1 /* $OpenBSD: zlib.c,v 1.12 2003/12/10 07:22:42 itojun Exp $ */
2 /* $NetBSD: zlib.c,v 1.2 1996/03/16 23:55:40 christos Exp $ */
3
4 /*
5 * This file is derived from various .h and .c files from the zlib-0.95
6 * distribution by Jean-loup Gailly and Mark Adler, with some additions
7 * by Paul Mackerras to aid in implementing Deflate compression and
8 * decompression for PPP packets. See zlib.h for conditions of
9 * distribution and use.
10 *
11 * Changes that have been made include:
12 * - changed functions not used outside this file to "local"
13 * - added minCompression parameter to deflateInit2
14 * - added Z_PACKET_FLUSH (see zlib.h for details)
15 * - added inflateIncomp
16 */
17
18
19 /*+++++*/
20 /* zutil.h -- internal interface and configuration of the compression library
21 * Copyright (C) 1995 Jean-loup Gailly.
22 * For conditions of distribution and use, see copyright notice in zlib.h
23 */
24
25 /* WARNING: this file should *not* be used by applications. It is
26 part of the implementation of the compression library and is
27 subject to change. Applications should only use zlib.h.
28 */
29
30 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
31
32 #define _Z_UTIL_H
33
34 #include "zlib.h"
35
36 #include <sys/param.h>
37 #include <sys/types.h>
38 #ifdef _STANDALONE
39 #include <stand.h>
40 #else
41 #include <sys/systm.h>
42 #endif
43
44 #ifndef local
45 # define local static
46 #endif
47 /* compile with -Dlocal if your debugger can't find static symbols */
48
49 #define FAR
50
51 typedef unsigned char uch;
52 typedef uch FAR uchf;
53 typedef unsigned short ush;
54 typedef ush FAR ushf;
55 typedef unsigned long ulg;
56
57 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
58
59 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
60 /* To be used only when the state is known to be valid */
61
62 #ifndef NULL
63 #define NULL ((void *) 0)
64 #endif
65
66 /* common constants */
67
68 #define DEFLATED 8
69
70 #ifndef DEF_WBITS
71 # define DEF_WBITS MAX_WBITS
72 #endif
73 /* default windowBits for decompression. MAX_WBITS is for compression only */
74
75 #if MAX_MEM_LEVEL >= 8
76 # define DEF_MEM_LEVEL 8
77 #else
78 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
79 #endif
80 /* default memLevel */
81
82 #define STORED_BLOCK 0
83 #define STATIC_TREES 1
84 #define DYN_TREES 2
85 /* The three kinds of block type */
86
87 #define MIN_MATCH 3
88 #define MAX_MATCH 258
89 /* The minimum and maximum match lengths */
90
91 /* functions */
92
93 #if defined(KERNEL) || defined(_KERNEL)
94 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
95 # define zmemzero bzero
96 #else
97 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
98 # define HAVE_MEMCPY
99 #endif
100 #ifdef HAVE_MEMCPY
101 # define zmemcpy memcpy
102 # define zmemzero(dest, len) memset(dest, 0, len)
103 #else
104 extern void zmemcpy OF((Bytef* dest, Bytef* source, uInt len));
105 extern void zmemzero OF((Bytef* dest, uInt len));
106 #endif
107 #endif
108
109 /* Diagnostic functions */
110 #ifdef DEBUG_ZLIB
111 # include <stdio.h>
112 # ifndef verbose
113 # define verbose 0
114 # endif
115 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
116 # define Trace(x) fprintf x
117 # define Tracev(x) {if (verbose) fprintf x ;}
118 # define Tracevv(x) {if (verbose>1) fprintf x ;}
119 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
120 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
121 #else
122 # define Assert(cond,msg)
123 # define Trace(x)
124 # define Tracev(x)
125 # define Tracevv(x)
126 # define Tracec(c,x)
127 # define Tracecv(c,x)
128 #endif
129
130
131 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
132
133 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
134 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
135
136 #define ZALLOC(strm, items, size) \
137 (*((strm)->zalloc))((strm)->opaque, (items), (size))
138 #define ZFREE(strm, addr, size) \
139 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
140 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
141
142 #ifndef NO_DEFLATE
143
144 /* deflate.h -- internal compression state
145 * Copyright (C) 1995 Jean-loup Gailly
146 * For conditions of distribution and use, see copyright notice in zlib.h
147 */
148
149 /* WARNING: this file should *not* be used by applications. It is
150 part of the implementation of the compression library and is
151 subject to change. Applications should only use zlib.h.
152 */
153
154
155 /*+++++*/
156 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
157
158 /* ===========================================================================
159 * Internal compression state.
160 */
161
162 /* Data type */
163 #define BINARY 0
164 #define ASCII 1
165 #define UNKNOWN 2
166
167 #define LENGTH_CODES 29
168 /* number of length codes, not counting the special END_BLOCK code */
169
170 #define LITERALS 256
171 /* number of literal bytes 0..255 */
172
173 #define L_CODES (LITERALS+1+LENGTH_CODES)
174 /* number of Literal or Length codes, including the END_BLOCK code */
175
176 #define D_CODES 30
177 /* number of distance codes */
178
179 #define BL_CODES 19
180 /* number of codes used to transfer the bit lengths */
181
182 #define HEAP_SIZE (2*L_CODES+1)
183 /* maximum heap size */
184
185 #define MAX_BITS 15
186 /* All codes must not exceed MAX_BITS bits */
187
188 #define INIT_STATE 42
189 #define BUSY_STATE 113
190 #define FLUSH_STATE 124
191 #define FINISH_STATE 666
192 /* Stream status */
193
194
195 /* Data structure describing a single value and its code string. */
196 typedef struct ct_data_s {
197 union {
198 ush freq; /* frequency count */
199 ush code; /* bit string */
200 } fc;
201 union {
202 ush dad; /* father node in Huffman tree */
203 ush len; /* length of bit string */
204 } dl;
205 } FAR ct_data;
206
207 #define Freq fc.freq
208 #define Code fc.code
209 #define Dad dl.dad
210 #define Len dl.len
211
212 typedef struct static_tree_desc_s static_tree_desc;
213
214 typedef struct tree_desc_s {
215 ct_data *dyn_tree; /* the dynamic tree */
216 int max_code; /* largest code with non zero frequency */
217 const static_tree_desc *stat_desc; /* the corresponding static tree */
218 } FAR tree_desc;
219
220 typedef ush Pos;
221 typedef Pos FAR Posf;
222 typedef unsigned IPos;
223
224 /* A Pos is an index in the character window. We use short instead of int to
225 * save space in the various tables. IPos is used only for parameter passing.
226 */
227
228 typedef struct deflate_state {
229 z_stream *strm; /* pointer back to this zlib stream */
230 int status; /* as the name implies */
231 Bytef *pending_buf; /* output still pending */
232 Bytef *pending_out; /* next pending byte to output to the stream */
233 int pending; /* nb of bytes in the pending buffer */
234 uLong adler; /* adler32 of uncompressed data */
235 int noheader; /* suppress zlib header and adler32 */
236 Byte data_type; /* UNKNOWN, BINARY or ASCII */
237 Byte method; /* STORED (for zip only) or DEFLATED */
238 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
239
240 /* used by deflate.c: */
241
242 uInt w_size; /* LZ77 window size (32K by default) */
243 uInt w_bits; /* log2(w_size) (8..16) */
244 uInt w_mask; /* w_size - 1 */
245
246 Bytef *window;
247 /* Sliding window. Input bytes are read into the second half of the window,
248 * and move to the first half later to keep a dictionary of at least wSize
249 * bytes. With this organization, matches are limited to a distance of
250 * wSize-MAX_MATCH bytes, but this ensures that IO is always
251 * performed with a length multiple of the block size. Also, it limits
252 * the window size to 64K, which is quite useful on MSDOS.
253 * To do: use the user input buffer as sliding window.
254 */
255
256 ulg window_size;
257 /* Actual size of window: 2*wSize, except when the user input buffer
258 * is directly used as sliding window.
259 */
260
261 Posf *prev;
262 /* Link to older string with same hash index. To limit the size of this
263 * array to 64K, this link is maintained only for the last 32K strings.
264 * An index in this array is thus a window index modulo 32K.
265 */
266
267 Posf *head; /* Heads of the hash chains or NIL. */
268
269 uInt ins_h; /* hash index of string to be inserted */
270 uInt hash_size; /* number of elements in hash table */
271 uInt hash_bits; /* log2(hash_size) */
272 uInt hash_mask; /* hash_size-1 */
273
274 uInt hash_shift;
275 /* Number of bits by which ins_h must be shifted at each input
276 * step. It must be such that after MIN_MATCH steps, the oldest
277 * byte no longer takes part in the hash key, that is:
278 * hash_shift * MIN_MATCH >= hash_bits
279 */
280
281 long block_start;
282 /* Window position at the beginning of the current output block. Gets
283 * negative when the window is moved backwards.
284 */
285
286 uInt match_length; /* length of best match */
287 IPos prev_match; /* previous match */
288 int match_available; /* set if previous match exists */
289 uInt strstart; /* start of string to insert */
290 uInt match_start; /* start of matching string */
291 uInt lookahead; /* number of valid bytes ahead in window */
292
293 uInt prev_length;
294 /* Length of the best match at previous step. Matches not greater than this
295 * are discarded. This is used in the lazy match evaluation.
296 */
297
298 uInt max_chain_length;
299 /* To speed up deflation, hash chains are never searched beyond this
300 * length. A higher limit improves compression ratio but degrades the
301 * speed.
302 */
303
304 uInt max_lazy_match;
305 /* Attempt to find a better match only when the current match is strictly
306 * smaller than this value. This mechanism is used only for compression
307 * levels >= 4.
308 */
309 # define max_insert_length max_lazy_match
310 /* Insert new strings in the hash table only if the match length is not
311 * greater than this length. This saves time but degrades compression.
312 * max_insert_length is used only for compression levels <= 3.
313 */
314
315 int level; /* compression level (1..9) */
316 int strategy; /* favor or force Huffman coding*/
317
318 uInt good_match;
319 /* Use a faster search when the previous match is longer than this */
320
321 int nice_match; /* Stop searching when current match exceeds this */
322
323 /* used by trees.c: */
324 /* Didn't use ct_data typedef below to supress compiler warning */
325 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
326 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
327 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
328
329 struct tree_desc_s l_desc; /* desc. for literal tree */
330 struct tree_desc_s d_desc; /* desc. for distance tree */
331 struct tree_desc_s bl_desc; /* desc. for bit length tree */
332
333 ush bl_count[MAX_BITS+1];
334 /* number of codes at each bit length for an optimal tree */
335
336 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
337 int heap_len; /* number of elements in the heap */
338 int heap_max; /* element of largest frequency */
339 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
340 * The same heap array is used to build all trees.
341 */
342
343 uch depth[2*L_CODES+1];
344 /* Depth of each subtree used as tie breaker for trees of equal frequency
345 */
346
347 uchf *l_buf; /* buffer for literals or lengths */
348
349 uInt lit_bufsize;
350 /* Size of match buffer for literals/lengths. There are 4 reasons for
351 * limiting lit_bufsize to 64K:
352 * - frequencies can be kept in 16 bit counters
353 * - if compression is not successful for the first block, all input
354 * data is still in the window so we can still emit a stored block even
355 * when input comes from standard input. (This can also be done for
356 * all blocks if lit_bufsize is not greater than 32K.)
357 * - if compression is not successful for a file smaller than 64K, we can
358 * even emit a stored file instead of a stored block (saving 5 bytes).
359 * This is applicable only for zip (not gzip or zlib).
360 * - creating new Huffman trees less frequently may not provide fast
361 * adaptation to changes in the input data statistics. (Take for
362 * example a binary file with poorly compressible code followed by
363 * a highly compressible string table.) Smaller buffer sizes give
364 * fast adaptation but have of course the overhead of transmitting
365 * trees more frequently.
366 * - I can't count above 4
367 */
368
369 uInt last_lit; /* running index in l_buf */
370
371 ushf *d_buf;
372 /* Buffer for distances. To simplify the code, d_buf and l_buf have
373 * the same number of elements. To use different lengths, an extra flag
374 * array would be necessary.
375 */
376
377 ulg opt_len; /* bit length of current block with optimal trees */
378 ulg static_len; /* bit length of current block with static trees */
379 ulg compressed_len; /* total bit length of compressed file */
380 uInt matches; /* number of string matches in current block */
381 int last_eob_len; /* bit length of EOB code for last block */
382
383 #ifdef DEBUG_ZLIB
384 ulg bits_sent; /* bit length of the compressed data */
385 #endif
386
387 ush bi_buf;
388 /* Output buffer. bits are inserted starting at the bottom (least
389 * significant bits).
390 */
391 int bi_valid;
392 /* Number of valid bits in bi_buf. All bits above the last valid bit
393 * are always zero.
394 */
395
396 uInt blocks_in_packet;
397 /* Number of blocks produced since the last time Z_PACKET_FLUSH
398 * was used.
399 */
400
401 } FAR deflate_state;
402
403 /* Output a byte on the stream.
404 * IN assertion: there is enough room in pending_buf.
405 */
406 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
407
408
409 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
410 /* Minimum amount of lookahead, except at the end of the input file.
411 * See deflate.c for comments about the MIN_MATCH+1.
412 */
413
414 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
415 /* In order to simplify the code, particularly on 16 bit machines, match
416 * distances are limited to MAX_DIST instead of WSIZE.
417 */
418
419 /* in trees.c */
420 local void ct_init OF((deflate_state *s));
421 local int ct_tally OF((deflate_state *s, int dist, int lc));
422 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
423 int flush));
424 local void ct_align OF((deflate_state *s));
425 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
426 int eof));
427 local void ct_stored_type_only OF((deflate_state *s));
428
429 /*+++++*/
430 /* deflate.c -- compress data using the deflation algorithm
431 * Copyright (C) 1995 Jean-loup Gailly.
432 * For conditions of distribution and use, see copyright notice in zlib.h
433 */
434
435 /*
436 * ALGORITHM
437 *
438 * The "deflation" process depends on being able to identify portions
439 * of the input text which are identical to earlier input (within a
440 * sliding window trailing behind the input currently being processed).
441 *
442 * The most straightforward technique turns out to be the fastest for
443 * most input files: try all possible matches and select the longest.
444 * The key feature of this algorithm is that insertions into the string
445 * dictionary are very simple and thus fast, and deletions are avoided
446 * completely. Insertions are performed at each input character, whereas
447 * string matches are performed only when the previous match ends. So it
448 * is preferable to spend more time in matches to allow very fast string
449 * insertions and avoid deletions. The matching algorithm for small
450 * strings is inspired from that of Rabin & Karp. A brute force approach
451 * is used to find longer strings when a small match has been found.
452 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
453 * (by Leonid Broukhis).
454 * A previous version of this file used a more sophisticated algorithm
455 * (by Fiala and Greene) which is guaranteed to run in linear amortized
456 * time, but has a larger average cost, uses more memory and is patented.
457 * However the F&G algorithm may be faster for some highly redundant
458 * files if the parameter max_chain_length (described below) is too large.
459 *
460 * ACKNOWLEDGEMENTS
461 *
462 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
463 * I found it in 'freeze' written by Leonid Broukhis.
464 * Thanks to many people for bug reports and testing.
465 *
466 * REFERENCES
467 *
468 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
469 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
470 *
471 * A description of the Rabin and Karp algorithm is given in the book
472 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
473 *
474 * Fiala,E.R., and Greene,D.H.
475 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
476 *
477 */
478
479 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
480
481 #if 0
482 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
483 #endif
484 /*
485 If you use the zlib library in a product, an acknowledgment is welcome
486 in the documentation of your product. If for some reason you cannot
487 include such an acknowledgment, I would appreciate that you keep this
488 copyright string in the executable of your product.
489 */
490
491 #define NIL 0
492 /* Tail of hash chains */
493
494 #ifndef TOO_FAR
495 # define TOO_FAR 4096
496 #endif
497 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
498
499 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
500 /* Minimum amount of lookahead, except at the end of the input file.
501 * See deflate.c for comments about the MIN_MATCH+1.
502 */
503
504 /* Values for max_lazy_match, good_match and max_chain_length, depending on
505 * the desired pack level (0..9). The values given below have been tuned to
506 * exclude worst case performance for pathological files. Better values may be
507 * found for specific files.
508 */
509
510 typedef struct config_s {
511 ush good_length; /* reduce lazy search above this match length */
512 ush max_lazy; /* do not perform lazy search above this match length */
513 ush nice_length; /* quit search above this match length */
514 ush max_chain;
515 } config;
516
517 local config configuration_table[10] = {
518 /* good lazy nice chain */
519 /* 0 */ {0, 0, 0, 0}, /* store only */
520 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
521 /* 2 */ {4, 5, 16, 8},
522 /* 3 */ {4, 6, 32, 32},
523
524 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
525 /* 5 */ {8, 16, 32, 32},
526 /* 6 */ {8, 16, 128, 128},
527 /* 7 */ {8, 32, 128, 256},
528 /* 8 */ {32, 128, 258, 1024},
529 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
530
531 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
532 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
533 * meaning.
534 */
535
536 #define EQUAL 0
537 /* result of memcmp for equal strings */
538
539 /* ===========================================================================
540 * Prototypes for local functions.
541 */
542
543 local void fill_window OF((deflate_state *s));
544 local int deflate_fast OF((deflate_state *s, int flush));
545 local int deflate_slow OF((deflate_state *s, int flush));
546 local void lm_init OF((deflate_state *s));
547 local int longest_match OF((deflate_state *s, IPos cur_match));
548 local void putShortMSB OF((deflate_state *s, uInt b));
549 local void flush_pending OF((z_stream *strm));
550 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
551 #ifdef ASMV
552 void match_init OF((void)); /* asm code initialization */
553 #endif
554
555 #ifdef DEBUG_ZLIB
556 local void check_match OF((deflate_state *s, IPos start, IPos match,
557 int length));
558 #endif
559
560
561 /* ===========================================================================
562 * Update a hash value with the given input byte
563 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
564 * input characters, so that a running hash key can be computed from the
565 * previous key instead of complete recalculation each time.
566 */
567 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
568
569
570 /* ===========================================================================
571 * Insert string str in the dictionary and set match_head to the previous head
572 * of the hash chain (the most recent string with same hash key). Return
573 * the previous length of the hash chain.
574 * IN assertion: all calls to to INSERT_STRING are made with consecutive
575 * input characters and the first MIN_MATCH bytes of str are valid
576 * (except for the last MIN_MATCH-1 bytes of the input file).
577 */
578 #define INSERT_STRING(s, str, match_head) \
579 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
580 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
581 s->head[s->ins_h] = (str))
582
583 /* ===========================================================================
584 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
585 * prev[] will be initialized on the fly.
586 */
587 #define CLEAR_HASH(s) \
588 s->head[s->hash_size-1] = NIL; \
589 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
590
591 /* ========================================================================= */
592 int deflateInit (strm, level)
593 z_stream *strm;
594 int level;
595 {
596 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
597 0, 0);
598 /* To do: ignore strm->next_in if we use it as window */
599 }
600
601 /* ========================================================================= */
602 int deflateInit2 (strm, level, method, windowBits, memLevel,
603 strategy, minCompression)
604 z_stream *strm;
605 int level;
606 int method;
607 int windowBits;
608 int memLevel;
609 int strategy;
610 int minCompression;
611 {
612 deflate_state *s;
613 int noheader = 0;
614
615 if (strm == Z_NULL) return Z_STREAM_ERROR;
616
617 strm->msg = Z_NULL;
618 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
619 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
620
621 if (level == Z_DEFAULT_COMPRESSION) level = 6;
622
623 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
624 noheader = 1;
625 windowBits = -windowBits;
626 }
627 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
628 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
629 return Z_STREAM_ERROR;
630 }
631 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
632 if (s == Z_NULL) return Z_MEM_ERROR;
633 strm->state = (struct internal_state FAR *)s;
634 s->strm = strm;
635
636 s->noheader = noheader;
637 s->w_bits = windowBits;
638 s->w_size = 1 << s->w_bits;
639 s->w_mask = s->w_size - 1;
640
641 s->hash_bits = memLevel + 7;
642 s->hash_size = 1 << s->hash_bits;
643 s->hash_mask = s->hash_size - 1;
644 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
645
646 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
647 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
648 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
649
650 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
651
652 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
653
654 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
655 s->pending_buf == Z_NULL) {
656 strm->msg = z_errmsg[1-Z_MEM_ERROR];
657 deflateEnd (strm);
658 return Z_MEM_ERROR;
659 }
660 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
661 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
662 /* We overlay pending_buf and d_buf+l_buf. This works since the average
663 * output size for (length,distance) codes is <= 32 bits (worst case
664 * is 15+15+13=33).
665 */
666
667 s->level = level;
668 s->strategy = strategy;
669 s->method = (Byte)method;
670 s->minCompr = minCompression;
671 s->blocks_in_packet = 0;
672
673 return deflateReset(strm);
674 }
675
676 /* ========================================================================= */
677 int deflateReset (strm)
678 z_stream *strm;
679 {
680 deflate_state *s;
681
682 if (strm == Z_NULL || strm->state == Z_NULL ||
683 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
684
685 strm->total_in = strm->total_out = 0;
686 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
687 strm->data_type = Z_UNKNOWN;
688
689 s = (deflate_state *)strm->state;
690 s->pending = 0;
691 s->pending_out = s->pending_buf;
692
693 if (s->noheader < 0) {
694 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
695 }
696 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
697 s->adler = 1;
698
699 ct_init(s);
700 lm_init(s);
701
702 return Z_OK;
703 }
704
705 /* =========================================================================
706 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
707 * IN assertion: the stream state is correct and there is enough room in
708 * pending_buf.
709 */
710 local void putShortMSB (s, b)
711 deflate_state *s;
712 uInt b;
713 {
714 put_byte(s, (Byte)(b >> 8));
715 put_byte(s, (Byte)(b & 0xff));
716 }
717
718 /* =========================================================================
719 * Flush as much pending output as possible.
720 */
721 local void flush_pending(strm)
722 z_stream *strm;
723 {
724 deflate_state *state = (deflate_state *) strm->state;
725 unsigned len = state->pending;
726
727 if (len > strm->avail_out) len = strm->avail_out;
728 if (len == 0) return;
729
730 if (strm->next_out != NULL) {
731 zmemcpy(strm->next_out, state->pending_out, len);
732 strm->next_out += len;
733 }
734 state->pending_out += len;
735 strm->total_out += len;
736 strm->avail_out -= len;
737 state->pending -= len;
738 if (state->pending == 0) {
739 state->pending_out = state->pending_buf;
740 }
741 }
742
743 /* ========================================================================= */
744 int deflate (strm, flush)
745 z_stream *strm;
746 int flush;
747 {
748 deflate_state *state = (deflate_state *) strm->state;
749
750 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
751
752 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
753 ERR_RETURN(strm, Z_STREAM_ERROR);
754 }
755 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
756
757 state->strm = strm; /* just in case */
758
759 /* Write the zlib header */
760 if (state->status == INIT_STATE) {
761
762 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
763 uInt level_flags = (state->level-1) >> 1;
764
765 if (level_flags > 3) level_flags = 3;
766 header |= (level_flags << 6);
767 header += 31 - (header % 31);
768
769 state->status = BUSY_STATE;
770 putShortMSB(state, header);
771 }
772
773 /* Flush as much pending output as possible */
774 if (state->pending != 0) {
775 flush_pending(strm);
776 if (strm->avail_out == 0) return Z_OK;
777 }
778
779 /* If we came back in here to get the last output from
780 * a previous flush, we're done for now.
781 */
782 if (state->status == FLUSH_STATE) {
783 state->status = BUSY_STATE;
784 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
785 return Z_OK;
786 }
787
788 /* User must not provide more input after the first FINISH: */
789 if (state->status == FINISH_STATE && strm->avail_in != 0) {
790 ERR_RETURN(strm, Z_BUF_ERROR);
791 }
792
793 /* Start a new block or continue the current one.
794 */
795 if (strm->avail_in != 0 || state->lookahead != 0 ||
796 (flush == Z_FINISH && state->status != FINISH_STATE)) {
797 int quit;
798
799 if (flush == Z_FINISH) {
800 state->status = FINISH_STATE;
801 }
802 if (state->level <= 3) {
803 quit = deflate_fast(state, flush);
804 } else {
805 quit = deflate_slow(state, flush);
806 }
807 if (quit || strm->avail_out == 0)
808 return Z_OK;
809 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
810 * of deflate should use the same flush parameter to make sure
811 * that the flush is complete. So we don't have to output an
812 * empty block here, this will be done at next call. This also
813 * ensures that for a very small output buffer, we emit at most
814 * one empty block.
815 */
816 }
817
818 /* If a flush was requested, we have a little more to output now. */
819 if (flush != Z_NO_FLUSH && flush != Z_FINISH
820 && state->status != FINISH_STATE) {
821 switch (flush) {
822 case Z_PARTIAL_FLUSH:
823 ct_align(state);
824 break;
825 case Z_PACKET_FLUSH:
826 /* Output just the 3-bit `stored' block type value,
827 but not a zero length. */
828 ct_stored_type_only(state);
829 break;
830 default:
831 ct_stored_block(state, (char*)0, 0L, 0);
832 /* For a full flush, this empty block will be recognized
833 * as a special marker by inflate_sync().
834 */
835 if (flush == Z_FULL_FLUSH) {
836 CLEAR_HASH(state); /* forget history */
837 }
838 }
839 flush_pending(strm);
840 if (strm->avail_out == 0) {
841 /* We'll have to come back to get the rest of the output;
842 * this ensures we don't output a second zero-length stored
843 * block (or whatever).
844 */
845 state->status = FLUSH_STATE;
846 return Z_OK;
847 }
848 }
849
850 Assert(strm->avail_out > 0, "bug2");
851
852 if (flush != Z_FINISH) return Z_OK;
853 if (state->noheader) return Z_STREAM_END;
854
855 /* Write the zlib trailer (adler32) */
856 putShortMSB(state, (uInt)(state->adler >> 16));
857 putShortMSB(state, (uInt)(state->adler & 0xffff));
858 flush_pending(strm);
859 /* If avail_out is zero, the application will call deflate again
860 * to flush the rest.
861 */
862 state->noheader = -1; /* write the trailer only once! */
863 return state->pending != 0 ? Z_OK : Z_STREAM_END;
864 }
865
866 /* ========================================================================= */
867 int deflateEnd (strm)
868 z_stream *strm;
869 {
870 deflate_state *state = (deflate_state *) strm->state;
871
872 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
873
874 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
875 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
876 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
877 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
878
879 ZFREE(strm, state, sizeof(deflate_state));
880 strm->state = Z_NULL;
881
882 return Z_OK;
883 }
884
885 /* ===========================================================================
886 * Read a new buffer from the current input stream, update the adler32
887 * and total number of bytes read.
888 */
889 local int read_buf(strm, buf, size)
890 z_stream *strm;
891 charf *buf;
892 unsigned size;
893 {
894 unsigned len = strm->avail_in;
895 deflate_state *state = (deflate_state *) strm->state;
896
897 if (len > size) len = size;
898 if (len == 0) return 0;
899
900 strm->avail_in -= len;
901
902 if (!state->noheader) {
903 state->adler = adler32(state->adler, strm->next_in, len);
904 }
905 zmemcpy(buf, strm->next_in, len);
906 strm->next_in += len;
907 strm->total_in += len;
908
909 return (int)len;
910 }
911
912 /* ===========================================================================
913 * Initialize the "longest match" routines for a new zlib stream
914 */
915 local void lm_init (s)
916 deflate_state *s;
917 {
918 s->window_size = (ulg)2L*s->w_size;
919
920 CLEAR_HASH(s);
921
922 /* Set the default configuration parameters:
923 */
924 s->max_lazy_match = configuration_table[s->level].max_lazy;
925 s->good_match = configuration_table[s->level].good_length;
926 s->nice_match = configuration_table[s->level].nice_length;
927 s->max_chain_length = configuration_table[s->level].max_chain;
928
929 s->strstart = 0;
930 s->block_start = 0L;
931 s->lookahead = 0;
932 s->match_length = MIN_MATCH-1;
933 s->match_available = 0;
934 s->ins_h = 0;
935 #ifdef ASMV
936 match_init(); /* initialize the asm code */
937 #endif
938 }
939
940 /* ===========================================================================
941 * Set match_start to the longest match starting at the given string and
942 * return its length. Matches shorter or equal to prev_length are discarded,
943 * in which case the result is equal to prev_length and match_start is
944 * garbage.
945 * IN assertions: cur_match is the head of the hash chain for the current
946 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
947 */
948 #ifndef ASMV
949 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
950 * match.S. The code will be functionally equivalent.
951 */
952 local int longest_match(s, cur_match)
953 deflate_state *s;
954 IPos cur_match; /* current match */
955 {
956 unsigned chain_length = s->max_chain_length;/* max hash chain length */
957 Bytef *scan = s->window + s->strstart; /* current string */
958 Bytef *match; /* matched string */
959 int len; /* length of current match */
960 int best_len = s->prev_length; /* best match length so far */
961 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
962 s->strstart - (IPos)MAX_DIST(s) : NIL;
963 /* Stop when cur_match becomes <= limit. To simplify the code,
964 * we prevent matches with the string of window index 0.
965 */
966 Posf *prev = s->prev;
967 uInt wmask = s->w_mask;
968
969 #ifdef UNALIGNED_OK
970 /* Compare two bytes at a time. Note: this is not always beneficial.
971 * Try with and without -DUNALIGNED_OK to check.
972 */
973 Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
974 ush scan_start = *(ushf*)scan;
975 ush scan_end = *(ushf*)(scan+best_len-1);
976 #else
977 Bytef *strend = s->window + s->strstart + MAX_MATCH;
978 Byte scan_end1 = scan[best_len-1];
979 Byte scan_end = scan[best_len];
980 #endif
981
982 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
983 * It is easy to get rid of this optimization if necessary.
984 */
985 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
986
987 /* Do not waste too much time if we already have a good match: */
988 if (s->prev_length >= s->good_match) {
989 chain_length >>= 2;
990 }
991 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
992
993 do {
994 Assert(cur_match < s->strstart, "no future");
995 match = s->window + cur_match;
996
997 /* Skip to next match if the match length cannot increase
998 * or if the match length is less than 2:
999 */
1000 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1001 /* This code assumes sizeof(unsigned short) == 2. Do not use
1002 * UNALIGNED_OK if your compiler uses a different size.
1003 */
1004 if (*(ushf*)(match+best_len-1) != scan_end ||
1005 *(ushf*)match != scan_start) continue;
1006
1007 /* It is not necessary to compare scan[2] and match[2] since they are
1008 * always equal when the other bytes match, given that the hash keys
1009 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1010 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1011 * lookahead only every 4th comparison; the 128th check will be made
1012 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1013 * necessary to put more guard bytes at the end of the window, or
1014 * to check more often for insufficient lookahead.
1015 */
1016 Assert(scan[2] == match[2], "scan[2]?");
1017 scan++, match++;
1018 do {
1019 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1020 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1021 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1022 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1023 scan < strend);
1024 /* The funny "do {}" generates better code on most compilers */
1025
1026 /* Here, scan <= window+strstart+257 */
1027 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1028 if (*scan == *match) scan++;
1029
1030 len = (MAX_MATCH - 1) - (int)(strend-scan);
1031 scan = strend - (MAX_MATCH-1);
1032
1033 #else /* UNALIGNED_OK */
1034
1035 if (match[best_len] != scan_end ||
1036 match[best_len-1] != scan_end1 ||
1037 *match != *scan ||
1038 *++match != scan[1]) continue;
1039
1040 /* The check at best_len-1 can be removed because it will be made
1041 * again later. (This heuristic is not always a win.)
1042 * It is not necessary to compare scan[2] and match[2] since they
1043 * are always equal when the other bytes match, given that
1044 * the hash keys are equal and that HASH_BITS >= 8.
1045 */
1046 scan += 2, match++;
1047 Assert(*scan == *match, "match[2]?");
1048
1049 /* We check for insufficient lookahead only every 8th comparison;
1050 * the 256th check will be made at strstart+258.
1051 */
1052 do {
1053 } while (*++scan == *++match && *++scan == *++match &&
1054 *++scan == *++match && *++scan == *++match &&
1055 *++scan == *++match && *++scan == *++match &&
1056 *++scan == *++match && *++scan == *++match &&
1057 scan < strend);
1058
1059 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1060
1061 len = MAX_MATCH - (int)(strend - scan);
1062 scan = strend - MAX_MATCH;
1063
1064 #endif /* UNALIGNED_OK */
1065
1066 if (len > best_len) {
1067 s->match_start = cur_match;
1068 best_len = len;
1069 if (len >= s->nice_match) break;
1070 #ifdef UNALIGNED_OK
1071 scan_end = *(ushf*)(scan+best_len-1);
1072 #else
1073 scan_end1 = scan[best_len-1];
1074 scan_end = scan[best_len];
1075 #endif
1076 }
1077 } while ((cur_match = prev[cur_match & wmask]) > limit
1078 && --chain_length != 0);
1079
1080 return best_len;
1081 }
1082 #endif /* ASMV */
1083
1084 #ifdef DEBUG_ZLIB
1085 /* ===========================================================================
1086 * Check that the match at match_start is indeed a match.
1087 */
1088 local void check_match(s, start, match, length)
1089 deflate_state *s;
1090 IPos start, match;
1091 int length;
1092 {
1093 /* check that the match is indeed a match */
1094 if (memcmp((charf *)s->window + match,
1095 (charf *)s->window + start, length) != EQUAL) {
1096 fprintf(stderr,
1097 " start %u, match %u, length %d\n",
1098 start, match, length);
1099 do { fprintf(stderr, "%c%c", s->window[match++],
1100 s->window[start++]); } while (--length != 0);
1101 z_error("invalid match");
1102 }
1103 if (verbose > 1) {
1104 fprintf(stderr,"\\[%d,%d]", start-match, length);
1105 do { putc(s->window[start++], stderr); } while (--length != 0);
1106 }
1107 }
1108 #else
1109 # define check_match(s, start, match, length)
1110 #endif
1111
1112 /* ===========================================================================
1113 * Fill the window when the lookahead becomes insufficient.
1114 * Updates strstart and lookahead.
1115 *
1116 * IN assertion: lookahead < MIN_LOOKAHEAD
1117 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1118 * At least one byte has been read, or avail_in == 0; reads are
1119 * performed for at least two bytes (required for the zip translate_eol
1120 * option -- not supported here).
1121 */
1122 local void fill_window(s)
1123 deflate_state *s;
1124 {
1125 unsigned n, m;
1126 Posf *p;
1127 unsigned more; /* Amount of free space at the end of the window. */
1128 uInt wsize = s->w_size;
1129
1130 do {
1131 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1132
1133 /* Deal with !@#$% 64K limit: */
1134 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1135 more = wsize;
1136 } else if (more == (unsigned)(-1)) {
1137 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1138 * and lookahead == 1 (input done one byte at time)
1139 */
1140 more--;
1141
1142 /* If the window is almost full and there is insufficient lookahead,
1143 * move the upper half to the lower one to make room in the upper half.
1144 */
1145 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1146
1147 /* By the IN assertion, the window is not empty so we can't confuse
1148 * more == 0 with more == 64K on a 16 bit machine.
1149 */
1150 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1151 (unsigned)wsize);
1152 s->match_start -= wsize;
1153 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1154
1155 s->block_start -= (long) wsize;
1156
1157 /* Slide the hash table (could be avoided with 32 bit values
1158 at the expense of memory usage):
1159 */
1160 n = s->hash_size;
1161 p = &s->head[n];
1162 do {
1163 m = *--p;
1164 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1165 } while (--n);
1166
1167 n = wsize;
1168 p = &s->prev[n];
1169 do {
1170 m = *--p;
1171 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1172 /* If n is not on any hash chain, prev[n] is garbage but
1173 * its value will never be used.
1174 */
1175 } while (--n);
1176
1177 more += wsize;
1178 }
1179 if (s->strm->avail_in == 0) return;
1180
1181 /* If there was no sliding:
1182 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1183 * more == window_size - lookahead - strstart
1184 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1185 * => more >= window_size - 2*WSIZE + 2
1186 * In the BIG_MEM or MMAP case (not yet supported),
1187 * window_size == input_size + MIN_LOOKAHEAD &&
1188 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1189 * Otherwise, window_size == 2*WSIZE so more >= 2.
1190 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1191 */
1192 Assert(more >= 2, "more < 2");
1193
1194 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1195 more);
1196 s->lookahead += n;
1197
1198 /* Initialize the hash value now that we have some input: */
1199 if (s->lookahead >= MIN_MATCH) {
1200 s->ins_h = s->window[s->strstart];
1201 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1202 #if MIN_MATCH != 3
1203 Call UPDATE_HASH() MIN_MATCH-3 more times
1204 #endif
1205 }
1206 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1207 * but this is not important since only literal bytes will be emitted.
1208 */
1209
1210 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1211 }
1212
1213 /* ===========================================================================
1214 * Flush the current block, with given end-of-file flag.
1215 * IN assertion: strstart is set to the end of the current match.
1216 */
1217 #define FLUSH_BLOCK_ONLY(s, flush) { \
1218 ct_flush_block(s, (s->block_start >= 0L ? \
1219 (charf *)&s->window[(unsigned)s->block_start] : \
1220 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1221 s->block_start = s->strstart; \
1222 flush_pending(s->strm); \
1223 Tracev((stderr,"[FLUSH]")); \
1224 }
1225
1226 /* Same but force premature exit if necessary. */
1227 #define FLUSH_BLOCK(s, flush) { \
1228 FLUSH_BLOCK_ONLY(s, flush); \
1229 if (s->strm->avail_out == 0) return 1; \
1230 }
1231
1232 /* ===========================================================================
1233 * Compress as much as possible from the input stream, return true if
1234 * processing was terminated prematurely (no more input or output space).
1235 * This function does not perform lazy evaluationof matches and inserts
1236 * new strings in the dictionary only for unmatched strings or for short
1237 * matches. It is used only for the fast compression options.
1238 */
1239 local int deflate_fast(s, flush)
1240 deflate_state *s;
1241 int flush;
1242 {
1243 IPos hash_head = NIL; /* head of the hash chain */
1244 int bflush; /* set if current block must be flushed */
1245
1246 s->prev_length = MIN_MATCH-1;
1247
1248 for (;;) {
1249 /* Make sure that we always have enough lookahead, except
1250 * at the end of the input file. We need MAX_MATCH bytes
1251 * for the next match, plus MIN_MATCH bytes to insert the
1252 * string following the next match.
1253 */
1254 if (s->lookahead < MIN_LOOKAHEAD) {
1255 fill_window(s);
1256 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1257
1258 if (s->lookahead == 0) break; /* flush the current block */
1259 }
1260
1261 /* Insert the string window[strstart .. strstart+2] in the
1262 * dictionary, and set hash_head to the head of the hash chain:
1263 */
1264 if (s->lookahead >= MIN_MATCH) {
1265 INSERT_STRING(s, s->strstart, hash_head);
1266 }
1267
1268 /* Find the longest match, discarding those <= prev_length.
1269 * At this point we have always match_length < MIN_MATCH
1270 */
1271 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1272 /* To simplify the code, we prevent matches with the string
1273 * of window index 0 (in particular we have to avoid a match
1274 * of the string with itself at the start of the input file).
1275 */
1276 if (s->strategy != Z_HUFFMAN_ONLY) {
1277 s->match_length = longest_match (s, hash_head);
1278 }
1279 /* longest_match() sets match_start */
1280
1281 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1282 }
1283 if (s->match_length >= MIN_MATCH) {
1284 check_match(s, s->strstart, s->match_start, s->match_length);
1285
1286 bflush = ct_tally(s, s->strstart - s->match_start,
1287 s->match_length - MIN_MATCH);
1288
1289 s->lookahead -= s->match_length;
1290
1291 /* Insert new strings in the hash table only if the match length
1292 * is not too large. This saves time but degrades compression.
1293 */
1294 if (s->match_length <= s->max_insert_length &&
1295 s->lookahead >= MIN_MATCH) {
1296 s->match_length--; /* string at strstart already in hash table */
1297 do {
1298 s->strstart++;
1299 INSERT_STRING(s, s->strstart, hash_head);
1300 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1301 * always MIN_MATCH bytes ahead.
1302 */
1303 } while (--s->match_length != 0);
1304 s->strstart++;
1305 } else {
1306 s->strstart += s->match_length;
1307 s->match_length = 0;
1308 s->ins_h = s->window[s->strstart];
1309 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1310 #if MIN_MATCH != 3
1311 Call UPDATE_HASH() MIN_MATCH-3 more times
1312 #endif
1313 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1314 * matter since it will be recomputed at next deflate call.
1315 */
1316 }
1317 } else {
1318 /* No match, output a literal byte */
1319 Tracevv((stderr,"%c", s->window[s->strstart]));
1320 bflush = ct_tally (s, 0, s->window[s->strstart]);
1321 s->lookahead--;
1322 s->strstart++;
1323 }
1324 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1325 }
1326 FLUSH_BLOCK(s, flush);
1327 return 0; /* normal exit */
1328 }
1329
1330 /* ===========================================================================
1331 * Same as above, but achieves better compression. We use a lazy
1332 * evaluation for matches: a match is finally adopted only if there is
1333 * no better match at the next window position.
1334 */
1335 local int deflate_slow(s, flush)
1336 deflate_state *s;
1337 int flush;
1338 {
1339 IPos hash_head = NIL; /* head of hash chain */
1340 int bflush; /* set if current block must be flushed */
1341
1342 /* Process the input block. */
1343 for (;;) {
1344 /* Make sure that we always have enough lookahead, except
1345 * at the end of the input file. We need MAX_MATCH bytes
1346 * for the next match, plus MIN_MATCH bytes to insert the
1347 * string following the next match.
1348 */
1349 if (s->lookahead < MIN_LOOKAHEAD) {
1350 fill_window(s);
1351 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1352
1353 if (s->lookahead == 0) break; /* flush the current block */
1354 }
1355
1356 /* Insert the string window[strstart .. strstart+2] in the
1357 * dictionary, and set hash_head to the head of the hash chain:
1358 */
1359 if (s->lookahead >= MIN_MATCH) {
1360 INSERT_STRING(s, s->strstart, hash_head);
1361 }
1362
1363 /* Find the longest match, discarding those <= prev_length.
1364 */
1365 s->prev_length = s->match_length, s->prev_match = s->match_start;
1366 s->match_length = MIN_MATCH-1;
1367
1368 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1369 s->strstart - hash_head <= MAX_DIST(s)) {
1370 /* To simplify the code, we prevent matches with the string
1371 * of window index 0 (in particular we have to avoid a match
1372 * of the string with itself at the start of the input file).
1373 */
1374 if (s->strategy != Z_HUFFMAN_ONLY) {
1375 s->match_length = longest_match (s, hash_head);
1376 }
1377 /* longest_match() sets match_start */
1378 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1379
1380 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1381 (s->match_length == MIN_MATCH &&
1382 s->strstart - s->match_start > TOO_FAR))) {
1383
1384 /* If prev_match is also MIN_MATCH, match_start is garbage
1385 * but we will ignore the current match anyway.
1386 */
1387 s->match_length = MIN_MATCH-1;
1388 }
1389 }
1390 /* If there was a match at the previous step and the current
1391 * match is not better, output the previous match:
1392 */
1393 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1394 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1395 /* Do not insert strings in hash table beyond this. */
1396
1397 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1398
1399 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1400 s->prev_length - MIN_MATCH);
1401
1402 /* Insert in hash table all strings up to the end of the match.
1403 * strstart-1 and strstart are already inserted. If there is not
1404 * enough lookahead, the last two strings are not inserted in
1405 * the hash table.
1406 */
1407 s->lookahead -= s->prev_length-1;
1408 s->prev_length -= 2;
1409 do {
1410 if (++s->strstart <= max_insert) {
1411 INSERT_STRING(s, s->strstart, hash_head);
1412 }
1413 } while (--s->prev_length != 0);
1414 s->match_available = 0;
1415 s->match_length = MIN_MATCH-1;
1416 s->strstart++;
1417
1418 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1419
1420 } else if (s->match_available) {
1421 /* If there was no match at the previous position, output a
1422 * single literal. If there was a match but the current match
1423 * is longer, truncate the previous match to a single literal.
1424 */
1425 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1426 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1427 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1428 }
1429 s->strstart++;
1430 s->lookahead--;
1431 if (s->strm->avail_out == 0) return 1;
1432 } else {
1433 /* There is no previous match to compare with, wait for
1434 * the next step to decide.
1435 */
1436 s->match_available = 1;
1437 s->strstart++;
1438 s->lookahead--;
1439 }
1440 }
1441 Assert (flush != Z_NO_FLUSH, "no flush?");
1442 if (s->match_available) {
1443 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1444 ct_tally (s, 0, s->window[s->strstart-1]);
1445 s->match_available = 0;
1446 }
1447 FLUSH_BLOCK(s, flush);
1448 return 0;
1449 }
1450
1451
1452 /*+++++*/
1453 /* trees.c -- output deflated data using Huffman coding
1454 * Copyright (C) 1995 Jean-loup Gailly
1455 * For conditions of distribution and use, see copyright notice in zlib.h
1456 */
1457
1458 /*
1459 * ALGORITHM
1460 *
1461 * The "deflation" process uses several Huffman trees. The more
1462 * common source values are represented by shorter bit sequences.
1463 *
1464 * Each code tree is stored in a compressed form which is itself
1465 * a Huffman encoding of the lengths of all the code strings (in
1466 * ascending order by source values). The actual code strings are
1467 * reconstructed from the lengths in the inflate process, as described
1468 * in the deflate specification.
1469 *
1470 * REFERENCES
1471 *
1472 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1473 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1474 *
1475 * Storer, James A.
1476 * Data Compression: Methods and Theory, pp. 49-50.
1477 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1478 *
1479 * Sedgewick, R.
1480 * Algorithms, p290.
1481 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1482 */
1483
1484 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1485
1486 #ifdef DEBUG_ZLIB
1487 # include <ctype.h>
1488 #endif
1489
1490 /* ===========================================================================
1491 * Constants
1492 */
1493
1494 #define MAX_BL_BITS 7
1495 /* Bit length codes must not exceed MAX_BL_BITS bits */
1496
1497 #define END_BLOCK 256
1498 /* end of block literal code */
1499
1500 #define REP_3_6 16
1501 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1502
1503 #define REPZ_3_10 17
1504 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1505
1506 #define REPZ_11_138 18
1507 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1508
1509 local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1510 = {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};
1511
1512 local const int extra_dbits[D_CODES] /* extra bits for each distance code */
1513 = {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};
1514
1515 local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1516 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1517
1518 local const uch bl_order[BL_CODES]
1519 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1520 /* The lengths of the bit length codes are sent in order of decreasing
1521 * probability, to avoid transmitting the lengths for unused bit length codes.
1522 */
1523
1524 #define Buf_size (8 * 2*sizeof(char))
1525 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1526 * more than 16 bits on some systems.)
1527 */
1528
1529 /* ===========================================================================
1530 * Local data. These are initialized only once.
1531 * To do: initialize at compile time to be completely reentrant. ???
1532 */
1533
1534 local ct_data static_ltree[L_CODES+2];
1535 /* The static literal tree. Since the bit lengths are imposed, there is no
1536 * need for the L_CODES extra codes used during heap construction. However
1537 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1538 * below).
1539 */
1540
1541 local ct_data static_dtree[D_CODES];
1542 /* The static distance tree. (Actually a trivial tree since all codes use
1543 * 5 bits.)
1544 */
1545
1546 local uch dist_code[512];
1547 /* distance codes. The first 256 values correspond to the distances
1548 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1549 * the 15 bit distances.
1550 */
1551
1552 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1553 /* length code for each normalized match length (0 == MIN_MATCH) */
1554
1555 local int base_length[LENGTH_CODES];
1556 /* First normalized length for each code (0 = MIN_MATCH) */
1557
1558 local int base_dist[D_CODES];
1559 /* First normalized distance for each code (0 = distance of 1) */
1560
1561 struct static_tree_desc_s {
1562 ct_data *static_tree; /* static tree or NULL */
1563 const intf *extra_bits; /* extra bits for each code or NULL */
1564 int extra_base; /* base index for extra_bits */
1565 int elems; /* max number of elements in the tree */
1566 int max_length; /* max bit length for the codes */
1567 };
1568
1569 local const static_tree_desc static_l_desc =
1570 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1571
1572 local const static_tree_desc static_d_desc =
1573 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1574
1575 local const static_tree_desc static_bl_desc =
1576 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1577
1578 /* ===========================================================================
1579 * Local (static) routines in this file.
1580 */
1581
1582 local void ct_static_init OF((void));
1583 local void init_block OF((deflate_state *s));
1584 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1585 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1586 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1587 local void build_tree OF((deflate_state *s, tree_desc *desc));
1588 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1589 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1590 local int build_bl_tree OF((deflate_state *s));
1591 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1592 int blcodes));
1593 local void compress_block OF((deflate_state *s, ct_data *ltree,
1594 ct_data *dtree));
1595 local void set_data_type OF((deflate_state *s));
1596 local unsigned bi_reverse OF((unsigned value, int length));
1597 local void bi_windup OF((deflate_state *s));
1598 local void bi_flush OF((deflate_state *s));
1599 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1600 int header));
1601
1602 #ifndef DEBUG_ZLIB
1603 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1604 /* Send a code of the given tree. c and tree must not have side effects */
1605
1606 #else /* DEBUG_ZLIB */
1607 # define send_code(s, c, tree) \
1608 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1609 send_bits(s, tree[c].Code, tree[c].Len); }
1610 #endif
1611
1612 #define d_code(dist) \
1613 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1614 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1615 * must not have side effects. dist_code[256] and dist_code[257] are never
1616 * used.
1617 */
1618
1619 /* ===========================================================================
1620 * Output a short LSB first on the stream.
1621 * IN assertion: there is enough room in pendingBuf.
1622 */
1623 #define put_short(s, w) { \
1624 put_byte(s, (uch)((w) & 0xff)); \
1625 put_byte(s, (uch)((ush)(w) >> 8)); \
1626 }
1627
1628 /* ===========================================================================
1629 * Send a value on a given number of bits.
1630 * IN assertion: length <= 16 and value fits in length bits.
1631 */
1632 #ifdef DEBUG_ZLIB
1633 local void send_bits OF((deflate_state *s, int value, int length));
1634
1635 local void send_bits(s, value, length)
1636 deflate_state *s;
1637 int value; /* value to send */
1638 int length; /* number of bits */
1639 {
1640 Tracev((stderr," l %2d v %4x ", length, value));
1641 Assert(length > 0 && length <= 15, "invalid length");
1642 s->bits_sent += (ulg)length;
1643
1644 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1645 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1646 * unused bits in value.
1647 */
1648 if (s->bi_valid > (int)Buf_size - length) {
1649 s->bi_buf |= (value << s->bi_valid);
1650 put_short(s, s->bi_buf);
1651 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1652 s->bi_valid += length - Buf_size;
1653 } else {
1654 s->bi_buf |= value << s->bi_valid;
1655 s->bi_valid += length;
1656 }
1657 }
1658 #else /* !DEBUG_ZLIB */
1659
1660 #define send_bits(s, value, length) \
1661 { int len = length;\
1662 if (s->bi_valid > (int)Buf_size - len) {\
1663 int val = value;\
1664 s->bi_buf |= (val << s->bi_valid);\
1665 put_short(s, s->bi_buf);\
1666 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1667 s->bi_valid += len - Buf_size;\
1668 } else {\
1669 s->bi_buf |= (value) << s->bi_valid;\
1670 s->bi_valid += len;\
1671 }\
1672 }
1673 #endif /* DEBUG_ZLIB */
1674
1675
1676 /* the arguments must not have side effects */
1677
1678 /* ===========================================================================
1679 * Initialize the various 'constant' tables.
1680 * To do: do this at compile time.
1681 */
1682 local void ct_static_init()
1683 {
1684 int n; /* iterates over tree elements */
1685 int bits; /* bit counter */
1686 int length; /* length value */
1687 int code; /* code value */
1688 int dist; /* distance index */
1689 ush bl_count[MAX_BITS+1];
1690 /* number of codes at each bit length for an optimal tree */
1691
1692 /* Initialize the mapping length (0..255) -> length code (0..28) */
1693 length = 0;
1694 for (code = 0; code < LENGTH_CODES-1; code++) {
1695 base_length[code] = length;
1696 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1697 length_code[length++] = (uch)code;
1698 }
1699 }
1700 Assert (length == 256, "ct_static_init: length != 256");
1701 /* Note that the length 255 (match length 258) can be represented
1702 * in two different ways: code 284 + 5 bits or code 285, so we
1703 * overwrite length_code[255] to use the best encoding:
1704 */
1705 length_code[length-1] = (uch)code;
1706
1707 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1708 dist = 0;
1709 for (code = 0 ; code < 16; code++) {
1710 base_dist[code] = dist;
1711 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1712 dist_code[dist++] = (uch)code;
1713 }
1714 }
1715 Assert (dist == 256, "ct_static_init: dist != 256");
1716 dist >>= 7; /* from now on, all distances are divided by 128 */
1717 for ( ; code < D_CODES; code++) {
1718 base_dist[code] = dist << 7;
1719 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1720 dist_code[256 + dist++] = (uch)code;
1721 }
1722 }
1723 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1724
1725 /* Construct the codes of the static literal tree */
1726 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1727 n = 0;
1728 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1729 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1730 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1731 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1732 /* Codes 286 and 287 do not exist, but we must include them in the
1733 * tree construction to get a canonical Huffman tree (longest code
1734 * all ones)
1735 */
1736 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1737
1738 /* The static distance tree is trivial: */
1739 for (n = 0; n < D_CODES; n++) {
1740 static_dtree[n].Len = 5;
1741 static_dtree[n].Code = bi_reverse(n, 5);
1742 }
1743 }
1744
1745 /* ===========================================================================
1746 * Initialize the tree data structures for a new zlib stream.
1747 */
1748 local void ct_init(s)
1749 deflate_state *s;
1750 {
1751 if (static_dtree[0].Len == 0) {
1752 ct_static_init(); /* To do: at compile time */
1753 }
1754
1755 s->compressed_len = 0L;
1756
1757 s->l_desc.dyn_tree = s->dyn_ltree;
1758 s->l_desc.stat_desc = &static_l_desc;
1759
1760 s->d_desc.dyn_tree = s->dyn_dtree;
1761 s->d_desc.stat_desc = &static_d_desc;
1762
1763 s->bl_desc.dyn_tree = s->bl_tree;
1764 s->bl_desc.stat_desc = &static_bl_desc;
1765
1766 s->bi_buf = 0;
1767 s->bi_valid = 0;
1768 s->last_eob_len = 8; /* enough lookahead for inflate */
1769 #ifdef DEBUG_ZLIB
1770 s->bits_sent = 0L;
1771 #endif
1772 s->blocks_in_packet = 0;
1773
1774 /* Initialize the first block of the first file: */
1775 init_block(s);
1776 }
1777
1778 /* ===========================================================================
1779 * Initialize a new block.
1780 */
1781 local void init_block(s)
1782 deflate_state *s;
1783 {
1784 int n; /* iterates over tree elements */
1785
1786 /* Initialize the trees. */
1787 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1788 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1789 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1790
1791 s->dyn_ltree[END_BLOCK].Freq = 1;
1792 s->opt_len = s->static_len = 0L;
1793 s->last_lit = s->matches = 0;
1794 }
1795
1796 #define SMALLEST 1
1797 /* Index within the heap array of least frequent node in the Huffman tree */
1798
1799
1800 /* ===========================================================================
1801 * Remove the smallest element from the heap and recreate the heap with
1802 * one less element. Updates heap and heap_len.
1803 */
1804 #define pqremove(s, tree, top) \
1805 {\
1806 top = s->heap[SMALLEST]; \
1807 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1808 pqdownheap(s, tree, SMALLEST); \
1809 }
1810
1811 /* ===========================================================================
1812 * Compares to subtrees, using the tree depth as tie breaker when
1813 * the subtrees have equal frequency. This minimizes the worst case length.
1814 */
1815 #define smaller(tree, n, m, depth) \
1816 (tree[n].Freq < tree[m].Freq || \
1817 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1818
1819 /* ===========================================================================
1820 * Restore the heap property by moving down the tree starting at node k,
1821 * exchanging a node with the smallest of its two sons if necessary, stopping
1822 * when the heap property is re-established (each father smaller than its
1823 * two sons).
1824 */
1825 local void pqdownheap(s, tree, k)
1826 deflate_state *s;
1827 ct_data *tree; /* the tree to restore */
1828 int k; /* node to move down */
1829 {
1830 int v = s->heap[k];
1831 int j = k << 1; /* left son of k */
1832 while (j <= s->heap_len) {
1833 /* Set j to the smallest of the two sons: */
1834 if (j < s->heap_len &&
1835 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1836 j++;
1837 }
1838 /* Exit if v is smaller than both sons */
1839 if (smaller(tree, v, s->heap[j], s->depth)) break;
1840
1841 /* Exchange v with the smallest son */
1842 s->heap[k] = s->heap[j]; k = j;
1843
1844 /* And continue down the tree, setting j to the left son of k */
1845 j <<= 1;
1846 }
1847 s->heap[k] = v;
1848 }
1849
1850 /* ===========================================================================
1851 * Compute the optimal bit lengths for a tree and update the total bit length
1852 * for the current block.
1853 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1854 * above are the tree nodes sorted by increasing frequency.
1855 * OUT assertions: the field len is set to the optimal bit length, the
1856 * array bl_count contains the frequencies for each bit length.
1857 * The length opt_len is updated; static_len is also updated if stree is
1858 * not null.
1859 */
1860 local void gen_bitlen(s, desc)
1861 deflate_state *s;
1862 tree_desc *desc; /* the tree descriptor */
1863 {
1864 ct_data *tree = desc->dyn_tree;
1865 int max_code = desc->max_code;
1866 ct_data *stree = desc->stat_desc->static_tree;
1867 const intf *extra = desc->stat_desc->extra_bits;
1868 int base = desc->stat_desc->extra_base;
1869 int max_length = desc->stat_desc->max_length;
1870 int h; /* heap index */
1871 int n, m; /* iterate over the tree elements */
1872 int bits; /* bit length */
1873 int xbits; /* extra bits */
1874 ush f; /* frequency */
1875 int overflow = 0; /* number of elements with bit length too large */
1876
1877 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1878
1879 /* In a first pass, compute the optimal bit lengths (which may
1880 * overflow in the case of the bit length tree).
1881 */
1882 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1883
1884 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1885 n = s->heap[h];
1886 bits = tree[tree[n].Dad].Len + 1;
1887 if (bits > max_length) bits = max_length, overflow++;
1888 tree[n].Len = (ush)bits;
1889 /* We overwrite tree[n].Dad which is no longer needed */
1890
1891 if (n > max_code) continue; /* not a leaf node */
1892
1893 s->bl_count[bits]++;
1894 xbits = 0;
1895 if (n >= base) xbits = extra[n-base];
1896 f = tree[n].Freq;
1897 s->opt_len += (ulg)f * (bits + xbits);
1898 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1899 }
1900 if (overflow == 0) return;
1901
1902 Trace((stderr,"\nbit length overflow\n"));
1903 /* This happens for example on obj2 and pic of the Calgary corpus */
1904
1905 /* Find the first bit length which could increase: */
1906 do {
1907 bits = max_length-1;
1908 while (s->bl_count[bits] == 0) bits--;
1909 s->bl_count[bits]--; /* move one leaf down the tree */
1910 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1911 s->bl_count[max_length]--;
1912 /* The brother of the overflow item also moves one step up,
1913 * but this does not affect bl_count[max_length]
1914 */
1915 overflow -= 2;
1916 } while (overflow > 0);
1917
1918 /* Now recompute all bit lengths, scanning in increasing frequency.
1919 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1920 * lengths instead of fixing only the wrong ones. This idea is taken
1921 * from 'ar' written by Haruhiko Okumura.)
1922 */
1923 for (bits = max_length; bits != 0; bits--) {
1924 n = s->bl_count[bits];
1925 while (n != 0) {
1926 m = s->heap[--h];
1927 if (m > max_code) continue;
1928 if (tree[m].Len != (unsigned) bits) {
1929 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1930 s->opt_len += ((long)bits - (long)tree[m].Len)
1931 *(long)tree[m].Freq;
1932 tree[m].Len = (ush)bits;
1933 }
1934 n--;
1935 }
1936 }
1937 }
1938
1939 /* ===========================================================================
1940 * Generate the codes for a given tree and bit counts (which need not be
1941 * optimal).
1942 * IN assertion: the array bl_count contains the bit length statistics for
1943 * the given tree and the field len is set for all tree elements.
1944 * OUT assertion: the field code is set for all tree elements of non
1945 * zero code length.
1946 */
1947 local void gen_codes (tree, max_code, bl_count)
1948 ct_data *tree; /* the tree to decorate */
1949 int max_code; /* largest code with non zero frequency */
1950 ushf *bl_count; /* number of codes at each bit length */
1951 {
1952 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1953 ush code = 0; /* running code value */
1954 int bits; /* bit index */
1955 int n; /* code index */
1956
1957 /* The distribution counts are first used to generate the code values
1958 * without bit reversal.
1959 */
1960 for (bits = 1; bits <= MAX_BITS; bits++) {
1961 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1962 }
1963 /* Check that the bit counts in bl_count are consistent. The last code
1964 * must be all ones.
1965 */
1966 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1967 "inconsistent bit counts");
1968 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1969
1970 for (n = 0; n <= max_code; n++) {
1971 int len = tree[n].Len;
1972 if (len == 0) continue;
1973 /* Now reverse the bits */
1974 tree[n].Code = bi_reverse(next_code[len]++, len);
1975
1976 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1977 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1978 }
1979 }
1980
1981 /* ===========================================================================
1982 * Construct one Huffman tree and assigns the code bit strings and lengths.
1983 * Update the total bit length for the current block.
1984 * IN assertion: the field freq is set for all tree elements.
1985 * OUT assertions: the fields len and code are set to the optimal bit length
1986 * and corresponding code. The length opt_len is updated; static_len is
1987 * also updated if stree is not null. The field max_code is set.
1988 */
1989 local void build_tree(s, desc)
1990 deflate_state *s;
1991 tree_desc *desc; /* the tree descriptor */
1992 {
1993 ct_data *tree = desc->dyn_tree;
1994 ct_data *stree = desc->stat_desc->static_tree;
1995 int elems = desc->stat_desc->elems;
1996 int n, m; /* iterate over heap elements */
1997 int max_code = -1; /* largest code with non zero frequency */
1998 int node; /* new node being created */
1999
2000 /* Construct the initial heap, with least frequent element in
2001 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2002 * heap[0] is not used.
2003 */
2004 s->heap_len = 0, s->heap_max = HEAP_SIZE;
2005
2006 for (n = 0; n < elems; n++) {
2007 if (tree[n].Freq != 0) {
2008 s->heap[++(s->heap_len)] = max_code = n;
2009 s->depth[n] = 0;
2010 } else {
2011 tree[n].Len = 0;
2012 }
2013 }
2014
2015 /* The pkzip format requires that at least one distance code exists,
2016 * and that at least one bit should be sent even if there is only one
2017 * possible code. So to avoid special checks later on we force at least
2018 * two codes of non zero frequency.
2019 */
2020 while (s->heap_len < 2) {
2021 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2022 tree[node].Freq = 1;
2023 s->depth[node] = 0;
2024 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2025 /* node is 0 or 1 so it does not have extra bits */
2026 }
2027 desc->max_code = max_code;
2028
2029 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2030 * establish sub-heaps of increasing lengths:
2031 */
2032 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2033
2034 /* Construct the Huffman tree by repeatedly combining the least two
2035 * frequent nodes.
2036 */
2037 node = elems; /* next internal node of the tree */
2038 do {
2039 pqremove(s, tree, n); /* n = node of least frequency */
2040 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2041
2042 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2043 s->heap[--(s->heap_max)] = m;
2044
2045 /* Create a new node father of n and m */
2046 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2047 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2048 tree[n].Dad = tree[m].Dad = (ush)node;
2049 #ifdef DUMP_BL_TREE
2050 if (tree == s->bl_tree) {
2051 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2052 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2053 }
2054 #endif
2055 /* and insert the new node in the heap */
2056 s->heap[SMALLEST] = node++;
2057 pqdownheap(s, tree, SMALLEST);
2058
2059 } while (s->heap_len >= 2);
2060
2061 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2062
2063 /* At this point, the fields freq and dad are set. We can now
2064 * generate the bit lengths.
2065 */
2066 gen_bitlen(s, (tree_desc *)desc);
2067
2068 /* The field len is now set, we can generate the bit codes */
2069 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2070 }
2071
2072 /* ===========================================================================
2073 * Scan a literal or distance tree to determine the frequencies of the codes
2074 * in the bit length tree.
2075 */
2076 local void scan_tree (s, tree, max_code)
2077 deflate_state *s;
2078 ct_data *tree; /* the tree to be scanned */
2079 int max_code; /* and its largest code of non zero frequency */
2080 {
2081 int n; /* iterates over all tree elements */
2082 int prevlen = -1; /* last emitted length */
2083 int curlen; /* length of current code */
2084 int nextlen = tree[0].Len; /* length of next code */
2085 int count = 0; /* repeat count of the current code */
2086 int max_count = 7; /* max repeat count */
2087 int min_count = 4; /* min repeat count */
2088
2089 if (nextlen == 0) max_count = 138, min_count = 3;
2090 tree[max_code+1].Len = (ush)0xffff; /* guard */
2091
2092 for (n = 0; n <= max_code; n++) {
2093 curlen = nextlen; nextlen = tree[n+1].Len;
2094 if (++count < max_count && curlen == nextlen) {
2095 continue;
2096 } else if (count < min_count) {
2097 s->bl_tree[curlen].Freq += count;
2098 } else if (curlen != 0) {
2099 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2100 s->bl_tree[REP_3_6].Freq++;
2101 } else if (count <= 10) {
2102 s->bl_tree[REPZ_3_10].Freq++;
2103 } else {
2104 s->bl_tree[REPZ_11_138].Freq++;
2105 }
2106 count = 0; prevlen = curlen;
2107 if (nextlen == 0) {
2108 max_count = 138, min_count = 3;
2109 } else if (curlen == nextlen) {
2110 max_count = 6, min_count = 3;
2111 } else {
2112 max_count = 7, min_count = 4;
2113 }
2114 }
2115 }
2116
2117 /* ===========================================================================
2118 * Send a literal or distance tree in compressed form, using the codes in
2119 * bl_tree.
2120 */
2121 local void send_tree (s, tree, max_code)
2122 deflate_state *s;
2123 ct_data *tree; /* the tree to be scanned */
2124 int max_code; /* and its largest code of non zero frequency */
2125 {
2126 int n; /* iterates over all tree elements */
2127 int prevlen = -1; /* last emitted length */
2128 int curlen; /* length of current code */
2129 int nextlen = tree[0].Len; /* length of next code */
2130 int count = 0; /* repeat count of the current code */
2131 int max_count = 7; /* max repeat count */
2132 int min_count = 4; /* min repeat count */
2133
2134 /* tree[max_code+1].Len = -1; */ /* guard already set */
2135 if (nextlen == 0) max_count = 138, min_count = 3;
2136
2137 for (n = 0; n <= max_code; n++) {
2138 curlen = nextlen; nextlen = tree[n+1].Len;
2139 if (++count < max_count && curlen == nextlen) {
2140 continue;
2141 } else if (count < min_count) {
2142 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2143
2144 } else if (curlen != 0) {
2145 if (curlen != prevlen) {
2146 send_code(s, curlen, s->bl_tree); count--;
2147 }
2148 Assert(count >= 3 && count <= 6, " 3_6?");
2149 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2150
2151 } else if (count <= 10) {
2152 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2153
2154 } else {
2155 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2156 }
2157 count = 0; prevlen = curlen;
2158 if (nextlen == 0) {
2159 max_count = 138, min_count = 3;
2160 } else if (curlen == nextlen) {
2161 max_count = 6, min_count = 3;
2162 } else {
2163 max_count = 7, min_count = 4;
2164 }
2165 }
2166 }
2167
2168 /* ===========================================================================
2169 * Construct the Huffman tree for the bit lengths and return the index in
2170 * bl_order of the last bit length code to send.
2171 */
2172 local int build_bl_tree(s)
2173 deflate_state *s;
2174 {
2175 int max_blindex; /* index of last bit length code of non zero freq */
2176
2177 /* Determine the bit length frequencies for literal and distance trees */
2178 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2179 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2180
2181 /* Build the bit length tree: */
2182 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2183 /* opt_len now includes the length of the tree representations, except
2184 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2185 */
2186
2187 /* Determine the number of bit length codes to send. The pkzip format
2188 * requires that at least 4 bit length codes be sent. (appnote.txt says
2189 * 3 but the actual value used is 4.)
2190 */
2191 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2192 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2193 }
2194 /* Update opt_len to include the bit length tree and counts */
2195 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2196 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2197 s->opt_len, s->static_len));
2198
2199 return max_blindex;
2200 }
2201
2202 /* ===========================================================================
2203 * Send the header for a block using dynamic Huffman trees: the counts, the
2204 * lengths of the bit length codes, the literal tree and the distance tree.
2205 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2206 */
2207 local void send_all_trees(s, lcodes, dcodes, blcodes)
2208 deflate_state *s;
2209 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2210 {
2211 int rank; /* index in bl_order */
2212
2213 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2214 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2215 "too many codes");
2216 Tracev((stderr, "\nbl counts: "));
2217 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2218 send_bits(s, dcodes-1, 5);
2219 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2220 for (rank = 0; rank < blcodes; rank++) {
2221 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2222 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2223 }
2224 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2225
2226 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2227 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2228
2229 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2230 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2231 }
2232
2233 /* ===========================================================================
2234 * Send a stored block
2235 */
2236 local void ct_stored_block(s, buf, stored_len, eof)
2237 deflate_state *s;
2238 charf *buf; /* input block */
2239 ulg stored_len; /* length of input block */
2240 int eof; /* true if this is the last block for a file */
2241 {
2242 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2243 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2244 s->compressed_len += (stored_len + 4) << 3;
2245
2246 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2247 }
2248
2249 /* Send just the `stored block' type code without any length bytes or data.
2250 */
2251 local void ct_stored_type_only(s)
2252 deflate_state *s;
2253 {
2254 send_bits(s, (STORED_BLOCK << 1), 3);
2255 bi_windup(s);
2256 s->compressed_len = (s->compressed_len + 3) & ~7L;
2257 }
2258
2259
2260 /* ===========================================================================
2261 * Send one empty static block to give enough lookahead for inflate.
2262 * This takes 10 bits, of which 7 may remain in the bit buffer.
2263 * The current inflate code requires 9 bits of lookahead. If the EOB
2264 * code for the previous block was coded on 5 bits or less, inflate
2265 * may have only 5+3 bits of lookahead to decode this EOB.
2266 * (There are no problems if the previous block is stored or fixed.)
2267 */
2268 local void ct_align(s)
2269 deflate_state *s;
2270 {
2271 send_bits(s, STATIC_TREES<<1, 3);
2272 send_code(s, END_BLOCK, static_ltree);
2273 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2274 bi_flush(s);
2275 /* Of the 10 bits for the empty block, we have already sent
2276 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2277 * block was thus its length plus what we have just sent.
2278 */
2279 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2280 send_bits(s, STATIC_TREES<<1, 3);
2281 send_code(s, END_BLOCK, static_ltree);
2282 s->compressed_len += 10L;
2283 bi_flush(s);
2284 }
2285 s->last_eob_len = 7;
2286 }
2287
2288 /* ===========================================================================
2289 * Determine the best encoding for the current block: dynamic trees, static
2290 * trees or store, and output the encoded block to the zip file. This function
2291 * returns the total compressed length for the file so far.
2292 */
2293 local ulg ct_flush_block(s, buf, stored_len, flush)
2294 deflate_state *s;
2295 charf *buf; /* input block, or NULL if too old */
2296 ulg stored_len; /* length of input block */
2297 int flush; /* Z_FINISH if this is the last block for a file */
2298 {
2299 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2300 int max_blindex; /* index of last bit length code of non zero freq */
2301 int eof = flush == Z_FINISH;
2302
2303 ++s->blocks_in_packet;
2304
2305 /* Check if the file is ascii or binary */
2306 if (s->data_type == UNKNOWN) set_data_type(s);
2307
2308 /* Construct the literal and distance trees */
2309 build_tree(s, (tree_desc *)(&(s->l_desc)));
2310 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2311 s->static_len));
2312
2313 build_tree(s, (tree_desc *)(&(s->d_desc)));
2314 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2315 s->static_len));
2316 /* At this point, opt_len and static_len are the total bit lengths of
2317 * the compressed block data, excluding the tree representations.
2318 */
2319
2320 /* Build the bit length tree for the above two trees, and get the index
2321 * in bl_order of the last bit length code to send.
2322 */
2323 max_blindex = build_bl_tree(s);
2324
2325 /* Determine the best encoding. Compute first the block length in bytes */
2326 opt_lenb = (s->opt_len+3+7)>>3;
2327 static_lenb = (s->static_len+3+7)>>3;
2328
2329 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2330 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2331 s->last_lit));
2332
2333 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2334
2335 /* If compression failed and this is the first and last block,
2336 * and if the .zip file can be seeked (to rewrite the local header),
2337 * the whole file is transformed into a stored file:
2338 */
2339 #ifdef STORED_FILE_OK
2340 # ifdef FORCE_STORED_FILE
2341 if (eof && compressed_len == 0L) /* force stored file */
2342 # else
2343 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2344 # endif
2345 {
2346 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2347 if (buf == (charf*)0) error ("block vanished");
2348
2349 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2350 s->compressed_len = stored_len << 3;
2351 s->method = STORED;
2352 } else
2353 #endif /* STORED_FILE_OK */
2354
2355 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2356 * compression, and this block contains all the data since the last
2357 * time we used Z_PACKET_FLUSH, then just omit this block completely
2358 * from the output.
2359 */
2360 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2361 && opt_lenb > stored_len - s->minCompr) {
2362 s->blocks_in_packet = 0;
2363 /* output nothing */
2364 } else
2365
2366 #ifdef FORCE_STORED
2367 if (buf != (char*)0) /* force stored block */
2368 #else
2369 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2370 /* 4: two words for the lengths */
2371 #endif
2372 {
2373 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2374 * Otherwise we can't have processed more than WSIZE input bytes since
2375 * the last block flush, because compression would have been
2376 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2377 * transform a block into a stored block.
2378 */
2379 ct_stored_block(s, buf, stored_len, eof);
2380 } else
2381
2382 #ifdef FORCE_STATIC
2383 if (static_lenb >= 0) /* force static trees */
2384 #else
2385 if (static_lenb == opt_lenb)
2386 #endif
2387 {
2388 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2389 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2390 s->compressed_len += 3 + s->static_len;
2391 } else {
2392 send_bits(s, (DYN_TREES<<1)+eof, 3);
2393 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2394 max_blindex+1);
2395 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2396 s->compressed_len += 3 + s->opt_len;
2397 }
2398 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2399 init_block(s);
2400
2401 if (eof) {
2402 bi_windup(s);
2403 s->compressed_len += 7; /* align on byte boundary */
2404 }
2405 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2406 s->compressed_len-7*eof));
2407
2408 return s->compressed_len >> 3;
2409 }
2410
2411 /* ===========================================================================
2412 * Save the match info and tally the frequency counts. Return true if
2413 * the current block must be flushed.
2414 */
2415 local int ct_tally (s, dist, lc)
2416 deflate_state *s;
2417 int dist; /* distance of matched string */
2418 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2419 {
2420 s->d_buf[s->last_lit] = (ush)dist;
2421 s->l_buf[s->last_lit++] = (uch)lc;
2422 if (dist == 0) {
2423 /* lc is the unmatched char */
2424 s->dyn_ltree[lc].Freq++;
2425 } else {
2426 s->matches++;
2427 /* Here, lc is the match length - MIN_MATCH */
2428 dist--; /* dist = match distance - 1 */
2429 Assert((ush)dist < (ush)MAX_DIST(s) &&
2430 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2431 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2432
2433 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2434 s->dyn_dtree[d_code(dist)].Freq++;
2435 }
2436
2437 /* Try to guess if it is profitable to stop the current block here */
2438 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2439 /* Compute an upper bound for the compressed length */
2440 ulg out_length = (ulg)s->last_lit*8L;
2441 ulg in_length = (ulg)s->strstart - s->block_start;
2442 int dcode;
2443 for (dcode = 0; dcode < D_CODES; dcode++) {
2444 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2445 (5L+extra_dbits[dcode]);
2446 }
2447 out_length >>= 3;
2448 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2449 s->last_lit, in_length, out_length,
2450 100L - out_length*100L/in_length));
2451 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2452 }
2453 return (s->last_lit == s->lit_bufsize-1);
2454 /* We avoid equality with lit_bufsize because of wraparound at 64K
2455 * on 16 bit machines and because stored blocks are restricted to
2456 * 64K-1 bytes.
2457 */
2458 }
2459
2460 /* ===========================================================================
2461 * Send the block data compressed using the given Huffman trees
2462 */
2463 local void compress_block(s, ltree, dtree)
2464 deflate_state *s;
2465 ct_data *ltree; /* literal tree */
2466 ct_data *dtree; /* distance tree */
2467 {
2468 unsigned dist; /* distance of matched string */
2469 int lc; /* match length or unmatched char (if dist == 0) */
2470 unsigned lx = 0; /* running index in l_buf */
2471 unsigned code; /* the code to send */
2472 int extra; /* number of extra bits to send */
2473
2474 if (s->last_lit != 0) do {
2475 dist = s->d_buf[lx];
2476 lc = s->l_buf[lx++];
2477 if (dist == 0) {
2478 send_code(s, lc, ltree); /* send a literal byte */
2479 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2480 } else {
2481 /* Here, lc is the match length - MIN_MATCH */
2482 code = length_code[lc];
2483 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2484 extra = extra_lbits[code];
2485 if (extra != 0) {
2486 lc -= base_length[code];
2487 send_bits(s, lc, extra); /* send the extra length bits */
2488 }
2489 dist--; /* dist is now the match distance - 1 */
2490 code = d_code(dist);
2491 Assert (code < D_CODES, "bad d_code");
2492
2493 send_code(s, code, dtree); /* send the distance code */
2494 extra = extra_dbits[code];
2495 if (extra != 0) {
2496 dist -= base_dist[code];
2497 send_bits(s, dist, extra); /* send the extra distance bits */
2498 }
2499 } /* literal or match pair ? */
2500
2501 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2502 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2503
2504 } while (lx < s->last_lit);
2505
2506 send_code(s, END_BLOCK, ltree);
2507 s->last_eob_len = ltree[END_BLOCK].Len;
2508 }
2509
2510 /* ===========================================================================
2511 * Set the data type to ASCII or BINARY, using a crude approximation:
2512 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2513 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2514 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2515 */
2516 local void set_data_type(s)
2517 deflate_state *s;
2518 {
2519 int n = 0;
2520 unsigned ascii_freq = 0;
2521 unsigned bin_freq = 0;
2522 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2523 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2524 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2525 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2526 }
2527
2528 /* ===========================================================================
2529 * Reverse the first len bits of a code, using straightforward code (a faster
2530 * method would use a table)
2531 * IN assertion: 1 <= len <= 15
2532 */
2533 local unsigned bi_reverse(code, len)
2534 unsigned code; /* the value to invert */
2535 int len; /* its bit length */
2536 {
2537 unsigned res = 0;
2538 do {
2539 res |= code & 1;
2540 code >>= 1, res <<= 1;
2541 } while (--len > 0);
2542 return res >> 1;
2543 }
2544
2545 /* ===========================================================================
2546 * Flush the bit buffer, keeping at most 7 bits in it.
2547 */
2548 local void bi_flush(s)
2549 deflate_state *s;
2550 {
2551 if (s->bi_valid == 16) {
2552 put_short(s, s->bi_buf);
2553 s->bi_buf = 0;
2554 s->bi_valid = 0;
2555 } else if (s->bi_valid >= 8) {
2556 put_byte(s, (Byte)s->bi_buf);
2557 s->bi_buf >>= 8;
2558 s->bi_valid -= 8;
2559 }
2560 }
2561
2562 /* ===========================================================================
2563 * Flush the bit buffer and align the output on a byte boundary
2564 */
2565 local void bi_windup(s)
2566 deflate_state *s;
2567 {
2568 if (s->bi_valid > 8) {
2569 put_short(s, s->bi_buf);
2570 } else if (s->bi_valid > 0) {
2571 put_byte(s, (Byte)s->bi_buf);
2572 }
2573 s->bi_buf = 0;
2574 s->bi_valid = 0;
2575 #ifdef DEBUG_ZLIB
2576 s->bits_sent = (s->bits_sent+7) & ~7;
2577 #endif
2578 }
2579
2580 /* ===========================================================================
2581 * Copy a stored block, storing first the length and its
2582 * one's complement if requested.
2583 */
2584 local void copy_block(s, buf, len, header)
2585 deflate_state *s;
2586 charf *buf; /* the input data */
2587 unsigned len; /* its length */
2588 int header; /* true if block header must be written */
2589 {
2590 bi_windup(s); /* align on byte boundary */
2591 s->last_eob_len = 8; /* enough lookahead for inflate */
2592
2593 if (header) {
2594 put_short(s, (ush)len);
2595 put_short(s, (ush)~len);
2596 #ifdef DEBUG_ZLIB
2597 s->bits_sent += 2*16;
2598 #endif
2599 }
2600 #ifdef DEBUG_ZLIB
2601 s->bits_sent += (ulg)len<<3;
2602 #endif
2603 while (len--) {
2604 put_byte(s, *buf++);
2605 }
2606 }
2607 #endif /* NO_DEFLATE */
2608
2609 /*+++++*/
2610 /* infblock.h -- header to use infblock.c
2611 * Copyright (C) 1995 Mark Adler
2612 * For conditions of distribution and use, see copyright notice in zlib.h
2613 */
2614
2615 /* WARNING: this file should *not* be used by applications. It is
2616 part of the implementation of the compression library and is
2617 subject to change. Applications should only use zlib.h.
2618 */
2619
2620 struct inflate_blocks_state;
2621 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2622
2623 local inflate_blocks_statef * inflate_blocks_new OF((
2624 z_stream *z,
2625 check_func c, /* check function */
2626 uInt w)); /* window size */
2627
2628 local int inflate_blocks OF((
2629 inflate_blocks_statef *,
2630 z_stream *,
2631 int)); /* initial return code */
2632
2633 local void inflate_blocks_reset OF((
2634 inflate_blocks_statef *,
2635 z_stream *,
2636 uLongf *)); /* check value on output */
2637
2638 local int inflate_blocks_free OF((
2639 inflate_blocks_statef *,
2640 z_stream *,
2641 uLongf *)); /* check value on output */
2642
2643 local int inflate_addhistory OF((
2644 inflate_blocks_statef *,
2645 z_stream *));
2646
2647 local int inflate_packet_flush OF((
2648 inflate_blocks_statef *));
2649
2650 /*+++++*/
2651 /* inftrees.h -- header to use inftrees.c
2652 * Copyright (C) 1995 Mark Adler
2653 * For conditions of distribution and use, see copyright notice in zlib.h
2654 */
2655
2656 /* WARNING: this file should *not* be used by applications. It is
2657 part of the implementation of the compression library and is
2658 subject to change. Applications should only use zlib.h.
2659 */
2660
2661 /* Huffman code lookup table entry--this entry is four bytes for machines
2662 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2663
2664 typedef struct inflate_huft_s FAR inflate_huft;
2665
2666 struct inflate_huft_s {
2667 union {
2668 struct {
2669 Byte Exop; /* number of extra bits or operation */
2670 Byte Bits; /* number of bits in this code or subcode */
2671 } what;
2672 uInt Nalloc; /* number of these allocated here */
2673 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2674 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2675 union {
2676 uInt Base; /* literal, length base, or distance base */
2677 inflate_huft *Next; /* pointer to next level of table */
2678 } more;
2679 };
2680
2681 #ifdef DEBUG_ZLIB
2682 local uInt inflate_hufts;
2683 #endif
2684
2685 local int inflate_trees_bits OF((
2686 uIntf *, /* 19 code lengths */
2687 uIntf *, /* bits tree desired/actual depth */
2688 inflate_huft * FAR *, /* bits tree result */
2689 z_stream *)); /* for zalloc, zfree functions */
2690
2691 local int inflate_trees_dynamic OF((
2692 uInt, /* number of literal/length codes */
2693 uInt, /* number of distance codes */
2694 uIntf *, /* that many (total) code lengths */
2695 uIntf *, /* literal desired/actual bit depth */
2696 uIntf *, /* distance desired/actual bit depth */
2697 inflate_huft * FAR *, /* literal/length tree result */
2698 inflate_huft * FAR *, /* distance tree result */
2699 z_stream *)); /* for zalloc, zfree functions */
2700
2701 local int inflate_trees_fixed OF((
2702 uIntf *, /* literal desired/actual bit depth */
2703 uIntf *, /* distance desired/actual bit depth */
2704 inflate_huft * FAR *, /* literal/length tree result */
2705 inflate_huft * FAR *)); /* distance tree result */
2706
2707 local int inflate_trees_free OF((
2708 inflate_huft *, /* tables to free */
2709 z_stream *)); /* for zfree function */
2710
2711
2712 /*+++++*/
2713 /* infcodes.h -- header to use infcodes.c
2714 * Copyright (C) 1995 Mark Adler
2715 * For conditions of distribution and use, see copyright notice in zlib.h
2716 */
2717
2718 /* WARNING: this file should *not* be used by applications. It is
2719 part of the implementation of the compression library and is
2720 subject to change. Applications should only use zlib.h.
2721 */
2722
2723 struct inflate_codes_state;
2724 typedef struct inflate_codes_state FAR inflate_codes_statef;
2725
2726 local inflate_codes_statef *inflate_codes_new OF((
2727 uInt, uInt,
2728 inflate_huft *, inflate_huft *,
2729 z_stream *));
2730
2731 local int inflate_codes OF((
2732 inflate_blocks_statef *,
2733 z_stream *,
2734 int));
2735
2736 local void inflate_codes_free OF((
2737 inflate_codes_statef *,
2738 z_stream *));
2739
2740
2741 /*+++++*/
2742 /* inflate.c -- zlib interface to inflate modules
2743 * Copyright (C) 1995 Mark Adler
2744 * For conditions of distribution and use, see copyright notice in zlib.h
2745 */
2746
2747 /* inflate private state */
2748 struct internal_state {
2749
2750 /* mode */
2751 enum {
2752 METHOD, /* waiting for method byte */
2753 FLAG, /* waiting for flag byte */
2754 BLOCKS, /* decompressing blocks */
2755 CHECK4, /* four check bytes to go */
2756 CHECK3, /* three check bytes to go */
2757 CHECK2, /* two check bytes to go */
2758 CHECK1, /* one check byte to go */
2759 DONE, /* finished check, done */
2760 BAD} /* got an error--stay here */
2761 mode; /* current inflate mode */
2762
2763 /* mode dependent information */
2764 union {
2765 uInt method; /* if FLAGS, method byte */
2766 struct {
2767 uLong was; /* computed check value */
2768 uLong need; /* stream check value */
2769 } check; /* if CHECK, check values to compare */
2770 uInt marker; /* if BAD, inflateSync's marker bytes count */
2771 } sub; /* submode */
2772
2773 /* mode independent information */
2774 int nowrap; /* flag for no wrapper */
2775 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2776 inflate_blocks_statef
2777 *blocks; /* current inflate_blocks state */
2778
2779 };
2780
2781
2782 int inflateReset(z)
2783 z_stream *z;
2784 {
2785 uLong c;
2786
2787 if (z == Z_NULL || z->state == Z_NULL)
2788 return Z_STREAM_ERROR;
2789 z->total_in = z->total_out = 0;
2790 z->msg = Z_NULL;
2791 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2792 inflate_blocks_reset(z->state->blocks, z, &c);
2793 Trace((stderr, "inflate: reset\n"));
2794 return Z_OK;
2795 }
2796
2797
2798 int inflateEnd(z)
2799 z_stream *z;
2800 {
2801 uLong c;
2802
2803 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2804 return Z_STREAM_ERROR;
2805 if (z->state->blocks != Z_NULL)
2806 inflate_blocks_free(z->state->blocks, z, &c);
2807 ZFREE(z, z->state, sizeof(struct internal_state));
2808 z->state = Z_NULL;
2809 Trace((stderr, "inflate: end\n"));
2810 return Z_OK;
2811 }
2812
2813
2814 int inflateInit2(z, w)
2815 z_stream *z;
2816 int w;
2817 {
2818 /* initialize state */
2819 if (z == Z_NULL)
2820 return Z_STREAM_ERROR;
2821 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2822 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2823 if ((z->state = (struct internal_state FAR *)
2824 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2825 return Z_MEM_ERROR;
2826 z->state->blocks = Z_NULL;
2827
2828 /* handle undocumented nowrap option (no zlib header or check) */
2829 z->state->nowrap = 0;
2830 if (w < 0)
2831 {
2832 w = - w;
2833 z->state->nowrap = 1;
2834 }
2835
2836 /* set window size */
2837 if (w < 8 || w > 15)
2838 {
2839 inflateEnd(z);
2840 return Z_STREAM_ERROR;
2841 }
2842 z->state->wbits = (uInt)w;
2843
2844 /* create inflate_blocks state */
2845 if ((z->state->blocks =
2846 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2847 == Z_NULL)
2848 {
2849 inflateEnd(z);
2850 return Z_MEM_ERROR;
2851 }
2852 Trace((stderr, "inflate: allocated\n"));
2853
2854 /* reset state */
2855 inflateReset(z);
2856 return Z_OK;
2857 }
2858
2859
2860 int inflateInit(z)
2861 z_stream *z;
2862 {
2863 return inflateInit2(z, DEF_WBITS);
2864 }
2865
2866
2867 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2868 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2869
2870 int inflate(z, f)
2871 z_stream *z;
2872 int f;
2873 {
2874 int r;
2875 uInt b;
2876
2877 if (z == Z_NULL || z->next_in == Z_NULL)
2878 return Z_STREAM_ERROR;
2879 r = Z_BUF_ERROR;
2880 while (1) switch (z->state->mode)
2881 {
2882 case METHOD:
2883 NEEDBYTE
2884 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2885 {
2886 z->state->mode = BAD;
2887 z->msg = "unknown compression method";
2888 z->state->sub.marker = 5; /* can't try inflateSync */
2889 break;
2890 }
2891 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2892 {
2893 z->state->mode = BAD;
2894 z->msg = "invalid window size";
2895 z->state->sub.marker = 5; /* can't try inflateSync */
2896 break;
2897 }
2898 z->state->mode = FLAG;
2899 case FLAG:
2900 NEEDBYTE
2901 if ((b = NEXTBYTE) & 0x20)
2902 {
2903 z->state->mode = BAD;
2904 z->msg = "invalid reserved bit";
2905 z->state->sub.marker = 5; /* can't try inflateSync */
2906 break;
2907 }
2908 if (((z->state->sub.method << 8) + b) % 31)
2909 {
2910 z->state->mode = BAD;
2911 z->msg = "incorrect header check";
2912 z->state->sub.marker = 5; /* can't try inflateSync */
2913 break;
2914 }
2915 Trace((stderr, "inflate: zlib header ok\n"));
2916 z->state->mode = BLOCKS;
2917 case BLOCKS:
2918 r = inflate_blocks(z->state->blocks, z, r);
2919 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2920 r = inflate_packet_flush(z->state->blocks);
2921 if (r == Z_DATA_ERROR)
2922 {
2923 z->state->mode = BAD;
2924 z->state->sub.marker = 0; /* can try inflateSync */
2925 break;
2926 }
2927 if (r != Z_STREAM_END)
2928 return r;
2929 r = Z_OK;
2930 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2931 if (z->state->nowrap)
2932 {
2933 z->state->mode = DONE;
2934 break;
2935 }
2936 z->state->mode = CHECK4;
2937 case CHECK4:
2938 NEEDBYTE
2939 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2940 z->state->mode = CHECK3;
2941 case CHECK3:
2942 NEEDBYTE
2943 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2944 z->state->mode = CHECK2;
2945 case CHECK2:
2946 NEEDBYTE
2947 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2948 z->state->mode = CHECK1;
2949 case CHECK1:
2950 NEEDBYTE
2951 z->state->sub.check.need += (uLong)NEXTBYTE;
2952
2953 if (z->state->sub.check.was != z->state->sub.check.need)
2954 {
2955 z->state->mode = BAD;
2956 z->msg = "incorrect data check";
2957 z->state->sub.marker = 5; /* can't try inflateSync */
2958 break;
2959 }
2960 Trace((stderr, "inflate: zlib check ok\n"));
2961 z->state->mode = DONE;
2962 case DONE:
2963 return Z_STREAM_END;
2964 case BAD:
2965 return Z_DATA_ERROR;
2966 default:
2967 return Z_STREAM_ERROR;
2968 }
2969
2970 empty:
2971 if (f != Z_PACKET_FLUSH)
2972 return r;
2973 z->state->mode = BAD;
2974 z->state->sub.marker = 0; /* can try inflateSync */
2975 return Z_DATA_ERROR;
2976 }
2977
2978 /*
2979 * This subroutine adds the data at next_in/avail_in to the output history
2980 * without performing any output. The output buffer must be "caught up";
2981 * i.e. no pending output (hence s->read equals s->write), and the state must
2982 * be BLOCKS (i.e. we should be willing to see the start of a series of
2983 * BLOCKS). On exit, the output will also be caught up, and the checksum
2984 * will have been updated if need be.
2985 */
2986
2987 int inflateIncomp(z)
2988 z_stream *z;
2989 {
2990 if (z->state->mode != BLOCKS)
2991 return Z_DATA_ERROR;
2992 return inflate_addhistory(z->state->blocks, z);
2993 }
2994
2995
2996 int inflateSync(z)
2997 z_stream *z;
2998 {
2999 uInt n; /* number of bytes to look at */
3000 Bytef *p; /* pointer to bytes */
3001 uInt m; /* number of marker bytes found in a row */
3002 uLong r, w; /* temporaries to save total_in and total_out */
3003
3004 /* set up */
3005 if (z == Z_NULL || z->state == Z_NULL)
3006 return Z_STREAM_ERROR;
3007 if (z->state->mode != BAD)
3008 {
3009 z->state->mode = BAD;
3010 z->state->sub.marker = 0;
3011 }
3012 if ((n = z->avail_in) == 0)
3013 return Z_BUF_ERROR;
3014 p = z->next_in;
3015 m = z->state->sub.marker;
3016
3017 /* search */
3018 while (n && m < 4)
3019 {
3020 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3021 m++;
3022 else if (*p)
3023 m = 0;
3024 else
3025 m = 4 - m;
3026 p++, n--;
3027 }
3028
3029 /* restore */
3030 z->total_in += p - z->next_in;
3031 z->next_in = p;
3032 z->avail_in = n;
3033 z->state->sub.marker = m;
3034
3035 /* return no joy or set up to restart on a new block */
3036 if (m != 4)
3037 return Z_DATA_ERROR;
3038 r = z->total_in; w = z->total_out;
3039 inflateReset(z);
3040 z->total_in = r; z->total_out = w;
3041 z->state->mode = BLOCKS;
3042 return Z_OK;
3043 }
3044
3045 #undef NEEDBYTE
3046 #undef NEXTBYTE
3047
3048 /*+++++*/
3049 /* infutil.h -- types and macros common to blocks and codes
3050 * Copyright (C) 1995 Mark Adler
3051 * For conditions of distribution and use, see copyright notice in zlib.h
3052 */
3053
3054 /* WARNING: this file should *not* be used by applications. It is
3055 part of the implementation of the compression library and is
3056 subject to change. Applications should only use zlib.h.
3057 */
3058
3059 /* inflate blocks semi-private state */
3060 struct inflate_blocks_state {
3061
3062 /* mode */
3063 enum {
3064 TYPE, /* get type bits (3, including end bit) */
3065 LENS, /* get lengths for stored */
3066 STORED, /* processing stored block */
3067 TABLE, /* get table lengths */
3068 BTREE, /* get bit lengths tree for a dynamic block */
3069 DTREE, /* get length, distance trees for a dynamic block */
3070 CODES, /* processing fixed or dynamic block */
3071 DRY, /* output remaining window bytes */
3072 DONEB, /* finished last block, done */
3073 BADB} /* got a data error--stuck here */
3074 mode; /* current inflate_block mode */
3075
3076 /* mode dependent information */
3077 union {
3078 uInt left; /* if STORED, bytes left to copy */
3079 struct {
3080 uInt table; /* table lengths (14 bits) */
3081 uInt index; /* index into blens (or border) */
3082 uIntf *blens; /* bit lengths of codes */
3083 uInt bb; /* bit length tree depth */
3084 inflate_huft *tb; /* bit length decoding tree */
3085 int nblens; /* # elements allocated at blens */
3086 } trees; /* if DTREE, decoding info for trees */
3087 struct {
3088 inflate_huft *tl, *td; /* trees to free */
3089 inflate_codes_statef
3090 *codes;
3091 } decode; /* if CODES, current state */
3092 } sub; /* submode */
3093 uInt last; /* true if this block is the last block */
3094
3095 /* mode independent information */
3096 uInt bitk; /* bits in bit buffer */
3097 uLong bitb; /* bit buffer */
3098 Bytef *window; /* sliding window */
3099 Bytef *end; /* one byte after sliding window */
3100 Bytef *read; /* window read pointer */
3101 Bytef *write; /* window write pointer */
3102 check_func checkfn; /* check function */
3103 uLong check; /* check on output */
3104
3105 };
3106
3107
3108 /* defines for inflate input/output */
3109 /* update pointers and return */
3110 #define UPDBITS {s->bitb=b;s->bitk=k;}
3111 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3112 #define UPDOUT {s->write=q;}
3113 #define UPDATE {UPDBITS UPDIN UPDOUT}
3114 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3115 /* get bytes and bits */
3116 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3117 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3118 #define NEXTBYTE (n--,*p++)
3119 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3120 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3121 /* output bytes */
3122 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3123 #define LOADOUT {q=s->write;m=WAVAIL;}
3124 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3125 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3126 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3127 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3128 /* load local pointers */
3129 #define LOAD {LOADIN LOADOUT}
3130
3131 /* And'ing with mask[n] masks the lower n bits */
3132 local const uInt inflate_mask[] = {
3133 0x0000,
3134 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3135 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3136 };
3137
3138 /* copy as much as possible from the sliding window to the output area */
3139 local int inflate_flush OF((
3140 inflate_blocks_statef *,
3141 z_stream *,
3142 int));
3143
3144 /*+++++*/
3145 /* inffast.h -- header to use inffast.c
3146 * Copyright (C) 1995 Mark Adler
3147 * For conditions of distribution and use, see copyright notice in zlib.h
3148 */
3149
3150 /* WARNING: this file should *not* be used by applications. It is
3151 part of the implementation of the compression library and is
3152 subject to change. Applications should only use zlib.h.
3153 */
3154
3155 local int inflate_fast OF((
3156 uInt,
3157 uInt,
3158 inflate_huft *,
3159 inflate_huft *,
3160 inflate_blocks_statef *,
3161 z_stream *));
3162
3163
3164 /*+++++*/
3165 /* infblock.c -- interpret and process block types to last block
3166 * Copyright (C) 1995 Mark Adler
3167 * For conditions of distribution and use, see copyright notice in zlib.h
3168 */
3169
3170 /* Table for deflate from PKZIP's appnote.txt. */
3171 local uInt border[] = { /* Order of the bit length code lengths */
3172 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3173
3174 /*
3175 Notes beyond the 1.93a appnote.txt:
3176
3177 1. Distance pointers never point before the beginning of the output
3178 stream.
3179 2. Distance pointers can point back across blocks, up to 32k away.
3180 3. There is an implied maximum of 7 bits for the bit length table and
3181 15 bits for the actual data.
3182 4. If only one code exists, then it is encoded using one bit. (Zero
3183 would be more efficient, but perhaps a little confusing.) If two
3184 codes exist, they are coded using one bit each (0 and 1).
3185 5. There is no way of sending zero distance codes--a dummy must be
3186 sent if there are none. (History: a pre 2.0 version of PKZIP would
3187 store blocks with no distance codes, but this was discovered to be
3188 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3189 zero distance codes, which is sent as one code of zero bits in
3190 length.
3191 6. There are up to 286 literal/length codes. Code 256 represents the
3192 end-of-block. Note however that the static length tree defines
3193 288 codes just to fill out the Huffman codes. Codes 286 and 287
3194 cannot be used though, since there is no length base or extra bits
3195 defined for them. Similarily, there are up to 30 distance codes.
3196 However, static trees define 32 codes (all 5 bits) to fill out the
3197 Huffman codes, but the last two had better not show up in the data.
3198 7. Unzip can check dynamic Huffman blocks for complete code sets.
3199 The exception is that a single code would not be complete (see #4).
3200 8. The five bits following the block type is really the number of
3201 literal codes sent minus 257.
3202 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3203 (1+6+6). Therefore, to output three times the length, you output
3204 three codes (1+1+1), whereas to output four times the same length,
3205 you only need two codes (1+3). Hmm.
3206 10. In the tree reconstruction algorithm, Code = Code + Increment
3207 only if BitLength(i) is not zero. (Pretty obvious.)
3208 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3209 12. Note: length code 284 can represent 227-258, but length code 285
3210 really is 258. The last length deserves its own, short code
3211 since it gets used a lot in very redundant files. The length
3212 258 is special since 258 - 3 (the min match length) is 255.
3213 13. The literal/length and distance code bit lengths are read as a
3214 single stream of lengths. It is possible (and advantageous) for
3215 a repeat code (16, 17, or 18) to go across the boundary between
3216 the two sets of lengths.
3217 */
3218
3219
3220 local void inflate_blocks_reset(s, z, c)
3221 inflate_blocks_statef *s;
3222 z_stream *z;
3223 uLongf *c;
3224 {
3225 if (s->checkfn != Z_NULL)
3226 *c = s->check;
3227 if (s->mode == BTREE || s->mode == DTREE)
3228 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3229 if (s->mode == CODES)
3230 {
3231 inflate_codes_free(s->sub.decode.codes, z);
3232 inflate_trees_free(s->sub.decode.td, z);
3233 inflate_trees_free(s->sub.decode.tl, z);
3234 }
3235 s->mode = TYPE;
3236 s->bitk = 0;
3237 s->bitb = 0;
3238 s->read = s->write = s->window;
3239 if (s->checkfn != Z_NULL)
3240 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3241 Trace((stderr, "inflate: blocks reset\n"));
3242 }
3243
3244
3245 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3246 z_stream *z;
3247 check_func c;
3248 uInt w;
3249 {
3250 inflate_blocks_statef *s;
3251
3252 if ((s = (inflate_blocks_statef *)ZALLOC
3253 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3254 return s;
3255 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3256 {
3257 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3258 return Z_NULL;
3259 }
3260 s->end = s->window + w;
3261 s->checkfn = c;
3262 s->mode = TYPE;
3263 Trace((stderr, "inflate: blocks allocated\n"));
3264 inflate_blocks_reset(s, z, &s->check);
3265 return s;
3266 }
3267
3268
3269 local int inflate_blocks(s, z, r)
3270 inflate_blocks_statef *s;
3271 z_stream *z;
3272 int r;
3273 {
3274 uInt t; /* temporary storage */
3275 uLong b; /* bit buffer */
3276 uInt k; /* bits in bit buffer */
3277 Bytef *p; /* input data pointer */
3278 uInt n; /* bytes available there */
3279 Bytef *q; /* output window write pointer */
3280 uInt m; /* bytes to end of window or read pointer */
3281
3282 /* copy input/output information to locals (UPDATE macro restores) */
3283 LOAD
3284
3285 /* process input based on current state */
3286 while (1) switch (s->mode)
3287 {
3288 case TYPE:
3289 NEEDBITS(3)
3290 t = (uInt)b & 7;
3291 s->last = t & 1;
3292 switch (t >> 1)
3293 {
3294 case 0: /* stored */
3295 Trace((stderr, "inflate: stored block%s\n",
3296 s->last ? " (last)" : ""));
3297 DUMPBITS(3)
3298 t = k & 7; /* go to byte boundary */
3299 DUMPBITS(t)
3300 s->mode = LENS; /* get length of stored block */
3301 break;
3302 case 1: /* fixed */
3303 Trace((stderr, "inflate: fixed codes block%s\n",
3304 s->last ? " (last)" : ""));
3305 {
3306 uInt bl, bd;
3307 inflate_huft *tl, *td;
3308
3309 inflate_trees_fixed(&bl, &bd, &tl, &td);
3310 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3311 if (s->sub.decode.codes == Z_NULL)
3312 {
3313 r = Z_MEM_ERROR;
3314 LEAVE
3315 }
3316 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3317 s->sub.decode.td = Z_NULL;
3318 }
3319 DUMPBITS(3)
3320 s->mode = CODES;
3321 break;
3322 case 2: /* dynamic */
3323 Trace((stderr, "inflate: dynamic codes block%s\n",
3324 s->last ? " (last)" : ""));
3325 DUMPBITS(3)
3326 s->mode = TABLE;
3327 break;
3328 case 3: /* illegal */
3329 DUMPBITS(3)
3330 s->mode = BADB;
3331 z->msg = "invalid block type";
3332 r = Z_DATA_ERROR;
3333 LEAVE
3334 }
3335 break;
3336 case LENS:
3337 NEEDBITS(32)
3338 if (((~b) >> 16) != (b & 0xffff))
3339 {
3340 s->mode = BADB;
3341 z->msg = "invalid stored block lengths";
3342 r = Z_DATA_ERROR;
3343 LEAVE
3344 }
3345 s->sub.left = (uInt)b & 0xffff;
3346 b = k = 0; /* dump bits */
3347 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3348 s->mode = s->sub.left ? STORED : TYPE;
3349 break;
3350 case STORED:
3351 if (n == 0)
3352 LEAVE
3353 NEEDOUT
3354 t = s->sub.left;
3355 if (t > n) t = n;
3356 if (t > m) t = m;
3357 zmemcpy(q, p, t);
3358 p += t; n -= t;
3359 q += t; m -= t;
3360 if ((s->sub.left -= t) != 0)
3361 break;
3362 Tracev((stderr, "inflate: stored end, %lu total out\n",
3363 z->total_out + (q >= s->read ? q - s->read :
3364 (s->end - s->read) + (q - s->window))));
3365 s->mode = s->last ? DRY : TYPE;
3366 break;
3367 case TABLE:
3368 NEEDBITS(14)
3369 s->sub.trees.table = t = (uInt)b & 0x3fff;
3370 #ifndef PKZIP_BUG_WORKAROUND
3371 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3372 {
3373 s->mode = BADB;
3374 z->msg = "too many length or distance symbols";
3375 r = Z_DATA_ERROR;
3376 LEAVE
3377 }
3378 #endif
3379 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3380 if (t < 19)
3381 t = 19;
3382 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3383 {
3384 r = Z_MEM_ERROR;
3385 LEAVE
3386 }
3387 s->sub.trees.nblens = t;
3388 DUMPBITS(14)
3389 s->sub.trees.index = 0;
3390 Tracev((stderr, "inflate: table sizes ok\n"));
3391 s->mode = BTREE;
3392 case BTREE:
3393 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3394 {
3395 NEEDBITS(3)
3396 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3397 DUMPBITS(3)
3398 }
3399 while (s->sub.trees.index < 19)
3400 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3401 s->sub.trees.bb = 7;
3402 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3403 &s->sub.trees.tb, z);
3404 if (t != Z_OK)
3405 {
3406 r = t;
3407 if (r == Z_DATA_ERROR)
3408 {
3409 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3410 s->mode = BADB;
3411 }
3412 LEAVE
3413 }
3414 s->sub.trees.index = 0;
3415 Tracev((stderr, "inflate: bits tree ok\n"));
3416 s->mode = DTREE;
3417 case DTREE:
3418 while (t = s->sub.trees.table,
3419 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3420 {
3421 inflate_huft *h;
3422 uInt i, j, c;
3423
3424 t = s->sub.trees.bb;
3425 NEEDBITS(t)
3426 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3427 t = h->word.what.Bits;
3428 c = h->more.Base;
3429 if (c < 16)
3430 {
3431 DUMPBITS(t)
3432 s->sub.trees.blens[s->sub.trees.index++] = c;
3433 }
3434 else /* c == 16..18 */
3435 {
3436 i = c == 18 ? 7 : c - 14;
3437 j = c == 18 ? 11 : 3;
3438 NEEDBITS(t + i)
3439 DUMPBITS(t)
3440 j += (uInt)b & inflate_mask[i];
3441 DUMPBITS(i)
3442 i = s->sub.trees.index;
3443 t = s->sub.trees.table;
3444 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3445 (c == 16 && i < 1))
3446 {
3447 s->mode = BADB;
3448 z->msg = "invalid bit length repeat";
3449 r = Z_DATA_ERROR;
3450 LEAVE
3451 }
3452 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3453 do {
3454 s->sub.trees.blens[i++] = c;
3455 } while (--j);
3456 s->sub.trees.index = i;
3457 }
3458 }
3459 inflate_trees_free(s->sub.trees.tb, z);
3460 s->sub.trees.tb = Z_NULL;
3461 {
3462 uInt bl, bd;
3463 inflate_huft *tl, *td;
3464 inflate_codes_statef *c;
3465
3466 bl = 9; /* must be <= 9 for lookahead assumptions */
3467 bd = 6; /* must be <= 9 for lookahead assumptions */
3468 t = s->sub.trees.table;
3469 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3470 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3471 if (t != Z_OK)
3472 {
3473 if (t == (uInt)Z_DATA_ERROR)
3474 {
3475 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3476 s->mode = BADB;
3477 }
3478 r = t;
3479 LEAVE
3480 }
3481 Tracev((stderr, "inflate: trees ok\n"));
3482 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3483 {
3484 inflate_trees_free(td, z);
3485 inflate_trees_free(tl, z);
3486 r = Z_MEM_ERROR;
3487 LEAVE
3488 }
3489 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3490 s->sub.decode.codes = c;
3491 s->sub.decode.tl = tl;
3492 s->sub.decode.td = td;
3493 }
3494 s->mode = CODES;
3495 case CODES:
3496 UPDATE
3497 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3498 return inflate_flush(s, z, r);
3499 r = Z_OK;
3500 inflate_codes_free(s->sub.decode.codes, z);
3501 inflate_trees_free(s->sub.decode.td, z);
3502 inflate_trees_free(s->sub.decode.tl, z);
3503 LOAD
3504 Tracev((stderr, "inflate: codes end, %lu total out\n",
3505 z->total_out + (q >= s->read ? q - s->read :
3506 (s->end - s->read) + (q - s->window))));
3507 if (!s->last)
3508 {
3509 s->mode = TYPE;
3510 break;
3511 }
3512 if (k > 7) /* return unused byte, if any */
3513 {
3514 Assert(k < 16, "inflate_codes grabbed too many bytes")
3515 k -= 8;
3516 n++;
3517 p--; /* can always return one */
3518 }
3519 s->mode = DRY;
3520 case DRY:
3521 FLUSH
3522 if (s->read != s->write)
3523 LEAVE
3524 s->mode = DONEB;
3525 case DONEB:
3526 r = Z_STREAM_END;
3527 LEAVE
3528 case BADB:
3529 r = Z_DATA_ERROR;
3530 LEAVE
3531 default:
3532 r = Z_STREAM_ERROR;
3533 LEAVE
3534 }
3535 }
3536
3537
3538 local int inflate_blocks_free(s, z, c)
3539 inflate_blocks_statef *s;
3540 z_stream *z;
3541 uLongf *c;
3542 {
3543 inflate_blocks_reset(s, z, c);
3544 ZFREE(z, s->window, s->end - s->window);
3545 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3546 Trace((stderr, "inflate: blocks freed\n"));
3547 return Z_OK;
3548 }
3549
3550 /*
3551 * This subroutine adds the data at next_in/avail_in to the output history
3552 * without performing any output. The output buffer must be "caught up";
3553 * i.e. no pending output (hence s->read equals s->write), and the state must
3554 * be BLOCKS (i.e. we should be willing to see the start of a series of
3555 * BLOCKS). On exit, the output will also be caught up, and the checksum
3556 * will have been updated if need be.
3557 */
3558 local int inflate_addhistory(s, z)
3559 inflate_blocks_statef *s;
3560 z_stream *z;
3561 {
3562 uLong b; /* bit buffer */ /* NOT USED HERE */
3563 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3564 uInt t; /* temporary storage */
3565 Bytef *p; /* input data pointer */
3566 uInt n; /* bytes available there */
3567 Bytef *q; /* output window write pointer */
3568 uInt m; /* bytes to end of window or read pointer */
3569
3570 if (s->read != s->write)
3571 return Z_STREAM_ERROR;
3572 if (s->mode != TYPE)
3573 return Z_DATA_ERROR;
3574
3575 /* we're ready to rock */
3576 LOAD
3577 /* while there is input ready, copy to output buffer, moving
3578 * pointers as needed.
3579 */
3580 while (n) {
3581 t = n; /* how many to do */
3582 /* is there room until end of buffer? */
3583 if (t > m) t = m;
3584 /* update check information */
3585 if (s->checkfn != Z_NULL)
3586 s->check = (*s->checkfn)(s->check, q, t);
3587 zmemcpy(q, p, t);
3588 q += t;
3589 p += t;
3590 n -= t;
3591 z->total_out += t;
3592 s->read = q; /* drag read pointer forward */
3593 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3594 if (q == s->end) {
3595 s->read = q = s->window;
3596 m = WAVAIL;
3597 }
3598 }
3599 UPDATE
3600 return Z_OK;
3601 }
3602
3603
3604 /*
3605 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3606 * a `stored' block type value but not the (zero) length bytes.
3607 */
3608 local int inflate_packet_flush(s)
3609 inflate_blocks_statef *s;
3610 {
3611 if (s->mode != LENS)
3612 return Z_DATA_ERROR;
3613 s->mode = TYPE;
3614 return Z_OK;
3615 }
3616
3617
3618 /*+++++*/
3619 /* inftrees.c -- generate Huffman trees for efficient decoding
3620 * Copyright (C) 1995 Mark Adler
3621 * For conditions of distribution and use, see copyright notice in zlib.h
3622 */
3623
3624 /* simplify the use of the inflate_huft type with some defines */
3625 #define base more.Base
3626 #define next more.Next
3627 #define exop word.what.Exop
3628 #define bits word.what.Bits
3629
3630
3631 local int huft_build OF((
3632 uIntf *, /* code lengths in bits */
3633 uInt, /* number of codes */
3634 uInt, /* number of "simple" codes */
3635 const uIntf *, /* list of base values for non-simple codes */
3636 const uIntf *, /* list of extra bits for non-simple codes */
3637 inflate_huft * FAR*,/* result: starting table */
3638 uIntf *, /* maximum lookup bits (returns actual) */
3639 z_stream *)); /* for zalloc function */
3640
3641 local voidpf falloc OF((
3642 voidpf, /* opaque pointer (not used) */
3643 uInt, /* number of items */
3644 uInt)); /* size of item */
3645
3646 local void ffree OF((
3647 voidpf q, /* opaque pointer (not used) */
3648 voidpf p, /* what to free (not used) */
3649 uInt n)); /* number of bytes (not used) */
3650
3651 /* Tables for deflate from PKZIP's appnote.txt. */
3652 local const uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3653 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3654 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3655 /* actually lengths - 2; also see note #13 above about 258 */
3656 local const uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3657 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3658 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3659 local const uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3660 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3661 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3662 8193, 12289, 16385, 24577};
3663 local const uInt cpdext[] = { /* Extra bits for distance codes */
3664 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3665 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3666 12, 12, 13, 13};
3667
3668 /*
3669 Huffman code decoding is performed using a multi-level table lookup.
3670 The fastest way to decode is to simply build a lookup table whose
3671 size is determined by the longest code. However, the time it takes
3672 to build this table can also be a factor if the data being decoded
3673 is not very long. The most common codes are necessarily the
3674 shortest codes, so those codes dominate the decoding time, and hence
3675 the speed. The idea is you can have a shorter table that decodes the
3676 shorter, more probable codes, and then point to subsidiary tables for
3677 the longer codes. The time it costs to decode the longer codes is
3678 then traded against the time it takes to make longer tables.
3679
3680 This results of this trade are in the variables lbits and dbits
3681 below. lbits is the number of bits the first level table for literal/
3682 length codes can decode in one step, and dbits is the same thing for
3683 the distance codes. Subsequent tables are also less than or equal to
3684 those sizes. These values may be adjusted either when all of the
3685 codes are shorter than that, in which case the longest code length in
3686 bits is used, or when the shortest code is *longer* than the requested
3687 table size, in which case the length of the shortest code in bits is
3688 used.
3689
3690 There are two different values for the two tables, since they code a
3691 different number of possibilities each. The literal/length table
3692 codes 286 possible values, or in a flat code, a little over eight
3693 bits. The distance table codes 30 possible values, or a little less
3694 than five bits, flat. The optimum values for speed end up being
3695 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3696 The optimum values may differ though from machine to machine, and
3697 possibly even between compilers. Your mileage may vary.
3698 */
3699
3700
3701 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3702 #define BMAX 15 /* maximum bit length of any code */
3703 #define N_MAX 288 /* maximum number of codes in any set */
3704
3705 #ifdef DEBUG_ZLIB
3706 uInt inflate_hufts;
3707 #endif
3708
3709 local int huft_build(b, n, s, d, e, t, m, zs)
3710 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3711 uInt n; /* number of codes (assumed <= N_MAX) */
3712 uInt s; /* number of simple-valued codes (0..s-1) */
3713 const uIntf *d; /* list of base values for non-simple codes */
3714 const uIntf *e; /* list of extra bits for non-simple codes */
3715 inflate_huft * FAR *t; /* result: starting table */
3716 uIntf *m; /* maximum lookup bits, returns actual */
3717 z_stream *zs; /* for zalloc function */
3718 /* Given a list of code lengths and a maximum table size, make a set of
3719 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3720 if the given code set is incomplete (the tables are still built in this
3721 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3722 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3723 {
3724
3725 uInt a; /* counter for codes of length k */
3726 uInt c[BMAX+1]; /* bit length count table */
3727 uInt f; /* i repeats in table every f entries */
3728 int g; /* maximum code length */
3729 int h; /* table level */
3730 uInt i; /* counter, current code */
3731 uInt j; /* counter */
3732 int k; /* number of bits in current code */
3733 int l; /* bits per table (returned in m) */
3734 uIntf *p; /* pointer into c[], b[], or v[] */
3735 inflate_huft *q; /* points to current table */
3736 struct inflate_huft_s r; /* table entry for structure assignment */
3737 inflate_huft *u[BMAX]; /* table stack */
3738 uInt v[N_MAX]; /* values in order of bit length */
3739 int w; /* bits before this table == (l * h) */
3740 uInt x[BMAX+1]; /* bit offsets, then code stack */
3741 uIntf *xp; /* pointer into x */
3742 int y; /* number of dummy codes added */
3743 uInt z; /* number of entries in current table */
3744
3745
3746 /* Generate counts for each bit length */
3747 p = c;
3748 #define C0 *p++ = 0;
3749 #define C2 C0 C0 C0 C0
3750 #define C4 C2 C2 C2 C2
3751 C4 /* clear c[]--assume BMAX+1 is 16 */
3752 p = b; i = n;
3753 do {
3754 c[*p++]++; /* assume all entries <= BMAX */
3755 } while (--i);
3756 if (c[0] == n) /* null input--all zero length codes */
3757 {
3758 *t = (inflate_huft *)Z_NULL;
3759 *m = 0;
3760 return Z_OK;
3761 }
3762
3763
3764 /* Find minimum and maximum length, bound *m by those */
3765 l = *m;
3766 for (j = 1; j <= BMAX; j++)
3767 if (c[j])
3768 break;
3769 k = j; /* minimum code length */
3770 if ((uInt)l < j)
3771 l = j;
3772 for (i = BMAX; i; i--)
3773 if (c[i])
3774 break;
3775 g = i; /* maximum code length */
3776 if ((uInt)l > i)
3777 l = i;
3778 *m = l;
3779
3780
3781 /* Adjust last length count to fill out codes, if needed */
3782 for (y = 1 << j; j < i; j++, y <<= 1)
3783 if ((y -= c[j]) < 0)
3784 return Z_DATA_ERROR;
3785 if ((y -= c[i]) < 0)
3786 return Z_DATA_ERROR;
3787 c[i] += y;
3788
3789
3790 /* Generate starting offsets into the value table for each length */
3791 x[1] = j = 0;
3792 p = c + 1; xp = x + 2;
3793 while (--i) { /* note that i == g from above */
3794 *xp++ = (j += *p++);
3795 }
3796
3797
3798 /* Make a table of values in order of bit lengths */
3799 p = b; i = 0;
3800 do {
3801 if ((j = *p++) != 0)
3802 v[x[j]++] = i;
3803 } while (++i < n);
3804
3805
3806 /* Generate the Huffman codes and for each, make the table entries */
3807 x[0] = i = 0; /* first Huffman code is zero */
3808 p = v; /* grab values in bit order */
3809 h = -1; /* no tables yet--level -1 */
3810 w = -l; /* bits decoded == (l * h) */
3811 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3812 q = (inflate_huft *)Z_NULL; /* ditto */
3813 z = 0; /* ditto */
3814
3815 /* go through the bit lengths (k already is bits in shortest code) */
3816 for (; k <= g; k++)
3817 {
3818 a = c[k];
3819 while (a--)
3820 {
3821 /* here i is the Huffman code of length k bits for value *p */
3822 /* make tables up to required level */
3823 while (k > w + l)
3824 {
3825 h++;
3826 w += l; /* previous table always l bits */
3827
3828 /* compute minimum size table less than or equal to l bits */
3829 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3830 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3831 { /* too few codes for k-w bit table */
3832 f -= a + 1; /* deduct codes from patterns left */
3833 xp = c + k;
3834 if (j < z)
3835 while (++j < z) /* try smaller tables up to z bits */
3836 {
3837 if ((f <<= 1) <= *++xp)
3838 break; /* enough codes to use up j bits */
3839 f -= *xp; /* else deduct codes from patterns */
3840 }
3841 }
3842 z = 1 << j; /* table entries for j-bit table */
3843
3844 /* allocate and link in new table */
3845 if ((q = (inflate_huft *)ZALLOC
3846 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3847 {
3848 if (h)
3849 inflate_trees_free(u[0], zs);
3850 return Z_MEM_ERROR; /* not enough memory */
3851 }
3852 q->word.Nalloc = z + 1;
3853 #ifdef DEBUG_ZLIB
3854 inflate_hufts += z + 1;
3855 #endif
3856 *t = q + 1; /* link to list for huft_free() */
3857 *(t = &(q->next)) = Z_NULL;
3858 u[h] = ++q; /* table starts after link */
3859
3860 /* connect to last table, if there is one */
3861 if (h)
3862 {
3863 x[h] = i; /* save pattern for backing up */
3864 r.bits = (Byte)l; /* bits to dump before this table */
3865 r.exop = (Byte)j; /* bits in this table */
3866 r.next = q; /* pointer to this table */
3867 j = i >> (w - l); /* (get around Turbo C bug) */
3868 u[h-1][j] = r; /* connect to last table */
3869 }
3870 }
3871
3872 /* set up table entry in r */
3873 r.bits = (Byte)(k - w);
3874 if (p >= v + n)
3875 r.exop = 128 + 64; /* out of values--invalid code */
3876 else if (*p < s)
3877 {
3878 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3879 r.base = *p++; /* simple code is just the value */
3880 }
3881 else
3882 {
3883 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3884 r.base = d[*p++ - s];
3885 }
3886
3887 /* fill code-like entries with r */
3888 f = 1 << (k - w);
3889 for (j = i >> w; j < z; j += f)
3890 q[j] = r;
3891
3892 /* backwards increment the k-bit code i */
3893 for (j = 1 << (k - 1); i & j; j >>= 1)
3894 i ^= j;
3895 i ^= j;
3896
3897 /* backup over finished tables */
3898 while ((i & ((1 << w) - 1)) != x[h])
3899 {
3900 h--; /* don't need to update q */
3901 w -= l;
3902 }
3903 }
3904 }
3905
3906
3907 /* Return Z_BUF_ERROR if we were given an incomplete table */
3908 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3909 }
3910
3911
3912 local int inflate_trees_bits(c, bb, tb, z)
3913 uIntf *c; /* 19 code lengths */
3914 uIntf *bb; /* bits tree desired/actual depth */
3915 inflate_huft * FAR *tb; /* bits tree result */
3916 z_stream *z; /* for zfree function */
3917 {
3918 int r;
3919
3920 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3921 if (r == Z_DATA_ERROR)
3922 z->msg = "oversubscribed dynamic bit lengths tree";
3923 else if (r == Z_BUF_ERROR)
3924 {
3925 inflate_trees_free(*tb, z);
3926 z->msg = "incomplete dynamic bit lengths tree";
3927 r = Z_DATA_ERROR;
3928 }
3929 return r;
3930 }
3931
3932
3933 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3934 uInt nl; /* number of literal/length codes */
3935 uInt nd; /* number of distance codes */
3936 uIntf *c; /* that many (total) code lengths */
3937 uIntf *bl; /* literal desired/actual bit depth */
3938 uIntf *bd; /* distance desired/actual bit depth */
3939 inflate_huft * FAR *tl; /* literal/length tree result */
3940 inflate_huft * FAR *td; /* distance tree result */
3941 z_stream *z; /* for zfree function */
3942 {
3943 int r;
3944
3945 /* build literal/length tree */
3946 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3947 {
3948 if (r == Z_DATA_ERROR)
3949 z->msg = "oversubscribed literal/length tree";
3950 else if (r == Z_BUF_ERROR)
3951 {
3952 inflate_trees_free(*tl, z);
3953 z->msg = "incomplete literal/length tree";
3954 r = Z_DATA_ERROR;
3955 }
3956 return r;
3957 }
3958
3959 /* build distance tree */
3960 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3961 {
3962 if (r == Z_DATA_ERROR)
3963 z->msg = "oversubscribed literal/length tree";
3964 else if (r == Z_BUF_ERROR) {
3965 #ifdef PKZIP_BUG_WORKAROUND
3966 r = Z_OK;
3967 }
3968 #else
3969 inflate_trees_free(*td, z);
3970 z->msg = "incomplete literal/length tree";
3971 r = Z_DATA_ERROR;
3972 }
3973 inflate_trees_free(*tl, z);
3974 return r;
3975 #endif
3976 }
3977
3978 /* done */
3979 return Z_OK;
3980 }
3981
3982
3983 /* build fixed tables only once--keep them here */
3984 local int fixed_lock = 0;
3985 local int fixed_built = 0;
3986 #define FIXEDH 530 /* number of hufts used by fixed tables */
3987 local uInt fixed_left = FIXEDH;
3988 local inflate_huft fixed_mem[FIXEDH];
3989 local uInt fixed_bl;
3990 local uInt fixed_bd;
3991 local inflate_huft *fixed_tl;
3992 local inflate_huft *fixed_td;
3993
3994
3995 local voidpf falloc(q, n, s)
3996 voidpf q; /* opaque pointer (not used) */
3997 uInt n; /* number of items */
3998 uInt s; /* size of item */
3999 {
4000 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
4001 "inflate_trees falloc overflow");
4002 if (q) s++; /* to make some compilers happy */
4003 fixed_left -= n;
4004 return (voidpf)(fixed_mem + fixed_left);
4005 }
4006
4007
4008 local void ffree(q, p, n)
4009 voidpf q;
4010 voidpf p;
4011 uInt n;
4012 {
4013 Assert(0, "inflate_trees ffree called!");
4014 if (q) q = p; /* to make some compilers happy */
4015 }
4016
4017
4018 local int inflate_trees_fixed(bl, bd, tl, td)
4019 uIntf *bl; /* literal desired/actual bit depth */
4020 uIntf *bd; /* distance desired/actual bit depth */
4021 inflate_huft * FAR *tl; /* literal/length tree result */
4022 inflate_huft * FAR *td; /* distance tree result */
4023 {
4024 /* build fixed tables if not built already--lock out other instances */
4025 while (++fixed_lock > 1)
4026 fixed_lock--;
4027 if (!fixed_built)
4028 {
4029 int k; /* temporary variable */
4030 unsigned c[288]; /* length list for huft_build */
4031 z_stream z; /* for falloc function */
4032
4033 /* set up fake z_stream for memory routines */
4034 z.zalloc = falloc;
4035 z.zfree = ffree;
4036 z.opaque = Z_NULL;
4037
4038 /* literal table */
4039 for (k = 0; k < 144; k++)
4040 c[k] = 8;
4041 for (; k < 256; k++)
4042 c[k] = 9;
4043 for (; k < 280; k++)
4044 c[k] = 7;
4045 for (; k < 288; k++)
4046 c[k] = 8;
4047 fixed_bl = 7;
4048 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4049
4050 /* distance table */
4051 for (k = 0; k < 30; k++)
4052 c[k] = 5;
4053 fixed_bd = 5;
4054 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4055
4056 /* done */
4057 fixed_built = 1;
4058 }
4059 fixed_lock--;
4060 *bl = fixed_bl;
4061 *bd = fixed_bd;
4062 *tl = fixed_tl;
4063 *td = fixed_td;
4064 return Z_OK;
4065 }
4066
4067
4068 local int inflate_trees_free(t, z)
4069 inflate_huft *t; /* table to free */
4070 z_stream *z; /* for zfree function */
4071 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4072 list of the tables it made, with the links in a dummy first entry of
4073 each table. */
4074 {
4075 inflate_huft *p, *q;
4076
4077 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4078 p = t;
4079 while (p != Z_NULL)
4080 {
4081 q = (--p)->next;
4082 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4083 p = q;
4084 }
4085 return Z_OK;
4086 }
4087
4088 /*+++++*/
4089 /* infcodes.c -- process literals and length/distance pairs
4090 * Copyright (C) 1995 Mark Adler
4091 * For conditions of distribution and use, see copyright notice in zlib.h
4092 */
4093
4094 /* simplify the use of the inflate_huft type with some defines */
4095 #define base more.Base
4096 #define next more.Next
4097 #define exop word.what.Exop
4098 #define bits word.what.Bits
4099
4100 /* inflate codes private state */
4101 struct inflate_codes_state {
4102
4103 /* mode */
4104 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4105 START, /* x: set up for LEN */
4106 LEN, /* i: get length/literal/eob next */
4107 LENEXT, /* i: getting length extra (have base) */
4108 DIST, /* i: get distance next */
4109 DISTEXT, /* i: getting distance extra */
4110 COPY, /* o: copying bytes in window, waiting for space */
4111 LIT, /* o: got literal, waiting for output space */
4112 WASH, /* o: got eob, possibly still output waiting */
4113 END, /* x: got eob and all data flushed */
4114 BADCODE} /* x: got error */
4115 mode; /* current inflate_codes mode */
4116
4117 /* mode dependent information */
4118 uInt len;
4119 union {
4120 struct {
4121 inflate_huft *tree; /* pointer into tree */
4122 uInt need; /* bits needed */
4123 } code; /* if LEN or DIST, where in tree */
4124 uInt lit; /* if LIT, literal */
4125 struct {
4126 uInt get; /* bits to get for extra */
4127 uInt dist; /* distance back to copy from */
4128 } copy; /* if EXT or COPY, where and how much */
4129 } sub; /* submode */
4130
4131 /* mode independent information */
4132 Byte lbits; /* ltree bits decoded per branch */
4133 Byte dbits; /* dtree bits decoder per branch */
4134 inflate_huft *ltree; /* literal/length/eob tree */
4135 inflate_huft *dtree; /* distance tree */
4136
4137 };
4138
4139
4140 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4141 uInt bl, bd;
4142 inflate_huft *tl, *td;
4143 z_stream *z;
4144 {
4145 inflate_codes_statef *c;
4146
4147 if ((c = (inflate_codes_statef *)
4148 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4149 {
4150 c->mode = START;
4151 c->lbits = (Byte)bl;
4152 c->dbits = (Byte)bd;
4153 c->ltree = tl;
4154 c->dtree = td;
4155 Tracev((stderr, "inflate: codes new\n"));
4156 }
4157 return c;
4158 }
4159
4160
4161 local int inflate_codes(s, z, r)
4162 inflate_blocks_statef *s;
4163 z_stream *z;
4164 int r;
4165 {
4166 uInt j; /* temporary storage */
4167 inflate_huft *t; /* temporary pointer */
4168 uInt e; /* extra bits or operation */
4169 uLong b; /* bit buffer */
4170 uInt k; /* bits in bit buffer */
4171 Bytef *p; /* input data pointer */
4172 uInt n; /* bytes available there */
4173 Bytef *q; /* output window write pointer */
4174 uInt m; /* bytes to end of window or read pointer */
4175 Bytef *f; /* pointer to copy strings from */
4176 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4177
4178 /* copy input/output information to locals (UPDATE macro restores) */
4179 LOAD
4180
4181 /* process input and output based on current state */
4182 while (1) switch (c->mode)
4183 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4184 case START: /* x: set up for LEN */
4185 #ifndef SLOW
4186 if (m >= 258 && n >= 10)
4187 {
4188 UPDATE
4189 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4190 LOAD
4191 if (r != Z_OK)
4192 {
4193 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4194 break;
4195 }
4196 }
4197 #endif /* !SLOW */
4198 c->sub.code.need = c->lbits;
4199 c->sub.code.tree = c->ltree;
4200 c->mode = LEN;
4201 case LEN: /* i: get length/literal/eob next */
4202 j = c->sub.code.need;
4203 NEEDBITS(j)
4204 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4205 DUMPBITS(t->bits)
4206 e = (uInt)(t->exop);
4207 if (e == 0) /* literal */
4208 {
4209 c->sub.lit = t->base;
4210 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4211 "inflate: literal '%c'\n" :
4212 "inflate: literal 0x%02x\n", t->base));
4213 c->mode = LIT;
4214 break;
4215 }
4216 if (e & 16) /* length */
4217 {
4218 c->sub.copy.get = e & 15;
4219 c->len = t->base;
4220 c->mode = LENEXT;
4221 break;
4222 }
4223 if ((e & 64) == 0) /* next table */
4224 {
4225 c->sub.code.need = e;
4226 c->sub.code.tree = t->next;
4227 break;
4228 }
4229 if (e & 32) /* end of block */
4230 {
4231 Tracevv((stderr, "inflate: end of block\n"));
4232 c->mode = WASH;
4233 break;
4234 }
4235 c->mode = BADCODE; /* invalid code */
4236 z->msg = "invalid literal/length code";
4237 r = Z_DATA_ERROR;
4238 LEAVE
4239 case LENEXT: /* i: getting length extra (have base) */
4240 j = c->sub.copy.get;
4241 NEEDBITS(j)
4242 c->len += (uInt)b & inflate_mask[j];
4243 DUMPBITS(j)
4244 c->sub.code.need = c->dbits;
4245 c->sub.code.tree = c->dtree;
4246 Tracevv((stderr, "inflate: length %u\n", c->len));
4247 c->mode = DIST;
4248 case DIST: /* i: get distance next */
4249 j = c->sub.code.need;
4250 NEEDBITS(j)
4251 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4252 DUMPBITS(t->bits)
4253 e = (uInt)(t->exop);
4254 if (e & 16) /* distance */
4255 {
4256 c->sub.copy.get = e & 15;
4257 c->sub.copy.dist = t->base;
4258 c->mode = DISTEXT;
4259 break;
4260 }
4261 if ((e & 64) == 0) /* next table */
4262 {
4263 c->sub.code.need = e;
4264 c->sub.code.tree = t->next;
4265 break;
4266 }
4267 c->mode = BADCODE; /* invalid code */
4268 z->msg = "invalid distance code";
4269 r = Z_DATA_ERROR;
4270 LEAVE
4271 case DISTEXT: /* i: getting distance extra */
4272 j = c->sub.copy.get;
4273 NEEDBITS(j)
4274 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4275 DUMPBITS(j)
4276 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4277 c->mode = COPY;
4278 case COPY: /* o: copying bytes in window, waiting for space */
4279 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4280 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4281 s->end - (c->sub.copy.dist - (q - s->window)) :
4282 q - c->sub.copy.dist;
4283 #else
4284 f = q - c->sub.copy.dist;
4285 if ((uInt)(q - s->window) < c->sub.copy.dist)
4286 f = s->end - (c->sub.copy.dist - (q - s->window));
4287 #endif
4288 while (c->len)
4289 {
4290 NEEDOUT
4291 OUTBYTE(*f++)
4292 if (f == s->end)
4293 f = s->window;
4294 c->len--;
4295 }
4296 c->mode = START;
4297 break;
4298 case LIT: /* o: got literal, waiting for output space */
4299 NEEDOUT
4300 OUTBYTE(c->sub.lit)
4301 c->mode = START;
4302 break;
4303 case WASH: /* o: got eob, possibly more output */
4304 FLUSH
4305 if (s->read != s->write)
4306 LEAVE
4307 c->mode = END;
4308 case END:
4309 r = Z_STREAM_END;
4310 LEAVE
4311 case BADCODE: /* x: got error */
4312 r = Z_DATA_ERROR;
4313 LEAVE
4314 default:
4315 r = Z_STREAM_ERROR;
4316 LEAVE
4317 }
4318 }
4319
4320
4321 local void inflate_codes_free(c, z)
4322 inflate_codes_statef *c;
4323 z_stream *z;
4324 {
4325 ZFREE(z, c, sizeof(struct inflate_codes_state));
4326 Tracev((stderr, "inflate: codes free\n"));
4327 }
4328
4329 /*+++++*/
4330 /* inflate_util.c -- data and routines common to blocks and codes
4331 * Copyright (C) 1995 Mark Adler
4332 * For conditions of distribution and use, see copyright notice in zlib.h
4333 */
4334
4335 /* copy as much as possible from the sliding window to the output area */
4336 local int inflate_flush(s, z, r)
4337 inflate_blocks_statef *s;
4338 z_stream *z;
4339 int r;
4340 {
4341 uInt n;
4342 Bytef *p, *q;
4343
4344 /* local copies of source and destination pointers */
4345 p = z->next_out;
4346 q = s->read;
4347
4348 /* compute number of bytes to copy as far as end of window */
4349 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4350 if (n > z->avail_out) n = z->avail_out;
4351 if (n && r == Z_BUF_ERROR) r = Z_OK;
4352
4353 /* update counters */
4354 z->avail_out -= n;
4355 z->total_out += n;
4356
4357 /* update check information */
4358 if (s->checkfn != Z_NULL)
4359 s->check = (*s->checkfn)(s->check, q, n);
4360
4361 /* copy as far as end of window */
4362 if (p != NULL) {
4363 zmemcpy(p, q, n);
4364 p += n;
4365 }
4366 q += n;
4367
4368 /* see if more to copy at beginning of window */
4369 if (q == s->end)
4370 {
4371 /* wrap pointers */
4372 q = s->window;
4373 if (s->write == s->end)
4374 s->write = s->window;
4375
4376 /* compute bytes to copy */
4377 n = (uInt)(s->write - q);
4378 if (n > z->avail_out) n = z->avail_out;
4379 if (n && r == Z_BUF_ERROR) r = Z_OK;
4380
4381 /* update counters */
4382 z->avail_out -= n;
4383 z->total_out += n;
4384
4385 /* update check information */
4386 if (s->checkfn != Z_NULL)
4387 s->check = (*s->checkfn)(s->check, q, n);
4388
4389 /* copy */
4390 if (p != NULL) {
4391 zmemcpy(p, q, n);
4392 p += n;
4393 }
4394 q += n;
4395 }
4396
4397 /* update pointers */
4398 z->next_out = p;
4399 s->read = q;
4400
4401 /* done */
4402 return r;
4403 }
4404
4405
4406 /*+++++*/
4407 /* inffast.c -- process literals and length/distance pairs fast
4408 * Copyright (C) 1995 Mark Adler
4409 * For conditions of distribution and use, see copyright notice in zlib.h
4410 */
4411
4412 /* simplify the use of the inflate_huft type with some defines */
4413 #define base more.Base
4414 #define next more.Next
4415 #define exop word.what.Exop
4416 #define bits word.what.Bits
4417
4418 /* macros for bit input with no checking and for returning unused bytes */
4419 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4420 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4421
4422 /* Called with number of bytes left to write in window at least 258
4423 (the maximum string length) and number of input bytes available
4424 at least ten. The ten bytes are six bytes for the longest length/
4425 distance pair plus four bytes for overloading the bit buffer. */
4426
4427 local int inflate_fast(bl, bd, tl, td, s, z)
4428 uInt bl, bd;
4429 inflate_huft *tl, *td;
4430 inflate_blocks_statef *s;
4431 z_stream *z;
4432 {
4433 inflate_huft *t; /* temporary pointer */
4434 uInt e; /* extra bits or operation */
4435 uLong b; /* bit buffer */
4436 uInt k; /* bits in bit buffer */
4437 Bytef *p; /* input data pointer */
4438 uInt n; /* bytes available there */
4439 Bytef *q; /* output window write pointer */
4440 uInt m; /* bytes to end of window or read pointer */
4441 uInt ml; /* mask for literal/length tree */
4442 uInt md; /* mask for distance tree */
4443 uInt c; /* bytes to copy */
4444 uInt d; /* distance back to copy from */
4445 Bytef *r; /* copy source pointer */
4446
4447 /* load input, output, bit values */
4448 LOAD
4449
4450 /* initialize masks */
4451 ml = inflate_mask[bl];
4452 md = inflate_mask[bd];
4453
4454 /* do until not enough input or output space for fast loop */
4455 do { /* assume called with m >= 258 && n >= 10 */
4456 /* get literal/length code */
4457 GRABBITS(20) /* max bits for literal/length code */
4458 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4459 {
4460 DUMPBITS(t->bits)
4461 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4462 "inflate: * literal '%c'\n" :
4463 "inflate: * literal 0x%02x\n", t->base));
4464 *q++ = (Byte)t->base;
4465 m--;
4466 continue;
4467 }
4468 do {
4469 DUMPBITS(t->bits)
4470 if (e & 16)
4471 {
4472 /* get extra bits for length */
4473 e &= 15;
4474 c = t->base + ((uInt)b & inflate_mask[e]);
4475 DUMPBITS(e)
4476 Tracevv((stderr, "inflate: * length %u\n", c));
4477
4478 /* decode distance base of block to copy */
4479 GRABBITS(15); /* max bits for distance code */
4480 e = (t = td + ((uInt)b & md))->exop;
4481 do {
4482 DUMPBITS(t->bits)
4483 if (e & 16)
4484 {
4485 /* get extra bits to add to distance base */
4486 e &= 15;
4487 GRABBITS(e) /* get extra bits (up to 13) */
4488 d = t->base + ((uInt)b & inflate_mask[e]);
4489 DUMPBITS(e)
4490 Tracevv((stderr, "inflate: * distance %u\n", d));
4491
4492 /* do the copy */
4493 m -= c;
4494 if ((uInt)(q - s->window) >= d) /* offset before dest */
4495 { /* just copy */
4496 r = q - d;
4497 *q++ = *r++; c--; /* minimum count is three, */
4498 *q++ = *r++; c--; /* so unroll loop a little */
4499 }
4500 else /* else offset after destination */
4501 {
4502 e = d - (q - s->window); /* bytes from offset to end */
4503 r = s->end - e; /* pointer to offset */
4504 if (c > e) /* if source crosses, */
4505 {
4506 c -= e; /* copy to end of window */
4507 do {
4508 *q++ = *r++;
4509 } while (--e);
4510 r = s->window; /* copy rest from start of window */
4511 }
4512 }
4513 do { /* copy all or what's left */
4514 *q++ = *r++;
4515 } while (--c);
4516 break;
4517 }
4518 else if ((e & 64) == 0)
4519 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4520 else
4521 {
4522 z->msg = "invalid distance code";
4523 UNGRAB
4524 UPDATE
4525 return Z_DATA_ERROR;
4526 }
4527 } while (1);
4528 break;
4529 }
4530 if ((e & 64) == 0)
4531 {
4532 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4533 {
4534 DUMPBITS(t->bits)
4535 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4536 "inflate: * literal '%c'\n" :
4537 "inflate: * literal 0x%02x\n", t->base));
4538 *q++ = (Byte)t->base;
4539 m--;
4540 break;
4541 }
4542 }
4543 else if (e & 32)
4544 {
4545 Tracevv((stderr, "inflate: * end of block\n"));
4546 UNGRAB
4547 UPDATE
4548 return Z_STREAM_END;
4549 }
4550 else
4551 {
4552 z->msg = "invalid literal/length code";
4553 UNGRAB
4554 UPDATE
4555 return Z_DATA_ERROR;
4556 }
4557 } while (1);
4558 } while (m >= 258 && n >= 10);
4559
4560 /* not enough input or output--restore pointers and return */
4561 UNGRAB
4562 UPDATE
4563 return Z_OK;
4564 }
4565
4566
4567 /*+++++*/
4568 /* zutil.c -- target dependent utility functions for the compression library
4569 * Copyright (C) 1995 Jean-loup Gailly.
4570 * For conditions of distribution and use, see copyright notice in zlib.h
4571 */
4572
4573 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4574
4575 char *zlib_version = ZLIB_VERSION;
4576
4577 #ifndef NO_DEFLATE
4578 char *z_errmsg[] = {
4579 "stream end", /* Z_STREAM_END 1 */
4580 "", /* Z_OK 0 */
4581 "file error", /* Z_ERRNO (-1) */
4582 "stream error", /* Z_STREAM_ERROR (-2) */
4583 "data error", /* Z_DATA_ERROR (-3) */
4584 "insufficient memory", /* Z_MEM_ERROR (-4) */
4585 "buffer error", /* Z_BUF_ERROR (-5) */
4586 ""};
4587 #endif /* NO_DEFLATE */
4588
4589 /*+++++*/
4590 /* adler32.c -- compute the Adler-32 checksum of a data stream
4591 * Copyright (C) 1995 Mark Adler
4592 * For conditions of distribution and use, see copyright notice in zlib.h
4593 */
4594
4595 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4596
4597 #define BASE 65521L /* largest prime smaller than 65536 */
4598 #define NMAX 5552
4599 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4600
4601 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4602 #define DO2(buf) DO1(buf); DO1(buf);
4603 #define DO4(buf) DO2(buf); DO2(buf);
4604 #define DO8(buf) DO4(buf); DO4(buf);
4605 #define DO16(buf) DO8(buf); DO8(buf);
4606
4607 /* ========================================================================= */
4608 uLong adler32(adler, buf, len)
4609 uLong adler;
4610 Bytef *buf;
4611 uInt len;
4612 {
4613 unsigned long s1 = adler & 0xffff;
4614 unsigned long s2 = (adler >> 16) & 0xffff;
4615 int k;
4616
4617 if (buf == Z_NULL) return 1L;
4618
4619 while (len > 0) {
4620 k = len < NMAX ? len : NMAX;
4621 len -= k;
4622 while (k >= 16) {
4623 DO16(buf);
4624 k -= 16;
4625 }
4626 if (k != 0) do {
4627 DO1(buf);
4628 } while (--k);
4629 s1 %= BASE;
4630 s2 %= BASE;
4631 }
4632 return (s2 << 16) | s1;
4633 }