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1 /*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
11 *
12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22 /*
23 * This file is derived from various .h and .c files from the zlib-1.0.4
24 * distribution by Jean-loup Gailly and Mark Adler, with some additions
25 * by Paul Mackerras to aid in implementing Deflate compression and
26 * decompression for PPP packets. See zlib.h for conditions of
27 * distribution and use.
28 *
29 * Changes that have been made include:
30 * - added Z_PACKET_FLUSH (see zlib.h for details)
31 * - added inflateIncomp and deflateOutputPending
32 * - allow strm->next_out to be NULL, meaning discard the output
33 *
34 * $FreeBSD: src/sys/net/zlib.c,v 1.10 1999/12/29 04:38:38 peter Exp $
35 */
36
37 #define NO_DUMMY_DECL
38 #define NO_ZCFUNCS
39 #define MY_ZCALLOC
40
41 /* +++ zutil.h */
42 /* zutil.h -- internal interface and configuration of the compression library
43 * Copyright (C) 1995-2002 Jean-loup Gailly.
44 * For conditions of distribution and use, see copyright notice in zlib.h
45 */
46
47 /* WARNING: this file should *not* be used by applications. It is
48 part of the implementation of the compression library and is
49 subject to change. Applications should only use zlib.h.
50 */
51
52 /* @(#) $Id: zlib.c,v 1.8 2002/03/29 03:16:07 lindak Exp $ */
53
54 #ifndef _Z_UTIL_H
55 #define _Z_UTIL_H
56
57 #ifdef KERNEL
58 #include <net/zlib.h>
59 #else
60 #include "zlib.h"
61 #endif
62
63 #ifdef KERNEL
64 /* Assume this is a *BSD or SVR4 kernel */
65 #include <sys/types.h>
66 #include <sys/time.h>
67 #include <sys/systm.h>
68 # define HAVE_MEMCPY
69 # define memcpy(d, s, n) bcopy((s), (d), (n))
70 # define memset(d, v, n) bzero((d), (n))
71 # define memcmp bcmp
72
73 #else
74 #if defined(__KERNEL__)
75 /* Assume this is a Linux kernel */
76 #include <linux/string.h>
77 #define HAVE_MEMCPY
78
79 #else /* not kernel */
80 #ifdef STDC
81 # include <stddef.h>
82 # include <string.h>
83 # include <stdlib.h>
84 #endif
85 #ifdef NO_ERRNO_H
86 extern int errno;
87 #else
88 # include <errno.h>
89 #endif
90 #endif /* __KERNEL__ */
91 #endif /* KERNEL */
92
93 #ifndef local
94 # define local static
95 #endif
96 /* compile with -Dlocal if your debugger can't find static symbols */
97
98 typedef unsigned char uch;
99 typedef uch FAR uchf;
100 typedef unsigned short ush;
101 typedef ush FAR ushf;
102 typedef unsigned long ulg;
103
104 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
105 /* (size given to avoid silly warnings with Visual C++) */
106
107 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
108
109 #define ERR_RETURN(strm,err) \
110 return (strm->msg = (char*)ERR_MSG(err), (err))
111 /* To be used only when the state is known to be valid */
112
113 /* common constants */
114
115 #ifndef DEF_WBITS
116 # define DEF_WBITS MAX_WBITS
117 #endif
118 /* default windowBits for decompression. MAX_WBITS is for compression only */
119
120 #if MAX_MEM_LEVEL >= 8
121 # define DEF_MEM_LEVEL 8
122 #else
123 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
124 #endif
125 /* default memLevel */
126
127 #define STORED_BLOCK 0
128 #define STATIC_TREES 1
129 #define DYN_TREES 2
130 /* The three kinds of block type */
131
132 #define MIN_MATCH 3
133 #define MAX_MATCH 258
134 /* The minimum and maximum match lengths */
135
136 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
137
138 /* target dependencies */
139
140 #ifdef MSDOS
141 # define OS_CODE 0x00
142 # if defined(__TURBOC__) || defined(__BORLANDC__)
143 # if(__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
144 /* Allow compilation with ANSI keywords only enabled */
145 void _Cdecl farfree( void *block );
146 void *_Cdecl farmalloc( unsigned long nbytes );
147 # else
148 # include <alloc.h>
149 # endif
150 # else /* MSC or DJGPP */
151 # include <malloc.h>
152 # endif
153 #endif
154
155 #ifdef OS2
156 # define OS_CODE 0x06
157 #endif
158
159 #ifdef WIN32 /* Window 95 & Windows NT */
160 # define OS_CODE 0x0b
161 #endif
162
163 #if defined(VAXC) || defined(VMS)
164 # define OS_CODE 0x02
165 # define F_OPEN(name, mode) \
166 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
167 #endif
168
169 #ifdef AMIGA
170 # define OS_CODE 0x01
171 #endif
172
173 #if defined(ATARI) || defined(atarist)
174 # define OS_CODE 0x05
175 #endif
176
177 #if defined(MACOS) || defined(TARGET_OS_MAC)
178 # define OS_CODE 0x07
179 # if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
180 # include <unix.h> /* for fdopen */
181 # else
182 # ifndef fdopen
183 # define fdopen(fd,mode) NULL /* No fdopen() */
184 # endif
185 # endif
186 #endif
187
188 #ifdef __50SERIES /* Prime/PRIMOS */
189 # define OS_CODE 0x0F
190 #endif
191
192 #ifdef TOPS20
193 # define OS_CODE 0x0a
194 #endif
195
196 #if defined(_BEOS_) || defined(RISCOS)
197 # define fdopen(fd,mode) NULL /* No fdopen() */
198 #endif
199
200 #if (defined(_MSC_VER) && (_MSC_VER > 600))
201 # define fdopen(fd,type) _fdopen(fd,type)
202 #endif
203
204
205 /* Common defaults */
206
207 #ifndef OS_CODE
208 # define OS_CODE 0x03 /* assume Unix */
209 #endif
210
211 #ifndef F_OPEN
212 # define F_OPEN(name, mode) fopen((name), (mode))
213 #endif
214
215 /* functions */
216
217 #ifdef HAVE_STRERROR
218 extern char *strerror OF((int));
219 # define zstrerror(errnum) strerror(errnum)
220 #else
221 # define zstrerror(errnum) ""
222 #endif
223
224 #if defined(pyr)
225 # define NO_MEMCPY
226 #endif
227 #if defined(SMALL_MEDIUM) && !defined(_MSC_VER) && !defined(__SC__)
228 /* Use our own functions for small and medium model with MSC <= 5.0.
229 * You may have to use the same strategy for Borland C (untested).
230 * The __SC__ check is for Symantec.
231 */
232 # define NO_MEMCPY
233 #endif
234 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
235 # define HAVE_MEMCPY
236 #endif
237 #ifdef HAVE_MEMCPY
238 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
239 # define zmemcpy _fmemcpy
240 # define zmemcmp _fmemcmp
241 # define zmemzero(dest, len) _fmemset(dest, 0, len)
242 # else
243 # define zmemcpy memcpy
244 # define zmemcmp memcmp
245 # define zmemzero(dest, len) memset(dest, 0, len)
246 # endif
247 #else
248 extern void zmemcpy OF((Bytef* dest, const Bytef* source, uInt len));
249 extern int zmemcmp OF((const Bytef* s1, const Bytef* s2, uInt len));
250 extern void zmemzero OF((Bytef* dest, uInt len));
251 #endif
252
253 /* Diagnostic functions */
254 #ifdef DEBUG_ZLIB
255 # include <stdio.h>
256 extern int z_verbose;
257 extern void z_error OF((char *m));
258 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
259 # define Trace(x) {if (z_verbose>=0) fprintf x ;}
260 # define Tracev(x) {if (z_verbose>0) fprintf x ;}
261 # define Tracevv(x) {if (z_verbose>1) fprintf x ;}
262 # define Tracec(c,x) {if (z_verbose>0 && (c)) fprintf x ;}
263 # define Tracecv(c,x) {if (z_verbose>1 && (c)) fprintf x ;}
264 #else
265 # define Assert(cond,msg)
266 # define Trace(x)
267 # define Tracev(x)
268 # define Tracevv(x)
269 # define Tracec(c,x)
270 # define Tracecv(c,x)
271 #endif
272
273
274 typedef uLong (ZEXPORT *check_func) OF((uLong check, const Bytef *buf,
275 uInt len));
276 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
277 void zcfree OF((voidpf opaque, voidpf ptr));
278
279 #define ZALLOC(strm, items, size) \
280 (*((strm)->zalloc))((strm)->opaque, (items), (size))
281 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
282 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
283
284 #endif /* _Z_UTIL_H */
285 /* --- zutil.h */
286
287 /* +++ deflate.h */
288 /* deflate.h -- internal compression state
289 * Copyright (C) 1995-2002 Jean-loup Gailly
290 * For conditions of distribution and use, see copyright notice in zlib.h
291 */
292
293 /* WARNING: this file should *not* be used by applications. It is
294 part of the implementation of the compression library and is
295 subject to change. Applications should only use zlib.h.
296 */
297
298 /* @(#) $Id: zlib.c,v 1.8 2002/03/29 03:16:07 lindak Exp $ */
299
300 #ifndef _DEFLATE_H
301 #define _DEFLATE_H
302
303 /* #include "zutil.h" */
304
305 /* ===========================================================================
306 * Internal compression state.
307 */
308
309 #define LENGTH_CODES 29
310 /* number of length codes, not counting the special END_BLOCK code */
311
312 #define LITERALS 256
313 /* number of literal bytes 0..255 */
314
315 #define L_CODES (LITERALS+1+LENGTH_CODES)
316 /* number of Literal or Length codes, including the END_BLOCK code */
317
318 #define D_CODES 30
319 /* number of distance codes */
320
321 #define BL_CODES 19
322 /* number of codes used to transfer the bit lengths */
323
324 #define HEAP_SIZE (2*L_CODES+1)
325 /* maximum heap size */
326
327 #define MAX_BITS 15
328 /* All codes must not exceed MAX_BITS bits */
329
330 #define INIT_STATE 42
331 #define BUSY_STATE 113
332 #define FINISH_STATE 666
333 /* Stream status */
334
335
336 /* Data structure describing a single value and its code string. */
337 typedef struct ct_data_s {
338 union {
339 ush freq; /* frequency count */
340 ush code; /* bit string */
341 } fc;
342 union {
343 ush dad; /* father node in Huffman tree */
344 ush len; /* length of bit string */
345 } dl;
346 } FAR ct_data;
347
348 #define Freq fc.freq
349 #define Code fc.code
350 #define Dad dl.dad
351 #define Len dl.len
352
353 typedef struct static_tree_desc_s static_tree_desc;
354
355 typedef struct tree_desc_s {
356 ct_data *dyn_tree; /* the dynamic tree */
357 int max_code; /* largest code with non zero frequency */
358 static_tree_desc *stat_desc; /* the corresponding static tree */
359 } FAR tree_desc;
360
361 typedef ush Pos;
362 typedef Pos FAR Posf;
363 typedef unsigned IPos;
364
365 /* A Pos is an index in the character window. We use short instead of int to
366 * save space in the various tables. IPos is used only for parameter passing.
367 */
368
369 typedef struct deflate_state {
370 z_streamp strm; /* pointer back to this zlib stream */
371 int status; /* as the name implies */
372 Bytef *pending_buf; /* output still pending */
373 ulg pending_buf_size; /* size of pending_buf */
374 Bytef *pending_out; /* next pending byte to output to the stream */
375 int pending; /* nb of bytes in the pending buffer */
376 int noheader; /* suppress zlib header and adler32 */
377 Byte data_type; /* UNKNOWN, BINARY or ASCII */
378 Byte method; /* STORED (for zip only) or DEFLATED */
379 int last_flush; /* value of flush param for previous deflate call */
380
381 /* used by deflate.c: */
382
383 uInt w_size; /* LZ77 window size (32K by default) */
384 uInt w_bits; /* log2(w_size) (8..16) */
385 uInt w_mask; /* w_size - 1 */
386
387 Bytef *window;
388 /* Sliding window. Input bytes are read into the second half of the window,
389 * and move to the first half later to keep a dictionary of at least wSize
390 * bytes. With this organization, matches are limited to a distance of
391 * wSize-MAX_MATCH bytes, but this ensures that IO is always
392 * performed with a length multiple of the block size. Also, it limits
393 * the window size to 64K, which is quite useful on MSDOS.
394 * To do: use the user input buffer as sliding window.
395 */
396
397 ulg window_size;
398 /* Actual size of window: 2*wSize, except when the user input buffer
399 * is directly used as sliding window.
400 */
401
402 Posf *prev;
403 /* Link to older string with same hash index. To limit the size of this
404 * array to 64K, this link is maintained only for the last 32K strings.
405 * An index in this array is thus a window index modulo 32K.
406 */
407
408 Posf *head; /* Heads of the hash chains or NIL. */
409
410 uInt ins_h; /* hash index of string to be inserted */
411 uInt hash_size; /* number of elements in hash table */
412 uInt hash_bits; /* log2(hash_size) */
413 uInt hash_mask; /* hash_size-1 */
414
415 uInt hash_shift;
416 /* Number of bits by which ins_h must be shifted at each input
417 * step. It must be such that after MIN_MATCH steps, the oldest
418 * byte no longer takes part in the hash key, that is:
419 * hash_shift * MIN_MATCH >= hash_bits
420 */
421
422 long block_start;
423 /* Window position at the beginning of the current output block. Gets
424 * negative when the window is moved backwards.
425 */
426
427 uInt match_length; /* length of best match */
428 IPos prev_match; /* previous match */
429 int match_available; /* set if previous match exists */
430 uInt strstart; /* start of string to insert */
431 uInt match_start; /* start of matching string */
432 uInt lookahead; /* number of valid bytes ahead in window */
433
434 uInt prev_length;
435 /* Length of the best match at previous step. Matches not greater than this
436 * are discarded. This is used in the lazy match evaluation.
437 */
438
439 uInt max_chain_length;
440 /* To speed up deflation, hash chains are never searched beyond this
441 * length. A higher limit improves compression ratio but degrades the
442 * speed.
443 */
444
445 uInt max_lazy_match;
446 /* Attempt to find a better match only when the current match is strictly
447 * smaller than this value. This mechanism is used only for compression
448 * levels >= 4.
449 */
450 # define max_insert_length max_lazy_match
451 /* Insert new strings in the hash table only if the match length is not
452 * greater than this length. This saves time but degrades compression.
453 * max_insert_length is used only for compression levels <= 3.
454 */
455
456 int level; /* compression level (1..9) */
457 int strategy; /* favor or force Huffman coding*/
458
459 uInt good_match;
460 /* Use a faster search when the previous match is longer than this */
461
462 int nice_match; /* Stop searching when current match exceeds this */
463
464 /* used by trees.c: */
465 /* Didn't use ct_data typedef below to supress compiler warning */
466 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
467 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
468 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
469
470 struct tree_desc_s l_desc; /* desc. for literal tree */
471 struct tree_desc_s d_desc; /* desc. for distance tree */
472 struct tree_desc_s bl_desc; /* desc. for bit length tree */
473
474 ush bl_count[MAX_BITS+1];
475 /* number of codes at each bit length for an optimal tree */
476
477 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
478 int heap_len; /* number of elements in the heap */
479 int heap_max; /* element of largest frequency */
480 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
481 * The same heap array is used to build all trees.
482 */
483
484 uch depth[2*L_CODES+1];
485 /* Depth of each subtree used as tie breaker for trees of equal frequency
486 */
487
488 uchf *l_buf; /* buffer for literals or lengths */
489
490 uInt lit_bufsize;
491 /* Size of match buffer for literals/lengths. There are 4 reasons for
492 * limiting lit_bufsize to 64K:
493 * - frequencies can be kept in 16 bit counters
494 * - if compression is not successful for the first block, all input
495 * data is still in the window so we can still emit a stored block even
496 * when input comes from standard input. (This can also be done for
497 * all blocks if lit_bufsize is not greater than 32K.)
498 * - if compression is not successful for a file smaller than 64K, we can
499 * even emit a stored file instead of a stored block (saving 5 bytes).
500 * This is applicable only for zip (not gzip or zlib).
501 * - creating new Huffman trees less frequently may not provide fast
502 * adaptation to changes in the input data statistics. (Take for
503 * example a binary file with poorly compressible code followed by
504 * a highly compressible string table.) Smaller buffer sizes give
505 * fast adaptation but have of course the overhead of transmitting
506 * trees more frequently.
507 * - I can't count above 4
508 */
509
510 uInt last_lit; /* running index in l_buf */
511
512 ushf *d_buf;
513 /* Buffer for distances. To simplify the code, d_buf and l_buf have
514 * the same number of elements. To use different lengths, an extra flag
515 * array would be necessary.
516 */
517
518 ulg opt_len; /* bit length of current block with optimal trees */
519 ulg static_len; /* bit length of current block with static trees */
520 uInt matches; /* number of string matches in current block */
521 int last_eob_len; /* bit length of EOB code for last block */
522
523 #ifdef DEBUG_ZLIB
524 ulg compressed_len; /* total bit length of compressed file mod 2^32 */
525 ulg bits_sent; /* bit length of compressed data sent mod 2^32 */
526 #endif
527
528 ush bi_buf;
529 /* Output buffer. bits are inserted starting at the bottom (least
530 * significant bits).
531 */
532 int bi_valid;
533 /* Number of valid bits in bi_buf. All bits above the last valid bit
534 * are always zero.
535 */
536
537 } FAR deflate_state;
538
539 /* Output a byte on the stream.
540 * IN assertion: there is enough room in pending_buf.
541 */
542 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
543
544
545 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
546 /* Minimum amount of lookahead, except at the end of the input file.
547 * See deflate.c for comments about the MIN_MATCH+1.
548 */
549
550 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
551 /* In order to simplify the code, particularly on 16 bit machines, match
552 * distances are limited to MAX_DIST instead of WSIZE.
553 */
554
555 /* in trees.c */
556 void _tr_init OF((deflate_state *s));
557 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
558 void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
559 int eof));
560 void _tr_align OF((deflate_state *s));
561 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
562 int eof));
563
564 #define d_code(dist) \
565 ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
566 /* Mapping from a distance to a distance code. dist is the distance - 1 and
567 * must not have side effects. _dist_code[256] and _dist_code[257] are never
568 * used.
569 */
570
571 #ifndef DEBUG_ZLIB
572 /* Inline versions of _tr_tally for speed: */
573
574 #if defined(GEN_TREES_H) || !defined(STDC)
575 extern uch _length_code[];
576 extern uch _dist_code[];
577 #else
578 extern const uch _length_code[];
579 extern const uch _dist_code[];
580 #endif
581
582 # define _tr_tally_lit(s, c, flush) \
583 { uch cc = (c); \
584 s->d_buf[s->last_lit] = 0; \
585 s->l_buf[s->last_lit++] = cc; \
586 s->dyn_ltree[cc].Freq++; \
587 flush = (s->last_lit == s->lit_bufsize-1); \
588 }
589 # define _tr_tally_dist(s, distance, length, flush) \
590 { uch len = (length); \
591 ush dist = (distance); \
592 s->d_buf[s->last_lit] = dist; \
593 s->l_buf[s->last_lit++] = len; \
594 dist--; \
595 s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
596 s->dyn_dtree[d_code(dist)].Freq++; \
597 flush = (s->last_lit == s->lit_bufsize-1); \
598 }
599 #else
600 # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
601 # define _tr_tally_dist(s, distance, length, flush) \
602 flush = _tr_tally(s, distance, length)
603 #endif
604
605 #endif
606 /* --- deflate.h */
607
608 /* +++ deflate.c */
609 /* deflate.c -- compress data using the deflation algorithm
610 * Copyright (C) 1995-2002 Jean-loup Gailly.
611 * For conditions of distribution and use, see copyright notice in zlib.h
612 */
613
614 /*
615 * ALGORITHM
616 *
617 * The "deflation" process depends on being able to identify portions
618 * of the input text which are identical to earlier input (within a
619 * sliding window trailing behind the input currently being processed).
620 *
621 * The most straightforward technique turns out to be the fastest for
622 * most input files: try all possible matches and select the longest.
623 * The key feature of this algorithm is that insertions into the string
624 * dictionary are very simple and thus fast, and deletions are avoided
625 * completely. Insertions are performed at each input character, whereas
626 * string matches are performed only when the previous match ends. So it
627 * is preferable to spend more time in matches to allow very fast string
628 * insertions and avoid deletions. The matching algorithm for small
629 * strings is inspired from that of Rabin & Karp. A brute force approach
630 * is used to find longer strings when a small match has been found.
631 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
632 * (by Leonid Broukhis).
633 * A previous version of this file used a more sophisticated algorithm
634 * (by Fiala and Greene) which is guaranteed to run in linear amortized
635 * time, but has a larger average cost, uses more memory and is patented.
636 * However the F&G algorithm may be faster for some highly redundant
637 * files if the parameter max_chain_length (described below) is too large.
638 *
639 * ACKNOWLEDGEMENTS
640 *
641 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
642 * I found it in 'freeze' written by Leonid Broukhis.
643 * Thanks to many people for bug reports and testing.
644 *
645 * REFERENCES
646 *
647 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
648 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
649 *
650 * A description of the Rabin and Karp algorithm is given in the book
651 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
652 *
653 * Fiala,E.R., and Greene,D.H.
654 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
655 *
656 */
657
658 /* @(#) $Id: zlib.c,v 1.8 2002/03/29 03:16:07 lindak Exp $ */
659
660 /* #include "deflate.h" */
661
662 const char deflate_copyright[] =
663 " deflate 1.1.4 Copyright 1995-2002 Jean-loup Gailly ";
664 /*
665 If you use the zlib library in a product, an acknowledgment is welcome
666 in the documentation of your product. If for some reason you cannot
667 include such an acknowledgment, I would appreciate that you keep this
668 copyright string in the executable of your product.
669 */
670
671 /* ===========================================================================
672 * Function prototypes.
673 */
674 typedef enum {
675 need_more, /* block not completed, need more input or more output */
676 block_done, /* block flush performed */
677 finish_started, /* finish started, need only more output at next deflate */
678 finish_done /* finish done, accept no more input or output */
679 } block_state;
680
681 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
682 /* Compression function. Returns the block state after the call. */
683
684 local void fill_window OF((deflate_state *s));
685 local block_state deflate_stored OF((deflate_state *s, int flush));
686 local block_state deflate_fast OF((deflate_state *s, int flush));
687 local block_state deflate_slow OF((deflate_state *s, int flush));
688 local void lm_init OF((deflate_state *s));
689 local void putShortMSB OF((deflate_state *s, uInt b));
690 local void flush_pending OF((z_streamp strm));
691 local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
692 #ifdef ASMV
693 void match_init OF((void)); /* asm code initialization */
694 uInt longest_match OF((deflate_state *s, IPos cur_match));
695 #else
696 local uInt longest_match OF((deflate_state *s, IPos cur_match));
697 #endif
698
699 #ifdef DEBUG_ZLIB
700 local void check_match OF((deflate_state *s, IPos start, IPos match,
701 int length));
702 #endif
703
704 /* ===========================================================================
705 * Local data
706 */
707
708 #define NIL 0
709 /* Tail of hash chains */
710
711 #ifndef TOO_FAR
712 # define TOO_FAR 4096
713 #endif
714 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
715
716 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
717 /* Minimum amount of lookahead, except at the end of the input file.
718 * See deflate.c for comments about the MIN_MATCH+1.
719 */
720
721 /* Values for max_lazy_match, good_match and max_chain_length, depending on
722 * the desired pack level (0..9). The values given below have been tuned to
723 * exclude worst case performance for pathological files. Better values may be
724 * found for specific files.
725 */
726 typedef struct config_s {
727 ush good_length; /* reduce lazy search above this match length */
728 ush max_lazy; /* do not perform lazy search above this match length */
729 ush nice_length; /* quit search above this match length */
730 ush max_chain;
731 compress_func func;
732 } config;
733
734 local const config configuration_table[10] = {
735 /* good lazy nice chain */
736 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
737 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
738 /* 2 */ {4, 5, 16, 8, deflate_fast},
739 /* 3 */ {4, 6, 32, 32, deflate_fast},
740
741 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
742 /* 5 */ {8, 16, 32, 32, deflate_slow},
743 /* 6 */ {8, 16, 128, 128, deflate_slow},
744 /* 7 */ {8, 32, 128, 256, deflate_slow},
745 /* 8 */ {32, 128, 258, 1024, deflate_slow},
746 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
747
748 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
749 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
750 * meaning.
751 */
752
753 #define EQUAL 0
754 /* result of memcmp for equal strings */
755
756 #ifndef NO_DUMMY_DECL
757 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
758 #endif
759
760 /* ===========================================================================
761 * Update a hash value with the given input byte
762 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
763 * input characters, so that a running hash key can be computed from the
764 * previous key instead of complete recalculation each time.
765 */
766 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
767
768
769 /* ===========================================================================
770 * Insert string str in the dictionary and set match_head to the previous head
771 * of the hash chain (the most recent string with same hash key). Return
772 * the previous length of the hash chain.
773 * If this file is compiled with -DFASTEST, the compression level is forced
774 * to 1, and no hash chains are maintained.
775 * IN assertion: all calls to to INSERT_STRING are made with consecutive
776 * input characters and the first MIN_MATCH bytes of str are valid
777 * (except for the last MIN_MATCH-1 bytes of the input file).
778 */
779 #ifdef FASTEST
780 #define INSERT_STRING(s, str, match_head) \
781 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
782 match_head = s->head[s->ins_h], \
783 s->head[s->ins_h] = (Pos)(str))
784 #else
785 #define INSERT_STRING(s, str, match_head) \
786 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
787 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
788 s->head[s->ins_h] = (Pos)(str))
789 #endif
790
791 /* ===========================================================================
792 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
793 * prev[] will be initialized on the fly.
794 */
795 #define CLEAR_HASH(s) \
796 s->head[s->hash_size-1] = NIL; \
797 zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
798
799 /* ========================================================================= */
800 int ZEXPORT deflateInit_(strm, level, version, stream_size)
801 z_streamp strm;
802 int level;
803 const char *version;
804 int stream_size;
805 {
806 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
807 Z_DEFAULT_STRATEGY, version, stream_size);
808 /* To do: ignore strm->next_in if we use it as window */
809 }
810
811 /* ========================================================================= */
812 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
813 version, stream_size)
814 z_streamp strm;
815 int level;
816 int method;
817 int windowBits;
818 int memLevel;
819 int strategy;
820 const char *version;
821 int stream_size;
822 {
823 deflate_state *s;
824 int noheader = 0;
825 static const char* my_version = ZLIB_VERSION;
826
827 ushf *overlay;
828 /* We overlay pending_buf and d_buf+l_buf. This works since the average
829 * output size for (length,distance) codes is <= 24 bits.
830 */
831
832 if (version == Z_NULL || version[0] != my_version[0] ||
833 stream_size != sizeof(z_stream)) {
834 return Z_VERSION_ERROR;
835 }
836 if (strm == Z_NULL) return Z_STREAM_ERROR;
837
838 strm->msg = Z_NULL;
839 #ifndef NO_ZCFUNCS
840 if (strm->zalloc == Z_NULL) {
841 strm->zalloc = zcalloc;
842 strm->opaque = (voidpf)0;
843 }
844 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
845 #endif
846
847 if (level == Z_DEFAULT_COMPRESSION) level = 6;
848 #ifdef FASTEST
849 level = 1;
850 #endif
851
852 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
853 noheader = 1;
854 windowBits = -windowBits;
855 }
856 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
857 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
858 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
859 return Z_STREAM_ERROR;
860 }
861 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
862 if (s == Z_NULL) return Z_MEM_ERROR;
863 strm->state = (struct internal_state FAR *)s;
864 s->strm = strm;
865
866 s->noheader = noheader;
867 s->w_bits = windowBits;
868 s->w_size = 1 << s->w_bits;
869 s->w_mask = s->w_size - 1;
870
871 s->hash_bits = memLevel + 7;
872 s->hash_size = 1 << s->hash_bits;
873 s->hash_mask = s->hash_size - 1;
874 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
875
876 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
877 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
878 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
879
880 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
881
882 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
883 s->pending_buf = (uchf *) overlay;
884 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
885
886 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
887 s->pending_buf == Z_NULL) {
888 strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
889 deflateEnd (strm);
890 return Z_MEM_ERROR;
891 }
892 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
893 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
894
895 s->level = level;
896 s->strategy = strategy;
897 s->method = (Byte)method;
898
899 return deflateReset(strm);
900 }
901
902 /* ========================================================================= */
903 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
904 z_streamp strm;
905 const Bytef *dictionary;
906 uInt dictLength;
907 {
908 deflate_state *s;
909 uInt length = dictLength;
910 uInt n;
911 IPos hash_head = 0;
912
913 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL ||
914 ((deflate_state*)strm->state)->status != INIT_STATE) return Z_STREAM_ERROR;
915
916 s = (deflate_state*)strm->state;
917 strm->adler = adler32(strm->adler, dictionary, dictLength);
918
919 if (length < MIN_MATCH) return Z_OK;
920 if (length > MAX_DIST(s)) {
921 length = MAX_DIST(s);
922 #ifndef USE_DICT_HEAD
923 dictionary += dictLength - length; /* use the tail of the dictionary */
924 #endif
925 }
926 zmemcpy(s->window, dictionary, length);
927 s->strstart = length;
928 s->block_start = (long)length;
929
930 /* Insert all strings in the hash table (except for the last two bytes).
931 * s->lookahead stays null, so s->ins_h will be recomputed at the next
932 * call of fill_window.
933 */
934 s->ins_h = s->window[0];
935 UPDATE_HASH(s, s->ins_h, s->window[1]);
936 for (n = 0; n <= length - MIN_MATCH; n++) {
937 INSERT_STRING(s, n, hash_head);
938 }
939 if (hash_head) hash_head = 0; /* to make compiler happy */
940 return Z_OK;
941 }
942
943 /* ========================================================================= */
944 int ZEXPORT deflateReset (strm)
945 z_streamp strm;
946 {
947 deflate_state *s;
948
949 if (strm == Z_NULL || strm->state == Z_NULL ||
950 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
951
952 strm->total_in = strm->total_out = 0;
953 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
954 strm->data_type = Z_UNKNOWN;
955
956 s = (deflate_state *)strm->state;
957 s->pending = 0;
958 s->pending_out = s->pending_buf;
959
960 if (s->noheader < 0) {
961 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
962 }
963 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
964 strm->adler = 1;
965 s->last_flush = Z_NO_FLUSH;
966
967 _tr_init(s);
968 lm_init(s);
969
970 return Z_OK;
971 }
972
973 /* ========================================================================= */
974 int ZEXPORT deflateParams(strm, level, strategy)
975 z_streamp strm;
976 int level;
977 int strategy;
978 {
979 deflate_state *s;
980 compress_func func;
981 int err = Z_OK;
982
983 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
984 s = (deflate_state*)strm->state;
985
986 if (level == Z_DEFAULT_COMPRESSION) {
987 level = 6;
988 }
989 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
990 return Z_STREAM_ERROR;
991 }
992 func = configuration_table[s->level].func;
993
994 if (func != configuration_table[level].func && strm->total_in != 0) {
995 /* Flush the last buffer: */
996 err = deflate(strm, Z_PARTIAL_FLUSH);
997 }
998 if (s->level != level) {
999 s->level = level;
1000 s->max_lazy_match = configuration_table[level].max_lazy;
1001 s->good_match = configuration_table[level].good_length;
1002 s->nice_match = configuration_table[level].nice_length;
1003 s->max_chain_length = configuration_table[level].max_chain;
1004 }
1005 s->strategy = strategy;
1006 return err;
1007 }
1008
1009 /* =========================================================================
1010 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
1011 * IN assertion: the stream state is correct and there is enough room in
1012 * pending_buf.
1013 */
1014 local void putShortMSB (s, b)
1015 deflate_state *s;
1016 uInt b;
1017 {
1018 put_byte(s, (Byte)(b >> 8));
1019 put_byte(s, (Byte)(b & 0xff));
1020 }
1021
1022 /* =========================================================================
1023 * Flush as much pending output as possible. All deflate() output goes
1024 * through this function so some applications may wish to modify it
1025 * to avoid allocating a large strm->next_out buffer and copying into it.
1026 * (See also read_buf()).
1027 */
1028 local void flush_pending(strm)
1029 z_streamp strm;
1030 {
1031 deflate_state* s = (deflate_state*)strm->state;
1032 unsigned len = s->pending;
1033
1034 if (len > strm->avail_out) len = strm->avail_out;
1035 if (len == 0) return;
1036
1037 zmemcpy(strm->next_out, s->pending_out, len);
1038 strm->next_out += len;
1039 s->pending_out += len;
1040 strm->total_out += len;
1041 strm->avail_out -= len;
1042 s->pending -= len;
1043 if (s->pending == 0) {
1044 s->pending_out = s->pending_buf;
1045 }
1046 }
1047
1048 /* ========================================================================= */
1049 int ZEXPORT deflate (strm, flush)
1050 z_streamp strm;
1051 int flush;
1052 {
1053 int old_flush; /* value of flush param for previous deflate call */
1054 deflate_state *s;
1055
1056 if (strm == Z_NULL || strm->state == Z_NULL ||
1057 flush > Z_FINISH || flush < 0) {
1058 return Z_STREAM_ERROR;
1059 }
1060 s = (deflate_state*)strm->state;
1061
1062 if (strm->next_out == Z_NULL ||
1063 (strm->next_in == Z_NULL && strm->avail_in != 0) ||
1064 (s->status == FINISH_STATE && flush != Z_FINISH)) {
1065 ERR_RETURN(strm, Z_STREAM_ERROR);
1066 }
1067 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
1068
1069 s->strm = strm; /* just in case */
1070 old_flush = s->last_flush;
1071 s->last_flush = flush;
1072
1073 /* Write the zlib header */
1074 if (s->status == INIT_STATE) {
1075
1076 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1077 uInt level_flags = (s->level-1) >> 1;
1078
1079 if (level_flags > 3) level_flags = 3;
1080 header |= (level_flags << 6);
1081 if (s->strstart != 0) header |= PRESET_DICT;
1082 header += 31 - (header % 31);
1083
1084 s->status = BUSY_STATE;
1085 putShortMSB(s, header);
1086
1087 /* Save the adler32 of the preset dictionary: */
1088 if (s->strstart != 0) {
1089 putShortMSB(s, (uInt)(strm->adler >> 16));
1090 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1091 }
1092 strm->adler = 1L;
1093 }
1094
1095 /* Flush as much pending output as possible */
1096 if (s->pending != 0) {
1097 flush_pending(strm);
1098 if (strm->avail_out == 0) {
1099 /* Since avail_out is 0, deflate will be called again with
1100 * more output space, but possibly with both pending and
1101 * avail_in equal to zero. There won't be anything to do,
1102 * but this is not an error situation so make sure we
1103 * return OK instead of BUF_ERROR at next call of deflate:
1104 */
1105 s->last_flush = -1;
1106 return Z_OK;
1107 }
1108
1109 /* Make sure there is something to do and avoid duplicate consecutive
1110 * flushes. For repeated and useless calls with Z_FINISH, we keep
1111 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1112 */
1113 } else if (strm->avail_in == 0 && flush <= old_flush &&
1114 flush != Z_FINISH) {
1115 ERR_RETURN(strm, Z_BUF_ERROR);
1116 }
1117
1118 /* User must not provide more input after the first FINISH: */
1119 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1120 ERR_RETURN(strm, Z_BUF_ERROR);
1121 }
1122
1123 /* Start a new block or continue the current one.
1124 */
1125 if (strm->avail_in != 0 || s->lookahead != 0 ||
1126 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1127 block_state bstate;
1128
1129 bstate = (*(configuration_table[s->level].func))(s, flush);
1130
1131 if (bstate == finish_started || bstate == finish_done) {
1132 s->status = FINISH_STATE;
1133 }
1134 if (bstate == need_more || bstate == finish_started) {
1135 if (strm->avail_out == 0) {
1136 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1137 }
1138 return Z_OK;
1139 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1140 * of deflate should use the same flush parameter to make sure
1141 * that the flush is complete. So we don't have to output an
1142 * empty block here, this will be done at next call. This also
1143 * ensures that for a very small output buffer, we emit at most
1144 * one empty block.
1145 */
1146 }
1147 if (bstate == block_done) {
1148 if (flush == Z_PARTIAL_FLUSH) {
1149 _tr_align(s);
1150 } else { /* FULL_FLUSH or SYNC_FLUSH */
1151 _tr_stored_block(s, (char*)0, 0L, 0);
1152 /* For a full flush, this empty block will be recognized
1153 * as a special marker by inflate_sync().
1154 */
1155 if (flush == Z_FULL_FLUSH) {
1156 CLEAR_HASH(s); /* forget history */
1157 }
1158 }
1159 flush_pending(strm);
1160 if (strm->avail_out == 0) {
1161 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1162 return Z_OK;
1163 }
1164 }
1165 }
1166 Assert(strm->avail_out > 0, "bug2");
1167
1168 if (flush != Z_FINISH) return Z_OK;
1169 if (s->noheader) return Z_STREAM_END;
1170
1171 /* Write the zlib trailer (adler32) */
1172 putShortMSB(s, (uInt)(strm->adler >> 16));
1173 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1174 flush_pending(strm);
1175 /* If avail_out is zero, the application will call deflate again
1176 * to flush the rest.
1177 */
1178 s->noheader = -1; /* write the trailer only once! */
1179 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1180 }
1181
1182 /* ========================================================================= */
1183 int ZEXPORT deflateEnd (strm)
1184 z_streamp strm;
1185 {
1186 deflate_state* s;
1187 int status;
1188
1189 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1190
1191 s = (deflate_state*)strm->state;
1192 status = s->status;
1193 if (status != INIT_STATE && status != BUSY_STATE &&
1194 status != FINISH_STATE) {
1195 return Z_STREAM_ERROR;
1196 }
1197
1198 /* Deallocate in reverse order of allocations: */
1199 TRY_FREE(strm, s->pending_buf);
1200 TRY_FREE(strm, s->head);
1201 TRY_FREE(strm, s->prev);
1202 TRY_FREE(strm, s->window);
1203
1204 ZFREE(strm, s);
1205 strm->state = Z_NULL;
1206
1207 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1208 }
1209
1210 /* =========================================================================
1211 * Copy the source state to the destination state.
1212 * To simplify the source, this is not supported for 16-bit MSDOS (which
1213 * doesn't have enough memory anyway to duplicate compression states).
1214 */
1215 int ZEXPORT deflateCopy (dest, source)
1216 z_streamp dest;
1217 z_streamp source;
1218 {
1219 #ifdef MAXSEG_64K
1220 return Z_STREAM_ERROR;
1221 #else
1222 deflate_state *ds;
1223 deflate_state *ss;
1224 ushf *overlay;
1225
1226
1227 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
1228 return Z_STREAM_ERROR;
1229 }
1230
1231 ss = (deflate_state*)source->state;
1232
1233 *dest = *source;
1234
1235 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1236 if (ds == Z_NULL) return Z_MEM_ERROR;
1237 dest->state = (struct internal_state FAR *) ds;
1238 *ds = *ss;
1239 ds->strm = dest;
1240
1241 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1242 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1243 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1244 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1245 ds->pending_buf = (uchf *) overlay;
1246
1247 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1248 ds->pending_buf == Z_NULL) {
1249 deflateEnd (dest);
1250 return Z_MEM_ERROR;
1251 }
1252 /* following zmemcpy do not work for 16-bit MSDOS */
1253 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1254 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1255 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1256 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1257
1258 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1259 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1260 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1261
1262 ds->l_desc.dyn_tree = ds->dyn_ltree;
1263 ds->d_desc.dyn_tree = ds->dyn_dtree;
1264 ds->bl_desc.dyn_tree = ds->bl_tree;
1265
1266 return Z_OK;
1267 #endif
1268 }
1269
1270 /* ===========================================================================
1271 * Read a new buffer from the current input stream, update the adler32
1272 * and total number of bytes read. All deflate() input goes through
1273 * this function so some applications may wish to modify it to avoid
1274 * allocating a large strm->next_in buffer and copying from it.
1275 * (See also flush_pending()).
1276 */
1277 local int read_buf(strm, buf, size)
1278 z_streamp strm;
1279 Bytef *buf;
1280 unsigned size;
1281 {
1282 unsigned len = strm->avail_in;
1283
1284 if (len > size) len = size;
1285 if (len == 0) return 0;
1286
1287 strm->avail_in -= len;
1288
1289 if (!((deflate_state*)strm->state)->noheader) {
1290 strm->adler = adler32(strm->adler, strm->next_in, len);
1291 }
1292 zmemcpy(buf, strm->next_in, len);
1293 strm->next_in += len;
1294 strm->total_in += len;
1295
1296 return (int)len;
1297 }
1298
1299 /* ===========================================================================
1300 * Initialize the "longest match" routines for a new zlib stream
1301 */
1302 local void lm_init (s)
1303 deflate_state *s;
1304 {
1305 s->window_size = (ulg)2L*s->w_size;
1306
1307 CLEAR_HASH(s);
1308
1309 /* Set the default configuration parameters:
1310 */
1311 s->max_lazy_match = configuration_table[s->level].max_lazy;
1312 s->good_match = configuration_table[s->level].good_length;
1313 s->nice_match = configuration_table[s->level].nice_length;
1314 s->max_chain_length = configuration_table[s->level].max_chain;
1315
1316 s->strstart = 0;
1317 s->block_start = 0L;
1318 s->lookahead = 0;
1319 s->match_length = s->prev_length = MIN_MATCH-1;
1320 s->match_available = 0;
1321 s->ins_h = 0;
1322 #ifdef ASMV
1323 match_init(); /* initialize the asm code */
1324 #endif
1325 }
1326
1327 /* ===========================================================================
1328 * Set match_start to the longest match starting at the given string and
1329 * return its length. Matches shorter or equal to prev_length are discarded,
1330 * in which case the result is equal to prev_length and match_start is
1331 * garbage.
1332 * IN assertions: cur_match is the head of the hash chain for the current
1333 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1334 * OUT assertion: the match length is not greater than s->lookahead.
1335 */
1336 #ifndef ASMV
1337 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1338 * match.S. The code will be functionally equivalent.
1339 */
1340 #ifndef FASTEST
1341 local uInt longest_match(s, cur_match)
1342 deflate_state *s;
1343 IPos cur_match; /* current match */
1344 {
1345 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1346 register Bytef *scan = s->window + s->strstart; /* current string */
1347 register Bytef *match; /* matched string */
1348 register int len; /* length of current match */
1349 int best_len = s->prev_length; /* best match length so far */
1350 int nice_match = s->nice_match; /* stop if match long enough */
1351 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1352 s->strstart - (IPos)MAX_DIST(s) : NIL;
1353 /* Stop when cur_match becomes <= limit. To simplify the code,
1354 * we prevent matches with the string of window index 0.
1355 */
1356 Posf *prev = s->prev;
1357 uInt wmask = s->w_mask;
1358
1359 #ifdef UNALIGNED_OK
1360 /* Compare two bytes at a time. Note: this is not always beneficial.
1361 * Try with and without -DUNALIGNED_OK to check.
1362 */
1363 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1364 register ush scan_start = *(ushf*)scan;
1365 register ush scan_end = *(ushf*)(scan+best_len-1);
1366 #else
1367 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1368 register Byte scan_end1 = scan[best_len-1];
1369 register Byte scan_end = scan[best_len];
1370 #endif
1371
1372 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1373 * It is easy to get rid of this optimization if necessary.
1374 */
1375 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1376
1377 /* Do not waste too much time if we already have a good match: */
1378 if (s->prev_length >= s->good_match) {
1379 chain_length >>= 2;
1380 }
1381 /* Do not look for matches beyond the end of the input. This is necessary
1382 * to make deflate deterministic.
1383 */
1384 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1385
1386 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1387
1388 do {
1389 Assert(cur_match < s->strstart, "no future");
1390 match = s->window + cur_match;
1391
1392 /* Skip to next match if the match length cannot increase
1393 * or if the match length is less than 2:
1394 */
1395 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1396 /* This code assumes sizeof(unsigned short) == 2. Do not use
1397 * UNALIGNED_OK if your compiler uses a different size.
1398 */
1399 if (*(ushf*)(match+best_len-1) != scan_end ||
1400 *(ushf*)match != scan_start) continue;
1401
1402 /* It is not necessary to compare scan[2] and match[2] since they are
1403 * always equal when the other bytes match, given that the hash keys
1404 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1405 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1406 * lookahead only every 4th comparison; the 128th check will be made
1407 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1408 * necessary to put more guard bytes at the end of the window, or
1409 * to check more often for insufficient lookahead.
1410 */
1411 Assert(scan[2] == match[2], "scan[2]?");
1412 scan++, match++;
1413 do {
1414 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1415 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1416 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1417 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1418 scan < strend);
1419 /* The funny "do {}" generates better code on most compilers */
1420
1421 /* Here, scan <= window+strstart+257 */
1422 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1423 if (*scan == *match) scan++;
1424
1425 len = (MAX_MATCH - 1) - (int)(strend-scan);
1426 scan = strend - (MAX_MATCH-1);
1427
1428 #else /* UNALIGNED_OK */
1429
1430 if (match[best_len] != scan_end ||
1431 match[best_len-1] != scan_end1 ||
1432 *match != *scan ||
1433 *++match != scan[1]) continue;
1434
1435 /* The check at best_len-1 can be removed because it will be made
1436 * again later. (This heuristic is not always a win.)
1437 * It is not necessary to compare scan[2] and match[2] since they
1438 * are always equal when the other bytes match, given that
1439 * the hash keys are equal and that HASH_BITS >= 8.
1440 */
1441 scan += 2, match++;
1442 Assert(*scan == *match, "match[2]?");
1443
1444 /* We check for insufficient lookahead only every 8th comparison;
1445 * the 256th check will be made at strstart+258.
1446 */
1447 do {
1448 } while (*++scan == *++match && *++scan == *++match &&
1449 *++scan == *++match && *++scan == *++match &&
1450 *++scan == *++match && *++scan == *++match &&
1451 *++scan == *++match && *++scan == *++match &&
1452 scan < strend);
1453
1454 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1455
1456 len = MAX_MATCH - (int)(strend - scan);
1457 scan = strend - MAX_MATCH;
1458
1459 #endif /* UNALIGNED_OK */
1460
1461 if (len > best_len) {
1462 s->match_start = cur_match;
1463 best_len = len;
1464 if (len >= nice_match) break;
1465 #ifdef UNALIGNED_OK
1466 scan_end = *(ushf*)(scan+best_len-1);
1467 #else
1468 scan_end1 = scan[best_len-1];
1469 scan_end = scan[best_len];
1470 #endif
1471 }
1472 } while ((cur_match = prev[cur_match & wmask]) > limit
1473 && --chain_length != 0);
1474
1475 if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1476 return s->lookahead;
1477 }
1478
1479 #else /* FASTEST */
1480 /* ---------------------------------------------------------------------------
1481 * Optimized version for level == 1 only
1482 */
1483 local uInt longest_match(s, cur_match)
1484 deflate_state *s;
1485 IPos cur_match; /* current match */
1486 {
1487 register Bytef *scan = s->window + s->strstart; /* current string */
1488 register Bytef *match; /* matched string */
1489 register int len; /* length of current match */
1490 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1491
1492 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1493 * It is easy to get rid of this optimization if necessary.
1494 */
1495 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1496
1497 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1498
1499 Assert(cur_match < s->strstart, "no future");
1500
1501 match = s->window + cur_match;
1502
1503 /* Return failure if the match length is less than 2:
1504 */
1505 if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1506
1507 /* The check at best_len-1 can be removed because it will be made
1508 * again later. (This heuristic is not always a win.)
1509 * It is not necessary to compare scan[2] and match[2] since they
1510 * are always equal when the other bytes match, given that
1511 * the hash keys are equal and that HASH_BITS >= 8.
1512 */
1513 scan += 2, match += 2;
1514 Assert(*scan == *match, "match[2]?");
1515
1516 /* We check for insufficient lookahead only every 8th comparison;
1517 * the 256th check will be made at strstart+258.
1518 */
1519 do {
1520 } while (*++scan == *++match && *++scan == *++match &&
1521 *++scan == *++match && *++scan == *++match &&
1522 *++scan == *++match && *++scan == *++match &&
1523 *++scan == *++match && *++scan == *++match &&
1524 scan < strend);
1525
1526 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1527
1528 len = MAX_MATCH - (int)(strend - scan);
1529
1530 if (len < MIN_MATCH) return MIN_MATCH - 1;
1531
1532 s->match_start = cur_match;
1533 return len <= s->lookahead ? len : s->lookahead;
1534 }
1535 #endif /* FASTEST */
1536 #endif /* ASMV */
1537
1538 #ifdef DEBUG_ZLIB
1539 /* ===========================================================================
1540 * Check that the match at match_start is indeed a match.
1541 */
1542 local void check_match(s, start, match, length)
1543 deflate_state *s;
1544 IPos start, match;
1545 int length;
1546 {
1547 /* check that the match is indeed a match */
1548 if (zmemcmp(s->window + match,
1549 s->window + start, length) != EQUAL) {
1550 fprintf(stderr, " start %u, match %u, length %d\n",
1551 start, match, length);
1552 do {
1553 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1554 } while (--length != 0);
1555 z_error("invalid match");
1556 }
1557 if (z_verbose > 1) {
1558 fprintf(stderr,"\\[%d,%d]", start-match, length);
1559 do { putc(s->window[start++], stderr); } while (--length != 0);
1560 }
1561 }
1562 #else
1563 # define check_match(s, start, match, length)
1564 #endif
1565
1566 /* ===========================================================================
1567 * Fill the window when the lookahead becomes insufficient.
1568 * Updates strstart and lookahead.
1569 *
1570 * IN assertion: lookahead < MIN_LOOKAHEAD
1571 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1572 * At least one byte has been read, or avail_in == 0; reads are
1573 * performed for at least two bytes (required for the zip translate_eol
1574 * option -- not supported here).
1575 */
1576 local void fill_window(s)
1577 deflate_state *s;
1578 {
1579 register unsigned n, m;
1580 register Posf *p;
1581 unsigned more; /* Amount of free space at the end of the window. */
1582 uInt wsize = s->w_size;
1583
1584 do {
1585 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1586
1587 /* Deal with !@#$% 64K limit: */
1588 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1589 more = wsize;
1590
1591 } else if (more == (unsigned)(-1)) {
1592 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1593 * and lookahead == 1 (input done one byte at time)
1594 */
1595 more--;
1596
1597 /* If the window is almost full and there is insufficient lookahead,
1598 * move the upper half to the lower one to make room in the upper half.
1599 */
1600 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1601
1602 zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
1603 s->match_start -= wsize;
1604 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1605 s->block_start -= (long) wsize;
1606
1607 /* Slide the hash table (could be avoided with 32 bit values
1608 at the expense of memory usage). We slide even when level == 0
1609 to keep the hash table consistent if we switch back to level > 0
1610 later. (Using level 0 permanently is not an optimal usage of
1611 zlib, so we don't care about this pathological case.)
1612 */
1613 n = s->hash_size;
1614 p = &s->head[n];
1615 do {
1616 m = *--p;
1617 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1618 } while (--n);
1619
1620 n = wsize;
1621 #ifndef FASTEST
1622 p = &s->prev[n];
1623 do {
1624 m = *--p;
1625 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1626 /* If n is not on any hash chain, prev[n] is garbage but
1627 * its value will never be used.
1628 */
1629 } while (--n);
1630 #endif
1631 more += wsize;
1632 }
1633 if (s->strm->avail_in == 0) return;
1634
1635 /* If there was no sliding:
1636 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1637 * more == window_size - lookahead - strstart
1638 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1639 * => more >= window_size - 2*WSIZE + 2
1640 * In the BIG_MEM or MMAP case (not yet supported),
1641 * window_size == input_size + MIN_LOOKAHEAD &&
1642 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1643 * Otherwise, window_size == 2*WSIZE so more >= 2.
1644 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1645 */
1646 Assert(more >= 2, "more < 2");
1647
1648 n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1649 s->lookahead += n;
1650
1651 /* Initialize the hash value now that we have some input: */
1652 if (s->lookahead >= MIN_MATCH) {
1653 s->ins_h = s->window[s->strstart];
1654 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1655 #if MIN_MATCH != 3
1656 Call UPDATE_HASH() MIN_MATCH-3 more times
1657 #endif
1658 }
1659 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1660 * but this is not important since only literal bytes will be emitted.
1661 */
1662
1663 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1664 }
1665
1666 /* ===========================================================================
1667 * Flush the current block, with given end-of-file flag.
1668 * IN assertion: strstart is set to the end of the current match.
1669 */
1670 #define FLUSH_BLOCK_ONLY(s, eof) { \
1671 _tr_flush_block(s, (s->block_start >= 0L ? \
1672 (charf *)&s->window[(unsigned)s->block_start] : \
1673 (charf *)Z_NULL), \
1674 (ulg)((long)s->strstart - s->block_start), \
1675 (eof)); \
1676 s->block_start = s->strstart; \
1677 flush_pending(s->strm); \
1678 Tracev((stderr,"[FLUSH]")); \
1679 }
1680
1681 /* Same but force premature exit if necessary. */
1682 #define FLUSH_BLOCK(s, eof) { \
1683 FLUSH_BLOCK_ONLY(s, eof); \
1684 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1685 }
1686
1687 /* ===========================================================================
1688 * Copy without compression as much as possible from the input stream, return
1689 * the current block state.
1690 * This function does not insert new strings in the dictionary since
1691 * uncompressible data is probably not useful. This function is used
1692 * only for the level=0 compression option.
1693 * NOTE: this function should be optimized to avoid extra copying from
1694 * window to pending_buf.
1695 */
1696 local block_state deflate_stored(s, flush)
1697 deflate_state *s;
1698 int flush;
1699 {
1700 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1701 * to pending_buf_size, and each stored block has a 5 byte header:
1702 */
1703 ulg max_block_size = 0xffff;
1704 ulg max_start;
1705
1706 if (max_block_size > s->pending_buf_size - 5) {
1707 max_block_size = s->pending_buf_size - 5;
1708 }
1709
1710 /* Copy as much as possible from input to output: */
1711 for (;;) {
1712 /* Fill the window as much as possible: */
1713 if (s->lookahead <= 1) {
1714
1715 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1716 s->block_start >= (long)s->w_size, "slide too late");
1717
1718 fill_window(s);
1719 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1720
1721 if (s->lookahead == 0) break; /* flush the current block */
1722 }
1723 Assert(s->block_start >= 0L, "block gone");
1724
1725 s->strstart += s->lookahead;
1726 s->lookahead = 0;
1727
1728 /* Emit a stored block if pending_buf will be full: */
1729 max_start = s->block_start + max_block_size;
1730 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1731 /* strstart == 0 is possible when wraparound on 16-bit machine */
1732 s->lookahead = (uInt)(s->strstart - max_start);
1733 s->strstart = (uInt)max_start;
1734 FLUSH_BLOCK(s, 0);
1735 }
1736 /* Flush if we may have to slide, otherwise block_start may become
1737 * negative and the data will be gone:
1738 */
1739 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1740 FLUSH_BLOCK(s, 0);
1741 }
1742 }
1743 FLUSH_BLOCK(s, flush == Z_FINISH);
1744 return flush == Z_FINISH ? finish_done : block_done;
1745 }
1746
1747 /* ===========================================================================
1748 * Compress as much as possible from the input stream, return the current
1749 * block state.
1750 * This function does not perform lazy evaluation of matches and inserts
1751 * new strings in the dictionary only for unmatched strings or for short
1752 * matches. It is used only for the fast compression options.
1753 */
1754 local block_state deflate_fast(s, flush)
1755 deflate_state *s;
1756 int flush;
1757 {
1758 IPos hash_head = NIL; /* head of the hash chain */
1759 int bflush; /* set if current block must be flushed */
1760
1761 for (;;) {
1762 /* Make sure that we always have enough lookahead, except
1763 * at the end of the input file. We need MAX_MATCH bytes
1764 * for the next match, plus MIN_MATCH bytes to insert the
1765 * string following the next match.
1766 */
1767 if (s->lookahead < MIN_LOOKAHEAD) {
1768 fill_window(s);
1769 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1770 return need_more;
1771 }
1772 if (s->lookahead == 0) break; /* flush the current block */
1773 }
1774
1775 /* Insert the string window[strstart .. strstart+2] in the
1776 * dictionary, and set hash_head to the head of the hash chain:
1777 */
1778 if (s->lookahead >= MIN_MATCH) {
1779 INSERT_STRING(s, s->strstart, hash_head);
1780 }
1781
1782 /* Find the longest match, discarding those <= prev_length.
1783 * At this point we have always match_length < MIN_MATCH
1784 */
1785 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1786 /* To simplify the code, we prevent matches with the string
1787 * of window index 0 (in particular we have to avoid a match
1788 * of the string with itself at the start of the input file).
1789 */
1790 if (s->strategy != Z_HUFFMAN_ONLY) {
1791 s->match_length = longest_match (s, hash_head);
1792 }
1793 /* longest_match() sets match_start */
1794 }
1795 if (s->match_length >= MIN_MATCH) {
1796 check_match(s, s->strstart, s->match_start, s->match_length);
1797
1798 _tr_tally_dist(s, s->strstart - s->match_start,
1799 s->match_length - MIN_MATCH, bflush);
1800
1801 s->lookahead -= s->match_length;
1802
1803 /* Insert new strings in the hash table only if the match length
1804 * is not too large. This saves time but degrades compression.
1805 */
1806 #ifndef FASTEST
1807 if (s->match_length <= s->max_insert_length &&
1808 s->lookahead >= MIN_MATCH) {
1809 s->match_length--; /* string at strstart already in hash table */
1810 do {
1811 s->strstart++;
1812 INSERT_STRING(s, s->strstart, hash_head);
1813 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1814 * always MIN_MATCH bytes ahead.
1815 */
1816 } while (--s->match_length != 0);
1817 s->strstart++;
1818 } else
1819 #endif
1820 {
1821 s->strstart += s->match_length;
1822 s->match_length = 0;
1823 s->ins_h = s->window[s->strstart];
1824 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1825 #if MIN_MATCH != 3
1826 Call UPDATE_HASH() MIN_MATCH-3 more times
1827 #endif
1828 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1829 * matter since it will be recomputed at next deflate call.
1830 */
1831 }
1832 } else {
1833 /* No match, output a literal byte */
1834 Tracevv((stderr,"%c", s->window[s->strstart]));
1835 _tr_tally_lit (s, s->window[s->strstart], bflush);
1836 s->lookahead--;
1837 s->strstart++;
1838 }
1839 if (bflush) FLUSH_BLOCK(s, 0);
1840 }
1841 FLUSH_BLOCK(s, flush == Z_FINISH);
1842 return flush == Z_FINISH ? finish_done : block_done;
1843 }
1844
1845 /* ===========================================================================
1846 * Same as above, but achieves better compression. We use a lazy
1847 * evaluation for matches: a match is finally adopted only if there is
1848 * no better match at the next window position.
1849 */
1850 local block_state deflate_slow(s, flush)
1851 deflate_state *s;
1852 int flush;
1853 {
1854 IPos hash_head = NIL; /* head of hash chain */
1855 int bflush; /* set if current block must be flushed */
1856
1857 /* Process the input block. */
1858 for (;;) {
1859 /* Make sure that we always have enough lookahead, except
1860 * at the end of the input file. We need MAX_MATCH bytes
1861 * for the next match, plus MIN_MATCH bytes to insert the
1862 * string following the next match.
1863 */
1864 if (s->lookahead < MIN_LOOKAHEAD) {
1865 fill_window(s);
1866 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1867 return need_more;
1868 }
1869 if (s->lookahead == 0) break; /* flush the current block */
1870 }
1871
1872 /* Insert the string window[strstart .. strstart+2] in the
1873 * dictionary, and set hash_head to the head of the hash chain:
1874 */
1875 if (s->lookahead >= MIN_MATCH) {
1876 INSERT_STRING(s, s->strstart, hash_head);
1877 }
1878
1879 /* Find the longest match, discarding those <= prev_length.
1880 */
1881 s->prev_length = s->match_length, s->prev_match = s->match_start;
1882 s->match_length = MIN_MATCH-1;
1883
1884 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1885 s->strstart - hash_head <= MAX_DIST(s)) {
1886 /* To simplify the code, we prevent matches with the string
1887 * of window index 0 (in particular we have to avoid a match
1888 * of the string with itself at the start of the input file).
1889 */
1890 if (s->strategy != Z_HUFFMAN_ONLY) {
1891 s->match_length = longest_match (s, hash_head);
1892 }
1893 /* longest_match() sets match_start */
1894
1895 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1896 (s->match_length == MIN_MATCH &&
1897 s->strstart - s->match_start > TOO_FAR))) {
1898
1899 /* If prev_match is also MIN_MATCH, match_start is garbage
1900 * but we will ignore the current match anyway.
1901 */
1902 s->match_length = MIN_MATCH-1;
1903 }
1904 }
1905 /* If there was a match at the previous step and the current
1906 * match is not better, output the previous match:
1907 */
1908 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1909 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1910 /* Do not insert strings in hash table beyond this. */
1911
1912 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1913
1914 _tr_tally_dist(s, s->strstart -1 - s->prev_match,
1915 s->prev_length - MIN_MATCH, bflush);
1916
1917 /* Insert in hash table all strings up to the end of the match.
1918 * strstart-1 and strstart are already inserted. If there is not
1919 * enough lookahead, the last two strings are not inserted in
1920 * the hash table.
1921 */
1922 s->lookahead -= s->prev_length-1;
1923 s->prev_length -= 2;
1924 do {
1925 if (++s->strstart <= max_insert) {
1926 INSERT_STRING(s, s->strstart, hash_head);
1927 }
1928 } while (--s->prev_length != 0);
1929 s->match_available = 0;
1930 s->match_length = MIN_MATCH-1;
1931 s->strstart++;
1932
1933 if (bflush) FLUSH_BLOCK(s, 0);
1934
1935 } else if (s->match_available) {
1936 /* If there was no match at the previous position, output a
1937 * single literal. If there was a match but the current match
1938 * is longer, truncate the previous match to a single literal.
1939 */
1940 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1941 _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1942 if (bflush) {
1943 FLUSH_BLOCK_ONLY(s, 0);
1944 }
1945 s->strstart++;
1946 s->lookahead--;
1947 if (s->strm->avail_out == 0) return need_more;
1948 } else {
1949 /* There is no previous match to compare with, wait for
1950 * the next step to decide.
1951 */
1952 s->match_available = 1;
1953 s->strstart++;
1954 s->lookahead--;
1955 }
1956 }
1957 Assert (flush != Z_NO_FLUSH, "no flush?");
1958 if (s->match_available) {
1959 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1960 _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1961 s->match_available = 0;
1962 }
1963 FLUSH_BLOCK(s, flush == Z_FINISH);
1964 return flush == Z_FINISH ? finish_done : block_done;
1965 }
1966 /* --- deflate.c */
1967
1968 /* +++ trees.c */
1969 /* trees.c -- output deflated data using Huffman coding
1970 * Copyright (C) 1995-2002 Jean-loup Gailly
1971 * For conditions of distribution and use, see copyright notice in zlib.h
1972 */
1973
1974 /*
1975 * ALGORITHM
1976 *
1977 * The "deflation" process uses several Huffman trees. The more
1978 * common source values are represented by shorter bit sequences.
1979 *
1980 * Each code tree is stored in a compressed form which is itself
1981 * a Huffman encoding of the lengths of all the code strings (in
1982 * ascending order by source values). The actual code strings are
1983 * reconstructed from the lengths in the inflate process, as described
1984 * in the deflate specification.
1985 *
1986 * REFERENCES
1987 *
1988 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1989 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1990 *
1991 * Storer, James A.
1992 * Data Compression: Methods and Theory, pp. 49-50.
1993 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1994 *
1995 * Sedgewick, R.
1996 * Algorithms, p290.
1997 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1998 */
1999
2000 /* @(#) $Id: zlib.c,v 1.8 2002/03/29 03:16:07 lindak Exp $ */
2001
2002 /* #define GEN_TREES_H */
2003
2004 /* #include "deflate.h" */
2005
2006 #ifdef DEBUG_ZLIB
2007 # include <ctype.h>
2008 #endif
2009
2010 /* ===========================================================================
2011 * Constants
2012 */
2013
2014 #define MAX_BL_BITS 7
2015 /* Bit length codes must not exceed MAX_BL_BITS bits */
2016
2017 #define END_BLOCK 256
2018 /* end of block literal code */
2019
2020 #define REP_3_6 16
2021 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2022
2023 #define REPZ_3_10 17
2024 /* repeat a zero length 3-10 times (3 bits of repeat count) */
2025
2026 #define REPZ_11_138 18
2027 /* repeat a zero length 11-138 times (7 bits of repeat count) */
2028
2029 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2030 = {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};
2031
2032 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
2033 = {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};
2034
2035 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
2036 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
2037
2038 local const uch bl_order[BL_CODES]
2039 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
2040 /* The lengths of the bit length codes are sent in order of decreasing
2041 * probability, to avoid transmitting the lengths for unused bit length codes.
2042 */
2043
2044 #define Buf_size (8 * 2*sizeof(char))
2045 /* Number of bits used within bi_buf. (bi_buf might be implemented on
2046 * more than 16 bits on some systems.)
2047 */
2048
2049 /* ===========================================================================
2050 * Local data. These are initialized only once.
2051 */
2052
2053 #define DIST_CODE_LEN 512 /* see definition of array dist_code below */
2054
2055 #if defined(GEN_TREES_H) || !defined(STDC)
2056 /* non ANSI compilers may not accept trees.h */
2057
2058 local ct_data static_ltree[L_CODES+2];
2059 /* The static literal tree. Since the bit lengths are imposed, there is no
2060 * need for the L_CODES extra codes used during heap construction. However
2061 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
2062 * below).
2063 */
2064
2065 local ct_data static_dtree[D_CODES];
2066 /* The static distance tree. (Actually a trivial tree since all codes use
2067 * 5 bits.)
2068 */
2069
2070 uch _dist_code[DIST_CODE_LEN];
2071 /* Distance codes. The first 256 values correspond to the distances
2072 * 3 .. 258, the last 256 values correspond to the top 8 bits of
2073 * the 15 bit distances.
2074 */
2075
2076 uch _length_code[MAX_MATCH-MIN_MATCH+1];
2077 /* length code for each normalized match length (0 == MIN_MATCH) */
2078
2079 local int base_length[LENGTH_CODES];
2080 /* First normalized length for each code (0 = MIN_MATCH) */
2081
2082 local int base_dist[D_CODES];
2083 /* First normalized distance for each code (0 = distance of 1) */
2084
2085 #else
2086 /* +++ trees.h */
2087 /* header created automatically with -DGEN_TREES_H */
2088
2089 local const ct_data static_ltree[L_CODES+2] = {
2090 {{ 12},{ 8}}, {{140},{ 8}}, {{ 76},{ 8}}, {{204},{ 8}}, {{ 44},{ 8}},
2091 {{172},{ 8}}, {{108},{ 8}}, {{236},{ 8}}, {{ 28},{ 8}}, {{156},{ 8}},
2092 {{ 92},{ 8}}, {{220},{ 8}}, {{ 60},{ 8}}, {{188},{ 8}}, {{124},{ 8}},
2093 {{252},{ 8}}, {{ 2},{ 8}}, {{130},{ 8}}, {{ 66},{ 8}}, {{194},{ 8}},
2094 {{ 34},{ 8}}, {{162},{ 8}}, {{ 98},{ 8}}, {{226},{ 8}}, {{ 18},{ 8}},
2095 {{146},{ 8}}, {{ 82},{ 8}}, {{210},{ 8}}, {{ 50},{ 8}}, {{178},{ 8}},
2096 {{114},{ 8}}, {{242},{ 8}}, {{ 10},{ 8}}, {{138},{ 8}}, {{ 74},{ 8}},
2097 {{202},{ 8}}, {{ 42},{ 8}}, {{170},{ 8}}, {{106},{ 8}}, {{234},{ 8}},
2098 {{ 26},{ 8}}, {{154},{ 8}}, {{ 90},{ 8}}, {{218},{ 8}}, {{ 58},{ 8}},
2099 {{186},{ 8}}, {{122},{ 8}}, {{250},{ 8}}, {{ 6},{ 8}}, {{134},{ 8}},
2100 {{ 70},{ 8}}, {{198},{ 8}}, {{ 38},{ 8}}, {{166},{ 8}}, {{102},{ 8}},
2101 {{230},{ 8}}, {{ 22},{ 8}}, {{150},{ 8}}, {{ 86},{ 8}}, {{214},{ 8}},
2102 {{ 54},{ 8}}, {{182},{ 8}}, {{118},{ 8}}, {{246},{ 8}}, {{ 14},{ 8}},
2103 {{142},{ 8}}, {{ 78},{ 8}}, {{206},{ 8}}, {{ 46},{ 8}}, {{174},{ 8}},
2104 {{110},{ 8}}, {{238},{ 8}}, {{ 30},{ 8}}, {{158},{ 8}}, {{ 94},{ 8}},
2105 {{222},{ 8}}, {{ 62},{ 8}}, {{190},{ 8}}, {{126},{ 8}}, {{254},{ 8}},
2106 {{ 1},{ 8}}, {{129},{ 8}}, {{ 65},{ 8}}, {{193},{ 8}}, {{ 33},{ 8}},
2107 {{161},{ 8}}, {{ 97},{ 8}}, {{225},{ 8}}, {{ 17},{ 8}}, {{145},{ 8}},
2108 {{ 81},{ 8}}, {{209},{ 8}}, {{ 49},{ 8}}, {{177},{ 8}}, {{113},{ 8}},
2109 {{241},{ 8}}, {{ 9},{ 8}}, {{137},{ 8}}, {{ 73},{ 8}}, {{201},{ 8}},
2110 {{ 41},{ 8}}, {{169},{ 8}}, {{105},{ 8}}, {{233},{ 8}}, {{ 25},{ 8}},
2111 {{153},{ 8}}, {{ 89},{ 8}}, {{217},{ 8}}, {{ 57},{ 8}}, {{185},{ 8}},
2112 {{121},{ 8}}, {{249},{ 8}}, {{ 5},{ 8}}, {{133},{ 8}}, {{ 69},{ 8}},
2113 {{197},{ 8}}, {{ 37},{ 8}}, {{165},{ 8}}, {{101},{ 8}}, {{229},{ 8}},
2114 {{ 21},{ 8}}, {{149},{ 8}}, {{ 85},{ 8}}, {{213},{ 8}}, {{ 53},{ 8}},
2115 {{181},{ 8}}, {{117},{ 8}}, {{245},{ 8}}, {{ 13},{ 8}}, {{141},{ 8}},
2116 {{ 77},{ 8}}, {{205},{ 8}}, {{ 45},{ 8}}, {{173},{ 8}}, {{109},{ 8}},
2117 {{237},{ 8}}, {{ 29},{ 8}}, {{157},{ 8}}, {{ 93},{ 8}}, {{221},{ 8}},
2118 {{ 61},{ 8}}, {{189},{ 8}}, {{125},{ 8}}, {{253},{ 8}}, {{ 19},{ 9}},
2119 {{275},{ 9}}, {{147},{ 9}}, {{403},{ 9}}, {{ 83},{ 9}}, {{339},{ 9}},
2120 {{211},{ 9}}, {{467},{ 9}}, {{ 51},{ 9}}, {{307},{ 9}}, {{179},{ 9}},
2121 {{435},{ 9}}, {{115},{ 9}}, {{371},{ 9}}, {{243},{ 9}}, {{499},{ 9}},
2122 {{ 11},{ 9}}, {{267},{ 9}}, {{139},{ 9}}, {{395},{ 9}}, {{ 75},{ 9}},
2123 {{331},{ 9}}, {{203},{ 9}}, {{459},{ 9}}, {{ 43},{ 9}}, {{299},{ 9}},
2124 {{171},{ 9}}, {{427},{ 9}}, {{107},{ 9}}, {{363},{ 9}}, {{235},{ 9}},
2125 {{491},{ 9}}, {{ 27},{ 9}}, {{283},{ 9}}, {{155},{ 9}}, {{411},{ 9}},
2126 {{ 91},{ 9}}, {{347},{ 9}}, {{219},{ 9}}, {{475},{ 9}}, {{ 59},{ 9}},
2127 {{315},{ 9}}, {{187},{ 9}}, {{443},{ 9}}, {{123},{ 9}}, {{379},{ 9}},
2128 {{251},{ 9}}, {{507},{ 9}}, {{ 7},{ 9}}, {{263},{ 9}}, {{135},{ 9}},
2129 {{391},{ 9}}, {{ 71},{ 9}}, {{327},{ 9}}, {{199},{ 9}}, {{455},{ 9}},
2130 {{ 39},{ 9}}, {{295},{ 9}}, {{167},{ 9}}, {{423},{ 9}}, {{103},{ 9}},
2131 {{359},{ 9}}, {{231},{ 9}}, {{487},{ 9}}, {{ 23},{ 9}}, {{279},{ 9}},
2132 {{151},{ 9}}, {{407},{ 9}}, {{ 87},{ 9}}, {{343},{ 9}}, {{215},{ 9}},
2133 {{471},{ 9}}, {{ 55},{ 9}}, {{311},{ 9}}, {{183},{ 9}}, {{439},{ 9}},
2134 {{119},{ 9}}, {{375},{ 9}}, {{247},{ 9}}, {{503},{ 9}}, {{ 15},{ 9}},
2135 {{271},{ 9}}, {{143},{ 9}}, {{399},{ 9}}, {{ 79},{ 9}}, {{335},{ 9}},
2136 {{207},{ 9}}, {{463},{ 9}}, {{ 47},{ 9}}, {{303},{ 9}}, {{175},{ 9}},
2137 {{431},{ 9}}, {{111},{ 9}}, {{367},{ 9}}, {{239},{ 9}}, {{495},{ 9}},
2138 {{ 31},{ 9}}, {{287},{ 9}}, {{159},{ 9}}, {{415},{ 9}}, {{ 95},{ 9}},
2139 {{351},{ 9}}, {{223},{ 9}}, {{479},{ 9}}, {{ 63},{ 9}}, {{319},{ 9}},
2140 {{191},{ 9}}, {{447},{ 9}}, {{127},{ 9}}, {{383},{ 9}}, {{255},{ 9}},
2141 {{511},{ 9}}, {{ 0},{ 7}}, {{ 64},{ 7}}, {{ 32},{ 7}}, {{ 96},{ 7}},
2142 {{ 16},{ 7}}, {{ 80},{ 7}}, {{ 48},{ 7}}, {{112},{ 7}}, {{ 8},{ 7}},
2143 {{ 72},{ 7}}, {{ 40},{ 7}}, {{104},{ 7}}, {{ 24},{ 7}}, {{ 88},{ 7}},
2144 {{ 56},{ 7}}, {{120},{ 7}}, {{ 4},{ 7}}, {{ 68},{ 7}}, {{ 36},{ 7}},
2145 {{100},{ 7}}, {{ 20},{ 7}}, {{ 84},{ 7}}, {{ 52},{ 7}}, {{116},{ 7}},
2146 {{ 3},{ 8}}, {{131},{ 8}}, {{ 67},{ 8}}, {{195},{ 8}}, {{ 35},{ 8}},
2147 {{163},{ 8}}, {{ 99},{ 8}}, {{227},{ 8}}
2148 };
2149
2150 local const ct_data static_dtree[D_CODES] = {
2151 {{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
2152 {{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
2153 {{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
2154 {{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
2155 {{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
2156 {{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
2157 };
2158
2159 const uch _dist_code[DIST_CODE_LEN] = {
2160 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8,
2161 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10,
2162 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
2163 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
2164 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
2165 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
2166 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
2167 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
2168 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
2169 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15,
2170 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
2171 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
2172 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0, 0, 16, 17,
2173 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
2174 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2175 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2176 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2177 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
2178 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2179 27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2180 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2181 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2182 28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
2183 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
2184 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
2185 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
2186 };
2187
2188 const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {
2189 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
2190 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
2191 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
2192 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
2193 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
2194 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
2195 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2196 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2197 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2198 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
2199 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2200 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2201 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
2202 };
2203
2204 local const int base_length[LENGTH_CODES] = {
2205 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
2206 64, 80, 96, 112, 128, 160, 192, 224, 0
2207 };
2208
2209 local const int base_dist[D_CODES] = {
2210 0, 1, 2, 3, 4, 6, 8, 12, 16, 24,
2211 32, 48, 64, 96, 128, 192, 256, 384, 512, 768,
2212 1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576
2213 };
2214
2215 /* --- trees.h */
2216 #endif /* GEN_TREES_H */
2217
2218 struct static_tree_desc_s {
2219 const ct_data *static_tree; /* static tree or NULL */
2220 const intf *extra_bits; /* extra bits for each code or NULL */
2221 int extra_base; /* base index for extra_bits */
2222 int elems; /* max number of elements in the tree */
2223 int max_length; /* max bit length for the codes */
2224 };
2225
2226 local static_tree_desc static_l_desc =
2227 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
2228
2229 local static_tree_desc static_d_desc =
2230 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
2231
2232 local static_tree_desc static_bl_desc =
2233 {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
2234
2235 /* ===========================================================================
2236 * Local (static) routines in this file.
2237 */
2238
2239 local void tr_static_init OF((void));
2240 local void init_block OF((deflate_state *s));
2241 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
2242 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
2243 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
2244 local void build_tree OF((deflate_state *s, tree_desc *desc));
2245 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
2246 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
2247 local int build_bl_tree OF((deflate_state *s));
2248 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
2249 int blcodes));
2250 local void compress_block OF((deflate_state *s, ct_data *ltree,
2251 ct_data *dtree));
2252 local void set_data_type OF((deflate_state *s));
2253 local unsigned bi_reverse OF((unsigned value, int length));
2254 local void bi_windup OF((deflate_state *s));
2255 local void bi_flush OF((deflate_state *s));
2256 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
2257 int header));
2258
2259 #ifdef GEN_TREES_H
2260 local void gen_trees_header OF((void));
2261 #endif
2262
2263 #ifndef DEBUG_ZLIB
2264 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
2265 /* Send a code of the given tree. c and tree must not have side effects */
2266
2267 #else /* DEBUG_ZLIB */
2268 # define send_code(s, c, tree) \
2269 { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
2270 send_bits(s, tree[c].Code, tree[c].Len); }
2271 #endif
2272
2273 /* ===========================================================================
2274 * Output a short LSB first on the stream.
2275 * IN assertion: there is enough room in pendingBuf.
2276 */
2277 #define put_short(s, w) { \
2278 put_byte(s, (uch)((w) & 0xff)); \
2279 put_byte(s, (uch)((ush)(w) >> 8)); \
2280 }
2281
2282 /* ===========================================================================
2283 * Send a value on a given number of bits.
2284 * IN assertion: length <= 16 and value fits in length bits.
2285 */
2286 #ifdef DEBUG_ZLIB
2287 local void send_bits OF((deflate_state *s, int value, int length));
2288
2289 local void send_bits(s, value, length)
2290 deflate_state *s;
2291 int value; /* value to send */
2292 int length; /* number of bits */
2293 {
2294 Tracevv((stderr," l %2d v %4x ", length, value));
2295 Assert(length > 0 && length <= 15, "invalid length");
2296 s->bits_sent += (ulg)length;
2297
2298 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2299 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2300 * unused bits in value.
2301 */
2302 if (s->bi_valid > (int)Buf_size - length) {
2303 s->bi_buf |= (value << s->bi_valid);
2304 put_short(s, s->bi_buf);
2305 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2306 s->bi_valid += length - Buf_size;
2307 } else {
2308 s->bi_buf |= value << s->bi_valid;
2309 s->bi_valid += length;
2310 }
2311 }
2312 #else /* !DEBUG_ZLIB */
2313
2314 #define send_bits(s, value, length) \
2315 { int len = length;\
2316 if (s->bi_valid > (int)Buf_size - len) {\
2317 int val = value;\
2318 s->bi_buf |= (val << s->bi_valid);\
2319 put_short(s, s->bi_buf);\
2320 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2321 s->bi_valid += len - Buf_size;\
2322 } else {\
2323 s->bi_buf |= (value) << s->bi_valid;\
2324 s->bi_valid += len;\
2325 }\
2326 }
2327 #endif /* DEBUG_ZLIB */
2328
2329
2330 #ifndef MAX
2331 #define MAX(a,b) (a >= b ? a : b)
2332 #endif
2333 /* the arguments must not have side effects */
2334
2335 /* ===========================================================================
2336 * Initialize the various 'constant' tables.
2337 */
2338 local void tr_static_init()
2339 {
2340 #if defined(GEN_TREES_H) || !defined(STDC)
2341 static int static_init_done = 0;
2342 int n; /* iterates over tree elements */
2343 int bits; /* bit counter */
2344 int length; /* length value */
2345 int code; /* code value */
2346 int dist; /* distance index */
2347 ush bl_count[MAX_BITS+1];
2348 /* number of codes at each bit length for an optimal tree */
2349
2350 if (static_init_done) return;
2351
2352 /* For some embedded targets, global variables are not initialized: */
2353 static_l_desc.static_tree = static_ltree;
2354 static_l_desc.extra_bits = extra_lbits;
2355 static_d_desc.static_tree = static_dtree;
2356 static_d_desc.extra_bits = extra_dbits;
2357 static_bl_desc.extra_bits = extra_blbits;
2358
2359 /* Initialize the mapping length (0..255) -> length code (0..28) */
2360 length = 0;
2361 for (code = 0; code < LENGTH_CODES-1; code++) {
2362 base_length[code] = length;
2363 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2364 _length_code[length++] = (uch)code;
2365 }
2366 }
2367 Assert (length == 256, "tr_static_init: length != 256");
2368 /* Note that the length 255 (match length 258) can be represented
2369 * in two different ways: code 284 + 5 bits or code 285, so we
2370 * overwrite length_code[255] to use the best encoding:
2371 */
2372 _length_code[length-1] = (uch)code;
2373
2374 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2375 dist = 0;
2376 for (code = 0 ; code < 16; code++) {
2377 base_dist[code] = dist;
2378 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2379 _dist_code[dist++] = (uch)code;
2380 }
2381 }
2382 Assert (dist == 256, "tr_static_init: dist != 256");
2383 dist >>= 7; /* from now on, all distances are divided by 128 */
2384 for ( ; code < D_CODES; code++) {
2385 base_dist[code] = dist << 7;
2386 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2387 _dist_code[256 + dist++] = (uch)code;
2388 }
2389 }
2390 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2391
2392 /* Construct the codes of the static literal tree */
2393 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2394 n = 0;
2395 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2396 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2397 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2398 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2399 /* Codes 286 and 287 do not exist, but we must include them in the
2400 * tree construction to get a canonical Huffman tree (longest code
2401 * all ones)
2402 */
2403 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2404
2405 /* The static distance tree is trivial: */
2406 for (n = 0; n < D_CODES; n++) {
2407 static_dtree[n].Len = 5;
2408 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2409 }
2410 static_init_done = 1;
2411
2412 # ifdef GEN_TREES_H
2413 gen_trees_header();
2414 # endif
2415 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
2416 }
2417
2418 /* ===========================================================================
2419 * Genererate the file trees.h describing the static trees.
2420 */
2421 #ifdef GEN_TREES_H
2422 # ifndef DEBUG_ZLIB
2423 # include <stdio.h>
2424 # endif
2425
2426 # define SEPARATOR(i, last, width) \
2427 ((i) == (last)? "\n};\n\n" : \
2428 ((i) % (width) == (width)-1 ? ",\n" : ", "))
2429
2430 void gen_trees_header()
2431 {
2432 FILE *header = fopen("trees.h", "w");
2433 int i;
2434
2435 Assert (header != NULL, "Can't open trees.h");
2436 fprintf(header,
2437 "/* header created automatically with -DGEN_TREES_H */\n\n");
2438
2439 fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
2440 for (i = 0; i < L_CODES+2; i++) {
2441 fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
2442 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
2443 }
2444
2445 fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
2446 for (i = 0; i < D_CODES; i++) {
2447 fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
2448 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
2449 }
2450
2451 fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
2452 for (i = 0; i < DIST_CODE_LEN; i++) {
2453 fprintf(header, "%2u%s", _dist_code[i],
2454 SEPARATOR(i, DIST_CODE_LEN-1, 20));
2455 }
2456
2457 fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
2458 for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
2459 fprintf(header, "%2u%s", _length_code[i],
2460 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
2461 }
2462
2463 fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
2464 for (i = 0; i < LENGTH_CODES; i++) {
2465 fprintf(header, "%1u%s", base_length[i],
2466 SEPARATOR(i, LENGTH_CODES-1, 20));
2467 }
2468
2469 fprintf(header, "local const int base_dist[D_CODES] = {\n");
2470 for (i = 0; i < D_CODES; i++) {
2471 fprintf(header, "%5u%s", base_dist[i],
2472 SEPARATOR(i, D_CODES-1, 10));
2473 }
2474
2475 fclose(header);
2476 }
2477 #endif /* GEN_TREES_H */
2478
2479 /* ===========================================================================
2480 * Initialize the tree data structures for a new zlib stream.
2481 */
2482 void _tr_init(s)
2483 deflate_state *s;
2484 {
2485 tr_static_init();
2486
2487 s->l_desc.dyn_tree = s->dyn_ltree;
2488 s->l_desc.stat_desc = &static_l_desc;
2489
2490 s->d_desc.dyn_tree = s->dyn_dtree;
2491 s->d_desc.stat_desc = &static_d_desc;
2492
2493 s->bl_desc.dyn_tree = s->bl_tree;
2494 s->bl_desc.stat_desc = &static_bl_desc;
2495
2496 s->bi_buf = 0;
2497 s->bi_valid = 0;
2498 s->last_eob_len = 8; /* enough lookahead for inflate */
2499 #ifdef DEBUG_ZLIB
2500 s->compressed_len = 0L;
2501 s->bits_sent = 0L;
2502 #endif
2503
2504 /* Initialize the first block of the first file: */
2505 init_block(s);
2506 }
2507
2508 /* ===========================================================================
2509 * Initialize a new block.
2510 */
2511 local void init_block(s)
2512 deflate_state *s;
2513 {
2514 int n; /* iterates over tree elements */
2515
2516 /* Initialize the trees. */
2517 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2518 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2519 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2520
2521 s->dyn_ltree[END_BLOCK].Freq = 1;
2522 s->opt_len = s->static_len = 0L;
2523 s->last_lit = s->matches = 0;
2524 }
2525
2526 #define SMALLEST 1
2527 /* Index within the heap array of least frequent node in the Huffman tree */
2528
2529
2530 /* ===========================================================================
2531 * Remove the smallest element from the heap and recreate the heap with
2532 * one less element. Updates heap and heap_len.
2533 */
2534 #define pqremove(s, tree, top) \
2535 {\
2536 top = s->heap[SMALLEST]; \
2537 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2538 pqdownheap(s, tree, SMALLEST); \
2539 }
2540
2541 /* ===========================================================================
2542 * Compares to subtrees, using the tree depth as tie breaker when
2543 * the subtrees have equal frequency. This minimizes the worst case length.
2544 */
2545 #define smaller(tree, n, m, depth) \
2546 (tree[n].Freq < tree[m].Freq || \
2547 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2548
2549 /* ===========================================================================
2550 * Restore the heap property by moving down the tree starting at node k,
2551 * exchanging a node with the smallest of its two sons if necessary, stopping
2552 * when the heap property is re-established (each father smaller than its
2553 * two sons).
2554 */
2555 local void pqdownheap(s, tree, k)
2556 deflate_state *s;
2557 ct_data *tree; /* the tree to restore */
2558 int k; /* node to move down */
2559 {
2560 int v = s->heap[k];
2561 int j = k << 1; /* left son of k */
2562 while (j <= s->heap_len) {
2563 /* Set j to the smallest of the two sons: */
2564 if (j < s->heap_len &&
2565 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2566 j++;
2567 }
2568 /* Exit if v is smaller than both sons */
2569 if (smaller(tree, v, s->heap[j], s->depth)) break;
2570
2571 /* Exchange v with the smallest son */
2572 s->heap[k] = s->heap[j]; k = j;
2573
2574 /* And continue down the tree, setting j to the left son of k */
2575 j <<= 1;
2576 }
2577 s->heap[k] = v;
2578 }
2579
2580 /* ===========================================================================
2581 * Compute the optimal bit lengths for a tree and update the total bit length
2582 * for the current block.
2583 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2584 * above are the tree nodes sorted by increasing frequency.
2585 * OUT assertions: the field len is set to the optimal bit length, the
2586 * array bl_count contains the frequencies for each bit length.
2587 * The length opt_len is updated; static_len is also updated if stree is
2588 * not null.
2589 */
2590 local void gen_bitlen(s, desc)
2591 deflate_state *s;
2592 tree_desc *desc; /* the tree descriptor */
2593 {
2594 ct_data *tree = desc->dyn_tree;
2595 int max_code = desc->max_code;
2596 const ct_data *stree = desc->stat_desc->static_tree;
2597 const intf *extra = desc->stat_desc->extra_bits;
2598 int base = desc->stat_desc->extra_base;
2599 int max_length = desc->stat_desc->max_length;
2600 int h; /* heap index */
2601 int n, m; /* iterate over the tree elements */
2602 int bits; /* bit length */
2603 int xbits; /* extra bits */
2604 ush f; /* frequency */
2605 int overflow = 0; /* number of elements with bit length too large */
2606
2607 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2608
2609 /* In a first pass, compute the optimal bit lengths (which may
2610 * overflow in the case of the bit length tree).
2611 */
2612 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2613
2614 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2615 n = s->heap[h];
2616 bits = tree[tree[n].Dad].Len + 1;
2617 if (bits > max_length) bits = max_length, overflow++;
2618 tree[n].Len = (ush)bits;
2619 /* We overwrite tree[n].Dad which is no longer needed */
2620
2621 if (n > max_code) continue; /* not a leaf node */
2622
2623 s->bl_count[bits]++;
2624 xbits = 0;
2625 if (n >= base) xbits = extra[n-base];
2626 f = tree[n].Freq;
2627 s->opt_len += (ulg)f * (bits + xbits);
2628 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2629 }
2630 if (overflow == 0) return;
2631
2632 Trace((stderr,"\nbit length overflow\n"));
2633 /* This happens for example on obj2 and pic of the Calgary corpus */
2634
2635 /* Find the first bit length which could increase: */
2636 do {
2637 bits = max_length-1;
2638 while (s->bl_count[bits] == 0) bits--;
2639 s->bl_count[bits]--; /* move one leaf down the tree */
2640 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2641 s->bl_count[max_length]--;
2642 /* The brother of the overflow item also moves one step up,
2643 * but this does not affect bl_count[max_length]
2644 */
2645 overflow -= 2;
2646 } while (overflow > 0);
2647
2648 /* Now recompute all bit lengths, scanning in increasing frequency.
2649 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2650 * lengths instead of fixing only the wrong ones. This idea is taken
2651 * from 'ar' written by Haruhiko Okumura.)
2652 */
2653 for (bits = max_length; bits != 0; bits--) {
2654 n = s->bl_count[bits];
2655 while (n != 0) {
2656 m = s->heap[--h];
2657 if (m > max_code) continue;
2658 if (tree[m].Len != (unsigned) bits) {
2659 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2660 s->opt_len += ((long)bits - (long)tree[m].Len)
2661 *(long)tree[m].Freq;
2662 tree[m].Len = (ush)bits;
2663 }
2664 n--;
2665 }
2666 }
2667 }
2668
2669 /* ===========================================================================
2670 * Generate the codes for a given tree and bit counts (which need not be
2671 * optimal).
2672 * IN assertion: the array bl_count contains the bit length statistics for
2673 * the given tree and the field len is set for all tree elements.
2674 * OUT assertion: the field code is set for all tree elements of non
2675 * zero code length.
2676 */
2677 local void gen_codes (tree, max_code, bl_count)
2678 ct_data *tree; /* the tree to decorate */
2679 int max_code; /* largest code with non zero frequency */
2680 ushf *bl_count; /* number of codes at each bit length */
2681 {
2682 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2683 ush code = 0; /* running code value */
2684 int bits; /* bit index */
2685 int n; /* code index */
2686
2687 /* The distribution counts are first used to generate the code values
2688 * without bit reversal.
2689 */
2690 for (bits = 1; bits <= MAX_BITS; bits++) {
2691 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2692 }
2693 /* Check that the bit counts in bl_count are consistent. The last code
2694 * must be all ones.
2695 */
2696 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2697 "inconsistent bit counts");
2698 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2699
2700 for (n = 0; n <= max_code; n++) {
2701 int len = tree[n].Len;
2702 if (len == 0) continue;
2703 /* Now reverse the bits */
2704 tree[n].Code = bi_reverse(next_code[len]++, len);
2705
2706 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2707 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2708 }
2709 }
2710
2711 /* ===========================================================================
2712 * Construct one Huffman tree and assigns the code bit strings and lengths.
2713 * Update the total bit length for the current block.
2714 * IN assertion: the field freq is set for all tree elements.
2715 * OUT assertions: the fields len and code are set to the optimal bit length
2716 * and corresponding code. The length opt_len is updated; static_len is
2717 * also updated if stree is not null. The field max_code is set.
2718 */
2719 local void build_tree(s, desc)
2720 deflate_state *s;
2721 tree_desc *desc; /* the tree descriptor */
2722 {
2723 ct_data *tree = desc->dyn_tree;
2724 const ct_data *stree = desc->stat_desc->static_tree;
2725 int elems = desc->stat_desc->elems;
2726 int n, m; /* iterate over heap elements */
2727 int max_code = -1; /* largest code with non zero frequency */
2728 int node; /* new node being created */
2729
2730 /* Construct the initial heap, with least frequent element in
2731 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2732 * heap[0] is not used.
2733 */
2734 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2735
2736 for (n = 0; n < elems; n++) {
2737 if (tree[n].Freq != 0) {
2738 s->heap[++(s->heap_len)] = max_code = n;
2739 s->depth[n] = 0;
2740 } else {
2741 tree[n].Len = 0;
2742 }
2743 }
2744
2745 /* The pkzip format requires that at least one distance code exists,
2746 * and that at least one bit should be sent even if there is only one
2747 * possible code. So to avoid special checks later on we force at least
2748 * two codes of non zero frequency.
2749 */
2750 while (s->heap_len < 2) {
2751 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2752 tree[node].Freq = 1;
2753 s->depth[node] = 0;
2754 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2755 /* node is 0 or 1 so it does not have extra bits */
2756 }
2757 desc->max_code = max_code;
2758
2759 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2760 * establish sub-heaps of increasing lengths:
2761 */
2762 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2763
2764 /* Construct the Huffman tree by repeatedly combining the least two
2765 * frequent nodes.
2766 */
2767 node = elems; /* next internal node of the tree */
2768 do {
2769 pqremove(s, tree, n); /* n = node of least frequency */
2770 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2771
2772 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2773 s->heap[--(s->heap_max)] = m;
2774
2775 /* Create a new node father of n and m */
2776 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2777 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2778 tree[n].Dad = tree[m].Dad = (ush)node;
2779 #ifdef DUMP_BL_TREE
2780 if (tree == s->bl_tree) {
2781 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2782 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2783 }
2784 #endif
2785 /* and insert the new node in the heap */
2786 s->heap[SMALLEST] = node++;
2787 pqdownheap(s, tree, SMALLEST);
2788
2789 } while (s->heap_len >= 2);
2790
2791 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2792
2793 /* At this point, the fields freq and dad are set. We can now
2794 * generate the bit lengths.
2795 */
2796 gen_bitlen(s, (tree_desc *)desc);
2797
2798 /* The field len is now set, we can generate the bit codes */
2799 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2800 }
2801
2802 /* ===========================================================================
2803 * Scan a literal or distance tree to determine the frequencies of the codes
2804 * in the bit length tree.
2805 */
2806 local void scan_tree (s, tree, max_code)
2807 deflate_state *s;
2808 ct_data *tree; /* the tree to be scanned */
2809 int max_code; /* and its largest code of non zero frequency */
2810 {
2811 int n; /* iterates over all tree elements */
2812 int prevlen = -1; /* last emitted length */
2813 int curlen; /* length of current code */
2814 int nextlen = tree[0].Len; /* length of next code */
2815 int count = 0; /* repeat count of the current code */
2816 int max_count = 7; /* max repeat count */
2817 int min_count = 4; /* min repeat count */
2818
2819 if (nextlen == 0) max_count = 138, min_count = 3;
2820 tree[max_code+1].Len = (ush)0xffff; /* guard */
2821
2822 for (n = 0; n <= max_code; n++) {
2823 curlen = nextlen; nextlen = tree[n+1].Len;
2824 if (++count < max_count && curlen == nextlen) {
2825 continue;
2826 } else if (count < min_count) {
2827 s->bl_tree[curlen].Freq += count;
2828 } else if (curlen != 0) {
2829 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2830 s->bl_tree[REP_3_6].Freq++;
2831 } else if (count <= 10) {
2832 s->bl_tree[REPZ_3_10].Freq++;
2833 } else {
2834 s->bl_tree[REPZ_11_138].Freq++;
2835 }
2836 count = 0; prevlen = curlen;
2837 if (nextlen == 0) {
2838 max_count = 138, min_count = 3;
2839 } else if (curlen == nextlen) {
2840 max_count = 6, min_count = 3;
2841 } else {
2842 max_count = 7, min_count = 4;
2843 }
2844 }
2845 }
2846
2847 /* ===========================================================================
2848 * Send a literal or distance tree in compressed form, using the codes in
2849 * bl_tree.
2850 */
2851 local void send_tree (s, tree, max_code)
2852 deflate_state *s;
2853 ct_data *tree; /* the tree to be scanned */
2854 int max_code; /* and its largest code of non zero frequency */
2855 {
2856 int n; /* iterates over all tree elements */
2857 int prevlen = -1; /* last emitted length */
2858 int curlen; /* length of current code */
2859 int nextlen = tree[0].Len; /* length of next code */
2860 int count = 0; /* repeat count of the current code */
2861 int max_count = 7; /* max repeat count */
2862 int min_count = 4; /* min repeat count */
2863
2864 /* tree[max_code+1].Len = -1; */ /* guard already set */
2865 if (nextlen == 0) max_count = 138, min_count = 3;
2866
2867 for (n = 0; n <= max_code; n++) {
2868 curlen = nextlen; nextlen = tree[n+1].Len;
2869 if (++count < max_count && curlen == nextlen) {
2870 continue;
2871 } else if (count < min_count) {
2872 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2873
2874 } else if (curlen != 0) {
2875 if (curlen != prevlen) {
2876 send_code(s, curlen, s->bl_tree); count--;
2877 }
2878 Assert(count >= 3 && count <= 6, " 3_6?");
2879 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2880
2881 } else if (count <= 10) {
2882 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2883
2884 } else {
2885 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2886 }
2887 count = 0; prevlen = curlen;
2888 if (nextlen == 0) {
2889 max_count = 138, min_count = 3;
2890 } else if (curlen == nextlen) {
2891 max_count = 6, min_count = 3;
2892 } else {
2893 max_count = 7, min_count = 4;
2894 }
2895 }
2896 }
2897
2898 /* ===========================================================================
2899 * Construct the Huffman tree for the bit lengths and return the index in
2900 * bl_order of the last bit length code to send.
2901 */
2902 local int build_bl_tree(s)
2903 deflate_state *s;
2904 {
2905 int max_blindex; /* index of last bit length code of non zero freq */
2906
2907 /* Determine the bit length frequencies for literal and distance trees */
2908 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2909 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2910
2911 /* Build the bit length tree: */
2912 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2913 /* opt_len now includes the length of the tree representations, except
2914 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2915 */
2916
2917 /* Determine the number of bit length codes to send. The pkzip format
2918 * requires that at least 4 bit length codes be sent. (appnote.txt says
2919 * 3 but the actual value used is 4.)
2920 */
2921 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2922 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2923 }
2924 /* Update opt_len to include the bit length tree and counts */
2925 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2926 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2927 s->opt_len, s->static_len));
2928
2929 return max_blindex;
2930 }
2931
2932 /* ===========================================================================
2933 * Send the header for a block using dynamic Huffman trees: the counts, the
2934 * lengths of the bit length codes, the literal tree and the distance tree.
2935 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2936 */
2937 local void send_all_trees(s, lcodes, dcodes, blcodes)
2938 deflate_state *s;
2939 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2940 {
2941 int rank; /* index in bl_order */
2942
2943 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2944 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2945 "too many codes");
2946 Tracev((stderr, "\nbl counts: "));
2947 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2948 send_bits(s, dcodes-1, 5);
2949 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2950 for (rank = 0; rank < blcodes; rank++) {
2951 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2952 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2953 }
2954 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2955
2956 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2957 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2958
2959 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2960 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2961 }
2962
2963 /* ===========================================================================
2964 * Send a stored block
2965 */
2966 void _tr_stored_block(s, buf, stored_len, eof)
2967 deflate_state *s;
2968 charf *buf; /* input block */
2969 ulg stored_len; /* length of input block */
2970 int eof; /* true if this is the last block for a file */
2971 {
2972 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2973 #ifdef DEBUG_ZLIB
2974 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2975 s->compressed_len += (stored_len + 4) << 3;
2976 #endif
2977 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2978 }
2979
2980 /* ===========================================================================
2981 * Send one empty static block to give enough lookahead for inflate.
2982 * This takes 10 bits, of which 7 may remain in the bit buffer.
2983 * The current inflate code requires 9 bits of lookahead. If the
2984 * last two codes for the previous block (real code plus EOB) were coded
2985 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2986 * the last real code. In this case we send two empty static blocks instead
2987 * of one. (There are no problems if the previous block is stored or fixed.)
2988 * To simplify the code, we assume the worst case of last real code encoded
2989 * on one bit only.
2990 */
2991 void _tr_align(s)
2992 deflate_state *s;
2993 {
2994 send_bits(s, STATIC_TREES<<1, 3);
2995 send_code(s, END_BLOCK, static_ltree);
2996 #ifdef DEBUG_ZLIB
2997 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2998 #endif
2999 bi_flush(s);
3000 /* Of the 10 bits for the empty block, we have already sent
3001 * (10 - bi_valid) bits. The lookahead for the last real code (before
3002 * the EOB of the previous block) was thus at least one plus the length
3003 * of the EOB plus what we have just sent of the empty static block.
3004 */
3005 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
3006 send_bits(s, STATIC_TREES<<1, 3);
3007 send_code(s, END_BLOCK, static_ltree);
3008 #ifdef DEBUG_ZLIB
3009 s->compressed_len += 10L;
3010 #endif
3011 bi_flush(s);
3012 }
3013 s->last_eob_len = 7;
3014 }
3015
3016 /* ===========================================================================
3017 * Determine the best encoding for the current block: dynamic trees, static
3018 * trees or store, and output the encoded block to the zip file.
3019 */
3020 void _tr_flush_block(s, buf, stored_len, eof)
3021 deflate_state *s;
3022 charf *buf; /* input block, or NULL if too old */
3023 ulg stored_len; /* length of input block */
3024 int eof; /* true if this is the last block for a file */
3025 {
3026 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
3027 int max_blindex = 0; /* index of last bit length code of non zero freq */
3028
3029 /* Build the Huffman trees unless a stored block is forced */
3030 if (s->level > 0) {
3031
3032 /* Check if the file is ascii or binary */
3033 if (s->data_type == Z_UNKNOWN) set_data_type(s);
3034
3035 /* Construct the literal and distance trees */
3036 build_tree(s, (tree_desc *)(&(s->l_desc)));
3037 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
3038 s->static_len));
3039
3040 build_tree(s, (tree_desc *)(&(s->d_desc)));
3041 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
3042 s->static_len));
3043 /* At this point, opt_len and static_len are the total bit lengths of
3044 * the compressed block data, excluding the tree representations.
3045 */
3046
3047 /* Build the bit length tree for the above two trees, and get the index
3048 * in bl_order of the last bit length code to send.
3049 */
3050 max_blindex = build_bl_tree(s);
3051
3052 /* Determine the best encoding. Compute first the block length in bytes*/
3053 opt_lenb = (s->opt_len+3+7)>>3;
3054 static_lenb = (s->static_len+3+7)>>3;
3055
3056 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
3057 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
3058 s->last_lit));
3059
3060 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
3061
3062 } else {
3063 Assert(buf != (char*)0, "lost buf");
3064 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
3065 }
3066
3067 #ifdef FORCE_STORED
3068 if (buf != (char*)0) { /* force stored block */
3069 #else
3070 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
3071 /* 4: two words for the lengths */
3072 #endif
3073 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
3074 * Otherwise we can't have processed more than WSIZE input bytes since
3075 * the last block flush, because compression would have been
3076 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
3077 * transform a block into a stored block.
3078 */
3079 _tr_stored_block(s, buf, stored_len, eof);
3080
3081 #ifdef FORCE_STATIC
3082 } else if (static_lenb >= 0) { /* force static trees */
3083 #else
3084 } else if (static_lenb == opt_lenb) {
3085 #endif
3086 send_bits(s, (STATIC_TREES<<1)+eof, 3);
3087 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
3088 #ifdef DEBUG_ZLIB
3089 s->compressed_len += 3 + s->static_len;
3090 #endif
3091 } else {
3092 send_bits(s, (DYN_TREES<<1)+eof, 3);
3093 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
3094 max_blindex+1);
3095 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
3096 #ifdef DEBUG_ZLIB
3097 s->compressed_len += 3 + s->opt_len;
3098 #endif
3099 }
3100 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
3101 /* The above check is made mod 2^32, for files larger than 512 MB
3102 * and uLong implemented on 32 bits.
3103 */
3104 init_block(s);
3105
3106 if (eof) {
3107 bi_windup(s);
3108 #ifdef DEBUG_ZLIB
3109 s->compressed_len += 7; /* align on byte boundary */
3110 #endif
3111 }
3112 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
3113 s->compressed_len-7*eof));
3114 }
3115
3116 /* ===========================================================================
3117 * Save the match info and tally the frequency counts. Return true if
3118 * the current block must be flushed.
3119 */
3120 int _tr_tally (s, dist, lc)
3121 deflate_state *s;
3122 unsigned dist; /* distance of matched string */
3123 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
3124 {
3125 s->d_buf[s->last_lit] = (ush)dist;
3126 s->l_buf[s->last_lit++] = (uch)lc;
3127 if (dist == 0) {
3128 /* lc is the unmatched char */
3129 s->dyn_ltree[lc].Freq++;
3130 } else {
3131 s->matches++;
3132 /* Here, lc is the match length - MIN_MATCH */
3133 dist--; /* dist = match distance - 1 */
3134 Assert((ush)dist < (ush)MAX_DIST(s) &&
3135 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
3136 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
3137
3138 s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
3139 s->dyn_dtree[d_code(dist)].Freq++;
3140 }
3141
3142 #ifdef TRUNCATE_BLOCK
3143 /* Try to guess if it is profitable to stop the current block here */
3144 if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
3145 /* Compute an upper bound for the compressed length */
3146 ulg out_length = (ulg)s->last_lit*8L;
3147 ulg in_length = (ulg)((long)s->strstart - s->block_start);
3148 int dcode;
3149 for (dcode = 0; dcode < D_CODES; dcode++) {
3150 out_length += (ulg)s->dyn_dtree[dcode].Freq *
3151 (5L+extra_dbits[dcode]);
3152 }
3153 out_length >>= 3;
3154 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
3155 s->last_lit, in_length, out_length,
3156 100L - out_length*100L/in_length));
3157 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
3158 }
3159 #endif
3160 return (s->last_lit == s->lit_bufsize-1);
3161 /* We avoid equality with lit_bufsize because of wraparound at 64K
3162 * on 16 bit machines and because stored blocks are restricted to
3163 * 64K-1 bytes.
3164 */
3165 }
3166
3167 /* ===========================================================================
3168 * Send the block data compressed using the given Huffman trees
3169 */
3170 local void compress_block(s, ltree, dtree)
3171 deflate_state *s;
3172 ct_data *ltree; /* literal tree */
3173 ct_data *dtree; /* distance tree */
3174 {
3175 unsigned dist; /* distance of matched string */
3176 int lc; /* match length or unmatched char (if dist == 0) */
3177 unsigned lx = 0; /* running index in l_buf */
3178 unsigned code; /* the code to send */
3179 int extra; /* number of extra bits to send */
3180
3181 if (s->last_lit != 0) do {
3182 dist = s->d_buf[lx];
3183 lc = s->l_buf[lx++];
3184 if (dist == 0) {
3185 send_code(s, lc, ltree); /* send a literal byte */
3186 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
3187 } else {
3188 /* Here, lc is the match length - MIN_MATCH */
3189 code = _length_code[lc];
3190 send_code(s, code+LITERALS+1, ltree); /* send the length code */
3191 extra = extra_lbits[code];
3192 if (extra != 0) {
3193 lc -= base_length[code];
3194 send_bits(s, lc, extra); /* send the extra length bits */
3195 }
3196 dist--; /* dist is now the match distance - 1 */
3197 code = d_code(dist);
3198 Assert (code < D_CODES, "bad d_code");
3199
3200 send_code(s, code, dtree); /* send the distance code */
3201 extra = extra_dbits[code];
3202 if (extra != 0) {
3203 dist -= base_dist[code];
3204 send_bits(s, dist, extra); /* send the extra distance bits */
3205 }
3206 } /* literal or match pair ? */
3207
3208 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
3209 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
3210
3211 } while (lx < s->last_lit);
3212
3213 send_code(s, END_BLOCK, ltree);
3214 s->last_eob_len = ltree[END_BLOCK].Len;
3215 }
3216
3217 /* ===========================================================================
3218 * Set the data type to ASCII or BINARY, using a crude approximation:
3219 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
3220 * IN assertion: the fields freq of dyn_ltree are set and the total of all
3221 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
3222 */
3223 local void set_data_type(s)
3224 deflate_state *s;
3225 {
3226 int n = 0;
3227 unsigned ascii_freq = 0;
3228 unsigned bin_freq = 0;
3229 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
3230 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
3231 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
3232 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
3233 }
3234
3235 /* ===========================================================================
3236 * Reverse the first len bits of a code, using straightforward code (a faster
3237 * method would use a table)
3238 * IN assertion: 1 <= len <= 15
3239 */
3240 local unsigned bi_reverse(code, len)
3241 unsigned code; /* the value to invert */
3242 int len; /* its bit length */
3243 {
3244 register unsigned res = 0;
3245 do {
3246 res |= code & 1;
3247 code >>= 1, res <<= 1;
3248 } while (--len > 0);
3249 return res >> 1;
3250 }
3251
3252 /* ===========================================================================
3253 * Flush the bit buffer, keeping at most 7 bits in it.
3254 */
3255 local void bi_flush(s)
3256 deflate_state *s;
3257 {
3258 if (s->bi_valid == 16) {
3259 put_short(s, s->bi_buf);
3260 s->bi_buf = 0;
3261 s->bi_valid = 0;
3262 } else if (s->bi_valid >= 8) {
3263 put_byte(s, (Byte)s->bi_buf);
3264 s->bi_buf >>= 8;
3265 s->bi_valid -= 8;
3266 }
3267 }
3268
3269 /* ===========================================================================
3270 * Flush the bit buffer and align the output on a byte boundary
3271 */
3272 local void bi_windup(s)
3273 deflate_state *s;
3274 {
3275 if (s->bi_valid > 8) {
3276 put_short(s, s->bi_buf);
3277 } else if (s->bi_valid > 0) {
3278 put_byte(s, (Byte)s->bi_buf);
3279 }
3280 s->bi_buf = 0;
3281 s->bi_valid = 0;
3282 #ifdef DEBUG_ZLIB
3283 s->bits_sent = (s->bits_sent+7) & ~7;
3284 #endif
3285 }
3286
3287 /* ===========================================================================
3288 * Copy a stored block, storing first the length and its
3289 * one's complement if requested.
3290 */
3291 local void copy_block(s, buf, len, header)
3292 deflate_state *s;
3293 charf *buf; /* the input data */
3294 unsigned len; /* its length */
3295 int header; /* true if block header must be written */
3296 {
3297 bi_windup(s); /* align on byte boundary */
3298 s->last_eob_len = 8; /* enough lookahead for inflate */
3299
3300 if (header) {
3301 put_short(s, (ush)len);
3302 put_short(s, (ush)~len);
3303 #ifdef DEBUG_ZLIB
3304 s->bits_sent += 2*16;
3305 #endif
3306 }
3307 #ifdef DEBUG_ZLIB
3308 s->bits_sent += (ulg)len<<3;
3309 #endif
3310 while (len--) {
3311 put_byte(s, *buf++);
3312 }
3313 }
3314 /* --- trees.c */
3315
3316 /* +++ inflate.c */
3317 /* inflate.c -- zlib interface to inflate modules
3318 * Copyright (C) 1995-2002 Mark Adler
3319 * For conditions of distribution and use, see copyright notice in zlib.h
3320 */
3321
3322 /* #include "zutil.h" */
3323
3324 /* +++ infblock.h */
3325 /* infblock.h -- header to use infblock.c
3326 * Copyright (C) 1995-2002 Mark Adler
3327 * For conditions of distribution and use, see copyright notice in zlib.h
3328 */
3329
3330 /* WARNING: this file should *not* be used by applications. It is
3331 part of the implementation of the compression library and is
3332 subject to change. Applications should only use zlib.h.
3333 */
3334
3335 struct inflate_blocks_state;
3336 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3337
3338 extern inflate_blocks_statef * inflate_blocks_new OF((
3339 z_streamp z,
3340 check_func c, /* check function */
3341 uInt w)); /* window size */
3342
3343 extern int inflate_blocks OF((
3344 inflate_blocks_statef *,
3345 z_streamp ,
3346 int)); /* initial return code */
3347
3348 extern void inflate_blocks_reset OF((
3349 inflate_blocks_statef *,
3350 z_streamp ,
3351 uLongf *)); /* check value on output */
3352
3353 extern int inflate_blocks_free OF((
3354 inflate_blocks_statef *,
3355 z_streamp));
3356
3357 extern void inflate_set_dictionary OF((
3358 inflate_blocks_statef *s,
3359 const Bytef *d, /* dictionary */
3360 uInt n)); /* dictionary length */
3361
3362 extern int inflate_blocks_sync_point OF((
3363 inflate_blocks_statef *s));
3364 /* --- infblock.h */
3365
3366 #ifndef NO_DUMMY_DECL
3367 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3368 #endif
3369
3370 /* inflate private state */
3371 typedef struct inflate_state {
3372
3373 /* mode */
3374 enum {
3375 METHOD, /* waiting for method byte */
3376 FLAG, /* waiting for flag byte */
3377 DICT4, /* four dictionary check bytes to go */
3378 DICT3, /* three dictionary check bytes to go */
3379 DICT2, /* two dictionary check bytes to go */
3380 DICT1, /* one dictionary check byte to go */
3381 DICT0, /* waiting for inflateSetDictionary */
3382 BLOCKS, /* decompressing blocks */
3383 CHECK4, /* four check bytes to go */
3384 CHECK3, /* three check bytes to go */
3385 CHECK2, /* two check bytes to go */
3386 CHECK1, /* one check byte to go */
3387 DONE, /* finished check, done */
3388 BAD} /* got an error--stay here */
3389 mode; /* current inflate mode */
3390
3391 /* mode dependent information */
3392 union {
3393 uInt method; /* if FLAGS, method byte */
3394 struct {
3395 uLong was; /* computed check value */
3396 uLong need; /* stream check value */
3397 } check; /* if CHECK, check values to compare */
3398 uInt marker; /* if BAD, inflateSync's marker bytes count */
3399 } sub; /* submode */
3400
3401 /* mode independent information */
3402 int nowrap; /* flag for no wrapper */
3403 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3404 inflate_blocks_statef
3405 *blocks; /* current inflate_blocks state */
3406
3407 }inflate_state;
3408
3409
3410 int ZEXPORT inflateReset(z)
3411 z_streamp z;
3412 {
3413 inflate_state* s;
3414 if (z == Z_NULL || z->state == Z_NULL)
3415 return Z_STREAM_ERROR;
3416
3417 s = (inflate_state*)z->state;
3418 z->total_in = z->total_out = 0;
3419 z->msg = Z_NULL;
3420 s->mode = s->nowrap ? BLOCKS : METHOD;
3421 inflate_blocks_reset(s->blocks, z, Z_NULL);
3422 Tracev((stderr, "inflate: reset\n"));
3423 return Z_OK;
3424 }
3425
3426
3427 int ZEXPORT inflateEnd(z)
3428 z_streamp z;
3429 {
3430 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3431 return Z_STREAM_ERROR;
3432 if (((inflate_state*)z->state)->blocks != Z_NULL)
3433 inflate_blocks_free(((inflate_state*)z->state)->blocks, z);
3434 ZFREE(z, z->state);
3435 z->state = Z_NULL;
3436 Tracev((stderr, "inflate: end\n"));
3437 return Z_OK;
3438 }
3439
3440
3441 int ZEXPORT inflateInit2_(z, w, version, stream_size)
3442 z_streamp z;
3443 int w;
3444 const char *version;
3445 int stream_size;
3446 {
3447 inflate_state* s;
3448 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3449 stream_size != sizeof(z_stream))
3450 return Z_VERSION_ERROR;
3451
3452 /* initialize state */
3453 if (z == Z_NULL)
3454 return Z_STREAM_ERROR;
3455 z->msg = Z_NULL;
3456 #ifndef NO_ZCFUNCS
3457 if (z->zalloc == Z_NULL)
3458 {
3459 z->zalloc = zcalloc;
3460 z->opaque = (voidpf)0;
3461 }
3462 if (z->zfree == Z_NULL) z->zfree = zcfree;
3463 #endif
3464 if ((z->state = (struct internal_state FAR *)
3465 ZALLOC(z,1,sizeof(struct inflate_state))) == Z_NULL)
3466 return Z_MEM_ERROR;
3467 s = (inflate_state*)z->state;
3468 s->blocks = Z_NULL;
3469
3470 /* handle undocumented nowrap option (no zlib header or check) */
3471 s->nowrap = 0;
3472 if (w < 0)
3473 {
3474 w = - w;
3475 s->nowrap = 1;
3476 }
3477
3478 /* set window size */
3479 if (w < 8 || w > 15)
3480 {
3481 inflateEnd(z);
3482 return Z_STREAM_ERROR;
3483 }
3484 s->wbits = (uInt)w;
3485
3486 /* create inflate_blocks state */
3487 if ((s->blocks =
3488 inflate_blocks_new(z, s->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3489 == Z_NULL)
3490 {
3491 inflateEnd(z);
3492 return Z_MEM_ERROR;
3493 }
3494 Tracev((stderr, "inflate: allocated\n"));
3495
3496 /* reset state */
3497 inflateReset(z);
3498 return Z_OK;
3499 }
3500
3501
3502 int ZEXPORT inflateInit_(z, version, stream_size)
3503 z_streamp z;
3504 const char *version;
3505 int stream_size;
3506 {
3507 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3508 }
3509
3510
3511 #define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
3512 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3513
3514 int ZEXPORT inflate(z, f)
3515 z_streamp z;
3516 int f;
3517 {
3518 int r;
3519 uInt b;
3520 inflate_state* s;
3521
3522 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
3523 return Z_STREAM_ERROR;
3524 f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
3525 r = Z_BUF_ERROR;
3526 s = (inflate_state*)z->state;
3527 while (1) switch (s->mode)
3528 {
3529 case METHOD:
3530 NEEDBYTE
3531 if (((s->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3532 {
3533 s->mode = BAD;
3534 z->msg = (char*)"unknown compression method";
3535 s->sub.marker = 5; /* can't try inflateSync */
3536 break;
3537 }
3538 if ((s->sub.method >> 4) + 8 > s->wbits)
3539 {
3540 s->mode = BAD;
3541 z->msg = (char*)"invalid window size";
3542 s->sub.marker = 5; /* can't try inflateSync */
3543 break;
3544 }
3545 s->mode = FLAG;
3546 case FLAG:
3547 NEEDBYTE
3548 b = NEXTBYTE;
3549 if (((s->sub.method << 8) + b) % 31)
3550 {
3551 s->mode = BAD;
3552 z->msg = (char*)"incorrect header check";
3553 s->sub.marker = 5; /* can't try inflateSync */
3554 break;
3555 }
3556 Tracev((stderr, "inflate: zlib header ok\n"));
3557 if (!(b & PRESET_DICT))
3558 {
3559 s->mode = BLOCKS;
3560 break;
3561 }
3562 s->mode = DICT4;
3563 case DICT4:
3564 NEEDBYTE
3565 s->sub.check.need = (uLong)NEXTBYTE << 24;
3566 s->mode = DICT3;
3567 case DICT3:
3568 NEEDBYTE
3569 s->sub.check.need += (uLong)NEXTBYTE << 16;
3570 s->mode = DICT2;
3571 case DICT2:
3572 NEEDBYTE
3573 s->sub.check.need += (uLong)NEXTBYTE << 8;
3574 s->mode = DICT1;
3575 case DICT1:
3576 NEEDBYTE
3577 s->sub.check.need += (uLong)NEXTBYTE;
3578 z->adler = s->sub.check.need;
3579 s->mode = DICT0;
3580 return Z_NEED_DICT;
3581 case DICT0:
3582 s->mode = BAD;
3583 z->msg = (char*)"need dictionary";
3584 s->sub.marker = 0; /* can try inflateSync */
3585 return Z_STREAM_ERROR;
3586 case BLOCKS:
3587 r = inflate_blocks(s->blocks, z, r);
3588 if (r == Z_DATA_ERROR)
3589 {
3590 s->mode = BAD;
3591 s->sub.marker = 0; /* can try inflateSync */
3592 break;
3593 }
3594 if (r == Z_OK)
3595 r = f;
3596 if (r != Z_STREAM_END)
3597 return r;
3598 r = f;
3599 inflate_blocks_reset(s->blocks, z, &s->sub.check.was);
3600 if (s->nowrap)
3601 {
3602 s->mode = DONE;
3603 break;
3604 }
3605 s->mode = CHECK4;
3606 case CHECK4:
3607 NEEDBYTE
3608 s->sub.check.need = (uLong)NEXTBYTE << 24;
3609 s->mode = CHECK3;
3610 case CHECK3:
3611 NEEDBYTE
3612 s->sub.check.need += (uLong)NEXTBYTE << 16;
3613 s->mode = CHECK2;
3614 case CHECK2:
3615 NEEDBYTE
3616 s->sub.check.need += (uLong)NEXTBYTE << 8;
3617 s->mode = CHECK1;
3618 case CHECK1:
3619 NEEDBYTE
3620 s->sub.check.need += (uLong)NEXTBYTE;
3621
3622 if (s->sub.check.was != s->sub.check.need)
3623 {
3624 s->mode = BAD;
3625 z->msg = (char*)"incorrect data check";
3626 s->sub.marker = 5; /* can't try inflateSync */
3627 break;
3628 }
3629 Tracev((stderr, "inflate: zlib check ok\n"));
3630 s->mode = DONE;
3631 case DONE:
3632 return Z_STREAM_END;
3633 case BAD:
3634 return Z_DATA_ERROR;
3635 default:
3636 return Z_STREAM_ERROR;
3637 }
3638 #ifdef NEED_DUMMY_RETURN
3639 return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
3640 #endif
3641 }
3642
3643
3644 int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
3645 z_streamp z;
3646 const Bytef *dictionary;
3647 uInt dictLength;
3648 {
3649 uInt length = dictLength;
3650 inflate_state* s;
3651
3652 if (z == Z_NULL || z->state == Z_NULL || ((inflate_state*)z->state)->mode != DICT0)
3653 return Z_STREAM_ERROR;
3654 s = (inflate_state*)z->state;
3655
3656 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3657 z->adler = 1L;
3658
3659 if (length >= ((uInt)1<<s->wbits))
3660 {
3661 length = (1<<s->wbits)-1;
3662 dictionary += dictLength - length;
3663 }
3664 inflate_set_dictionary(s->blocks, dictionary, length);
3665 s->mode = BLOCKS;
3666 return Z_OK;
3667 }
3668
3669
3670 int ZEXPORT inflateSync(z)
3671 z_streamp z;
3672 {
3673 uInt n; /* number of bytes to look at */
3674 Bytef *p; /* pointer to bytes */
3675 uInt m; /* number of marker bytes found in a row */
3676 uLong r, w; /* temporaries to save total_in and total_out */
3677 inflate_state* s;
3678
3679 /* set up */
3680 if (z == Z_NULL || z->state == Z_NULL)
3681 return Z_STREAM_ERROR;
3682 s = (inflate_state*)z->state;
3683 if (s->mode != BAD)
3684 {
3685 s->mode = BAD;
3686 s->sub.marker = 0;
3687 }
3688 if ((n = z->avail_in) == 0)
3689 return Z_BUF_ERROR;
3690 p = z->next_in;
3691 m = s->sub.marker;
3692
3693 /* search */
3694 while (n && m < 4)
3695 {
3696 static const Byte mark[4] = {0, 0, 0xff, 0xff};
3697 if (*p == mark[m])
3698 m++;
3699 else if (*p)
3700 m = 0;
3701 else
3702 m = 4 - m;
3703 p++, n--;
3704 }
3705
3706 /* restore */
3707 z->total_in += p - z->next_in;
3708 z->next_in = p;
3709 z->avail_in = n;
3710 s->sub.marker = m;
3711
3712 /* return no joy or set up to restart on a new block */
3713 if (m != 4)
3714 return Z_DATA_ERROR;
3715 r = z->total_in; w = z->total_out;
3716 inflateReset(z);
3717 z->total_in = r; z->total_out = w;
3718 s->mode = BLOCKS;
3719 return Z_OK;
3720 }
3721
3722
3723 /* Returns true if inflate is currently at the end of a block generated
3724 * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
3725 * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
3726 * but removes the length bytes of the resulting empty stored block. When
3727 * decompressing, PPP checks that at the end of input packet, inflate is
3728 * waiting for these length bytes.
3729 */
3730 int ZEXPORT inflateSyncPoint(z)
3731 z_streamp z;
3732 {
3733 if (z == Z_NULL || z->state == Z_NULL || ((inflate_state*)z->state)->blocks == Z_NULL)
3734 return Z_STREAM_ERROR;
3735 return inflate_blocks_sync_point(((inflate_state*)z->state)->blocks);
3736 }
3737 #undef NEEDBYTE
3738 #undef NEXTBYTE
3739 /* --- inflate.c */
3740
3741 /* +++ infblock.c */
3742 /* infblock.c -- interpret and process block types to last block
3743 * Copyright (C) 1995-2002 Mark Adler
3744 * For conditions of distribution and use, see copyright notice in zlib.h
3745 */
3746
3747 /* #include "zutil.h" */
3748 /* #include "infblock.h" */
3749
3750 /* +++ inftrees.h */
3751 /* inftrees.h -- header to use inftrees.c
3752 * Copyright (C) 1995-2002 Mark Adler
3753 * For conditions of distribution and use, see copyright notice in zlib.h
3754 */
3755
3756 /* WARNING: this file should *not* be used by applications. It is
3757 part of the implementation of the compression library and is
3758 subject to change. Applications should only use zlib.h.
3759 */
3760
3761 /* Huffman code lookup table entry--this entry is four bytes for machines
3762 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3763
3764 typedef struct inflate_huft_s FAR inflate_huft;
3765
3766 struct inflate_huft_s {
3767 union {
3768 struct {
3769 Byte Exop; /* number of extra bits or operation */
3770 Byte Bits; /* number of bits in this code or subcode */
3771 } what;
3772 uInt pad; /* pad structure to a power of 2 (4 bytes for */
3773 } word; /* 16-bit, 8 bytes for 32-bit int's) */
3774 uInt base; /* literal, length base, distance base,
3775 or table offset */
3776 };
3777
3778 /* Maximum size of dynamic tree. The maximum found in a long but non-
3779 exhaustive search was 1004 huft structures (850 for length/literals
3780 and 154 for distances, the latter actually the result of an
3781 exhaustive search). The actual maximum is not known, but the
3782 value below is more than safe. */
3783 #define MANY 1440
3784
3785 extern int inflate_trees_bits OF((
3786 uIntf *, /* 19 code lengths */
3787 uIntf *, /* bits tree desired/actual depth */
3788 inflate_huft * FAR *, /* bits tree result */
3789 inflate_huft *, /* space for trees */
3790 z_streamp)); /* for messages */
3791
3792 extern int inflate_trees_dynamic OF((
3793 uInt, /* number of literal/length codes */
3794 uInt, /* number of distance codes */
3795 uIntf *, /* that many (total) code lengths */
3796 uIntf *, /* literal desired/actual bit depth */
3797 uIntf *, /* distance desired/actual bit depth */
3798 inflate_huft * FAR *, /* literal/length tree result */
3799 inflate_huft * FAR *, /* distance tree result */
3800 inflate_huft *, /* space for trees */
3801 z_streamp)); /* for messages */
3802
3803 extern int inflate_trees_fixed OF((
3804 uIntf *, /* literal desired/actual bit depth */
3805 uIntf *, /* distance desired/actual bit depth */
3806 inflate_huft * FAR *, /* literal/length tree result */
3807 inflate_huft * FAR *, /* distance tree result */
3808 z_streamp)); /* for memory allocation */
3809 /* --- inftrees.h */
3810
3811 /* +++ infcodes.h */
3812 /* infcodes.h -- header to use infcodes.c
3813 * Copyright (C) 1995-2002 Mark Adler
3814 * For conditions of distribution and use, see copyright notice in zlib.h
3815 */
3816
3817 /* WARNING: this file should *not* be used by applications. It is
3818 part of the implementation of the compression library and is
3819 subject to change. Applications should only use zlib.h.
3820 */
3821
3822 struct inflate_codes_state;
3823 typedef struct inflate_codes_state FAR inflate_codes_statef;
3824
3825 extern inflate_codes_statef *inflate_codes_new OF((
3826 uInt, uInt,
3827 inflate_huft *, inflate_huft *,
3828 z_streamp ));
3829
3830 extern int inflate_codes OF((
3831 inflate_blocks_statef *,
3832 z_streamp ,
3833 int));
3834
3835 extern void inflate_codes_free OF((
3836 inflate_codes_statef *,
3837 z_streamp ));
3838
3839 /* --- infcodes.h */
3840
3841 /* +++ infutil.h */
3842 /* infutil.h -- types and macros common to blocks and codes
3843 * Copyright (C) 1995-2002 Mark Adler
3844 * For conditions of distribution and use, see copyright notice in zlib.h
3845 */
3846
3847 /* WARNING: this file should *not* be used by applications. It is
3848 part of the implementation of the compression library and is
3849 subject to change. Applications should only use zlib.h.
3850 */
3851
3852 #ifndef _INFUTIL_H
3853 #define _INFUTIL_H
3854
3855 typedef enum {
3856 TYPE, /* get type bits (3, including end bit) */
3857 LENS, /* get lengths for stored */
3858 STORED, /* processing stored block */
3859 TABLE, /* get table lengths */
3860 BTREE, /* get bit lengths tree for a dynamic block */
3861 DTREE, /* get length, distance trees for a dynamic block */
3862 CODES, /* processing fixed or dynamic block */
3863 DRY, /* output remaining window bytes */
3864 DONEB, /* finished last block, done */
3865 BADB} /* got a data error--stuck here */
3866 inflate_block_mode;
3867
3868 /* inflate blocks semi-private state */
3869 struct inflate_blocks_state {
3870
3871 /* mode */
3872 inflate_block_mode mode; /* current inflate_block mode */
3873
3874 /* mode dependent information */
3875 union {
3876 uInt left; /* if STORED, bytes left to copy */
3877 struct {
3878 uInt table; /* table lengths (14 bits) */
3879 uInt index; /* index into blens (or border) */
3880 uIntf *blens; /* bit lengths of codes */
3881 uInt bb; /* bit length tree depth */
3882 inflate_huft *tb; /* bit length decoding tree */
3883 } trees; /* if DTREE, decoding info for trees */
3884 struct {
3885 inflate_codes_statef
3886 *codes;
3887 } decode; /* if CODES, current state */
3888 } sub; /* submode */
3889 uInt last; /* true if this block is the last block */
3890
3891 /* mode independent information */
3892 uInt bitk; /* bits in bit buffer */
3893 uLong bitb; /* bit buffer */
3894 inflate_huft *hufts; /* single malloc for tree space */
3895 Bytef *window; /* sliding window */
3896 Bytef *end; /* one byte after sliding window */
3897 Bytef *read; /* window read pointer */
3898 Bytef *write; /* window write pointer */
3899 check_func checkfn; /* check function */
3900 uLong check; /* check on output */
3901
3902 };
3903
3904
3905 /* defines for inflate input/output */
3906 /* update pointers and return */
3907 #define UPDBITS {s->bitb=b;s->bitk=k;}
3908 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3909 #define UPDOUT {s->write=q;}
3910 #define UPDATE {UPDBITS UPDIN UPDOUT}
3911 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3912 /* get bytes and bits */
3913 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3914 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3915 #define NEXTBYTE (n--,*p++)
3916 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3917 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3918 /* output bytes */
3919 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3920 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3921 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3922 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3923 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3924 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3925 /* load local pointers */
3926 #define LOAD {LOADIN LOADOUT}
3927
3928 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3929 extern uInt inflate_mask[17];
3930
3931 /* copy as much as possible from the sliding window to the output area */
3932 extern int inflate_flush OF((
3933 inflate_blocks_statef *,
3934 z_streamp ,
3935 int));
3936
3937 #ifndef NO_DUMMY_DECL
3938 struct internal_state {int dummy;}; /* for buggy compilers */
3939 #endif
3940
3941 #endif
3942 /* --- infutil.h */
3943
3944 #ifndef NO_DUMMY_DECL
3945 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3946 #endif
3947
3948 /* simplify the use of the inflate_huft type with some defines */
3949 #define exop word.what.Exop
3950 #define bits word.what.Bits
3951
3952 /* Table for deflate from PKZIP's appnote.txt. */
3953 local const uInt border[] = { /* Order of the bit length code lengths */
3954 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3955
3956 /*
3957 Notes beyond the 1.93a appnote.txt:
3958
3959 1. Distance pointers never point before the beginning of the output
3960 stream.
3961 2. Distance pointers can point back across blocks, up to 32k away.
3962 3. There is an implied maximum of 7 bits for the bit length table and
3963 15 bits for the actual data.
3964 4. If only one code exists, then it is encoded using one bit. (Zero
3965 would be more efficient, but perhaps a little confusing.) If two
3966 codes exist, they are coded using one bit each (0 and 1).
3967 5. There is no way of sending zero distance codes--a dummy must be
3968 sent if there are none. (History: a pre 2.0 version of PKZIP would
3969 store blocks with no distance codes, but this was discovered to be
3970 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3971 zero distance codes, which is sent as one code of zero bits in
3972 length.
3973 6. There are up to 286 literal/length codes. Code 256 represents the
3974 end-of-block. Note however that the static length tree defines
3975 288 codes just to fill out the Huffman codes. Codes 286 and 287
3976 cannot be used though, since there is no length base or extra bits
3977 defined for them. Similarily, there are up to 30 distance codes.
3978 However, static trees define 32 codes (all 5 bits) to fill out the
3979 Huffman codes, but the last two had better not show up in the data.
3980 7. Unzip can check dynamic Huffman blocks for complete code sets.
3981 The exception is that a single code would not be complete (see #4).
3982 8. The five bits following the block type is really the number of
3983 literal codes sent minus 257.
3984 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3985 (1+6+6). Therefore, to output three times the length, you output
3986 three codes (1+1+1), whereas to output four times the same length,
3987 you only need two codes (1+3). Hmm.
3988 10. In the tree reconstruction algorithm, Code = Code + Increment
3989 only if BitLength(i) is not zero. (Pretty obvious.)
3990 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3991 12. Note: length code 284 can represent 227-258, but length code 285
3992 really is 258. The last length deserves its own, short code
3993 since it gets used a lot in very redundant files. The length
3994 258 is special since 258 - 3 (the min match length) is 255.
3995 13. The literal/length and distance code bit lengths are read as a
3996 single stream of lengths. It is possible (and advantageous) for
3997 a repeat code (16, 17, or 18) to go across the boundary between
3998 the two sets of lengths.
3999 */
4000
4001
4002 void inflate_blocks_reset(s, z, c)
4003 inflate_blocks_statef *s;
4004 z_streamp z;
4005 uLongf *c;
4006 {
4007 if (c != Z_NULL)
4008 *c = s->check;
4009 if (s->mode == BTREE || s->mode == DTREE)
4010 ZFREE(z, s->sub.trees.blens);
4011 if (s->mode == CODES)
4012 inflate_codes_free(s->sub.decode.codes, z);
4013 s->mode = TYPE;
4014 s->bitk = 0;
4015 s->bitb = 0;
4016 s->read = s->write = s->window;
4017 if (s->checkfn != Z_NULL)
4018 z->adler = s->check = (*s->checkfn)(0L, (const Bytef *)Z_NULL, 0);
4019 Tracev((stderr, "inflate: blocks reset\n"));
4020 }
4021
4022
4023 inflate_blocks_statef *inflate_blocks_new(z, c, w)
4024 z_streamp z;
4025 check_func c;
4026 uInt w;
4027 {
4028 inflate_blocks_statef *s;
4029
4030 if ((s = (inflate_blocks_statef *)ZALLOC
4031 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
4032 return s;
4033 if ((s->hufts =
4034 (inflate_huft *)ZALLOC(z, sizeof(inflate_huft), MANY)) == Z_NULL)
4035 {
4036 ZFREE(z, s);
4037 return Z_NULL;
4038 }
4039 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
4040 {
4041 ZFREE(z, s->hufts);
4042 ZFREE(z, s);
4043 return Z_NULL;
4044 }
4045 s->end = s->window + w;
4046 s->checkfn = c;
4047 s->mode = TYPE;
4048 Tracev((stderr, "inflate: blocks allocated\n"));
4049 inflate_blocks_reset(s, z, Z_NULL);
4050 return s;
4051 }
4052
4053
4054 int inflate_blocks(s, z, r)
4055 inflate_blocks_statef *s;
4056 z_streamp z;
4057 int r;
4058 {
4059 uInt t; /* temporary storage */
4060 uLong b; /* bit buffer */
4061 uInt k; /* bits in bit buffer */
4062 Bytef *p; /* input data pointer */
4063 uInt n; /* bytes available there */
4064 Bytef *q; /* output window write pointer */
4065 uInt m; /* bytes to end of window or read pointer */
4066
4067 /* copy input/output information to locals (UPDATE macro restores) */
4068 LOAD
4069
4070 /* process input based on current state */
4071 while (1) switch (s->mode)
4072 {
4073 case TYPE:
4074 NEEDBITS(3)
4075 t = (uInt)b & 7;
4076 s->last = t & 1;
4077 switch (t >> 1)
4078 {
4079 case 0: /* stored */
4080 Tracev((stderr, "inflate: stored block%s\n",
4081 s->last ? " (last)" : ""));
4082 DUMPBITS(3)
4083 t = k & 7; /* go to byte boundary */
4084 DUMPBITS(t)
4085 s->mode = LENS; /* get length of stored block */
4086 break;
4087 case 1: /* fixed */
4088 Tracev((stderr, "inflate: fixed codes block%s\n",
4089 s->last ? " (last)" : ""));
4090 {
4091 uInt bl, bd;
4092 inflate_huft *tl, *td;
4093
4094 inflate_trees_fixed(&bl, &bd, &tl, &td, z);
4095 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
4096 if (s->sub.decode.codes == Z_NULL)
4097 {
4098 r = Z_MEM_ERROR;
4099 LEAVE
4100 }
4101 }
4102 DUMPBITS(3)
4103 s->mode = CODES;
4104 break;
4105 case 2: /* dynamic */
4106 Tracev((stderr, "inflate: dynamic codes block%s\n",
4107 s->last ? " (last)" : ""));
4108 DUMPBITS(3)
4109 s->mode = TABLE;
4110 break;
4111 case 3: /* illegal */
4112 DUMPBITS(3)
4113 s->mode = BADB;
4114 z->msg = (char*)"invalid block type";
4115 r = Z_DATA_ERROR;
4116 LEAVE
4117 }
4118 break;
4119 case LENS:
4120 NEEDBITS(32)
4121 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
4122 {
4123 s->mode = BADB;
4124 z->msg = (char*)"invalid stored block lengths";
4125 r = Z_DATA_ERROR;
4126 LEAVE
4127 }
4128 s->sub.left = (uInt)b & 0xffff;
4129 b = k = 0; /* dump bits */
4130 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
4131 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
4132 break;
4133 case STORED:
4134 if (n == 0)
4135 LEAVE
4136 NEEDOUT
4137 t = s->sub.left;
4138 if (t > n) t = n;
4139 if (t > m) t = m;
4140 zmemcpy(q, p, t);
4141 p += t; n -= t;
4142 q += t; m -= t;
4143 if ((s->sub.left -= t) != 0)
4144 break;
4145 Tracev((stderr, "inflate: stored end, %lu total out\n",
4146 z->total_out + (q >= s->read ? q - s->read :
4147 (s->end - s->read) + (q - s->window))));
4148 s->mode = s->last ? DRY : TYPE;
4149 break;
4150 case TABLE:
4151 NEEDBITS(14)
4152 s->sub.trees.table = t = (uInt)b & 0x3fff;
4153 #ifndef PKZIP_BUG_WORKAROUND
4154 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
4155 {
4156 s->mode = BADB;
4157 z->msg = (char*)"too many length or distance symbols";
4158 r = Z_DATA_ERROR;
4159 LEAVE
4160 }
4161 #endif
4162 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
4163 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
4164 {
4165 r = Z_MEM_ERROR;
4166 LEAVE
4167 }
4168 DUMPBITS(14)
4169 s->sub.trees.index = 0;
4170 Tracev((stderr, "inflate: table sizes ok\n"));
4171 s->mode = BTREE;
4172 case BTREE:
4173 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
4174 {
4175 NEEDBITS(3)
4176 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
4177 DUMPBITS(3)
4178 }
4179 while (s->sub.trees.index < 19)
4180 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
4181 s->sub.trees.bb = 7;
4182 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
4183 &s->sub.trees.tb, s->hufts, z);
4184 if (t != Z_OK)
4185 {
4186 r = t;
4187 if (r == Z_DATA_ERROR)
4188 {
4189 ZFREE(z, s->sub.trees.blens);
4190 s->mode = BADB;
4191 }
4192 LEAVE
4193 }
4194 s->sub.trees.index = 0;
4195 Tracev((stderr, "inflate: bits tree ok\n"));
4196 s->mode = DTREE;
4197 case DTREE:
4198 while (t = s->sub.trees.table,
4199 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
4200 {
4201 inflate_huft *h;
4202 uInt i, j, c;
4203
4204 t = s->sub.trees.bb;
4205 NEEDBITS(t)
4206 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
4207 t = h->bits;
4208 c = h->base;
4209 if (c < 16)
4210 {
4211 DUMPBITS(t)
4212 s->sub.trees.blens[s->sub.trees.index++] = c;
4213 }
4214 else /* c == 16..18 */
4215 {
4216 i = c == 18 ? 7 : c - 14;
4217 j = c == 18 ? 11 : 3;
4218 NEEDBITS(t + i)
4219 DUMPBITS(t)
4220 j += (uInt)b & inflate_mask[i];
4221 DUMPBITS(i)
4222 i = s->sub.trees.index;
4223 t = s->sub.trees.table;
4224 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
4225 (c == 16 && i < 1))
4226 {
4227 ZFREE(z, s->sub.trees.blens);
4228 s->mode = BADB;
4229 z->msg = (char*)"invalid bit length repeat";
4230 r = Z_DATA_ERROR;
4231 LEAVE
4232 }
4233 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
4234 do {
4235 s->sub.trees.blens[i++] = c;
4236 } while (--j);
4237 s->sub.trees.index = i;
4238 }
4239 }
4240 s->sub.trees.tb = Z_NULL;
4241 {
4242 uInt bl, bd;
4243 inflate_huft *tl, *td;
4244 inflate_codes_statef *c;
4245
4246 bl = 9; /* must be <= 9 for lookahead assumptions */
4247 bd = 6; /* must be <= 9 for lookahead assumptions */
4248 t = s->sub.trees.table;
4249 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
4250 s->sub.trees.blens, &bl, &bd, &tl, &td,
4251 s->hufts, z);
4252 if (t != Z_OK)
4253 {
4254 if (t == (uInt)Z_DATA_ERROR)
4255 {
4256 ZFREE(z, s->sub.trees.blens);
4257 s->mode = BADB;
4258 }
4259 r = t;
4260 LEAVE
4261 }
4262 Tracev((stderr, "inflate: trees ok\n"));
4263 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
4264 {
4265 r = Z_MEM_ERROR;
4266 LEAVE
4267 }
4268 s->sub.decode.codes = c;
4269 }
4270 ZFREE(z, s->sub.trees.blens);
4271 s->mode = CODES;
4272 case CODES:
4273 UPDATE
4274 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
4275 return inflate_flush(s, z, r);
4276 r = Z_OK;
4277 inflate_codes_free(s->sub.decode.codes, z);
4278 LOAD
4279 Tracev((stderr, "inflate: codes end, %lu total out\n",
4280 z->total_out + (q >= s->read ? q - s->read :
4281 (s->end - s->read) + (q - s->window))));
4282 if (!s->last)
4283 {
4284 s->mode = TYPE;
4285 break;
4286 }
4287 s->mode = DRY;
4288 case DRY:
4289 FLUSH
4290 if (s->read != s->write)
4291 LEAVE
4292 s->mode = DONEB;
4293 case DONEB:
4294 r = Z_STREAM_END;
4295 LEAVE
4296 case BADB:
4297 r = Z_DATA_ERROR;
4298 LEAVE
4299 default:
4300 r = Z_STREAM_ERROR;
4301 LEAVE
4302 }
4303 }
4304
4305
4306 int inflate_blocks_free(s, z)
4307 inflate_blocks_statef *s;
4308 z_streamp z;
4309 {
4310 inflate_blocks_reset(s, z, Z_NULL);
4311 ZFREE(z, s->window);
4312 ZFREE(z, s->hufts);
4313 ZFREE(z, s);
4314 Tracev((stderr, "inflate: blocks freed\n"));
4315 return Z_OK;
4316 }
4317
4318
4319 void inflate_set_dictionary(s, d, n)
4320 inflate_blocks_statef *s;
4321 const Bytef *d;
4322 uInt n;
4323 {
4324 zmemcpy(s->window, d, n);
4325 s->read = s->write = s->window + n;
4326 }
4327
4328
4329 /* Returns true if inflate is currently at the end of a block generated
4330 * by Z_SYNC_FLUSH or Z_FULL_FLUSH.
4331 * IN assertion: s != Z_NULL
4332 */
4333 int inflate_blocks_sync_point(s)
4334 inflate_blocks_statef *s;
4335 {
4336 return s->mode == LENS;
4337 }
4338 /* --- infblock.c */
4339
4340 /* +++ inftrees.c */
4341 /* inftrees.c -- generate Huffman trees for efficient decoding
4342 * Copyright (C) 1995-2002 Mark Adler
4343 * For conditions of distribution and use, see copyright notice in zlib.h
4344 */
4345
4346 /* #include "zutil.h" */
4347 /* #include "inftrees.h" */
4348
4349 #if !defined(BUILDFIXED) && !defined(STDC)
4350 # define BUILDFIXED /* non ANSI compilers may not accept inffixed.h */
4351 #endif
4352
4353 const char inflate_copyright[] =
4354 " inflate 1.1.4 Copyright 1995-2002 Mark Adler ";
4355 /*
4356 If you use the zlib library in a product, an acknowledgment is welcome
4357 in the documentation of your product. If for some reason you cannot
4358 include such an acknowledgment, I would appreciate that you keep this
4359 copyright string in the executable of your product.
4360 */
4361
4362 #ifndef NO_DUMMY_DECL
4363 struct internal_state {int dummy;}; /* for buggy compilers */
4364 #endif
4365
4366 /* simplify the use of the inflate_huft type with some defines */
4367 #define exop word.what.Exop
4368 #define bits word.what.Bits
4369
4370
4371 local int huft_build OF((
4372 uIntf *, /* code lengths in bits */
4373 uInt, /* number of codes */
4374 uInt, /* number of "simple" codes */
4375 const uIntf *, /* list of base values for non-simple codes */
4376 const uIntf *, /* list of extra bits for non-simple codes */
4377 inflate_huft * FAR*,/* result: starting table */
4378 uIntf *, /* maximum lookup bits (returns actual) */
4379 inflate_huft *, /* space for trees */
4380 uInt *, /* hufts used in space */
4381 uIntf * )); /* space for values */
4382
4383 /* Tables for deflate from PKZIP's appnote.txt. */
4384 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4385 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4386 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4387 /* see note #13 above about 258 */
4388 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4389 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4390 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4391 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4392 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4393 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4394 8193, 12289, 16385, 24577};
4395 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4396 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4397 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4398 12, 12, 13, 13};
4399
4400 /*
4401 Huffman code decoding is performed using a multi-level table lookup.
4402 The fastest way to decode is to simply build a lookup table whose
4403 size is determined by the longest code. However, the time it takes
4404 to build this table can also be a factor if the data being decoded
4405 is not very long. The most common codes are necessarily the
4406 shortest codes, so those codes dominate the decoding time, and hence
4407 the speed. The idea is you can have a shorter table that decodes the
4408 shorter, more probable codes, and then point to subsidiary tables for
4409 the longer codes. The time it costs to decode the longer codes is
4410 then traded against the time it takes to make longer tables.
4411
4412 This results of this trade are in the variables lbits and dbits
4413 below. lbits is the number of bits the first level table for literal/
4414 length codes can decode in one step, and dbits is the same thing for
4415 the distance codes. Subsequent tables are also less than or equal to
4416 those sizes. These values may be adjusted either when all of the
4417 codes are shorter than that, in which case the longest code length in
4418 bits is used, or when the shortest code is *longer* than the requested
4419 table size, in which case the length of the shortest code in bits is
4420 used.
4421
4422 There are two different values for the two tables, since they code a
4423 different number of possibilities each. The literal/length table
4424 codes 286 possible values, or in a flat code, a little over eight
4425 bits. The distance table codes 30 possible values, or a little less
4426 than five bits, flat. The optimum values for speed end up being
4427 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4428 The optimum values may differ though from machine to machine, and
4429 possibly even between compilers. Your mileage may vary.
4430 */
4431
4432
4433 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4434 #define BMAX 15 /* maximum bit length of any code */
4435
4436 local int huft_build(b, n, s, d, e, t, m, hp, hn, v)
4437 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4438 uInt n; /* number of codes (assumed <= 288) */
4439 uInt s; /* number of simple-valued codes (0..s-1) */
4440 const uIntf *d; /* list of base values for non-simple codes */
4441 const uIntf *e; /* list of extra bits for non-simple codes */
4442 inflate_huft * FAR *t; /* result: starting table */
4443 uIntf *m; /* maximum lookup bits, returns actual */
4444 inflate_huft *hp; /* space for trees */
4445 uInt *hn; /* hufts used in space */
4446 uIntf *v; /* working area: values in order of bit length */
4447 /* Given a list of code lengths and a maximum table size, make a set of
4448 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4449 if the given code set is incomplete (the tables are still built in this
4450 case), or Z_DATA_ERROR if the input is invalid. */
4451 {
4452
4453 uInt a; /* counter for codes of length k */
4454 uInt c[BMAX+1]; /* bit length count table */
4455 uInt f; /* i repeats in table every f entries */
4456 int g; /* maximum code length */
4457 int h; /* table level */
4458 register uInt i; /* counter, current code */
4459 register uInt j; /* counter */
4460 register int k; /* number of bits in current code */
4461 int l; /* bits per table (returned in m) */
4462 uInt mask; /* (1 << w) - 1, to avoid cc -O bug on HP */
4463 register uIntf *p; /* pointer into c[], b[], or v[] */
4464 inflate_huft *q; /* points to current table */
4465 struct inflate_huft_s r; /* table entry for structure assignment */
4466 inflate_huft *u[BMAX]; /* table stack */
4467 register int w; /* bits before this table == (l * h) */
4468 uInt x[BMAX+1]; /* bit offsets, then code stack */
4469 uIntf *xp; /* pointer into x */
4470 int y; /* number of dummy codes added */
4471 uInt z; /* number of entries in current table */
4472
4473
4474 /* Generate counts for each bit length */
4475 p = c;
4476 #define C0 *p++ = 0;
4477 #define C2 C0 C0 C0 C0
4478 #define C4 C2 C2 C2 C2
4479 C4 /* clear c[]--assume BMAX+1 is 16 */
4480 p = b; i = n;
4481 do {
4482 c[*p++]++; /* assume all entries <= BMAX */
4483 } while (--i);
4484 if (c[0] == n) /* null input--all zero length codes */
4485 {
4486 *t = (inflate_huft *)Z_NULL;
4487 *m = 0;
4488 return Z_OK;
4489 }
4490
4491
4492 /* Find minimum and maximum length, bound *m by those */
4493 l = *m;
4494 for (j = 1; j <= BMAX; j++)
4495 if (c[j])
4496 break;
4497 k = j; /* minimum code length */
4498 if ((uInt)l < j)
4499 l = j;
4500 for (i = BMAX; i; i--)
4501 if (c[i])
4502 break;
4503 g = i; /* maximum code length */
4504 if ((uInt)l > i)
4505 l = i;
4506 *m = l;
4507
4508
4509 /* Adjust last length count to fill out codes, if needed */
4510 for (y = 1 << j; j < i; j++, y <<= 1)
4511 if ((y -= c[j]) < 0)
4512 return Z_DATA_ERROR;
4513 if ((y -= c[i]) < 0)
4514 return Z_DATA_ERROR;
4515 c[i] += y;
4516
4517
4518 /* Generate starting offsets into the value table for each length */
4519 x[1] = j = 0;
4520 p = c + 1; xp = x + 2;
4521 while (--i) { /* note that i == g from above */
4522 *xp++ = (j += *p++);
4523 }
4524
4525
4526 /* Make a table of values in order of bit lengths */
4527 p = b; i = 0;
4528 do {
4529 if ((j = *p++) != 0)
4530 v[x[j]++] = i;
4531 } while (++i < n);
4532 n = x[g]; /* set n to length of v */
4533
4534
4535 /* Generate the Huffman codes and for each, make the table entries */
4536 x[0] = i = 0; /* first Huffman code is zero */
4537 p = v; /* grab values in bit order */
4538 h = -1; /* no tables yet--level -1 */
4539 w = -l; /* bits decoded == (l * h) */
4540 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4541 q = (inflate_huft *)Z_NULL; /* ditto */
4542 z = 0; /* ditto */
4543
4544 /* go through the bit lengths (k already is bits in shortest code) */
4545 for (; k <= g; k++)
4546 {
4547 a = c[k];
4548 while (a--)
4549 {
4550 /* here i is the Huffman code of length k bits for value *p */
4551 /* make tables up to required level */
4552 while (k > w + l)
4553 {
4554 h++;
4555 w += l; /* previous table always l bits */
4556
4557 /* compute minimum size table less than or equal to l bits */
4558 z = g - w;
4559 z = z > (uInt)l ? l : z; /* table size upper limit */
4560 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4561 { /* too few codes for k-w bit table */
4562 f -= a + 1; /* deduct codes from patterns left */
4563 xp = c + k;
4564 if (j < z)
4565 while (++j < z) /* try smaller tables up to z bits */
4566 {
4567 if ((f <<= 1) <= *++xp)
4568 break; /* enough codes to use up j bits */
4569 f -= *xp; /* else deduct codes from patterns */
4570 }
4571 }
4572 z = 1 << j; /* table entries for j-bit table */
4573
4574 /* allocate new table */
4575 if (*hn + z > MANY) /* (note: doesn't matter for fixed) */
4576 return Z_DATA_ERROR; /* overflow of MANY */
4577 u[h] = q = hp + *hn;
4578 *hn += z;
4579
4580 /* connect to last table, if there is one */
4581 if (h)
4582 {
4583 x[h] = i; /* save pattern for backing up */
4584 r.bits = (Byte)l; /* bits to dump before this table */
4585 r.exop = (Byte)j; /* bits in this table */
4586 j = i >> (w - l);
4587 r.base = (uInt)(q - u[h-1] - j); /* offset to this table */
4588 u[h-1][j] = r; /* connect to last table */
4589 }
4590 else
4591 *t = q; /* first table is returned result */
4592 }
4593
4594 /* set up table entry in r */
4595 r.bits = (Byte)(k - w);
4596 if (p >= v + n)
4597 r.exop = 128 + 64; /* out of values--invalid code */
4598 else if (*p < s)
4599 {
4600 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4601 r.base = *p++; /* simple code is just the value */
4602 }
4603 else
4604 {
4605 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4606 r.base = d[*p++ - s];
4607 }
4608
4609 /* fill code-like entries with r */
4610 f = 1 << (k - w);
4611 for (j = i >> w; j < z; j += f)
4612 q[j] = r;
4613
4614 /* backwards increment the k-bit code i */
4615 for (j = 1 << (k - 1); i & j; j >>= 1)
4616 i ^= j;
4617 i ^= j;
4618
4619 /* backup over finished tables */
4620 mask = (1 << w) - 1; /* needed on HP, cc -O bug */
4621 while ((i & mask) != x[h])
4622 {
4623 h--; /* don't need to update q */
4624 w -= l;
4625 mask = (1 << w) - 1;
4626 }
4627 }
4628 }
4629
4630
4631 /* Return Z_BUF_ERROR if we were given an incomplete table */
4632 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4633 }
4634
4635
4636 int inflate_trees_bits(c, bb, tb, hp, z)
4637 uIntf *c; /* 19 code lengths */
4638 uIntf *bb; /* bits tree desired/actual depth */
4639 inflate_huft * FAR *tb; /* bits tree result */
4640 inflate_huft *hp; /* space for trees */
4641 z_streamp z; /* for messages */
4642 {
4643 int r;
4644 uInt hn = 0; /* hufts used in space */
4645 uIntf *v; /* work area for huft_build */
4646
4647 if ((v = (uIntf*)ZALLOC(z, 19, sizeof(uInt))) == Z_NULL)
4648 return Z_MEM_ERROR;
4649 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL,
4650 tb, bb, hp, &hn, v);
4651 if (r == Z_DATA_ERROR)
4652 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4653 else if (r == Z_BUF_ERROR || *bb == 0)
4654 {
4655 z->msg = (char*)"incomplete dynamic bit lengths tree";
4656 r = Z_DATA_ERROR;
4657 }
4658 ZFREE(z, v);
4659 return r;
4660 }
4661
4662
4663 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, hp, z)
4664 uInt nl; /* number of literal/length codes */
4665 uInt nd; /* number of distance codes */
4666 uIntf *c; /* that many (total) code lengths */
4667 uIntf *bl; /* literal desired/actual bit depth */
4668 uIntf *bd; /* distance desired/actual bit depth */
4669 inflate_huft * FAR *tl; /* literal/length tree result */
4670 inflate_huft * FAR *td; /* distance tree result */
4671 inflate_huft *hp; /* space for trees */
4672 z_streamp z; /* for messages */
4673 {
4674 int r;
4675 uInt hn = 0; /* hufts used in space */
4676 uIntf *v; /* work area for huft_build */
4677
4678 /* allocate work area */
4679 if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4680 return Z_MEM_ERROR;
4681
4682 /* build literal/length tree */
4683 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
4684 if (r != Z_OK || *bl == 0)
4685 {
4686 if (r == Z_DATA_ERROR)
4687 z->msg = (char*)"oversubscribed literal/length tree";
4688 else if (r != Z_MEM_ERROR)
4689 {
4690 z->msg = (char*)"incomplete literal/length tree";
4691 r = Z_DATA_ERROR;
4692 }
4693 ZFREE(z, v);
4694 return r;
4695 }
4696
4697 /* build distance tree */
4698 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
4699 if (r != Z_OK || (*bd == 0 && nl > 257))
4700 {
4701 if (r == Z_DATA_ERROR)
4702 z->msg = (char*)"oversubscribed distance tree";
4703 else if (r == Z_BUF_ERROR) {
4704 #ifdef PKZIP_BUG_WORKAROUND
4705 r = Z_OK;
4706 }
4707 #else
4708 z->msg = (char*)"incomplete distance tree";
4709 r = Z_DATA_ERROR;
4710 }
4711 else if (r != Z_MEM_ERROR)
4712 {
4713 z->msg = (char*)"empty distance tree with lengths";
4714 r = Z_DATA_ERROR;
4715 }
4716 ZFREE(z, v);
4717 return r;
4718 #endif
4719 }
4720
4721 /* done */
4722 ZFREE(z, v);
4723 return Z_OK;
4724 }
4725
4726
4727 /* build fixed tables only once--keep them here */
4728 #ifdef BUILDFIXED
4729 local int fixed_built = 0;
4730 #define FIXEDH 544 /* number of hufts used by fixed tables */
4731 local inflate_huft fixed_mem[FIXEDH];
4732 local uInt fixed_bl;
4733 local uInt fixed_bd;
4734 local inflate_huft *fixed_tl;
4735 local inflate_huft *fixed_td;
4736 #else
4737 /* +++ inffixed.h */
4738 /* inffixed.h -- table for decoding fixed codes
4739 * Generated automatically by the maketree.c program
4740 */
4741
4742 /* WARNING: this file should *not* be used by applications. It is
4743 part of the implementation of the compression library and is
4744 subject to change. Applications should only use zlib.h.
4745 */
4746
4747 local uInt fixed_bl = 9;
4748 local uInt fixed_bd = 5;
4749 local inflate_huft fixed_tl[] = {
4750 {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4751 {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},192},
4752 {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},160},
4753 {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},224},
4754 {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},144},
4755 {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},208},
4756 {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},176},
4757 {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},240},
4758 {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4759 {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},200},
4760 {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},168},
4761 {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},232},
4762 {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},152},
4763 {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},216},
4764 {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},184},
4765 {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},248},
4766 {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4767 {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},196},
4768 {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},164},
4769 {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},228},
4770 {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},148},
4771 {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},212},
4772 {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},180},
4773 {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},244},
4774 {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4775 {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},204},
4776 {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},172},
4777 {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},236},
4778 {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},156},
4779 {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},220},
4780 {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},188},
4781 {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},252},
4782 {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4783 {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},194},
4784 {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},162},
4785 {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},226},
4786 {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},146},
4787 {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},210},
4788 {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},178},
4789 {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},242},
4790 {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
4791 {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},202},
4792 {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},170},
4793 {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},234},
4794 {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},154},
4795 {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},218},
4796 {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},186},
4797 {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},250},
4798 {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
4799 {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},198},
4800 {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},166},
4801 {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},230},
4802 {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},150},
4803 {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},214},
4804 {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},182},
4805 {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},246},
4806 {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
4807 {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},206},
4808 {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},174},
4809 {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},238},
4810 {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},158},
4811 {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},222},
4812 {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},190},
4813 {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},254},
4814 {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4815 {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},193},
4816 {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},161},
4817 {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},225},
4818 {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},145},
4819 {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},209},
4820 {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},177},
4821 {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},241},
4822 {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4823 {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},201},
4824 {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},169},
4825 {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},233},
4826 {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},153},
4827 {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},217},
4828 {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},185},
4829 {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},249},
4830 {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4831 {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},197},
4832 {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},165},
4833 {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},229},
4834 {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},149},
4835 {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},213},
4836 {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},181},
4837 {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},245},
4838 {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4839 {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},205},
4840 {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},173},
4841 {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},237},
4842 {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},157},
4843 {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},221},
4844 {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},189},
4845 {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},253},
4846 {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4847 {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},195},
4848 {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},163},
4849 {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},227},
4850 {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},147},
4851 {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},211},
4852 {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},179},
4853 {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},243},
4854 {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
4855 {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},203},
4856 {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},171},
4857 {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},235},
4858 {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},155},
4859 {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},219},
4860 {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},187},
4861 {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},251},
4862 {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
4863 {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},199},
4864 {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},167},
4865 {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},231},
4866 {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},151},
4867 {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},215},
4868 {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},183},
4869 {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},247},
4870 {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
4871 {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},207},
4872 {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},175},
4873 {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},239},
4874 {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},159},
4875 {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},223},
4876 {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},191},
4877 {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},255}
4878 };
4879 local inflate_huft fixed_td[] = {
4880 {{{80,5}},1}, {{{87,5}},257}, {{{83,5}},17}, {{{91,5}},4097},
4881 {{{81,5}},5}, {{{89,5}},1025}, {{{85,5}},65}, {{{93,5}},16385},
4882 {{{80,5}},3}, {{{88,5}},513}, {{{84,5}},33}, {{{92,5}},8193},
4883 {{{82,5}},9}, {{{90,5}},2049}, {{{86,5}},129}, {{{192,5}},24577},
4884 {{{80,5}},2}, {{{87,5}},385}, {{{83,5}},25}, {{{91,5}},6145},
4885 {{{81,5}},7}, {{{89,5}},1537}, {{{85,5}},97}, {{{93,5}},24577},
4886 {{{80,5}},4}, {{{88,5}},769}, {{{84,5}},49}, {{{92,5}},12289},
4887 {{{82,5}},13}, {{{90,5}},3073}, {{{86,5}},193}, {{{192,5}},24577}
4888 };
4889 /* --- inffixed.h */
4890 #endif
4891
4892
4893 int inflate_trees_fixed(bl, bd, tl, td, z)
4894 uIntf *bl; /* literal desired/actual bit depth */
4895 uIntf *bd; /* distance desired/actual bit depth */
4896 inflate_huft * FAR *tl; /* literal/length tree result */
4897 inflate_huft * FAR *td; /* distance tree result */
4898 z_streamp z; /* for memory allocation */
4899 {
4900 #ifdef BUILDFIXED
4901 /* build fixed tables if not already */
4902 if (!fixed_built)
4903 {
4904 int k; /* temporary variable */
4905 uInt f = 0; /* number of hufts used in fixed_mem */
4906 uIntf *c; /* length list for huft_build */
4907 uIntf *v; /* work area for huft_build */
4908
4909 /* allocate memory */
4910 if ((c = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4911 return Z_MEM_ERROR;
4912 if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4913 {
4914 ZFREE(z, c);
4915 return Z_MEM_ERROR;
4916 }
4917
4918 /* literal table */
4919 for (k = 0; k < 144; k++)
4920 c[k] = 8;
4921 for (; k < 256; k++)
4922 c[k] = 9;
4923 for (; k < 280; k++)
4924 c[k] = 7;
4925 for (; k < 288; k++)
4926 c[k] = 8;
4927 fixed_bl = 9;
4928 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl,
4929 fixed_mem, &f, v);
4930
4931 /* distance table */
4932 for (k = 0; k < 30; k++)
4933 c[k] = 5;
4934 fixed_bd = 5;
4935 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd,
4936 fixed_mem, &f, v);
4937
4938 /* done */
4939 ZFREE(z, v);
4940 ZFREE(z, c);
4941 fixed_built = 1;
4942 }
4943 #endif
4944 *bl = fixed_bl;
4945 *bd = fixed_bd;
4946 *tl = fixed_tl;
4947 *td = fixed_td;
4948 return Z_OK;
4949 }
4950 /* --- inftrees.c */
4951
4952 /* +++ infcodes.c */
4953 /* infcodes.c -- process literals and length/distance pairs
4954 * Copyright (C) 1995-2002 Mark Adler
4955 * For conditions of distribution and use, see copyright notice in zlib.h
4956 */
4957
4958 /* #include "zutil.h" */
4959 /* #include "inftrees.h" */
4960 /* #include "infblock.h" */
4961 /* #include "infcodes.h" */
4962 /* #include "infutil.h" */
4963
4964 /* +++ inffast.h */
4965 /* inffast.h -- header to use inffast.c
4966 * Copyright (C) 1995-2002 Mark Adler
4967 * For conditions of distribution and use, see copyright notice in zlib.h
4968 */
4969
4970 /* WARNING: this file should *not* be used by applications. It is
4971 part of the implementation of the compression library and is
4972 subject to change. Applications should only use zlib.h.
4973 */
4974
4975 extern int inflate_fast OF((
4976 uInt,
4977 uInt,
4978 inflate_huft *,
4979 inflate_huft *,
4980 inflate_blocks_statef *,
4981 z_streamp ));
4982 /* --- inffast.h */
4983
4984 /* simplify the use of the inflate_huft type with some defines */
4985 #define exop word.what.Exop
4986 #define bits word.what.Bits
4987
4988 typedef enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4989 START, /* x: set up for LEN */
4990 LEN, /* i: get length/literal/eob next */
4991 LENEXT, /* i: getting length extra (have base) */
4992 DIST, /* i: get distance next */
4993 DISTEXT, /* i: getting distance extra */
4994 COPY, /* o: copying bytes in window, waiting for space */
4995 LIT, /* o: got literal, waiting for output space */
4996 WASH, /* o: got eob, possibly still output waiting */
4997 END, /* x: got eob and all data flushed */
4998 BADCODE} /* x: got error */
4999 inflate_codes_mode;
5000
5001 /* inflate codes private state */
5002 struct inflate_codes_state {
5003
5004 /* mode */
5005 inflate_codes_mode mode; /* current inflate_codes mode */
5006
5007 /* mode dependent information */
5008 uInt len;
5009 union {
5010 struct {
5011 inflate_huft *tree; /* pointer into tree */
5012 uInt need; /* bits needed */
5013 } code; /* if LEN or DIST, where in tree */
5014 uInt lit; /* if LIT, literal */
5015 struct {
5016 uInt get; /* bits to get for extra */
5017 uInt dist; /* distance back to copy from */
5018 } copy; /* if EXT or COPY, where and how much */
5019 } sub; /* submode */
5020
5021 /* mode independent information */
5022 Byte lbits; /* ltree bits decoded per branch */
5023 Byte dbits; /* dtree bits decoder per branch */
5024 inflate_huft *ltree; /* literal/length/eob tree */
5025 inflate_huft *dtree; /* distance tree */
5026
5027 };
5028
5029
5030 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
5031 uInt bl, bd;
5032 inflate_huft *tl;
5033 inflate_huft *td; /* need separate declaration for Borland C++ */
5034 z_streamp z;
5035 {
5036 inflate_codes_statef *c;
5037
5038 if ((c = (inflate_codes_statef *)
5039 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
5040 {
5041 c->mode = START;
5042 c->lbits = (Byte)bl;
5043 c->dbits = (Byte)bd;
5044 c->ltree = tl;
5045 c->dtree = td;
5046 Tracev((stderr, "inflate: codes new\n"));
5047 }
5048 return c;
5049 }
5050
5051
5052 int inflate_codes(s, z, r)
5053 inflate_blocks_statef *s;
5054 z_streamp z;
5055 int r;
5056 {
5057 uInt j; /* temporary storage */
5058 inflate_huft *t; /* temporary pointer */
5059 uInt e; /* extra bits or operation */
5060 uLong b; /* bit buffer */
5061 uInt k; /* bits in bit buffer */
5062 Bytef *p; /* input data pointer */
5063 uInt n; /* bytes available there */
5064 Bytef *q; /* output window write pointer */
5065 uInt m; /* bytes to end of window or read pointer */
5066 Bytef *f; /* pointer to copy strings from */
5067 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
5068
5069 /* copy input/output information to locals (UPDATE macro restores) */
5070 LOAD
5071
5072 /* process input and output based on current state */
5073 while (1) switch (c->mode)
5074 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5075 case START: /* x: set up for LEN */
5076 #ifndef SLOW
5077 if (m >= 258 && n >= 10)
5078 {
5079 UPDATE
5080 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
5081 LOAD
5082 if (r != Z_OK)
5083 {
5084 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
5085 break;
5086 }
5087 }
5088 #endif /* !SLOW */
5089 c->sub.code.need = c->lbits;
5090 c->sub.code.tree = c->ltree;
5091 c->mode = LEN;
5092 case LEN: /* i: get length/literal/eob next */
5093 j = c->sub.code.need;
5094 NEEDBITS(j)
5095 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5096 DUMPBITS(t->bits)
5097 e = (uInt)(t->exop);
5098 if (e == 0) /* literal */
5099 {
5100 c->sub.lit = t->base;
5101 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5102 "inflate: literal '%c'\n" :
5103 "inflate: literal 0x%02x\n", t->base));
5104 c->mode = LIT;
5105 break;
5106 }
5107 if (e & 16) /* length */
5108 {
5109 c->sub.copy.get = e & 15;
5110 c->len = t->base;
5111 c->mode = LENEXT;
5112 break;
5113 }
5114 if ((e & 64) == 0) /* next table */
5115 {
5116 c->sub.code.need = e;
5117 c->sub.code.tree = t + t->base;
5118 break;
5119 }
5120 if (e & 32) /* end of block */
5121 {
5122 Tracevv((stderr, "inflate: end of block\n"));
5123 c->mode = WASH;
5124 break;
5125 }
5126 c->mode = BADCODE; /* invalid code */
5127 z->msg = (char*)"invalid literal/length code";
5128 r = Z_DATA_ERROR;
5129 LEAVE
5130 case LENEXT: /* i: getting length extra (have base) */
5131 j = c->sub.copy.get;
5132 NEEDBITS(j)
5133 c->len += (uInt)b & inflate_mask[j];
5134 DUMPBITS(j)
5135 c->sub.code.need = c->dbits;
5136 c->sub.code.tree = c->dtree;
5137 Tracevv((stderr, "inflate: length %u\n", c->len));
5138 c->mode = DIST;
5139 case DIST: /* i: get distance next */
5140 j = c->sub.code.need;
5141 NEEDBITS(j)
5142 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5143 DUMPBITS(t->bits)
5144 e = (uInt)(t->exop);
5145 if (e & 16) /* distance */
5146 {
5147 c->sub.copy.get = e & 15;
5148 c->sub.copy.dist = t->base;
5149 c->mode = DISTEXT;
5150 break;
5151 }
5152 if ((e & 64) == 0) /* next table */
5153 {
5154 c->sub.code.need = e;
5155 c->sub.code.tree = t + t->base;
5156 break;
5157 }
5158 c->mode = BADCODE; /* invalid code */
5159 z->msg = (char*)"invalid distance code";
5160 r = Z_DATA_ERROR;
5161 LEAVE
5162 case DISTEXT: /* i: getting distance extra */
5163 j = c->sub.copy.get;
5164 NEEDBITS(j)
5165 c->sub.copy.dist += (uInt)b & inflate_mask[j];
5166 DUMPBITS(j)
5167 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
5168 c->mode = COPY;
5169 case COPY: /* o: copying bytes in window, waiting for space */
5170 f = q - c->sub.copy.dist;
5171 while (f < s->window) /* modulo window size-"while" instead */
5172 f += s->end - s->window; /* of "if" handles invalid distances */
5173 while (c->len)
5174 {
5175 NEEDOUT
5176 OUTBYTE(*f++)
5177 if (f == s->end)
5178 f = s->window;
5179 c->len--;
5180 }
5181 c->mode = START;
5182 break;
5183 case LIT: /* o: got literal, waiting for output space */
5184 NEEDOUT
5185 OUTBYTE(c->sub.lit)
5186 c->mode = START;
5187 break;
5188 case WASH: /* o: got eob, possibly more output */
5189 if (k > 7) /* return unused byte, if any */
5190 {
5191 Assert(k < 16, "inflate_codes grabbed too many bytes")
5192 k -= 8;
5193 n++;
5194 p--; /* can always return one */
5195 }
5196 FLUSH
5197 if (s->read != s->write)
5198 LEAVE
5199 c->mode = END;
5200 case END:
5201 r = Z_STREAM_END;
5202 LEAVE
5203 case BADCODE: /* x: got error */
5204 r = Z_DATA_ERROR;
5205 LEAVE
5206 default:
5207 r = Z_STREAM_ERROR;
5208 LEAVE
5209 }
5210 #ifdef NEED_DUMMY_RETURN
5211 return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
5212 #endif
5213 }
5214
5215
5216 void inflate_codes_free(c, z)
5217 inflate_codes_statef *c;
5218 z_streamp z;
5219 {
5220 ZFREE(z, c);
5221 Tracev((stderr, "inflate: codes free\n"));
5222 }
5223 /* --- infcodes.c */
5224
5225 /* +++ infutil.c */
5226 /* inflate_util.c -- data and routines common to blocks and codes
5227 * Copyright (C) 1995-2002 Mark Adler
5228 * For conditions of distribution and use, see copyright notice in zlib.h
5229 */
5230
5231 /* #include "zutil.h" */
5232 /* #include "infblock.h" */
5233 /* #include "inftrees.h" */
5234 /* #include "infcodes.h" */
5235 /* #include "infutil.h" */
5236
5237 #ifndef NO_DUMMY_DECL
5238 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5239 #endif
5240
5241 /* And'ing with mask[n] masks the lower n bits */
5242 uInt inflate_mask[17] = {
5243 0x0000,
5244 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
5245 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
5246 };
5247
5248
5249 /* copy as much as possible from the sliding window to the output area */
5250 int inflate_flush(s, z, r)
5251 inflate_blocks_statef *s;
5252 z_streamp z;
5253 int r;
5254 {
5255 uInt n;
5256 Bytef *p;
5257 Bytef *q;
5258
5259 /* local copies of source and destination pointers */
5260 p = z->next_out;
5261 q = s->read;
5262
5263 /* compute number of bytes to copy as far as end of window */
5264 n = (uInt)((q <= s->write ? s->write : s->end) - q);
5265 if (n > z->avail_out) n = z->avail_out;
5266 if (n && r == Z_BUF_ERROR) r = Z_OK;
5267
5268 /* update counters */
5269 z->avail_out -= n;
5270 z->total_out += n;
5271
5272 /* update check information */
5273 if (s->checkfn != Z_NULL)
5274 z->adler = s->check = (*s->checkfn)(s->check, q, n);
5275
5276 /* copy as far as end of window */
5277 zmemcpy(p, q, n);
5278 p += n;
5279 q += n;
5280
5281 /* see if more to copy at beginning of window */
5282 if (q == s->end)
5283 {
5284 /* wrap pointers */
5285 q = s->window;
5286 if (s->write == s->end)
5287 s->write = s->window;
5288
5289 /* compute bytes to copy */
5290 n = (uInt)(s->write - q);
5291 if (n > z->avail_out) n = z->avail_out;
5292 if (n && r == Z_BUF_ERROR) r = Z_OK;
5293
5294 /* update counters */
5295 z->avail_out -= n;
5296 z->total_out += n;
5297
5298 /* update check information */
5299 if (s->checkfn != Z_NULL)
5300 z->adler = s->check = (*s->checkfn)(s->check, q, n);
5301
5302 /* copy */
5303 zmemcpy(p, q, n);
5304 p += n;
5305 q += n;
5306 }
5307
5308 /* update pointers */
5309 z->next_out = p;
5310 s->read = q;
5311
5312 /* done */
5313 return r;
5314 }
5315 /* --- infutil.c */
5316
5317 /* +++ inffast.c */
5318 /* inffast.c -- process literals and length/distance pairs fast
5319 * Copyright (C) 1995-2002 Mark Adler
5320 * For conditions of distribution and use, see copyright notice in zlib.h
5321 */
5322
5323 /* #include "zutil.h" */
5324 /* #include "inftrees.h" */
5325 /* #include "infblock.h" */
5326 /* #include "infcodes.h" */
5327 /* #include "infutil.h" */
5328 /* #include "inffast.h" */
5329
5330 #ifndef NO_DUMMY_DECL
5331 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5332 #endif
5333
5334 /* simplify the use of the inflate_huft type with some defines */
5335 #define exop word.what.Exop
5336 #define bits word.what.Bits
5337
5338 /* macros for bit input with no checking and for returning unused bytes */
5339 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
5340 #define UNGRAB {c=z->avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;}
5341
5342 /* Called with number of bytes left to write in window at least 258
5343 (the maximum string length) and number of input bytes available
5344 at least ten. The ten bytes are six bytes for the longest length/
5345 distance pair plus four bytes for overloading the bit buffer. */
5346
5347 int inflate_fast(bl, bd, tl, td, s, z)
5348 uInt bl, bd;
5349 inflate_huft *tl;
5350 inflate_huft *td; /* need separate declaration for Borland C++ */
5351 inflate_blocks_statef *s;
5352 z_streamp z;
5353 {
5354 inflate_huft *t; /* temporary pointer */
5355 uInt e; /* extra bits or operation */
5356 uLong b; /* bit buffer */
5357 uInt k; /* bits in bit buffer */
5358 Bytef *p; /* input data pointer */
5359 uInt n; /* bytes available there */
5360 Bytef *q; /* output window write pointer */
5361 uInt m; /* bytes to end of window or read pointer */
5362 uInt ml; /* mask for literal/length tree */
5363 uInt md; /* mask for distance tree */
5364 uInt c; /* bytes to copy */
5365 uInt d; /* distance back to copy from */
5366 Bytef *r; /* copy source pointer */
5367
5368 /* load input, output, bit values */
5369 LOAD
5370
5371 /* initialize masks */
5372 ml = inflate_mask[bl];
5373 md = inflate_mask[bd];
5374
5375 /* do until not enough input or output space for fast loop */
5376 do { /* assume called with m >= 258 && n >= 10 */
5377 /* get literal/length code */
5378 GRABBITS(20) /* max bits for literal/length code */
5379 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5380 {
5381 DUMPBITS(t->bits)
5382 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5383 "inflate: * literal '%c'\n" :
5384 "inflate: * literal 0x%02x\n", t->base));
5385 *q++ = (Byte)t->base;
5386 m--;
5387 continue;
5388 }
5389 do {
5390 DUMPBITS(t->bits)
5391 if (e & 16)
5392 {
5393 /* get extra bits for length */
5394 e &= 15;
5395 c = t->base + ((uInt)b & inflate_mask[e]);
5396 DUMPBITS(e)
5397 Tracevv((stderr, "inflate: * length %u\n", c));
5398
5399 /* decode distance base of block to copy */
5400 GRABBITS(15); /* max bits for distance code */
5401 e = (t = td + ((uInt)b & md))->exop;
5402 do {
5403 DUMPBITS(t->bits)
5404 if (e & 16)
5405 {
5406 /* get extra bits to add to distance base */
5407 e &= 15;
5408 GRABBITS(e) /* get extra bits (up to 13) */
5409 d = t->base + ((uInt)b & inflate_mask[e]);
5410 DUMPBITS(e)
5411 Tracevv((stderr, "inflate: * distance %u\n", d));
5412
5413 /* do the copy */
5414 m -= c;
5415 r = q - d;
5416 if (r < s->window) /* wrap if needed */
5417 {
5418 do {
5419 r += s->end - s->window; /* force pointer in window */
5420 } while (r < s->window); /* covers invalid distances */
5421 e = s->end - r;
5422 if (c > e)
5423 {
5424 c -= e; /* wrapped copy */
5425 do {
5426 *q++ = *r++;
5427 } while (--e);
5428 r = s->window;
5429 do {
5430 *q++ = *r++;
5431 } while (--c);
5432 }
5433 else /* normal copy */
5434 {
5435 *q++ = *r++; c--;
5436 *q++ = *r++; c--;
5437 do {
5438 *q++ = *r++;
5439 } while (--c);
5440 }
5441 }
5442 else /* normal copy */
5443 {
5444 *q++ = *r++; c--;
5445 *q++ = *r++; c--;
5446 do {
5447 *q++ = *r++;
5448 } while (--c);
5449 }
5450 break;
5451 }
5452 else if ((e & 64) == 0)
5453 {
5454 t += t->base;
5455 e = (t += ((uInt)b & inflate_mask[e]))->exop;
5456 }
5457 else
5458 {
5459 z->msg = (char*)"invalid distance code";
5460 UNGRAB
5461 UPDATE
5462 return Z_DATA_ERROR;
5463 }
5464 } while (1);
5465 break;
5466 }
5467 if ((e & 64) == 0)
5468 {
5469 t += t->base;
5470 if ((e = (t += ((uInt)b & inflate_mask[e]))->exop) == 0)
5471 {
5472 DUMPBITS(t->bits)
5473 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5474 "inflate: * literal '%c'\n" :
5475 "inflate: * literal 0x%02x\n", t->base));
5476 *q++ = (Byte)t->base;
5477 m--;
5478 break;
5479 }
5480 }
5481 else if (e & 32)
5482 {
5483 Tracevv((stderr, "inflate: * end of block\n"));
5484 UNGRAB
5485 UPDATE
5486 return Z_STREAM_END;
5487 }
5488 else
5489 {
5490 z->msg = (char*)"invalid literal/length code";
5491 UNGRAB
5492 UPDATE
5493 return Z_DATA_ERROR;
5494 }
5495 } while (1);
5496 } while (m >= 258 && n >= 10);
5497
5498 /* not enough input or output--restore pointers and return */
5499 UNGRAB
5500 UPDATE
5501 return Z_OK;
5502 }
5503 /* --- inffast.c */
5504
5505 /* +++ zutil.c */
5506 /* zutil.c -- target dependent utility functions for the compression library
5507 * Copyright (C) 1995-2002 Jean-loup Gailly.
5508 * For conditions of distribution and use, see copyright notice in zlib.h
5509 */
5510
5511 /* @(#) $Id: zlib.c,v 1.8 2002/03/29 03:16:07 lindak Exp $ */
5512
5513 /* #include "zutil.h" */
5514
5515 #ifndef NO_DUMMY_DECL
5516 struct internal_state {int dummy;}; /* for buggy compilers */
5517 #endif
5518
5519 #ifndef STDC
5520 extern void exit OF((int));
5521 #endif
5522
5523 const char *z_errmsg[10] = {
5524 "need dictionary", /* Z_NEED_DICT 2 */
5525 "stream end", /* Z_STREAM_END 1 */
5526 "", /* Z_OK 0 */
5527 "file error", /* Z_ERRNO (-1) */
5528 "stream error", /* Z_STREAM_ERROR (-2) */
5529 "data error", /* Z_DATA_ERROR (-3) */
5530 "insufficient memory", /* Z_MEM_ERROR (-4) */
5531 "buffer error", /* Z_BUF_ERROR (-5) */
5532 "incompatible version",/* Z_VERSION_ERROR (-6) */
5533 ""};
5534
5535
5536 const char * ZEXPORT zlibVersion()
5537 {
5538 return ZLIB_VERSION;
5539 }
5540
5541 #ifdef DEBUG_ZLIB
5542
5543 # ifndef verbose
5544 # define verbose 0
5545 # endif
5546 int z_verbose = verbose;
5547
5548 void z_error (m)
5549 char *m;
5550 {
5551 fprintf(stderr, "%s\n", m);
5552 exit(1);
5553 }
5554 #endif
5555
5556 /* exported to allow conversion of error code to string for compress() and
5557 * uncompress()
5558 */
5559 const char * ZEXPORT zError(err)
5560 int err;
5561 {
5562 return ERR_MSG(err);
5563 }
5564
5565
5566 #ifndef HAVE_MEMCPY
5567
5568 void zmemcpy(dest, source, len)
5569 Bytef* dest;
5570 const Bytef* source;
5571 uInt len;
5572 {
5573 if (len == 0) return;
5574 do {
5575 *dest++ = *source++; /* ??? to be unrolled */
5576 } while (--len != 0);
5577 }
5578
5579 int zmemcmp(s1, s2, len)
5580 const Bytef* s1;
5581 const Bytef* s2;
5582 uInt len;
5583 {
5584 uInt j;
5585
5586 for (j = 0; j < len; j++) {
5587 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5588 }
5589 return 0;
5590 }
5591
5592 void zmemzero(dest, len)
5593 Bytef* dest;
5594 uInt len;
5595 {
5596 if (len == 0) return;
5597 do {
5598 *dest++ = 0; /* ??? to be unrolled */
5599 } while (--len != 0);
5600 }
5601 #endif
5602
5603 #ifdef __TURBOC__
5604 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5605 /* Small and medium model in Turbo C are for now limited to near allocation
5606 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5607 */
5608 # define MY_ZCALLOC
5609
5610 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5611 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5612 * must fix the pointer. Warning: the pointer must be put back to its
5613 * original form in order to free it, use zcfree().
5614 */
5615
5616 #define MAX_PTR 10
5617 /* 10*64K = 640K */
5618
5619 local int next_ptr = 0;
5620
5621 typedef struct ptr_table_s {
5622 voidpf org_ptr;
5623 voidpf new_ptr;
5624 } ptr_table;
5625
5626 local ptr_table table[MAX_PTR];
5627 /* This table is used to remember the original form of pointers
5628 * to large buffers (64K). Such pointers are normalized with a zero offset.
5629 * Since MSDOS is not a preemptive multitasking OS, this table is not
5630 * protected from concurrent access. This hack doesn't work anyway on
5631 * a protected system like OS/2. Use Microsoft C instead.
5632 */
5633
5634 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5635 {
5636 voidpf buf = opaque; /* just to make some compilers happy */
5637 ulg bsize = (ulg)items*size;
5638
5639 /* If we allocate less than 65520 bytes, we assume that farmalloc
5640 * will return a usable pointer which doesn't have to be normalized.
5641 */
5642 if (bsize < 65520L) {
5643 buf = farmalloc(bsize);
5644 if (*(ush*)&buf != 0) return buf;
5645 } else {
5646 buf = farmalloc(bsize + 16L);
5647 }
5648 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5649 table[next_ptr].org_ptr = buf;
5650
5651 /* Normalize the pointer to seg:0 */
5652 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5653 *(ush*)&buf = 0;
5654 table[next_ptr++].new_ptr = buf;
5655 return buf;
5656 }
5657
5658 void zcfree (voidpf opaque, voidpf ptr)
5659 {
5660 int n;
5661 if (*(ush*)&ptr != 0) { /* object < 64K */
5662 farfree(ptr);
5663 return;
5664 }
5665 /* Find the original pointer */
5666 for (n = 0; n < next_ptr; n++) {
5667 if (ptr != table[n].new_ptr) continue;
5668
5669 farfree(table[n].org_ptr);
5670 while (++n < next_ptr) {
5671 table[n-1] = table[n];
5672 }
5673 next_ptr--;
5674 return;
5675 }
5676 ptr = opaque; /* just to make some compilers happy */
5677 Assert(0, "zcfree: ptr not found");
5678 }
5679 #endif
5680 #endif /* __TURBOC__ */
5681
5682
5683 #if defined(M_I86) && !defined(__32BIT__)
5684 /* Microsoft C in 16-bit mode */
5685
5686 # define MY_ZCALLOC
5687
5688 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
5689 # define _halloc halloc
5690 # define _hfree hfree
5691 #endif
5692
5693 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5694 {
5695 if (opaque) opaque = 0; /* to make compiler happy */
5696 return _halloc((long)items, size);
5697 }
5698
5699 void zcfree (voidpf opaque, voidpf ptr)
5700 {
5701 if (opaque) opaque = 0; /* to make compiler happy */
5702 _hfree(ptr);
5703 }
5704
5705 #endif /* MSC */
5706
5707
5708 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5709
5710 #ifndef STDC
5711 extern voidp calloc OF((uInt items, uInt size));
5712 extern void free OF((voidpf ptr));
5713 #endif
5714
5715 voidpf zcalloc (opaque, items, size)
5716 voidpf opaque;
5717 unsigned items;
5718 unsigned size;
5719 {
5720 if (opaque) items += size - size; /* make compiler happy */
5721 return (voidpf)calloc(items, size);
5722 }
5723
5724 void zcfree (opaque, ptr)
5725 voidpf opaque;
5726 voidpf ptr;
5727 {
5728 _FREE(ptr);
5729 if (opaque) return; /* make compiler happy */
5730 }
5731
5732 #endif /* MY_ZCALLOC */
5733 /* --- zutil.c */
5734
5735 /* +++ adler32.c */
5736 /* adler32.c -- compute the Adler-32 checksum of a data stream
5737 * Copyright (C) 1995-2002 Mark Adler
5738 * For conditions of distribution and use, see copyright notice in zlib.h
5739 */
5740
5741 /* @(#) $Id: zlib.c,v 1.8 2002/03/29 03:16:07 lindak Exp $ */
5742
5743 /* #include "zlib.h" */
5744
5745 #define BASE 65521L /* largest prime smaller than 65536 */
5746 #define NMAX 5552
5747 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5748
5749 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
5750 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
5751 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
5752 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
5753 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5754
5755 /* ========================================================================= */
5756 uLong ZEXPORT adler32(adler, buf, len)
5757 uLong adler;
5758 const Bytef *buf;
5759 uInt len;
5760 {
5761 unsigned long s1 = adler & 0xffff;
5762 unsigned long s2 = (adler >> 16) & 0xffff;
5763 int k;
5764
5765 if (buf == Z_NULL) return 1L;
5766
5767 while (len > 0) {
5768 k = len < NMAX ? len : NMAX;
5769 len -= k;
5770 while (k >= 16) {
5771 DO16(buf);
5772 buf += 16;
5773 k -= 16;
5774 }
5775 if (k != 0) do {
5776 s1 += *buf++;
5777 s2 += s1;
5778 } while (--k);
5779 s1 %= BASE;
5780 s2 %= BASE;
5781 }
5782 return (s2 << 16) | s1;
5783 }
5784 /* --- adler32.c */