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 1.9 2005/12/11 13:28:53 swildner Exp $ 15 */ 16 17 /* 18 * ==FILEVERSION 971210== 19 * 20 * This marker is used by the Linux installation script to determine 21 * whether an up-to-date version of this file is already installed. 22 */ 23 24 #define NO_DUMMY_DECL 25 #define NO_ZCFUNCS 26 #define MY_ZCALLOC 27 28 #if (defined(__DragonFly__) || defined(__FreeBSD__)) && defined(_KERNEL) 29 #define inflate inflate_ppp /* FreeBSD already has an inflate :-( */ 30 #endif 31 32 33 /* +++ zutil.h */ 34 /* zutil.h -- internal interface and configuration of the compression library 35 * Copyright (C) 1995-1996 Jean-loup Gailly. 36 * For conditions of distribution and use, see copyright notice in zlib.h 37 */ 38 39 /* WARNING: this file should *not* be used by applications. It is 40 part of the implementation of the compression library and is 41 subject to change. Applications should only use zlib.h. 42 */ 43 44 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */ 45 46 #ifndef _Z_UTIL_H 47 #define _Z_UTIL_H 48 49 #ifdef _KERNEL 50 #include <net/zlib.h> 51 #else 52 #include "zlib.h" 53 #endif 54 55 #ifdef _KERNEL 56 /* Assume this is a *BSD or SVR4 kernel */ 57 #include <sys/param.h> 58 #include <sys/types.h> 59 #include <sys/time.h> 60 #include <sys/systm.h> 61 # 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 728 deflateInit_(z_streamp strm, int level, const char * version, 729 int stream_size) 730 { 731 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 732 Z_DEFAULT_STRATEGY, version, stream_size); 733 /* To do: ignore strm->next_in if we use it as window */ 734 } 735 736 /* ========================================================================= */ 737 int 738 deflateInit2_(z_streamp strm, int level, int method, int windowBits, 739 int memLevel, int strategy, const char *version, 740 int stream_size) 741 { 742 deflate_state *s; 743 int noheader = 0; 744 static char* my_version = ZLIB_VERSION; 745 746 ushf *overlay; 747 /* We overlay pending_buf and d_buf+l_buf. This works since the average 748 * output size for (length,distance) codes is <= 24 bits. 749 */ 750 751 if (version == Z_NULL || version[0] != my_version[0] || 752 stream_size != sizeof(z_stream)) { 753 return Z_VERSION_ERROR; 754 } 755 if (strm == Z_NULL) return Z_STREAM_ERROR; 756 757 strm->msg = Z_NULL; 758 #ifndef NO_ZCFUNCS 759 if (strm->zalloc == Z_NULL) { 760 strm->zalloc = zcalloc; 761 strm->opaque = (voidpf)0; 762 } 763 if (strm->zfree == Z_NULL) strm->zfree = zcfree; 764 #endif 765 766 if (level == Z_DEFAULT_COMPRESSION) level = 6; 767 768 if (windowBits < 0) { /* undocumented feature: suppress zlib header */ 769 noheader = 1; 770 windowBits = -windowBits; 771 } 772 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED || 773 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 || 774 strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 775 return Z_STREAM_ERROR; 776 } 777 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); 778 if (s == Z_NULL) return Z_MEM_ERROR; 779 strm->state = (struct internal_state FAR *)s; 780 s->strm = strm; 781 782 s->noheader = noheader; 783 s->w_bits = windowBits; 784 s->w_size = 1 << s->w_bits; 785 s->w_mask = s->w_size - 1; 786 787 s->hash_bits = memLevel + 7; 788 s->hash_size = 1 << s->hash_bits; 789 s->hash_mask = s->hash_size - 1; 790 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); 791 792 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); 793 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); 794 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); 795 796 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ 797 798 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2); 799 s->pending_buf = (uchf *) overlay; 800 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L); 801 802 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || 803 s->pending_buf == Z_NULL) { 804 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR); 805 deflateEnd (strm); 806 return Z_MEM_ERROR; 807 } 808 s->d_buf = overlay + s->lit_bufsize/sizeof(ush); 809 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize; 810 811 s->level = level; 812 s->strategy = strategy; 813 s->method = (Byte)method; 814 815 return deflateReset(strm); 816 } 817 818 /* ========================================================================= */ 819 int 820 deflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength) 821 { 822 deflate_state *s; 823 uInt length = dictLength; 824 uInt n; 825 IPos hash_head = 0; 826 827 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL) 828 return Z_STREAM_ERROR; 829 830 s = (deflate_state *) strm->state; 831 if (s->status != INIT_STATE) return Z_STREAM_ERROR; 832 833 strm->adler = adler32(strm->adler, dictionary, dictLength); 834 835 if (length < MIN_MATCH) return Z_OK; 836 if (length > MAX_DIST(s)) { 837 length = MAX_DIST(s); 838 #ifndef USE_DICT_HEAD 839 dictionary += dictLength - length; /* use the tail of the dictionary */ 840 #endif 841 } 842 zmemcpy((charf *)s->window, dictionary, length); 843 s->strstart = length; 844 s->block_start = (long)length; 845 846 /* Insert all strings in the hash table (except for the last two bytes). 847 * s->lookahead stays null, so s->ins_h will be recomputed at the next 848 * call of fill_window. 849 */ 850 s->ins_h = s->window[0]; 851 UPDATE_HASH(s, s->ins_h, s->window[1]); 852 for (n = 0; n <= length - MIN_MATCH; n++) { 853 INSERT_STRING(s, n, hash_head); 854 } 855 if (hash_head) hash_head = 0; /* to make compiler happy */ 856 return Z_OK; 857 } 858 859 /* ========================================================================= */ 860 int 861 deflateReset(z_streamp strm) 862 { 863 deflate_state *s; 864 865 if (strm == Z_NULL || strm->state == Z_NULL || 866 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; 867 868 strm->total_in = strm->total_out = 0; 869 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ 870 strm->data_type = Z_UNKNOWN; 871 872 s = (deflate_state *)strm->state; 873 s->pending = 0; 874 s->pending_out = s->pending_buf; 875 876 if (s->noheader < 0) { 877 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ 878 } 879 s->status = s->noheader ? BUSY_STATE : INIT_STATE; 880 strm->adler = 1; 881 s->last_flush = Z_NO_FLUSH; 882 883 _tr_init(s); 884 lm_init(s); 885 886 return Z_OK; 887 } 888 889 /* ========================================================================= */ 890 int 891 deflateParams(z_streamp strm, int level, int strategy) 892 { 893 deflate_state *s; 894 compress_func func; 895 int err = Z_OK; 896 897 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 898 s = (deflate_state *) strm->state; 899 900 if (level == Z_DEFAULT_COMPRESSION) { 901 level = 6; 902 } 903 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) { 904 return Z_STREAM_ERROR; 905 } 906 func = configuration_table[s->level].func; 907 908 if (func != configuration_table[level].func && strm->total_in != 0) { 909 /* Flush the last buffer: */ 910 err = deflate(strm, Z_PARTIAL_FLUSH); 911 } 912 if (s->level != level) { 913 s->level = level; 914 s->max_lazy_match = configuration_table[level].max_lazy; 915 s->good_match = configuration_table[level].good_length; 916 s->nice_match = configuration_table[level].nice_length; 917 s->max_chain_length = configuration_table[level].max_chain; 918 } 919 s->strategy = strategy; 920 return err; 921 } 922 923 /* ========================================================================= 924 * Put a short in the pending buffer. The 16-bit value is put in MSB order. 925 * IN assertion: the stream state is correct and there is enough room in 926 * pending_buf. 927 */ 928 local void 929 putShortMSB(deflate_state *s, uInt b) 930 { 931 put_byte(s, (Byte)(b >> 8)); 932 put_byte(s, (Byte)(b & 0xff)); 933 } 934 935 /* ========================================================================= 936 * Flush as much pending output as possible. All deflate() output goes 937 * through this function so some applications may wish to modify it 938 * to avoid allocating a large strm->next_out buffer and copying into it. 939 * (See also read_buf()). 940 */ 941 local void 942 flush_pending(z_streamp strm) 943 { 944 deflate_state *s = (deflate_state *) strm->state; 945 unsigned len = s->pending; 946 947 if (len > strm->avail_out) len = strm->avail_out; 948 if (len == 0) return; 949 950 if (strm->next_out != Z_NULL) { 951 zmemcpy(strm->next_out, s->pending_out, len); 952 strm->next_out += len; 953 } 954 s->pending_out += len; 955 strm->total_out += len; 956 strm->avail_out -= len; 957 s->pending -= len; 958 if (s->pending == 0) { 959 s->pending_out = s->pending_buf; 960 } 961 } 962 963 /* ========================================================================= */ 964 int 965 deflate(z_streamp strm, int flush) 966 { 967 int old_flush; /* value of flush param for previous deflate call */ 968 deflate_state *s; 969 970 if (strm == Z_NULL || strm->state == Z_NULL || 971 flush > Z_FINISH || flush < 0) { 972 return Z_STREAM_ERROR; 973 } 974 s = (deflate_state *) strm->state; 975 976 if ((strm->next_in == Z_NULL && strm->avail_in != 0) || 977 (s->status == FINISH_STATE && flush != Z_FINISH)) { 978 ERR_RETURN(strm, Z_STREAM_ERROR); 979 } 980 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); 981 982 s->strm = strm; /* just in case */ 983 old_flush = s->last_flush; 984 s->last_flush = flush; 985 986 /* Write the zlib header */ 987 if (s->status == INIT_STATE) { 988 989 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8; 990 uInt level_flags = (s->level-1) >> 1; 991 992 if (level_flags > 3) level_flags = 3; 993 header |= (level_flags << 6); 994 if (s->strstart != 0) header |= PRESET_DICT; 995 header += 31 - (header % 31); 996 997 s->status = BUSY_STATE; 998 putShortMSB(s, header); 999 1000 /* Save the adler32 of the preset dictionary: */ 1001 if (s->strstart != 0) { 1002 putShortMSB(s, (uInt)(strm->adler >> 16)); 1003 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1004 } 1005 strm->adler = 1L; 1006 } 1007 1008 /* Flush as much pending output as possible */ 1009 if (s->pending != 0) { 1010 flush_pending(strm); 1011 if (strm->avail_out == 0) { 1012 /* Since avail_out is 0, deflate will be called again with 1013 * more output space, but possibly with both pending and 1014 * avail_in equal to zero. There won't be anything to do, 1015 * but this is not an error situation so make sure we 1016 * return OK instead of BUF_ERROR at next call of deflate: 1017 */ 1018 s->last_flush = -1; 1019 return Z_OK; 1020 } 1021 1022 /* Make sure there is something to do and avoid duplicate consecutive 1023 * flushes. For repeated and useless calls with Z_FINISH, we keep 1024 * returning Z_STREAM_END instead of Z_BUFF_ERROR. 1025 */ 1026 } else if (strm->avail_in == 0 && flush <= old_flush && 1027 flush != Z_FINISH) { 1028 ERR_RETURN(strm, Z_BUF_ERROR); 1029 } 1030 1031 /* User must not provide more input after the first FINISH: */ 1032 if (s->status == FINISH_STATE && strm->avail_in != 0) { 1033 ERR_RETURN(strm, Z_BUF_ERROR); 1034 } 1035 1036 /* Start a new block or continue the current one. 1037 */ 1038 if (strm->avail_in != 0 || s->lookahead != 0 || 1039 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) { 1040 block_state bstate; 1041 1042 bstate = (*(configuration_table[s->level].func))(s, flush); 1043 1044 if (bstate == finish_started || bstate == finish_done) { 1045 s->status = FINISH_STATE; 1046 } 1047 if (bstate == need_more || bstate == finish_started) { 1048 if (strm->avail_out == 0) { 1049 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */ 1050 } 1051 return Z_OK; 1052 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call 1053 * of deflate should use the same flush parameter to make sure 1054 * that the flush is complete. So we don't have to output an 1055 * empty block here, this will be done at next call. This also 1056 * ensures that for a very small output buffer, we emit at most 1057 * one empty block. 1058 */ 1059 } 1060 if (bstate == block_done) { 1061 if (flush == Z_PARTIAL_FLUSH) { 1062 _tr_align(s); 1063 } else if (flush == Z_PACKET_FLUSH) { 1064 /* Output just the 3-bit `stored' block type value, 1065 but not a zero length. */ 1066 _tr_stored_type_only(s); 1067 } else { /* FULL_FLUSH or SYNC_FLUSH */ 1068 _tr_stored_block(s, (char*)0, 0L, 0); 1069 /* For a full flush, this empty block will be recognized 1070 * as a special marker by inflate_sync(). 1071 */ 1072 if (flush == Z_FULL_FLUSH) { 1073 CLEAR_HASH(s); /* forget history */ 1074 } 1075 } 1076 flush_pending(strm); 1077 if (strm->avail_out == 0) { 1078 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */ 1079 return Z_OK; 1080 } 1081 } 1082 } 1083 Assert(strm->avail_out > 0, "bug2"); 1084 1085 if (flush != Z_FINISH) return Z_OK; 1086 if (s->noheader) return Z_STREAM_END; 1087 1088 /* Write the zlib trailer (adler32) */ 1089 putShortMSB(s, (uInt)(strm->adler >> 16)); 1090 putShortMSB(s, (uInt)(strm->adler & 0xffff)); 1091 flush_pending(strm); 1092 /* If avail_out is zero, the application will call deflate again 1093 * to flush the rest. 1094 */ 1095 s->noheader = -1; /* write the trailer only once! */ 1096 return s->pending != 0 ? Z_OK : Z_STREAM_END; 1097 } 1098 1099 /* ========================================================================= */ 1100 int 1101 deflateEnd(z_streamp strm) 1102 { 1103 int status; 1104 deflate_state *s; 1105 1106 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; 1107 s = (deflate_state *) strm->state; 1108 1109 status = s->status; 1110 if (status != INIT_STATE && status != BUSY_STATE && 1111 status != FINISH_STATE) { 1112 return Z_STREAM_ERROR; 1113 } 1114 1115 /* Deallocate in reverse order of allocations: */ 1116 TRY_FREE(strm, s->pending_buf); 1117 TRY_FREE(strm, s->head); 1118 TRY_FREE(strm, s->prev); 1119 TRY_FREE(strm, s->window); 1120 1121 ZFREE(strm, s); 1122 strm->state = Z_NULL; 1123 1124 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK; 1125 } 1126 1127 /* ========================================================================= 1128 * Copy the source state to the destination state. 1129 */ 1130 int 1131 deflateCopy(z_streamp dest, z_streamp source) 1132 { 1133 deflate_state *ds; 1134 deflate_state *ss; 1135 ushf *overlay; 1136 1137 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) 1138 return Z_STREAM_ERROR; 1139 ss = (deflate_state *) source->state; 1140 1141 zmemcpy(dest, source, sizeof(*dest)); 1142 1143 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state)); 1144 if (ds == Z_NULL) return Z_MEM_ERROR; 1145 dest->state = (struct internal_state FAR *) ds; 1146 zmemcpy(ds, ss, sizeof(*ds)); 1147 ds->strm = dest; 1148 1149 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte)); 1150 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos)); 1151 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos)); 1152 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2); 1153 ds->pending_buf = (uchf *) overlay; 1154 1155 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL || 1156 ds->pending_buf == Z_NULL) { 1157 deflateEnd (dest); 1158 return Z_MEM_ERROR; 1159 } 1160 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */ 1161 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte)); 1162 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos)); 1163 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos)); 1164 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size); 1165 1166 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf); 1167 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush); 1168 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize; 1169 1170 ds->l_desc.dyn_tree = ds->dyn_ltree; 1171 ds->d_desc.dyn_tree = ds->dyn_dtree; 1172 ds->bl_desc.dyn_tree = ds->bl_tree; 1173 1174 return Z_OK; 1175 } 1176 1177 /* =========================================================================== 1178 * Return the number of bytes of output which are immediately available 1179 * for output from the decompressor. 1180 */ 1181 int 1182 deflateOutputPending(z_streamp strm) 1183 { 1184 if (strm == Z_NULL || strm->state == Z_NULL) return 0; 1185 1186 return ((deflate_state *)(strm->state))->pending; 1187 } 1188 1189 /* =========================================================================== 1190 * Read a new buffer from the current input stream, update the adler32 1191 * and total number of bytes read. All deflate() input goes through 1192 * this function so some applications may wish to modify it to avoid 1193 * allocating a large strm->next_in buffer and copying from it. 1194 * (See also flush_pending()). 1195 */ 1196 local int 1197 read_buf(z_streamp strm, charf *buf, unsigned size) 1198 { 1199 unsigned len = strm->avail_in; 1200 1201 if (len > size) len = size; 1202 if (len == 0) return 0; 1203 1204 strm->avail_in -= len; 1205 1206 if (!((deflate_state *)(strm->state))->noheader) { 1207 strm->adler = adler32(strm->adler, strm->next_in, len); 1208 } 1209 zmemcpy(buf, strm->next_in, len); 1210 strm->next_in += len; 1211 strm->total_in += len; 1212 1213 return (int)len; 1214 } 1215 1216 /* =========================================================================== 1217 * Initialize the "longest match" routines for a new zlib stream 1218 */ 1219 local void 1220 lm_init(deflate_state *s) 1221 { 1222 s->window_size = (ulg)2L*s->w_size; 1223 1224 CLEAR_HASH(s); 1225 1226 /* Set the default configuration parameters: 1227 */ 1228 s->max_lazy_match = configuration_table[s->level].max_lazy; 1229 s->good_match = configuration_table[s->level].good_length; 1230 s->nice_match = configuration_table[s->level].nice_length; 1231 s->max_chain_length = configuration_table[s->level].max_chain; 1232 1233 s->strstart = 0; 1234 s->block_start = 0L; 1235 s->lookahead = 0; 1236 s->match_length = s->prev_length = MIN_MATCH-1; 1237 s->match_available = 0; 1238 s->ins_h = 0; 1239 #ifdef ASMV 1240 match_init(); /* initialize the asm code */ 1241 #endif 1242 } 1243 1244 /* =========================================================================== 1245 * Set match_start to the longest match starting at the given string and 1246 * return its length. Matches shorter or equal to prev_length are discarded, 1247 * in which case the result is equal to prev_length and match_start is 1248 * garbage. 1249 * IN assertions: cur_match is the head of the hash chain for the current 1250 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 1251 * OUT assertion: the match length is not greater than s->lookahead. 1252 * 1253 * Parameters: 1254 * cur_match: current match 1255 */ 1256 #ifndef ASMV 1257 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or 1258 * match.S. The code will be functionally equivalent. 1259 */ 1260 local uInt 1261 longest_match(deflate_state *s, IPos cur_match) 1262 { 1263 unsigned chain_length = s->max_chain_length;/* max hash chain length */ 1264 Bytef *scan = s->window + s->strstart; /* current string */ 1265 Bytef *match; /* matched string */ 1266 int len; /* length of current match */ 1267 int best_len = s->prev_length; /* best match length so far */ 1268 int nice_match = s->nice_match; /* stop if match long enough */ 1269 IPos limit = s->strstart > (IPos)MAX_DIST(s) ? 1270 s->strstart - (IPos)MAX_DIST(s) : NIL; 1271 /* Stop when cur_match becomes <= limit. To simplify the code, 1272 * we prevent matches with the string of window index 0. 1273 */ 1274 Posf *prev = s->prev; 1275 uInt wmask = s->w_mask; 1276 1277 #ifdef UNALIGNED_OK 1278 /* Compare two bytes at a time. Note: this is not always beneficial. 1279 * Try with and without -DUNALIGNED_OK to check. 1280 */ 1281 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; 1282 ush scan_start = *(ushf*)scan; 1283 ush scan_end = *(ushf*)(scan+best_len-1); 1284 #else 1285 Bytef *strend = s->window + s->strstart + MAX_MATCH; 1286 Byte scan_end1 = scan[best_len-1]; 1287 Byte scan_end = scan[best_len]; 1288 #endif 1289 1290 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. 1291 * It is easy to get rid of this optimization if necessary. 1292 */ 1293 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); 1294 1295 /* Do not waste too much time if we already have a good match: */ 1296 if (s->prev_length >= s->good_match) { 1297 chain_length >>= 2; 1298 } 1299 /* Do not look for matches beyond the end of the input. This is necessary 1300 * to make deflate deterministic. 1301 */ 1302 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead; 1303 1304 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); 1305 1306 do { 1307 Assert(cur_match < s->strstart, "no future"); 1308 match = s->window + cur_match; 1309 1310 /* Skip to next match if the match length cannot increase 1311 * or if the match length is less than 2: 1312 */ 1313 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) 1314 /* This code assumes sizeof(unsigned short) == 2. Do not use 1315 * UNALIGNED_OK if your compiler uses a different size. 1316 */ 1317 if (*(ushf*)(match+best_len-1) != scan_end || 1318 *(ushf*)match != scan_start) continue; 1319 1320 /* It is not necessary to compare scan[2] and match[2] since they are 1321 * always equal when the other bytes match, given that the hash keys 1322 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at 1323 * strstart+3, +5, ... up to strstart+257. We check for insufficient 1324 * lookahead only every 4th comparison; the 128th check will be made 1325 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is 1326 * necessary to put more guard bytes at the end of the window, or 1327 * to check more often for insufficient lookahead. 1328 */ 1329 Assert(scan[2] == match[2], "scan[2]?"); 1330 scan++, match++; 1331 do { 1332 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1333 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1334 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1335 *(ushf*)(scan+=2) == *(ushf*)(match+=2) && 1336 scan < strend); 1337 /* The funny "do {}" generates better code on most compilers */ 1338 1339 /* Here, scan <= window+strstart+257 */ 1340 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1341 if (*scan == *match) scan++; 1342 1343 len = (MAX_MATCH - 1) - (int)(strend-scan); 1344 scan = strend - (MAX_MATCH-1); 1345 1346 #else /* UNALIGNED_OK */ 1347 1348 if (match[best_len] != scan_end || 1349 match[best_len-1] != scan_end1 || 1350 *match != *scan || 1351 *++match != scan[1]) continue; 1352 1353 /* The check at best_len-1 can be removed because it will be made 1354 * again later. (This heuristic is not always a win.) 1355 * It is not necessary to compare scan[2] and match[2] since they 1356 * are always equal when the other bytes match, given that 1357 * the hash keys are equal and that HASH_BITS >= 8. 1358 */ 1359 scan += 2, match++; 1360 Assert(*scan == *match, "match[2]?"); 1361 1362 /* We check for insufficient lookahead only every 8th comparison; 1363 * the 256th check will be made at strstart+258. 1364 */ 1365 do { 1366 } while (*++scan == *++match && *++scan == *++match && 1367 *++scan == *++match && *++scan == *++match && 1368 *++scan == *++match && *++scan == *++match && 1369 *++scan == *++match && *++scan == *++match && 1370 scan < strend); 1371 1372 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); 1373 1374 len = MAX_MATCH - (int)(strend - scan); 1375 scan = strend - MAX_MATCH; 1376 1377 #endif /* UNALIGNED_OK */ 1378 1379 if (len > best_len) { 1380 s->match_start = cur_match; 1381 best_len = len; 1382 if (len >= nice_match) break; 1383 #ifdef UNALIGNED_OK 1384 scan_end = *(ushf*)(scan+best_len-1); 1385 #else 1386 scan_end1 = scan[best_len-1]; 1387 scan_end = scan[best_len]; 1388 #endif 1389 } 1390 } while ((cur_match = prev[cur_match & wmask]) > limit 1391 && --chain_length != 0); 1392 1393 if ((uInt)best_len <= s->lookahead) return best_len; 1394 return s->lookahead; 1395 } 1396 #endif /* ASMV */ 1397 1398 #ifdef DEBUG_ZLIB 1399 /* =========================================================================== 1400 * Check that the match at match_start is indeed a match. 1401 */ 1402 local void 1403 check_match(deflate_state *s, IPos start, IPos match, int length) 1404 { 1405 /* check that the match is indeed a match */ 1406 if (zmemcmp((charf *)s->window + match, 1407 (charf *)s->window + start, length) != EQUAL) { 1408 fprintf(stderr, " start %u, match %u, length %d\n", 1409 start, match, length); 1410 do { 1411 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]); 1412 } while (--length != 0); 1413 z_error("invalid match"); 1414 } 1415 if (z_verbose > 1) { 1416 fprintf(stderr,"\\[%d,%d]", start-match, length); 1417 do { putc(s->window[start++], stderr); } while (--length != 0); 1418 } 1419 } 1420 #else 1421 # define check_match(s, start, match, length) 1422 #endif 1423 1424 /* =========================================================================== 1425 * Fill the window when the lookahead becomes insufficient. 1426 * Updates strstart and lookahead. 1427 * 1428 * IN assertion: lookahead < MIN_LOOKAHEAD 1429 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD 1430 * At least one byte has been read, or avail_in == 0; reads are 1431 * performed for at least two bytes (required for the zip translate_eol 1432 * option -- not supported here). 1433 */ 1434 local void 1435 fill_window(deflate_state *s) 1436 { 1437 unsigned n, m; 1438 Posf *p; 1439 unsigned more; /* Amount of free space at the end of the window. */ 1440 uInt wsize = s->w_size; 1441 1442 do { 1443 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); 1444 1445 /* Deal with !@#$% 64K limit: */ 1446 if (more == 0 && s->strstart == 0 && s->lookahead == 0) { 1447 more = wsize; 1448 1449 } else if (more == (unsigned)(-1)) { 1450 /* Very unlikely, but possible on 16 bit machine if strstart == 0 1451 * and lookahead == 1 (input done one byte at time) 1452 */ 1453 more--; 1454 1455 /* If the window is almost full and there is insufficient lookahead, 1456 * move the upper half to the lower one to make room in the upper half. 1457 */ 1458 } else if (s->strstart >= wsize+MAX_DIST(s)) { 1459 1460 zmemcpy((charf *)s->window, (charf *)s->window+wsize, 1461 (unsigned)wsize); 1462 s->match_start -= wsize; 1463 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ 1464 s->block_start -= (long) wsize; 1465 1466 /* Slide the hash table (could be avoided with 32 bit values 1467 at the expense of memory usage). We slide even when level == 0 1468 to keep the hash table consistent if we switch back to level > 0 1469 later. (Using level 0 permanently is not an optimal usage of 1470 zlib, so we don't care about this pathological case.) 1471 */ 1472 n = s->hash_size; 1473 p = &s->head[n]; 1474 do { 1475 m = *--p; 1476 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1477 } while (--n); 1478 1479 n = wsize; 1480 p = &s->prev[n]; 1481 do { 1482 m = *--p; 1483 *p = (Pos)(m >= wsize ? m-wsize : NIL); 1484 /* If n is not on any hash chain, prev[n] is garbage but 1485 * its value will never be used. 1486 */ 1487 } while (--n); 1488 more += wsize; 1489 } 1490 if (s->strm->avail_in == 0) return; 1491 1492 /* If there was no sliding: 1493 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && 1494 * more == window_size - lookahead - strstart 1495 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) 1496 * => more >= window_size - 2*WSIZE + 2 1497 * In the BIG_MEM or MMAP case (not yet supported), 1498 * window_size == input_size + MIN_LOOKAHEAD && 1499 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. 1500 * Otherwise, window_size == 2*WSIZE so more >= 2. 1501 * If there was sliding, more >= WSIZE. So in all cases, more >= 2. 1502 */ 1503 Assert(more >= 2, "more < 2"); 1504 1505 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, 1506 more); 1507 s->lookahead += n; 1508 1509 /* Initialize the hash value now that we have some input: */ 1510 if (s->lookahead >= MIN_MATCH) { 1511 s->ins_h = s->window[s->strstart]; 1512 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1513 #if MIN_MATCH != 3 1514 Call UPDATE_HASH() MIN_MATCH-3 more times 1515 #endif 1516 } 1517 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, 1518 * but this is not important since only literal bytes will be emitted. 1519 */ 1520 1521 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); 1522 } 1523 1524 /* =========================================================================== 1525 * Flush the current block, with given end-of-file flag. 1526 * IN assertion: strstart is set to the end of the current match. 1527 */ 1528 #define FLUSH_BLOCK_ONLY(s, eof) { \ 1529 _tr_flush_block(s, (s->block_start >= 0L ? \ 1530 (charf *)&s->window[(unsigned)s->block_start] : \ 1531 (charf *)Z_NULL), \ 1532 (ulg)((long)s->strstart - s->block_start), \ 1533 (eof)); \ 1534 s->block_start = s->strstart; \ 1535 flush_pending(s->strm); \ 1536 Tracev((stderr,"[FLUSH]")); \ 1537 } 1538 1539 /* Same but force premature exit if necessary. */ 1540 #define FLUSH_BLOCK(s, eof) { \ 1541 FLUSH_BLOCK_ONLY(s, eof); \ 1542 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \ 1543 } 1544 1545 /* =========================================================================== 1546 * Copy without compression as much as possible from the input stream, return 1547 * the current block state. 1548 * This function does not insert new strings in the dictionary since 1549 * uncompressible data is probably not useful. This function is used 1550 * only for the level=0 compression option. 1551 * NOTE: this function should be optimized to avoid extra copying from 1552 * window to pending_buf. 1553 */ 1554 local block_state 1555 deflate_stored(deflate_state *s, int flush) 1556 { 1557 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited 1558 * to pending_buf_size, and each stored block has a 5 byte header: 1559 */ 1560 ulg max_block_size = 0xffff; 1561 ulg max_start; 1562 1563 if (max_block_size > s->pending_buf_size - 5) { 1564 max_block_size = s->pending_buf_size - 5; 1565 } 1566 1567 /* Copy as much as possible from input to output: */ 1568 for (;;) { 1569 /* Fill the window as much as possible: */ 1570 if (s->lookahead <= 1) { 1571 1572 Assert(s->strstart < s->w_size+MAX_DIST(s) || 1573 s->block_start >= (long)s->w_size, "slide too late"); 1574 1575 fill_window(s); 1576 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more; 1577 1578 if (s->lookahead == 0) break; /* flush the current block */ 1579 } 1580 Assert(s->block_start >= 0L, "block gone"); 1581 1582 s->strstart += s->lookahead; 1583 s->lookahead = 0; 1584 1585 /* Emit a stored block if pending_buf will be full: */ 1586 max_start = s->block_start + max_block_size; 1587 if (s->strstart == 0 || (ulg)s->strstart >= max_start) { 1588 /* strstart == 0 is possible when wraparound on 16-bit machine */ 1589 s->lookahead = (uInt)(s->strstart - max_start); 1590 s->strstart = (uInt)max_start; 1591 FLUSH_BLOCK(s, 0); 1592 } 1593 /* Flush if we may have to slide, otherwise block_start may become 1594 * negative and the data will be gone: 1595 */ 1596 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) { 1597 FLUSH_BLOCK(s, 0); 1598 } 1599 } 1600 FLUSH_BLOCK(s, flush == Z_FINISH); 1601 return flush == Z_FINISH ? finish_done : block_done; 1602 } 1603 1604 /* =========================================================================== 1605 * Compress as much as possible from the input stream, return the current 1606 * block state. 1607 * This function does not perform lazy evaluation of matches and inserts 1608 * new strings in the dictionary only for unmatched strings or for short 1609 * matches. It is used only for the fast compression options. 1610 */ 1611 local block_state 1612 deflate_fast(deflate_state *s, int flush) 1613 { 1614 IPos hash_head = NIL; /* head of the hash chain */ 1615 int bflush; /* set if current block must be flushed */ 1616 1617 for (;;) { 1618 /* Make sure that we always have enough lookahead, except 1619 * at the end of the input file. We need MAX_MATCH bytes 1620 * for the next match, plus MIN_MATCH bytes to insert the 1621 * string following the next match. 1622 */ 1623 if (s->lookahead < MIN_LOOKAHEAD) { 1624 fill_window(s); 1625 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1626 return need_more; 1627 } 1628 if (s->lookahead == 0) break; /* flush the current block */ 1629 } 1630 1631 /* Insert the string window[strstart .. strstart+2] in the 1632 * dictionary, and set hash_head to the head of the hash chain: 1633 */ 1634 if (s->lookahead >= MIN_MATCH) { 1635 INSERT_STRING(s, s->strstart, hash_head); 1636 } 1637 1638 /* Find the longest match, discarding those <= prev_length. 1639 * At this point we have always match_length < MIN_MATCH 1640 */ 1641 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { 1642 /* To simplify the code, we prevent matches with the string 1643 * of window index 0 (in particular we have to avoid a match 1644 * of the string with itself at the start of the input file). 1645 */ 1646 if (s->strategy != Z_HUFFMAN_ONLY) { 1647 s->match_length = longest_match (s, hash_head); 1648 } 1649 /* longest_match() sets match_start */ 1650 } 1651 if (s->match_length >= MIN_MATCH) { 1652 check_match(s, s->strstart, s->match_start, s->match_length); 1653 1654 bflush = _tr_tally(s, s->strstart - s->match_start, 1655 s->match_length - MIN_MATCH); 1656 1657 s->lookahead -= s->match_length; 1658 1659 /* Insert new strings in the hash table only if the match length 1660 * is not too large. This saves time but degrades compression. 1661 */ 1662 if (s->match_length <= s->max_insert_length && 1663 s->lookahead >= MIN_MATCH) { 1664 s->match_length--; /* string at strstart already in hash table */ 1665 do { 1666 s->strstart++; 1667 INSERT_STRING(s, s->strstart, hash_head); 1668 /* strstart never exceeds WSIZE-MAX_MATCH, so there are 1669 * always MIN_MATCH bytes ahead. 1670 */ 1671 } while (--s->match_length != 0); 1672 s->strstart++; 1673 } else { 1674 s->strstart += s->match_length; 1675 s->match_length = 0; 1676 s->ins_h = s->window[s->strstart]; 1677 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); 1678 #if MIN_MATCH != 3 1679 Call UPDATE_HASH() MIN_MATCH-3 more times 1680 #endif 1681 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not 1682 * matter since it will be recomputed at next deflate call. 1683 */ 1684 } 1685 } else { 1686 /* No match, output a literal byte */ 1687 Tracevv((stderr,"%c", s->window[s->strstart])); 1688 bflush = _tr_tally (s, 0, s->window[s->strstart]); 1689 s->lookahead--; 1690 s->strstart++; 1691 } 1692 if (bflush) FLUSH_BLOCK(s, 0); 1693 } 1694 FLUSH_BLOCK(s, flush == Z_FINISH); 1695 return flush == Z_FINISH ? finish_done : block_done; 1696 } 1697 1698 /* =========================================================================== 1699 * Same as above, but achieves better compression. We use a lazy 1700 * evaluation for matches: a match is finally adopted only if there is 1701 * no better match at the next window position. 1702 */ 1703 local block_state 1704 deflate_slow(deflate_state *s, int flush) 1705 { 1706 IPos hash_head = NIL; /* head of hash chain */ 1707 int bflush; /* set if current block must be flushed */ 1708 1709 /* Process the input block. */ 1710 for (;;) { 1711 /* Make sure that we always have enough lookahead, except 1712 * at the end of the input file. We need MAX_MATCH bytes 1713 * for the next match, plus MIN_MATCH bytes to insert the 1714 * string following the next match. 1715 */ 1716 if (s->lookahead < MIN_LOOKAHEAD) { 1717 fill_window(s); 1718 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) { 1719 return need_more; 1720 } 1721 if (s->lookahead == 0) break; /* flush the current block */ 1722 } 1723 1724 /* Insert the string window[strstart .. strstart+2] in the 1725 * dictionary, and set hash_head to the head of the hash chain: 1726 */ 1727 if (s->lookahead >= MIN_MATCH) { 1728 INSERT_STRING(s, s->strstart, hash_head); 1729 } 1730 1731 /* Find the longest match, discarding those <= prev_length. 1732 */ 1733 s->prev_length = s->match_length, s->prev_match = s->match_start; 1734 s->match_length = MIN_MATCH-1; 1735 1736 if (hash_head != NIL && s->prev_length < s->max_lazy_match && 1737 s->strstart - hash_head <= MAX_DIST(s)) { 1738 /* To simplify the code, we prevent matches with the string 1739 * of window index 0 (in particular we have to avoid a match 1740 * of the string with itself at the start of the input file). 1741 */ 1742 if (s->strategy != Z_HUFFMAN_ONLY) { 1743 s->match_length = longest_match (s, hash_head); 1744 } 1745 /* longest_match() sets match_start */ 1746 1747 if (s->match_length <= 5 && (s->strategy == Z_FILTERED || 1748 (s->match_length == MIN_MATCH && 1749 s->strstart - s->match_start > TOO_FAR))) { 1750 1751 /* If prev_match is also MIN_MATCH, match_start is garbage 1752 * but we will ignore the current match anyway. 1753 */ 1754 s->match_length = MIN_MATCH-1; 1755 } 1756 } 1757 /* If there was a match at the previous step and the current 1758 * match is not better, output the previous match: 1759 */ 1760 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { 1761 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; 1762 /* Do not insert strings in hash table beyond this. */ 1763 1764 check_match(s, s->strstart-1, s->prev_match, s->prev_length); 1765 1766 bflush = _tr_tally(s, s->strstart -1 - s->prev_match, 1767 s->prev_length - MIN_MATCH); 1768 1769 /* Insert in hash table all strings up to the end of the match. 1770 * strstart-1 and strstart are already inserted. If there is not 1771 * enough lookahead, the last two strings are not inserted in 1772 * the hash table. 1773 */ 1774 s->lookahead -= s->prev_length-1; 1775 s->prev_length -= 2; 1776 do { 1777 if (++s->strstart <= max_insert) { 1778 INSERT_STRING(s, s->strstart, hash_head); 1779 } 1780 } while (--s->prev_length != 0); 1781 s->match_available = 0; 1782 s->match_length = MIN_MATCH-1; 1783 s->strstart++; 1784 1785 if (bflush) FLUSH_BLOCK(s, 0); 1786 1787 } else if (s->match_available) { 1788 /* If there was no match at the previous position, output a 1789 * single literal. If there was a match but the current match 1790 * is longer, truncate the previous match to a single literal. 1791 */ 1792 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1793 if (_tr_tally (s, 0, s->window[s->strstart-1])) { 1794 FLUSH_BLOCK_ONLY(s, 0); 1795 } 1796 s->strstart++; 1797 s->lookahead--; 1798 if (s->strm->avail_out == 0) return need_more; 1799 } else { 1800 /* There is no previous match to compare with, wait for 1801 * the next step to decide. 1802 */ 1803 s->match_available = 1; 1804 s->strstart++; 1805 s->lookahead--; 1806 } 1807 } 1808 Assert (flush != Z_NO_FLUSH, "no flush?"); 1809 if (s->match_available) { 1810 Tracevv((stderr,"%c", s->window[s->strstart-1])); 1811 _tr_tally (s, 0, s->window[s->strstart-1]); 1812 s->match_available = 0; 1813 } 1814 FLUSH_BLOCK(s, flush == Z_FINISH); 1815 return flush == Z_FINISH ? finish_done : block_done; 1816 } 1817 /* --- deflate.c */ 1818 1819 /* +++ trees.c */ 1820 /* trees.c -- output deflated data using Huffman coding 1821 * Copyright (C) 1995-1996 Jean-loup Gailly 1822 * For conditions of distribution and use, see copyright notice in zlib.h 1823 */ 1824 1825 /* 1826 * ALGORITHM 1827 * 1828 * The "deflation" process uses several Huffman trees. The more 1829 * common source values are represented by shorter bit sequences. 1830 * 1831 * Each code tree is stored in a compressed form which is itself 1832 * a Huffman encoding of the lengths of all the code strings (in 1833 * ascending order by source values). The actual code strings are 1834 * reconstructed from the lengths in the inflate process, as described 1835 * in the deflate specification. 1836 * 1837 * REFERENCES 1838 * 1839 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". 1840 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc 1841 * 1842 * Storer, James A. 1843 * Data Compression: Methods and Theory, pp. 49-50. 1844 * Computer Science Press, 1988. ISBN 0-7167-8156-5. 1845 * 1846 * Sedgewick, R. 1847 * Algorithms, p290. 1848 * Addison-Wesley, 1983. ISBN 0-201-06672-6. 1849 */ 1850 1851 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */ 1852 1853 /* #include "deflate.h" */ 1854 1855 #ifdef DEBUG_ZLIB 1856 # include <ctype.h> 1857 #endif 1858 1859 /* =========================================================================== 1860 * Constants 1861 */ 1862 1863 #define MAX_BL_BITS 7 1864 /* Bit length codes must not exceed MAX_BL_BITS bits */ 1865 1866 #define END_BLOCK 256 1867 /* end of block literal code */ 1868 1869 #define REP_3_6 16 1870 /* repeat previous bit length 3-6 times (2 bits of repeat count) */ 1871 1872 #define REPZ_3_10 17 1873 /* repeat a zero length 3-10 times (3 bits of repeat count) */ 1874 1875 #define REPZ_11_138 18 1876 /* repeat a zero length 11-138 times (7 bits of repeat count) */ 1877 1878 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ 1879 = {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}; 1880 1881 local int extra_dbits[D_CODES] /* extra bits for each distance code */ 1882 = {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}; 1883 1884 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ 1885 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; 1886 1887 local uch bl_order[BL_CODES] 1888 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; 1889 /* The lengths of the bit length codes are sent in order of decreasing 1890 * probability, to avoid transmitting the lengths for unused bit length codes. 1891 */ 1892 1893 #define Buf_size (8 * 2*sizeof(char)) 1894 /* Number of bits used within bi_buf. (bi_buf might be implemented on 1895 * more than 16 bits on some systems.) 1896 */ 1897 1898 /* =========================================================================== 1899 * Local data. These are initialized only once. 1900 */ 1901 1902 local ct_data static_ltree[L_CODES+2]; 1903 /* The static literal tree. Since the bit lengths are imposed, there is no 1904 * need for the L_CODES extra codes used during heap construction. However 1905 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init 1906 * below). 1907 */ 1908 1909 local ct_data static_dtree[D_CODES]; 1910 /* The static distance tree. (Actually a trivial tree since all codes use 1911 * 5 bits.) 1912 */ 1913 1914 local uch dist_code[512]; 1915 /* distance codes. The first 256 values correspond to the distances 1916 * 3 .. 258, the last 256 values correspond to the top 8 bits of 1917 * the 15 bit distances. 1918 */ 1919 1920 local uch length_code[MAX_MATCH-MIN_MATCH+1]; 1921 /* length code for each normalized match length (0 == MIN_MATCH) */ 1922 1923 local int base_length[LENGTH_CODES]; 1924 /* First normalized length for each code (0 = MIN_MATCH) */ 1925 1926 local int base_dist[D_CODES]; 1927 /* First normalized distance for each code (0 = distance of 1) */ 1928 1929 struct static_tree_desc_s { 1930 ct_data *static_tree; /* static tree or NULL */ 1931 intf *extra_bits; /* extra bits for each code or NULL */ 1932 int extra_base; /* base index for extra_bits */ 1933 int elems; /* max number of elements in the tree */ 1934 int max_length; /* max bit length for the codes */ 1935 }; 1936 1937 local static_tree_desc static_l_desc = 1938 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; 1939 1940 local static_tree_desc static_d_desc = 1941 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; 1942 1943 local static_tree_desc static_bl_desc = 1944 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; 1945 1946 /* =========================================================================== 1947 * Local (static) routines in this file. 1948 */ 1949 1950 local void tr_static_init OF((void)); 1951 local void init_block OF((deflate_state *s)); 1952 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); 1953 local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); 1954 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); 1955 local void build_tree OF((deflate_state *s, tree_desc *desc)); 1956 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1957 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); 1958 local int build_bl_tree OF((deflate_state *s)); 1959 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, 1960 int blcodes)); 1961 local void compress_block OF((deflate_state *s, ct_data *ltree, 1962 ct_data *dtree)); 1963 local void set_data_type OF((deflate_state *s)); 1964 local unsigned bi_reverse OF((unsigned value, int length)); 1965 local void bi_windup OF((deflate_state *s)); 1966 local void bi_flush OF((deflate_state *s)); 1967 local void copy_block OF((deflate_state *s, charf *buf, unsigned len, 1968 int header)); 1969 1970 #ifndef DEBUG_ZLIB 1971 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) 1972 /* Send a code of the given tree. c and tree must not have side effects */ 1973 1974 #else /* DEBUG_ZLIB */ 1975 # define send_code(s, c, tree) \ 1976 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \ 1977 send_bits(s, tree[c].Code, tree[c].Len); } 1978 #endif 1979 1980 #define d_code(dist) \ 1981 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) 1982 /* Mapping from a distance to a distance code. dist is the distance - 1 and 1983 * must not have side effects. dist_code[256] and dist_code[257] are never 1984 * used. 1985 */ 1986 1987 /* =========================================================================== 1988 * Output a short LSB first on the stream. 1989 * IN assertion: there is enough room in pendingBuf. 1990 */ 1991 #define put_short(s, w) { \ 1992 put_byte(s, (uch)((w) & 0xff)); \ 1993 put_byte(s, (uch)((ush)(w) >> 8)); \ 1994 } 1995 1996 /* =========================================================================== 1997 * Send a value on a given number of bits. 1998 * IN assertion: length <= 16 and value fits in length bits. 1999 * 2000 * Parameters: 2001 * value: value to send 2002 * length: number of bits 2003 */ 2004 #ifdef DEBUG_ZLIB 2005 local void send_bits OF((deflate_state *s, int value, int length)); 2006 2007 local void 2008 send_bits(deflate_state *s, int value, int length) 2009 { 2010 Tracevv((stderr," l %2d v %4x ", length, value)); 2011 Assert(length > 0 && length <= 15, "invalid length"); 2012 s->bits_sent += (ulg)length; 2013 2014 /* If not enough room in bi_buf, use (valid) bits from bi_buf and 2015 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) 2016 * unused bits in value. 2017 */ 2018 if (s->bi_valid > (int)Buf_size - length) { 2019 s->bi_buf |= (value << s->bi_valid); 2020 put_short(s, s->bi_buf); 2021 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); 2022 s->bi_valid += length - Buf_size; 2023 } else { 2024 s->bi_buf |= value << s->bi_valid; 2025 s->bi_valid += length; 2026 } 2027 } 2028 #else /* !DEBUG_ZLIB */ 2029 2030 #define send_bits(s, value, length) \ 2031 { int len = length;\ 2032 if (s->bi_valid > (int)Buf_size - len) {\ 2033 int val = value;\ 2034 s->bi_buf |= (val << s->bi_valid);\ 2035 put_short(s, s->bi_buf);\ 2036 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ 2037 s->bi_valid += len - Buf_size;\ 2038 } else {\ 2039 s->bi_buf |= (value) << s->bi_valid;\ 2040 s->bi_valid += len;\ 2041 }\ 2042 } 2043 #endif /* DEBUG_ZLIB */ 2044 2045 /* the arguments must not have side effects */ 2046 2047 /* =========================================================================== 2048 * Initialize the various 'constant' tables. In a multi-threaded environment, 2049 * this function may be called by two threads concurrently, but this is 2050 * harmless since both invocations do exactly the same thing. 2051 */ 2052 local void 2053 tr_static_init(void) 2054 { 2055 static int static_init_done = 0; 2056 int n; /* iterates over tree elements */ 2057 int bits; /* bit counter */ 2058 int length; /* length value */ 2059 int code; /* code value */ 2060 int dist; /* distance index */ 2061 ush bl_count[MAX_BITS+1]; 2062 /* number of codes at each bit length for an optimal tree */ 2063 2064 if (static_init_done) return; 2065 2066 /* Initialize the mapping length (0..255) -> length code (0..28) */ 2067 length = 0; 2068 for (code = 0; code < LENGTH_CODES-1; code++) { 2069 base_length[code] = length; 2070 for (n = 0; n < (1<<extra_lbits[code]); n++) { 2071 length_code[length++] = (uch)code; 2072 } 2073 } 2074 Assert (length == 256, "tr_static_init: length != 256"); 2075 /* Note that the length 255 (match length 258) can be represented 2076 * in two different ways: code 284 + 5 bits or code 285, so we 2077 * overwrite length_code[255] to use the best encoding: 2078 */ 2079 length_code[length-1] = (uch)code; 2080 2081 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ 2082 dist = 0; 2083 for (code = 0 ; code < 16; code++) { 2084 base_dist[code] = dist; 2085 for (n = 0; n < (1<<extra_dbits[code]); n++) { 2086 dist_code[dist++] = (uch)code; 2087 } 2088 } 2089 Assert (dist == 256, "tr_static_init: dist != 256"); 2090 dist >>= 7; /* from now on, all distances are divided by 128 */ 2091 for ( ; code < D_CODES; code++) { 2092 base_dist[code] = dist << 7; 2093 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { 2094 dist_code[256 + dist++] = (uch)code; 2095 } 2096 } 2097 Assert (dist == 256, "tr_static_init: 256+dist != 512"); 2098 2099 /* Construct the codes of the static literal tree */ 2100 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; 2101 n = 0; 2102 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; 2103 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; 2104 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; 2105 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; 2106 /* Codes 286 and 287 do not exist, but we must include them in the 2107 * tree construction to get a canonical Huffman tree (longest code 2108 * all ones) 2109 */ 2110 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); 2111 2112 /* The static distance tree is trivial: */ 2113 for (n = 0; n < D_CODES; n++) { 2114 static_dtree[n].Len = 5; 2115 static_dtree[n].Code = bi_reverse((unsigned)n, 5); 2116 } 2117 static_init_done = 1; 2118 } 2119 2120 /* =========================================================================== 2121 * Initialize the tree data structures for a new zlib stream. 2122 */ 2123 void 2124 _tr_init(deflate_state *s) 2125 { 2126 tr_static_init(); 2127 2128 s->compressed_len = 0L; 2129 2130 s->l_desc.dyn_tree = s->dyn_ltree; 2131 s->l_desc.stat_desc = &static_l_desc; 2132 2133 s->d_desc.dyn_tree = s->dyn_dtree; 2134 s->d_desc.stat_desc = &static_d_desc; 2135 2136 s->bl_desc.dyn_tree = s->bl_tree; 2137 s->bl_desc.stat_desc = &static_bl_desc; 2138 2139 s->bi_buf = 0; 2140 s->bi_valid = 0; 2141 s->last_eob_len = 8; /* enough lookahead for inflate */ 2142 #ifdef DEBUG_ZLIB 2143 s->bits_sent = 0L; 2144 #endif 2145 2146 /* Initialize the first block of the first file: */ 2147 init_block(s); 2148 } 2149 2150 /* =========================================================================== 2151 * Initialize a new block. 2152 */ 2153 local void 2154 init_block(deflate_state *s) 2155 { 2156 int n; /* iterates over tree elements */ 2157 2158 /* Initialize the trees. */ 2159 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; 2160 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; 2161 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; 2162 2163 s->dyn_ltree[END_BLOCK].Freq = 1; 2164 s->opt_len = s->static_len = 0L; 2165 s->last_lit = s->matches = 0; 2166 } 2167 2168 #define SMALLEST 1 2169 /* Index within the heap array of least frequent node in the Huffman tree */ 2170 2171 2172 /* =========================================================================== 2173 * Remove the smallest element from the heap and recreate the heap with 2174 * one less element. Updates heap and heap_len. 2175 */ 2176 #define pqremove(s, tree, top) \ 2177 {\ 2178 top = s->heap[SMALLEST]; \ 2179 s->heap[SMALLEST] = s->heap[s->heap_len--]; \ 2180 pqdownheap(s, tree, SMALLEST); \ 2181 } 2182 2183 /* =========================================================================== 2184 * Compares to subtrees, using the tree depth as tie breaker when 2185 * the subtrees have equal frequency. This minimizes the worst case length. 2186 */ 2187 #define smaller(tree, n, m, depth) \ 2188 (tree[n].Freq < tree[m].Freq || \ 2189 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) 2190 2191 /* =========================================================================== 2192 * Restore the heap property by moving down the tree starting at node k, 2193 * exchanging a node with the smallest of its two sons if necessary, stopping 2194 * when the heap property is re-established (each father smaller than its 2195 * two sons). 2196 * 2197 * Parameters: 2198 * tree: the tree to restore 2199 * k: node to move down 2200 */ 2201 local void 2202 pqdownheap(deflate_state *s, ct_data *tree, int k) 2203 { 2204 int v = s->heap[k]; 2205 int j = k << 1; /* left son of k */ 2206 while (j <= s->heap_len) { 2207 /* Set j to the smallest of the two sons: */ 2208 if (j < s->heap_len && 2209 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { 2210 j++; 2211 } 2212 /* Exit if v is smaller than both sons */ 2213 if (smaller(tree, v, s->heap[j], s->depth)) break; 2214 2215 /* Exchange v with the smallest son */ 2216 s->heap[k] = s->heap[j]; k = j; 2217 2218 /* And continue down the tree, setting j to the left son of k */ 2219 j <<= 1; 2220 } 2221 s->heap[k] = v; 2222 } 2223 2224 /* =========================================================================== 2225 * Compute the optimal bit lengths for a tree and update the total bit length 2226 * for the current block. 2227 * IN assertion: the fields freq and dad are set, heap[heap_max] and 2228 * above are the tree nodes sorted by increasing frequency. 2229 * OUT assertions: the field len is set to the optimal bit length, the 2230 * array bl_count contains the frequencies for each bit length. 2231 * The length opt_len is updated; static_len is also updated if stree is 2232 * not null. 2233 * 2234 * Parameters: 2235 * desc: the tree descriptor 2236 */ 2237 local void 2238 gen_bitlen(deflate_state *s, tree_desc *desc) 2239 { 2240 ct_data *tree = desc->dyn_tree; 2241 int max_code = desc->max_code; 2242 ct_data *stree = desc->stat_desc->static_tree; 2243 intf *extra = desc->stat_desc->extra_bits; 2244 int base = desc->stat_desc->extra_base; 2245 int max_length = desc->stat_desc->max_length; 2246 int h; /* heap index */ 2247 int n, m; /* iterate over the tree elements */ 2248 int bits; /* bit length */ 2249 int xbits; /* extra bits */ 2250 ush f; /* frequency */ 2251 int overflow = 0; /* number of elements with bit length too large */ 2252 2253 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; 2254 2255 /* In a first pass, compute the optimal bit lengths (which may 2256 * overflow in the case of the bit length tree). 2257 */ 2258 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ 2259 2260 for (h = s->heap_max+1; h < HEAP_SIZE; h++) { 2261 n = s->heap[h]; 2262 bits = tree[tree[n].Dad].Len + 1; 2263 if (bits > max_length) bits = max_length, overflow++; 2264 tree[n].Len = (ush)bits; 2265 /* We overwrite tree[n].Dad which is no longer needed */ 2266 2267 if (n > max_code) continue; /* not a leaf node */ 2268 2269 s->bl_count[bits]++; 2270 xbits = 0; 2271 if (n >= base) xbits = extra[n-base]; 2272 f = tree[n].Freq; 2273 s->opt_len += (ulg)f * (bits + xbits); 2274 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); 2275 } 2276 if (overflow == 0) return; 2277 2278 Trace((stderr,"\nbit length overflow\n")); 2279 /* This happens for example on obj2 and pic of the Calgary corpus */ 2280 2281 /* Find the first bit length which could increase: */ 2282 do { 2283 bits = max_length-1; 2284 while (s->bl_count[bits] == 0) bits--; 2285 s->bl_count[bits]--; /* move one leaf down the tree */ 2286 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ 2287 s->bl_count[max_length]--; 2288 /* The brother of the overflow item also moves one step up, 2289 * but this does not affect bl_count[max_length] 2290 */ 2291 overflow -= 2; 2292 } while (overflow > 0); 2293 2294 /* Now recompute all bit lengths, scanning in increasing frequency. 2295 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all 2296 * lengths instead of fixing only the wrong ones. This idea is taken 2297 * from 'ar' written by Haruhiko Okumura.) 2298 */ 2299 for (bits = max_length; bits != 0; bits--) { 2300 n = s->bl_count[bits]; 2301 while (n != 0) { 2302 m = s->heap[--h]; 2303 if (m > max_code) continue; 2304 if (tree[m].Len != (unsigned) bits) { 2305 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); 2306 s->opt_len += ((long)bits - (long)tree[m].Len) 2307 *(long)tree[m].Freq; 2308 tree[m].Len = (ush)bits; 2309 } 2310 n--; 2311 } 2312 } 2313 } 2314 2315 /* =========================================================================== 2316 * Generate the codes for a given tree and bit counts (which need not be 2317 * optimal). 2318 * IN assertion: the array bl_count contains the bit length statistics for 2319 * the given tree and the field len is set for all tree elements. 2320 * OUT assertion: the field code is set for all tree elements of non 2321 * zero code length. 2322 * 2323 * Parameters: 2324 * tree: the tree to decorate 2325 * max_code: largest code with non zero frequency 2326 * bl_count: number of codes at each bit length 2327 */ 2328 local void 2329 gen_codes(ct_data *tree, int max_code, ushf *bl_count) 2330 { 2331 ush next_code[MAX_BITS+1]; /* next code value for each bit length */ 2332 ush code = 0; /* running code value */ 2333 int bits; /* bit index */ 2334 int n; /* code index */ 2335 2336 /* The distribution counts are first used to generate the code values 2337 * without bit reversal. 2338 */ 2339 for (bits = 1; bits <= MAX_BITS; bits++) { 2340 next_code[bits] = code = (code + bl_count[bits-1]) << 1; 2341 } 2342 /* Check that the bit counts in bl_count are consistent. The last code 2343 * must be all ones. 2344 */ 2345 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, 2346 "inconsistent bit counts"); 2347 Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); 2348 2349 for (n = 0; n <= max_code; n++) { 2350 int len = tree[n].Len; 2351 if (len == 0) continue; 2352 /* Now reverse the bits */ 2353 tree[n].Code = bi_reverse(next_code[len]++, len); 2354 2355 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", 2356 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); 2357 } 2358 } 2359 2360 /* =========================================================================== 2361 * Construct one Huffman tree and assigns the code bit strings and lengths. 2362 * Update the total bit length for the current block. 2363 * IN assertion: the field freq is set for all tree elements. 2364 * OUT assertions: the fields len and code are set to the optimal bit length 2365 * and corresponding code. The length opt_len is updated; static_len is 2366 * also updated if stree is not null. The field max_code is set. 2367 * 2368 * Parameters: 2369 * desc: the tree descriptor 2370 */ 2371 local void 2372 build_tree(deflate_state *s, tree_desc *desc) 2373 { 2374 ct_data *tree = desc->dyn_tree; 2375 ct_data *stree = desc->stat_desc->static_tree; 2376 int elems = desc->stat_desc->elems; 2377 int n, m; /* iterate over heap elements */ 2378 int max_code = -1; /* largest code with non zero frequency */ 2379 int node; /* new node being created */ 2380 2381 /* Construct the initial heap, with least frequent element in 2382 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. 2383 * heap[0] is not used. 2384 */ 2385 s->heap_len = 0, s->heap_max = HEAP_SIZE; 2386 2387 for (n = 0; n < elems; n++) { 2388 if (tree[n].Freq != 0) { 2389 s->heap[++(s->heap_len)] = max_code = n; 2390 s->depth[n] = 0; 2391 } else { 2392 tree[n].Len = 0; 2393 } 2394 } 2395 2396 /* The pkzip format requires that at least one distance code exists, 2397 * and that at least one bit should be sent even if there is only one 2398 * possible code. So to avoid special checks later on we force at least 2399 * two codes of non zero frequency. 2400 */ 2401 while (s->heap_len < 2) { 2402 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); 2403 tree[node].Freq = 1; 2404 s->depth[node] = 0; 2405 s->opt_len--; if (stree) s->static_len -= stree[node].Len; 2406 /* node is 0 or 1 so it does not have extra bits */ 2407 } 2408 desc->max_code = max_code; 2409 2410 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, 2411 * establish sub-heaps of increasing lengths: 2412 */ 2413 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); 2414 2415 /* Construct the Huffman tree by repeatedly combining the least two 2416 * frequent nodes. 2417 */ 2418 node = elems; /* next internal node of the tree */ 2419 do { 2420 pqremove(s, tree, n); /* n = node of least frequency */ 2421 m = s->heap[SMALLEST]; /* m = node of next least frequency */ 2422 2423 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ 2424 s->heap[--(s->heap_max)] = m; 2425 2426 /* Create a new node father of n and m */ 2427 tree[node].Freq = tree[n].Freq + tree[m].Freq; 2428 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); 2429 tree[n].Dad = tree[m].Dad = (ush)node; 2430 #ifdef DUMP_BL_TREE 2431 if (tree == s->bl_tree) { 2432 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", 2433 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); 2434 } 2435 #endif 2436 /* and insert the new node in the heap */ 2437 s->heap[SMALLEST] = node++; 2438 pqdownheap(s, tree, SMALLEST); 2439 2440 } while (s->heap_len >= 2); 2441 2442 s->heap[--(s->heap_max)] = s->heap[SMALLEST]; 2443 2444 /* At this point, the fields freq and dad are set. We can now 2445 * generate the bit lengths. 2446 */ 2447 gen_bitlen(s, (tree_desc *)desc); 2448 2449 /* The field len is now set, we can generate the bit codes */ 2450 gen_codes ((ct_data *)tree, max_code, s->bl_count); 2451 } 2452 2453 /* =========================================================================== 2454 * Scan a literal or distance tree to determine the frequencies of the codes 2455 * in the bit length tree. 2456 * 2457 * Parameters: 2458 * tree: the tree to be scanned 2459 * max_code: and its largest code of non zero frequency 2460 */ 2461 local void 2462 scan_tree (deflate_state *s, ct_data *tree, int max_code) 2463 { 2464 int n; /* iterates over all tree elements */ 2465 int prevlen = -1; /* last emitted length */ 2466 int curlen; /* length of current code */ 2467 int nextlen = tree[0].Len; /* length of next code */ 2468 int count = 0; /* repeat count of the current code */ 2469 int max_count = 7; /* max repeat count */ 2470 int min_count = 4; /* min repeat count */ 2471 2472 if (nextlen == 0) max_count = 138, min_count = 3; 2473 tree[max_code+1].Len = (ush)0xffff; /* guard */ 2474 2475 for (n = 0; n <= max_code; n++) { 2476 curlen = nextlen; nextlen = tree[n+1].Len; 2477 if (++count < max_count && curlen == nextlen) { 2478 continue; 2479 } else if (count < min_count) { 2480 s->bl_tree[curlen].Freq += count; 2481 } else if (curlen != 0) { 2482 if (curlen != prevlen) s->bl_tree[curlen].Freq++; 2483 s->bl_tree[REP_3_6].Freq++; 2484 } else if (count <= 10) { 2485 s->bl_tree[REPZ_3_10].Freq++; 2486 } else { 2487 s->bl_tree[REPZ_11_138].Freq++; 2488 } 2489 count = 0; prevlen = curlen; 2490 if (nextlen == 0) { 2491 max_count = 138, min_count = 3; 2492 } else if (curlen == nextlen) { 2493 max_count = 6, min_count = 3; 2494 } else { 2495 max_count = 7, min_count = 4; 2496 } 2497 } 2498 } 2499 2500 /* =========================================================================== 2501 * Send a literal or distance tree in compressed form, using the codes in 2502 * bl_tree. 2503 * 2504 * Parameters: 2505 * tree: the tree to be scanned 2506 * max_code: and its largest code of non zero frequency 2507 */ 2508 local void 2509 send_tree(deflate_state *s, ct_data *tree, int max_code) 2510 { 2511 int n; /* iterates over all tree elements */ 2512 int prevlen = -1; /* last emitted length */ 2513 int curlen; /* length of current code */ 2514 int nextlen = tree[0].Len; /* length of next code */ 2515 int count = 0; /* repeat count of the current code */ 2516 int max_count = 7; /* max repeat count */ 2517 int min_count = 4; /* min repeat count */ 2518 2519 /* tree[max_code+1].Len = -1; */ /* guard already set */ 2520 if (nextlen == 0) max_count = 138, min_count = 3; 2521 2522 for (n = 0; n <= max_code; n++) { 2523 curlen = nextlen; nextlen = tree[n+1].Len; 2524 if (++count < max_count && curlen == nextlen) { 2525 continue; 2526 } else if (count < min_count) { 2527 do { send_code(s, curlen, s->bl_tree); } while (--count != 0); 2528 2529 } else if (curlen != 0) { 2530 if (curlen != prevlen) { 2531 send_code(s, curlen, s->bl_tree); count--; 2532 } 2533 Assert(count >= 3 && count <= 6, " 3_6?"); 2534 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); 2535 2536 } else if (count <= 10) { 2537 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); 2538 2539 } else { 2540 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); 2541 } 2542 count = 0; prevlen = curlen; 2543 if (nextlen == 0) { 2544 max_count = 138, min_count = 3; 2545 } else if (curlen == nextlen) { 2546 max_count = 6, min_count = 3; 2547 } else { 2548 max_count = 7, min_count = 4; 2549 } 2550 } 2551 } 2552 2553 /* =========================================================================== 2554 * Construct the Huffman tree for the bit lengths and return the index in 2555 * bl_order of the last bit length code to send. 2556 */ 2557 local int 2558 build_bl_tree(deflate_state *s) 2559 { 2560 int max_blindex; /* index of last bit length code of non zero freq */ 2561 2562 /* Determine the bit length frequencies for literal and distance trees */ 2563 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); 2564 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); 2565 2566 /* Build the bit length tree: */ 2567 build_tree(s, (tree_desc *)(&(s->bl_desc))); 2568 /* opt_len now includes the length of the tree representations, except 2569 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. 2570 */ 2571 2572 /* Determine the number of bit length codes to send. The pkzip format 2573 * requires that at least 4 bit length codes be sent. (appnote.txt says 2574 * 3 but the actual value used is 4.) 2575 */ 2576 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { 2577 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; 2578 } 2579 /* Update opt_len to include the bit length tree and counts */ 2580 s->opt_len += 3*(max_blindex+1) + 5+5+4; 2581 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", 2582 s->opt_len, s->static_len)); 2583 2584 return max_blindex; 2585 } 2586 2587 /* =========================================================================== 2588 * Send the header for a block using dynamic Huffman trees: the counts, the 2589 * lengths of the bit length codes, the literal tree and the distance tree. 2590 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. 2591 * 2592 * Parameters: 2593 * lcodes, dcodes, blcodes: number of codes for each tree 2594 */ 2595 local void 2596 send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes) 2597 { 2598 int rank; /* index in bl_order */ 2599 2600 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); 2601 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, 2602 "too many codes"); 2603 Tracev((stderr, "\nbl counts: ")); 2604 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ 2605 send_bits(s, dcodes-1, 5); 2606 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ 2607 for (rank = 0; rank < blcodes; rank++) { 2608 Tracev((stderr, "\nbl code %2d ", bl_order[rank])); 2609 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); 2610 } 2611 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); 2612 2613 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ 2614 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); 2615 2616 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ 2617 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); 2618 } 2619 2620 /* =========================================================================== 2621 * Send a stored block 2622 * 2623 * Parameters: 2624 * buf: input block 2625 * stored_len: length of input block 2626 * eof: true if this is the last block for a file 2627 */ 2628 void 2629 _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof) 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 2641 _tr_stored_type_only(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 2661 _tr_align(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 * Parameters: 2687 * buf: input block, or NULL if too old 2688 * stored_len: length of input block 2689 * eof: true if this is the last block for a file 2690 */ 2691 ulg 2692 _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) 2693 { 2694 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ 2695 int max_blindex = 0; /* index of last bit length code of non zero freq */ 2696 2697 /* Build the Huffman trees unless a stored block is forced */ 2698 if (s->level > 0) { 2699 2700 /* Check if the file is ascii or binary */ 2701 if (s->data_type == Z_UNKNOWN) set_data_type(s); 2702 2703 /* Construct the literal and distance trees */ 2704 build_tree(s, (tree_desc *)(&(s->l_desc))); 2705 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, 2706 s->static_len)); 2707 2708 build_tree(s, (tree_desc *)(&(s->d_desc))); 2709 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, 2710 s->static_len)); 2711 /* At this point, opt_len and static_len are the total bit lengths of 2712 * the compressed block data, excluding the tree representations. 2713 */ 2714 2715 /* Build the bit length tree for the above two trees, and get the index 2716 * in bl_order of the last bit length code to send. 2717 */ 2718 max_blindex = build_bl_tree(s); 2719 2720 /* Determine the best encoding. Compute first the block length in bytes*/ 2721 opt_lenb = (s->opt_len+3+7)>>3; 2722 static_lenb = (s->static_len+3+7)>>3; 2723 2724 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", 2725 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, 2726 s->last_lit)); 2727 2728 if (static_lenb <= opt_lenb) opt_lenb = static_lenb; 2729 2730 } else { 2731 Assert(buf != (char*)0, "lost buf"); 2732 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */ 2733 } 2734 2735 /* If compression failed and this is the first and last block, 2736 * and if the .zip file can be seeked (to rewrite the local header), 2737 * the whole file is transformed into a stored file: 2738 */ 2739 #ifdef STORED_FILE_OK 2740 # ifdef FORCE_STORED_FILE 2741 if (eof && s->compressed_len == 0L) { /* force stored file */ 2742 # else 2743 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { 2744 # endif 2745 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ 2746 if (buf == (charf*)0) error ("block vanished"); 2747 2748 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */ 2749 s->compressed_len = stored_len << 3; 2750 s->method = STORED; 2751 } else 2752 #endif /* STORED_FILE_OK */ 2753 2754 #ifdef FORCE_STORED 2755 if (buf != (char*)0) { /* force stored block */ 2756 #else 2757 if (stored_len+4 <= opt_lenb && buf != (char*)0) { 2758 /* 4: two words for the lengths */ 2759 #endif 2760 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. 2761 * Otherwise we can't have processed more than WSIZE input bytes since 2762 * the last block flush, because compression would have been 2763 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to 2764 * transform a block into a stored block. 2765 */ 2766 _tr_stored_block(s, buf, stored_len, eof); 2767 2768 #ifdef FORCE_STATIC 2769 } else if (static_lenb >= 0) { /* force static trees */ 2770 #else 2771 } else if (static_lenb == opt_lenb) { 2772 #endif 2773 send_bits(s, (STATIC_TREES<<1)+eof, 3); 2774 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); 2775 s->compressed_len += 3 + s->static_len; 2776 } else { 2777 send_bits(s, (DYN_TREES<<1)+eof, 3); 2778 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, 2779 max_blindex+1); 2780 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); 2781 s->compressed_len += 3 + s->opt_len; 2782 } 2783 Assert (s->compressed_len == s->bits_sent, "bad compressed size"); 2784 init_block(s); 2785 2786 if (eof) { 2787 bi_windup(s); 2788 s->compressed_len += 7; /* align on byte boundary */ 2789 } 2790 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, 2791 s->compressed_len-7*eof)); 2792 2793 return s->compressed_len >> 3; 2794 } 2795 2796 /* =========================================================================== 2797 * Save the match info and tally the frequency counts. Return true if 2798 * the current block must be flushed. 2799 * 2800 * Parameters: 2801 * dist: distance of matched string 2802 * lc: match length-MIN_MATCH or unmatched char (if dist==0) 2803 */ 2804 int 2805 _tr_tally(deflate_state *s, unsigned dist, unsigned lc) 2806 { 2807 s->d_buf[s->last_lit] = (ush)dist; 2808 s->l_buf[s->last_lit++] = (uch)lc; 2809 if (dist == 0) { 2810 /* lc is the unmatched char */ 2811 s->dyn_ltree[lc].Freq++; 2812 } else { 2813 s->matches++; 2814 /* Here, lc is the match length - MIN_MATCH */ 2815 dist--; /* dist = match distance - 1 */ 2816 Assert((ush)dist < (ush)MAX_DIST(s) && 2817 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && 2818 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match"); 2819 2820 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; 2821 s->dyn_dtree[d_code(dist)].Freq++; 2822 } 2823 2824 /* Try to guess if it is profitable to stop the current block here */ 2825 if (s->level > 2 && (s->last_lit & 0xfff) == 0) { 2826 /* Compute an upper bound for the compressed length */ 2827 ulg out_length = (ulg)s->last_lit*8L; 2828 ulg in_length = (ulg)((long)s->strstart - s->block_start); 2829 int dcode; 2830 for (dcode = 0; dcode < D_CODES; dcode++) { 2831 out_length += (ulg)s->dyn_dtree[dcode].Freq * 2832 (5L+extra_dbits[dcode]); 2833 } 2834 out_length >>= 3; 2835 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", 2836 s->last_lit, in_length, out_length, 2837 100L - out_length*100L/in_length)); 2838 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; 2839 } 2840 return (s->last_lit == s->lit_bufsize-1); 2841 /* We avoid equality with lit_bufsize because of wraparound at 64K 2842 * on 16 bit machines and because stored blocks are restricted to 2843 * 64K-1 bytes. 2844 */ 2845 } 2846 2847 /* =========================================================================== 2848 * Send the block data compressed using the given Huffman trees 2849 * 2850 * Parameters: 2851 * ltree: literal tree 2852 * dtree: distance tree 2853 */ 2854 local void 2855 compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) 2856 { 2857 unsigned dist; /* distance of matched string */ 2858 int lc; /* match length or unmatched char (if dist == 0) */ 2859 unsigned lx = 0; /* running index in l_buf */ 2860 unsigned code; /* the code to send */ 2861 int extra; /* number of extra bits to send */ 2862 2863 if (s->last_lit != 0) do { 2864 dist = s->d_buf[lx]; 2865 lc = s->l_buf[lx++]; 2866 if (dist == 0) { 2867 send_code(s, lc, ltree); /* send a literal byte */ 2868 Tracecv(isgraph(lc), (stderr," '%c' ", lc)); 2869 } else { 2870 /* Here, lc is the match length - MIN_MATCH */ 2871 code = length_code[lc]; 2872 send_code(s, code+LITERALS+1, ltree); /* send the length code */ 2873 extra = extra_lbits[code]; 2874 if (extra != 0) { 2875 lc -= base_length[code]; 2876 send_bits(s, lc, extra); /* send the extra length bits */ 2877 } 2878 dist--; /* dist is now the match distance - 1 */ 2879 code = d_code(dist); 2880 Assert (code < D_CODES, "bad d_code"); 2881 2882 send_code(s, code, dtree); /* send the distance code */ 2883 extra = extra_dbits[code]; 2884 if (extra != 0) { 2885 dist -= base_dist[code]; 2886 send_bits(s, dist, extra); /* send the extra distance bits */ 2887 } 2888 } /* literal or match pair ? */ 2889 2890 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ 2891 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); 2892 2893 } while (lx < s->last_lit); 2894 2895 send_code(s, END_BLOCK, ltree); 2896 s->last_eob_len = ltree[END_BLOCK].Len; 2897 } 2898 2899 /* =========================================================================== 2900 * Set the data type to ASCII or BINARY, using a crude approximation: 2901 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. 2902 * IN assertion: the fields freq of dyn_ltree are set and the total of all 2903 * frequencies does not exceed 64K (to fit in an int on 16 bit machines). 2904 */ 2905 local void 2906 set_data_type(deflate_state *s) 2907 { 2908 int n = 0; 2909 unsigned ascii_freq = 0; 2910 unsigned bin_freq = 0; 2911 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; 2912 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; 2913 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; 2914 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII); 2915 } 2916 2917 /* =========================================================================== 2918 * Reverse the first len bits of a code, using straightforward code (a faster 2919 * method would use a table) 2920 * IN assertion: 1 <= len <= 15 2921 * 2922 * Parameters: 2923 * code: the value to invert 2924 * len: its bit length 2925 */ 2926 local unsigned 2927 bi_reverse(unsigned code, int len) 2928 { 2929 unsigned res = 0; 2930 do { 2931 res |= code & 1; 2932 code >>= 1, res <<= 1; 2933 } while (--len > 0); 2934 return res >> 1; 2935 } 2936 2937 /* =========================================================================== 2938 * Flush the bit buffer, keeping at most 7 bits in it. 2939 */ 2940 local void 2941 bi_flush(deflate_state *s) 2942 { 2943 if (s->bi_valid == 16) { 2944 put_short(s, s->bi_buf); 2945 s->bi_buf = 0; 2946 s->bi_valid = 0; 2947 } else if (s->bi_valid >= 8) { 2948 put_byte(s, (Byte)s->bi_buf); 2949 s->bi_buf >>= 8; 2950 s->bi_valid -= 8; 2951 } 2952 } 2953 2954 /* =========================================================================== 2955 * Flush the bit buffer and align the output on a byte boundary 2956 */ 2957 local void 2958 bi_windup(deflate_state *s) 2959 { 2960 if (s->bi_valid > 8) { 2961 put_short(s, s->bi_buf); 2962 } else if (s->bi_valid > 0) { 2963 put_byte(s, (Byte)s->bi_buf); 2964 } 2965 s->bi_buf = 0; 2966 s->bi_valid = 0; 2967 #ifdef DEBUG_ZLIB 2968 s->bits_sent = (s->bits_sent+7) & ~7; 2969 #endif 2970 } 2971 2972 /* =========================================================================== 2973 * Copy a stored block, storing first the length and its 2974 * one's complement if requested. 2975 * 2976 * Parameters: 2977 * buf: the input data 2978 * len: its length 2979 * header: true if block header must be written 2980 */ 2981 local void 2982 copy_block(deflate_state *s, charf *buf, unsigned len, int header) 2983 { 2984 bi_windup(s); /* align on byte boundary */ 2985 s->last_eob_len = 8; /* enough lookahead for inflate */ 2986 2987 if (header) { 2988 put_short(s, (ush)len); 2989 put_short(s, (ush)~len); 2990 #ifdef DEBUG_ZLIB 2991 s->bits_sent += 2*16; 2992 #endif 2993 } 2994 #ifdef DEBUG_ZLIB 2995 s->bits_sent += (ulg)len<<3; 2996 #endif 2997 /* bundle up the put_byte(s, *buf++) calls */ 2998 zmemcpy(&s->pending_buf[s->pending], buf, len); 2999 s->pending += len; 3000 } 3001 /* --- trees.c */ 3002 3003 /* +++ inflate.c */ 3004 /* inflate.c -- zlib interface to inflate modules 3005 * Copyright (C) 1995-1996 Mark Adler 3006 * For conditions of distribution and use, see copyright notice in zlib.h 3007 */ 3008 3009 /* #include "zutil.h" */ 3010 3011 /* +++ infblock.h */ 3012 /* infblock.h -- header to use infblock.c 3013 * Copyright (C) 1995-1996 Mark Adler 3014 * For conditions of distribution and use, see copyright notice in zlib.h 3015 */ 3016 3017 /* WARNING: this file should *not* be used by applications. It is 3018 part of the implementation of the compression library and is 3019 subject to change. Applications should only use zlib.h. 3020 */ 3021 3022 struct inflate_blocks_state; 3023 typedef struct inflate_blocks_state FAR inflate_blocks_statef; 3024 3025 extern inflate_blocks_statef * inflate_blocks_new OF(( 3026 z_streamp z, 3027 check_func c, /* check function */ 3028 uInt w)); /* window size */ 3029 3030 extern int inflate_blocks OF(( 3031 inflate_blocks_statef *, 3032 z_streamp , 3033 int)); /* initial return code */ 3034 3035 extern void inflate_blocks_reset OF(( 3036 inflate_blocks_statef *, 3037 z_streamp , 3038 uLongf *)); /* check value on output */ 3039 3040 extern int inflate_blocks_free OF(( 3041 inflate_blocks_statef *, 3042 z_streamp , 3043 uLongf *)); /* check value on output */ 3044 3045 extern void inflate_set_dictionary OF(( 3046 inflate_blocks_statef *s, 3047 const Bytef *d, /* dictionary */ 3048 uInt n)); /* dictionary length */ 3049 3050 extern int inflate_addhistory OF(( 3051 inflate_blocks_statef *, 3052 z_streamp)); 3053 3054 extern int inflate_packet_flush OF(( 3055 inflate_blocks_statef *)); 3056 /* --- infblock.h */ 3057 3058 #ifndef NO_DUMMY_DECL 3059 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ 3060 #endif 3061 3062 /* inflate private state */ 3063 struct internal_state { 3064 3065 /* mode */ 3066 enum { 3067 METHOD, /* waiting for method byte */ 3068 FLAG, /* waiting for flag byte */ 3069 DICT4, /* four dictionary check bytes to go */ 3070 DICT3, /* three dictionary check bytes to go */ 3071 DICT2, /* two dictionary check bytes to go */ 3072 DICT1, /* one dictionary check byte to go */ 3073 DICT0, /* waiting for inflateSetDictionary */ 3074 BLOCKS, /* decompressing blocks */ 3075 CHECK4, /* four check bytes to go */ 3076 CHECK3, /* three check bytes to go */ 3077 CHECK2, /* two check bytes to go */ 3078 CHECK1, /* one check byte to go */ 3079 DONE, /* finished check, done */ 3080 BAD} /* got an error--stay here */ 3081 mode; /* current inflate mode */ 3082 3083 /* mode dependent information */ 3084 union { 3085 uInt method; /* if FLAGS, method byte */ 3086 struct { 3087 uLong was; /* computed check value */ 3088 uLong need; /* stream check value */ 3089 } check; /* if CHECK, check values to compare */ 3090 uInt marker; /* if BAD, inflateSync's marker bytes count */ 3091 } sub; /* submode */ 3092 3093 /* mode independent information */ 3094 int nowrap; /* flag for no wrapper */ 3095 uInt wbits; /* log2(window size) (8..15, defaults to 15) */ 3096 inflate_blocks_statef 3097 *blocks; /* current inflate_blocks state */ 3098 3099 }; 3100 3101 3102 int 3103 inflateReset(z_streamp z) 3104 { 3105 uLong c; 3106 3107 if (z == Z_NULL || z->state == Z_NULL) 3108 return Z_STREAM_ERROR; 3109 z->total_in = z->total_out = 0; 3110 z->msg = Z_NULL; 3111 z->state->mode = z->state->nowrap ? BLOCKS : METHOD; 3112 inflate_blocks_reset(z->state->blocks, z, &c); 3113 Trace((stderr, "inflate: reset\n")); 3114 return Z_OK; 3115 } 3116 3117 3118 int 3119 inflateEnd(z_streamp z) 3120 { 3121 uLong c; 3122 3123 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) 3124 return Z_STREAM_ERROR; 3125 if (z->state->blocks != Z_NULL) 3126 inflate_blocks_free(z->state->blocks, z, &c); 3127 ZFREE(z, z->state); 3128 z->state = Z_NULL; 3129 Trace((stderr, "inflate: end\n")); 3130 return Z_OK; 3131 } 3132 3133 3134 int 3135 inflateInit2_(z_streamp z, int w, const char *version, int stream_size) 3136 { 3137 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || 3138 stream_size != sizeof(z_stream)) 3139 return Z_VERSION_ERROR; 3140 3141 /* initialize state */ 3142 if (z == Z_NULL) 3143 return Z_STREAM_ERROR; 3144 z->msg = Z_NULL; 3145 #ifndef NO_ZCFUNCS 3146 if (z->zalloc == Z_NULL) 3147 { 3148 z->zalloc = zcalloc; 3149 z->opaque = (voidpf)0; 3150 } 3151 if (z->zfree == Z_NULL) z->zfree = zcfree; 3152 #endif 3153 if ((z->state = (struct internal_state FAR *) 3154 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) 3155 return Z_MEM_ERROR; 3156 z->state->blocks = Z_NULL; 3157 3158 /* handle undocumented nowrap option (no zlib header or check) */ 3159 z->state->nowrap = 0; 3160 if (w < 0) 3161 { 3162 w = - w; 3163 z->state->nowrap = 1; 3164 } 3165 3166 /* set window size */ 3167 if (w < 8 || w > 15) 3168 { 3169 inflateEnd(z); 3170 return Z_STREAM_ERROR; 3171 } 3172 z->state->wbits = (uInt)w; 3173 3174 /* create inflate_blocks state */ 3175 if ((z->state->blocks = 3176 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w)) 3177 == Z_NULL) 3178 { 3179 inflateEnd(z); 3180 return Z_MEM_ERROR; 3181 } 3182 Trace((stderr, "inflate: allocated\n")); 3183 3184 /* reset state */ 3185 inflateReset(z); 3186 return Z_OK; 3187 } 3188 3189 3190 int 3191 inflateInit_(z_streamp z, const char *version, int stream_size) 3192 { 3193 return inflateInit2_(z, DEF_WBITS, version, stream_size); 3194 } 3195 3196 3197 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} 3198 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) 3199 3200 int 3201 inflate(z_streamp z, int f) 3202 { 3203 int r; 3204 uInt b; 3205 3206 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0) 3207 return Z_STREAM_ERROR; 3208 r = Z_BUF_ERROR; 3209 while (1) switch (z->state->mode) 3210 { 3211 case METHOD: 3212 NEEDBYTE 3213 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED) 3214 { 3215 z->state->mode = BAD; 3216 z->msg = (char*)"unknown compression method"; 3217 z->state->sub.marker = 5; /* can't try inflateSync */ 3218 break; 3219 } 3220 if ((z->state->sub.method >> 4) + 8 > z->state->wbits) 3221 { 3222 z->state->mode = BAD; 3223 z->msg = (char*)"invalid window size"; 3224 z->state->sub.marker = 5; /* can't try inflateSync */ 3225 break; 3226 } 3227 z->state->mode = FLAG; 3228 case FLAG: 3229 NEEDBYTE 3230 b = NEXTBYTE; 3231 if (((z->state->sub.method << 8) + b) % 31) 3232 { 3233 z->state->mode = BAD; 3234 z->msg = (char*)"incorrect header check"; 3235 z->state->sub.marker = 5; /* can't try inflateSync */ 3236 break; 3237 } 3238 Trace((stderr, "inflate: zlib header ok\n")); 3239 if (!(b & PRESET_DICT)) 3240 { 3241 z->state->mode = BLOCKS; 3242 break; 3243 } 3244 z->state->mode = DICT4; 3245 case DICT4: 3246 NEEDBYTE 3247 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3248 z->state->mode = DICT3; 3249 case DICT3: 3250 NEEDBYTE 3251 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3252 z->state->mode = DICT2; 3253 case DICT2: 3254 NEEDBYTE 3255 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3256 z->state->mode = DICT1; 3257 case DICT1: 3258 NEEDBYTE 3259 z->state->sub.check.need += (uLong)NEXTBYTE; 3260 z->adler = z->state->sub.check.need; 3261 z->state->mode = DICT0; 3262 return Z_NEED_DICT; 3263 case DICT0: 3264 z->state->mode = BAD; 3265 z->msg = (char*)"need dictionary"; 3266 z->state->sub.marker = 0; /* can try inflateSync */ 3267 return Z_STREAM_ERROR; 3268 case BLOCKS: 3269 r = inflate_blocks(z->state->blocks, z, r); 3270 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) 3271 r = inflate_packet_flush(z->state->blocks); 3272 if (r == Z_DATA_ERROR) 3273 { 3274 z->state->mode = BAD; 3275 z->state->sub.marker = 0; /* can try inflateSync */ 3276 break; 3277 } 3278 if (r != Z_STREAM_END) 3279 return r; 3280 r = Z_OK; 3281 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); 3282 if (z->state->nowrap) 3283 { 3284 z->state->mode = DONE; 3285 break; 3286 } 3287 z->state->mode = CHECK4; 3288 case CHECK4: 3289 NEEDBYTE 3290 z->state->sub.check.need = (uLong)NEXTBYTE << 24; 3291 z->state->mode = CHECK3; 3292 case CHECK3: 3293 NEEDBYTE 3294 z->state->sub.check.need += (uLong)NEXTBYTE << 16; 3295 z->state->mode = CHECK2; 3296 case CHECK2: 3297 NEEDBYTE 3298 z->state->sub.check.need += (uLong)NEXTBYTE << 8; 3299 z->state->mode = CHECK1; 3300 case CHECK1: 3301 NEEDBYTE 3302 z->state->sub.check.need += (uLong)NEXTBYTE; 3303 3304 if (z->state->sub.check.was != z->state->sub.check.need) 3305 { 3306 z->state->mode = BAD; 3307 z->msg = (char*)"incorrect data check"; 3308 z->state->sub.marker = 5; /* can't try inflateSync */ 3309 break; 3310 } 3311 Trace((stderr, "inflate: zlib check ok\n")); 3312 z->state->mode = DONE; 3313 case DONE: 3314 return Z_STREAM_END; 3315 case BAD: 3316 return Z_DATA_ERROR; 3317 default: 3318 return Z_STREAM_ERROR; 3319 } 3320 3321 empty: 3322 if (f != Z_PACKET_FLUSH) 3323 return r; 3324 z->state->mode = BAD; 3325 z->msg = (char *)"need more for packet flush"; 3326 z->state->sub.marker = 0; /* can try inflateSync */ 3327 return Z_DATA_ERROR; 3328 } 3329 3330 3331 int 3332 inflateSetDictionary(z_streamp z, const Bytef *dictionary, uInt dictLength) 3333 { 3334 uInt length = dictLength; 3335 3336 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0) 3337 return Z_STREAM_ERROR; 3338 3339 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR; 3340 z->adler = 1L; 3341 3342 if (length >= ((uInt)1<<z->state->wbits)) 3343 { 3344 length = (1<<z->state->wbits)-1; 3345 dictionary += dictLength - length; 3346 } 3347 inflate_set_dictionary(z->state->blocks, dictionary, length); 3348 z->state->mode = BLOCKS; 3349 return Z_OK; 3350 } 3351 3352 /* 3353 * This subroutine adds the data at next_in/avail_in to the output history 3354 * without performing any output. The output buffer must be "caught up"; 3355 * i.e. no pending output (hence s->read equals s->write), and the state must 3356 * be BLOCKS (i.e. we should be willing to see the start of a series of 3357 * BLOCKS). On exit, the output will also be caught up, and the checksum 3358 * will have been updated if need be. 3359 */ 3360 3361 int 3362 inflateIncomp(z_stream *z) 3363 { 3364 if (z->state->mode != BLOCKS) 3365 return Z_DATA_ERROR; 3366 return inflate_addhistory(z->state->blocks, z); 3367 } 3368 3369 3370 int 3371 inflateSync(z_streamp z) 3372 { 3373 uInt n; /* number of bytes to look at */ 3374 Bytef *p; /* pointer to bytes */ 3375 uInt m; /* number of marker bytes found in a row */ 3376 uLong r, w; /* temporaries to save total_in and total_out */ 3377 3378 /* set up */ 3379 if (z == Z_NULL || z->state == Z_NULL) 3380 return Z_STREAM_ERROR; 3381 if (z->state->mode != BAD) 3382 { 3383 z->state->mode = BAD; 3384 z->state->sub.marker = 0; 3385 } 3386 if ((n = z->avail_in) == 0) 3387 return Z_BUF_ERROR; 3388 p = z->next_in; 3389 m = z->state->sub.marker; 3390 3391 /* search */ 3392 while (n && m < 4) 3393 { 3394 if (*p == (Byte)(m < 2 ? 0 : 0xff)) 3395 m++; 3396 else if (*p) 3397 m = 0; 3398 else 3399 m = 4 - m; 3400 p++, n--; 3401 } 3402 3403 /* restore */ 3404 z->total_in += p - z->next_in; 3405 z->next_in = p; 3406 z->avail_in = n; 3407 z->state->sub.marker = m; 3408 3409 /* return no joy or set up to restart on a new block */ 3410 if (m != 4) 3411 return Z_DATA_ERROR; 3412 r = z->total_in; w = z->total_out; 3413 inflateReset(z); 3414 z->total_in = r; z->total_out = w; 3415 z->state->mode = BLOCKS; 3416 return Z_OK; 3417 } 3418 3419 #undef NEEDBYTE 3420 #undef NEXTBYTE 3421 /* --- inflate.c */ 3422 3423 /* +++ infblock.c */ 3424 /* infblock.c -- interpret and process block types to last block 3425 * Copyright (C) 1995-1996 Mark Adler 3426 * For conditions of distribution and use, see copyright notice in zlib.h 3427 */ 3428 3429 /* #include "zutil.h" */ 3430 /* #include "infblock.h" */ 3431 3432 /* +++ inftrees.h */ 3433 /* inftrees.h -- header to use inftrees.c 3434 * Copyright (C) 1995-1996 Mark Adler 3435 * For conditions of distribution and use, see copyright notice in zlib.h 3436 */ 3437 3438 /* WARNING: this file should *not* be used by applications. It is 3439 part of the implementation of the compression library and is 3440 subject to change. Applications should only use zlib.h. 3441 */ 3442 3443 /* Huffman code lookup table entry--this entry is four bytes for machines 3444 that have 16-bit pointers (e.g. PC's in the small or medium model). */ 3445 3446 typedef struct inflate_huft_s FAR inflate_huft; 3447 3448 struct inflate_huft_s { 3449 union { 3450 struct { 3451 Byte Exop; /* number of extra bits or operation */ 3452 Byte Bits; /* number of bits in this code or subcode */ 3453 } what; 3454 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ 3455 } word; /* 16-bit, 8 bytes for 32-bit machines) */ 3456 union { 3457 uInt Base; /* literal, length base, or distance base */ 3458 inflate_huft *Next; /* pointer to next level of table */ 3459 } more; 3460 }; 3461 3462 #ifdef DEBUG_ZLIB 3463 extern uInt inflate_hufts; 3464 #endif 3465 3466 extern int inflate_trees_bits OF(( 3467 uIntf *, /* 19 code lengths */ 3468 uIntf *, /* bits tree desired/actual depth */ 3469 inflate_huft * FAR *, /* bits tree result */ 3470 z_streamp )); /* for zalloc, zfree functions */ 3471 3472 extern int inflate_trees_dynamic OF(( 3473 uInt, /* number of literal/length codes */ 3474 uInt, /* number of distance codes */ 3475 uIntf *, /* that many (total) code lengths */ 3476 uIntf *, /* literal desired/actual bit depth */ 3477 uIntf *, /* distance desired/actual bit depth */ 3478 inflate_huft * FAR *, /* literal/length tree result */ 3479 inflate_huft * FAR *, /* distance tree result */ 3480 z_streamp )); /* for zalloc, zfree functions */ 3481 3482 extern int inflate_trees_fixed OF(( 3483 uIntf *, /* literal desired/actual bit depth */ 3484 uIntf *, /* distance desired/actual bit depth */ 3485 inflate_huft * FAR *, /* literal/length tree result */ 3486 inflate_huft * FAR *)); /* distance tree result */ 3487 3488 extern int inflate_trees_free OF(( 3489 inflate_huft *, /* tables to free */ 3490 z_streamp )); /* for zfree function */ 3491 3492 /* --- inftrees.h */ 3493 3494 /* +++ infcodes.h */ 3495 /* infcodes.h -- header to use infcodes.c 3496 * Copyright (C) 1995-1996 Mark Adler 3497 * For conditions of distribution and use, see copyright notice in zlib.h 3498 */ 3499 3500 /* WARNING: this file should *not* be used by applications. It is 3501 part of the implementation of the compression library and is 3502 subject to change. Applications should only use zlib.h. 3503 */ 3504 3505 struct inflate_codes_state; 3506 typedef struct inflate_codes_state FAR inflate_codes_statef; 3507 3508 extern inflate_codes_statef *inflate_codes_new OF(( 3509 uInt, uInt, 3510 inflate_huft *, inflate_huft *, 3511 z_streamp )); 3512 3513 extern int inflate_codes OF(( 3514 inflate_blocks_statef *, 3515 z_streamp , 3516 int)); 3517 3518 extern void inflate_codes_free OF(( 3519 inflate_codes_statef *, 3520 z_streamp )); 3521 3522 /* --- infcodes.h */ 3523 3524 /* +++ infutil.h */ 3525 /* infutil.h -- types and macros common to blocks and codes 3526 * Copyright (C) 1995-1996 Mark Adler 3527 * For conditions of distribution and use, see copyright notice in zlib.h 3528 */ 3529 3530 /* WARNING: this file should *not* be used by applications. It is 3531 part of the implementation of the compression library and is 3532 subject to change. Applications should only use zlib.h. 3533 */ 3534 3535 #ifndef _INFUTIL_H 3536 #define _INFUTIL_H 3537 3538 typedef enum { 3539 TYPE, /* get type bits (3, including end bit) */ 3540 LENS, /* get lengths for stored */ 3541 STORED, /* processing stored block */ 3542 TABLE, /* get table lengths */ 3543 BTREE, /* get bit lengths tree for a dynamic block */ 3544 DTREE, /* get length, distance trees for a dynamic block */ 3545 CODES, /* processing fixed or dynamic block */ 3546 DRY, /* output remaining window bytes */ 3547 DONEB, /* finished last block, done */ 3548 BADB} /* got a data error--stuck here */ 3549 inflate_block_mode; 3550 3551 /* inflate blocks semi-private state */ 3552 struct inflate_blocks_state { 3553 3554 /* mode */ 3555 inflate_block_mode mode; /* current inflate_block mode */ 3556 3557 /* mode dependent information */ 3558 union { 3559 uInt left; /* if STORED, bytes left to copy */ 3560 struct { 3561 uInt table; /* table lengths (14 bits) */ 3562 uInt index; /* index into blens (or border) */ 3563 uIntf *blens; /* bit lengths of codes */ 3564 uInt bb; /* bit length tree depth */ 3565 inflate_huft *tb; /* bit length decoding tree */ 3566 } trees; /* if DTREE, decoding info for trees */ 3567 struct { 3568 inflate_huft *tl; 3569 inflate_huft *td; /* trees to free */ 3570 inflate_codes_statef 3571 *codes; 3572 } decode; /* if CODES, current state */ 3573 } sub; /* submode */ 3574 uInt last; /* true if this block is the last block */ 3575 3576 /* mode independent information */ 3577 uInt bitk; /* bits in bit buffer */ 3578 uLong bitb; /* bit buffer */ 3579 Bytef *window; /* sliding window */ 3580 Bytef *end; /* one byte after sliding window */ 3581 Bytef *read; /* window read pointer */ 3582 Bytef *write; /* window write pointer */ 3583 check_func checkfn; /* check function */ 3584 uLong check; /* check on output */ 3585 3586 }; 3587 3588 3589 /* defines for inflate input/output */ 3590 /* update pointers and return */ 3591 #define UPDBITS {s->bitb=b;s->bitk=k;} 3592 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} 3593 #define UPDOUT {s->write=q;} 3594 #define UPDATE {UPDBITS UPDIN UPDOUT} 3595 #define LEAVE {UPDATE return inflate_flush(s,z,r);} 3596 /* get bytes and bits */ 3597 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} 3598 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} 3599 #define NEXTBYTE (n--,*p++) 3600 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} 3601 #define DUMPBITS(j) {b>>=(j);k-=(j);} 3602 /* output bytes */ 3603 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) 3604 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;} 3605 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} 3606 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} 3607 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;} 3608 #define OUTBYTE(a) {*q++=(Byte)(a);m--;} 3609 /* load local pointers */ 3610 #define LOAD {LOADIN LOADOUT} 3611 3612 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */ 3613 extern uInt inflate_mask[17]; 3614 3615 /* copy as much as possible from the sliding window to the output area */ 3616 extern int inflate_flush OF(( 3617 inflate_blocks_statef *, 3618 z_streamp , 3619 int)); 3620 3621 #ifndef NO_DUMMY_DECL 3622 struct internal_state {int dummy;}; /* for buggy compilers */ 3623 #endif 3624 3625 #endif 3626 /* --- infutil.h */ 3627 3628 #ifndef NO_DUMMY_DECL 3629 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 3630 #endif 3631 3632 /* Table for deflate from PKZIP's appnote.txt. */ 3633 local const uInt border[] = { /* Order of the bit length code lengths */ 3634 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; 3635 3636 /* 3637 Notes beyond the 1.93a appnote.txt: 3638 3639 1. Distance pointers never point before the beginning of the output 3640 stream. 3641 2. Distance pointers can point back across blocks, up to 32k away. 3642 3. There is an implied maximum of 7 bits for the bit length table and 3643 15 bits for the actual data. 3644 4. If only one code exists, then it is encoded using one bit. (Zero 3645 would be more efficient, but perhaps a little confusing.) If two 3646 codes exist, they are coded using one bit each (0 and 1). 3647 5. There is no way of sending zero distance codes--a dummy must be 3648 sent if there are none. (History: a pre 2.0 version of PKZIP would 3649 store blocks with no distance codes, but this was discovered to be 3650 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow 3651 zero distance codes, which is sent as one code of zero bits in 3652 length. 3653 6. There are up to 286 literal/length codes. Code 256 represents the 3654 end-of-block. Note however that the static length tree defines 3655 288 codes just to fill out the Huffman codes. Codes 286 and 287 3656 cannot be used though, since there is no length base or extra bits 3657 defined for them. Similarily, there are up to 30 distance codes. 3658 However, static trees define 32 codes (all 5 bits) to fill out the 3659 Huffman codes, but the last two had better not show up in the data. 3660 7. Unzip can check dynamic Huffman blocks for complete code sets. 3661 The exception is that a single code would not be complete (see #4). 3662 8. The five bits following the block type is really the number of 3663 literal codes sent minus 257. 3664 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits 3665 (1+6+6). Therefore, to output three times the length, you output 3666 three codes (1+1+1), whereas to output four times the same length, 3667 you only need two codes (1+3). Hmm. 3668 10. In the tree reconstruction algorithm, Code = Code + Increment 3669 only if BitLength(i) is not zero. (Pretty obvious.) 3670 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) 3671 12. Note: length code 284 can represent 227-258, but length code 285 3672 really is 258. The last length deserves its own, short code 3673 since it gets used a lot in very redundant files. The length 3674 258 is special since 258 - 3 (the min match length) is 255. 3675 13. The literal/length and distance code bit lengths are read as a 3676 single stream of lengths. It is possible (and advantageous) for 3677 a repeat code (16, 17, or 18) to go across the boundary between 3678 the two sets of lengths. 3679 */ 3680 3681 3682 void 3683 inflate_blocks_reset(inflate_blocks_statef *s, z_streamp z, uLongf *c) 3684 { 3685 if (s->checkfn != Z_NULL) 3686 *c = s->check; 3687 if (s->mode == BTREE || s->mode == DTREE) 3688 ZFREE(z, s->sub.trees.blens); 3689 if (s->mode == CODES) 3690 { 3691 inflate_codes_free(s->sub.decode.codes, z); 3692 inflate_trees_free(s->sub.decode.td, z); 3693 inflate_trees_free(s->sub.decode.tl, z); 3694 } 3695 s->mode = TYPE; 3696 s->bitk = 0; 3697 s->bitb = 0; 3698 s->read = s->write = s->window; 3699 if (s->checkfn != Z_NULL) 3700 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0); 3701 Trace((stderr, "inflate: blocks reset\n")); 3702 } 3703 3704 3705 inflate_blocks_statef * 3706 inflate_blocks_new(z_streamp z, check_func c, uInt w) 3707 { 3708 inflate_blocks_statef *s; 3709 3710 if ((s = (inflate_blocks_statef *)ZALLOC 3711 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) 3712 return s; 3713 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) 3714 { 3715 ZFREE(z, s); 3716 return Z_NULL; 3717 } 3718 s->end = s->window + w; 3719 s->checkfn = c; 3720 s->mode = TYPE; 3721 Trace((stderr, "inflate: blocks allocated\n")); 3722 inflate_blocks_reset(s, z, &s->check); 3723 return s; 3724 } 3725 3726 3727 #ifdef DEBUG_ZLIB 3728 extern uInt inflate_hufts; 3729 #endif 3730 3731 int 3732 inflate_blocks(inflate_blocks_statef *s, z_streamp z, int r) 3733 { 3734 uInt t; /* temporary storage */ 3735 uLong b; /* bit buffer */ 3736 uInt k; /* bits in bit buffer */ 3737 Bytef *p; /* input data pointer */ 3738 uInt n; /* bytes available there */ 3739 Bytef *q; /* output window write pointer */ 3740 uInt m; /* bytes to end of window or read pointer */ 3741 3742 /* copy input/output information to locals (UPDATE macro restores) */ 3743 LOAD 3744 3745 /* process input based on current state */ 3746 while (1) switch (s->mode) 3747 { 3748 case TYPE: 3749 NEEDBITS(3) 3750 t = (uInt)b & 7; 3751 s->last = t & 1; 3752 switch (t >> 1) 3753 { 3754 case 0: /* stored */ 3755 Trace((stderr, "inflate: stored block%s\n", 3756 s->last ? " (last)" : "")); 3757 DUMPBITS(3) 3758 t = k & 7; /* go to byte boundary */ 3759 DUMPBITS(t) 3760 s->mode = LENS; /* get length of stored block */ 3761 break; 3762 case 1: /* fixed */ 3763 Trace((stderr, "inflate: fixed codes block%s\n", 3764 s->last ? " (last)" : "")); 3765 { 3766 uInt bl, bd; 3767 inflate_huft *tl, *td; 3768 3769 inflate_trees_fixed(&bl, &bd, &tl, &td); 3770 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); 3771 if (s->sub.decode.codes == Z_NULL) 3772 { 3773 r = Z_MEM_ERROR; 3774 LEAVE 3775 } 3776 s->sub.decode.tl = Z_NULL; /* don't try to free these */ 3777 s->sub.decode.td = Z_NULL; 3778 } 3779 DUMPBITS(3) 3780 s->mode = CODES; 3781 break; 3782 case 2: /* dynamic */ 3783 Trace((stderr, "inflate: dynamic codes block%s\n", 3784 s->last ? " (last)" : "")); 3785 DUMPBITS(3) 3786 s->mode = TABLE; 3787 break; 3788 case 3: /* illegal */ 3789 DUMPBITS(3) 3790 s->mode = BADB; 3791 z->msg = (char*)"invalid block type"; 3792 r = Z_DATA_ERROR; 3793 LEAVE 3794 } 3795 break; 3796 case LENS: 3797 NEEDBITS(32) 3798 if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) 3799 { 3800 s->mode = BADB; 3801 z->msg = (char*)"invalid stored block lengths"; 3802 r = Z_DATA_ERROR; 3803 LEAVE 3804 } 3805 s->sub.left = (uInt)b & 0xffff; 3806 b = k = 0; /* dump bits */ 3807 Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); 3808 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); 3809 break; 3810 case STORED: 3811 if (n == 0) 3812 LEAVE 3813 NEEDOUT 3814 t = s->sub.left; 3815 if (t > n) t = n; 3816 if (t > m) t = m; 3817 zmemcpy(q, p, t); 3818 p += t; n -= t; 3819 q += t; m -= t; 3820 if ((s->sub.left -= t) != 0) 3821 break; 3822 Tracev((stderr, "inflate: stored end, %lu total out\n", 3823 z->total_out + (q >= s->read ? q - s->read : 3824 (s->end - s->read) + (q - s->window)))); 3825 s->mode = s->last ? DRY : TYPE; 3826 break; 3827 case TABLE: 3828 NEEDBITS(14) 3829 s->sub.trees.table = t = (uInt)b & 0x3fff; 3830 #ifndef PKZIP_BUG_WORKAROUND 3831 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) 3832 { 3833 s->mode = BADB; 3834 z->msg = (char*)"too many length or distance symbols"; 3835 r = Z_DATA_ERROR; 3836 LEAVE 3837 } 3838 #endif 3839 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); 3840 if (t < 19) 3841 t = 19; 3842 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) 3843 { 3844 r = Z_MEM_ERROR; 3845 LEAVE 3846 } 3847 DUMPBITS(14) 3848 s->sub.trees.index = 0; 3849 Tracev((stderr, "inflate: table sizes ok\n")); 3850 s->mode = BTREE; 3851 case BTREE: 3852 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) 3853 { 3854 NEEDBITS(3) 3855 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; 3856 DUMPBITS(3) 3857 } 3858 while (s->sub.trees.index < 19) 3859 s->sub.trees.blens[border[s->sub.trees.index++]] = 0; 3860 s->sub.trees.bb = 7; 3861 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, 3862 &s->sub.trees.tb, z); 3863 if (t != Z_OK) 3864 { 3865 r = t; 3866 if (r == Z_DATA_ERROR) { 3867 ZFREE(z, s->sub.trees.blens); 3868 s->mode = BADB; 3869 } 3870 LEAVE 3871 } 3872 s->sub.trees.index = 0; 3873 Tracev((stderr, "inflate: bits tree ok\n")); 3874 s->mode = DTREE; 3875 case DTREE: 3876 while (t = s->sub.trees.table, 3877 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) 3878 { 3879 inflate_huft *h; 3880 uInt i, j, c; 3881 3882 t = s->sub.trees.bb; 3883 NEEDBITS(t) 3884 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); 3885 t = h->word.what.Bits; 3886 c = h->more.Base; 3887 if (c < 16) 3888 { 3889 DUMPBITS(t) 3890 s->sub.trees.blens[s->sub.trees.index++] = c; 3891 } 3892 else /* c == 16..18 */ 3893 { 3894 i = c == 18 ? 7 : c - 14; 3895 j = c == 18 ? 11 : 3; 3896 NEEDBITS(t + i) 3897 DUMPBITS(t) 3898 j += (uInt)b & inflate_mask[i]; 3899 DUMPBITS(i) 3900 i = s->sub.trees.index; 3901 t = s->sub.trees.table; 3902 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || 3903 (c == 16 && i < 1)) 3904 { 3905 inflate_trees_free(s->sub.trees.tb, z); 3906 ZFREE(z, s->sub.trees.blens); 3907 s->mode = BADB; 3908 z->msg = (char*)"invalid bit length repeat"; 3909 r = Z_DATA_ERROR; 3910 LEAVE 3911 } 3912 c = c == 16 ? s->sub.trees.blens[i - 1] : 0; 3913 do { 3914 s->sub.trees.blens[i++] = c; 3915 } while (--j); 3916 s->sub.trees.index = i; 3917 } 3918 } 3919 inflate_trees_free(s->sub.trees.tb, z); 3920 s->sub.trees.tb = Z_NULL; 3921 { 3922 uInt bl, bd; 3923 inflate_huft *tl, *td; 3924 inflate_codes_statef *c; 3925 3926 bl = 9; /* must be <= 9 for lookahead assumptions */ 3927 bd = 6; /* must be <= 9 for lookahead assumptions */ 3928 t = s->sub.trees.table; 3929 #ifdef DEBUG_ZLIB 3930 inflate_hufts = 0; 3931 #endif 3932 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), 3933 s->sub.trees.blens, &bl, &bd, &tl, &td, z); 3934 if (t != Z_OK) 3935 { 3936 if (t == (uInt)Z_DATA_ERROR) { 3937 ZFREE(z, s->sub.trees.blens); 3938 s->mode = BADB; 3939 } 3940 r = t; 3941 LEAVE 3942 } 3943 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n", 3944 inflate_hufts, sizeof(inflate_huft))); 3945 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) 3946 { 3947 inflate_trees_free(td, z); 3948 inflate_trees_free(tl, z); 3949 r = Z_MEM_ERROR; 3950 LEAVE 3951 } 3952 /* 3953 * this ZFREE must occur *BEFORE* we mess with sub.decode, because 3954 * sub.trees is union'd with sub.decode. 3955 */ 3956 ZFREE(z, s->sub.trees.blens); 3957 s->sub.decode.codes = c; 3958 s->sub.decode.tl = tl; 3959 s->sub.decode.td = td; 3960 } 3961 s->mode = CODES; 3962 case CODES: 3963 UPDATE 3964 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) 3965 return inflate_flush(s, z, r); 3966 r = Z_OK; 3967 inflate_codes_free(s->sub.decode.codes, z); 3968 inflate_trees_free(s->sub.decode.td, z); 3969 inflate_trees_free(s->sub.decode.tl, z); 3970 LOAD 3971 Tracev((stderr, "inflate: codes end, %lu total out\n", 3972 z->total_out + (q >= s->read ? q - s->read : 3973 (s->end - s->read) + (q - s->window)))); 3974 if (!s->last) 3975 { 3976 s->mode = TYPE; 3977 break; 3978 } 3979 if (k > 7) /* return unused byte, if any */ 3980 { 3981 Assert(k < 16, "inflate_codes grabbed too many bytes") 3982 k -= 8; 3983 n++; 3984 p--; /* can always return one */ 3985 } 3986 s->mode = DRY; 3987 case DRY: 3988 FLUSH 3989 if (s->read != s->write) 3990 LEAVE 3991 s->mode = DONEB; 3992 case DONEB: 3993 r = Z_STREAM_END; 3994 LEAVE 3995 case BADB: 3996 r = Z_DATA_ERROR; 3997 LEAVE 3998 default: 3999 r = Z_STREAM_ERROR; 4000 LEAVE 4001 } 4002 } 4003 4004 4005 int 4006 inflate_blocks_free(inflate_blocks_statef *s, z_streamp z, uLongf *c) 4007 { 4008 inflate_blocks_reset(s, z, c); 4009 ZFREE(z, s->window); 4010 ZFREE(z, s); 4011 Trace((stderr, "inflate: blocks freed\n")); 4012 return Z_OK; 4013 } 4014 4015 4016 void 4017 inflate_set_dictionary(inflate_blocks_statef *s, const Bytef *d, uInt n) 4018 { 4019 zmemcpy((charf *)s->window, d, n); 4020 s->read = s->write = s->window + n; 4021 } 4022 4023 /* 4024 * This subroutine adds the data at next_in/avail_in to the output history 4025 * without performing any output. The output buffer must be "caught up"; 4026 * i.e. no pending output (hence s->read equals s->write), and the state must 4027 * be BLOCKS (i.e. we should be willing to see the start of a series of 4028 * BLOCKS). On exit, the output will also be caught up, and the checksum 4029 * will have been updated if need be. 4030 */ 4031 int 4032 inflate_addhistory(inflate_blocks_statef *s, z_stream *z) 4033 { 4034 uLong b; /* bit buffer */ /* NOT USED HERE */ 4035 uInt k; /* bits in bit buffer */ /* NOT USED HERE */ 4036 uInt t; /* temporary storage */ 4037 Bytef *p; /* input data pointer */ 4038 uInt n; /* bytes available there */ 4039 Bytef *q; /* output window write pointer */ 4040 uInt m; /* bytes to end of window or read pointer */ 4041 4042 if (s->read != s->write) 4043 return Z_STREAM_ERROR; 4044 if (s->mode != TYPE) 4045 return Z_DATA_ERROR; 4046 4047 /* we're ready to rock */ 4048 LOAD 4049 /* while there is input ready, copy to output buffer, moving 4050 * pointers as needed. 4051 */ 4052 while (n) { 4053 t = n; /* how many to do */ 4054 /* is there room until end of buffer? */ 4055 if (t > m) t = m; 4056 /* update check information */ 4057 if (s->checkfn != Z_NULL) 4058 s->check = (*s->checkfn)(s->check, q, t); 4059 zmemcpy(q, p, t); 4060 q += t; 4061 p += t; 4062 n -= t; 4063 z->total_out += t; 4064 s->read = q; /* drag read pointer forward */ 4065 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */ 4066 if (q == s->end) { 4067 s->read = q = s->window; 4068 m = WAVAIL; 4069 } 4070 } 4071 UPDATE 4072 return Z_OK; 4073 } 4074 4075 4076 /* 4077 * At the end of a Deflate-compressed PPP packet, we expect to have seen 4078 * a `stored' block type value but not the (zero) length bytes. 4079 */ 4080 int 4081 inflate_packet_flush(inflate_blocks_statef *s) 4082 { 4083 if (s->mode != LENS) 4084 return Z_DATA_ERROR; 4085 s->mode = TYPE; 4086 return Z_OK; 4087 } 4088 /* --- infblock.c */ 4089 4090 /* +++ inftrees.c */ 4091 /* inftrees.c -- generate Huffman trees for efficient decoding 4092 * Copyright (C) 1995-1996 Mark Adler 4093 * For conditions of distribution and use, see copyright notice in zlib.h 4094 */ 4095 4096 /* #include "zutil.h" */ 4097 /* #include "inftrees.h" */ 4098 4099 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler "; 4100 /* 4101 If you use the zlib library in a product, an acknowledgment is welcome 4102 in the documentation of your product. If for some reason you cannot 4103 include such an acknowledgment, I would appreciate that you keep this 4104 copyright string in the executable of your product. 4105 */ 4106 4107 #ifndef NO_DUMMY_DECL 4108 struct internal_state {int dummy;}; /* for buggy compilers */ 4109 #endif 4110 4111 /* simplify the use of the inflate_huft type with some defines */ 4112 #define base more.Base 4113 #define next more.Next 4114 #define exop word.what.Exop 4115 #define bits word.what.Bits 4116 4117 4118 local int huft_build OF(( 4119 uIntf *, /* code lengths in bits */ 4120 uInt, /* number of codes */ 4121 uInt, /* number of "simple" codes */ 4122 const uIntf *, /* list of base values for non-simple codes */ 4123 const uIntf *, /* list of extra bits for non-simple codes */ 4124 inflate_huft * FAR*,/* result: starting table */ 4125 uIntf *, /* maximum lookup bits (returns actual) */ 4126 z_streamp )); /* for zalloc function */ 4127 4128 local voidpf falloc OF(( 4129 voidpf, /* opaque pointer (not used) */ 4130 uInt, /* number of items */ 4131 uInt)); /* size of item */ 4132 4133 /* Tables for deflate from PKZIP's appnote.txt. */ 4134 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */ 4135 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 4136 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; 4137 /* see note #13 above about 258 */ 4138 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */ 4139 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 4140 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */ 4141 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */ 4142 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 4143 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 4144 8193, 12289, 16385, 24577}; 4145 local const uInt cpdext[30] = { /* Extra bits for distance codes */ 4146 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 4147 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 4148 12, 12, 13, 13}; 4149 4150 /* 4151 Huffman code decoding is performed using a multi-level table lookup. 4152 The fastest way to decode is to simply build a lookup table whose 4153 size is determined by the longest code. However, the time it takes 4154 to build this table can also be a factor if the data being decoded 4155 is not very long. The most common codes are necessarily the 4156 shortest codes, so those codes dominate the decoding time, and hence 4157 the speed. The idea is you can have a shorter table that decodes the 4158 shorter, more probable codes, and then point to subsidiary tables for 4159 the longer codes. The time it costs to decode the longer codes is 4160 then traded against the time it takes to make longer tables. 4161 4162 This results of this trade are in the variables lbits and dbits 4163 below. lbits is the number of bits the first level table for literal/ 4164 length codes can decode in one step, and dbits is the same thing for 4165 the distance codes. Subsequent tables are also less than or equal to 4166 those sizes. These values may be adjusted either when all of the 4167 codes are shorter than that, in which case the longest code length in 4168 bits is used, or when the shortest code is *longer* than the requested 4169 table size, in which case the length of the shortest code in bits is 4170 used. 4171 4172 There are two different values for the two tables, since they code a 4173 different number of possibilities each. The literal/length table 4174 codes 286 possible values, or in a flat code, a little over eight 4175 bits. The distance table codes 30 possible values, or a little less 4176 than five bits, flat. The optimum values for speed end up being 4177 about one bit more than those, so lbits is 8+1 and dbits is 5+1. 4178 The optimum values may differ though from machine to machine, and 4179 possibly even between compilers. Your mileage may vary. 4180 */ 4181 4182 4183 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ 4184 #define BMAX 15 /* maximum bit length of any code */ 4185 #define N_MAX 288 /* maximum number of codes in any set */ 4186 4187 #ifdef DEBUG_ZLIB 4188 uInt inflate_hufts; 4189 #endif 4190 4191 /* 4192 * Parameters: 4193 * b: code lengths in bits (all assumed <= BMAX) 4194 * n: number of codes (assumed <= N_MAX) 4195 * s: number of simple-valued codes (0..s-1) 4196 * d: list of base values for non-simple codes 4197 * e: list of extra bits for non-simple codes 4198 * t: result: starting table 4199 * m: maximum lookup bits, returns actual 4200 * zs: for zalloc function 4201 * 4202 * Given a list of code lengths and a maximum table size, make a set of 4203 * tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR 4204 * if the given code set is incomplete (the tables are still built in this 4205 * case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of 4206 * lengths), or Z_MEM_ERROR if not enough memory. 4207 */ 4208 local int 4209 huft_build(uIntf *b, uInt n, uInt s, const uIntf *d, const uIntf *e, 4210 inflate_huft * FAR *t, uIntf *m, z_streamp zs) 4211 { 4212 4213 uInt a; /* counter for codes of length k */ 4214 uInt c[BMAX+1]; /* bit length count table */ 4215 uInt f; /* i repeats in table every f entries */ 4216 int g; /* maximum code length */ 4217 int h; /* table level */ 4218 uInt i; /* counter, current code */ 4219 uInt j; /* counter */ 4220 int k; /* number of bits in current code */ 4221 int l; /* bits per table (returned in m) */ 4222 uIntf *p; /* pointer into c[], b[], or v[] */ 4223 inflate_huft *q; /* points to current table */ 4224 struct inflate_huft_s r; /* table entry for structure assignment */ 4225 inflate_huft *u[BMAX]; /* table stack */ 4226 uInt v[N_MAX]; /* values in order of bit length */ 4227 int w; /* bits before this table == (l * h) */ 4228 uInt x[BMAX+1]; /* bit offsets, then code stack */ 4229 uIntf *xp; /* pointer into x */ 4230 int y; /* number of dummy codes added */ 4231 uInt z; /* number of entries in current table */ 4232 4233 4234 /* Generate counts for each bit length */ 4235 p = c; 4236 #define C0 *p++ = 0; 4237 #define C2 C0 C0 C0 C0 4238 #define C4 C2 C2 C2 C2 4239 C4 /* clear c[]--assume BMAX+1 is 16 */ 4240 p = b; i = n; 4241 do { 4242 c[*p++]++; /* assume all entries <= BMAX */ 4243 } while (--i); 4244 if (c[0] == n) /* null input--all zero length codes */ 4245 { 4246 *t = (inflate_huft *)Z_NULL; 4247 *m = 0; 4248 return Z_OK; 4249 } 4250 4251 4252 /* Find minimum and maximum length, bound *m by those */ 4253 l = *m; 4254 for (j = 1; j <= BMAX; j++) 4255 if (c[j]) 4256 break; 4257 k = j; /* minimum code length */ 4258 if ((uInt)l < j) 4259 l = j; 4260 for (i = BMAX; i; i--) 4261 if (c[i]) 4262 break; 4263 g = i; /* maximum code length */ 4264 if ((uInt)l > i) 4265 l = i; 4266 *m = l; 4267 4268 4269 /* Adjust last length count to fill out codes, if needed */ 4270 for (y = 1 << j; j < i; j++, y <<= 1) 4271 if ((y -= c[j]) < 0) 4272 return Z_DATA_ERROR; 4273 if ((y -= c[i]) < 0) 4274 return Z_DATA_ERROR; 4275 c[i] += y; 4276 4277 4278 /* Generate starting offsets into the value table for each length */ 4279 x[1] = j = 0; 4280 p = c + 1; xp = x + 2; 4281 while (--i) { /* note that i == g from above */ 4282 *xp++ = (j += *p++); 4283 } 4284 4285 4286 /* Make a table of values in order of bit lengths */ 4287 p = b; i = 0; 4288 do { 4289 if ((j = *p++) != 0) 4290 v[x[j]++] = i; 4291 } while (++i < n); 4292 n = x[g]; /* set n to length of v */ 4293 4294 4295 /* Generate the Huffman codes and for each, make the table entries */ 4296 x[0] = i = 0; /* first Huffman code is zero */ 4297 p = v; /* grab values in bit order */ 4298 h = -1; /* no tables yet--level -1 */ 4299 w = -l; /* bits decoded == (l * h) */ 4300 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ 4301 q = (inflate_huft *)Z_NULL; /* ditto */ 4302 z = 0; /* ditto */ 4303 4304 /* go through the bit lengths (k already is bits in shortest code) */ 4305 for (; k <= g; k++) 4306 { 4307 a = c[k]; 4308 while (a--) 4309 { 4310 /* here i is the Huffman code of length k bits for value *p */ 4311 /* make tables up to required level */ 4312 while (k > w + l) 4313 { 4314 h++; 4315 w += l; /* previous table always l bits */ 4316 4317 /* compute minimum size table less than or equal to l bits */ 4318 z = g - w; 4319 z = z > (uInt)l ? l : z; /* table size upper limit */ 4320 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ 4321 { /* too few codes for k-w bit table */ 4322 f -= a + 1; /* deduct codes from patterns left */ 4323 xp = c + k; 4324 if (j < z) 4325 while (++j < z) /* try smaller tables up to z bits */ 4326 { 4327 if ((f <<= 1) <= *++xp) 4328 break; /* enough codes to use up j bits */ 4329 f -= *xp; /* else deduct codes from patterns */ 4330 } 4331 } 4332 z = 1 << j; /* table entries for j-bit table */ 4333 4334 /* allocate and link in new table */ 4335 if ((q = (inflate_huft *)ZALLOC 4336 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) 4337 { 4338 if (h) 4339 inflate_trees_free(u[0], zs); 4340 return Z_MEM_ERROR; /* not enough memory */ 4341 } 4342 #ifdef DEBUG_ZLIB 4343 inflate_hufts += z + 1; 4344 #endif 4345 *t = q + 1; /* link to list for huft_free() */ 4346 *(t = &(q->next)) = Z_NULL; 4347 u[h] = ++q; /* table starts after link */ 4348 4349 /* connect to last table, if there is one */ 4350 if (h) 4351 { 4352 x[h] = i; /* save pattern for backing up */ 4353 r.bits = (Byte)l; /* bits to dump before this table */ 4354 r.exop = (Byte)j; /* bits in this table */ 4355 r.next = q; /* pointer to this table */ 4356 j = i >> (w - l); /* (get around Turbo C bug) */ 4357 u[h-1][j] = r; /* connect to last table */ 4358 } 4359 } 4360 4361 /* set up table entry in r */ 4362 r.bits = (Byte)(k - w); 4363 if (p >= v + n) 4364 r.exop = 128 + 64; /* out of values--invalid code */ 4365 else if (*p < s) 4366 { 4367 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ 4368 r.base = *p++; /* simple code is just the value */ 4369 } 4370 else 4371 { 4372 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */ 4373 r.base = d[*p++ - s]; 4374 } 4375 4376 /* fill code-like entries with r */ 4377 f = 1 << (k - w); 4378 for (j = i >> w; j < z; j += f) 4379 q[j] = r; 4380 4381 /* backwards increment the k-bit code i */ 4382 for (j = 1 << (k - 1); i & j; j >>= 1) 4383 i ^= j; 4384 i ^= j; 4385 4386 /* backup over finished tables */ 4387 while ((i & ((1 << w) - 1)) != x[h]) 4388 { 4389 h--; /* don't need to update q */ 4390 w -= l; 4391 } 4392 } 4393 } 4394 4395 4396 /* Return Z_BUF_ERROR if we were given an incomplete table */ 4397 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; 4398 } 4399 4400 /* 4401 * Parameters: 4402 * c: 19 code lengths 4403 * bb: bits tree desired/actual depth 4404 * tb: bits tree result 4405 * z: for zfree function 4406 */ 4407 int 4408 inflate_trees_bits(uIntf *c, uIntf *bb, inflate_huft * FAR *tb, z_streamp z) 4409 { 4410 int r; 4411 4412 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); 4413 if (r == Z_DATA_ERROR) 4414 z->msg = (char*)"oversubscribed dynamic bit lengths tree"; 4415 else if (r == Z_BUF_ERROR || *bb == 0) 4416 { 4417 inflate_trees_free(*tb, z); 4418 z->msg = (char*)"incomplete dynamic bit lengths tree"; 4419 r = Z_DATA_ERROR; 4420 } 4421 return r; 4422 } 4423 4424 /* 4425 * Parameters: 4426 * nl: number of literal/length codes 4427 * nd: number of distance codes 4428 * c: that many (total) code lengths 4429 * bl: literal desired/actual bit depth 4430 * bd: distance desired/actual bit depth 4431 * tl: literal/length tree result 4432 * td: distance tree result 4433 * z: for zfree function 4434 */ 4435 int 4436 inflate_trees_dynamic(uInt nl, uInt nd, uIntf *c, uIntf *bl, uIntf *bd, 4437 inflate_huft * FAR *tl, inflate_huft * FAR *td, 4438 z_streamp z) 4439 { 4440 int r; 4441 4442 /* build literal/length tree */ 4443 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z); 4444 if (r != Z_OK || *bl == 0) 4445 { 4446 if (r == Z_DATA_ERROR) 4447 z->msg = (char*)"oversubscribed literal/length tree"; 4448 else if (r != Z_MEM_ERROR) 4449 { 4450 inflate_trees_free(*tl, z); 4451 z->msg = (char*)"incomplete literal/length tree"; 4452 r = Z_DATA_ERROR; 4453 } 4454 return r; 4455 } 4456 4457 /* build distance tree */ 4458 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z); 4459 if (r != Z_OK || (*bd == 0 && nl > 257)) 4460 { 4461 if (r == Z_DATA_ERROR) 4462 z->msg = (char*)"oversubscribed distance tree"; 4463 else if (r == Z_BUF_ERROR) { 4464 #ifdef PKZIP_BUG_WORKAROUND 4465 r = Z_OK; 4466 } 4467 #else 4468 inflate_trees_free(*td, z); 4469 z->msg = (char*)"incomplete distance tree"; 4470 r = Z_DATA_ERROR; 4471 } 4472 else if (r != Z_MEM_ERROR) 4473 { 4474 z->msg = (char*)"empty distance tree with lengths"; 4475 r = Z_DATA_ERROR; 4476 } 4477 inflate_trees_free(*tl, z); 4478 return r; 4479 #endif 4480 } 4481 4482 /* done */ 4483 return Z_OK; 4484 } 4485 4486 4487 /* build fixed tables only once--keep them here */ 4488 local int fixed_built = 0; 4489 #define FIXEDH 530 /* number of hufts used by fixed tables */ 4490 local inflate_huft fixed_mem[FIXEDH]; 4491 local uInt fixed_bl; 4492 local uInt fixed_bd; 4493 local inflate_huft *fixed_tl; 4494 local inflate_huft *fixed_td; 4495 4496 /* 4497 * Parameters: 4498 * q: opaque pointer 4499 * n: number of items 4500 * s: size of item 4501 */ 4502 local voidpf 4503 falloc(voidpf q, uInt n, uInt s) 4504 { 4505 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q, 4506 "inflate_trees falloc overflow"); 4507 *(intf *)q -= n+s-s; /* s-s to avoid warning */ 4508 return (voidpf)(fixed_mem + *(intf *)q); 4509 } 4510 4511 /* 4512 * Parameters: 4513 * bl: literal desired/actual bit depth 4514 * bd: distance desired/actual bit depth 4515 * tl: literal/length tree result 4516 * td: distance tree result 4517 */ 4518 int 4519 inflate_trees_fixed(uIntf *bl, uIntf *bd, inflate_huft * FAR *tl, 4520 inflate_huft * FAR *td) 4521 { 4522 /* build fixed tables if not already (multiple overlapped executions ok) */ 4523 if (!fixed_built) 4524 { 4525 int k; /* temporary variable */ 4526 unsigned c[288]; /* length list for huft_build */ 4527 z_stream z; /* for falloc function */ 4528 int f = FIXEDH; /* number of hufts left in fixed_mem */ 4529 4530 /* set up fake z_stream for memory routines */ 4531 z.zalloc = falloc; 4532 z.zfree = Z_NULL; 4533 z.opaque = (voidpf)&f; 4534 4535 /* literal table */ 4536 for (k = 0; k < 144; k++) 4537 c[k] = 8; 4538 for (; k < 256; k++) 4539 c[k] = 9; 4540 for (; k < 280; k++) 4541 c[k] = 7; 4542 for (; k < 288; k++) 4543 c[k] = 8; 4544 fixed_bl = 7; 4545 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); 4546 4547 /* distance table */ 4548 for (k = 0; k < 30; k++) 4549 c[k] = 5; 4550 fixed_bd = 5; 4551 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); 4552 4553 /* done */ 4554 Assert(f == 0, "invalid build of fixed tables"); 4555 fixed_built = 1; 4556 } 4557 *bl = fixed_bl; 4558 *bd = fixed_bd; 4559 *tl = fixed_tl; 4560 *td = fixed_td; 4561 return Z_OK; 4562 } 4563 4564 /* 4565 * Parameters: 4566 * t: table to free 4567 * z: for zfree function 4568 * Free the malloc'ed tables built by huft_build(), which makes a linked 4569 * list of the tables it made, with the links in a dummy first entry of 4570 * each table. 4571 */ 4572 int 4573 inflate_trees_free(inflate_huft *t, z_streamp z) 4574 { 4575 inflate_huft *p, *q, *r; 4576 4577 /* Reverse linked list */ 4578 p = Z_NULL; 4579 q = t; 4580 while (q != Z_NULL) 4581 { 4582 r = (q - 1)->next; 4583 (q - 1)->next = p; 4584 p = q; 4585 q = r; 4586 } 4587 /* Go through linked list, freeing from the malloced (t[-1]) address. */ 4588 while (p != Z_NULL) 4589 { 4590 q = (--p)->next; 4591 ZFREE(z,p); 4592 p = q; 4593 } 4594 return Z_OK; 4595 } 4596 /* --- inftrees.c */ 4597 4598 /* +++ infcodes.c */ 4599 /* infcodes.c -- process literals and length/distance pairs 4600 * Copyright (C) 1995-1996 Mark Adler 4601 * For conditions of distribution and use, see copyright notice in zlib.h 4602 */ 4603 4604 /* #include "zutil.h" */ 4605 /* #include "inftrees.h" */ 4606 /* #include "infblock.h" */ 4607 /* #include "infcodes.h" */ 4608 /* #include "infutil.h" */ 4609 4610 /* +++ inffast.h */ 4611 /* inffast.h -- header to use inffast.c 4612 * Copyright (C) 1995-1996 Mark Adler 4613 * For conditions of distribution and use, see copyright notice in zlib.h 4614 */ 4615 4616 /* WARNING: this file should *not* be used by applications. It is 4617 part of the implementation of the compression library and is 4618 subject to change. Applications should only use zlib.h. 4619 */ 4620 4621 extern int inflate_fast OF(( 4622 uInt, 4623 uInt, 4624 inflate_huft *, 4625 inflate_huft *, 4626 inflate_blocks_statef *, 4627 z_streamp )); 4628 /* --- inffast.h */ 4629 4630 /* simplify the use of the inflate_huft type with some defines */ 4631 #define base more.Base 4632 #define next more.Next 4633 #define exop word.what.Exop 4634 #define bits word.what.Bits 4635 4636 /* inflate codes private state */ 4637 struct inflate_codes_state { 4638 4639 /* mode */ 4640 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4641 START, /* x: set up for LEN */ 4642 LEN, /* i: get length/literal/eob next */ 4643 LENEXT, /* i: getting length extra (have base) */ 4644 DIST, /* i: get distance next */ 4645 DISTEXT, /* i: getting distance extra */ 4646 COPY, /* o: copying bytes in window, waiting for space */ 4647 LIT, /* o: got literal, waiting for output space */ 4648 WASH, /* o: got eob, possibly still output waiting */ 4649 END, /* x: got eob and all data flushed */ 4650 BADCODE} /* x: got error */ 4651 mode; /* current inflate_codes mode */ 4652 4653 /* mode dependent information */ 4654 uInt len; 4655 union { 4656 struct { 4657 inflate_huft *tree; /* pointer into tree */ 4658 uInt need; /* bits needed */ 4659 } code; /* if LEN or DIST, where in tree */ 4660 uInt lit; /* if LIT, literal */ 4661 struct { 4662 uInt get; /* bits to get for extra */ 4663 uInt dist; /* distance back to copy from */ 4664 } copy; /* if EXT or COPY, where and how much */ 4665 } sub; /* submode */ 4666 4667 /* mode independent information */ 4668 Byte lbits; /* ltree bits decoded per branch */ 4669 Byte dbits; /* dtree bits decoder per branch */ 4670 inflate_huft *ltree; /* literal/length/eob tree */ 4671 inflate_huft *dtree; /* distance tree */ 4672 4673 }; 4674 4675 /* 4676 * Parameters: 4677 * td: need separate declaration for Borland C++ 4678 */ 4679 inflate_codes_statef * 4680 inflate_codes_new(uInt bl, uInt bd, inflate_huft *tl, inflate_huft *td, 4681 z_streamp z) 4682 { 4683 inflate_codes_statef *c; 4684 4685 if ((c = (inflate_codes_statef *) 4686 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) 4687 { 4688 c->mode = START; 4689 c->lbits = (Byte)bl; 4690 c->dbits = (Byte)bd; 4691 c->ltree = tl; 4692 c->dtree = td; 4693 Tracev((stderr, "inflate: codes new\n")); 4694 } 4695 return c; 4696 } 4697 4698 4699 int 4700 inflate_codes(inflate_blocks_statef *s, z_streamp z, int r) 4701 { 4702 uInt j; /* temporary storage */ 4703 inflate_huft *t; /* temporary pointer */ 4704 uInt e; /* extra bits or operation */ 4705 uLong b; /* bit buffer */ 4706 uInt k; /* bits in bit buffer */ 4707 Bytef *p; /* input data pointer */ 4708 uInt n; /* bytes available there */ 4709 Bytef *q; /* output window write pointer */ 4710 uInt m; /* bytes to end of window or read pointer */ 4711 Bytef *f; /* pointer to copy strings from */ 4712 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ 4713 4714 /* copy input/output information to locals (UPDATE macro restores) */ 4715 LOAD 4716 4717 /* process input and output based on current state */ 4718 while (1) switch (c->mode) 4719 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ 4720 case START: /* x: set up for LEN */ 4721 #ifndef SLOW 4722 if (m >= 258 && n >= 10) 4723 { 4724 UPDATE 4725 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); 4726 LOAD 4727 if (r != Z_OK) 4728 { 4729 c->mode = r == Z_STREAM_END ? WASH : BADCODE; 4730 break; 4731 } 4732 } 4733 #endif /* !SLOW */ 4734 c->sub.code.need = c->lbits; 4735 c->sub.code.tree = c->ltree; 4736 c->mode = LEN; 4737 case LEN: /* i: get length/literal/eob next */ 4738 j = c->sub.code.need; 4739 NEEDBITS(j) 4740 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4741 DUMPBITS(t->bits) 4742 e = (uInt)(t->exop); 4743 if (e == 0) /* literal */ 4744 { 4745 c->sub.lit = t->base; 4746 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 4747 "inflate: literal '%c'\n" : 4748 "inflate: literal 0x%02x\n", t->base)); 4749 c->mode = LIT; 4750 break; 4751 } 4752 if (e & 16) /* length */ 4753 { 4754 c->sub.copy.get = e & 15; 4755 c->len = t->base; 4756 c->mode = LENEXT; 4757 break; 4758 } 4759 if ((e & 64) == 0) /* next table */ 4760 { 4761 c->sub.code.need = e; 4762 c->sub.code.tree = t->next; 4763 break; 4764 } 4765 if (e & 32) /* end of block */ 4766 { 4767 Tracevv((stderr, "inflate: end of block\n")); 4768 c->mode = WASH; 4769 break; 4770 } 4771 c->mode = BADCODE; /* invalid code */ 4772 z->msg = (char*)"invalid literal/length code"; 4773 r = Z_DATA_ERROR; 4774 LEAVE 4775 case LENEXT: /* i: getting length extra (have base) */ 4776 j = c->sub.copy.get; 4777 NEEDBITS(j) 4778 c->len += (uInt)b & inflate_mask[j]; 4779 DUMPBITS(j) 4780 c->sub.code.need = c->dbits; 4781 c->sub.code.tree = c->dtree; 4782 Tracevv((stderr, "inflate: length %u\n", c->len)); 4783 c->mode = DIST; 4784 case DIST: /* i: get distance next */ 4785 j = c->sub.code.need; 4786 NEEDBITS(j) 4787 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); 4788 DUMPBITS(t->bits) 4789 e = (uInt)(t->exop); 4790 if (e & 16) /* distance */ 4791 { 4792 c->sub.copy.get = e & 15; 4793 c->sub.copy.dist = t->base; 4794 c->mode = DISTEXT; 4795 break; 4796 } 4797 if ((e & 64) == 0) /* next table */ 4798 { 4799 c->sub.code.need = e; 4800 c->sub.code.tree = t->next; 4801 break; 4802 } 4803 c->mode = BADCODE; /* invalid code */ 4804 z->msg = (char*)"invalid distance code"; 4805 r = Z_DATA_ERROR; 4806 LEAVE 4807 case DISTEXT: /* i: getting distance extra */ 4808 j = c->sub.copy.get; 4809 NEEDBITS(j) 4810 c->sub.copy.dist += (uInt)b & inflate_mask[j]; 4811 DUMPBITS(j) 4812 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); 4813 c->mode = COPY; 4814 case COPY: /* o: copying bytes in window, waiting for space */ 4815 #ifndef __TURBOC__ /* Turbo C bug for following expression */ 4816 f = (uInt)(q - s->window) < c->sub.copy.dist ? 4817 s->end - (c->sub.copy.dist - (q - s->window)) : 4818 q - c->sub.copy.dist; 4819 #else 4820 f = q - c->sub.copy.dist; 4821 if ((uInt)(q - s->window) < c->sub.copy.dist) 4822 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window)); 4823 #endif 4824 while (c->len) 4825 { 4826 NEEDOUT 4827 OUTBYTE(*f++) 4828 if (f == s->end) 4829 f = s->window; 4830 c->len--; 4831 } 4832 c->mode = START; 4833 break; 4834 case LIT: /* o: got literal, waiting for output space */ 4835 NEEDOUT 4836 OUTBYTE(c->sub.lit) 4837 c->mode = START; 4838 break; 4839 case WASH: /* o: got eob, possibly more output */ 4840 FLUSH 4841 if (s->read != s->write) 4842 LEAVE 4843 c->mode = END; 4844 case END: 4845 r = Z_STREAM_END; 4846 LEAVE 4847 case BADCODE: /* x: got error */ 4848 r = Z_DATA_ERROR; 4849 LEAVE 4850 default: 4851 r = Z_STREAM_ERROR; 4852 LEAVE 4853 } 4854 } 4855 4856 4857 void 4858 inflate_codes_free(inflate_codes_statef *c, z_streamp z) 4859 { 4860 ZFREE(z, c); 4861 Tracev((stderr, "inflate: codes free\n")); 4862 } 4863 /* --- infcodes.c */ 4864 4865 /* +++ infutil.c */ 4866 /* inflate_util.c -- data and routines common to blocks and codes 4867 * Copyright (C) 1995-1996 Mark Adler 4868 * For conditions of distribution and use, see copyright notice in zlib.h 4869 */ 4870 4871 /* #include "zutil.h" */ 4872 /* #include "infblock.h" */ 4873 /* #include "inftrees.h" */ 4874 /* #include "infcodes.h" */ 4875 /* #include "infutil.h" */ 4876 4877 #ifndef NO_DUMMY_DECL 4878 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4879 #endif 4880 4881 /* And'ing with mask[n] masks the lower n bits */ 4882 uInt inflate_mask[17] = { 4883 0x0000, 4884 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 4885 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff 4886 }; 4887 4888 4889 /* copy as much as possible from the sliding window to the output area */ 4890 int 4891 inflate_flush(inflate_blocks_statef *s, z_streamp z, int r) 4892 { 4893 uInt n; 4894 Bytef *p; 4895 Bytef *q; 4896 4897 /* local copies of source and destination pointers */ 4898 p = z->next_out; 4899 q = s->read; 4900 4901 /* compute number of bytes to copy as far as end of window */ 4902 n = (uInt)((q <= s->write ? s->write : s->end) - q); 4903 if (n > z->avail_out) n = z->avail_out; 4904 if (n && r == Z_BUF_ERROR) r = Z_OK; 4905 4906 /* update counters */ 4907 z->avail_out -= n; 4908 z->total_out += n; 4909 4910 /* update check information */ 4911 if (s->checkfn != Z_NULL) 4912 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4913 4914 /* copy as far as end of window */ 4915 if (p != Z_NULL) { 4916 zmemcpy(p, q, n); 4917 p += n; 4918 } 4919 q += n; 4920 4921 /* see if more to copy at beginning of window */ 4922 if (q == s->end) 4923 { 4924 /* wrap pointers */ 4925 q = s->window; 4926 if (s->write == s->end) 4927 s->write = s->window; 4928 4929 /* compute bytes to copy */ 4930 n = (uInt)(s->write - q); 4931 if (n > z->avail_out) n = z->avail_out; 4932 if (n && r == Z_BUF_ERROR) r = Z_OK; 4933 4934 /* update counters */ 4935 z->avail_out -= n; 4936 z->total_out += n; 4937 4938 /* update check information */ 4939 if (s->checkfn != Z_NULL) 4940 z->adler = s->check = (*s->checkfn)(s->check, q, n); 4941 4942 /* copy */ 4943 if (p != Z_NULL) { 4944 zmemcpy(p, q, n); 4945 p += n; 4946 } 4947 q += n; 4948 } 4949 4950 /* update pointers */ 4951 z->next_out = p; 4952 s->read = q; 4953 4954 /* done */ 4955 return r; 4956 } 4957 /* --- infutil.c */ 4958 4959 /* +++ inffast.c */ 4960 /* inffast.c -- process literals and length/distance pairs fast 4961 * Copyright (C) 1995-1996 Mark Adler 4962 * For conditions of distribution and use, see copyright notice in zlib.h 4963 */ 4964 4965 /* #include "zutil.h" */ 4966 /* #include "inftrees.h" */ 4967 /* #include "infblock.h" */ 4968 /* #include "infcodes.h" */ 4969 /* #include "infutil.h" */ 4970 /* #include "inffast.h" */ 4971 4972 #ifndef NO_DUMMY_DECL 4973 struct inflate_codes_state {int dummy;}; /* for buggy compilers */ 4974 #endif 4975 4976 /* simplify the use of the inflate_huft type with some defines */ 4977 #define base more.Base 4978 #define next more.Next 4979 #define exop word.what.Exop 4980 #define bits word.what.Bits 4981 4982 /* macros for bit input with no checking and for returning unused bytes */ 4983 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} 4984 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} 4985 4986 /* Called with number of bytes left to write in window at least 258 4987 * (the maximum string length) and number of input bytes available 4988 * at least ten. The ten bytes are six bytes for the longest length/ 4989 * distance pair plus four bytes for overloading the bit buffer. 4990 * 4991 * Parameters: 4992 * td: need separate declaration for Borland C++ 4993 */ 4994 int 4995 inflate_fast(uInt bl, uInt bd, inflate_huft *tl, inflate_huft *td, 4996 inflate_blocks_statef *s, z_streamp z) 4997 { 4998 inflate_huft *t; /* temporary pointer */ 4999 uInt e; /* extra bits or operation */ 5000 uLong b; /* bit buffer */ 5001 uInt k; /* bits in bit buffer */ 5002 Bytef *p; /* input data pointer */ 5003 uInt n; /* bytes available there */ 5004 Bytef *q; /* output window write pointer */ 5005 uInt m; /* bytes to end of window or read pointer */ 5006 uInt ml; /* mask for literal/length tree */ 5007 uInt md; /* mask for distance tree */ 5008 uInt c; /* bytes to copy */ 5009 uInt d; /* distance back to copy from */ 5010 Bytef *r; /* copy source pointer */ 5011 5012 /* load input, output, bit values */ 5013 LOAD 5014 5015 /* initialize masks */ 5016 ml = inflate_mask[bl]; 5017 md = inflate_mask[bd]; 5018 5019 /* do until not enough input or output space for fast loop */ 5020 do { /* assume called with m >= 258 && n >= 10 */ 5021 /* get literal/length code */ 5022 GRABBITS(20) /* max bits for literal/length code */ 5023 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) 5024 { 5025 DUMPBITS(t->bits) 5026 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5027 "inflate: * literal '%c'\n" : 5028 "inflate: * literal 0x%02x\n", t->base)); 5029 *q++ = (Byte)t->base; 5030 m--; 5031 continue; 5032 } 5033 do { 5034 DUMPBITS(t->bits) 5035 if (e & 16) 5036 { 5037 /* get extra bits for length */ 5038 e &= 15; 5039 c = t->base + ((uInt)b & inflate_mask[e]); 5040 DUMPBITS(e) 5041 Tracevv((stderr, "inflate: * length %u\n", c)); 5042 5043 /* decode distance base of block to copy */ 5044 GRABBITS(15); /* max bits for distance code */ 5045 e = (t = td + ((uInt)b & md))->exop; 5046 do { 5047 DUMPBITS(t->bits) 5048 if (e & 16) 5049 { 5050 /* get extra bits to add to distance base */ 5051 e &= 15; 5052 GRABBITS(e) /* get extra bits (up to 13) */ 5053 d = t->base + ((uInt)b & inflate_mask[e]); 5054 DUMPBITS(e) 5055 Tracevv((stderr, "inflate: * distance %u\n", d)); 5056 5057 /* do the copy */ 5058 m -= c; 5059 if ((uInt)(q - s->window) >= d) /* offset before dest */ 5060 { /* just copy */ 5061 r = q - d; 5062 *q++ = *r++; c--; /* minimum count is three, */ 5063 *q++ = *r++; c--; /* so unroll loop a little */ 5064 } 5065 else /* else offset after destination */ 5066 { 5067 e = d - (uInt)(q - s->window); /* bytes from offset to end */ 5068 r = s->end - e; /* pointer to offset */ 5069 if (c > e) /* if source crosses, */ 5070 { 5071 c -= e; /* copy to end of window */ 5072 do { 5073 *q++ = *r++; 5074 } while (--e); 5075 r = s->window; /* copy rest from start of window */ 5076 } 5077 } 5078 do { /* copy all or what's left */ 5079 *q++ = *r++; 5080 } while (--c); 5081 break; 5082 } 5083 else if ((e & 64) == 0) 5084 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; 5085 else 5086 { 5087 z->msg = (char*)"invalid distance code"; 5088 UNGRAB 5089 UPDATE 5090 return Z_DATA_ERROR; 5091 } 5092 } while (1); 5093 break; 5094 } 5095 if ((e & 64) == 0) 5096 { 5097 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) 5098 { 5099 DUMPBITS(t->bits) 5100 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? 5101 "inflate: * literal '%c'\n" : 5102 "inflate: * literal 0x%02x\n", t->base)); 5103 *q++ = (Byte)t->base; 5104 m--; 5105 break; 5106 } 5107 } 5108 else if (e & 32) 5109 { 5110 Tracevv((stderr, "inflate: * end of block\n")); 5111 UNGRAB 5112 UPDATE 5113 return Z_STREAM_END; 5114 } 5115 else 5116 { 5117 z->msg = (char*)"invalid literal/length code"; 5118 UNGRAB 5119 UPDATE 5120 return Z_DATA_ERROR; 5121 } 5122 } while (1); 5123 } while (m >= 258 && n >= 10); 5124 5125 /* not enough input or output--restore pointers and return */ 5126 UNGRAB 5127 UPDATE 5128 return Z_OK; 5129 } 5130 /* --- inffast.c */ 5131 5132 /* +++ zutil.c */ 5133 /* zutil.c -- target dependent utility functions for the compression library 5134 * Copyright (C) 1995-1996 Jean-loup Gailly. 5135 * For conditions of distribution and use, see copyright notice in zlib.h 5136 */ 5137 5138 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */ 5139 5140 #ifdef DEBUG_ZLIB 5141 #include <stdio.h> 5142 #endif 5143 5144 /* #include "zutil.h" */ 5145 5146 #ifndef NO_DUMMY_DECL 5147 struct internal_state {int dummy;}; /* for buggy compilers */ 5148 #endif 5149 5150 #ifndef STDC 5151 extern void exit OF((int)); 5152 #endif 5153 5154 static const char *z_errmsg[10] = { 5155 "need dictionary", /* Z_NEED_DICT 2 */ 5156 "stream end", /* Z_STREAM_END 1 */ 5157 "", /* Z_OK 0 */ 5158 "file error", /* Z_ERRNO (-1) */ 5159 "stream error", /* Z_STREAM_ERROR (-2) */ 5160 "data error", /* Z_DATA_ERROR (-3) */ 5161 "insufficient memory", /* Z_MEM_ERROR (-4) */ 5162 "buffer error", /* Z_BUF_ERROR (-5) */ 5163 "incompatible version",/* Z_VERSION_ERROR (-6) */ 5164 ""}; 5165 5166 5167 const char 5168 *zlibVersion(void) 5169 { 5170 return ZLIB_VERSION; 5171 } 5172 5173 #ifdef DEBUG_ZLIB 5174 void 5175 z_error(char *m) 5176 { 5177 fprintf(stderr, "%s\n", m); 5178 exit(1); 5179 } 5180 #endif 5181 5182 #ifndef HAVE_MEMCPY 5183 5184 void 5185 zmemcpy(Bytef *dest, Bytef *source, uInt len) 5186 { 5187 if (len == 0) return; 5188 do { 5189 *dest++ = *source++; /* ??? to be unrolled */ 5190 } while (--len != 0); 5191 } 5192 5193 int 5194 zmemcmp(Bytef *s1, Bytef *s2, uInt len) 5195 { 5196 uInt j; 5197 5198 for (j = 0; j < len; j++) { 5199 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1; 5200 } 5201 return 0; 5202 } 5203 5204 void 5205 zmemzero(Bytef *dest, uInt len) 5206 { 5207 if (len == 0) return; 5208 do { 5209 *dest++ = 0; /* ??? to be unrolled */ 5210 } while (--len != 0); 5211 } 5212 #endif 5213 5214 #ifdef __TURBOC__ 5215 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__) 5216 /* Small and medium model in Turbo C are for now limited to near allocation 5217 * with reduced MAX_WBITS and MAX_MEM_LEVEL 5218 */ 5219 # define MY_ZCALLOC 5220 5221 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes 5222 * and farmalloc(64K) returns a pointer with an offset of 8, so we 5223 * must fix the pointer. Warning: the pointer must be put back to its 5224 * original form in order to free it, use zcfree(). 5225 */ 5226 5227 #define MAX_PTR 10 5228 /* 10*64K = 640K */ 5229 5230 local int next_ptr = 0; 5231 5232 typedef struct ptr_table_s { 5233 voidpf org_ptr; 5234 voidpf new_ptr; 5235 } ptr_table; 5236 5237 local ptr_table table[MAX_PTR]; 5238 /* This table is used to remember the original form of pointers 5239 * to large buffers (64K). Such pointers are normalized with a zero offset. 5240 * Since MSDOS is not a preemptive multitasking OS, this table is not 5241 * protected from concurrent access. This hack doesn't work anyway on 5242 * a protected system like OS/2. Use Microsoft C instead. 5243 */ 5244 5245 voidpf 5246 zcalloc(voidpf opaque, unsigned items, unsigned size) 5247 { 5248 voidpf buf = opaque; /* just to make some compilers happy */ 5249 ulg bsize = (ulg)items*size; 5250 5251 /* If we allocate less than 65520 bytes, we assume that farmalloc 5252 * will return a usable pointer which doesn't have to be normalized. 5253 */ 5254 if (bsize < 65520L) { 5255 buf = farmalloc(bsize); 5256 if (*(ush*)&buf != 0) return buf; 5257 } else { 5258 buf = farmalloc(bsize + 16L); 5259 } 5260 if (buf == NULL || next_ptr >= MAX_PTR) return NULL; 5261 table[next_ptr].org_ptr = buf; 5262 5263 /* Normalize the pointer to seg:0 */ 5264 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; 5265 *(ush*)&buf = 0; 5266 table[next_ptr++].new_ptr = buf; 5267 return buf; 5268 } 5269 5270 void 5271 zcfree(voidpf opaque, voidpf ptr) 5272 { 5273 int n; 5274 if (*(ush*)&ptr != 0) { /* object < 64K */ 5275 farfree(ptr); 5276 return; 5277 } 5278 /* Find the original pointer */ 5279 for (n = 0; n < next_ptr; n++) { 5280 if (ptr != table[n].new_ptr) continue; 5281 5282 farfree(table[n].org_ptr); 5283 while (++n < next_ptr) { 5284 table[n-1] = table[n]; 5285 } 5286 next_ptr--; 5287 return; 5288 } 5289 ptr = opaque; /* just to make some compilers happy */ 5290 Assert(0, "zcfree: ptr not found"); 5291 } 5292 #endif 5293 #endif /* __TURBOC__ */ 5294 5295 5296 #if defined(M_I86) && !defined(__32BIT__) 5297 /* Microsoft C in 16-bit mode */ 5298 5299 # define MY_ZCALLOC 5300 5301 #if (!defined(_MSC_VER) || (_MSC_VER < 600)) 5302 # define _halloc halloc 5303 # define _hfree hfree 5304 #endif 5305 5306 voidpf 5307 zcalloc(voidpf opaque, unsigned items, unsigned size) 5308 { 5309 if (opaque) opaque = 0; /* to make compiler happy */ 5310 return _halloc((long)items, size); 5311 } 5312 5313 void 5314 zcfree(voidpf opaque, voidpf ptr) 5315 { 5316 if (opaque) opaque = 0; /* to make compiler happy */ 5317 _hfree(ptr); 5318 } 5319 5320 #endif /* MSC */ 5321 5322 5323 #ifndef MY_ZCALLOC /* Any system without a special alloc function */ 5324 5325 #ifndef STDC 5326 extern voidp calloc OF((uInt items, uInt size)); 5327 extern void free OF((voidpf ptr)); 5328 #endif 5329 5330 voidpf 5331 zcalloc(voidpf opaque, unsigned items, unsigned size) 5332 { 5333 if (opaque) items += size - size; /* make compiler happy */ 5334 return (voidpf)calloc(items, size); 5335 } 5336 5337 void 5338 zcfree(voidpf opaque, voidpf ptr) 5339 { 5340 free(ptr); 5341 if (opaque) return; /* make compiler happy */ 5342 } 5343 5344 #endif /* MY_ZCALLOC */ 5345 /* --- zutil.c */ 5346 5347 /* +++ adler32.c */ 5348 /* adler32.c -- compute the Adler-32 checksum of a data stream 5349 * Copyright (C) 1995-1996 Mark Adler 5350 * For conditions of distribution and use, see copyright notice in zlib.h 5351 */ 5352 5353 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */ 5354 5355 /* #include "zlib.h" */ 5356 5357 #define BASE 65521L /* largest prime smaller than 65536 */ 5358 #define NMAX 5552 5359 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ 5360 5361 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;} 5362 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1); 5363 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2); 5364 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4); 5365 #define DO16(buf) DO8(buf,0); DO8(buf,8); 5366 5367 /* ========================================================================= */ 5368 uLong 5369 adler32(uLong adler, const Bytef *buf, uInt len) 5370 { 5371 unsigned long s1 = adler & 0xffff; 5372 unsigned long s2 = (adler >> 16) & 0xffff; 5373 int k; 5374 5375 if (buf == Z_NULL) return 1L; 5376 5377 while (len > 0) { 5378 k = len < NMAX ? len : NMAX; 5379 len -= k; 5380 while (k >= 16) { 5381 DO16(buf); 5382 buf += 16; 5383 k -= 16; 5384 } 5385 if (k != 0) do { 5386 s1 += *buf++; 5387 s2 += s1; 5388 } while (--k); 5389 s1 %= BASE; 5390 s2 %= BASE; 5391 } 5392 return (s2 << 16) | s1; 5393 } 5394 /* --- adler32.c */ 5395