf *overlay; 754 /* We overlay pending_buf and d_buf+l_buf. This works since the average 755 * output size for (length,distance) codes is <= 24 bits. 756 */ 757 758 if (version == Z_NULL || version[0] != my_version[0] || 759 stream_size != sizeof(z_stream)) { 760 return Z_VERSION_ERROR; 761 } 762 if (strm == Z_NULL) return Z_STREAM_ERROR; 763 764 strm->msg = Z_NULL; 765 #ifndef NO_ZCFUNCS 766 if (strm->zalloc == Z_NULL) { 767 strm->zalloc = zcalloc; 768 strm->opaque = (voidpf)0; 769 } 770 if (strm->zfree == Z_NULL) strm->zfree = zcfree; 771 #endif 772 773 if (level == Z_DEFAULT_COMPRESSION) level = 6; 774 775 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 776 noheader = 1; 777 windowBits = -windowBits; 778 } 779 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || 780 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 || 781 strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 782 return Z_STREAM_ERROR; 783 } 784 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 785 if (s == Z_NULL) return Z_MEM_ERROR; 786 strm->state = (struct internal_state FAR *)s; 787 s->strm = strm; 788 789 s->noheader = noheader; 790 s->w_bits = windowBits; 791 s->w_size = 1 << s->w_bits; 792 s->w_mask = s->w_size - 1; 793 794 s->hash_bits = memLevel + 7; 795 s->hash_size = 1 << s->hash_bits; 796 s->hash_mask = s->hash_size - 1; 797 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 798 799 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 800 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 801 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 802 803 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 804 805 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); 806 s->pending_buf = (uchf *) overlay; 807 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); 808 809 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 810 s->pending_buf == Z_NULL) { 811 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR); 812 deflateEnd (strm); 813 return Z_MEM_ERROR; 814 } 815 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); 816 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; 817 818 s->level = level; 819 s->strategy = strategy; 820 s->method = (Byte)method; 821 822 return deflateReset(strm); 823 } 824 825 /* ========================================================================= */ 826 int deflateSetDictionary (strm, dictionary, dictLength) 827 z_streamp strm; 828 const Bytef *dictionary; 829 uInt dictLength; 830 { 831 deflate_state *s; 832 uInt length = dictLength; 833 uInt n; 834 IPos hash_head = 0; 835 836 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) 837 return Z_STREAM_ERROR; 838 839 s = (deflate_state *) strm->state; 840 if (s->status != INIT_STATE) return Z_STREAM_ERROR; 841 842 strm->adler = adler32(strm->adler, dictionary, dictLength); 843 844 if (length < MIN_MATCH) return Z_OK; 845 if (length > MAX_DIST(s)) { 846 length = MAX_DIST(s); 847 #ifndef USE_DICT_HEAD 848 dictionary += dictLength - length; /* use the tail of the dictionary */ 849 #endif 850 } 851 zmemcpy((charf *)s->window, dictionary, length); 852 s->strstart = length; 853 s->block_start = (long)length; 854 855 /* Insert all strings in the hash table (except for the last two bytes). 856 * s->lookahead stays null, so s->ins_h will be recomputed at the next 857 * call of fill_window. 858 */ 859 s->ins_h = s->window[0]; 860 UPDATE_HASH(s, s->ins_h, s->window[1]); 861 for (n = 0; n <= length - MIN_MATCH; n++) { 862 INSERT_STRING(s, n, hash_head); 863 } 864 if (hash_head) hash_head = 0; /* to make compiler happy */ 865 return Z_OK; 866 } 867 868 /* ========================================================================= */ 869 int deflateReset (strm) 870 z_streamp strm; 871 { 872 deflate_state *s; 873 874 if (strm == Z_NULL || strm->state == Z_NULL || 875 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 876 877 strm->total_in = strm->total_out = 0; 878 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 879 strm->data_type = Z_UNKNOWN; 880 881 s = (deflate_state *)strm->state; 882 s->pending = 0; 883 s->pending_out = s->pending_buf; 884 885 if (s->noheader < 0) { 886 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 887 } 888 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 889 strm->adler = 1; 890 s->last_flush = Z_NO_FLUSH; 891 892 _tr_init(s); 893 lm_init(s); 894 895 return Z_OK; 896 } 897 898 /* ========================================================================= */ 899 int deflateParams(strm, level, strategy) 900 z_streamp strm; 901 int level; 902 int strategy; 903 { 904 deflate_state *s; 905 compress_func func; 906 int err = Z_OK; 907 908 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 909 s = (deflate_state *) strm->state; 910 911 if (level == Z_DEFAULT_COMPRESSION) { 912 level = 6; 913 } 914 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 915 return Z_STREAM_ERROR; 916 } 917 func = configuration_table[s->level].func; 918 919 if (func != configuration_table[level].func && strm->total_in != 0) { 920 /* Flush the last buffer: */ 921 err = deflate(strm, Z_PARTIAL_FLUSH); 922 } 923 if (s->level != level) { 924 s->level = level; 925 s->max_lazy_match = configuration_table[level].max_lazy; 926 s->good_match = configuration_table[level].good_length; 927 s->nice_match = configuration_table[level].nice_length; 928 s->max_chain_length = configuration_table[level].max_chain; 929 } 930 s->strategy = strategy; 931 return err; 932 } 933 934 /* ========================================================================= 935 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 936 * IN assertion: the stream state is correct and there is enough room in 937 * pending_buf. 938 */ 939 local void putShortMSB (s, b) 940 deflate_state *s; 941 uInt b; 942 { 943 put_byte(s, (Byte)(b >> 8)); 944 put_byte(s, (Byte)(b & 0xff)); 945 } 946 947 /* ========================================================================= 948 * Flush as much pending output as possible. All deflate() output goes 949 * through this function so some applications may wish to modify it 950 * to avoid allocating a large strm->next_out buffer and copying into it. 951 * (See also read_buf()). 952 */ 953 local void flush_pending(strm) 954 z_streamp strm; 955 { 956 deflate_state *s = (deflate_state *) strm->state; 957 unsigned len = s->pending; 958 959 if (len > strm->avail_out) len = strm->avail_out; 960 if (len == 0) return; 961 962 if (strm->next_out != Z_NULL) { 963 zmemcpy(strm->next_out, s->pending_out, len); 964 strm->next_out += len; 965 } 966 s->pending_out += len; 967 strm->total_out += len; 968 strm->avail_out -= len; 969 s->pending -= len; 970 if (s->pending == 0) { 971 s->pending_out = s->pending_buf; 972 } 973 } 974 975 /* ========================================================================= */ 976 int deflate (strm, flush) 977 z_streamp strm; 978 int flush; 979 { 980 int old_flush; /* value of flush param for previous deflate call */ 981 deflate_state *s; 982 983 if (strm == Z_NULL || strm->state == Z_NULL || 984 flush > Z_FINISH || flush < 0) { 985 return Z_STREAM_ERROR; 986 } 987 s = (deflate_state *) strm->state; 988 989 if ((strm->next_in == Z_NULL && strm->avail_in != 0) || 990 (s->status == FINISH_STATE && flush != Z_FINISH)) { 991 ERR_RETURN(strm, Z_STREAM_ERROR); 992 } 993 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 994 995 s->strm = strm; /* just in case */ 996 old_flush = s->last_flush; 997 s->last_flush = flush; 998 999 /* Write the zlib header */ 1000 if (s->status == INIT_STATE) { 1001 1002 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; 1003 uInt level_flags = (s->level-1) >> 1; 1004 1005 if (level_flags > 3) level_flags = 3; 1006 header |= (level_flags << 6); 1007 if (s->strstart != 0) header |= PRESET_DICT; 1008 header += 31 - (header % 31); 1009 1010 s->status = BUSY_STATE; 1011 putShortMSB(s, header); 1012 1013 /* Save the adler32 of the preset dictionary: */ 1014 if (s->strstart != 0) { 1015 putShortMSB(s, (uInt)(strm->adler >> 16)); 1016 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1017 } 1018 strm->adler = 1L; 1019 } 1020 1021 /* Flush as much pending output as possible */ 1022 if (s->pending != 0) { 1023 flush_pending(strm); 1024 if (strm->avail_out == 0) { 1025 /* Since avail_out is 0, deflate will be called again with 1026 * more output space, but possibly with both pending and 1027 * avail_in equal to zero. There won't be anything to do, 1028 * but this is not an error situation so make sure we 1029 * return OK instead of BUF_ERROR at next call of deflate: 1030 */ 1031 s->last_flush = -1; 1032 return Z_OK; 1033 } 1034 1035 /* Make sure there is something to do and avoid duplicate consecutive 1036 * flushes. For repeated and useless calls with Z_FINISH, we keep 1037 * returning Z_STREAM_END instead of Z_BUFF_ERROR. 1038 */ 1039 } else if (strm->avail_in == 0 && flush <= old_flush && 1040 flush != Z_FINISH) { 1041 ERR_RETURN(strm, Z_BUF_ERROR); 1042 } 1043 1044 /* User must not provide more input after the first FINISH: */ 1045 if (s->status == FINISH_STATE && strm->avail_in != 0) { 1046 ERR_RETURN(strm, Z_BUF_ERROR); 1047 } 1048 1049 /* Start a new block or continue the current one. 1050 */ 1051 if (strm->avail_in != 0 || s->lookahead != 0 || 1052 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { 1053 block_state bstate; 1054 1055 bstate = (*(configuration_table[s->level].func))(s, flush); 1056 1057 if (bstate == finish_started || bstate == finish_done) { 1058 s->status = FINISH_STATE; 1059 } 1060 if (bstate == need_more || bstate == finish_started) { 1061 if (strm->avail_out == 0) { 1062 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ 1063 } 1064 return Z_OK; 1065 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 1066 * of deflate should use the same flush parameter to make sure 1067 * that the flush is complete. So we don't have to output an 1068 * empty block here, this will be done at next call. This also 1069 * ensures that for a very small output buffer, we emit at most 1070 * one empty block. 1071 */ 1072 } 1073 if (bstate == block_done) { 1074 if (flush == Z_PARTIAL_FLUSH) { 1075 _tr_align(s); 1076 } else if (flush == Z_PACKET_FLUSH) { 1077 /* Output just the 3-bit `stored' block type value, 1078 but not a zero length. */ 1079 _tr_stored_type_only(s); 1080 } else { /* FULL_FLUSH or SYNC_FLUSH */ 1081 _tr_stored_block(s, (char*)0, 0L, 0); 1082 /* For a full flush, this empty block will be recognized 1083 * as a special marker by inflate_sync(). 1084 */ 1085 if (flush == Z_FULL_FLUSH) { 1086 CLEAR_HASH(s); /* forget history */ 1087 } 1088 } 1089 flush_pending(strm); 1090 if (strm->avail_out == 0) { 1091 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ 1092 return Z_OK; 1093 } 1094 } 1095 } 1096 Assert(strm->avail_out > 0, "bug2"); 1097 1098 if (flush != Z_FINISH) return Z_OK; 1099 if (s->noheader) return Z_STREAM_END; 1100 1101 /* Write the zlib trailer (adler32) */ 1102 putShortMSB(s, (uInt)(strm->adler >> 16)); 1103 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1104 flush_pending(strm); 1105 /* If avail_out is zero, the application will call deflate again 1106 * to flush the rest. 1107 */ 1108 s->noheader = -1; /* write the trailer only once! */ 1109 return s->pending != 0 ? Z_OK : Z_STREAM_END; 1110 } 1111 1112 /* ========================================================================= */ 1113 int deflateEnd (strm) 1114 z_streamp strm; 1115 { 1116 int status; 1117 deflate_state *s; 1118 1119 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 1120 s = (deflate_state *) strm->state; 1121 1122 status = s->status; 1123 if (status != INIT_STATE && status != BUSY_STATE && 1124 status != FINISH_STATE) { 1125 return Z_STREAM_ERROR; 1126 } 1127 1128 /* Deallocate in reverse order of allocations: */ 1129 TRY_FREE(strm, s->pending_buf); 1130 TRY_FREE(strm, s->head); 1131 TRY_FREE(strm, s->prev); 1132 TRY_FREE(strm, s->window); 1133 1134 ZFREE(strm, s); 1135 strm->state = Z_NULL; 1136 1137 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; 1138 } 1139 1140 /* ========================================================================= 1141 * Copy the source state to the destination state. 1142 */ 1143 int deflateCopy (dest, source) 1144 z_streamp dest; 1145 z_streamp source; 1146 { 1147 deflate_state *ds; 1148 deflate_state *ss; 1149 ushf *overlay; 1150 1151 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) 1152 return Z_STREAM_ERROR; 1153 ss = (deflate_state *) source->state; 1154 1155 zmemcpy(dest, source, sizeof(*dest)); 1156 1157 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); 1158 if (ds == Z_NULL) return Z_MEM_ERROR; 1159 dest->state = (struct internal_state FAR *) ds; 1160 zmemcpy(ds, ss, sizeof(*ds)); 1161 ds->strm = dest; 1162 1163 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); 1164 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); 1165 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); 1166 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); 1167 ds->pending_buf = (uchf *) overlay; 1168 1169 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || 1170 ds->pending_buf == Z_NULL) { 1171 deflateEnd (dest); 1172 return Z_MEM_ERROR; 1173 } 1174 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ 1175 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); 1176 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); 1177 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); 1178 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); 1179 1180 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); 1181 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); 1182 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; 1183 1184 ds->l_desc.dyn_tree = ds->dyn_ltree; 1185 ds->d_desc.dyn_tree = ds->dyn_dtree; 1186 ds->bl_desc.dyn_tree = ds->bl_tree; 1187 1188 return Z_OK; 1189 } 1190 1191 /* =========================================================================== 1192 * Return the number of bytes of output which are immediately available 1193 * for output from the decompressor. 1194 */ 1195 int deflateOutputPending (strm) 1196 z_streamp strm; 1197 { 1198 if (strm == Z_NULL || strm->state == Z_NULL) return 0; 1199 1200 return ((deflate_state *)(strm->state))->pending; 1201 } 1202 1203 /* =========================================================================== 1204 * Read a new buffer from the current input stream, update the adler32 1205 * and total number of bytes read. All deflate() input goes through 1206 * this function so some applications may wish to modify it to avoid 1207 * allocating a large strm->next_in buffer and copying from it. 1208 * (See also flush_pending()). 1209 */ 1210 local int read_buf(strm, buf, size) 1211 z_streamp strm; 1212 charf *buf; 1213 unsigned size; 1214 { 1215 unsigned len = strm->avail_in; 1216 1217 if (len > size) len = size; 1218 if (len == 0) return 0; 1219 1220 strm->avail_in -= len; 1221 1222 if (!((deflate_state *)(strm->state))->noheader) { 1223 strm->adler = adler32(strm->adler, strm->next_in, len); 1224 } 1225 zmemcpy(buf, strm->next_in, len); 1226 strm->next_in += len; 1227 strm->total_in += len; 1228 1229 return (int)len; 1230 } 1231 1232 /* =========================================================================== 1233 * Initialize the "longest match" routines for a new zlib stream 1234 */ 1235 local void lm_init (s) 1236 deflate_state *s; 1237 { 1238 s->window_size = (ulg)2L*s->w_size; 1239 1240 CLEAR_HASH(s); 1241 1242 /* Set the default configuration parameters: 1243 */ 1244 s->max_lazy_match = configuration_table[s->level].max_lazy; 1245 s->good_match = configuration_table[s->level].good_length; 1246 s->nice_match = configuration_table[s->level].nice_length; 1247 s->max_chain_length = configuration_table[s->level].max_chain; 1248 1249 s->strstart = 0; 1250 s->block_start = 0L; 1251 s->lookahead = 0; 1252 s->match_length = s->prev_length = MIN_MATCH-1; 1253 s->match_available = 0; 1254 s->ins_h = 0; 1255 #ifdef ASMV 1256 match_init(); /* initialize the asm code */ 1257 #endif 1258 } 1259 1260 /* =========================================================================== 1261 * Set match_start to the longest match starting at the given string and 1262 * return its length. Matches shorter or equal to prev_length are discarded, 1263 * in which case the result is equal to prev_length and match_start is 1264 * garbage. 1265 * IN assertions: cur_match is the head of the hash chain for the current 1266 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 1267 * OUT assertion: the match length is not greater than s->lookahead. 1268 */ 1269 #ifndef ASMV 1270 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or 1271 * match.S. The code will be functionally equivalent. 1272 */ 1273 local uInt longest_match(s, cur_match) 1274 deflate_state *s; 1275 IPos cur_match; /* current match */ 1276 { 1277 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 1278 register Bytef *scan = s->window + s->strstart; /* current string */ 1279 register Bytef *match; /* matched string */ 1280 register int len; /* length of current match */ 1281 int best_len = s->prev_length; /* best match length so far */ 1282 int nice_match = s->nice_match; /* stop if match long enough */ 1283 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 1284 s->strstart - (IPos)MAX_DIST(s) : NIL; 1285 /* Stop when cur_match becomes <= limit. To simplify the code, 1286 * we prevent matches with the string of window index 0. 1287 */ 1288 Posf *prev = s->prev; 1289 uInt wmask = s->w_mask; 1290 1291 #ifdef UNALIGNED_OK 1292 /* Compare two bytes at a time. Note: this is not always beneficial. 1293 * Try with and without -DUNALIGNED_OK to check. 1294 */ 1295 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 1296 register ush scan_start = *(ushf*)scan; 1297 register ush scan_end = *(ushf*)(scan+best_len-1); 1298 #else 1299 register Bytef *strend = s->window + s->strstart + MAX_MATCH; 1300 register Byte scan_end1 = scan[best_len-1]; 1301 register Byte scan_end = scan[best_len]; 1302 #endif 1303 1304 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 1305 * It is easy to get rid of this optimization if necessary. 1306 */ 1307 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 1308 1309 /* Do not waste too much time if we already have a good match: */ 1310 if (s->prev_length >= s->good_match) { 1311 chain_length >>= 2; 1312 } 1313 /* Do not look for matches beyond the end of the input. This is necessary 1314 * to make deflate deterministic. 1315 */ 1316 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; 1317 1318 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1319 1320 do { 1321 Assert(cur_match < s->strstart, "no future"); 1322 match = s->window + cur_match; 1323 1324 /* Skip to next match if the match length cannot increase 1325 * or if the match length is less than 2: 1326 */ 1327 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1328 /* This code assumes sizeof(unsigned short) == 2. Do not use 1329 * UNALIGNED_OK if your compiler uses a different size. 1330 */ 1331 if (*(ushf*)(match+best_len-1) != scan_end || 1332 *(ushf*)match != scan_start) continue; 1333 1334 /* It is not necessary to compare scan[2] and match[2] since they are 1335 * always equal when the other bytes match, given that the hash keys 1336 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1337 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1338 * lookahead only every 4th comparison; the 128th check will be made 1339 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1340 * necessary to put more guard bytes at the end of the window, or 1341 * to check more often for insufficient lookahead. 1342 */ 1343 Assert(scan[2] == match[2], "scan[2]?"); 1344 scan++, match++; 1345 do { 1346 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1347 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1348 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1349 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1350 scan < strend); 1351 /* The funny "do {}" generates better code on most compilers */ 1352 1353 /* Here, scan <= window+strstart+257 */ 1354 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1355 if (*scan == *match) scan++; 1356 1357 len = (MAX_MATCH - 1) - (int)(strend-scan); 1358 scan = strend - (MAX_MATCH-1); 1359 1360 #else /* UNALIGNED_OK */ 1361 1362 if (match[best_len] != scan_end || 1363 match[best_len-1] != scan_end1 || 1364 *match != *scan || 1365 *++match != scan[1]) continue; 1366 1367 /* The check at best_len-1 can be removed because it will be made 1368 * again later. (This heuristic is not always a win.) 1369 * It is not necessary to compare scan[2] and match[2] since they 1370 * are always equal when the other bytes match, given that 1371 * the hash keys are equal and that HASH_BITS >= 8. 1372 */ 1373 scan += 2, match++; 1374 Assert(*scan == *match, "match[2]?"); 1375 1376 /* We check for insufficient lookahead only every 8th comparison; 1377 * the 256th check will be made at strstart+258. 1378 */ 1379 do { 1380 } while (*++scan == *++match && *++scan == *++match && 1381 *++scan == *++match && *++scan == *++match && 1382 *++scan == *++match && *++scan == *++match && 1383 *++scan == *++match && *++scan == *++match && 1384 scan < strend); 1385 1386 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1387 1388 len = MAX_MATCH - (int)(strend - scan); 1389 scan = strend - MAX_MATCH; 1390 1391 #endif /* UNALIGNED_OK */ 1392 1393 if (len > best_len) { 1394 s->match_start = cur_match; 1395 best_len = len; 1396 if (len >= nice_match) break; 1397 #ifdef UNALIGNED_OK 1398 scan_end = *(ushf*)(scan+best_len-1); 1399 #else 1400 scan_end1 = scan[best_len-1]; 1401 scan_end = scan[best_len]; 1402 #endif 1403 } 1404 } while ((cur_match = prev[cur_match & wmask]) > limit 1405 && --chain_length != 0); 1406 1407 if ((uInt)best_len <= s->lookahead) return best_len; 1408 return s->lookahead; 1409 } 1410 #endif /* ASMV */ 1411 1412 #ifdef DEBUG_ZLIB 1413 /* =========================================================================== 1414 * Check that the match at match_start is indeed a match. 1415 */ 1416 local void check_match(s, start, match, length) 1417 deflate_state *s; 1418 IPos start, match; 1419 int length; 1420 { 1421 /* check that the match is indeed a match */ 1422 if (zmemcmp((charf *)s->window + match, 1423 (charf *)s->window + start, length) != EQUAL) { 1424 fprintf(stderr, " start %u, match %u, length %d\n", 1425 start, match, length); 1426 do { 1427 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); 1428 } while (--length != 0); 1429 z_error("invalid match"); 1430 } 1431 if (z_verbose > 1) { 1432 fprintf(stderr,"\\[%d,%d]", start-match, length); 1433 do { putc(s->window[start++], stderr); } while (--length != 0); 1434 } 1435 } 1436 #else 1437 # define check_match(s, start, match, length) 1438 #endif 1439 1440 /* =========================================================================== 1441 * Fill the window when the lookahead becomes insufficient. 1442 * Updates strstart and lookahead. 1443 * 1444 * IN assertion: lookahead < MIN_LOOKAHEAD 1445 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1446 * At least one byte has been read, or avail_in == 0; reads are 1447 * performed for at least two bytes (required for the zip translate_eol 1448 * option -- not supported here). 1449 */ 1450 local void fill_window(s) 1451 deflate_state *s; 1452 { 1453 register unsigned n, m; 1454 register Posf *p; 1455 unsigned more; /* Amount of free space at the end of the window. */ 1456 uInt wsize = s->w_size; 1457 1458 do { 1459 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1460 1461 /* Deal with !@#$% 64K limit: */ 1462 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1463 more = wsize; 1464 1465 } else if (more == (unsigned)(-1)) { 1466 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1467 * and lookahead == 1 (input done one byte at time) 1468 */ 1469 more--; 1470 1471 /* If the window is almost full and there is insufficient lookahead, 1472 * move the upper half to the lower one to make room in the upper half. 1473 */ 1474 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1475 1476 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1477 (unsigned)wsize); 1478 s->match_start -= wsize; 1479 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1480 s->block_start -= (long) wsize; 1481 1482 /* Slide the hash table (could be avoided with 32 bit values 1483 at the expense of memory usage). We slide even when level == 0 1484 to keep the hash table consistent if we switch back to level > 0 1485 later. (Using level 0 permanently is not an optimal usage of 1486 zlib, so we don't care about this pathological case.) 1487 */ 1488 n = s->hash_size; 1489 p = &s->head[n]; 1490 do { 1491 m = *--p; 1492 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1493 } while (--n); 1494 1495 n = wsize; 1496 p = &s->prev[n]; 1497 do { 1498 m = *--p; 1499 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1500 /* If n is not on any hash chain, prev[n] is garbage but 1501 * its value will never be used. 1502 */ 1503 } while (--n); 1504 more += wsize; 1505 } 1506 if (s->strm->avail_in == 0) return; 1507 1508 /* If there was no sliding: 1509 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1510 * more == window_size - lookahead - strstart 1511 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1512 * => more >= window_size - 2*WSIZE + 2 1513 * In the BIG_MEM or MMAP case (not yet supported), 1514 * window_size == input_size + MIN_LOOKAHEAD && 1515 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1516 * Otherwise, window_size == 2*WSIZE so more >= 2. 1517 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1518 */ 1519 Assert(more >= 2, "more < 2"); 1520 1521 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1522 more); 1523 s->lookahead += n; 1524 1525 /* Initialize the hash value now that we have some input: */ 1526 if (s->lookahead >= MIN_MATCH) { 1527 s->ins_h = s->window[s->strstart]; 1528 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1529 #if MIN_MATCH != 3 1530 Call UPDATE_HASH() MIN_MATCH-3 more times 1531 #endif 1532 } 1533 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1534 * but this is not important since only literal bytes will be emitted. 1535 */ 1536 1537 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1538 } 1539 1540 /* =========================================================================== 1541 * Flush the current block, with given end-of-file flag. 1542 * IN assertion: strstart is set to the end of the current match. 1543 */ 1544 #define FLUSH_BLOCK_ONLY(s, eof) { \ 1545 _tr_flush_block(s, (s->block_start >= 0L ? \ 1546 (charf *)&s->window[(unsigned)s->block_start] : \ 1547 (charf *)Z_NULL), \ 1548 (ulg)((long)s->strstart - s->block_start), \ 1549 (eof)); \ 1550 s->block_start = s->strstart; \ 1551 flush_pending(s->strm); \ 1552 Tracev((stderr,"[FLUSH]")); \ 1553 } 1554 1555 /* Same but force premature exit if necessary. */ 1556 #define FLUSH_BLOCK(s, eof) { \ 1557 FLUSH_BLOCK_ONLY(s, eof); \ 1558 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ 1559 } 1560 1561 /* =========================================================================== 1562 * Copy without compression as much as possible from the input stream, return 1563 * the current block state. 1564 * This function does not insert new strings in the dictionary since 1565 * uncompressible data is probably not useful. This function is used 1566 * only for the level=0 compression option. 1567 * NOTE: this function should be optimized to avoid extra copying from 1568 * window to pending_buf. 1569 */ 1570 local block_state deflate_stored(s, flush) 1571 deflate_state *s; 1572 int flush; 1573 { 1574 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited 1575 * to pending_buf_size, and each stored block has a 5 byte header: 1576 */ 1577 ulg max_block_size = 0xffff; 1578 ulg max_start; 1579 1580 if (max_block_size > s->pending_buf_size - 5) { 1581 max_block_size = s->pending_buf_size - 5; 1582 } 1583 1584 /* Copy as much as possible from input to output: */ 1585 for (;;) { 1586 /* Fill the window as much as possible: */ 1587 if (s->lookahead <= 1) { 1588 1589 Assert(s->strstart < s->w_size+MAX_DIST(s) || 1590 s->block_start >= (long)s->w_size, "slide too late"); 1591 1592 fill_window(s); 1593 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; 1594 1595 if (s->lookahead == 0) break; /* flush the current block */ 1596 } 1597 Assert(s->block_start >= 0L, "block gone"); 1598 1599 s->strstart += s->lookahead; 1600 s->lookahead = 0; 1601 1602 /* Emit a stored block if pending_buf will be full: */ 1603 max_start = s->block_start + max_block_size; 1604 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { 1605 /* strstart == 0 is possible when wraparound on 16-bit machine */ 1606 s->lookahead = (uInt)(s->strstart - max_start); 1607 s->strstart = (uInt)max_start; 1608 FLUSH_BLOCK(s, 0); 1609 } 1610 /* Flush if we may have to slide, otherwise block_start may become 1611 * negative and the data will be gone: 1612 */ 1613 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { 1614 FLUSH_BLOCK(s, 0); 1615 } 1616 } 1617 FLUSH_BLOCK(s, flush == Z_FINISH); 1618 return flush == Z_FINISH ? finish_done : block_done; 1619 } 1620 1621 /* =========================================================================== 1622 * Compress as much as possible from the input stream, return the current 1623 * block state. 1624 * This function does not perform lazy evaluation of matches and inserts 1625 * new strings in the dictionary only for unmatched strings or for short 1626 * matches. It is used only for the fast compression options. 1627 */ 1628 local block_state deflate_fast(s, flush) 1629 deflate_state *s; 1630 int flush; 1631 { 1632 IPos hash_head = NIL; /* head of the hash chain */ 1633 int bflush; /* set if current block must be flushed */ 1634 1635 for (;;) { 1636 /* Make sure that we always have enough lookahead, except 1637 * at the end of the input file. We need MAX_MATCH bytes 1638 * for the next match, plus MIN_MATCH bytes to insert the 1639 * string following the next match. 1640 */ 1641 if (s->lookahead < MIN_LOOKAHEAD) { 1642 fill_window(s); 1643 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1644 return need_more; 1645 } 1646 if (s->lookahead == 0) break; /* flush the current block */ 1647 } 1648 1649 /* Insert the string window[strstart .. strstart+2] in the 1650 * dictionary, and set hash_head to the head of the hash chain: 1651 */ 1652 if (s->lookahead >= MIN_MATCH) { 1653 INSERT_STRING(s, s->strstart, hash_head); 1654 } 1655 1656 /* Find the longest match, discarding those <= prev_length. 1657 * At this point we have always match_length < MIN_MATCH 1658 */ 1659 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1660 /* To simplify the code, we prevent matches with the string 1661 * of window index 0 (in particular we have to avoid a match 1662 * of the string with itself at the start of the input file). 1663 */ 1664 if (s->strategy != Z_HUFFMAN_ONLY) { 1665 s->match_length = longest_match (s, hash_head); 1666 } 1667 /* longest_match() sets match_start */ 1668 } 1669 if (s->match_length >= MIN_MATCH) { 1670 check_match(s, s->strstart, s->match_start, s->match_length); 1671 1672 bflush = _tr_tally(s, s->strstart - s->match_start, 1673 s->match_length - MIN_MATCH); 1674 1675 s->lookahead -= s->match_length; 1676 1677 /* Insert new strings in the hash table only if the match length 1678 * is not too large. This saves time but degrades compression. 1679 */ 1680 if (s->match_length <= s->max_insert_length && 1681 s->lookahead >= MIN_MATCH) { 1682 s->match_length--; /* string at strstart already in hash table */ 1683 do { 1684 s->strstart++; 1685 INSERT_STRING(s, s->strstart, hash_head); 1686 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1687 * always MIN_MATCH bytes ahead. 1688 */ 1689 } while (--s->match_length != 0); 1690 s->strstart++; 1691 } else { 1692 s->strstart += s->match_length; 1693 s->match_length = 0; 1694 s->ins_h = s->window[s->strstart]; 1695 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1696 #if MIN_MATCH != 3 1697 Call UPDATE_HASH() MIN_MATCH-3 more times 1698 #endif 1699 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1700 * matter since it will be recomputed at next deflate call. 1701 */ 1702 } 1703 } else { 1704 /* No match, output a literal byte */ 1705 Tracevv((stderr,"%c", s->window[s->strstart])); 1706 bflush = _tr_tally (s, 0, s->window[s->strstart]); 1707 s->lookahead--; 1708 s->strstart++; 1709 } 1710 if (bflush) FLUSH_BLOCK(s, 0); 1711 } 1712 FLUSH_BLOCK(s, flush == Z_FINISH); 1713 return flush == Z_FINISH ? finish_done : block_done; 1714 } 1715 1716 /* =========================================================================== 1717 * Same as above, but achieves better compression. We use a lazy 1718 * evaluation for matches: a match is finally adopted only if there is 1719 * no better match at the next window position. 1720 */ 1721 local block_state deflate_slow(s, flush) 1722 deflate_state *s; 1723 int flush; 1724 { 1725 IPos hash_head = NIL; /* head of hash chain */ 1726 int bflush; /* set if current block must be flushed */ 1727 1728 /* Process the input block. */ 1729 for (;;) { 1730 /* Make sure that we always have enough lookahead, except 1731 * at the end of the input file. We need MAX_MATCH bytes 1732 * for the next match, plus MIN_MATCH bytes to insert the 1733 * string following the next match. 1734 */ 1735 if (s->lookahead < MIN_LOOKAHEAD) { 1736 fill_window(s); 1737 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1738 return need_more; 1739 } 1740 if (s->lookahead == 0) break; /* flush the current block */ 1741 } 1742 1743 /* Insert the string window[strstart .. strstart+2] in the 1744 * dictionary, and set hash_head to the head of the hash chain: 1745 */ 1746 if (s->lookahead >= MIN_MATCH) { 1747 INSERT_STRING(s, s->strstart, hash_head); 1748 } 1749 1750 /* Find the longest match, discarding those <= prev_length. 1751 */ 1752 s->prev_length = s->match_length, s->prev_match = s->match_start; 1753 s->match_length = MIN_MATCH-1; 1754 1755 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1756 s->strstart - hash_head <= MAX_DIST(s)) { 1757 /* To simplify the code, we prevent matches with the string 1758 * of window index 0 (in particular we have to avoid a match 1759 * of the string with itself at the start of the input file). 1760 */ 1761 if (s->strategy != Z_HUFFMAN_ONLY) { 1762 s->match_length = longest_match (s, hash_head); 1763 } 1764 /* longest_match() sets match_start */ 1765 1766 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1767 (s->match_length == MIN_MATCH && 1768 s->strstart - s->match_start > TOO_FAR))) { 1769 1770 /* If prev_match is also MIN_MATCH, match_start is garbage 1771 * but we will ignore the current match anyway. 1772 */ 1773 s->match_length = MIN_MATCH-1; 1774 } 1775 } 1776 /* If there was a match at the previous step and the current 1777 * match is not better, output the previous match: 1778 */ 1779 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1780 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1781 /* Do not insert strings in hash table beyond this. */ 1782 1783 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1784 1785 bflush = _tr_tally(s, s->strstart -1 - s->prev_match, 1786 s->prev_length - MIN_MATCH); 1787 1788 /* Insert in hash table all strings up to the end of the match. 1789 * strstart-1 and strstart are already inserted. If there is not 1790 * enough lookahead, the last two strings are not inserted in 1791 * the hash table. 1792 */ 1793 s->lookahead -= s->prev_length-1; 1794 s->prev_length -= 2; 1795 do { 1796 if (++s->strstart <= max_insert) { 1797 INSERT_STRING(s, s->strstart, hash_head); 1798 } 1799 } while (--s->prev_length != 0); 1800 s->match_available = 0; 1801 s->match_length = MIN_MATCH-1; 1802 s->strstart++; 1803 1804 if (bflush) FLUSH_BLOCK(s, 0); 1805 1806 } else if (s->match_available) { 1807 /* If there was no match at the previous position, output a 1808 * single literal. If there was a match but the current match 1809 * is longer, truncate the previous match to a single literal. 1810 */ 1811 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1812 if (_tr_tally (s, 0, s->window[s->strstart-1])) { 1813 FLUSH_BLOCK_ONLY(s, 0); 1814 } 1815 s->strstart++; 1816 s->lookahead--; 1817 if (s->strm->avail_out == 0) return need_more; 1818 } else { 1819 /* There is no previous match to compare with, wait for 1820 * the next step to decide. 1821 */ 1822 s->match_available = 1; 1823 s->strstart++; 1824 s->lookahead--; 1825 } 1826 } 1827 Assert (flush != Z_NO_FLUSH, "no flush?"); 1828 if (s->match_available) { 1829 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1830 _tr_tally (s, 0, s->window[s->strstart-1]); 1831 s->match_available = 0; 1832 } 1833 FLUSH_BLOCK(s, flush == Z_FINISH); 1834 return flush == Z_FINISH ? finish_done : block_done; 1835 } 1836 /* --- deflate.c */ 1837 1838 /* +++ trees.c */ 1839 /* trees.c -- output deflated data using Huffman coding 1840 * Copyright (C) 1995-1996 Jean-loup Gailly 1841 * For conditions of distribution and use, see copyright notice in zlib.h 1842 */ 1843 1844 /* 1845 * ALGORITHM 1846 * 1847 * The "deflation" process uses several Huffman trees. The more 1848 * common source values are represented by shorter bit sequences. 1849 * 1850 * Each code tree is stored in a compressed form which is itself 1851 * a Huffman encoding of the lengths of all the code strings (in 1852 * ascending order by source values). The actual code strings are 1853 * reconstructed from the lengths in the inflate process, as described 1854 * in the deflate specification. 1855 * 1856 * REFERENCES 1857 * 1858 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1859 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1860 * 1861 * Storer, James A. 1862 * Data Compression: Methods and Theory, pp. 49-50. 1863 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1864 * 1865 * Sedgewick, R. 1866 * Algorithms, p290. 1867 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1868 */ 1869 1870 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ 1871 1872 /* #include "deflate.h" */ 1873 1874 #ifdef DEBUG_ZLIB 1875 # include <ctype.h> 1876 #endif 1877 1878 /* =========================================================================== 1879 * Constants 1880 */ 1881 1882 #define MAX_BL_BITS 7 1883 /* Bit length codes must not exceed MAX_BL_BITS bits */ 1884 1885 #define END_BLOCK 256 1886 /* end of block literal code */ 1887 1888 #define REP_3_6 16 1889 /* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1890 1891 #define REPZ_3_10 17 1892 /* repeat a zero length 3-10 times (3 bits of repeat count) */ 1893 1894 #define REPZ_11_138 18 1895 /* repeat a zero length 11-138 times (7 bits of repeat count) */ 1896 1897 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1898 = {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}; 1899 1900 local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1901 = {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}; 1902 1903 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1904 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1905 1906 local uch bl_order[BL_CODES] 1907 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1908 /* The lengths of the bit length codes are sent in order of decreasing 1909 * probability, to avoid transmitting the lengths for unused bit length codes. 1910 */ 1911 1912 #define Buf_size (8 * 2*sizeof(char)) 1913 /* Number of bits used within bi_buf. (bi_buf might be implemented on 1914 * more than 16 bits on some systems.) 1915 */ 1916 1917 /* =========================================================================== 1918 * Local data. These are initialized only once. 1919 */ 1920 1921 local ct_data static_ltree[L_CODES+2]; 1922 /* The static literal tree. Since the bit lengths are imposed, there is no 1923 * need for the L_CODES extra codes used during heap construction. However 1924 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 1925 * below). 1926 */ 1927 1928 local ct_data static_dtree[D_CODES]; 1929 /* The static distance tree. (Actually a trivial tree since all codes use 1930 * 5 bits.) 1931 */ 1932 1933 local uch dist_code[512]; 1934 /* distance codes. The first 256 values correspond to the distances 1935 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1936 * the 15 bit distances. 1937 */ 1938 1939 local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1940 /* length code for each normalized match length (0 == MIN_MATCH) */ 1941 1942 local int base_length[LENGTH_CODES]; 1943 /* First normalized length for each code (0 = MIN_MATCH) */ 1944 1945 local int base_dist[D_CODES]; 1946 /* First normalized distance for each code (0 = distance of 1) */ 1947 1948 struct static_tree_desc_s { 1949 ct_data *static_tree; /* static tree or NULL */ 1950 intf *extra_bits; /* extra bits for each code or NULL */ 1951 int extra_base; /* base index for extra_bits */ 1952 int elems; /* max number of elements in the tree */ 1953 int max_length; /* max bit length for the codes */ 1954 }; 1955 1956 local static_tree_desc static_l_desc = 1957 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1958 1959 local static_tree_desc static_d_desc = 1960 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1961 1962 local static_tree_desc static_bl_desc = 1963 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1964 1965 /* =========================================================================== 1966 * Local (static) routines in this file. 1967 */ 1968 1969 local void tr_static_init OF((void)); 1970 local void init_block OF((deflate_state *s)); 1971 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1972 local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1973 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1974 local void build_tree OF((deflate_state *s, tree_desc *desc)); 1975 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1976 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1977 local int build_bl_tree OF((deflate_state *s)); 1978 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1979 int blcodes)); 1980 local void compress_block OF((deflate_state *s, ct_data *ltree, 1981 ct_data *dtree)); 1982 local void set_data_type OF((deflate_state *s)); 1983 local unsigned bi_reverse OF((unsigned value, int length)); 1984 local void bi_windup OF((deflate_state *s)); 1985 local void bi_flush OF((deflate_state *s)); 1986 local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1987 int header)); 1988 1989 #ifndef DEBUG_ZLIB 1990 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 1991 /* Send a code of the given tree. c and tree must not have side effects */ 1992 1993 #else /* DEBUG_ZLIB */ 1994 # define send_code(s, c, tree) \ 1995 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 1996 send_bits(s, tree[c].Code, tree[c].Len); } 1997 #endif 1998 1999 #define d_code(dist) \ 2000 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 2001 /* Mapping from a distance to a distance code. dist is the distance - 1 and 2002 * must not have side effects. dist_code[256] and dist_code[257] are never 2003 * used. 2004 */ 2005 2006 /* =========================================================================== 2007 * Output a short LSB first on the stream. 2008 * IN assertion: there is enough room in pendingBuf. 2009 */ 2010 #define put_short(s, w) { \ 2011 put_byte(s, (uch)((w) & 0xff)); \ 2012 put_byte(s, (uch)((ush)(w) >> 8)); \ 2013 } 2014 2015 /* =========================================================================== 2016 * Send a value on a given number of bits. 2017 * IN assertion: length <= 16 and value fits in length bits. 2018 */ 2019 #ifdef DEBUG_ZLIB 2020 local void send_bits OF((deflate_state *s, int value, int length)); 2021 2022 local void send_bits(s, value, length) 2023 deflate_state *s; 2024 int value; /* value to send */ 2025 int length; /* number of bits */ 2026 { 2027 Tracevv((stderr," l %2d v %4x ", length, value)); 2028 Assert(length > 0 && length <= 15, "invalid length"); 2029 s->bits_sent += (ulg)length; 2030 2031 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 2032 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 2033 * unused bits in value. 2034 */ 2035 if (s->bi_valid > (int)Buf_size - length) { 2036 s->bi_buf |= (value << s->bi_valid); 2037 put_short(s, s->bi_buf); 2038 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 2039 s->bi_valid += length - Buf_size; 2040 } else { 2041 s->bi_buf |= value << s->bi_valid; 2042 s->bi_valid += length; 2043 } 2044 } 2045 #else /* !DEBUG_ZLIB */ 2046 2047 #define send_bits(s, value, length) \ 2048 { int len = length;\ 2049 if (s->bi_valid > (int)Buf_size - len) {\ 2050 int val = value;\ 2051 s->bi_buf |= (val << s->bi_valid);\ 2052 put_short(s, s->bi_buf);\ 2053 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 2054 s->bi_valid += len - Buf_size;\ 2055 } else {\ 2056 s->bi_buf |= (value) << s->bi_valid;\ 2057 s->bi_valid += len;\ 2058 }\ 2059 } 2060 #endif /* DEBUG_ZLIB */ 2061 2062 2063 #define MAX(a,b) (a >= b ? a : b) 2064 /* the arguments must not have side effects */ 2065 2066 /* =========================================================================== 2067 * Initialize the various 'constant' tables. In a multi-threaded environment, 2068 * this function may be called by two threads concurrently, but this is 2069 * harmless since both invocations do exactly the same thing. 2070 */ 2071 local void tr_static_init() 2072 { 2073 static int static_init_done = 0; 2074 int n; /* iterates over tree elements */ 2075 int bits; /* bit counter */ 2076 int length; /* length value */ 2077 int code; /* code value */ 2078 int dist; /* distance index */ 2079 ush bl_count[MAX_BITS+1]; 2080 /* number of codes at each bit length for an optimal tree */ 2081 2082 if (static_init_done) return; 2083 2084 /* Initialize the mapping length (0..255) -> length code (0..28) */ 2085 length = 0; 2086 for (code = 0; code < LENGTH_CODES-1; code++) { 2087 base_length[code] = length; 2088 for (n = 0; n < (1<<extra_lbits[code]); n++) { 2089 length_code[length++] = (uch)code; 2090 } 2091 } 2092 Assert (length == 256, "tr_static_init: length != 256"); 2093 /* Note that the length 255 (match length 258) can be represented 2094 * in two different ways: code 284 + 5 bits or code 285, so we 2095 * overwrite length_code[255] to use the best encoding: 2096 */ 2097 length_code[length-1] = (uch)code; 2098 2099 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 2100 dist = 0; 2101 for (code = 0 ; code < 16; code++) { 2102 base_dist[code] = dist; 2103 for (n = 0; n < (1<<extra_dbits[code]); n++) { 2104 dist_code[dist++] = (uch)code; 2105 } 2106 } 2107 Assert (dist == 256, "tr_static_init: dist != 256"); 2108 dist >>= 7; /* from now on, all distances are divided by 128 */ 2109 for ( ; code < D_CODES; code++) { 2110 base_dist[code] = dist << 7; 2111 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 2112 dist_code[256 + dist++] = (uch)code; 2113 } 2114 } 2115 Assert (dist == 256, "tr_static_init: 256+dist != 512"); 2116 2117 /* Construct the codes of the static literal tree */ 2118 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 2119 n = 0; 2120 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 2121 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 2122 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 2123 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 2124 /* Codes 286 and 287 do not exist, but we must include them in the 2125 * tree construction to get a canonical Huffman tree (longest code 2126 * all ones) 2127 */ 2128 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 2129 2130 /* The static distance tree is trivial: */ 2131 for (n = 0; n < D_CODES; n++) { 2132 static_dtree[n].Len = 5; 2133 static_dtree[n].Code = bi_reverse((unsigned)n, 5); 2134 } 2135 static_init_done = 1; 2136 } 2137 2138 /* =========================================================================== 2139 * Initialize the tree data structures for a new zlib stream. 2140 */ 2141 void _tr_init(s) 2142 deflate_state *s; 2143 { 2144 tr_static_init(); 2145 2146 s->compressed_len = 0L; 2147 2148 s->l_desc.dyn_tree = s->dyn_ltree; 2149 s->l_desc.stat_desc = &static_l_desc; 2150 2151 s->d_desc.dyn_tree = s->dyn_dtree; 2152 s->d_desc.stat_desc = &static_d_desc; 2153 2154 s->bl_desc.dyn_tree = s->bl_tree; 2155 s->bl_desc.stat_desc = &static_bl_desc; 2156 2157 s->bi_buf = 0; 2158 s->bi_valid = 0; 2159 s->last_eob_len = 8; /* enough lookahead for inflate */ 2160 #ifdef DEBUG_ZLIB 2161 s->bits_sent = 0L; 2162 #endif 2163 2164 /* Initialize the first block of the first file: */ 2165 init_block(s); 2166 } 2167 2168 /* =========================================================================== 2169 * Initialize a new block. 2170 */ 2171 local void init_block(s) 2172 deflate_state *s; 2173 { 2174 int n; /* iterates over tree elements */ 2175 2176 /* Initialize the trees. */ 2177 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 2178 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 2179 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 2180 2181 s->dyn_ltree[END_BLOCK].Freq = 1; 2182 s->opt_len = s->static_len = 0L; 2183 s->last_lit = s->matches = 0; 2184 } 2185 2186 #define SMALLEST 1 2187 /* Index within the heap array of least frequent node in the Huffman tree */ 2188 2189 2190 /* =========================================================================== 2191 * Remove the smallest element from the heap and recreate the heap with 2192 * one less element. Updates heap and heap_len. 2193 */ 2194 #define pqremove(s, tree, top) \ 2195 {\ 2196 top = s->heap[SMALLEST]; \ 2197 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 2198 pqdownheap(s, tree, SMALLEST); \ 2199 } 2200 2201 /* =========================================================================== 2202 * Compares to subtrees, using the tree depth as tie breaker when 2203 * the subtrees have equal frequency. This minimizes the worst case length. 2204 */ 2205 #define smaller(tree, n, m, depth) \ 2206 (tree[n].Freq < tree[m].Freq || \ 2207 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 2208 2209 /* =========================================================================== 2210 * Restore the heap property by moving down the tree starting at node k, 2211 * exchanging a node with the smallest of its two sons if necessary, stopping 2212 * when the heap property is re-established (each father smaller than its 2213 * two sons). 2214 */ 2215 local void pqdownheap(s, tree, k) 2216 deflate_state *s; 2217 ct_data *tree; /* the tree to restore */ 2218 int k; /* node to move down */ 2219 { 2220 int v = s->heap[k]; 2221 int j = k << 1; /* left son of k */ 2222 while (j <= s->heap_len) { 2223 /* Set j to the smallest of the two sons: */ 2224 if (j < s->heap_len && 2225 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 2226 j++; 2227 } 2228 /* Exit if v is smaller than both sons */ 2229 if (smaller(tree, v, s->heap[j], s->depth)) break; 2230 2231 /* Exchange v with the smallest son */ 2232 s->heap[k] = s->heap[j]; k = j; 2233 2234 /* And continue down the tree, setting j to the left son of k */ 2235 j <<= 1; 2236 } 2237 s->heap[k] = v; 2238 } 2239 2240 /* =========================================================================== 2241 * Compute the optimal bit lengths for a tree and update the total bit length 2242 * for the current block. 2243 * IN assertion: the fields freq and dad are set, heap[heap_max] and 2244 * above are the tree nodes sorted by increasing frequency. 2245 * OUT assertions: the field len is set to the optimal bit length, the 2246 * array bl_count contains the frequencies for each bit length. 2247 * The length opt_len is updated; static_len is also updated if stree is 2248 * not null. 2249 */ 2250 local void gen_bitlen(s, desc) 2251 deflate_state *s; 2252 tree_desc *desc; /* the tree descriptor */ 2253 { 2254 ct_data *tree = desc->dyn_tree; 2255 int max_code = desc->max_code; 2256 ct_data *stree = desc->stat_desc->static_tree; 2257 intf *extra = desc->stat_desc->extra_bits; 2258 int base = desc->stat_desc->extra_base; 2259 int max_length = desc->stat_desc->max_length; 2260 int h; /* heap index */ 2261 int n, m; /* iterate over the tree elements */ 2262 int bits; /* bit length */ 2263 int xbits; /* extra bits */ 2264 ush f; /* frequency */ 2265 int overflow = 0; /* number of elements with bit length too large */ 2266 2267 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 2268 2269 /* In a first pass, compute the optimal bit lengths (which may 2270 * overflow in the case of the bit length tree). 2271 */ 2272 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 2273 2274 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 2275 n = s->heap[h]; 2276 bits = tree[tree[n].Dad].Len + 1; 2277 if (bits > max_length) bits = max_length, overflow++; 2278 tree[n].Len = (ush)bits; 2279 /* We overwrite tree[n].Dad which is no longer needed */ 2280 2281 if (n > max_code) continue; /* not a leaf node */ 2282 2283 s->bl_count[bits]++; 2284 xbits = 0; 2285 if (n >= base) xbits = extra[n-base]; 2286 f = tree[n].Freq; 2287 s->opt_len += (ulg)f * (bits + xbits); 2288 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 2289 } 2290 if (overflow == 0) return; 2291 2292 Trace((stderr,"\nbit length overflow\n")); 2293 /* This happens for example on obj2 and pic of the Calgary corpus */ 2294 2295 /* Find the first bit length which could increase: */ 2296 do { 2297 bits = max_length-1; 2298 while (s->bl_count[bits] == 0) bits--; 2299 s->bl_count[bits]--; /* move one leaf down the tree */ 2300 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 2301 s->bl_count[max_length]--; 2302 /* The brother of the overflow item also moves one step up, 2303 * but this does not affect bl_count[max_length] 2304 */ 2305 overflow -= 2; 2306 } while (overflow > 0); 2307 2308 /* Now recompute all bit lengths, scanning in increasing frequency. 2309 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 2310 * lengths instead of fixing only the wrong ones. This idea is taken 2311 * from 'ar' written by Haruhiko Okumura.) 2312 */ 2313 for (bits = max_length; bits != 0; bits--) { 2314 n = s->bl_count[bits]; 2315 while (n != 0) { 2316 m = s->heap[--h]; 2317 if (m > max_code) continue; 2318 if (tree[m].Len != (unsigned) bits) { 2319 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 2320 s->opt_len += ((long)bits - (long)tree[m].Len) 2321 *(long)tree[m].Freq; 2322 tree[m].Len = (ush)bits; 2323 } 2324 n--; 2325 } 2326 } 2327 } 2328 2329 /* =========================================================================== 2330 * Generate the codes for a given tree and bit counts (which need not be 2331 * optimal). 2332 * IN assertion: the array bl_count contains the bit length statistics for 2333 * the given tree and the field len is set for all tree elements. 2334 * OUT assertion: the field code is set for all tree elements of non 2335 * zero code length. 2336 */ 2337 local void gen_codes (tree, max_code, bl_count) 2338 ct_data *tree; /* the tree to decorate */ 2339 int max_code; /* largest code with non zero frequency */ 2340 ushf *bl_count; /* number of codes at each bit length */ 2341 { 2342 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 2343 ush code = 0; /* running code value */ 2344 int bits; /* bit index */ 2345 int n; /* code index */ 2346 2347 /* The distribution counts are first used to generate the code values 2348 * without bit reversal. 2349 */ 2350 for (bits = 1; bits <= MAX_BITS; bits++) { 2351 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 2352 } 2353 /* Check that the bit counts in bl_count are consistent. The last code 2354 * must be all ones. 2355 */ 2356 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 2357 "inconsistent bit counts"); 2358 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 2359 2360 for (n = 0; n <= max_code; n++) { 2361 int len = tree[n].Len; 2362 if (len == 0) continue; 2363 /* Now reverse the bits */ 2364 tree[n].Code = bi_reverse(next_code[len]++, len); 2365 2366 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 2367 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 2368 } 2369 } 2370 2371 /* =========================================================================== 2372 * Construct one Huffman tree and assigns the code bit strings and lengths. 2373 * Update the total bit length for the current block. 2374 * IN assertion: the field freq is set for all tree elements. 2375 * OUT assertions: the fields len and code are set to the optimal bit length 2376 * and corresponding code. The length opt_len is updated; static_len is 2377 * also updated if stree is not null. The field max_code is set. 2378 */ 2379 local void build_tree(s, desc) 2380 deflate_state *s; 2381 tree_desc *desc; /* the tree descriptor */ 2382 { 2383 ct_data *tree = desc->dyn_tree; 2384 ct_data *stree = desc->stat_desc->static_tree; 2385 int elems = desc->stat_desc->elems; 2386 int n, m; /* iterate over heap elements */ 2387 int max_code = -1; /* largest code with non zero frequency */ 2388 int node; /* new node being created */ 2389 2390 /* Construct the initial heap, with least frequent element in 2391 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2392 * heap[0] is not used. 2393 */ 2394 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2395 2396 for (n = 0; n < elems; n++) { 2397 if (tree[n].Freq != 0) { 2398 s->heap[++(s->heap_len)] = max_code = n; 2399 s->depth[n] = 0; 2400 } else { 2401 tree[n].Len = 0; 2402 } 2403 } 2404 2405 /* The pkzip format requires that at least one distance code exists, 2406 * and that at least one bit should be sent even if there is only one 2407 * possible code. So to avoid special checks later on we force at least 2408 * two codes of non zero frequency. 2409 */ 2410 while (s->heap_len < 2) { 2411 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2412 tree[node].Freq = 1; 2413 s->depth[node] = 0; 2414 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2415 /* node is 0 or 1 so it does not have extra bits */ 2416 } 2417 desc->max_code = max_code; 2418 2419 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2420 * establish sub-heaps of increasing lengths: 2421 */ 2422 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2423 2424 /* Construct the Huffman tree by repeatedly combining the least two 2425 * frequent nodes. 2426 */ 2427 node = elems; /* next internal node of the tree */ 2428 do { 2429 pqremove(s, tree, n); /* n = node of least frequency */ 2430 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2431 2432 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2433 s->heap[--(s->heap_max)] = m; 2434 2435 /* Create a new node father of n and m */ 2436 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2437 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2438 tree[n].Dad = tree[m].Dad = (ush)node; 2439 #ifdef DUMP_BL_TREE 2440 if (tree == s->bl_tree) { 2441 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2442 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2443 } 2444 #endif 2445 /* and insert the new node in the heap */ 2446 s->heap[SMALLEST] = node++; 2447 pqdownheap(s, tree, SMALLEST); 2448 2449 } while (s->heap_len >= 2); 2450 2451 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2452 2453 /* At this point, the fields freq and dad are set. We can now 2454 * generate the bit lengths. 2455 */ 2456 gen_bitlen(s, (tree_desc *)desc); 2457 2458 /* The field len is now set, we can generate the bit codes */ 2459 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2460 } 2461 2462 /* =========================================================================== 2463 * Scan a literal or distance tree to determine the frequencies of the codes 2464 * in the bit length tree. 2465 */ 2466 local void scan_tree (s, tree, max_code) 2467 deflate_state *s; 2468 ct_data *tree; /* the tree to be scanned */ 2469 int max_code; /* and its largest code of non zero frequency */ 2470 { 2471 int n; /* iterates over all tree elements */ 2472 int prevlen = -1; /* last emitted length */ 2473 int curlen; /* length of current code */ 2474 int nextlen = tree[0].Len; /* length of next code */ 2475 int count = 0; /* repeat count of the current code */ 2476 int max_count = 7; /* max repeat count */ 2477 int min_count = 4; /* min repeat count */ 2478 2479 if (nextlen == 0) max_count = 138, min_count = 3; 2480 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2481 2482 for (n = 0; n <= max_code; n++) { 2483 curlen = nextlen; nextlen = tree[n+1].Len; 2484 if (++count < max_count && curlen == nextlen) { 2485 continue; 2486 } else if (count < min_count) { 2487 s->bl_tree[curlen].Freq += count; 2488 } else if (curlen != 0) { 2489 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2490 s->bl_tree[REP_3_6].Freq++; 2491 } else if (count <= 10) { 2492 s->bl_tree[REPZ_3_10].Freq++; 2493 } else { 2494 s->bl_tree[REPZ_11_138].Freq++; 2495 } 2496 count = 0; prevlen = curlen; 2497 if (nextlen == 0) { 2498 max_count = 138, min_count = 3; 2499 } else if (curlen == nextlen) { 2500 max_count = 6, min_count = 3; 2501 } else { 2502 max_count = 7, min_count = 4; 2503 } 2504 } 2505 } 2506 2507 /* =========================================================================== 2508 * Send a literal or distance tree in compressed form, using the codes in 2509 * bl_tree. 2510 */ 2511 local void send_tree (s, tree, max_code) 2512 deflate_state *s; 2513 ct_data *tree; /* the tree to be scanned */ 2514 int max_code; /* and its largest code of non zero frequency */ 2515 { 2516 int n; /* iterates over all tree elements */ 2517 int prevlen = -1; /* last emitted length */ 2518 int curlen; /* length of current code */ 2519 int nextlen = tree[0].Len; /* length of next code */ 2520 int count = 0; /* repeat count of the current code */ 2521 int max_count = 7; /* max repeat count */ 2522 int min_count = 4; /* min repeat count */ 2523 2524 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2525 if (nextlen == 0) max_count = 138, min_count = 3; 2526 2527 for (n = 0; n <= max_code; n++) { 2528 curlen = nextlen; nextlen = tree[n+1].Len; 2529 if (++count < max_count && curlen == nextlen) { 2530 continue; 2531 } else if (count < min_count) { 2532 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2533 2534 } else if (curlen != 0) { 2535 if (curlen != prevlen) { 2536 send_code(s, curlen, s->bl_tree); count--; 2537 } 2538 Assert(count >= 3 && count <= 6, " 3_6?"); 2539 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2540 2541 } else if (count <= 10) { 2542 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2543 2544 } else { 2545 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2546 } 2547 count = 0; prevlen = curlen; 2548 if (nextlen == 0) { 2549 max_count = 138, min_count = 3; 2550 } else if (curlen == nextlen) { 2551 max_count = 6, min_count = 3; 2552 } else { 2553 max_count = 7, min_count = 4; 2554 } 2555 } 2556 } 2557 2558 /* =========================================================================== 2559 * Construct the Huffman tree for the bit lengths and return the index in 2560 * bl_order of the last bit length code to send. 2561 */ 2562 local int build_bl_tree(s) 2563 deflate_state *s; 2564 { 2565 int max_blindex; /* index of last bit length code of non zero freq */ 2566 2567 /* Determine the bit length frequencies for literal and distance trees */ 2568 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2569 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2570 2571 /* Build the bit length tree: */ 2572 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2573 /* opt_len now includes the length of the tree representations, except 2574 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2575 */ 2576 2577 /* Determine the number of bit length codes to send. The pkzip format 2578 * requires that at least 4 bit length codes be sent. (appnote.txt says 2579 * 3 but the actual value used is 4.) 2580 */ 2581 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2582 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2583 } 2584 /* Update opt_len to include the bit length tree and counts */ 2585 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2586 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2587 s->opt_len, s->static_len)); 2588 2589 return max_blindex; 2590 } 2591 2592 /* =========================================================================== 2593 * Send the header for a block using dynamic Huffman trees: the counts, the 2594 * lengths of the bit length codes, the literal tree and the distance tree. 2595 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2596 */ 2597 local void send_all_trees(s, lcodes, dcodes, blcodes) 2598 deflate_state *s; 2599 int lcodes, dcodes, blcodes; /* number of codes for each tree */ 2600 { 2601 int rank; /* index in bl_order */ 2602 2603 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2604 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2605 "too many codes"); 2606 Tracev((stderr, "\nbl counts: ")); 2607 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2608 send_bits(s, dcodes-1, 5); 2609 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2610 for (rank = 0; rank < blcodes; rank++) { 2611 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2612 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2613 } 2614 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2615 2616 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2617 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2618 2619 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2620 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2621 } 2622 2623 /* =========================================================================== 2624 * Send a stored block 2625 */ 2626 void _tr_stored_block(s, buf, stored_len, eof) 2627 deflate_state *s; 2628 charf *buf; /* input block */ 2629 ulg stored_len; /* length of input block */ 2630 int eof; /* true if this is the last block for a file */ 2631 { 2632 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2633 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; 2634 s->compressed_len += (stored_len + 4) << 3; 2635 2636 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2637 } 2638 2639 /* Send just the `stored block' type code without any length bytes or data. 2640 */ 2641 void _tr_stored_type_only(s) 2642 deflate_state *s; 2643 { 2644 send_bits(s, (STORED_BLOCK << 1), 3); 2645 bi_windup(s); 2646 s->compressed_len = (s->compressed_len + 3) & ~7L; 2647 } 2648 2649 2650 /* =========================================================================== 2651 * Send one empty static block to give enough lookahead for inflate. 2652 * This takes 10 bits, of which 7 may remain in the bit buffer. 2653 * The current inflate code requires 9 bits of lookahead. If the 2654 * last two codes for the previous block (real code plus EOB) were coded 2655 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode 2656 * the last real code. In this case we send two empty static blocks instead 2657 * of one. (There are no problems if the previous block is stored or fixed.) 2658 * To simplify the code, we assume the worst case of last real code encoded 2659 * on one bit only. 2660 */ 2661 void _tr_align(s) 2662 deflate_state *s; 2663 { 2664 send_bits(s, STATIC_TREES<<1, 3); 2665 send_code(s, END_BLOCK, static_ltree); 2666 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2667 bi_flush(s); 2668 /* Of the 10 bits for the empty block, we have already sent 2669 * (10 - bi_valid) bits. The lookahead for the last real code (before 2670 * the EOB of the previous block) was thus at least one plus the length 2671 * of the EOB plus what we have just sent of the empty static block. 2672 */ 2673 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { 2674 send_bits(s, STATIC_TREES<<1, 3); 2675 send_code(s, END_BLOCK, static_ltree); 2676 s->compressed_len += 10L; 2677 bi_flush(s); 2678 } 2679 s->last_eob_len = 7; 2680 } 2681 2682 /* =========================================================================== 2683 * Determine the best encoding for the current block: dynamic trees, static 2684 * trees or store, and output the encoded block to the zip file. This function 2685 * returns the total compressed length for the file so far. 2686 */ 2687 ulg _tr_flush_block(s, buf, stored_len, eof) 2688 deflate_state *s; 2689 charf *buf; /* input block, or NULL if too old */ 2690 ulg stored_len; /* length of input block */ 2691 int eof; /* true if this is the last block for a file */ 2692 { 2693 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2694 int max_blindex = 0; /* index of last bit length code of non zero freq */ 2695 2696 /* Build the Huffman trees unless a stored block is forced */ 2697 if (s->level > 0) { 2698 2699 /* Check if the file is ascii or binary */ 2700 if (s->data_type == Z_UNKNOWN) set_data_type(s); 2701 2702 /* Construct the literal and distance trees */ 2703 build_tree(s, (tree_desc *)(&(s->l_desc))); 2704 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2705 s->static_len)); 2706 2707 build_tree(s, (tree_desc *)(&(s->d_desc))); 2708 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2709 s->static_len)); 2710 /* At this point, opt_len and static_len are the total bit lengths of 2711 * the compressed block data, excluding the tree representations. 2712 */ 2713 2714 /* Build the bit length tree for the above two trees, and get the index 2715 * in bl_order of the last bit length code to send. 2716 */ 2717 max_blindex = build_bl_tree(s); 2718 2719 /* Determine the best encoding. Compute first the block length in bytes*/ 2720 opt_lenb = (s->opt_len+3+7)>>3; 2721 static_lenb = (s->static_len+3+7)>>3; 2722 2723 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2724 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2725 s->last_lit)); 2726 2727 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2728 2729 } else { 2730 Assert(buf != (char*)0, "lost buf"); 2731 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 2732 } 2733 2734 /* If compression failed and this is the first and last block, 2735 * and if the .zip file can be seeked (to rewrite the local header), 2736 * the whole file is transformed into a stored file: 2737 */ 2738 #ifdef STORED_FILE_OK 2739 # ifdef FORCE_STORED_FILE 2740 if (eof && s->compressed_len == 0L) { /* force stored file */ 2741 # else 2742 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { 2743 # endif 2744 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2745 if (buf == (charf*)0) error ("block vanished"); 2746 2747 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ 2748 s->compressed_len = stored_len << 3; 2749 s->method = STORED; 2750 } else 2751 #endif /* STORED_FILE_OK */ 2752 2753 #ifdef FORCE_STORED 2754 if (buf != (char*)0) { /* force stored block */ 2755 #else 2756 if (stored_len+4 <= opt_lenb && buf != (char*)0) { 2757 /* 4: two words for the lengths */ 2758 #endif 2759 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2760 * Otherwise we can't have processed more than WSIZE input bytes since 2761 * the last block flush, because compression would have been 2762 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2763 * transform a block into a stored block. 2764 */ 2765 _tr_stored_block(s, buf, stored_len, eof); 2766 2767 #ifdef FORCE_STATIC 2768 } else if (static_lenb >= 0) { /* force static trees */ 2769 #else 2770 } else if (static_lenb == opt_lenb) { 2771 #endif 2772 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2773 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2774 s->compressed_len += 3 + s->static_len; 2775 } else { 2776 send_bits(s, (DYN_TREES<<1)+eof, 3); 2777 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2778 max_blindex+1); 2779 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2780 s->compressed_len += 3 + s->opt_len; 2781 } 2782 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2783 init_block(s); 2784 2785 if (eof) { 2786 bi_windup(s); 2787 s->compressed_len += 7; /* align on byte boundary */ 2788 } 2789 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2790 s->compressed_len-7*eof)); 2791 2792 return s->compressed_len >> 3; 2793 } 2794 2795 /* =========================================================================== 2796 * Save the match info and tally the frequency counts. Return true if 2797 * the current block must be flushed. 2798 */ 2799 int _tr_tally (s, dist, lc) 2800 deflate_state *s; 2801 unsigned dist; /* distance of matched string */ 2802 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 2803 { 2804 s->d_buf[s->last_lit] = (ush)dist; 2805 s->l_buf[s->last_lit++] = (uch)lc; 2806 if (dist == 0) { 2807 /* lc is the unmatched char */ 2808 s->dyn_ltree[lc].Freq++; 2809 } else { 2810 s->matches++; 2811 /* Here, lc is the match length - MIN_MATCH */ 2812 dist--; /* dist = match distance - 1 */ 2813 Assert((ush)dist < (ush)MAX_DIST(s) && 2814 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2815 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 2816 2817 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2818 s->dyn_dtree[d_code(dist)].Freq++; 2819 } 2820 2821 /* Try to guess if it is profitable to stop the current block here */ 2822 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2823 /* Compute an upper bound for the compressed length */ 2824 ulg out_length = (ulg)s->last_lit*8L; 2825 ulg in_length = (ulg)((long)s->strstart - s->block_start); 2826 int dcode; 2827 for (dcode = 0; dcode < D_CODES; dcode++) { 2828 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2829 (5L+extra_dbits[dcode]); 2830 } 2831 out_length >>= 3; 2832 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2833 s->last_lit, in_length, out_length, 2834 100L - out_length*100L/in_length)); 2835 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2836 } 2837 return (s->last_lit == s->lit_bufsize-1); 2838 /* We avoid equality with lit_bufsize because of wraparound at 64K 2839 * on 16 bit machines and because stored blocks are restricted to 2840 * 64K-1 bytes. 2841 */ 2842 } 2843 2844 /* =========================================================================== 2845 * Send the block data compressed using the given Huffman trees 2846 */ 2847 local void compress_block(s, ltree, dtree) 2848 deflate_state *s; 2849 ct_data *ltree; /* literal tree */ 2850 ct_data *dtree; /* distance tree */ 2851 { 2852 unsigned dist; /* distance of matched string */ 2853 int lc; /* match length or unmatched char (if dist == 0) */ 2854 unsigned lx = 0; /* running index in l_buf */ 2855 unsigned code; /* the code to send */ 2856 int extra; /* number of extra bits to send */ 2857 2858 if (s->last_lit != 0) do { 2859 dist = s->d_buf[lx]; 2860 lc = s->l_buf[lx++]; 2861 if (dist == 0) { 2862 send_code(s, lc, ltree); /* send a literal byte */ 2863 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2864 } else { 2865 /* Here, lc is the match length - MIN_MATCH */ 2866 code = length_code[lc]; 2867 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2868 extra = extra_lbits[code]; 2869 if (extra != 0) { 2870 lc -= base_length[code]; 2871 send_bits(s, lc, extra); /* send the extra length bits */ 2872 } 2873 dist--; /* dist is now the match distance - 1 */ 2874 code = d_code(dist); 2875 Assert (code < D_CODES, "bad d_code"); 2876 2877 send_code(s, code, dtree); /* send the distance code */ 2878 extra = extra_dbits[code]; 2879 if (extra != 0) { 2880 dist -= base_dist[code]; 2881 send_bits(s, dist, extra); /* send the extra distance bits */ 2882 } 2883 } /* literal or match pair ? */ 2884 2885 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2886 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2887 2888 } while (lx < s->last_lit); 2889 2890 send_code(s, END_BLOCK, ltree); 2891 s->last_eob_len = ltree[END_BLOCK].Len; 2892 } 2893 2894 /* =========================================================================== 2895 * Set the data type to ASCII or BINARY, using a crude approximation: 2896 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2897 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2898 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2899 */ 2900 local void set_data_type(s) 2901 deflate_state *s; 2902 { 2903 int n = 0; 2904 unsigned ascii_freq = 0; 2905 unsigned bin_freq = 0; 2906 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2907 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2908 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2909 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 2910 } 2911 2912 /* =========================================================================== 2913 * Reverse the first len bits of a code, using straightforward code (a faster 2914 * method would use a table) 2915 * IN assertion: 1 <= len <= 15 2916 */ 2917 local unsigned bi_reverse(code, len) 2918 unsigned code; /* the value to invert */ 2919 int len; /* its bit length */ 2920 { 2921 register unsigned res = 0; 2922 do { 2923 res |= code & 1; 2924 code >>= 1, res <<= 1; 2925 } while (--len > 0); 2926 return res >> 1; 2927 } 2928 2929 /* =========================================================================== 2930 * Flush the bit buffer, keeping at most 7 bits in it. 2931 */ 2932 local void bi_flush(s) 2933 deflate_state *s; 2934 { 2935 if (s->bi_valid == 16) { 2936 put_short(s, s->bi_buf); 2937 s->bi_buf = 0; 2938 s->bi_valid = 0; 2939 } else if (s->bi_valid >= 8) { 2940 put_byte(s, (Byte)s->bi_buf); 2941 s->bi_buf >>= 8; 2942 s->bi_valid -= 8; 2943 } 2944 } 2945 2946 /* =========================================================================== 2947 * Flush the bit buffer and align the output on a byte boundary 2948 */ 2949 local void bi_windup(s) 2950 deflate_state *s; 2951 { 2952 if (s->bi_valid > 8) { 2953 put_short(s, s->bi_buf); 2954 } else if (s->bi_valid > 0) { 2955 put_byte(s, (Byte)s->bi_buf); 2956 } 2957 s->bi_buf = 0; 2958 s->bi_valid = 0; 2959 #ifdef DEBUG_ZLIB 2960 s->bits_sent = (s->bits_sent+7) & ~7; 2961 #endif 2962 } 2963 2964 /* =========================================================================== 2965 * Copy a stored block, storing first the length and its 2966 * one's complement if requested. 2967 */ 2968 local void copy_block(s, buf, len, header) 2969 deflate_state *s; 2970 charf *buf; /* the input data */ 2971 unsigned len; /* its length */ 2972 int header; /* true if block header must be written */ 2973 { 2974 bi_windup(s); /* align on byte boundary */ 2975 s->last_eob_len = 8; /* enough lookahead for inflate */ 2976 2977 if (header) { 2978 put_short(s, (ush)len); 2979 put_short(s, (ush)~len); 2980 #ifdef DEBUG_ZLIB 2981 s->bits_sent += 2*16; 2982 #endif 2983 } 2984 #ifdef DEBUG_ZLIB 2985 s->bits_sent += (ulg)len<<3; 2986 #endif 2987 /* bundle up the put_byte(s, *buf++) calls */ 2988 zmemcpy(&s->pending_buf[s->pending], buf, len); 2989 s->pending += len; 2990 } 2991 /* --- trees.c */ 2992 2993 /* +++ inflate.c */ 2994 /* inflate.c -- zlib interface to inflate modules 2995 * Copyright (C) 1995-1996 Mark Adler 2996 * For conditions of distribution and use, see copyright notice in zlib.h 2997 */ 2998 2999 /* #include "zutil.h" */ 3000 3001 /* +++ infblock.h */ 3002 /* infblock.h -- header to use infblock.c 3003 * Copyright (C) 1995-1996 Mark Adler 3004 * For conditions of distribution and use, see copyright notice in zlib.h 3005 */ 3006 3007 /* WARNING: this file should *not* be used by applications. It is 3008 part of the implementation of the compression library and is 3009 subject to change. Applications should only use zlib.h. 3010 */ 3011 3012 struct inflate_blocks_state; 3013 typedef struct inflate_blocks_state FAR inflate_blocks_statef; 3014 3015 extern inflate_blocks_statef * inflate_blocks_new OF(( 3016 z_streamp z, 3017 check_func c, /* check function */ 3018 uInt w)); /* window size */ 3019 3020 extern int inflate_blocks OF(( 3021 inflate_blocks_statef *, 3022 z_streamp , 3023 int)); /* initial return code */ 3024 3025 extern void inflate_blocks_reset OF(( 3026 inflate_blocks_statef *, 3027 z_streamp , 3028 uLongf *)); /* check value on output */ 3029 3030 extern int inflate_blocks_free OF(( 3031 inflate_blocks_statef *, 3032 z_streamp , 3033 uLongf *)); /* check value on output */ 3034 3035 extern void inflate_set_dictionary OF(( 3036 inflate_blocks_statef *s, 3037 const Bytef *d, /* dictionary */ 3038 uInt n)); /* dictionary length */ 3039 3040 extern int inflate_addhistory OF(( 3041 inflate_blocks_statef *, 3042 z_streamp)); 3043 3044 extern int inflate_packet_flush OF(( 3045 inflate_blocks_statef *)); 3046 /* --- infblock.h */ 3047 3048 #ifndef NO_DUMMY_DECL 3049 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ 3050 #endif 3051 3052 /* inflate private state */ 3053 struct internal_state { 3054 3055 /* mode */ 3056 enum { 3057 METHOD, /* waiting for method byte */ 3058 FLAG, /* waiting for flag byte */ 3059 DICT4, /* four dictionary check bytes to go */ 3060 DICT3, /* three dictionary check bytes to go */ 3061 DICT2, /* two dictionary check bytes to go */ 3062 DICT1, /* one dictionary check byte to go */ 3063 DICT0, /* waiting for inflateSetDictionary */ 3064 BLOCKS, /* decompressing blocks */ 3065 CHECK4, /* four check bytes to go */ 3066 CHECK3, /* three check bytes to go */ 3067 CHECK2, /* two check bytes to go */ 3068 CHECK1, /* one check byte to go */ 3069 DONE, /* finished check, done */ 3070 BAD} /* got an error--stay here */ 3071 mode; /* current inflate mode */ 3072 3073 /* mode dependent information */ 3074 union { 3075 uInt method; /* if FLAGS, method byte */ 3076 struct { 3077 uLong was; /* computed check value */ 3078 uLong need; /* stream check value */ 3079 } check; /* if CHECK, check values to compare */ 3080 uInt marker; /* if BAD, inflateSync's marker bytes count */ 3081 } sub; /* submode */ 3082 3083 /* mode independent information */ 3084 int nowrap; /* flag for no wrapper */ 3085 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 3086 inflate_blocks_statef 3087 *blocks; /* current inflate_blocks state */ 3088 3089 }; 3090 3091 3092 int inflateReset(z) 3093 z_streamp z; 3094 { 3095 uLong c; 3096 3097 if (z == Z_NULL || z->state == Z_NULL) 3098 return Z_STREAM_ERROR; 3099 z->total_in = z->total_out = 0; 3100 z->msg = Z_NULL; 3101 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 3102 inflate_blocks_reset(z->state->blocks, z, &c); 3103 Trace((stderr, "inflate: reset\n")); 3104 return Z_OK; 3105 } 3106 3107 3108 int inflateEnd(z) 3109 z_streamp z; 3110 { 3111 uLong c; 3112 3113 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 3114 return Z_STREAM_ERROR; 3115 if (z->state->blocks != Z_NULL) 3116 inflate_blocks_free(z->state->blocks, z, &c); 3117 ZFREE(z, z->state); 3118 z->state = Z_NULL; 3119 Trace((stderr, "inflate: end\n")); 3120 return Z_OK; 3121 } 3122 3123 3124 int inflateInit2_(z, w, version, stream_size) 3125 z_streamp z; 3126 int w; 3127 const char *version; 3128 int stream_size; 3129 { 3130 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || 3131 stream_size != sizeof(z_stream)) 3132 return Z_VERSION_ERROR; 3133 3134 /* initialize state */ 3135 if (z == Z_NULL) 3136 return Z_STREAM_ERROR; 3137 z->msg = Z_NULL; 3138 #ifndef NO_ZCFUNCS 3139 if (z->zalloc == Z_NULL) 3140 { 3141 z->zalloc = zcalloc; 3142 z->opaque = (voidpf)0; 3143 } 3144 if (z->zfree == Z_NULL) z->zfree = zcfree; 3145 #endif 3146 if ((z->state = (struct internal_state FAR *) 3147 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 3148 return Z_MEM_ERROR; 3149 z->state->blocks = Z_NULL; 3150 3151 /* handle undocumented nowrap option (no zlib header or check) */ 3152 z->state->nowrap = 0; 3153 if (w < 0) 3154 { 3155 w = - w; 3156 z->state->nowrap = 1; 3157 } 3158 3159 /* set window size */ 3160 if (w < 8 || w > 15) 3161 { 3162 inflateEnd(z); 3163 return Z_STREAM_ERROR; 3164 } 3165 z->state->wbits = (uInt)w; 3166 3167 /* create inflate_blocks state */ 3168 if ((z->state->blocks = 3169 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) 3170 == Z_NULL) 3171 { 3172 inflateEnd(z); 3173 return Z_MEM_ERROR; 3174 } 3175 Trace((stderr, "inflate: allocated\n")); 3176 3177 /* reset state */ 3178 inflateReset(z); 3179 return Z_OK; 3180 } 3181 3182 3183 int inflateInit_(z, version, stream_size) 3184 z_streamp z; 3185 const char *version; 3186 int stream_size; 3187 { 3188 return inflateInit2_(z, DEF_WBITS, version, stream_size); 3189 } 3190 3191 3192 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 3193 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 3194 3195 int inflate(z, f) 3196 z_streamp z; 3197 int f; 3198 { 3199 int r; 3200 uInt b; 3201 3202 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) 3203 return Z_STREAM_ERROR; 3204 r = Z_BUF_ERROR; 3205 while (1) switch (z->state->mode) 3206 { 3207 case METHOD: 3208 NEEDBYTE 3209 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) 3210 { 3211 z->state->mode = BAD; 3212 z->msg = (char*)"unknown compression method"; 3213 z->state->sub.marker = 5; /* can't try inflateSync */ 3214 break; 3215 } 3216 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 3217 { 3218 z->state->mode = BAD; 3219 z->msg = (char*)"invalid window size"; 3220 z->state->sub.marker = 5; /* can't try inflateSync */ 3221 break; 3222 } 3223 z->state->mode = FLAG; 3224 case FLAG: 3225 NEEDBYTE 3226 b = NEXTBYTE; 3227 if (((z->state->sub.method << 8) + b) % 31) 3228 { 3229 z->state->mode = BAD; 3230 z->msg = (char*)"incorrect header check"; 3231 z->state->sub.marker = 5; /* can't try inflateSync */ 3232 break; 3233 } 3234 Trace((stderr, "inflate: zlib header ok\n")); 3235 if (!(b & PRESET_DICT)) 3236 { 3237 z->state->mode = BLOCKS; 3238 break; 3239 } 3240 z->state->mode = DICT4; 3241 case DICT4: 3242 NEEDBYTE 3243 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3244 z->state->mode = DICT3; 3245 case DICT3: 3246 NEEDBYTE 3247 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3248 z->state->mode = DICT2; 3249 case DICT2: 3250 NEEDBYTE 3251 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3252 z->state->mode = DICT1; 3253 case DICT1: 3254 NEEDBYTE 3255 z->state->sub.check.need += (uLong)NEXTBYTE; 3256 z->adler = z->state->sub.check.need; 3257 z->state->mode = DICT0; 3258 return Z_NEED_DICT; 3259 case DICT0: 3260 z->state->mode = BAD; 3261 z->msg = (char*)"need dictionary"; 3262 z->state->sub.marker = 0; /* can try inflateSync */ 3263 return Z_STREAM_ERROR; 3264 case BLOCKS: 3265 r = inflate_blocks(z->state->blocks, z, r); 3266 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 3267 r = inflate_packet_flush(z->state->blocks); 3268 if (r == Z_DATA_ERROR) 3269 { 3270 z->state->mode = BAD; 3271 z->state->sub.marker = 0; /* can try inflateSync */ 3272 break; 3273 } 3274 if (r != Z_STREAM_END) 3275 return r; 3276 r = Z_OK; 3277 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 3278 if (z->state->nowrap) 3279 { 3280 z->state->mode = DONE; 3281 break; 3282 } 3283 z->state->mode = CHECK4; 3284 case CHECK4: 3285 NEEDBYTE 3286 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3287 z->state->mode = CHECK3; 3288 case CHECK3: 3289 NEEDBYTE 3290 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3291 z->state->mode = CHECK2; 3292 case CHECK2: 3293 NEEDBYTE 3294 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3295 z->state->mode = CHECK1; 3296 case CHECK1: 3297 NEEDBYTE 3298 z->state->sub.check.need += (uLong)NEXTBYTE; 3299 3300 if (z->state->sub.check.was != z->state->sub.check.need) 3301 { 3302 z->state->mode = BAD; 3303 z->msg = (char*)"incorrect data check"; 3304 z->state->sub.marker = 5; /* can't try inflateSync */ 3305 break; 3306 } 3307 Trace((stderr, "inflate: zlib check ok\n")); 3308 z->state->mode = DONE; 3309 case DONE: 3310 return Z_STREAM_END; 3311 case BAD: 3312 return Z_DATA_ERROR; 3313 default: 3314 return Z_STREAM_ERROR; 3315 } 3316 3317 empty: 3318 if (f != Z_PACKET_FLUSH) 3319 return r; 3320 z->state->mode = BAD; 3321 z->msg = (char *)"need more for packet flush"; 3322 z->state->sub.marker = 0; /* can try inflateSync */ 3323 return Z_DATA_ERROR; 3324 } 3325 3326 3327 int inflateSetDictionary(z, dictionary, dictLength) 3328 z_streamp z; 3329 const Bytef *dictionary; 3330 uInt dictLength; 3331 { 3332 uInt length = dictLength; 3333 3334 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) 3335 return Z_STREAM_ERROR; 3336 3337 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; 3338 z->adler = 1L; 3339 3340 if (length >= ((uInt)1<<z->state->wbits)) 3341 { 3342 length = (1<<z->state->wbits)-1; 3343 dictionary += dictLength - length; 3344 } 3345 inflate_set_dictionary(z->state->blocks, dictionary, length); 3346 z->state->mode = BLOCKS; 3347 return Z_OK; 3348 } 3349 3350 /* 3351 * This subroutine adds the data at next_in/avail_in to the output history 3352 * without performing any output. The output buffer must be "caught up"; 3353 * i.e. no pending output (hence s->read equals s->write), and the state must 3354 * be BLOCKS (i.e. we should be willing to see the start of a series of 3355 * BLOCKS). On exit, the output will also be caught up, and the checksum 3356 * will have been updated if need be. 3357 */ 3358 3359 int inflateIncomp(z) 3360 z_stream *z; 3361 { 3362 if (z->state->mode != BLOCKS) 3363 return Z_DATA_ERROR; 3364 return inflate_addhistory(z->state->blocks, z); 3365 } 3366 3367 3368 int inflateSync(z) 3369 z_streamp z; 3370 { 3371 uInt n; /* number of bytes to look at */ 3372 Bytef *p; /* pointer to bytes */ 3373 uInt m; /* number of marker bytes found in a row */ 3374 uLong r, w; /* temporaries to save total_in and total_out */ 3375 3376 /* set up */ 3377 if (z == Z_NULL || z->state == Z_NULL) 3378 return Z_STREAM_ERROR; 3379 if (z->state->mode != BAD) 3380 { 3381 z->state->mode = BAD; 3382 z->state->sub.marker = 0; 3383 } 3384 if ((n = z->avail_in) == 0) 3385 return Z_BUF_ERROR; 3386 p = z->next_in; 3387 m = z->state->sub.marker; 3388 3389 /* search */ 3390 while (n && m < 4) 3391 { 3392 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3393 m++; 3394 else if (*p) 3395 m = 0; 3396 else 3397 m = 4 - m; 3398 p++, n--; 3399 } 3400 3401 /* restore */ 3402 z->total_in += p - z->next_in; 3403 z->next_in = p; 3404 z->avail_in = n; 3405 z->state->sub.marker = m; 3406 3407 /* return no joy or set up to restart on a new block */ 3408 if (m != 4) 3409 return Z_DATA_ERROR; 3410 r = z->total_in; w = z->total_out; 3411 inflateReset(z); 3412 z->total_in = r; z->total_out = w; 3413 z->state->mode = BLOCKS; 3414 return Z_OK; 3415 } 3416 3417 #undef NEEDBYTE 3418 #undef NEXTBYTE 3419 /* --- inflate.c */ 3420 3421 /* +++ infblock.c */ 3422 /* infblock.c -- interpret and process block types to last block 3423 * Copyright (C) 1995-1996 Mark Adler 3424 * For conditions of distribution and use, see copyright notice in zlib.h 3425 */ 3426 3427 /* #include "zutil.h" */ 3428 /* #include "infblock.h" */ 3429 3430 /* +++ inftrees.h */ 3431 /* inftrees.h -- header to use inftrees.c 3432 * Copyright (C) 1995-1996 Mark Adler 3433 * For conditions of distribution and use, see copyright notice in zlib.h 3434 */ 3435 3436 /* WARNING: this file should *not* be used by applications. It is 3437 part of the implementation of the compression library and is 3438 subject to change. Applications should only use zlib.h. 3439 */ 3440 3441 /* Huffman code lookup table entry--this entry is four bytes for machines 3442 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 3443 3444 typedef struct inflate_huft_s FAR inflate_huft; 3445 3446 struct inflate_huft_s { 3447 union { 3448 struct { 3449 Byte Exop; /* number of extra bits or operation */ 3450 Byte Bits; /* number of bits in this code or subcode */ 3451 } what; 3452 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 3453 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 3454 union { 3455 uInt Base; /* literal, length base, or distance base */ 3456 inflate_huft *Next; /* pointer to next level of table */ 3457 } more; 3458 }; 3459 3460 #ifdef DEBUG_ZLIB 3461 extern uInt inflate_hufts; 3462 #endif 3463 3464 extern int inflate_trees_bits OF(( 3465 uIntf *, /* 19 code lengths */ 3466 uIntf *, /* bits tree desired/actual depth */ 3467 inflate_huft * FAR *, /* bits tree result */ 3468 z_streamp )); /* for zalloc, zfree functions */ 3469 3470 extern int inflate_trees_dynamic OF(( 3471 uInt, /* number of literal/length codes */ 3472 uInt, /* number of distance codes */ 3473 uIntf *, /* that many (total) code lengths */ 3474 uIntf *, /* literal desired/actual bit depth */ 3475 uIntf *, /* distance desired/actual bit depth */ 3476 inflate_huft * FAR *, /* literal/length tree result */ 3477 inflate_huft * FAR *, /* distance tree result */ 3478 z_streamp )); /* for zalloc, zfree functions */ 3479 3480 extern int inflate_trees_fixed OF(( 3481 uIntf *, /* literal desired/actual bit depth */ 3482 uIntf *, /* distance desired/actual bit depth */ 3483 inflate_huft * FAR *, /* literal/length tree result */ 3484 inflate_huft * FAR *)); /* distance tree result */ 3485 3486 extern int inflate_trees_free OF(( 3487 inflate_huft *, /* tables to free */ 3488 z_streamp )); /* for zfree function */ 3489 3490 /* --- inftrees.h */ 3491 3492 /* +++ infcodes.h */ 3493 /* infcodes.h -- header to use infcodes.c 3494 * Copyright (C) 1995-1996 Mark Adler 3495 * For conditions of distribution and use, see copyright notice in zlib.h 3496 */ 3497 3498 /* WARNING: this file should *not* be used by applications. It is 3499 part of the implementation of the compression library and is 3500 subject to change. Applications should only use zlib.h. 3501 */ 3502 3503 struct inflate_codes_state; 3504 typedef struct inflate_codes_state FAR inflate_codes_statef; 3505 3506 extern inflate_codes_statef *inflate_codes_new OF(( 3507 uInt, uInt, 3508 inflate_huft *, inflate_huft *, 3509 z_streamp )); 3510 3511 extern int inflate_codes OF(( 3512 inflate_blocks_statef *, 3513 z_streamp , 3514 int)); 3515 3516 extern void inflate_codes_free OF(( 3517 inflate_codes_statef *, 3518 z_streamp )); 3519 3520 /* --- infcodes.h */ 3521 3522 /* +++ infutil.h */ 3523 /* infutil.h -- types and macros common to blocks and codes 3524 * Copyright (C) 1995-1996 Mark Adler 3525 * For conditions of distribution and use, see copyright notice in zlib.h 3526 */ 3527 3528 /* WARNING: this file should *not* be used by applications. It is 3529 part of the implementation of the compression library and is 3530 subject to change. Applications should only use zlib.h. 3531 */ 3532 3533 #ifndef _INFUTIL_H 3534 #define _INFUTIL_H 3535 3536 typedef enum { 3537 TYPE, /* get type bits (3, including end bit) */ 3538 LENS, /* get lengths for stored */ 3539 STORED, /* processing stored block */ 3540 TABLE, /* get table lengths */ 3541 BTREE, /* get bit lengths tree for a dynamic block */ 3542 DTREE, /* get length, distance trees for a dynamic block */ 3543 CODES, /* processing fixed or dynamic block */ 3544 DRY, /* output remaining window bytes */ 3545 DONEB, /* finished last block, done */ 3546 BADB} /* got a data error--stuck here */ 3547 inflate_block_mode; 3548 3549 /* inflate blocks semi-private state */ 3550 struct inflate_blocks_state { 3551 3552 /* mode */ 3553 inflate_block_mode mode; /* current inflate_block mode */ 3554 3555 /* mode dependent information */ 3556 union { 3557 uInt left; /* if STORED, bytes left to copy */ 3558 struct { 3559 uInt table; /* table lengths (14 bits) */ 3560 uInt index; /* index into blens (or border) */ 3561 uIntf *blens; /* bit lengths of codes */ 3562 uInt bb; /* bit length tree depth */ 3563 inflate_huft *tb; /* bit length decoding tree */ 3564 } trees; /* if DTREE, decoding info for trees */ 3565 struct { 3566 inflate_huft *tl; 3567 inflate_huft *td; /* trees to free */ 3568 inflate_codes_statef 3569 *codes; 3570 } decode; /* if CODES, current state */ 3571 } sub; /* submode */ 3572 uInt last; /* true if this block is the last block */ 3573 3574 /* mode independent information */ 3575 uInt bitk; /* bits in bit buffer */ 3576 uLong bitb; /* bit buffer */ 3577 Bytef *window; /* sliding window */ 3578 Bytef *end; /* one byte after sliding window */ 3579 Bytef *read; /* window read pointer */ 3580 Bytef *write; /* window write pointer */ 3581 check_func checkfn; /* check function */ 3582 uLong check; /* check on output */ 3583 3584 }; 3585 3586 3587 /* defines for inflate input/output */ 3588 /* update pointers and return */ 3589 #define UPDBITS {s->bitb=b;s->bitk=k;} 3590 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3591 #define UPDOUT {s->write=q;} 3592 #define UPDATE {UPDBITS UPDIN UPDOUT} 3593 #define LEAVE {UPDATE return inflate_flush(s,z,r);} 3594 /* get bytes and bits */ 3595 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3596 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3597 #define NEXTBYTE (n--,*p++) 3598 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3599 #define DUMPBITS(j) {b>>=(j);k-=(j);} 3600 /* output bytes */ 3601 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) 3602 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} 3603 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} 3604 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3605 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} 3606 #define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3607 /* load local pointers */ 3608 #define LOAD {LOADIN LOADOUT} 3609 3610 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ 3611 extern uInt inflate_mask[17]; 3612 3613 /* copy as much as possible from the sliding window to the output area */ 3614 extern int inflate_flush OF(( 3615 inflate_blocks_statef *, 3616 z_streamp , 3617 int)); 3618 3619 #ifndef NO_DUMMY_DECL 3620 struct internal_state {int dummy;}; /* for buggy compilers */ 3621 #endif 3622 3623 #endif 3624 /* --- infutil.h */ 3625 3626 #ifndef NO_DUMMY_DECL 3627 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 3628 #endif 3629 3630 /* Table for deflate from PKZIP's appnote.txt. */ 3631 local const uInt border[] = { /* Order of the bit length code lengths */ 3632 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3633 3634 /* 3635 Notes beyond the 1.93a appnote.txt: 3636 3637 1. Distance pointers never point before the beginning of the output 3638 stream. 3639 2. Distance pointers can point back across blocks, up to 32k away. 3640 3. There is an implied maximum of 7 bits for the bit length table and 3641 15 bits for the actual data. 3642 4. If only one code exists, then it is encoded using one bit. (Zero 3643 would be more efficient, but perhaps a little confusing.) If two 3644 codes exist, they are coded using one bit each (0 and 1). 3645 5. There is no way of sending zero distance codes--a dummy must be 3646 sent if there are none. (History: a pre 2.0 version of PKZIP would 3647 store blocks with no distance codes, but this was discovered to be 3648 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3649 zero distance codes, which is sent as one code of zero bits in 3650 length. 3651 6. There are up to 286 literal/length codes. Code 256 represents the 3652 end-of-block. Note however that the static length tree defines 3653 288 codes just to fill out the Huffman codes. Codes 286 and 287 3654 cannot be used though, since there is no length base or extra bits 3655 defined for them. Similarily, there are up to 30 distance codes. 3656 However, static trees define 32 codes (all 5 bits) to fill out the 3657 Huffman codes, but the last two had better not show up in the data. 3658 7. Unzip can check dynamic Huffman blocks for complete code sets. 3659 The exception is that a single code would not be complete (see #4). 3660 8. The five bits following the block type is really the number of 3661 literal codes sent minus 257. 3662 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3663 (1+6+6). Therefore, to output three times the length, you output 3664 three codes (1+1+1), whereas to output four times the same length, 3665 you only need two codes (1+3). Hmm. 3666 10. In the tree reconstruction algorithm, Code = Code + Increment 3667 only if BitLength(i) is not zero. (Pretty obvious.) 3668 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3669 12. Note: length code 284 can represent 227-258, but length code 285 3670 really is 258. The last length deserves its own, short code 3671 since it gets used a lot in very redundant files. The length 3672 258 is special since 258 - 3 (the min match length) is 255. 3673 13. The literal/length and distance code bit lengths are read as a 3674 single stream of lengths. It is possible (and advantageous) for 3675 a repeat code (16, 17, or 18) to go across the boundary between 3676 the two sets of lengths. 3677 */ 3678 3679 3680 void inflate_blocks_reset(s, z, c) 3681 inflate_blocks_statef *s; 3682 z_streamp z; 3683 uLongf *c; 3684 { 3685 if (s->checkfn != Z_NULL) 3686 *c = s->check; 3687 if (s->mode == BTREE || s->mode == DTREE) 3688 ZFREE(z, s->sub.trees.blens); 3689 if (s->mode == CODES) 3690 { 3691 inflate_codes_free(s->sub.decode.codes, z); 3692 inflate_trees_free(s->sub.decode.td, z); 3693 inflate_trees_free(s->sub.decode.tl, z); 3694 } 3695 s->mode = TYPE; 3696 s->bitk = 0; 3697 s->bitb = 0; 3698 s->read = s->write = s->window; 3699 if (s->checkfn != Z_NULL) 3700 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); 3701 Trace((stderr, "inflate: blocks reset\n")); 3702 } 3703 3704 3705 inflate_blocks_statef *inflate_blocks_new(z, c, w) 3706 z_streamp z; 3707 check_func c; 3708 uInt w; 3709 { 3710 inflate_blocks_statef *s; 3711 3712 if ((s = (inflate_blocks_statef *)ZALLOC 3713 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3714 return s; 3715 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3716 { 3717 ZFREE(z, s); 3718 return Z_NULL; 3719 } 3720 s->end = s->window + w; 3721 s->checkfn = c; 3722 s->mode = TYPE; 3723 Trace((stderr, "inflate: blocks allocated\n")); 3724 inflate_blocks_reset(s, z, &s->check); 3725 return s; 3726 } 3727 3728 3729 #ifdef DEBUG_ZLIB 3730 extern uInt inflate_hufts; 3731 #endif 3732 int inflate_blocks(s, z, r) 3733 inflate_blocks_statef *s; 3734 z_streamp z; 3735 int r; 3736 { 3737 uInt t; /* temporary storage */ 3738 uLong b; /* bit buffer */ 3739 uInt k; /* bits in bit buffer */ 3740 Bytef *p; /* input data pointer */ 3741 uInt n; /* bytes available there */ 3742 Bytef *q; /* output window write pointer */ 3743 uInt m; /* bytes to end of window or read pointer */ 3744 3745 /* copy input/output information to locals (UPDATE macro restores) */ 3746 LOAD 3747 3748 /* process input based on current state */ 3749 while (1) switch (s->mode) 3750 { 3751 case TYPE: 3752 NEEDBITS(3) 3753 t = (uInt)b & 7; 3754 s->last = t & 1; 3755 switch (t >> 1) 3756 { 3757 case 0: /* stored */ 3758 Trace((stderr, "inflate: stored block%s\n", 3759 s->last ? " (last)" : "")); 3760 DUMPBITS(3) 3761 t = k & 7; /* go to byte boundary */ 3762 DUMPBITS(t) 3763 s->mode = LENS; /* get length of stored block */ 3764 break; 3765 case 1: /* fixed */ 3766 Trace((stderr, "inflate: fixed codes block%s\n", 3767 s->last ? " (last)" : "")); 3768 { 3769 uInt bl, bd; 3770 inflate_huft *tl, *td; 3771 3772 inflate_trees_fixed(&bl, &bd, &tl, &td); 3773 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3774 if (s->sub.decode.codes == Z_NULL) 3775 { 3776 r = Z_MEM_ERROR; 3777 LEAVE 3778 } 3779 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3780 s->sub.decode.td = Z_NULL; 3781 } 3782 DUMPBITS(3) 3783 s->mode = CODES; 3784 break; 3785 case 2: /* dynamic */ 3786 Trace((stderr, "inflate: dynamic codes block%s\n", 3787 s->last ? " (last)" : "")); 3788 DUMPBITS(3) 3789 s->mode = TABLE; 3790 break; 3791 case 3: /* illegal */ 3792 DUMPBITS(3) 3793 s->mode = BADB; 3794 z->msg = (char*)"invalid block type"; 3795 r = Z_DATA_ERROR; 3796 LEAVE 3797 } 3798 break; 3799 case LENS: 3800 NEEDBITS(32) 3801 if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) 3802 { 3803 s->mode = BADB; 3804 z->msg = (char*)"invalid stored block lengths"; 3805 r = Z_DATA_ERROR; 3806 LEAVE 3807 } 3808 s->sub.left = (uInt)b & 0xffff; 3809 b = k = 0; /* dump bits */ 3810 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3811 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); 3812 break; 3813 case STORED: 3814 if (n == 0) 3815 LEAVE 3816 NEEDOUT 3817 t = s->sub.left; 3818 if (t > n) t = n; 3819 if (t > m) t = m; 3820 zmemcpy(q, p, t); 3821 p += t; n -= t; 3822 q += t; m -= t; 3823 if ((s->sub.left -= t) != 0) 3824 break; 3825 Tracev((stderr, "inflate: stored end, %lu total out\n", 3826 z->total_out + (q >= s->read ? q - s->read : 3827 (s->end - s->read) + (q - s->window)))); 3828 s->mode = s->last ? DRY : TYPE; 3829 break; 3830 case TABLE: 3831 NEEDBITS(14) 3832 s->sub.trees.table = t = (uInt)b & 0x3fff; 3833 #ifndef PKZIP_BUG_WORKAROUND 3834 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3835 { 3836 s->mode = BADB; 3837 z->msg = (char*)"too many length or distance symbols"; 3838 r = Z_DATA_ERROR; 3839 LEAVE 3840 } 3841 #endif 3842 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3843 if (t < 19) 3844 t = 19; 3845 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3846 { 3847 r = Z_MEM_ERROR; 3848 LEAVE 3849 } 3850 DUMPBITS(14) 3851 s->sub.trees.index = 0; 3852 Tracev((stderr, "inflate: table sizes ok\n")); 3853 s->mode = BTREE; 3854 case BTREE: 3855 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3856 { 3857 NEEDBITS(3) 3858 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3859 DUMPBITS(3) 3860 } 3861 while (s->sub.trees.index < 19) 3862 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3863 s->sub.trees.bb = 7; 3864 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3865 &s->sub.trees.tb, z); 3866 if (t != Z_OK) 3867 { 3868 r = t; 3869 if (r == Z_DATA_ERROR) { 3870 ZFREE(z, s->sub.trees.blens); 3871 s->mode = BADB; 3872 } 3873 LEAVE 3874 } 3875 s->sub.trees.index = 0; 3876 Tracev((stderr, "inflate: bits tree ok\n")); 3877 s->mode = DTREE; 3878 case DTREE: 3879 while (t = s->sub.trees.table, 3880 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3881 { 3882 inflate_huft *h; 3883 uInt i, j, c; 3884 3885 t = s->sub.trees.bb; 3886 NEEDBITS(t) 3887 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3888 t = h->word.what.Bits; 3889 c = h->more.Base; 3890 if (c < 16) 3891 { 3892 DUMPBITS(t) 3893 s->sub.trees.blens[s->sub.trees.index++] = c; 3894 } 3895 else /* c == 16..18 */ 3896 { 3897 i = c == 18 ? 7 : c - 14; 3898 j = c == 18 ? 11 : 3; 3899 NEEDBITS(t + i) 3900 DUMPBITS(t) 3901 j += (uInt)b & inflate_mask[i]; 3902 DUMPBITS(i) 3903 i = s->sub.trees.index; 3904 t = s->sub.trees.table; 3905 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3906 (c == 16 && i < 1)) 3907 { 3908 inflate_trees_free(s->sub.trees.tb, z); 3909 ZFREE(z, s->sub.trees.blens); 3910 s->mode = BADB; 3911 z->msg = (char*)"invalid bit length repeat"; 3912 r = Z_DATA_ERROR; 3913 LEAVE 3914 } 3915 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3916 do { 3917 s->sub.trees.blens[i++] = c; 3918 } while (--j); 3919 s->sub.trees.index = i; 3920 } 3921 } 3922 inflate_trees_free(s->sub.trees.tb, z); 3923 s->sub.trees.tb = Z_NULL; 3924 { 3925 uInt bl, bd; 3926 inflate_huft *tl, *td; 3927 inflate_codes_statef *c; 3928 3929 bl = 9; /* must be <= 9 for lookahead assumptions */ 3930 bd = 6; /* must be <= 9 for lookahead assumptions */ 3931 t = s->sub.trees.table; 3932 #ifdef DEBUG_ZLIB 3933 inflate_hufts = 0; 3934 #endif 3935 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3936 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3937 if (t != Z_OK) 3938 { 3939 if (t == (uInt)Z_DATA_ERROR) { 3940 ZFREE(z, s->sub.trees.blens); 3941 s->mode = BADB; 3942 } 3943 r = t; 3944 LEAVE 3945 } 3946 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", 3947 inflate_hufts, sizeof(inflate_huft))); 3948 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3949 { 3950 inflate_trees_free(td, z); 3951 inflate_trees_free(tl, z); 3952 r = Z_MEM_ERROR; 3953 LEAVE 3954 } 3955 /* 3956 * this ZFREE must occur *BEFORE* we mess with sub.decode, because 3957 * sub.trees is union'd with sub.decode. 3958 */ 3959 ZFREE(z, s->sub.trees.blens); 3960 s->sub.decode.codes = c; 3961 s->sub.decode.tl = tl; 3962 s->sub.decode.td = td; 3963 } 3964 s->mode = CODES; 3965 case CODES: 3966 UPDATE 3967 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3968 return inflate_flush(s, z, r); 3969 r = Z_OK; 3970 inflate_codes_free(s->sub.decode.codes, z); 3971 inflate_trees_free(s->sub.decode.td, z); 3972 inflate_trees_free(s->sub.decode.tl, z); 3973 LOAD 3974 Tracev((stderr, "inflate: codes end, %lu total out\n", 3975 z->total_out + (q >= s->read ? q - s->read : 3976 (s->end - s->read) + (q - s->window)))); 3977 if (!s->last) 3978 { 3979 s->mode = TYPE; 3980 break; 3981 } 3982 if (k > 7) /* return unused byte, if any */ 3983 { 3984 Assert(k < 16, "inflate_codes grabbed too many bytes") 3985 k -= 8; 3986 n++; 3987 p--; /* can always return one */ 3988 } 3989 s->mode = DRY; 3990 case DRY: 3991 FLUSH 3992 if (s->read != s->write) 3993 LEAVE 3994 s->mode = DONEB; 3995 case DONEB: 3996 r = Z_STREAM_END; 3997 LEAVE 3998 case BADB: 3999 r = Z_DATA_ERROR; 4000 LEAVE 4001 default: 4002 r = Z_STREAM_ERROR; 4003 LEAVE 4004 } 4005 } 4006 4007 4008 int inflate_blocks_free(s, z, c) 4009 inflate_blocks_statef *s; 4010 z_streamp z; 4011 uLongf *c; 4012 { 4013 inflate_blocks_reset(s, z, c); 4014 ZFREE(z, s->window); 4015 ZFREE(z, s); 4016 Trace((stderr, "inflate: blocks freed\n")); 4017 return Z_OK; 4018 } 4019 4020 4021 void inflate_set_dictionary(s, d, n) 4022 inflate_blocks_statef *s; 4023 const Bytef *d; 4024 uInt n; 4025 { 4026 zmemcpy((charf *)s->window, d, n); 4027 s->read = s->write = s->window + n; 4028 } 4029 4030 /* 4031 * This subroutine adds the data at next_in/avail_in to the output history 4032 * without performing any output. The output buffer must be "caught up"; 4033 * i.e. no pending output (hence s->read equals s->write), and the state must 4034 * be BLOCKS (i.e. we should be willing to see the start of a series of 4035 * BLOCKS). On exit, the output will also be caught up, and the checksum 4036 * will have been updated if need be. 4037 */ 4038 int inflate_addhistory(s, z) 4039 inflate_blocks_statef *s; 4040 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 inflate_packet_flush(s) 4089 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 falloc 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 local int huft_build(b, n, s, d, e, t, m, zs) 4200 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ 4201 uInt n; /* number of codes (assumed <= N_MAX) */ 4202 uInt s; /* number of simple-valued codes (0..s-1) */ 4203 const uIntf *d; /* list of base values for non-simple codes */ 4204 const uIntf *e; /* list of extra bits for non-simple codes */ 4205 inflate_huft * FAR *t; /* result: starting table */ 4206 uIntf *m; /* maximum lookup bits, returns actual */ 4207 z_streamp zs; /* for zalloc function */ 4208 /* Given a list of code lengths and a maximum table size, make a set of 4209 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 4210 if the given code set is incomplete (the tables are still built in this 4211 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of 4212 lengths), or Z_MEM_ERROR if not enough memory. */ 4213 { 4214 4215 uInt a; /* counter for codes of length k */ 4216 uInt c[BMAX+1]; /* bit length count table */ 4217 uInt f; /* i repeats in table every f entries */ 4218 int g; /* maximum code length */ 4219 int h; /* table level */ 4220 register uInt i; /* counter, current code */ 4221 register uInt j; /* counter */ 4222 register int k; /* number of bits in current code */ 4223 int l; /* bits per table (returned in m) */ 4224 register uIntf *p; /* pointer into c[], b[], or v[] */ 4225 inflate_huft *q; /* points to current table */ 4226 struct inflate_huft_s r; /* table entry for structure assignment */ 4227 inflate_huft *u[BMAX]; /* table stack */ 4228 uInt v[N_MAX]; /* values in order of bit length */ 4229 register int w; /* bits before this table == (l * h) */ 4230 uInt x[BMAX+1]; /* bit offsets, then code stack */ 4231 uIntf *xp; /* pointer into x */ 4232 int y; /* number of dummy codes added */ 4233 uInt z; /* number of entries in current table */ 4234 4235 4236 /* Generate counts for each bit length */ 4237 p = c; 4238 #define C0 *p++ = 0; 4239 #define C2 C0 C0 C0 C0 4240 #define C4 C2 C2 C2 C2 4241 C4 /* clear c[]--assume BMAX+1 is 16 */ 4242 p = b; i = n; 4243 do { 4244 c[*p++]++; /* assume all entries <= BMAX */ 4245 } while (--i); 4246 if (c[0] == n) /* null input--all zero length codes */ 4247 { 4248 *t = (inflate_huft *)Z_NULL; 4249 *m = 0; 4250 return Z_OK; 4251 } 4252 4253 4254 /* Find minimum and maximum length, bound *m by those */ 4255 l = *m; 4256 for (j = 1; j <= BMAX; j++) 4257 if (c[j]) 4258 break; 4259 k = j; /* minimum code length */ 4260 if ((uInt)l < j) 4261 l = j; 4262 for (i = BMAX; i; i--) 4263 if (c[i]) 4264 break; 4265 g = i; /* maximum code length */ 4266 if ((uInt)l > i) 4267 l = i; 4268 *m = l; 4269 4270 4271 /* Adjust last length count to fill out codes, if needed */ 4272 for (y = 1 << j; j < i; j++, y <<= 1) 4273 if ((y -= c[j]) < 0) 4274 return Z_DATA_ERROR; 4275 if ((y -= c[i]) < 0) 4276 return Z_DATA_ERROR; 4277 c[i] += y; 4278 4279 4280 /* Generate starting offsets into the value table for each length */ 4281 x[1] = j = 0; 4282 p = c + 1; xp = x + 2; 4283 while (--i) { /* note that i == g from above */ 4284 *xp++ = (j += *p++); 4285 } 4286 4287 4288 /* Make a table of values in order of bit lengths */ 4289 p = b; i = 0; 4290 do { 4291 if ((j = *p++) != 0) 4292 v[x[j]++] = i; 4293 } while (++i < n); 4294 n = x[g]; /* set n to length of v */ 4295 4296 4297 /* Generate the Huffman codes and for each, make the table entries */ 4298 x[0] = i = 0; /* first Huffman code is zero */ 4299 p = v; /* grab values in bit order */ 4300 h = -1; /* no tables yet--level -1 */ 4301 w = -l; /* bits decoded == (l * h) */ 4302 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 4303 q = (inflate_huft *)Z_NULL; /* ditto */ 4304 z = 0; /* ditto */ 4305 4306 /* go through the bit lengths (k already is bits in shortest code) */ 4307 for (; k <= g; k++) 4308 { 4309 a = c[k]; 4310 while (a--) 4311 { 4312 /* here i is the Huffman code of length k bits for value *p */ 4313 /* make tables up to required level */ 4314 while (k > w + l) 4315 { 4316 h++; 4317 w += l; /* previous table always l bits */ 4318 4319 /* compute minimum size table less than or equal to l bits */ 4320 z = g - w; 4321 z = z > (uInt)l ? l : z; /* table size upper limit */ 4322 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 4323 { /* too few codes for k-w bit table */ 4324 f -= a + 1; /* deduct codes from patterns left */ 4325 xp = c + k; 4326 if (j < z) 4327 while (++j < z) /* try smaller tables up to z bits */ 4328 { 4329 if ((f <<= 1) <= *++xp) 4330 break; /* enough codes to use up j bits */ 4331 f -= *xp; /* else deduct codes from patterns */ 4332 } 4333 } 4334 z = 1 << j; /* table entries for j-bit table */ 4335 4336 /* allocate and link in new table */ 4337 if ((q = (inflate_huft *)ZALLOC 4338 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 4339 { 4340 if (h) 4341 inflate_trees_free(u[0], zs); 4342 return Z_MEM_ERROR; /* not enough memory */ 4343 } 4344 #ifdef DEBUG_ZLIB 4345 inflate_hufts += z + 1; 4346 #endif 4347 *t = q + 1; /* link to list for huft_free() */ 4348 *(t = &(q->next)) = Z_NULL; 4349 u[h] = ++q; /* table starts after link */ 4350 4351 /* connect to last table, if there is one */ 4352 if (h) 4353 { 4354 x[h] = i; /* save pattern for backing up */ 4355 r.bits = (Byte)l; /* bits to dump before this table */ 4356 r.exop = (Byte)j; /* bits in this table */ 4357 r.next = q; /* pointer to this table */ 4358 j = i >> (w - l); /* (get around Turbo C bug) */ 4359 u[h-1][j] = r; /* connect to last table */ 4360 } 4361 } 4362 4363 /* set up table entry in r */ 4364 r.bits = (Byte)(k - w); 4365 if (p >= v + n) 4366 r.exop = 128 + 64; /* out of values--invalid code */ 4367 else if (*p < s) 4368 { 4369 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 4370 r.base = *p++; /* simple code is just the value */ 4371 } 4372 else 4373 { 4374 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ 4375 r.base = d[*p++ - s]; 4376 } 4377 4378 /* fill code-like entries with r */ 4379 f = 1 << (k - w); 4380 for (j = i >> w; j < z; j += f) 4381 q[j] = r; 4382 4383 /* backwards increment the k-bit code i */ 4384 for (j = 1 << (k - 1); i & j; j >>= 1) 4385 i ^= j; 4386 i ^= j; 4387 4388 /* backup over finished tables */ 4389 while ((i & ((1 << w) - 1)) != x[h]) 4390 { 4391 h--; /* don't need to update q */ 4392 w -= l; 4393 } 4394 } 4395 } 4396 4397 4398 /* Return Z_BUF_ERROR if we were given an incomplete table */ 4399 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 4400 } 4401 4402 4403 int inflate_trees_bits(c, bb, tb, z) 4404 uIntf *c; /* 19 code lengths */ 4405 uIntf *bb; /* bits tree desired/actual depth */ 4406 inflate_huft * FAR *tb; /* bits tree result */ 4407 z_streamp z; /* for zfree function */ 4408 { 4409 int r; 4410 4411 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 4412 if (r == Z_DATA_ERROR) 4413 z->msg = (char*)"oversubscribed dynamic bit lengths tree"; 4414 else if (r == Z_BUF_ERROR || *bb == 0) 4415 { 4416 inflate_trees_free(*tb, z); 4417 z->msg = (char*)"incomplete dynamic bit lengths tree"; 4418 r = Z_DATA_ERROR; 4419 } 4420 return r; 4421 } 4422 4423 4424 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) 4425 uInt nl; /* number of literal/length codes */ 4426 uInt nd; /* number of distance codes */ 4427 uIntf *c; /* that many (total) code lengths */ 4428 uIntf *bl; /* literal desired/actual bit depth */ 4429 uIntf *bd; /* distance desired/actual bit depth */ 4430 inflate_huft * FAR *tl; /* literal/length tree result */ 4431 inflate_huft * FAR *td; /* distance tree result */ 4432 z_streamp z; /* for zfree function */ 4433 { 4434 int r; 4435 4436 /* build literal/length tree */ 4437 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); 4438 if (r != Z_OK || *bl == 0) 4439 { 4440 if (r == Z_DATA_ERROR) 4441 z->msg = (char*)"oversubscribed literal/length tree"; 4442 else if (r != Z_MEM_ERROR) 4443 { 4444 inflate_trees_free(*tl, z); 4445 z->msg = (char*)"incomplete literal/length tree"; 4446 r = Z_DATA_ERROR; 4447 } 4448 return r; 4449 } 4450 4451 /* build distance tree */ 4452 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); 4453 if (r != Z_OK || (*bd == 0 && nl > 257)) 4454 { 4455 if (r == Z_DATA_ERROR) 4456 z->msg = (char*)"oversubscribed distance tree"; 4457 else if (r == Z_BUF_ERROR) { 4458 #ifdef PKZIP_BUG_WORKAROUND 4459 r = Z_OK; 4460 } 4461 #else 4462 inflate_trees_free(*td, z); 4463 z->msg = (char*)"incomplete distance tree"; 4464 r = Z_DATA_ERROR; 4465 } 4466 else if (r != Z_MEM_ERROR) 4467 { 4468 z->msg = (char*)"empty distance tree with lengths"; 4469 r = Z_DATA_ERROR; 4470 } 4471 inflate_trees_free(*tl, z); 4472 return r; 4473 #endif 4474 } 4475 4476 /* done */ 4477 return Z_OK; 4478 } 4479 4480 4481 /* build fixed tables only once--keep them here */ 4482 local int fixed_built = 0; 4483 #define FIXEDH 530 /* number of hufts used by fixed tables */ 4484 local inflate_huft fixed_mem[FIXEDH]; 4485 local uInt fixed_bl; 4486 local uInt fixed_bd; 4487 local inflate_huft *fixed_tl; 4488 local inflate_huft *fixed_td; 4489 4490 4491 local voidpf falloc(q, n, s) 4492 voidpf q; /* opaque pointer */ 4493 uInt n; /* number of items */ 4494 uInt s; /* size of item */ 4495 { 4496 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, 4497 "inflate_trees falloc overflow"); 4498 *(intf *)q -= n+s-s; /* s-s to avoid warning */ 4499 return (voidpf)(fixed_mem + *(intf *)q); 4500 } 4501 4502 4503 int inflate_trees_fixed(bl, bd, tl, td) 4504 uIntf *bl; /* literal desired/actual bit depth */ 4505 uIntf *bd; /* distance desired/actual bit depth */ 4506 inflate_huft * FAR *tl; /* literal/length tree result */ 4507 inflate_huft * FAR *td; /* distance tree result */ 4508 { 4509 /* build fixed tables if not already (multiple overlapped executions ok) */ 4510 if (!fixed_built) 4511 { 4512 int k; /* temporary variable */ 4513 unsigned c[288]; /* length list for huft_build */ 4514 z_stream z; /* for falloc function */ 4515 int f = FIXEDH; /* number of hufts left in fixed_mem */ 4516 4517 /* set up fake z_stream for memory routines */ 4518 z.zalloc = falloc; 4519 z.zfree = Z_NULL; 4520 z.opaque = (voidpf)&f; 4521 4522 /* literal table */ 4523 for (k = 0; k < 144; k++) 4524 c[k] = 8; 4525 for (; k < 256; k++) 4526 c[k] = 9; 4527 for (; k < 280; k++) 4528 c[k] = 7; 4529 for (; k < 288; k++) 4530 c[k] = 8; 4531 fixed_bl = 7; 4532 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4533 4534 /* distance table */ 4535 for (k = 0; k < 30; k++) 4536 c[k] = 5; 4537 fixed_bd = 5; 4538 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4539 4540 /* done */ 4541 Assert(f == 0, "invalid build of fixed tables"); 4542 fixed_built = 1; 4543 } 4544 *bl = fixed_bl; 4545 *bd = fixed_bd; 4546 *tl = fixed_tl; 4547 *td = fixed_td; 4548 return Z_OK; 4549 } 4550 4551 4552 int inflate_trees_free(t, z) 4553 inflate_huft *t; /* table to free */ 4554 z_streamp z; /* for zfree function */ 4555 /* Free the malloc'ed tables built by huft_build(), which makes a linked 4556 list of the tables it made, with the links in a dummy first entry of 4557 each table. */ 4558 { 4559 register inflate_huft *p, *q, *r; 4560 4561 /* Reverse linked list */ 4562 p = Z_NULL; 4563 q = t; 4564 while (q != Z_NULL) 4565 { 4566 r = (q - 1)->next; 4567 (q - 1)->next = p; 4568 p = q; 4569 q = r; 4570 } 4571 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4572 while (p != Z_NULL) 4573 { 4574 q = (--p)->next; 4575 ZFREE(z,p); 4576 p = q; 4577 } 4578 return Z_OK; 4579 } 4580 /* --- inftrees.c */ 4581 4582 /* +++ infcodes.c */ 4583 /* infcodes.c -- process literals and length/distance pairs 4584 * Copyright (C) 1995-1996 Mark Adler 4585 * For conditions of distribution and use, see copyright notice in zlib.h 4586 */ 4587 4588 /* #include "zutil.h" */ 4589 /* #include "inftrees.h" */ 4590 /* #include "infblock.h" */ 4591 /* #include "infcodes.h" */ 4592 /* #include "infutil.h" */ 4593 4594 /* +++ inffast.h */ 4595 /* inffast.h -- header to use inffast.c 4596 * Copyright (C) 1995-1996 Mark Adler 4597 * For conditions of distribution and use, see copyright notice in zlib.h 4598 */ 4599 4600 /* WARNING: this file should *not* be used by applications. It is 4601 part of the implementation of the compression library and is 4602 subject to change. Applications should only use zlib.h. 4603 */ 4604 4605 extern int inflate_fast OF(( 4606 uInt, 4607 uInt, 4608 inflate_huft *, 4609 inflate_huft *, 4610 inflate_blocks_statef *, 4611 z_streamp )); 4612 /* --- inffast.h */ 4613 4614 /* simplify the use of the inflate_huft type with some defines */ 4615 #define base more.Base 4616 #define next more.Next 4617 #define exop word.what.Exop 4618 #define bits word.what.Bits 4619 4620 /* inflate codes private state */ 4621 struct inflate_codes_state { 4622 4623 /* mode */ 4624 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4625 START, /* x: set up for LEN */ 4626 LEN, /* i: get length/literal/eob next */ 4627 LENEXT, /* i: getting length extra (have base) */ 4628 DIST, /* i: get distance next */ 4629 DISTEXT, /* i: getting distance extra */ 4630 COPY, /* o: copying bytes in window, waiting for space */ 4631 LIT, /* o: got literal, waiting for output space */ 4632 WASH, /* o: got eob, possibly still output waiting */ 4633 END, /* x: got eob and all data flushed */ 4634 BADCODE} /* x: got error */ 4635 mode; /* current inflate_codes mode */ 4636 4637 /* mode dependent information */ 4638 uInt len; 4639 union { 4640 struct { 4641 inflate_huft *tree; /* pointer into tree */ 4642 uInt need; /* bits needed */ 4643 } code; /* if LEN or DIST, where in tree */ 4644 uInt lit; /* if LIT, literal */ 4645 struct { 4646 uInt get; /* bits to get for extra */ 4647 uInt dist; /* distance back to copy from */ 4648 } copy; /* if EXT or COPY, where and how much */ 4649 } sub; /* submode */ 4650 4651 /* mode independent information */ 4652 Byte lbits; /* ltree bits decoded per branch */ 4653 Byte dbits; /* dtree bits decoder per branch */ 4654 inflate_huft *ltree; /* literal/length/eob tree */ 4655 inflate_huft *dtree; /* distance tree */ 4656 4657 }; 4658 4659 4660 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) 4661 uInt bl, bd; 4662 inflate_huft *tl; 4663 inflate_huft *td; /* need separate declaration for Borland C++ */ 4664 z_streamp z; 4665 { 4666 inflate_codes_statef *c; 4667 4668 if ((c = (inflate_codes_statef *) 4669 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4670 { 4671 c->mode = START; 4672 c->lbits = (Byte)bl; 4673 c->dbits = (Byte)bd; 4674 c->ltree = tl; 4675 c->dtree = td; 4676 Tracev((stderr, "inflate: codes new\n")); 4677 } 4678 return c; 4679 } 4680 4681 4682 int inflate_codes(s, z, r) 4683 inflate_blocks_statef *s; 4684 z_streamp z; 4685 int r; 4686 { 4687 uInt j; /* temporary storage */ 4688 inflate_huft *t; /* temporary pointer */ 4689 uInt e; /* extra bits or operation */ 4690 uLong b; /* bit buffer */ 4691 uInt k; /* bits in bit buffer */ 4692 Bytef *p; /* input data pointer */ 4693 uInt n; /* bytes available there */ 4694 Bytef *q; /* output window write pointer */ 4695 uInt m; /* bytes to end of window or read pointer */ 4696 Bytef *f; /* pointer to copy strings from */ 4697 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4698 4699 /* copy input/output information to locals (UPDATE macro restores) */ 4700 LOAD 4701 4702 /* process input and output based on current state */ 4703 while (1) switch (c->mode) 4704 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4705 case START: /* x: set up for LEN */ 4706 #ifndef SLOW 4707 if (m >= 258 && n >= 10) 4708 { 4709 UPDATE 4710 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4711 LOAD 4712 if (r != Z_OK) 4713 { 4714 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4715 break; 4716 } 4717 } 4718 #endif /* !SLOW */ 4719 c->sub.code.need = c->lbits; 4720 c->sub.code.tree = c->ltree; 4721 c->mode = LEN; 4722 case LEN: /* i: get length/literal/eob next */ 4723 j = c->sub.code.need; 4724 NEEDBITS(j) 4725 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4726 DUMPBITS(t->bits) 4727 e = (uInt)(t->exop); 4728 if (e == 0) /* literal */ 4729 { 4730 c->sub.lit = t->base; 4731 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4732 "inflate: literal '%c'\n" : 4733 "inflate: literal 0x%02x\n", t->base)); 4734 c->mode = LIT; 4735 break; 4736 } 4737 if (e & 16) /* length */ 4738 { 4739 c->sub.copy.get = e & 15; 4740 c->len = t->base; 4741 c->mode = LENEXT; 4742 break; 4743 } 4744 if ((e & 64) == 0) /* next table */ 4745 { 4746 c->sub.code.need = e; 4747 c->sub.code.tree = t->next; 4748 break; 4749 } 4750 if (e & 32) /* end of block */ 4751 { 4752 Tracevv((stderr, "inflate: end of block\n")); 4753 c->mode = WASH; 4754 break; 4755 } 4756 c->mode = BADCODE; /* invalid code */ 4757 z->msg = (char*)"invalid literal/length code"; 4758 r = Z_DATA_ERROR; 4759 LEAVE 4760 case LENEXT: /* i: getting length extra (have base) */ 4761 j = c->sub.copy.get; 4762 NEEDBITS(j) 4763 c->len += (uInt)b & inflate_mask[j]; 4764 DUMPBITS(j) 4765 c->sub.code.need = c->dbits; 4766 c->sub.code.tree = c->dtree; 4767 Tracevv((stderr, "inflate: length %u\n", c->len)); 4768 c->mode = DIST; 4769 case DIST: /* i: get distance next */ 4770 j = c->sub.code.need; 4771 NEEDBITS(j) 4772 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4773 DUMPBITS(t->bits) 4774 e = (uInt)(t->exop); 4775 if (e & 16) /* distance */ 4776 { 4777 c->sub.copy.get = e & 15; 4778 c->sub.copy.dist = t->base; 4779 c->mode = DISTEXT; 4780 break; 4781 } 4782 if ((e & 64) == 0) /* next table */ 4783 { 4784 c->sub.code.need = e; 4785 c->sub.code.tree = t->next; 4786 break; 4787 } 4788 c->mode = BADCODE; /* invalid code */ 4789 z->msg = (char*)"invalid distance code"; 4790 r = Z_DATA_ERROR; 4791 LEAVE 4792 case DISTEXT: /* i: getting distance extra */ 4793 j = c->sub.copy.get; 4794 NEEDBITS(j) 4795 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4796 DUMPBITS(j) 4797 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4798 c->mode = COPY; 4799 case COPY: /* o: copying bytes in window, waiting for space */ 4800 #ifndef __TURBOC__ /* Turbo C bug for following expression */ 4801 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4802 s->end - (c->sub.copy.dist - (q - s->window)) : 4803 q - c->sub.copy.dist; 4804 #else 4805 f = q - c->sub.copy.dist; 4806 if ((uInt)(q - s->window) < c->sub.copy.dist) 4807 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); 4808 #endif 4809 while (c->len) 4810 { 4811 NEEDOUT 4812 OUTBYTE(*f++) 4813 if (f == s->end) 4814 f = s->window; 4815 c->len--; 4816 } 4817 c->mode = START; 4818 break; 4819 case LIT: /* o: got literal, waiting for output space */ 4820 NEEDOUT 4821 OUTBYTE(c->sub.lit) 4822 c->mode = START; 4823 break; 4824 case WASH: /* o: got eob, possibly more output */ 4825 FLUSH 4826 if (s->read != s->write) 4827 LEAVE 4828 c->mode = END; 4829 case END: 4830 r = Z_STREAM_END; 4831 LEAVE 4832 case BADCODE: /* x: got error */ 4833 r = Z_DATA_ERROR; 4834 LEAVE 4835 default: 4836 r = Z_STREAM_ERROR; 4837 LEAVE 4838 } 4839 } 4840 4841 4842 void inflate_codes_free(c, z) 4843 inflate_codes_statef *c; 4844 z_streamp z; 4845 { 4846 ZFREE(z, c); 4847 Tracev((stderr, "inflate: codes free\n")); 4848 } 4849 /* --- infcodes.c */ 4850 4851 /* +++ infutil.c */ 4852 /* inflate_util.c -- data and routines common to blocks and codes 4853 * Copyright (C) 1995-1996 Mark Adler 4854 * For conditions of distribution and use, see copyright notice in zlib.h 4855 */ 4856 4857 /* #include "zutil.h" */ 4858 /* #include "infblock.h" */ 4859 /* #include "inftrees.h" */ 4860 /* #include "infcodes.h" */ 4861 /* #include "infutil.h" */ 4862 4863 #ifndef NO_DUMMY_DECL 4864 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4865 #endif 4866 4867 /* And'ing with mask[n] masks the lower n bits */ 4868 uInt inflate_mask[17] = { 4869 0x0000, 4870 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 4871 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 4872 }; 4873 4874 4875 /* copy as much as possible from the sliding window to the output area */ 4876 int inflate_flush(s, z, r) 4877 inflate_blocks_statef *s; 4878 z_streamp z; 4879 int r; 4880 { 4881 uInt n; 4882 Bytef *p; 4883 Bytef *q; 4884 4885 /* local copies of source and destination pointers */ 4886 p = z->next_out; 4887 q = s->read; 4888 4889 /* compute number of bytes to copy as far as end of window */ 4890 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4891 if (n > z->avail_out) n = z->avail_out; 4892 if (n && r == Z_BUF_ERROR) r = Z_OK; 4893 4894 /* update counters */ 4895 z->avail_out -= n; 4896 z->total_out += n; 4897 4898 /* update check information */ 4899 if (s->checkfn != Z_NULL) 4900 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4901 4902 /* copy as far as end of window */ 4903 if (p != Z_NULL) { 4904 zmemcpy(p, q, n); 4905 p += n; 4906 } 4907 q += n; 4908 4909 /* see if more to copy at beginning of window */ 4910 if (q == s->end) 4911 { 4912 /* wrap pointers */ 4913 q = s->window; 4914 if (s->write == s->end) 4915 s->write = s->window; 4916 4917 /* compute bytes to copy */ 4918 n = (uInt)(s->write - q); 4919 if (n > z->avail_out) n = z->avail_out; 4920 if (n && r == Z_BUF_ERROR) r = Z_OK; 4921 4922 /* update counters */ 4923 z->avail_out -= n; 4924 z->total_out += n; 4925 4926 /* update check information */ 4927 if (s->checkfn != Z_NULL) 4928 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4929 4930 /* copy */ 4931 if (p != Z_NULL) { 4932 zmemcpy(p, q, n); 4933 p += n; 4934 } 4935 q += n; 4936 } 4937 4938 /* update pointers */ 4939 z->next_out = p; 4940 s->read = q; 4941 4942 /* done */ 4943 return r; 4944 } 4945 /* --- infutil.c */ 4946 4947 /* +++ inffast.c */ 4948 /* inffast.c -- process literals and length/distance pairs fast 4949 * Copyright (C) 1995-1996 Mark Adler 4950 * For conditions of distribution and use, see copyright notice in zlib.h 4951 */ 4952 4953 /* #include "zutil.h" */ 4954 /* #include "inftrees.h" */ 4955 /* #include "infblock.h" */ 4956 /* #include "infcodes.h" */ 4957 /* #include "infutil.h" */ 4958 /* #include "inffast.h" */ 4959 4960 #ifndef NO_DUMMY_DECL 4961 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4962 #endif 4963 4964 /* simplify the use of the inflate_huft type with some defines */ 4965 #define base more.Base 4966 #define next more.Next 4967 #define exop word.what.Exop 4968 #define bits word.what.Bits 4969 4970 /* macros for bit input with no checking and for returning unused bytes */ 4971 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4972 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4973 4974 /* Called with number of bytes left to write in window at least 258 4975 (the maximum string length) and number of input bytes available 4976 at least ten. The ten bytes are six bytes for the longest length/ 4977 distance pair plus four bytes for overloading the bit buffer. */ 4978 4979 int inflate_fast(bl, bd, tl, td, s, z) 4980 uInt bl, bd; 4981 inflate_huft *tl; 4982 inflate_huft *td; /* need separate declaration for Borland C++ */ 4983 inflate_blocks_statef *s; 4984 z_streamp z; 4985 { 4986 inflate_huft *t; /* temporary pointer */ 4987 uInt e; /* extra bits or operation */ 4988 uLong b; /* bit buffer */ 4989 uInt k; /* bits in bit buffer */ 4990 Bytef *p; /* input data pointer */ 4991 uInt n; /* bytes available there */ 4992 Bytef *q; /* output window write pointer */ 4993 uInt m; /* bytes to end of window or read pointer */ 4994 uInt ml; /* mask for literal/length tree */ 4995 uInt md; /* mask for distance tree */ 4996 uInt c; /* bytes to copy */ 4997 uInt d; /* distance back to copy from */ 4998 Bytef *r; /* copy source pointer */ 4999 5000 /* load input, output, bit values */ 5001 LOAD 5002 5003 /* initialize masks */ 5004 ml = inflate_mask[bl]; 5005 md = inflate_mask[bd]; 5006 5007 /* do until not enough input or output space for fast loop */ 5008 do { /* assume called with m >= 258 && n >= 10 */ 5009 /* get literal/length code */ 5010 GRABBITS(20) /* max bits for literal/length code */ 5011 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 5012 { 5013 DUMPBITS(t->bits) 5014 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5015 "inflate: * literal '%c'\n" : 5016 "inflate: * literal 0x%02x\n", t->base)); 5017 *q++ = (Byte)t->base; 5018 m--; 5019 continue; 5020 } 5021 do { 5022 DUMPBITS(t->bits) 5023 if (e & 16) 5024 { 5025 /* get extra bits for length */ 5026 e &= 15; 5027 c = t->base + ((uInt)b & inflate_mask[e]); 5028 DUMPBITS(e) 5029 Tracevv((stderr, "inflate: * length %u\n", c)); 5030 5031 /* decode distance base of block to copy */ 5032 GRABBITS(15); /* max bits for distance code */ 5033 e = (t = td + ((uInt)b & md))->exop; 5034 do { 5035 DUMPBITS(t->bits) 5036 if (e & 16) 5037 { 5038 /* get extra bits to add to distance base */ 5039 e &= 15; 5040 GRABBITS(e) /* get extra bits (up to 13) */ 5041 d = t->base + ((uInt)b & inflate_mask[e]); 5042 DUMPBITS(e) 5043 Tracevv((stderr, "inflate: * distance %u\n", d)); 5044 5045 /* do the copy */ 5046 m -= c; 5047 if ((uInt)(q - s->window) >= d) /* offset before dest */ 5048 { /* just copy */ 5049 r = q - d; 5050 *q++ = *r++; c--; /* minimum count is three, */ 5051 *q++ = *r++; c--; /* so unroll loop a little */ 5052 } 5053 else /* else offset after destination */ 5054 { 5055 e = d - (uInt)(q - s->window); /* bytes from offset to end */ 5056 r = s->end - e; /* pointer to offset */ 5057 if (c > e) /* if source crosses, */ 5058 { 5059 c -= e; /* copy to end of window */ 5060 do { 5061 *q++ = *r++; 5062 } while (--e); 5063 r = s->window; /* copy rest from start of window */ 5064 } 5065 } 5066 do { /* copy all or what's left */ 5067 *q++ = *r++; 5068 } while (--c); 5069 break; 5070 } 5071 else if ((e & 64) == 0) 5072 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 5073 else 5074 { 5075 z->msg = (char*)"invalid distance code"; 5076 UNGRAB 5077 UPDATE 5078 return Z_DATA_ERROR; 5079 } 5080 } while (1); 5081 break; 5082 } 5083 if ((e & 64) == 0) 5084 { 5085 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 5086 { 5087 DUMPBITS(t->bits) 5088 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5089 "inflate: * literal '%c'\n" : 5090 "inflate: * literal 0x%02x\n", t->base)); 5091 *q++ = (Byte)t->base; 5092 m--; 5093 break; 5094 } 5095 } 5096 else if (e & 32) 5097 { 5098 Tracevv((stderr, "inflate: * end of block\n")); 5099 UNGRAB 5100 UPDATE 5101 return Z_STREAM_END; 5102 } 5103 else 5104 { 5105 z->msg = (char*)"invalid literal/length code"; 5106 UNGRAB 5107 UPDATE 5108 return Z_DATA_ERROR; 5109 } 5110 } while (1); 5111 } while (m >= 258 && n >= 10); 5112 5113 /* not enough input or output--restore pointers and return */ 5114 UNGRAB 5115 UPDATE 5116 return Z_OK; 5117 } 5118 /* --- inffast.c */ 5119 5120 /* +++ zutil.c */ 5121 /* zutil.c -- target dependent utility functions for the compression library 5122 * Copyright (C) 1995-1996 Jean-loup Gailly. 5123 * For conditions of distribution and use, see copyright notice in zlib.h 5124 */ 5125 5126 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ 5127 5128 #ifdef DEBUG_ZLIB 5129 #include <stdio.h> 5130 #endif 5131 5132 /* #include "zutil.h" */ 5133 5134 #ifndef NO_DUMMY_DECL 5135 struct internal_state {int dummy;}; /* for buggy compilers */ 5136 #endif 5137 5138 #ifndef STDC 5139 extern void exit OF((int)); 5140 #endif 5141 5142 static const char *z_errmsg[10] = { 5143 "need dictionary", /* Z_NEED_DICT 2 */ 5144 "stream end", /* Z_STREAM_END 1 */ 5145 "", /* Z_OK 0 */ 5146 "file error", /* Z_ERRNO (-1) */ 5147 "stream error", /* Z_STREAM_ERROR (-2) */ 5148 "data error", /* Z_DATA_ERROR (-3) */ 5149 "insufficient memory", /* Z_MEM_ERROR (-4) */ 5150 "buffer error", /* Z_BUF_ERROR (-5) */ 5151 "incompatible version",/* Z_VERSION_ERROR (-6) */ 5152 ""}; 5153 5154 5155 const char *zlibVersion() 5156 { 5157 return ZLIB_VERSION; 5158 } 5159 5160 #ifdef DEBUG_ZLIB 5161 void z_error (m) 5162 char *m; 5163 { 5164 fprintf(stderr, "%s\n", m); 5165 exit(1); 5166 } 5167 #endif 5168 5169 #ifndef HAVE_MEMCPY 5170 5171 void zmemcpy(dest, source, len) 5172 Bytef* dest; 5173 Bytef* source; 5174 uInt len; 5175 { 5176 if (len == 0) return; 5177 do { 5178 *dest++ = *source++; /* ??? to be unrolled */ 5179 } while (--len != 0); 5180 } 5181 5182 int zmemcmp(s1, s2, len) 5183 Bytef* s1; 5184 Bytef* s2; 5185 uInt len; 5186 { 5187 uInt j; 5188 5189 for (j = 0; j < len; j++) { 5190 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 5191 } 5192 return 0; 5193 } 5194 5195 void zmemzero(dest, len) 5196 Bytef* dest; 5197 uInt len; 5198 { 5199 if (len == 0) return; 5200 do { 5201 *dest++ = 0; /* ??? to be unrolled */ 5202 } while (--len != 0); 5203 } 5204 #endif 5205 5206 #ifdef __TURBOC__ 5207 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 5208 /* Small and medium model in Turbo C are for now limited to near allocation 5209 * with reduced MAX_WBITS and MAX_MEM_LEVEL 5210 */ 5211 # define MY_ZCALLOC 5212 5213 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes 5214 * and farmalloc(64K) returns a pointer with an offset of 8, so we 5215 * must fix the pointer. Warning: the pointer must be put back to its 5216 * original form in order to free it, use zcfree(). 5217 */ 5218 5219 #define MAX_PTR 10 5220 /* 10*64K = 640K */ 5221 5222 local int next_ptr = 0; 5223 5224 typedef struct ptr_table_s { 5225 voidpf org_ptr; 5226 voidpf new_ptr; 5227 } ptr_table; 5228 5229 local ptr_table table[MAX_PTR]; 5230 /* This table is used to remember the original form of pointers 5231 * to large buffers (64K). Such pointers are normalized with a zero offset. 5232 * Since MSDOS is not a preemptive multitasking OS, this table is not 5233 * protected from concurrent access. This hack doesn't work anyway on 5234 * a protected system like OS/2. Use Microsoft C instead. 5235 */ 5236 5237 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5238 { 5239 voidpf buf = opaque; /* just to make some compilers happy */ 5240 ulg bsize = (ulg)items*size; 5241 5242 /* If we allocate less than 65520 bytes, we assume that farmalloc 5243 * will return a usable pointer which doesn't have to be normalized. 5244 */ 5245 if (bsize < 65520L) { 5246 buf = farmalloc(bsize); 5247 if (*(ush*)&buf != 0) return buf; 5248 } else { 5249 buf = farmalloc(bsize + 16L); 5250 } 5251 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 5252 table[next_ptr].org_ptr = buf; 5253 5254 /* Normalize the pointer to seg:0 */ 5255 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 5256 *(ush*)&buf = 0; 5257 table[next_ptr++].new_ptr = buf; 5258 return buf; 5259 } 5260 5261 void zcfree (voidpf opaque, voidpf ptr) 5262 { 5263 int n; 5264 if (*(ush*)&ptr != 0) { /* object < 64K */ 5265 farfree(ptr); 5266 return; 5267 } 5268 /* Find the original pointer */ 5269 for (n = 0; n < next_ptr; n++) { 5270 if (ptr != table[n].new_ptr) continue; 5271 5272 farfree(table[n].org_ptr); 5273 while (++n < next_ptr) { 5274 table[n-1] = table[n]; 5275 } 5276 next_ptr--; 5277 return; 5278 } 5279 ptr = opaque; /* just to make some compilers happy */ 5280 Assert(0, "zcfree: ptr not found"); 5281 } 5282 #endif 5283 #endif /* __TURBOC__ */ 5284 5285 5286 #if defined(M_I86) && !defined(__32BIT__) 5287 /* Microsoft C in 16-bit mode */ 5288 5289 # define MY_ZCALLOC 5290 5291 #if (!defined(_MSC_VER) || (_MSC_VER < 600)) 5292 # define _halloc halloc 5293 # define _hfree hfree 5294 #endif 5295 5296 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5297 { 5298 if (opaque) opaque = 0; /* to make compiler happy */ 5299 return _halloc((long)items, size); 5300 } 5301 5302 void zcfree (voidpf opaque, voidpf ptr) 5303 { 5304 if (opaque) opaque = 0; /* to make compiler happy */ 5305 _hfree(ptr); 5306 } 5307 5308 #endif /* MSC */ 5309 5310 5311 #ifndef MY_ZCALLOC /* Any system without a special alloc function */ 5312 5313 #ifndef STDC 5314 extern voidp calloc OF((uInt items, uInt size)); 5315 extern void free OF((voidpf ptr)); 5316 #endif 5317 5318 voidpf zcalloc (opaque, items, size) 5319 voidpf opaque; 5320 unsigned items; 5321 unsigned size; 5322 { 5323 if (opaque) items += size - size; /* make compiler happy */ 5324 return (voidpf)calloc(items, size); 5325 } 5326 5327 void zcfree (opaque, ptr) 5328 voidpf opaque; 5329 voidpf ptr; 5330 { 5331 free(ptr); 5332 if (opaque) return; /* make compiler happy */ 5333 } 5334 5335 #endif /* MY_ZCALLOC */ 5336 /* --- zutil.c */ 5337 5338 /* +++ adler32.c */ 5339 /* adler32.c -- compute the Adler-32 checksum of a data stream 5340 * Copyright (C) 1995-1996 Mark Adler 5341 * For conditions of distribution and use, see copyright notice in zlib.h 5342 */ 5343 5344 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ 5345 5346 /* #include "zlib.h" */ 5347 5348 #define BASE 65521L /* largest prime smaller than 65536 */ 5349 #define NMAX 5552 5350 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 5351 5352 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;} 5353 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1); 5354 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2); 5355 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); 5356 #define DO16(buf) DO8(buf,0); DO8(buf,8); 5357 5358 /* ========================================================================= */ 5359 uLong adler32(adler, buf, len) 5360 uLong adler; 5361 const Bytef *buf; 5362 uInt len; 5363 { 5364 unsigned long s1 = adler & 0xffff; 5365 unsigned long s2 = (adler >> 16) & 0xffff; 5366 int k; 5367 5368 if (buf == Z_NULL) return 1L; 5369 5370 while (len > 0) { 5371 k = len < NMAX ? len : NMAX; 5372 len -= k; 5373 while (k >= 16) { 5374 DO16(buf); 5375 buf += 16; 5376 k -= 16; 5377 } 5378 if (k != 0) do { 5379 s1 += *buf++; 5380 s2 += s1; 5381 } while (--k); 5382 s1 %= BASE; 5383 s2 %= BASE; 5384 } 5385 return (s2 << 16) | s1; 5386 } 5387 /* --- adler32.c */ 5388