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 1.5 2003/07/28 00:02:44 hmp 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/param.h> 58 #include <sys/types.h> 59 #include <sys/time.h> 60 #include <sys/systm.h> 61 # define HAVE_MEMCPY 62 # define memcpy(d, s, n) bcopy((s), (d), (n)) 63 # define memset(d, v, n) bzero((d), (n)) 64 # define memcmp bcmp 65 66 #else 67 #if defined(__KERNEL__) 68 /* Assume this is a Linux kernel */ 69 #include <linux/string.h> 70 #define HAVE_MEMCPY 71 72 #else /* not kernel */ 73 74 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS) 75 # include <stddef.h> 76 # include <errno.h> 77 #else 78 extern int errno; 79 #endif 80 #ifdef STDC 81 # include <string.h> 82 # include <stdlib.h> 83 #endif 84 #endif /* __KERNEL__ */ 85 #endif /* _KERNEL */ 86 87 #ifndef local 88 # define local static 89 #endif 90 /* compile with -Dlocal if your debugger can't find static symbols */ 91 92 typedef unsigned char uch; 93 typedef uch FAR uchf; 94 typedef unsigned short ush; 95 typedef ush FAR ushf; 96 typedef unsigned long ulg; 97 98 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */ 99 /* (size given to avoid silly warnings with Visual C++) */ 100 101 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)] 102 103 #define ERR_RETURN(strm,err) \ 104 return (strm->msg = (const char*)ERR_MSG(err), (err)) 105 /* To be used only when the state is known to be valid */ 106 107 /* common constants */ 108 109 #ifndef DEF_WBITS 110 # define DEF_WBITS MAX_WBITS 111 #endif 112 /* default windowBits for decompression. MAX_WBITS is for compression only */ 113 114 #if MAX_MEM_LEVEL >= 8 115 # define DEF_MEM_LEVEL 8 116 #else 117 # define DEF_MEM_LEVEL MAX_MEM_LEVEL 118 #endif 119 /* default memLevel */ 120 121 #define STORED_BLOCK 0 122 #define STATIC_TREES 1 123 #define DYN_TREES 2 124 /* The three kinds of block type */ 125 126 #define MIN_MATCH 3 127 #define MAX_MATCH 258 128 /* The minimum and maximum match lengths */ 129 130 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */ 131 132 /* target dependencies */ 133 134 #ifdef MSDOS 135 # define OS_CODE 0x00 136 # ifdef __TURBOC__ 137 # include <alloc.h> 138 # else /* MSC or DJGPP */ 139 # include <malloc.h> 140 # endif 141 #endif 142 143 #ifdef OS2 144 # define OS_CODE 0x06 145 #endif 146 147 #ifdef WIN32 /* Window 95 & Windows NT */ 148 # define OS_CODE 0x0b 149 #endif 150 151 #if defined(VAXC) || defined(VMS) 152 # define OS_CODE 0x02 153 # define FOPEN(name, mode) \ 154 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") 155 #endif 156 157 #ifdef AMIGA 158 # define OS_CODE 0x01 159 #endif 160 161 #if defined(ATARI) || defined(atarist) 162 # define OS_CODE 0x05 163 #endif 164 165 #ifdef MACOS 166 # define OS_CODE 0x07 167 #endif 168 169 #ifdef __50SERIES /* Prime/PRIMOS */ 170 # define OS_CODE 0x0F 171 #endif 172 173 #ifdef TOPS20 174 # define OS_CODE 0x0a 175 #endif 176 177 #if defined(_BEOS_) || defined(RISCOS) 178 # define fdopen(fd,mode) NULL /* No fdopen() */ 179 #endif 180 181 /* Common defaults */ 182 183 #ifndef OS_CODE 184 # define OS_CODE 0x03 /* assume Unix */ 185 #endif 186 187 #ifndef FOPEN 188 # define FOPEN(name, mode) fopen((name), (mode)) 189 #endif 190 191 /* functions */ 192 193 #ifdef HAVE_STRERROR 194 extern char *strerror OF((int)); 195 # define zstrerror(errnum) strerror(errnum) 196 #else 197 # define zstrerror(errnum) "" 198 #endif 199 200 #if defined(pyr) 201 # define NO_MEMCPY 202 #endif 203 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER) 204 /* Use our own functions for small and medium model with MSC <= 5.0. 205 * You may have to use the same strategy for Borland C (untested). 206 */ 207 # define NO_MEMCPY 208 #endif 209 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY) 210 # define HAVE_MEMCPY 211 #endif 212 #ifdef HAVE_MEMCPY 213 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */ 214 # define zmemcpy _fmemcpy 215 # define zmemcmp _fmemcmp 216 # define zmemzero(dest, len) _fmemset(dest, 0, len) 217 # else 218 # define zmemcpy memcpy 219 # define zmemcmp memcmp 220 # define zmemzero(dest, len) memset(dest, 0, len) 221 # endif 222 #else 223 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len)); 224 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len)); 225 extern void zmemzero OF((Bytef* dest, uInt len)); 226 #endif 227 228 /* Diagnostic functions */ 229 #ifdef DEBUG_ZLIB 230 # include <stdio.h> 231 # ifndef verbose 232 # define verbose 0 233 # endif 234 extern void z_error OF((char *m)); 235 # define Assert(cond,msg) {if(!(cond)) z_error(msg);} 236 # define Trace(x) fprintf x 237 # define Tracev(x) {if (verbose) fprintf x ;} 238 # define Tracevv(x) {if (verbose>1) fprintf x ;} 239 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} 240 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} 241 #else 242 # define Assert(cond,msg) 243 # define Trace(x) 244 # define Tracev(x) 245 # define Tracevv(x) 246 # define Tracec(c,x) 247 # define Tracecv(c,x) 248 #endif 249 250 251 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len)); 252 253 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); 254 void zcfree OF((voidpf opaque, voidpf ptr)); 255 256 #define ZALLOC(strm, items, size) \ 257 (*((strm)->zalloc))((strm)->opaque, (items), (size)) 258 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr)) 259 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);} 260 261 #endif /* _Z_UTIL_H */ 262 /* --- zutil.h */ 263 264 /* +++ deflate.h */ 265 /* deflate.h -- internal compression state 266 * Copyright (C) 1995-1996 Jean-loup Gailly 267 * For conditions of distribution and use, see copyright notice in zlib.h 268 */ 269 270 /* WARNING: this file should *not* be used by applications. It is 271 part of the implementation of the compression library and is 272 subject to change. Applications should only use zlib.h. 273 */ 274 275 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */ 276 277 #ifndef _DEFLATE_H 278 #define _DEFLATE_H 279 280 /* #include "zutil.h" */ 281 282 /* =========================================================================== 283 * Internal compression state. 284 */ 285 286 #define LENGTH_CODES 29 287 /* number of length codes, not counting the special END_BLOCK code */ 288 289 #define LITERALS 256 290 /* number of literal bytes 0..255 */ 291 292 #define L_CODES (LITERALS+1+LENGTH_CODES) 293 /* number of Literal or Length codes, including the END_BLOCK code */ 294 295 #define D_CODES 30 296 /* number of distance codes */ 297 298 #define BL_CODES 19 299 /* number of codes used to transfer the bit lengths */ 300 301 #define HEAP_SIZE (2*L_CODES+1) 302 /* maximum heap size */ 303 304 #define MAX_BITS 15 305 /* All codes must not exceed MAX_BITS bits */ 306 307 #define INIT_STATE 42 308 #define BUSY_STATE 113 309 #define FINISH_STATE 666 310 /* Stream status */ 311 312 313 /* Data structure describing a single value and its code string. */ 314 typedef struct ct_data_s { 315 union { 316 ush freq; /* frequency count */ 317 ush code; /* bit string */ 318 } fc; 319 union { 320 ush dad; /* father node in Huffman tree */ 321 ush len; /* length of bit string */ 322 } dl; 323 } FAR ct_data; 324 325 #define Freq fc.freq 326 #define Code fc.code 327 #define Dad dl.dad 328 #define Len dl.len 329 330 typedef struct static_tree_desc_s static_tree_desc; 331 332 typedef struct tree_desc_s { 333 ct_data *dyn_tree; /* the dynamic tree */ 334 int max_code; /* largest code with non zero frequency */ 335 static_tree_desc *stat_desc; /* the corresponding static tree */ 336 } FAR tree_desc; 337 338 typedef ush Pos; 339 typedef Pos FAR Posf; 340 typedef unsigned IPos; 341 342 /* A Pos is an index in the character window. We use short instead of int to 343 * save space in the various tables. IPos is used only for parameter passing. 344 */ 345 346 typedef struct deflate_state { 347 z_streamp strm; /* pointer back to this zlib stream */ 348 int status; /* as the name implies */ 349 Bytef *pending_buf; /* output still pending */ 350 ulg pending_buf_size; /* size of pending_buf */ 351 Bytef *pending_out; /* next pending byte to output to the stream */ 352 int pending; /* nb of bytes in the pending buffer */ 353 int noheader; /* suppress zlib header and adler32 */ 354 Byte data_type; /* UNKNOWN, BINARY or ASCII */ 355 Byte method; /* STORED (for zip only) or DEFLATED */ 356 int last_flush; /* value of flush param for previous deflate call */ 357 358 /* used by deflate.c: */ 359 360 uInt w_size; /* LZ77 window size (32K by default) */ 361 uInt w_bits; /* log2(w_size) (8..16) */ 362 uInt w_mask; /* w_size - 1 */ 363 364 Bytef *window; 365 /* Sliding window. Input bytes are read into the second half of the window, 366 * and move to the first half later to keep a dictionary of at least wSize 367 * bytes. With this organization, matches are limited to a distance of 368 * wSize-MAX_MATCH bytes, but this ensures that IO is always 369 * performed with a length multiple of the block size. Also, it limits 370 * the window size to 64K, which is quite useful on MSDOS. 371 * To do: use the user input buffer as sliding window. 372 */ 373 374 ulg window_size; 375 /* Actual size of window: 2*wSize, except when the user input buffer 376 * is directly used as sliding window. 377 */ 378 379 Posf *prev; 380 /* Link to older string with same hash index. To limit the size of this 381 * array to 64K, this link is maintained only for the last 32K strings. 382 * An index in this array is thus a window index modulo 32K. 383 */ 384 385 Posf *head; /* Heads of the hash chains or NIL. */ 386 387 uInt ins_h; /* hash index of string to be inserted */ 388 uInt hash_size; /* number of elements in hash table */ 389 uInt hash_bits; /* log2(hash_size) */ 390 uInt hash_mask; /* hash_size-1 */ 391 392 uInt hash_shift; 393 /* Number of bits by which ins_h must be shifted at each input 394 * step. It must be such that after MIN_MATCH steps, the oldest 395 * byte no longer takes part in the hash key, that is: 396 * hash_shift * MIN_MATCH >= hash_bits 397 */ 398 399 long block_start; 400 /* Window position at the beginning of the current output block. Gets 401 * negative when the window is moved backwards. 402 */ 403 404 uInt match_length; /* length of best match */ 405 IPos prev_match; /* previous match */ 406 int match_available; /* set if previous match exists */ 407 uInt strstart; /* start of string to insert */ 408 uInt match_start; /* start of matching string */ 409 uInt lookahead; /* number of valid bytes ahead in window */ 410 411 uInt prev_length; 412 /* Length of the best match at previous step. Matches not greater than this 413 * are discarded. This is used in the lazy match evaluation. 414 */ 415 416 uInt max_chain_length; 417 /* To speed up deflation, hash chains are never searched beyond this 418 * length. A higher limit improves compression ratio but degrades the 419 * speed. 420 */ 421 422 uInt max_lazy_match; 423 /* Attempt to find a better match only when the current match is strictly 424 * smaller than this value. This mechanism is used only for compression 425 * levels >= 4. 426 */ 427 # define max_insert_length max_lazy_match 428 /* Insert new strings in the hash table only if the match length is not 429 * greater than this length. This saves time but degrades compression. 430 * max_insert_length is used only for compression levels <= 3. 431 */ 432 433 int level; /* compression level (1..9) */ 434 int strategy; /* favor or force Huffman coding*/ 435 436 uInt good_match; 437 /* Use a faster search when the previous match is longer than this */ 438 439 int nice_match; /* Stop searching when current match exceeds this */ 440 441 /* used by trees.c: */ 442 /* Didn't use ct_data typedef below to supress compiler warning */ 443 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ 444 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ 445 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ 446 447 struct tree_desc_s l_desc; /* desc. for literal tree */ 448 struct tree_desc_s d_desc; /* desc. for distance tree */ 449 struct tree_desc_s bl_desc; /* desc. for bit length tree */ 450 451 ush bl_count[MAX_BITS+1]; 452 /* number of codes at each bit length for an optimal tree */ 453 454 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ 455 int heap_len; /* number of elements in the heap */ 456 int heap_max; /* element of largest frequency */ 457 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. 458 * The same heap array is used to build all trees. 459 */ 460 461 uch depth[2*L_CODES+1]; 462 /* Depth of each subtree used as tie breaker for trees of equal frequency 463 */ 464 465 uchf *l_buf; /* buffer for literals or lengths */ 466 467 uInt lit_bufsize; 468 /* Size of match buffer for literals/lengths. There are 4 reasons for 469 * limiting lit_bufsize to 64K: 470 * - frequencies can be kept in 16 bit counters 471 * - if compression is not successful for the first block, all input 472 * data is still in the window so we can still emit a stored block even 473 * when input comes from standard input. (This can also be done for 474 * all blocks if lit_bufsize is not greater than 32K.) 475 * - if compression is not successful for a file smaller than 64K, we can 476 * even emit a stored file instead of a stored block (saving 5 bytes). 477 * This is applicable only for zip (not gzip or zlib). 478 * - creating new Huffman trees less frequently may not provide fast 479 * adaptation to changes in the input data statistics. (Take for 480 * example a binary file with poorly compressible code followed by 481 * a highly compressible string table.) Smaller buffer sizes give 482 * fast adaptation but have of course the overhead of transmitting 483 * trees more frequently. 484 * - I can't count above 4 485 */ 486 487 uInt last_lit; /* running index in l_buf */ 488 489 ushf *d_buf; 490 /* Buffer for distances. To simplify the code, d_buf and l_buf have 491 * the same number of elements. To use different lengths, an extra flag 492 * array would be necessary. 493 */ 494 495 ulg opt_len; /* bit length of current block with optimal trees */ 496 ulg static_len; /* bit length of current block with static trees */ 497 ulg compressed_len; /* total bit length of compressed file */ 498 uInt matches; /* number of string matches in current block */ 499 int last_eob_len; /* bit length of EOB code for last block */ 500 501 #ifdef DEBUG_ZLIB 502 ulg bits_sent; /* bit length of the compressed data */ 503 #endif 504 505 ush bi_buf; 506 /* Output buffer. bits are inserted starting at the bottom (least 507 * significant bits). 508 */ 509 int bi_valid; 510 /* Number of valid bits in bi_buf. All bits above the last valid bit 511 * are always zero. 512 */ 513 514 } FAR deflate_state; 515 516 /* Output a byte on the stream. 517 * IN assertion: there is enough room in pending_buf. 518 */ 519 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} 520 521 522 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 523 /* Minimum amount of lookahead, except at the end of the input file. 524 * See deflate.c for comments about the MIN_MATCH+1. 525 */ 526 527 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) 528 /* In order to simplify the code, particularly on 16 bit machines, match 529 * distances are limited to MAX_DIST instead of WSIZE. 530 */ 531 532 /* in trees.c */ 533 void _tr_init OF((deflate_state *s)); 534 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc)); 535 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, 536 int eof)); 537 void _tr_align OF((deflate_state *s)); 538 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, 539 int eof)); 540 void _tr_stored_type_only OF((deflate_state *)); 541 542 #endif 543 /* --- deflate.h */ 544 545 /* +++ deflate.c */ 546 /* deflate.c -- compress data using the deflation algorithm 547 * Copyright (C) 1995-1996 Jean-loup Gailly. 548 * For conditions of distribution and use, see copyright notice in zlib.h 549 */ 550 551 /* 552 * ALGORITHM 553 * 554 * The "deflation" process depends on being able to identify portions 555 * of the input text which are identical to earlier input (within a 556 * sliding window trailing behind the input currently being processed). 557 * 558 * The most straightforward technique turns out to be the fastest for 559 * most input files: try all possible matches and select the longest. 560 * The key feature of this algorithm is that insertions into the string 561 * dictionary are very simple and thus fast, and deletions are avoided 562 * completely. Insertions are performed at each input character, whereas 563 * string matches are performed only when the previous match ends. So it 564 * is preferable to spend more time in matches to allow very fast string 565 * insertions and avoid deletions. The matching algorithm for small 566 * strings is inspired from that of Rabin & Karp. A brute force approach 567 * is used to find longer strings when a small match has been found. 568 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze 569 * (by Leonid Broukhis). 570 * A previous version of this file used a more sophisticated algorithm 571 * (by Fiala and Greene) which is guaranteed to run in linear amortized 572 * time, but has a larger average cost, uses more memory and is patented. 573 * However the F&G algorithm may be faster for some highly redundant 574 * files if the parameter max_chain_length (described below) is too large. 575 * 576 * ACKNOWLEDGEMENTS 577 * 578 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and 579 * I found it in 'freeze' written by Leonid Broukhis. 580 * Thanks to many people for bug reports and testing. 581 * 582 * REFERENCES 583 * 584 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification". 585 * Available in ftp://ds.internic.net/rfc/rfc1951.txt 586 * 587 * A description of the Rabin and Karp algorithm is given in the book 588 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. 589 * 590 * Fiala,E.R., and Greene,D.H. 591 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 592 * 593 */ 594 595 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */ 596 597 /* #include "deflate.h" */ 598 599 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly "; 600 /* 601 If you use the zlib library in a product, an acknowledgment is welcome 602 in the documentation of your product. If for some reason you cannot 603 include such an acknowledgment, I would appreciate that you keep this 604 copyright string in the executable of your product. 605 */ 606 607 /* =========================================================================== 608 * Function prototypes. 609 */ 610 typedef enum { 611 need_more, /* block not completed, need more input or more output */ 612 block_done, /* block flush performed */ 613 finish_started, /* finish started, need only more output at next deflate */ 614 finish_done /* finish done, accept no more input or output */ 615 } block_state; 616 617 typedef block_state (*compress_func) OF((deflate_state *s, int flush)); 618 /* Compression function. Returns the block state after the call. */ 619 620 local void fill_window OF((deflate_state *s)); 621 local block_state deflate_stored OF((deflate_state *s, int flush)); 622 local block_state deflate_fast OF((deflate_state *s, int flush)); 623 local block_state deflate_slow OF((deflate_state *s, int flush)); 624 local void lm_init OF((deflate_state *s)); 625 local void putShortMSB OF((deflate_state *s, uInt b)); 626 local void flush_pending OF((z_streamp strm)); 627 local int read_buf OF((z_streamp strm, charf *buf, unsigned size)); 628 #ifdef ASMV 629 void match_init OF((void)); /* asm code initialization */ 630 uInt longest_match OF((deflate_state *s, IPos cur_match)); 631 #else 632 local uInt longest_match OF((deflate_state *s, IPos cur_match)); 633 #endif 634 635 #ifdef DEBUG_ZLIB 636 local void check_match OF((deflate_state *s, IPos start, IPos match, 637 int length)); 638 #endif 639 640 /* =========================================================================== 641 * Local data 642 */ 643 644 #define NIL 0 645 /* Tail of hash chains */ 646 647 #ifndef TOO_FAR 648 # define TOO_FAR 4096 649 #endif 650 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ 651 652 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) 653 /* Minimum amount of lookahead, except at the end of the input file. 654 * See deflate.c for comments about the MIN_MATCH+1. 655 */ 656 657 /* Values for max_lazy_match, good_match and max_chain_length, depending on 658 * the desired pack level (0..9). The values given below have been tuned to 659 * exclude worst case performance for pathological files. Better values may be 660 * found for specific files. 661 */ 662 typedef struct config_s { 663 ush good_length; /* reduce lazy search above this match length */ 664 ush max_lazy; /* do not perform lazy search above this match length */ 665 ush nice_length; /* quit search above this match length */ 666 ush max_chain; 667 compress_func func; 668 } config; 669 670 local config configuration_table[10] = { 671 /* good lazy nice chain */ 672 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */ 673 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */ 674 /* 2 */ {4, 5, 16, 8, deflate_fast}, 675 /* 3 */ {4, 6, 32, 32, deflate_fast}, 676 677 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */ 678 /* 5 */ {8, 16, 32, 32, deflate_slow}, 679 /* 6 */ {8, 16, 128, 128, deflate_slow}, 680 /* 7 */ {8, 32, 128, 256, deflate_slow}, 681 /* 8 */ {32, 128, 258, 1024, deflate_slow}, 682 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */ 683 684 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 685 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different 686 * meaning. 687 */ 688 689 #define EQUAL 0 690 /* result of memcmp for equal strings */ 691 692 #ifndef NO_DUMMY_DECL 693 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ 694 #endif 695 696 /* =========================================================================== 697 * Update a hash value with the given input byte 698 * IN assertion: all calls to to UPDATE_HASH are made with consecutive 699 * input characters, so that a running hash key can be computed from the 700 * previous key instead of complete recalculation each time. 701 */ 702 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) 703 704 705 /* =========================================================================== 706 * Insert string str in the dictionary and set match_head to the previous head 707 * of the hash chain (the most recent string with same hash key). Return 708 * the previous length of the hash chain. 709 * IN assertion: all calls to to INSERT_STRING are made with consecutive 710 * input characters and the first MIN_MATCH bytes of str are valid 711 * (except for the last MIN_MATCH-1 bytes of the input file). 712 */ 713 #define INSERT_STRING(s, str, match_head) \ 714 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ 715 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ 716 s->head[s->ins_h] = (Pos)(str)) 717 718 /* =========================================================================== 719 * Initialize the hash table (avoiding 64K overflow for 16 bit systems). 720 * prev[] will be initialized on the fly. 721 */ 722 #define CLEAR_HASH(s) \ 723 s->head[s->hash_size-1] = NIL; \ 724 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); 725 726 /* ========================================================================= */ 727 int deflateInit_(strm, level, version, stream_size) 728 z_streamp strm; 729 int level; 730 const char *version; 731 int stream_size; 732 { 733 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 734 Z_DEFAULT_STRATEGY, version, stream_size); 735 /* To do: ignore strm->next_in if we use it as window */ 736 } 737 738 /* ========================================================================= */ 739 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy, 740 version, stream_size) 741 z_streamp strm; 742 int level; 743 int method; 744 int windowBits; 745 int memLevel; 746 int strategy; 747 const char *version; 748 int stream_size; 749 { 750 deflate_state *s; 751 int noheader = 0; 752 static char* my_version = ZLIB_VERSION; 753 754 ushf *overlay; 755 /* We overlay pending_buf and d_buf+l_buf. This works since the average 756 * output size for (length,distance) codes is <= 24 bits. 757 */ 758 759 if (version == Z_NULL || version[0] != my_version[0] || 760 stream_size != sizeof(z_stream)) { 761 return Z_VERSION_ERROR; 762 } 763 if (strm == Z_NULL) return Z_STREAM_ERROR; 764 765 strm->msg = Z_NULL; 766 #ifndef NO_ZCFUNCS 767 if (strm->zalloc == Z_NULL) { 768 strm->zalloc = zcalloc; 769 strm->opaque = (voidpf)0; 770 } 771 if (strm->zfree == Z_NULL) strm->zfree = zcfree; 772 #endif 773 774 if (level == Z_DEFAULT_COMPRESSION) level = 6; 775 776 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 777 noheader = 1; 778 windowBits = -windowBits; 779 } 780 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || 781 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 || 782 strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 783 return Z_STREAM_ERROR; 784 } 785 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 786 if (s == Z_NULL) return Z_MEM_ERROR; 787 strm->state = (struct internal_state FAR *)s; 788 s->strm = strm; 789 790 s->noheader = noheader; 791 s->w_bits = windowBits; 792 s->w_size = 1 << s->w_bits; 793 s->w_mask = s->w_size - 1; 794 795 s->hash_bits = memLevel + 7; 796 s->hash_size = 1 << s->hash_bits; 797 s->hash_mask = s->hash_size - 1; 798 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 799 800 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 801 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 802 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 803 804 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 805 806 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); 807 s->pending_buf = (uchf *) overlay; 808 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); 809 810 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 811 s->pending_buf == Z_NULL) { 812 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR); 813 deflateEnd (strm); 814 return Z_MEM_ERROR; 815 } 816 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); 817 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; 818 819 s->level = level; 820 s->strategy = strategy; 821 s->method = (Byte)method; 822 823 return deflateReset(strm); 824 } 825 826 /* ========================================================================= */ 827 int deflateSetDictionary (strm, dictionary, dictLength) 828 z_streamp strm; 829 const Bytef *dictionary; 830 uInt dictLength; 831 { 832 deflate_state *s; 833 uInt length = dictLength; 834 uInt n; 835 IPos hash_head = 0; 836 837 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) 838 return Z_STREAM_ERROR; 839 840 s = (deflate_state *) strm->state; 841 if (s->status != INIT_STATE) return Z_STREAM_ERROR; 842 843 strm->adler = adler32(strm->adler, dictionary, dictLength); 844 845 if (length < MIN_MATCH) return Z_OK; 846 if (length > MAX_DIST(s)) { 847 length = MAX_DIST(s); 848 #ifndef USE_DICT_HEAD 849 dictionary += dictLength - length; /* use the tail of the dictionary */ 850 #endif 851 } 852 zmemcpy((charf *)s->window, dictionary, length); 853 s->strstart = length; 854 s->block_start = (long)length; 855 856 /* Insert all strings in the hash table (except for the last two bytes). 857 * s->lookahead stays null, so s->ins_h will be recomputed at the next 858 * call of fill_window. 859 */ 860 s->ins_h = s->window[0]; 861 UPDATE_HASH(s, s->ins_h, s->window[1]); 862 for (n = 0; n <= length - MIN_MATCH; n++) { 863 INSERT_STRING(s, n, hash_head); 864 } 865 if (hash_head) hash_head = 0; /* to make compiler happy */ 866 return Z_OK; 867 } 868 869 /* ========================================================================= */ 870 int deflateReset (strm) 871 z_streamp strm; 872 { 873 deflate_state *s; 874 875 if (strm == Z_NULL || strm->state == Z_NULL || 876 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 877 878 strm->total_in = strm->total_out = 0; 879 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 880 strm->data_type = Z_UNKNOWN; 881 882 s = (deflate_state *)strm->state; 883 s->pending = 0; 884 s->pending_out = s->pending_buf; 885 886 if (s->noheader < 0) { 887 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 888 } 889 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 890 strm->adler = 1; 891 s->last_flush = Z_NO_FLUSH; 892 893 _tr_init(s); 894 lm_init(s); 895 896 return Z_OK; 897 } 898 899 /* ========================================================================= */ 900 int deflateParams(strm, level, strategy) 901 z_streamp strm; 902 int level; 903 int strategy; 904 { 905 deflate_state *s; 906 compress_func func; 907 int err = Z_OK; 908 909 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 910 s = (deflate_state *) strm->state; 911 912 if (level == Z_DEFAULT_COMPRESSION) { 913 level = 6; 914 } 915 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 916 return Z_STREAM_ERROR; 917 } 918 func = configuration_table[s->level].func; 919 920 if (func != configuration_table[level].func && strm->total_in != 0) { 921 /* Flush the last buffer: */ 922 err = deflate(strm, Z_PARTIAL_FLUSH); 923 } 924 if (s->level != level) { 925 s->level = level; 926 s->max_lazy_match = configuration_table[level].max_lazy; 927 s->good_match = configuration_table[level].good_length; 928 s->nice_match = configuration_table[level].nice_length; 929 s->max_chain_length = configuration_table[level].max_chain; 930 } 931 s->strategy = strategy; 932 return err; 933 } 934 935 /* ========================================================================= 936 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 937 * IN assertion: the stream state is correct and there is enough room in 938 * pending_buf. 939 */ 940 local void putShortMSB (s, b) 941 deflate_state *s; 942 uInt b; 943 { 944 put_byte(s, (Byte)(b >> 8)); 945 put_byte(s, (Byte)(b & 0xff)); 946 } 947 948 /* ========================================================================= 949 * Flush as much pending output as possible. All deflate() output goes 950 * through this function so some applications may wish to modify it 951 * to avoid allocating a large strm->next_out buffer and copying into it. 952 * (See also read_buf()). 953 */ 954 local void flush_pending(strm) 955 z_streamp strm; 956 { 957 deflate_state *s = (deflate_state *) strm->state; 958 unsigned len = s->pending; 959 960 if (len > strm->avail_out) len = strm->avail_out; 961 if (len == 0) return; 962 963 if (strm->next_out != Z_NULL) { 964 zmemcpy(strm->next_out, s->pending_out, len); 965 strm->next_out += len; 966 } 967 s->pending_out += len; 968 strm->total_out += len; 969 strm->avail_out -= len; 970 s->pending -= len; 971 if (s->pending == 0) { 972 s->pending_out = s->pending_buf; 973 } 974 } 975 976 /* ========================================================================= */ 977 int deflate (strm, flush) 978 z_streamp strm; 979 int flush; 980 { 981 int old_flush; /* value of flush param for previous deflate call */ 982 deflate_state *s; 983 984 if (strm == Z_NULL || strm->state == Z_NULL || 985 flush > Z_FINISH || flush < 0) { 986 return Z_STREAM_ERROR; 987 } 988 s = (deflate_state *) strm->state; 989 990 if ((strm->next_in == Z_NULL && strm->avail_in != 0) || 991 (s->status == FINISH_STATE && flush != Z_FINISH)) { 992 ERR_RETURN(strm, Z_STREAM_ERROR); 993 } 994 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 995 996 s->strm = strm; /* just in case */ 997 old_flush = s->last_flush; 998 s->last_flush = flush; 999 1000 /* Write the zlib header */ 1001 if (s->status == INIT_STATE) { 1002 1003 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; 1004 uInt level_flags = (s->level-1) >> 1; 1005 1006 if (level_flags > 3) level_flags = 3; 1007 header |= (level_flags << 6); 1008 if (s->strstart != 0) header |= PRESET_DICT; 1009 header += 31 - (header % 31); 1010 1011 s->status = BUSY_STATE; 1012 putShortMSB(s, header); 1013 1014 /* Save the adler32 of the preset dictionary: */ 1015 if (s->strstart != 0) { 1016 putShortMSB(s, (uInt)(strm->adler >> 16)); 1017 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1018 } 1019 strm->adler = 1L; 1020 } 1021 1022 /* Flush as much pending output as possible */ 1023 if (s->pending != 0) { 1024 flush_pending(strm); 1025 if (strm->avail_out == 0) { 1026 /* Since avail_out is 0, deflate will be called again with 1027 * more output space, but possibly with both pending and 1028 * avail_in equal to zero. There won't be anything to do, 1029 * but this is not an error situation so make sure we 1030 * return OK instead of BUF_ERROR at next call of deflate: 1031 */ 1032 s->last_flush = -1; 1033 return Z_OK; 1034 } 1035 1036 /* Make sure there is something to do and avoid duplicate consecutive 1037 * flushes. For repeated and useless calls with Z_FINISH, we keep 1038 * returning Z_STREAM_END instead of Z_BUFF_ERROR. 1039 */ 1040 } else if (strm->avail_in == 0 && flush <= old_flush && 1041 flush != Z_FINISH) { 1042 ERR_RETURN(strm, Z_BUF_ERROR); 1043 } 1044 1045 /* User must not provide more input after the first FINISH: */ 1046 if (s->status == FINISH_STATE && strm->avail_in != 0) { 1047 ERR_RETURN(strm, Z_BUF_ERROR); 1048 } 1049 1050 /* Start a new block or continue the current one. 1051 */ 1052 if (strm->avail_in != 0 || s->lookahead != 0 || 1053 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { 1054 block_state bstate; 1055 1056 bstate = (*(configuration_table[s->level].func))(s, flush); 1057 1058 if (bstate == finish_started || bstate == finish_done) { 1059 s->status = FINISH_STATE; 1060 } 1061 if (bstate == need_more || bstate == finish_started) { 1062 if (strm->avail_out == 0) { 1063 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ 1064 } 1065 return Z_OK; 1066 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 1067 * of deflate should use the same flush parameter to make sure 1068 * that the flush is complete. So we don't have to output an 1069 * empty block here, this will be done at next call. This also 1070 * ensures that for a very small output buffer, we emit at most 1071 * one empty block. 1072 */ 1073 } 1074 if (bstate == block_done) { 1075 if (flush == Z_PARTIAL_FLUSH) { 1076 _tr_align(s); 1077 } else if (flush == Z_PACKET_FLUSH) { 1078 /* Output just the 3-bit `stored' block type value, 1079 but not a zero length. */ 1080 _tr_stored_type_only(s); 1081 } else { /* FULL_FLUSH or SYNC_FLUSH */ 1082 _tr_stored_block(s, (char*)0, 0L, 0); 1083 /* For a full flush, this empty block will be recognized 1084 * as a special marker by inflate_sync(). 1085 */ 1086 if (flush == Z_FULL_FLUSH) { 1087 CLEAR_HASH(s); /* forget history */ 1088 } 1089 } 1090 flush_pending(strm); 1091 if (strm->avail_out == 0) { 1092 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ 1093 return Z_OK; 1094 } 1095 } 1096 } 1097 Assert(strm->avail_out > 0, "bug2"); 1098 1099 if (flush != Z_FINISH) return Z_OK; 1100 if (s->noheader) return Z_STREAM_END; 1101 1102 /* Write the zlib trailer (adler32) */ 1103 putShortMSB(s, (uInt)(strm->adler >> 16)); 1104 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1105 flush_pending(strm); 1106 /* If avail_out is zero, the application will call deflate again 1107 * to flush the rest. 1108 */ 1109 s->noheader = -1; /* write the trailer only once! */ 1110 return s->pending != 0 ? Z_OK : Z_STREAM_END; 1111 } 1112 1113 /* ========================================================================= */ 1114 int deflateEnd (strm) 1115 z_streamp strm; 1116 { 1117 int status; 1118 deflate_state *s; 1119 1120 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 1121 s = (deflate_state *) strm->state; 1122 1123 status = s->status; 1124 if (status != INIT_STATE && status != BUSY_STATE && 1125 status != FINISH_STATE) { 1126 return Z_STREAM_ERROR; 1127 } 1128 1129 /* Deallocate in reverse order of allocations: */ 1130 TRY_FREE(strm, s->pending_buf); 1131 TRY_FREE(strm, s->head); 1132 TRY_FREE(strm, s->prev); 1133 TRY_FREE(strm, s->window); 1134 1135 ZFREE(strm, s); 1136 strm->state = Z_NULL; 1137 1138 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; 1139 } 1140 1141 /* ========================================================================= 1142 * Copy the source state to the destination state. 1143 */ 1144 int deflateCopy (dest, source) 1145 z_streamp dest; 1146 z_streamp source; 1147 { 1148 deflate_state *ds; 1149 deflate_state *ss; 1150 ushf *overlay; 1151 1152 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) 1153 return Z_STREAM_ERROR; 1154 ss = (deflate_state *) source->state; 1155 1156 zmemcpy(dest, source, sizeof(*dest)); 1157 1158 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); 1159 if (ds == Z_NULL) return Z_MEM_ERROR; 1160 dest->state = (struct internal_state FAR *) ds; 1161 zmemcpy(ds, ss, sizeof(*ds)); 1162 ds->strm = dest; 1163 1164 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); 1165 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); 1166 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); 1167 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); 1168 ds->pending_buf = (uchf *) overlay; 1169 1170 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || 1171 ds->pending_buf == Z_NULL) { 1172 deflateEnd (dest); 1173 return Z_MEM_ERROR; 1174 } 1175 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ 1176 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); 1177 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); 1178 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); 1179 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); 1180 1181 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); 1182 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); 1183 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; 1184 1185 ds->l_desc.dyn_tree = ds->dyn_ltree; 1186 ds->d_desc.dyn_tree = ds->dyn_dtree; 1187 ds->bl_desc.dyn_tree = ds->bl_tree; 1188 1189 return Z_OK; 1190 } 1191 1192 /* =========================================================================== 1193 * Return the number of bytes of output which are immediately available 1194 * for output from the decompressor. 1195 */ 1196 int deflateOutputPending (strm) 1197 z_streamp strm; 1198 { 1199 if (strm == Z_NULL || strm->state == Z_NULL) return 0; 1200 1201 return ((deflate_state *)(strm->state))->pending; 1202 } 1203 1204 /* =========================================================================== 1205 * Read a new buffer from the current input stream, update the adler32 1206 * and total number of bytes read. All deflate() input goes through 1207 * this function so some applications may wish to modify it to avoid 1208 * allocating a large strm->next_in buffer and copying from it. 1209 * (See also flush_pending()). 1210 */ 1211 local int read_buf(strm, buf, size) 1212 z_streamp strm; 1213 charf *buf; 1214 unsigned size; 1215 { 1216 unsigned len = strm->avail_in; 1217 1218 if (len > size) len = size; 1219 if (len == 0) return 0; 1220 1221 strm->avail_in -= len; 1222 1223 if (!((deflate_state *)(strm->state))->noheader) { 1224 strm->adler = adler32(strm->adler, strm->next_in, len); 1225 } 1226 zmemcpy(buf, strm->next_in, len); 1227 strm->next_in += len; 1228 strm->total_in += len; 1229 1230 return (int)len; 1231 } 1232 1233 /* =========================================================================== 1234 * Initialize the "longest match" routines for a new zlib stream 1235 */ 1236 local void lm_init (s) 1237 deflate_state *s; 1238 { 1239 s->window_size = (ulg)2L*s->w_size; 1240 1241 CLEAR_HASH(s); 1242 1243 /* Set the default configuration parameters: 1244 */ 1245 s->max_lazy_match = configuration_table[s->level].max_lazy; 1246 s->good_match = configuration_table[s->level].good_length; 1247 s->nice_match = configuration_table[s->level].nice_length; 1248 s->max_chain_length = configuration_table[s->level].max_chain; 1249 1250 s->strstart = 0; 1251 s->block_start = 0L; 1252 s->lookahead = 0; 1253 s->match_length = s->prev_length = MIN_MATCH-1; 1254 s->match_available = 0; 1255 s->ins_h = 0; 1256 #ifdef ASMV 1257 match_init(); /* initialize the asm code */ 1258 #endif 1259 } 1260 1261 /* =========================================================================== 1262 * Set match_start to the longest match starting at the given string and 1263 * return its length. Matches shorter or equal to prev_length are discarded, 1264 * in which case the result is equal to prev_length and match_start is 1265 * garbage. 1266 * IN assertions: cur_match is the head of the hash chain for the current 1267 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 1268 * OUT assertion: the match length is not greater than s->lookahead. 1269 */ 1270 #ifndef ASMV 1271 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or 1272 * match.S. The code will be functionally equivalent. 1273 */ 1274 local uInt longest_match(s, cur_match) 1275 deflate_state *s; 1276 IPos cur_match; /* current match */ 1277 { 1278 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 1279 Bytef *scan = s->window + s->strstart; /* current string */ 1280 Bytef *match; /* matched string */ 1281 int len; /* length of current match */ 1282 int best_len = s->prev_length; /* best match length so far */ 1283 int nice_match = s->nice_match; /* stop if match long enough */ 1284 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 1285 s->strstart - (IPos)MAX_DIST(s) : NIL; 1286 /* Stop when cur_match becomes <= limit. To simplify the code, 1287 * we prevent matches with the string of window index 0. 1288 */ 1289 Posf *prev = s->prev; 1290 uInt wmask = s->w_mask; 1291 1292 #ifdef UNALIGNED_OK 1293 /* Compare two bytes at a time. Note: this is not always beneficial. 1294 * Try with and without -DUNALIGNED_OK to check. 1295 */ 1296 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 1297 ush scan_start = *(ushf*)scan; 1298 ush scan_end = *(ushf*)(scan+best_len-1); 1299 #else 1300 Bytef *strend = s->window + s->strstart + MAX_MATCH; 1301 Byte scan_end1 = scan[best_len-1]; 1302 Byte scan_end = scan[best_len]; 1303 #endif 1304 1305 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 1306 * It is easy to get rid of this optimization if necessary. 1307 */ 1308 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 1309 1310 /* Do not waste too much time if we already have a good match: */ 1311 if (s->prev_length >= s->good_match) { 1312 chain_length >>= 2; 1313 } 1314 /* Do not look for matches beyond the end of the input. This is necessary 1315 * to make deflate deterministic. 1316 */ 1317 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; 1318 1319 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1320 1321 do { 1322 Assert(cur_match < s->strstart, "no future"); 1323 match = s->window + cur_match; 1324 1325 /* Skip to next match if the match length cannot increase 1326 * or if the match length is less than 2: 1327 */ 1328 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1329 /* This code assumes sizeof(unsigned short) == 2. Do not use 1330 * UNALIGNED_OK if your compiler uses a different size. 1331 */ 1332 if (*(ushf*)(match+best_len-1) != scan_end || 1333 *(ushf*)match != scan_start) continue; 1334 1335 /* It is not necessary to compare scan[2] and match[2] since they are 1336 * always equal when the other bytes match, given that the hash keys 1337 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1338 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1339 * lookahead only every 4th comparison; the 128th check will be made 1340 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1341 * necessary to put more guard bytes at the end of the window, or 1342 * to check more often for insufficient lookahead. 1343 */ 1344 Assert(scan[2] == match[2], "scan[2]?"); 1345 scan++, match++; 1346 do { 1347 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1348 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1349 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1350 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1351 scan < strend); 1352 /* The funny "do {}" generates better code on most compilers */ 1353 1354 /* Here, scan <= window+strstart+257 */ 1355 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1356 if (*scan == *match) scan++; 1357 1358 len = (MAX_MATCH - 1) - (int)(strend-scan); 1359 scan = strend - (MAX_MATCH-1); 1360 1361 #else /* UNALIGNED_OK */ 1362 1363 if (match[best_len] != scan_end || 1364 match[best_len-1] != scan_end1 || 1365 *match != *scan || 1366 *++match != scan[1]) continue; 1367 1368 /* The check at best_len-1 can be removed because it will be made 1369 * again later. (This heuristic is not always a win.) 1370 * It is not necessary to compare scan[2] and match[2] since they 1371 * are always equal when the other bytes match, given that 1372 * the hash keys are equal and that HASH_BITS >= 8. 1373 */ 1374 scan += 2, match++; 1375 Assert(*scan == *match, "match[2]?"); 1376 1377 /* We check for insufficient lookahead only every 8th comparison; 1378 * the 256th check will be made at strstart+258. 1379 */ 1380 do { 1381 } while (*++scan == *++match && *++scan == *++match && 1382 *++scan == *++match && *++scan == *++match && 1383 *++scan == *++match && *++scan == *++match && 1384 *++scan == *++match && *++scan == *++match && 1385 scan < strend); 1386 1387 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1388 1389 len = MAX_MATCH - (int)(strend - scan); 1390 scan = strend - MAX_MATCH; 1391 1392 #endif /* UNALIGNED_OK */ 1393 1394 if (len > best_len) { 1395 s->match_start = cur_match; 1396 best_len = len; 1397 if (len >= nice_match) break; 1398 #ifdef UNALIGNED_OK 1399 scan_end = *(ushf*)(scan+best_len-1); 1400 #else 1401 scan_end1 = scan[best_len-1]; 1402 scan_end = scan[best_len]; 1403 #endif 1404 } 1405 } while ((cur_match = prev[cur_match & wmask]) > limit 1406 && --chain_length != 0); 1407 1408 if ((uInt)best_len <= s->lookahead) return best_len; 1409 return s->lookahead; 1410 } 1411 #endif /* ASMV */ 1412 1413 #ifdef DEBUG_ZLIB 1414 /* =========================================================================== 1415 * Check that the match at match_start is indeed a match. 1416 */ 1417 local void check_match(s, start, match, length) 1418 deflate_state *s; 1419 IPos start, match; 1420 int length; 1421 { 1422 /* check that the match is indeed a match */ 1423 if (zmemcmp((charf *)s->window + match, 1424 (charf *)s->window + start, length) != EQUAL) { 1425 fprintf(stderr, " start %u, match %u, length %d\n", 1426 start, match, length); 1427 do { 1428 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); 1429 } while (--length != 0); 1430 z_error("invalid match"); 1431 } 1432 if (z_verbose > 1) { 1433 fprintf(stderr,"\\[%d,%d]", start-match, length); 1434 do { putc(s->window[start++], stderr); } while (--length != 0); 1435 } 1436 } 1437 #else 1438 # define check_match(s, start, match, length) 1439 #endif 1440 1441 /* =========================================================================== 1442 * Fill the window when the lookahead becomes insufficient. 1443 * Updates strstart and lookahead. 1444 * 1445 * IN assertion: lookahead < MIN_LOOKAHEAD 1446 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1447 * At least one byte has been read, or avail_in == 0; reads are 1448 * performed for at least two bytes (required for the zip translate_eol 1449 * option -- not supported here). 1450 */ 1451 local void fill_window(s) 1452 deflate_state *s; 1453 { 1454 unsigned n, m; 1455 Posf *p; 1456 unsigned more; /* Amount of free space at the end of the window. */ 1457 uInt wsize = s->w_size; 1458 1459 do { 1460 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1461 1462 /* Deal with !@#$% 64K limit: */ 1463 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1464 more = wsize; 1465 1466 } else if (more == (unsigned)(-1)) { 1467 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1468 * and lookahead == 1 (input done one byte at time) 1469 */ 1470 more--; 1471 1472 /* If the window is almost full and there is insufficient lookahead, 1473 * move the upper half to the lower one to make room in the upper half. 1474 */ 1475 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1476 1477 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1478 (unsigned)wsize); 1479 s->match_start -= wsize; 1480 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1481 s->block_start -= (long) wsize; 1482 1483 /* Slide the hash table (could be avoided with 32 bit values 1484 at the expense of memory usage). We slide even when level == 0 1485 to keep the hash table consistent if we switch back to level > 0 1486 later. (Using level 0 permanently is not an optimal usage of 1487 zlib, so we don't care about this pathological case.) 1488 */ 1489 n = s->hash_size; 1490 p = &s->head[n]; 1491 do { 1492 m = *--p; 1493 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1494 } while (--n); 1495 1496 n = wsize; 1497 p = &s->prev[n]; 1498 do { 1499 m = *--p; 1500 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1501 /* If n is not on any hash chain, prev[n] is garbage but 1502 * its value will never be used. 1503 */ 1504 } while (--n); 1505 more += wsize; 1506 } 1507 if (s->strm->avail_in == 0) return; 1508 1509 /* If there was no sliding: 1510 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1511 * more == window_size - lookahead - strstart 1512 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1513 * => more >= window_size - 2*WSIZE + 2 1514 * In the BIG_MEM or MMAP case (not yet supported), 1515 * window_size == input_size + MIN_LOOKAHEAD && 1516 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1517 * Otherwise, window_size == 2*WSIZE so more >= 2. 1518 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1519 */ 1520 Assert(more >= 2, "more < 2"); 1521 1522 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1523 more); 1524 s->lookahead += n; 1525 1526 /* Initialize the hash value now that we have some input: */ 1527 if (s->lookahead >= MIN_MATCH) { 1528 s->ins_h = s->window[s->strstart]; 1529 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1530 #if MIN_MATCH != 3 1531 Call UPDATE_HASH() MIN_MATCH-3 more times 1532 #endif 1533 } 1534 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1535 * but this is not important since only literal bytes will be emitted. 1536 */ 1537 1538 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1539 } 1540 1541 /* =========================================================================== 1542 * Flush the current block, with given end-of-file flag. 1543 * IN assertion: strstart is set to the end of the current match. 1544 */ 1545 #define FLUSH_BLOCK_ONLY(s, eof) { \ 1546 _tr_flush_block(s, (s->block_start >= 0L ? \ 1547 (charf *)&s->window[(unsigned)s->block_start] : \ 1548 (charf *)Z_NULL), \ 1549 (ulg)((long)s->strstart - s->block_start), \ 1550 (eof)); \ 1551 s->block_start = s->strstart; \ 1552 flush_pending(s->strm); \ 1553 Tracev((stderr,"[FLUSH]")); \ 1554 } 1555 1556 /* Same but force premature exit if necessary. */ 1557 #define FLUSH_BLOCK(s, eof) { \ 1558 FLUSH_BLOCK_ONLY(s, eof); \ 1559 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ 1560 } 1561 1562 /* =========================================================================== 1563 * Copy without compression as much as possible from the input stream, return 1564 * the current block state. 1565 * This function does not insert new strings in the dictionary since 1566 * uncompressible data is probably not useful. This function is used 1567 * only for the level=0 compression option. 1568 * NOTE: this function should be optimized to avoid extra copying from 1569 * window to pending_buf. 1570 */ 1571 local block_state deflate_stored(s, flush) 1572 deflate_state *s; 1573 int flush; 1574 { 1575 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited 1576 * to pending_buf_size, and each stored block has a 5 byte header: 1577 */ 1578 ulg max_block_size = 0xffff; 1579 ulg max_start; 1580 1581 if (max_block_size > s->pending_buf_size - 5) { 1582 max_block_size = s->pending_buf_size - 5; 1583 } 1584 1585 /* Copy as much as possible from input to output: */ 1586 for (;;) { 1587 /* Fill the window as much as possible: */ 1588 if (s->lookahead <= 1) { 1589 1590 Assert(s->strstart < s->w_size+MAX_DIST(s) || 1591 s->block_start >= (long)s->w_size, "slide too late"); 1592 1593 fill_window(s); 1594 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; 1595 1596 if (s->lookahead == 0) break; /* flush the current block */ 1597 } 1598 Assert(s->block_start >= 0L, "block gone"); 1599 1600 s->strstart += s->lookahead; 1601 s->lookahead = 0; 1602 1603 /* Emit a stored block if pending_buf will be full: */ 1604 max_start = s->block_start + max_block_size; 1605 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { 1606 /* strstart == 0 is possible when wraparound on 16-bit machine */ 1607 s->lookahead = (uInt)(s->strstart - max_start); 1608 s->strstart = (uInt)max_start; 1609 FLUSH_BLOCK(s, 0); 1610 } 1611 /* Flush if we may have to slide, otherwise block_start may become 1612 * negative and the data will be gone: 1613 */ 1614 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { 1615 FLUSH_BLOCK(s, 0); 1616 } 1617 } 1618 FLUSH_BLOCK(s, flush == Z_FINISH); 1619 return flush == Z_FINISH ? finish_done : block_done; 1620 } 1621 1622 /* =========================================================================== 1623 * Compress as much as possible from the input stream, return the current 1624 * block state. 1625 * This function does not perform lazy evaluation of matches and inserts 1626 * new strings in the dictionary only for unmatched strings or for short 1627 * matches. It is used only for the fast compression options. 1628 */ 1629 local block_state deflate_fast(s, flush) 1630 deflate_state *s; 1631 int flush; 1632 { 1633 IPos hash_head = NIL; /* head of the hash chain */ 1634 int bflush; /* set if current block must be flushed */ 1635 1636 for (;;) { 1637 /* Make sure that we always have enough lookahead, except 1638 * at the end of the input file. We need MAX_MATCH bytes 1639 * for the next match, plus MIN_MATCH bytes to insert the 1640 * string following the next match. 1641 */ 1642 if (s->lookahead < MIN_LOOKAHEAD) { 1643 fill_window(s); 1644 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1645 return need_more; 1646 } 1647 if (s->lookahead == 0) break; /* flush the current block */ 1648 } 1649 1650 /* Insert the string window[strstart .. strstart+2] in the 1651 * dictionary, and set hash_head to the head of the hash chain: 1652 */ 1653 if (s->lookahead >= MIN_MATCH) { 1654 INSERT_STRING(s, s->strstart, hash_head); 1655 } 1656 1657 /* Find the longest match, discarding those <= prev_length. 1658 * At this point we have always match_length < MIN_MATCH 1659 */ 1660 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1661 /* To simplify the code, we prevent matches with the string 1662 * of window index 0 (in particular we have to avoid a match 1663 * of the string with itself at the start of the input file). 1664 */ 1665 if (s->strategy != Z_HUFFMAN_ONLY) { 1666 s->match_length = longest_match (s, hash_head); 1667 } 1668 /* longest_match() sets match_start */ 1669 } 1670 if (s->match_length >= MIN_MATCH) { 1671 check_match(s, s->strstart, s->match_start, s->match_length); 1672 1673 bflush = _tr_tally(s, s->strstart - s->match_start, 1674 s->match_length - MIN_MATCH); 1675 1676 s->lookahead -= s->match_length; 1677 1678 /* Insert new strings in the hash table only if the match length 1679 * is not too large. This saves time but degrades compression. 1680 */ 1681 if (s->match_length <= s->max_insert_length && 1682 s->lookahead >= MIN_MATCH) { 1683 s->match_length--; /* string at strstart already in hash table */ 1684 do { 1685 s->strstart++; 1686 INSERT_STRING(s, s->strstart, hash_head); 1687 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1688 * always MIN_MATCH bytes ahead. 1689 */ 1690 } while (--s->match_length != 0); 1691 s->strstart++; 1692 } else { 1693 s->strstart += s->match_length; 1694 s->match_length = 0; 1695 s->ins_h = s->window[s->strstart]; 1696 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1697 #if MIN_MATCH != 3 1698 Call UPDATE_HASH() MIN_MATCH-3 more times 1699 #endif 1700 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1701 * matter since it will be recomputed at next deflate call. 1702 */ 1703 } 1704 } else { 1705 /* No match, output a literal byte */ 1706 Tracevv((stderr,"%c", s->window[s->strstart])); 1707 bflush = _tr_tally (s, 0, s->window[s->strstart]); 1708 s->lookahead--; 1709 s->strstart++; 1710 } 1711 if (bflush) FLUSH_BLOCK(s, 0); 1712 } 1713 FLUSH_BLOCK(s, flush == Z_FINISH); 1714 return flush == Z_FINISH ? finish_done : block_done; 1715 } 1716 1717 /* =========================================================================== 1718 * Same as above, but achieves better compression. We use a lazy 1719 * evaluation for matches: a match is finally adopted only if there is 1720 * no better match at the next window position. 1721 */ 1722 local block_state deflate_slow(s, flush) 1723 deflate_state *s; 1724 int flush; 1725 { 1726 IPos hash_head = NIL; /* head of hash chain */ 1727 int bflush; /* set if current block must be flushed */ 1728 1729 /* Process the input block. */ 1730 for (;;) { 1731 /* Make sure that we always have enough lookahead, except 1732 * at the end of the input file. We need MAX_MATCH bytes 1733 * for the next match, plus MIN_MATCH bytes to insert the 1734 * string following the next match. 1735 */ 1736 if (s->lookahead < MIN_LOOKAHEAD) { 1737 fill_window(s); 1738 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1739 return need_more; 1740 } 1741 if (s->lookahead == 0) break; /* flush the current block */ 1742 } 1743 1744 /* Insert the string window[strstart .. strstart+2] in the 1745 * dictionary, and set hash_head to the head of the hash chain: 1746 */ 1747 if (s->lookahead >= MIN_MATCH) { 1748 INSERT_STRING(s, s->strstart, hash_head); 1749 } 1750 1751 /* Find the longest match, discarding those <= prev_length. 1752 */ 1753 s->prev_length = s->match_length, s->prev_match = s->match_start; 1754 s->match_length = MIN_MATCH-1; 1755 1756 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1757 s->strstart - hash_head <= MAX_DIST(s)) { 1758 /* To simplify the code, we prevent matches with the string 1759 * of window index 0 (in particular we have to avoid a match 1760 * of the string with itself at the start of the input file). 1761 */ 1762 if (s->strategy != Z_HUFFMAN_ONLY) { 1763 s->match_length = longest_match (s, hash_head); 1764 } 1765 /* longest_match() sets match_start */ 1766 1767 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1768 (s->match_length == MIN_MATCH && 1769 s->strstart - s->match_start > TOO_FAR))) { 1770 1771 /* If prev_match is also MIN_MATCH, match_start is garbage 1772 * but we will ignore the current match anyway. 1773 */ 1774 s->match_length = MIN_MATCH-1; 1775 } 1776 } 1777 /* If there was a match at the previous step and the current 1778 * match is not better, output the previous match: 1779 */ 1780 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1781 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1782 /* Do not insert strings in hash table beyond this. */ 1783 1784 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1785 1786 bflush = _tr_tally(s, s->strstart -1 - s->prev_match, 1787 s->prev_length - MIN_MATCH); 1788 1789 /* Insert in hash table all strings up to the end of the match. 1790 * strstart-1 and strstart are already inserted. If there is not 1791 * enough lookahead, the last two strings are not inserted in 1792 * the hash table. 1793 */ 1794 s->lookahead -= s->prev_length-1; 1795 s->prev_length -= 2; 1796 do { 1797 if (++s->strstart <= max_insert) { 1798 INSERT_STRING(s, s->strstart, hash_head); 1799 } 1800 } while (--s->prev_length != 0); 1801 s->match_available = 0; 1802 s->match_length = MIN_MATCH-1; 1803 s->strstart++; 1804 1805 if (bflush) FLUSH_BLOCK(s, 0); 1806 1807 } else if (s->match_available) { 1808 /* If there was no match at the previous position, output a 1809 * single literal. If there was a match but the current match 1810 * is longer, truncate the previous match to a single literal. 1811 */ 1812 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1813 if (_tr_tally (s, 0, s->window[s->strstart-1])) { 1814 FLUSH_BLOCK_ONLY(s, 0); 1815 } 1816 s->strstart++; 1817 s->lookahead--; 1818 if (s->strm->avail_out == 0) return need_more; 1819 } else { 1820 /* There is no previous match to compare with, wait for 1821 * the next step to decide. 1822 */ 1823 s->match_available = 1; 1824 s->strstart++; 1825 s->lookahead--; 1826 } 1827 } 1828 Assert (flush != Z_NO_FLUSH, "no flush?"); 1829 if (s->match_available) { 1830 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1831 _tr_tally (s, 0, s->window[s->strstart-1]); 1832 s->match_available = 0; 1833 } 1834 FLUSH_BLOCK(s, flush == Z_FINISH); 1835 return flush == Z_FINISH ? finish_done : block_done; 1836 } 1837 /* --- deflate.c */ 1838 1839 /* +++ trees.c */ 1840 /* trees.c -- output deflated data using Huffman coding 1841 * Copyright (C) 1995-1996 Jean-loup Gailly 1842 * For conditions of distribution and use, see copyright notice in zlib.h 1843 */ 1844 1845 /* 1846 * ALGORITHM 1847 * 1848 * The "deflation" process uses several Huffman trees. The more 1849 * common source values are represented by shorter bit sequences. 1850 * 1851 * Each code tree is stored in a compressed form which is itself 1852 * a Huffman encoding of the lengths of all the code strings (in 1853 * ascending order by source values). The actual code strings are 1854 * reconstructed from the lengths in the inflate process, as described 1855 * in the deflate specification. 1856 * 1857 * REFERENCES 1858 * 1859 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1860 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1861 * 1862 * Storer, James A. 1863 * Data Compression: Methods and Theory, pp. 49-50. 1864 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1865 * 1866 * Sedgewick, R. 1867 * Algorithms, p290. 1868 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1869 */ 1870 1871 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ 1872 1873 /* #include "deflate.h" */ 1874 1875 #ifdef DEBUG_ZLIB 1876 # include <ctype.h> 1877 #endif 1878 1879 /* =========================================================================== 1880 * Constants 1881 */ 1882 1883 #define MAX_BL_BITS 7 1884 /* Bit length codes must not exceed MAX_BL_BITS bits */ 1885 1886 #define END_BLOCK 256 1887 /* end of block literal code */ 1888 1889 #define REP_3_6 16 1890 /* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1891 1892 #define REPZ_3_10 17 1893 /* repeat a zero length 3-10 times (3 bits of repeat count) */ 1894 1895 #define REPZ_11_138 18 1896 /* repeat a zero length 11-138 times (7 bits of repeat count) */ 1897 1898 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1899 = {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}; 1900 1901 local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1902 = {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}; 1903 1904 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1905 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1906 1907 local uch bl_order[BL_CODES] 1908 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1909 /* The lengths of the bit length codes are sent in order of decreasing 1910 * probability, to avoid transmitting the lengths for unused bit length codes. 1911 */ 1912 1913 #define Buf_size (8 * 2*sizeof(char)) 1914 /* Number of bits used within bi_buf. (bi_buf might be implemented on 1915 * more than 16 bits on some systems.) 1916 */ 1917 1918 /* =========================================================================== 1919 * Local data. These are initialized only once. 1920 */ 1921 1922 local ct_data static_ltree[L_CODES+2]; 1923 /* The static literal tree. Since the bit lengths are imposed, there is no 1924 * need for the L_CODES extra codes used during heap construction. However 1925 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 1926 * below). 1927 */ 1928 1929 local ct_data static_dtree[D_CODES]; 1930 /* The static distance tree. (Actually a trivial tree since all codes use 1931 * 5 bits.) 1932 */ 1933 1934 local uch dist_code[512]; 1935 /* distance codes. The first 256 values correspond to the distances 1936 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1937 * the 15 bit distances. 1938 */ 1939 1940 local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1941 /* length code for each normalized match length (0 == MIN_MATCH) */ 1942 1943 local int base_length[LENGTH_CODES]; 1944 /* First normalized length for each code (0 = MIN_MATCH) */ 1945 1946 local int base_dist[D_CODES]; 1947 /* First normalized distance for each code (0 = distance of 1) */ 1948 1949 struct static_tree_desc_s { 1950 ct_data *static_tree; /* static tree or NULL */ 1951 intf *extra_bits; /* extra bits for each code or NULL */ 1952 int extra_base; /* base index for extra_bits */ 1953 int elems; /* max number of elements in the tree */ 1954 int max_length; /* max bit length for the codes */ 1955 }; 1956 1957 local static_tree_desc static_l_desc = 1958 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1959 1960 local static_tree_desc static_d_desc = 1961 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1962 1963 local static_tree_desc static_bl_desc = 1964 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1965 1966 /* =========================================================================== 1967 * Local (static) routines in this file. 1968 */ 1969 1970 local void tr_static_init OF((void)); 1971 local void init_block OF((deflate_state *s)); 1972 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1973 local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1974 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1975 local void build_tree OF((deflate_state *s, tree_desc *desc)); 1976 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1977 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1978 local int build_bl_tree OF((deflate_state *s)); 1979 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1980 int blcodes)); 1981 local void compress_block OF((deflate_state *s, ct_data *ltree, 1982 ct_data *dtree)); 1983 local void set_data_type OF((deflate_state *s)); 1984 local unsigned bi_reverse OF((unsigned value, int length)); 1985 local void bi_windup OF((deflate_state *s)); 1986 local void bi_flush OF((deflate_state *s)); 1987 local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1988 int header)); 1989 1990 #ifndef DEBUG_ZLIB 1991 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 1992 /* Send a code of the given tree. c and tree must not have side effects */ 1993 1994 #else /* DEBUG_ZLIB */ 1995 # define send_code(s, c, tree) \ 1996 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 1997 send_bits(s, tree[c].Code, tree[c].Len); } 1998 #endif 1999 2000 #define d_code(dist) \ 2001 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 2002 /* Mapping from a distance to a distance code. dist is the distance - 1 and 2003 * must not have side effects. dist_code[256] and dist_code[257] are never 2004 * used. 2005 */ 2006 2007 /* =========================================================================== 2008 * Output a short LSB first on the stream. 2009 * IN assertion: there is enough room in pendingBuf. 2010 */ 2011 #define put_short(s, w) { \ 2012 put_byte(s, (uch)((w) & 0xff)); \ 2013 put_byte(s, (uch)((ush)(w) >> 8)); \ 2014 } 2015 2016 /* =========================================================================== 2017 * Send a value on a given number of bits. 2018 * IN assertion: length <= 16 and value fits in length bits. 2019 */ 2020 #ifdef DEBUG_ZLIB 2021 local void send_bits OF((deflate_state *s, int value, int length)); 2022 2023 local void send_bits(s, value, length) 2024 deflate_state *s; 2025 int value; /* value to send */ 2026 int length; /* number of bits */ 2027 { 2028 Tracevv((stderr," l %2d v %4x ", length, value)); 2029 Assert(length > 0 && length <= 15, "invalid length"); 2030 s->bits_sent += (ulg)length; 2031 2032 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 2033 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 2034 * unused bits in value. 2035 */ 2036 if (s->bi_valid > (int)Buf_size - length) { 2037 s->bi_buf |= (value << s->bi_valid); 2038 put_short(s, s->bi_buf); 2039 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 2040 s->bi_valid += length - Buf_size; 2041 } else { 2042 s->bi_buf |= value << s->bi_valid; 2043 s->bi_valid += length; 2044 } 2045 } 2046 #else /* !DEBUG_ZLIB */ 2047 2048 #define send_bits(s, value, length) \ 2049 { int len = length;\ 2050 if (s->bi_valid > (int)Buf_size - len) {\ 2051 int val = value;\ 2052 s->bi_buf |= (val << s->bi_valid);\ 2053 put_short(s, s->bi_buf);\ 2054 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 2055 s->bi_valid += len - Buf_size;\ 2056 } else {\ 2057 s->bi_buf |= (value) << s->bi_valid;\ 2058 s->bi_valid += len;\ 2059 }\ 2060 } 2061 #endif /* DEBUG_ZLIB */ 2062 2063 /* the arguments must not have side effects */ 2064 2065 /* =========================================================================== 2066 * Initialize the various 'constant' tables. In a multi-threaded environment, 2067 * this function may be called by two threads concurrently, but this is 2068 * harmless since both invocations do exactly the same thing. 2069 */ 2070 local void tr_static_init() 2071 { 2072 static int static_init_done = 0; 2073 int n; /* iterates over tree elements */ 2074 int bits; /* bit counter */ 2075 int length; /* length value */ 2076 int code; /* code value */ 2077 int dist; /* distance index */ 2078 ush bl_count[MAX_BITS+1]; 2079 /* number of codes at each bit length for an optimal tree */ 2080 2081 if (static_init_done) return; 2082 2083 /* Initialize the mapping length (0..255) -> length code (0..28) */ 2084 length = 0; 2085 for (code = 0; code < LENGTH_CODES-1; code++) { 2086 base_length[code] = length; 2087 for (n = 0; n < (1<<extra_lbits[code]); n++) { 2088 length_code[length++] = (uch)code; 2089 } 2090 } 2091 Assert (length == 256, "tr_static_init: length != 256"); 2092 /* Note that the length 255 (match length 258) can be represented 2093 * in two different ways: code 284 + 5 bits or code 285, so we 2094 * overwrite length_code[255] to use the best encoding: 2095 */ 2096 length_code[length-1] = (uch)code; 2097 2098 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 2099 dist = 0; 2100 for (code = 0 ; code < 16; code++) { 2101 base_dist[code] = dist; 2102 for (n = 0; n < (1<<extra_dbits[code]); n++) { 2103 dist_code[dist++] = (uch)code; 2104 } 2105 } 2106 Assert (dist == 256, "tr_static_init: dist != 256"); 2107 dist >>= 7; /* from now on, all distances are divided by 128 */ 2108 for ( ; code < D_CODES; code++) { 2109 base_dist[code] = dist << 7; 2110 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 2111 dist_code[256 + dist++] = (uch)code; 2112 } 2113 } 2114 Assert (dist == 256, "tr_static_init: 256+dist != 512"); 2115 2116 /* Construct the codes of the static literal tree */ 2117 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 2118 n = 0; 2119 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 2120 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 2121 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 2122 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 2123 /* Codes 286 and 287 do not exist, but we must include them in the 2124 * tree construction to get a canonical Huffman tree (longest code 2125 * all ones) 2126 */ 2127 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 2128 2129 /* The static distance tree is trivial: */ 2130 for (n = 0; n < D_CODES; n++) { 2131 static_dtree[n].Len = 5; 2132 static_dtree[n].Code = bi_reverse((unsigned)n, 5); 2133 } 2134 static_init_done = 1; 2135 } 2136 2137 /* =========================================================================== 2138 * Initialize the tree data structures for a new zlib stream. 2139 */ 2140 void _tr_init(s) 2141 deflate_state *s; 2142 { 2143 tr_static_init(); 2144 2145 s->compressed_len = 0L; 2146 2147 s->l_desc.dyn_tree = s->dyn_ltree; 2148 s->l_desc.stat_desc = &static_l_desc; 2149 2150 s->d_desc.dyn_tree = s->dyn_dtree; 2151 s->d_desc.stat_desc = &static_d_desc; 2152 2153 s->bl_desc.dyn_tree = s->bl_tree; 2154 s->bl_desc.stat_desc = &static_bl_desc; 2155 2156 s->bi_buf = 0; 2157 s->bi_valid = 0; 2158 s->last_eob_len = 8; /* enough lookahead for inflate */ 2159 #ifdef DEBUG_ZLIB 2160 s->bits_sent = 0L; 2161 #endif 2162 2163 /* Initialize the first block of the first file: */ 2164 init_block(s); 2165 } 2166 2167 /* =========================================================================== 2168 * Initialize a new block. 2169 */ 2170 local void init_block(s) 2171 deflate_state *s; 2172 { 2173 int n; /* iterates over tree elements */ 2174 2175 /* Initialize the trees. */ 2176 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 2177 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 2178 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 2179 2180 s->dyn_ltree[END_BLOCK].Freq = 1; 2181 s->opt_len = s->static_len = 0L; 2182 s->last_lit = s->matches = 0; 2183 } 2184 2185 #define SMALLEST 1 2186 /* Index within the heap array of least frequent node in the Huffman tree */ 2187 2188 2189 /* =========================================================================== 2190 * Remove the smallest element from the heap and recreate the heap with 2191 * one less element. Updates heap and heap_len. 2192 */ 2193 #define pqremove(s, tree, top) \ 2194 {\ 2195 top = s->heap[SMALLEST]; \ 2196 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 2197 pqdownheap(s, tree, SMALLEST); \ 2198 } 2199 2200 /* =========================================================================== 2201 * Compares to subtrees, using the tree depth as tie breaker when 2202 * the subtrees have equal frequency. This minimizes the worst case length. 2203 */ 2204 #define smaller(tree, n, m, depth) \ 2205 (tree[n].Freq < tree[m].Freq || \ 2206 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 2207 2208 /* =========================================================================== 2209 * Restore the heap property by moving down the tree starting at node k, 2210 * exchanging a node with the smallest of its two sons if necessary, stopping 2211 * when the heap property is re-established (each father smaller than its 2212 * two sons). 2213 */ 2214 local void pqdownheap(s, tree, k) 2215 deflate_state *s; 2216 ct_data *tree; /* the tree to restore */ 2217 int k; /* node to move down */ 2218 { 2219 int v = s->heap[k]; 2220 int j = k << 1; /* left son of k */ 2221 while (j <= s->heap_len) { 2222 /* Set j to the smallest of the two sons: */ 2223 if (j < s->heap_len && 2224 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 2225 j++; 2226 } 2227 /* Exit if v is smaller than both sons */ 2228 if (smaller(tree, v, s->heap[j], s->depth)) break; 2229 2230 /* Exchange v with the smallest son */ 2231 s->heap[k] = s->heap[j]; k = j; 2232 2233 /* And continue down the tree, setting j to the left son of k */ 2234 j <<= 1; 2235 } 2236 s->heap[k] = v; 2237 } 2238 2239 /* =========================================================================== 2240 * Compute the optimal bit lengths for a tree and update the total bit length 2241 * for the current block. 2242 * IN assertion: the fields freq and dad are set, heap[heap_max] and 2243 * above are the tree nodes sorted by increasing frequency. 2244 * OUT assertions: the field len is set to the optimal bit length, the 2245 * array bl_count contains the frequencies for each bit length. 2246 * The length opt_len is updated; static_len is also updated if stree is 2247 * not null. 2248 */ 2249 local void gen_bitlen(s, desc) 2250 deflate_state *s; 2251 tree_desc *desc; /* the tree descriptor */ 2252 { 2253 ct_data *tree = desc->dyn_tree; 2254 int max_code = desc->max_code; 2255 ct_data *stree = desc->stat_desc->static_tree; 2256 intf *extra = desc->stat_desc->extra_bits; 2257 int base = desc->stat_desc->extra_base; 2258 int max_length = desc->stat_desc->max_length; 2259 int h; /* heap index */ 2260 int n, m; /* iterate over the tree elements */ 2261 int bits; /* bit length */ 2262 int xbits; /* extra bits */ 2263 ush f; /* frequency */ 2264 int overflow = 0; /* number of elements with bit length too large */ 2265 2266 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 2267 2268 /* In a first pass, compute the optimal bit lengths (which may 2269 * overflow in the case of the bit length tree). 2270 */ 2271 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 2272 2273 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 2274 n = s->heap[h]; 2275 bits = tree[tree[n].Dad].Len + 1; 2276 if (bits > max_length) bits = max_length, overflow++; 2277 tree[n].Len = (ush)bits; 2278 /* We overwrite tree[n].Dad which is no longer needed */ 2279 2280 if (n > max_code) continue; /* not a leaf node */ 2281 2282 s->bl_count[bits]++; 2283 xbits = 0; 2284 if (n >= base) xbits = extra[n-base]; 2285 f = tree[n].Freq; 2286 s->opt_len += (ulg)f * (bits + xbits); 2287 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 2288 } 2289 if (overflow == 0) return; 2290 2291 Trace((stderr,"\nbit length overflow\n")); 2292 /* This happens for example on obj2 and pic of the Calgary corpus */ 2293 2294 /* Find the first bit length which could increase: */ 2295 do { 2296 bits = max_length-1; 2297 while (s->bl_count[bits] == 0) bits--; 2298 s->bl_count[bits]--; /* move one leaf down the tree */ 2299 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 2300 s->bl_count[max_length]--; 2301 /* The brother of the overflow item also moves one step up, 2302 * but this does not affect bl_count[max_length] 2303 */ 2304 overflow -= 2; 2305 } while (overflow > 0); 2306 2307 /* Now recompute all bit lengths, scanning in increasing frequency. 2308 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 2309 * lengths instead of fixing only the wrong ones. This idea is taken 2310 * from 'ar' written by Haruhiko Okumura.) 2311 */ 2312 for (bits = max_length; bits != 0; bits--) { 2313 n = s->bl_count[bits]; 2314 while (n != 0) { 2315 m = s->heap[--h]; 2316 if (m > max_code) continue; 2317 if (tree[m].Len != (unsigned) bits) { 2318 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 2319 s->opt_len += ((long)bits - (long)tree[m].Len) 2320 *(long)tree[m].Freq; 2321 tree[m].Len = (ush)bits; 2322 } 2323 n--; 2324 } 2325 } 2326 } 2327 2328 /* =========================================================================== 2329 * Generate the codes for a given tree and bit counts (which need not be 2330 * optimal). 2331 * IN assertion: the array bl_count contains the bit length statistics for 2332 * the given tree and the field len is set for all tree elements. 2333 * OUT assertion: the field code is set for all tree elements of non 2334 * zero code length. 2335 */ 2336 local void gen_codes (tree, max_code, bl_count) 2337 ct_data *tree; /* the tree to decorate */ 2338 int max_code; /* largest code with non zero frequency */ 2339 ushf *bl_count; /* number of codes at each bit length */ 2340 { 2341 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 2342 ush code = 0; /* running code value */ 2343 int bits; /* bit index */ 2344 int n; /* code index */ 2345 2346 /* The distribution counts are first used to generate the code values 2347 * without bit reversal. 2348 */ 2349 for (bits = 1; bits <= MAX_BITS; bits++) { 2350 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 2351 } 2352 /* Check that the bit counts in bl_count are consistent. The last code 2353 * must be all ones. 2354 */ 2355 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 2356 "inconsistent bit counts"); 2357 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 2358 2359 for (n = 0; n <= max_code; n++) { 2360 int len = tree[n].Len; 2361 if (len == 0) continue; 2362 /* Now reverse the bits */ 2363 tree[n].Code = bi_reverse(next_code[len]++, len); 2364 2365 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 2366 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 2367 } 2368 } 2369 2370 /* =========================================================================== 2371 * Construct one Huffman tree and assigns the code bit strings and lengths. 2372 * Update the total bit length for the current block. 2373 * IN assertion: the field freq is set for all tree elements. 2374 * OUT assertions: the fields len and code are set to the optimal bit length 2375 * and corresponding code. The length opt_len is updated; static_len is 2376 * also updated if stree is not null. The field max_code is set. 2377 */ 2378 local void build_tree(s, desc) 2379 deflate_state *s; 2380 tree_desc *desc; /* the tree descriptor */ 2381 { 2382 ct_data *tree = desc->dyn_tree; 2383 ct_data *stree = desc->stat_desc->static_tree; 2384 int elems = desc->stat_desc->elems; 2385 int n, m; /* iterate over heap elements */ 2386 int max_code = -1; /* largest code with non zero frequency */ 2387 int node; /* new node being created */ 2388 2389 /* Construct the initial heap, with least frequent element in 2390 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2391 * heap[0] is not used. 2392 */ 2393 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2394 2395 for (n = 0; n < elems; n++) { 2396 if (tree[n].Freq != 0) { 2397 s->heap[++(s->heap_len)] = max_code = n; 2398 s->depth[n] = 0; 2399 } else { 2400 tree[n].Len = 0; 2401 } 2402 } 2403 2404 /* The pkzip format requires that at least one distance code exists, 2405 * and that at least one bit should be sent even if there is only one 2406 * possible code. So to avoid special checks later on we force at least 2407 * two codes of non zero frequency. 2408 */ 2409 while (s->heap_len < 2) { 2410 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2411 tree[node].Freq = 1; 2412 s->depth[node] = 0; 2413 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2414 /* node is 0 or 1 so it does not have extra bits */ 2415 } 2416 desc->max_code = max_code; 2417 2418 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2419 * establish sub-heaps of increasing lengths: 2420 */ 2421 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2422 2423 /* Construct the Huffman tree by repeatedly combining the least two 2424 * frequent nodes. 2425 */ 2426 node = elems; /* next internal node of the tree */ 2427 do { 2428 pqremove(s, tree, n); /* n = node of least frequency */ 2429 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2430 2431 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2432 s->heap[--(s->heap_max)] = m; 2433 2434 /* Create a new node father of n and m */ 2435 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2436 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2437 tree[n].Dad = tree[m].Dad = (ush)node; 2438 #ifdef DUMP_BL_TREE 2439 if (tree == s->bl_tree) { 2440 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2441 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2442 } 2443 #endif 2444 /* and insert the new node in the heap */ 2445 s->heap[SMALLEST] = node++; 2446 pqdownheap(s, tree, SMALLEST); 2447 2448 } while (s->heap_len >= 2); 2449 2450 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2451 2452 /* At this point, the fields freq and dad are set. We can now 2453 * generate the bit lengths. 2454 */ 2455 gen_bitlen(s, (tree_desc *)desc); 2456 2457 /* The field len is now set, we can generate the bit codes */ 2458 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2459 } 2460 2461 /* =========================================================================== 2462 * Scan a literal or distance tree to determine the frequencies of the codes 2463 * in the bit length tree. 2464 */ 2465 local void scan_tree (s, tree, max_code) 2466 deflate_state *s; 2467 ct_data *tree; /* the tree to be scanned */ 2468 int max_code; /* and its largest code of non zero frequency */ 2469 { 2470 int n; /* iterates over all tree elements */ 2471 int prevlen = -1; /* last emitted length */ 2472 int curlen; /* length of current code */ 2473 int nextlen = tree[0].Len; /* length of next code */ 2474 int count = 0; /* repeat count of the current code */ 2475 int max_count = 7; /* max repeat count */ 2476 int min_count = 4; /* min repeat count */ 2477 2478 if (nextlen == 0) max_count = 138, min_count = 3; 2479 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2480 2481 for (n = 0; n <= max_code; n++) { 2482 curlen = nextlen; nextlen = tree[n+1].Len; 2483 if (++count < max_count && curlen == nextlen) { 2484 continue; 2485 } else if (count < min_count) { 2486 s->bl_tree[curlen].Freq += count; 2487 } else if (curlen != 0) { 2488 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2489 s->bl_tree[REP_3_6].Freq++; 2490 } else if (count <= 10) { 2491 s->bl_tree[REPZ_3_10].Freq++; 2492 } else { 2493 s->bl_tree[REPZ_11_138].Freq++; 2494 } 2495 count = 0; prevlen = curlen; 2496 if (nextlen == 0) { 2497 max_count = 138, min_count = 3; 2498 } else if (curlen == nextlen) { 2499 max_count = 6, min_count = 3; 2500 } else { 2501 max_count = 7, min_count = 4; 2502 } 2503 } 2504 } 2505 2506 /* =========================================================================== 2507 * Send a literal or distance tree in compressed form, using the codes in 2508 * bl_tree. 2509 */ 2510 local void send_tree (s, tree, max_code) 2511 deflate_state *s; 2512 ct_data *tree; /* the tree to be scanned */ 2513 int max_code; /* and its largest code of non zero frequency */ 2514 { 2515 int n; /* iterates over all tree elements */ 2516 int prevlen = -1; /* last emitted length */ 2517 int curlen; /* length of current code */ 2518 int nextlen = tree[0].Len; /* length of next code */ 2519 int count = 0; /* repeat count of the current code */ 2520 int max_count = 7; /* max repeat count */ 2521 int min_count = 4; /* min repeat count */ 2522 2523 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2524 if (nextlen == 0) max_count = 138, min_count = 3; 2525 2526 for (n = 0; n <= max_code; n++) { 2527 curlen = nextlen; nextlen = tree[n+1].Len; 2528 if (++count < max_count && curlen == nextlen) { 2529 continue; 2530 } else if (count < min_count) { 2531 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2532 2533 } else if (curlen != 0) { 2534 if (curlen != prevlen) { 2535 send_code(s, curlen, s->bl_tree); count--; 2536 } 2537 Assert(count >= 3 && count <= 6, " 3_6?"); 2538 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2539 2540 } else if (count <= 10) { 2541 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2542 2543 } else { 2544 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2545 } 2546 count = 0; prevlen = curlen; 2547 if (nextlen == 0) { 2548 max_count = 138, min_count = 3; 2549 } else if (curlen == nextlen) { 2550 max_count = 6, min_count = 3; 2551 } else { 2552 max_count = 7, min_count = 4; 2553 } 2554 } 2555 } 2556 2557 /* =========================================================================== 2558 * Construct the Huffman tree for the bit lengths and return the index in 2559 * bl_order of the last bit length code to send. 2560 */ 2561 local int build_bl_tree(s) 2562 deflate_state *s; 2563 { 2564 int max_blindex; /* index of last bit length code of non zero freq */ 2565 2566 /* Determine the bit length frequencies for literal and distance trees */ 2567 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2568 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2569 2570 /* Build the bit length tree: */ 2571 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2572 /* opt_len now includes the length of the tree representations, except 2573 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2574 */ 2575 2576 /* Determine the number of bit length codes to send. The pkzip format 2577 * requires that at least 4 bit length codes be sent. (appnote.txt says 2578 * 3 but the actual value used is 4.) 2579 */ 2580 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2581 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2582 } 2583 /* Update opt_len to include the bit length tree and counts */ 2584 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2585 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2586 s->opt_len, s->static_len)); 2587 2588 return max_blindex; 2589 } 2590 2591 /* =========================================================================== 2592 * Send the header for a block using dynamic Huffman trees: the counts, the 2593 * lengths of the bit length codes, the literal tree and the distance tree. 2594 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2595 */ 2596 local void send_all_trees(s, lcodes, dcodes, blcodes) 2597 deflate_state *s; 2598 int lcodes, dcodes, blcodes; /* number of codes for each tree */ 2599 { 2600 int rank; /* index in bl_order */ 2601 2602 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2603 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2604 "too many codes"); 2605 Tracev((stderr, "\nbl counts: ")); 2606 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2607 send_bits(s, dcodes-1, 5); 2608 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2609 for (rank = 0; rank < blcodes; rank++) { 2610 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2611 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2612 } 2613 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2614 2615 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2616 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2617 2618 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2619 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2620 } 2621 2622 /* =========================================================================== 2623 * Send a stored block 2624 */ 2625 void _tr_stored_block(s, buf, stored_len, eof) 2626 deflate_state *s; 2627 charf *buf; /* input block */ 2628 ulg stored_len; /* length of input block */ 2629 int eof; /* true if this is the last block for a file */ 2630 { 2631 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ 2632 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L; 2633 s->compressed_len += (stored_len + 4) << 3; 2634 2635 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ 2636 } 2637 2638 /* Send just the `stored block' type code without any length bytes or data. 2639 */ 2640 void _tr_stored_type_only(s) 2641 deflate_state *s; 2642 { 2643 send_bits(s, (STORED_BLOCK << 1), 3); 2644 bi_windup(s); 2645 s->compressed_len = (s->compressed_len + 3) & ~7L; 2646 } 2647 2648 2649 /* =========================================================================== 2650 * Send one empty static block to give enough lookahead for inflate. 2651 * This takes 10 bits, of which 7 may remain in the bit buffer. 2652 * The current inflate code requires 9 bits of lookahead. If the 2653 * last two codes for the previous block (real code plus EOB) were coded 2654 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode 2655 * the last real code. In this case we send two empty static blocks instead 2656 * of one. (There are no problems if the previous block is stored or fixed.) 2657 * To simplify the code, we assume the worst case of last real code encoded 2658 * on one bit only. 2659 */ 2660 void _tr_align(s) 2661 deflate_state *s; 2662 { 2663 send_bits(s, STATIC_TREES<<1, 3); 2664 send_code(s, END_BLOCK, static_ltree); 2665 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ 2666 bi_flush(s); 2667 /* Of the 10 bits for the empty block, we have already sent 2668 * (10 - bi_valid) bits. The lookahead for the last real code (before 2669 * the EOB of the previous block) was thus at least one plus the length 2670 * of the EOB plus what we have just sent of the empty static block. 2671 */ 2672 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) { 2673 send_bits(s, STATIC_TREES<<1, 3); 2674 send_code(s, END_BLOCK, static_ltree); 2675 s->compressed_len += 10L; 2676 bi_flush(s); 2677 } 2678 s->last_eob_len = 7; 2679 } 2680 2681 /* =========================================================================== 2682 * Determine the best encoding for the current block: dynamic trees, static 2683 * trees or store, and output the encoded block to the zip file. This function 2684 * returns the total compressed length for the file so far. 2685 */ 2686 ulg _tr_flush_block(s, buf, stored_len, eof) 2687 deflate_state *s; 2688 charf *buf; /* input block, or NULL if too old */ 2689 ulg stored_len; /* length of input block */ 2690 int eof; /* true if this is the last block for a file */ 2691 { 2692 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2693 int max_blindex = 0; /* index of last bit length code of non zero freq */ 2694 2695 /* Build the Huffman trees unless a stored block is forced */ 2696 if (s->level > 0) { 2697 2698 /* Check if the file is ascii or binary */ 2699 if (s->data_type == Z_UNKNOWN) set_data_type(s); 2700 2701 /* Construct the literal and distance trees */ 2702 build_tree(s, (tree_desc *)(&(s->l_desc))); 2703 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2704 s->static_len)); 2705 2706 build_tree(s, (tree_desc *)(&(s->d_desc))); 2707 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2708 s->static_len)); 2709 /* At this point, opt_len and static_len are the total bit lengths of 2710 * the compressed block data, excluding the tree representations. 2711 */ 2712 2713 /* Build the bit length tree for the above two trees, and get the index 2714 * in bl_order of the last bit length code to send. 2715 */ 2716 max_blindex = build_bl_tree(s); 2717 2718 /* Determine the best encoding. Compute first the block length in bytes*/ 2719 opt_lenb = (s->opt_len+3+7)>>3; 2720 static_lenb = (s->static_len+3+7)>>3; 2721 2722 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2723 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2724 s->last_lit)); 2725 2726 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2727 2728 } else { 2729 Assert(buf != (char*)0, "lost buf"); 2730 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 2731 } 2732 2733 /* If compression failed and this is the first and last block, 2734 * and if the .zip file can be seeked (to rewrite the local header), 2735 * the whole file is transformed into a stored file: 2736 */ 2737 #ifdef STORED_FILE_OK 2738 # ifdef FORCE_STORED_FILE 2739 if (eof && s->compressed_len == 0L) { /* force stored file */ 2740 # else 2741 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { 2742 # endif 2743 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2744 if (buf == (charf*)0) error ("block vanished"); 2745 2746 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ 2747 s->compressed_len = stored_len << 3; 2748 s->method = STORED; 2749 } else 2750 #endif /* STORED_FILE_OK */ 2751 2752 #ifdef FORCE_STORED 2753 if (buf != (char*)0) { /* force stored block */ 2754 #else 2755 if (stored_len+4 <= opt_lenb && buf != (char*)0) { 2756 /* 4: two words for the lengths */ 2757 #endif 2758 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2759 * Otherwise we can't have processed more than WSIZE input bytes since 2760 * the last block flush, because compression would have been 2761 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2762 * transform a block into a stored block. 2763 */ 2764 _tr_stored_block(s, buf, stored_len, eof); 2765 2766 #ifdef FORCE_STATIC 2767 } else if (static_lenb >= 0) { /* force static trees */ 2768 #else 2769 } else if (static_lenb == opt_lenb) { 2770 #endif 2771 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2772 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2773 s->compressed_len += 3 + s->static_len; 2774 } else { 2775 send_bits(s, (DYN_TREES<<1)+eof, 3); 2776 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2777 max_blindex+1); 2778 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2779 s->compressed_len += 3 + s->opt_len; 2780 } 2781 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2782 init_block(s); 2783 2784 if (eof) { 2785 bi_windup(s); 2786 s->compressed_len += 7; /* align on byte boundary */ 2787 } 2788 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2789 s->compressed_len-7*eof)); 2790 2791 return s->compressed_len >> 3; 2792 } 2793 2794 /* =========================================================================== 2795 * Save the match info and tally the frequency counts. Return true if 2796 * the current block must be flushed. 2797 */ 2798 int _tr_tally (s, dist, lc) 2799 deflate_state *s; 2800 unsigned dist; /* distance of matched string */ 2801 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ 2802 { 2803 s->d_buf[s->last_lit] = (ush)dist; 2804 s->l_buf[s->last_lit++] = (uch)lc; 2805 if (dist == 0) { 2806 /* lc is the unmatched char */ 2807 s->dyn_ltree[lc].Freq++; 2808 } else { 2809 s->matches++; 2810 /* Here, lc is the match length - MIN_MATCH */ 2811 dist--; /* dist = match distance - 1 */ 2812 Assert((ush)dist < (ush)MAX_DIST(s) && 2813 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2814 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 2815 2816 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2817 s->dyn_dtree[d_code(dist)].Freq++; 2818 } 2819 2820 /* Try to guess if it is profitable to stop the current block here */ 2821 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2822 /* Compute an upper bound for the compressed length */ 2823 ulg out_length = (ulg)s->last_lit*8L; 2824 ulg in_length = (ulg)((long)s->strstart - s->block_start); 2825 int dcode; 2826 for (dcode = 0; dcode < D_CODES; dcode++) { 2827 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2828 (5L+extra_dbits[dcode]); 2829 } 2830 out_length >>= 3; 2831 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2832 s->last_lit, in_length, out_length, 2833 100L - out_length*100L/in_length)); 2834 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2835 } 2836 return (s->last_lit == s->lit_bufsize-1); 2837 /* We avoid equality with lit_bufsize because of wraparound at 64K 2838 * on 16 bit machines and because stored blocks are restricted to 2839 * 64K-1 bytes. 2840 */ 2841 } 2842 2843 /* =========================================================================== 2844 * Send the block data compressed using the given Huffman trees 2845 */ 2846 local void compress_block(s, ltree, dtree) 2847 deflate_state *s; 2848 ct_data *ltree; /* literal tree */ 2849 ct_data *dtree; /* distance tree */ 2850 { 2851 unsigned dist; /* distance of matched string */ 2852 int lc; /* match length or unmatched char (if dist == 0) */ 2853 unsigned lx = 0; /* running index in l_buf */ 2854 unsigned code; /* the code to send */ 2855 int extra; /* number of extra bits to send */ 2856 2857 if (s->last_lit != 0) do { 2858 dist = s->d_buf[lx]; 2859 lc = s->l_buf[lx++]; 2860 if (dist == 0) { 2861 send_code(s, lc, ltree); /* send a literal byte */ 2862 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2863 } else { 2864 /* Here, lc is the match length - MIN_MATCH */ 2865 code = length_code[lc]; 2866 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2867 extra = extra_lbits[code]; 2868 if (extra != 0) { 2869 lc -= base_length[code]; 2870 send_bits(s, lc, extra); /* send the extra length bits */ 2871 } 2872 dist--; /* dist is now the match distance - 1 */ 2873 code = d_code(dist); 2874 Assert (code < D_CODES, "bad d_code"); 2875 2876 send_code(s, code, dtree); /* send the distance code */ 2877 extra = extra_dbits[code]; 2878 if (extra != 0) { 2879 dist -= base_dist[code]; 2880 send_bits(s, dist, extra); /* send the extra distance bits */ 2881 } 2882 } /* literal or match pair ? */ 2883 2884 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2885 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2886 2887 } while (lx < s->last_lit); 2888 2889 send_code(s, END_BLOCK, ltree); 2890 s->last_eob_len = ltree[END_BLOCK].Len; 2891 } 2892 2893 /* =========================================================================== 2894 * Set the data type to ASCII or BINARY, using a crude approximation: 2895 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2896 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2897 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2898 */ 2899 local void set_data_type(s) 2900 deflate_state *s; 2901 { 2902 int n = 0; 2903 unsigned ascii_freq = 0; 2904 unsigned bin_freq = 0; 2905 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2906 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2907 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2908 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 2909 } 2910 2911 /* =========================================================================== 2912 * Reverse the first len bits of a code, using straightforward code (a faster 2913 * method would use a table) 2914 * IN assertion: 1 <= len <= 15 2915 */ 2916 local unsigned bi_reverse(code, len) 2917 unsigned code; /* the value to invert */ 2918 int len; /* its bit length */ 2919 { 2920 unsigned res = 0; 2921 do { 2922 res |= code & 1; 2923 code >>= 1, res <<= 1; 2924 } while (--len > 0); 2925 return res >> 1; 2926 } 2927 2928 /* =========================================================================== 2929 * Flush the bit buffer, keeping at most 7 bits in it. 2930 */ 2931 local void bi_flush(s) 2932 deflate_state *s; 2933 { 2934 if (s->bi_valid == 16) { 2935 put_short(s, s->bi_buf); 2936 s->bi_buf = 0; 2937 s->bi_valid = 0; 2938 } else if (s->bi_valid >= 8) { 2939 put_byte(s, (Byte)s->bi_buf); 2940 s->bi_buf >>= 8; 2941 s->bi_valid -= 8; 2942 } 2943 } 2944 2945 /* =========================================================================== 2946 * Flush the bit buffer and align the output on a byte boundary 2947 */ 2948 local void bi_windup(s) 2949 deflate_state *s; 2950 { 2951 if (s->bi_valid > 8) { 2952 put_short(s, s->bi_buf); 2953 } else if (s->bi_valid > 0) { 2954 put_byte(s, (Byte)s->bi_buf); 2955 } 2956 s->bi_buf = 0; 2957 s->bi_valid = 0; 2958 #ifdef DEBUG_ZLIB 2959 s->bits_sent = (s->bits_sent+7) & ~7; 2960 #endif 2961 } 2962 2963 /* =========================================================================== 2964 * Copy a stored block, storing first the length and its 2965 * one's complement if requested. 2966 */ 2967 local void copy_block(s, buf, len, header) 2968 deflate_state *s; 2969 charf *buf; /* the input data */ 2970 unsigned len; /* its length */ 2971 int header; /* true if block header must be written */ 2972 { 2973 bi_windup(s); /* align on byte boundary */ 2974 s->last_eob_len = 8; /* enough lookahead for inflate */ 2975 2976 if (header) { 2977 put_short(s, (ush)len); 2978 put_short(s, (ush)~len); 2979 #ifdef DEBUG_ZLIB 2980 s->bits_sent += 2*16; 2981 #endif 2982 } 2983 #ifdef DEBUG_ZLIB 2984 s->bits_sent += (ulg)len<<3; 2985 #endif 2986 /* bundle up the put_byte(s, *buf++) calls */ 2987 zmemcpy(&s->pending_buf[s->pending], buf, len); 2988 s->pending += len; 2989 } 2990 /* --- trees.c */ 2991 2992 /* +++ inflate.c */ 2993 /* inflate.c -- zlib interface to inflate modules 2994 * Copyright (C) 1995-1996 Mark Adler 2995 * For conditions of distribution and use, see copyright notice in zlib.h 2996 */ 2997 2998 /* #include "zutil.h" */ 2999 3000 /* +++ infblock.h */ 3001 /* infblock.h -- header to use infblock.c 3002 * Copyright (C) 1995-1996 Mark Adler 3003 * For conditions of distribution and use, see copyright notice in zlib.h 3004 */ 3005 3006 /* WARNING: this file should *not* be used by applications. It is 3007 part of the implementation of the compression library and is 3008 subject to change. Applications should only use zlib.h. 3009 */ 3010 3011 struct inflate_blocks_state; 3012 typedef struct inflate_blocks_state FAR inflate_blocks_statef; 3013 3014 extern inflate_blocks_statef * inflate_blocks_new OF(( 3015 z_streamp z, 3016 check_func c, /* check function */ 3017 uInt w)); /* window size */ 3018 3019 extern int inflate_blocks OF(( 3020 inflate_blocks_statef *, 3021 z_streamp , 3022 int)); /* initial return code */ 3023 3024 extern void inflate_blocks_reset OF(( 3025 inflate_blocks_statef *, 3026 z_streamp , 3027 uLongf *)); /* check value on output */ 3028 3029 extern int inflate_blocks_free OF(( 3030 inflate_blocks_statef *, 3031 z_streamp , 3032 uLongf *)); /* check value on output */ 3033 3034 extern void inflate_set_dictionary OF(( 3035 inflate_blocks_statef *s, 3036 const Bytef *d, /* dictionary */ 3037 uInt n)); /* dictionary length */ 3038 3039 extern int inflate_addhistory OF(( 3040 inflate_blocks_statef *, 3041 z_streamp)); 3042 3043 extern int inflate_packet_flush OF(( 3044 inflate_blocks_statef *)); 3045 /* --- infblock.h */ 3046 3047 #ifndef NO_DUMMY_DECL 3048 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ 3049 #endif 3050 3051 /* inflate private state */ 3052 struct internal_state { 3053 3054 /* mode */ 3055 enum { 3056 METHOD, /* waiting for method byte */ 3057 FLAG, /* waiting for flag byte */ 3058 DICT4, /* four dictionary check bytes to go */ 3059 DICT3, /* three dictionary check bytes to go */ 3060 DICT2, /* two dictionary check bytes to go */ 3061 DICT1, /* one dictionary check byte to go */ 3062 DICT0, /* waiting for inflateSetDictionary */ 3063 BLOCKS, /* decompressing blocks */ 3064 CHECK4, /* four check bytes to go */ 3065 CHECK3, /* three check bytes to go */ 3066 CHECK2, /* two check bytes to go */ 3067 CHECK1, /* one check byte to go */ 3068 DONE, /* finished check, done */ 3069 BAD} /* got an error--stay here */ 3070 mode; /* current inflate mode */ 3071 3072 /* mode dependent information */ 3073 union { 3074 uInt method; /* if FLAGS, method byte */ 3075 struct { 3076 uLong was; /* computed check value */ 3077 uLong need; /* stream check value */ 3078 } check; /* if CHECK, check values to compare */ 3079 uInt marker; /* if BAD, inflateSync's marker bytes count */ 3080 } sub; /* submode */ 3081 3082 /* mode independent information */ 3083 int nowrap; /* flag for no wrapper */ 3084 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 3085 inflate_blocks_statef 3086 *blocks; /* current inflate_blocks state */ 3087 3088 }; 3089 3090 3091 int inflateReset(z) 3092 z_streamp z; 3093 { 3094 uLong c; 3095 3096 if (z == Z_NULL || z->state == Z_NULL) 3097 return Z_STREAM_ERROR; 3098 z->total_in = z->total_out = 0; 3099 z->msg = Z_NULL; 3100 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 3101 inflate_blocks_reset(z->state->blocks, z, &c); 3102 Trace((stderr, "inflate: reset\n")); 3103 return Z_OK; 3104 } 3105 3106 3107 int inflateEnd(z) 3108 z_streamp z; 3109 { 3110 uLong c; 3111 3112 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 3113 return Z_STREAM_ERROR; 3114 if (z->state->blocks != Z_NULL) 3115 inflate_blocks_free(z->state->blocks, z, &c); 3116 ZFREE(z, z->state); 3117 z->state = Z_NULL; 3118 Trace((stderr, "inflate: end\n")); 3119 return Z_OK; 3120 } 3121 3122 3123 int inflateInit2_(z, w, version, stream_size) 3124 z_streamp z; 3125 int w; 3126 const char *version; 3127 int stream_size; 3128 { 3129 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || 3130 stream_size != sizeof(z_stream)) 3131 return Z_VERSION_ERROR; 3132 3133 /* initialize state */ 3134 if (z == Z_NULL) 3135 return Z_STREAM_ERROR; 3136 z->msg = Z_NULL; 3137 #ifndef NO_ZCFUNCS 3138 if (z->zalloc == Z_NULL) 3139 { 3140 z->zalloc = zcalloc; 3141 z->opaque = (voidpf)0; 3142 } 3143 if (z->zfree == Z_NULL) z->zfree = zcfree; 3144 #endif 3145 if ((z->state = (struct internal_state FAR *) 3146 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 3147 return Z_MEM_ERROR; 3148 z->state->blocks = Z_NULL; 3149 3150 /* handle undocumented nowrap option (no zlib header or check) */ 3151 z->state->nowrap = 0; 3152 if (w < 0) 3153 { 3154 w = - w; 3155 z->state->nowrap = 1; 3156 } 3157 3158 /* set window size */ 3159 if (w < 8 || w > 15) 3160 { 3161 inflateEnd(z); 3162 return Z_STREAM_ERROR; 3163 } 3164 z->state->wbits = (uInt)w; 3165 3166 /* create inflate_blocks state */ 3167 if ((z->state->blocks = 3168 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) 3169 == Z_NULL) 3170 { 3171 inflateEnd(z); 3172 return Z_MEM_ERROR; 3173 } 3174 Trace((stderr, "inflate: allocated\n")); 3175 3176 /* reset state */ 3177 inflateReset(z); 3178 return Z_OK; 3179 } 3180 3181 3182 int inflateInit_(z, version, stream_size) 3183 z_streamp z; 3184 const char *version; 3185 int stream_size; 3186 { 3187 return inflateInit2_(z, DEF_WBITS, version, stream_size); 3188 } 3189 3190 3191 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 3192 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 3193 3194 int inflate(z, f) 3195 z_streamp z; 3196 int f; 3197 { 3198 int r; 3199 uInt b; 3200 3201 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) 3202 return Z_STREAM_ERROR; 3203 r = Z_BUF_ERROR; 3204 while (1) switch (z->state->mode) 3205 { 3206 case METHOD: 3207 NEEDBYTE 3208 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) 3209 { 3210 z->state->mode = BAD; 3211 z->msg = (char*)"unknown compression method"; 3212 z->state->sub.marker = 5; /* can't try inflateSync */ 3213 break; 3214 } 3215 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 3216 { 3217 z->state->mode = BAD; 3218 z->msg = (char*)"invalid window size"; 3219 z->state->sub.marker = 5; /* can't try inflateSync */ 3220 break; 3221 } 3222 z->state->mode = FLAG; 3223 case FLAG: 3224 NEEDBYTE 3225 b = NEXTBYTE; 3226 if (((z->state->sub.method << 8) + b) % 31) 3227 { 3228 z->state->mode = BAD; 3229 z->msg = (char*)"incorrect header check"; 3230 z->state->sub.marker = 5; /* can't try inflateSync */ 3231 break; 3232 } 3233 Trace((stderr, "inflate: zlib header ok\n")); 3234 if (!(b & PRESET_DICT)) 3235 { 3236 z->state->mode = BLOCKS; 3237 break; 3238 } 3239 z->state->mode = DICT4; 3240 case DICT4: 3241 NEEDBYTE 3242 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3243 z->state->mode = DICT3; 3244 case DICT3: 3245 NEEDBYTE 3246 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3247 z->state->mode = DICT2; 3248 case DICT2: 3249 NEEDBYTE 3250 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3251 z->state->mode = DICT1; 3252 case DICT1: 3253 NEEDBYTE 3254 z->state->sub.check.need += (uLong)NEXTBYTE; 3255 z->adler = z->state->sub.check.need; 3256 z->state->mode = DICT0; 3257 return Z_NEED_DICT; 3258 case DICT0: 3259 z->state->mode = BAD; 3260 z->msg = (char*)"need dictionary"; 3261 z->state->sub.marker = 0; /* can try inflateSync */ 3262 return Z_STREAM_ERROR; 3263 case BLOCKS: 3264 r = inflate_blocks(z->state->blocks, z, r); 3265 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 3266 r = inflate_packet_flush(z->state->blocks); 3267 if (r == Z_DATA_ERROR) 3268 { 3269 z->state->mode = BAD; 3270 z->state->sub.marker = 0; /* can try inflateSync */ 3271 break; 3272 } 3273 if (r != Z_STREAM_END) 3274 return r; 3275 r = Z_OK; 3276 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 3277 if (z->state->nowrap) 3278 { 3279 z->state->mode = DONE; 3280 break; 3281 } 3282 z->state->mode = CHECK4; 3283 case CHECK4: 3284 NEEDBYTE 3285 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3286 z->state->mode = CHECK3; 3287 case CHECK3: 3288 NEEDBYTE 3289 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3290 z->state->mode = CHECK2; 3291 case CHECK2: 3292 NEEDBYTE 3293 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3294 z->state->mode = CHECK1; 3295 case CHECK1: 3296 NEEDBYTE 3297 z->state->sub.check.need += (uLong)NEXTBYTE; 3298 3299 if (z->state->sub.check.was != z->state->sub.check.need) 3300 { 3301 z->state->mode = BAD; 3302 z->msg = (char*)"incorrect data check"; 3303 z->state->sub.marker = 5; /* can't try inflateSync */ 3304 break; 3305 } 3306 Trace((stderr, "inflate: zlib check ok\n")); 3307 z->state->mode = DONE; 3308 case DONE: 3309 return Z_STREAM_END; 3310 case BAD: 3311 return Z_DATA_ERROR; 3312 default: 3313 return Z_STREAM_ERROR; 3314 } 3315 3316 empty: 3317 if (f != Z_PACKET_FLUSH) 3318 return r; 3319 z->state->mode = BAD; 3320 z->msg = (char *)"need more for packet flush"; 3321 z->state->sub.marker = 0; /* can try inflateSync */ 3322 return Z_DATA_ERROR; 3323 } 3324 3325 3326 int inflateSetDictionary(z, dictionary, dictLength) 3327 z_streamp z; 3328 const Bytef *dictionary; 3329 uInt dictLength; 3330 { 3331 uInt length = dictLength; 3332 3333 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) 3334 return Z_STREAM_ERROR; 3335 3336 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; 3337 z->adler = 1L; 3338 3339 if (length >= ((uInt)1<<z->state->wbits)) 3340 { 3341 length = (1<<z->state->wbits)-1; 3342 dictionary += dictLength - length; 3343 } 3344 inflate_set_dictionary(z->state->blocks, dictionary, length); 3345 z->state->mode = BLOCKS; 3346 return Z_OK; 3347 } 3348 3349 /* 3350 * This subroutine adds the data at next_in/avail_in to the output history 3351 * without performing any output. The output buffer must be "caught up"; 3352 * i.e. no pending output (hence s->read equals s->write), and the state must 3353 * be BLOCKS (i.e. we should be willing to see the start of a series of 3354 * BLOCKS). On exit, the output will also be caught up, and the checksum 3355 * will have been updated if need be. 3356 */ 3357 3358 int inflateIncomp(z) 3359 z_stream *z; 3360 { 3361 if (z->state->mode != BLOCKS) 3362 return Z_DATA_ERROR; 3363 return inflate_addhistory(z->state->blocks, z); 3364 } 3365 3366 3367 int inflateSync(z) 3368 z_streamp z; 3369 { 3370 uInt n; /* number of bytes to look at */ 3371 Bytef *p; /* pointer to bytes */ 3372 uInt m; /* number of marker bytes found in a row */ 3373 uLong r, w; /* temporaries to save total_in and total_out */ 3374 3375 /* set up */ 3376 if (z == Z_NULL || z->state == Z_NULL) 3377 return Z_STREAM_ERROR; 3378 if (z->state->mode != BAD) 3379 { 3380 z->state->mode = BAD; 3381 z->state->sub.marker = 0; 3382 } 3383 if ((n = z->avail_in) == 0) 3384 return Z_BUF_ERROR; 3385 p = z->next_in; 3386 m = z->state->sub.marker; 3387 3388 /* search */ 3389 while (n && m < 4) 3390 { 3391 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3392 m++; 3393 else if (*p) 3394 m = 0; 3395 else 3396 m = 4 - m; 3397 p++, n--; 3398 } 3399 3400 /* restore */ 3401 z->total_in += p - z->next_in; 3402 z->next_in = p; 3403 z->avail_in = n; 3404 z->state->sub.marker = m; 3405 3406 /* return no joy or set up to restart on a new block */ 3407 if (m != 4) 3408 return Z_DATA_ERROR; 3409 r = z->total_in; w = z->total_out; 3410 inflateReset(z); 3411 z->total_in = r; z->total_out = w; 3412 z->state->mode = BLOCKS; 3413 return Z_OK; 3414 } 3415 3416 #undef NEEDBYTE 3417 #undef NEXTBYTE 3418 /* --- inflate.c */ 3419 3420 /* +++ infblock.c */ 3421 /* infblock.c -- interpret and process block types to last block 3422 * Copyright (C) 1995-1996 Mark Adler 3423 * For conditions of distribution and use, see copyright notice in zlib.h 3424 */ 3425 3426 /* #include "zutil.h" */ 3427 /* #include "infblock.h" */ 3428 3429 /* +++ inftrees.h */ 3430 /* inftrees.h -- header to use inftrees.c 3431 * Copyright (C) 1995-1996 Mark Adler 3432 * For conditions of distribution and use, see copyright notice in zlib.h 3433 */ 3434 3435 /* WARNING: this file should *not* be used by applications. It is 3436 part of the implementation of the compression library and is 3437 subject to change. Applications should only use zlib.h. 3438 */ 3439 3440 /* Huffman code lookup table entry--this entry is four bytes for machines 3441 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 3442 3443 typedef struct inflate_huft_s FAR inflate_huft; 3444 3445 struct inflate_huft_s { 3446 union { 3447 struct { 3448 Byte Exop; /* number of extra bits or operation */ 3449 Byte Bits; /* number of bits in this code or subcode */ 3450 } what; 3451 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 3452 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 3453 union { 3454 uInt Base; /* literal, length base, or distance base */ 3455 inflate_huft *Next; /* pointer to next level of table */ 3456 } more; 3457 }; 3458 3459 #ifdef DEBUG_ZLIB 3460 extern uInt inflate_hufts; 3461 #endif 3462 3463 extern int inflate_trees_bits OF(( 3464 uIntf *, /* 19 code lengths */ 3465 uIntf *, /* bits tree desired/actual depth */ 3466 inflate_huft * FAR *, /* bits tree result */ 3467 z_streamp )); /* for zalloc, zfree functions */ 3468 3469 extern int inflate_trees_dynamic OF(( 3470 uInt, /* number of literal/length codes */ 3471 uInt, /* number of distance codes */ 3472 uIntf *, /* that many (total) code lengths */ 3473 uIntf *, /* literal desired/actual bit depth */ 3474 uIntf *, /* distance desired/actual bit depth */ 3475 inflate_huft * FAR *, /* literal/length tree result */ 3476 inflate_huft * FAR *, /* distance tree result */ 3477 z_streamp )); /* for zalloc, zfree functions */ 3478 3479 extern int inflate_trees_fixed OF(( 3480 uIntf *, /* literal desired/actual bit depth */ 3481 uIntf *, /* distance desired/actual bit depth */ 3482 inflate_huft * FAR *, /* literal/length tree result */ 3483 inflate_huft * FAR *)); /* distance tree result */ 3484 3485 extern int inflate_trees_free OF(( 3486 inflate_huft *, /* tables to free */ 3487 z_streamp )); /* for zfree function */ 3488 3489 /* --- inftrees.h */ 3490 3491 /* +++ infcodes.h */ 3492 /* infcodes.h -- header to use infcodes.c 3493 * Copyright (C) 1995-1996 Mark Adler 3494 * For conditions of distribution and use, see copyright notice in zlib.h 3495 */ 3496 3497 /* WARNING: this file should *not* be used by applications. It is 3498 part of the implementation of the compression library and is 3499 subject to change. Applications should only use zlib.h. 3500 */ 3501 3502 struct inflate_codes_state; 3503 typedef struct inflate_codes_state FAR inflate_codes_statef; 3504 3505 extern inflate_codes_statef *inflate_codes_new OF(( 3506 uInt, uInt, 3507 inflate_huft *, inflate_huft *, 3508 z_streamp )); 3509 3510 extern int inflate_codes OF(( 3511 inflate_blocks_statef *, 3512 z_streamp , 3513 int)); 3514 3515 extern void inflate_codes_free OF(( 3516 inflate_codes_statef *, 3517 z_streamp )); 3518 3519 /* --- infcodes.h */ 3520 3521 /* +++ infutil.h */ 3522 /* infutil.h -- types and macros common to blocks and codes 3523 * Copyright (C) 1995-1996 Mark Adler 3524 * For conditions of distribution and use, see copyright notice in zlib.h 3525 */ 3526 3527 /* WARNING: this file should *not* be used by applications. It is 3528 part of the implementation of the compression library and is 3529 subject to change. Applications should only use zlib.h. 3530 */ 3531 3532 #ifndef _INFUTIL_H 3533 #define _INFUTIL_H 3534 3535 typedef enum { 3536 TYPE, /* get type bits (3, including end bit) */ 3537 LENS, /* get lengths for stored */ 3538 STORED, /* processing stored block */ 3539 TABLE, /* get table lengths */ 3540 BTREE, /* get bit lengths tree for a dynamic block */ 3541 DTREE, /* get length, distance trees for a dynamic block */ 3542 CODES, /* processing fixed or dynamic block */ 3543 DRY, /* output remaining window bytes */ 3544 DONEB, /* finished last block, done */ 3545 BADB} /* got a data error--stuck here */ 3546 inflate_block_mode; 3547 3548 /* inflate blocks semi-private state */ 3549 struct inflate_blocks_state { 3550 3551 /* mode */ 3552 inflate_block_mode mode; /* current inflate_block mode */ 3553 3554 /* mode dependent information */ 3555 union { 3556 uInt left; /* if STORED, bytes left to copy */ 3557 struct { 3558 uInt table; /* table lengths (14 bits) */ 3559 uInt index; /* index into blens (or border) */ 3560 uIntf *blens; /* bit lengths of codes */ 3561 uInt bb; /* bit length tree depth */ 3562 inflate_huft *tb; /* bit length decoding tree */ 3563 } trees; /* if DTREE, decoding info for trees */ 3564 struct { 3565 inflate_huft *tl; 3566 inflate_huft *td; /* trees to free */ 3567 inflate_codes_statef 3568 *codes; 3569 } decode; /* if CODES, current state */ 3570 } sub; /* submode */ 3571 uInt last; /* true if this block is the last block */ 3572 3573 /* mode independent information */ 3574 uInt bitk; /* bits in bit buffer */ 3575 uLong bitb; /* bit buffer */ 3576 Bytef *window; /* sliding window */ 3577 Bytef *end; /* one byte after sliding window */ 3578 Bytef *read; /* window read pointer */ 3579 Bytef *write; /* window write pointer */ 3580 check_func checkfn; /* check function */ 3581 uLong check; /* check on output */ 3582 3583 }; 3584 3585 3586 /* defines for inflate input/output */ 3587 /* update pointers and return */ 3588 #define UPDBITS {s->bitb=b;s->bitk=k;} 3589 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3590 #define UPDOUT {s->write=q;} 3591 #define UPDATE {UPDBITS UPDIN UPDOUT} 3592 #define LEAVE {UPDATE return inflate_flush(s,z,r);} 3593 /* get bytes and bits */ 3594 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3595 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3596 #define NEXTBYTE (n--,*p++) 3597 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3598 #define DUMPBITS(j) {b>>=(j);k-=(j);} 3599 /* output bytes */ 3600 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) 3601 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} 3602 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} 3603 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3604 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} 3605 #define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3606 /* load local pointers */ 3607 #define LOAD {LOADIN LOADOUT} 3608 3609 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ 3610 extern uInt inflate_mask[17]; 3611 3612 /* copy as much as possible from the sliding window to the output area */ 3613 extern int inflate_flush OF(( 3614 inflate_blocks_statef *, 3615 z_streamp , 3616 int)); 3617 3618 #ifndef NO_DUMMY_DECL 3619 struct internal_state {int dummy;}; /* for buggy compilers */ 3620 #endif 3621 3622 #endif 3623 /* --- infutil.h */ 3624 3625 #ifndef NO_DUMMY_DECL 3626 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 3627 #endif 3628 3629 /* Table for deflate from PKZIP's appnote.txt. */ 3630 local const uInt border[] = { /* Order of the bit length code lengths */ 3631 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3632 3633 /* 3634 Notes beyond the 1.93a appnote.txt: 3635 3636 1. Distance pointers never point before the beginning of the output 3637 stream. 3638 2. Distance pointers can point back across blocks, up to 32k away. 3639 3. There is an implied maximum of 7 bits for the bit length table and 3640 15 bits for the actual data. 3641 4. If only one code exists, then it is encoded using one bit. (Zero 3642 would be more efficient, but perhaps a little confusing.) If two 3643 codes exist, they are coded using one bit each (0 and 1). 3644 5. There is no way of sending zero distance codes--a dummy must be 3645 sent if there are none. (History: a pre 2.0 version of PKZIP would 3646 store blocks with no distance codes, but this was discovered to be 3647 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3648 zero distance codes, which is sent as one code of zero bits in 3649 length. 3650 6. There are up to 286 literal/length codes. Code 256 represents the 3651 end-of-block. Note however that the static length tree defines 3652 288 codes just to fill out the Huffman codes. Codes 286 and 287 3653 cannot be used though, since there is no length base or extra bits 3654 defined for them. Similarily, there are up to 30 distance codes. 3655 However, static trees define 32 codes (all 5 bits) to fill out the 3656 Huffman codes, but the last two had better not show up in the data. 3657 7. Unzip can check dynamic Huffman blocks for complete code sets. 3658 The exception is that a single code would not be complete (see #4). 3659 8. The five bits following the block type is really the number of 3660 literal codes sent minus 257. 3661 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3662 (1+6+6). Therefore, to output three times the length, you output 3663 three codes (1+1+1), whereas to output four times the same length, 3664 you only need two codes (1+3). Hmm. 3665 10. In the tree reconstruction algorithm, Code = Code + Increment 3666 only if BitLength(i) is not zero. (Pretty obvious.) 3667 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3668 12. Note: length code 284 can represent 227-258, but length code 285 3669 really is 258. The last length deserves its own, short code 3670 since it gets used a lot in very redundant files. The length 3671 258 is special since 258 - 3 (the min match length) is 255. 3672 13. The literal/length and distance code bit lengths are read as a 3673 single stream of lengths. It is possible (and advantageous) for 3674 a repeat code (16, 17, or 18) to go across the boundary between 3675 the two sets of lengths. 3676 */ 3677 3678 3679 void inflate_blocks_reset(s, z, c) 3680 inflate_blocks_statef *s; 3681 z_streamp z; 3682 uLongf *c; 3683 { 3684 if (s->checkfn != Z_NULL) 3685 *c = s->check; 3686 if (s->mode == BTREE || s->mode == DTREE) 3687 ZFREE(z, s->sub.trees.blens); 3688 if (s->mode == CODES) 3689 { 3690 inflate_codes_free(s->sub.decode.codes, z); 3691 inflate_trees_free(s->sub.decode.td, z); 3692 inflate_trees_free(s->sub.decode.tl, z); 3693 } 3694 s->mode = TYPE; 3695 s->bitk = 0; 3696 s->bitb = 0; 3697 s->read = s->write = s->window; 3698 if (s->checkfn != Z_NULL) 3699 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); 3700 Trace((stderr, "inflate: blocks reset\n")); 3701 } 3702 3703 3704 inflate_blocks_statef *inflate_blocks_new(z, c, w) 3705 z_streamp z; 3706 check_func c; 3707 uInt w; 3708 { 3709 inflate_blocks_statef *s; 3710 3711 if ((s = (inflate_blocks_statef *)ZALLOC 3712 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3713 return s; 3714 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3715 { 3716 ZFREE(z, s); 3717 return Z_NULL; 3718 } 3719 s->end = s->window + w; 3720 s->checkfn = c; 3721 s->mode = TYPE; 3722 Trace((stderr, "inflate: blocks allocated\n")); 3723 inflate_blocks_reset(s, z, &s->check); 3724 return s; 3725 } 3726 3727 3728 #ifdef DEBUG_ZLIB 3729 extern uInt inflate_hufts; 3730 #endif 3731 int inflate_blocks(s, z, r) 3732 inflate_blocks_statef *s; 3733 z_streamp z; 3734 int r; 3735 { 3736 uInt t; /* temporary storage */ 3737 uLong b; /* bit buffer */ 3738 uInt k; /* bits in bit buffer */ 3739 Bytef *p; /* input data pointer */ 3740 uInt n; /* bytes available there */ 3741 Bytef *q; /* output window write pointer */ 3742 uInt m; /* bytes to end of window or read pointer */ 3743 3744 /* copy input/output information to locals (UPDATE macro restores) */ 3745 LOAD 3746 3747 /* process input based on current state */ 3748 while (1) switch (s->mode) 3749 { 3750 case TYPE: 3751 NEEDBITS(3) 3752 t = (uInt)b & 7; 3753 s->last = t & 1; 3754 switch (t >> 1) 3755 { 3756 case 0: /* stored */ 3757 Trace((stderr, "inflate: stored block%s\n", 3758 s->last ? " (last)" : "")); 3759 DUMPBITS(3) 3760 t = k & 7; /* go to byte boundary */ 3761 DUMPBITS(t) 3762 s->mode = LENS; /* get length of stored block */ 3763 break; 3764 case 1: /* fixed */ 3765 Trace((stderr, "inflate: fixed codes block%s\n", 3766 s->last ? " (last)" : "")); 3767 { 3768 uInt bl, bd; 3769 inflate_huft *tl, *td; 3770 3771 inflate_trees_fixed(&bl, &bd, &tl, &td); 3772 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3773 if (s->sub.decode.codes == Z_NULL) 3774 { 3775 r = Z_MEM_ERROR; 3776 LEAVE 3777 } 3778 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3779 s->sub.decode.td = Z_NULL; 3780 } 3781 DUMPBITS(3) 3782 s->mode = CODES; 3783 break; 3784 case 2: /* dynamic */ 3785 Trace((stderr, "inflate: dynamic codes block%s\n", 3786 s->last ? " (last)" : "")); 3787 DUMPBITS(3) 3788 s->mode = TABLE; 3789 break; 3790 case 3: /* illegal */ 3791 DUMPBITS(3) 3792 s->mode = BADB; 3793 z->msg = (char*)"invalid block type"; 3794 r = Z_DATA_ERROR; 3795 LEAVE 3796 } 3797 break; 3798 case LENS: 3799 NEEDBITS(32) 3800 if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) 3801 { 3802 s->mode = BADB; 3803 z->msg = (char*)"invalid stored block lengths"; 3804 r = Z_DATA_ERROR; 3805 LEAVE 3806 } 3807 s->sub.left = (uInt)b & 0xffff; 3808 b = k = 0; /* dump bits */ 3809 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3810 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); 3811 break; 3812 case STORED: 3813 if (n == 0) 3814 LEAVE 3815 NEEDOUT 3816 t = s->sub.left; 3817 if (t > n) t = n; 3818 if (t > m) t = m; 3819 zmemcpy(q, p, t); 3820 p += t; n -= t; 3821 q += t; m -= t; 3822 if ((s->sub.left -= t) != 0) 3823 break; 3824 Tracev((stderr, "inflate: stored end, %lu total out\n", 3825 z->total_out + (q >= s->read ? q - s->read : 3826 (s->end - s->read) + (q - s->window)))); 3827 s->mode = s->last ? DRY : TYPE; 3828 break; 3829 case TABLE: 3830 NEEDBITS(14) 3831 s->sub.trees.table = t = (uInt)b & 0x3fff; 3832 #ifndef PKZIP_BUG_WORKAROUND 3833 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3834 { 3835 s->mode = BADB; 3836 z->msg = (char*)"too many length or distance symbols"; 3837 r = Z_DATA_ERROR; 3838 LEAVE 3839 } 3840 #endif 3841 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3842 if (t < 19) 3843 t = 19; 3844 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3845 { 3846 r = Z_MEM_ERROR; 3847 LEAVE 3848 } 3849 DUMPBITS(14) 3850 s->sub.trees.index = 0; 3851 Tracev((stderr, "inflate: table sizes ok\n")); 3852 s->mode = BTREE; 3853 case BTREE: 3854 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3855 { 3856 NEEDBITS(3) 3857 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3858 DUMPBITS(3) 3859 } 3860 while (s->sub.trees.index < 19) 3861 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3862 s->sub.trees.bb = 7; 3863 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3864 &s->sub.trees.tb, z); 3865 if (t != Z_OK) 3866 { 3867 r = t; 3868 if (r == Z_DATA_ERROR) { 3869 ZFREE(z, s->sub.trees.blens); 3870 s->mode = BADB; 3871 } 3872 LEAVE 3873 } 3874 s->sub.trees.index = 0; 3875 Tracev((stderr, "inflate: bits tree ok\n")); 3876 s->mode = DTREE; 3877 case DTREE: 3878 while (t = s->sub.trees.table, 3879 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3880 { 3881 inflate_huft *h; 3882 uInt i, j, c; 3883 3884 t = s->sub.trees.bb; 3885 NEEDBITS(t) 3886 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3887 t = h->word.what.Bits; 3888 c = h->more.Base; 3889 if (c < 16) 3890 { 3891 DUMPBITS(t) 3892 s->sub.trees.blens[s->sub.trees.index++] = c; 3893 } 3894 else /* c == 16..18 */ 3895 { 3896 i = c == 18 ? 7 : c - 14; 3897 j = c == 18 ? 11 : 3; 3898 NEEDBITS(t + i) 3899 DUMPBITS(t) 3900 j += (uInt)b & inflate_mask[i]; 3901 DUMPBITS(i) 3902 i = s->sub.trees.index; 3903 t = s->sub.trees.table; 3904 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3905 (c == 16 && i < 1)) 3906 { 3907 inflate_trees_free(s->sub.trees.tb, z); 3908 ZFREE(z, s->sub.trees.blens); 3909 s->mode = BADB; 3910 z->msg = (char*)"invalid bit length repeat"; 3911 r = Z_DATA_ERROR; 3912 LEAVE 3913 } 3914 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3915 do { 3916 s->sub.trees.blens[i++] = c; 3917 } while (--j); 3918 s->sub.trees.index = i; 3919 } 3920 } 3921 inflate_trees_free(s->sub.trees.tb, z); 3922 s->sub.trees.tb = Z_NULL; 3923 { 3924 uInt bl, bd; 3925 inflate_huft *tl, *td; 3926 inflate_codes_statef *c; 3927 3928 bl = 9; /* must be <= 9 for lookahead assumptions */ 3929 bd = 6; /* must be <= 9 for lookahead assumptions */ 3930 t = s->sub.trees.table; 3931 #ifdef DEBUG_ZLIB 3932 inflate_hufts = 0; 3933 #endif 3934 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3935 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3936 if (t != Z_OK) 3937 { 3938 if (t == (uInt)Z_DATA_ERROR) { 3939 ZFREE(z, s->sub.trees.blens); 3940 s->mode = BADB; 3941 } 3942 r = t; 3943 LEAVE 3944 } 3945 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", 3946 inflate_hufts, sizeof(inflate_huft))); 3947 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3948 { 3949 inflate_trees_free(td, z); 3950 inflate_trees_free(tl, z); 3951 r = Z_MEM_ERROR; 3952 LEAVE 3953 } 3954 /* 3955 * this ZFREE must occur *BEFORE* we mess with sub.decode, because 3956 * sub.trees is union'd with sub.decode. 3957 */ 3958 ZFREE(z, s->sub.trees.blens); 3959 s->sub.decode.codes = c; 3960 s->sub.decode.tl = tl; 3961 s->sub.decode.td = td; 3962 } 3963 s->mode = CODES; 3964 case CODES: 3965 UPDATE 3966 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3967 return inflate_flush(s, z, r); 3968 r = Z_OK; 3969 inflate_codes_free(s->sub.decode.codes, z); 3970 inflate_trees_free(s->sub.decode.td, z); 3971 inflate_trees_free(s->sub.decode.tl, z); 3972 LOAD 3973 Tracev((stderr, "inflate: codes end, %lu total out\n", 3974 z->total_out + (q >= s->read ? q - s->read : 3975 (s->end - s->read) + (q - s->window)))); 3976 if (!s->last) 3977 { 3978 s->mode = TYPE; 3979 break; 3980 } 3981 if (k > 7) /* return unused byte, if any */ 3982 { 3983 Assert(k < 16, "inflate_codes grabbed too many bytes") 3984 k -= 8; 3985 n++; 3986 p--; /* can always return one */ 3987 } 3988 s->mode = DRY; 3989 case DRY: 3990 FLUSH 3991 if (s->read != s->write) 3992 LEAVE 3993 s->mode = DONEB; 3994 case DONEB: 3995 r = Z_STREAM_END; 3996 LEAVE 3997 case BADB: 3998 r = Z_DATA_ERROR; 3999 LEAVE 4000 default: 4001 r = Z_STREAM_ERROR; 4002 LEAVE 4003 } 4004 } 4005 4006 4007 int inflate_blocks_free(s, z, c) 4008 inflate_blocks_statef *s; 4009 z_streamp z; 4010 uLongf *c; 4011 { 4012 inflate_blocks_reset(s, z, c); 4013 ZFREE(z, s->window); 4014 ZFREE(z, s); 4015 Trace((stderr, "inflate: blocks freed\n")); 4016 return Z_OK; 4017 } 4018 4019 4020 void inflate_set_dictionary(s, d, n) 4021 inflate_blocks_statef *s; 4022 const Bytef *d; 4023 uInt n; 4024 { 4025 zmemcpy((charf *)s->window, d, n); 4026 s->read = s->write = s->window + n; 4027 } 4028 4029 /* 4030 * This subroutine adds the data at next_in/avail_in to the output history 4031 * without performing any output. The output buffer must be "caught up"; 4032 * i.e. no pending output (hence s->read equals s->write), and the state must 4033 * be BLOCKS (i.e. we should be willing to see the start of a series of 4034 * BLOCKS). On exit, the output will also be caught up, and the checksum 4035 * will have been updated if need be. 4036 */ 4037 int inflate_addhistory(s, z) 4038 inflate_blocks_statef *s; 4039 z_stream *z; 4040 { 4041 uLong b; /* bit buffer */ /* NOT USED HERE */ 4042 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 4043 uInt t; /* temporary storage */ 4044 Bytef *p; /* input data pointer */ 4045 uInt n; /* bytes available there */ 4046 Bytef *q; /* output window write pointer */ 4047 uInt m; /* bytes to end of window or read pointer */ 4048 4049 if (s->read != s->write) 4050 return Z_STREAM_ERROR; 4051 if (s->mode != TYPE) 4052 return Z_DATA_ERROR; 4053 4054 /* we're ready to rock */ 4055 LOAD 4056 /* while there is input ready, copy to output buffer, moving 4057 * pointers as needed. 4058 */ 4059 while (n) { 4060 t = n; /* how many to do */ 4061 /* is there room until end of buffer? */ 4062 if (t > m) t = m; 4063 /* update check information */ 4064 if (s->checkfn != Z_NULL) 4065 s->check = (*s->checkfn)(s->check, q, t); 4066 zmemcpy(q, p, t); 4067 q += t; 4068 p += t; 4069 n -= t; 4070 z->total_out += t; 4071 s->read = q; /* drag read pointer forward */ 4072 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */ 4073 if (q == s->end) { 4074 s->read = q = s->window; 4075 m = WAVAIL; 4076 } 4077 } 4078 UPDATE 4079 return Z_OK; 4080 } 4081 4082 4083 /* 4084 * At the end of a Deflate-compressed PPP packet, we expect to have seen 4085 * a `stored' block type value but not the (zero) length bytes. 4086 */ 4087 int inflate_packet_flush(s) 4088 inflate_blocks_statef *s; 4089 { 4090 if (s->mode != LENS) 4091 return Z_DATA_ERROR; 4092 s->mode = TYPE; 4093 return Z_OK; 4094 } 4095 /* --- infblock.c */ 4096 4097 /* +++ inftrees.c */ 4098 /* inftrees.c -- generate Huffman trees for efficient decoding 4099 * Copyright (C) 1995-1996 Mark Adler 4100 * For conditions of distribution and use, see copyright notice in zlib.h 4101 */ 4102 4103 /* #include "zutil.h" */ 4104 /* #include "inftrees.h" */ 4105 4106 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler "; 4107 /* 4108 If you use the zlib library in a product, an acknowledgment is welcome 4109 in the documentation of your product. If for some reason you cannot 4110 include such an acknowledgment, I would appreciate that you keep this 4111 copyright string in the executable of your product. 4112 */ 4113 4114 #ifndef NO_DUMMY_DECL 4115 struct internal_state {int dummy;}; /* for buggy compilers */ 4116 #endif 4117 4118 /* simplify the use of the inflate_huft type with some defines */ 4119 #define base more.Base 4120 #define next more.Next 4121 #define exop word.what.Exop 4122 #define bits word.what.Bits 4123 4124 4125 local int huft_build OF(( 4126 uIntf *, /* code lengths in bits */ 4127 uInt, /* number of codes */ 4128 uInt, /* number of "simple" codes */ 4129 const uIntf *, /* list of base values for non-simple codes */ 4130 const uIntf *, /* list of extra bits for non-simple codes */ 4131 inflate_huft * FAR*,/* result: starting table */ 4132 uIntf *, /* maximum lookup bits (returns actual) */ 4133 z_streamp )); /* for zalloc function */ 4134 4135 local voidpf falloc OF(( 4136 voidpf, /* opaque pointer (not used) */ 4137 uInt, /* number of items */ 4138 uInt)); /* size of item */ 4139 4140 /* Tables for deflate from PKZIP's appnote.txt. */ 4141 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */ 4142 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 4143 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 4144 /* see note #13 above about 258 */ 4145 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */ 4146 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 4147 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */ 4148 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */ 4149 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 4150 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 4151 8193, 12289, 16385, 24577}; 4152 local const uInt cpdext[30] = { /* Extra bits for distance codes */ 4153 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 4154 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 4155 12, 12, 13, 13}; 4156 4157 /* 4158 Huffman code decoding is performed using a multi-level table lookup. 4159 The fastest way to decode is to simply build a lookup table whose 4160 size is determined by the longest code. However, the time it takes 4161 to build this table can also be a factor if the data being decoded 4162 is not very long. The most common codes are necessarily the 4163 shortest codes, so those codes dominate the decoding time, and hence 4164 the speed. The idea is you can have a shorter table that decodes the 4165 shorter, more probable codes, and then point to subsidiary tables for 4166 the longer codes. The time it costs to decode the longer codes is 4167 then traded against the time it takes to make longer tables. 4168 4169 This results of this trade are in the variables lbits and dbits 4170 below. lbits is the number of bits the first level table for literal/ 4171 length codes can decode in one step, and dbits is the same thing for 4172 the distance codes. Subsequent tables are also less than or equal to 4173 those sizes. These values may be adjusted either when all of the 4174 codes are shorter than that, in which case the longest code length in 4175 bits is used, or when the shortest code is *longer* than the requested 4176 table size, in which case the length of the shortest code in bits is 4177 used. 4178 4179 There are two different values for the two tables, since they code a 4180 different number of possibilities each. The literal/length table 4181 codes 286 possible values, or in a flat code, a little over eight 4182 bits. The distance table codes 30 possible values, or a little less 4183 than five bits, flat. The optimum values for speed end up being 4184 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 4185 The optimum values may differ though from machine to machine, and 4186 possibly even between compilers. Your mileage may vary. 4187 */ 4188 4189 4190 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 4191 #define BMAX 15 /* maximum bit length of any code */ 4192 #define N_MAX 288 /* maximum number of codes in any set */ 4193 4194 #ifdef DEBUG_ZLIB 4195 uInt inflate_hufts; 4196 #endif 4197 4198 local int huft_build(b, n, s, d, e, t, m, zs) 4199 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ 4200 uInt n; /* number of codes (assumed <= N_MAX) */ 4201 uInt s; /* number of simple-valued codes (0..s-1) */ 4202 const uIntf *d; /* list of base values for non-simple codes */ 4203 const uIntf *e; /* list of extra bits for non-simple codes */ 4204 inflate_huft * FAR *t; /* result: starting table */ 4205 uIntf *m; /* maximum lookup bits, returns actual */ 4206 z_streamp zs; /* for zalloc function */ 4207 /* Given a list of code lengths and a maximum table size, make a set of 4208 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 4209 if the given code set is incomplete (the tables are still built in this 4210 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of 4211 lengths), or Z_MEM_ERROR if not enough memory. */ 4212 { 4213 4214 uInt a; /* counter for codes of length k */ 4215 uInt c[BMAX+1]; /* bit length count table */ 4216 uInt f; /* i repeats in table every f entries */ 4217 int g; /* maximum code length */ 4218 int h; /* table level */ 4219 uInt i; /* counter, current code */ 4220 uInt j; /* counter */ 4221 int k; /* number of bits in current code */ 4222 int l; /* bits per table (returned in m) */ 4223 uIntf *p; /* pointer into c[], b[], or v[] */ 4224 inflate_huft *q; /* points to current table */ 4225 struct inflate_huft_s r; /* table entry for structure assignment */ 4226 inflate_huft *u[BMAX]; /* table stack */ 4227 uInt v[N_MAX]; /* values in order of bit length */ 4228 int w; /* bits before this table == (l * h) */ 4229 uInt x[BMAX+1]; /* bit offsets, then code stack */ 4230 uIntf *xp; /* pointer into x */ 4231 int y; /* number of dummy codes added */ 4232 uInt z; /* number of entries in current table */ 4233 4234 4235 /* Generate counts for each bit length */ 4236 p = c; 4237 #define C0 *p++ = 0; 4238 #define C2 C0 C0 C0 C0 4239 #define C4 C2 C2 C2 C2 4240 C4 /* clear c[]--assume BMAX+1 is 16 */ 4241 p = b; i = n; 4242 do { 4243 c[*p++]++; /* assume all entries <= BMAX */ 4244 } while (--i); 4245 if (c[0] == n) /* null input--all zero length codes */ 4246 { 4247 *t = (inflate_huft *)Z_NULL; 4248 *m = 0; 4249 return Z_OK; 4250 } 4251 4252 4253 /* Find minimum and maximum length, bound *m by those */ 4254 l = *m; 4255 for (j = 1; j <= BMAX; j++) 4256 if (c[j]) 4257 break; 4258 k = j; /* minimum code length */ 4259 if ((uInt)l < j) 4260 l = j; 4261 for (i = BMAX; i; i--) 4262 if (c[i]) 4263 break; 4264 g = i; /* maximum code length */ 4265 if ((uInt)l > i) 4266 l = i; 4267 *m = l; 4268 4269 4270 /* Adjust last length count to fill out codes, if needed */ 4271 for (y = 1 << j; j < i; j++, y <<= 1) 4272 if ((y -= c[j]) < 0) 4273 return Z_DATA_ERROR; 4274 if ((y -= c[i]) < 0) 4275 return Z_DATA_ERROR; 4276 c[i] += y; 4277 4278 4279 /* Generate starting offsets into the value table for each length */ 4280 x[1] = j = 0; 4281 p = c + 1; xp = x + 2; 4282 while (--i) { /* note that i == g from above */ 4283 *xp++ = (j += *p++); 4284 } 4285 4286 4287 /* Make a table of values in order of bit lengths */ 4288 p = b; i = 0; 4289 do { 4290 if ((j = *p++) != 0) 4291 v[x[j]++] = i; 4292 } while (++i < n); 4293 n = x[g]; /* set n to length of v */ 4294 4295 4296 /* Generate the Huffman codes and for each, make the table entries */ 4297 x[0] = i = 0; /* first Huffman code is zero */ 4298 p = v; /* grab values in bit order */ 4299 h = -1; /* no tables yet--level -1 */ 4300 w = -l; /* bits decoded == (l * h) */ 4301 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 4302 q = (inflate_huft *)Z_NULL; /* ditto */ 4303 z = 0; /* ditto */ 4304 4305 /* go through the bit lengths (k already is bits in shortest code) */ 4306 for (; k <= g; k++) 4307 { 4308 a = c[k]; 4309 while (a--) 4310 { 4311 /* here i is the Huffman code of length k bits for value *p */ 4312 /* make tables up to required level */ 4313 while (k > w + l) 4314 { 4315 h++; 4316 w += l; /* previous table always l bits */ 4317 4318 /* compute minimum size table less than or equal to l bits */ 4319 z = g - w; 4320 z = z > (uInt)l ? l : z; /* table size upper limit */ 4321 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 4322 { /* too few codes for k-w bit table */ 4323 f -= a + 1; /* deduct codes from patterns left */ 4324 xp = c + k; 4325 if (j < z) 4326 while (++j < z) /* try smaller tables up to z bits */ 4327 { 4328 if ((f <<= 1) <= *++xp) 4329 break; /* enough codes to use up j bits */ 4330 f -= *xp; /* else deduct codes from patterns */ 4331 } 4332 } 4333 z = 1 << j; /* table entries for j-bit table */ 4334 4335 /* allocate and link in new table */ 4336 if ((q = (inflate_huft *)ZALLOC 4337 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 4338 { 4339 if (h) 4340 inflate_trees_free(u[0], zs); 4341 return Z_MEM_ERROR; /* not enough memory */ 4342 } 4343 #ifdef DEBUG_ZLIB 4344 inflate_hufts += z + 1; 4345 #endif 4346 *t = q + 1; /* link to list for huft_free() */ 4347 *(t = &(q->next)) = Z_NULL; 4348 u[h] = ++q; /* table starts after link */ 4349 4350 /* connect to last table, if there is one */ 4351 if (h) 4352 { 4353 x[h] = i; /* save pattern for backing up */ 4354 r.bits = (Byte)l; /* bits to dump before this table */ 4355 r.exop = (Byte)j; /* bits in this table */ 4356 r.next = q; /* pointer to this table */ 4357 j = i >> (w - l); /* (get around Turbo C bug) */ 4358 u[h-1][j] = r; /* connect to last table */ 4359 } 4360 } 4361 4362 /* set up table entry in r */ 4363 r.bits = (Byte)(k - w); 4364 if (p >= v + n) 4365 r.exop = 128 + 64; /* out of values--invalid code */ 4366 else if (*p < s) 4367 { 4368 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 4369 r.base = *p++; /* simple code is just the value */ 4370 } 4371 else 4372 { 4373 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ 4374 r.base = d[*p++ - s]; 4375 } 4376 4377 /* fill code-like entries with r */ 4378 f = 1 << (k - w); 4379 for (j = i >> w; j < z; j += f) 4380 q[j] = r; 4381 4382 /* backwards increment the k-bit code i */ 4383 for (j = 1 << (k - 1); i & j; j >>= 1) 4384 i ^= j; 4385 i ^= j; 4386 4387 /* backup over finished tables */ 4388 while ((i & ((1 << w) - 1)) != x[h]) 4389 { 4390 h--; /* don't need to update q */ 4391 w -= l; 4392 } 4393 } 4394 } 4395 4396 4397 /* Return Z_BUF_ERROR if we were given an incomplete table */ 4398 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 4399 } 4400 4401 4402 int inflate_trees_bits(c, bb, tb, z) 4403 uIntf *c; /* 19 code lengths */ 4404 uIntf *bb; /* bits tree desired/actual depth */ 4405 inflate_huft * FAR *tb; /* bits tree result */ 4406 z_streamp z; /* for zfree function */ 4407 { 4408 int r; 4409 4410 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 4411 if (r == Z_DATA_ERROR) 4412 z->msg = (char*)"oversubscribed dynamic bit lengths tree"; 4413 else if (r == Z_BUF_ERROR || *bb == 0) 4414 { 4415 inflate_trees_free(*tb, z); 4416 z->msg = (char*)"incomplete dynamic bit lengths tree"; 4417 r = Z_DATA_ERROR; 4418 } 4419 return r; 4420 } 4421 4422 4423 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) 4424 uInt nl; /* number of literal/length codes */ 4425 uInt nd; /* number of distance codes */ 4426 uIntf *c; /* that many (total) code lengths */ 4427 uIntf *bl; /* literal desired/actual bit depth */ 4428 uIntf *bd; /* distance desired/actual bit depth */ 4429 inflate_huft * FAR *tl; /* literal/length tree result */ 4430 inflate_huft * FAR *td; /* distance tree result */ 4431 z_streamp z; /* for zfree function */ 4432 { 4433 int r; 4434 4435 /* build literal/length tree */ 4436 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); 4437 if (r != Z_OK || *bl == 0) 4438 { 4439 if (r == Z_DATA_ERROR) 4440 z->msg = (char*)"oversubscribed literal/length tree"; 4441 else if (r != Z_MEM_ERROR) 4442 { 4443 inflate_trees_free(*tl, z); 4444 z->msg = (char*)"incomplete literal/length tree"; 4445 r = Z_DATA_ERROR; 4446 } 4447 return r; 4448 } 4449 4450 /* build distance tree */ 4451 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); 4452 if (r != Z_OK || (*bd == 0 && nl > 257)) 4453 { 4454 if (r == Z_DATA_ERROR) 4455 z->msg = (char*)"oversubscribed distance tree"; 4456 else if (r == Z_BUF_ERROR) { 4457 #ifdef PKZIP_BUG_WORKAROUND 4458 r = Z_OK; 4459 } 4460 #else 4461 inflate_trees_free(*td, z); 4462 z->msg = (char*)"incomplete distance tree"; 4463 r = Z_DATA_ERROR; 4464 } 4465 else if (r != Z_MEM_ERROR) 4466 { 4467 z->msg = (char*)"empty distance tree with lengths"; 4468 r = Z_DATA_ERROR; 4469 } 4470 inflate_trees_free(*tl, z); 4471 return r; 4472 #endif 4473 } 4474 4475 /* done */ 4476 return Z_OK; 4477 } 4478 4479 4480 /* build fixed tables only once--keep them here */ 4481 local int fixed_built = 0; 4482 #define FIXEDH 530 /* number of hufts used by fixed tables */ 4483 local inflate_huft fixed_mem[FIXEDH]; 4484 local uInt fixed_bl; 4485 local uInt fixed_bd; 4486 local inflate_huft *fixed_tl; 4487 local inflate_huft *fixed_td; 4488 4489 4490 local voidpf falloc(q, n, s) 4491 voidpf q; /* opaque pointer */ 4492 uInt n; /* number of items */ 4493 uInt s; /* size of item */ 4494 { 4495 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, 4496 "inflate_trees falloc overflow"); 4497 *(intf *)q -= n+s-s; /* s-s to avoid warning */ 4498 return (voidpf)(fixed_mem + *(intf *)q); 4499 } 4500 4501 4502 int inflate_trees_fixed(bl, bd, tl, td) 4503 uIntf *bl; /* literal desired/actual bit depth */ 4504 uIntf *bd; /* distance desired/actual bit depth */ 4505 inflate_huft * FAR *tl; /* literal/length tree result */ 4506 inflate_huft * FAR *td; /* distance tree result */ 4507 { 4508 /* build fixed tables if not already (multiple overlapped executions ok) */ 4509 if (!fixed_built) 4510 { 4511 int k; /* temporary variable */ 4512 unsigned c[288]; /* length list for huft_build */ 4513 z_stream z; /* for falloc function */ 4514 int f = FIXEDH; /* number of hufts left in fixed_mem */ 4515 4516 /* set up fake z_stream for memory routines */ 4517 z.zalloc = falloc; 4518 z.zfree = Z_NULL; 4519 z.opaque = (voidpf)&f; 4520 4521 /* literal table */ 4522 for (k = 0; k < 144; k++) 4523 c[k] = 8; 4524 for (; k < 256; k++) 4525 c[k] = 9; 4526 for (; k < 280; k++) 4527 c[k] = 7; 4528 for (; k < 288; k++) 4529 c[k] = 8; 4530 fixed_bl = 7; 4531 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4532 4533 /* distance table */ 4534 for (k = 0; k < 30; k++) 4535 c[k] = 5; 4536 fixed_bd = 5; 4537 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4538 4539 /* done */ 4540 Assert(f == 0, "invalid build of fixed tables"); 4541 fixed_built = 1; 4542 } 4543 *bl = fixed_bl; 4544 *bd = fixed_bd; 4545 *tl = fixed_tl; 4546 *td = fixed_td; 4547 return Z_OK; 4548 } 4549 4550 4551 int inflate_trees_free(t, z) 4552 inflate_huft *t; /* table to free */ 4553 z_streamp z; /* for zfree function */ 4554 /* Free the malloc'ed tables built by huft_build(), which makes a linked 4555 list of the tables it made, with the links in a dummy first entry of 4556 each table. */ 4557 { 4558 inflate_huft *p, *q, *r; 4559 4560 /* Reverse linked list */ 4561 p = Z_NULL; 4562 q = t; 4563 while (q != Z_NULL) 4564 { 4565 r = (q - 1)->next; 4566 (q - 1)->next = p; 4567 p = q; 4568 q = r; 4569 } 4570 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4571 while (p != Z_NULL) 4572 { 4573 q = (--p)->next; 4574 ZFREE(z,p); 4575 p = q; 4576 } 4577 return Z_OK; 4578 } 4579 /* --- inftrees.c */ 4580 4581 /* +++ infcodes.c */ 4582 /* infcodes.c -- process literals and length/distance pairs 4583 * Copyright (C) 1995-1996 Mark Adler 4584 * For conditions of distribution and use, see copyright notice in zlib.h 4585 */ 4586 4587 /* #include "zutil.h" */ 4588 /* #include "inftrees.h" */ 4589 /* #include "infblock.h" */ 4590 /* #include "infcodes.h" */ 4591 /* #include "infutil.h" */ 4592 4593 /* +++ inffast.h */ 4594 /* inffast.h -- header to use inffast.c 4595 * Copyright (C) 1995-1996 Mark Adler 4596 * For conditions of distribution and use, see copyright notice in zlib.h 4597 */ 4598 4599 /* WARNING: this file should *not* be used by applications. It is 4600 part of the implementation of the compression library and is 4601 subject to change. Applications should only use zlib.h. 4602 */ 4603 4604 extern int inflate_fast OF(( 4605 uInt, 4606 uInt, 4607 inflate_huft *, 4608 inflate_huft *, 4609 inflate_blocks_statef *, 4610 z_streamp )); 4611 /* --- inffast.h */ 4612 4613 /* simplify the use of the inflate_huft type with some defines */ 4614 #define base more.Base 4615 #define next more.Next 4616 #define exop word.what.Exop 4617 #define bits word.what.Bits 4618 4619 /* inflate codes private state */ 4620 struct inflate_codes_state { 4621 4622 /* mode */ 4623 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4624 START, /* x: set up for LEN */ 4625 LEN, /* i: get length/literal/eob next */ 4626 LENEXT, /* i: getting length extra (have base) */ 4627 DIST, /* i: get distance next */ 4628 DISTEXT, /* i: getting distance extra */ 4629 COPY, /* o: copying bytes in window, waiting for space */ 4630 LIT, /* o: got literal, waiting for output space */ 4631 WASH, /* o: got eob, possibly still output waiting */ 4632 END, /* x: got eob and all data flushed */ 4633 BADCODE} /* x: got error */ 4634 mode; /* current inflate_codes mode */ 4635 4636 /* mode dependent information */ 4637 uInt len; 4638 union { 4639 struct { 4640 inflate_huft *tree; /* pointer into tree */ 4641 uInt need; /* bits needed */ 4642 } code; /* if LEN or DIST, where in tree */ 4643 uInt lit; /* if LIT, literal */ 4644 struct { 4645 uInt get; /* bits to get for extra */ 4646 uInt dist; /* distance back to copy from */ 4647 } copy; /* if EXT or COPY, where and how much */ 4648 } sub; /* submode */ 4649 4650 /* mode independent information */ 4651 Byte lbits; /* ltree bits decoded per branch */ 4652 Byte dbits; /* dtree bits decoder per branch */ 4653 inflate_huft *ltree; /* literal/length/eob tree */ 4654 inflate_huft *dtree; /* distance tree */ 4655 4656 }; 4657 4658 4659 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) 4660 uInt bl, bd; 4661 inflate_huft *tl; 4662 inflate_huft *td; /* need separate declaration for Borland C++ */ 4663 z_streamp z; 4664 { 4665 inflate_codes_statef *c; 4666 4667 if ((c = (inflate_codes_statef *) 4668 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4669 { 4670 c->mode = START; 4671 c->lbits = (Byte)bl; 4672 c->dbits = (Byte)bd; 4673 c->ltree = tl; 4674 c->dtree = td; 4675 Tracev((stderr, "inflate: codes new\n")); 4676 } 4677 return c; 4678 } 4679 4680 4681 int inflate_codes(s, z, r) 4682 inflate_blocks_statef *s; 4683 z_streamp z; 4684 int r; 4685 { 4686 uInt j; /* temporary storage */ 4687 inflate_huft *t; /* temporary pointer */ 4688 uInt e; /* extra bits or operation */ 4689 uLong b; /* bit buffer */ 4690 uInt k; /* bits in bit buffer */ 4691 Bytef *p; /* input data pointer */ 4692 uInt n; /* bytes available there */ 4693 Bytef *q; /* output window write pointer */ 4694 uInt m; /* bytes to end of window or read pointer */ 4695 Bytef *f; /* pointer to copy strings from */ 4696 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4697 4698 /* copy input/output information to locals (UPDATE macro restores) */ 4699 LOAD 4700 4701 /* process input and output based on current state */ 4702 while (1) switch (c->mode) 4703 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4704 case START: /* x: set up for LEN */ 4705 #ifndef SLOW 4706 if (m >= 258 && n >= 10) 4707 { 4708 UPDATE 4709 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4710 LOAD 4711 if (r != Z_OK) 4712 { 4713 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4714 break; 4715 } 4716 } 4717 #endif /* !SLOW */ 4718 c->sub.code.need = c->lbits; 4719 c->sub.code.tree = c->ltree; 4720 c->mode = LEN; 4721 case LEN: /* i: get length/literal/eob next */ 4722 j = c->sub.code.need; 4723 NEEDBITS(j) 4724 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4725 DUMPBITS(t->bits) 4726 e = (uInt)(t->exop); 4727 if (e == 0) /* literal */ 4728 { 4729 c->sub.lit = t->base; 4730 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4731 "inflate: literal '%c'\n" : 4732 "inflate: literal 0x%02x\n", t->base)); 4733 c->mode = LIT; 4734 break; 4735 } 4736 if (e & 16) /* length */ 4737 { 4738 c->sub.copy.get = e & 15; 4739 c->len = t->base; 4740 c->mode = LENEXT; 4741 break; 4742 } 4743 if ((e & 64) == 0) /* next table */ 4744 { 4745 c->sub.code.need = e; 4746 c->sub.code.tree = t->next; 4747 break; 4748 } 4749 if (e & 32) /* end of block */ 4750 { 4751 Tracevv((stderr, "inflate: end of block\n")); 4752 c->mode = WASH; 4753 break; 4754 } 4755 c->mode = BADCODE; /* invalid code */ 4756 z->msg = (char*)"invalid literal/length code"; 4757 r = Z_DATA_ERROR; 4758 LEAVE 4759 case LENEXT: /* i: getting length extra (have base) */ 4760 j = c->sub.copy.get; 4761 NEEDBITS(j) 4762 c->len += (uInt)b & inflate_mask[j]; 4763 DUMPBITS(j) 4764 c->sub.code.need = c->dbits; 4765 c->sub.code.tree = c->dtree; 4766 Tracevv((stderr, "inflate: length %u\n", c->len)); 4767 c->mode = DIST; 4768 case DIST: /* i: get distance next */ 4769 j = c->sub.code.need; 4770 NEEDBITS(j) 4771 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4772 DUMPBITS(t->bits) 4773 e = (uInt)(t->exop); 4774 if (e & 16) /* distance */ 4775 { 4776 c->sub.copy.get = e & 15; 4777 c->sub.copy.dist = t->base; 4778 c->mode = DISTEXT; 4779 break; 4780 } 4781 if ((e & 64) == 0) /* next table */ 4782 { 4783 c->sub.code.need = e; 4784 c->sub.code.tree = t->next; 4785 break; 4786 } 4787 c->mode = BADCODE; /* invalid code */ 4788 z->msg = (char*)"invalid distance code"; 4789 r = Z_DATA_ERROR; 4790 LEAVE 4791 case DISTEXT: /* i: getting distance extra */ 4792 j = c->sub.copy.get; 4793 NEEDBITS(j) 4794 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4795 DUMPBITS(j) 4796 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4797 c->mode = COPY; 4798 case COPY: /* o: copying bytes in window, waiting for space */ 4799 #ifndef __TURBOC__ /* Turbo C bug for following expression */ 4800 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4801 s->end - (c->sub.copy.dist - (q - s->window)) : 4802 q - c->sub.copy.dist; 4803 #else 4804 f = q - c->sub.copy.dist; 4805 if ((uInt)(q - s->window) < c->sub.copy.dist) 4806 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); 4807 #endif 4808 while (c->len) 4809 { 4810 NEEDOUT 4811 OUTBYTE(*f++) 4812 if (f == s->end) 4813 f = s->window; 4814 c->len--; 4815 } 4816 c->mode = START; 4817 break; 4818 case LIT: /* o: got literal, waiting for output space */ 4819 NEEDOUT 4820 OUTBYTE(c->sub.lit) 4821 c->mode = START; 4822 break; 4823 case WASH: /* o: got eob, possibly more output */ 4824 FLUSH 4825 if (s->read != s->write) 4826 LEAVE 4827 c->mode = END; 4828 case END: 4829 r = Z_STREAM_END; 4830 LEAVE 4831 case BADCODE: /* x: got error */ 4832 r = Z_DATA_ERROR; 4833 LEAVE 4834 default: 4835 r = Z_STREAM_ERROR; 4836 LEAVE 4837 } 4838 } 4839 4840 4841 void inflate_codes_free(c, z) 4842 inflate_codes_statef *c; 4843 z_streamp z; 4844 { 4845 ZFREE(z, c); 4846 Tracev((stderr, "inflate: codes free\n")); 4847 } 4848 /* --- infcodes.c */ 4849 4850 /* +++ infutil.c */ 4851 /* inflate_util.c -- data and routines common to blocks and codes 4852 * Copyright (C) 1995-1996 Mark Adler 4853 * For conditions of distribution and use, see copyright notice in zlib.h 4854 */ 4855 4856 /* #include "zutil.h" */ 4857 /* #include "infblock.h" */ 4858 /* #include "inftrees.h" */ 4859 /* #include "infcodes.h" */ 4860 /* #include "infutil.h" */ 4861 4862 #ifndef NO_DUMMY_DECL 4863 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4864 #endif 4865 4866 /* And'ing with mask[n] masks the lower n bits */ 4867 uInt inflate_mask[17] = { 4868 0x0000, 4869 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 4870 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 4871 }; 4872 4873 4874 /* copy as much as possible from the sliding window to the output area */ 4875 int inflate_flush(s, z, r) 4876 inflate_blocks_statef *s; 4877 z_streamp z; 4878 int r; 4879 { 4880 uInt n; 4881 Bytef *p; 4882 Bytef *q; 4883 4884 /* local copies of source and destination pointers */ 4885 p = z->next_out; 4886 q = s->read; 4887 4888 /* compute number of bytes to copy as far as end of window */ 4889 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4890 if (n > z->avail_out) n = z->avail_out; 4891 if (n && r == Z_BUF_ERROR) r = Z_OK; 4892 4893 /* update counters */ 4894 z->avail_out -= n; 4895 z->total_out += n; 4896 4897 /* update check information */ 4898 if (s->checkfn != Z_NULL) 4899 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4900 4901 /* copy as far as end of window */ 4902 if (p != Z_NULL) { 4903 zmemcpy(p, q, n); 4904 p += n; 4905 } 4906 q += n; 4907 4908 /* see if more to copy at beginning of window */ 4909 if (q == s->end) 4910 { 4911 /* wrap pointers */ 4912 q = s->window; 4913 if (s->write == s->end) 4914 s->write = s->window; 4915 4916 /* compute bytes to copy */ 4917 n = (uInt)(s->write - q); 4918 if (n > z->avail_out) n = z->avail_out; 4919 if (n && r == Z_BUF_ERROR) r = Z_OK; 4920 4921 /* update counters */ 4922 z->avail_out -= n; 4923 z->total_out += n; 4924 4925 /* update check information */ 4926 if (s->checkfn != Z_NULL) 4927 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4928 4929 /* copy */ 4930 if (p != Z_NULL) { 4931 zmemcpy(p, q, n); 4932 p += n; 4933 } 4934 q += n; 4935 } 4936 4937 /* update pointers */ 4938 z->next_out = p; 4939 s->read = q; 4940 4941 /* done */ 4942 return r; 4943 } 4944 /* --- infutil.c */ 4945 4946 /* +++ inffast.c */ 4947 /* inffast.c -- process literals and length/distance pairs fast 4948 * Copyright (C) 1995-1996 Mark Adler 4949 * For conditions of distribution and use, see copyright notice in zlib.h 4950 */ 4951 4952 /* #include "zutil.h" */ 4953 /* #include "inftrees.h" */ 4954 /* #include "infblock.h" */ 4955 /* #include "infcodes.h" */ 4956 /* #include "infutil.h" */ 4957 /* #include "inffast.h" */ 4958 4959 #ifndef NO_DUMMY_DECL 4960 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4961 #endif 4962 4963 /* simplify the use of the inflate_huft type with some defines */ 4964 #define base more.Base 4965 #define next more.Next 4966 #define exop word.what.Exop 4967 #define bits word.what.Bits 4968 4969 /* macros for bit input with no checking and for returning unused bytes */ 4970 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4971 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4972 4973 /* Called with number of bytes left to write in window at least 258 4974 (the maximum string length) and number of input bytes available 4975 at least ten. The ten bytes are six bytes for the longest length/ 4976 distance pair plus four bytes for overloading the bit buffer. */ 4977 4978 int inflate_fast(bl, bd, tl, td, s, z) 4979 uInt bl, bd; 4980 inflate_huft *tl; 4981 inflate_huft *td; /* need separate declaration for Borland C++ */ 4982 inflate_blocks_statef *s; 4983 z_streamp z; 4984 { 4985 inflate_huft *t; /* temporary pointer */ 4986 uInt e; /* extra bits or operation */ 4987 uLong b; /* bit buffer */ 4988 uInt k; /* bits in bit buffer */ 4989 Bytef *p; /* input data pointer */ 4990 uInt n; /* bytes available there */ 4991 Bytef *q; /* output window write pointer */ 4992 uInt m; /* bytes to end of window or read pointer */ 4993 uInt ml; /* mask for literal/length tree */ 4994 uInt md; /* mask for distance tree */ 4995 uInt c; /* bytes to copy */ 4996 uInt d; /* distance back to copy from */ 4997 Bytef *r; /* copy source pointer */ 4998 4999 /* load input, output, bit values */ 5000 LOAD 5001 5002 /* initialize masks */ 5003 ml = inflate_mask[bl]; 5004 md = inflate_mask[bd]; 5005 5006 /* do until not enough input or output space for fast loop */ 5007 do { /* assume called with m >= 258 && n >= 10 */ 5008 /* get literal/length code */ 5009 GRABBITS(20) /* max bits for literal/length code */ 5010 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 5011 { 5012 DUMPBITS(t->bits) 5013 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5014 "inflate: * literal '%c'\n" : 5015 "inflate: * literal 0x%02x\n", t->base)); 5016 *q++ = (Byte)t->base; 5017 m--; 5018 continue; 5019 } 5020 do { 5021 DUMPBITS(t->bits) 5022 if (e & 16) 5023 { 5024 /* get extra bits for length */ 5025 e &= 15; 5026 c = t->base + ((uInt)b & inflate_mask[e]); 5027 DUMPBITS(e) 5028 Tracevv((stderr, "inflate: * length %u\n", c)); 5029 5030 /* decode distance base of block to copy */ 5031 GRABBITS(15); /* max bits for distance code */ 5032 e = (t = td + ((uInt)b & md))->exop; 5033 do { 5034 DUMPBITS(t->bits) 5035 if (e & 16) 5036 { 5037 /* get extra bits to add to distance base */ 5038 e &= 15; 5039 GRABBITS(e) /* get extra bits (up to 13) */ 5040 d = t->base + ((uInt)b & inflate_mask[e]); 5041 DUMPBITS(e) 5042 Tracevv((stderr, "inflate: * distance %u\n", d)); 5043 5044 /* do the copy */ 5045 m -= c; 5046 if ((uInt)(q - s->window) >= d) /* offset before dest */ 5047 { /* just copy */ 5048 r = q - d; 5049 *q++ = *r++; c--; /* minimum count is three, */ 5050 *q++ = *r++; c--; /* so unroll loop a little */ 5051 } 5052 else /* else offset after destination */ 5053 { 5054 e = d - (uInt)(q - s->window); /* bytes from offset to end */ 5055 r = s->end - e; /* pointer to offset */ 5056 if (c > e) /* if source crosses, */ 5057 { 5058 c -= e; /* copy to end of window */ 5059 do { 5060 *q++ = *r++; 5061 } while (--e); 5062 r = s->window; /* copy rest from start of window */ 5063 } 5064 } 5065 do { /* copy all or what's left */ 5066 *q++ = *r++; 5067 } while (--c); 5068 break; 5069 } 5070 else if ((e & 64) == 0) 5071 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 5072 else 5073 { 5074 z->msg = (char*)"invalid distance code"; 5075 UNGRAB 5076 UPDATE 5077 return Z_DATA_ERROR; 5078 } 5079 } while (1); 5080 break; 5081 } 5082 if ((e & 64) == 0) 5083 { 5084 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 5085 { 5086 DUMPBITS(t->bits) 5087 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5088 "inflate: * literal '%c'\n" : 5089 "inflate: * literal 0x%02x\n", t->base)); 5090 *q++ = (Byte)t->base; 5091 m--; 5092 break; 5093 } 5094 } 5095 else if (e & 32) 5096 { 5097 Tracevv((stderr, "inflate: * end of block\n")); 5098 UNGRAB 5099 UPDATE 5100 return Z_STREAM_END; 5101 } 5102 else 5103 { 5104 z->msg = (char*)"invalid literal/length code"; 5105 UNGRAB 5106 UPDATE 5107 return Z_DATA_ERROR; 5108 } 5109 } while (1); 5110 } while (m >= 258 && n >= 10); 5111 5112 /* not enough input or output--restore pointers and return */ 5113 UNGRAB 5114 UPDATE 5115 return Z_OK; 5116 } 5117 /* --- inffast.c */ 5118 5119 /* +++ zutil.c */ 5120 /* zutil.c -- target dependent utility functions for the compression library 5121 * Copyright (C) 1995-1996 Jean-loup Gailly. 5122 * For conditions of distribution and use, see copyright notice in zlib.h 5123 */ 5124 5125 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ 5126 5127 #ifdef DEBUG_ZLIB 5128 #include <stdio.h> 5129 #endif 5130 5131 /* #include "zutil.h" */ 5132 5133 #ifndef NO_DUMMY_DECL 5134 struct internal_state {int dummy;}; /* for buggy compilers */ 5135 #endif 5136 5137 #ifndef STDC 5138 extern void exit OF((int)); 5139 #endif 5140 5141 static const char *z_errmsg[10] = { 5142 "need dictionary", /* Z_NEED_DICT 2 */ 5143 "stream end", /* Z_STREAM_END 1 */ 5144 "", /* Z_OK 0 */ 5145 "file error", /* Z_ERRNO (-1) */ 5146 "stream error", /* Z_STREAM_ERROR (-2) */ 5147 "data error", /* Z_DATA_ERROR (-3) */ 5148 "insufficient memory", /* Z_MEM_ERROR (-4) */ 5149 "buffer error", /* Z_BUF_ERROR (-5) */ 5150 "incompatible version",/* Z_VERSION_ERROR (-6) */ 5151 ""}; 5152 5153 5154 const char *zlibVersion() 5155 { 5156 return ZLIB_VERSION; 5157 } 5158 5159 #ifdef DEBUG_ZLIB 5160 void z_error (m) 5161 char *m; 5162 { 5163 fprintf(stderr, "%s\n", m); 5164 exit(1); 5165 } 5166 #endif 5167 5168 #ifndef HAVE_MEMCPY 5169 5170 void zmemcpy(dest, source, len) 5171 Bytef* dest; 5172 Bytef* source; 5173 uInt len; 5174 { 5175 if (len == 0) return; 5176 do { 5177 *dest++ = *source++; /* ??? to be unrolled */ 5178 } while (--len != 0); 5179 } 5180 5181 int zmemcmp(s1, s2, len) 5182 Bytef* s1; 5183 Bytef* s2; 5184 uInt len; 5185 { 5186 uInt j; 5187 5188 for (j = 0; j < len; j++) { 5189 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 5190 } 5191 return 0; 5192 } 5193 5194 void zmemzero(dest, len) 5195 Bytef* dest; 5196 uInt len; 5197 { 5198 if (len == 0) return; 5199 do { 5200 *dest++ = 0; /* ??? to be unrolled */ 5201 } while (--len != 0); 5202 } 5203 #endif 5204 5205 #ifdef __TURBOC__ 5206 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 5207 /* Small and medium model in Turbo C are for now limited to near allocation 5208 * with reduced MAX_WBITS and MAX_MEM_LEVEL 5209 */ 5210 # define MY_ZCALLOC 5211 5212 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes 5213 * and farmalloc(64K) returns a pointer with an offset of 8, so we 5214 * must fix the pointer. Warning: the pointer must be put back to its 5215 * original form in order to free it, use zcfree(). 5216 */ 5217 5218 #define MAX_PTR 10 5219 /* 10*64K = 640K */ 5220 5221 local int next_ptr = 0; 5222 5223 typedef struct ptr_table_s { 5224 voidpf org_ptr; 5225 voidpf new_ptr; 5226 } ptr_table; 5227 5228 local ptr_table table[MAX_PTR]; 5229 /* This table is used to remember the original form of pointers 5230 * to large buffers (64K). Such pointers are normalized with a zero offset. 5231 * Since MSDOS is not a preemptive multitasking OS, this table is not 5232 * protected from concurrent access. This hack doesn't work anyway on 5233 * a protected system like OS/2. Use Microsoft C instead. 5234 */ 5235 5236 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5237 { 5238 voidpf buf = opaque; /* just to make some compilers happy */ 5239 ulg bsize = (ulg)items*size; 5240 5241 /* If we allocate less than 65520 bytes, we assume that farmalloc 5242 * will return a usable pointer which doesn't have to be normalized. 5243 */ 5244 if (bsize < 65520L) { 5245 buf = farmalloc(bsize); 5246 if (*(ush*)&buf != 0) return buf; 5247 } else { 5248 buf = farmalloc(bsize + 16L); 5249 } 5250 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 5251 table[next_ptr].org_ptr = buf; 5252 5253 /* Normalize the pointer to seg:0 */ 5254 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 5255 *(ush*)&buf = 0; 5256 table[next_ptr++].new_ptr = buf; 5257 return buf; 5258 } 5259 5260 void zcfree (voidpf opaque, voidpf ptr) 5261 { 5262 int n; 5263 if (*(ush*)&ptr != 0) { /* object < 64K */ 5264 farfree(ptr); 5265 return; 5266 } 5267 /* Find the original pointer */ 5268 for (n = 0; n < next_ptr; n++) { 5269 if (ptr != table[n].new_ptr) continue; 5270 5271 farfree(table[n].org_ptr); 5272 while (++n < next_ptr) { 5273 table[n-1] = table[n]; 5274 } 5275 next_ptr--; 5276 return; 5277 } 5278 ptr = opaque; /* just to make some compilers happy */ 5279 Assert(0, "zcfree: ptr not found"); 5280 } 5281 #endif 5282 #endif /* __TURBOC__ */ 5283 5284 5285 #if defined(M_I86) && !defined(__32BIT__) 5286 /* Microsoft C in 16-bit mode */ 5287 5288 # define MY_ZCALLOC 5289 5290 #if (!defined(_MSC_VER) || (_MSC_VER < 600)) 5291 # define _halloc halloc 5292 # define _hfree hfree 5293 #endif 5294 5295 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size) 5296 { 5297 if (opaque) opaque = 0; /* to make compiler happy */ 5298 return _halloc((long)items, size); 5299 } 5300 5301 void zcfree (voidpf opaque, voidpf ptr) 5302 { 5303 if (opaque) opaque = 0; /* to make compiler happy */ 5304 _hfree(ptr); 5305 } 5306 5307 #endif /* MSC */ 5308 5309 5310 #ifndef MY_ZCALLOC /* Any system without a special alloc function */ 5311 5312 #ifndef STDC 5313 extern voidp calloc OF((uInt items, uInt size)); 5314 extern void free OF((voidpf ptr)); 5315 #endif 5316 5317 voidpf zcalloc (opaque, items, size) 5318 voidpf opaque; 5319 unsigned items; 5320 unsigned size; 5321 { 5322 if (opaque) items += size - size; /* make compiler happy */ 5323 return (voidpf)calloc(items, size); 5324 } 5325 5326 void zcfree (opaque, ptr) 5327 voidpf opaque; 5328 voidpf ptr; 5329 { 5330 free(ptr); 5331 if (opaque) return; /* make compiler happy */ 5332 } 5333 5334 #endif /* MY_ZCALLOC */ 5335 /* --- zutil.c */ 5336 5337 /* +++ adler32.c */ 5338 /* adler32.c -- compute the Adler-32 checksum of a data stream 5339 * Copyright (C) 1995-1996 Mark Adler 5340 * For conditions of distribution and use, see copyright notice in zlib.h 5341 */ 5342 5343 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ 5344 5345 /* #include "zlib.h" */ 5346 5347 #define BASE 65521L /* largest prime smaller than 65536 */ 5348 #define NMAX 5552 5349 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 5350 5351 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;} 5352 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1); 5353 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2); 5354 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); 5355 #define DO16(buf) DO8(buf,0); DO8(buf,8); 5356 5357 /* ========================================================================= */ 5358 uLong adler32(adler, buf, len) 5359 uLong adler; 5360 const Bytef *buf; 5361 uInt len; 5362 { 5363 unsigned long s1 = adler & 0xffff; 5364 unsigned long s2 = (adler >> 16) & 0xffff; 5365 int k; 5366 5367 if (buf == Z_NULL) return 1L; 5368 5369 while (len > 0) { 5370 k = len < NMAX ? len : NMAX; 5371 len -= k; 5372 while (k >= 16) { 5373 DO16(buf); 5374 buf += 16; 5375 k -= 16; 5376 } 5377 if (k != 0) do { 5378 s1 += *buf++; 5379 s2 += s1; 5380 } while (--k); 5381 s1 %= BASE; 5382 s2 %= BASE; 5383 } 5384 return (s2 << 16) | s1; 5385 } 5386 /* --- adler32.c */ 5387