FreeBSD/Linux Kernel Cross Reference
sys/net/zlib.c
1 /*
2 * This file is derived from various .h and .c files from the zlib-1.0.4
3 * distribution by Jean-loup Gailly and Mark Adler, with some additions
4 * by Paul Mackerras to aid in implementing Deflate compression and
5 * decompression for PPP packets. See zlib.h for conditions of
6 * distribution and use.
7 *
8 * Changes that have been made include:
9 * - added Z_PACKET_FLUSH (see zlib.h for details)
10 * - added inflateIncomp and deflateOutputPending
11 * - allow strm->next_out to be NULL, meaning discard the output
12 *
13 * $FreeBSD$
14 */
15
16 /*
17 * ==FILEVERSION 971210==
18 *
19 * This marker is used by the Linux installation script to determine
20 * whether an up-to-date version of this file is already installed.
21 */
22
23 #define NO_DUMMY_DECL
24 #define NO_ZCFUNCS
25 #define MY_ZCALLOC
26
27 #if defined(__FreeBSD__) && defined(_KERNEL)
28 #define inflate inflate_ppp /* FreeBSD already has an inflate :-( */
29 #endif
30
31
32 /* +++ zutil.h */
33 /*-
34 * zutil.h -- internal interface and configuration of the compression library
35 * Copyright (C) 1995-1996 Jean-loup Gailly.
36 * For conditions of distribution and use, see copyright notice in zlib.h
37 */
38
39 /* WARNING: this file should *not* be used by applications. It is
40 part of the implementation of the compression library and is
41 subject to change. Applications should only use zlib.h.
42 */
43
44 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
45
46 #ifndef _Z_UTIL_H
47 #define _Z_UTIL_H
48
49 #ifdef _KERNEL
50 #include <net/zlib.h>
51 #else
52 #include "zlib.h"
53 #endif
54
55 #ifdef _KERNEL
56 /* Assume this is a *BSD or SVR4 kernel */
57 #include <sys/types.h>
58 #include <sys/time.h>
59 #include <sys/systm.h>
60 #include <sys/param.h>
61 #include <sys/kernel.h>
62 #include <sys/module.h>
63 # define HAVE_MEMCPY
64
65 #else
66 #if defined(__KERNEL__)
67 /* Assume this is a Linux kernel */
68 #include <linux/string.h>
69 #define HAVE_MEMCPY
70
71 #else /* not kernel */
72
73 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
74 # include <stddef.h>
75 # include <errno.h>
76 #else
77 extern int errno;
78 #endif
79 #ifdef STDC
80 # include <string.h>
81 # include <stdlib.h>
82 #endif
83 #endif /* __KERNEL__ */
84 #endif /* _KERNEL */
85
86 #ifndef local
87 # define local static
88 #endif
89 /* compile with -Dlocal if your debugger can't find static symbols */
90
91 typedef unsigned char uch;
92 typedef uch FAR uchf;
93 typedef unsigned short ush;
94 typedef ush FAR ushf;
95 typedef unsigned long ulg;
96
97 static const char *z_errmsg[10]; /* indexed by 2-zlib_error */
98 /* (size given to avoid silly warnings with Visual C++) */
99
100 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
101
102 #define ERR_RETURN(strm,err) \
103 return (strm->msg = (const char*)ERR_MSG(err), (err))
104 /* To be used only when the state is known to be valid */
105
106 /* common constants */
107
108 #ifndef DEF_WBITS
109 # define DEF_WBITS MAX_WBITS
110 #endif
111 /* default windowBits for decompression. MAX_WBITS is for compression only */
112
113 #if MAX_MEM_LEVEL >= 8
114 # define DEF_MEM_LEVEL 8
115 #else
116 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
117 #endif
118 /* default memLevel */
119
120 #define STORED_BLOCK 0
121 #define STATIC_TREES 1
122 #define DYN_TREES 2
123 /* The three kinds of block type */
124
125 #define MIN_MATCH 3
126 #define MAX_MATCH 258
127 /* The minimum and maximum match lengths */
128
129 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
130
131 /* target dependencies */
132
133 #ifdef MSDOS
134 # define OS_CODE 0x00
135 # ifdef __TURBOC__
136 # include <alloc.h>
137 # else /* MSC or DJGPP */
138 # include <malloc.h>
139 # endif
140 #endif
141
142 #ifdef OS2
143 # define OS_CODE 0x06
144 #endif
145
146 #ifdef WIN32 /* Window 95 & Windows NT */
147 # define OS_CODE 0x0b
148 #endif
149
150 #if defined(VAXC) || defined(VMS)
151 # define OS_CODE 0x02
152 # define FOPEN(name, mode) \
153 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
154 #endif
155
156 #ifdef AMIGA
157 # define OS_CODE 0x01
158 #endif
159
160 #if defined(ATARI) || defined(atarist)
161 # define OS_CODE 0x05
162 #endif
163
164 #ifdef MACOS
165 # define OS_CODE 0x07
166 #endif
167
168 #ifdef __50SERIES /* Prime/PRIMOS */
169 # define OS_CODE 0x0F
170 #endif
171
172 #ifdef TOPS20
173 # define OS_CODE 0x0a
174 #endif
175
176 #if defined(_BEOS_) || defined(RISCOS)
177 # define fdopen(fd,mode) NULL /* No fdopen() */
178 #endif
179
180 /* Common defaults */
181
182 #ifndef OS_CODE
183 # define OS_CODE 0x03 /* assume Unix */
184 #endif
185
186 #ifndef FOPEN
187 # define FOPEN(name, mode) fopen((name), (mode))
188 #endif
189
190 /* functions */
191
192 #ifdef HAVE_STRERROR
193 extern char *strerror OF((int));
194 # define zstrerror(errnum) strerror(errnum)
195 #else
196 # define zstrerror(errnum) ""
197 #endif
198
199 #if defined(pyr)
200 # define NO_MEMCPY
201 #endif
202 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
203 /* Use our own functions for small and medium model with MSC <= 5.0.
204 * You may have to use the same strategy for Borland C (untested).
205 */
206 # define NO_MEMCPY
207 #endif
208 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
209 # define HAVE_MEMCPY
210 #endif
211 #ifdef HAVE_MEMCPY
212 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
213 # define zmemcpy _fmemcpy
214 # define zmemcmp _fmemcmp
215 # define zmemzero(dest, len) _fmemset(dest, 0, len)
216 # else
217 # define zmemcpy memcpy
218 # define zmemcmp memcmp
219 # define zmemzero(dest, len) memset(dest, 0, len)
220 # endif
221 #else
222 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
223 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
224 extern void zmemzero OF((Bytef* dest, uInt len));
225 #endif
226
227 /* Diagnostic functions */
228 #ifdef DEBUG_ZLIB
229 # include <stdio.h>
230 # ifndef verbose
231 # define verbose 0
232 # endif
233 extern void z_error OF((char *m));
234 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
235 # define Trace(x) fprintf x
236 # define Tracev(x) {if (verbose) fprintf x ;}
237 # define Tracevv(x) {if (verbose>1) fprintf x ;}
238 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
239 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
240 #else
241 # define Assert(cond,msg)
242 # define Trace(x)
243 # define Tracev(x)
244 # define Tracevv(x)
245 # define Tracec(c,x)
246 # define Tracecv(c,x)
247 #endif
248
249
250 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
251
252 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
253 void zcfree OF((voidpf opaque, voidpf ptr));
254
255 #define ZALLOC(strm, items, size) \
256 (*((strm)->zalloc))((strm)->opaque, (items), (size))
257 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
258 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
259
260 #endif /* _Z_UTIL_H */
261 /* --- zutil.h */
262
263 /* +++ deflate.h */
264 /* deflate.h -- internal compression state
265 * Copyright (C) 1995-1996 Jean-loup Gailly
266 * For conditions of distribution and use, see copyright notice in zlib.h
267 */
268
269 /* WARNING: this file should *not* be used by applications. It is
270 part of the implementation of the compression library and is
271 subject to change. Applications should only use zlib.h.
272 */
273
274 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
275
276 #ifndef _DEFLATE_H
277 #define _DEFLATE_H
278
279 /* #include "zutil.h" */
280
281 /* ===========================================================================
282 * Internal compression state.
283 */
284
285 #define LENGTH_CODES 29
286 /* number of length codes, not counting the special END_BLOCK code */
287
288 #define LITERALS 256
289 /* number of literal bytes 0..255 */
290
291 #define L_CODES (LITERALS+1+LENGTH_CODES)
292 /* number of Literal or Length codes, including the END_BLOCK code */
293
294 #define D_CODES 30
295 /* number of distance codes */
296
297 #define BL_CODES 19
298 /* number of codes used to transfer the bit lengths */
299
300 #define HEAP_SIZE (2*L_CODES+1)
301 /* maximum heap size */
302
303 #define MAX_BITS 15
304 /* All codes must not exceed MAX_BITS bits */
305
306 #define INIT_STATE 42
307 #define BUSY_STATE 113
308 #define FINISH_STATE 666
309 /* Stream status */
310
311
312 /* Data structure describing a single value and its code string. */
313 typedef struct ct_data_s {
314 union {
315 ush freq; /* frequency count */
316 ush code; /* bit string */
317 } fc;
318 union {
319 ush dad; /* father node in Huffman tree */
320 ush len; /* length of bit string */
321 } dl;
322 } FAR ct_data;
323
324 #define Freq fc.freq
325 #define Code fc.code
326 #define Dad dl.dad
327 #define Len dl.len
328
329 typedef struct static_tree_desc_s static_tree_desc;
330
331 typedef struct tree_desc_s {
332 ct_data *dyn_tree; /* the dynamic tree */
333 int max_code; /* largest code with non zero frequency */
334 static_tree_desc *stat_desc; /* the corresponding static tree */
335 } FAR tree_desc;
336
337 typedef ush Pos;
338 typedef Pos FAR Posf;
339 typedef unsigned IPos;
340
341 /* A Pos is an index in the character window. We use short instead of int to
342 * save space in the various tables. IPos is used only for parameter passing.
343 */
344
345 typedef struct deflate_state {
346 z_streamp strm; /* pointer back to this zlib stream */
347 int status; /* as the name implies */
348 Bytef *pending_buf; /* output still pending */
349 ulg pending_buf_size; /* size of pending_buf */
350 Bytef *pending_out; /* next pending byte to output to the stream */
351 int pending; /* nb of bytes in the pending buffer */
352 int noheader; /* suppress zlib header and adler32 */
353 Byte data_type; /* UNKNOWN, BINARY or ASCII */
354 Byte method; /* STORED (for zip only) or DEFLATED */
355 int last_flush; /* value of flush param for previous deflate call */
356
357 /* used by deflate.c: */
358
359 uInt w_size; /* LZ77 window size (32K by default) */
360 uInt w_bits; /* log2(w_size) (8..16) */
361 uInt w_mask; /* w_size - 1 */
362
363 Bytef *window;
364 /* Sliding window. Input bytes are read into the second half of the window,
365 * and move to the first half later to keep a dictionary of at least wSize
366 * bytes. With this organization, matches are limited to a distance of
367 * wSize-MAX_MATCH bytes, but this ensures that IO is always
368 * performed with a length multiple of the block size. Also, it limits
369 * the window size to 64K, which is quite useful on MSDOS.
370 * To do: use the user input buffer as sliding window.
371 */
372
373 ulg window_size;
374 /* Actual size of window: 2*wSize, except when the user input buffer
375 * is directly used as sliding window.
376 */
377
378 Posf *prev;
379 /* Link to older string with same hash index. To limit the size of this
380 * array to 64K, this link is maintained only for the last 32K strings.
381 * An index in this array is thus a window index modulo 32K.
382 */
383
384 Posf *head; /* Heads of the hash chains or NIL. */
385
386 uInt ins_h; /* hash index of string to be inserted */
387 uInt hash_size; /* number of elements in hash table */
388 uInt hash_bits; /* log2(hash_size) */
389 uInt hash_mask; /* hash_size-1 */
390
391 uInt hash_shift;
392 /* Number of bits by which ins_h must be shifted at each input
393 * step. It must be such that after MIN_MATCH steps, the oldest
394 * byte no longer takes part in the hash key, that is:
395 * hash_shift * MIN_MATCH >= hash_bits
396 */
397
398 long block_start;
399 /* Window position at the beginning of the current output block. Gets
400 * negative when the window is moved backwards.
401 */
402
403 uInt match_length; /* length of best match */
404 IPos prev_match; /* previous match */
405 int match_available; /* set if previous match exists */
406 uInt strstart; /* start of string to insert */
407 uInt match_start; /* start of matching string */
408 uInt lookahead; /* number of valid bytes ahead in window */
409
410 uInt prev_length;
411 /* Length of the best match at previous step. Matches not greater than this
412 * are discarded. This is used in the lazy match evaluation.
413 */
414
415 uInt max_chain_length;
416 /* To speed up deflation, hash chains are never searched beyond this
417 * length. A higher limit improves compression ratio but degrades the
418 * speed.
419 */
420
421 uInt max_lazy_match;
422 /* Attempt to find a better match only when the current match is strictly
423 * smaller than this value. This mechanism is used only for compression
424 * levels >= 4.
425 */
426 # define max_insert_length max_lazy_match
427 /* Insert new strings in the hash table only if the match length is not
428 * greater than this length. This saves time but degrades compression.
429 * max_insert_length is used only for compression levels <= 3.
430 */
431
432 int level; /* compression level (1..9) */
433 int strategy; /* favor or force Huffman coding*/
434
435 uInt good_match;
436 /* Use a faster search when the previous match is longer than this */
437
438 int nice_match; /* Stop searching when current match exceeds this */
439
440 /* used by trees.c: */
441 /* Didn't use ct_data typedef below to supress compiler warning */
442 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
443 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
444 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
445
446 struct tree_desc_s l_desc; /* desc. for literal tree */
447 struct tree_desc_s d_desc; /* desc. for distance tree */
448 struct tree_desc_s bl_desc; /* desc. for bit length tree */
449
450 ush bl_count[MAX_BITS+1];
451 /* number of codes at each bit length for an optimal tree */
452
453 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
454 int heap_len; /* number of elements in the heap */
455 int heap_max; /* element of largest frequency */
456 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
457 * The same heap array is used to build all trees.
458 */
459
460 uch depth[2*L_CODES+1];
461 /* Depth of each subtree used as tie breaker for trees of equal frequency
462 */
463
464 uchf *l_buf; /* buffer for literals or lengths */
465
466 uInt lit_bufsize;
467 /* Size of match buffer for literals/lengths. There are 4 reasons for
468 * limiting lit_bufsize to 64K:
469 * - frequencies can be kept in 16 bit counters
470 * - if compression is not successful for the first block, all input
471 * data is still in the window so we can still emit a stored block even
472 * when input comes from standard input. (This can also be done for
473 * all blocks if lit_bufsize is not greater than 32K.)
474 * - if compression is not successful for a file smaller than 64K, we can
475 * even emit a stored file instead of a stored block (saving 5 bytes).
476 * This is applicable only for zip (not gzip or zlib).
477 * - creating new Huffman trees less frequently may not provide fast
478 * adaptation to changes in the input data statistics. (Take for
479 * example a binary file with poorly compressible code followed by
480 * a highly compressible string table.) Smaller buffer sizes give
481 * fast adaptation but have of course the overhead of transmitting
482 * trees more frequently.
483 * - I can't count above 4
484 */
485
486 uInt last_lit; /* running index in l_buf */
487
488 ushf *d_buf;
489 /* Buffer for distances. To simplify the code, d_buf and l_buf have
490 * the same number of elements. To use different lengths, an extra flag
491 * array would be necessary.
492 */
493
494 ulg opt_len; /* bit length of current block with optimal trees */
495 ulg static_len; /* bit length of current block with static trees */
496 ulg compressed_len; /* total bit length of compressed file */
497 uInt matches; /* number of string matches in current block */
498 int last_eob_len; /* bit length of EOB code for last block */
499
500 #ifdef DEBUG_ZLIB
501 ulg bits_sent; /* bit length of the compressed data */
502 #endif
503
504 ush bi_buf;
505 /* Output buffer. bits are inserted starting at the bottom (least
506 * significant bits).
507 */
508 int bi_valid;
509 /* Number of valid bits in bi_buf. All bits above the last valid bit
510 * are always zero.
511 */
512
513 } FAR deflate_state;
514
515 /* Output a byte on the stream.
516 * IN assertion: there is enough room in pending_buf.
517 */
518 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
519
520
521 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
522 /* Minimum amount of lookahead, except at the end of the input file.
523 * See deflate.c for comments about the MIN_MATCH+1.
524 */
525
526 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
527 /* In order to simplify the code, particularly on 16 bit machines, match
528 * distances are limited to MAX_DIST instead of WSIZE.
529 */
530
531 /* in trees.c */
532 void _tr_init OF((deflate_state *s));
533 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
534 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
535 int eof));
536 void _tr_align OF((deflate_state *s));
537 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
538 int eof));
539 void _tr_stored_type_only OF((deflate_state *));
540
541 #endif
542 /* --- deflate.h */
543
544 /* +++ deflate.c */
545 /* deflate.c -- compress data using the deflation algorithm
546 * Copyright (C) 1995-1996 Jean-loup Gailly.
547 * For conditions of distribution and use, see copyright notice in zlib.h
548 */
549
550 /*
551 * ALGORITHM
552 *
553 * The "deflation" process depends on being able to identify portions
554 * of the input text which are identical to earlier input (within a
555 * sliding window trailing behind the input currently being processed).
556 *
557 * The most straightforward technique turns out to be the fastest for
558 * most input files: try all possible matches and select the longest.
559 * The key feature of this algorithm is that insertions into the string
560 * dictionary are very simple and thus fast, and deletions are avoided
561 * completely. Insertions are performed at each input character, whereas
562 * string matches are performed only when the previous match ends. So it
563 * is preferable to spend more time in matches to allow very fast string
564 * insertions and avoid deletions. The matching algorithm for small
565 * strings is inspired from that of Rabin & Karp. A brute force approach
566 * is used to find longer strings when a small match has been found.
567 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
568 * (by Leonid Broukhis).
569 * A previous version of this file used a more sophisticated algorithm
570 * (by Fiala and Greene) which is guaranteed to run in linear amortized
571 * time, but has a larger average cost, uses more memory and is patented.
572 * However the F&G algorithm may be faster for some highly redundant
573 * files if the parameter max_chain_length (described below) is too large.
574 *
575 * ACKNOWLEDGEMENTS
576 *
577 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
578 * I found it in 'freeze' written by Leonid Broukhis.
579 * Thanks to many people for bug reports and testing.
580 *
581 * REFERENCES
582 *
583 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
584 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
585 *
586 * A description of the Rabin and Karp algorithm is given in the book
587 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
588 *
589 * Fiala,E.R., and Greene,D.H.
590 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
591 *
592 */
593
594 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
595
596 /* #include "deflate.h" */
597
598 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
599 /*
600 If you use the zlib library in a product, an acknowledgment is welcome
601 in the documentation of your product. If for some reason you cannot
602 include such an acknowledgment, I would appreciate that you keep this
603 copyright string in the executable of your product.
604 */
605
606 /* ===========================================================================
607 * Function prototypes.
608 */
609 typedef enum {
610 need_more, /* block not completed, need more input or more output */
611 block_done, /* block flush performed */
612 finish_started, /* finish started, need only more output at next deflate */
613 finish_done /* finish done, accept no more input or output */
614 } block_state;
615
616 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
617 /* Compression function. Returns the block state after the call. */
618
619 local void fill_window OF((deflate_state *s));
620 local block_state deflate_stored OF((deflate_state *s, int flush));
621 local block_state deflate_fast OF((deflate_state *s, int flush));
622 local block_state deflate_slow OF((deflate_state *s, int flush));
623 local void lm_init OF((deflate_state *s));
624 local void putShortMSB OF((deflate_state *s, uInt b));
625 local void flush_pending OF((z_streamp strm));
626 local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
627 #ifdef ASMV
628 void match_init OF((void)); /* asm code initialization */
629 uInt longest_match OF((deflate_state *s, IPos cur_match));
630 #else
631 local uInt longest_match OF((deflate_state *s, IPos cur_match));
632 #endif
633
634 #ifdef DEBUG_ZLIB
635 local void check_match OF((deflate_state *s, IPos start, IPos match,
636 int length));
637 #endif
638
639 /* ===========================================================================
640 * Local data
641 */
642
643 #define NIL 0
644 /* Tail of hash chains */
645
646 #ifndef TOO_FAR
647 # define TOO_FAR 4096
648 #endif
649 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
650
651 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
652 /* Minimum amount of lookahead, except at the end of the input file.
653 * See deflate.c for comments about the MIN_MATCH+1.
654 */
655
656 /* Values for max_lazy_match, good_match and max_chain_length, depending on
657 * the desired pack level (0..9). The values given below have been tuned to
658 * exclude worst case performance for pathological files. Better values may be
659 * found for specific files.
660 */
661 typedef struct config_s {
662 ush good_length; /* reduce lazy search above this match length */
663 ush max_lazy; /* do not perform lazy search above this match length */
664 ush nice_length; /* quit search above this match length */
665 ush max_chain;
666 compress_func func;
667 } config;
668
669 local config configuration_table[10] = {
670 /* good lazy nice chain */
671 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
672 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
673 /* 2 */ {4, 5, 16, 8, deflate_fast},
674 /* 3 */ {4, 6, 32, 32, deflate_fast},
675
676 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
677 /* 5 */ {8, 16, 32, 32, deflate_slow},
678 /* 6 */ {8, 16, 128, 128, deflate_slow},
679 /* 7 */ {8, 32, 128, 256, deflate_slow},
680 /* 8 */ {32, 128, 258, 1024, deflate_slow},
681 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
682
683 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
684 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
685 * meaning.
686 */
687
688 #define EQUAL 0
689 /* result of memcmp for equal strings */
690
691 #ifndef NO_DUMMY_DECL
692 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
693 #endif
694
695 /* ===========================================================================
696 * Update a hash value with the given input byte
697 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
698 * input characters, so that a running hash key can be computed from the
699 * previous key instead of complete recalculation each time.
700 */
701 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
702
703
704 /* ===========================================================================
705 * Insert string str in the dictionary and set match_head to the previous head
706 * of the hash chain (the most recent string with same hash key). Return
707 * the previous length of the hash chain.
708 * IN assertion: all calls to to INSERT_STRING are made with consecutive
709 * input characters and the first MIN_MATCH bytes of str are valid
710 * (except for the last MIN_MATCH-1 bytes of the input file).
711 */
712 #define INSERT_STRING(s, str, match_head) \
713 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
714 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
715 s->head[s->ins_h] = (Pos)(str))
716
717 /* ===========================================================================
718 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
719 * prev[] will be initialized on the fly.
720 */
721 #define CLEAR_HASH(s) \
722 s->head[s->hash_size-1] = NIL; \
723 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
724
725 /* ========================================================================= */
726 int deflateInit_(strm, level, version, stream_size)
727 z_streamp strm;
728 int level;
729 const char *version;
730 int stream_size;
731 {
732 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
733 Z_DEFAULT_STRATEGY, version, stream_size);
734 /* To do: ignore strm->next_in if we use it as window */
735 }
736
737 /* ========================================================================= */
738 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
739 version, stream_size)
740 z_streamp strm;
741 int level;
742 int method;
743 int windowBits;
744 int memLevel;
745 int strategy;
746 const char *version;
747 int stream_size;
748 {
749 deflate_state *s;
750 int noheader = 0;
751 static char* my_version = ZLIB_VERSION;
752
753 ushf *overlay;
754 /* We overlay pending_buf and d_buf+l_buf. This works since the average
755 * output size for (length,distance) codes is <= 24 bits.
756 */
757
758 if (version == Z_NULL || version[0] != my_version[0] ||
759 stream_size != sizeof(z_stream)) {
760 return Z_VERSION_ERROR;
761 }
762 if (strm == Z_NULL) return Z_STREAM_ERROR;
763
764 strm->msg = Z_NULL;
765 #ifndef NO_ZCFUNCS
766 if (strm->zalloc == Z_NULL) {
767 strm->zalloc = zcalloc;
768 strm->opaque = (voidpf)0;
769 }
770 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
771 #endif
772
773 if (level == Z_DEFAULT_COMPRESSION) level = 6;
774
775 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
776 noheader = 1;
777 windowBits = -windowBits;
778 }
779 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
780 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
781 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
782 return Z_STREAM_ERROR;
783 }
784 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
785 if (s == Z_NULL) return Z_MEM_ERROR;
786 strm->state = (struct internal_state FAR *)s;
787 s->strm = strm;
788
789 s->noheader = noheader;
790 s->w_bits = windowBits;
791 s->w_size = 1 << s->w_bits;
792 s->w_mask = s->w_size - 1;
793
794 s->hash_bits = memLevel + 7;
795 s->hash_size = 1 << s->hash_bits;
796 s->hash_mask = s->hash_size - 1;
797 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
798
799 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
800 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
801 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
802
803 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
804
805 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
806 s->pending_buf = (uchf *) overlay;
807 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
808
809 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
810 s->pending_buf == Z_NULL) {
811 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
812 deflateEnd (strm);
813 return Z_MEM_ERROR;
814 }
815 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
816 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
817
818 s->level = level;
819 s->strategy = strategy;
820 s->method = (Byte)method;
821
822 return deflateReset(strm);
823 }
824
825 /* ========================================================================= */
826 int deflateSetDictionary (strm, dictionary, dictLength)
827 z_streamp strm;
828 const Bytef *dictionary;
829 uInt dictLength;
830 {
831 deflate_state *s;
832 uInt length = dictLength;
833 uInt n;
834 IPos hash_head = 0;
835
836 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
837 return Z_STREAM_ERROR;
838
839 s = (deflate_state *) strm->state;
840 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
841
842 strm->adler = adler32(strm->adler, dictionary, dictLength);
843
844 if (length < MIN_MATCH) return Z_OK;
845 if (length > MAX_DIST(s)) {
846 length = MAX_DIST(s);
847 #ifndef USE_DICT_HEAD
848 dictionary += dictLength - length; /* use the tail of the dictionary */
849 #endif
850 }
851 zmemcpy((charf *)s->window, dictionary, length);
852 s->strstart = length;
853 s->block_start = (long)length;
854
855 /* Insert all strings in the hash table (except for the last two bytes).
856 * s->lookahead stays null, so s->ins_h will be recomputed at the next
857 * call of fill_window.
858 */
859 s->ins_h = s->window[0];
860 UPDATE_HASH(s, s->ins_h, s->window[1]);
861 for (n = 0; n <= length - MIN_MATCH; n++) {
862 INSERT_STRING(s, n, hash_head);
863 }
864 if (hash_head) hash_head = 0; /* to make compiler happy */
865 return Z_OK;
866 }
867
868 /* ========================================================================= */
869 int deflateReset (strm)
870 z_streamp strm;
871 {
872 deflate_state *s;
873
874 if (strm == Z_NULL || strm->state == Z_NULL ||
875 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
876
877 strm->total_in = strm->total_out = 0;
878 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
879 strm->data_type = Z_UNKNOWN;
880
881 s = (deflate_state *)strm->state;
882 s->pending = 0;
883 s->pending_out = s->pending_buf;
884
885 if (s->noheader < 0) {
886 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
887 }
888 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
889 strm->adler = 1;
890 s->last_flush = Z_NO_FLUSH;
891
892 _tr_init(s);
893 lm_init(s);
894
895 return Z_OK;
896 }
897
898 /* ========================================================================= */
899 int deflateParams(strm, level, strategy)
900 z_streamp strm;
901 int level;
902 int strategy;
903 {
904 deflate_state *s;
905 compress_func func;
906 int err = Z_OK;
907
908 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
909 s = (deflate_state *) strm->state;
910
911 if (level == Z_DEFAULT_COMPRESSION) {
912 level = 6;
913 }
914 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
915 return Z_STREAM_ERROR;
916 }
917 func = configuration_table[s->level].func;
918
919 if (func != configuration_table[level].func && strm->total_in != 0) {
920 /* Flush the last buffer: */
921 err = deflate(strm, Z_PARTIAL_FLUSH);
922 }
923 if (s->level != level) {
924 s->level = level;
925 s->max_lazy_match = configuration_table[level].max_lazy;
926 s->good_match = configuration_table[level].good_length;
927 s->nice_match = configuration_table[level].nice_length;
928 s->max_chain_length = configuration_table[level].max_chain;
929 }
930 s->strategy = strategy;
931 return err;
932 }
933
934 /* =========================================================================
935 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
936 * IN assertion: the stream state is correct and there is enough room in
937 * pending_buf.
938 */
939 local void putShortMSB (s, b)
940 deflate_state *s;
941 uInt b;
942 {
943 put_byte(s, (Byte)(b >> 8));
944 put_byte(s, (Byte)(b & 0xff));
945 }
946
947 /* =========================================================================
948 * Flush as much pending output as possible. All deflate() output goes
949 * through this function so some applications may wish to modify it
950 * to avoid allocating a large strm->next_out buffer and copying into it.
951 * (See also read_buf()).
952 */
953 local void flush_pending(strm)
954 z_streamp strm;
955 {
956 deflate_state *s = (deflate_state *) strm->state;
957 unsigned len = s->pending;
958
959 if (len > strm->avail_out) len = strm->avail_out;
960 if (len == 0) return;
961
962 if (strm->next_out != Z_NULL) {
963 zmemcpy(strm->next_out, s->pending_out, len);
964 strm->next_out += len;
965 }
966 s->pending_out += len;
967 strm->total_out += len;
968 strm->avail_out -= len;
969 s->pending -= len;
970 if (s->pending == 0) {
971 s->pending_out = s->pending_buf;
972 }
973 }
974
975 /* ========================================================================= */
976 int deflate (strm, flush)
977 z_streamp strm;
978 int flush;
979 {
980 int old_flush; /* value of flush param for previous deflate call */
981 deflate_state *s;
982
983 if (strm == Z_NULL || strm->state == Z_NULL ||
984 flush > Z_FINISH || flush < 0) {
985 return Z_STREAM_ERROR;
986 }
987 s = (deflate_state *) strm->state;
988
989 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
990 (s->status == FINISH_STATE && flush != Z_FINISH)) {
991 ERR_RETURN(strm, Z_STREAM_ERROR);
992 }
993 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
994
995 s->strm = strm; /* just in case */
996 old_flush = s->last_flush;
997 s->last_flush = flush;
998
999 /* Write the zlib header */
1000 if (s->status == INIT_STATE) {
1001
1002 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1003 uInt level_flags = (s->level-1) >> 1;
1004
1005 if (level_flags > 3) level_flags = 3;
1006 header |= (level_flags << 6);
1007 if (s->strstart != 0) header |= PRESET_DICT;
1008 header += 31 - (header % 31);
1009
1010 s->status = BUSY_STATE;
1011 putShortMSB(s, header);
1012
1013 /* Save the adler32 of the preset dictionary: */
1014 if (s->strstart != 0) {
1015 putShortMSB(s, (uInt)(strm->adler >> 16));
1016 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1017 }
1018 strm->adler = 1L;
1019 }
1020
1021 /* Flush as much pending output as possible */
1022 if (s->pending != 0) {
1023 flush_pending(strm);
1024 if (strm->avail_out == 0) {
1025 /* Since avail_out is 0, deflate will be called again with
1026 * more output space, but possibly with both pending and
1027 * avail_in equal to zero. There won't be anything to do,
1028 * but this is not an error situation so make sure we
1029 * return OK instead of BUF_ERROR at next call of deflate:
1030 */
1031 s->last_flush = -1;
1032 return Z_OK;
1033 }
1034
1035 /* Make sure there is something to do and avoid duplicate consecutive
1036 * flushes. For repeated and useless calls with Z_FINISH, we keep
1037 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1038 */
1039 } else if (strm->avail_in == 0 && flush <= old_flush &&
1040 flush != Z_FINISH) {
1041 ERR_RETURN(strm, Z_BUF_ERROR);
1042 }
1043
1044 /* User must not provide more input after the first FINISH: */
1045 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1046 ERR_RETURN(strm, Z_BUF_ERROR);
1047 }
1048
1049 /* Start a new block or continue the current one.
1050 */
1051 if (strm->avail_in != 0 || s->lookahead != 0 ||
1052 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1053 block_state bstate;
1054
1055 bstate = (*(configuration_table[s->level].func))(s, flush);
1056
1057 if (bstate == finish_started || bstate == finish_done) {
1058 s->status = FINISH_STATE;
1059 }
1060 if (bstate == need_more || bstate == finish_started) {
1061 if (strm->avail_out == 0) {
1062 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1063 }
1064 return Z_OK;
1065 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1066 * of deflate should use the same flush parameter to make sure
1067 * that the flush is complete. So we don't have to output an
1068 * empty block here, this will be done at next call. This also
1069 * ensures that for a very small output buffer, we emit at most
1070 * one empty block.
1071 */
1072 }
1073 if (bstate == block_done) {
1074 if (flush == Z_PARTIAL_FLUSH) {
1075 _tr_align(s);
1076 } else if (flush == Z_PACKET_FLUSH) {
1077 /* Output just the 3-bit `stored' block type value,
1078 but not a zero length. */
1079 _tr_stored_type_only(s);
1080 } else { /* FULL_FLUSH or SYNC_FLUSH */
1081 _tr_stored_block(s, (char*)0, 0L, 0);
1082 /* For a full flush, this empty block will be recognized
1083 * as a special marker by inflate_sync().
1084 */
1085 if (flush == Z_FULL_FLUSH) {
1086 CLEAR_HASH(s); /* forget history */
1087 }
1088 }
1089 flush_pending(strm);
1090 if (strm->avail_out == 0) {
1091 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1092 return Z_OK;
1093 }
1094 }
1095 }
1096 Assert(strm->avail_out > 0, "bug2");
1097
1098 if (flush != Z_FINISH) return Z_OK;
1099 if (s->noheader) return Z_STREAM_END;
1100
1101 /* Write the zlib trailer (adler32) */
1102 putShortMSB(s, (uInt)(strm->adler >> 16));
1103 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1104 flush_pending(strm);
1105 /* If avail_out is zero, the application will call deflate again
1106 * to flush the rest.
1107 */
1108 s->noheader = -1; /* write the trailer only once! */
1109 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1110 }
1111
1112 /* ========================================================================= */
1113 int deflateEnd (strm)
1114 z_streamp strm;
1115 {
1116 int status;
1117 deflate_state *s;
1118
1119 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1120 s = (deflate_state *) strm->state;
1121
1122 status = s->status;
1123 if (status != INIT_STATE && status != BUSY_STATE &&
1124 status != FINISH_STATE) {
1125 return Z_STREAM_ERROR;
1126 }
1127
1128 /* Deallocate in reverse order of allocations: */
1129 TRY_FREE(strm, s->pending_buf);
1130 TRY_FREE(strm, s->head);
1131 TRY_FREE(strm, s->prev);
1132 TRY_FREE(strm, s->window);
1133
1134 ZFREE(strm, s);
1135 strm->state = Z_NULL;
1136
1137 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1138 }
1139
1140 /* =========================================================================
1141 * Copy the source state to the destination state.
1142 */
1143 int deflateCopy (dest, source)
1144 z_streamp dest;
1145 z_streamp source;
1146 {
1147 deflate_state *ds;
1148 deflate_state *ss;
1149 ushf *overlay;
1150
1151 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1152 return Z_STREAM_ERROR;
1153 ss = (deflate_state *) source->state;
1154
1155 zmemcpy(dest, source, sizeof(*dest));
1156
1157 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1158 if (ds == Z_NULL) return Z_MEM_ERROR;
1159 dest->state = (struct internal_state FAR *) ds;
1160 zmemcpy(ds, ss, sizeof(*ds));
1161 ds->strm = dest;
1162
1163 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1164 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1165 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1166 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1167 ds->pending_buf = (uchf *) overlay;
1168
1169 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1170 ds->pending_buf == Z_NULL) {
1171 deflateEnd (dest);
1172 return Z_MEM_ERROR;
1173 }
1174 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1175 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1176 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1177 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1178 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1179
1180 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1181 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1182 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1183
1184 ds->l_desc.dyn_tree = ds->dyn_ltree;
1185 ds->d_desc.dyn_tree = ds->dyn_dtree;
1186 ds->bl_desc.dyn_tree = ds->bl_tree;
1187
1188 return Z_OK;
1189 }
1190
1191 /* ===========================================================================
1192 * Return the number of bytes of output which are immediately available
1193 * for output from the decompressor.
1194 */
1195 int deflateOutputPending (strm)
1196 z_streamp strm;
1197 {
1198 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1199
1200 return ((deflate_state *)(strm->state))->pending;
1201 }
1202
1203 /* ===========================================================================
1204 * Read a new buffer from the current input stream, update the adler32
1205 * and total number of bytes read. All deflate() input goes through
1206 * this function so some applications may wish to modify it to avoid
1207 * allocating a large strm->next_in buffer and copying from it.
1208 * (See also flush_pending()).
1209 */
1210 local int read_buf(strm, buf, size)
1211 z_streamp strm;
1212 charf *buf;
1213 unsigned size;
1214 {
1215 unsigned len = strm->avail_in;
1216
1217 if (len > size) len = size;
1218 if (len == 0) return 0;
1219
1220 strm->avail_in -= len;
1221
1222 if (!((deflate_state *)(strm->state))->noheader) {
1223 strm->adler = adler32(strm->adler, strm->next_in, len);
1224 }
1225 zmemcpy(buf, strm->next_in, len);
1226 strm->next_in += len;
1227 strm->total_in += len;
1228
1229 return (int)len;
1230 }
1231
1232 /* ===========================================================================
1233 * Initialize the "longest match" routines for a new zlib stream
1234 */
1235 local void lm_init (s)
1236 deflate_state *s;
1237 {
1238 s->window_size = (ulg)2L*s->w_size;
1239
1240 CLEAR_HASH(s);
1241
1242 /* Set the default configuration parameters:
1243 */
1244 s->max_lazy_match = configuration_table[s->level].max_lazy;
1245 s->good_match = configuration_table[s->level].good_length;
1246 s->nice_match = configuration_table[s->level].nice_length;
1247 s->max_chain_length = configuration_table[s->level].max_chain;
1248
1249 s->strstart = 0;
1250 s->block_start = 0L;
1251 s->lookahead = 0;
1252 s->match_length = s->prev_length = MIN_MATCH-1;
1253 s->match_available = 0;
1254 s->ins_h = 0;
1255 #ifdef ASMV
1256 match_init(); /* initialize the asm code */
1257 #endif
1258 }
1259
1260 /* ===========================================================================
1261 * Set match_start to the longest match starting at the given string and
1262 * return its length. Matches shorter or equal to prev_length are discarded,
1263 * in which case the result is equal to prev_length and match_start is
1264 * garbage.
1265 * IN assertions: cur_match is the head of the hash chain for the current
1266 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1267 * OUT assertion: the match length is not greater than s->lookahead.
1268 */
1269 #ifndef ASMV
1270 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1271 * match.S. The code will be functionally equivalent.
1272 */
1273 local uInt longest_match(s, cur_match)
1274 deflate_state *s;
1275 IPos cur_match; /* current match */
1276 {
1277 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1278 register Bytef *scan = s->window + s->strstart; /* current string */
1279 register Bytef *match; /* matched string */
1280 register int len; /* length of current match */
1281 int best_len = s->prev_length; /* best match length so far */
1282 int nice_match = s->nice_match; /* stop if match long enough */
1283 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1284 s->strstart - (IPos)MAX_DIST(s) : NIL;
1285 /* Stop when cur_match becomes <= limit. To simplify the code,
1286 * we prevent matches with the string of window index 0.
1287 */
1288 Posf *prev = s->prev;
1289 uInt wmask = s->w_mask;
1290
1291 #ifdef UNALIGNED_OK
1292 /* Compare two bytes at a time. Note: this is not always beneficial.
1293 * Try with and without -DUNALIGNED_OK to check.
1294 */
1295 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1296 register ush scan_start = *(ushf*)scan;
1297 register ush scan_end = *(ushf*)(scan+best_len-1);
1298 #else
1299 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1300 register Byte scan_end1 = scan[best_len-1];
1301 register Byte scan_end = scan[best_len];
1302 #endif
1303
1304 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1305 * It is easy to get rid of this optimization if necessary.
1306 */
1307 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1308
1309 /* Do not waste too much time if we already have a good match: */
1310 if (s->prev_length >= s->good_match) {
1311 chain_length >>= 2;
1312 }
1313 /* Do not look for matches beyond the end of the input. This is necessary
1314 * to make deflate deterministic.
1315 */
1316 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1317
1318 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1319
1320 do {
1321 Assert(cur_match < s->strstart, "no future");
1322 match = s->window + cur_match;
1323
1324 /* Skip to next match if the match length cannot increase
1325 * or if the match length is less than 2:
1326 */
1327 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1328 /* This code assumes sizeof(unsigned short) == 2. Do not use
1329 * UNALIGNED_OK if your compiler uses a different size.
1330 */
1331 if (*(ushf*)(match+best_len-1) != scan_end ||
1332 *(ushf*)match != scan_start) continue;
1333
1334 /* It is not necessary to compare scan[2] and match[2] since they are
1335 * always equal when the other bytes match, given that the hash keys
1336 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1337 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1338 * lookahead only every 4th comparison; the 128th check will be made
1339 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1340 * necessary to put more guard bytes at the end of the window, or
1341 * to check more often for insufficient lookahead.
1342 */
1343 Assert(scan[2] == match[2], "scan[2]?");
1344 scan++, match++;
1345 do {
1346 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1347 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1348 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1349 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1350 scan < strend);
1351 /* The funny "do {}" generates better code on most compilers */
1352
1353 /* Here, scan <= window+strstart+257 */
1354 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1355 if (*scan == *match) scan++;
1356
1357 len = (MAX_MATCH - 1) - (int)(strend-scan);
1358 scan = strend - (MAX_MATCH-1);
1359
1360 #else /* UNALIGNED_OK */
1361
1362 if (match[best_len] != scan_end ||
1363 match[best_len-1] != scan_end1 ||
1364 *match != *scan ||
1365 *++match != scan[1]) continue;
1366
1367 /* The check at best_len-1 can be removed because it will be made
1368 * again later. (This heuristic is not always a win.)
1369 * It is not necessary to compare scan[2] and match[2] since they
1370 * are always equal when the other bytes match, given that
1371 * the hash keys are equal and that HASH_BITS >= 8.
1372 */
1373 scan += 2, match++;
1374 Assert(*scan == *match, "match[2]?");
1375
1376 /* We check for insufficient lookahead only every 8th comparison;
1377 * the 256th check will be made at strstart+258.
1378 */
1379 do {
1380 } while (*++scan == *++match && *++scan == *++match &&
1381 *++scan == *++match && *++scan == *++match &&
1382 *++scan == *++match && *++scan == *++match &&
1383 *++scan == *++match && *++scan == *++match &&
1384 scan < strend);
1385
1386 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1387
1388 len = MAX_MATCH - (int)(strend - scan);
1389 scan = strend - MAX_MATCH;
1390
1391 #endif /* UNALIGNED_OK */
1392
1393 if (len > best_len) {
1394 s->match_start = cur_match;
1395 best_len = len;
1396 if (len >= nice_match) break;
1397 #ifdef UNALIGNED_OK
1398 scan_end = *(ushf*)(scan+best_len-1);
1399 #else
1400 scan_end1 = scan[best_len-1];
1401 scan_end = scan[best_len];
1402 #endif
1403 }
1404 } while ((cur_match = prev[cur_match & wmask]) > limit
1405 && --chain_length != 0);
1406
1407 if ((uInt)best_len <= s->lookahead) return best_len;
1408 return s->lookahead;
1409 }
1410 #endif /* ASMV */
1411
1412 #ifdef DEBUG_ZLIB
1413 /* ===========================================================================
1414 * Check that the match at match_start is indeed a match.
1415 */
1416 local void check_match(s, start, match, length)
1417 deflate_state *s;
1418 IPos start, match;
1419 int length;
1420 {
1421 /* check that the match is indeed a match */
1422 if (zmemcmp((charf *)s->window + match,
1423 (charf *)s->window + start, length) != EQUAL) {
1424 fprintf(stderr, " start %u, match %u, length %d\n",
1425 start, match, length);
1426 do {
1427 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1428 } while (--length != 0);
1429 z_error("invalid match");
1430 }
1431 if (z_verbose > 1) {
1432 fprintf(stderr,"\\[%d,%d]", start-match, length);
1433 do { putc(s->window[start++], stderr); } while (--length != 0);
1434 }
1435 }
1436 #else
1437 # define check_match(s, start, match, length)
1438 #endif
1439
1440 /* ===========================================================================
1441 * Fill the window when the lookahead becomes insufficient.
1442 * Updates strstart and lookahead.
1443 *
1444 * IN assertion: lookahead < MIN_LOOKAHEAD
1445 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1446 * At least one byte has been read, or avail_in == 0; reads are
1447 * performed for at least two bytes (required for the zip translate_eol
1448 * option -- not supported here).
1449 */
1450 local void fill_window(s)
1451 deflate_state *s;
1452 {
1453 register unsigned n, m;
1454 register Posf *p;
1455 unsigned more; /* Amount of free space at the end of the window. */
1456 uInt wsize = s->w_size;
1457
1458 do {
1459 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1460
1461 /* Deal with !@#$% 64K limit: */
1462 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1463 more = wsize;
1464
1465 } else if (more == (unsigned)(-1)) {
1466 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1467 * and lookahead == 1 (input done one byte at time)
1468 */
1469 more--;
1470
1471 /* If the window is almost full and there is insufficient lookahead,
1472 * move the upper half to the lower one to make room in the upper half.
1473 */
1474 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1475
1476 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1477 (unsigned)wsize);
1478 s->match_start -= wsize;
1479 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1480 s->block_start -= (long) wsize;
1481
1482 /* Slide the hash table (could be avoided with 32 bit values
1483 at the expense of memory usage). We slide even when level == 0
1484 to keep the hash table consistent if we switch back to level > 0
1485 later. (Using level 0 permanently is not an optimal usage of
1486 zlib, so we don't care about this pathological case.)
1487 */
1488 n = s->hash_size;
1489 p = &s->head[n];
1490 do {
1491 m = *--p;
1492 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1493 } while (--n);
1494
1495 n = wsize;
1496 p = &s->prev[n];
1497 do {
1498 m = *--p;
1499 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1500 /* If n is not on any hash chain, prev[n] is garbage but
1501 * its value will never be used.
1502 */
1503 } while (--n);
1504 more += wsize;
1505 }
1506 if (s->strm->avail_in == 0) return;
1507
1508 /* If there was no sliding:
1509 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1510 * more == window_size - lookahead - strstart
1511 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1512 * => more >= window_size - 2*WSIZE + 2
1513 * In the BIG_MEM or MMAP case (not yet supported),
1514 * window_size == input_size + MIN_LOOKAHEAD &&
1515 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1516 * Otherwise, window_size == 2*WSIZE so more >= 2.
1517 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1518 */
1519 Assert(more >= 2, "more < 2");
1520
1521 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1522 more);
1523 s->lookahead += n;
1524
1525 /* Initialize the hash value now that we have some input: */
1526 if (s->lookahead >= MIN_MATCH) {
1527 s->ins_h = s->window[s->strstart];
1528 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1529 #if MIN_MATCH != 3
1530 Call UPDATE_HASH() MIN_MATCH-3 more times
1531 #endif
1532 }
1533 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1534 * but this is not important since only literal bytes will be emitted.
1535 */
1536
1537 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1538 }
1539
1540 /* ===========================================================================
1541 * Flush the current block, with given end-of-file flag.
1542 * IN assertion: strstart is set to the end of the current match.
1543 */
1544 #define FLUSH_BLOCK_ONLY(s, eof) { \
1545 _tr_flush_block(s, (s->block_start >= 0L ? \
1546 (charf *)&s->window[(unsigned)s->block_start] : \
1547 (charf *)Z_NULL), \
1548 (ulg)((long)s->strstart - s->block_start), \
1549 (eof)); \
1550 s->block_start = s->strstart; \
1551 flush_pending(s->strm); \
1552 Tracev((stderr,"[FLUSH]")); \
1553 }
1554
1555 /* Same but force premature exit if necessary. */
1556 #define FLUSH_BLOCK(s, eof) { \
1557 FLUSH_BLOCK_ONLY(s, eof); \
1558 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1559 }
1560
1561 /* ===========================================================================
1562 * Copy without compression as much as possible from the input stream, return
1563 * the current block state.
1564 * This function does not insert new strings in the dictionary since
1565 * uncompressible data is probably not useful. This function is used
1566 * only for the level=0 compression option.
1567 * NOTE: this function should be optimized to avoid extra copying from
1568 * window to pending_buf.
1569 */
1570 local block_state deflate_stored(s, flush)
1571 deflate_state *s;
1572 int flush;
1573 {
1574 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1575 * to pending_buf_size, and each stored block has a 5 byte header:
1576 */
1577 ulg max_block_size = 0xffff;
1578 ulg max_start;
1579
1580 if (max_block_size > s->pending_buf_size - 5) {
1581 max_block_size = s->pending_buf_size - 5;
1582 }
1583
1584 /* Copy as much as possible from input to output: */
1585 for (;;) {
1586 /* Fill the window as much as possible: */
1587 if (s->lookahead <= 1) {
1588
1589 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1590 s->block_start >= (long)s->w_size, "slide too late");
1591
1592 fill_window(s);
1593 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1594
1595 if (s->lookahead == 0) break; /* flush the current block */
1596 }
1597 Assert(s->block_start >= 0L, "block gone");
1598
1599 s->strstart += s->lookahead;
1600 s->lookahead = 0;
1601
1602 /* Emit a stored block if pending_buf will be full: */
1603 max_start = s->block_start + max_block_size;
1604 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1605 /* strstart == 0 is possible when wraparound on 16-bit machine */
1606 s->lookahead = (uInt)(s->strstart - max_start);
1607 s->strstart = (uInt)max_start;
1608 FLUSH_BLOCK(s, 0);
1609 }
1610 /* Flush if we may have to slide, otherwise block_start may become
1611 * negative and the data will be gone:
1612 */
1613 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1614 FLUSH_BLOCK(s, 0);
1615 }
1616 }
1617 FLUSH_BLOCK(s, flush == Z_FINISH);
1618 return flush == Z_FINISH ? finish_done : block_done;
1619 }
1620
1621 /* ===========================================================================
1622 * Compress as much as possible from the input stream, return the current
1623 * block state.
1624 * This function does not perform lazy evaluation of matches and inserts
1625 * new strings in the dictionary only for unmatched strings or for short
1626 * matches. It is used only for the fast compression options.
1627 */
1628 local block_state deflate_fast(s, flush)
1629 deflate_state *s;
1630 int flush;
1631 {
1632 IPos hash_head = NIL; /* head of the hash chain */
1633 int bflush; /* set if current block must be flushed */
1634
1635 for (;;) {
1636 /* Make sure that we always have enough lookahead, except
1637 * at the end of the input file. We need MAX_MATCH bytes
1638 * for the next match, plus MIN_MATCH bytes to insert the
1639 * string following the next match.
1640 */
1641 if (s->lookahead < MIN_LOOKAHEAD) {
1642 fill_window(s);
1643 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1644 return need_more;
1645 }
1646 if (s->lookahead == 0) break; /* flush the current block */
1647 }
1648
1649 /* Insert the string window[strstart .. strstart+2] in the
1650 * dictionary, and set hash_head to the head of the hash chain:
1651 */
1652 if (s->lookahead >= MIN_MATCH) {
1653 INSERT_STRING(s, s->strstart, hash_head);
1654 }
1655
1656 /* Find the longest match, discarding those <= prev_length.
1657 * At this point we have always match_length < MIN_MATCH
1658 */
1659 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1660 /* To simplify the code, we prevent matches with the string
1661 * of window index 0 (in particular we have to avoid a match
1662 * of the string with itself at the start of the input file).
1663 */
1664 if (s->strategy != Z_HUFFMAN_ONLY) {
1665 s->match_length = longest_match (s, hash_head);
1666 }
1667 /* longest_match() sets match_start */
1668 }
1669 if (s->match_length >= MIN_MATCH) {
1670 check_match(s, s->strstart, s->match_start, s->match_length);
1671
1672 bflush = _tr_tally(s, s->strstart - s->match_start,
1673 s->match_length - MIN_MATCH);
1674
1675 s->lookahead -= s->match_length;
1676
1677 /* Insert new strings in the hash table only if the match length
1678 * is not too large. This saves time but degrades compression.
1679 */
1680 if (s->match_length <= s->max_insert_length &&
1681 s->lookahead >= MIN_MATCH) {
1682 s->match_length--; /* string at strstart already in hash table */
1683 do {
1684 s->strstart++;
1685 INSERT_STRING(s, s->strstart, hash_head);
1686 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1687 * always MIN_MATCH bytes ahead.
1688 */
1689 } while (--s->match_length != 0);
1690 s->strstart++;
1691 } else {
1692 s->strstart += s->match_length;
1693 s->match_length = 0;
1694 s->ins_h = s->window[s->strstart];
1695 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1696 #if MIN_MATCH != 3
1697 Call UPDATE_HASH() MIN_MATCH-3 more times
1698 #endif
1699 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1700 * matter since it will be recomputed at next deflate call.
1701 */
1702 }
1703 } else {
1704 /* No match, output a literal byte */
1705 Tracevv((stderr,"%c", s->window[s->strstart]));
1706 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1707 s->lookahead--;
1708 s->strstart++;
1709 }
1710 if (bflush) FLUSH_BLOCK(s, 0);
1711 }
1712 FLUSH_BLOCK(s, flush == Z_FINISH);
1713 return flush == Z_FINISH ? finish_done : block_done;
1714 }
1715
1716 /* ===========================================================================
1717 * Same as above, but achieves better compression. We use a lazy
1718 * evaluation for matches: a match is finally adopted only if there is
1719 * no better match at the next window position.
1720 */
1721 local block_state deflate_slow(s, flush)
1722 deflate_state *s;
1723 int flush;
1724 {
1725 IPos hash_head = NIL; /* head of hash chain */
1726 int bflush; /* set if current block must be flushed */
1727
1728 /* Process the input block. */
1729 for (;;) {
1730 /* Make sure that we always have enough lookahead, except
1731 * at the end of the input file. We need MAX_MATCH bytes
1732 * for the next match, plus MIN_MATCH bytes to insert the
1733 * string following the next match.
1734 */
1735 if (s->lookahead < MIN_LOOKAHEAD) {
1736 fill_window(s);
1737 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1738 return need_more;
1739 }
1740 if (s->lookahead == 0) break; /* flush the current block */
1741 }
1742
1743 /* Insert the string window[strstart .. strstart+2] in the
1744 * dictionary, and set hash_head to the head of the hash chain:
1745 */
1746 if (s->lookahead >= MIN_MATCH) {
1747 INSERT_STRING(s, s->strstart, hash_head);
1748 }
1749
1750 /* Find the longest match, discarding those <= prev_length.
1751 */
1752 s->prev_length = s->match_length, s->prev_match = s->match_start;
1753 s->match_length = MIN_MATCH-1;
1754
1755 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1756 s->strstart - hash_head <= MAX_DIST(s)) {
1757 /* To simplify the code, we prevent matches with the string
1758 * of window index 0 (in particular we have to avoid a match
1759 * of the string with itself at the start of the input file).
1760 */
1761 if (s->strategy != Z_HUFFMAN_ONLY) {
1762 s->match_length = longest_match (s, hash_head);
1763 }
1764 /* longest_match() sets match_start */
1765
1766 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1767 (s->match_length == MIN_MATCH &&
1768 s->strstart - s->match_start > TOO_FAR))) {
1769
1770 /* If prev_match is also MIN_MATCH, match_start is garbage
1771 * but we will ignore the current match anyway.
1772 */
1773 s->match_length = MIN_MATCH-1;
1774 }
1775 }
1776 /* If there was a match at the previous step and the current
1777 * match is not better, output the previous match:
1778 */
1779 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1780 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1781 /* Do not insert strings in hash table beyond this. */
1782
1783 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1784
1785 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1786 s->prev_length - MIN_MATCH);
1787
1788 /* Insert in hash table all strings up to the end of the match.
1789 * strstart-1 and strstart are already inserted. If there is not
1790 * enough lookahead, the last two strings are not inserted in
1791 * the hash table.
1792 */
1793 s->lookahead -= s->prev_length-1;
1794 s->prev_length -= 2;
1795 do {
1796 if (++s->strstart <= max_insert) {
1797 INSERT_STRING(s, s->strstart, hash_head);
1798 }
1799 } while (--s->prev_length != 0);
1800 s->match_available = 0;
1801 s->match_length = MIN_MATCH-1;
1802 s->strstart++;
1803
1804 if (bflush) FLUSH_BLOCK(s, 0);
1805
1806 } else if (s->match_available) {
1807 /* If there was no match at the previous position, output a
1808 * single literal. If there was a match but the current match
1809 * is longer, truncate the previous match to a single literal.
1810 */
1811 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1812 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1813 FLUSH_BLOCK_ONLY(s, 0);
1814 }
1815 s->strstart++;
1816 s->lookahead--;
1817 if (s->strm->avail_out == 0) return need_more;
1818 } else {
1819 /* There is no previous match to compare with, wait for
1820 * the next step to decide.
1821 */
1822 s->match_available = 1;
1823 s->strstart++;
1824 s->lookahead--;
1825 }
1826 }
1827 Assert (flush != Z_NO_FLUSH, "no flush?");
1828 if (s->match_available) {
1829 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1830 _tr_tally (s, 0, s->window[s->strstart-1]);
1831 s->match_available = 0;
1832 }
1833 FLUSH_BLOCK(s, flush == Z_FINISH);
1834 return flush == Z_FINISH ? finish_done : block_done;
1835 }
1836 /* --- deflate.c */
1837
1838 /* +++ trees.c */
1839 /* trees.c -- output deflated data using Huffman coding
1840 * Copyright (C) 1995-1996 Jean-loup Gailly
1841 * For conditions of distribution and use, see copyright notice in zlib.h
1842 */
1843
1844 /*
1845 * ALGORITHM
1846 *
1847 * The "deflation" process uses several Huffman trees. The more
1848 * common source values are represented by shorter bit sequences.
1849 *
1850 * Each code tree is stored in a compressed form which is itself
1851 * a Huffman encoding of the lengths of all the code strings (in
1852 * ascending order by source values). The actual code strings are
1853 * reconstructed from the lengths in the inflate process, as described
1854 * in the deflate specification.
1855 *
1856 * REFERENCES
1857 *
1858 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1859 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1860 *
1861 * Storer, James A.
1862 * Data Compression: Methods and Theory, pp. 49-50.
1863 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1864 *
1865 * Sedgewick, R.
1866 * Algorithms, p290.
1867 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1868 */
1869
1870 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1871
1872 /* #include "deflate.h" */
1873
1874 #ifdef DEBUG_ZLIB
1875 # include <ctype.h>
1876 #endif
1877
1878 /* ===========================================================================
1879 * Constants
1880 */
1881
1882 #define MAX_BL_BITS 7
1883 /* Bit length codes must not exceed MAX_BL_BITS bits */
1884
1885 #define END_BLOCK 256
1886 /* end of block literal code */
1887
1888 #define REP_3_6 16
1889 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1890
1891 #define REPZ_3_10 17
1892 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1893
1894 #define REPZ_11_138 18
1895 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1896
1897 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1898 = {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};
1899
1900 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1901 = {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};
1902
1903 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1904 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1905
1906 local uch bl_order[BL_CODES]
1907 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1908 /* The lengths of the bit length codes are sent in order of decreasing
1909 * probability, to avoid transmitting the lengths for unused bit length codes.
1910 */
1911
1912 #define Buf_size (8 * 2*sizeof(char))
1913 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1914 * more than 16 bits on some systems.)
1915 */
1916
1917 /* ===========================================================================
1918 * Local data. These are initialized only once.
1919 */
1920
1921 local ct_data static_ltree[L_CODES+2];
1922 /* The static literal tree. Since the bit lengths are imposed, there is no
1923 * need for the L_CODES extra codes used during heap construction. However
1924 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1925 * below).
1926 */
1927
1928 local ct_data static_dtree[D_CODES];
1929 /* The static distance tree. (Actually a trivial tree since all codes use
1930 * 5 bits.)
1931 */
1932
1933 local uch dist_code[512];
1934 /* distance codes. The first 256 values correspond to the distances
1935 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1936 * the 15 bit distances.
1937 */
1938
1939 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1940 /* length code for each normalized match length (0 == MIN_MATCH) */
1941
1942 local int base_length[LENGTH_CODES];
1943 /* First normalized length for each code (0 = MIN_MATCH) */
1944
1945 local int base_dist[D_CODES];
1946 /* First normalized distance for each code (0 = distance of 1) */
1947
1948 struct static_tree_desc_s {
1949 ct_data *static_tree; /* static tree or NULL */
1950 intf *extra_bits; /* extra bits for each code or NULL */
1951 int extra_base; /* base index for extra_bits */
1952 int elems; /* max number of elements in the tree */
1953 int max_length; /* max bit length for the codes */
1954 };
1955
1956 local static_tree_desc static_l_desc =
1957 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1958
1959 local static_tree_desc static_d_desc =
1960 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1961
1962 local static_tree_desc static_bl_desc =
1963 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1964
1965 /* ===========================================================================
1966 * Local (static) routines in this file.
1967 */
1968
1969 local void tr_static_init OF((void));
1970 local void init_block OF((deflate_state *s));
1971 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1972 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1973 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1974 local void build_tree OF((deflate_state *s, tree_desc *desc));
1975 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1976 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1977 local int build_bl_tree OF((deflate_state *s));
1978 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1979 int blcodes));
1980 local void compress_block OF((deflate_state *s, ct_data *ltree,
1981 ct_data *dtree));
1982 local void set_data_type OF((deflate_state *s));
1983 local unsigned bi_reverse OF((unsigned value, int length));
1984 local void bi_windup OF((deflate_state *s));
1985 local void bi_flush OF((deflate_state *s));
1986 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1987 int header));
1988
1989 #ifndef DEBUG_ZLIB
1990 # define send_code(s, c, tree) send_bits(s, tree[(c)].Code, tree[(c)].Len)
1991 /* Send a code of the given tree. c and tree must not have side effects */
1992
1993 #else /* DEBUG_ZLIB */
1994 # define send_code(s, c, tree) \
1995 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
1996 send_bits(s, tree[c].Code, tree[c].Len); }
1997 #endif
1998
1999 #define d_code(dist) \
2000 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2001 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2002 * must not have side effects. dist_code[256] and dist_code[257] are never
2003 * used.
2004 */
2005
2006 /* ===========================================================================
2007 * Output a short LSB first on the stream.
2008 * IN assertion: there is enough room in pendingBuf.
2009 */
2010 #define put_short(s, w) { \
2011 put_byte(s, (uch)((w) & 0xff)); \
2012 put_byte(s, (uch)((ush)(w) >> 8)); \
2013 }
2014
2015 /* ===========================================================================
2016 * Send a value on a given number of bits.
2017 * IN assertion: length <= 16 and value fits in length bits.
2018 */
2019 #ifdef DEBUG_ZLIB
2020 local void send_bits OF((deflate_state *s, int value, int length));
2021
2022 local void send_bits(s, value, length)
2023 deflate_state *s;
2024 int value; /* value to send */
2025 int length; /* number of bits */
2026 {
2027 Tracevv((stderr," l %2d v %4x ", length, value));
2028 Assert(length > 0 && length <= 15, "invalid length");
2029 s->bits_sent += (ulg)length;
2030
2031 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2032 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2033 * unused bits in value.
2034 */
2035 if (s->bi_valid > (int)Buf_size - length) {
2036 s->bi_buf |= (value << s->bi_valid);
2037 put_short(s, s->bi_buf);
2038 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2039 s->bi_valid += length - Buf_size;
2040 } else {
2041 s->bi_buf |= value << s->bi_valid;
2042 s->bi_valid += length;
2043 }
2044 }
2045 #else /* !DEBUG_ZLIB */
2046
2047 #define send_bits(s, value, length) \
2048 { int len = (length);\
2049 if ((s)->bi_valid > (int)Buf_size - len) {\
2050 int val = (value);\
2051 (s)->bi_buf |= (val << (s)->bi_valid);\
2052 put_short((s), (s)->bi_buf);\
2053 (s)->bi_buf = (ush)val >> (Buf_size - (s)->bi_valid);\
2054 (s)->bi_valid += len - Buf_size;\
2055 } else {\
2056 (s)->bi_buf |= (value) << (s)->bi_valid;\
2057 (s)->bi_valid += len;\
2058 }\
2059 }
2060 #endif /* DEBUG_ZLIB */
2061
2062 /* the arguments must not have side effects */
2063
2064 /* ===========================================================================
2065 * Initialize the various 'constant' tables. In a multi-threaded environment,
2066 * this function may be called by two threads concurrently, but this is
2067 * harmless since both invocations do exactly the same thing.
2068 */
2069 local void tr_static_init()
2070 {
2071 static int static_init_done = 0;
2072 int n; /* iterates over tree elements */
2073 int bits; /* bit counter */
2074 int length; /* length value */
2075 int code; /* code value */
2076 int dist; /* distance index */
2077 ush bl_count[MAX_BITS+1];
2078 /* number of codes at each bit length for an optimal tree */
2079
2080 if (static_init_done) return;
2081
2082 /* Initialize the mapping length (0..255) -> length code (0..28) */
2083 length = 0;
2084 for (code = 0; code < LENGTH_CODES-1; code++) {
2085 base_length[code] = length;
2086 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2087 length_code[length++] = (uch)code;
2088 }
2089 }
2090 Assert (length == 256, "tr_static_init: length != 256");
2091 /* Note that the length 255 (match length 258) can be represented
2092 * in two different ways: code 284 + 5 bits or code 285, so we
2093 * overwrite length_code[255] to use the best encoding:
2094 */
2095 length_code[length-1] = (uch)code;
2096
2097 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2098 dist = 0;
2099 for (code = 0 ; code < 16; code++) {
2100 base_dist[code] = dist;
2101 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2102 dist_code[dist++] = (uch)code;
2103 }
2104 }
2105 Assert (dist == 256, "tr_static_init: dist != 256");
2106 dist >>= 7; /* from now on, all distances are divided by 128 */
2107 for ( ; code < D_CODES; code++) {
2108 base_dist[code] = dist << 7;
2109 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2110 dist_code[256 + dist++] = (uch)code;
2111 }
2112 }
2113 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2114
2115 /* Construct the codes of the static literal tree */
2116 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2117 n = 0;
2118 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2119 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2120 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2121 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2122 /* Codes 286 and 287 do not exist, but we must include them in the
2123 * tree construction to get a canonical Huffman tree (longest code
2124 * all ones)
2125 */
2126 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2127
2128 /* The static distance tree is trivial: */
2129 for (n = 0; n < D_CODES; n++) {
2130 static_dtree[n].Len = 5;
2131 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2132 }
2133 static_init_done = 1;
2134 }
2135
2136 /* ===========================================================================
2137 * Initialize the tree data structures for a new zlib stream.
2138 */
2139 void _tr_init(s)
2140 deflate_state *s;
2141 {
2142 tr_static_init();
2143
2144 s->compressed_len = 0L;
2145
2146 s->l_desc.dyn_tree = s->dyn_ltree;
2147 s->l_desc.stat_desc = &static_l_desc;
2148
2149 s->d_desc.dyn_tree = s->dyn_dtree;
2150 s->d_desc.stat_desc = &static_d_desc;
2151
2152 s->bl_desc.dyn_tree = s->bl_tree;
2153 s->bl_desc.stat_desc = &static_bl_desc;
2154
2155 s->bi_buf = 0;
2156 s->bi_valid = 0;
2157 s->last_eob_len = 8; /* enough lookahead for inflate */
2158 #ifdef DEBUG_ZLIB
2159 s->bits_sent = 0L;
2160 #endif
2161
2162 /* Initialize the first block of the first file: */
2163 init_block(s);
2164 }
2165
2166 /* ===========================================================================
2167 * Initialize a new block.
2168 */
2169 local void init_block(s)
2170 deflate_state *s;
2171 {
2172 int n; /* iterates over tree elements */
2173
2174 /* Initialize the trees. */
2175 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2176 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2177 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2178
2179 s->dyn_ltree[END_BLOCK].Freq = 1;
2180 s->opt_len = s->static_len = 0L;
2181 s->last_lit = s->matches = 0;
2182 }
2183
2184 #define SMALLEST 1
2185 /* Index within the heap array of least frequent node in the Huffman tree */
2186
2187
2188 /* ===========================================================================
2189 * Remove the smallest element from the heap and recreate the heap with
2190 * one less element. Updates heap and heap_len.
2191 */
2192 #define pqremove(s, tree, top) \
2193 {\
2194 top = s->heap[SMALLEST]; \
2195 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2196 pqdownheap(s, tree, SMALLEST); \
2197 }
2198
2199 /* ===========================================================================
2200 * Compares to subtrees, using the tree depth as tie breaker when
2201 * the subtrees have equal frequency. This minimizes the worst case length.
2202 */
2203 #define smaller(tree, n, m, depth) \
2204 (tree[n].Freq < tree[m].Freq || \
2205 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2206
2207 /* ===========================================================================
2208 * Restore the heap property by moving down the tree starting at node k,
2209 * exchanging a node with the smallest of its two sons if necessary, stopping
2210 * when the heap property is re-established (each father smaller than its
2211 * two sons).
2212 */
2213 local void pqdownheap(s, tree, k)
2214 deflate_state *s;
2215 ct_data *tree; /* the tree to restore */
2216 int k; /* node to move down */
2217 {
2218 int v = s->heap[k];
2219 int j = k << 1; /* left son of k */
2220 while (j <= s->heap_len) {
2221 /* Set j to the smallest of the two sons: */
2222 if (j < s->heap_len &&
2223 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2224 j++;
2225 }
2226 /* Exit if v is smaller than both sons */
2227 if (smaller(tree, v, s->heap[j], s->depth)) break;
2228
2229 /* Exchange v with the smallest son */
2230 s->heap[k] = s->heap[j]; k = j;
2231
2232 /* And continue down the tree, setting j to the left son of k */
2233 j <<= 1;
2234 }
2235 s->heap[k] = v;
2236 }
2237
2238 /* ===========================================================================
2239 * Compute the optimal bit lengths for a tree and update the total bit length
2240 * for the current block.
2241 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2242 * above are the tree nodes sorted by increasing frequency.
2243 * OUT assertions: the field len is set to the optimal bit length, the
2244 * array bl_count contains the frequencies for each bit length.
2245 * The length opt_len is updated; static_len is also updated if stree is
2246 * not null.
2247 */
2248 local void gen_bitlen(s, desc)
2249 deflate_state *s;
2250 tree_desc *desc; /* the tree descriptor */
2251 {
2252 ct_data *tree = desc->dyn_tree;
2253 int max_code = desc->max_code;
2254 ct_data *stree = desc->stat_desc->static_tree;
2255 intf *extra = desc->stat_desc->extra_bits;
2256 int base = desc->stat_desc->extra_base;
2257 int max_length = desc->stat_desc->max_length;
2258 int h; /* heap index */
2259 int n, m; /* iterate over the tree elements */
2260 int bits; /* bit length */
2261 int xbits; /* extra bits */
2262 ush f; /* frequency */
2263 int overflow = 0; /* number of elements with bit length too large */
2264
2265 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2266
2267 /* In a first pass, compute the optimal bit lengths (which may
2268 * overflow in the case of the bit length tree).
2269 */
2270 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2271
2272 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2273 n = s->heap[h];
2274 bits = tree[tree[n].Dad].Len + 1;
2275 if (bits > max_length) bits = max_length, overflow++;
2276 tree[n].Len = (ush)bits;
2277 /* We overwrite tree[n].Dad which is no longer needed */
2278
2279 if (n > max_code) continue; /* not a leaf node */
2280
2281 s->bl_count[bits]++;
2282 xbits = 0;
2283 if (n >= base) xbits = extra[n-base];
2284 f = tree[n].Freq;
2285 s->opt_len += (ulg)f * (bits + xbits);
2286 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2287 }
2288 if (overflow == 0) return;
2289
2290 Trace((stderr,"\nbit length overflow\n"));
2291 /* This happens for example on obj2 and pic of the Calgary corpus */
2292
2293 /* Find the first bit length which could increase: */
2294 do {
2295 bits = max_length-1;
2296 while (s->bl_count[bits] == 0) bits--;
2297 s->bl_count[bits]--; /* move one leaf down the tree */
2298 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2299 s->bl_count[max_length]--;
2300 /* The brother of the overflow item also moves one step up,
2301 * but this does not affect bl_count[max_length]
2302 */
2303 overflow -= 2;
2304 } while (overflow > 0);
2305
2306 /* Now recompute all bit lengths, scanning in increasing frequency.
2307 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2308 * lengths instead of fixing only the wrong ones. This idea is taken
2309 * from 'ar' written by Haruhiko Okumura.)
2310 */
2311 for (bits = max_length; bits != 0; bits--) {
2312 n = s->bl_count[bits];
2313 while (n != 0) {
2314 m = s->heap[--h];
2315 if (m > max_code) continue;
2316 if (tree[m].Len != (unsigned) bits) {
2317 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2318 s->opt_len += ((long)bits - (long)tree[m].Len)
2319 *(long)tree[m].Freq;
2320 tree[m].Len = (ush)bits;
2321 }
2322 n--;
2323 }
2324 }
2325 }
2326
2327 /* ===========================================================================
2328 * Generate the codes for a given tree and bit counts (which need not be
2329 * optimal).
2330 * IN assertion: the array bl_count contains the bit length statistics for
2331 * the given tree and the field len is set for all tree elements.
2332 * OUT assertion: the field code is set for all tree elements of non
2333 * zero code length.
2334 */
2335 local void gen_codes (tree, max_code, bl_count)
2336 ct_data *tree; /* the tree to decorate */
2337 int max_code; /* largest code with non zero frequency */
2338 ushf *bl_count; /* number of codes at each bit length */
2339 {
2340 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2341 ush code = 0; /* running code value */
2342 int bits; /* bit index */
2343 int n; /* code index */
2344
2345 /* The distribution counts are first used to generate the code values
2346 * without bit reversal.
2347 */
2348 for (bits = 1; bits <= MAX_BITS; bits++) {
2349 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2350 }
2351 /* Check that the bit counts in bl_count are consistent. The last code
2352 * must be all ones.
2353 */
2354 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2355 "inconsistent bit counts");
2356 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2357
2358 for (n = 0; n <= max_code; n++) {
2359 int len = tree[n].Len;
2360 if (len == 0) continue;
2361 /* Now reverse the bits */
2362 tree[n].Code = bi_reverse(next_code[len]++, len);
2363
2364 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2365 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2366 }
2367 }
2368
2369 /* ===========================================================================
2370 * Construct one Huffman tree and assigns the code bit strings and lengths.
2371 * Update the total bit length for the current block.
2372 * IN assertion: the field freq is set for all tree elements.
2373 * OUT assertions: the fields len and code are set to the optimal bit length
2374 * and corresponding code. The length opt_len is updated; static_len is
2375 * also updated if stree is not null. The field max_code is set.
2376 */
2377 local void build_tree(s, desc)
2378 deflate_state *s;
2379 tree_desc *desc; /* the tree descriptor */
2380 {
2381 ct_data *tree = desc->dyn_tree;
2382 ct_data *stree = desc->stat_desc->static_tree;
2383 int elems = desc->stat_desc->elems;
2384 int n, m; /* iterate over heap elements */
2385 int max_code = -1; /* largest code with non zero frequency */
2386 int node; /* new node being created */
2387
2388 /* Construct the initial heap, with least frequent element in
2389 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2390 * heap[0] is not used.
2391 */
2392 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2393
2394 for (n = 0; n < elems; n++) {
2395 if (tree[n].Freq != 0) {
2396 s->heap[++(s->heap_len)] = max_code = n;
2397 s->depth[n] = 0;
2398 } else {
2399 tree[n].Len = 0;
2400 }
2401 }
2402
2403 /* The pkzip format requires that at least one distance code exists,
2404 * and that at least one bit should be sent even if there is only one
2405 * possible code. So to avoid special checks later on we force at least
2406 * two codes of non zero frequency.
2407 */
2408 while (s->heap_len < 2) {
2409 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2410 tree[node].Freq = 1;
2411 s->depth[node] = 0;
2412 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2413 /* node is 0 or 1 so it does not have extra bits */
2414 }
2415 desc->max_code = max_code;
2416
2417 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2418 * establish sub-heaps of increasing lengths:
2419 */
2420 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2421
2422 /* Construct the Huffman tree by repeatedly combining the least two
2423 * frequent nodes.
2424 */
2425 node = elems; /* next internal node of the tree */
2426 do {
2427 pqremove(s, tree, n); /* n = node of least frequency */
2428 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2429
2430 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2431 s->heap[--(s->heap_max)] = m;
2432
2433 /* Create a new node father of n and m */
2434 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2435 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2436 tree[n].Dad = tree[m].Dad = (ush)node;
2437 #ifdef DUMP_BL_TREE
2438 if (tree == s->bl_tree) {
2439 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2440 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2441 }
2442 #endif
2443 /* and insert the new node in the heap */
2444 s->heap[SMALLEST] = node++;
2445 pqdownheap(s, tree, SMALLEST);
2446
2447 } while (s->heap_len >= 2);
2448
2449 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2450
2451 /* At this point, the fields freq and dad are set. We can now
2452 * generate the bit lengths.
2453 */
2454 gen_bitlen(s, (tree_desc *)desc);
2455
2456 /* The field len is now set, we can generate the bit codes */
2457 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2458 }
2459
2460 /* ===========================================================================
2461 * Scan a literal or distance tree to determine the frequencies of the codes
2462 * in the bit length tree.
2463 */
2464 local void scan_tree (s, tree, max_code)
2465 deflate_state *s;
2466 ct_data *tree; /* the tree to be scanned */
2467 int max_code; /* and its largest code of non zero frequency */
2468 {
2469 int n; /* iterates over all tree elements */
2470 int prevlen = -1; /* last emitted length */
2471 int curlen; /* length of current code */
2472 int nextlen = tree[0].Len; /* length of next code */
2473 int count = 0; /* repeat count of the current code */
2474 int max_count = 7; /* max repeat count */
2475 int min_count = 4; /* min repeat count */
2476
2477 if (nextlen == 0) max_count = 138, min_count = 3;
2478 tree[max_code+1].Len = (ush)0xffff; /* guard */
2479
2480 for (n = 0; n <= max_code; n++) {
2481 curlen = nextlen; nextlen = tree[n+1].Len;
2482 if (++count < max_count && curlen == nextlen) {
2483 continue;
2484 } else if (count < min_count) {
2485 s->bl_tree[curlen].Freq += count;
2486 } else if (curlen != 0) {
2487 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2488 s->bl_tree[REP_3_6].Freq++;
2489 } else if (count <= 10) {
2490 s->bl_tree[REPZ_3_10].Freq++;
2491 } else {
2492 s->bl_tree[REPZ_11_138].Freq++;
2493 }
2494 count = 0; prevlen = curlen;
2495 if (nextlen == 0) {
2496 max_count = 138, min_count = 3;
2497 } else if (curlen == nextlen) {
2498 max_count = 6, min_count = 3;
2499 } else {
2500 max_count = 7, min_count = 4;
2501 }
2502 }
2503 }
2504
2505 /* ===========================================================================
2506 * Send a literal or distance tree in compressed form, using the codes in
2507 * bl_tree.
2508 */
2509 local void send_tree (s, tree, max_code)
2510 deflate_state *s;
2511 ct_data *tree; /* the tree to be scanned */
2512 int max_code; /* and its largest code of non zero frequency */
2513 {
2514 int n; /* iterates over all tree elements */
2515 int prevlen = -1; /* last emitted length */
2516 int curlen; /* length of current code */
2517 int nextlen = tree[0].Len; /* length of next code */
2518 int count = 0; /* repeat count of the current code */
2519 int max_count = 7; /* max repeat count */
2520 int min_count = 4; /* min repeat count */
2521
2522 /* tree[max_code+1].Len = -1; */ /* guard already set */
2523 if (nextlen == 0) max_count = 138, min_count = 3;
2524
2525 for (n = 0; n <= max_code; n++) {
2526 curlen = nextlen; nextlen = tree[n+1].Len;
2527 if (++count < max_count && curlen == nextlen) {
2528 continue;
2529 } else if (count < min_count) {
2530 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2531
2532 } else if (curlen != 0) {
2533 if (curlen != prevlen) {
2534 send_code(s, curlen, s->bl_tree); count--;
2535 }
2536 Assert(count >= 3 && count <= 6, " 3_6?");
2537 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2538
2539 } else if (count <= 10) {
2540 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2541
2542 } else {
2543 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2544 }
2545 count = 0; prevlen = curlen;
2546 if (nextlen == 0) {
2547 max_count = 138, min_count = 3;
2548 } else if (curlen == nextlen) {
2549 max_count = 6, min_count = 3;
2550 } else {
2551 max_count = 7, min_count = 4;
2552 }
2553 }
2554 }
2555
2556 /* ===========================================================================
2557 * Construct the Huffman tree for the bit lengths and return the index in
2558 * bl_order of the last bit length code to send.
2559 */
2560 local int build_bl_tree(s)
2561 deflate_state *s;
2562 {
2563 int max_blindex; /* index of last bit length code of non zero freq */
2564
2565 /* Determine the bit length frequencies for literal and distance trees */
2566 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2567 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2568
2569 /* Build the bit length tree: */
2570 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2571 /* opt_len now includes the length of the tree representations, except
2572 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2573 */
2574
2575 /* Determine the number of bit length codes to send. The pkzip format
2576 * requires that at least 4 bit length codes be sent. (appnote.txt says
2577 * 3 but the actual value used is 4.)
2578 */
2579 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2580 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2581 }
2582 /* Update opt_len to include the bit length tree and counts */
2583 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2584 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2585 s->opt_len, s->static_len));
2586
2587 return max_blindex;
2588 }
2589
2590 /* ===========================================================================
2591 * Send the header for a block using dynamic Huffman trees: the counts, the
2592 * lengths of the bit length codes, the literal tree and the distance tree.
2593 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2594 */
2595 local void send_all_trees(s, lcodes, dcodes, blcodes)
2596 deflate_state *s;
2597 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2598 {
2599 int rank; /* index in bl_order */
2600
2601 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2602 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2603 "too many codes");
2604 Tracev((stderr, "\nbl counts: "));
2605 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2606 send_bits(s, dcodes-1, 5);
2607 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2608 for (rank = 0; rank < blcodes; rank++) {
2609 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2610 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2611 }
2612 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2613
2614 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2615 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2616
2617 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2618 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2619 }
2620
2621 /* ===========================================================================
2622 * Send a stored block
2623 */
2624 void _tr_stored_block(s, buf, stored_len, eof)
2625 deflate_state *s;
2626 charf *buf; /* input block */
2627 ulg stored_len; /* length of input block */
2628 int eof; /* true if this is the last block for a file */
2629 {
2630 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2631 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2632 s->compressed_len += (stored_len + 4) << 3;
2633
2634 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2635 }
2636
2637 /* Send just the `stored block' type code without any length bytes or data.
2638 */
2639 void _tr_stored_type_only(s)
2640 deflate_state *s;
2641 {
2642 send_bits(s, (STORED_BLOCK << 1), 3);
2643 bi_windup(s);
2644 s->compressed_len = (s->compressed_len + 3) & ~7L;
2645 }
2646
2647
2648 /* ===========================================================================
2649 * Send one empty static block to give enough lookahead for inflate.
2650 * This takes 10 bits, of which 7 may remain in the bit buffer.
2651 * The current inflate code requires 9 bits of lookahead. If the
2652 * last two codes for the previous block (real code plus EOB) were coded
2653 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2654 * the last real code. In this case we send two empty static blocks instead
2655 * of one. (There are no problems if the previous block is stored or fixed.)
2656 * To simplify the code, we assume the worst case of last real code encoded
2657 * on one bit only.
2658 */
2659 void _tr_align(s)
2660 deflate_state *s;
2661 {
2662 send_bits(s, STATIC_TREES<<1, 3);
2663 send_code(s, END_BLOCK, static_ltree);
2664 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2665 bi_flush(s);
2666 /* Of the 10 bits for the empty block, we have already sent
2667 * (10 - bi_valid) bits. The lookahead for the last real code (before
2668 * the EOB of the previous block) was thus at least one plus the length
2669 * of the EOB plus what we have just sent of the empty static block.
2670 */
2671 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2672 send_bits(s, STATIC_TREES<<1, 3);
2673 send_code(s, END_BLOCK, static_ltree);
2674 s->compressed_len += 10L;
2675 bi_flush(s);
2676 }
2677 s->last_eob_len = 7;
2678 }
2679
2680 /* ===========================================================================
2681 * Determine the best encoding for the current block: dynamic trees, static
2682 * trees or store, and output the encoded block to the zip file. This function
2683 * returns the total compressed length for the file so far.
2684 */
2685 ulg _tr_flush_block(s, buf, stored_len, eof)
2686 deflate_state *s;
2687 charf *buf; /* input block, or NULL if too old */
2688 ulg stored_len; /* length of input block */
2689 int eof; /* true if this is the last block for a file */
2690 {
2691 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2692 int max_blindex = 0; /* index of last bit length code of non zero freq */
2693
2694 /* Build the Huffman trees unless a stored block is forced */
2695 if (s->level > 0) {
2696
2697 /* Check if the file is ascii or binary */
2698 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2699
2700 /* Construct the literal and distance trees */
2701 build_tree(s, (tree_desc *)(&(s->l_desc)));
2702 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2703 s->static_len));
2704
2705 build_tree(s, (tree_desc *)(&(s->d_desc)));
2706 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2707 s->static_len));
2708 /* At this point, opt_len and static_len are the total bit lengths of
2709 * the compressed block data, excluding the tree representations.
2710 */
2711
2712 /* Build the bit length tree for the above two trees, and get the index
2713 * in bl_order of the last bit length code to send.
2714 */
2715 max_blindex = build_bl_tree(s);
2716
2717 /* Determine the best encoding. Compute first the block length in bytes*/
2718 opt_lenb = (s->opt_len+3+7)>>3;
2719 static_lenb = (s->static_len+3+7)>>3;
2720
2721 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2722 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2723 s->last_lit));
2724
2725 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2726
2727 } else {
2728 Assert(buf != (char*)0, "lost buf");
2729 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2730 }
2731
2732 /* If compression failed and this is the first and last block,
2733 * and if the .zip file can be seeked (to rewrite the local header),
2734 * the whole file is transformed into a stored file:
2735 */
2736 #ifdef STORED_FILE_OK
2737 # ifdef FORCE_STORED_FILE
2738 if (eof && s->compressed_len == 0L) { /* force stored file */
2739 # else
2740 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2741 # endif
2742 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2743 if (buf == (charf*)0) error ("block vanished");
2744
2745 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2746 s->compressed_len = stored_len << 3;
2747 s->method = STORED;
2748 } else
2749 #endif /* STORED_FILE_OK */
2750
2751 #ifdef FORCE_STORED
2752 if (buf != (char*)0) { /* force stored block */
2753 #else
2754 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2755 /* 4: two words for the lengths */
2756 #endif
2757 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2758 * Otherwise we can't have processed more than WSIZE input bytes since
2759 * the last block flush, because compression would have been
2760 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2761 * transform a block into a stored block.
2762 */
2763 _tr_stored_block(s, buf, stored_len, eof);
2764
2765 #ifdef FORCE_STATIC
2766 } else if (static_lenb >= 0) { /* force static trees */
2767 #else
2768 } else if (static_lenb == opt_lenb) {
2769 #endif
2770 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2771 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2772 s->compressed_len += 3 + s->static_len;
2773 } else {
2774 send_bits(s, (DYN_TREES<<1)+eof, 3);
2775 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2776 max_blindex+1);
2777 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2778 s->compressed_len += 3 + s->opt_len;
2779 }
2780 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2781 init_block(s);
2782
2783 if (eof) {
2784 bi_windup(s);
2785 s->compressed_len += 7; /* align on byte boundary */
2786 }
2787 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2788 s->compressed_len-7*eof));
2789
2790 return s->compressed_len >> 3;
2791 }
2792
2793 /* ===========================================================================
2794 * Save the match info and tally the frequency counts. Return true if
2795 * the current block must be flushed.
2796 */
2797 int _tr_tally (s, dist, lc)
2798 deflate_state *s;
2799 unsigned dist; /* distance of matched string */
2800 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2801 {
2802 s->d_buf[s->last_lit] = (ush)dist;
2803 s->l_buf[s->last_lit++] = (uch)lc;
2804 if (dist == 0) {
2805 /* lc is the unmatched char */
2806 s->dyn_ltree[lc].Freq++;
2807 } else {
2808 s->matches++;
2809 /* Here, lc is the match length - MIN_MATCH */
2810 dist--; /* dist = match distance - 1 */
2811 Assert((ush)dist < (ush)MAX_DIST(s) &&
2812 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2813 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2814
2815 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2816 s->dyn_dtree[d_code(dist)].Freq++;
2817 }
2818
2819 /* Try to guess if it is profitable to stop the current block here */
2820 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2821 /* Compute an upper bound for the compressed length */
2822 ulg out_length = (ulg)s->last_lit*8L;
2823 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2824 int dcode;
2825 for (dcode = 0; dcode < D_CODES; dcode++) {
2826 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2827 (5L+extra_dbits[dcode]);
2828 }
2829 out_length >>= 3;
2830 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2831 s->last_lit, in_length, out_length,
2832 100L - out_length*100L/in_length));
2833 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2834 }
2835 return (s->last_lit == s->lit_bufsize-1);
2836 /* We avoid equality with lit_bufsize because of wraparound at 64K
2837 * on 16 bit machines and because stored blocks are restricted to
2838 * 64K-1 bytes.
2839 */
2840 }
2841
2842 /* ===========================================================================
2843 * Send the block data compressed using the given Huffman trees
2844 */
2845 local void compress_block(s, ltree, dtree)
2846 deflate_state *s;
2847 ct_data *ltree; /* literal tree */
2848 ct_data *dtree; /* distance tree */
2849 {
2850 unsigned dist; /* distance of matched string */
2851 int lc; /* match length or unmatched char (if dist == 0) */
2852 unsigned lx = 0; /* running index in l_buf */
2853 unsigned code; /* the code to send */
2854 int extra; /* number of extra bits to send */
2855
2856 if (s->last_lit != 0) do {
2857 dist = s->d_buf[lx];
2858 lc = s->l_buf[lx++];
2859 if (dist == 0) {
2860 send_code(s, lc, ltree); /* send a literal byte */
2861 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2862 } else {
2863 /* Here, lc is the match length - MIN_MATCH */
2864 code = length_code[lc];
2865 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2866 extra = extra_lbits[code];
2867 if (extra != 0) {
2868 lc -= base_length[code];
2869 send_bits(s, lc, extra); /* send the extra length bits */
2870 }
2871 dist--; /* dist is now the match distance - 1 */
2872 code = d_code(dist);
2873 Assert (code < D_CODES, "bad d_code");
2874
2875 send_code(s, code, dtree); /* send the distance code */
2876 extra = extra_dbits[code];
2877 if (extra != 0) {
2878 dist -= base_dist[code];
2879 send_bits(s, dist, extra); /* send the extra distance bits */
2880 }
2881 } /* literal or match pair ? */
2882
2883 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2884 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2885
2886 } while (lx < s->last_lit);
2887
2888 send_code(s, END_BLOCK, ltree);
2889 s->last_eob_len = ltree[END_BLOCK].Len;
2890 }
2891
2892 /* ===========================================================================
2893 * Set the data type to ASCII or BINARY, using a crude approximation:
2894 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2895 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2896 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2897 */
2898 local void set_data_type(s)
2899 deflate_state *s;
2900 {
2901 int n = 0;
2902 unsigned ascii_freq = 0;
2903 unsigned bin_freq = 0;
2904 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2905 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2906 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2907 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2908 }
2909
2910 /* ===========================================================================
2911 * Reverse the first len bits of a code, using straightforward code (a faster
2912 * method would use a table)
2913 * IN assertion: 1 <= len <= 15
2914 */
2915 local unsigned bi_reverse(code, len)
2916 unsigned code; /* the value to invert */
2917 int len; /* its bit length */
2918 {
2919 register unsigned res = 0;
2920 do {
2921 res |= code & 1;
2922 code >>= 1, res <<= 1;
2923 } while (--len > 0);
2924 return res >> 1;
2925 }
2926
2927 /* ===========================================================================
2928 * Flush the bit buffer, keeping at most 7 bits in it.
2929 */
2930 local void bi_flush(s)
2931 deflate_state *s;
2932 {
2933 if (s->bi_valid == 16) {
2934 put_short(s, s->bi_buf);
2935 s->bi_buf = 0;
2936 s->bi_valid = 0;
2937 } else if (s->bi_valid >= 8) {
2938 put_byte(s, (Byte)s->bi_buf);
2939 s->bi_buf >>= 8;
2940 s->bi_valid -= 8;
2941 }
2942 }
2943
2944 /* ===========================================================================
2945 * Flush the bit buffer and align the output on a byte boundary
2946 */
2947 local void bi_windup(s)
2948 deflate_state *s;
2949 {
2950 if (s->bi_valid > 8) {
2951 put_short(s, s->bi_buf);
2952 } else if (s->bi_valid > 0) {
2953 put_byte(s, (Byte)s->bi_buf);
2954 }
2955 s->bi_buf = 0;
2956 s->bi_valid = 0;
2957 #ifdef DEBUG_ZLIB
2958 s->bits_sent = (s->bits_sent+7) & ~7;
2959 #endif
2960 }
2961
2962 /* ===========================================================================
2963 * Copy a stored block, storing first the length and its
2964 * one's complement if requested.
2965 */
2966 local void copy_block(s, buf, len, header)
2967 deflate_state *s;
2968 charf *buf; /* the input data */
2969 unsigned len; /* its length */
2970 int header; /* true if block header must be written */
2971 {
2972 bi_windup(s); /* align on byte boundary */
2973 s->last_eob_len = 8; /* enough lookahead for inflate */
2974
2975 if (header) {
2976 put_short(s, (ush)len);
2977 put_short(s, (ush)~len);
2978 #ifdef DEBUG_ZLIB
2979 s->bits_sent += 2*16;
2980 #endif
2981 }
2982 #ifdef DEBUG_ZLIB
2983 s->bits_sent += (ulg)len<<3;
2984 #endif
2985 /* bundle up the put_byte(s, *buf++) calls */
2986 zmemcpy(&s->pending_buf[s->pending], buf, len);
2987 s->pending += len;
2988 }
2989 /* --- trees.c */
2990
2991 /* +++ inflate.c */
2992 /* inflate.c -- zlib interface to inflate modules
2993 * Copyright (C) 1995-1996 Mark Adler
2994 * For conditions of distribution and use, see copyright notice in zlib.h
2995 */
2996
2997 /* #include "zutil.h" */
2998
2999 /* +++ infblock.h */
3000 /* infblock.h -- header to use infblock.c
3001 * Copyright (C) 1995-1996 Mark Adler
3002 * For conditions of distribution and use, see copyright notice in zlib.h
3003 */
3004
3005 /* WARNING: this file should *not* be used by applications. It is
3006 part of the implementation of the compression library and is
3007 subject to change. Applications should only use zlib.h.
3008 */
3009
3010 struct inflate_blocks_state;
3011 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3012
3013 extern inflate_blocks_statef * inflate_blocks_new OF((
3014 z_streamp z,
3015 check_func c, /* check function */
3016 uInt w)); /* window size */
3017
3018 extern int inflate_blocks OF((
3019 inflate_blocks_statef *,
3020 z_streamp ,
3021 int)); /* initial return code */
3022
3023 extern void inflate_blocks_reset OF((
3024 inflate_blocks_statef *,
3025 z_streamp ,
3026 uLongf *)); /* check value on output */
3027
3028 extern int inflate_blocks_free OF((
3029 inflate_blocks_statef *,
3030 z_streamp ,
3031 uLongf *)); /* check value on output */
3032
3033 extern void inflate_set_dictionary OF((
3034 inflate_blocks_statef *s,
3035 const Bytef *d, /* dictionary */
3036 uInt n)); /* dictionary length */
3037
3038 extern int inflate_addhistory OF((
3039 inflate_blocks_statef *,
3040 z_streamp));
3041
3042 extern int inflate_packet_flush OF((
3043 inflate_blocks_statef *));
3044 /* --- infblock.h */
3045
3046 #ifndef NO_DUMMY_DECL
3047 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3048 #endif
3049
3050 /* inflate private state */
3051 struct internal_state {
3052
3053 /* mode */
3054 enum {
3055 METHOD, /* waiting for method byte */
3056 FLAG, /* waiting for flag byte */
3057 DICT4, /* four dictionary check bytes to go */
3058 DICT3, /* three dictionary check bytes to go */
3059 DICT2, /* two dictionary check bytes to go */
3060 DICT1, /* one dictionary check byte to go */
3061 DICT0, /* waiting for inflateSetDictionary */
3062 BLOCKS, /* decompressing blocks */
3063 CHECK4, /* four check bytes to go */
3064 CHECK3, /* three check bytes to go */
3065 CHECK2, /* two check bytes to go */
3066 CHECK1, /* one check byte to go */
3067 DONE, /* finished check, done */
3068 BAD} /* got an error--stay here */
3069 mode; /* current inflate mode */
3070
3071 /* mode dependent information */
3072 union {
3073 uInt method; /* if FLAGS, method byte */
3074 struct {
3075 uLong was; /* computed check value */
3076 uLong need; /* stream check value */
3077 } check; /* if CHECK, check values to compare */
3078 uInt marker; /* if BAD, inflateSync's marker bytes count */
3079 } sub; /* submode */
3080
3081 /* mode independent information */
3082 int nowrap; /* flag for no wrapper */
3083 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3084 inflate_blocks_statef
3085 *blocks; /* current inflate_blocks state */
3086
3087 };
3088
3089
3090 int inflateReset(z)
3091 z_streamp z;
3092 {
3093 uLong c;
3094
3095 if (z == Z_NULL || z->state == Z_NULL)
3096 return Z_STREAM_ERROR;
3097 z->total_in = z->total_out = 0;
3098 z->msg = Z_NULL;
3099 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3100 inflate_blocks_reset(z->state->blocks, z, &c);
3101 Trace((stderr, "inflate: reset\n"));
3102 return Z_OK;
3103 }
3104
3105
3106 int inflateEnd(z)
3107 z_streamp z;
3108 {
3109 uLong c;
3110
3111 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3112 return Z_STREAM_ERROR;
3113 if (z->state->blocks != Z_NULL)
3114 inflate_blocks_free(z->state->blocks, z, &c);
3115 ZFREE(z, z->state);
3116 z->state = Z_NULL;
3117 Trace((stderr, "inflate: end\n"));
3118 return Z_OK;
3119 }
3120
3121
3122 int inflateInit2_(z, w, version, stream_size)
3123 z_streamp z;
3124 int w;
3125 const char *version;
3126 int stream_size;
3127 {
3128 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3129 stream_size != sizeof(z_stream))
3130 return Z_VERSION_ERROR;
3131
3132 /* initialize state */
3133 if (z == Z_NULL)
3134 return Z_STREAM_ERROR;
3135 z->msg = Z_NULL;
3136 #ifndef NO_ZCFUNCS
3137 if (z->zalloc == Z_NULL)
3138 {
3139 z->zalloc = zcalloc;
3140 z->opaque = (voidpf)0;
3141 }
3142 if (z->zfree == Z_NULL) z->zfree = zcfree;
3143 #endif
3144 if ((z->state = (struct internal_state FAR *)
3145 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3146 return Z_MEM_ERROR;
3147 z->state->blocks = Z_NULL;
3148
3149 /* handle undocumented nowrap option (no zlib header or check) */
3150 z->state->nowrap = 0;
3151 if (w < 0)
3152 {
3153 w = - w;
3154 z->state->nowrap = 1;
3155 }
3156
3157 /* set window size */
3158 if (w < 8 || w > 15)
3159 {
3160 inflateEnd(z);
3161 return Z_STREAM_ERROR;
3162 }
3163 z->state->wbits = (uInt)w;
3164
3165 /* create inflate_blocks state */
3166 if ((z->state->blocks =
3167 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3168 == Z_NULL)
3169 {
3170 inflateEnd(z);
3171 return Z_MEM_ERROR;
3172 }
3173 Trace((stderr, "inflate: allocated\n"));
3174
3175 /* reset state */
3176 inflateReset(z);
3177 return Z_OK;
3178 }
3179
3180
3181 int inflateInit_(z, version, stream_size)
3182 z_streamp z;
3183 const char *version;
3184 int stream_size;
3185 {
3186 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3187 }
3188
3189
3190 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3191 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3192
3193 int inflate(z, f)
3194 z_streamp z;
3195 int f;
3196 {
3197 int r;
3198 uInt b;
3199
3200 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3201 return Z_STREAM_ERROR;
3202 r = Z_BUF_ERROR;
3203 while (1) switch (z->state->mode)
3204 {
3205 case METHOD:
3206 NEEDBYTE
3207 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3208 {
3209 z->state->mode = BAD;
3210 z->msg = (char*)"unknown compression method";
3211 z->state->sub.marker = 5; /* can't try inflateSync */
3212 break;
3213 }
3214 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3215 {
3216 z->state->mode = BAD;
3217 z->msg = (char*)"invalid window size";
3218 z->state->sub.marker = 5; /* can't try inflateSync */
3219 break;
3220 }
3221 z->state->mode = FLAG;
3222 case FLAG:
3223 NEEDBYTE
3224 b = NEXTBYTE;
3225 if (((z->state->sub.method << 8) + b) % 31)
3226 {
3227 z->state->mode = BAD;
3228 z->msg = (char*)"incorrect header check";
3229 z->state->sub.marker = 5; /* can't try inflateSync */
3230 break;
3231 }
3232 Trace((stderr, "inflate: zlib header ok\n"));
3233 if (!(b & PRESET_DICT))
3234 {
3235 z->state->mode = BLOCKS;
3236 break;
3237 }
3238 z->state->mode = DICT4;
3239 case DICT4:
3240 NEEDBYTE
3241 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3242 z->state->mode = DICT3;
3243 case DICT3:
3244 NEEDBYTE
3245 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3246 z->state->mode = DICT2;
3247 case DICT2:
3248 NEEDBYTE
3249 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3250 z->state->mode = DICT1;
3251 case DICT1:
3252 NEEDBYTE
3253 z->state->sub.check.need += (uLong)NEXTBYTE;
3254 z->adler = z->state->sub.check.need;
3255 z->state->mode = DICT0;
3256 return Z_NEED_DICT;
3257 case DICT0:
3258 z->state->mode = BAD;
3259 z->msg = (char*)"need dictionary";
3260 z->state->sub.marker = 0; /* can try inflateSync */
3261 return Z_STREAM_ERROR;
3262 case BLOCKS:
3263 r = inflate_blocks(z->state->blocks, z, r);
3264 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3265 r = inflate_packet_flush(z->state->blocks);
3266 if (r == Z_DATA_ERROR)
3267 {
3268 z->state->mode = BAD;
3269 z->state->sub.marker = 0; /* can try inflateSync */
3270 break;
3271 }
3272 if (r != Z_STREAM_END)
3273 return r;
3274 r = Z_OK;
3275 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3276 if (z->state->nowrap)
3277 {
3278 z->state->mode = DONE;
3279 break;
3280 }
3281 z->state->mode = CHECK4;
3282 case CHECK4:
3283 NEEDBYTE
3284 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3285 z->state->mode = CHECK3;
3286 case CHECK3:
3287 NEEDBYTE
3288 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3289 z->state->mode = CHECK2;
3290 case CHECK2:
3291 NEEDBYTE
3292 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3293 z->state->mode = CHECK1;
3294 case CHECK1:
3295 NEEDBYTE
3296 z->state->sub.check.need += (uLong)NEXTBYTE;
3297
3298 if (z->state->sub.check.was != z->state->sub.check.need)
3299 {
3300 z->state->mode = BAD;
3301 z->msg = (char*)"incorrect data check";
3302 z->state->sub.marker = 5; /* can't try inflateSync */
3303 break;
3304 }
3305 Trace((stderr, "inflate: zlib check ok\n"));
3306 z->state->mode = DONE;
3307 case DONE:
3308 return Z_STREAM_END;
3309 case BAD:
3310 return Z_DATA_ERROR;
3311 default:
3312 return Z_STREAM_ERROR;
3313 }
3314
3315 empty:
3316 if (f != Z_PACKET_FLUSH)
3317 return r;
3318 z->state->mode = BAD;
3319 z->msg = (char *)"need more for packet flush";
3320 z->state->sub.marker = 0; /* can try inflateSync */
3321 return Z_DATA_ERROR;
3322 }
3323
3324
3325 int inflateSetDictionary(z, dictionary, dictLength)
3326 z_streamp z;
3327 const Bytef *dictionary;
3328 uInt dictLength;
3329 {
3330 uInt length = dictLength;
3331
3332 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3333 return Z_STREAM_ERROR;
3334
3335 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3336 z->adler = 1L;
3337
3338 if (length >= ((uInt)1<<z->state->wbits))
3339 {
3340 length = (1<<z->state->wbits)-1;
3341 dictionary += dictLength - length;
3342 }
3343 inflate_set_dictionary(z->state->blocks, dictionary, length);
3344 z->state->mode = BLOCKS;
3345 return Z_OK;
3346 }
3347
3348 /*
3349 * This subroutine adds the data at next_in/avail_in to the output history
3350 * without performing any output. The output buffer must be "caught up";
3351 * i.e. no pending output (hence s->read equals s->write), and the state must
3352 * be BLOCKS (i.e. we should be willing to see the start of a series of
3353 * BLOCKS). On exit, the output will also be caught up, and the checksum
3354 * will have been updated if need be.
3355 */
3356
3357 int inflateIncomp(z)
3358 z_stream *z;
3359 {
3360 if (z->state->mode != BLOCKS)
3361 return Z_DATA_ERROR;
3362 return inflate_addhistory(z->state->blocks, z);
3363 }
3364
3365
3366 int inflateSync(z)
3367 z_streamp z;
3368 {
3369 uInt n; /* number of bytes to look at */
3370 Bytef *p; /* pointer to bytes */
3371 uInt m; /* number of marker bytes found in a row */
3372 uLong r, w; /* temporaries to save total_in and total_out */
3373
3374 /* set up */
3375 if (z == Z_NULL || z->state == Z_NULL)
3376 return Z_STREAM_ERROR;
3377 if (z->state->mode != BAD)
3378 {
3379 z->state->mode = BAD;
3380 z->state->sub.marker = 0;
3381 }
3382 if ((n = z->avail_in) == 0)
3383 return Z_BUF_ERROR;
3384 p = z->next_in;
3385 m = z->state->sub.marker;
3386
3387 /* search */
3388 while (n && m < 4)
3389 {
3390 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3391 m++;
3392 else if (*p)
3393 m = 0;
3394 else
3395 m = 4 - m;
3396 p++, n--;
3397 }
3398
3399 /* restore */
3400 z->total_in += p - z->next_in;
3401 z->next_in = p;
3402 z->avail_in = n;
3403 z->state->sub.marker = m;
3404
3405 /* return no joy or set up to restart on a new block */
3406 if (m != 4)
3407 return Z_DATA_ERROR;
3408 r = z->total_in; w = z->total_out;
3409 inflateReset(z);
3410 z->total_in = r; z->total_out = w;
3411 z->state->mode = BLOCKS;
3412 return Z_OK;
3413 }
3414
3415 #undef NEEDBYTE
3416 #undef NEXTBYTE
3417 /* --- inflate.c */
3418
3419 /* +++ infblock.c */
3420 /* infblock.c -- interpret and process block types to last block
3421 * Copyright (C) 1995-1996 Mark Adler
3422 * For conditions of distribution and use, see copyright notice in zlib.h
3423 */
3424
3425 /* #include "zutil.h" */
3426 /* #include "infblock.h" */
3427
3428 /* +++ inftrees.h */
3429 /* inftrees.h -- header to use inftrees.c
3430 * Copyright (C) 1995-1996 Mark Adler
3431 * For conditions of distribution and use, see copyright notice in zlib.h
3432 */
3433
3434 /* WARNING: this file should *not* be used by applications. It is
3435 part of the implementation of the compression library and is
3436 subject to change. Applications should only use zlib.h.
3437 */
3438
3439 /* Huffman code lookup table entry--this entry is four bytes for machines
3440 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3441
3442 typedef struct inflate_huft_s FAR inflate_huft;
3443
3444 struct inflate_huft_s {
3445 union {
3446 struct {
3447 Byte Exop; /* number of extra bits or operation */
3448 Byte Bits; /* number of bits in this code or subcode */
3449 } what;
3450 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3451 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3452 union {
3453 uInt Base; /* literal, length base, or distance base */
3454 inflate_huft *Next; /* pointer to next level of table */
3455 } more;
3456 };
3457
3458 #ifdef DEBUG_ZLIB
3459 extern uInt inflate_hufts;
3460 #endif
3461
3462 extern int inflate_trees_bits OF((
3463 uIntf *, /* 19 code lengths */
3464 uIntf *, /* bits tree desired/actual depth */
3465 inflate_huft * FAR *, /* bits tree result */
3466 z_streamp )); /* for zalloc, zfree functions */
3467
3468 extern int inflate_trees_dynamic OF((
3469 uInt, /* number of literal/length codes */
3470 uInt, /* number of distance codes */
3471 uIntf *, /* that many (total) code lengths */
3472 uIntf *, /* literal desired/actual bit depth */
3473 uIntf *, /* distance desired/actual bit depth */
3474 inflate_huft * FAR *, /* literal/length tree result */
3475 inflate_huft * FAR *, /* distance tree result */
3476 z_streamp )); /* for zalloc, zfree functions */
3477
3478 extern int inflate_trees_fixed OF((
3479 uIntf *, /* literal desired/actual bit depth */
3480 uIntf *, /* distance desired/actual bit depth */
3481 inflate_huft * FAR *, /* literal/length tree result */
3482 inflate_huft * FAR *)); /* distance tree result */
3483
3484 extern int inflate_trees_free OF((
3485 inflate_huft *, /* tables to free */
3486 z_streamp )); /* for zfree function */
3487
3488 /* --- inftrees.h */
3489
3490 /* +++ infcodes.h */
3491 /* infcodes.h -- header to use infcodes.c
3492 * Copyright (C) 1995-1996 Mark Adler
3493 * For conditions of distribution and use, see copyright notice in zlib.h
3494 */
3495
3496 /* WARNING: this file should *not* be used by applications. It is
3497 part of the implementation of the compression library and is
3498 subject to change. Applications should only use zlib.h.
3499 */
3500
3501 struct inflate_codes_state;
3502 typedef struct inflate_codes_state FAR inflate_codes_statef;
3503
3504 extern inflate_codes_statef *inflate_codes_new OF((
3505 uInt, uInt,
3506 inflate_huft *, inflate_huft *,
3507 z_streamp ));
3508
3509 extern int inflate_codes OF((
3510 inflate_blocks_statef *,
3511 z_streamp ,
3512 int));
3513
3514 extern void inflate_codes_free OF((
3515 inflate_codes_statef *,
3516 z_streamp ));
3517
3518 /* --- infcodes.h */
3519
3520 /* +++ infutil.h */
3521 /* infutil.h -- types and macros common to blocks and codes
3522 * Copyright (C) 1995-1996 Mark Adler
3523 * For conditions of distribution and use, see copyright notice in zlib.h
3524 */
3525
3526 /* WARNING: this file should *not* be used by applications. It is
3527 part of the implementation of the compression library and is
3528 subject to change. Applications should only use zlib.h.
3529 */
3530
3531 #ifndef _INFUTIL_H
3532 #define _INFUTIL_H
3533
3534 typedef enum {
3535 TYPE, /* get type bits (3, including end bit) */
3536 LENS, /* get lengths for stored */
3537 STORED, /* processing stored block */
3538 TABLE, /* get table lengths */
3539 BTREE, /* get bit lengths tree for a dynamic block */
3540 DTREE, /* get length, distance trees for a dynamic block */
3541 CODES, /* processing fixed or dynamic block */
3542 DRY, /* output remaining window bytes */
3543 DONEB, /* finished last block, done */
3544 BADB} /* got a data error--stuck here */
3545 inflate_block_mode;
3546
3547 /* inflate blocks semi-private state */
3548 struct inflate_blocks_state {
3549
3550 /* mode */
3551 inflate_block_mode mode; /* current inflate_block mode */
3552
3553 /* mode dependent information */
3554 union {
3555 uInt left; /* if STORED, bytes left to copy */
3556 struct {
3557 uInt table; /* table lengths (14 bits) */
3558 uInt index; /* index into blens (or border) */
3559 uIntf *blens; /* bit lengths of codes */
3560 uInt bb; /* bit length tree depth */
3561 inflate_huft *tb; /* bit length decoding tree */
3562 } trees; /* if DTREE, decoding info for trees */
3563 struct {
3564 inflate_huft *tl;
3565 inflate_huft *td; /* trees to free */
3566 inflate_codes_statef
3567 *codes;
3568 } decode; /* if CODES, current state */
3569 } sub; /* submode */
3570 uInt last; /* true if this block is the last block */
3571
3572 /* mode independent information */
3573 uInt bitk; /* bits in bit buffer */
3574 uLong bitb; /* bit buffer */
3575 Bytef *window; /* sliding window */
3576 Bytef *end; /* one byte after sliding window */
3577 Bytef *read; /* window read pointer */
3578 Bytef *write; /* window write pointer */
3579 check_func checkfn; /* check function */
3580 uLong check; /* check on output */
3581
3582 };
3583
3584
3585 /* defines for inflate input/output */
3586 /* update pointers and return */
3587 #define UPDBITS {s->bitb=b;s->bitk=k;}
3588 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3589 #define UPDOUT {s->write=q;}
3590 #define UPDATE {UPDBITS UPDIN UPDOUT}
3591 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3592 /* get bytes and bits */
3593 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3594 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3595 #define NEXTBYTE (n--,*p++)
3596 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3597 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3598 /* output bytes */
3599 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3600 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3601 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3602 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3603 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3604 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3605 /* load local pointers */
3606 #define LOAD {LOADIN LOADOUT}
3607
3608 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3609 extern uInt inflate_mask[17];
3610
3611 /* copy as much as possible from the sliding window to the output area */
3612 extern int inflate_flush OF((
3613 inflate_blocks_statef *,
3614 z_streamp ,
3615 int));
3616
3617 #ifndef NO_DUMMY_DECL
3618 struct internal_state {int dummy;}; /* for buggy compilers */
3619 #endif
3620
3621 #endif
3622 /* --- infutil.h */
3623
3624 #ifndef NO_DUMMY_DECL
3625 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3626 #endif
3627
3628 /* Table for deflate from PKZIP's appnote.txt. */
3629 local const uInt border[] = { /* Order of the bit length code lengths */
3630 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3631
3632 /*
3633 Notes beyond the 1.93a appnote.txt:
3634
3635 1. Distance pointers never point before the beginning of the output
3636 stream.
3637 2. Distance pointers can point back across blocks, up to 32k away.
3638 3. There is an implied maximum of 7 bits for the bit length table and
3639 15 bits for the actual data.
3640 4. If only one code exists, then it is encoded using one bit. (Zero
3641 would be more efficient, but perhaps a little confusing.) If two
3642 codes exist, they are coded using one bit each (0 and 1).
3643 5. There is no way of sending zero distance codes--a dummy must be
3644 sent if there are none. (History: a pre 2.0 version of PKZIP would
3645 store blocks with no distance codes, but this was discovered to be
3646 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3647 zero distance codes, which is sent as one code of zero bits in
3648 length.
3649 6. There are up to 286 literal/length codes. Code 256 represents the
3650 end-of-block. Note however that the static length tree defines
3651 288 codes just to fill out the Huffman codes. Codes 286 and 287
3652 cannot be used though, since there is no length base or extra bits
3653 defined for them. Similarily, there are up to 30 distance codes.
3654 However, static trees define 32 codes (all 5 bits) to fill out the
3655 Huffman codes, but the last two had better not show up in the data.
3656 7. Unzip can check dynamic Huffman blocks for complete code sets.
3657 The exception is that a single code would not be complete (see #4).
3658 8. The five bits following the block type is really the number of
3659 literal codes sent minus 257.
3660 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3661 (1+6+6). Therefore, to output three times the length, you output
3662 three codes (1+1+1), whereas to output four times the same length,
3663 you only need two codes (1+3). Hmm.
3664 10. In the tree reconstruction algorithm, Code = Code + Increment
3665 only if BitLength(i) is not zero. (Pretty obvious.)
3666 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3667 12. Note: length code 284 can represent 227-258, but length code 285
3668 really is 258. The last length deserves its own, short code
3669 since it gets used a lot in very redundant files. The length
3670 258 is special since 258 - 3 (the min match length) is 255.
3671 13. The literal/length and distance code bit lengths are read as a
3672 single stream of lengths. It is possible (and advantageous) for
3673 a repeat code (16, 17, or 18) to go across the boundary between
3674 the two sets of lengths.
3675 */
3676
3677
3678 void inflate_blocks_reset(s, z, c)
3679 inflate_blocks_statef *s;
3680 z_streamp z;
3681 uLongf *c;
3682 {
3683 if (s->checkfn != Z_NULL)
3684 *c = s->check;
3685 if (s->mode == BTREE || s->mode == DTREE)
3686 ZFREE(z, s->sub.trees.blens);
3687 if (s->mode == CODES)
3688 {
3689 inflate_codes_free(s->sub.decode.codes, z);
3690 inflate_trees_free(s->sub.decode.td, z);
3691 inflate_trees_free(s->sub.decode.tl, z);
3692 }
3693 s->mode = TYPE;
3694 s->bitk = 0;
3695 s->bitb = 0;
3696 s->read = s->write = s->window;
3697 if (s->checkfn != Z_NULL)
3698 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3699 Trace((stderr, "inflate: blocks reset\n"));
3700 }
3701
3702
3703 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3704 z_streamp z;
3705 check_func c;
3706 uInt w;
3707 {
3708 inflate_blocks_statef *s;
3709
3710 if ((s = (inflate_blocks_statef *)ZALLOC
3711 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3712 return s;
3713 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3714 {
3715 ZFREE(z, s);
3716 return Z_NULL;
3717 }
3718 s->end = s->window + w;
3719 s->checkfn = c;
3720 s->mode = TYPE;
3721 Trace((stderr, "inflate: blocks allocated\n"));
3722 inflate_blocks_reset(s, z, &s->check);
3723 return s;
3724 }
3725
3726
3727 #ifdef DEBUG_ZLIB
3728 extern uInt inflate_hufts;
3729 #endif
3730 int inflate_blocks(s, z, r)
3731 inflate_blocks_statef *s;
3732 z_streamp z;
3733 int r;
3734 {
3735 uInt t; /* temporary storage */
3736 uLong b; /* bit buffer */
3737 uInt k; /* bits in bit buffer */
3738 Bytef *p; /* input data pointer */
3739 uInt n; /* bytes available there */
3740 Bytef *q; /* output window write pointer */
3741 uInt m; /* bytes to end of window or read pointer */
3742
3743 /* copy input/output information to locals (UPDATE macro restores) */
3744 LOAD
3745
3746 /* process input based on current state */
3747 while (1) switch (s->mode)
3748 {
3749 case TYPE:
3750 NEEDBITS(3)
3751 t = (uInt)b & 7;
3752 s->last = t & 1;
3753 switch (t >> 1)
3754 {
3755 case 0: /* stored */
3756 Trace((stderr, "inflate: stored block%s\n",
3757 s->last ? " (last)" : ""));
3758 DUMPBITS(3)
3759 t = k & 7; /* go to byte boundary */
3760 DUMPBITS(t)
3761 s->mode = LENS; /* get length of stored block */
3762 break;
3763 case 1: /* fixed */
3764 Trace((stderr, "inflate: fixed codes block%s\n",
3765 s->last ? " (last)" : ""));
3766 {
3767 uInt bl, bd;
3768 inflate_huft *tl, *td;
3769
3770 inflate_trees_fixed(&bl, &bd, &tl, &td);
3771 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3772 if (s->sub.decode.codes == Z_NULL)
3773 {
3774 r = Z_MEM_ERROR;
3775 LEAVE
3776 }
3777 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3778 s->sub.decode.td = Z_NULL;
3779 }
3780 DUMPBITS(3)
3781 s->mode = CODES;
3782 break;
3783 case 2: /* dynamic */
3784 Trace((stderr, "inflate: dynamic codes block%s\n",
3785 s->last ? " (last)" : ""));
3786 DUMPBITS(3)
3787 s->mode = TABLE;
3788 break;
3789 case 3: /* illegal */
3790 DUMPBITS(3)
3791 s->mode = BADB;
3792 z->msg = (char*)"invalid block type";
3793 r = Z_DATA_ERROR;
3794 LEAVE
3795 }
3796 break;
3797 case LENS:
3798 NEEDBITS(32)
3799 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3800 {
3801 s->mode = BADB;
3802 z->msg = (char*)"invalid stored block lengths";
3803 r = Z_DATA_ERROR;
3804 LEAVE
3805 }
3806 s->sub.left = (uInt)b & 0xffff;
3807 b = k = 0; /* dump bits */
3808 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3809 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3810 break;
3811 case STORED:
3812 if (n == 0)
3813 LEAVE
3814 NEEDOUT
3815 t = s->sub.left;
3816 if (t > n) t = n;
3817 if (t > m) t = m;
3818 zmemcpy(q, p, t);
3819 p += t; n -= t;
3820 q += t; m -= t;
3821 if ((s->sub.left -= t) != 0)
3822 break;
3823 Tracev((stderr, "inflate: stored end, %lu total out\n",
3824 z->total_out + (q >= s->read ? q - s->read :
3825 (s->end - s->read) + (q - s->window))));
3826 s->mode = s->last ? DRY : TYPE;
3827 break;
3828 case TABLE:
3829 NEEDBITS(14)
3830 s->sub.trees.table = t = (uInt)b & 0x3fff;
3831 #ifndef PKZIP_BUG_WORKAROUND
3832 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3833 {
3834 s->mode = BADB;
3835 z->msg = (char*)"too many length or distance symbols";
3836 r = Z_DATA_ERROR;
3837 LEAVE
3838 }
3839 #endif
3840 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3841 if (t < 19)
3842 t = 19;
3843 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3844 {
3845 r = Z_MEM_ERROR;
3846 LEAVE
3847 }
3848 DUMPBITS(14)
3849 s->sub.trees.index = 0;
3850 Tracev((stderr, "inflate: table sizes ok\n"));
3851 s->mode = BTREE;
3852 case BTREE:
3853 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3854 {
3855 NEEDBITS(3)
3856 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3857 DUMPBITS(3)
3858 }
3859 while (s->sub.trees.index < 19)
3860 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3861 s->sub.trees.bb = 7;
3862 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3863 &s->sub.trees.tb, z);
3864 if (t != Z_OK)
3865 {
3866 r = t;
3867 if (r == Z_DATA_ERROR) {
3868 ZFREE(z, s->sub.trees.blens);
3869 s->mode = BADB;
3870 }
3871 LEAVE
3872 }
3873 s->sub.trees.index = 0;
3874 Tracev((stderr, "inflate: bits tree ok\n"));
3875 s->mode = DTREE;
3876 case DTREE:
3877 while (t = s->sub.trees.table,
3878 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3879 {
3880 inflate_huft *h;
3881 uInt i, j, c;
3882
3883 t = s->sub.trees.bb;
3884 NEEDBITS(t)
3885 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3886 t = h->word.what.Bits;
3887 c = h->more.Base;
3888 if (c < 16)
3889 {
3890 DUMPBITS(t)
3891 s->sub.trees.blens[s->sub.trees.index++] = c;
3892 }
3893 else /* c == 16..18 */
3894 {
3895 i = c == 18 ? 7 : c - 14;
3896 j = c == 18 ? 11 : 3;
3897 NEEDBITS(t + i)
3898 DUMPBITS(t)
3899 j += (uInt)b & inflate_mask[i];
3900 DUMPBITS(i)
3901 i = s->sub.trees.index;
3902 t = s->sub.trees.table;
3903 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3904 (c == 16 && i < 1))
3905 {
3906 inflate_trees_free(s->sub.trees.tb, z);
3907 ZFREE(z, s->sub.trees.blens);
3908 s->mode = BADB;
3909 z->msg = (char*)"invalid bit length repeat";
3910 r = Z_DATA_ERROR;
3911 LEAVE
3912 }
3913 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3914 do {
3915 s->sub.trees.blens[i++] = c;
3916 } while (--j);
3917 s->sub.trees.index = i;
3918 }
3919 }
3920 inflate_trees_free(s->sub.trees.tb, z);
3921 s->sub.trees.tb = Z_NULL;
3922 {
3923 uInt bl, bd;
3924 inflate_huft *tl, *td;
3925 inflate_codes_statef *c;
3926
3927 bl = 9; /* must be <= 9 for lookahead assumptions */
3928 bd = 6; /* must be <= 9 for lookahead assumptions */
3929 t = s->sub.trees.table;
3930 #ifdef DEBUG_ZLIB
3931 inflate_hufts = 0;
3932 #endif
3933 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3934 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3935 if (t != Z_OK)
3936 {
3937 if (t == (uInt)Z_DATA_ERROR) {
3938 ZFREE(z, s->sub.trees.blens);
3939 s->mode = BADB;
3940 }
3941 r = t;
3942 LEAVE
3943 }
3944 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3945 inflate_hufts, sizeof(inflate_huft)));
3946 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3947 {
3948 inflate_trees_free(td, z);
3949 inflate_trees_free(tl, z);
3950 r = Z_MEM_ERROR;
3951 LEAVE
3952 }
3953 /*
3954 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3955 * sub.trees is union'd with sub.decode.
3956 */
3957 ZFREE(z, s->sub.trees.blens);
3958 s->sub.decode.codes = c;
3959 s->sub.decode.tl = tl;
3960 s->sub.decode.td = td;
3961 }
3962 s->mode = CODES;
3963 case CODES:
3964 UPDATE
3965 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3966 return inflate_flush(s, z, r);
3967 r = Z_OK;
3968 inflate_codes_free(s->sub.decode.codes, z);
3969 inflate_trees_free(s->sub.decode.td, z);
3970 inflate_trees_free(s->sub.decode.tl, z);
3971 LOAD
3972 Tracev((stderr, "inflate: codes end, %lu total out\n",
3973 z->total_out + (q >= s->read ? q - s->read :
3974 (s->end - s->read) + (q - s->window))));
3975 if (!s->last)
3976 {
3977 s->mode = TYPE;
3978 break;
3979 }
3980 if (k > 7) /* return unused byte, if any */
3981 {
3982 Assert(k < 16, "inflate_codes grabbed too many bytes")
3983 k -= 8;
3984 n++;
3985 p--; /* can always return one */
3986 }
3987 s->mode = DRY;
3988 case DRY:
3989 FLUSH
3990 if (s->read != s->write)
3991 LEAVE
3992 s->mode = DONEB;
3993 case DONEB:
3994 r = Z_STREAM_END;
3995 LEAVE
3996 case BADB:
3997 r = Z_DATA_ERROR;
3998 LEAVE
3999 default:
4000 r = Z_STREAM_ERROR;
4001 LEAVE
4002 }
4003 }
4004
4005
4006 int inflate_blocks_free(s, z, c)
4007 inflate_blocks_statef *s;
4008 z_streamp z;
4009 uLongf *c;
4010 {
4011 inflate_blocks_reset(s, z, c);
4012 ZFREE(z, s->window);
4013 ZFREE(z, s);
4014 Trace((stderr, "inflate: blocks freed\n"));
4015 return Z_OK;
4016 }
4017
4018
4019 void inflate_set_dictionary(s, d, n)
4020 inflate_blocks_statef *s;
4021 const Bytef *d;
4022 uInt n;
4023 {
4024 zmemcpy((charf *)s->window, d, n);
4025 s->read = s->write = s->window + n;
4026 }
4027
4028 /*
4029 * This subroutine adds the data at next_in/avail_in to the output history
4030 * without performing any output. The output buffer must be "caught up";
4031 * i.e. no pending output (hence s->read equals s->write), and the state must
4032 * be BLOCKS (i.e. we should be willing to see the start of a series of
4033 * BLOCKS). On exit, the output will also be caught up, and the checksum
4034 * will have been updated if need be.
4035 */
4036 int inflate_addhistory(s, z)
4037 inflate_blocks_statef *s;
4038 z_stream *z;
4039 {
4040 uLong b; /* bit buffer */ /* NOT USED HERE */
4041 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4042 uInt t; /* temporary storage */
4043 Bytef *p; /* input data pointer */
4044 uInt n; /* bytes available there */
4045 Bytef *q; /* output window write pointer */
4046 uInt m; /* bytes to end of window or read pointer */
4047
4048 if (s->read != s->write)
4049 return Z_STREAM_ERROR;
4050 if (s->mode != TYPE)
4051 return Z_DATA_ERROR;
4052
4053 /* we're ready to rock */
4054 LOAD
4055 /* while there is input ready, copy to output buffer, moving
4056 * pointers as needed.
4057 */
4058 while (n) {
4059 t = n; /* how many to do */
4060 /* is there room until end of buffer? */
4061 if (t > m) t = m;
4062 /* update check information */
4063 if (s->checkfn != Z_NULL)
4064 s->check = (*s->checkfn)(s->check, q, t);
4065 zmemcpy(q, p, t);
4066 q += t;
4067 p += t;
4068 n -= t;
4069 z->total_out += t;
4070 s->read = q; /* drag read pointer forward */
4071 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4072 if (q == s->end) {
4073 s->read = q = s->window;
4074 m = WAVAIL;
4075 }
4076 }
4077 UPDATE
4078 return Z_OK;
4079 }
4080
4081
4082 /*
4083 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4084 * a `stored' block type value but not the (zero) length bytes.
4085 */
4086 int inflate_packet_flush(s)
4087 inflate_blocks_statef *s;
4088 {
4089 if (s->mode != LENS)
4090 return Z_DATA_ERROR;
4091 s->mode = TYPE;
4092 return Z_OK;
4093 }
4094 /* --- infblock.c */
4095
4096 /* +++ inftrees.c */
4097 /* inftrees.c -- generate Huffman trees for efficient decoding
4098 * Copyright (C) 1995-1996 Mark Adler
4099 * For conditions of distribution and use, see copyright notice in zlib.h
4100 */
4101
4102 /* #include "zutil.h" */
4103 /* #include "inftrees.h" */
4104
4105 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4106 /*
4107 If you use the zlib library in a product, an acknowledgment is welcome
4108 in the documentation of your product. If for some reason you cannot
4109 include such an acknowledgment, I would appreciate that you keep this
4110 copyright string in the executable of your product.
4111 */
4112
4113 #ifndef NO_DUMMY_DECL
4114 struct internal_state {int dummy;}; /* for buggy compilers */
4115 #endif
4116
4117 /* simplify the use of the inflate_huft type with some defines */
4118 #define base more.Base
4119 #define next more.Next
4120 #define exop word.what.Exop
4121 #define bits word.what.Bits
4122
4123
4124 local int huft_build OF((
4125 uIntf *, /* code lengths in bits */
4126 uInt, /* number of codes */
4127 uInt, /* number of "simple" codes */
4128 const uIntf *, /* list of base values for non-simple codes */
4129 const uIntf *, /* list of extra bits for non-simple codes */
4130 inflate_huft * FAR*,/* result: starting table */
4131 uIntf *, /* maximum lookup bits (returns actual) */
4132 z_streamp )); /* for zalloc function */
4133
4134 local voidpf falloc OF((
4135 voidpf, /* opaque pointer (not used) */
4136 uInt, /* number of items */
4137 uInt)); /* size of item */
4138
4139 /* Tables for deflate from PKZIP's appnote.txt. */
4140 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4141 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4142 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4143 /* see note #13 above about 258 */
4144 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4145 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4146 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4147 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4148 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4149 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4150 8193, 12289, 16385, 24577};
4151 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4152 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4153 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4154 12, 12, 13, 13};
4155
4156 /*
4157 Huffman code decoding is performed using a multi-level table lookup.
4158 The fastest way to decode is to simply build a lookup table whose
4159 size is determined by the longest code. However, the time it takes
4160 to build this table can also be a factor if the data being decoded
4161 is not very long. The most common codes are necessarily the
4162 shortest codes, so those codes dominate the decoding time, and hence
4163 the speed. The idea is you can have a shorter table that decodes the
4164 shorter, more probable codes, and then point to subsidiary tables for
4165 the longer codes. The time it costs to decode the longer codes is
4166 then traded against the time it takes to make longer tables.
4167
4168 This results of this trade are in the variables lbits and dbits
4169 below. lbits is the number of bits the first level table for literal/
4170 length codes can decode in one step, and dbits is the same thing for
4171 the distance codes. Subsequent tables are also less than or equal to
4172 those sizes. These values may be adjusted either when all of the
4173 codes are shorter than that, in which case the longest code length in
4174 bits is used, or when the shortest code is *longer* than the requested
4175 table size, in which case the length of the shortest code in bits is
4176 used.
4177
4178 There are two different values for the two tables, since they code a
4179 different number of possibilities each. The literal/length table
4180 codes 286 possible values, or in a flat code, a little over eight
4181 bits. The distance table codes 30 possible values, or a little less
4182 than five bits, flat. The optimum values for speed end up being
4183 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4184 The optimum values may differ though from machine to machine, and
4185 possibly even between compilers. Your mileage may vary.
4186 */
4187
4188
4189 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4190 #define BMAX 15 /* maximum bit length of any code */
4191 #define N_MAX 288 /* maximum number of codes in any set */
4192
4193 #ifdef DEBUG_ZLIB
4194 uInt inflate_hufts;
4195 #endif
4196
4197 local int huft_build(b, n, s, d, e, t, m, zs)
4198 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4199 uInt n; /* number of codes (assumed <= N_MAX) */
4200 uInt s; /* number of simple-valued codes (0..s-1) */
4201 const uIntf *d; /* list of base values for non-simple codes */
4202 const uIntf *e; /* list of extra bits for non-simple codes */
4203 inflate_huft * FAR *t; /* result: starting table */
4204 uIntf *m; /* maximum lookup bits, returns actual */
4205 z_streamp zs; /* for zalloc function */
4206 /* Given a list of code lengths and a maximum table size, make a set of
4207 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4208 if the given code set is incomplete (the tables are still built in this
4209 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4210 lengths), or Z_MEM_ERROR if not enough memory. */
4211 {
4212
4213 uInt a; /* counter for codes of length k */
4214 uInt c[BMAX+1]; /* bit length count table */
4215 uInt f; /* i repeats in table every f entries */
4216 int g; /* maximum code length */
4217 int h; /* table level */
4218 register uInt i; /* counter, current code */
4219 register uInt j; /* counter */
4220 register int k; /* number of bits in current code */
4221 int l; /* bits per table (returned in m) */
4222 register uIntf *p; /* pointer into c[], b[], or v[] */
4223 inflate_huft *q; /* points to current table */
4224 struct inflate_huft_s r; /* table entry for structure assignment */
4225 inflate_huft *u[BMAX]; /* table stack */
4226 uInt v[N_MAX]; /* values in order of bit length */
4227 register int w; /* bits before this table == (l * h) */
4228 uInt x[BMAX+1]; /* bit offsets, then code stack */
4229 uIntf *xp; /* pointer into x */
4230 int y; /* number of dummy codes added */
4231 uInt z; /* number of entries in current table */
4232
4233
4234 /* Generate counts for each bit length */
4235 p = c;
4236 #define C0 *p++ = 0;
4237 #define C2 C0 C0 C0 C0
4238 #define C4 C2 C2 C2 C2
4239 C4 /* clear c[]--assume BMAX+1 is 16 */
4240 p = b; i = n;
4241 do {
4242 c[*p++]++; /* assume all entries <= BMAX */
4243 } while (--i);
4244 if (c[0] == n) /* null input--all zero length codes */
4245 {
4246 *t = (inflate_huft *)Z_NULL;
4247 *m = 0;
4248 return Z_OK;
4249 }
4250
4251
4252 /* Find minimum and maximum length, bound *m by those */
4253 l = *m;
4254 for (j = 1; j <= BMAX; j++)
4255 if (c[j])
4256 break;
4257 k = j; /* minimum code length */
4258 if ((uInt)l < j)
4259 l = j;
4260 for (i = BMAX; i; i--)
4261 if (c[i])
4262 break;
4263 g = i; /* maximum code length */
4264 if ((uInt)l > i)
4265 l = i;
4266 *m = l;
4267
4268
4269 /* Adjust last length count to fill out codes, if needed */
4270 for (y = 1 << j; j < i; j++, y <<= 1)
4271 if ((y -= c[j]) < 0)
4272 return Z_DATA_ERROR;
4273 if ((y -= c[i]) < 0)
4274 return Z_DATA_ERROR;
4275 c[i] += y;
4276
4277
4278 /* Generate starting offsets into the value table for each length */
4279 x[1] = j = 0;
4280 p = c + 1; xp = x + 2;
4281 while (--i) { /* note that i == g from above */
4282 *xp++ = (j += *p++);
4283 }
4284
4285
4286 /* Make a table of values in order of bit lengths */
4287 p = b; i = 0;
4288 do {
4289 if ((j = *p++) != 0)
4290 v[x[j]++] = i;
4291 } while (++i < n);
4292 n = x[g]; /* set n to length of v */
4293
4294
4295 /* Generate the Huffman codes and for each, make the table entries */
4296 x[0] = i = 0; /* first Huffman code is zero */
4297 p = v; /* grab values in bit order */
4298 h = -1; /* no tables yet--level -1 */
4299 w = -l; /* bits decoded == (l * h) */
4300 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4301 q = (inflate_huft *)Z_NULL; /* ditto */
4302 z = 0; /* ditto */
4303
4304 /* go through the bit lengths (k already is bits in shortest code) */
4305 for (; k <= g; k++)
4306 {
4307 a = c[k];
4308 while (a--)
4309 {
4310 /* here i is the Huffman code of length k bits for value *p */
4311 /* make tables up to required level */
4312 while (k > w + l)
4313 {
4314 h++;
4315 w += l; /* previous table always l bits */
4316
4317 /* compute minimum size table less than or equal to l bits */
4318 z = g - w;
4319 z = z > (uInt)l ? l : z; /* table size upper limit */
4320 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4321 { /* too few codes for k-w bit table */
4322 f -= a + 1; /* deduct codes from patterns left */
4323 xp = c + k;
4324 if (j < z)
4325 while (++j < z) /* try smaller tables up to z bits */
4326 {
4327 if ((f <<= 1) <= *++xp)
4328 break; /* enough codes to use up j bits */
4329 f -= *xp; /* else deduct codes from patterns */
4330 }
4331 }
4332 z = 1 << j; /* table entries for j-bit table */
4333
4334 /* allocate and link in new table */
4335 if ((q = (inflate_huft *)ZALLOC
4336 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4337 {
4338 if (h)
4339 inflate_trees_free(u[0], zs);
4340 return Z_MEM_ERROR; /* not enough memory */
4341 }
4342 #ifdef DEBUG_ZLIB
4343 inflate_hufts += z + 1;
4344 #endif
4345 *t = q + 1; /* link to list for huft_free() */
4346 *(t = &(q->next)) = Z_NULL;
4347 u[h] = ++q; /* table starts after link */
4348
4349 /* connect to last table, if there is one */
4350 if (h)
4351 {
4352 x[h] = i; /* save pattern for backing up */
4353 r.bits = (Byte)l; /* bits to dump before this table */
4354 r.exop = (Byte)j; /* bits in this table */
4355 r.next = q; /* pointer to this table */
4356 j = i >> (w - l); /* (get around Turbo C bug) */
4357 u[h-1][j] = r; /* connect to last table */
4358 }
4359 }
4360
4361 /* set up table entry in r */
4362 r.bits = (Byte)(k - w);
4363 if (p >= v + n)
4364 r.exop = 128 + 64; /* out of values--invalid code */
4365 else if (*p < s)
4366 {
4367 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4368 r.base = *p++; /* simple code is just the value */
4369 }
4370 else
4371 {
4372 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4373 r.base = d[*p++ - s];
4374 }
4375
4376 /* fill code-like entries with r */
4377 f = 1 << (k - w);
4378 for (j = i >> w; j < z; j += f)
4379 q[j] = r;
4380
4381 /* backwards increment the k-bit code i */
4382 for (j = 1 << (k - 1); i & j; j >>= 1)
4383 i ^= j;
4384 i ^= j;
4385
4386 /* backup over finished tables */
4387 while ((i & ((1 << w) - 1)) != x[h])
4388 {
4389 h--; /* don't need to update q */
4390 w -= l;
4391 }
4392 }
4393 }
4394
4395
4396 /* Return Z_BUF_ERROR if we were given an incomplete table */
4397 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4398 }
4399
4400
4401 int inflate_trees_bits(c, bb, tb, z)
4402 uIntf *c; /* 19 code lengths */
4403 uIntf *bb; /* bits tree desired/actual depth */
4404 inflate_huft * FAR *tb; /* bits tree result */
4405 z_streamp z; /* for zfree function */
4406 {
4407 int r;
4408
4409 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4410 if (r == Z_DATA_ERROR)
4411 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4412 else if (r == Z_BUF_ERROR || *bb == 0)
4413 {
4414 inflate_trees_free(*tb, z);
4415 z->msg = (char*)"incomplete dynamic bit lengths tree";
4416 r = Z_DATA_ERROR;
4417 }
4418 return r;
4419 }
4420
4421
4422 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4423 uInt nl; /* number of literal/length codes */
4424 uInt nd; /* number of distance codes */
4425 uIntf *c; /* that many (total) code lengths */
4426 uIntf *bl; /* literal desired/actual bit depth */
4427 uIntf *bd; /* distance desired/actual bit depth */
4428 inflate_huft * FAR *tl; /* literal/length tree result */
4429 inflate_huft * FAR *td; /* distance tree result */
4430 z_streamp z; /* for zfree function */
4431 {
4432 int r;
4433
4434 /* build literal/length tree */
4435 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4436 if (r != Z_OK || *bl == 0)
4437 {
4438 if (r == Z_DATA_ERROR)
4439 z->msg = (char*)"oversubscribed literal/length tree";
4440 else if (r != Z_MEM_ERROR)
4441 {
4442 inflate_trees_free(*tl, z);
4443 z->msg = (char*)"incomplete literal/length tree";
4444 r = Z_DATA_ERROR;
4445 }
4446 return r;
4447 }
4448
4449 /* build distance tree */
4450 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4451 if (r != Z_OK || (*bd == 0 && nl > 257))
4452 {
4453 if (r == Z_DATA_ERROR)
4454 z->msg = (char*)"oversubscribed distance tree";
4455 else if (r == Z_BUF_ERROR) {
4456 #ifdef PKZIP_BUG_WORKAROUND
4457 r = Z_OK;
4458 }
4459 #else
4460 inflate_trees_free(*td, z);
4461 z->msg = (char*)"incomplete distance tree";
4462 r = Z_DATA_ERROR;
4463 }
4464 else if (r != Z_MEM_ERROR)
4465 {
4466 z->msg = (char*)"empty distance tree with lengths";
4467 r = Z_DATA_ERROR;
4468 }
4469 inflate_trees_free(*tl, z);
4470 return r;
4471 #endif
4472 }
4473
4474 /* done */
4475 return Z_OK;
4476 }
4477
4478
4479 /* build fixed tables only once--keep them here */
4480 local int fixed_built = 0;
4481 #define FIXEDH 530 /* number of hufts used by fixed tables */
4482 local inflate_huft fixed_mem[FIXEDH];
4483 local uInt fixed_bl;
4484 local uInt fixed_bd;
4485 local inflate_huft *fixed_tl;
4486 local inflate_huft *fixed_td;
4487
4488
4489 local voidpf falloc(q, n, s)
4490 voidpf q; /* opaque pointer */
4491 uInt n; /* number of items */
4492 uInt s; /* size of item */
4493 {
4494 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4495 "inflate_trees falloc overflow");
4496 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4497 return (voidpf)(fixed_mem + *(intf *)q);
4498 }
4499
4500
4501 int inflate_trees_fixed(bl, bd, tl, td)
4502 uIntf *bl; /* literal desired/actual bit depth */
4503 uIntf *bd; /* distance desired/actual bit depth */
4504 inflate_huft * FAR *tl; /* literal/length tree result */
4505 inflate_huft * FAR *td; /* distance tree result */
4506 {
4507 /* build fixed tables if not already (multiple overlapped executions ok) */
4508 if (!fixed_built)
4509 {
4510 int k; /* temporary variable */
4511 unsigned c[288]; /* length list for huft_build */
4512 z_stream z; /* for falloc function */
4513 int f = FIXEDH; /* number of hufts left in fixed_mem */
4514
4515 /* set up fake z_stream for memory routines */
4516 z.zalloc = falloc;
4517 z.zfree = Z_NULL;
4518 z.opaque = (voidpf)&f;
4519
4520 /* literal table */
4521 for (k = 0; k < 144; k++)
4522 c[k] = 8;
4523 for (; k < 256; k++)
4524 c[k] = 9;
4525 for (; k < 280; k++)
4526 c[k] = 7;
4527 for (; k < 288; k++)
4528 c[k] = 8;
4529 fixed_bl = 7;
4530 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4531
4532 /* distance table */
4533 for (k = 0; k < 30; k++)
4534 c[k] = 5;
4535 fixed_bd = 5;
4536 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4537
4538 /* done */
4539 Assert(f == 0, "invalid build of fixed tables");
4540 fixed_built = 1;
4541 }
4542 *bl = fixed_bl;
4543 *bd = fixed_bd;
4544 *tl = fixed_tl;
4545 *td = fixed_td;
4546 return Z_OK;
4547 }
4548
4549
4550 int inflate_trees_free(t, z)
4551 inflate_huft *t; /* table to free */
4552 z_streamp z; /* for zfree function */
4553 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4554 list of the tables it made, with the links in a dummy first entry of
4555 each table. */
4556 {
4557 register inflate_huft *p, *q, *r;
4558
4559 /* Reverse linked list */
4560 p = Z_NULL;
4561 q = t;
4562 while (q != Z_NULL)
4563 {
4564 r = (q - 1)->next;
4565 (q - 1)->next = p;
4566 p = q;
4567 q = r;
4568 }
4569 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4570 while (p != Z_NULL)
4571 {
4572 q = (--p)->next;
4573 ZFREE(z,p);
4574 p = q;
4575 }
4576 return Z_OK;
4577 }
4578 /* --- inftrees.c */
4579
4580 /* +++ infcodes.c */
4581 /* infcodes.c -- process literals and length/distance pairs
4582 * Copyright (C) 1995-1996 Mark Adler
4583 * For conditions of distribution and use, see copyright notice in zlib.h
4584 */
4585
4586 /* #include "zutil.h" */
4587 /* #include "inftrees.h" */
4588 /* #include "infblock.h" */
4589 /* #include "infcodes.h" */
4590 /* #include "infutil.h" */
4591
4592 /* +++ inffast.h */
4593 /* inffast.h -- header to use inffast.c
4594 * Copyright (C) 1995-1996 Mark Adler
4595 * For conditions of distribution and use, see copyright notice in zlib.h
4596 */
4597
4598 /* WARNING: this file should *not* be used by applications. It is
4599 part of the implementation of the compression library and is
4600 subject to change. Applications should only use zlib.h.
4601 */
4602
4603 extern int inflate_fast OF((
4604 uInt,
4605 uInt,
4606 inflate_huft *,
4607 inflate_huft *,
4608 inflate_blocks_statef *,
4609 z_streamp ));
4610 /* --- inffast.h */
4611
4612 /* simplify the use of the inflate_huft type with some defines */
4613 #define base more.Base
4614 #define next more.Next
4615 #define exop word.what.Exop
4616 #define bits word.what.Bits
4617
4618 /* inflate codes private state */
4619 struct inflate_codes_state {
4620
4621 /* mode */
4622 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4623 START, /* x: set up for LEN */
4624 LEN, /* i: get length/literal/eob next */
4625 LENEXT, /* i: getting length extra (have base) */
4626 DIST, /* i: get distance next */
4627 DISTEXT, /* i: getting distance extra */
4628 COPY, /* o: copying bytes in window, waiting for space */
4629 LIT, /* o: got literal, waiting for output space */
4630 WASH, /* o: got eob, possibly still output waiting */
4631 END, /* x: got eob and all data flushed */
4632 BADCODE} /* x: got error */
4633 mode; /* current inflate_codes mode */
4634
4635 /* mode dependent information */
4636 uInt len;
4637 union {
4638 struct {
4639 inflate_huft *tree; /* pointer into tree */
4640 uInt need; /* bits needed */
4641 } code; /* if LEN or DIST, where in tree */
4642 uInt lit; /* if LIT, literal */
4643 struct {
4644 uInt get; /* bits to get for extra */
4645 uInt dist; /* distance back to copy from */
4646 } copy; /* if EXT or COPY, where and how much */
4647 } sub; /* submode */
4648
4649 /* mode independent information */
4650 Byte lbits; /* ltree bits decoded per branch */
4651 Byte dbits; /* dtree bits decoder per branch */
4652 inflate_huft *ltree; /* literal/length/eob tree */
4653 inflate_huft *dtree; /* distance tree */
4654
4655 };
4656
4657
4658 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4659 uInt bl, bd;
4660 inflate_huft *tl;
4661 inflate_huft *td; /* need separate declaration for Borland C++ */
4662 z_streamp z;
4663 {
4664 inflate_codes_statef *c;
4665
4666 if ((c = (inflate_codes_statef *)
4667 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4668 {
4669 c->mode = START;
4670 c->lbits = (Byte)bl;
4671 c->dbits = (Byte)bd;
4672 c->ltree = tl;
4673 c->dtree = td;
4674 Tracev((stderr, "inflate: codes new\n"));
4675 }
4676 return c;
4677 }
4678
4679
4680 int inflate_codes(s, z, r)
4681 inflate_blocks_statef *s;
4682 z_streamp z;
4683 int r;
4684 {
4685 uInt j; /* temporary storage */
4686 inflate_huft *t; /* temporary pointer */
4687 uInt e; /* extra bits or operation */
4688 uLong b; /* bit buffer */
4689 uInt k; /* bits in bit buffer */
4690 Bytef *p; /* input data pointer */
4691 uInt n; /* bytes available there */
4692 Bytef *q; /* output window write pointer */
4693 uInt m; /* bytes to end of window or read pointer */
4694 Bytef *f; /* pointer to copy strings from */
4695 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4696
4697 /* copy input/output information to locals (UPDATE macro restores) */
4698 LOAD
4699
4700 /* process input and output based on current state */
4701 while (1) switch (c->mode)
4702 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4703 case START: /* x: set up for LEN */
4704 #ifndef SLOW
4705 if (m >= 258 && n >= 10)
4706 {
4707 UPDATE
4708 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4709 LOAD
4710 if (r != Z_OK)
4711 {
4712 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4713 break;
4714 }
4715 }
4716 #endif /* !SLOW */
4717 c->sub.code.need = c->lbits;
4718 c->sub.code.tree = c->ltree;
4719 c->mode = LEN;
4720 case LEN: /* i: get length/literal/eob next */
4721 j = c->sub.code.need;
4722 NEEDBITS(j)
4723 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4724 DUMPBITS(t->bits)
4725 e = (uInt)(t->exop);
4726 if (e == 0) /* literal */
4727 {
4728 c->sub.lit = t->base;
4729 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4730 "inflate: literal '%c'\n" :
4731 "inflate: literal 0x%02x\n", t->base));
4732 c->mode = LIT;
4733 break;
4734 }
4735 if (e & 16) /* length */
4736 {
4737 c->sub.copy.get = e & 15;
4738 c->len = t->base;
4739 c->mode = LENEXT;
4740 break;
4741 }
4742 if ((e & 64) == 0) /* next table */
4743 {
4744 c->sub.code.need = e;
4745 c->sub.code.tree = t->next;
4746 break;
4747 }
4748 if (e & 32) /* end of block */
4749 {
4750 Tracevv((stderr, "inflate: end of block\n"));
4751 c->mode = WASH;
4752 break;
4753 }
4754 c->mode = BADCODE; /* invalid code */
4755 z->msg = (char*)"invalid literal/length code";
4756 r = Z_DATA_ERROR;
4757 LEAVE
4758 case LENEXT: /* i: getting length extra (have base) */
4759 j = c->sub.copy.get;
4760 NEEDBITS(j)
4761 c->len += (uInt)b & inflate_mask[j];
4762 DUMPBITS(j)
4763 c->sub.code.need = c->dbits;
4764 c->sub.code.tree = c->dtree;
4765 Tracevv((stderr, "inflate: length %u\n", c->len));
4766 c->mode = DIST;
4767 case DIST: /* i: get distance next */
4768 j = c->sub.code.need;
4769 NEEDBITS(j)
4770 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4771 DUMPBITS(t->bits)
4772 e = (uInt)(t->exop);
4773 if (e & 16) /* distance */
4774 {
4775 c->sub.copy.get = e & 15;
4776 c->sub.copy.dist = t->base;
4777 c->mode = DISTEXT;
4778 break;
4779 }
4780 if ((e & 64) == 0) /* next table */
4781 {
4782 c->sub.code.need = e;
4783 c->sub.code.tree = t->next;
4784 break;
4785 }
4786 c->mode = BADCODE; /* invalid code */
4787 z->msg = (char*)"invalid distance code";
4788 r = Z_DATA_ERROR;
4789 LEAVE
4790 case DISTEXT: /* i: getting distance extra */
4791 j = c->sub.copy.get;
4792 NEEDBITS(j)
4793 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4794 DUMPBITS(j)
4795 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4796 c->mode = COPY;
4797 case COPY: /* o: copying bytes in window, waiting for space */
4798 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4799 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4800 s->end - (c->sub.copy.dist - (q - s->window)) :
4801 q - c->sub.copy.dist;
4802 #else
4803 f = q - c->sub.copy.dist;
4804 if ((uInt)(q - s->window) < c->sub.copy.dist)
4805 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4806 #endif
4807 while (c->len)
4808 {
4809 NEEDOUT
4810 OUTBYTE(*f++)
4811 if (f == s->end)
4812 f = s->window;
4813 c->len--;
4814 }
4815 c->mode = START;
4816 break;
4817 case LIT: /* o: got literal, waiting for output space */
4818 NEEDOUT
4819 OUTBYTE(c->sub.lit)
4820 c->mode = START;
4821 break;
4822 case WASH: /* o: got eob, possibly more output */
4823 FLUSH
4824 if (s->read != s->write)
4825 LEAVE
4826 c->mode = END;
4827 case END:
4828 r = Z_STREAM_END;
4829 LEAVE
4830 case BADCODE: /* x: got error */
4831 r = Z_DATA_ERROR;
4832 LEAVE
4833 default:
4834 r = Z_STREAM_ERROR;
4835 LEAVE
4836 }
4837 }
4838
4839
4840 void inflate_codes_free(c, z)
4841 inflate_codes_statef *c;
4842 z_streamp z;
4843 {
4844 ZFREE(z, c);
4845 Tracev((stderr, "inflate: codes free\n"));
4846 }
4847 /* --- infcodes.c */
4848
4849 /* +++ infutil.c */
4850 /* inflate_util.c -- data and routines common to blocks and codes
4851 * Copyright (C) 1995-1996 Mark Adler
4852 * For conditions of distribution and use, see copyright notice in zlib.h
4853 */
4854
4855 /* #include "zutil.h" */
4856 /* #include "infblock.h" */
4857 /* #include "inftrees.h" */
4858 /* #include "infcodes.h" */
4859 /* #include "infutil.h" */
4860
4861 #ifndef NO_DUMMY_DECL
4862 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4863 #endif
4864
4865 /* And'ing with mask[n] masks the lower n bits */
4866 uInt inflate_mask[17] = {
4867 0x0000,
4868 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4869 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4870 };
4871
4872
4873 /* copy as much as possible from the sliding window to the output area */
4874 int inflate_flush(s, z, r)
4875 inflate_blocks_statef *s;
4876 z_streamp z;
4877 int r;
4878 {
4879 uInt n;
4880 Bytef *p;
4881 Bytef *q;
4882
4883 /* local copies of source and destination pointers */
4884 p = z->next_out;
4885 q = s->read;
4886
4887 /* compute number of bytes to copy as far as end of window */
4888 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4889 if (n > z->avail_out) n = z->avail_out;
4890 if (n && r == Z_BUF_ERROR) r = Z_OK;
4891
4892 /* update counters */
4893 z->avail_out -= n;
4894 z->total_out += n;
4895
4896 /* update check information */
4897 if (s->checkfn != Z_NULL)
4898 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4899
4900 /* copy as far as end of window */
4901 if (p != Z_NULL) {
4902 zmemcpy(p, q, n);
4903 p += n;
4904 }
4905 q += n;
4906
4907 /* see if more to copy at beginning of window */
4908 if (q == s->end)
4909 {
4910 /* wrap pointers */
4911 q = s->window;
4912 if (s->write == s->end)
4913 s->write = s->window;
4914
4915 /* compute bytes to copy */
4916 n = (uInt)(s->write - q);
4917 if (n > z->avail_out) n = z->avail_out;
4918 if (n && r == Z_BUF_ERROR) r = Z_OK;
4919
4920 /* update counters */
4921 z->avail_out -= n;
4922 z->total_out += n;
4923
4924 /* update check information */
4925 if (s->checkfn != Z_NULL)
4926 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4927
4928 /* copy */
4929 if (p != Z_NULL) {
4930 zmemcpy(p, q, n);
4931 p += n;
4932 }
4933 q += n;
4934 }
4935
4936 /* update pointers */
4937 z->next_out = p;
4938 s->read = q;
4939
4940 /* done */
4941 return r;
4942 }
4943 /* --- infutil.c */
4944
4945 /* +++ inffast.c */
4946 /* inffast.c -- process literals and length/distance pairs fast
4947 * Copyright (C) 1995-1996 Mark Adler
4948 * For conditions of distribution and use, see copyright notice in zlib.h
4949 */
4950
4951 /* #include "zutil.h" */
4952 /* #include "inftrees.h" */
4953 /* #include "infblock.h" */
4954 /* #include "infcodes.h" */
4955 /* #include "infutil.h" */
4956 /* #include "inffast.h" */
4957
4958 #ifndef NO_DUMMY_DECL
4959 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4960 #endif
4961
4962 /* simplify the use of the inflate_huft type with some defines */
4963 #define base more.Base
4964 #define next more.Next
4965 #define exop word.what.Exop
4966 #define bits word.what.Bits
4967
4968 /* macros for bit input with no checking and for returning unused bytes */
4969 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4970 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4971
4972 /* Called with number of bytes left to write in window at least 258
4973 (the maximum string length) and number of input bytes available
4974 at least ten. The ten bytes are six bytes for the longest length/
4975 distance pair plus four bytes for overloading the bit buffer. */
4976
4977 int inflate_fast(bl, bd, tl, td, s, z)
4978 uInt bl, bd;
4979 inflate_huft *tl;
4980 inflate_huft *td; /* need separate declaration for Borland C++ */
4981 inflate_blocks_statef *s;
4982 z_streamp z;
4983 {
4984 inflate_huft *t; /* temporary pointer */
4985 uInt e; /* extra bits or operation */
4986 uLong b; /* bit buffer */
4987 uInt k; /* bits in bit buffer */
4988 Bytef *p; /* input data pointer */
4989 uInt n; /* bytes available there */
4990 Bytef *q; /* output window write pointer */
4991 uInt m; /* bytes to end of window or read pointer */
4992 uInt ml; /* mask for literal/length tree */
4993 uInt md; /* mask for distance tree */
4994 uInt c; /* bytes to copy */
4995 uInt d; /* distance back to copy from */
4996 Bytef *r; /* copy source pointer */
4997
4998 /* load input, output, bit values */
4999 LOAD
5000
5001 /* initialize masks */
5002 ml = inflate_mask[bl];
5003 md = inflate_mask[bd];
5004
5005 /* do until not enough input or output space for fast loop */
5006 do { /* assume called with m >= 258 && n >= 10 */
5007 /* get literal/length code */
5008 GRABBITS(20) /* max bits for literal/length code */
5009 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5010 {
5011 DUMPBITS(t->bits)
5012 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5013 "inflate: * literal '%c'\n" :
5014 "inflate: * literal 0x%02x\n", t->base));
5015 *q++ = (Byte)t->base;
5016 m--;
5017 continue;
5018 }
5019 do {
5020 DUMPBITS(t->bits)
5021 if (e & 16)
5022 {
5023 /* get extra bits for length */
5024 e &= 15;
5025 c = t->base + ((uInt)b & inflate_mask[e]);
5026 DUMPBITS(e)
5027 Tracevv((stderr, "inflate: * length %u\n", c));
5028
5029 /* decode distance base of block to copy */
5030 GRABBITS(15); /* max bits for distance code */
5031 e = (t = td + ((uInt)b & md))->exop;
5032 do {
5033 DUMPBITS(t->bits)
5034 if (e & 16)
5035 {
5036 /* get extra bits to add to distance base */
5037 e &= 15;
5038 GRABBITS(e) /* get extra bits (up to 13) */
5039 d = t->base + ((uInt)b & inflate_mask[e]);
5040 DUMPBITS(e)
5041 Tracevv((stderr, "inflate: * distance %u\n", d));
5042
5043 /* do the copy */
5044 m -= c;
5045 if ((uInt)(q - s->window) >= d) /* offset before dest */
5046 { /* just copy */
5047 r = q - d;
5048 *q++ = *r++; c--; /* minimum count is three, */
5049 *q++ = *r++; c--; /* so unroll loop a little */
5050 }
5051 else /* else offset after destination */
5052 {
5053 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5054 r = s->end - e; /* pointer to offset */
5055 if (c > e) /* if source crosses, */
5056 {
5057 c -= e; /* copy to end of window */
5058 do {
5059 *q++ = *r++;
5060 } while (--e);
5061 r = s->window; /* copy rest from start of window */
5062 }
5063 }
5064 do { /* copy all or what's left */
5065 *q++ = *r++;
5066 } while (--c);
5067 break;
5068 }
5069 else if ((e & 64) == 0)
5070 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5071 else
5072 {
5073 z->msg = (char*)"invalid distance code";
5074 UNGRAB
5075 UPDATE
5076 return Z_DATA_ERROR;
5077 }
5078 } while (1);
5079 break;
5080 }
5081 if ((e & 64) == 0)
5082 {
5083 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5084 {
5085 DUMPBITS(t->bits)
5086 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5087 "inflate: * literal '%c'\n" :
5088 "inflate: * literal 0x%02x\n", t->base));
5089 *q++ = (Byte)t->base;
5090 m--;
5091 break;
5092 }
5093 }
5094 else if (e & 32)
5095 {
5096 Tracevv((stderr, "inflate: * end of block\n"));
5097 UNGRAB
5098 UPDATE
5099 return Z_STREAM_END;
5100 }
5101 else
5102 {
5103 z->msg = (char*)"invalid literal/length code";
5104 UNGRAB
5105 UPDATE
5106 return Z_DATA_ERROR;
5107 }
5108 } while (1);
5109 } while (m >= 258 && n >= 10);
5110
5111 /* not enough input or output--restore pointers and return */
5112 UNGRAB
5113 UPDATE
5114 return Z_OK;
5115 }
5116 /* --- inffast.c */
5117
5118 /* +++ zutil.c */
5119 /* zutil.c -- target dependent utility functions for the compression library
5120 * Copyright (C) 1995-1996 Jean-loup Gailly.
5121 * For conditions of distribution and use, see copyright notice in zlib.h
5122 */
5123
5124 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5125
5126 #ifdef DEBUG_ZLIB
5127 #include <stdio.h>
5128 #endif
5129
5130 /* #include "zutil.h" */
5131
5132 #ifndef NO_DUMMY_DECL
5133 struct internal_state {int dummy;}; /* for buggy compilers */
5134 #endif
5135
5136 #ifndef STDC
5137 extern void exit OF((int));
5138 #endif
5139
5140 static const char *z_errmsg[10] = {
5141 "need dictionary", /* Z_NEED_DICT 2 */
5142 "stream end", /* Z_STREAM_END 1 */
5143 "", /* Z_OK 0 */
5144 "file error", /* Z_ERRNO (-1) */
5145 "stream error", /* Z_STREAM_ERROR (-2) */
5146 "data error", /* Z_DATA_ERROR (-3) */
5147 "insufficient memory", /* Z_MEM_ERROR (-4) */
5148 "buffer error", /* Z_BUF_ERROR (-5) */
5149 "incompatible version",/* Z_VERSION_ERROR (-6) */
5150 ""};
5151
5152
5153 const char *zlibVersion()
5154 {
5155 return ZLIB_VERSION;
5156 }
5157
5158 #ifdef DEBUG_ZLIB
5159 void z_error (m)
5160 char *m;
5161 {
5162 fprintf(stderr, "%s\n", m);
5163 exit(1);
5164 }
5165 #endif
5166
5167 #ifndef HAVE_MEMCPY
5168
5169 void zmemcpy(dest, source, len)
5170 Bytef* dest;
5171 Bytef* source;
5172 uInt len;
5173 {
5174 if (len == 0) return;
5175 do {
5176 *dest++ = *source++; /* ??? to be unrolled */
5177 } while (--len != 0);
5178 }
5179
5180 int zmemcmp(s1, s2, len)
5181 Bytef* s1;
5182 Bytef* s2;
5183 uInt len;
5184 {
5185 uInt j;
5186
5187 for (j = 0; j < len; j++) {
5188 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5189 }
5190 return 0;
5191 }
5192
5193 void zmemzero(dest, len)
5194 Bytef* dest;
5195 uInt len;
5196 {
5197 if (len == 0) return;
5198 do {
5199 *dest++ = 0; /* ??? to be unrolled */
5200 } while (--len != 0);
5201 }
5202 #endif
5203
5204 #ifdef __TURBOC__
5205 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5206 /* Small and medium model in Turbo C are for now limited to near allocation
5207 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5208 */
5209 # define MY_ZCALLOC
5210
5211 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5212 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5213 * must fix the pointer. Warning: the pointer must be put back to its
5214 * original form in order to free it, use zcfree().
5215 */
5216
5217 #define MAX_PTR 10
5218 /* 10*64K = 640K */
5219
5220 local int next_ptr = 0;
5221
5222 typedef struct ptr_table_s {
5223 voidpf org_ptr;
5224 voidpf new_ptr;
5225 } ptr_table;
5226
5227 local ptr_table table[MAX_PTR];
5228 /* This table is used to remember the original form of pointers
5229 * to large buffers (64K). Such pointers are normalized with a zero offset.
5230 * Since MSDOS is not a preemptive multitasking OS, this table is not
5231 * protected from concurrent access. This hack doesn't work anyway on
5232 * a protected system like OS/2. Use Microsoft C instead.
5233 */
5234
5235 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5236 {
5237 voidpf buf = opaque; /* just to make some compilers happy */
5238 ulg bsize = (ulg)items*size;
5239
5240 /* If we allocate less than 65520 bytes, we assume that farmalloc
5241 * will return a usable pointer which doesn't have to be normalized.
5242 */
5243 if (bsize < 65520L) {
5244 buf = farmalloc(bsize);
5245 if (*(ush*)&buf != 0) return buf;
5246 } else {
5247 buf = farmalloc(bsize + 16L);
5248 }
5249 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5250 table[next_ptr].org_ptr = buf;
5251
5252 /* Normalize the pointer to seg:0 */
5253 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5254 *(ush*)&buf = 0;
5255 table[next_ptr++].new_ptr = buf;
5256 return buf;
5257 }
5258
5259 void zcfree (voidpf opaque, voidpf ptr)
5260 {
5261 int n;
5262 if (*(ush*)&ptr != 0) { /* object < 64K */
5263 farfree(ptr);
5264 return;
5265 }
5266 /* Find the original pointer */
5267 for (n = 0; n < next_ptr; n++) {
5268 if (ptr != table[n].new_ptr) continue;
5269
5270 farfree(table[n].org_ptr);
5271 while (++n < next_ptr) {
5272 table[n-1] = table[n];
5273 }
5274 next_ptr--;
5275 return;
5276 }
5277 ptr = opaque; /* just to make some compilers happy */
5278 Assert(0, "zcfree: ptr not found");
5279 }
5280 #endif
5281 #endif /* __TURBOC__ */
5282
5283
5284 #if defined(M_I86) && !defined(__32BIT__)
5285 /* Microsoft C in 16-bit mode */
5286
5287 # define MY_ZCALLOC
5288
5289 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5290 # define _halloc halloc
5291 # define _hfree hfree
5292 #endif
5293
5294 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5295 {
5296 if (opaque) opaque = 0; /* to make compiler happy */
5297 return _halloc((long)items, size);
5298 }
5299
5300 void zcfree (voidpf opaque, voidpf ptr)
5301 {
5302 if (opaque) opaque = 0; /* to make compiler happy */
5303 _hfree(ptr);
5304 }
5305
5306 #endif /* MSC */
5307
5308
5309 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5310
5311 #ifndef STDC
5312 extern voidp calloc OF((uInt items, uInt size));
5313 extern void free OF((voidpf ptr));
5314 #endif
5315
5316 voidpf zcalloc (opaque, items, size)
5317 voidpf opaque;
5318 unsigned items;
5319 unsigned size;
5320 {
5321 if (opaque) items += size - size; /* make compiler happy */
5322 return (voidpf)calloc(items, size);
5323 }
5324
5325 void zcfree (opaque, ptr)
5326 voidpf opaque;
5327 voidpf ptr;
5328 {
5329 free(ptr);
5330 if (opaque) return; /* make compiler happy */
5331 }
5332
5333 #endif /* MY_ZCALLOC */
5334 /* --- zutil.c */
5335
5336 /* +++ adler32.c */
5337 /* adler32.c -- compute the Adler-32 checksum of a data stream
5338 * Copyright (C) 1995-1996 Mark Adler
5339 * For conditions of distribution and use, see copyright notice in zlib.h
5340 */
5341
5342 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5343
5344 /* #include "zlib.h" */
5345
5346 #define BASE 65521L /* largest prime smaller than 65536 */
5347 #define NMAX 5552
5348 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5349
5350 #define DO1(buf,i) {s1 += buf[(i)]; s2 += s1;}
5351 #define DO2(buf,i) DO1(buf,i); DO1(buf,(i)+1);
5352 #define DO4(buf,i) DO2(buf,i); DO2(buf,(i)+2);
5353 #define DO8(buf,i) DO4(buf,i); DO4(buf,(i)+4);
5354 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5355
5356 /* ========================================================================= */
5357 uLong adler32(adler, buf, len)
5358 uLong adler;
5359 const Bytef *buf;
5360 uInt len;
5361 {
5362 unsigned long s1 = adler & 0xffff;
5363 unsigned long s2 = (adler >> 16) & 0xffff;
5364 int k;
5365
5366 if (buf == Z_NULL) return 1L;
5367
5368 while (len > 0) {
5369 k = len < NMAX ? len : NMAX;
5370 len -= k;
5371 while (k >= 16) {
5372 DO16(buf);
5373 buf += 16;
5374 k -= 16;
5375 }
5376 if (k != 0) do {
5377 s1 += *buf++;
5378 s2 += s1;
5379 } while (--k);
5380 s1 %= BASE;
5381 s2 %= BASE;
5382 }
5383 return (s2 << 16) | s1;
5384 }
5385 /* --- adler32.c */
5386
5387 #ifdef _KERNEL
5388 static int
5389 zlib_modevent(module_t mod, int type, void *unused)
5390 {
5391 switch (type) {
5392 case MOD_LOAD:
5393 return 0;
5394 case MOD_UNLOAD:
5395 return 0;
5396 }
5397 return EINVAL;
5398 }
5399
5400 static moduledata_t zlib_mod = {
5401 "zlib",
5402 zlib_modevent,
5403 0
5404 };
5405 DECLARE_MODULE(zlib, zlib_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
5406 MODULE_VERSION(zlib, 1);
5407 #endif /* _KERNEL */
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