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1 /*
2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23 /*
24 * This file is derived from various .h and .c files from the zlib-1.0.4
25 * distribution by Jean-loup Gailly and Mark Adler, with some additions
26 * by Paul Mackerras to aid in implementing Deflate compression and
27 * decompression for PPP packets. See zlib.h for conditions of
28 * distribution and use.
29 *
30 * Changes that have been made include:
31 * - added Z_PACKET_FLUSH (see zlib.h for details)
32 * - added inflateIncomp and deflateOutputPending
33 * - allow strm->next_out to be NULL, meaning discard the output
34 *
35 * $FreeBSD: src/sys/net/zlib.c,v 1.10 1999/12/29 04:38:38 peter Exp $
36 */
37
38 #define NO_DUMMY_DECL
39 #define NO_ZCFUNCS
40 #define MY_ZCALLOC
41
42 /* +++ zutil.h */
43 /* zutil.h -- internal interface and configuration of the compression library
44 * Copyright (C) 1995-2002 Jean-loup Gailly.
45 * For conditions of distribution and use, see copyright notice in zlib.h
46 */
47
48 /* WARNING: this file should *not* be used by applications. It is
49 part of the implementation of the compression library and is
50 subject to change. Applications should only use zlib.h.
51 */
52
53 /* @(#) $Id: zlib.c,v 1.10 2004/07/29 19:17:20 lindak Exp $ */
54
55 #ifndef _Z_UTIL_H
56 #define _Z_UTIL_H
57
58 #ifdef KERNEL
59 #include <net/zlib.h>
60 #else
61 #include "zlib.h"
62 #endif
63
64 #ifdef KERNEL
65 /* Assume this is a *BSD or SVR4 kernel */
66 #include <sys/types.h>
67 #include <sys/time.h>
68 #include <sys/systm.h>
69 # define HAVE_MEMCPY
70 # define memcpy(d, s, n) bcopy((s), (d), (n))
71 # define memset(d, v, n) bzero((d), (n))
72 # define memcmp bcmp
73
74 #else
75 #if defined(__KERNEL__)
76 /* Assume this is a Linux kernel */
77 #include <linux/string.h>
78 #define HAVE_MEMCPY
79
80 #else /* not kernel */
81 #ifdef STDC
82 # include <stddef.h>
83 # include <string.h>
84 # include <stdlib.h>
85 #endif
86 #ifdef NO_ERRNO_H
87 extern int errno;
88 #else
89 # include <errno.h>
90 #endif
91 #endif /* __KERNEL__ */
92 #endif /* KERNEL */
93
94 #ifndef local
95 # define local static
96 #endif
97 /* compile with -Dlocal if your debugger can't find static symbols */
98
99 typedef unsigned char uch;
100 typedef uch FAR uchf;
101 typedef unsigned short ush;
102 typedef ush FAR ushf;
103 typedef unsigned long ulg;
104
105 extern const char *z_errmsg[10]; /* indexed by 2-zlib_error */
106 /* (size given to avoid silly warnings with Visual C++) */
107
108 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
109
110 #define ERR_RETURN(strm,err) \
111 return (strm->msg = (char*)ERR_MSG(err), (err))
112 /* To be used only when the state is known to be valid */
113
114 /* common constants */
115
116 #ifndef DEF_WBITS
117 # define DEF_WBITS MAX_WBITS
118 #endif
119 /* default windowBits for decompression. MAX_WBITS is for compression only */
120
121 #if MAX_MEM_LEVEL >= 8
122 # define DEF_MEM_LEVEL 8
123 #else
124 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
125 #endif
126 /* default memLevel */
127
128 #define STORED_BLOCK 0
129 #define STATIC_TREES 1
130 #define DYN_TREES 2
131 /* The three kinds of block type */
132
133 #define MIN_MATCH 3
134 #define MAX_MATCH 258
135 /* The minimum and maximum match lengths */
136
137 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
138
139 /* target dependencies */
140
141 #ifdef MSDOS
142 # define OS_CODE 0x00
143 # if defined(__TURBOC__) || defined(__BORLANDC__)
144 # if(__STDC__ == 1) && (defined(__LARGE__) || defined(__COMPACT__))
145 /* Allow compilation with ANSI keywords only enabled */
146 void _Cdecl farfree( void *block );
147 void *_Cdecl farmalloc( unsigned long nbytes );
148 # else
149 # include <alloc.h>
150 # endif
151 # else /* MSC or DJGPP */
152 # include <malloc.h>
153 # endif
154 #endif
155
156 #ifdef OS2
157 # define OS_CODE 0x06
158 #endif
159
160 #ifdef WIN32 /* Window 95 & Windows NT */
161 # define OS_CODE 0x0b
162 #endif
163
164 #if defined(VAXC) || defined(VMS)
165 # define OS_CODE 0x02
166 # define F_OPEN(name, mode) \
167 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
168 #endif
169
170 #ifdef AMIGA
171 # define OS_CODE 0x01
172 #endif
173
174 #if defined(ATARI) || defined(atarist)
175 # define OS_CODE 0x05
176 #endif
177
178 #if defined(MACOS) || defined(TARGET_OS_MAC)
179 # define OS_CODE 0x07
180 # if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
181 # include <unix.h> /* for fdopen */
182 # else
183 # ifndef fdopen
184 # define fdopen(fd,mode) NULL /* No fdopen() */
185 # endif
186 # endif
187 #endif
188
189 #ifdef __50SERIES /* Prime/PRIMOS */
190 # define OS_CODE 0x0F
191 #endif
192
193 #ifdef TOPS20
194 # define OS_CODE 0x0a
195 #endif
196
197 #if defined(_BEOS_) || defined(RISCOS)
198 # define fdopen(fd,mode) NULL /* No fdopen() */
199 #endif
200
201 #if (defined(_MSC_VER) && (_MSC_VER > 600))
202 # define fdopen(fd,type) _fdopen(fd,type)
203 #endif
204
205
206 /* Common defaults */
207
208 #ifndef OS_CODE
209 # define OS_CODE 0x03 /* assume Unix */
210 #endif
211
212 #ifndef F_OPEN
213 # define F_OPEN(name, mode) fopen((name), (mode))
214 #endif
215
216 /* functions */
217
218 #ifdef HAVE_STRERROR
219 extern char *strerror OF((int));
220 # define zstrerror(errnum) strerror(errnum)
221 #else
222 # define zstrerror(errnum) ""
223 #endif
224
225 #if defined(pyr)
226 # define NO_MEMCPY
227 #endif
228 #if defined(SMALL_MEDIUM) && !defined(_MSC_VER) && !defined(__SC__)
229 /* Use our own functions for small and medium model with MSC <= 5.0.
230 * You may have to use the same strategy for Borland C (untested).
231 * The __SC__ check is for Symantec.
232 */
233 # define NO_MEMCPY
234 #endif
235 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
236 # define HAVE_MEMCPY
237 #endif
238 #ifdef HAVE_MEMCPY
239 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
240 # define zmemcpy _fmemcpy
241 # define zmemcmp _fmemcmp
242 # define zmemzero(dest, len) _fmemset(dest, 0, len)
243 # else
244 # define zmemcpy memcpy
245 # define zmemcmp memcmp
246 # define zmemzero(dest, len) memset(dest, 0, len)
247 # endif
248 #else
249 extern void zmemcpy OF((Bytef* dest, const Bytef* source, uInt len));
250 extern int zmemcmp OF((const Bytef* s1, const Bytef* s2, uInt len));
251 extern void zmemzero OF((Bytef* dest, uInt len));
252 #endif
253
254 /* Diagnostic functions */
255 #ifdef DEBUG_ZLIB
256 # include <stdio.h>
257 extern int z_verbose;
258 extern void z_error OF((char *m));
259 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
260 # define Trace(x) {if (z_verbose>=0) fprintf x ;}
261 # define Tracev(x) {if (z_verbose>0) fprintf x ;}
262 # define Tracevv(x) {if (z_verbose>1) fprintf x ;}
263 # define Tracec(c,x) {if (z_verbose>0 && (c)) fprintf x ;}
264 # define Tracecv(c,x) {if (z_verbose>1 && (c)) fprintf x ;}
265 #else
266 # define Assert(cond,msg)
267 # define Trace(x)
268 # define Tracev(x)
269 # define Tracevv(x)
270 # define Tracec(c,x)
271 # define Tracecv(c,x)
272 #endif
273
274
275 typedef uLong (ZEXPORT *check_func) OF((uLong check, const Bytef *buf,
276 uInt len));
277 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
278 void zcfree OF((voidpf opaque, voidpf ptr));
279
280 #define ZALLOC(strm, items, size) \
281 (*((strm)->zalloc))((strm)->opaque, (items), (size))
282 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
283 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
284
285 #endif /* _Z_UTIL_H */
286 /* --- zutil.h */
287
288 /* +++ deflate.h */
289 /* deflate.h -- internal compression state
290 * Copyright (C) 1995-2002 Jean-loup Gailly
291 * For conditions of distribution and use, see copyright notice in zlib.h
292 */
293
294 /* WARNING: this file should *not* be used by applications. It is
295 part of the implementation of the compression library and is
296 subject to change. Applications should only use zlib.h.
297 */
298
299 /* @(#) $Id: zlib.c,v 1.10 2004/07/29 19:17:20 lindak Exp $ */
300
301 #ifndef _DEFLATE_H
302 #define _DEFLATE_H
303
304 /* #include "zutil.h" */
305
306 /* ===========================================================================
307 * Internal compression state.
308 */
309
310 #define LENGTH_CODES 29
311 /* number of length codes, not counting the special END_BLOCK code */
312
313 #define LITERALS 256
314 /* number of literal bytes 0..255 */
315
316 #define L_CODES (LITERALS+1+LENGTH_CODES)
317 /* number of Literal or Length codes, including the END_BLOCK code */
318
319 #define D_CODES 30
320 /* number of distance codes */
321
322 #define BL_CODES 19
323 /* number of codes used to transfer the bit lengths */
324
325 #define HEAP_SIZE (2*L_CODES+1)
326 /* maximum heap size */
327
328 #define MAX_BITS 15
329 /* All codes must not exceed MAX_BITS bits */
330
331 #define INIT_STATE 42
332 #define BUSY_STATE 113
333 #define FINISH_STATE 666
334 /* Stream status */
335
336
337 /* Data structure describing a single value and its code string. */
338 typedef struct ct_data_s {
339 union {
340 ush freq; /* frequency count */
341 ush code; /* bit string */
342 } fc;
343 union {
344 ush dad; /* father node in Huffman tree */
345 ush len; /* length of bit string */
346 } dl;
347 } FAR ct_data;
348
349 #define Freq fc.freq
350 #define Code fc.code
351 #define Dad dl.dad
352 #define Len dl.len
353
354 typedef struct static_tree_desc_s static_tree_desc;
355
356 typedef struct tree_desc_s {
357 ct_data *dyn_tree; /* the dynamic tree */
358 int max_code; /* largest code with non zero frequency */
359 static_tree_desc *stat_desc; /* the corresponding static tree */
360 } FAR tree_desc;
361
362 typedef ush Pos;
363 typedef Pos FAR Posf;
364 typedef unsigned IPos;
365
366 /* A Pos is an index in the character window. We use short instead of int to
367 * save space in the various tables. IPos is used only for parameter passing.
368 */
369
370 typedef struct deflate_state {
371 z_streamp strm; /* pointer back to this zlib stream */
372 int status; /* as the name implies */
373 Bytef *pending_buf; /* output still pending */
374 ulg pending_buf_size; /* size of pending_buf */
375 Bytef *pending_out; /* next pending byte to output to the stream */
376 int pending; /* nb of bytes in the pending buffer */
377 int noheader; /* suppress zlib header and adler32 */
378 Byte data_type; /* UNKNOWN, BINARY or ASCII */
379 Byte method; /* STORED (for zip only) or DEFLATED */
380 int last_flush; /* value of flush param for previous deflate call */
381
382 /* used by deflate.c: */
383
384 uInt w_size; /* LZ77 window size (32K by default) */
385 uInt w_bits; /* log2(w_size) (8..16) */
386 uInt w_mask; /* w_size - 1 */
387
388 Bytef *window;
389 /* Sliding window. Input bytes are read into the second half of the window,
390 * and move to the first half later to keep a dictionary of at least wSize
391 * bytes. With this organization, matches are limited to a distance of
392 * wSize-MAX_MATCH bytes, but this ensures that IO is always
393 * performed with a length multiple of the block size. Also, it limits
394 * the window size to 64K, which is quite useful on MSDOS.
395 * To do: use the user input buffer as sliding window.
396 */
397
398 ulg window_size;
399 /* Actual size of window: 2*wSize, except when the user input buffer
400 * is directly used as sliding window.
401 */
402
403 Posf *prev;
404 /* Link to older string with same hash index. To limit the size of this
405 * array to 64K, this link is maintained only for the last 32K strings.
406 * An index in this array is thus a window index modulo 32K.
407 */
408
409 Posf *head; /* Heads of the hash chains or NIL. */
410
411 uInt ins_h; /* hash index of string to be inserted */
412 uInt hash_size; /* number of elements in hash table */
413 uInt hash_bits; /* log2(hash_size) */
414 uInt hash_mask; /* hash_size-1 */
415
416 uInt hash_shift;
417 /* Number of bits by which ins_h must be shifted at each input
418 * step. It must be such that after MIN_MATCH steps, the oldest
419 * byte no longer takes part in the hash key, that is:
420 * hash_shift * MIN_MATCH >= hash_bits
421 */
422
423 long block_start;
424 /* Window position at the beginning of the current output block. Gets
425 * negative when the window is moved backwards.
426 */
427
428 uInt match_length; /* length of best match */
429 IPos prev_match; /* previous match */
430 int match_available; /* set if previous match exists */
431 uInt strstart; /* start of string to insert */
432 uInt match_start; /* start of matching string */
433 uInt lookahead; /* number of valid bytes ahead in window */
434
435 uInt prev_length;
436 /* Length of the best match at previous step. Matches not greater than this
437 * are discarded. This is used in the lazy match evaluation.
438 */
439
440 uInt max_chain_length;
441 /* To speed up deflation, hash chains are never searched beyond this
442 * length. A higher limit improves compression ratio but degrades the
443 * speed.
444 */
445
446 uInt max_lazy_match;
447 /* Attempt to find a better match only when the current match is strictly
448 * smaller than this value. This mechanism is used only for compression
449 * levels >= 4.
450 */
451 # define max_insert_length max_lazy_match
452 /* Insert new strings in the hash table only if the match length is not
453 * greater than this length. This saves time but degrades compression.
454 * max_insert_length is used only for compression levels <= 3.
455 */
456
457 int level; /* compression level (1..9) */
458 int strategy; /* favor or force Huffman coding*/
459
460 uInt good_match;
461 /* Use a faster search when the previous match is longer than this */
462
463 int nice_match; /* Stop searching when current match exceeds this */
464
465 /* used by trees.c: */
466 /* Didn't use ct_data typedef below to supress compiler warning */
467 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
468 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
469 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
470
471 struct tree_desc_s l_desc; /* desc. for literal tree */
472 struct tree_desc_s d_desc; /* desc. for distance tree */
473 struct tree_desc_s bl_desc; /* desc. for bit length tree */
474
475 ush bl_count[MAX_BITS+1];
476 /* number of codes at each bit length for an optimal tree */
477
478 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
479 int heap_len; /* number of elements in the heap */
480 int heap_max; /* element of largest frequency */
481 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
482 * The same heap array is used to build all trees.
483 */
484
485 uch depth[2*L_CODES+1];
486 /* Depth of each subtree used as tie breaker for trees of equal frequency
487 */
488
489 uchf *l_buf; /* buffer for literals or lengths */
490
491 uInt lit_bufsize;
492 /* Size of match buffer for literals/lengths. There are 4 reasons for
493 * limiting lit_bufsize to 64K:
494 * - frequencies can be kept in 16 bit counters
495 * - if compression is not successful for the first block, all input
496 * data is still in the window so we can still emit a stored block even
497 * when input comes from standard input. (This can also be done for
498 * all blocks if lit_bufsize is not greater than 32K.)
499 * - if compression is not successful for a file smaller than 64K, we can
500 * even emit a stored file instead of a stored block (saving 5 bytes).
501 * This is applicable only for zip (not gzip or zlib).
502 * - creating new Huffman trees less frequently may not provide fast
503 * adaptation to changes in the input data statistics. (Take for
504 * example a binary file with poorly compressible code followed by
505 * a highly compressible string table.) Smaller buffer sizes give
506 * fast adaptation but have of course the overhead of transmitting
507 * trees more frequently.
508 * - I can't count above 4
509 */
510
511 uInt last_lit; /* running index in l_buf */
512
513 ushf *d_buf;
514 /* Buffer for distances. To simplify the code, d_buf and l_buf have
515 * the same number of elements. To use different lengths, an extra flag
516 * array would be necessary.
517 */
518
519 ulg opt_len; /* bit length of current block with optimal trees */
520 ulg static_len; /* bit length of current block with static trees */
521 uInt matches; /* number of string matches in current block */
522 int last_eob_len; /* bit length of EOB code for last block */
523
524 #ifdef DEBUG_ZLIB
525 ulg compressed_len; /* total bit length of compressed file mod 2^32 */
526 ulg bits_sent; /* bit length of compressed data sent mod 2^32 */
527 #endif
528
529 ush bi_buf;
530 /* Output buffer. bits are inserted starting at the bottom (least
531 * significant bits).
532 */
533 int bi_valid;
534 /* Number of valid bits in bi_buf. All bits above the last valid bit
535 * are always zero.
536 */
537
538 } FAR deflate_state;
539
540 /* Output a byte on the stream.
541 * IN assertion: there is enough room in pending_buf.
542 */
543 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
544
545
546 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
547 /* Minimum amount of lookahead, except at the end of the input file.
548 * See deflate.c for comments about the MIN_MATCH+1.
549 */
550
551 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
552 /* In order to simplify the code, particularly on 16 bit machines, match
553 * distances are limited to MAX_DIST instead of WSIZE.
554 */
555
556 /* in trees.c */
557 void _tr_init OF((deflate_state *s));
558 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
559 void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
560 int eof));
561 void _tr_align OF((deflate_state *s));
562 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
563 int eof));
564
565 #define d_code(dist) \
566 ((dist) < 256 ? _dist_code[dist] : _dist_code[256+((dist)>>7)])
567 /* Mapping from a distance to a distance code. dist is the distance - 1 and
568 * must not have side effects. _dist_code[256] and _dist_code[257] are never
569 * used.
570 */
571
572 #ifndef DEBUG_ZLIB
573 /* Inline versions of _tr_tally for speed: */
574
575 #if defined(GEN_TREES_H) || !defined(STDC)
576 extern uch _length_code[];
577 extern uch _dist_code[];
578 #else
579 extern const uch _length_code[];
580 extern const uch _dist_code[];
581 #endif
582
583 # define _tr_tally_lit(s, c, flush) \
584 { uch cc = (c); \
585 s->d_buf[s->last_lit] = 0; \
586 s->l_buf[s->last_lit++] = cc; \
587 s->dyn_ltree[cc].Freq++; \
588 flush = (s->last_lit == s->lit_bufsize-1); \
589 }
590 # define _tr_tally_dist(s, distance, length, flush) \
591 { uch len = (length); \
592 ush dist = (distance); \
593 s->d_buf[s->last_lit] = dist; \
594 s->l_buf[s->last_lit++] = len; \
595 dist--; \
596 s->dyn_ltree[_length_code[len]+LITERALS+1].Freq++; \
597 s->dyn_dtree[d_code(dist)].Freq++; \
598 flush = (s->last_lit == s->lit_bufsize-1); \
599 }
600 #else
601 # define _tr_tally_lit(s, c, flush) flush = _tr_tally(s, 0, c)
602 # define _tr_tally_dist(s, distance, length, flush) \
603 flush = _tr_tally(s, distance, length)
604 #endif
605
606 #endif
607 /* --- deflate.h */
608
609 /* +++ deflate.c */
610 /* deflate.c -- compress data using the deflation algorithm
611 * Copyright (C) 1995-2002 Jean-loup Gailly.
612 * For conditions of distribution and use, see copyright notice in zlib.h
613 */
614
615 /*
616 * ALGORITHM
617 *
618 * The "deflation" process depends on being able to identify portions
619 * of the input text which are identical to earlier input (within a
620 * sliding window trailing behind the input currently being processed).
621 *
622 * The most straightforward technique turns out to be the fastest for
623 * most input files: try all possible matches and select the longest.
624 * The key feature of this algorithm is that insertions into the string
625 * dictionary are very simple and thus fast, and deletions are avoided
626 * completely. Insertions are performed at each input character, whereas
627 * string matches are performed only when the previous match ends. So it
628 * is preferable to spend more time in matches to allow very fast string
629 * insertions and avoid deletions. The matching algorithm for small
630 * strings is inspired from that of Rabin & Karp. A brute force approach
631 * is used to find longer strings when a small match has been found.
632 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
633 * (by Leonid Broukhis).
634 * A previous version of this file used a more sophisticated algorithm
635 * (by Fiala and Greene) which is guaranteed to run in linear amortized
636 * time, but has a larger average cost, uses more memory and is patented.
637 * However the F&G algorithm may be faster for some highly redundant
638 * files if the parameter max_chain_length (described below) is too large.
639 *
640 * ACKNOWLEDGEMENTS
641 *
642 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
643 * I found it in 'freeze' written by Leonid Broukhis.
644 * Thanks to many people for bug reports and testing.
645 *
646 * REFERENCES
647 *
648 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
649 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
650 *
651 * A description of the Rabin and Karp algorithm is given in the book
652 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
653 *
654 * Fiala,E.R., and Greene,D.H.
655 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
656 *
657 */
658
659 /* @(#) $Id: zlib.c,v 1.10 2004/07/29 19:17:20 lindak Exp $ */
660
661 /* #include "deflate.h" */
662
663 const char deflate_copyright[] =
664 " deflate 1.1.4 Copyright 1995-2002 Jean-loup Gailly ";
665 /*
666 If you use the zlib library in a product, an acknowledgment is welcome
667 in the documentation of your product. If for some reason you cannot
668 include such an acknowledgment, I would appreciate that you keep this
669 copyright string in the executable of your product.
670 */
671
672 /* ===========================================================================
673 * Function prototypes.
674 */
675 typedef enum {
676 need_more, /* block not completed, need more input or more output */
677 block_done, /* block flush performed */
678 finish_started, /* finish started, need only more output at next deflate */
679 finish_done /* finish done, accept no more input or output */
680 } block_state;
681
682 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
683 /* Compression function. Returns the block state after the call. */
684
685 local void fill_window OF((deflate_state *s));
686 local block_state deflate_stored OF((deflate_state *s, int flush));
687 local block_state deflate_fast OF((deflate_state *s, int flush));
688 local block_state deflate_slow OF((deflate_state *s, int flush));
689 local void lm_init OF((deflate_state *s));
690 local void putShortMSB OF((deflate_state *s, uInt b));
691 local void flush_pending OF((z_streamp strm));
692 local int read_buf OF((z_streamp strm, Bytef *buf, unsigned size));
693 #ifdef ASMV
694 void match_init OF((void)); /* asm code initialization */
695 uInt longest_match OF((deflate_state *s, IPos cur_match));
696 #else
697 local uInt longest_match OF((deflate_state *s, IPos cur_match));
698 #endif
699
700 #ifdef DEBUG_ZLIB
701 local void check_match OF((deflate_state *s, IPos start, IPos match,
702 int length));
703 #endif
704
705 /* ===========================================================================
706 * Local data
707 */
708
709 #define NIL 0
710 /* Tail of hash chains */
711
712 #ifndef TOO_FAR
713 # define TOO_FAR 4096
714 #endif
715 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
716
717 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
718 /* Minimum amount of lookahead, except at the end of the input file.
719 * See deflate.c for comments about the MIN_MATCH+1.
720 */
721
722 /* Values for max_lazy_match, good_match and max_chain_length, depending on
723 * the desired pack level (0..9). The values given below have been tuned to
724 * exclude worst case performance for pathological files. Better values may be
725 * found for specific files.
726 */
727 typedef struct config_s {
728 ush good_length; /* reduce lazy search above this match length */
729 ush max_lazy; /* do not perform lazy search above this match length */
730 ush nice_length; /* quit search above this match length */
731 ush max_chain;
732 compress_func func;
733 } config;
734
735 local const config configuration_table[10] = {
736 /* good lazy nice chain */
737 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
738 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
739 /* 2 */ {4, 5, 16, 8, deflate_fast},
740 /* 3 */ {4, 6, 32, 32, deflate_fast},
741
742 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
743 /* 5 */ {8, 16, 32, 32, deflate_slow},
744 /* 6 */ {8, 16, 128, 128, deflate_slow},
745 /* 7 */ {8, 32, 128, 256, deflate_slow},
746 /* 8 */ {32, 128, 258, 1024, deflate_slow},
747 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
748
749 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
750 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
751 * meaning.
752 */
753
754 #define EQUAL 0
755 /* result of memcmp for equal strings */
756
757 #ifndef NO_DUMMY_DECL
758 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
759 #endif
760
761 /* ===========================================================================
762 * Update a hash value with the given input byte
763 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
764 * input characters, so that a running hash key can be computed from the
765 * previous key instead of complete recalculation each time.
766 */
767 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
768
769
770 /* ===========================================================================
771 * Insert string str in the dictionary and set match_head to the previous head
772 * of the hash chain (the most recent string with same hash key). Return
773 * the previous length of the hash chain.
774 * If this file is compiled with -DFASTEST, the compression level is forced
775 * to 1, and no hash chains are maintained.
776 * IN assertion: all calls to to INSERT_STRING are made with consecutive
777 * input characters and the first MIN_MATCH bytes of str are valid
778 * (except for the last MIN_MATCH-1 bytes of the input file).
779 */
780 #ifdef FASTEST
781 #define INSERT_STRING(s, str, match_head) \
782 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
783 match_head = s->head[s->ins_h], \
784 s->head[s->ins_h] = (Pos)(str))
785 #else
786 #define INSERT_STRING(s, str, match_head) \
787 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
788 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
789 s->head[s->ins_h] = (Pos)(str))
790 #endif
791
792 /* ===========================================================================
793 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
794 * prev[] will be initialized on the fly.
795 */
796 #define CLEAR_HASH(s) \
797 s->head[s->hash_size-1] = NIL; \
798 zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
799
800 /* ========================================================================= */
801 int ZEXPORT deflateInit_(strm, level, version, stream_size)
802 z_streamp strm;
803 int level;
804 const char *version;
805 int stream_size;
806 {
807 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
808 Z_DEFAULT_STRATEGY, version, stream_size);
809 /* To do: ignore strm->next_in if we use it as window */
810 }
811
812 /* ========================================================================= */
813 int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
814 version, stream_size)
815 z_streamp strm;
816 int level;
817 int method;
818 int windowBits;
819 int memLevel;
820 int strategy;
821 const char *version;
822 int stream_size;
823 {
824 deflate_state *s;
825 int noheader = 0;
826 static const char* my_version = ZLIB_VERSION;
827
828 ushf *overlay;
829 /* We overlay pending_buf and d_buf+l_buf. This works since the average
830 * output size for (length,distance) codes is <= 24 bits.
831 */
832
833 if (version == Z_NULL || version[0] != my_version[0] ||
834 stream_size != sizeof(z_stream)) {
835 return Z_VERSION_ERROR;
836 }
837 if (strm == Z_NULL) return Z_STREAM_ERROR;
838
839 strm->msg = Z_NULL;
840 #ifndef NO_ZCFUNCS
841 if (strm->zalloc == Z_NULL) {
842 strm->zalloc = zcalloc;
843 strm->opaque = (voidpf)0;
844 }
845 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
846 #endif
847
848 if (level == Z_DEFAULT_COMPRESSION) level = 6;
849 #ifdef FASTEST
850 level = 1;
851 #endif
852
853 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
854 noheader = 1;
855 windowBits = -windowBits;
856 }
857 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
858 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
859 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
860 return Z_STREAM_ERROR;
861 }
862 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
863 if (s == Z_NULL) return Z_MEM_ERROR;
864 strm->state = (struct internal_state FAR *)s;
865 s->strm = strm;
866
867 s->noheader = noheader;
868 s->w_bits = windowBits;
869 s->w_size = 1 << s->w_bits;
870 s->w_mask = s->w_size - 1;
871
872 s->hash_bits = memLevel + 7;
873 s->hash_size = 1 << s->hash_bits;
874 s->hash_mask = s->hash_size - 1;
875 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
876
877 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
878 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
879 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
880
881 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
882
883 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
884 s->pending_buf = (uchf *) overlay;
885 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
886
887 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
888 s->pending_buf == Z_NULL) {
889 strm->msg = (char*)ERR_MSG(Z_MEM_ERROR);
890 deflateEnd (strm);
891 return Z_MEM_ERROR;
892 }
893 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
894 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
895
896 s->level = level;
897 s->strategy = strategy;
898 s->method = (Byte)method;
899
900 return deflateReset(strm);
901 }
902
903 /* ========================================================================= */
904 int ZEXPORT deflateSetDictionary (strm, dictionary, dictLength)
905 z_streamp strm;
906 const Bytef *dictionary;
907 uInt dictLength;
908 {
909 deflate_state *s;
910 uInt length = dictLength;
911 uInt n;
912 IPos hash_head = 0;
913
914 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL ||
915 ((deflate_state*)strm->state)->status != INIT_STATE) return Z_STREAM_ERROR;
916
917 s = (deflate_state*)strm->state;
918 strm->adler = adler32(strm->adler, dictionary, dictLength);
919
920 if (length < MIN_MATCH) return Z_OK;
921 if (length > MAX_DIST(s)) {
922 length = MAX_DIST(s);
923 #ifndef USE_DICT_HEAD
924 dictionary += dictLength - length; /* use the tail of the dictionary */
925 #endif
926 }
927 zmemcpy(s->window, dictionary, length);
928 s->strstart = length;
929 s->block_start = (long)length;
930
931 /* Insert all strings in the hash table (except for the last two bytes).
932 * s->lookahead stays null, so s->ins_h will be recomputed at the next
933 * call of fill_window.
934 */
935 s->ins_h = s->window[0];
936 UPDATE_HASH(s, s->ins_h, s->window[1]);
937 for (n = 0; n <= length - MIN_MATCH; n++) {
938 INSERT_STRING(s, n, hash_head);
939 }
940 if (hash_head) hash_head = 0; /* to make compiler happy */
941 return Z_OK;
942 }
943
944 /* ========================================================================= */
945 int ZEXPORT deflateReset (strm)
946 z_streamp strm;
947 {
948 deflate_state *s;
949
950 if (strm == Z_NULL || strm->state == Z_NULL ||
951 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
952
953 strm->total_in = strm->total_out = 0;
954 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
955 strm->data_type = Z_UNKNOWN;
956
957 s = (deflate_state *)strm->state;
958 s->pending = 0;
959 s->pending_out = s->pending_buf;
960
961 if (s->noheader < 0) {
962 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
963 }
964 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
965 strm->adler = 1;
966 s->last_flush = Z_NO_FLUSH;
967
968 _tr_init(s);
969 lm_init(s);
970
971 return Z_OK;
972 }
973
974 /* ========================================================================= */
975 int ZEXPORT deflateParams(strm, level, strategy)
976 z_streamp strm;
977 int level;
978 int strategy;
979 {
980 deflate_state *s;
981 compress_func func;
982 int err = Z_OK;
983
984 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
985 s = (deflate_state*)strm->state;
986
987 if (level == Z_DEFAULT_COMPRESSION) {
988 level = 6;
989 }
990 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
991 return Z_STREAM_ERROR;
992 }
993 func = configuration_table[s->level].func;
994
995 if (func != configuration_table[level].func && strm->total_in != 0) {
996 /* Flush the last buffer: */
997 err = deflate(strm, Z_PARTIAL_FLUSH);
998 }
999 if (s->level != level) {
1000 s->level = level;
1001 s->max_lazy_match = configuration_table[level].max_lazy;
1002 s->good_match = configuration_table[level].good_length;
1003 s->nice_match = configuration_table[level].nice_length;
1004 s->max_chain_length = configuration_table[level].max_chain;
1005 }
1006 s->strategy = strategy;
1007 return err;
1008 }
1009
1010 /* =========================================================================
1011 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
1012 * IN assertion: the stream state is correct and there is enough room in
1013 * pending_buf.
1014 */
1015 local void putShortMSB (s, b)
1016 deflate_state *s;
1017 uInt b;
1018 {
1019 put_byte(s, (Byte)(b >> 8));
1020 put_byte(s, (Byte)(b & 0xff));
1021 }
1022
1023 /* =========================================================================
1024 * Flush as much pending output as possible. All deflate() output goes
1025 * through this function so some applications may wish to modify it
1026 * to avoid allocating a large strm->next_out buffer and copying into it.
1027 * (See also read_buf()).
1028 */
1029 local void flush_pending(strm)
1030 z_streamp strm;
1031 {
1032 deflate_state* s = (deflate_state*)strm->state;
1033 unsigned len = s->pending;
1034
1035 if (len > strm->avail_out) len = strm->avail_out;
1036 if (len == 0) return;
1037
1038 zmemcpy(strm->next_out, s->pending_out, len);
1039 strm->next_out += len;
1040 s->pending_out += len;
1041 strm->total_out += len;
1042 strm->avail_out -= len;
1043 s->pending -= len;
1044 if (s->pending == 0) {
1045 s->pending_out = s->pending_buf;
1046 }
1047 }
1048
1049 /* ========================================================================= */
1050 int ZEXPORT deflate (strm, flush)
1051 z_streamp strm;
1052 int flush;
1053 {
1054 int old_flush; /* value of flush param for previous deflate call */
1055 deflate_state *s;
1056
1057 if (strm == Z_NULL || strm->state == Z_NULL ||
1058 flush > Z_FINISH || flush < 0) {
1059 return Z_STREAM_ERROR;
1060 }
1061 s = (deflate_state*)strm->state;
1062
1063 if (strm->next_out == Z_NULL ||
1064 (strm->next_in == Z_NULL && strm->avail_in != 0) ||
1065 (s->status == FINISH_STATE && flush != Z_FINISH)) {
1066 ERR_RETURN(strm, Z_STREAM_ERROR);
1067 }
1068 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
1069
1070 s->strm = strm; /* just in case */
1071 old_flush = s->last_flush;
1072 s->last_flush = flush;
1073
1074 /* Write the zlib header */
1075 if (s->status == INIT_STATE) {
1076
1077 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1078 uInt level_flags = (s->level-1) >> 1;
1079
1080 if (level_flags > 3) level_flags = 3;
1081 header |= (level_flags << 6);
1082 if (s->strstart != 0) header |= PRESET_DICT;
1083 header += 31 - (header % 31);
1084
1085 s->status = BUSY_STATE;
1086 putShortMSB(s, header);
1087
1088 /* Save the adler32 of the preset dictionary: */
1089 if (s->strstart != 0) {
1090 putShortMSB(s, (uInt)(strm->adler >> 16));
1091 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1092 }
1093 strm->adler = 1L;
1094 }
1095
1096 /* Flush as much pending output as possible */
1097 if (s->pending != 0) {
1098 flush_pending(strm);
1099 if (strm->avail_out == 0) {
1100 /* Since avail_out is 0, deflate will be called again with
1101 * more output space, but possibly with both pending and
1102 * avail_in equal to zero. There won't be anything to do,
1103 * but this is not an error situation so make sure we
1104 * return OK instead of BUF_ERROR at next call of deflate:
1105 */
1106 s->last_flush = -1;
1107 return Z_OK;
1108 }
1109
1110 /* Make sure there is something to do and avoid duplicate consecutive
1111 * flushes. For repeated and useless calls with Z_FINISH, we keep
1112 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1113 */
1114 } else if (strm->avail_in == 0 && flush <= old_flush &&
1115 flush != Z_FINISH) {
1116 ERR_RETURN(strm, Z_BUF_ERROR);
1117 }
1118
1119 /* User must not provide more input after the first FINISH: */
1120 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1121 ERR_RETURN(strm, Z_BUF_ERROR);
1122 }
1123
1124 /* Start a new block or continue the current one.
1125 */
1126 if (strm->avail_in != 0 || s->lookahead != 0 ||
1127 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1128 block_state bstate;
1129
1130 bstate = (*(configuration_table[s->level].func))(s, flush);
1131
1132 if (bstate == finish_started || bstate == finish_done) {
1133 s->status = FINISH_STATE;
1134 }
1135 if (bstate == need_more || bstate == finish_started) {
1136 if (strm->avail_out == 0) {
1137 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1138 }
1139 return Z_OK;
1140 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1141 * of deflate should use the same flush parameter to make sure
1142 * that the flush is complete. So we don't have to output an
1143 * empty block here, this will be done at next call. This also
1144 * ensures that for a very small output buffer, we emit at most
1145 * one empty block.
1146 */
1147 }
1148 if (bstate == block_done) {
1149 if (flush == Z_PARTIAL_FLUSH) {
1150 _tr_align(s);
1151 } else { /* FULL_FLUSH or SYNC_FLUSH */
1152 _tr_stored_block(s, (char*)0, 0L, 0);
1153 /* For a full flush, this empty block will be recognized
1154 * as a special marker by inflate_sync().
1155 */
1156 if (flush == Z_FULL_FLUSH) {
1157 CLEAR_HASH(s); /* forget history */
1158 }
1159 }
1160 flush_pending(strm);
1161 if (strm->avail_out == 0) {
1162 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1163 return Z_OK;
1164 }
1165 }
1166 }
1167 Assert(strm->avail_out > 0, "bug2");
1168
1169 if (flush != Z_FINISH) return Z_OK;
1170 if (s->noheader) return Z_STREAM_END;
1171
1172 /* Write the zlib trailer (adler32) */
1173 putShortMSB(s, (uInt)(strm->adler >> 16));
1174 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1175 flush_pending(strm);
1176 /* If avail_out is zero, the application will call deflate again
1177 * to flush the rest.
1178 */
1179 s->noheader = -1; /* write the trailer only once! */
1180 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1181 }
1182
1183 /* ========================================================================= */
1184 int ZEXPORT deflateEnd (strm)
1185 z_streamp strm;
1186 {
1187 deflate_state* s;
1188 int status;
1189
1190 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1191
1192 s = (deflate_state*)strm->state;
1193 status = s->status;
1194 if (status != INIT_STATE && status != BUSY_STATE &&
1195 status != FINISH_STATE) {
1196 return Z_STREAM_ERROR;
1197 }
1198
1199 /* Deallocate in reverse order of allocations: */
1200 TRY_FREE(strm, s->pending_buf);
1201 TRY_FREE(strm, s->head);
1202 TRY_FREE(strm, s->prev);
1203 TRY_FREE(strm, s->window);
1204
1205 ZFREE(strm, s);
1206 strm->state = Z_NULL;
1207
1208 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1209 }
1210
1211 /* =========================================================================
1212 * Copy the source state to the destination state.
1213 * To simplify the source, this is not supported for 16-bit MSDOS (which
1214 * doesn't have enough memory anyway to duplicate compression states).
1215 */
1216 int ZEXPORT deflateCopy (dest, source)
1217 z_streamp dest;
1218 z_streamp source;
1219 {
1220 #ifdef MAXSEG_64K
1221 return Z_STREAM_ERROR;
1222 #else
1223 deflate_state *ds;
1224 deflate_state *ss;
1225 ushf *overlay;
1226
1227
1228 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) {
1229 return Z_STREAM_ERROR;
1230 }
1231
1232 ss = (deflate_state*)source->state;
1233
1234 *dest = *source;
1235
1236 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1237 if (ds == Z_NULL) return Z_MEM_ERROR;
1238 dest->state = (struct internal_state FAR *) ds;
1239 *ds = *ss;
1240 ds->strm = dest;
1241
1242 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1243 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1244 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1245 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1246 ds->pending_buf = (uchf *) overlay;
1247
1248 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1249 ds->pending_buf == Z_NULL) {
1250 deflateEnd (dest);
1251 return Z_MEM_ERROR;
1252 }
1253 /* following zmemcpy do not work for 16-bit MSDOS */
1254 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1255 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1256 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1257 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1258
1259 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1260 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1261 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1262
1263 ds->l_desc.dyn_tree = ds->dyn_ltree;
1264 ds->d_desc.dyn_tree = ds->dyn_dtree;
1265 ds->bl_desc.dyn_tree = ds->bl_tree;
1266
1267 return Z_OK;
1268 #endif
1269 }
1270
1271 /* ===========================================================================
1272 * Read a new buffer from the current input stream, update the adler32
1273 * and total number of bytes read. All deflate() input goes through
1274 * this function so some applications may wish to modify it to avoid
1275 * allocating a large strm->next_in buffer and copying from it.
1276 * (See also flush_pending()).
1277 */
1278 local int read_buf(strm, buf, size)
1279 z_streamp strm;
1280 Bytef *buf;
1281 unsigned size;
1282 {
1283 unsigned len = strm->avail_in;
1284
1285 if (len > size) len = size;
1286 if (len == 0) return 0;
1287
1288 strm->avail_in -= len;
1289
1290 if (!((deflate_state*)strm->state)->noheader) {
1291 strm->adler = adler32(strm->adler, strm->next_in, len);
1292 }
1293 zmemcpy(buf, strm->next_in, len);
1294 strm->next_in += len;
1295 strm->total_in += len;
1296
1297 return (int)len;
1298 }
1299
1300 /* ===========================================================================
1301 * Initialize the "longest match" routines for a new zlib stream
1302 */
1303 local void lm_init (s)
1304 deflate_state *s;
1305 {
1306 s->window_size = (ulg)2L*s->w_size;
1307
1308 CLEAR_HASH(s);
1309
1310 /* Set the default configuration parameters:
1311 */
1312 s->max_lazy_match = configuration_table[s->level].max_lazy;
1313 s->good_match = configuration_table[s->level].good_length;
1314 s->nice_match = configuration_table[s->level].nice_length;
1315 s->max_chain_length = configuration_table[s->level].max_chain;
1316
1317 s->strstart = 0;
1318 s->block_start = 0L;
1319 s->lookahead = 0;
1320 s->match_length = s->prev_length = MIN_MATCH-1;
1321 s->match_available = 0;
1322 s->ins_h = 0;
1323 #ifdef ASMV
1324 match_init(); /* initialize the asm code */
1325 #endif
1326 }
1327
1328 /* ===========================================================================
1329 * Set match_start to the longest match starting at the given string and
1330 * return its length. Matches shorter or equal to prev_length are discarded,
1331 * in which case the result is equal to prev_length and match_start is
1332 * garbage.
1333 * IN assertions: cur_match is the head of the hash chain for the current
1334 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1335 * OUT assertion: the match length is not greater than s->lookahead.
1336 */
1337 #ifndef ASMV
1338 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1339 * match.S. The code will be functionally equivalent.
1340 */
1341 #ifndef FASTEST
1342 local uInt longest_match(s, cur_match)
1343 deflate_state *s;
1344 IPos cur_match; /* current match */
1345 {
1346 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1347 register Bytef *scan = s->window + s->strstart; /* current string */
1348 register Bytef *match; /* matched string */
1349 register int len; /* length of current match */
1350 int best_len = s->prev_length; /* best match length so far */
1351 int nice_match = s->nice_match; /* stop if match long enough */
1352 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1353 s->strstart - (IPos)MAX_DIST(s) : NIL;
1354 /* Stop when cur_match becomes <= limit. To simplify the code,
1355 * we prevent matches with the string of window index 0.
1356 */
1357 Posf *prev = s->prev;
1358 uInt wmask = s->w_mask;
1359
1360 #ifdef UNALIGNED_OK
1361 /* Compare two bytes at a time. Note: this is not always beneficial.
1362 * Try with and without -DUNALIGNED_OK to check.
1363 */
1364 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1365 register ush scan_start = *(ushf*)scan;
1366 register ush scan_end = *(ushf*)(scan+best_len-1);
1367 #else
1368 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1369 register Byte scan_end1 = scan[best_len-1];
1370 register Byte scan_end = scan[best_len];
1371 #endif
1372
1373 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1374 * It is easy to get rid of this optimization if necessary.
1375 */
1376 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1377
1378 /* Do not waste too much time if we already have a good match: */
1379 if (s->prev_length >= s->good_match) {
1380 chain_length >>= 2;
1381 }
1382 /* Do not look for matches beyond the end of the input. This is necessary
1383 * to make deflate deterministic.
1384 */
1385 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1386
1387 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1388
1389 do {
1390 Assert(cur_match < s->strstart, "no future");
1391 match = s->window + cur_match;
1392
1393 /* Skip to next match if the match length cannot increase
1394 * or if the match length is less than 2:
1395 */
1396 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1397 /* This code assumes sizeof(unsigned short) == 2. Do not use
1398 * UNALIGNED_OK if your compiler uses a different size.
1399 */
1400 if (*(ushf*)(match+best_len-1) != scan_end ||
1401 *(ushf*)match != scan_start) continue;
1402
1403 /* It is not necessary to compare scan[2] and match[2] since they are
1404 * always equal when the other bytes match, given that the hash keys
1405 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1406 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1407 * lookahead only every 4th comparison; the 128th check will be made
1408 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1409 * necessary to put more guard bytes at the end of the window, or
1410 * to check more often for insufficient lookahead.
1411 */
1412 Assert(scan[2] == match[2], "scan[2]?");
1413 scan++, match++;
1414 do {
1415 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1416 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1417 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1418 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1419 scan < strend);
1420 /* The funny "do {}" generates better code on most compilers */
1421
1422 /* Here, scan <= window+strstart+257 */
1423 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1424 if (*scan == *match) scan++;
1425
1426 len = (MAX_MATCH - 1) - (int)(strend-scan);
1427 scan = strend - (MAX_MATCH-1);
1428
1429 #else /* UNALIGNED_OK */
1430
1431 if (match[best_len] != scan_end ||
1432 match[best_len-1] != scan_end1 ||
1433 *match != *scan ||
1434 *++match != scan[1]) continue;
1435
1436 /* The check at best_len-1 can be removed because it will be made
1437 * again later. (This heuristic is not always a win.)
1438 * It is not necessary to compare scan[2] and match[2] since they
1439 * are always equal when the other bytes match, given that
1440 * the hash keys are equal and that HASH_BITS >= 8.
1441 */
1442 scan += 2, match++;
1443 Assert(*scan == *match, "match[2]?");
1444
1445 /* We check for insufficient lookahead only every 8th comparison;
1446 * the 256th check will be made at strstart+258.
1447 */
1448 do {
1449 } while (*++scan == *++match && *++scan == *++match &&
1450 *++scan == *++match && *++scan == *++match &&
1451 *++scan == *++match && *++scan == *++match &&
1452 *++scan == *++match && *++scan == *++match &&
1453 scan < strend);
1454
1455 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1456
1457 len = MAX_MATCH - (int)(strend - scan);
1458 scan = strend - MAX_MATCH;
1459
1460 #endif /* UNALIGNED_OK */
1461
1462 if (len > best_len) {
1463 s->match_start = cur_match;
1464 best_len = len;
1465 if (len >= nice_match) break;
1466 #ifdef UNALIGNED_OK
1467 scan_end = *(ushf*)(scan+best_len-1);
1468 #else
1469 scan_end1 = scan[best_len-1];
1470 scan_end = scan[best_len];
1471 #endif
1472 }
1473 } while ((cur_match = prev[cur_match & wmask]) > limit
1474 && --chain_length != 0);
1475
1476 if ((uInt)best_len <= s->lookahead) return (uInt)best_len;
1477 return s->lookahead;
1478 }
1479
1480 #else /* FASTEST */
1481 /* ---------------------------------------------------------------------------
1482 * Optimized version for level == 1 only
1483 */
1484 local uInt longest_match(s, cur_match)
1485 deflate_state *s;
1486 IPos cur_match; /* current match */
1487 {
1488 register Bytef *scan = s->window + s->strstart; /* current string */
1489 register Bytef *match; /* matched string */
1490 register int len; /* length of current match */
1491 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1492
1493 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1494 * It is easy to get rid of this optimization if necessary.
1495 */
1496 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1497
1498 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1499
1500 Assert(cur_match < s->strstart, "no future");
1501
1502 match = s->window + cur_match;
1503
1504 /* Return failure if the match length is less than 2:
1505 */
1506 if (match[0] != scan[0] || match[1] != scan[1]) return MIN_MATCH-1;
1507
1508 /* The check at best_len-1 can be removed because it will be made
1509 * again later. (This heuristic is not always a win.)
1510 * It is not necessary to compare scan[2] and match[2] since they
1511 * are always equal when the other bytes match, given that
1512 * the hash keys are equal and that HASH_BITS >= 8.
1513 */
1514 scan += 2, match += 2;
1515 Assert(*scan == *match, "match[2]?");
1516
1517 /* We check for insufficient lookahead only every 8th comparison;
1518 * the 256th check will be made at strstart+258.
1519 */
1520 do {
1521 } while (*++scan == *++match && *++scan == *++match &&
1522 *++scan == *++match && *++scan == *++match &&
1523 *++scan == *++match && *++scan == *++match &&
1524 *++scan == *++match && *++scan == *++match &&
1525 scan < strend);
1526
1527 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1528
1529 len = MAX_MATCH - (int)(strend - scan);
1530
1531 if (len < MIN_MATCH) return MIN_MATCH - 1;
1532
1533 s->match_start = cur_match;
1534 return len <= s->lookahead ? len : s->lookahead;
1535 }
1536 #endif /* FASTEST */
1537 #endif /* ASMV */
1538
1539 #ifdef DEBUG_ZLIB
1540 /* ===========================================================================
1541 * Check that the match at match_start is indeed a match.
1542 */
1543 local void check_match(s, start, match, length)
1544 deflate_state *s;
1545 IPos start, match;
1546 int length;
1547 {
1548 /* check that the match is indeed a match */
1549 if (zmemcmp(s->window + match,
1550 s->window + start, length) != EQUAL) {
1551 fprintf(stderr, " start %u, match %u, length %d\n",
1552 start, match, length);
1553 do {
1554 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1555 } while (--length != 0);
1556 z_error("invalid match");
1557 }
1558 if (z_verbose > 1) {
1559 fprintf(stderr,"\\[%d,%d]", start-match, length);
1560 do { putc(s->window[start++], stderr); } while (--length != 0);
1561 }
1562 }
1563 #else
1564 # define check_match(s, start, match, length)
1565 #endif
1566
1567 /* ===========================================================================
1568 * Fill the window when the lookahead becomes insufficient.
1569 * Updates strstart and lookahead.
1570 *
1571 * IN assertion: lookahead < MIN_LOOKAHEAD
1572 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1573 * At least one byte has been read, or avail_in == 0; reads are
1574 * performed for at least two bytes (required for the zip translate_eol
1575 * option -- not supported here).
1576 */
1577 local void fill_window(s)
1578 deflate_state *s;
1579 {
1580 register unsigned n, m;
1581 register Posf *p;
1582 unsigned more; /* Amount of free space at the end of the window. */
1583 uInt wsize = s->w_size;
1584
1585 do {
1586 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1587
1588 /* Deal with !@#$% 64K limit: */
1589 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1590 more = wsize;
1591
1592 } else if (more == (unsigned)(-1)) {
1593 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1594 * and lookahead == 1 (input done one byte at time)
1595 */
1596 more--;
1597
1598 /* If the window is almost full and there is insufficient lookahead,
1599 * move the upper half to the lower one to make room in the upper half.
1600 */
1601 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1602
1603 zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
1604 s->match_start -= wsize;
1605 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1606 s->block_start -= (long) wsize;
1607
1608 /* Slide the hash table (could be avoided with 32 bit values
1609 at the expense of memory usage). We slide even when level == 0
1610 to keep the hash table consistent if we switch back to level > 0
1611 later. (Using level 0 permanently is not an optimal usage of
1612 zlib, so we don't care about this pathological case.)
1613 */
1614 n = s->hash_size;
1615 p = &s->head[n];
1616 do {
1617 m = *--p;
1618 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1619 } while (--n);
1620
1621 n = wsize;
1622 #ifndef FASTEST
1623 p = &s->prev[n];
1624 do {
1625 m = *--p;
1626 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1627 /* If n is not on any hash chain, prev[n] is garbage but
1628 * its value will never be used.
1629 */
1630 } while (--n);
1631 #endif
1632 more += wsize;
1633 }
1634 if (s->strm->avail_in == 0) return;
1635
1636 /* If there was no sliding:
1637 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1638 * more == window_size - lookahead - strstart
1639 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1640 * => more >= window_size - 2*WSIZE + 2
1641 * In the BIG_MEM or MMAP case (not yet supported),
1642 * window_size == input_size + MIN_LOOKAHEAD &&
1643 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1644 * Otherwise, window_size == 2*WSIZE so more >= 2.
1645 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1646 */
1647 Assert(more >= 2, "more < 2");
1648
1649 n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
1650 s->lookahead += n;
1651
1652 /* Initialize the hash value now that we have some input: */
1653 if (s->lookahead >= MIN_MATCH) {
1654 s->ins_h = s->window[s->strstart];
1655 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1656 #if MIN_MATCH != 3
1657 Call UPDATE_HASH() MIN_MATCH-3 more times
1658 #endif
1659 }
1660 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1661 * but this is not important since only literal bytes will be emitted.
1662 */
1663
1664 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1665 }
1666
1667 /* ===========================================================================
1668 * Flush the current block, with given end-of-file flag.
1669 * IN assertion: strstart is set to the end of the current match.
1670 */
1671 #define FLUSH_BLOCK_ONLY(s, eof) { \
1672 _tr_flush_block(s, (s->block_start >= 0L ? \
1673 (charf *)&s->window[(unsigned)s->block_start] : \
1674 (charf *)Z_NULL), \
1675 (ulg)((long)s->strstart - s->block_start), \
1676 (eof)); \
1677 s->block_start = s->strstart; \
1678 flush_pending(s->strm); \
1679 Tracev((stderr,"[FLUSH]")); \
1680 }
1681
1682 /* Same but force premature exit if necessary. */
1683 #define FLUSH_BLOCK(s, eof) { \
1684 FLUSH_BLOCK_ONLY(s, eof); \
1685 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1686 }
1687
1688 /* ===========================================================================
1689 * Copy without compression as much as possible from the input stream, return
1690 * the current block state.
1691 * This function does not insert new strings in the dictionary since
1692 * uncompressible data is probably not useful. This function is used
1693 * only for the level=0 compression option.
1694 * NOTE: this function should be optimized to avoid extra copying from
1695 * window to pending_buf.
1696 */
1697 local block_state deflate_stored(s, flush)
1698 deflate_state *s;
1699 int flush;
1700 {
1701 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1702 * to pending_buf_size, and each stored block has a 5 byte header:
1703 */
1704 ulg max_block_size = 0xffff;
1705 ulg max_start;
1706
1707 if (max_block_size > s->pending_buf_size - 5) {
1708 max_block_size = s->pending_buf_size - 5;
1709 }
1710
1711 /* Copy as much as possible from input to output: */
1712 for (;;) {
1713 /* Fill the window as much as possible: */
1714 if (s->lookahead <= 1) {
1715
1716 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1717 s->block_start >= (long)s->w_size, "slide too late");
1718
1719 fill_window(s);
1720 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1721
1722 if (s->lookahead == 0) break; /* flush the current block */
1723 }
1724 Assert(s->block_start >= 0L, "block gone");
1725
1726 s->strstart += s->lookahead;
1727 s->lookahead = 0;
1728
1729 /* Emit a stored block if pending_buf will be full: */
1730 max_start = s->block_start + max_block_size;
1731 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1732 /* strstart == 0 is possible when wraparound on 16-bit machine */
1733 s->lookahead = (uInt)(s->strstart - max_start);
1734 s->strstart = (uInt)max_start;
1735 FLUSH_BLOCK(s, 0);
1736 }
1737 /* Flush if we may have to slide, otherwise block_start may become
1738 * negative and the data will be gone:
1739 */
1740 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1741 FLUSH_BLOCK(s, 0);
1742 }
1743 }
1744 FLUSH_BLOCK(s, flush == Z_FINISH);
1745 return flush == Z_FINISH ? finish_done : block_done;
1746 }
1747
1748 /* ===========================================================================
1749 * Compress as much as possible from the input stream, return the current
1750 * block state.
1751 * This function does not perform lazy evaluation of matches and inserts
1752 * new strings in the dictionary only for unmatched strings or for short
1753 * matches. It is used only for the fast compression options.
1754 */
1755 local block_state deflate_fast(s, flush)
1756 deflate_state *s;
1757 int flush;
1758 {
1759 IPos hash_head = NIL; /* head of the hash chain */
1760 int bflush; /* set if current block must be flushed */
1761
1762 for (;;) {
1763 /* Make sure that we always have enough lookahead, except
1764 * at the end of the input file. We need MAX_MATCH bytes
1765 * for the next match, plus MIN_MATCH bytes to insert the
1766 * string following the next match.
1767 */
1768 if (s->lookahead < MIN_LOOKAHEAD) {
1769 fill_window(s);
1770 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1771 return need_more;
1772 }
1773 if (s->lookahead == 0) break; /* flush the current block */
1774 }
1775
1776 /* Insert the string window[strstart .. strstart+2] in the
1777 * dictionary, and set hash_head to the head of the hash chain:
1778 */
1779 if (s->lookahead >= MIN_MATCH) {
1780 INSERT_STRING(s, s->strstart, hash_head);
1781 }
1782
1783 /* Find the longest match, discarding those <= prev_length.
1784 * At this point we have always match_length < MIN_MATCH
1785 */
1786 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1787 /* To simplify the code, we prevent matches with the string
1788 * of window index 0 (in particular we have to avoid a match
1789 * of the string with itself at the start of the input file).
1790 */
1791 if (s->strategy != Z_HUFFMAN_ONLY) {
1792 s->match_length = longest_match (s, hash_head);
1793 }
1794 /* longest_match() sets match_start */
1795 }
1796 if (s->match_length >= MIN_MATCH) {
1797 check_match(s, s->strstart, s->match_start, s->match_length);
1798
1799 _tr_tally_dist(s, s->strstart - s->match_start,
1800 s->match_length - MIN_MATCH, bflush);
1801
1802 s->lookahead -= s->match_length;
1803
1804 /* Insert new strings in the hash table only if the match length
1805 * is not too large. This saves time but degrades compression.
1806 */
1807 #ifndef FASTEST
1808 if (s->match_length <= s->max_insert_length &&
1809 s->lookahead >= MIN_MATCH) {
1810 s->match_length--; /* string at strstart already in hash table */
1811 do {
1812 s->strstart++;
1813 INSERT_STRING(s, s->strstart, hash_head);
1814 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1815 * always MIN_MATCH bytes ahead.
1816 */
1817 } while (--s->match_length != 0);
1818 s->strstart++;
1819 } else
1820 #endif
1821 {
1822 s->strstart += s->match_length;
1823 s->match_length = 0;
1824 s->ins_h = s->window[s->strstart];
1825 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1826 #if MIN_MATCH != 3
1827 Call UPDATE_HASH() MIN_MATCH-3 more times
1828 #endif
1829 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1830 * matter since it will be recomputed at next deflate call.
1831 */
1832 }
1833 } else {
1834 /* No match, output a literal byte */
1835 Tracevv((stderr,"%c", s->window[s->strstart]));
1836 _tr_tally_lit (s, s->window[s->strstart], bflush);
1837 s->lookahead--;
1838 s->strstart++;
1839 }
1840 if (bflush) FLUSH_BLOCK(s, 0);
1841 }
1842 FLUSH_BLOCK(s, flush == Z_FINISH);
1843 return flush == Z_FINISH ? finish_done : block_done;
1844 }
1845
1846 /* ===========================================================================
1847 * Same as above, but achieves better compression. We use a lazy
1848 * evaluation for matches: a match is finally adopted only if there is
1849 * no better match at the next window position.
1850 */
1851 local block_state deflate_slow(s, flush)
1852 deflate_state *s;
1853 int flush;
1854 {
1855 IPos hash_head = NIL; /* head of hash chain */
1856 int bflush; /* set if current block must be flushed */
1857
1858 /* Process the input block. */
1859 for (;;) {
1860 /* Make sure that we always have enough lookahead, except
1861 * at the end of the input file. We need MAX_MATCH bytes
1862 * for the next match, plus MIN_MATCH bytes to insert the
1863 * string following the next match.
1864 */
1865 if (s->lookahead < MIN_LOOKAHEAD) {
1866 fill_window(s);
1867 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1868 return need_more;
1869 }
1870 if (s->lookahead == 0) break; /* flush the current block */
1871 }
1872
1873 /* Insert the string window[strstart .. strstart+2] in the
1874 * dictionary, and set hash_head to the head of the hash chain:
1875 */
1876 if (s->lookahead >= MIN_MATCH) {
1877 INSERT_STRING(s, s->strstart, hash_head);
1878 }
1879
1880 /* Find the longest match, discarding those <= prev_length.
1881 */
1882 s->prev_length = s->match_length, s->prev_match = s->match_start;
1883 s->match_length = MIN_MATCH-1;
1884
1885 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1886 s->strstart - hash_head <= MAX_DIST(s)) {
1887 /* To simplify the code, we prevent matches with the string
1888 * of window index 0 (in particular we have to avoid a match
1889 * of the string with itself at the start of the input file).
1890 */
1891 if (s->strategy != Z_HUFFMAN_ONLY) {
1892 s->match_length = longest_match (s, hash_head);
1893 }
1894 /* longest_match() sets match_start */
1895
1896 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1897 (s->match_length == MIN_MATCH &&
1898 s->strstart - s->match_start > TOO_FAR))) {
1899
1900 /* If prev_match is also MIN_MATCH, match_start is garbage
1901 * but we will ignore the current match anyway.
1902 */
1903 s->match_length = MIN_MATCH-1;
1904 }
1905 }
1906 /* If there was a match at the previous step and the current
1907 * match is not better, output the previous match:
1908 */
1909 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1910 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1911 /* Do not insert strings in hash table beyond this. */
1912
1913 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1914
1915 _tr_tally_dist(s, s->strstart -1 - s->prev_match,
1916 s->prev_length - MIN_MATCH, bflush);
1917
1918 /* Insert in hash table all strings up to the end of the match.
1919 * strstart-1 and strstart are already inserted. If there is not
1920 * enough lookahead, the last two strings are not inserted in
1921 * the hash table.
1922 */
1923 s->lookahead -= s->prev_length-1;
1924 s->prev_length -= 2;
1925 do {
1926 if (++s->strstart <= max_insert) {
1927 INSERT_STRING(s, s->strstart, hash_head);
1928 }
1929 } while (--s->prev_length != 0);
1930 s->match_available = 0;
1931 s->match_length = MIN_MATCH-1;
1932 s->strstart++;
1933
1934 if (bflush) FLUSH_BLOCK(s, 0);
1935
1936 } else if (s->match_available) {
1937 /* If there was no match at the previous position, output a
1938 * single literal. If there was a match but the current match
1939 * is longer, truncate the previous match to a single literal.
1940 */
1941 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1942 _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1943 if (bflush) {
1944 FLUSH_BLOCK_ONLY(s, 0);
1945 }
1946 s->strstart++;
1947 s->lookahead--;
1948 if (s->strm->avail_out == 0) return need_more;
1949 } else {
1950 /* There is no previous match to compare with, wait for
1951 * the next step to decide.
1952 */
1953 s->match_available = 1;
1954 s->strstart++;
1955 s->lookahead--;
1956 }
1957 }
1958 Assert (flush != Z_NO_FLUSH, "no flush?");
1959 if (s->match_available) {
1960 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1961 _tr_tally_lit(s, s->window[s->strstart-1], bflush);
1962 s->match_available = 0;
1963 }
1964 FLUSH_BLOCK(s, flush == Z_FINISH);
1965 return flush == Z_FINISH ? finish_done : block_done;
1966 }
1967 /* --- deflate.c */
1968
1969 /* +++ trees.c */
1970 /* trees.c -- output deflated data using Huffman coding
1971 * Copyright (C) 1995-2002 Jean-loup Gailly
1972 * For conditions of distribution and use, see copyright notice in zlib.h
1973 */
1974
1975 /*
1976 * ALGORITHM
1977 *
1978 * The "deflation" process uses several Huffman trees. The more
1979 * common source values are represented by shorter bit sequences.
1980 *
1981 * Each code tree is stored in a compressed form which is itself
1982 * a Huffman encoding of the lengths of all the code strings (in
1983 * ascending order by source values). The actual code strings are
1984 * reconstructed from the lengths in the inflate process, as described
1985 * in the deflate specification.
1986 *
1987 * REFERENCES
1988 *
1989 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1990 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1991 *
1992 * Storer, James A.
1993 * Data Compression: Methods and Theory, pp. 49-50.
1994 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1995 *
1996 * Sedgewick, R.
1997 * Algorithms, p290.
1998 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1999 */
2000
2001 /* @(#) $Id: zlib.c,v 1.10 2004/07/29 19:17:20 lindak Exp $ */
2002
2003 /* #define GEN_TREES_H */
2004
2005 /* #include "deflate.h" */
2006
2007 #ifdef DEBUG_ZLIB
2008 # include <ctype.h>
2009 #endif
2010
2011 /* ===========================================================================
2012 * Constants
2013 */
2014
2015 #define MAX_BL_BITS 7
2016 /* Bit length codes must not exceed MAX_BL_BITS bits */
2017
2018 #define END_BLOCK 256
2019 /* end of block literal code */
2020
2021 #define REP_3_6 16
2022 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2023
2024 #define REPZ_3_10 17
2025 /* repeat a zero length 3-10 times (3 bits of repeat count) */
2026
2027 #define REPZ_11_138 18
2028 /* repeat a zero length 11-138 times (7 bits of repeat count) */
2029
2030 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2031 = {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};
2032
2033 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
2034 = {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};
2035
2036 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
2037 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
2038
2039 local const uch bl_order[BL_CODES]
2040 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
2041 /* The lengths of the bit length codes are sent in order of decreasing
2042 * probability, to avoid transmitting the lengths for unused bit length codes.
2043 */
2044
2045 #define Buf_size (8 * 2*sizeof(char))
2046 /* Number of bits used within bi_buf. (bi_buf might be implemented on
2047 * more than 16 bits on some systems.)
2048 */
2049
2050 /* ===========================================================================
2051 * Local data. These are initialized only once.
2052 */
2053
2054 #define DIST_CODE_LEN 512 /* see definition of array dist_code below */
2055
2056 #if defined(GEN_TREES_H) || !defined(STDC)
2057 /* non ANSI compilers may not accept trees.h */
2058
2059 local ct_data *static_ltree = Z_NULL;
2060 /* The static literal tree. Since the bit lengths are imposed, there is no
2061 * need for the L_CODES extra codes used during heap construction. However
2062 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
2063 * below).
2064 */
2065
2066 local ct_data *static_dtree = Z_NULL;
2067 /* The static distance tree. (Actually a trivial tree since all codes use
2068 * 5 bits.)
2069 */
2070
2071 uch *_dist_code = Z_NULL;
2072 /* Distance codes. The first 256 values correspond to the distances
2073 * 3 .. 258, the last 256 values correspond to the top 8 bits of
2074 * the 15 bit distances.
2075 */
2076
2077 uch *_length_code = Z_NULL;
2078 /* length code for each normalized match length (0 == MIN_MATCH) */
2079
2080 local int *base_length = Z_NULL;
2081 /* First normalized length for each code (0 = MIN_MATCH) */
2082
2083 local int *base_dist = Z_NULL;
2084 /* First normalized distance for each code (0 = distance of 1) */
2085
2086 #else
2087 /* +++ trees.h */
2088 /* header created automatically with -DGEN_TREES_H */
2089
2090 local const ct_data static_ltree[L_CODES+2] = {
2091 {{ 12},{ 8}}, {{140},{ 8}}, {{ 76},{ 8}}, {{204},{ 8}}, {{ 44},{ 8}},
2092 {{172},{ 8}}, {{108},{ 8}}, {{236},{ 8}}, {{ 28},{ 8}}, {{156},{ 8}},
2093 {{ 92},{ 8}}, {{220},{ 8}}, {{ 60},{ 8}}, {{188},{ 8}}, {{124},{ 8}},
2094 {{252},{ 8}}, {{ 2},{ 8}}, {{130},{ 8}}, {{ 66},{ 8}}, {{194},{ 8}},
2095 {{ 34},{ 8}}, {{162},{ 8}}, {{ 98},{ 8}}, {{226},{ 8}}, {{ 18},{ 8}},
2096 {{146},{ 8}}, {{ 82},{ 8}}, {{210},{ 8}}, {{ 50},{ 8}}, {{178},{ 8}},
2097 {{114},{ 8}}, {{242},{ 8}}, {{ 10},{ 8}}, {{138},{ 8}}, {{ 74},{ 8}},
2098 {{202},{ 8}}, {{ 42},{ 8}}, {{170},{ 8}}, {{106},{ 8}}, {{234},{ 8}},
2099 {{ 26},{ 8}}, {{154},{ 8}}, {{ 90},{ 8}}, {{218},{ 8}}, {{ 58},{ 8}},
2100 {{186},{ 8}}, {{122},{ 8}}, {{250},{ 8}}, {{ 6},{ 8}}, {{134},{ 8}},
2101 {{ 70},{ 8}}, {{198},{ 8}}, {{ 38},{ 8}}, {{166},{ 8}}, {{102},{ 8}},
2102 {{230},{ 8}}, {{ 22},{ 8}}, {{150},{ 8}}, {{ 86},{ 8}}, {{214},{ 8}},
2103 {{ 54},{ 8}}, {{182},{ 8}}, {{118},{ 8}}, {{246},{ 8}}, {{ 14},{ 8}},
2104 {{142},{ 8}}, {{ 78},{ 8}}, {{206},{ 8}}, {{ 46},{ 8}}, {{174},{ 8}},
2105 {{110},{ 8}}, {{238},{ 8}}, {{ 30},{ 8}}, {{158},{ 8}}, {{ 94},{ 8}},
2106 {{222},{ 8}}, {{ 62},{ 8}}, {{190},{ 8}}, {{126},{ 8}}, {{254},{ 8}},
2107 {{ 1},{ 8}}, {{129},{ 8}}, {{ 65},{ 8}}, {{193},{ 8}}, {{ 33},{ 8}},
2108 {{161},{ 8}}, {{ 97},{ 8}}, {{225},{ 8}}, {{ 17},{ 8}}, {{145},{ 8}},
2109 {{ 81},{ 8}}, {{209},{ 8}}, {{ 49},{ 8}}, {{177},{ 8}}, {{113},{ 8}},
2110 {{241},{ 8}}, {{ 9},{ 8}}, {{137},{ 8}}, {{ 73},{ 8}}, {{201},{ 8}},
2111 {{ 41},{ 8}}, {{169},{ 8}}, {{105},{ 8}}, {{233},{ 8}}, {{ 25},{ 8}},
2112 {{153},{ 8}}, {{ 89},{ 8}}, {{217},{ 8}}, {{ 57},{ 8}}, {{185},{ 8}},
2113 {{121},{ 8}}, {{249},{ 8}}, {{ 5},{ 8}}, {{133},{ 8}}, {{ 69},{ 8}},
2114 {{197},{ 8}}, {{ 37},{ 8}}, {{165},{ 8}}, {{101},{ 8}}, {{229},{ 8}},
2115 {{ 21},{ 8}}, {{149},{ 8}}, {{ 85},{ 8}}, {{213},{ 8}}, {{ 53},{ 8}},
2116 {{181},{ 8}}, {{117},{ 8}}, {{245},{ 8}}, {{ 13},{ 8}}, {{141},{ 8}},
2117 {{ 77},{ 8}}, {{205},{ 8}}, {{ 45},{ 8}}, {{173},{ 8}}, {{109},{ 8}},
2118 {{237},{ 8}}, {{ 29},{ 8}}, {{157},{ 8}}, {{ 93},{ 8}}, {{221},{ 8}},
2119 {{ 61},{ 8}}, {{189},{ 8}}, {{125},{ 8}}, {{253},{ 8}}, {{ 19},{ 9}},
2120 {{275},{ 9}}, {{147},{ 9}}, {{403},{ 9}}, {{ 83},{ 9}}, {{339},{ 9}},
2121 {{211},{ 9}}, {{467},{ 9}}, {{ 51},{ 9}}, {{307},{ 9}}, {{179},{ 9}},
2122 {{435},{ 9}}, {{115},{ 9}}, {{371},{ 9}}, {{243},{ 9}}, {{499},{ 9}},
2123 {{ 11},{ 9}}, {{267},{ 9}}, {{139},{ 9}}, {{395},{ 9}}, {{ 75},{ 9}},
2124 {{331},{ 9}}, {{203},{ 9}}, {{459},{ 9}}, {{ 43},{ 9}}, {{299},{ 9}},
2125 {{171},{ 9}}, {{427},{ 9}}, {{107},{ 9}}, {{363},{ 9}}, {{235},{ 9}},
2126 {{491},{ 9}}, {{ 27},{ 9}}, {{283},{ 9}}, {{155},{ 9}}, {{411},{ 9}},
2127 {{ 91},{ 9}}, {{347},{ 9}}, {{219},{ 9}}, {{475},{ 9}}, {{ 59},{ 9}},
2128 {{315},{ 9}}, {{187},{ 9}}, {{443},{ 9}}, {{123},{ 9}}, {{379},{ 9}},
2129 {{251},{ 9}}, {{507},{ 9}}, {{ 7},{ 9}}, {{263},{ 9}}, {{135},{ 9}},
2130 {{391},{ 9}}, {{ 71},{ 9}}, {{327},{ 9}}, {{199},{ 9}}, {{455},{ 9}},
2131 {{ 39},{ 9}}, {{295},{ 9}}, {{167},{ 9}}, {{423},{ 9}}, {{103},{ 9}},
2132 {{359},{ 9}}, {{231},{ 9}}, {{487},{ 9}}, {{ 23},{ 9}}, {{279},{ 9}},
2133 {{151},{ 9}}, {{407},{ 9}}, {{ 87},{ 9}}, {{343},{ 9}}, {{215},{ 9}},
2134 {{471},{ 9}}, {{ 55},{ 9}}, {{311},{ 9}}, {{183},{ 9}}, {{439},{ 9}},
2135 {{119},{ 9}}, {{375},{ 9}}, {{247},{ 9}}, {{503},{ 9}}, {{ 15},{ 9}},
2136 {{271},{ 9}}, {{143},{ 9}}, {{399},{ 9}}, {{ 79},{ 9}}, {{335},{ 9}},
2137 {{207},{ 9}}, {{463},{ 9}}, {{ 47},{ 9}}, {{303},{ 9}}, {{175},{ 9}},
2138 {{431},{ 9}}, {{111},{ 9}}, {{367},{ 9}}, {{239},{ 9}}, {{495},{ 9}},
2139 {{ 31},{ 9}}, {{287},{ 9}}, {{159},{ 9}}, {{415},{ 9}}, {{ 95},{ 9}},
2140 {{351},{ 9}}, {{223},{ 9}}, {{479},{ 9}}, {{ 63},{ 9}}, {{319},{ 9}},
2141 {{191},{ 9}}, {{447},{ 9}}, {{127},{ 9}}, {{383},{ 9}}, {{255},{ 9}},
2142 {{511},{ 9}}, {{ 0},{ 7}}, {{ 64},{ 7}}, {{ 32},{ 7}}, {{ 96},{ 7}},
2143 {{ 16},{ 7}}, {{ 80},{ 7}}, {{ 48},{ 7}}, {{112},{ 7}}, {{ 8},{ 7}},
2144 {{ 72},{ 7}}, {{ 40},{ 7}}, {{104},{ 7}}, {{ 24},{ 7}}, {{ 88},{ 7}},
2145 {{ 56},{ 7}}, {{120},{ 7}}, {{ 4},{ 7}}, {{ 68},{ 7}}, {{ 36},{ 7}},
2146 {{100},{ 7}}, {{ 20},{ 7}}, {{ 84},{ 7}}, {{ 52},{ 7}}, {{116},{ 7}},
2147 {{ 3},{ 8}}, {{131},{ 8}}, {{ 67},{ 8}}, {{195},{ 8}}, {{ 35},{ 8}},
2148 {{163},{ 8}}, {{ 99},{ 8}}, {{227},{ 8}}
2149 };
2150
2151 local const ct_data static_dtree[D_CODES] = {
2152 {{ 0},{ 5}}, {{16},{ 5}}, {{ 8},{ 5}}, {{24},{ 5}}, {{ 4},{ 5}},
2153 {{20},{ 5}}, {{12},{ 5}}, {{28},{ 5}}, {{ 2},{ 5}}, {{18},{ 5}},
2154 {{10},{ 5}}, {{26},{ 5}}, {{ 6},{ 5}}, {{22},{ 5}}, {{14},{ 5}},
2155 {{30},{ 5}}, {{ 1},{ 5}}, {{17},{ 5}}, {{ 9},{ 5}}, {{25},{ 5}},
2156 {{ 5},{ 5}}, {{21},{ 5}}, {{13},{ 5}}, {{29},{ 5}}, {{ 3},{ 5}},
2157 {{19},{ 5}}, {{11},{ 5}}, {{27},{ 5}}, {{ 7},{ 5}}, {{23},{ 5}}
2158 };
2159
2160 const uch _dist_code[DIST_CODE_LEN] = {
2161 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8,
2162 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10,
2163 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
2164 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
2165 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
2166 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
2167 13, 13, 13, 13, 13, 13, 13, 13, 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, 14, 14, 14, 14, 14, 14, 14, 14,
2170 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 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, 15, 15, 15, 15,
2173 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0, 0, 16, 17,
2174 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22,
2175 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2176 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2177 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2178 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
2179 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2180 27, 27, 27, 27, 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, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
2183 28, 28, 28, 28, 28, 28, 28, 28, 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, 29, 29, 29, 29, 29, 29, 29, 29,
2186 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29
2187 };
2188
2189 const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {
2190 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
2191 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
2192 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
2193 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
2194 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
2195 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
2196 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2197 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
2198 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
2199 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
2200 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
2201 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
2202 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28
2203 };
2204
2205 local const int base_length[LENGTH_CODES] = {
2206 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
2207 64, 80, 96, 112, 128, 160, 192, 224, 0
2208 };
2209
2210 local const int base_dist[D_CODES] = {
2211 0, 1, 2, 3, 4, 6, 8, 12, 16, 24,
2212 32, 48, 64, 96, 128, 192, 256, 384, 512, 768,
2213 1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576
2214 };
2215
2216 /* --- trees.h */
2217 #endif /* GEN_TREES_H */
2218
2219 struct static_tree_desc_s {
2220 const ct_data *static_tree; /* static tree or NULL */
2221 const intf *extra_bits; /* extra bits for each code or NULL */
2222 int extra_base; /* base index for extra_bits */
2223 int elems; /* max number of elements in the tree */
2224 int max_length; /* max bit length for the codes */
2225 };
2226
2227 local static_tree_desc static_l_desc =
2228 {NULL, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
2229
2230 local static_tree_desc static_d_desc =
2231 {NULL, extra_dbits, 0, D_CODES, MAX_BITS};
2232
2233 local static_tree_desc static_bl_desc =
2234 {(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
2235
2236 /* ===========================================================================
2237 * Local (static) routines in this file.
2238 */
2239
2240 local int tr_static_init OF((z_streamp z));
2241 local void init_block OF((deflate_state *s));
2242 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
2243 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
2244 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
2245 local void build_tree OF((deflate_state *s, tree_desc *desc));
2246 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
2247 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
2248 local int build_bl_tree OF((deflate_state *s));
2249 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
2250 int blcodes));
2251 local void compress_block OF((deflate_state *s, ct_data *ltree,
2252 ct_data *dtree));
2253 local void set_data_type OF((deflate_state *s));
2254 local unsigned bi_reverse OF((unsigned value, int length));
2255 local void bi_windup OF((deflate_state *s));
2256 local void bi_flush OF((deflate_state *s));
2257 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
2258 int header));
2259
2260 #ifdef GEN_TREES_H
2261 local void gen_trees_header OF((void));
2262 #endif
2263
2264 #ifndef DEBUG_ZLIB
2265 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
2266 /* Send a code of the given tree. c and tree must not have side effects */
2267
2268 #else /* DEBUG_ZLIB */
2269 # define send_code(s, c, tree) \
2270 { if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
2271 send_bits(s, tree[c].Code, tree[c].Len); }
2272 #endif
2273
2274 /* ===========================================================================
2275 * Output a short LSB first on the stream.
2276 * IN assertion: there is enough room in pendingBuf.
2277 */
2278 #define put_short(s, w) { \
2279 put_byte(s, (uch)((w) & 0xff)); \
2280 put_byte(s, (uch)((ush)(w) >> 8)); \
2281 }
2282
2283 /* ===========================================================================
2284 * Send a value on a given number of bits.
2285 * IN assertion: length <= 16 and value fits in length bits.
2286 */
2287 #ifdef DEBUG_ZLIB
2288 local void send_bits OF((deflate_state *s, int value, int length));
2289
2290 local void send_bits(s, value, length)
2291 deflate_state *s;
2292 int value; /* value to send */
2293 int length; /* number of bits */
2294 {
2295 Tracevv((stderr," l %2d v %4x ", length, value));
2296 Assert(length > 0 && length <= 15, "invalid length");
2297 s->bits_sent += (ulg)length;
2298
2299 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2300 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2301 * unused bits in value.
2302 */
2303 if (s->bi_valid > (int)Buf_size - length) {
2304 s->bi_buf |= (value << s->bi_valid);
2305 put_short(s, s->bi_buf);
2306 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2307 s->bi_valid += length - Buf_size;
2308 } else {
2309 s->bi_buf |= value << s->bi_valid;
2310 s->bi_valid += length;
2311 }
2312 }
2313 #else /* !DEBUG_ZLIB */
2314
2315 #define send_bits(s, value, length) \
2316 { int len = length;\
2317 if (s->bi_valid > (int)Buf_size - len) {\
2318 int val = value;\
2319 s->bi_buf |= (val << s->bi_valid);\
2320 put_short(s, s->bi_buf);\
2321 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
2322 s->bi_valid += len - Buf_size;\
2323 } else {\
2324 s->bi_buf |= (value) << s->bi_valid;\
2325 s->bi_valid += len;\
2326 }\
2327 }
2328 #endif /* DEBUG_ZLIB */
2329
2330
2331 #ifndef MAX
2332 #define MAX(a,b) (a >= b ? a : b)
2333 #endif
2334 /* the arguments must not have side effects */
2335
2336 typedef struct {
2337 ct_data static_ltree[L_CODES+2];
2338 ct_data static_dtree[D_CODES];
2339 uch _dist_code[DIST_CODE_LEN];
2340 uch _length_code[MAX_MATCH-MIN_MATCH+1];
2341 int base_length[LENGTH_CODES];
2342 int base_dist[D_CODES];
2343 } __used_to_be_static;
2344
2345 static __used_to_be_static *static_storage = Z_NULL;
2346
2347 /* ===========================================================================
2348 * Initialize the various 'constant' tables.
2349 */
2350 local int tr_static_init(
2351 z_streamp z)
2352 {
2353 #if defined(GEN_TREES_H) || !defined(STDC)
2354 static int static_init_done = 0;
2355 int n; /* iterates over tree elements */
2356 int bits; /* bit counter */
2357 int length; /* length value */
2358 int code; /* code value */
2359 int dist; /* distance index */
2360 ush bl_count[MAX_BITS+1];
2361 /* number of codes at each bit length for an optimal tree */
2362
2363 if (static_init_done) return Z_OK;
2364
2365 /* allocate storage for static structures */
2366 if (static_storage == Z_NULL) {
2367 static_storage = (__used_to_be_static*)ZALLOC(z, 1, sizeof(__used_to_be_static));
2368 if (static_storage == Z_NULL)
2369 return Z_MEM_ERROR;
2370 }
2371
2372 static_ltree = static_storage->static_ltree;
2373 static_dtree = static_storage->static_dtree;
2374 _dist_code = static_storage->_dist_code;
2375 _length_code = static_storage->_length_code;
2376 base_length = static_storage->base_length;
2377 base_dist = static_storage->base_dist;
2378
2379 /* For some embedded targets, global variables are not initialized: */
2380 static_l_desc.static_tree = static_ltree;
2381 static_l_desc.extra_bits = extra_lbits;
2382 static_d_desc.static_tree = static_dtree;
2383 static_d_desc.extra_bits = extra_dbits;
2384 static_bl_desc.extra_bits = extra_blbits;
2385
2386 /* Initialize the mapping length (0..255) -> length code (0..28) */
2387 length = 0;
2388 for (code = 0; code < LENGTH_CODES-1; code++) {
2389 base_length[code] = length;
2390 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2391 _length_code[length++] = (uch)code;
2392 }
2393 }
2394 Assert (length == 256, "tr_static_init: length != 256");
2395 /* Note that the length 255 (match length 258) can be represented
2396 * in two different ways: code 284 + 5 bits or code 285, so we
2397 * overwrite length_code[255] to use the best encoding:
2398 */
2399 _length_code[length-1] = (uch)code;
2400
2401 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2402 dist = 0;
2403 for (code = 0 ; code < 16; code++) {
2404 base_dist[code] = dist;
2405 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2406 _dist_code[dist++] = (uch)code;
2407 }
2408 }
2409 Assert (dist == 256, "tr_static_init: dist != 256");
2410 dist >>= 7; /* from now on, all distances are divided by 128 */
2411 for ( ; code < D_CODES; code++) {
2412 base_dist[code] = dist << 7;
2413 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2414 _dist_code[256 + dist++] = (uch)code;
2415 }
2416 }
2417 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2418
2419 /* Construct the codes of the static literal tree */
2420 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2421 n = 0;
2422 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2423 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2424 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2425 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2426 /* Codes 286 and 287 do not exist, but we must include them in the
2427 * tree construction to get a canonical Huffman tree (longest code
2428 * all ones)
2429 */
2430 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2431
2432 /* The static distance tree is trivial: */
2433 for (n = 0; n < D_CODES; n++) {
2434 static_dtree[n].Len = 5;
2435 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2436 }
2437 static_init_done = 1;
2438
2439 # ifdef GEN_TREES_H
2440 gen_trees_header();
2441 # endif
2442 #endif /* defined(GEN_TREES_H) || !defined(STDC) */
2443 return Z_OK;
2444 }
2445
2446 /* ===========================================================================
2447 * Genererate the file trees.h describing the static trees.
2448 */
2449 #ifdef GEN_TREES_H
2450 # ifndef DEBUG_ZLIB
2451 # include <stdio.h>
2452 # endif
2453
2454 # define SEPARATOR(i, last, width) \
2455 ((i) == (last)? "\n};\n\n" : \
2456 ((i) % (width) == (width)-1 ? ",\n" : ", "))
2457
2458 void gen_trees_header()
2459 {
2460 FILE *header = fopen("trees.h", "w");
2461 int i;
2462
2463 Assert (header != NULL, "Can't open trees.h");
2464 fprintf(header,
2465 "/* header created automatically with -DGEN_TREES_H */\n\n");
2466
2467 fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
2468 for (i = 0; i < L_CODES+2; i++) {
2469 fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
2470 static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
2471 }
2472
2473 fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
2474 for (i = 0; i < D_CODES; i++) {
2475 fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
2476 static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
2477 }
2478
2479 fprintf(header, "const uch _dist_code[DIST_CODE_LEN] = {\n");
2480 for (i = 0; i < DIST_CODE_LEN; i++) {
2481 fprintf(header, "%2u%s", _dist_code[i],
2482 SEPARATOR(i, DIST_CODE_LEN-1, 20));
2483 }
2484
2485 fprintf(header, "const uch _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
2486 for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
2487 fprintf(header, "%2u%s", _length_code[i],
2488 SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
2489 }
2490
2491 fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
2492 for (i = 0; i < LENGTH_CODES; i++) {
2493 fprintf(header, "%1u%s", base_length[i],
2494 SEPARATOR(i, LENGTH_CODES-1, 20));
2495 }
2496
2497 fprintf(header, "local const int base_dist[D_CODES] = {\n");
2498 for (i = 0; i < D_CODES; i++) {
2499 fprintf(header, "%5u%s", base_dist[i],
2500 SEPARATOR(i, D_CODES-1, 10));
2501 }
2502
2503 fclose(header);
2504 }
2505 #endif /* GEN_TREES_H */
2506
2507 /* ===========================================================================
2508 * Initialize the tree data structures for a new zlib stream.
2509 */
2510 void _tr_init(s)
2511 deflate_state *s;
2512 {
2513 tr_static_init(s->strm);
2514
2515 s->l_desc.dyn_tree = s->dyn_ltree;
2516 s->l_desc.stat_desc = &static_l_desc;
2517
2518 s->d_desc.dyn_tree = s->dyn_dtree;
2519 s->d_desc.stat_desc = &static_d_desc;
2520
2521 s->bl_desc.dyn_tree = s->bl_tree;
2522 s->bl_desc.stat_desc = &static_bl_desc;
2523
2524 s->bi_buf = 0;
2525 s->bi_valid = 0;
2526 s->last_eob_len = 8; /* enough lookahead for inflate */
2527 #ifdef DEBUG_ZLIB
2528 s->compressed_len = 0L;
2529 s->bits_sent = 0L;
2530 #endif
2531
2532 /* Initialize the first block of the first file: */
2533 init_block(s);
2534 }
2535
2536 /* ===========================================================================
2537 * Initialize a new block.
2538 */
2539 local void init_block(s)
2540 deflate_state *s;
2541 {
2542 int n; /* iterates over tree elements */
2543
2544 /* Initialize the trees. */
2545 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2546 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2547 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2548
2549 s->dyn_ltree[END_BLOCK].Freq = 1;
2550 s->opt_len = s->static_len = 0L;
2551 s->last_lit = s->matches = 0;
2552 }
2553
2554 #define SMALLEST 1
2555 /* Index within the heap array of least frequent node in the Huffman tree */
2556
2557
2558 /* ===========================================================================
2559 * Remove the smallest element from the heap and recreate the heap with
2560 * one less element. Updates heap and heap_len.
2561 */
2562 #define pqremove(s, tree, top) \
2563 {\
2564 top = s->heap[SMALLEST]; \
2565 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2566 pqdownheap(s, tree, SMALLEST); \
2567 }
2568
2569 /* ===========================================================================
2570 * Compares to subtrees, using the tree depth as tie breaker when
2571 * the subtrees have equal frequency. This minimizes the worst case length.
2572 */
2573 #define smaller(tree, n, m, depth) \
2574 (tree[n].Freq < tree[m].Freq || \
2575 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2576
2577 /* ===========================================================================
2578 * Restore the heap property by moving down the tree starting at node k,
2579 * exchanging a node with the smallest of its two sons if necessary, stopping
2580 * when the heap property is re-established (each father smaller than its
2581 * two sons).
2582 */
2583 local void pqdownheap(s, tree, k)
2584 deflate_state *s;
2585 ct_data *tree; /* the tree to restore */
2586 int k; /* node to move down */
2587 {
2588 int v = s->heap[k];
2589 int j = k << 1; /* left son of k */
2590 while (j <= s->heap_len) {
2591 /* Set j to the smallest of the two sons: */
2592 if (j < s->heap_len &&
2593 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2594 j++;
2595 }
2596 /* Exit if v is smaller than both sons */
2597 if (smaller(tree, v, s->heap[j], s->depth)) break;
2598
2599 /* Exchange v with the smallest son */
2600 s->heap[k] = s->heap[j]; k = j;
2601
2602 /* And continue down the tree, setting j to the left son of k */
2603 j <<= 1;
2604 }
2605 s->heap[k] = v;
2606 }
2607
2608 /* ===========================================================================
2609 * Compute the optimal bit lengths for a tree and update the total bit length
2610 * for the current block.
2611 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2612 * above are the tree nodes sorted by increasing frequency.
2613 * OUT assertions: the field len is set to the optimal bit length, the
2614 * array bl_count contains the frequencies for each bit length.
2615 * The length opt_len is updated; static_len is also updated if stree is
2616 * not null.
2617 */
2618 local void gen_bitlen(s, desc)
2619 deflate_state *s;
2620 tree_desc *desc; /* the tree descriptor */
2621 {
2622 ct_data *tree = desc->dyn_tree;
2623 int max_code = desc->max_code;
2624 const ct_data *stree = desc->stat_desc->static_tree;
2625 const intf *extra = desc->stat_desc->extra_bits;
2626 int base = desc->stat_desc->extra_base;
2627 int max_length = desc->stat_desc->max_length;
2628 int h; /* heap index */
2629 int n, m; /* iterate over the tree elements */
2630 int bits; /* bit length */
2631 int xbits; /* extra bits */
2632 ush f; /* frequency */
2633 int overflow = 0; /* number of elements with bit length too large */
2634
2635 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2636
2637 /* In a first pass, compute the optimal bit lengths (which may
2638 * overflow in the case of the bit length tree).
2639 */
2640 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2641
2642 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2643 n = s->heap[h];
2644 bits = tree[tree[n].Dad].Len + 1;
2645 if (bits > max_length) bits = max_length, overflow++;
2646 tree[n].Len = (ush)bits;
2647 /* We overwrite tree[n].Dad which is no longer needed */
2648
2649 if (n > max_code) continue; /* not a leaf node */
2650
2651 s->bl_count[bits]++;
2652 xbits = 0;
2653 if (n >= base) xbits = extra[n-base];
2654 f = tree[n].Freq;
2655 s->opt_len += (ulg)f * (bits + xbits);
2656 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2657 }
2658 if (overflow == 0) return;
2659
2660 Trace((stderr,"\nbit length overflow\n"));
2661 /* This happens for example on obj2 and pic of the Calgary corpus */
2662
2663 /* Find the first bit length which could increase: */
2664 do {
2665 bits = max_length-1;
2666 while (s->bl_count[bits] == 0) bits--;
2667 s->bl_count[bits]--; /* move one leaf down the tree */
2668 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2669 s->bl_count[max_length]--;
2670 /* The brother of the overflow item also moves one step up,
2671 * but this does not affect bl_count[max_length]
2672 */
2673 overflow -= 2;
2674 } while (overflow > 0);
2675
2676 /* Now recompute all bit lengths, scanning in increasing frequency.
2677 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2678 * lengths instead of fixing only the wrong ones. This idea is taken
2679 * from 'ar' written by Haruhiko Okumura.)
2680 */
2681 for (bits = max_length; bits != 0; bits--) {
2682 n = s->bl_count[bits];
2683 while (n != 0) {
2684 m = s->heap[--h];
2685 if (m > max_code) continue;
2686 if (tree[m].Len != (unsigned) bits) {
2687 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2688 s->opt_len += ((long)bits - (long)tree[m].Len)
2689 *(long)tree[m].Freq;
2690 tree[m].Len = (ush)bits;
2691 }
2692 n--;
2693 }
2694 }
2695 }
2696
2697 /* ===========================================================================
2698 * Generate the codes for a given tree and bit counts (which need not be
2699 * optimal).
2700 * IN assertion: the array bl_count contains the bit length statistics for
2701 * the given tree and the field len is set for all tree elements.
2702 * OUT assertion: the field code is set for all tree elements of non
2703 * zero code length.
2704 */
2705 local void gen_codes (tree, max_code, bl_count)
2706 ct_data *tree; /* the tree to decorate */
2707 int max_code; /* largest code with non zero frequency */
2708 ushf *bl_count; /* number of codes at each bit length */
2709 {
2710 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2711 ush code = 0; /* running code value */
2712 int bits; /* bit index */
2713 int n; /* code index */
2714
2715 /* The distribution counts are first used to generate the code values
2716 * without bit reversal.
2717 */
2718 for (bits = 1; bits <= MAX_BITS; bits++) {
2719 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2720 }
2721 /* Check that the bit counts in bl_count are consistent. The last code
2722 * must be all ones.
2723 */
2724 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2725 "inconsistent bit counts");
2726 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2727
2728 for (n = 0; n <= max_code; n++) {
2729 int len = tree[n].Len;
2730 if (len == 0) continue;
2731 /* Now reverse the bits */
2732 tree[n].Code = bi_reverse(next_code[len]++, len);
2733
2734 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2735 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2736 }
2737 }
2738
2739 /* ===========================================================================
2740 * Construct one Huffman tree and assigns the code bit strings and lengths.
2741 * Update the total bit length for the current block.
2742 * IN assertion: the field freq is set for all tree elements.
2743 * OUT assertions: the fields len and code are set to the optimal bit length
2744 * and corresponding code. The length opt_len is updated; static_len is
2745 * also updated if stree is not null. The field max_code is set.
2746 */
2747 local void build_tree(s, desc)
2748 deflate_state *s;
2749 tree_desc *desc; /* the tree descriptor */
2750 {
2751 ct_data *tree = desc->dyn_tree;
2752 const ct_data *stree = desc->stat_desc->static_tree;
2753 int elems = desc->stat_desc->elems;
2754 int n, m; /* iterate over heap elements */
2755 int max_code = -1; /* largest code with non zero frequency */
2756 int node; /* new node being created */
2757
2758 /* Construct the initial heap, with least frequent element in
2759 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2760 * heap[0] is not used.
2761 */
2762 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2763
2764 for (n = 0; n < elems; n++) {
2765 if (tree[n].Freq != 0) {
2766 s->heap[++(s->heap_len)] = max_code = n;
2767 s->depth[n] = 0;
2768 } else {
2769 tree[n].Len = 0;
2770 }
2771 }
2772
2773 /* The pkzip format requires that at least one distance code exists,
2774 * and that at least one bit should be sent even if there is only one
2775 * possible code. So to avoid special checks later on we force at least
2776 * two codes of non zero frequency.
2777 */
2778 while (s->heap_len < 2) {
2779 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2780 tree[node].Freq = 1;
2781 s->depth[node] = 0;
2782 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2783 /* node is 0 or 1 so it does not have extra bits */
2784 }
2785 desc->max_code = max_code;
2786
2787 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2788 * establish sub-heaps of increasing lengths:
2789 */
2790 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2791
2792 /* Construct the Huffman tree by repeatedly combining the least two
2793 * frequent nodes.
2794 */
2795 node = elems; /* next internal node of the tree */
2796 do {
2797 pqremove(s, tree, n); /* n = node of least frequency */
2798 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2799
2800 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2801 s->heap[--(s->heap_max)] = m;
2802
2803 /* Create a new node father of n and m */
2804 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2805 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2806 tree[n].Dad = tree[m].Dad = (ush)node;
2807 #ifdef DUMP_BL_TREE
2808 if (tree == s->bl_tree) {
2809 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2810 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2811 }
2812 #endif
2813 /* and insert the new node in the heap */
2814 s->heap[SMALLEST] = node++;
2815 pqdownheap(s, tree, SMALLEST);
2816
2817 } while (s->heap_len >= 2);
2818
2819 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2820
2821 /* At this point, the fields freq and dad are set. We can now
2822 * generate the bit lengths.
2823 */
2824 gen_bitlen(s, (tree_desc *)desc);
2825
2826 /* The field len is now set, we can generate the bit codes */
2827 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2828 }
2829
2830 /* ===========================================================================
2831 * Scan a literal or distance tree to determine the frequencies of the codes
2832 * in the bit length tree.
2833 */
2834 local void scan_tree (s, tree, max_code)
2835 deflate_state *s;
2836 ct_data *tree; /* the tree to be scanned */
2837 int max_code; /* and its largest code of non zero frequency */
2838 {
2839 int n; /* iterates over all tree elements */
2840 int prevlen = -1; /* last emitted length */
2841 int curlen; /* length of current code */
2842 int nextlen = tree[0].Len; /* length of next code */
2843 int count = 0; /* repeat count of the current code */
2844 int max_count = 7; /* max repeat count */
2845 int min_count = 4; /* min repeat count */
2846
2847 if (nextlen == 0) max_count = 138, min_count = 3;
2848 tree[max_code+1].Len = (ush)0xffff; /* guard */
2849
2850 for (n = 0; n <= max_code; n++) {
2851 curlen = nextlen; nextlen = tree[n+1].Len;
2852 if (++count < max_count && curlen == nextlen) {
2853 continue;
2854 } else if (count < min_count) {
2855 s->bl_tree[curlen].Freq += count;
2856 } else if (curlen != 0) {
2857 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2858 s->bl_tree[REP_3_6].Freq++;
2859 } else if (count <= 10) {
2860 s->bl_tree[REPZ_3_10].Freq++;
2861 } else {
2862 s->bl_tree[REPZ_11_138].Freq++;
2863 }
2864 count = 0; prevlen = curlen;
2865 if (nextlen == 0) {
2866 max_count = 138, min_count = 3;
2867 } else if (curlen == nextlen) {
2868 max_count = 6, min_count = 3;
2869 } else {
2870 max_count = 7, min_count = 4;
2871 }
2872 }
2873 }
2874
2875 /* ===========================================================================
2876 * Send a literal or distance tree in compressed form, using the codes in
2877 * bl_tree.
2878 */
2879 local void send_tree (s, tree, max_code)
2880 deflate_state *s;
2881 ct_data *tree; /* the tree to be scanned */
2882 int max_code; /* and its largest code of non zero frequency */
2883 {
2884 int n; /* iterates over all tree elements */
2885 int prevlen = -1; /* last emitted length */
2886 int curlen; /* length of current code */
2887 int nextlen = tree[0].Len; /* length of next code */
2888 int count = 0; /* repeat count of the current code */
2889 int max_count = 7; /* max repeat count */
2890 int min_count = 4; /* min repeat count */
2891
2892 /* tree[max_code+1].Len = -1; */ /* guard already set */
2893 if (nextlen == 0) max_count = 138, min_count = 3;
2894
2895 for (n = 0; n <= max_code; n++) {
2896 curlen = nextlen; nextlen = tree[n+1].Len;
2897 if (++count < max_count && curlen == nextlen) {
2898 continue;
2899 } else if (count < min_count) {
2900 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2901
2902 } else if (curlen != 0) {
2903 if (curlen != prevlen) {
2904 send_code(s, curlen, s->bl_tree); count--;
2905 }
2906 Assert(count >= 3 && count <= 6, " 3_6?");
2907 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2908
2909 } else if (count <= 10) {
2910 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2911
2912 } else {
2913 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2914 }
2915 count = 0; prevlen = curlen;
2916 if (nextlen == 0) {
2917 max_count = 138, min_count = 3;
2918 } else if (curlen == nextlen) {
2919 max_count = 6, min_count = 3;
2920 } else {
2921 max_count = 7, min_count = 4;
2922 }
2923 }
2924 }
2925
2926 /* ===========================================================================
2927 * Construct the Huffman tree for the bit lengths and return the index in
2928 * bl_order of the last bit length code to send.
2929 */
2930 local int build_bl_tree(s)
2931 deflate_state *s;
2932 {
2933 int max_blindex; /* index of last bit length code of non zero freq */
2934
2935 /* Determine the bit length frequencies for literal and distance trees */
2936 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2937 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2938
2939 /* Build the bit length tree: */
2940 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2941 /* opt_len now includes the length of the tree representations, except
2942 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2943 */
2944
2945 /* Determine the number of bit length codes to send. The pkzip format
2946 * requires that at least 4 bit length codes be sent. (appnote.txt says
2947 * 3 but the actual value used is 4.)
2948 */
2949 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2950 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2951 }
2952 /* Update opt_len to include the bit length tree and counts */
2953 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2954 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2955 s->opt_len, s->static_len));
2956
2957 return max_blindex;
2958 }
2959
2960 /* ===========================================================================
2961 * Send the header for a block using dynamic Huffman trees: the counts, the
2962 * lengths of the bit length codes, the literal tree and the distance tree.
2963 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2964 */
2965 local void send_all_trees(s, lcodes, dcodes, blcodes)
2966 deflate_state *s;
2967 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2968 {
2969 int rank; /* index in bl_order */
2970
2971 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2972 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2973 "too many codes");
2974 Tracev((stderr, "\nbl counts: "));
2975 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2976 send_bits(s, dcodes-1, 5);
2977 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2978 for (rank = 0; rank < blcodes; rank++) {
2979 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2980 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2981 }
2982 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2983
2984 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2985 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2986
2987 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2988 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2989 }
2990
2991 /* ===========================================================================
2992 * Send a stored block
2993 */
2994 void _tr_stored_block(s, buf, stored_len, eof)
2995 deflate_state *s;
2996 charf *buf; /* input block */
2997 ulg stored_len; /* length of input block */
2998 int eof; /* true if this is the last block for a file */
2999 {
3000 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
3001 #ifdef DEBUG_ZLIB
3002 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
3003 s->compressed_len += (stored_len + 4) << 3;
3004 #endif
3005 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
3006 }
3007
3008 /* ===========================================================================
3009 * Send one empty static block to give enough lookahead for inflate.
3010 * This takes 10 bits, of which 7 may remain in the bit buffer.
3011 * The current inflate code requires 9 bits of lookahead. If the
3012 * last two codes for the previous block (real code plus EOB) were coded
3013 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
3014 * the last real code. In this case we send two empty static blocks instead
3015 * of one. (There are no problems if the previous block is stored or fixed.)
3016 * To simplify the code, we assume the worst case of last real code encoded
3017 * on one bit only.
3018 */
3019 void _tr_align(s)
3020 deflate_state *s;
3021 {
3022 send_bits(s, STATIC_TREES<<1, 3);
3023 send_code(s, END_BLOCK, static_ltree);
3024 #ifdef DEBUG_ZLIB
3025 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
3026 #endif
3027 bi_flush(s);
3028 /* Of the 10 bits for the empty block, we have already sent
3029 * (10 - bi_valid) bits. The lookahead for the last real code (before
3030 * the EOB of the previous block) was thus at least one plus the length
3031 * of the EOB plus what we have just sent of the empty static block.
3032 */
3033 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
3034 send_bits(s, STATIC_TREES<<1, 3);
3035 send_code(s, END_BLOCK, static_ltree);
3036 #ifdef DEBUG_ZLIB
3037 s->compressed_len += 10L;
3038 #endif
3039 bi_flush(s);
3040 }
3041 s->last_eob_len = 7;
3042 }
3043
3044 /* ===========================================================================
3045 * Determine the best encoding for the current block: dynamic trees, static
3046 * trees or store, and output the encoded block to the zip file.
3047 */
3048 void _tr_flush_block(s, buf, stored_len, eof)
3049 deflate_state *s;
3050 charf *buf; /* input block, or NULL if too old */
3051 ulg stored_len; /* length of input block */
3052 int eof; /* true if this is the last block for a file */
3053 {
3054 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
3055 int max_blindex = 0; /* index of last bit length code of non zero freq */
3056
3057 /* Build the Huffman trees unless a stored block is forced */
3058 if (s->level > 0) {
3059
3060 /* Check if the file is ascii or binary */
3061 if (s->data_type == Z_UNKNOWN) set_data_type(s);
3062
3063 /* Construct the literal and distance trees */
3064 build_tree(s, (tree_desc *)(&(s->l_desc)));
3065 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
3066 s->static_len));
3067
3068 build_tree(s, (tree_desc *)(&(s->d_desc)));
3069 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
3070 s->static_len));
3071 /* At this point, opt_len and static_len are the total bit lengths of
3072 * the compressed block data, excluding the tree representations.
3073 */
3074
3075 /* Build the bit length tree for the above two trees, and get the index
3076 * in bl_order of the last bit length code to send.
3077 */
3078 max_blindex = build_bl_tree(s);
3079
3080 /* Determine the best encoding. Compute first the block length in bytes*/
3081 opt_lenb = (s->opt_len+3+7)>>3;
3082 static_lenb = (s->static_len+3+7)>>3;
3083
3084 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
3085 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
3086 s->last_lit));
3087
3088 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
3089
3090 } else {
3091 Assert(buf != (char*)0, "lost buf");
3092 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
3093 }
3094
3095 #ifdef FORCE_STORED
3096 if (buf != (char*)0) { /* force stored block */
3097 #else
3098 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
3099 /* 4: two words for the lengths */
3100 #endif
3101 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
3102 * Otherwise we can't have processed more than WSIZE input bytes since
3103 * the last block flush, because compression would have been
3104 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
3105 * transform a block into a stored block.
3106 */
3107 _tr_stored_block(s, buf, stored_len, eof);
3108
3109 #ifdef FORCE_STATIC
3110 } else if (static_lenb >= 0) { /* force static trees */
3111 #else
3112 } else if (static_lenb == opt_lenb) {
3113 #endif
3114 send_bits(s, (STATIC_TREES<<1)+eof, 3);
3115 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
3116 #ifdef DEBUG_ZLIB
3117 s->compressed_len += 3 + s->static_len;
3118 #endif
3119 } else {
3120 send_bits(s, (DYN_TREES<<1)+eof, 3);
3121 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
3122 max_blindex+1);
3123 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
3124 #ifdef DEBUG_ZLIB
3125 s->compressed_len += 3 + s->opt_len;
3126 #endif
3127 }
3128 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
3129 /* The above check is made mod 2^32, for files larger than 512 MB
3130 * and uLong implemented on 32 bits.
3131 */
3132 init_block(s);
3133
3134 if (eof) {
3135 bi_windup(s);
3136 #ifdef DEBUG_ZLIB
3137 s->compressed_len += 7; /* align on byte boundary */
3138 #endif
3139 }
3140 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
3141 s->compressed_len-7*eof));
3142 }
3143
3144 /* ===========================================================================
3145 * Save the match info and tally the frequency counts. Return true if
3146 * the current block must be flushed.
3147 */
3148 int _tr_tally (s, dist, lc)
3149 deflate_state *s;
3150 unsigned dist; /* distance of matched string */
3151 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
3152 {
3153 s->d_buf[s->last_lit] = (ush)dist;
3154 s->l_buf[s->last_lit++] = (uch)lc;
3155 if (dist == 0) {
3156 /* lc is the unmatched char */
3157 s->dyn_ltree[lc].Freq++;
3158 } else {
3159 s->matches++;
3160 /* Here, lc is the match length - MIN_MATCH */
3161 dist--; /* dist = match distance - 1 */
3162 Assert((ush)dist < (ush)MAX_DIST(s) &&
3163 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
3164 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
3165
3166 s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;
3167 s->dyn_dtree[d_code(dist)].Freq++;
3168 }
3169
3170 #ifdef TRUNCATE_BLOCK
3171 /* Try to guess if it is profitable to stop the current block here */
3172 if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
3173 /* Compute an upper bound for the compressed length */
3174 ulg out_length = (ulg)s->last_lit*8L;
3175 ulg in_length = (ulg)((long)s->strstart - s->block_start);
3176 int dcode;
3177 for (dcode = 0; dcode < D_CODES; dcode++) {
3178 out_length += (ulg)s->dyn_dtree[dcode].Freq *
3179 (5L+extra_dbits[dcode]);
3180 }
3181 out_length >>= 3;
3182 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
3183 s->last_lit, in_length, out_length,
3184 100L - out_length*100L/in_length));
3185 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
3186 }
3187 #endif
3188 return (s->last_lit == s->lit_bufsize-1);
3189 /* We avoid equality with lit_bufsize because of wraparound at 64K
3190 * on 16 bit machines and because stored blocks are restricted to
3191 * 64K-1 bytes.
3192 */
3193 }
3194
3195 /* ===========================================================================
3196 * Send the block data compressed using the given Huffman trees
3197 */
3198 local void compress_block(s, ltree, dtree)
3199 deflate_state *s;
3200 ct_data *ltree; /* literal tree */
3201 ct_data *dtree; /* distance tree */
3202 {
3203 unsigned dist; /* distance of matched string */
3204 int lc; /* match length or unmatched char (if dist == 0) */
3205 unsigned lx = 0; /* running index in l_buf */
3206 unsigned code; /* the code to send */
3207 int extra; /* number of extra bits to send */
3208
3209 if (s->last_lit != 0) do {
3210 dist = s->d_buf[lx];
3211 lc = s->l_buf[lx++];
3212 if (dist == 0) {
3213 send_code(s, lc, ltree); /* send a literal byte */
3214 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
3215 } else {
3216 /* Here, lc is the match length - MIN_MATCH */
3217 code = _length_code[lc];
3218 send_code(s, code+LITERALS+1, ltree); /* send the length code */
3219 extra = extra_lbits[code];
3220 if (extra != 0) {
3221 lc -= base_length[code];
3222 send_bits(s, lc, extra); /* send the extra length bits */
3223 }
3224 dist--; /* dist is now the match distance - 1 */
3225 code = d_code(dist);
3226 Assert (code < D_CODES, "bad d_code");
3227
3228 send_code(s, code, dtree); /* send the distance code */
3229 extra = extra_dbits[code];
3230 if (extra != 0) {
3231 dist -= base_dist[code];
3232 send_bits(s, dist, extra); /* send the extra distance bits */
3233 }
3234 } /* literal or match pair ? */
3235
3236 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
3237 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
3238
3239 } while (lx < s->last_lit);
3240
3241 send_code(s, END_BLOCK, ltree);
3242 s->last_eob_len = ltree[END_BLOCK].Len;
3243 }
3244
3245 /* ===========================================================================
3246 * Set the data type to ASCII or BINARY, using a crude approximation:
3247 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
3248 * IN assertion: the fields freq of dyn_ltree are set and the total of all
3249 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
3250 */
3251 local void set_data_type(s)
3252 deflate_state *s;
3253 {
3254 int n = 0;
3255 unsigned ascii_freq = 0;
3256 unsigned bin_freq = 0;
3257 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
3258 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
3259 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
3260 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
3261 }
3262
3263 /* ===========================================================================
3264 * Reverse the first len bits of a code, using straightforward code (a faster
3265 * method would use a table)
3266 * IN assertion: 1 <= len <= 15
3267 */
3268 local unsigned bi_reverse(code, len)
3269 unsigned code; /* the value to invert */
3270 int len; /* its bit length */
3271 {
3272 register unsigned res = 0;
3273 do {
3274 res |= code & 1;
3275 code >>= 1, res <<= 1;
3276 } while (--len > 0);
3277 return res >> 1;
3278 }
3279
3280 /* ===========================================================================
3281 * Flush the bit buffer, keeping at most 7 bits in it.
3282 */
3283 local void bi_flush(s)
3284 deflate_state *s;
3285 {
3286 if (s->bi_valid == 16) {
3287 put_short(s, s->bi_buf);
3288 s->bi_buf = 0;
3289 s->bi_valid = 0;
3290 } else if (s->bi_valid >= 8) {
3291 put_byte(s, (Byte)s->bi_buf);
3292 s->bi_buf >>= 8;
3293 s->bi_valid -= 8;
3294 }
3295 }
3296
3297 /* ===========================================================================
3298 * Flush the bit buffer and align the output on a byte boundary
3299 */
3300 local void bi_windup(s)
3301 deflate_state *s;
3302 {
3303 if (s->bi_valid > 8) {
3304 put_short(s, s->bi_buf);
3305 } else if (s->bi_valid > 0) {
3306 put_byte(s, (Byte)s->bi_buf);
3307 }
3308 s->bi_buf = 0;
3309 s->bi_valid = 0;
3310 #ifdef DEBUG_ZLIB
3311 s->bits_sent = (s->bits_sent+7) & ~7;
3312 #endif
3313 }
3314
3315 /* ===========================================================================
3316 * Copy a stored block, storing first the length and its
3317 * one's complement if requested.
3318 */
3319 local void copy_block(s, buf, len, header)
3320 deflate_state *s;
3321 charf *buf; /* the input data */
3322 unsigned len; /* its length */
3323 int header; /* true if block header must be written */
3324 {
3325 bi_windup(s); /* align on byte boundary */
3326 s->last_eob_len = 8; /* enough lookahead for inflate */
3327
3328 if (header) {
3329 put_short(s, (ush)len);
3330 put_short(s, (ush)~len);
3331 #ifdef DEBUG_ZLIB
3332 s->bits_sent += 2*16;
3333 #endif
3334 }
3335 #ifdef DEBUG_ZLIB
3336 s->bits_sent += (ulg)len<<3;
3337 #endif
3338 while (len--) {
3339 put_byte(s, *buf++);
3340 }
3341 }
3342 /* --- trees.c */
3343
3344 /* +++ inflate.c */
3345 /* inflate.c -- zlib interface to inflate modules
3346 * Copyright (C) 1995-2002 Mark Adler
3347 * For conditions of distribution and use, see copyright notice in zlib.h
3348 */
3349
3350 /* #include "zutil.h" */
3351
3352 /* +++ infblock.h */
3353 /* infblock.h -- header to use infblock.c
3354 * Copyright (C) 1995-2002 Mark Adler
3355 * For conditions of distribution and use, see copyright notice in zlib.h
3356 */
3357
3358 /* WARNING: this file should *not* be used by applications. It is
3359 part of the implementation of the compression library and is
3360 subject to change. Applications should only use zlib.h.
3361 */
3362
3363 struct inflate_blocks_state;
3364 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3365
3366 extern inflate_blocks_statef * inflate_blocks_new OF((
3367 z_streamp z,
3368 check_func c, /* check function */
3369 uInt w)); /* window size */
3370
3371 extern int inflate_blocks OF((
3372 inflate_blocks_statef *,
3373 z_streamp ,
3374 int)); /* initial return code */
3375
3376 extern void inflate_blocks_reset OF((
3377 inflate_blocks_statef *,
3378 z_streamp ,
3379 uLongf *)); /* check value on output */
3380
3381 extern int inflate_blocks_free OF((
3382 inflate_blocks_statef *,
3383 z_streamp));
3384
3385 extern void inflate_set_dictionary OF((
3386 inflate_blocks_statef *s,
3387 const Bytef *d, /* dictionary */
3388 uInt n)); /* dictionary length */
3389
3390 extern int inflate_blocks_sync_point OF((
3391 inflate_blocks_statef *s));
3392 /* --- infblock.h */
3393
3394 #ifndef NO_DUMMY_DECL
3395 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3396 #endif
3397
3398 /* inflate private state */
3399 typedef struct inflate_state {
3400
3401 /* mode */
3402 enum {
3403 METHOD, /* waiting for method byte */
3404 FLAG, /* waiting for flag byte */
3405 DICT4, /* four dictionary check bytes to go */
3406 DICT3, /* three dictionary check bytes to go */
3407 DICT2, /* two dictionary check bytes to go */
3408 DICT1, /* one dictionary check byte to go */
3409 DICT0, /* waiting for inflateSetDictionary */
3410 BLOCKS, /* decompressing blocks */
3411 CHECK4, /* four check bytes to go */
3412 CHECK3, /* three check bytes to go */
3413 CHECK2, /* two check bytes to go */
3414 CHECK1, /* one check byte to go */
3415 DONE, /* finished check, done */
3416 BAD} /* got an error--stay here */
3417 mode; /* current inflate mode */
3418
3419 /* mode dependent information */
3420 union {
3421 uInt method; /* if FLAGS, method byte */
3422 struct {
3423 uLong was; /* computed check value */
3424 uLong need; /* stream check value */
3425 } check; /* if CHECK, check values to compare */
3426 uInt marker; /* if BAD, inflateSync's marker bytes count */
3427 } sub; /* submode */
3428
3429 /* mode independent information */
3430 int nowrap; /* flag for no wrapper */
3431 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3432 inflate_blocks_statef
3433 *blocks; /* current inflate_blocks state */
3434
3435 }inflate_state;
3436
3437
3438 int ZEXPORT inflateReset(z)
3439 z_streamp z;
3440 {
3441 inflate_state* s;
3442 if (z == Z_NULL || z->state == Z_NULL)
3443 return Z_STREAM_ERROR;
3444
3445 s = (inflate_state*)z->state;
3446 z->total_in = z->total_out = 0;
3447 z->msg = Z_NULL;
3448 s->mode = s->nowrap ? BLOCKS : METHOD;
3449 inflate_blocks_reset(s->blocks, z, Z_NULL);
3450 Tracev((stderr, "inflate: reset\n"));
3451 return Z_OK;
3452 }
3453
3454
3455 int ZEXPORT inflateEnd(z)
3456 z_streamp z;
3457 {
3458 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3459 return Z_STREAM_ERROR;
3460 if (((inflate_state*)z->state)->blocks != Z_NULL)
3461 inflate_blocks_free(((inflate_state*)z->state)->blocks, z);
3462 ZFREE(z, z->state);
3463 z->state = Z_NULL;
3464 Tracev((stderr, "inflate: end\n"));
3465 return Z_OK;
3466 }
3467
3468
3469 int ZEXPORT inflateInit2_(z, w, version, stream_size)
3470 z_streamp z;
3471 int w;
3472 const char *version;
3473 int stream_size;
3474 {
3475 inflate_state* s;
3476 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3477 stream_size != sizeof(z_stream))
3478 return Z_VERSION_ERROR;
3479
3480 /* initialize state */
3481 if (z == Z_NULL)
3482 return Z_STREAM_ERROR;
3483 z->msg = Z_NULL;
3484 #ifndef NO_ZCFUNCS
3485 if (z->zalloc == Z_NULL)
3486 {
3487 z->zalloc = zcalloc;
3488 z->opaque = (voidpf)0;
3489 }
3490 if (z->zfree == Z_NULL) z->zfree = zcfree;
3491 #endif
3492 if ((z->state = (struct internal_state FAR *)
3493 ZALLOC(z,1,sizeof(struct inflate_state))) == Z_NULL)
3494 return Z_MEM_ERROR;
3495 s = (inflate_state*)z->state;
3496 s->blocks = Z_NULL;
3497
3498 /* handle undocumented nowrap option (no zlib header or check) */
3499 s->nowrap = 0;
3500 if (w < 0)
3501 {
3502 w = - w;
3503 s->nowrap = 1;
3504 }
3505
3506 /* set window size */
3507 if (w < 8 || w > 15)
3508 {
3509 inflateEnd(z);
3510 return Z_STREAM_ERROR;
3511 }
3512 s->wbits = (uInt)w;
3513
3514 /* create inflate_blocks state */
3515 if ((s->blocks =
3516 inflate_blocks_new(z, s->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3517 == Z_NULL)
3518 {
3519 inflateEnd(z);
3520 return Z_MEM_ERROR;
3521 }
3522 Tracev((stderr, "inflate: allocated\n"));
3523
3524 /* reset state */
3525 inflateReset(z);
3526 return Z_OK;
3527 }
3528
3529
3530 int ZEXPORT inflateInit_(z, version, stream_size)
3531 z_streamp z;
3532 const char *version;
3533 int stream_size;
3534 {
3535 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3536 }
3537
3538
3539 #define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
3540 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3541
3542 int ZEXPORT inflate(z, f)
3543 z_streamp z;
3544 int f;
3545 {
3546 int r;
3547 uInt b;
3548 inflate_state* s;
3549
3550 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
3551 return Z_STREAM_ERROR;
3552 f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
3553 r = Z_BUF_ERROR;
3554 s = (inflate_state*)z->state;
3555 while (1) switch (s->mode)
3556 {
3557 case METHOD:
3558 NEEDBYTE
3559 if (((s->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3560 {
3561 s->mode = BAD;
3562 z->msg = (char*)"unknown compression method";
3563 s->sub.marker = 5; /* can't try inflateSync */
3564 break;
3565 }
3566 if ((s->sub.method >> 4) + 8 > s->wbits)
3567 {
3568 s->mode = BAD;
3569 z->msg = (char*)"invalid window size";
3570 s->sub.marker = 5; /* can't try inflateSync */
3571 break;
3572 }
3573 s->mode = FLAG;
3574 case FLAG:
3575 NEEDBYTE
3576 b = NEXTBYTE;
3577 if (((s->sub.method << 8) + b) % 31)
3578 {
3579 s->mode = BAD;
3580 z->msg = (char*)"incorrect header check";
3581 s->sub.marker = 5; /* can't try inflateSync */
3582 break;
3583 }
3584 Tracev((stderr, "inflate: zlib header ok\n"));
3585 if (!(b & PRESET_DICT))
3586 {
3587 s->mode = BLOCKS;
3588 break;
3589 }
3590 s->mode = DICT4;
3591 case DICT4:
3592 NEEDBYTE
3593 s->sub.check.need = (uLong)NEXTBYTE << 24;
3594 s->mode = DICT3;
3595 case DICT3:
3596 NEEDBYTE
3597 s->sub.check.need += (uLong)NEXTBYTE << 16;
3598 s->mode = DICT2;
3599 case DICT2:
3600 NEEDBYTE
3601 s->sub.check.need += (uLong)NEXTBYTE << 8;
3602 s->mode = DICT1;
3603 case DICT1:
3604 NEEDBYTE
3605 s->sub.check.need += (uLong)NEXTBYTE;
3606 z->adler = s->sub.check.need;
3607 s->mode = DICT0;
3608 return Z_NEED_DICT;
3609 case DICT0:
3610 s->mode = BAD;
3611 z->msg = (char*)"need dictionary";
3612 s->sub.marker = 0; /* can try inflateSync */
3613 return Z_STREAM_ERROR;
3614 case BLOCKS:
3615 r = inflate_blocks(s->blocks, z, r);
3616 if (r == Z_DATA_ERROR)
3617 {
3618 s->mode = BAD;
3619 s->sub.marker = 0; /* can try inflateSync */
3620 break;
3621 }
3622 if (r == Z_OK)
3623 r = f;
3624 if (r != Z_STREAM_END)
3625 return r;
3626 r = f;
3627 inflate_blocks_reset(s->blocks, z, &s->sub.check.was);
3628 if (s->nowrap)
3629 {
3630 s->mode = DONE;
3631 break;
3632 }
3633 s->mode = CHECK4;
3634 case CHECK4:
3635 NEEDBYTE
3636 s->sub.check.need = (uLong)NEXTBYTE << 24;
3637 s->mode = CHECK3;
3638 case CHECK3:
3639 NEEDBYTE
3640 s->sub.check.need += (uLong)NEXTBYTE << 16;
3641 s->mode = CHECK2;
3642 case CHECK2:
3643 NEEDBYTE
3644 s->sub.check.need += (uLong)NEXTBYTE << 8;
3645 s->mode = CHECK1;
3646 case CHECK1:
3647 NEEDBYTE
3648 s->sub.check.need += (uLong)NEXTBYTE;
3649
3650 if (s->sub.check.was != s->sub.check.need)
3651 {
3652 s->mode = BAD;
3653 z->msg = (char*)"incorrect data check";
3654 s->sub.marker = 5; /* can't try inflateSync */
3655 break;
3656 }
3657 Tracev((stderr, "inflate: zlib check ok\n"));
3658 s->mode = DONE;
3659 case DONE:
3660 return Z_STREAM_END;
3661 case BAD:
3662 return Z_DATA_ERROR;
3663 default:
3664 return Z_STREAM_ERROR;
3665 }
3666 #ifdef NEED_DUMMY_RETURN
3667 return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
3668 #endif
3669 }
3670
3671
3672 int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
3673 z_streamp z;
3674 const Bytef *dictionary;
3675 uInt dictLength;
3676 {
3677 uInt length = dictLength;
3678 inflate_state* s;
3679
3680 if (z == Z_NULL || z->state == Z_NULL || ((inflate_state*)z->state)->mode != DICT0)
3681 return Z_STREAM_ERROR;
3682 s = (inflate_state*)z->state;
3683
3684 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3685 z->adler = 1L;
3686
3687 if (length >= ((uInt)1<<s->wbits))
3688 {
3689 length = (1<<s->wbits)-1;
3690 dictionary += dictLength - length;
3691 }
3692 inflate_set_dictionary(s->blocks, dictionary, length);
3693 s->mode = BLOCKS;
3694 return Z_OK;
3695 }
3696
3697
3698 int ZEXPORT inflateSync(z)
3699 z_streamp z;
3700 {
3701 uInt n; /* number of bytes to look at */
3702 Bytef *p; /* pointer to bytes */
3703 uInt m; /* number of marker bytes found in a row */
3704 uLong r, w; /* temporaries to save total_in and total_out */
3705 inflate_state* s;
3706
3707 /* set up */
3708 if (z == Z_NULL || z->state == Z_NULL)
3709 return Z_STREAM_ERROR;
3710 s = (inflate_state*)z->state;
3711 if (s->mode != BAD)
3712 {
3713 s->mode = BAD;
3714 s->sub.marker = 0;
3715 }
3716 if ((n = z->avail_in) == 0)
3717 return Z_BUF_ERROR;
3718 p = z->next_in;
3719 m = s->sub.marker;
3720
3721 /* search */
3722 while (n && m < 4)
3723 {
3724 static const Byte mark[4] = {0, 0, 0xff, 0xff};
3725 if (*p == mark[m])
3726 m++;
3727 else if (*p)
3728 m = 0;
3729 else
3730 m = 4 - m;
3731 p++, n--;
3732 }
3733
3734 /* restore */
3735 z->total_in += p - z->next_in;
3736 z->next_in = p;
3737 z->avail_in = n;
3738 s->sub.marker = m;
3739
3740 /* return no joy or set up to restart on a new block */
3741 if (m != 4)
3742 return Z_DATA_ERROR;
3743 r = z->total_in; w = z->total_out;
3744 inflateReset(z);
3745 z->total_in = r; z->total_out = w;
3746 s->mode = BLOCKS;
3747 return Z_OK;
3748 }
3749
3750
3751 /* Returns true if inflate is currently at the end of a block generated
3752 * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
3753 * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
3754 * but removes the length bytes of the resulting empty stored block. When
3755 * decompressing, PPP checks that at the end of input packet, inflate is
3756 * waiting for these length bytes.
3757 */
3758 int ZEXPORT inflateSyncPoint(z)
3759 z_streamp z;
3760 {
3761 if (z == Z_NULL || z->state == Z_NULL || ((inflate_state*)z->state)->blocks == Z_NULL)
3762 return Z_STREAM_ERROR;
3763 return inflate_blocks_sync_point(((inflate_state*)z->state)->blocks);
3764 }
3765 #undef NEEDBYTE
3766 #undef NEXTBYTE
3767 /* --- inflate.c */
3768
3769 /* +++ infblock.c */
3770 /* infblock.c -- interpret and process block types to last block
3771 * Copyright (C) 1995-2002 Mark Adler
3772 * For conditions of distribution and use, see copyright notice in zlib.h
3773 */
3774
3775 /* #include "zutil.h" */
3776 /* #include "infblock.h" */
3777
3778 /* +++ inftrees.h */
3779 /* inftrees.h -- header to use inftrees.c
3780 * Copyright (C) 1995-2002 Mark Adler
3781 * For conditions of distribution and use, see copyright notice in zlib.h
3782 */
3783
3784 /* WARNING: this file should *not* be used by applications. It is
3785 part of the implementation of the compression library and is
3786 subject to change. Applications should only use zlib.h.
3787 */
3788
3789 /* Huffman code lookup table entry--this entry is four bytes for machines
3790 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3791
3792 typedef struct inflate_huft_s FAR inflate_huft;
3793
3794 struct inflate_huft_s {
3795 union {
3796 struct {
3797 Byte Exop; /* number of extra bits or operation */
3798 Byte Bits; /* number of bits in this code or subcode */
3799 } what;
3800 uInt pad; /* pad structure to a power of 2 (4 bytes for */
3801 } word; /* 16-bit, 8 bytes for 32-bit int's) */
3802 uInt base; /* literal, length base, distance base,
3803 or table offset */
3804 };
3805
3806 /* Maximum size of dynamic tree. The maximum found in a long but non-
3807 exhaustive search was 1004 huft structures (850 for length/literals
3808 and 154 for distances, the latter actually the result of an
3809 exhaustive search). The actual maximum is not known, but the
3810 value below is more than safe. */
3811 #define MANY 1440
3812
3813 extern int inflate_trees_bits OF((
3814 uIntf *, /* 19 code lengths */
3815 uIntf *, /* bits tree desired/actual depth */
3816 inflate_huft * FAR *, /* bits tree result */
3817 inflate_huft *, /* space for trees */
3818 z_streamp)); /* for messages */
3819
3820 extern int inflate_trees_dynamic OF((
3821 uInt, /* number of literal/length codes */
3822 uInt, /* number of distance codes */
3823 uIntf *, /* that many (total) code lengths */
3824 uIntf *, /* literal desired/actual bit depth */
3825 uIntf *, /* distance desired/actual bit depth */
3826 inflate_huft * FAR *, /* literal/length tree result */
3827 inflate_huft * FAR *, /* distance tree result */
3828 inflate_huft *, /* space for trees */
3829 z_streamp)); /* for messages */
3830
3831 extern int inflate_trees_fixed OF((
3832 uIntf *, /* literal desired/actual bit depth */
3833 uIntf *, /* distance desired/actual bit depth */
3834 inflate_huft * FAR *, /* literal/length tree result */
3835 inflate_huft * FAR *, /* distance tree result */
3836 z_streamp)); /* for memory allocation */
3837 /* --- inftrees.h */
3838
3839 /* +++ infcodes.h */
3840 /* infcodes.h -- header to use infcodes.c
3841 * Copyright (C) 1995-2002 Mark Adler
3842 * For conditions of distribution and use, see copyright notice in zlib.h
3843 */
3844
3845 /* WARNING: this file should *not* be used by applications. It is
3846 part of the implementation of the compression library and is
3847 subject to change. Applications should only use zlib.h.
3848 */
3849
3850 struct inflate_codes_state;
3851 typedef struct inflate_codes_state FAR inflate_codes_statef;
3852
3853 extern inflate_codes_statef *inflate_codes_new OF((
3854 uInt, uInt,
3855 inflate_huft *, inflate_huft *,
3856 z_streamp ));
3857
3858 extern int inflate_codes OF((
3859 inflate_blocks_statef *,
3860 z_streamp ,
3861 int));
3862
3863 extern void inflate_codes_free OF((
3864 inflate_codes_statef *,
3865 z_streamp ));
3866
3867 /* --- infcodes.h */
3868
3869 /* +++ infutil.h */
3870 /* infutil.h -- types and macros common to blocks and codes
3871 * Copyright (C) 1995-2002 Mark Adler
3872 * For conditions of distribution and use, see copyright notice in zlib.h
3873 */
3874
3875 /* WARNING: this file should *not* be used by applications. It is
3876 part of the implementation of the compression library and is
3877 subject to change. Applications should only use zlib.h.
3878 */
3879
3880 #ifndef _INFUTIL_H
3881 #define _INFUTIL_H
3882
3883 typedef enum {
3884 TYPE, /* get type bits (3, including end bit) */
3885 LENS, /* get lengths for stored */
3886 STORED, /* processing stored block */
3887 TABLE, /* get table lengths */
3888 BTREE, /* get bit lengths tree for a dynamic block */
3889 DTREE, /* get length, distance trees for a dynamic block */
3890 CODES, /* processing fixed or dynamic block */
3891 DRY, /* output remaining window bytes */
3892 DONEB, /* finished last block, done */
3893 BADB} /* got a data error--stuck here */
3894 inflate_block_mode;
3895
3896 /* inflate blocks semi-private state */
3897 struct inflate_blocks_state {
3898
3899 /* mode */
3900 inflate_block_mode mode; /* current inflate_block mode */
3901
3902 /* mode dependent information */
3903 union {
3904 uInt left; /* if STORED, bytes left to copy */
3905 struct {
3906 uInt table; /* table lengths (14 bits) */
3907 uInt index; /* index into blens (or border) */
3908 uIntf *blens; /* bit lengths of codes */
3909 uInt bb; /* bit length tree depth */
3910 inflate_huft *tb; /* bit length decoding tree */
3911 } trees; /* if DTREE, decoding info for trees */
3912 struct {
3913 inflate_codes_statef
3914 *codes;
3915 } decode; /* if CODES, current state */
3916 } sub; /* submode */
3917 uInt last; /* true if this block is the last block */
3918
3919 /* mode independent information */
3920 uInt bitk; /* bits in bit buffer */
3921 uLong bitb; /* bit buffer */
3922 inflate_huft *hufts; /* single malloc for tree space */
3923 Bytef *window; /* sliding window */
3924 Bytef *end; /* one byte after sliding window */
3925 Bytef *read; /* window read pointer */
3926 Bytef *write; /* window write pointer */
3927 check_func checkfn; /* check function */
3928 uLong check; /* check on output */
3929
3930 };
3931
3932
3933 /* defines for inflate input/output */
3934 /* update pointers and return */
3935 #define UPDBITS {s->bitb=b;s->bitk=k;}
3936 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3937 #define UPDOUT {s->write=q;}
3938 #define UPDATE {UPDBITS UPDIN UPDOUT}
3939 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3940 /* get bytes and bits */
3941 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3942 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3943 #define NEXTBYTE (n--,*p++)
3944 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3945 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3946 /* output bytes */
3947 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3948 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3949 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3950 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3951 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3952 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3953 /* load local pointers */
3954 #define LOAD {LOADIN LOADOUT}
3955
3956 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3957 extern uInt inflate_mask[17];
3958
3959 /* copy as much as possible from the sliding window to the output area */
3960 extern int inflate_flush OF((
3961 inflate_blocks_statef *,
3962 z_streamp ,
3963 int));
3964
3965 #ifndef NO_DUMMY_DECL
3966 struct internal_state {int dummy;}; /* for buggy compilers */
3967 #endif
3968
3969 #endif
3970 /* --- infutil.h */
3971
3972 #ifndef NO_DUMMY_DECL
3973 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3974 #endif
3975
3976 /* simplify the use of the inflate_huft type with some defines */
3977 #define exop word.what.Exop
3978 #define bits word.what.Bits
3979
3980 /* Table for deflate from PKZIP's appnote.txt. */
3981 local const uInt border[] = { /* Order of the bit length code lengths */
3982 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3983
3984 /*
3985 Notes beyond the 1.93a appnote.txt:
3986
3987 1. Distance pointers never point before the beginning of the output
3988 stream.
3989 2. Distance pointers can point back across blocks, up to 32k away.
3990 3. There is an implied maximum of 7 bits for the bit length table and
3991 15 bits for the actual data.
3992 4. If only one code exists, then it is encoded using one bit. (Zero
3993 would be more efficient, but perhaps a little confusing.) If two
3994 codes exist, they are coded using one bit each (0 and 1).
3995 5. There is no way of sending zero distance codes--a dummy must be
3996 sent if there are none. (History: a pre 2.0 version of PKZIP would
3997 store blocks with no distance codes, but this was discovered to be
3998 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3999 zero distance codes, which is sent as one code of zero bits in
4000 length.
4001 6. There are up to 286 literal/length codes. Code 256 represents the
4002 end-of-block. Note however that the static length tree defines
4003 288 codes just to fill out the Huffman codes. Codes 286 and 287
4004 cannot be used though, since there is no length base or extra bits
4005 defined for them. Similarily, there are up to 30 distance codes.
4006 However, static trees define 32 codes (all 5 bits) to fill out the
4007 Huffman codes, but the last two had better not show up in the data.
4008 7. Unzip can check dynamic Huffman blocks for complete code sets.
4009 The exception is that a single code would not be complete (see #4).
4010 8. The five bits following the block type is really the number of
4011 literal codes sent minus 257.
4012 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
4013 (1+6+6). Therefore, to output three times the length, you output
4014 three codes (1+1+1), whereas to output four times the same length,
4015 you only need two codes (1+3). Hmm.
4016 10. In the tree reconstruction algorithm, Code = Code + Increment
4017 only if BitLength(i) is not zero. (Pretty obvious.)
4018 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
4019 12. Note: length code 284 can represent 227-258, but length code 285
4020 really is 258. The last length deserves its own, short code
4021 since it gets used a lot in very redundant files. The length
4022 258 is special since 258 - 3 (the min match length) is 255.
4023 13. The literal/length and distance code bit lengths are read as a
4024 single stream of lengths. It is possible (and advantageous) for
4025 a repeat code (16, 17, or 18) to go across the boundary between
4026 the two sets of lengths.
4027 */
4028
4029
4030 void inflate_blocks_reset(s, z, c)
4031 inflate_blocks_statef *s;
4032 z_streamp z;
4033 uLongf *c;
4034 {
4035 if (c != Z_NULL)
4036 *c = s->check;
4037 if (s->mode == BTREE || s->mode == DTREE)
4038 ZFREE(z, s->sub.trees.blens);
4039 if (s->mode == CODES)
4040 inflate_codes_free(s->sub.decode.codes, z);
4041 s->mode = TYPE;
4042 s->bitk = 0;
4043 s->bitb = 0;
4044 s->read = s->write = s->window;
4045 if (s->checkfn != Z_NULL)
4046 z->adler = s->check = (*s->checkfn)(0L, (const Bytef *)Z_NULL, 0);
4047 Tracev((stderr, "inflate: blocks reset\n"));
4048 }
4049
4050
4051 inflate_blocks_statef *inflate_blocks_new(z, c, w)
4052 z_streamp z;
4053 check_func c;
4054 uInt w;
4055 {
4056 inflate_blocks_statef *s;
4057
4058 if ((s = (inflate_blocks_statef *)ZALLOC
4059 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
4060 return s;
4061 if ((s->hufts =
4062 (inflate_huft *)ZALLOC(z, sizeof(inflate_huft), MANY)) == Z_NULL)
4063 {
4064 ZFREE(z, s);
4065 return Z_NULL;
4066 }
4067 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
4068 {
4069 ZFREE(z, s->hufts);
4070 ZFREE(z, s);
4071 return Z_NULL;
4072 }
4073 s->end = s->window + w;
4074 s->checkfn = c;
4075 s->mode = TYPE;
4076 Tracev((stderr, "inflate: blocks allocated\n"));
4077 inflate_blocks_reset(s, z, Z_NULL);
4078 return s;
4079 }
4080
4081
4082 int inflate_blocks(s, z, r)
4083 inflate_blocks_statef *s;
4084 z_streamp z;
4085 int r;
4086 {
4087 uInt t; /* temporary storage */
4088 uLong b; /* bit buffer */
4089 uInt k; /* bits in bit buffer */
4090 Bytef *p; /* input data pointer */
4091 uInt n; /* bytes available there */
4092 Bytef *q; /* output window write pointer */
4093 uInt m; /* bytes to end of window or read pointer */
4094
4095 /* copy input/output information to locals (UPDATE macro restores) */
4096 LOAD
4097
4098 /* process input based on current state */
4099 while (1) switch (s->mode)
4100 {
4101 case TYPE:
4102 NEEDBITS(3)
4103 t = (uInt)b & 7;
4104 s->last = t & 1;
4105 switch (t >> 1)
4106 {
4107 case 0: /* stored */
4108 Tracev((stderr, "inflate: stored block%s\n",
4109 s->last ? " (last)" : ""));
4110 DUMPBITS(3)
4111 t = k & 7; /* go to byte boundary */
4112 DUMPBITS(t)
4113 s->mode = LENS; /* get length of stored block */
4114 break;
4115 case 1: /* fixed */
4116 Tracev((stderr, "inflate: fixed codes block%s\n",
4117 s->last ? " (last)" : ""));
4118 {
4119 uInt bl, bd;
4120 inflate_huft *tl, *td;
4121
4122 inflate_trees_fixed(&bl, &bd, &tl, &td, z);
4123 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
4124 if (s->sub.decode.codes == Z_NULL)
4125 {
4126 r = Z_MEM_ERROR;
4127 LEAVE
4128 }
4129 }
4130 DUMPBITS(3)
4131 s->mode = CODES;
4132 break;
4133 case 2: /* dynamic */
4134 Tracev((stderr, "inflate: dynamic codes block%s\n",
4135 s->last ? " (last)" : ""));
4136 DUMPBITS(3)
4137 s->mode = TABLE;
4138 break;
4139 case 3: /* illegal */
4140 DUMPBITS(3)
4141 s->mode = BADB;
4142 z->msg = (char*)"invalid block type";
4143 r = Z_DATA_ERROR;
4144 LEAVE
4145 }
4146 break;
4147 case LENS:
4148 NEEDBITS(32)
4149 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
4150 {
4151 s->mode = BADB;
4152 z->msg = (char*)"invalid stored block lengths";
4153 r = Z_DATA_ERROR;
4154 LEAVE
4155 }
4156 s->sub.left = (uInt)b & 0xffff;
4157 b = k = 0; /* dump bits */
4158 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
4159 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
4160 break;
4161 case STORED:
4162 if (n == 0)
4163 LEAVE
4164 NEEDOUT
4165 t = s->sub.left;
4166 if (t > n) t = n;
4167 if (t > m) t = m;
4168 zmemcpy(q, p, t);
4169 p += t; n -= t;
4170 q += t; m -= t;
4171 if ((s->sub.left -= t) != 0)
4172 break;
4173 Tracev((stderr, "inflate: stored end, %lu total out\n",
4174 z->total_out + (q >= s->read ? q - s->read :
4175 (s->end - s->read) + (q - s->window))));
4176 s->mode = s->last ? DRY : TYPE;
4177 break;
4178 case TABLE:
4179 NEEDBITS(14)
4180 s->sub.trees.table = t = (uInt)b & 0x3fff;
4181 #ifndef PKZIP_BUG_WORKAROUND
4182 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
4183 {
4184 s->mode = BADB;
4185 z->msg = (char*)"too many length or distance symbols";
4186 r = Z_DATA_ERROR;
4187 LEAVE
4188 }
4189 #endif
4190 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
4191 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
4192 {
4193 r = Z_MEM_ERROR;
4194 LEAVE
4195 }
4196 DUMPBITS(14)
4197 s->sub.trees.index = 0;
4198 Tracev((stderr, "inflate: table sizes ok\n"));
4199 s->mode = BTREE;
4200 case BTREE:
4201 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
4202 {
4203 NEEDBITS(3)
4204 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
4205 DUMPBITS(3)
4206 }
4207 while (s->sub.trees.index < 19)
4208 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
4209 s->sub.trees.bb = 7;
4210 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
4211 &s->sub.trees.tb, s->hufts, z);
4212 if (t != Z_OK)
4213 {
4214 r = t;
4215 if (r == Z_DATA_ERROR)
4216 {
4217 ZFREE(z, s->sub.trees.blens);
4218 s->mode = BADB;
4219 }
4220 LEAVE
4221 }
4222 s->sub.trees.index = 0;
4223 Tracev((stderr, "inflate: bits tree ok\n"));
4224 s->mode = DTREE;
4225 case DTREE:
4226 while (t = s->sub.trees.table,
4227 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
4228 {
4229 inflate_huft *h;
4230 uInt i, j, c;
4231
4232 t = s->sub.trees.bb;
4233 NEEDBITS(t)
4234 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
4235 t = h->bits;
4236 c = h->base;
4237 if (c < 16)
4238 {
4239 DUMPBITS(t)
4240 s->sub.trees.blens[s->sub.trees.index++] = c;
4241 }
4242 else /* c == 16..18 */
4243 {
4244 i = c == 18 ? 7 : c - 14;
4245 j = c == 18 ? 11 : 3;
4246 NEEDBITS(t + i)
4247 DUMPBITS(t)
4248 j += (uInt)b & inflate_mask[i];
4249 DUMPBITS(i)
4250 i = s->sub.trees.index;
4251 t = s->sub.trees.table;
4252 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
4253 (c == 16 && i < 1))
4254 {
4255 ZFREE(z, s->sub.trees.blens);
4256 s->mode = BADB;
4257 z->msg = (char*)"invalid bit length repeat";
4258 r = Z_DATA_ERROR;
4259 LEAVE
4260 }
4261 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
4262 do {
4263 s->sub.trees.blens[i++] = c;
4264 } while (--j);
4265 s->sub.trees.index = i;
4266 }
4267 }
4268 s->sub.trees.tb = Z_NULL;
4269 {
4270 uInt bl, bd;
4271 inflate_huft *tl, *td;
4272 inflate_codes_statef *c;
4273
4274 bl = 9; /* must be <= 9 for lookahead assumptions */
4275 bd = 6; /* must be <= 9 for lookahead assumptions */
4276 t = s->sub.trees.table;
4277 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
4278 s->sub.trees.blens, &bl, &bd, &tl, &td,
4279 s->hufts, z);
4280 if (t != Z_OK)
4281 {
4282 if (t == (uInt)Z_DATA_ERROR)
4283 {
4284 ZFREE(z, s->sub.trees.blens);
4285 s->mode = BADB;
4286 }
4287 r = t;
4288 LEAVE
4289 }
4290 Tracev((stderr, "inflate: trees ok\n"));
4291 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
4292 {
4293 r = Z_MEM_ERROR;
4294 LEAVE
4295 }
4296 s->sub.decode.codes = c;
4297 }
4298 ZFREE(z, s->sub.trees.blens);
4299 s->mode = CODES;
4300 case CODES:
4301 UPDATE
4302 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
4303 return inflate_flush(s, z, r);
4304 r = Z_OK;
4305 inflate_codes_free(s->sub.decode.codes, z);
4306 LOAD
4307 Tracev((stderr, "inflate: codes end, %lu total out\n",
4308 z->total_out + (q >= s->read ? q - s->read :
4309 (s->end - s->read) + (q - s->window))));
4310 if (!s->last)
4311 {
4312 s->mode = TYPE;
4313 break;
4314 }
4315 s->mode = DRY;
4316 case DRY:
4317 FLUSH
4318 if (s->read != s->write)
4319 LEAVE
4320 s->mode = DONEB;
4321 case DONEB:
4322 r = Z_STREAM_END;
4323 LEAVE
4324 case BADB:
4325 r = Z_DATA_ERROR;
4326 LEAVE
4327 default:
4328 r = Z_STREAM_ERROR;
4329 LEAVE
4330 }
4331 }
4332
4333
4334 int inflate_blocks_free(s, z)
4335 inflate_blocks_statef *s;
4336 z_streamp z;
4337 {
4338 inflate_blocks_reset(s, z, Z_NULL);
4339 ZFREE(z, s->window);
4340 ZFREE(z, s->hufts);
4341 ZFREE(z, s);
4342 Tracev((stderr, "inflate: blocks freed\n"));
4343 return Z_OK;
4344 }
4345
4346
4347 void inflate_set_dictionary(s, d, n)
4348 inflate_blocks_statef *s;
4349 const Bytef *d;
4350 uInt n;
4351 {
4352 zmemcpy(s->window, d, n);
4353 s->read = s->write = s->window + n;
4354 }
4355
4356
4357 /* Returns true if inflate is currently at the end of a block generated
4358 * by Z_SYNC_FLUSH or Z_FULL_FLUSH.
4359 * IN assertion: s != Z_NULL
4360 */
4361 int inflate_blocks_sync_point(s)
4362 inflate_blocks_statef *s;
4363 {
4364 return s->mode == LENS;
4365 }
4366 /* --- infblock.c */
4367
4368 /* +++ inftrees.c */
4369 /* inftrees.c -- generate Huffman trees for efficient decoding
4370 * Copyright (C) 1995-2002 Mark Adler
4371 * For conditions of distribution and use, see copyright notice in zlib.h
4372 */
4373
4374 /* #include "zutil.h" */
4375 /* #include "inftrees.h" */
4376
4377 #if !defined(BUILDFIXED) && !defined(STDC)
4378 # define BUILDFIXED /* non ANSI compilers may not accept inffixed.h */
4379 #endif
4380
4381 const char inflate_copyright[] =
4382 " inflate 1.1.4 Copyright 1995-2002 Mark Adler ";
4383 /*
4384 If you use the zlib library in a product, an acknowledgment is welcome
4385 in the documentation of your product. If for some reason you cannot
4386 include such an acknowledgment, I would appreciate that you keep this
4387 copyright string in the executable of your product.
4388 */
4389
4390 #ifndef NO_DUMMY_DECL
4391 struct internal_state {int dummy;}; /* for buggy compilers */
4392 #endif
4393
4394 /* simplify the use of the inflate_huft type with some defines */
4395 #define exop word.what.Exop
4396 #define bits word.what.Bits
4397
4398
4399 local int huft_build OF((
4400 uIntf *, /* code lengths in bits */
4401 uInt, /* number of codes */
4402 uInt, /* number of "simple" codes */
4403 const uIntf *, /* list of base values for non-simple codes */
4404 const uIntf *, /* list of extra bits for non-simple codes */
4405 inflate_huft * FAR*,/* result: starting table */
4406 uIntf *, /* maximum lookup bits (returns actual) */
4407 inflate_huft *, /* space for trees */
4408 uInt *, /* hufts used in space */
4409 uIntf * )); /* space for values */
4410
4411 /* Tables for deflate from PKZIP's appnote.txt. */
4412 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4413 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4414 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4415 /* see note #13 above about 258 */
4416 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4417 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4418 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4419 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4420 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4421 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4422 8193, 12289, 16385, 24577};
4423 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4424 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4425 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4426 12, 12, 13, 13};
4427
4428 /*
4429 Huffman code decoding is performed using a multi-level table lookup.
4430 The fastest way to decode is to simply build a lookup table whose
4431 size is determined by the longest code. However, the time it takes
4432 to build this table can also be a factor if the data being decoded
4433 is not very long. The most common codes are necessarily the
4434 shortest codes, so those codes dominate the decoding time, and hence
4435 the speed. The idea is you can have a shorter table that decodes the
4436 shorter, more probable codes, and then point to subsidiary tables for
4437 the longer codes. The time it costs to decode the longer codes is
4438 then traded against the time it takes to make longer tables.
4439
4440 This results of this trade are in the variables lbits and dbits
4441 below. lbits is the number of bits the first level table for literal/
4442 length codes can decode in one step, and dbits is the same thing for
4443 the distance codes. Subsequent tables are also less than or equal to
4444 those sizes. These values may be adjusted either when all of the
4445 codes are shorter than that, in which case the longest code length in
4446 bits is used, or when the shortest code is *longer* than the requested
4447 table size, in which case the length of the shortest code in bits is
4448 used.
4449
4450 There are two different values for the two tables, since they code a
4451 different number of possibilities each. The literal/length table
4452 codes 286 possible values, or in a flat code, a little over eight
4453 bits. The distance table codes 30 possible values, or a little less
4454 than five bits, flat. The optimum values for speed end up being
4455 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4456 The optimum values may differ though from machine to machine, and
4457 possibly even between compilers. Your mileage may vary.
4458 */
4459
4460
4461 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4462 #define BMAX 15 /* maximum bit length of any code */
4463
4464 local int huft_build(b, n, s, d, e, t, m, hp, hn, v)
4465 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4466 uInt n; /* number of codes (assumed <= 288) */
4467 uInt s; /* number of simple-valued codes (0..s-1) */
4468 const uIntf *d; /* list of base values for non-simple codes */
4469 const uIntf *e; /* list of extra bits for non-simple codes */
4470 inflate_huft * FAR *t; /* result: starting table */
4471 uIntf *m; /* maximum lookup bits, returns actual */
4472 inflate_huft *hp; /* space for trees */
4473 uInt *hn; /* hufts used in space */
4474 uIntf *v; /* working area: values in order of bit length */
4475 /* Given a list of code lengths and a maximum table size, make a set of
4476 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4477 if the given code set is incomplete (the tables are still built in this
4478 case), or Z_DATA_ERROR if the input is invalid. */
4479 {
4480
4481 uInt a; /* counter for codes of length k */
4482 uInt c[BMAX+1]; /* bit length count table */
4483 uInt f; /* i repeats in table every f entries */
4484 int g; /* maximum code length */
4485 int h; /* table level */
4486 register uInt i; /* counter, current code */
4487 register uInt j; /* counter */
4488 register int k; /* number of bits in current code */
4489 int l; /* bits per table (returned in m) */
4490 uInt mask; /* (1 << w) - 1, to avoid cc -O bug on HP */
4491 register uIntf *p; /* pointer into c[], b[], or v[] */
4492 inflate_huft *q; /* points to current table */
4493 struct inflate_huft_s r; /* table entry for structure assignment */
4494 inflate_huft *u[BMAX]; /* table stack */
4495 register int w; /* bits before this table == (l * h) */
4496 uInt x[BMAX+1]; /* bit offsets, then code stack */
4497 uIntf *xp; /* pointer into x */
4498 int y; /* number of dummy codes added */
4499 uInt z; /* number of entries in current table */
4500
4501
4502 /* Generate counts for each bit length */
4503 p = c;
4504 #define C0 *p++ = 0;
4505 #define C2 C0 C0 C0 C0
4506 #define C4 C2 C2 C2 C2
4507 C4 /* clear c[]--assume BMAX+1 is 16 */
4508 p = b; i = n;
4509 do {
4510 c[*p++]++; /* assume all entries <= BMAX */
4511 } while (--i);
4512 if (c[0] == n) /* null input--all zero length codes */
4513 {
4514 *t = (inflate_huft *)Z_NULL;
4515 *m = 0;
4516 return Z_OK;
4517 }
4518
4519
4520 /* Find minimum and maximum length, bound *m by those */
4521 l = *m;
4522 for (j = 1; j <= BMAX; j++)
4523 if (c[j])
4524 break;
4525 k = j; /* minimum code length */
4526 if ((uInt)l < j)
4527 l = j;
4528 for (i = BMAX; i; i--)
4529 if (c[i])
4530 break;
4531 g = i; /* maximum code length */
4532 if ((uInt)l > i)
4533 l = i;
4534 *m = l;
4535
4536
4537 /* Adjust last length count to fill out codes, if needed */
4538 for (y = 1 << j; j < i; j++, y <<= 1)
4539 if ((y -= c[j]) < 0)
4540 return Z_DATA_ERROR;
4541 if ((y -= c[i]) < 0)
4542 return Z_DATA_ERROR;
4543 c[i] += y;
4544
4545
4546 /* Generate starting offsets into the value table for each length */
4547 x[1] = j = 0;
4548 p = c + 1; xp = x + 2;
4549 while (--i) { /* note that i == g from above */
4550 *xp++ = (j += *p++);
4551 }
4552
4553
4554 /* Make a table of values in order of bit lengths */
4555 p = b; i = 0;
4556 do {
4557 if ((j = *p++) != 0)
4558 v[x[j]++] = i;
4559 } while (++i < n);
4560 n = x[g]; /* set n to length of v */
4561
4562
4563 /* Generate the Huffman codes and for each, make the table entries */
4564 x[0] = i = 0; /* first Huffman code is zero */
4565 p = v; /* grab values in bit order */
4566 h = -1; /* no tables yet--level -1 */
4567 w = -l; /* bits decoded == (l * h) */
4568 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4569 q = (inflate_huft *)Z_NULL; /* ditto */
4570 z = 0; /* ditto */
4571
4572 /* go through the bit lengths (k already is bits in shortest code) */
4573 for (; k <= g; k++)
4574 {
4575 a = c[k];
4576 while (a--)
4577 {
4578 /* here i is the Huffman code of length k bits for value *p */
4579 /* make tables up to required level */
4580 while (k > w + l)
4581 {
4582 h++;
4583 w += l; /* previous table always l bits */
4584
4585 /* compute minimum size table less than or equal to l bits */
4586 z = g - w;
4587 z = z > (uInt)l ? l : z; /* table size upper limit */
4588 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4589 { /* too few codes for k-w bit table */
4590 f -= a + 1; /* deduct codes from patterns left */
4591 xp = c + k;
4592 if (j < z)
4593 while (++j < z) /* try smaller tables up to z bits */
4594 {
4595 if ((f <<= 1) <= *++xp)
4596 break; /* enough codes to use up j bits */
4597 f -= *xp; /* else deduct codes from patterns */
4598 }
4599 }
4600 z = 1 << j; /* table entries for j-bit table */
4601
4602 /* allocate new table */
4603 if (*hn + z > MANY) /* (note: doesn't matter for fixed) */
4604 return Z_DATA_ERROR; /* overflow of MANY */
4605 u[h] = q = hp + *hn;
4606 *hn += z;
4607
4608 /* connect to last table, if there is one */
4609 if (h)
4610 {
4611 x[h] = i; /* save pattern for backing up */
4612 r.bits = (Byte)l; /* bits to dump before this table */
4613 r.exop = (Byte)j; /* bits in this table */
4614 j = i >> (w - l);
4615 r.base = (uInt)(q - u[h-1] - j); /* offset to this table */
4616 u[h-1][j] = r; /* connect to last table */
4617 }
4618 else
4619 *t = q; /* first table is returned result */
4620 }
4621
4622 /* set up table entry in r */
4623 r.bits = (Byte)(k - w);
4624 if (p >= v + n)
4625 r.exop = 128 + 64; /* out of values--invalid code */
4626 else if (*p < s)
4627 {
4628 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4629 r.base = *p++; /* simple code is just the value */
4630 }
4631 else
4632 {
4633 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4634 r.base = d[*p++ - s];
4635 }
4636
4637 /* fill code-like entries with r */
4638 f = 1 << (k - w);
4639 for (j = i >> w; j < z; j += f)
4640 q[j] = r;
4641
4642 /* backwards increment the k-bit code i */
4643 for (j = 1 << (k - 1); i & j; j >>= 1)
4644 i ^= j;
4645 i ^= j;
4646
4647 /* backup over finished tables */
4648 mask = (1 << w) - 1; /* needed on HP, cc -O bug */
4649 while ((i & mask) != x[h])
4650 {
4651 h--; /* don't need to update q */
4652 w -= l;
4653 mask = (1 << w) - 1;
4654 }
4655 }
4656 }
4657
4658
4659 /* Return Z_BUF_ERROR if we were given an incomplete table */
4660 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4661 }
4662
4663
4664 int inflate_trees_bits(c, bb, tb, hp, z)
4665 uIntf *c; /* 19 code lengths */
4666 uIntf *bb; /* bits tree desired/actual depth */
4667 inflate_huft * FAR *tb; /* bits tree result */
4668 inflate_huft *hp; /* space for trees */
4669 z_streamp z; /* for messages */
4670 {
4671 int r;
4672 uInt hn = 0; /* hufts used in space */
4673 uIntf *v; /* work area for huft_build */
4674
4675 if ((v = (uIntf*)ZALLOC(z, 19, sizeof(uInt))) == Z_NULL)
4676 return Z_MEM_ERROR;
4677 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL,
4678 tb, bb, hp, &hn, v);
4679 if (r == Z_DATA_ERROR)
4680 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4681 else if (r == Z_BUF_ERROR || *bb == 0)
4682 {
4683 z->msg = (char*)"incomplete dynamic bit lengths tree";
4684 r = Z_DATA_ERROR;
4685 }
4686 ZFREE(z, v);
4687 return r;
4688 }
4689
4690
4691 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, hp, z)
4692 uInt nl; /* number of literal/length codes */
4693 uInt nd; /* number of distance codes */
4694 uIntf *c; /* that many (total) code lengths */
4695 uIntf *bl; /* literal desired/actual bit depth */
4696 uIntf *bd; /* distance desired/actual bit depth */
4697 inflate_huft * FAR *tl; /* literal/length tree result */
4698 inflate_huft * FAR *td; /* distance tree result */
4699 inflate_huft *hp; /* space for trees */
4700 z_streamp z; /* for messages */
4701 {
4702 int r;
4703 uInt hn = 0; /* hufts used in space */
4704 uIntf *v; /* work area for huft_build */
4705
4706 /* allocate work area */
4707 if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4708 return Z_MEM_ERROR;
4709
4710 /* build literal/length tree */
4711 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, hp, &hn, v);
4712 if (r != Z_OK || *bl == 0)
4713 {
4714 if (r == Z_DATA_ERROR)
4715 z->msg = (char*)"oversubscribed literal/length tree";
4716 else if (r != Z_MEM_ERROR)
4717 {
4718 z->msg = (char*)"incomplete literal/length tree";
4719 r = Z_DATA_ERROR;
4720 }
4721 ZFREE(z, v);
4722 return r;
4723 }
4724
4725 /* build distance tree */
4726 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, hp, &hn, v);
4727 if (r != Z_OK || (*bd == 0 && nl > 257))
4728 {
4729 if (r == Z_DATA_ERROR)
4730 z->msg = (char*)"oversubscribed distance tree";
4731 else if (r == Z_BUF_ERROR) {
4732 #ifdef PKZIP_BUG_WORKAROUND
4733 r = Z_OK;
4734 }
4735 #else
4736 z->msg = (char*)"incomplete distance tree";
4737 r = Z_DATA_ERROR;
4738 }
4739 else if (r != Z_MEM_ERROR)
4740 {
4741 z->msg = (char*)"empty distance tree with lengths";
4742 r = Z_DATA_ERROR;
4743 }
4744 ZFREE(z, v);
4745 return r;
4746 #endif
4747 }
4748
4749 /* done */
4750 ZFREE(z, v);
4751 return Z_OK;
4752 }
4753
4754
4755 /* build fixed tables only once--keep them here */
4756 #ifdef BUILDFIXED
4757 local int fixed_built = 0;
4758 #define FIXEDH 544 /* number of hufts used by fixed tables */
4759 local inflate_huft *fixed_mem = NULL;
4760 local uInt fixed_bl;
4761 local uInt fixed_bd;
4762 local inflate_huft *fixed_tl;
4763 local inflate_huft *fixed_td;
4764 #else
4765 /* +++ inffixed.h */
4766 /* inffixed.h -- table for decoding fixed codes
4767 * Generated automatically by the maketree.c program
4768 */
4769
4770 /* WARNING: this file should *not* be used by applications. It is
4771 part of the implementation of the compression library and is
4772 subject to change. Applications should only use zlib.h.
4773 */
4774
4775 local uInt fixed_bl = 9;
4776 local uInt fixed_bd = 5;
4777 local inflate_huft fixed_tl[] = {
4778 {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4779 {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},192},
4780 {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},160},
4781 {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},224},
4782 {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},144},
4783 {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},208},
4784 {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},176},
4785 {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},240},
4786 {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4787 {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},200},
4788 {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},168},
4789 {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},232},
4790 {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},152},
4791 {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},216},
4792 {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},184},
4793 {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},248},
4794 {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4795 {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},196},
4796 {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},164},
4797 {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},228},
4798 {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},148},
4799 {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},212},
4800 {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},180},
4801 {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},244},
4802 {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4803 {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},204},
4804 {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},172},
4805 {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},236},
4806 {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},156},
4807 {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},220},
4808 {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},188},
4809 {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},252},
4810 {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4811 {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},194},
4812 {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},162},
4813 {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},226},
4814 {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},146},
4815 {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},210},
4816 {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},178},
4817 {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},242},
4818 {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
4819 {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},202},
4820 {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},170},
4821 {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},234},
4822 {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},154},
4823 {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},218},
4824 {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},186},
4825 {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},250},
4826 {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
4827 {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},198},
4828 {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},166},
4829 {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},230},
4830 {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},150},
4831 {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},214},
4832 {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},182},
4833 {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},246},
4834 {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
4835 {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},206},
4836 {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},174},
4837 {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},238},
4838 {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},158},
4839 {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},222},
4840 {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},190},
4841 {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},254},
4842 {{{96,7}},256}, {{{0,8}},80}, {{{0,8}},16}, {{{84,8}},115},
4843 {{{82,7}},31}, {{{0,8}},112}, {{{0,8}},48}, {{{0,9}},193},
4844 {{{80,7}},10}, {{{0,8}},96}, {{{0,8}},32}, {{{0,9}},161},
4845 {{{0,8}},0}, {{{0,8}},128}, {{{0,8}},64}, {{{0,9}},225},
4846 {{{80,7}},6}, {{{0,8}},88}, {{{0,8}},24}, {{{0,9}},145},
4847 {{{83,7}},59}, {{{0,8}},120}, {{{0,8}},56}, {{{0,9}},209},
4848 {{{81,7}},17}, {{{0,8}},104}, {{{0,8}},40}, {{{0,9}},177},
4849 {{{0,8}},8}, {{{0,8}},136}, {{{0,8}},72}, {{{0,9}},241},
4850 {{{80,7}},4}, {{{0,8}},84}, {{{0,8}},20}, {{{85,8}},227},
4851 {{{83,7}},43}, {{{0,8}},116}, {{{0,8}},52}, {{{0,9}},201},
4852 {{{81,7}},13}, {{{0,8}},100}, {{{0,8}},36}, {{{0,9}},169},
4853 {{{0,8}},4}, {{{0,8}},132}, {{{0,8}},68}, {{{0,9}},233},
4854 {{{80,7}},8}, {{{0,8}},92}, {{{0,8}},28}, {{{0,9}},153},
4855 {{{84,7}},83}, {{{0,8}},124}, {{{0,8}},60}, {{{0,9}},217},
4856 {{{82,7}},23}, {{{0,8}},108}, {{{0,8}},44}, {{{0,9}},185},
4857 {{{0,8}},12}, {{{0,8}},140}, {{{0,8}},76}, {{{0,9}},249},
4858 {{{80,7}},3}, {{{0,8}},82}, {{{0,8}},18}, {{{85,8}},163},
4859 {{{83,7}},35}, {{{0,8}},114}, {{{0,8}},50}, {{{0,9}},197},
4860 {{{81,7}},11}, {{{0,8}},98}, {{{0,8}},34}, {{{0,9}},165},
4861 {{{0,8}},2}, {{{0,8}},130}, {{{0,8}},66}, {{{0,9}},229},
4862 {{{80,7}},7}, {{{0,8}},90}, {{{0,8}},26}, {{{0,9}},149},
4863 {{{84,7}},67}, {{{0,8}},122}, {{{0,8}},58}, {{{0,9}},213},
4864 {{{82,7}},19}, {{{0,8}},106}, {{{0,8}},42}, {{{0,9}},181},
4865 {{{0,8}},10}, {{{0,8}},138}, {{{0,8}},74}, {{{0,9}},245},
4866 {{{80,7}},5}, {{{0,8}},86}, {{{0,8}},22}, {{{192,8}},0},
4867 {{{83,7}},51}, {{{0,8}},118}, {{{0,8}},54}, {{{0,9}},205},
4868 {{{81,7}},15}, {{{0,8}},102}, {{{0,8}},38}, {{{0,9}},173},
4869 {{{0,8}},6}, {{{0,8}},134}, {{{0,8}},70}, {{{0,9}},237},
4870 {{{80,7}},9}, {{{0,8}},94}, {{{0,8}},30}, {{{0,9}},157},
4871 {{{84,7}},99}, {{{0,8}},126}, {{{0,8}},62}, {{{0,9}},221},
4872 {{{82,7}},27}, {{{0,8}},110}, {{{0,8}},46}, {{{0,9}},189},
4873 {{{0,8}},14}, {{{0,8}},142}, {{{0,8}},78}, {{{0,9}},253},
4874 {{{96,7}},256}, {{{0,8}},81}, {{{0,8}},17}, {{{85,8}},131},
4875 {{{82,7}},31}, {{{0,8}},113}, {{{0,8}},49}, {{{0,9}},195},
4876 {{{80,7}},10}, {{{0,8}},97}, {{{0,8}},33}, {{{0,9}},163},
4877 {{{0,8}},1}, {{{0,8}},129}, {{{0,8}},65}, {{{0,9}},227},
4878 {{{80,7}},6}, {{{0,8}},89}, {{{0,8}},25}, {{{0,9}},147},
4879 {{{83,7}},59}, {{{0,8}},121}, {{{0,8}},57}, {{{0,9}},211},
4880 {{{81,7}},17}, {{{0,8}},105}, {{{0,8}},41}, {{{0,9}},179},
4881 {{{0,8}},9}, {{{0,8}},137}, {{{0,8}},73}, {{{0,9}},243},
4882 {{{80,7}},4}, {{{0,8}},85}, {{{0,8}},21}, {{{80,8}},258},
4883 {{{83,7}},43}, {{{0,8}},117}, {{{0,8}},53}, {{{0,9}},203},
4884 {{{81,7}},13}, {{{0,8}},101}, {{{0,8}},37}, {{{0,9}},171},
4885 {{{0,8}},5}, {{{0,8}},133}, {{{0,8}},69}, {{{0,9}},235},
4886 {{{80,7}},8}, {{{0,8}},93}, {{{0,8}},29}, {{{0,9}},155},
4887 {{{84,7}},83}, {{{0,8}},125}, {{{0,8}},61}, {{{0,9}},219},
4888 {{{82,7}},23}, {{{0,8}},109}, {{{0,8}},45}, {{{0,9}},187},
4889 {{{0,8}},13}, {{{0,8}},141}, {{{0,8}},77}, {{{0,9}},251},
4890 {{{80,7}},3}, {{{0,8}},83}, {{{0,8}},19}, {{{85,8}},195},
4891 {{{83,7}},35}, {{{0,8}},115}, {{{0,8}},51}, {{{0,9}},199},
4892 {{{81,7}},11}, {{{0,8}},99}, {{{0,8}},35}, {{{0,9}},167},
4893 {{{0,8}},3}, {{{0,8}},131}, {{{0,8}},67}, {{{0,9}},231},
4894 {{{80,7}},7}, {{{0,8}},91}, {{{0,8}},27}, {{{0,9}},151},
4895 {{{84,7}},67}, {{{0,8}},123}, {{{0,8}},59}, {{{0,9}},215},
4896 {{{82,7}},19}, {{{0,8}},107}, {{{0,8}},43}, {{{0,9}},183},
4897 {{{0,8}},11}, {{{0,8}},139}, {{{0,8}},75}, {{{0,9}},247},
4898 {{{80,7}},5}, {{{0,8}},87}, {{{0,8}},23}, {{{192,8}},0},
4899 {{{83,7}},51}, {{{0,8}},119}, {{{0,8}},55}, {{{0,9}},207},
4900 {{{81,7}},15}, {{{0,8}},103}, {{{0,8}},39}, {{{0,9}},175},
4901 {{{0,8}},7}, {{{0,8}},135}, {{{0,8}},71}, {{{0,9}},239},
4902 {{{80,7}},9}, {{{0,8}},95}, {{{0,8}},31}, {{{0,9}},159},
4903 {{{84,7}},99}, {{{0,8}},127}, {{{0,8}},63}, {{{0,9}},223},
4904 {{{82,7}},27}, {{{0,8}},111}, {{{0,8}},47}, {{{0,9}},191},
4905 {{{0,8}},15}, {{{0,8}},143}, {{{0,8}},79}, {{{0,9}},255}
4906 };
4907 local inflate_huft fixed_td[] = {
4908 {{{80,5}},1}, {{{87,5}},257}, {{{83,5}},17}, {{{91,5}},4097},
4909 {{{81,5}},5}, {{{89,5}},1025}, {{{85,5}},65}, {{{93,5}},16385},
4910 {{{80,5}},3}, {{{88,5}},513}, {{{84,5}},33}, {{{92,5}},8193},
4911 {{{82,5}},9}, {{{90,5}},2049}, {{{86,5}},129}, {{{192,5}},24577},
4912 {{{80,5}},2}, {{{87,5}},385}, {{{83,5}},25}, {{{91,5}},6145},
4913 {{{81,5}},7}, {{{89,5}},1537}, {{{85,5}},97}, {{{93,5}},24577},
4914 {{{80,5}},4}, {{{88,5}},769}, {{{84,5}},49}, {{{92,5}},12289},
4915 {{{82,5}},13}, {{{90,5}},3073}, {{{86,5}},193}, {{{192,5}},24577}
4916 };
4917 /* --- inffixed.h */
4918 #endif
4919
4920
4921 int inflate_trees_fixed(bl, bd, tl, td, z)
4922 uIntf *bl; /* literal desired/actual bit depth */
4923 uIntf *bd; /* distance desired/actual bit depth */
4924 inflate_huft * FAR *tl; /* literal/length tree result */
4925 inflate_huft * FAR *td; /* distance tree result */
4926 z_streamp z; /* for memory allocation */
4927 {
4928 #ifdef BUILDFIXED
4929 /* build fixed tables if not already */
4930 if (!fixed_built)
4931 {
4932 int k; /* temporary variable */
4933 uInt f = 0; /* number of hufts used in fixed_mem */
4934 uIntf *c; /* length list for huft_build */
4935 uIntf *v; /* work area for huft_build */
4936
4937 /* allocate memory */
4938 if ((c = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4939 return Z_MEM_ERROR;
4940 if ((v = (uIntf*)ZALLOC(z, 288, sizeof(uInt))) == Z_NULL)
4941 {
4942 ZFREE(z, c);
4943 return Z_MEM_ERROR;
4944 }
4945
4946 if ((fixed_mem = (inflate_huft*)ZALLOC(z, FIXEDH, sizeof(inflate_huft))) == Z_NULL)
4947 {
4948 ZFREE(z, c);
4949 ZFREE(z, v);
4950 return Z_MEM_ERROR;
4951 }
4952
4953 /* literal table */
4954 for (k = 0; k < 144; k++)
4955 c[k] = 8;
4956 for (; k < 256; k++)
4957 c[k] = 9;
4958 for (; k < 280; k++)
4959 c[k] = 7;
4960 for (; k < 288; k++)
4961 c[k] = 8;
4962 fixed_bl = 9;
4963 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl,
4964 fixed_mem, &f, v);
4965
4966 /* distance table */
4967 for (k = 0; k < 30; k++)
4968 c[k] = 5;
4969 fixed_bd = 5;
4970 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd,
4971 fixed_mem, &f, v);
4972
4973 /* done */
4974 ZFREE(z, v);
4975 ZFREE(z, c);
4976 fixed_built = 1;
4977 }
4978 #endif
4979 *bl = fixed_bl;
4980 *bd = fixed_bd;
4981 *tl = fixed_tl;
4982 *td = fixed_td;
4983 return Z_OK;
4984 }
4985 /* --- inftrees.c */
4986
4987 /* +++ infcodes.c */
4988 /* infcodes.c -- process literals and length/distance pairs
4989 * Copyright (C) 1995-2002 Mark Adler
4990 * For conditions of distribution and use, see copyright notice in zlib.h
4991 */
4992
4993 /* #include "zutil.h" */
4994 /* #include "inftrees.h" */
4995 /* #include "infblock.h" */
4996 /* #include "infcodes.h" */
4997 /* #include "infutil.h" */
4998
4999 /* +++ inffast.h */
5000 /* inffast.h -- header to use inffast.c
5001 * Copyright (C) 1995-2002 Mark Adler
5002 * For conditions of distribution and use, see copyright notice in zlib.h
5003 */
5004
5005 /* WARNING: this file should *not* be used by applications. It is
5006 part of the implementation of the compression library and is
5007 subject to change. Applications should only use zlib.h.
5008 */
5009
5010 extern int inflate_fast OF((
5011 uInt,
5012 uInt,
5013 inflate_huft *,
5014 inflate_huft *,
5015 inflate_blocks_statef *,
5016 z_streamp ));
5017 /* --- inffast.h */
5018
5019 /* simplify the use of the inflate_huft type with some defines */
5020 #define exop word.what.Exop
5021 #define bits word.what.Bits
5022
5023 typedef enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5024 START, /* x: set up for LEN */
5025 LEN, /* i: get length/literal/eob next */
5026 LENEXT, /* i: getting length extra (have base) */
5027 DIST, /* i: get distance next */
5028 DISTEXT, /* i: getting distance extra */
5029 COPY, /* o: copying bytes in window, waiting for space */
5030 LIT, /* o: got literal, waiting for output space */
5031 WASH, /* o: got eob, possibly still output waiting */
5032 END, /* x: got eob and all data flushed */
5033 BADCODE} /* x: got error */
5034 inflate_codes_mode;
5035
5036 /* inflate codes private state */
5037 struct inflate_codes_state {
5038
5039 /* mode */
5040 inflate_codes_mode mode; /* current inflate_codes mode */
5041
5042 /* mode dependent information */
5043 uInt len;
5044 union {
5045 struct {
5046 inflate_huft *tree; /* pointer into tree */
5047 uInt need; /* bits needed */
5048 } code; /* if LEN or DIST, where in tree */
5049 uInt lit; /* if LIT, literal */
5050 struct {
5051 uInt get; /* bits to get for extra */
5052 uInt dist; /* distance back to copy from */
5053 } copy; /* if EXT or COPY, where and how much */
5054 } sub; /* submode */
5055
5056 /* mode independent information */
5057 Byte lbits; /* ltree bits decoded per branch */
5058 Byte dbits; /* dtree bits decoder per branch */
5059 inflate_huft *ltree; /* literal/length/eob tree */
5060 inflate_huft *dtree; /* distance tree */
5061
5062 };
5063
5064
5065 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
5066 uInt bl, bd;
5067 inflate_huft *tl;
5068 inflate_huft *td; /* need separate declaration for Borland C++ */
5069 z_streamp z;
5070 {
5071 inflate_codes_statef *c;
5072
5073 if ((c = (inflate_codes_statef *)
5074 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
5075 {
5076 c->mode = START;
5077 c->lbits = (Byte)bl;
5078 c->dbits = (Byte)bd;
5079 c->ltree = tl;
5080 c->dtree = td;
5081 Tracev((stderr, "inflate: codes new\n"));
5082 }
5083 return c;
5084 }
5085
5086
5087 int inflate_codes(s, z, r)
5088 inflate_blocks_statef *s;
5089 z_streamp z;
5090 int r;
5091 {
5092 uInt j; /* temporary storage */
5093 inflate_huft *t; /* temporary pointer */
5094 uInt e; /* extra bits or operation */
5095 uLong b; /* bit buffer */
5096 uInt k; /* bits in bit buffer */
5097 Bytef *p; /* input data pointer */
5098 uInt n; /* bytes available there */
5099 Bytef *q; /* output window write pointer */
5100 uInt m; /* bytes to end of window or read pointer */
5101 Bytef *f; /* pointer to copy strings from */
5102 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
5103
5104 /* copy input/output information to locals (UPDATE macro restores) */
5105 LOAD
5106
5107 /* process input and output based on current state */
5108 while (1) switch (c->mode)
5109 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
5110 case START: /* x: set up for LEN */
5111 #ifndef SLOW
5112 if (m >= 258 && n >= 10)
5113 {
5114 UPDATE
5115 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
5116 LOAD
5117 if (r != Z_OK)
5118 {
5119 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
5120 break;
5121 }
5122 }
5123 #endif /* !SLOW */
5124 c->sub.code.need = c->lbits;
5125 c->sub.code.tree = c->ltree;
5126 c->mode = LEN;
5127 case LEN: /* i: get length/literal/eob next */
5128 j = c->sub.code.need;
5129 NEEDBITS(j)
5130 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5131 DUMPBITS(t->bits)
5132 e = (uInt)(t->exop);
5133 if (e == 0) /* literal */
5134 {
5135 c->sub.lit = t->base;
5136 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5137 "inflate: literal '%c'\n" :
5138 "inflate: literal 0x%02x\n", t->base));
5139 c->mode = LIT;
5140 break;
5141 }
5142 if (e & 16) /* length */
5143 {
5144 c->sub.copy.get = e & 15;
5145 c->len = t->base;
5146 c->mode = LENEXT;
5147 break;
5148 }
5149 if ((e & 64) == 0) /* next table */
5150 {
5151 c->sub.code.need = e;
5152 c->sub.code.tree = t + t->base;
5153 break;
5154 }
5155 if (e & 32) /* end of block */
5156 {
5157 Tracevv((stderr, "inflate: end of block\n"));
5158 c->mode = WASH;
5159 break;
5160 }
5161 c->mode = BADCODE; /* invalid code */
5162 z->msg = (char*)"invalid literal/length code";
5163 r = Z_DATA_ERROR;
5164 LEAVE
5165 case LENEXT: /* i: getting length extra (have base) */
5166 j = c->sub.copy.get;
5167 NEEDBITS(j)
5168 c->len += (uInt)b & inflate_mask[j];
5169 DUMPBITS(j)
5170 c->sub.code.need = c->dbits;
5171 c->sub.code.tree = c->dtree;
5172 Tracevv((stderr, "inflate: length %u\n", c->len));
5173 c->mode = DIST;
5174 case DIST: /* i: get distance next */
5175 j = c->sub.code.need;
5176 NEEDBITS(j)
5177 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
5178 DUMPBITS(t->bits)
5179 e = (uInt)(t->exop);
5180 if (e & 16) /* distance */
5181 {
5182 c->sub.copy.get = e & 15;
5183 c->sub.copy.dist = t->base;
5184 c->mode = DISTEXT;
5185 break;
5186 }
5187 if ((e & 64) == 0) /* next table */
5188 {
5189 c->sub.code.need = e;
5190 c->sub.code.tree = t + t->base;
5191 break;
5192 }
5193 c->mode = BADCODE; /* invalid code */
5194 z->msg = (char*)"invalid distance code";
5195 r = Z_DATA_ERROR;
5196 LEAVE
5197 case DISTEXT: /* i: getting distance extra */
5198 j = c->sub.copy.get;
5199 NEEDBITS(j)
5200 c->sub.copy.dist += (uInt)b & inflate_mask[j];
5201 DUMPBITS(j)
5202 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
5203 c->mode = COPY;
5204 case COPY: /* o: copying bytes in window, waiting for space */
5205 f = q - c->sub.copy.dist;
5206 while (f < s->window) /* modulo window size-"while" instead */
5207 f += s->end - s->window; /* of "if" handles invalid distances */
5208 while (c->len)
5209 {
5210 NEEDOUT
5211 OUTBYTE(*f++)
5212 if (f == s->end)
5213 f = s->window;
5214 c->len--;
5215 }
5216 c->mode = START;
5217 break;
5218 case LIT: /* o: got literal, waiting for output space */
5219 NEEDOUT
5220 OUTBYTE(c->sub.lit)
5221 c->mode = START;
5222 break;
5223 case WASH: /* o: got eob, possibly more output */
5224 if (k > 7) /* return unused byte, if any */
5225 {
5226 Assert(k < 16, "inflate_codes grabbed too many bytes")
5227 k -= 8;
5228 n++;
5229 p--; /* can always return one */
5230 }
5231 FLUSH
5232 if (s->read != s->write)
5233 LEAVE
5234 c->mode = END;
5235 case END:
5236 r = Z_STREAM_END;
5237 LEAVE
5238 case BADCODE: /* x: got error */
5239 r = Z_DATA_ERROR;
5240 LEAVE
5241 default:
5242 r = Z_STREAM_ERROR;
5243 LEAVE
5244 }
5245 #ifdef NEED_DUMMY_RETURN
5246 return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
5247 #endif
5248 }
5249
5250
5251 void inflate_codes_free(c, z)
5252 inflate_codes_statef *c;
5253 z_streamp z;
5254 {
5255 ZFREE(z, c);
5256 Tracev((stderr, "inflate: codes free\n"));
5257 }
5258 /* --- infcodes.c */
5259
5260 /* +++ infutil.c */
5261 /* inflate_util.c -- data and routines common to blocks and codes
5262 * Copyright (C) 1995-2002 Mark Adler
5263 * For conditions of distribution and use, see copyright notice in zlib.h
5264 */
5265
5266 /* #include "zutil.h" */
5267 /* #include "infblock.h" */
5268 /* #include "inftrees.h" */
5269 /* #include "infcodes.h" */
5270 /* #include "infutil.h" */
5271
5272 #ifndef NO_DUMMY_DECL
5273 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5274 #endif
5275
5276 /* And'ing with mask[n] masks the lower n bits */
5277 uInt inflate_mask[17] = {
5278 0x0000,
5279 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
5280 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
5281 };
5282
5283
5284 /* copy as much as possible from the sliding window to the output area */
5285 int inflate_flush(s, z, r)
5286 inflate_blocks_statef *s;
5287 z_streamp z;
5288 int r;
5289 {
5290 uInt n;
5291 Bytef *p;
5292 Bytef *q;
5293
5294 /* local copies of source and destination pointers */
5295 p = z->next_out;
5296 q = s->read;
5297
5298 /* compute number of bytes to copy as far as end of window */
5299 n = (uInt)((q <= s->write ? s->write : s->end) - q);
5300 if (n > z->avail_out) n = z->avail_out;
5301 if (n && r == Z_BUF_ERROR) r = Z_OK;
5302
5303 /* update counters */
5304 z->avail_out -= n;
5305 z->total_out += n;
5306
5307 /* update check information */
5308 if (s->checkfn != Z_NULL)
5309 z->adler = s->check = (*s->checkfn)(s->check, q, n);
5310
5311 /* copy as far as end of window */
5312 zmemcpy(p, q, n);
5313 p += n;
5314 q += n;
5315
5316 /* see if more to copy at beginning of window */
5317 if (q == s->end)
5318 {
5319 /* wrap pointers */
5320 q = s->window;
5321 if (s->write == s->end)
5322 s->write = s->window;
5323
5324 /* compute bytes to copy */
5325 n = (uInt)(s->write - q);
5326 if (n > z->avail_out) n = z->avail_out;
5327 if (n && r == Z_BUF_ERROR) r = Z_OK;
5328
5329 /* update counters */
5330 z->avail_out -= n;
5331 z->total_out += n;
5332
5333 /* update check information */
5334 if (s->checkfn != Z_NULL)
5335 z->adler = s->check = (*s->checkfn)(s->check, q, n);
5336
5337 /* copy */
5338 zmemcpy(p, q, n);
5339 p += n;
5340 q += n;
5341 }
5342
5343 /* update pointers */
5344 z->next_out = p;
5345 s->read = q;
5346
5347 /* done */
5348 return r;
5349 }
5350 /* --- infutil.c */
5351
5352 /* +++ inffast.c */
5353 /* inffast.c -- process literals and length/distance pairs fast
5354 * Copyright (C) 1995-2002 Mark Adler
5355 * For conditions of distribution and use, see copyright notice in zlib.h
5356 */
5357
5358 /* #include "zutil.h" */
5359 /* #include "inftrees.h" */
5360 /* #include "infblock.h" */
5361 /* #include "infcodes.h" */
5362 /* #include "infutil.h" */
5363 /* #include "inffast.h" */
5364
5365 #ifndef NO_DUMMY_DECL
5366 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
5367 #endif
5368
5369 /* simplify the use of the inflate_huft type with some defines */
5370 #define exop word.what.Exop
5371 #define bits word.what.Bits
5372
5373 /* macros for bit input with no checking and for returning unused bytes */
5374 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
5375 #define UNGRAB {c=z->avail_in-n;c=(k>>3)<c?k>>3:c;n+=c;p-=c;k-=c<<3;}
5376
5377 /* Called with number of bytes left to write in window at least 258
5378 (the maximum string length) and number of input bytes available
5379 at least ten. The ten bytes are six bytes for the longest length/
5380 distance pair plus four bytes for overloading the bit buffer. */
5381
5382 int inflate_fast(bl, bd, tl, td, s, z)
5383 uInt bl, bd;
5384 inflate_huft *tl;
5385 inflate_huft *td; /* need separate declaration for Borland C++ */
5386 inflate_blocks_statef *s;
5387 z_streamp z;
5388 {
5389 inflate_huft *t; /* temporary pointer */
5390 uInt e; /* extra bits or operation */
5391 uLong b; /* bit buffer */
5392 uInt k; /* bits in bit buffer */
5393 Bytef *p; /* input data pointer */
5394 uInt n; /* bytes available there */
5395 Bytef *q; /* output window write pointer */
5396 uInt m; /* bytes to end of window or read pointer */
5397 uInt ml; /* mask for literal/length tree */
5398 uInt md; /* mask for distance tree */
5399 uInt c; /* bytes to copy */
5400 uInt d; /* distance back to copy from */
5401 Bytef *r; /* copy source pointer */
5402
5403 /* load input, output, bit values */
5404 LOAD
5405
5406 /* initialize masks */
5407 ml = inflate_mask[bl];
5408 md = inflate_mask[bd];
5409
5410 /* do until not enough input or output space for fast loop */
5411 do { /* assume called with m >= 258 && n >= 10 */
5412 /* get literal/length code */
5413 GRABBITS(20) /* max bits for literal/length code */
5414 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5415 {
5416 DUMPBITS(t->bits)
5417 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5418 "inflate: * literal '%c'\n" :
5419 "inflate: * literal 0x%02x\n", t->base));
5420 *q++ = (Byte)t->base;
5421 m--;
5422 continue;
5423 }
5424 do {
5425 DUMPBITS(t->bits)
5426 if (e & 16)
5427 {
5428 /* get extra bits for length */
5429 e &= 15;
5430 c = t->base + ((uInt)b & inflate_mask[e]);
5431 DUMPBITS(e)
5432 Tracevv((stderr, "inflate: * length %u\n", c));
5433
5434 /* decode distance base of block to copy */
5435 GRABBITS(15); /* max bits for distance code */
5436 e = (t = td + ((uInt)b & md))->exop;
5437 do {
5438 DUMPBITS(t->bits)
5439 if (e & 16)
5440 {
5441 /* get extra bits to add to distance base */
5442 e &= 15;
5443 GRABBITS(e) /* get extra bits (up to 13) */
5444 d = t->base + ((uInt)b & inflate_mask[e]);
5445 DUMPBITS(e)
5446 Tracevv((stderr, "inflate: * distance %u\n", d));
5447
5448 /* do the copy */
5449 m -= c;
5450 r = q - d;
5451 if (r < s->window) /* wrap if needed */
5452 {
5453 do {
5454 r += s->end - s->window; /* force pointer in window */
5455 } while (r < s->window); /* covers invalid distances */
5456 e = s->end - r;
5457 if (c > e)
5458 {
5459 c -= e; /* wrapped copy */
5460 do {
5461 *q++ = *r++;
5462 } while (--e);
5463 r = s->window;
5464 do {
5465 *q++ = *r++;
5466 } while (--c);
5467 }
5468 else /* normal copy */
5469 {
5470 *q++ = *r++; c--;
5471 *q++ = *r++; c--;
5472 do {
5473 *q++ = *r++;
5474 } while (--c);
5475 }
5476 }
5477 else /* normal copy */
5478 {
5479 *q++ = *r++; c--;
5480 *q++ = *r++; c--;
5481 do {
5482 *q++ = *r++;
5483 } while (--c);
5484 }
5485 break;
5486 }
5487 else if ((e & 64) == 0)
5488 {
5489 t += t->base;
5490 e = (t += ((uInt)b & inflate_mask[e]))->exop;
5491 }
5492 else
5493 {
5494 z->msg = (char*)"invalid distance code";
5495 UNGRAB
5496 UPDATE
5497 return Z_DATA_ERROR;
5498 }
5499 } while (1);
5500 break;
5501 }
5502 if ((e & 64) == 0)
5503 {
5504 t += t->base;
5505 if ((e = (t += ((uInt)b & inflate_mask[e]))->exop) == 0)
5506 {
5507 DUMPBITS(t->bits)
5508 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5509 "inflate: * literal '%c'\n" :
5510 "inflate: * literal 0x%02x\n", t->base));
5511 *q++ = (Byte)t->base;
5512 m--;
5513 break;
5514 }
5515 }
5516 else if (e & 32)
5517 {
5518 Tracevv((stderr, "inflate: * end of block\n"));
5519 UNGRAB
5520 UPDATE
5521 return Z_STREAM_END;
5522 }
5523 else
5524 {
5525 z->msg = (char*)"invalid literal/length code";
5526 UNGRAB
5527 UPDATE
5528 return Z_DATA_ERROR;
5529 }
5530 } while (1);
5531 } while (m >= 258 && n >= 10);
5532
5533 /* not enough input or output--restore pointers and return */
5534 UNGRAB
5535 UPDATE
5536 return Z_OK;
5537 }
5538 /* --- inffast.c */
5539
5540 /* +++ zutil.c */
5541 /* zutil.c -- target dependent utility functions for the compression library
5542 * Copyright (C) 1995-2002 Jean-loup Gailly.
5543 * For conditions of distribution and use, see copyright notice in zlib.h
5544 */
5545
5546 /* @(#) $Id: zlib.c,v 1.10 2004/07/29 19:17:20 lindak Exp $ */
5547
5548 /* #include "zutil.h" */
5549
5550 #ifndef NO_DUMMY_DECL
5551 struct internal_state {int dummy;}; /* for buggy compilers */
5552 #endif
5553
5554 #ifndef STDC
5555 extern void exit OF((int));
5556 #endif
5557
5558 const char *z_errmsg[10] = {
5559 "need dictionary", /* Z_NEED_DICT 2 */
5560 "stream end", /* Z_STREAM_END 1 */
5561 "", /* Z_OK 0 */
5562 "file error", /* Z_ERRNO (-1) */
5563 "stream error", /* Z_STREAM_ERROR (-2) */
5564 "data error", /* Z_DATA_ERROR (-3) */
5565 "insufficient memory", /* Z_MEM_ERROR (-4) */
5566 "buffer error", /* Z_BUF_ERROR (-5) */
5567 "incompatible version",/* Z_VERSION_ERROR (-6) */
5568 ""};
5569
5570
5571 const char * ZEXPORT zlibVersion()
5572 {
5573 return ZLIB_VERSION;
5574 }
5575
5576 #ifdef DEBUG_ZLIB
5577
5578 # ifndef verbose
5579 # define verbose 0
5580 # endif
5581 int z_verbose = verbose;
5582
5583 void z_error (m)
5584 char *m;
5585 {
5586 fprintf(stderr, "%s\n", m);
5587 exit(1);
5588 }
5589 #endif
5590
5591 /* exported to allow conversion of error code to string for compress() and
5592 * uncompress()
5593 */
5594 const char * ZEXPORT zError(err)
5595 int err;
5596 {
5597 return ERR_MSG(err);
5598 }
5599
5600
5601 #ifndef HAVE_MEMCPY
5602
5603 void zmemcpy(dest, source, len)
5604 Bytef* dest;
5605 const Bytef* source;
5606 uInt len;
5607 {
5608 if (len == 0) return;
5609 do {
5610 *dest++ = *source++; /* ??? to be unrolled */
5611 } while (--len != 0);
5612 }
5613
5614 int zmemcmp(s1, s2, len)
5615 const Bytef* s1;
5616 const Bytef* s2;
5617 uInt len;
5618 {
5619 uInt j;
5620
5621 for (j = 0; j < len; j++) {
5622 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5623 }
5624 return 0;
5625 }
5626
5627 void zmemzero(dest, len)
5628 Bytef* dest;
5629 uInt len;
5630 {
5631 if (len == 0) return;
5632 do {
5633 *dest++ = 0; /* ??? to be unrolled */
5634 } while (--len != 0);
5635 }
5636 #endif
5637
5638 #ifdef __TURBOC__
5639 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5640 /* Small and medium model in Turbo C are for now limited to near allocation
5641 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5642 */
5643 # define MY_ZCALLOC
5644
5645 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5646 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5647 * must fix the pointer. Warning: the pointer must be put back to its
5648 * original form in order to free it, use zcfree().
5649 */
5650
5651 #define MAX_PTR 10
5652 /* 10*64K = 640K */
5653
5654 local int next_ptr = 0;
5655
5656 typedef struct ptr_table_s {
5657 voidpf org_ptr;
5658 voidpf new_ptr;
5659 } ptr_table;
5660
5661 local ptr_table table[MAX_PTR];
5662 /* This table is used to remember the original form of pointers
5663 * to large buffers (64K). Such pointers are normalized with a zero offset.
5664 * Since MSDOS is not a preemptive multitasking OS, this table is not
5665 * protected from concurrent access. This hack doesn't work anyway on
5666 * a protected system like OS/2. Use Microsoft C instead.
5667 */
5668
5669 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5670 {
5671 voidpf buf = opaque; /* just to make some compilers happy */
5672 ulg bsize = (ulg)items*size;
5673
5674 /* If we allocate less than 65520 bytes, we assume that farmalloc
5675 * will return a usable pointer which doesn't have to be normalized.
5676 */
5677 if (bsize < 65520L) {
5678 buf = farmalloc(bsize);
5679 if (*(ush*)&buf != 0) return buf;
5680 } else {
5681 buf = farmalloc(bsize + 16L);
5682 }
5683 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5684 table[next_ptr].org_ptr = buf;
5685
5686 /* Normalize the pointer to seg:0 */
5687 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5688 *(ush*)&buf = 0;
5689 table[next_ptr++].new_ptr = buf;
5690 return buf;
5691 }
5692
5693 void zcfree (voidpf opaque, voidpf ptr)
5694 {
5695 int n;
5696 if (*(ush*)&ptr != 0) { /* object < 64K */
5697 farfree(ptr);
5698 return;
5699 }
5700 /* Find the original pointer */
5701 for (n = 0; n < next_ptr; n++) {
5702 if (ptr != table[n].new_ptr) continue;
5703
5704 farfree(table[n].org_ptr);
5705 while (++n < next_ptr) {
5706 table[n-1] = table[n];
5707 }
5708 next_ptr--;
5709 return;
5710 }
5711 ptr = opaque; /* just to make some compilers happy */
5712 Assert(0, "zcfree: ptr not found");
5713 }
5714 #endif
5715 #endif /* __TURBOC__ */
5716
5717
5718 #if defined(M_I86) && !defined(__32BIT__)
5719 /* Microsoft C in 16-bit mode */
5720
5721 # define MY_ZCALLOC
5722
5723 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
5724 # define _halloc halloc
5725 # define _hfree hfree
5726 #endif
5727
5728 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5729 {
5730 if (opaque) opaque = 0; /* to make compiler happy */
5731 return _halloc((long)items, size);
5732 }
5733
5734 void zcfree (voidpf opaque, voidpf ptr)
5735 {
5736 if (opaque) opaque = 0; /* to make compiler happy */
5737 _hfree(ptr);
5738 }
5739
5740 #endif /* MSC */
5741
5742
5743 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5744
5745 #ifndef STDC
5746 extern voidp calloc OF((uInt items, uInt size));
5747 extern void free OF((voidpf ptr));
5748 #endif
5749
5750 voidpf zcalloc (opaque, items, size)
5751 voidpf opaque;
5752 unsigned items;
5753 unsigned size;
5754 {
5755 if (opaque) items += size - size; /* make compiler happy */
5756 return (voidpf)calloc(items, size);
5757 }
5758
5759 void zcfree (opaque, ptr)
5760 voidpf opaque;
5761 voidpf ptr;
5762 {
5763 _FREE(ptr);
5764 if (opaque) return; /* make compiler happy */
5765 }
5766
5767 #endif /* MY_ZCALLOC */
5768 /* --- zutil.c */
5769
5770 /* +++ adler32.c */
5771 /* adler32.c -- compute the Adler-32 checksum of a data stream
5772 * Copyright (C) 1995-2002 Mark Adler
5773 * For conditions of distribution and use, see copyright notice in zlib.h
5774 */
5775
5776 /* @(#) $Id: zlib.c,v 1.10 2004/07/29 19:17:20 lindak Exp $ */
5777
5778 /* #include "zlib.h" */
5779
5780 #define BASE 65521L /* largest prime smaller than 65536 */
5781 #define NMAX 5552
5782 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5783
5784 #define DO1(buf,i) {s1 += buf[i]; s2 += s1;}
5785 #define DO2(buf,i) DO1(buf,i); DO1(buf,i+1);
5786 #define DO4(buf,i) DO2(buf,i); DO2(buf,i+2);
5787 #define DO8(buf,i) DO4(buf,i); DO4(buf,i+4);
5788 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5789
5790 /* ========================================================================= */
5791 uLong ZEXPORT adler32(adler, buf, len)
5792 uLong adler;
5793 const Bytef *buf;
5794 uInt len;
5795 {
5796 unsigned long s1 = adler & 0xffff;
5797 unsigned long s2 = (adler >> 16) & 0xffff;
5798 int k;
5799
5800 if (buf == Z_NULL) return 1L;
5801
5802 while (len > 0) {
5803 k = len < NMAX ? len : NMAX;
5804 len -= k;
5805 while (k >= 16) {
5806 DO16(buf);
5807 buf += 16;
5808 k -= 16;
5809 }
5810 if (k != 0) do {
5811 s1 += *buf++;
5812 s2 += s1;
5813 } while (--k);
5814 s1 %= BASE;
5815 s2 %= BASE;
5816 }
5817 return (s2 << 16) | s1;
5818 }
5819 /* --- adler32.c */