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