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: releng/10.3/sys/net/zlib.c 245102 2013-01-06 14:59:59Z peter $
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 _tr_init _zlib104_tr_init
29 #define _tr_align _zlib104_tr_align
30 #define _tr_tally _zlib104_tr_tally
31 #define _tr_flush_block _zlib104_tr_flush_block
32 #define _tr_stored_block _zlib104_tr_stored_block
33 #define inflate_fast _zlib104_inflate_fast
34 #define inflate _zlib104_inflate
35 #define zlibVersion _zlib104_Version
36 #endif
37
38
39 /* +++ zutil.h */
40 /*-
41 * zutil.h -- internal interface and configuration of the compression library
42 * Copyright (C) 1995-1996 Jean-loup Gailly.
43 * For conditions of distribution and use, see copyright notice in zlib.h
44 */
45
46 /* WARNING: this file should *not* be used by applications. It is
47 part of the implementation of the compression library and is
48 subject to change. Applications should only use zlib.h.
49 */
50
51 /* From: zutil.h,v 1.16 1996/07/24 13:41:13 me Exp $ */
52
53 #ifndef _Z_UTIL_H
54 #define _Z_UTIL_H
55
56 #ifdef _KERNEL
57 #include <net/zlib.h>
58 #else
59 #include "zlib.h"
60 #endif
61
62 #ifdef _KERNEL
63 /* Assume this is a *BSD or SVR4 kernel */
64 #include <sys/types.h>
65 #include <sys/time.h>
66 #include <sys/systm.h>
67 #include <sys/param.h>
68 #include <sys/kernel.h>
69 #include <sys/module.h>
70 # define HAVE_MEMCPY
71
72 #else
73 #if defined(__KERNEL__)
74 /* Assume this is a Linux kernel */
75 #include <linux/string.h>
76 #define HAVE_MEMCPY
77
78 #else /* not kernel */
79
80 #if defined(MSDOS)||defined(VMS)||defined(CRAY)||defined(WIN32)||defined(RISCOS)
81 # include <stddef.h>
82 # include <errno.h>
83 #else
84 extern int errno;
85 #endif
86 #ifdef STDC
87 # include <string.h>
88 # include <stdlib.h>
89 #endif
90 #endif /* __KERNEL__ */
91 #endif /* _KERNEL */
92
93 #ifndef local
94 # define local static
95 #endif
96 /* compile with -Dlocal if your debugger can't find static symbols */
97
98 typedef unsigned char uch;
99 typedef uch FAR uchf;
100 typedef unsigned short ush;
101 typedef ush FAR ushf;
102 typedef unsigned long ulg;
103
104 static const char *z_errmsg[10]; /* indexed by 2-zlib_error */
105 /* (size given to avoid silly warnings with Visual C++) */
106
107 #define ERR_MSG(err) z_errmsg[Z_NEED_DICT-(err)]
108
109 #define ERR_RETURN(strm,err) \
110 return (strm->msg = (const char*)ERR_MSG(err), (err))
111 /* To be used only when the state is known to be valid */
112
113 /* common constants */
114
115 #ifndef DEF_WBITS
116 # define DEF_WBITS MAX_WBITS
117 #endif
118 /* default windowBits for decompression. MAX_WBITS is for compression only */
119
120 #if MAX_MEM_LEVEL >= 8
121 # define DEF_MEM_LEVEL 8
122 #else
123 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
124 #endif
125 /* default memLevel */
126
127 #define STORED_BLOCK 0
128 #define STATIC_TREES 1
129 #define DYN_TREES 2
130 /* The three kinds of block type */
131
132 #define MIN_MATCH 3
133 #define MAX_MATCH 258
134 /* The minimum and maximum match lengths */
135
136 #define PRESET_DICT 0x20 /* preset dictionary flag in zlib header */
137
138 /* target dependencies */
139
140 #ifdef MSDOS
141 # define OS_CODE 0x00
142 # ifdef __TURBOC__
143 # include <alloc.h>
144 # else /* MSC or DJGPP */
145 # include <malloc.h>
146 # endif
147 #endif
148
149 #ifdef OS2
150 # define OS_CODE 0x06
151 #endif
152
153 #ifdef WIN32 /* Window 95 & Windows NT */
154 # define OS_CODE 0x0b
155 #endif
156
157 #if defined(VAXC) || defined(VMS)
158 # define OS_CODE 0x02
159 # define FOPEN(name, mode) \
160 fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512")
161 #endif
162
163 #ifdef AMIGA
164 # define OS_CODE 0x01
165 #endif
166
167 #if defined(ATARI) || defined(atarist)
168 # define OS_CODE 0x05
169 #endif
170
171 #ifdef MACOS
172 # define OS_CODE 0x07
173 #endif
174
175 #ifdef __50SERIES /* Prime/PRIMOS */
176 # define OS_CODE 0x0F
177 #endif
178
179 #ifdef TOPS20
180 # define OS_CODE 0x0a
181 #endif
182
183 #if defined(_BEOS_) || defined(RISCOS)
184 # define fdopen(fd,mode) NULL /* No fdopen() */
185 #endif
186
187 /* Common defaults */
188
189 #ifndef OS_CODE
190 # define OS_CODE 0x03 /* assume Unix */
191 #endif
192
193 #ifndef FOPEN
194 # define FOPEN(name, mode) fopen((name), (mode))
195 #endif
196
197 /* functions */
198
199 #ifdef HAVE_STRERROR
200 extern char *strerror OF((int));
201 # define zstrerror(errnum) strerror(errnum)
202 #else
203 # define zstrerror(errnum) ""
204 #endif
205
206 #if defined(pyr)
207 # define NO_MEMCPY
208 #endif
209 #if (defined(M_I86SM) || defined(M_I86MM)) && !defined(_MSC_VER)
210 /* Use our own functions for small and medium model with MSC <= 5.0.
211 * You may have to use the same strategy for Borland C (untested).
212 */
213 # define NO_MEMCPY
214 #endif
215 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
216 # define HAVE_MEMCPY
217 #endif
218 #ifdef HAVE_MEMCPY
219 # ifdef SMALL_MEDIUM /* MSDOS small or medium model */
220 # define zmemcpy _fmemcpy
221 # define zmemcmp _fmemcmp
222 # define zmemzero(dest, len) _fmemset(dest, 0, len)
223 # else
224 # define zmemcpy memcpy
225 # define zmemcmp memcmp
226 # define zmemzero(dest, len) memset(dest, 0, len)
227 # endif
228 #else
229 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
230 extern int zmemcmp OF((Bytef* s1, Bytef* s2, uInt len));
231 extern void zmemzero OF((Bytef* dest, uInt len));
232 #endif
233
234 /* Diagnostic functions */
235 #ifdef DEBUG_ZLIB
236 # include <stdio.h>
237 # ifndef verbose
238 # define verbose 0
239 # endif
240 extern void z_error OF((char *m));
241 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
242 # define Trace(x) fprintf x
243 # define Tracev(x) {if (verbose) fprintf x ;}
244 # define Tracevv(x) {if (verbose>1) fprintf x ;}
245 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
246 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
247 #else
248 # define Assert(cond,msg)
249 # define Trace(x)
250 # define Tracev(x)
251 # define Tracevv(x)
252 # define Tracec(c,x)
253 # define Tracecv(c,x)
254 #endif
255
256
257 typedef uLong (*check_func) OF((uLong check, const Bytef *buf, uInt len));
258
259 voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size));
260 void zcfree OF((voidpf opaque, voidpf ptr));
261
262 #define ZALLOC(strm, items, size) \
263 (*((strm)->zalloc))((strm)->opaque, (items), (size))
264 #define ZFREE(strm, addr) (*((strm)->zfree))((strm)->opaque, (voidpf)(addr))
265 #define TRY_FREE(s, p) {if (p) ZFREE(s, p);}
266
267 #endif /* _Z_UTIL_H */
268 /* --- zutil.h */
269
270 /* +++ deflate.h */
271 /* deflate.h -- internal compression state
272 * Copyright (C) 1995-1996 Jean-loup Gailly
273 * For conditions of distribution and use, see copyright notice in zlib.h
274 */
275
276 /* WARNING: this file should *not* be used by applications. It is
277 part of the implementation of the compression library and is
278 subject to change. Applications should only use zlib.h.
279 */
280
281 /* From: deflate.h,v 1.10 1996/07/02 12:41:00 me Exp $ */
282
283 #ifndef _DEFLATE_H
284 #define _DEFLATE_H
285
286 /* #include "zutil.h" */
287
288 /* ===========================================================================
289 * Internal compression state.
290 */
291
292 #define LENGTH_CODES 29
293 /* number of length codes, not counting the special END_BLOCK code */
294
295 #define LITERALS 256
296 /* number of literal bytes 0..255 */
297
298 #define L_CODES (LITERALS+1+LENGTH_CODES)
299 /* number of Literal or Length codes, including the END_BLOCK code */
300
301 #define D_CODES 30
302 /* number of distance codes */
303
304 #define BL_CODES 19
305 /* number of codes used to transfer the bit lengths */
306
307 #define HEAP_SIZE (2*L_CODES+1)
308 /* maximum heap size */
309
310 #define MAX_BITS 15
311 /* All codes must not exceed MAX_BITS bits */
312
313 #define INIT_STATE 42
314 #define BUSY_STATE 113
315 #define FINISH_STATE 666
316 /* Stream status */
317
318
319 /* Data structure describing a single value and its code string. */
320 typedef struct ct_data_s {
321 union {
322 ush freq; /* frequency count */
323 ush code; /* bit string */
324 } fc;
325 union {
326 ush dad; /* father node in Huffman tree */
327 ush len; /* length of bit string */
328 } dl;
329 } FAR ct_data;
330
331 #define Freq fc.freq
332 #define Code fc.code
333 #define Dad dl.dad
334 #define Len dl.len
335
336 typedef struct static_tree_desc_s static_tree_desc;
337
338 typedef struct tree_desc_s {
339 ct_data *dyn_tree; /* the dynamic tree */
340 int max_code; /* largest code with non zero frequency */
341 static_tree_desc *stat_desc; /* the corresponding static tree */
342 } FAR tree_desc;
343
344 typedef ush Pos;
345 typedef Pos FAR Posf;
346 typedef unsigned IPos;
347
348 /* A Pos is an index in the character window. We use short instead of int to
349 * save space in the various tables. IPos is used only for parameter passing.
350 */
351
352 typedef struct deflate_state {
353 z_streamp strm; /* pointer back to this zlib stream */
354 int status; /* as the name implies */
355 Bytef *pending_buf; /* output still pending */
356 ulg pending_buf_size; /* size of pending_buf */
357 Bytef *pending_out; /* next pending byte to output to the stream */
358 int pending; /* nb of bytes in the pending buffer */
359 int noheader; /* suppress zlib header and adler32 */
360 Byte data_type; /* UNKNOWN, BINARY or ASCII */
361 Byte method; /* STORED (for zip only) or DEFLATED */
362 int last_flush; /* value of flush param for previous deflate call */
363
364 /* used by deflate.c: */
365
366 uInt w_size; /* LZ77 window size (32K by default) */
367 uInt w_bits; /* log2(w_size) (8..16) */
368 uInt w_mask; /* w_size - 1 */
369
370 Bytef *window;
371 /* Sliding window. Input bytes are read into the second half of the window,
372 * and move to the first half later to keep a dictionary of at least wSize
373 * bytes. With this organization, matches are limited to a distance of
374 * wSize-MAX_MATCH bytes, but this ensures that IO is always
375 * performed with a length multiple of the block size. Also, it limits
376 * the window size to 64K, which is quite useful on MSDOS.
377 * To do: use the user input buffer as sliding window.
378 */
379
380 ulg window_size;
381 /* Actual size of window: 2*wSize, except when the user input buffer
382 * is directly used as sliding window.
383 */
384
385 Posf *prev;
386 /* Link to older string with same hash index. To limit the size of this
387 * array to 64K, this link is maintained only for the last 32K strings.
388 * An index in this array is thus a window index modulo 32K.
389 */
390
391 Posf *head; /* Heads of the hash chains or NIL. */
392
393 uInt ins_h; /* hash index of string to be inserted */
394 uInt hash_size; /* number of elements in hash table */
395 uInt hash_bits; /* log2(hash_size) */
396 uInt hash_mask; /* hash_size-1 */
397
398 uInt hash_shift;
399 /* Number of bits by which ins_h must be shifted at each input
400 * step. It must be such that after MIN_MATCH steps, the oldest
401 * byte no longer takes part in the hash key, that is:
402 * hash_shift * MIN_MATCH >= hash_bits
403 */
404
405 long block_start;
406 /* Window position at the beginning of the current output block. Gets
407 * negative when the window is moved backwards.
408 */
409
410 uInt match_length; /* length of best match */
411 IPos prev_match; /* previous match */
412 int match_available; /* set if previous match exists */
413 uInt strstart; /* start of string to insert */
414 uInt match_start; /* start of matching string */
415 uInt lookahead; /* number of valid bytes ahead in window */
416
417 uInt prev_length;
418 /* Length of the best match at previous step. Matches not greater than this
419 * are discarded. This is used in the lazy match evaluation.
420 */
421
422 uInt max_chain_length;
423 /* To speed up deflation, hash chains are never searched beyond this
424 * length. A higher limit improves compression ratio but degrades the
425 * speed.
426 */
427
428 uInt max_lazy_match;
429 /* Attempt to find a better match only when the current match is strictly
430 * smaller than this value. This mechanism is used only for compression
431 * levels >= 4.
432 */
433 # define max_insert_length max_lazy_match
434 /* Insert new strings in the hash table only if the match length is not
435 * greater than this length. This saves time but degrades compression.
436 * max_insert_length is used only for compression levels <= 3.
437 */
438
439 int level; /* compression level (1..9) */
440 int strategy; /* favor or force Huffman coding*/
441
442 uInt good_match;
443 /* Use a faster search when the previous match is longer than this */
444
445 int nice_match; /* Stop searching when current match exceeds this */
446
447 /* used by trees.c: */
448 /* Didn't use ct_data typedef below to supress compiler warning */
449 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
450 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
451 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
452
453 struct tree_desc_s l_desc; /* desc. for literal tree */
454 struct tree_desc_s d_desc; /* desc. for distance tree */
455 struct tree_desc_s bl_desc; /* desc. for bit length tree */
456
457 ush bl_count[MAX_BITS+1];
458 /* number of codes at each bit length for an optimal tree */
459
460 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
461 int heap_len; /* number of elements in the heap */
462 int heap_max; /* element of largest frequency */
463 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
464 * The same heap array is used to build all trees.
465 */
466
467 uch depth[2*L_CODES+1];
468 /* Depth of each subtree used as tie breaker for trees of equal frequency
469 */
470
471 uchf *l_buf; /* buffer for literals or lengths */
472
473 uInt lit_bufsize;
474 /* Size of match buffer for literals/lengths. There are 4 reasons for
475 * limiting lit_bufsize to 64K:
476 * - frequencies can be kept in 16 bit counters
477 * - if compression is not successful for the first block, all input
478 * data is still in the window so we can still emit a stored block even
479 * when input comes from standard input. (This can also be done for
480 * all blocks if lit_bufsize is not greater than 32K.)
481 * - if compression is not successful for a file smaller than 64K, we can
482 * even emit a stored file instead of a stored block (saving 5 bytes).
483 * This is applicable only for zip (not gzip or zlib).
484 * - creating new Huffman trees less frequently may not provide fast
485 * adaptation to changes in the input data statistics. (Take for
486 * example a binary file with poorly compressible code followed by
487 * a highly compressible string table.) Smaller buffer sizes give
488 * fast adaptation but have of course the overhead of transmitting
489 * trees more frequently.
490 * - I can't count above 4
491 */
492
493 uInt last_lit; /* running index in l_buf */
494
495 ushf *d_buf;
496 /* Buffer for distances. To simplify the code, d_buf and l_buf have
497 * the same number of elements. To use different lengths, an extra flag
498 * array would be necessary.
499 */
500
501 ulg opt_len; /* bit length of current block with optimal trees */
502 ulg static_len; /* bit length of current block with static trees */
503 ulg compressed_len; /* total bit length of compressed file */
504 uInt matches; /* number of string matches in current block */
505 int last_eob_len; /* bit length of EOB code for last block */
506
507 #ifdef DEBUG_ZLIB
508 ulg bits_sent; /* bit length of the compressed data */
509 #endif
510
511 ush bi_buf;
512 /* Output buffer. bits are inserted starting at the bottom (least
513 * significant bits).
514 */
515 int bi_valid;
516 /* Number of valid bits in bi_buf. All bits above the last valid bit
517 * are always zero.
518 */
519
520 } FAR deflate_state;
521
522 /* Output a byte on the stream.
523 * IN assertion: there is enough room in pending_buf.
524 */
525 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
526
527
528 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
529 /* Minimum amount of lookahead, except at the end of the input file.
530 * See deflate.c for comments about the MIN_MATCH+1.
531 */
532
533 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
534 /* In order to simplify the code, particularly on 16 bit machines, match
535 * distances are limited to MAX_DIST instead of WSIZE.
536 */
537
538 /* in trees.c */
539 void _tr_init OF((deflate_state *s));
540 int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
541 ulg _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
542 int eof));
543 void _tr_align OF((deflate_state *s));
544 void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
545 int eof));
546 void _tr_stored_type_only OF((deflate_state *));
547
548 #endif
549 /* --- deflate.h */
550
551 /* +++ deflate.c */
552 /* deflate.c -- compress data using the deflation algorithm
553 * Copyright (C) 1995-1996 Jean-loup Gailly.
554 * For conditions of distribution and use, see copyright notice in zlib.h
555 */
556
557 /*
558 * ALGORITHM
559 *
560 * The "deflation" process depends on being able to identify portions
561 * of the input text which are identical to earlier input (within a
562 * sliding window trailing behind the input currently being processed).
563 *
564 * The most straightforward technique turns out to be the fastest for
565 * most input files: try all possible matches and select the longest.
566 * The key feature of this algorithm is that insertions into the string
567 * dictionary are very simple and thus fast, and deletions are avoided
568 * completely. Insertions are performed at each input character, whereas
569 * string matches are performed only when the previous match ends. So it
570 * is preferable to spend more time in matches to allow very fast string
571 * insertions and avoid deletions. The matching algorithm for small
572 * strings is inspired from that of Rabin & Karp. A brute force approach
573 * is used to find longer strings when a small match has been found.
574 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
575 * (by Leonid Broukhis).
576 * A previous version of this file used a more sophisticated algorithm
577 * (by Fiala and Greene) which is guaranteed to run in linear amortized
578 * time, but has a larger average cost, uses more memory and is patented.
579 * However the F&G algorithm may be faster for some highly redundant
580 * files if the parameter max_chain_length (described below) is too large.
581 *
582 * ACKNOWLEDGEMENTS
583 *
584 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
585 * I found it in 'freeze' written by Leonid Broukhis.
586 * Thanks to many people for bug reports and testing.
587 *
588 * REFERENCES
589 *
590 * Deutsch, L.P.,"DEFLATE Compressed Data Format Specification".
591 * Available in ftp://ds.internic.net/rfc/rfc1951.txt
592 *
593 * A description of the Rabin and Karp algorithm is given in the book
594 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
595 *
596 * Fiala,E.R., and Greene,D.H.
597 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
598 *
599 */
600
601 /* From: deflate.c,v 1.15 1996/07/24 13:40:58 me Exp $ */
602
603 /* #include "deflate.h" */
604
605 char deflate_copyright[] = " deflate 1.0.4 Copyright 1995-1996 Jean-loup Gailly ";
606 /*
607 If you use the zlib library in a product, an acknowledgment is welcome
608 in the documentation of your product. If for some reason you cannot
609 include such an acknowledgment, I would appreciate that you keep this
610 copyright string in the executable of your product.
611 */
612
613 /* ===========================================================================
614 * Function prototypes.
615 */
616 typedef enum {
617 need_more, /* block not completed, need more input or more output */
618 block_done, /* block flush performed */
619 finish_started, /* finish started, need only more output at next deflate */
620 finish_done /* finish done, accept no more input or output */
621 } block_state;
622
623 typedef block_state (*compress_func) OF((deflate_state *s, int flush));
624 /* Compression function. Returns the block state after the call. */
625
626 local void fill_window OF((deflate_state *s));
627 local block_state deflate_stored OF((deflate_state *s, int flush));
628 local block_state deflate_fast OF((deflate_state *s, int flush));
629 local block_state deflate_slow OF((deflate_state *s, int flush));
630 local void lm_init OF((deflate_state *s));
631 local void putShortMSB OF((deflate_state *s, uInt b));
632 local void flush_pending OF((z_streamp strm));
633 local int read_buf OF((z_streamp strm, charf *buf, unsigned size));
634 #ifdef ASMV
635 void match_init OF((void)); /* asm code initialization */
636 uInt longest_match OF((deflate_state *s, IPos cur_match));
637 #else
638 local uInt longest_match OF((deflate_state *s, IPos cur_match));
639 #endif
640
641 #ifdef DEBUG_ZLIB
642 local void check_match OF((deflate_state *s, IPos start, IPos match,
643 int length));
644 #endif
645
646 /* ===========================================================================
647 * Local data
648 */
649
650 #define NIL 0
651 /* Tail of hash chains */
652
653 #ifndef TOO_FAR
654 # define TOO_FAR 4096
655 #endif
656 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
657
658 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
659 /* Minimum amount of lookahead, except at the end of the input file.
660 * See deflate.c for comments about the MIN_MATCH+1.
661 */
662
663 /* Values for max_lazy_match, good_match and max_chain_length, depending on
664 * the desired pack level (0..9). The values given below have been tuned to
665 * exclude worst case performance for pathological files. Better values may be
666 * found for specific files.
667 */
668 typedef struct config_s {
669 ush good_length; /* reduce lazy search above this match length */
670 ush max_lazy; /* do not perform lazy search above this match length */
671 ush nice_length; /* quit search above this match length */
672 ush max_chain;
673 compress_func func;
674 } config;
675
676 local config configuration_table[10] = {
677 /* good lazy nice chain */
678 /* 0 */ {0, 0, 0, 0, deflate_stored}, /* store only */
679 /* 1 */ {4, 4, 8, 4, deflate_fast}, /* maximum speed, no lazy matches */
680 /* 2 */ {4, 5, 16, 8, deflate_fast},
681 /* 3 */ {4, 6, 32, 32, deflate_fast},
682
683 /* 4 */ {4, 4, 16, 16, deflate_slow}, /* lazy matches */
684 /* 5 */ {8, 16, 32, 32, deflate_slow},
685 /* 6 */ {8, 16, 128, 128, deflate_slow},
686 /* 7 */ {8, 32, 128, 256, deflate_slow},
687 /* 8 */ {32, 128, 258, 1024, deflate_slow},
688 /* 9 */ {32, 258, 258, 4096, deflate_slow}}; /* maximum compression */
689
690 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
691 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
692 * meaning.
693 */
694
695 #define EQUAL 0
696 /* result of memcmp for equal strings */
697
698 #ifndef NO_DUMMY_DECL
699 struct static_tree_desc_s {int dummy;}; /* for buggy compilers */
700 #endif
701
702 /* ===========================================================================
703 * Update a hash value with the given input byte
704 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
705 * input characters, so that a running hash key can be computed from the
706 * previous key instead of complete recalculation each time.
707 */
708 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
709
710
711 /* ===========================================================================
712 * Insert string str in the dictionary and set match_head to the previous head
713 * of the hash chain (the most recent string with same hash key). Return
714 * the previous length of the hash chain.
715 * IN assertion: all calls to to INSERT_STRING are made with consecutive
716 * input characters and the first MIN_MATCH bytes of str are valid
717 * (except for the last MIN_MATCH-1 bytes of the input file).
718 */
719 #define INSERT_STRING(s, str, match_head) \
720 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
721 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
722 s->head[s->ins_h] = (Pos)(str))
723
724 /* ===========================================================================
725 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
726 * prev[] will be initialized on the fly.
727 */
728 #define CLEAR_HASH(s) \
729 s->head[s->hash_size-1] = NIL; \
730 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
731
732 /* ========================================================================= */
733 int deflateInit_(strm, level, version, stream_size)
734 z_streamp strm;
735 int level;
736 const char *version;
737 int stream_size;
738 {
739 return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
740 Z_DEFAULT_STRATEGY, version, stream_size);
741 /* To do: ignore strm->next_in if we use it as window */
742 }
743
744 /* ========================================================================= */
745 int deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
746 version, stream_size)
747 z_streamp strm;
748 int level;
749 int method;
750 int windowBits;
751 int memLevel;
752 int strategy;
753 const char *version;
754 int stream_size;
755 {
756 deflate_state *s;
757 int noheader = 0;
758 static char* my_version = ZLIB_VERSION;
759
760 ushf *overlay;
761 /* We overlay pending_buf and d_buf+l_buf. This works since the average
762 * output size for (length,distance) codes is <= 24 bits.
763 */
764
765 if (version == Z_NULL || version[0] != my_version[0] ||
766 stream_size != sizeof(z_stream)) {
767 return Z_VERSION_ERROR;
768 }
769 if (strm == Z_NULL) return Z_STREAM_ERROR;
770
771 strm->msg = Z_NULL;
772 #ifndef NO_ZCFUNCS
773 if (strm->zalloc == Z_NULL) {
774 strm->zalloc = zcalloc;
775 strm->opaque = (voidpf)0;
776 }
777 if (strm->zfree == Z_NULL) strm->zfree = zcfree;
778 #endif
779
780 if (level == Z_DEFAULT_COMPRESSION) level = 6;
781
782 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
783 noheader = 1;
784 windowBits = -windowBits;
785 }
786 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != Z_DEFLATED ||
787 windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
788 strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
789 return Z_STREAM_ERROR;
790 }
791 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
792 if (s == Z_NULL) return Z_MEM_ERROR;
793 strm->state = (struct internal_state FAR *)s;
794 s->strm = strm;
795
796 s->noheader = noheader;
797 s->w_bits = windowBits;
798 s->w_size = 1 << s->w_bits;
799 s->w_mask = s->w_size - 1;
800
801 s->hash_bits = memLevel + 7;
802 s->hash_size = 1 << s->hash_bits;
803 s->hash_mask = s->hash_size - 1;
804 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
805
806 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
807 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
808 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
809
810 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
811
812 overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
813 s->pending_buf = (uchf *) overlay;
814 s->pending_buf_size = (ulg)s->lit_bufsize * (sizeof(ush)+2L);
815
816 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
817 s->pending_buf == Z_NULL) {
818 strm->msg = (const char*)ERR_MSG(Z_MEM_ERROR);
819 deflateEnd (strm);
820 return Z_MEM_ERROR;
821 }
822 s->d_buf = overlay + s->lit_bufsize/sizeof(ush);
823 s->l_buf = s->pending_buf + (1+sizeof(ush))*s->lit_bufsize;
824
825 s->level = level;
826 s->strategy = strategy;
827 s->method = (Byte)method;
828
829 return deflateReset(strm);
830 }
831
832 /* ========================================================================= */
833 int deflateSetDictionary (strm, dictionary, dictLength)
834 z_streamp strm;
835 const Bytef *dictionary;
836 uInt dictLength;
837 {
838 deflate_state *s;
839 uInt length = dictLength;
840 uInt n;
841 IPos hash_head = 0;
842
843 if (strm == Z_NULL || strm->state == Z_NULL || dictionary == Z_NULL)
844 return Z_STREAM_ERROR;
845
846 s = (deflate_state *) strm->state;
847 if (s->status != INIT_STATE) return Z_STREAM_ERROR;
848
849 strm->adler = adler32(strm->adler, dictionary, dictLength);
850
851 if (length < MIN_MATCH) return Z_OK;
852 if (length > MAX_DIST(s)) {
853 length = MAX_DIST(s);
854 #ifndef USE_DICT_HEAD
855 dictionary += dictLength - length; /* use the tail of the dictionary */
856 #endif
857 }
858 zmemcpy((charf *)s->window, dictionary, length);
859 s->strstart = length;
860 s->block_start = (long)length;
861
862 /* Insert all strings in the hash table (except for the last two bytes).
863 * s->lookahead stays null, so s->ins_h will be recomputed at the next
864 * call of fill_window.
865 */
866 s->ins_h = s->window[0];
867 UPDATE_HASH(s, s->ins_h, s->window[1]);
868 for (n = 0; n <= length - MIN_MATCH; n++) {
869 INSERT_STRING(s, n, hash_head);
870 }
871 if (hash_head) hash_head = 0; /* to make compiler happy */
872 return Z_OK;
873 }
874
875 /* ========================================================================= */
876 int deflateReset (strm)
877 z_streamp strm;
878 {
879 deflate_state *s;
880
881 if (strm == Z_NULL || strm->state == Z_NULL ||
882 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
883
884 strm->total_in = strm->total_out = 0;
885 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
886 strm->data_type = Z_UNKNOWN;
887
888 s = (deflate_state *)strm->state;
889 s->pending = 0;
890 s->pending_out = s->pending_buf;
891
892 if (s->noheader < 0) {
893 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
894 }
895 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
896 strm->adler = 1;
897 s->last_flush = Z_NO_FLUSH;
898
899 _tr_init(s);
900 lm_init(s);
901
902 return Z_OK;
903 }
904
905 /* ========================================================================= */
906 int deflateParams(strm, level, strategy)
907 z_streamp strm;
908 int level;
909 int strategy;
910 {
911 deflate_state *s;
912 compress_func func;
913 int err = Z_OK;
914
915 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
916 s = (deflate_state *) strm->state;
917
918 if (level == Z_DEFAULT_COMPRESSION) {
919 level = 6;
920 }
921 if (level < 0 || level > 9 || strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
922 return Z_STREAM_ERROR;
923 }
924 func = configuration_table[s->level].func;
925
926 if (func != configuration_table[level].func && strm->total_in != 0) {
927 /* Flush the last buffer: */
928 err = deflate(strm, Z_PARTIAL_FLUSH);
929 }
930 if (s->level != level) {
931 s->level = level;
932 s->max_lazy_match = configuration_table[level].max_lazy;
933 s->good_match = configuration_table[level].good_length;
934 s->nice_match = configuration_table[level].nice_length;
935 s->max_chain_length = configuration_table[level].max_chain;
936 }
937 s->strategy = strategy;
938 return err;
939 }
940
941 /* =========================================================================
942 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
943 * IN assertion: the stream state is correct and there is enough room in
944 * pending_buf.
945 */
946 local void putShortMSB (s, b)
947 deflate_state *s;
948 uInt b;
949 {
950 put_byte(s, (Byte)(b >> 8));
951 put_byte(s, (Byte)(b & 0xff));
952 }
953
954 /* =========================================================================
955 * Flush as much pending output as possible. All deflate() output goes
956 * through this function so some applications may wish to modify it
957 * to avoid allocating a large strm->next_out buffer and copying into it.
958 * (See also read_buf()).
959 */
960 local void flush_pending(strm)
961 z_streamp strm;
962 {
963 deflate_state *s = (deflate_state *) strm->state;
964 unsigned len = s->pending;
965
966 if (len > strm->avail_out) len = strm->avail_out;
967 if (len == 0) return;
968
969 if (strm->next_out != Z_NULL) {
970 zmemcpy(strm->next_out, s->pending_out, len);
971 strm->next_out += len;
972 }
973 s->pending_out += len;
974 strm->total_out += len;
975 strm->avail_out -= len;
976 s->pending -= len;
977 if (s->pending == 0) {
978 s->pending_out = s->pending_buf;
979 }
980 }
981
982 /* ========================================================================= */
983 int deflate (strm, flush)
984 z_streamp strm;
985 int flush;
986 {
987 int old_flush; /* value of flush param for previous deflate call */
988 deflate_state *s;
989
990 if (strm == Z_NULL || strm->state == Z_NULL ||
991 flush > Z_FINISH || flush < 0) {
992 return Z_STREAM_ERROR;
993 }
994 s = (deflate_state *) strm->state;
995
996 if ((strm->next_in == Z_NULL && strm->avail_in != 0) ||
997 (s->status == FINISH_STATE && flush != Z_FINISH)) {
998 ERR_RETURN(strm, Z_STREAM_ERROR);
999 }
1000 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
1001
1002 s->strm = strm; /* just in case */
1003 old_flush = s->last_flush;
1004 s->last_flush = flush;
1005
1006 /* Write the zlib header */
1007 if (s->status == INIT_STATE) {
1008
1009 uInt header = (Z_DEFLATED + ((s->w_bits-8)<<4)) << 8;
1010 uInt level_flags = (s->level-1) >> 1;
1011
1012 if (level_flags > 3) level_flags = 3;
1013 header |= (level_flags << 6);
1014 if (s->strstart != 0) header |= PRESET_DICT;
1015 header += 31 - (header % 31);
1016
1017 s->status = BUSY_STATE;
1018 putShortMSB(s, header);
1019
1020 /* Save the adler32 of the preset dictionary: */
1021 if (s->strstart != 0) {
1022 putShortMSB(s, (uInt)(strm->adler >> 16));
1023 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1024 }
1025 strm->adler = 1L;
1026 }
1027
1028 /* Flush as much pending output as possible */
1029 if (s->pending != 0) {
1030 flush_pending(strm);
1031 if (strm->avail_out == 0) {
1032 /* Since avail_out is 0, deflate will be called again with
1033 * more output space, but possibly with both pending and
1034 * avail_in equal to zero. There won't be anything to do,
1035 * but this is not an error situation so make sure we
1036 * return OK instead of BUF_ERROR at next call of deflate:
1037 */
1038 s->last_flush = -1;
1039 return Z_OK;
1040 }
1041
1042 /* Make sure there is something to do and avoid duplicate consecutive
1043 * flushes. For repeated and useless calls with Z_FINISH, we keep
1044 * returning Z_STREAM_END instead of Z_BUFF_ERROR.
1045 */
1046 } else if (strm->avail_in == 0 && flush <= old_flush &&
1047 flush != Z_FINISH) {
1048 ERR_RETURN(strm, Z_BUF_ERROR);
1049 }
1050
1051 /* User must not provide more input after the first FINISH: */
1052 if (s->status == FINISH_STATE && strm->avail_in != 0) {
1053 ERR_RETURN(strm, Z_BUF_ERROR);
1054 }
1055
1056 /* Start a new block or continue the current one.
1057 */
1058 if (strm->avail_in != 0 || s->lookahead != 0 ||
1059 (flush != Z_NO_FLUSH && s->status != FINISH_STATE)) {
1060 block_state bstate;
1061
1062 bstate = (*(configuration_table[s->level].func))(s, flush);
1063
1064 if (bstate == finish_started || bstate == finish_done) {
1065 s->status = FINISH_STATE;
1066 }
1067 if (bstate == need_more || bstate == finish_started) {
1068 if (strm->avail_out == 0) {
1069 s->last_flush = -1; /* avoid BUF_ERROR next call, see above */
1070 }
1071 return Z_OK;
1072 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
1073 * of deflate should use the same flush parameter to make sure
1074 * that the flush is complete. So we don't have to output an
1075 * empty block here, this will be done at next call. This also
1076 * ensures that for a very small output buffer, we emit at most
1077 * one empty block.
1078 */
1079 }
1080 if (bstate == block_done) {
1081 if (flush == Z_PARTIAL_FLUSH) {
1082 _tr_align(s);
1083 } else if (flush == Z_PACKET_FLUSH) {
1084 /* Output just the 3-bit `stored' block type value,
1085 but not a zero length. */
1086 _tr_stored_type_only(s);
1087 } else { /* FULL_FLUSH or SYNC_FLUSH */
1088 _tr_stored_block(s, (char*)0, 0L, 0);
1089 /* For a full flush, this empty block will be recognized
1090 * as a special marker by inflate_sync().
1091 */
1092 if (flush == Z_FULL_FLUSH) {
1093 CLEAR_HASH(s); /* forget history */
1094 }
1095 }
1096 flush_pending(strm);
1097 if (strm->avail_out == 0) {
1098 s->last_flush = -1; /* avoid BUF_ERROR at next call, see above */
1099 return Z_OK;
1100 }
1101 }
1102 }
1103 Assert(strm->avail_out > 0, "bug2");
1104
1105 if (flush != Z_FINISH) return Z_OK;
1106 if (s->noheader) return Z_STREAM_END;
1107
1108 /* Write the zlib trailer (adler32) */
1109 putShortMSB(s, (uInt)(strm->adler >> 16));
1110 putShortMSB(s, (uInt)(strm->adler & 0xffff));
1111 flush_pending(strm);
1112 /* If avail_out is zero, the application will call deflate again
1113 * to flush the rest.
1114 */
1115 s->noheader = -1; /* write the trailer only once! */
1116 return s->pending != 0 ? Z_OK : Z_STREAM_END;
1117 }
1118
1119 /* ========================================================================= */
1120 int deflateEnd (strm)
1121 z_streamp strm;
1122 {
1123 int status;
1124 deflate_state *s;
1125
1126 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1127 s = (deflate_state *) strm->state;
1128
1129 status = s->status;
1130 if (status != INIT_STATE && status != BUSY_STATE &&
1131 status != FINISH_STATE) {
1132 return Z_STREAM_ERROR;
1133 }
1134
1135 /* Deallocate in reverse order of allocations: */
1136 TRY_FREE(strm, s->pending_buf);
1137 TRY_FREE(strm, s->head);
1138 TRY_FREE(strm, s->prev);
1139 TRY_FREE(strm, s->window);
1140
1141 ZFREE(strm, s);
1142 strm->state = Z_NULL;
1143
1144 return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
1145 }
1146
1147 /* =========================================================================
1148 * Copy the source state to the destination state.
1149 */
1150 int deflateCopy (dest, source)
1151 z_streamp dest;
1152 z_streamp source;
1153 {
1154 deflate_state *ds;
1155 deflate_state *ss;
1156 ushf *overlay;
1157
1158 if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL)
1159 return Z_STREAM_ERROR;
1160 ss = (deflate_state *) source->state;
1161
1162 zmemcpy(dest, source, sizeof(*dest));
1163
1164 ds = (deflate_state *) ZALLOC(dest, 1, sizeof(deflate_state));
1165 if (ds == Z_NULL) return Z_MEM_ERROR;
1166 dest->state = (struct internal_state FAR *) ds;
1167 zmemcpy(ds, ss, sizeof(*ds));
1168 ds->strm = dest;
1169
1170 ds->window = (Bytef *) ZALLOC(dest, ds->w_size, 2*sizeof(Byte));
1171 ds->prev = (Posf *) ZALLOC(dest, ds->w_size, sizeof(Pos));
1172 ds->head = (Posf *) ZALLOC(dest, ds->hash_size, sizeof(Pos));
1173 overlay = (ushf *) ZALLOC(dest, ds->lit_bufsize, sizeof(ush)+2);
1174 ds->pending_buf = (uchf *) overlay;
1175
1176 if (ds->window == Z_NULL || ds->prev == Z_NULL || ds->head == Z_NULL ||
1177 ds->pending_buf == Z_NULL) {
1178 deflateEnd (dest);
1179 return Z_MEM_ERROR;
1180 }
1181 /* ??? following zmemcpy doesn't work for 16-bit MSDOS */
1182 zmemcpy(ds->window, ss->window, ds->w_size * 2 * sizeof(Byte));
1183 zmemcpy(ds->prev, ss->prev, ds->w_size * sizeof(Pos));
1184 zmemcpy(ds->head, ss->head, ds->hash_size * sizeof(Pos));
1185 zmemcpy(ds->pending_buf, ss->pending_buf, (uInt)ds->pending_buf_size);
1186
1187 ds->pending_out = ds->pending_buf + (ss->pending_out - ss->pending_buf);
1188 ds->d_buf = overlay + ds->lit_bufsize/sizeof(ush);
1189 ds->l_buf = ds->pending_buf + (1+sizeof(ush))*ds->lit_bufsize;
1190
1191 ds->l_desc.dyn_tree = ds->dyn_ltree;
1192 ds->d_desc.dyn_tree = ds->dyn_dtree;
1193 ds->bl_desc.dyn_tree = ds->bl_tree;
1194
1195 return Z_OK;
1196 }
1197
1198 /* ===========================================================================
1199 * Return the number of bytes of output which are immediately available
1200 * for output from the decompressor.
1201 */
1202 int deflateOutputPending (strm)
1203 z_streamp strm;
1204 {
1205 if (strm == Z_NULL || strm->state == Z_NULL) return 0;
1206
1207 return ((deflate_state *)(strm->state))->pending;
1208 }
1209
1210 /* ===========================================================================
1211 * Read a new buffer from the current input stream, update the adler32
1212 * and total number of bytes read. All deflate() input goes through
1213 * this function so some applications may wish to modify it to avoid
1214 * allocating a large strm->next_in buffer and copying from it.
1215 * (See also flush_pending()).
1216 */
1217 local int read_buf(strm, buf, size)
1218 z_streamp strm;
1219 charf *buf;
1220 unsigned size;
1221 {
1222 unsigned len = strm->avail_in;
1223
1224 if (len > size) len = size;
1225 if (len == 0) return 0;
1226
1227 strm->avail_in -= len;
1228
1229 if (!((deflate_state *)(strm->state))->noheader) {
1230 strm->adler = adler32(strm->adler, strm->next_in, len);
1231 }
1232 zmemcpy(buf, strm->next_in, len);
1233 strm->next_in += len;
1234 strm->total_in += len;
1235
1236 return (int)len;
1237 }
1238
1239 /* ===========================================================================
1240 * Initialize the "longest match" routines for a new zlib stream
1241 */
1242 local void lm_init (s)
1243 deflate_state *s;
1244 {
1245 s->window_size = (ulg)2L*s->w_size;
1246
1247 CLEAR_HASH(s);
1248
1249 /* Set the default configuration parameters:
1250 */
1251 s->max_lazy_match = configuration_table[s->level].max_lazy;
1252 s->good_match = configuration_table[s->level].good_length;
1253 s->nice_match = configuration_table[s->level].nice_length;
1254 s->max_chain_length = configuration_table[s->level].max_chain;
1255
1256 s->strstart = 0;
1257 s->block_start = 0L;
1258 s->lookahead = 0;
1259 s->match_length = s->prev_length = MIN_MATCH-1;
1260 s->match_available = 0;
1261 s->ins_h = 0;
1262 #ifdef ASMV
1263 match_init(); /* initialize the asm code */
1264 #endif
1265 }
1266
1267 /* ===========================================================================
1268 * Set match_start to the longest match starting at the given string and
1269 * return its length. Matches shorter or equal to prev_length are discarded,
1270 * in which case the result is equal to prev_length and match_start is
1271 * garbage.
1272 * IN assertions: cur_match is the head of the hash chain for the current
1273 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1274 * OUT assertion: the match length is not greater than s->lookahead.
1275 */
1276 #ifndef ASMV
1277 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
1278 * match.S. The code will be functionally equivalent.
1279 */
1280 local uInt longest_match(s, cur_match)
1281 deflate_state *s;
1282 IPos cur_match; /* current match */
1283 {
1284 unsigned chain_length = s->max_chain_length;/* max hash chain length */
1285 register Bytef *scan = s->window + s->strstart; /* current string */
1286 register Bytef *match; /* matched string */
1287 register int len; /* length of current match */
1288 int best_len = s->prev_length; /* best match length so far */
1289 int nice_match = s->nice_match; /* stop if match long enough */
1290 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
1291 s->strstart - (IPos)MAX_DIST(s) : NIL;
1292 /* Stop when cur_match becomes <= limit. To simplify the code,
1293 * we prevent matches with the string of window index 0.
1294 */
1295 Posf *prev = s->prev;
1296 uInt wmask = s->w_mask;
1297
1298 #ifdef UNALIGNED_OK
1299 /* Compare two bytes at a time. Note: this is not always beneficial.
1300 * Try with and without -DUNALIGNED_OK to check.
1301 */
1302 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
1303 register ush scan_start = *(ushf*)scan;
1304 register ush scan_end = *(ushf*)(scan+best_len-1);
1305 #else
1306 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
1307 register Byte scan_end1 = scan[best_len-1];
1308 register Byte scan_end = scan[best_len];
1309 #endif
1310
1311 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1312 * It is easy to get rid of this optimization if necessary.
1313 */
1314 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
1315
1316 /* Do not waste too much time if we already have a good match: */
1317 if (s->prev_length >= s->good_match) {
1318 chain_length >>= 2;
1319 }
1320 /* Do not look for matches beyond the end of the input. This is necessary
1321 * to make deflate deterministic.
1322 */
1323 if ((uInt)nice_match > s->lookahead) nice_match = s->lookahead;
1324
1325 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
1326
1327 do {
1328 Assert(cur_match < s->strstart, "no future");
1329 match = s->window + cur_match;
1330
1331 /* Skip to next match if the match length cannot increase
1332 * or if the match length is less than 2:
1333 */
1334 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1335 /* This code assumes sizeof(unsigned short) == 2. Do not use
1336 * UNALIGNED_OK if your compiler uses a different size.
1337 */
1338 if (*(ushf*)(match+best_len-1) != scan_end ||
1339 *(ushf*)match != scan_start) continue;
1340
1341 /* It is not necessary to compare scan[2] and match[2] since they are
1342 * always equal when the other bytes match, given that the hash keys
1343 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1344 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1345 * lookahead only every 4th comparison; the 128th check will be made
1346 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1347 * necessary to put more guard bytes at the end of the window, or
1348 * to check more often for insufficient lookahead.
1349 */
1350 Assert(scan[2] == match[2], "scan[2]?");
1351 scan++, match++;
1352 do {
1353 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1354 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1355 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1356 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1357 scan < strend);
1358 /* The funny "do {}" generates better code on most compilers */
1359
1360 /* Here, scan <= window+strstart+257 */
1361 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1362 if (*scan == *match) scan++;
1363
1364 len = (MAX_MATCH - 1) - (int)(strend-scan);
1365 scan = strend - (MAX_MATCH-1);
1366
1367 #else /* UNALIGNED_OK */
1368
1369 if (match[best_len] != scan_end ||
1370 match[best_len-1] != scan_end1 ||
1371 *match != *scan ||
1372 *++match != scan[1]) continue;
1373
1374 /* The check at best_len-1 can be removed because it will be made
1375 * again later. (This heuristic is not always a win.)
1376 * It is not necessary to compare scan[2] and match[2] since they
1377 * are always equal when the other bytes match, given that
1378 * the hash keys are equal and that HASH_BITS >= 8.
1379 */
1380 scan += 2, match++;
1381 Assert(*scan == *match, "match[2]?");
1382
1383 /* We check for insufficient lookahead only every 8th comparison;
1384 * the 256th check will be made at strstart+258.
1385 */
1386 do {
1387 } while (*++scan == *++match && *++scan == *++match &&
1388 *++scan == *++match && *++scan == *++match &&
1389 *++scan == *++match && *++scan == *++match &&
1390 *++scan == *++match && *++scan == *++match &&
1391 scan < strend);
1392
1393 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1394
1395 len = MAX_MATCH - (int)(strend - scan);
1396 scan = strend - MAX_MATCH;
1397
1398 #endif /* UNALIGNED_OK */
1399
1400 if (len > best_len) {
1401 s->match_start = cur_match;
1402 best_len = len;
1403 if (len >= nice_match) break;
1404 #ifdef UNALIGNED_OK
1405 scan_end = *(ushf*)(scan+best_len-1);
1406 #else
1407 scan_end1 = scan[best_len-1];
1408 scan_end = scan[best_len];
1409 #endif
1410 }
1411 } while ((cur_match = prev[cur_match & wmask]) > limit
1412 && --chain_length != 0);
1413
1414 if ((uInt)best_len <= s->lookahead) return best_len;
1415 return s->lookahead;
1416 }
1417 #endif /* ASMV */
1418
1419 #ifdef DEBUG_ZLIB
1420 /* ===========================================================================
1421 * Check that the match at match_start is indeed a match.
1422 */
1423 local void check_match(s, start, match, length)
1424 deflate_state *s;
1425 IPos start, match;
1426 int length;
1427 {
1428 /* check that the match is indeed a match */
1429 if (zmemcmp((charf *)s->window + match,
1430 (charf *)s->window + start, length) != EQUAL) {
1431 fprintf(stderr, " start %u, match %u, length %d\n",
1432 start, match, length);
1433 do {
1434 fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
1435 } while (--length != 0);
1436 z_error("invalid match");
1437 }
1438 if (z_verbose > 1) {
1439 fprintf(stderr,"\\[%d,%d]", start-match, length);
1440 do { putc(s->window[start++], stderr); } while (--length != 0);
1441 }
1442 }
1443 #else
1444 # define check_match(s, start, match, length)
1445 #endif
1446
1447 /* ===========================================================================
1448 * Fill the window when the lookahead becomes insufficient.
1449 * Updates strstart and lookahead.
1450 *
1451 * IN assertion: lookahead < MIN_LOOKAHEAD
1452 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1453 * At least one byte has been read, or avail_in == 0; reads are
1454 * performed for at least two bytes (required for the zip translate_eol
1455 * option -- not supported here).
1456 */
1457 local void fill_window(s)
1458 deflate_state *s;
1459 {
1460 register unsigned n, m;
1461 register Posf *p;
1462 unsigned more; /* Amount of free space at the end of the window. */
1463 uInt wsize = s->w_size;
1464
1465 do {
1466 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1467
1468 /* Deal with !@#$% 64K limit: */
1469 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1470 more = wsize;
1471
1472 } else if (more == (unsigned)(-1)) {
1473 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1474 * and lookahead == 1 (input done one byte at time)
1475 */
1476 more--;
1477
1478 /* If the window is almost full and there is insufficient lookahead,
1479 * move the upper half to the lower one to make room in the upper half.
1480 */
1481 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1482
1483 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1484 (unsigned)wsize);
1485 s->match_start -= wsize;
1486 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1487 s->block_start -= (long) wsize;
1488
1489 /* Slide the hash table (could be avoided with 32 bit values
1490 at the expense of memory usage). We slide even when level == 0
1491 to keep the hash table consistent if we switch back to level > 0
1492 later. (Using level 0 permanently is not an optimal usage of
1493 zlib, so we don't care about this pathological case.)
1494 */
1495 n = s->hash_size;
1496 p = &s->head[n];
1497 do {
1498 m = *--p;
1499 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1500 } while (--n);
1501
1502 n = wsize;
1503 p = &s->prev[n];
1504 do {
1505 m = *--p;
1506 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1507 /* If n is not on any hash chain, prev[n] is garbage but
1508 * its value will never be used.
1509 */
1510 } while (--n);
1511 more += wsize;
1512 }
1513 if (s->strm->avail_in == 0) return;
1514
1515 /* If there was no sliding:
1516 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1517 * more == window_size - lookahead - strstart
1518 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1519 * => more >= window_size - 2*WSIZE + 2
1520 * In the BIG_MEM or MMAP case (not yet supported),
1521 * window_size == input_size + MIN_LOOKAHEAD &&
1522 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1523 * Otherwise, window_size == 2*WSIZE so more >= 2.
1524 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1525 */
1526 Assert(more >= 2, "more < 2");
1527
1528 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1529 more);
1530 s->lookahead += n;
1531
1532 /* Initialize the hash value now that we have some input: */
1533 if (s->lookahead >= MIN_MATCH) {
1534 s->ins_h = s->window[s->strstart];
1535 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1536 #if MIN_MATCH != 3
1537 Call UPDATE_HASH() MIN_MATCH-3 more times
1538 #endif
1539 }
1540 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1541 * but this is not important since only literal bytes will be emitted.
1542 */
1543
1544 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1545 }
1546
1547 /* ===========================================================================
1548 * Flush the current block, with given end-of-file flag.
1549 * IN assertion: strstart is set to the end of the current match.
1550 */
1551 #define FLUSH_BLOCK_ONLY(s, eof) { \
1552 _tr_flush_block(s, (s->block_start >= 0L ? \
1553 (charf *)&s->window[(unsigned)s->block_start] : \
1554 (charf *)Z_NULL), \
1555 (ulg)((long)s->strstart - s->block_start), \
1556 (eof)); \
1557 s->block_start = s->strstart; \
1558 flush_pending(s->strm); \
1559 Tracev((stderr,"[FLUSH]")); \
1560 }
1561
1562 /* Same but force premature exit if necessary. */
1563 #define FLUSH_BLOCK(s, eof) { \
1564 FLUSH_BLOCK_ONLY(s, eof); \
1565 if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
1566 }
1567
1568 /* ===========================================================================
1569 * Copy without compression as much as possible from the input stream, return
1570 * the current block state.
1571 * This function does not insert new strings in the dictionary since
1572 * uncompressible data is probably not useful. This function is used
1573 * only for the level=0 compression option.
1574 * NOTE: this function should be optimized to avoid extra copying from
1575 * window to pending_buf.
1576 */
1577 local block_state deflate_stored(s, flush)
1578 deflate_state *s;
1579 int flush;
1580 {
1581 /* Stored blocks are limited to 0xffff bytes, pending_buf is limited
1582 * to pending_buf_size, and each stored block has a 5 byte header:
1583 */
1584 ulg max_block_size = 0xffff;
1585 ulg max_start;
1586
1587 if (max_block_size > s->pending_buf_size - 5) {
1588 max_block_size = s->pending_buf_size - 5;
1589 }
1590
1591 /* Copy as much as possible from input to output: */
1592 for (;;) {
1593 /* Fill the window as much as possible: */
1594 if (s->lookahead <= 1) {
1595
1596 Assert(s->strstart < s->w_size+MAX_DIST(s) ||
1597 s->block_start >= (long)s->w_size, "slide too late");
1598
1599 fill_window(s);
1600 if (s->lookahead == 0 && flush == Z_NO_FLUSH) return need_more;
1601
1602 if (s->lookahead == 0) break; /* flush the current block */
1603 }
1604 Assert(s->block_start >= 0L, "block gone");
1605
1606 s->strstart += s->lookahead;
1607 s->lookahead = 0;
1608
1609 /* Emit a stored block if pending_buf will be full: */
1610 max_start = s->block_start + max_block_size;
1611 if (s->strstart == 0 || (ulg)s->strstart >= max_start) {
1612 /* strstart == 0 is possible when wraparound on 16-bit machine */
1613 s->lookahead = (uInt)(s->strstart - max_start);
1614 s->strstart = (uInt)max_start;
1615 FLUSH_BLOCK(s, 0);
1616 }
1617 /* Flush if we may have to slide, otherwise block_start may become
1618 * negative and the data will be gone:
1619 */
1620 if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
1621 FLUSH_BLOCK(s, 0);
1622 }
1623 }
1624 FLUSH_BLOCK(s, flush == Z_FINISH);
1625 return flush == Z_FINISH ? finish_done : block_done;
1626 }
1627
1628 /* ===========================================================================
1629 * Compress as much as possible from the input stream, return the current
1630 * block state.
1631 * This function does not perform lazy evaluation of matches and inserts
1632 * new strings in the dictionary only for unmatched strings or for short
1633 * matches. It is used only for the fast compression options.
1634 */
1635 local block_state deflate_fast(s, flush)
1636 deflate_state *s;
1637 int flush;
1638 {
1639 IPos hash_head = NIL; /* head of the hash chain */
1640 int bflush; /* set if current block must be flushed */
1641
1642 for (;;) {
1643 /* Make sure that we always have enough lookahead, except
1644 * at the end of the input file. We need MAX_MATCH bytes
1645 * for the next match, plus MIN_MATCH bytes to insert the
1646 * string following the next match.
1647 */
1648 if (s->lookahead < MIN_LOOKAHEAD) {
1649 fill_window(s);
1650 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1651 return need_more;
1652 }
1653 if (s->lookahead == 0) break; /* flush the current block */
1654 }
1655
1656 /* Insert the string window[strstart .. strstart+2] in the
1657 * dictionary, and set hash_head to the head of the hash chain:
1658 */
1659 if (s->lookahead >= MIN_MATCH) {
1660 INSERT_STRING(s, s->strstart, hash_head);
1661 }
1662
1663 /* Find the longest match, discarding those <= prev_length.
1664 * At this point we have always match_length < MIN_MATCH
1665 */
1666 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1667 /* To simplify the code, we prevent matches with the string
1668 * of window index 0 (in particular we have to avoid a match
1669 * of the string with itself at the start of the input file).
1670 */
1671 if (s->strategy != Z_HUFFMAN_ONLY) {
1672 s->match_length = longest_match (s, hash_head);
1673 }
1674 /* longest_match() sets match_start */
1675 }
1676 if (s->match_length >= MIN_MATCH) {
1677 check_match(s, s->strstart, s->match_start, s->match_length);
1678
1679 bflush = _tr_tally(s, s->strstart - s->match_start,
1680 s->match_length - MIN_MATCH);
1681
1682 s->lookahead -= s->match_length;
1683
1684 /* Insert new strings in the hash table only if the match length
1685 * is not too large. This saves time but degrades compression.
1686 */
1687 if (s->match_length <= s->max_insert_length &&
1688 s->lookahead >= MIN_MATCH) {
1689 s->match_length--; /* string at strstart already in hash table */
1690 do {
1691 s->strstart++;
1692 INSERT_STRING(s, s->strstart, hash_head);
1693 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1694 * always MIN_MATCH bytes ahead.
1695 */
1696 } while (--s->match_length != 0);
1697 s->strstart++;
1698 } else {
1699 s->strstart += s->match_length;
1700 s->match_length = 0;
1701 s->ins_h = s->window[s->strstart];
1702 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1703 #if MIN_MATCH != 3
1704 Call UPDATE_HASH() MIN_MATCH-3 more times
1705 #endif
1706 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1707 * matter since it will be recomputed at next deflate call.
1708 */
1709 }
1710 } else {
1711 /* No match, output a literal byte */
1712 Tracevv((stderr,"%c", s->window[s->strstart]));
1713 bflush = _tr_tally (s, 0, s->window[s->strstart]);
1714 s->lookahead--;
1715 s->strstart++;
1716 }
1717 if (bflush) FLUSH_BLOCK(s, 0);
1718 }
1719 FLUSH_BLOCK(s, flush == Z_FINISH);
1720 return flush == Z_FINISH ? finish_done : block_done;
1721 }
1722
1723 /* ===========================================================================
1724 * Same as above, but achieves better compression. We use a lazy
1725 * evaluation for matches: a match is finally adopted only if there is
1726 * no better match at the next window position.
1727 */
1728 local block_state deflate_slow(s, flush)
1729 deflate_state *s;
1730 int flush;
1731 {
1732 IPos hash_head = NIL; /* head of hash chain */
1733 int bflush; /* set if current block must be flushed */
1734
1735 /* Process the input block. */
1736 for (;;) {
1737 /* Make sure that we always have enough lookahead, except
1738 * at the end of the input file. We need MAX_MATCH bytes
1739 * for the next match, plus MIN_MATCH bytes to insert the
1740 * string following the next match.
1741 */
1742 if (s->lookahead < MIN_LOOKAHEAD) {
1743 fill_window(s);
1744 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
1745 return need_more;
1746 }
1747 if (s->lookahead == 0) break; /* flush the current block */
1748 }
1749
1750 /* Insert the string window[strstart .. strstart+2] in the
1751 * dictionary, and set hash_head to the head of the hash chain:
1752 */
1753 if (s->lookahead >= MIN_MATCH) {
1754 INSERT_STRING(s, s->strstart, hash_head);
1755 }
1756
1757 /* Find the longest match, discarding those <= prev_length.
1758 */
1759 s->prev_length = s->match_length, s->prev_match = s->match_start;
1760 s->match_length = MIN_MATCH-1;
1761
1762 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1763 s->strstart - hash_head <= MAX_DIST(s)) {
1764 /* To simplify the code, we prevent matches with the string
1765 * of window index 0 (in particular we have to avoid a match
1766 * of the string with itself at the start of the input file).
1767 */
1768 if (s->strategy != Z_HUFFMAN_ONLY) {
1769 s->match_length = longest_match (s, hash_head);
1770 }
1771 /* longest_match() sets match_start */
1772
1773 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1774 (s->match_length == MIN_MATCH &&
1775 s->strstart - s->match_start > TOO_FAR))) {
1776
1777 /* If prev_match is also MIN_MATCH, match_start is garbage
1778 * but we will ignore the current match anyway.
1779 */
1780 s->match_length = MIN_MATCH-1;
1781 }
1782 }
1783 /* If there was a match at the previous step and the current
1784 * match is not better, output the previous match:
1785 */
1786 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1787 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1788 /* Do not insert strings in hash table beyond this. */
1789
1790 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1791
1792 bflush = _tr_tally(s, s->strstart -1 - s->prev_match,
1793 s->prev_length - MIN_MATCH);
1794
1795 /* Insert in hash table all strings up to the end of the match.
1796 * strstart-1 and strstart are already inserted. If there is not
1797 * enough lookahead, the last two strings are not inserted in
1798 * the hash table.
1799 */
1800 s->lookahead -= s->prev_length-1;
1801 s->prev_length -= 2;
1802 do {
1803 if (++s->strstart <= max_insert) {
1804 INSERT_STRING(s, s->strstart, hash_head);
1805 }
1806 } while (--s->prev_length != 0);
1807 s->match_available = 0;
1808 s->match_length = MIN_MATCH-1;
1809 s->strstart++;
1810
1811 if (bflush) FLUSH_BLOCK(s, 0);
1812
1813 } else if (s->match_available) {
1814 /* If there was no match at the previous position, output a
1815 * single literal. If there was a match but the current match
1816 * is longer, truncate the previous match to a single literal.
1817 */
1818 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1819 if (_tr_tally (s, 0, s->window[s->strstart-1])) {
1820 FLUSH_BLOCK_ONLY(s, 0);
1821 }
1822 s->strstart++;
1823 s->lookahead--;
1824 if (s->strm->avail_out == 0) return need_more;
1825 } else {
1826 /* There is no previous match to compare with, wait for
1827 * the next step to decide.
1828 */
1829 s->match_available = 1;
1830 s->strstart++;
1831 s->lookahead--;
1832 }
1833 }
1834 Assert (flush != Z_NO_FLUSH, "no flush?");
1835 if (s->match_available) {
1836 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1837 _tr_tally (s, 0, s->window[s->strstart-1]);
1838 s->match_available = 0;
1839 }
1840 FLUSH_BLOCK(s, flush == Z_FINISH);
1841 return flush == Z_FINISH ? finish_done : block_done;
1842 }
1843 /* --- deflate.c */
1844
1845 /* +++ trees.c */
1846 /* trees.c -- output deflated data using Huffman coding
1847 * Copyright (C) 1995-1996 Jean-loup Gailly
1848 * For conditions of distribution and use, see copyright notice in zlib.h
1849 */
1850
1851 /*
1852 * ALGORITHM
1853 *
1854 * The "deflation" process uses several Huffman trees. The more
1855 * common source values are represented by shorter bit sequences.
1856 *
1857 * Each code tree is stored in a compressed form which is itself
1858 * a Huffman encoding of the lengths of all the code strings (in
1859 * ascending order by source values). The actual code strings are
1860 * reconstructed from the lengths in the inflate process, as described
1861 * in the deflate specification.
1862 *
1863 * REFERENCES
1864 *
1865 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1866 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1867 *
1868 * Storer, James A.
1869 * Data Compression: Methods and Theory, pp. 49-50.
1870 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1871 *
1872 * Sedgewick, R.
1873 * Algorithms, p290.
1874 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1875 */
1876
1877 /* From: trees.c,v 1.11 1996/07/24 13:41:06 me Exp $ */
1878
1879 /* #include "deflate.h" */
1880
1881 #ifdef DEBUG_ZLIB
1882 # include <ctype.h>
1883 #endif
1884
1885 /* ===========================================================================
1886 * Constants
1887 */
1888
1889 #define MAX_BL_BITS 7
1890 /* Bit length codes must not exceed MAX_BL_BITS bits */
1891
1892 #define END_BLOCK 256
1893 /* end of block literal code */
1894
1895 #define REP_3_6 16
1896 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1897
1898 #define REPZ_3_10 17
1899 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1900
1901 #define REPZ_11_138 18
1902 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1903
1904 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1905 = {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};
1906
1907 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1908 = {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};
1909
1910 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1911 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1912
1913 local uch bl_order[BL_CODES]
1914 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1915 /* The lengths of the bit length codes are sent in order of decreasing
1916 * probability, to avoid transmitting the lengths for unused bit length codes.
1917 */
1918
1919 #define Buf_size (8 * 2*sizeof(char))
1920 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1921 * more than 16 bits on some systems.)
1922 */
1923
1924 /* ===========================================================================
1925 * Local data. These are initialized only once.
1926 */
1927
1928 local ct_data static_ltree[L_CODES+2];
1929 /* The static literal tree. Since the bit lengths are imposed, there is no
1930 * need for the L_CODES extra codes used during heap construction. However
1931 * The codes 286 and 287 are needed to build a canonical tree (see _tr_init
1932 * below).
1933 */
1934
1935 local ct_data static_dtree[D_CODES];
1936 /* The static distance tree. (Actually a trivial tree since all codes use
1937 * 5 bits.)
1938 */
1939
1940 local uch dist_code[512];
1941 /* distance codes. The first 256 values correspond to the distances
1942 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1943 * the 15 bit distances.
1944 */
1945
1946 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1947 /* length code for each normalized match length (0 == MIN_MATCH) */
1948
1949 local int base_length[LENGTH_CODES];
1950 /* First normalized length for each code (0 = MIN_MATCH) */
1951
1952 local int base_dist[D_CODES];
1953 /* First normalized distance for each code (0 = distance of 1) */
1954
1955 struct static_tree_desc_s {
1956 ct_data *static_tree; /* static tree or NULL */
1957 intf *extra_bits; /* extra bits for each code or NULL */
1958 int extra_base; /* base index for extra_bits */
1959 int elems; /* max number of elements in the tree */
1960 int max_length; /* max bit length for the codes */
1961 };
1962
1963 local static_tree_desc static_l_desc =
1964 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1965
1966 local static_tree_desc static_d_desc =
1967 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1968
1969 local static_tree_desc static_bl_desc =
1970 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1971
1972 /* ===========================================================================
1973 * Local (static) routines in this file.
1974 */
1975
1976 local void tr_static_init OF((void));
1977 local void init_block OF((deflate_state *s));
1978 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1979 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1980 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1981 local void build_tree OF((deflate_state *s, tree_desc *desc));
1982 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1983 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1984 local int build_bl_tree OF((deflate_state *s));
1985 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1986 int blcodes));
1987 local void compress_block OF((deflate_state *s, ct_data *ltree,
1988 ct_data *dtree));
1989 local void set_data_type OF((deflate_state *s));
1990 local unsigned bi_reverse OF((unsigned value, int length));
1991 local void bi_windup OF((deflate_state *s));
1992 local void bi_flush OF((deflate_state *s));
1993 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1994 int header));
1995
1996 #ifndef DEBUG_ZLIB
1997 # define send_code(s, c, tree) send_bits(s, tree[(c)].Code, tree[(c)].Len)
1998 /* Send a code of the given tree. c and tree must not have side effects */
1999
2000 #else /* DEBUG_ZLIB */
2001 # define send_code(s, c, tree) \
2002 { if (verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \
2003 send_bits(s, tree[c].Code, tree[c].Len); }
2004 #endif
2005
2006 #define d_code(dist) \
2007 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2008 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2009 * must not have side effects. dist_code[256] and dist_code[257] are never
2010 * used.
2011 */
2012
2013 /* ===========================================================================
2014 * Output a short LSB first on the stream.
2015 * IN assertion: there is enough room in pendingBuf.
2016 */
2017 #define put_short(s, w) { \
2018 put_byte(s, (uch)((w) & 0xff)); \
2019 put_byte(s, (uch)((ush)(w) >> 8)); \
2020 }
2021
2022 /* ===========================================================================
2023 * Send a value on a given number of bits.
2024 * IN assertion: length <= 16 and value fits in length bits.
2025 */
2026 #ifdef DEBUG_ZLIB
2027 local void send_bits OF((deflate_state *s, int value, int length));
2028
2029 local void send_bits(s, value, length)
2030 deflate_state *s;
2031 int value; /* value to send */
2032 int length; /* number of bits */
2033 {
2034 Tracevv((stderr," l %2d v %4x ", length, value));
2035 Assert(length > 0 && length <= 15, "invalid length");
2036 s->bits_sent += (ulg)length;
2037
2038 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
2039 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
2040 * unused bits in value.
2041 */
2042 if (s->bi_valid > (int)Buf_size - length) {
2043 s->bi_buf |= (value << s->bi_valid);
2044 put_short(s, s->bi_buf);
2045 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
2046 s->bi_valid += length - Buf_size;
2047 } else {
2048 s->bi_buf |= value << s->bi_valid;
2049 s->bi_valid += length;
2050 }
2051 }
2052 #else /* !DEBUG_ZLIB */
2053
2054 #define send_bits(s, value, length) \
2055 { int len = (length);\
2056 if ((s)->bi_valid > (int)Buf_size - len) {\
2057 int val = (value);\
2058 (s)->bi_buf |= (val << (s)->bi_valid);\
2059 put_short((s), (s)->bi_buf);\
2060 (s)->bi_buf = (ush)val >> (Buf_size - (s)->bi_valid);\
2061 (s)->bi_valid += len - Buf_size;\
2062 } else {\
2063 (s)->bi_buf |= (value) << (s)->bi_valid;\
2064 (s)->bi_valid += len;\
2065 }\
2066 }
2067 #endif /* DEBUG_ZLIB */
2068
2069 /* the arguments must not have side effects */
2070
2071 /* ===========================================================================
2072 * Initialize the various 'constant' tables. In a multi-threaded environment,
2073 * this function may be called by two threads concurrently, but this is
2074 * harmless since both invocations do exactly the same thing.
2075 */
2076 local void tr_static_init()
2077 {
2078 static int static_init_done = 0;
2079 int n; /* iterates over tree elements */
2080 int bits; /* bit counter */
2081 int length; /* length value */
2082 int code; /* code value */
2083 int dist; /* distance index */
2084 ush bl_count[MAX_BITS+1];
2085 /* number of codes at each bit length for an optimal tree */
2086
2087 if (static_init_done) return;
2088
2089 /* Initialize the mapping length (0..255) -> length code (0..28) */
2090 length = 0;
2091 for (code = 0; code < LENGTH_CODES-1; code++) {
2092 base_length[code] = length;
2093 for (n = 0; n < (1<<extra_lbits[code]); n++) {
2094 length_code[length++] = (uch)code;
2095 }
2096 }
2097 Assert (length == 256, "tr_static_init: length != 256");
2098 /* Note that the length 255 (match length 258) can be represented
2099 * in two different ways: code 284 + 5 bits or code 285, so we
2100 * overwrite length_code[255] to use the best encoding:
2101 */
2102 length_code[length-1] = (uch)code;
2103
2104 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2105 dist = 0;
2106 for (code = 0 ; code < 16; code++) {
2107 base_dist[code] = dist;
2108 for (n = 0; n < (1<<extra_dbits[code]); n++) {
2109 dist_code[dist++] = (uch)code;
2110 }
2111 }
2112 Assert (dist == 256, "tr_static_init: dist != 256");
2113 dist >>= 7; /* from now on, all distances are divided by 128 */
2114 for ( ; code < D_CODES; code++) {
2115 base_dist[code] = dist << 7;
2116 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
2117 dist_code[256 + dist++] = (uch)code;
2118 }
2119 }
2120 Assert (dist == 256, "tr_static_init: 256+dist != 512");
2121
2122 /* Construct the codes of the static literal tree */
2123 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
2124 n = 0;
2125 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
2126 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
2127 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
2128 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
2129 /* Codes 286 and 287 do not exist, but we must include them in the
2130 * tree construction to get a canonical Huffman tree (longest code
2131 * all ones)
2132 */
2133 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
2134
2135 /* The static distance tree is trivial: */
2136 for (n = 0; n < D_CODES; n++) {
2137 static_dtree[n].Len = 5;
2138 static_dtree[n].Code = bi_reverse((unsigned)n, 5);
2139 }
2140 static_init_done = 1;
2141 }
2142
2143 /* ===========================================================================
2144 * Initialize the tree data structures for a new zlib stream.
2145 */
2146 void _tr_init(s)
2147 deflate_state *s;
2148 {
2149 tr_static_init();
2150
2151 s->compressed_len = 0L;
2152
2153 s->l_desc.dyn_tree = s->dyn_ltree;
2154 s->l_desc.stat_desc = &static_l_desc;
2155
2156 s->d_desc.dyn_tree = s->dyn_dtree;
2157 s->d_desc.stat_desc = &static_d_desc;
2158
2159 s->bl_desc.dyn_tree = s->bl_tree;
2160 s->bl_desc.stat_desc = &static_bl_desc;
2161
2162 s->bi_buf = 0;
2163 s->bi_valid = 0;
2164 s->last_eob_len = 8; /* enough lookahead for inflate */
2165 #ifdef DEBUG_ZLIB
2166 s->bits_sent = 0L;
2167 #endif
2168
2169 /* Initialize the first block of the first file: */
2170 init_block(s);
2171 }
2172
2173 /* ===========================================================================
2174 * Initialize a new block.
2175 */
2176 local void init_block(s)
2177 deflate_state *s;
2178 {
2179 int n; /* iterates over tree elements */
2180
2181 /* Initialize the trees. */
2182 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
2183 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
2184 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
2185
2186 s->dyn_ltree[END_BLOCK].Freq = 1;
2187 s->opt_len = s->static_len = 0L;
2188 s->last_lit = s->matches = 0;
2189 }
2190
2191 #define SMALLEST 1
2192 /* Index within the heap array of least frequent node in the Huffman tree */
2193
2194
2195 /* ===========================================================================
2196 * Remove the smallest element from the heap and recreate the heap with
2197 * one less element. Updates heap and heap_len.
2198 */
2199 #define pqremove(s, tree, top) \
2200 {\
2201 top = s->heap[SMALLEST]; \
2202 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
2203 pqdownheap(s, tree, SMALLEST); \
2204 }
2205
2206 /* ===========================================================================
2207 * Compares to subtrees, using the tree depth as tie breaker when
2208 * the subtrees have equal frequency. This minimizes the worst case length.
2209 */
2210 #define smaller(tree, n, m, depth) \
2211 (tree[n].Freq < tree[m].Freq || \
2212 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2213
2214 /* ===========================================================================
2215 * Restore the heap property by moving down the tree starting at node k,
2216 * exchanging a node with the smallest of its two sons if necessary, stopping
2217 * when the heap property is re-established (each father smaller than its
2218 * two sons).
2219 */
2220 local void pqdownheap(s, tree, k)
2221 deflate_state *s;
2222 ct_data *tree; /* the tree to restore */
2223 int k; /* node to move down */
2224 {
2225 int v = s->heap[k];
2226 int j = k << 1; /* left son of k */
2227 while (j <= s->heap_len) {
2228 /* Set j to the smallest of the two sons: */
2229 if (j < s->heap_len &&
2230 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
2231 j++;
2232 }
2233 /* Exit if v is smaller than both sons */
2234 if (smaller(tree, v, s->heap[j], s->depth)) break;
2235
2236 /* Exchange v with the smallest son */
2237 s->heap[k] = s->heap[j]; k = j;
2238
2239 /* And continue down the tree, setting j to the left son of k */
2240 j <<= 1;
2241 }
2242 s->heap[k] = v;
2243 }
2244
2245 /* ===========================================================================
2246 * Compute the optimal bit lengths for a tree and update the total bit length
2247 * for the current block.
2248 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2249 * above are the tree nodes sorted by increasing frequency.
2250 * OUT assertions: the field len is set to the optimal bit length, the
2251 * array bl_count contains the frequencies for each bit length.
2252 * The length opt_len is updated; static_len is also updated if stree is
2253 * not null.
2254 */
2255 local void gen_bitlen(s, desc)
2256 deflate_state *s;
2257 tree_desc *desc; /* the tree descriptor */
2258 {
2259 ct_data *tree = desc->dyn_tree;
2260 int max_code = desc->max_code;
2261 ct_data *stree = desc->stat_desc->static_tree;
2262 intf *extra = desc->stat_desc->extra_bits;
2263 int base = desc->stat_desc->extra_base;
2264 int max_length = desc->stat_desc->max_length;
2265 int h; /* heap index */
2266 int n, m; /* iterate over the tree elements */
2267 int bits; /* bit length */
2268 int xbits; /* extra bits */
2269 ush f; /* frequency */
2270 int overflow = 0; /* number of elements with bit length too large */
2271
2272 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
2273
2274 /* In a first pass, compute the optimal bit lengths (which may
2275 * overflow in the case of the bit length tree).
2276 */
2277 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
2278
2279 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
2280 n = s->heap[h];
2281 bits = tree[tree[n].Dad].Len + 1;
2282 if (bits > max_length) bits = max_length, overflow++;
2283 tree[n].Len = (ush)bits;
2284 /* We overwrite tree[n].Dad which is no longer needed */
2285
2286 if (n > max_code) continue; /* not a leaf node */
2287
2288 s->bl_count[bits]++;
2289 xbits = 0;
2290 if (n >= base) xbits = extra[n-base];
2291 f = tree[n].Freq;
2292 s->opt_len += (ulg)f * (bits + xbits);
2293 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
2294 }
2295 if (overflow == 0) return;
2296
2297 Trace((stderr,"\nbit length overflow\n"));
2298 /* This happens for example on obj2 and pic of the Calgary corpus */
2299
2300 /* Find the first bit length which could increase: */
2301 do {
2302 bits = max_length-1;
2303 while (s->bl_count[bits] == 0) bits--;
2304 s->bl_count[bits]--; /* move one leaf down the tree */
2305 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
2306 s->bl_count[max_length]--;
2307 /* The brother of the overflow item also moves one step up,
2308 * but this does not affect bl_count[max_length]
2309 */
2310 overflow -= 2;
2311 } while (overflow > 0);
2312
2313 /* Now recompute all bit lengths, scanning in increasing frequency.
2314 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2315 * lengths instead of fixing only the wrong ones. This idea is taken
2316 * from 'ar' written by Haruhiko Okumura.)
2317 */
2318 for (bits = max_length; bits != 0; bits--) {
2319 n = s->bl_count[bits];
2320 while (n != 0) {
2321 m = s->heap[--h];
2322 if (m > max_code) continue;
2323 if (tree[m].Len != (unsigned) bits) {
2324 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
2325 s->opt_len += ((long)bits - (long)tree[m].Len)
2326 *(long)tree[m].Freq;
2327 tree[m].Len = (ush)bits;
2328 }
2329 n--;
2330 }
2331 }
2332 }
2333
2334 /* ===========================================================================
2335 * Generate the codes for a given tree and bit counts (which need not be
2336 * optimal).
2337 * IN assertion: the array bl_count contains the bit length statistics for
2338 * the given tree and the field len is set for all tree elements.
2339 * OUT assertion: the field code is set for all tree elements of non
2340 * zero code length.
2341 */
2342 local void gen_codes (tree, max_code, bl_count)
2343 ct_data *tree; /* the tree to decorate */
2344 int max_code; /* largest code with non zero frequency */
2345 ushf *bl_count; /* number of codes at each bit length */
2346 {
2347 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
2348 ush code = 0; /* running code value */
2349 int bits; /* bit index */
2350 int n; /* code index */
2351
2352 /* The distribution counts are first used to generate the code values
2353 * without bit reversal.
2354 */
2355 for (bits = 1; bits <= MAX_BITS; bits++) {
2356 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
2357 }
2358 /* Check that the bit counts in bl_count are consistent. The last code
2359 * must be all ones.
2360 */
2361 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
2362 "inconsistent bit counts");
2363 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
2364
2365 for (n = 0; n <= max_code; n++) {
2366 int len = tree[n].Len;
2367 if (len == 0) continue;
2368 /* Now reverse the bits */
2369 tree[n].Code = bi_reverse(next_code[len]++, len);
2370
2371 Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
2372 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
2373 }
2374 }
2375
2376 /* ===========================================================================
2377 * Construct one Huffman tree and assigns the code bit strings and lengths.
2378 * Update the total bit length for the current block.
2379 * IN assertion: the field freq is set for all tree elements.
2380 * OUT assertions: the fields len and code are set to the optimal bit length
2381 * and corresponding code. The length opt_len is updated; static_len is
2382 * also updated if stree is not null. The field max_code is set.
2383 */
2384 local void build_tree(s, desc)
2385 deflate_state *s;
2386 tree_desc *desc; /* the tree descriptor */
2387 {
2388 ct_data *tree = desc->dyn_tree;
2389 ct_data *stree = desc->stat_desc->static_tree;
2390 int elems = desc->stat_desc->elems;
2391 int n, m; /* iterate over heap elements */
2392 int max_code = -1; /* largest code with non zero frequency */
2393 int node; /* new node being created */
2394
2395 /* Construct the initial heap, with least frequent element in
2396 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2397 * heap[0] is not used.
2398 */
2399 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2400
2401 for (n = 0; n < elems; n++) {
2402 if (tree[n].Freq != 0) {
2403 s->heap[++(s->heap_len)] = max_code = n;
2404 s->depth[n] = 0;
2405 } else {
2406 tree[n].Len = 0;
2407 }
2408 }
2409
2410 /* The pkzip format requires that at least one distance code exists,
2411 * and that at least one bit should be sent even if there is only one
2412 * possible code. So to avoid special checks later on we force at least
2413 * two codes of non zero frequency.
2414 */
2415 while (s->heap_len < 2) {
2416 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2417 tree[node].Freq = 1;
2418 s->depth[node] = 0;
2419 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2420 /* node is 0 or 1 so it does not have extra bits */
2421 }
2422 desc->max_code = max_code;
2423
2424 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2425 * establish sub-heaps of increasing lengths:
2426 */
2427 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2428
2429 /* Construct the Huffman tree by repeatedly combining the least two
2430 * frequent nodes.
2431 */
2432 node = elems; /* next internal node of the tree */
2433 do {
2434 pqremove(s, tree, n); /* n = node of least frequency */
2435 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2436
2437 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2438 s->heap[--(s->heap_max)] = m;
2439
2440 /* Create a new node father of n and m */
2441 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2442 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2443 tree[n].Dad = tree[m].Dad = (ush)node;
2444 #ifdef DUMP_BL_TREE
2445 if (tree == s->bl_tree) {
2446 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2447 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2448 }
2449 #endif
2450 /* and insert the new node in the heap */
2451 s->heap[SMALLEST] = node++;
2452 pqdownheap(s, tree, SMALLEST);
2453
2454 } while (s->heap_len >= 2);
2455
2456 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2457
2458 /* At this point, the fields freq and dad are set. We can now
2459 * generate the bit lengths.
2460 */
2461 gen_bitlen(s, (tree_desc *)desc);
2462
2463 /* The field len is now set, we can generate the bit codes */
2464 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2465 }
2466
2467 /* ===========================================================================
2468 * Scan a literal or distance tree to determine the frequencies of the codes
2469 * in the bit length tree.
2470 */
2471 local void scan_tree (s, tree, max_code)
2472 deflate_state *s;
2473 ct_data *tree; /* the tree to be scanned */
2474 int max_code; /* and its largest code of non zero frequency */
2475 {
2476 int n; /* iterates over all tree elements */
2477 int prevlen = -1; /* last emitted length */
2478 int curlen; /* length of current code */
2479 int nextlen = tree[0].Len; /* length of next code */
2480 int count = 0; /* repeat count of the current code */
2481 int max_count = 7; /* max repeat count */
2482 int min_count = 4; /* min repeat count */
2483
2484 if (nextlen == 0) max_count = 138, min_count = 3;
2485 tree[max_code+1].Len = (ush)0xffff; /* guard */
2486
2487 for (n = 0; n <= max_code; n++) {
2488 curlen = nextlen; nextlen = tree[n+1].Len;
2489 if (++count < max_count && curlen == nextlen) {
2490 continue;
2491 } else if (count < min_count) {
2492 s->bl_tree[curlen].Freq += count;
2493 } else if (curlen != 0) {
2494 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2495 s->bl_tree[REP_3_6].Freq++;
2496 } else if (count <= 10) {
2497 s->bl_tree[REPZ_3_10].Freq++;
2498 } else {
2499 s->bl_tree[REPZ_11_138].Freq++;
2500 }
2501 count = 0; prevlen = curlen;
2502 if (nextlen == 0) {
2503 max_count = 138, min_count = 3;
2504 } else if (curlen == nextlen) {
2505 max_count = 6, min_count = 3;
2506 } else {
2507 max_count = 7, min_count = 4;
2508 }
2509 }
2510 }
2511
2512 /* ===========================================================================
2513 * Send a literal or distance tree in compressed form, using the codes in
2514 * bl_tree.
2515 */
2516 local void send_tree (s, tree, max_code)
2517 deflate_state *s;
2518 ct_data *tree; /* the tree to be scanned */
2519 int max_code; /* and its largest code of non zero frequency */
2520 {
2521 int n; /* iterates over all tree elements */
2522 int prevlen = -1; /* last emitted length */
2523 int curlen; /* length of current code */
2524 int nextlen = tree[0].Len; /* length of next code */
2525 int count = 0; /* repeat count of the current code */
2526 int max_count = 7; /* max repeat count */
2527 int min_count = 4; /* min repeat count */
2528
2529 /* tree[max_code+1].Len = -1; */ /* guard already set */
2530 if (nextlen == 0) max_count = 138, min_count = 3;
2531
2532 for (n = 0; n <= max_code; n++) {
2533 curlen = nextlen; nextlen = tree[n+1].Len;
2534 if (++count < max_count && curlen == nextlen) {
2535 continue;
2536 } else if (count < min_count) {
2537 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2538
2539 } else if (curlen != 0) {
2540 if (curlen != prevlen) {
2541 send_code(s, curlen, s->bl_tree); count--;
2542 }
2543 Assert(count >= 3 && count <= 6, " 3_6?");
2544 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2545
2546 } else if (count <= 10) {
2547 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2548
2549 } else {
2550 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2551 }
2552 count = 0; prevlen = curlen;
2553 if (nextlen == 0) {
2554 max_count = 138, min_count = 3;
2555 } else if (curlen == nextlen) {
2556 max_count = 6, min_count = 3;
2557 } else {
2558 max_count = 7, min_count = 4;
2559 }
2560 }
2561 }
2562
2563 /* ===========================================================================
2564 * Construct the Huffman tree for the bit lengths and return the index in
2565 * bl_order of the last bit length code to send.
2566 */
2567 local int build_bl_tree(s)
2568 deflate_state *s;
2569 {
2570 int max_blindex; /* index of last bit length code of non zero freq */
2571
2572 /* Determine the bit length frequencies for literal and distance trees */
2573 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2574 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2575
2576 /* Build the bit length tree: */
2577 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2578 /* opt_len now includes the length of the tree representations, except
2579 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2580 */
2581
2582 /* Determine the number of bit length codes to send. The pkzip format
2583 * requires that at least 4 bit length codes be sent. (appnote.txt says
2584 * 3 but the actual value used is 4.)
2585 */
2586 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2587 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2588 }
2589 /* Update opt_len to include the bit length tree and counts */
2590 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2591 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2592 s->opt_len, s->static_len));
2593
2594 return max_blindex;
2595 }
2596
2597 /* ===========================================================================
2598 * Send the header for a block using dynamic Huffman trees: the counts, the
2599 * lengths of the bit length codes, the literal tree and the distance tree.
2600 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2601 */
2602 local void send_all_trees(s, lcodes, dcodes, blcodes)
2603 deflate_state *s;
2604 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2605 {
2606 int rank; /* index in bl_order */
2607
2608 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2609 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2610 "too many codes");
2611 Tracev((stderr, "\nbl counts: "));
2612 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2613 send_bits(s, dcodes-1, 5);
2614 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2615 for (rank = 0; rank < blcodes; rank++) {
2616 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2617 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2618 }
2619 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2620
2621 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2622 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2623
2624 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2625 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2626 }
2627
2628 /* ===========================================================================
2629 * Send a stored block
2630 */
2631 void _tr_stored_block(s, buf, stored_len, eof)
2632 deflate_state *s;
2633 charf *buf; /* input block */
2634 ulg stored_len; /* length of input block */
2635 int eof; /* true if this is the last block for a file */
2636 {
2637 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2638 s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
2639 s->compressed_len += (stored_len + 4) << 3;
2640
2641 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2642 }
2643
2644 /* Send just the `stored block' type code without any length bytes or data.
2645 */
2646 void _tr_stored_type_only(s)
2647 deflate_state *s;
2648 {
2649 send_bits(s, (STORED_BLOCK << 1), 3);
2650 bi_windup(s);
2651 s->compressed_len = (s->compressed_len + 3) & ~7L;
2652 }
2653
2654
2655 /* ===========================================================================
2656 * Send one empty static block to give enough lookahead for inflate.
2657 * This takes 10 bits, of which 7 may remain in the bit buffer.
2658 * The current inflate code requires 9 bits of lookahead. If the
2659 * last two codes for the previous block (real code plus EOB) were coded
2660 * on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
2661 * the last real code. In this case we send two empty static blocks instead
2662 * of one. (There are no problems if the previous block is stored or fixed.)
2663 * To simplify the code, we assume the worst case of last real code encoded
2664 * on one bit only.
2665 */
2666 void _tr_align(s)
2667 deflate_state *s;
2668 {
2669 send_bits(s, STATIC_TREES<<1, 3);
2670 send_code(s, END_BLOCK, static_ltree);
2671 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2672 bi_flush(s);
2673 /* Of the 10 bits for the empty block, we have already sent
2674 * (10 - bi_valid) bits. The lookahead for the last real code (before
2675 * the EOB of the previous block) was thus at least one plus the length
2676 * of the EOB plus what we have just sent of the empty static block.
2677 */
2678 if (1 + s->last_eob_len + 10 - s->bi_valid < 9) {
2679 send_bits(s, STATIC_TREES<<1, 3);
2680 send_code(s, END_BLOCK, static_ltree);
2681 s->compressed_len += 10L;
2682 bi_flush(s);
2683 }
2684 s->last_eob_len = 7;
2685 }
2686
2687 /* ===========================================================================
2688 * Determine the best encoding for the current block: dynamic trees, static
2689 * trees or store, and output the encoded block to the zip file. This function
2690 * returns the total compressed length for the file so far.
2691 */
2692 ulg _tr_flush_block(s, buf, stored_len, eof)
2693 deflate_state *s;
2694 charf *buf; /* input block, or NULL if too old */
2695 ulg stored_len; /* length of input block */
2696 int eof; /* true if this is the last block for a file */
2697 {
2698 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2699 int max_blindex = 0; /* index of last bit length code of non zero freq */
2700
2701 /* Build the Huffman trees unless a stored block is forced */
2702 if (s->level > 0) {
2703
2704 /* Check if the file is ascii or binary */
2705 if (s->data_type == Z_UNKNOWN) set_data_type(s);
2706
2707 /* Construct the literal and distance trees */
2708 build_tree(s, (tree_desc *)(&(s->l_desc)));
2709 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2710 s->static_len));
2711
2712 build_tree(s, (tree_desc *)(&(s->d_desc)));
2713 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2714 s->static_len));
2715 /* At this point, opt_len and static_len are the total bit lengths of
2716 * the compressed block data, excluding the tree representations.
2717 */
2718
2719 /* Build the bit length tree for the above two trees, and get the index
2720 * in bl_order of the last bit length code to send.
2721 */
2722 max_blindex = build_bl_tree(s);
2723
2724 /* Determine the best encoding. Compute first the block length in bytes*/
2725 opt_lenb = (s->opt_len+3+7)>>3;
2726 static_lenb = (s->static_len+3+7)>>3;
2727
2728 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2729 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2730 s->last_lit));
2731
2732 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2733
2734 } else {
2735 Assert(buf != (char*)0, "lost buf");
2736 opt_lenb = static_lenb = stored_len + 5; /* force a stored block */
2737 }
2738
2739 /* If compression failed and this is the first and last block,
2740 * and if the .zip file can be seeked (to rewrite the local header),
2741 * the whole file is transformed into a stored file:
2742 */
2743 #ifdef STORED_FILE_OK
2744 # ifdef FORCE_STORED_FILE
2745 if (eof && s->compressed_len == 0L) { /* force stored file */
2746 # else
2747 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) {
2748 # endif
2749 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2750 if (buf == (charf*)0) error ("block vanished");
2751
2752 copy_block(s, buf, (unsigned)stored_len, 0); /* without header */
2753 s->compressed_len = stored_len << 3;
2754 s->method = STORED;
2755 } else
2756 #endif /* STORED_FILE_OK */
2757
2758 #ifdef FORCE_STORED
2759 if (buf != (char*)0) { /* force stored block */
2760 #else
2761 if (stored_len+4 <= opt_lenb && buf != (char*)0) {
2762 /* 4: two words for the lengths */
2763 #endif
2764 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2765 * Otherwise we can't have processed more than WSIZE input bytes since
2766 * the last block flush, because compression would have been
2767 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2768 * transform a block into a stored block.
2769 */
2770 _tr_stored_block(s, buf, stored_len, eof);
2771
2772 #ifdef FORCE_STATIC
2773 } else if (static_lenb >= 0) { /* force static trees */
2774 #else
2775 } else if (static_lenb == opt_lenb) {
2776 #endif
2777 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2778 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2779 s->compressed_len += 3 + s->static_len;
2780 } else {
2781 send_bits(s, (DYN_TREES<<1)+eof, 3);
2782 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2783 max_blindex+1);
2784 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2785 s->compressed_len += 3 + s->opt_len;
2786 }
2787 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2788 init_block(s);
2789
2790 if (eof) {
2791 bi_windup(s);
2792 s->compressed_len += 7; /* align on byte boundary */
2793 }
2794 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2795 s->compressed_len-7*eof));
2796
2797 return s->compressed_len >> 3;
2798 }
2799
2800 /* ===========================================================================
2801 * Save the match info and tally the frequency counts. Return true if
2802 * the current block must be flushed.
2803 */
2804 int _tr_tally (s, dist, lc)
2805 deflate_state *s;
2806 unsigned dist; /* distance of matched string */
2807 unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2808 {
2809 s->d_buf[s->last_lit] = (ush)dist;
2810 s->l_buf[s->last_lit++] = (uch)lc;
2811 if (dist == 0) {
2812 /* lc is the unmatched char */
2813 s->dyn_ltree[lc].Freq++;
2814 } else {
2815 s->matches++;
2816 /* Here, lc is the match length - MIN_MATCH */
2817 dist--; /* dist = match distance - 1 */
2818 Assert((ush)dist < (ush)MAX_DIST(s) &&
2819 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2820 (ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");
2821
2822 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2823 s->dyn_dtree[d_code(dist)].Freq++;
2824 }
2825
2826 /* Try to guess if it is profitable to stop the current block here */
2827 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2828 /* Compute an upper bound for the compressed length */
2829 ulg out_length = (ulg)s->last_lit*8L;
2830 ulg in_length = (ulg)((long)s->strstart - s->block_start);
2831 int dcode;
2832 for (dcode = 0; dcode < D_CODES; dcode++) {
2833 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2834 (5L+extra_dbits[dcode]);
2835 }
2836 out_length >>= 3;
2837 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2838 s->last_lit, in_length, out_length,
2839 100L - out_length*100L/in_length));
2840 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2841 }
2842 return (s->last_lit == s->lit_bufsize-1);
2843 /* We avoid equality with lit_bufsize because of wraparound at 64K
2844 * on 16 bit machines and because stored blocks are restricted to
2845 * 64K-1 bytes.
2846 */
2847 }
2848
2849 /* ===========================================================================
2850 * Send the block data compressed using the given Huffman trees
2851 */
2852 local void compress_block(s, ltree, dtree)
2853 deflate_state *s;
2854 ct_data *ltree; /* literal tree */
2855 ct_data *dtree; /* distance tree */
2856 {
2857 unsigned dist; /* distance of matched string */
2858 int lc; /* match length or unmatched char (if dist == 0) */
2859 unsigned lx = 0; /* running index in l_buf */
2860 unsigned code; /* the code to send */
2861 int extra; /* number of extra bits to send */
2862
2863 if (s->last_lit != 0) do {
2864 dist = s->d_buf[lx];
2865 lc = s->l_buf[lx++];
2866 if (dist == 0) {
2867 send_code(s, lc, ltree); /* send a literal byte */
2868 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2869 } else {
2870 /* Here, lc is the match length - MIN_MATCH */
2871 code = length_code[lc];
2872 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2873 extra = extra_lbits[code];
2874 if (extra != 0) {
2875 lc -= base_length[code];
2876 send_bits(s, lc, extra); /* send the extra length bits */
2877 }
2878 dist--; /* dist is now the match distance - 1 */
2879 code = d_code(dist);
2880 Assert (code < D_CODES, "bad d_code");
2881
2882 send_code(s, code, dtree); /* send the distance code */
2883 extra = extra_dbits[code];
2884 if (extra != 0) {
2885 dist -= base_dist[code];
2886 send_bits(s, dist, extra); /* send the extra distance bits */
2887 }
2888 } /* literal or match pair ? */
2889
2890 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2891 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2892
2893 } while (lx < s->last_lit);
2894
2895 send_code(s, END_BLOCK, ltree);
2896 s->last_eob_len = ltree[END_BLOCK].Len;
2897 }
2898
2899 /* ===========================================================================
2900 * Set the data type to ASCII or BINARY, using a crude approximation:
2901 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2902 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2903 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2904 */
2905 local void set_data_type(s)
2906 deflate_state *s;
2907 {
2908 int n = 0;
2909 unsigned ascii_freq = 0;
2910 unsigned bin_freq = 0;
2911 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2912 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2913 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2914 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII);
2915 }
2916
2917 /* ===========================================================================
2918 * Reverse the first len bits of a code, using straightforward code (a faster
2919 * method would use a table)
2920 * IN assertion: 1 <= len <= 15
2921 */
2922 local unsigned bi_reverse(code, len)
2923 unsigned code; /* the value to invert */
2924 int len; /* its bit length */
2925 {
2926 register unsigned res = 0;
2927 do {
2928 res |= code & 1;
2929 code >>= 1, res <<= 1;
2930 } while (--len > 0);
2931 return res >> 1;
2932 }
2933
2934 /* ===========================================================================
2935 * Flush the bit buffer, keeping at most 7 bits in it.
2936 */
2937 local void bi_flush(s)
2938 deflate_state *s;
2939 {
2940 if (s->bi_valid == 16) {
2941 put_short(s, s->bi_buf);
2942 s->bi_buf = 0;
2943 s->bi_valid = 0;
2944 } else if (s->bi_valid >= 8) {
2945 put_byte(s, (Byte)s->bi_buf);
2946 s->bi_buf >>= 8;
2947 s->bi_valid -= 8;
2948 }
2949 }
2950
2951 /* ===========================================================================
2952 * Flush the bit buffer and align the output on a byte boundary
2953 */
2954 local void bi_windup(s)
2955 deflate_state *s;
2956 {
2957 if (s->bi_valid > 8) {
2958 put_short(s, s->bi_buf);
2959 } else if (s->bi_valid > 0) {
2960 put_byte(s, (Byte)s->bi_buf);
2961 }
2962 s->bi_buf = 0;
2963 s->bi_valid = 0;
2964 #ifdef DEBUG_ZLIB
2965 s->bits_sent = (s->bits_sent+7) & ~7;
2966 #endif
2967 }
2968
2969 /* ===========================================================================
2970 * Copy a stored block, storing first the length and its
2971 * one's complement if requested.
2972 */
2973 local void copy_block(s, buf, len, header)
2974 deflate_state *s;
2975 charf *buf; /* the input data */
2976 unsigned len; /* its length */
2977 int header; /* true if block header must be written */
2978 {
2979 bi_windup(s); /* align on byte boundary */
2980 s->last_eob_len = 8; /* enough lookahead for inflate */
2981
2982 if (header) {
2983 put_short(s, (ush)len);
2984 put_short(s, (ush)~len);
2985 #ifdef DEBUG_ZLIB
2986 s->bits_sent += 2*16;
2987 #endif
2988 }
2989 #ifdef DEBUG_ZLIB
2990 s->bits_sent += (ulg)len<<3;
2991 #endif
2992 /* bundle up the put_byte(s, *buf++) calls */
2993 zmemcpy(&s->pending_buf[s->pending], buf, len);
2994 s->pending += len;
2995 }
2996 /* --- trees.c */
2997
2998 /* +++ inflate.c */
2999 /* inflate.c -- zlib interface to inflate modules
3000 * Copyright (C) 1995-1996 Mark Adler
3001 * For conditions of distribution and use, see copyright notice in zlib.h
3002 */
3003
3004 /* #include "zutil.h" */
3005
3006 /* +++ infblock.h */
3007 /* infblock.h -- header to use infblock.c
3008 * Copyright (C) 1995-1996 Mark Adler
3009 * For conditions of distribution and use, see copyright notice in zlib.h
3010 */
3011
3012 /* WARNING: this file should *not* be used by applications. It is
3013 part of the implementation of the compression library and is
3014 subject to change. Applications should only use zlib.h.
3015 */
3016
3017 struct inflate_blocks_state;
3018 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
3019
3020 extern inflate_blocks_statef * inflate_blocks_new OF((
3021 z_streamp z,
3022 check_func c, /* check function */
3023 uInt w)); /* window size */
3024
3025 extern int inflate_blocks OF((
3026 inflate_blocks_statef *,
3027 z_streamp ,
3028 int)); /* initial return code */
3029
3030 extern void inflate_blocks_reset OF((
3031 inflate_blocks_statef *,
3032 z_streamp ,
3033 uLongf *)); /* check value on output */
3034
3035 extern int inflate_blocks_free OF((
3036 inflate_blocks_statef *,
3037 z_streamp ,
3038 uLongf *)); /* check value on output */
3039
3040 extern void inflate_set_dictionary OF((
3041 inflate_blocks_statef *s,
3042 const Bytef *d, /* dictionary */
3043 uInt n)); /* dictionary length */
3044
3045 extern int inflate_addhistory OF((
3046 inflate_blocks_statef *,
3047 z_streamp));
3048
3049 extern int inflate_packet_flush OF((
3050 inflate_blocks_statef *));
3051 /* --- infblock.h */
3052
3053 #ifndef NO_DUMMY_DECL
3054 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
3055 #endif
3056
3057 /* inflate private state */
3058 struct internal_state {
3059
3060 /* mode */
3061 enum {
3062 METHOD, /* waiting for method byte */
3063 FLAG, /* waiting for flag byte */
3064 DICT4, /* four dictionary check bytes to go */
3065 DICT3, /* three dictionary check bytes to go */
3066 DICT2, /* two dictionary check bytes to go */
3067 DICT1, /* one dictionary check byte to go */
3068 DICT0, /* waiting for inflateSetDictionary */
3069 BLOCKS, /* decompressing blocks */
3070 CHECK4, /* four check bytes to go */
3071 CHECK3, /* three check bytes to go */
3072 CHECK2, /* two check bytes to go */
3073 CHECK1, /* one check byte to go */
3074 DONE, /* finished check, done */
3075 BAD} /* got an error--stay here */
3076 mode; /* current inflate mode */
3077
3078 /* mode dependent information */
3079 union {
3080 uInt method; /* if FLAGS, method byte */
3081 struct {
3082 uLong was; /* computed check value */
3083 uLong need; /* stream check value */
3084 } check; /* if CHECK, check values to compare */
3085 uInt marker; /* if BAD, inflateSync's marker bytes count */
3086 } sub; /* submode */
3087
3088 /* mode independent information */
3089 int nowrap; /* flag for no wrapper */
3090 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
3091 inflate_blocks_statef
3092 *blocks; /* current inflate_blocks state */
3093
3094 };
3095
3096
3097 int inflateReset(z)
3098 z_streamp z;
3099 {
3100 uLong c;
3101
3102 if (z == Z_NULL || z->state == Z_NULL)
3103 return Z_STREAM_ERROR;
3104 z->total_in = z->total_out = 0;
3105 z->msg = Z_NULL;
3106 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
3107 inflate_blocks_reset(z->state->blocks, z, &c);
3108 Trace((stderr, "inflate: reset\n"));
3109 return Z_OK;
3110 }
3111
3112
3113 int inflateEnd(z)
3114 z_streamp z;
3115 {
3116 uLong c;
3117
3118 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
3119 return Z_STREAM_ERROR;
3120 if (z->state->blocks != Z_NULL)
3121 inflate_blocks_free(z->state->blocks, z, &c);
3122 ZFREE(z, z->state);
3123 z->state = Z_NULL;
3124 Trace((stderr, "inflate: end\n"));
3125 return Z_OK;
3126 }
3127
3128
3129 int inflateInit2_(z, w, version, stream_size)
3130 z_streamp z;
3131 int w;
3132 const char *version;
3133 int stream_size;
3134 {
3135 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
3136 stream_size != sizeof(z_stream))
3137 return Z_VERSION_ERROR;
3138
3139 /* initialize state */
3140 if (z == Z_NULL)
3141 return Z_STREAM_ERROR;
3142 z->msg = Z_NULL;
3143 #ifndef NO_ZCFUNCS
3144 if (z->zalloc == Z_NULL)
3145 {
3146 z->zalloc = zcalloc;
3147 z->opaque = (voidpf)0;
3148 }
3149 if (z->zfree == Z_NULL) z->zfree = zcfree;
3150 #endif
3151 if ((z->state = (struct internal_state FAR *)
3152 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
3153 return Z_MEM_ERROR;
3154 z->state->blocks = Z_NULL;
3155
3156 /* handle undocumented nowrap option (no zlib header or check) */
3157 z->state->nowrap = 0;
3158 if (w < 0)
3159 {
3160 w = - w;
3161 z->state->nowrap = 1;
3162 }
3163
3164 /* set window size */
3165 if (w < 8 || w > 15)
3166 {
3167 inflateEnd(z);
3168 return Z_STREAM_ERROR;
3169 }
3170 z->state->wbits = (uInt)w;
3171
3172 /* create inflate_blocks state */
3173 if ((z->state->blocks =
3174 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
3175 == Z_NULL)
3176 {
3177 inflateEnd(z);
3178 return Z_MEM_ERROR;
3179 }
3180 Trace((stderr, "inflate: allocated\n"));
3181
3182 /* reset state */
3183 inflateReset(z);
3184 return Z_OK;
3185 }
3186
3187
3188 int inflateInit_(z, version, stream_size)
3189 z_streamp z;
3190 const char *version;
3191 int stream_size;
3192 {
3193 return inflateInit2_(z, DEF_WBITS, version, stream_size);
3194 }
3195
3196
3197 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
3198 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
3199
3200 int inflate(z, f)
3201 z_streamp z;
3202 int f;
3203 {
3204 int r;
3205 uInt b;
3206
3207 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL || f < 0)
3208 return Z_STREAM_ERROR;
3209 r = Z_BUF_ERROR;
3210 while (1) switch (z->state->mode)
3211 {
3212 case METHOD:
3213 NEEDBYTE
3214 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
3215 {
3216 z->state->mode = BAD;
3217 z->msg = (char*)"unknown compression method";
3218 z->state->sub.marker = 5; /* can't try inflateSync */
3219 break;
3220 }
3221 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
3222 {
3223 z->state->mode = BAD;
3224 z->msg = (char*)"invalid window size";
3225 z->state->sub.marker = 5; /* can't try inflateSync */
3226 break;
3227 }
3228 z->state->mode = FLAG;
3229 case FLAG:
3230 NEEDBYTE
3231 b = NEXTBYTE;
3232 if (((z->state->sub.method << 8) + b) % 31)
3233 {
3234 z->state->mode = BAD;
3235 z->msg = (char*)"incorrect header check";
3236 z->state->sub.marker = 5; /* can't try inflateSync */
3237 break;
3238 }
3239 Trace((stderr, "inflate: zlib header ok\n"));
3240 if (!(b & PRESET_DICT))
3241 {
3242 z->state->mode = BLOCKS;
3243 break;
3244 }
3245 z->state->mode = DICT4;
3246 case DICT4:
3247 NEEDBYTE
3248 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3249 z->state->mode = DICT3;
3250 case DICT3:
3251 NEEDBYTE
3252 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3253 z->state->mode = DICT2;
3254 case DICT2:
3255 NEEDBYTE
3256 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3257 z->state->mode = DICT1;
3258 case DICT1:
3259 NEEDBYTE
3260 z->state->sub.check.need += (uLong)NEXTBYTE;
3261 z->adler = z->state->sub.check.need;
3262 z->state->mode = DICT0;
3263 return Z_NEED_DICT;
3264 case DICT0:
3265 z->state->mode = BAD;
3266 z->msg = (char*)"need dictionary";
3267 z->state->sub.marker = 0; /* can try inflateSync */
3268 return Z_STREAM_ERROR;
3269 case BLOCKS:
3270 r = inflate_blocks(z->state->blocks, z, r);
3271 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
3272 r = inflate_packet_flush(z->state->blocks);
3273 if (r == Z_DATA_ERROR)
3274 {
3275 z->state->mode = BAD;
3276 z->state->sub.marker = 0; /* can try inflateSync */
3277 break;
3278 }
3279 if (r != Z_STREAM_END)
3280 return r;
3281 r = Z_OK;
3282 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
3283 if (z->state->nowrap)
3284 {
3285 z->state->mode = DONE;
3286 break;
3287 }
3288 z->state->mode = CHECK4;
3289 case CHECK4:
3290 NEEDBYTE
3291 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
3292 z->state->mode = CHECK3;
3293 case CHECK3:
3294 NEEDBYTE
3295 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
3296 z->state->mode = CHECK2;
3297 case CHECK2:
3298 NEEDBYTE
3299 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
3300 z->state->mode = CHECK1;
3301 case CHECK1:
3302 NEEDBYTE
3303 z->state->sub.check.need += (uLong)NEXTBYTE;
3304
3305 if (z->state->sub.check.was != z->state->sub.check.need)
3306 {
3307 z->state->mode = BAD;
3308 z->msg = (char*)"incorrect data check";
3309 z->state->sub.marker = 5; /* can't try inflateSync */
3310 break;
3311 }
3312 Trace((stderr, "inflate: zlib check ok\n"));
3313 z->state->mode = DONE;
3314 case DONE:
3315 return Z_STREAM_END;
3316 case BAD:
3317 return Z_DATA_ERROR;
3318 default:
3319 return Z_STREAM_ERROR;
3320 }
3321
3322 empty:
3323 if (f != Z_PACKET_FLUSH)
3324 return r;
3325 z->state->mode = BAD;
3326 z->msg = (char *)"need more for packet flush";
3327 z->state->sub.marker = 0; /* can try inflateSync */
3328 return Z_DATA_ERROR;
3329 }
3330
3331
3332 int inflateSetDictionary(z, dictionary, dictLength)
3333 z_streamp z;
3334 const Bytef *dictionary;
3335 uInt dictLength;
3336 {
3337 uInt length = dictLength;
3338
3339 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
3340 return Z_STREAM_ERROR;
3341
3342 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
3343 z->adler = 1L;
3344
3345 if (length >= ((uInt)1<<z->state->wbits))
3346 {
3347 length = (1<<z->state->wbits)-1;
3348 dictionary += dictLength - length;
3349 }
3350 inflate_set_dictionary(z->state->blocks, dictionary, length);
3351 z->state->mode = BLOCKS;
3352 return Z_OK;
3353 }
3354
3355 /*
3356 * This subroutine adds the data at next_in/avail_in to the output history
3357 * without performing any output. The output buffer must be "caught up";
3358 * i.e. no pending output (hence s->read equals s->write), and the state must
3359 * be BLOCKS (i.e. we should be willing to see the start of a series of
3360 * BLOCKS). On exit, the output will also be caught up, and the checksum
3361 * will have been updated if need be.
3362 */
3363
3364 int inflateIncomp(z)
3365 z_stream *z;
3366 {
3367 if (z->state->mode != BLOCKS)
3368 return Z_DATA_ERROR;
3369 return inflate_addhistory(z->state->blocks, z);
3370 }
3371
3372
3373 int inflateSync(z)
3374 z_streamp z;
3375 {
3376 uInt n; /* number of bytes to look at */
3377 Bytef *p; /* pointer to bytes */
3378 uInt m; /* number of marker bytes found in a row */
3379 uLong r, w; /* temporaries to save total_in and total_out */
3380
3381 /* set up */
3382 if (z == Z_NULL || z->state == Z_NULL)
3383 return Z_STREAM_ERROR;
3384 if (z->state->mode != BAD)
3385 {
3386 z->state->mode = BAD;
3387 z->state->sub.marker = 0;
3388 }
3389 if ((n = z->avail_in) == 0)
3390 return Z_BUF_ERROR;
3391 p = z->next_in;
3392 m = z->state->sub.marker;
3393
3394 /* search */
3395 while (n && m < 4)
3396 {
3397 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3398 m++;
3399 else if (*p)
3400 m = 0;
3401 else
3402 m = 4 - m;
3403 p++, n--;
3404 }
3405
3406 /* restore */
3407 z->total_in += p - z->next_in;
3408 z->next_in = p;
3409 z->avail_in = n;
3410 z->state->sub.marker = m;
3411
3412 /* return no joy or set up to restart on a new block */
3413 if (m != 4)
3414 return Z_DATA_ERROR;
3415 r = z->total_in; w = z->total_out;
3416 inflateReset(z);
3417 z->total_in = r; z->total_out = w;
3418 z->state->mode = BLOCKS;
3419 return Z_OK;
3420 }
3421
3422 #undef NEEDBYTE
3423 #undef NEXTBYTE
3424 /* --- inflate.c */
3425
3426 /* +++ infblock.c */
3427 /* infblock.c -- interpret and process block types to last block
3428 * Copyright (C) 1995-1996 Mark Adler
3429 * For conditions of distribution and use, see copyright notice in zlib.h
3430 */
3431
3432 /* #include "zutil.h" */
3433 /* #include "infblock.h" */
3434
3435 /* +++ inftrees.h */
3436 /* inftrees.h -- header to use inftrees.c
3437 * Copyright (C) 1995-1996 Mark Adler
3438 * For conditions of distribution and use, see copyright notice in zlib.h
3439 */
3440
3441 /* WARNING: this file should *not* be used by applications. It is
3442 part of the implementation of the compression library and is
3443 subject to change. Applications should only use zlib.h.
3444 */
3445
3446 /* Huffman code lookup table entry--this entry is four bytes for machines
3447 that have 16-bit pointers (e.g. PC's in the small or medium model). */
3448
3449 typedef struct inflate_huft_s FAR inflate_huft;
3450
3451 struct inflate_huft_s {
3452 union {
3453 struct {
3454 Byte Exop; /* number of extra bits or operation */
3455 Byte Bits; /* number of bits in this code or subcode */
3456 } what;
3457 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
3458 } word; /* 16-bit, 8 bytes for 32-bit machines) */
3459 union {
3460 uInt Base; /* literal, length base, or distance base */
3461 inflate_huft *Next; /* pointer to next level of table */
3462 } more;
3463 };
3464
3465 #ifdef DEBUG_ZLIB
3466 extern uInt inflate_hufts;
3467 #endif
3468
3469 extern int inflate_trees_bits OF((
3470 uIntf *, /* 19 code lengths */
3471 uIntf *, /* bits tree desired/actual depth */
3472 inflate_huft * FAR *, /* bits tree result */
3473 z_streamp )); /* for zalloc, zfree functions */
3474
3475 extern int inflate_trees_dynamic OF((
3476 uInt, /* number of literal/length codes */
3477 uInt, /* number of distance codes */
3478 uIntf *, /* that many (total) code lengths */
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 z_streamp )); /* for zalloc, zfree functions */
3484
3485 extern int inflate_trees_fixed OF((
3486 uIntf *, /* literal desired/actual bit depth */
3487 uIntf *, /* distance desired/actual bit depth */
3488 inflate_huft * FAR *, /* literal/length tree result */
3489 inflate_huft * FAR *)); /* distance tree result */
3490
3491 extern int inflate_trees_free OF((
3492 inflate_huft *, /* tables to free */
3493 z_streamp )); /* for zfree function */
3494
3495 /* --- inftrees.h */
3496
3497 /* +++ infcodes.h */
3498 /* infcodes.h -- header to use infcodes.c
3499 * Copyright (C) 1995-1996 Mark Adler
3500 * For conditions of distribution and use, see copyright notice in zlib.h
3501 */
3502
3503 /* WARNING: this file should *not* be used by applications. It is
3504 part of the implementation of the compression library and is
3505 subject to change. Applications should only use zlib.h.
3506 */
3507
3508 struct inflate_codes_state;
3509 typedef struct inflate_codes_state FAR inflate_codes_statef;
3510
3511 extern inflate_codes_statef *inflate_codes_new OF((
3512 uInt, uInt,
3513 inflate_huft *, inflate_huft *,
3514 z_streamp ));
3515
3516 extern int inflate_codes OF((
3517 inflate_blocks_statef *,
3518 z_streamp ,
3519 int));
3520
3521 extern void inflate_codes_free OF((
3522 inflate_codes_statef *,
3523 z_streamp ));
3524
3525 /* --- infcodes.h */
3526
3527 /* +++ infutil.h */
3528 /* infutil.h -- types and macros common to blocks and codes
3529 * Copyright (C) 1995-1996 Mark Adler
3530 * For conditions of distribution and use, see copyright notice in zlib.h
3531 */
3532
3533 /* WARNING: this file should *not* be used by applications. It is
3534 part of the implementation of the compression library and is
3535 subject to change. Applications should only use zlib.h.
3536 */
3537
3538 #ifndef _INFUTIL_H
3539 #define _INFUTIL_H
3540
3541 typedef enum {
3542 TYPE, /* get type bits (3, including end bit) */
3543 LENS, /* get lengths for stored */
3544 STORED, /* processing stored block */
3545 TABLE, /* get table lengths */
3546 BTREE, /* get bit lengths tree for a dynamic block */
3547 DTREE, /* get length, distance trees for a dynamic block */
3548 CODES, /* processing fixed or dynamic block */
3549 DRY, /* output remaining window bytes */
3550 DONEB, /* finished last block, done */
3551 BADB} /* got a data error--stuck here */
3552 inflate_block_mode;
3553
3554 /* inflate blocks semi-private state */
3555 struct inflate_blocks_state {
3556
3557 /* mode */
3558 inflate_block_mode mode; /* current inflate_block mode */
3559
3560 /* mode dependent information */
3561 union {
3562 uInt left; /* if STORED, bytes left to copy */
3563 struct {
3564 uInt table; /* table lengths (14 bits) */
3565 uInt index; /* index into blens (or border) */
3566 uIntf *blens; /* bit lengths of codes */
3567 uInt bb; /* bit length tree depth */
3568 inflate_huft *tb; /* bit length decoding tree */
3569 } trees; /* if DTREE, decoding info for trees */
3570 struct {
3571 inflate_huft *tl;
3572 inflate_huft *td; /* trees to free */
3573 inflate_codes_statef
3574 *codes;
3575 } decode; /* if CODES, current state */
3576 } sub; /* submode */
3577 uInt last; /* true if this block is the last block */
3578
3579 /* mode independent information */
3580 uInt bitk; /* bits in bit buffer */
3581 uLong bitb; /* bit buffer */
3582 Bytef *window; /* sliding window */
3583 Bytef *end; /* one byte after sliding window */
3584 Bytef *read; /* window read pointer */
3585 Bytef *write; /* window write pointer */
3586 check_func checkfn; /* check function */
3587 uLong check; /* check on output */
3588
3589 };
3590
3591
3592 /* defines for inflate input/output */
3593 /* update pointers and return */
3594 #define UPDBITS {s->bitb=b;s->bitk=k;}
3595 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3596 #define UPDOUT {s->write=q;}
3597 #define UPDATE {UPDBITS UPDIN UPDOUT}
3598 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3599 /* get bytes and bits */
3600 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3601 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3602 #define NEXTBYTE (n--,*p++)
3603 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3604 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3605 /* output bytes */
3606 #define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q)
3607 #define LOADOUT {q=s->write;m=(uInt)WAVAIL;}
3608 #define WWRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}}
3609 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3610 #define NEEDOUT {if(m==0){WWRAP if(m==0){FLUSH WWRAP if(m==0) LEAVE}}r=Z_OK;}
3611 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3612 /* load local pointers */
3613 #define LOAD {LOADIN LOADOUT}
3614
3615 /* masks for lower bits (size given to avoid silly warnings with Visual C++) */
3616 extern uInt inflate_mask[17];
3617
3618 /* copy as much as possible from the sliding window to the output area */
3619 extern int inflate_flush OF((
3620 inflate_blocks_statef *,
3621 z_streamp ,
3622 int));
3623
3624 #ifndef NO_DUMMY_DECL
3625 struct internal_state {int dummy;}; /* for buggy compilers */
3626 #endif
3627
3628 #endif
3629 /* --- infutil.h */
3630
3631 #ifndef NO_DUMMY_DECL
3632 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
3633 #endif
3634
3635 /* Table for deflate from PKZIP's appnote.txt. */
3636 local const uInt border[] = { /* Order of the bit length code lengths */
3637 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3638
3639 /*
3640 Notes beyond the 1.93a appnote.txt:
3641
3642 1. Distance pointers never point before the beginning of the output
3643 stream.
3644 2. Distance pointers can point back across blocks, up to 32k away.
3645 3. There is an implied maximum of 7 bits for the bit length table and
3646 15 bits for the actual data.
3647 4. If only one code exists, then it is encoded using one bit. (Zero
3648 would be more efficient, but perhaps a little confusing.) If two
3649 codes exist, they are coded using one bit each (0 and 1).
3650 5. There is no way of sending zero distance codes--a dummy must be
3651 sent if there are none. (History: a pre 2.0 version of PKZIP would
3652 store blocks with no distance codes, but this was discovered to be
3653 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3654 zero distance codes, which is sent as one code of zero bits in
3655 length.
3656 6. There are up to 286 literal/length codes. Code 256 represents the
3657 end-of-block. Note however that the static length tree defines
3658 288 codes just to fill out the Huffman codes. Codes 286 and 287
3659 cannot be used though, since there is no length base or extra bits
3660 defined for them. Similarily, there are up to 30 distance codes.
3661 However, static trees define 32 codes (all 5 bits) to fill out the
3662 Huffman codes, but the last two had better not show up in the data.
3663 7. Unzip can check dynamic Huffman blocks for complete code sets.
3664 The exception is that a single code would not be complete (see #4).
3665 8. The five bits following the block type is really the number of
3666 literal codes sent minus 257.
3667 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3668 (1+6+6). Therefore, to output three times the length, you output
3669 three codes (1+1+1), whereas to output four times the same length,
3670 you only need two codes (1+3). Hmm.
3671 10. In the tree reconstruction algorithm, Code = Code + Increment
3672 only if BitLength(i) is not zero. (Pretty obvious.)
3673 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3674 12. Note: length code 284 can represent 227-258, but length code 285
3675 really is 258. The last length deserves its own, short code
3676 since it gets used a lot in very redundant files. The length
3677 258 is special since 258 - 3 (the min match length) is 255.
3678 13. The literal/length and distance code bit lengths are read as a
3679 single stream of lengths. It is possible (and advantageous) for
3680 a repeat code (16, 17, or 18) to go across the boundary between
3681 the two sets of lengths.
3682 */
3683
3684
3685 void inflate_blocks_reset(s, z, c)
3686 inflate_blocks_statef *s;
3687 z_streamp z;
3688 uLongf *c;
3689 {
3690 if (s->checkfn != Z_NULL)
3691 *c = s->check;
3692 if (s->mode == BTREE || s->mode == DTREE)
3693 ZFREE(z, s->sub.trees.blens);
3694 if (s->mode == CODES)
3695 {
3696 inflate_codes_free(s->sub.decode.codes, z);
3697 inflate_trees_free(s->sub.decode.td, z);
3698 inflate_trees_free(s->sub.decode.tl, z);
3699 }
3700 s->mode = TYPE;
3701 s->bitk = 0;
3702 s->bitb = 0;
3703 s->read = s->write = s->window;
3704 if (s->checkfn != Z_NULL)
3705 z->adler = s->check = (*s->checkfn)(0L, Z_NULL, 0);
3706 Trace((stderr, "inflate: blocks reset\n"));
3707 }
3708
3709
3710 inflate_blocks_statef *inflate_blocks_new(z, c, w)
3711 z_streamp z;
3712 check_func c;
3713 uInt w;
3714 {
3715 inflate_blocks_statef *s;
3716
3717 if ((s = (inflate_blocks_statef *)ZALLOC
3718 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3719 return s;
3720 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3721 {
3722 ZFREE(z, s);
3723 return Z_NULL;
3724 }
3725 s->end = s->window + w;
3726 s->checkfn = c;
3727 s->mode = TYPE;
3728 Trace((stderr, "inflate: blocks allocated\n"));
3729 inflate_blocks_reset(s, z, &s->check);
3730 return s;
3731 }
3732
3733
3734 #ifdef DEBUG_ZLIB
3735 extern uInt inflate_hufts;
3736 #endif
3737 int inflate_blocks(s, z, r)
3738 inflate_blocks_statef *s;
3739 z_streamp z;
3740 int r;
3741 {
3742 uInt t; /* temporary storage */
3743 uLong b; /* bit buffer */
3744 uInt k; /* bits in bit buffer */
3745 Bytef *p; /* input data pointer */
3746 uInt n; /* bytes available there */
3747 Bytef *q; /* output window write pointer */
3748 uInt m; /* bytes to end of window or read pointer */
3749
3750 /* copy input/output information to locals (UPDATE macro restores) */
3751 LOAD
3752
3753 /* process input based on current state */
3754 while (1) switch (s->mode)
3755 {
3756 case TYPE:
3757 NEEDBITS(3)
3758 t = (uInt)b & 7;
3759 s->last = t & 1;
3760 switch (t >> 1)
3761 {
3762 case 0: /* stored */
3763 Trace((stderr, "inflate: stored block%s\n",
3764 s->last ? " (last)" : ""));
3765 DUMPBITS(3)
3766 t = k & 7; /* go to byte boundary */
3767 DUMPBITS(t)
3768 s->mode = LENS; /* get length of stored block */
3769 break;
3770 case 1: /* fixed */
3771 Trace((stderr, "inflate: fixed codes block%s\n",
3772 s->last ? " (last)" : ""));
3773 {
3774 uInt bl, bd;
3775 inflate_huft *tl, *td;
3776
3777 inflate_trees_fixed(&bl, &bd, &tl, &td);
3778 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3779 if (s->sub.decode.codes == Z_NULL)
3780 {
3781 r = Z_MEM_ERROR;
3782 LEAVE
3783 }
3784 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3785 s->sub.decode.td = Z_NULL;
3786 }
3787 DUMPBITS(3)
3788 s->mode = CODES;
3789 break;
3790 case 2: /* dynamic */
3791 Trace((stderr, "inflate: dynamic codes block%s\n",
3792 s->last ? " (last)" : ""));
3793 DUMPBITS(3)
3794 s->mode = TABLE;
3795 break;
3796 case 3: /* illegal */
3797 DUMPBITS(3)
3798 s->mode = BADB;
3799 z->msg = (char*)"invalid block type";
3800 r = Z_DATA_ERROR;
3801 LEAVE
3802 }
3803 break;
3804 case LENS:
3805 NEEDBITS(32)
3806 if ((((~b) >> 16) & 0xffff) != (b & 0xffff))
3807 {
3808 s->mode = BADB;
3809 z->msg = (char*)"invalid stored block lengths";
3810 r = Z_DATA_ERROR;
3811 LEAVE
3812 }
3813 s->sub.left = (uInt)b & 0xffff;
3814 b = k = 0; /* dump bits */
3815 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3816 s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE);
3817 break;
3818 case STORED:
3819 if (n == 0)
3820 LEAVE
3821 NEEDOUT
3822 t = s->sub.left;
3823 if (t > n) t = n;
3824 if (t > m) t = m;
3825 zmemcpy(q, p, t);
3826 p += t; n -= t;
3827 q += t; m -= t;
3828 if ((s->sub.left -= t) != 0)
3829 break;
3830 Tracev((stderr, "inflate: stored end, %lu total out\n",
3831 z->total_out + (q >= s->read ? q - s->read :
3832 (s->end - s->read) + (q - s->window))));
3833 s->mode = s->last ? DRY : TYPE;
3834 break;
3835 case TABLE:
3836 NEEDBITS(14)
3837 s->sub.trees.table = t = (uInt)b & 0x3fff;
3838 #ifndef PKZIP_BUG_WORKAROUND
3839 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3840 {
3841 s->mode = BADB;
3842 z->msg = (char*)"too many length or distance symbols";
3843 r = Z_DATA_ERROR;
3844 LEAVE
3845 }
3846 #endif
3847 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3848 if (t < 19)
3849 t = 19;
3850 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3851 {
3852 r = Z_MEM_ERROR;
3853 LEAVE
3854 }
3855 DUMPBITS(14)
3856 s->sub.trees.index = 0;
3857 Tracev((stderr, "inflate: table sizes ok\n"));
3858 s->mode = BTREE;
3859 case BTREE:
3860 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3861 {
3862 NEEDBITS(3)
3863 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3864 DUMPBITS(3)
3865 }
3866 while (s->sub.trees.index < 19)
3867 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3868 s->sub.trees.bb = 7;
3869 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3870 &s->sub.trees.tb, z);
3871 if (t != Z_OK)
3872 {
3873 r = t;
3874 if (r == Z_DATA_ERROR) {
3875 ZFREE(z, s->sub.trees.blens);
3876 s->mode = BADB;
3877 }
3878 LEAVE
3879 }
3880 s->sub.trees.index = 0;
3881 Tracev((stderr, "inflate: bits tree ok\n"));
3882 s->mode = DTREE;
3883 case DTREE:
3884 while (t = s->sub.trees.table,
3885 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3886 {
3887 inflate_huft *h;
3888 uInt i, j, c;
3889
3890 t = s->sub.trees.bb;
3891 NEEDBITS(t)
3892 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3893 t = h->word.what.Bits;
3894 c = h->more.Base;
3895 if (c < 16)
3896 {
3897 DUMPBITS(t)
3898 s->sub.trees.blens[s->sub.trees.index++] = c;
3899 }
3900 else /* c == 16..18 */
3901 {
3902 i = c == 18 ? 7 : c - 14;
3903 j = c == 18 ? 11 : 3;
3904 NEEDBITS(t + i)
3905 DUMPBITS(t)
3906 j += (uInt)b & inflate_mask[i];
3907 DUMPBITS(i)
3908 i = s->sub.trees.index;
3909 t = s->sub.trees.table;
3910 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3911 (c == 16 && i < 1))
3912 {
3913 inflate_trees_free(s->sub.trees.tb, z);
3914 ZFREE(z, s->sub.trees.blens);
3915 s->mode = BADB;
3916 z->msg = (char*)"invalid bit length repeat";
3917 r = Z_DATA_ERROR;
3918 LEAVE
3919 }
3920 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3921 do {
3922 s->sub.trees.blens[i++] = c;
3923 } while (--j);
3924 s->sub.trees.index = i;
3925 }
3926 }
3927 inflate_trees_free(s->sub.trees.tb, z);
3928 s->sub.trees.tb = Z_NULL;
3929 {
3930 uInt bl, bd;
3931 inflate_huft *tl, *td;
3932 inflate_codes_statef *c;
3933
3934 bl = 9; /* must be <= 9 for lookahead assumptions */
3935 bd = 6; /* must be <= 9 for lookahead assumptions */
3936 t = s->sub.trees.table;
3937 #ifdef DEBUG_ZLIB
3938 inflate_hufts = 0;
3939 #endif
3940 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3941 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3942 if (t != Z_OK)
3943 {
3944 if (t == (uInt)Z_DATA_ERROR) {
3945 ZFREE(z, s->sub.trees.blens);
3946 s->mode = BADB;
3947 }
3948 r = t;
3949 LEAVE
3950 }
3951 Tracev((stderr, "inflate: trees ok, %d * %d bytes used\n",
3952 inflate_hufts, sizeof(inflate_huft)));
3953 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3954 {
3955 inflate_trees_free(td, z);
3956 inflate_trees_free(tl, z);
3957 r = Z_MEM_ERROR;
3958 LEAVE
3959 }
3960 /*
3961 * this ZFREE must occur *BEFORE* we mess with sub.decode, because
3962 * sub.trees is union'd with sub.decode.
3963 */
3964 ZFREE(z, s->sub.trees.blens);
3965 s->sub.decode.codes = c;
3966 s->sub.decode.tl = tl;
3967 s->sub.decode.td = td;
3968 }
3969 s->mode = CODES;
3970 case CODES:
3971 UPDATE
3972 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3973 return inflate_flush(s, z, r);
3974 r = Z_OK;
3975 inflate_codes_free(s->sub.decode.codes, z);
3976 inflate_trees_free(s->sub.decode.td, z);
3977 inflate_trees_free(s->sub.decode.tl, z);
3978 LOAD
3979 Tracev((stderr, "inflate: codes end, %lu total out\n",
3980 z->total_out + (q >= s->read ? q - s->read :
3981 (s->end - s->read) + (q - s->window))));
3982 if (!s->last)
3983 {
3984 s->mode = TYPE;
3985 break;
3986 }
3987 if (k > 7) /* return unused byte, if any */
3988 {
3989 Assert(k < 16, "inflate_codes grabbed too many bytes")
3990 k -= 8;
3991 n++;
3992 p--; /* can always return one */
3993 }
3994 s->mode = DRY;
3995 case DRY:
3996 FLUSH
3997 if (s->read != s->write)
3998 LEAVE
3999 s->mode = DONEB;
4000 case DONEB:
4001 r = Z_STREAM_END;
4002 LEAVE
4003 case BADB:
4004 r = Z_DATA_ERROR;
4005 LEAVE
4006 default:
4007 r = Z_STREAM_ERROR;
4008 LEAVE
4009 }
4010 }
4011
4012
4013 int inflate_blocks_free(s, z, c)
4014 inflate_blocks_statef *s;
4015 z_streamp z;
4016 uLongf *c;
4017 {
4018 inflate_blocks_reset(s, z, c);
4019 ZFREE(z, s->window);
4020 ZFREE(z, s);
4021 Trace((stderr, "inflate: blocks freed\n"));
4022 return Z_OK;
4023 }
4024
4025
4026 void inflate_set_dictionary(s, d, n)
4027 inflate_blocks_statef *s;
4028 const Bytef *d;
4029 uInt n;
4030 {
4031 zmemcpy((charf *)s->window, d, n);
4032 s->read = s->write = s->window + n;
4033 }
4034
4035 /*
4036 * This subroutine adds the data at next_in/avail_in to the output history
4037 * without performing any output. The output buffer must be "caught up";
4038 * i.e. no pending output (hence s->read equals s->write), and the state must
4039 * be BLOCKS (i.e. we should be willing to see the start of a series of
4040 * BLOCKS). On exit, the output will also be caught up, and the checksum
4041 * will have been updated if need be.
4042 */
4043 int inflate_addhistory(s, z)
4044 inflate_blocks_statef *s;
4045 z_stream *z;
4046 {
4047 uLong b; /* bit buffer */ /* NOT USED HERE */
4048 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
4049 uInt t; /* temporary storage */
4050 Bytef *p; /* input data pointer */
4051 uInt n; /* bytes available there */
4052 Bytef *q; /* output window write pointer */
4053 uInt m; /* bytes to end of window or read pointer */
4054
4055 if (s->read != s->write)
4056 return Z_STREAM_ERROR;
4057 if (s->mode != TYPE)
4058 return Z_DATA_ERROR;
4059
4060 /* we're ready to rock */
4061 LOAD
4062 /* while there is input ready, copy to output buffer, moving
4063 * pointers as needed.
4064 */
4065 while (n) {
4066 t = n; /* how many to do */
4067 /* is there room until end of buffer? */
4068 if (t > m) t = m;
4069 /* update check information */
4070 if (s->checkfn != Z_NULL)
4071 s->check = (*s->checkfn)(s->check, q, t);
4072 zmemcpy(q, p, t);
4073 q += t;
4074 p += t;
4075 n -= t;
4076 z->total_out += t;
4077 s->read = q; /* drag read pointer forward */
4078 /* WWRAP */ /* expand WWRAP macro by hand to handle s->read */
4079 if (q == s->end) {
4080 s->read = q = s->window;
4081 m = WAVAIL;
4082 }
4083 }
4084 UPDATE
4085 return Z_OK;
4086 }
4087
4088
4089 /*
4090 * At the end of a Deflate-compressed PPP packet, we expect to have seen
4091 * a `stored' block type value but not the (zero) length bytes.
4092 */
4093 int inflate_packet_flush(s)
4094 inflate_blocks_statef *s;
4095 {
4096 if (s->mode != LENS)
4097 return Z_DATA_ERROR;
4098 s->mode = TYPE;
4099 return Z_OK;
4100 }
4101 /* --- infblock.c */
4102
4103 /* +++ inftrees.c */
4104 /* inftrees.c -- generate Huffman trees for efficient decoding
4105 * Copyright (C) 1995-1996 Mark Adler
4106 * For conditions of distribution and use, see copyright notice in zlib.h
4107 */
4108
4109 /* #include "zutil.h" */
4110 /* #include "inftrees.h" */
4111
4112 char inflate_copyright[] = " inflate 1.0.4 Copyright 1995-1996 Mark Adler ";
4113 /*
4114 If you use the zlib library in a product, an acknowledgment is welcome
4115 in the documentation of your product. If for some reason you cannot
4116 include such an acknowledgment, I would appreciate that you keep this
4117 copyright string in the executable of your product.
4118 */
4119
4120 #ifndef NO_DUMMY_DECL
4121 struct internal_state {int dummy;}; /* for buggy compilers */
4122 #endif
4123
4124 /* simplify the use of the inflate_huft type with some defines */
4125 #define base more.Base
4126 #define next more.Next
4127 #define exop word.what.Exop
4128 #define bits word.what.Bits
4129
4130
4131 local int huft_build OF((
4132 uIntf *, /* code lengths in bits */
4133 uInt, /* number of codes */
4134 uInt, /* number of "simple" codes */
4135 const uIntf *, /* list of base values for non-simple codes */
4136 const uIntf *, /* list of extra bits for non-simple codes */
4137 inflate_huft * FAR*,/* result: starting table */
4138 uIntf *, /* maximum lookup bits (returns actual) */
4139 z_streamp )); /* for zalloc function */
4140
4141 local voidpf falloc OF((
4142 voidpf, /* opaque pointer (not used) */
4143 uInt, /* number of items */
4144 uInt)); /* size of item */
4145
4146 /* Tables for deflate from PKZIP's appnote.txt. */
4147 local const uInt cplens[31] = { /* Copy lengths for literal codes 257..285 */
4148 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
4149 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
4150 /* see note #13 above about 258 */
4151 local const uInt cplext[31] = { /* Extra bits for literal codes 257..285 */
4152 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
4153 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 112, 112}; /* 112==invalid */
4154 local const uInt cpdist[30] = { /* Copy offsets for distance codes 0..29 */
4155 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
4156 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
4157 8193, 12289, 16385, 24577};
4158 local const uInt cpdext[30] = { /* Extra bits for distance codes */
4159 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
4160 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
4161 12, 12, 13, 13};
4162
4163 /*
4164 Huffman code decoding is performed using a multi-level table lookup.
4165 The fastest way to decode is to simply build a lookup table whose
4166 size is determined by the longest code. However, the time it takes
4167 to build this table can also be a factor if the data being decoded
4168 is not very long. The most common codes are necessarily the
4169 shortest codes, so those codes dominate the decoding time, and hence
4170 the speed. The idea is you can have a shorter table that decodes the
4171 shorter, more probable codes, and then point to subsidiary tables for
4172 the longer codes. The time it costs to decode the longer codes is
4173 then traded against the time it takes to make longer tables.
4174
4175 This results of this trade are in the variables lbits and dbits
4176 below. lbits is the number of bits the first level table for literal/
4177 length codes can decode in one step, and dbits is the same thing for
4178 the distance codes. Subsequent tables are also less than or equal to
4179 those sizes. These values may be adjusted either when all of the
4180 codes are shorter than that, in which case the longest code length in
4181 bits is used, or when the shortest code is *longer* than the requested
4182 table size, in which case the length of the shortest code in bits is
4183 used.
4184
4185 There are two different values for the two tables, since they code a
4186 different number of possibilities each. The literal/length table
4187 codes 286 possible values, or in a flat code, a little over eight
4188 bits. The distance table codes 30 possible values, or a little less
4189 than five bits, flat. The optimum values for speed end up being
4190 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
4191 The optimum values may differ though from machine to machine, and
4192 possibly even between compilers. Your mileage may vary.
4193 */
4194
4195
4196 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
4197 #define BMAX 15 /* maximum bit length of any code */
4198 #define N_MAX 288 /* maximum number of codes in any set */
4199
4200 #ifdef DEBUG_ZLIB
4201 uInt inflate_hufts;
4202 #endif
4203
4204 local int huft_build(b, n, s, d, e, t, m, zs)
4205 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
4206 uInt n; /* number of codes (assumed <= N_MAX) */
4207 uInt s; /* number of simple-valued codes (0..s-1) */
4208 const uIntf *d; /* list of base values for non-simple codes */
4209 const uIntf *e; /* list of extra bits for non-simple codes */
4210 inflate_huft * FAR *t; /* result: starting table */
4211 uIntf *m; /* maximum lookup bits, returns actual */
4212 z_streamp zs; /* for zalloc function */
4213 /* Given a list of code lengths and a maximum table size, make a set of
4214 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
4215 if the given code set is incomplete (the tables are still built in this
4216 case), Z_DATA_ERROR if the input is invalid (an over-subscribed set of
4217 lengths), or Z_MEM_ERROR if not enough memory. */
4218 {
4219
4220 uInt a; /* counter for codes of length k */
4221 uInt c[BMAX+1]; /* bit length count table */
4222 uInt f; /* i repeats in table every f entries */
4223 int g; /* maximum code length */
4224 int h; /* table level */
4225 register uInt i; /* counter, current code */
4226 register uInt j; /* counter */
4227 register int k; /* number of bits in current code */
4228 int l; /* bits per table (returned in m) */
4229 register uIntf *p; /* pointer into c[], b[], or v[] */
4230 inflate_huft *q; /* points to current table */
4231 struct inflate_huft_s r; /* table entry for structure assignment */
4232 inflate_huft *u[BMAX]; /* table stack */
4233 uInt v[N_MAX]; /* values in order of bit length */
4234 register int w; /* bits before this table == (l * h) */
4235 uInt x[BMAX+1]; /* bit offsets, then code stack */
4236 uIntf *xp; /* pointer into x */
4237 int y; /* number of dummy codes added */
4238 uInt z; /* number of entries in current table */
4239
4240
4241 /* Generate counts for each bit length */
4242 p = c;
4243 #define C0 *p++ = 0;
4244 #define C2 C0 C0 C0 C0
4245 #define C4 C2 C2 C2 C2
4246 C4 /* clear c[]--assume BMAX+1 is 16 */
4247 p = b; i = n;
4248 do {
4249 c[*p++]++; /* assume all entries <= BMAX */
4250 } while (--i);
4251 if (c[0] == n) /* null input--all zero length codes */
4252 {
4253 *t = (inflate_huft *)Z_NULL;
4254 *m = 0;
4255 return Z_OK;
4256 }
4257
4258
4259 /* Find minimum and maximum length, bound *m by those */
4260 l = *m;
4261 for (j = 1; j <= BMAX; j++)
4262 if (c[j])
4263 break;
4264 k = j; /* minimum code length */
4265 if ((uInt)l < j)
4266 l = j;
4267 for (i = BMAX; i; i--)
4268 if (c[i])
4269 break;
4270 g = i; /* maximum code length */
4271 if ((uInt)l > i)
4272 l = i;
4273 *m = l;
4274
4275
4276 /* Adjust last length count to fill out codes, if needed */
4277 for (y = 1 << j; j < i; j++, y <<= 1)
4278 if ((y -= c[j]) < 0)
4279 return Z_DATA_ERROR;
4280 if ((y -= c[i]) < 0)
4281 return Z_DATA_ERROR;
4282 c[i] += y;
4283
4284
4285 /* Generate starting offsets into the value table for each length */
4286 x[1] = j = 0;
4287 p = c + 1; xp = x + 2;
4288 while (--i) { /* note that i == g from above */
4289 *xp++ = (j += *p++);
4290 }
4291
4292
4293 /* Make a table of values in order of bit lengths */
4294 p = b; i = 0;
4295 do {
4296 if ((j = *p++) != 0)
4297 v[x[j]++] = i;
4298 } while (++i < n);
4299 n = x[g]; /* set n to length of v */
4300
4301
4302 /* Generate the Huffman codes and for each, make the table entries */
4303 x[0] = i = 0; /* first Huffman code is zero */
4304 p = v; /* grab values in bit order */
4305 h = -1; /* no tables yet--level -1 */
4306 w = -l; /* bits decoded == (l * h) */
4307 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
4308 q = (inflate_huft *)Z_NULL; /* ditto */
4309 z = 0; /* ditto */
4310
4311 /* go through the bit lengths (k already is bits in shortest code) */
4312 for (; k <= g; k++)
4313 {
4314 a = c[k];
4315 while (a--)
4316 {
4317 /* here i is the Huffman code of length k bits for value *p */
4318 /* make tables up to required level */
4319 while (k > w + l)
4320 {
4321 h++;
4322 w += l; /* previous table always l bits */
4323
4324 /* compute minimum size table less than or equal to l bits */
4325 z = g - w;
4326 z = z > (uInt)l ? l : z; /* table size upper limit */
4327 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
4328 { /* too few codes for k-w bit table */
4329 f -= a + 1; /* deduct codes from patterns left */
4330 xp = c + k;
4331 if (j < z)
4332 while (++j < z) /* try smaller tables up to z bits */
4333 {
4334 if ((f <<= 1) <= *++xp)
4335 break; /* enough codes to use up j bits */
4336 f -= *xp; /* else deduct codes from patterns */
4337 }
4338 }
4339 z = 1 << j; /* table entries for j-bit table */
4340
4341 /* allocate and link in new table */
4342 if ((q = (inflate_huft *)ZALLOC
4343 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
4344 {
4345 if (h)
4346 inflate_trees_free(u[0], zs);
4347 return Z_MEM_ERROR; /* not enough memory */
4348 }
4349 #ifdef DEBUG_ZLIB
4350 inflate_hufts += z + 1;
4351 #endif
4352 *t = q + 1; /* link to list for huft_free() */
4353 *(t = &(q->next)) = Z_NULL;
4354 u[h] = ++q; /* table starts after link */
4355
4356 /* connect to last table, if there is one */
4357 if (h)
4358 {
4359 x[h] = i; /* save pattern for backing up */
4360 r.bits = (Byte)l; /* bits to dump before this table */
4361 r.exop = (Byte)j; /* bits in this table */
4362 r.next = q; /* pointer to this table */
4363 j = i >> (w - l); /* (get around Turbo C bug) */
4364 u[h-1][j] = r; /* connect to last table */
4365 }
4366 }
4367
4368 /* set up table entry in r */
4369 r.bits = (Byte)(k - w);
4370 if (p >= v + n)
4371 r.exop = 128 + 64; /* out of values--invalid code */
4372 else if (*p < s)
4373 {
4374 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
4375 r.base = *p++; /* simple code is just the value */
4376 }
4377 else
4378 {
4379 r.exop = (Byte)(e[*p - s] + 16 + 64);/* non-simple--look up in lists */
4380 r.base = d[*p++ - s];
4381 }
4382
4383 /* fill code-like entries with r */
4384 f = 1 << (k - w);
4385 for (j = i >> w; j < z; j += f)
4386 q[j] = r;
4387
4388 /* backwards increment the k-bit code i */
4389 for (j = 1 << (k - 1); i & j; j >>= 1)
4390 i ^= j;
4391 i ^= j;
4392
4393 /* backup over finished tables */
4394 while ((i & ((1 << w) - 1)) != x[h])
4395 {
4396 h--; /* don't need to update q */
4397 w -= l;
4398 }
4399 }
4400 }
4401
4402
4403 /* Return Z_BUF_ERROR if we were given an incomplete table */
4404 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
4405 }
4406
4407
4408 int inflate_trees_bits(c, bb, tb, z)
4409 uIntf *c; /* 19 code lengths */
4410 uIntf *bb; /* bits tree desired/actual depth */
4411 inflate_huft * FAR *tb; /* bits tree result */
4412 z_streamp z; /* for zfree function */
4413 {
4414 int r;
4415
4416 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
4417 if (r == Z_DATA_ERROR)
4418 z->msg = (char*)"oversubscribed dynamic bit lengths tree";
4419 else if (r == Z_BUF_ERROR || *bb == 0)
4420 {
4421 inflate_trees_free(*tb, z);
4422 z->msg = (char*)"incomplete dynamic bit lengths tree";
4423 r = Z_DATA_ERROR;
4424 }
4425 return r;
4426 }
4427
4428
4429 int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
4430 uInt nl; /* number of literal/length codes */
4431 uInt nd; /* number of distance codes */
4432 uIntf *c; /* that many (total) code lengths */
4433 uIntf *bl; /* literal desired/actual bit depth */
4434 uIntf *bd; /* distance desired/actual bit depth */
4435 inflate_huft * FAR *tl; /* literal/length tree result */
4436 inflate_huft * FAR *td; /* distance tree result */
4437 z_streamp z; /* for zfree function */
4438 {
4439 int r;
4440
4441 /* build literal/length tree */
4442 r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z);
4443 if (r != Z_OK || *bl == 0)
4444 {
4445 if (r == Z_DATA_ERROR)
4446 z->msg = (char*)"oversubscribed literal/length tree";
4447 else if (r != Z_MEM_ERROR)
4448 {
4449 inflate_trees_free(*tl, z);
4450 z->msg = (char*)"incomplete literal/length tree";
4451 r = Z_DATA_ERROR;
4452 }
4453 return r;
4454 }
4455
4456 /* build distance tree */
4457 r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z);
4458 if (r != Z_OK || (*bd == 0 && nl > 257))
4459 {
4460 if (r == Z_DATA_ERROR)
4461 z->msg = (char*)"oversubscribed distance tree";
4462 else if (r == Z_BUF_ERROR) {
4463 #ifdef PKZIP_BUG_WORKAROUND
4464 r = Z_OK;
4465 }
4466 #else
4467 inflate_trees_free(*td, z);
4468 z->msg = (char*)"incomplete distance tree";
4469 r = Z_DATA_ERROR;
4470 }
4471 else if (r != Z_MEM_ERROR)
4472 {
4473 z->msg = (char*)"empty distance tree with lengths";
4474 r = Z_DATA_ERROR;
4475 }
4476 inflate_trees_free(*tl, z);
4477 return r;
4478 #endif
4479 }
4480
4481 /* done */
4482 return Z_OK;
4483 }
4484
4485
4486 /* build fixed tables only once--keep them here */
4487 local int fixed_built = 0;
4488 #define FIXEDH 530 /* number of hufts used by fixed tables */
4489 local inflate_huft fixed_mem[FIXEDH];
4490 local uInt fixed_bl;
4491 local uInt fixed_bd;
4492 local inflate_huft *fixed_tl;
4493 local inflate_huft *fixed_td;
4494
4495
4496 local voidpf falloc(q, n, s)
4497 voidpf q; /* opaque pointer */
4498 uInt n; /* number of items */
4499 uInt s; /* size of item */
4500 {
4501 Assert(s == sizeof(inflate_huft) && n <= *(intf *)q,
4502 "inflate_trees falloc overflow");
4503 *(intf *)q -= n+s-s; /* s-s to avoid warning */
4504 return (voidpf)(fixed_mem + *(intf *)q);
4505 }
4506
4507
4508 int inflate_trees_fixed(bl, bd, tl, td)
4509 uIntf *bl; /* literal desired/actual bit depth */
4510 uIntf *bd; /* distance desired/actual bit depth */
4511 inflate_huft * FAR *tl; /* literal/length tree result */
4512 inflate_huft * FAR *td; /* distance tree result */
4513 {
4514 /* build fixed tables if not already (multiple overlapped executions ok) */
4515 if (!fixed_built)
4516 {
4517 int k; /* temporary variable */
4518 unsigned c[288]; /* length list for huft_build */
4519 z_stream z; /* for falloc function */
4520 int f = FIXEDH; /* number of hufts left in fixed_mem */
4521
4522 /* set up fake z_stream for memory routines */
4523 z.zalloc = falloc;
4524 z.zfree = Z_NULL;
4525 z.opaque = (voidpf)&f;
4526
4527 /* literal table */
4528 for (k = 0; k < 144; k++)
4529 c[k] = 8;
4530 for (; k < 256; k++)
4531 c[k] = 9;
4532 for (; k < 280; k++)
4533 c[k] = 7;
4534 for (; k < 288; k++)
4535 c[k] = 8;
4536 fixed_bl = 7;
4537 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4538
4539 /* distance table */
4540 for (k = 0; k < 30; k++)
4541 c[k] = 5;
4542 fixed_bd = 5;
4543 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4544
4545 /* done */
4546 Assert(f == 0, "invalid build of fixed tables");
4547 fixed_built = 1;
4548 }
4549 *bl = fixed_bl;
4550 *bd = fixed_bd;
4551 *tl = fixed_tl;
4552 *td = fixed_td;
4553 return Z_OK;
4554 }
4555
4556
4557 int inflate_trees_free(t, z)
4558 inflate_huft *t; /* table to free */
4559 z_streamp z; /* for zfree function */
4560 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4561 list of the tables it made, with the links in a dummy first entry of
4562 each table. */
4563 {
4564 register inflate_huft *p, *q, *r;
4565
4566 /* Reverse linked list */
4567 p = Z_NULL;
4568 q = t;
4569 while (q != Z_NULL)
4570 {
4571 r = (q - 1)->next;
4572 (q - 1)->next = p;
4573 p = q;
4574 q = r;
4575 }
4576 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4577 while (p != Z_NULL)
4578 {
4579 q = (--p)->next;
4580 ZFREE(z,p);
4581 p = q;
4582 }
4583 return Z_OK;
4584 }
4585 /* --- inftrees.c */
4586
4587 /* +++ infcodes.c */
4588 /* infcodes.c -- process literals and length/distance pairs
4589 * Copyright (C) 1995-1996 Mark Adler
4590 * For conditions of distribution and use, see copyright notice in zlib.h
4591 */
4592
4593 /* #include "zutil.h" */
4594 /* #include "inftrees.h" */
4595 /* #include "infblock.h" */
4596 /* #include "infcodes.h" */
4597 /* #include "infutil.h" */
4598
4599 /* +++ inffast.h */
4600 /* inffast.h -- header to use inffast.c
4601 * Copyright (C) 1995-1996 Mark Adler
4602 * For conditions of distribution and use, see copyright notice in zlib.h
4603 */
4604
4605 /* WARNING: this file should *not* be used by applications. It is
4606 part of the implementation of the compression library and is
4607 subject to change. Applications should only use zlib.h.
4608 */
4609
4610 extern int inflate_fast OF((
4611 uInt,
4612 uInt,
4613 inflate_huft *,
4614 inflate_huft *,
4615 inflate_blocks_statef *,
4616 z_streamp ));
4617 /* --- inffast.h */
4618
4619 /* simplify the use of the inflate_huft type with some defines */
4620 #define base more.Base
4621 #define next more.Next
4622 #define exop word.what.Exop
4623 #define bits word.what.Bits
4624
4625 /* inflate codes private state */
4626 struct inflate_codes_state {
4627
4628 /* mode */
4629 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4630 START, /* x: set up for LEN */
4631 LEN, /* i: get length/literal/eob next */
4632 LENEXT, /* i: getting length extra (have base) */
4633 DIST, /* i: get distance next */
4634 DISTEXT, /* i: getting distance extra */
4635 COPY, /* o: copying bytes in window, waiting for space */
4636 LIT, /* o: got literal, waiting for output space */
4637 WASH, /* o: got eob, possibly still output waiting */
4638 END, /* x: got eob and all data flushed */
4639 BADCODE} /* x: got error */
4640 mode; /* current inflate_codes mode */
4641
4642 /* mode dependent information */
4643 uInt len;
4644 union {
4645 struct {
4646 inflate_huft *tree; /* pointer into tree */
4647 uInt need; /* bits needed */
4648 } code; /* if LEN or DIST, where in tree */
4649 uInt lit; /* if LIT, literal */
4650 struct {
4651 uInt get; /* bits to get for extra */
4652 uInt dist; /* distance back to copy from */
4653 } copy; /* if EXT or COPY, where and how much */
4654 } sub; /* submode */
4655
4656 /* mode independent information */
4657 Byte lbits; /* ltree bits decoded per branch */
4658 Byte dbits; /* dtree bits decoder per branch */
4659 inflate_huft *ltree; /* literal/length/eob tree */
4660 inflate_huft *dtree; /* distance tree */
4661
4662 };
4663
4664
4665 inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4666 uInt bl, bd;
4667 inflate_huft *tl;
4668 inflate_huft *td; /* need separate declaration for Borland C++ */
4669 z_streamp z;
4670 {
4671 inflate_codes_statef *c;
4672
4673 if ((c = (inflate_codes_statef *)
4674 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4675 {
4676 c->mode = START;
4677 c->lbits = (Byte)bl;
4678 c->dbits = (Byte)bd;
4679 c->ltree = tl;
4680 c->dtree = td;
4681 Tracev((stderr, "inflate: codes new\n"));
4682 }
4683 return c;
4684 }
4685
4686
4687 int inflate_codes(s, z, r)
4688 inflate_blocks_statef *s;
4689 z_streamp z;
4690 int r;
4691 {
4692 uInt j; /* temporary storage */
4693 inflate_huft *t; /* temporary pointer */
4694 uInt e; /* extra bits or operation */
4695 uLong b; /* bit buffer */
4696 uInt k; /* bits in bit buffer */
4697 Bytef *p; /* input data pointer */
4698 uInt n; /* bytes available there */
4699 Bytef *q; /* output window write pointer */
4700 uInt m; /* bytes to end of window or read pointer */
4701 Bytef *f; /* pointer to copy strings from */
4702 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4703
4704 /* copy input/output information to locals (UPDATE macro restores) */
4705 LOAD
4706
4707 /* process input and output based on current state */
4708 while (1) switch (c->mode)
4709 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4710 case START: /* x: set up for LEN */
4711 #ifndef SLOW
4712 if (m >= 258 && n >= 10)
4713 {
4714 UPDATE
4715 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4716 LOAD
4717 if (r != Z_OK)
4718 {
4719 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4720 break;
4721 }
4722 }
4723 #endif /* !SLOW */
4724 c->sub.code.need = c->lbits;
4725 c->sub.code.tree = c->ltree;
4726 c->mode = LEN;
4727 case LEN: /* i: get length/literal/eob next */
4728 j = c->sub.code.need;
4729 NEEDBITS(j)
4730 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4731 DUMPBITS(t->bits)
4732 e = (uInt)(t->exop);
4733 if (e == 0) /* literal */
4734 {
4735 c->sub.lit = t->base;
4736 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4737 "inflate: literal '%c'\n" :
4738 "inflate: literal 0x%02x\n", t->base));
4739 c->mode = LIT;
4740 break;
4741 }
4742 if (e & 16) /* length */
4743 {
4744 c->sub.copy.get = e & 15;
4745 c->len = t->base;
4746 c->mode = LENEXT;
4747 break;
4748 }
4749 if ((e & 64) == 0) /* next table */
4750 {
4751 c->sub.code.need = e;
4752 c->sub.code.tree = t->next;
4753 break;
4754 }
4755 if (e & 32) /* end of block */
4756 {
4757 Tracevv((stderr, "inflate: end of block\n"));
4758 c->mode = WASH;
4759 break;
4760 }
4761 c->mode = BADCODE; /* invalid code */
4762 z->msg = (char*)"invalid literal/length code";
4763 r = Z_DATA_ERROR;
4764 LEAVE
4765 case LENEXT: /* i: getting length extra (have base) */
4766 j = c->sub.copy.get;
4767 NEEDBITS(j)
4768 c->len += (uInt)b & inflate_mask[j];
4769 DUMPBITS(j)
4770 c->sub.code.need = c->dbits;
4771 c->sub.code.tree = c->dtree;
4772 Tracevv((stderr, "inflate: length %u\n", c->len));
4773 c->mode = DIST;
4774 case DIST: /* i: get distance next */
4775 j = c->sub.code.need;
4776 NEEDBITS(j)
4777 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4778 DUMPBITS(t->bits)
4779 e = (uInt)(t->exop);
4780 if (e & 16) /* distance */
4781 {
4782 c->sub.copy.get = e & 15;
4783 c->sub.copy.dist = t->base;
4784 c->mode = DISTEXT;
4785 break;
4786 }
4787 if ((e & 64) == 0) /* next table */
4788 {
4789 c->sub.code.need = e;
4790 c->sub.code.tree = t->next;
4791 break;
4792 }
4793 c->mode = BADCODE; /* invalid code */
4794 z->msg = (char*)"invalid distance code";
4795 r = Z_DATA_ERROR;
4796 LEAVE
4797 case DISTEXT: /* i: getting distance extra */
4798 j = c->sub.copy.get;
4799 NEEDBITS(j)
4800 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4801 DUMPBITS(j)
4802 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4803 c->mode = COPY;
4804 case COPY: /* o: copying bytes in window, waiting for space */
4805 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4806 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4807 s->end - (c->sub.copy.dist - (q - s->window)) :
4808 q - c->sub.copy.dist;
4809 #else
4810 f = q - c->sub.copy.dist;
4811 if ((uInt)(q - s->window) < c->sub.copy.dist)
4812 f = s->end - (c->sub.copy.dist - (uInt)(q - s->window));
4813 #endif
4814 while (c->len)
4815 {
4816 NEEDOUT
4817 OUTBYTE(*f++)
4818 if (f == s->end)
4819 f = s->window;
4820 c->len--;
4821 }
4822 c->mode = START;
4823 break;
4824 case LIT: /* o: got literal, waiting for output space */
4825 NEEDOUT
4826 OUTBYTE(c->sub.lit)
4827 c->mode = START;
4828 break;
4829 case WASH: /* o: got eob, possibly more output */
4830 FLUSH
4831 if (s->read != s->write)
4832 LEAVE
4833 c->mode = END;
4834 case END:
4835 r = Z_STREAM_END;
4836 LEAVE
4837 case BADCODE: /* x: got error */
4838 r = Z_DATA_ERROR;
4839 LEAVE
4840 default:
4841 r = Z_STREAM_ERROR;
4842 LEAVE
4843 }
4844 }
4845
4846
4847 void inflate_codes_free(c, z)
4848 inflate_codes_statef *c;
4849 z_streamp z;
4850 {
4851 ZFREE(z, c);
4852 Tracev((stderr, "inflate: codes free\n"));
4853 }
4854 /* --- infcodes.c */
4855
4856 /* +++ infutil.c */
4857 /* inflate_util.c -- data and routines common to blocks and codes
4858 * Copyright (C) 1995-1996 Mark Adler
4859 * For conditions of distribution and use, see copyright notice in zlib.h
4860 */
4861
4862 /* #include "zutil.h" */
4863 /* #include "infblock.h" */
4864 /* #include "inftrees.h" */
4865 /* #include "infcodes.h" */
4866 /* #include "infutil.h" */
4867
4868 #ifndef NO_DUMMY_DECL
4869 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4870 #endif
4871
4872 /* And'ing with mask[n] masks the lower n bits */
4873 uInt inflate_mask[17] = {
4874 0x0000,
4875 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
4876 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
4877 };
4878
4879
4880 /* copy as much as possible from the sliding window to the output area */
4881 int inflate_flush(s, z, r)
4882 inflate_blocks_statef *s;
4883 z_streamp z;
4884 int r;
4885 {
4886 uInt n;
4887 Bytef *p;
4888 Bytef *q;
4889
4890 /* local copies of source and destination pointers */
4891 p = z->next_out;
4892 q = s->read;
4893
4894 /* compute number of bytes to copy as far as end of window */
4895 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4896 if (n > z->avail_out) n = z->avail_out;
4897 if (n && r == Z_BUF_ERROR) r = Z_OK;
4898
4899 /* update counters */
4900 z->avail_out -= n;
4901 z->total_out += n;
4902
4903 /* update check information */
4904 if (s->checkfn != Z_NULL)
4905 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4906
4907 /* copy as far as end of window */
4908 if (p != Z_NULL) {
4909 zmemcpy(p, q, n);
4910 p += n;
4911 }
4912 q += n;
4913
4914 /* see if more to copy at beginning of window */
4915 if (q == s->end)
4916 {
4917 /* wrap pointers */
4918 q = s->window;
4919 if (s->write == s->end)
4920 s->write = s->window;
4921
4922 /* compute bytes to copy */
4923 n = (uInt)(s->write - q);
4924 if (n > z->avail_out) n = z->avail_out;
4925 if (n && r == Z_BUF_ERROR) r = Z_OK;
4926
4927 /* update counters */
4928 z->avail_out -= n;
4929 z->total_out += n;
4930
4931 /* update check information */
4932 if (s->checkfn != Z_NULL)
4933 z->adler = s->check = (*s->checkfn)(s->check, q, n);
4934
4935 /* copy */
4936 if (p != Z_NULL) {
4937 zmemcpy(p, q, n);
4938 p += n;
4939 }
4940 q += n;
4941 }
4942
4943 /* update pointers */
4944 z->next_out = p;
4945 s->read = q;
4946
4947 /* done */
4948 return r;
4949 }
4950 /* --- infutil.c */
4951
4952 /* +++ inffast.c */
4953 /* inffast.c -- process literals and length/distance pairs fast
4954 * Copyright (C) 1995-1996 Mark Adler
4955 * For conditions of distribution and use, see copyright notice in zlib.h
4956 */
4957
4958 /* #include "zutil.h" */
4959 /* #include "inftrees.h" */
4960 /* #include "infblock.h" */
4961 /* #include "infcodes.h" */
4962 /* #include "infutil.h" */
4963 /* #include "inffast.h" */
4964
4965 #ifndef NO_DUMMY_DECL
4966 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
4967 #endif
4968
4969 /* simplify the use of the inflate_huft type with some defines */
4970 #define base more.Base
4971 #define next more.Next
4972 #define exop word.what.Exop
4973 #define bits word.what.Bits
4974
4975 /* macros for bit input with no checking and for returning unused bytes */
4976 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4977 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4978
4979 /* Called with number of bytes left to write in window at least 258
4980 (the maximum string length) and number of input bytes available
4981 at least ten. The ten bytes are six bytes for the longest length/
4982 distance pair plus four bytes for overloading the bit buffer. */
4983
4984 int inflate_fast(bl, bd, tl, td, s, z)
4985 uInt bl, bd;
4986 inflate_huft *tl;
4987 inflate_huft *td; /* need separate declaration for Borland C++ */
4988 inflate_blocks_statef *s;
4989 z_streamp z;
4990 {
4991 inflate_huft *t; /* temporary pointer */
4992 uInt e; /* extra bits or operation */
4993 uLong b; /* bit buffer */
4994 uInt k; /* bits in bit buffer */
4995 Bytef *p; /* input data pointer */
4996 uInt n; /* bytes available there */
4997 Bytef *q; /* output window write pointer */
4998 uInt m; /* bytes to end of window or read pointer */
4999 uInt ml; /* mask for literal/length tree */
5000 uInt md; /* mask for distance tree */
5001 uInt c; /* bytes to copy */
5002 uInt d; /* distance back to copy from */
5003 Bytef *r; /* copy source pointer */
5004
5005 /* load input, output, bit values */
5006 LOAD
5007
5008 /* initialize masks */
5009 ml = inflate_mask[bl];
5010 md = inflate_mask[bd];
5011
5012 /* do until not enough input or output space for fast loop */
5013 do { /* assume called with m >= 258 && n >= 10 */
5014 /* get literal/length code */
5015 GRABBITS(20) /* max bits for literal/length code */
5016 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
5017 {
5018 DUMPBITS(t->bits)
5019 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5020 "inflate: * literal '%c'\n" :
5021 "inflate: * literal 0x%02x\n", t->base));
5022 *q++ = (Byte)t->base;
5023 m--;
5024 continue;
5025 }
5026 do {
5027 DUMPBITS(t->bits)
5028 if (e & 16)
5029 {
5030 /* get extra bits for length */
5031 e &= 15;
5032 c = t->base + ((uInt)b & inflate_mask[e]);
5033 DUMPBITS(e)
5034 Tracevv((stderr, "inflate: * length %u\n", c));
5035
5036 /* decode distance base of block to copy */
5037 GRABBITS(15); /* max bits for distance code */
5038 e = (t = td + ((uInt)b & md))->exop;
5039 do {
5040 DUMPBITS(t->bits)
5041 if (e & 16)
5042 {
5043 /* get extra bits to add to distance base */
5044 e &= 15;
5045 GRABBITS(e) /* get extra bits (up to 13) */
5046 d = t->base + ((uInt)b & inflate_mask[e]);
5047 DUMPBITS(e)
5048 Tracevv((stderr, "inflate: * distance %u\n", d));
5049
5050 /* do the copy */
5051 m -= c;
5052 if ((uInt)(q - s->window) >= d) /* offset before dest */
5053 { /* just copy */
5054 r = q - d;
5055 *q++ = *r++; c--; /* minimum count is three, */
5056 *q++ = *r++; c--; /* so unroll loop a little */
5057 }
5058 else /* else offset after destination */
5059 {
5060 e = d - (uInt)(q - s->window); /* bytes from offset to end */
5061 r = s->end - e; /* pointer to offset */
5062 if (c > e) /* if source crosses, */
5063 {
5064 c -= e; /* copy to end of window */
5065 do {
5066 *q++ = *r++;
5067 } while (--e);
5068 r = s->window; /* copy rest from start of window */
5069 }
5070 }
5071 do { /* copy all or what's left */
5072 *q++ = *r++;
5073 } while (--c);
5074 break;
5075 }
5076 else if ((e & 64) == 0)
5077 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
5078 else
5079 {
5080 z->msg = (char*)"invalid distance code";
5081 UNGRAB
5082 UPDATE
5083 return Z_DATA_ERROR;
5084 }
5085 } while (1);
5086 break;
5087 }
5088 if ((e & 64) == 0)
5089 {
5090 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
5091 {
5092 DUMPBITS(t->bits)
5093 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
5094 "inflate: * literal '%c'\n" :
5095 "inflate: * literal 0x%02x\n", t->base));
5096 *q++ = (Byte)t->base;
5097 m--;
5098 break;
5099 }
5100 }
5101 else if (e & 32)
5102 {
5103 Tracevv((stderr, "inflate: * end of block\n"));
5104 UNGRAB
5105 UPDATE
5106 return Z_STREAM_END;
5107 }
5108 else
5109 {
5110 z->msg = (char*)"invalid literal/length code";
5111 UNGRAB
5112 UPDATE
5113 return Z_DATA_ERROR;
5114 }
5115 } while (1);
5116 } while (m >= 258 && n >= 10);
5117
5118 /* not enough input or output--restore pointers and return */
5119 UNGRAB
5120 UPDATE
5121 return Z_OK;
5122 }
5123 /* --- inffast.c */
5124
5125 /* +++ zutil.c */
5126 /* zutil.c -- target dependent utility functions for the compression library
5127 * Copyright (C) 1995-1996 Jean-loup Gailly.
5128 * For conditions of distribution and use, see copyright notice in zlib.h
5129 */
5130
5131 /* From: zutil.c,v 1.17 1996/07/24 13:41:12 me Exp $ */
5132
5133 #ifdef DEBUG_ZLIB
5134 #include <stdio.h>
5135 #endif
5136
5137 /* #include "zutil.h" */
5138
5139 #ifndef NO_DUMMY_DECL
5140 struct internal_state {int dummy;}; /* for buggy compilers */
5141 #endif
5142
5143 #ifndef STDC
5144 extern void exit OF((int));
5145 #endif
5146
5147 static const char *z_errmsg[10] = {
5148 "need dictionary", /* Z_NEED_DICT 2 */
5149 "stream end", /* Z_STREAM_END 1 */
5150 "", /* Z_OK 0 */
5151 "file error", /* Z_ERRNO (-1) */
5152 "stream error", /* Z_STREAM_ERROR (-2) */
5153 "data error", /* Z_DATA_ERROR (-3) */
5154 "insufficient memory", /* Z_MEM_ERROR (-4) */
5155 "buffer error", /* Z_BUF_ERROR (-5) */
5156 "incompatible version",/* Z_VERSION_ERROR (-6) */
5157 ""};
5158
5159
5160 const char *zlibVersion()
5161 {
5162 return ZLIB_VERSION;
5163 }
5164
5165 #ifdef DEBUG_ZLIB
5166 void z_error (m)
5167 char *m;
5168 {
5169 fprintf(stderr, "%s\n", m);
5170 exit(1);
5171 }
5172 #endif
5173
5174 #ifndef HAVE_MEMCPY
5175
5176 void zmemcpy(dest, source, len)
5177 Bytef* dest;
5178 Bytef* source;
5179 uInt len;
5180 {
5181 if (len == 0) return;
5182 do {
5183 *dest++ = *source++; /* ??? to be unrolled */
5184 } while (--len != 0);
5185 }
5186
5187 int zmemcmp(s1, s2, len)
5188 Bytef* s1;
5189 Bytef* s2;
5190 uInt len;
5191 {
5192 uInt j;
5193
5194 for (j = 0; j < len; j++) {
5195 if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
5196 }
5197 return 0;
5198 }
5199
5200 void zmemzero(dest, len)
5201 Bytef* dest;
5202 uInt len;
5203 {
5204 if (len == 0) return;
5205 do {
5206 *dest++ = 0; /* ??? to be unrolled */
5207 } while (--len != 0);
5208 }
5209 #endif
5210
5211 #ifdef __TURBOC__
5212 #if (defined( __BORLANDC__) || !defined(SMALL_MEDIUM)) && !defined(__32BIT__)
5213 /* Small and medium model in Turbo C are for now limited to near allocation
5214 * with reduced MAX_WBITS and MAX_MEM_LEVEL
5215 */
5216 # define MY_ZCALLOC
5217
5218 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
5219 * and farmalloc(64K) returns a pointer with an offset of 8, so we
5220 * must fix the pointer. Warning: the pointer must be put back to its
5221 * original form in order to free it, use zcfree().
5222 */
5223
5224 #define MAX_PTR 10
5225 /* 10*64K = 640K */
5226
5227 local int next_ptr = 0;
5228
5229 typedef struct ptr_table_s {
5230 voidpf org_ptr;
5231 voidpf new_ptr;
5232 } ptr_table;
5233
5234 local ptr_table table[MAX_PTR];
5235 /* This table is used to remember the original form of pointers
5236 * to large buffers (64K). Such pointers are normalized with a zero offset.
5237 * Since MSDOS is not a preemptive multitasking OS, this table is not
5238 * protected from concurrent access. This hack doesn't work anyway on
5239 * a protected system like OS/2. Use Microsoft C instead.
5240 */
5241
5242 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5243 {
5244 voidpf buf = opaque; /* just to make some compilers happy */
5245 ulg bsize = (ulg)items*size;
5246
5247 /* If we allocate less than 65520 bytes, we assume that farmalloc
5248 * will return a usable pointer which doesn't have to be normalized.
5249 */
5250 if (bsize < 65520L) {
5251 buf = farmalloc(bsize);
5252 if (*(ush*)&buf != 0) return buf;
5253 } else {
5254 buf = farmalloc(bsize + 16L);
5255 }
5256 if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
5257 table[next_ptr].org_ptr = buf;
5258
5259 /* Normalize the pointer to seg:0 */
5260 *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
5261 *(ush*)&buf = 0;
5262 table[next_ptr++].new_ptr = buf;
5263 return buf;
5264 }
5265
5266 void zcfree (voidpf opaque, voidpf ptr)
5267 {
5268 int n;
5269 if (*(ush*)&ptr != 0) { /* object < 64K */
5270 farfree(ptr);
5271 return;
5272 }
5273 /* Find the original pointer */
5274 for (n = 0; n < next_ptr; n++) {
5275 if (ptr != table[n].new_ptr) continue;
5276
5277 farfree(table[n].org_ptr);
5278 while (++n < next_ptr) {
5279 table[n-1] = table[n];
5280 }
5281 next_ptr--;
5282 return;
5283 }
5284 ptr = opaque; /* just to make some compilers happy */
5285 Assert(0, "zcfree: ptr not found");
5286 }
5287 #endif
5288 #endif /* __TURBOC__ */
5289
5290
5291 #if defined(M_I86) && !defined(__32BIT__)
5292 /* Microsoft C in 16-bit mode */
5293
5294 # define MY_ZCALLOC
5295
5296 #if (!defined(_MSC_VER) || (_MSC_VER < 600))
5297 # define _halloc halloc
5298 # define _hfree hfree
5299 #endif
5300
5301 voidpf zcalloc (voidpf opaque, unsigned items, unsigned size)
5302 {
5303 if (opaque) opaque = 0; /* to make compiler happy */
5304 return _halloc((long)items, size);
5305 }
5306
5307 void zcfree (voidpf opaque, voidpf ptr)
5308 {
5309 if (opaque) opaque = 0; /* to make compiler happy */
5310 _hfree(ptr);
5311 }
5312
5313 #endif /* MSC */
5314
5315
5316 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
5317
5318 #ifndef STDC
5319 extern voidp calloc OF((uInt items, uInt size));
5320 extern void free OF((voidpf ptr));
5321 #endif
5322
5323 voidpf zcalloc (opaque, items, size)
5324 voidpf opaque;
5325 unsigned items;
5326 unsigned size;
5327 {
5328 if (opaque) items += size - size; /* make compiler happy */
5329 return (voidpf)calloc(items, size);
5330 }
5331
5332 void zcfree (opaque, ptr)
5333 voidpf opaque;
5334 voidpf ptr;
5335 {
5336 free(ptr);
5337 if (opaque) return; /* make compiler happy */
5338 }
5339
5340 #endif /* MY_ZCALLOC */
5341 /* --- zutil.c */
5342
5343 /* +++ adler32.c */
5344 /* adler32.c -- compute the Adler-32 checksum of a data stream
5345 * Copyright (C) 1995-1996 Mark Adler
5346 * For conditions of distribution and use, see copyright notice in zlib.h
5347 */
5348
5349 /* From: adler32.c,v 1.10 1996/05/22 11:52:18 me Exp $ */
5350
5351 /* #include "zlib.h" */
5352
5353 #define BASE 65521L /* largest prime smaller than 65536 */
5354 #define NMAX 5552
5355 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
5356
5357 #define DO1(buf,i) {s1 += buf[(i)]; s2 += s1;}
5358 #define DO2(buf,i) DO1(buf,i); DO1(buf,(i)+1);
5359 #define DO4(buf,i) DO2(buf,i); DO2(buf,(i)+2);
5360 #define DO8(buf,i) DO4(buf,i); DO4(buf,(i)+4);
5361 #define DO16(buf) DO8(buf,0); DO8(buf,8);
5362
5363 /* ========================================================================= */
5364 uLong adler32(adler, buf, len)
5365 uLong adler;
5366 const Bytef *buf;
5367 uInt len;
5368 {
5369 unsigned long s1 = adler & 0xffff;
5370 unsigned long s2 = (adler >> 16) & 0xffff;
5371 int k;
5372
5373 if (buf == Z_NULL) return 1L;
5374
5375 while (len > 0) {
5376 k = len < NMAX ? len : NMAX;
5377 len -= k;
5378 while (k >= 16) {
5379 DO16(buf);
5380 buf += 16;
5381 k -= 16;
5382 }
5383 if (k != 0) do {
5384 s1 += *buf++;
5385 s2 += s1;
5386 } while (--k);
5387 s1 %= BASE;
5388 s2 %= BASE;
5389 }
5390 return (s2 << 16) | s1;
5391 }
5392 /* --- adler32.c */
5393
5394 #ifdef _KERNEL
5395 static int
5396 zlib_modevent(module_t mod, int type, void *unused)
5397 {
5398 switch (type) {
5399 case MOD_LOAD:
5400 return 0;
5401 case MOD_UNLOAD:
5402 return 0;
5403 }
5404 return EINVAL;
5405 }
5406
5407 static moduledata_t zlib_mod = {
5408 "zlib",
5409 zlib_modevent,
5410 0
5411 };
5412 DECLARE_MODULE(zlib, zlib_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
5413 MODULE_VERSION(zlib, 1);
5414 #endif /* _KERNEL */
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