1 /*
2 * This file is derived from various .h and .c files from the zlib-0.95
3 * distribution by Jean-loup Gailly and Mark Adler, with some additions
4 * by Paul Mackerras to aid in implementing Deflate compression and
5 * decompression for PPP packets. See zlib.h for conditions of
6 * distribution and use.
7 *
8 * Changes that have been made include:
9 * - changed functions not used outside this file to "local"
10 * - added minCompression parameter to deflateInit2
11 * - added Z_PACKET_FLUSH (see zlib.h for details)
12 * - added inflateIncomp
13 *
14 * $Id: zlib.c,v 1.2 1999/04/01 07:26:30 paulus Exp $
15 */
16
17
18 /*+++++*/
19 /* zutil.h -- internal interface and configuration of the compression library
20 * Copyright (C) 1995 Jean-loup Gailly.
21 * For conditions of distribution and use, see copyright notice in zlib.h
22 */
23
24 /* WARNING: this file should *not* be used by applications. It is
25 part of the implementation of the compression library and is
26 subject to change. Applications should only use zlib.h.
27 */
28
29 /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */
30
31 #define _Z_UTIL_H
32
33 #include "zlib.h"
34
35 #ifdef STDC
36 # include <string.h>
37 #endif
38
39 #ifndef local
40 # define local static
41 #endif
42 /* compile with -Dlocal if your debugger can't find static symbols */
43
44 #define FAR
45
46 typedef unsigned char uch;
47 typedef uch FAR uchf;
48 typedef unsigned short ush;
49 typedef ush FAR ushf;
50 typedef unsigned long ulg;
51
52 extern char *z_errmsg[]; /* indexed by 1-zlib_error */
53
54 #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err)
55 /* To be used only when the state is known to be valid */
56
57 #ifndef NULL
58 #define NULL ((void *) 0)
59 #endif
60
61 /* common constants */
62
63 #define DEFLATED 8
64
65 #ifndef DEF_WBITS
66 # define DEF_WBITS MAX_WBITS
67 #endif
68 /* default windowBits for decompression. MAX_WBITS is for compression only */
69
70 #if MAX_MEM_LEVEL >= 8
71 # define DEF_MEM_LEVEL 8
72 #else
73 # define DEF_MEM_LEVEL MAX_MEM_LEVEL
74 #endif
75 /* default memLevel */
76
77 #define STORED_BLOCK 0
78 #define STATIC_TREES 1
79 #define DYN_TREES 2
80 /* The three kinds of block type */
81
82 #define MIN_MATCH 3
83 #define MAX_MATCH 258
84 /* The minimum and maximum match lengths */
85
86 /* functions */
87
88 #if defined(STDC) && !defined(HAVE_MEMCPY) && !defined(NO_MEMCPY)
89 # define HAVE_MEMCPY
90 #endif
91 #ifdef HAVE_MEMCPY
92 # define zmemcpy memcpy
93 # define zmemzero(dest, len) memset(dest, 0, len)
94 #else
95 # define zmemcpy(d, s, n) bcopy((s), (d), (n))
96 # define zmemzero bzero
97 #endif
98
99 /* Diagnostic functions */
100 #ifdef DEBUG_ZLIB
101 # include <stdio.h>
102 # ifndef verbose
103 # define verbose 0
104 # endif
105 # define Assert(cond,msg) {if(!(cond)) z_error(msg);}
106 # define Trace(x) fprintf x
107 # define Tracev(x) {if (verbose) fprintf x ;}
108 # define Tracevv(x) {if (verbose>1) fprintf x ;}
109 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
110 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
111 #else
112 # define Assert(cond,msg)
113 # define Trace(x)
114 # define Tracev(x)
115 # define Tracevv(x)
116 # define Tracec(c,x)
117 # define Tracecv(c,x)
118 #endif
119
120
121 typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len));
122
123 /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */
124 /* void zcfree OF((voidpf opaque, voidpf ptr)); */
125
126 #define ZALLOC(strm, items, size) \
127 (*((strm)->zalloc))((strm)->opaque, (items), (size))
128 #define ZFREE(strm, addr, size) \
129 (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size))
130 #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);}
131
132 /* deflate.h -- internal compression state
133 * Copyright (C) 1995 Jean-loup Gailly
134 * For conditions of distribution and use, see copyright notice in zlib.h
135 */
136
137 /* WARNING: this file should *not* be used by applications. It is
138 part of the implementation of the compression library and is
139 subject to change. Applications should only use zlib.h.
140 */
141
142
143 /*+++++*/
144 /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */
145
146 /* ===========================================================================
147 * Internal compression state.
148 */
149
150 /* Data type */
151 #define BINARY 0
152 #define ASCII 1
153 #define UNKNOWN 2
154
155 #define LENGTH_CODES 29
156 /* number of length codes, not counting the special END_BLOCK code */
157
158 #define LITERALS 256
159 /* number of literal bytes 0..255 */
160
161 #define L_CODES (LITERALS+1+LENGTH_CODES)
162 /* number of Literal or Length codes, including the END_BLOCK code */
163
164 #define D_CODES 30
165 /* number of distance codes */
166
167 #define BL_CODES 19
168 /* number of codes used to transfer the bit lengths */
169
170 #define HEAP_SIZE (2*L_CODES+1)
171 /* maximum heap size */
172
173 #define MAX_BITS 15
174 /* All codes must not exceed MAX_BITS bits */
175
176 #define INIT_STATE 42
177 #define BUSY_STATE 113
178 #define FLUSH_STATE 124
179 #define FINISH_STATE 666
180 /* Stream status */
181
182
183 /* Data structure describing a single value and its code string. */
184 typedef struct ct_data_s {
185 union {
186 ush freq; /* frequency count */
187 ush code; /* bit string */
188 } fc;
189 union {
190 ush dad; /* father node in Huffman tree */
191 ush len; /* length of bit string */
192 } dl;
193 } FAR ct_data;
194
195 #define Freq fc.freq
196 #define Code fc.code
197 #define Dad dl.dad
198 #define Len dl.len
199
200 typedef struct static_tree_desc_s static_tree_desc;
201
202 typedef struct tree_desc_s {
203 ct_data *dyn_tree; /* the dynamic tree */
204 int max_code; /* largest code with non zero frequency */
205 static_tree_desc *stat_desc; /* the corresponding static tree */
206 } FAR tree_desc;
207
208 typedef ush Pos;
209 typedef Pos FAR Posf;
210 typedef unsigned IPos;
211
212 /* A Pos is an index in the character window. We use short instead of int to
213 * save space in the various tables. IPos is used only for parameter passing.
214 */
215
216 typedef struct deflate_state {
217 z_stream *strm; /* pointer back to this zlib stream */
218 int status; /* as the name implies */
219 Bytef *pending_buf; /* output still pending */
220 Bytef *pending_out; /* next pending byte to output to the stream */
221 int pending; /* nb of bytes in the pending buffer */
222 uLong adler; /* adler32 of uncompressed data */
223 int noheader; /* suppress zlib header and adler32 */
224 Byte data_type; /* UNKNOWN, BINARY or ASCII */
225 Byte method; /* STORED (for zip only) or DEFLATED */
226 int minCompr; /* min size decrease for Z_FLUSH_NOSTORE */
227
228 /* used by deflate.c: */
229
230 uInt w_size; /* LZ77 window size (32K by default) */
231 uInt w_bits; /* log2(w_size) (8..16) */
232 uInt w_mask; /* w_size - 1 */
233
234 Bytef *window;
235 /* Sliding window. Input bytes are read into the second half of the window,
236 * and move to the first half later to keep a dictionary of at least wSize
237 * bytes. With this organization, matches are limited to a distance of
238 * wSize-MAX_MATCH bytes, but this ensures that IO is always
239 * performed with a length multiple of the block size. Also, it limits
240 * the window size to 64K, which is quite useful on MSDOS.
241 * To do: use the user input buffer as sliding window.
242 */
243
244 ulg window_size;
245 /* Actual size of window: 2*wSize, except when the user input buffer
246 * is directly used as sliding window.
247 */
248
249 Posf *prev;
250 /* Link to older string with same hash index. To limit the size of this
251 * array to 64K, this link is maintained only for the last 32K strings.
252 * An index in this array is thus a window index modulo 32K.
253 */
254
255 Posf *head; /* Heads of the hash chains or NIL. */
256
257 uInt ins_h; /* hash index of string to be inserted */
258 uInt hash_size; /* number of elements in hash table */
259 uInt hash_bits; /* log2(hash_size) */
260 uInt hash_mask; /* hash_size-1 */
261
262 uInt hash_shift;
263 /* Number of bits by which ins_h must be shifted at each input
264 * step. It must be such that after MIN_MATCH steps, the oldest
265 * byte no longer takes part in the hash key, that is:
266 * hash_shift * MIN_MATCH >= hash_bits
267 */
268
269 long block_start;
270 /* Window position at the beginning of the current output block. Gets
271 * negative when the window is moved backwards.
272 */
273
274 uInt match_length; /* length of best match */
275 IPos prev_match; /* previous match */
276 int match_available; /* set if previous match exists */
277 uInt strstart; /* start of string to insert */
278 uInt match_start; /* start of matching string */
279 uInt lookahead; /* number of valid bytes ahead in window */
280
281 uInt prev_length;
282 /* Length of the best match at previous step. Matches not greater than this
283 * are discarded. This is used in the lazy match evaluation.
284 */
285
286 uInt max_chain_length;
287 /* To speed up deflation, hash chains are never searched beyond this
288 * length. A higher limit improves compression ratio but degrades the
289 * speed.
290 */
291
292 uInt max_lazy_match;
293 /* Attempt to find a better match only when the current match is strictly
294 * smaller than this value. This mechanism is used only for compression
295 * levels >= 4.
296 */
297 # define max_insert_length max_lazy_match
298 /* Insert new strings in the hash table only if the match length is not
299 * greater than this length. This saves time but degrades compression.
300 * max_insert_length is used only for compression levels <= 3.
301 */
302
303 int level; /* compression level (1..9) */
304 int strategy; /* favor or force Huffman coding*/
305
306 uInt good_match;
307 /* Use a faster search when the previous match is longer than this */
308
309 int nice_match; /* Stop searching when current match exceeds this */
310
311 /* used by trees.c: */
312 /* Didn't use ct_data typedef below to supress compiler warning */
313 struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */
314 struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */
315 struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */
316
317 struct tree_desc_s l_desc; /* desc. for literal tree */
318 struct tree_desc_s d_desc; /* desc. for distance tree */
319 struct tree_desc_s bl_desc; /* desc. for bit length tree */
320
321 ush bl_count[MAX_BITS+1];
322 /* number of codes at each bit length for an optimal tree */
323
324 int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
325 int heap_len; /* number of elements in the heap */
326 int heap_max; /* element of largest frequency */
327 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
328 * The same heap array is used to build all trees.
329 */
330
331 uch depth[2*L_CODES+1];
332 /* Depth of each subtree used as tie breaker for trees of equal frequency
333 */
334
335 uchf *l_buf; /* buffer for literals or lengths */
336
337 uInt lit_bufsize;
338 /* Size of match buffer for literals/lengths. There are 4 reasons for
339 * limiting lit_bufsize to 64K:
340 * - frequencies can be kept in 16 bit counters
341 * - if compression is not successful for the first block, all input
342 * data is still in the window so we can still emit a stored block even
343 * when input comes from standard input. (This can also be done for
344 * all blocks if lit_bufsize is not greater than 32K.)
345 * - if compression is not successful for a file smaller than 64K, we can
346 * even emit a stored file instead of a stored block (saving 5 bytes).
347 * This is applicable only for zip (not gzip or zlib).
348 * - creating new Huffman trees less frequently may not provide fast
349 * adaptation to changes in the input data statistics. (Take for
350 * example a binary file with poorly compressible code followed by
351 * a highly compressible string table.) Smaller buffer sizes give
352 * fast adaptation but have of course the overhead of transmitting
353 * trees more frequently.
354 * - I can't count above 4
355 */
356
357 uInt last_lit; /* running index in l_buf */
358
359 ushf *d_buf;
360 /* Buffer for distances. To simplify the code, d_buf and l_buf have
361 * the same number of elements. To use different lengths, an extra flag
362 * array would be necessary.
363 */
364
365 ulg opt_len; /* bit length of current block with optimal trees */
366 ulg static_len; /* bit length of current block with static trees */
367 ulg compressed_len; /* total bit length of compressed file */
368 uInt matches; /* number of string matches in current block */
369 int last_eob_len; /* bit length of EOB code for last block */
370
371 #ifdef DEBUG_ZLIB
372 ulg bits_sent; /* bit length of the compressed data */
373 #endif
374
375 ush bi_buf;
376 /* Output buffer. bits are inserted starting at the bottom (least
377 * significant bits).
378 */
379 int bi_valid;
380 /* Number of valid bits in bi_buf. All bits above the last valid bit
381 * are always zero.
382 */
383
384 uInt blocks_in_packet;
385 /* Number of blocks produced since the last time Z_PACKET_FLUSH
386 * was used.
387 */
388
389 } FAR deflate_state;
390
391 /* Output a byte on the stream.
392 * IN assertion: there is enough room in pending_buf.
393 */
394 #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);}
395
396
397 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
398 /* Minimum amount of lookahead, except at the end of the input file.
399 * See deflate.c for comments about the MIN_MATCH+1.
400 */
401
402 #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD)
403 /* In order to simplify the code, particularly on 16 bit machines, match
404 * distances are limited to MAX_DIST instead of WSIZE.
405 */
406
407 /* in trees.c */
408 local void ct_init OF((deflate_state *s));
409 local int ct_tally OF((deflate_state *s, int dist, int lc));
410 local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
411 int flush));
412 local void ct_align OF((deflate_state *s));
413 local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
414 int eof));
415 local void ct_stored_type_only OF((deflate_state *s));
416
417
418 /*+++++*/
419 /* deflate.c -- compress data using the deflation algorithm
420 * Copyright (C) 1995 Jean-loup Gailly.
421 * For conditions of distribution and use, see copyright notice in zlib.h
422 */
423
424 /*
425 * ALGORITHM
426 *
427 * The "deflation" process depends on being able to identify portions
428 * of the input text which are identical to earlier input (within a
429 * sliding window trailing behind the input currently being processed).
430 *
431 * The most straightforward technique turns out to be the fastest for
432 * most input files: try all possible matches and select the longest.
433 * The key feature of this algorithm is that insertions into the string
434 * dictionary are very simple and thus fast, and deletions are avoided
435 * completely. Insertions are performed at each input character, whereas
436 * string matches are performed only when the previous match ends. So it
437 * is preferable to spend more time in matches to allow very fast string
438 * insertions and avoid deletions. The matching algorithm for small
439 * strings is inspired from that of Rabin & Karp. A brute force approach
440 * is used to find longer strings when a small match has been found.
441 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
442 * (by Leonid Broukhis).
443 * A previous version of this file used a more sophisticated algorithm
444 * (by Fiala and Greene) which is guaranteed to run in linear amortized
445 * time, but has a larger average cost, uses more memory and is patented.
446 * However the F&G algorithm may be faster for some highly redundant
447 * files if the parameter max_chain_length (described below) is too large.
448 *
449 * ACKNOWLEDGEMENTS
450 *
451 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
452 * I found it in 'freeze' written by Leonid Broukhis.
453 * Thanks to many people for bug reports and testing.
454 *
455 * REFERENCES
456 *
457 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
458 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
459 *
460 * A description of the Rabin and Karp algorithm is given in the book
461 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
462 *
463 * Fiala,E.R., and Greene,D.H.
464 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
465 *
466 */
467
468 /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */
469
470 local char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly ";
471 /*
472 If you use the zlib library in a product, an acknowledgment is welcome
473 in the documentation of your product. If for some reason you cannot
474 include such an acknowledgment, I would appreciate that you keep this
475 copyright string in the executable of your product.
476 */
477
478 #define NIL 0
479 /* Tail of hash chains */
480
481 #ifndef TOO_FAR
482 # define TOO_FAR 4096
483 #endif
484 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
485
486 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
487 /* Minimum amount of lookahead, except at the end of the input file.
488 * See deflate.c for comments about the MIN_MATCH+1.
489 */
490
491 /* Values for max_lazy_match, good_match and max_chain_length, depending on
492 * the desired pack level (0..9). The values given below have been tuned to
493 * exclude worst case performance for pathological files. Better values may be
494 * found for specific files.
495 */
496
497 typedef struct config_s {
498 ush good_length; /* reduce lazy search above this match length */
499 ush max_lazy; /* do not perform lazy search above this match length */
500 ush nice_length; /* quit search above this match length */
501 ush max_chain;
502 } config;
503
504 local config configuration_table[10] = {
505 /* good lazy nice chain */
506 /* 0 */ {0, 0, 0, 0}, /* store only */
507 /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */
508 /* 2 */ {4, 5, 16, 8},
509 /* 3 */ {4, 6, 32, 32},
510
511 /* 4 */ {4, 4, 16, 16}, /* lazy matches */
512 /* 5 */ {8, 16, 32, 32},
513 /* 6 */ {8, 16, 128, 128},
514 /* 7 */ {8, 32, 128, 256},
515 /* 8 */ {32, 128, 258, 1024},
516 /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */
517
518 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
519 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
520 * meaning.
521 */
522
523 #define EQUAL 0
524 /* result of memcmp for equal strings */
525
526 /* ===========================================================================
527 * Prototypes for local functions.
528 */
529
530 local void fill_window OF((deflate_state *s));
531 local int deflate_fast OF((deflate_state *s, int flush));
532 local int deflate_slow OF((deflate_state *s, int flush));
533 local void lm_init OF((deflate_state *s));
534 local int longest_match OF((deflate_state *s, IPos cur_match));
535 local void putShortMSB OF((deflate_state *s, uInt b));
536 local void flush_pending OF((z_stream *strm));
537 local int read_buf OF((z_stream *strm, charf *buf, unsigned size));
538 #ifdef ASMV
539 void match_init OF((void)); /* asm code initialization */
540 #endif
541
542 #ifdef DEBUG_ZLIB
543 local void check_match OF((deflate_state *s, IPos start, IPos match,
544 int length));
545 #endif
546
547
548 /* ===========================================================================
549 * Update a hash value with the given input byte
550 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
551 * input characters, so that a running hash key can be computed from the
552 * previous key instead of complete recalculation each time.
553 */
554 #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask)
555
556
557 /* ===========================================================================
558 * Insert string str in the dictionary and set match_head to the previous head
559 * of the hash chain (the most recent string with same hash key). Return
560 * the previous length of the hash chain.
561 * IN assertion: all calls to to INSERT_STRING are made with consecutive
562 * input characters and the first MIN_MATCH bytes of str are valid
563 * (except for the last MIN_MATCH-1 bytes of the input file).
564 */
565 #define INSERT_STRING(s, str, match_head) \
566 (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \
567 s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \
568 s->head[s->ins_h] = (str))
569
570 /* ===========================================================================
571 * Initialize the hash table (avoiding 64K overflow for 16 bit systems).
572 * prev[] will be initialized on the fly.
573 */
574 #define CLEAR_HASH(s) \
575 s->head[s->hash_size-1] = NIL; \
576 zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
577
578 /* ========================================================================= */
deflateInit(strm,level)579 int deflateInit (strm, level)
580 z_stream *strm;
581 int level;
582 {
583 return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
584 0, 0);
585 /* To do: ignore strm->next_in if we use it as window */
586 }
587
588 /* ========================================================================= */
deflateInit2(strm,level,method,windowBits,memLevel,strategy,minCompression)589 int deflateInit2 (strm, level, method, windowBits, memLevel,
590 strategy, minCompression)
591 z_stream *strm;
592 int level;
593 int method;
594 int windowBits;
595 int memLevel;
596 int strategy;
597 int minCompression;
598 {
599 deflate_state *s;
600 int noheader = 0;
601
602 if (strm == Z_NULL) return Z_STREAM_ERROR;
603
604 strm->msg = Z_NULL;
605 /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */
606 /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */
607
608 if (level == Z_DEFAULT_COMPRESSION) level = 6;
609
610 if (windowBits < 0) { /* undocumented feature: suppress zlib header */
611 noheader = 1;
612 windowBits = -windowBits;
613 }
614 if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED ||
615 windowBits < 8 || windowBits > 15 || level < 1 || level > 9) {
616 return Z_STREAM_ERROR;
617 }
618 s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state));
619 if (s == Z_NULL) return Z_MEM_ERROR;
620 strm->state = (struct internal_state FAR *)s;
621 s->strm = strm;
622
623 s->noheader = noheader;
624 s->w_bits = windowBits;
625 s->w_size = 1 << s->w_bits;
626 s->w_mask = s->w_size - 1;
627
628 s->hash_bits = memLevel + 7;
629 s->hash_size = 1 << s->hash_bits;
630 s->hash_mask = s->hash_size - 1;
631 s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH);
632
633 s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte));
634 s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos));
635 s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos));
636
637 s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
638
639 s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush));
640
641 if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL ||
642 s->pending_buf == Z_NULL) {
643 strm->msg = z_errmsg[1-Z_MEM_ERROR];
644 deflateEnd (strm);
645 return Z_MEM_ERROR;
646 }
647 s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]);
648 s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]);
649 /* We overlay pending_buf and d_buf+l_buf. This works since the average
650 * output size for (length,distance) codes is <= 32 bits (worst case
651 * is 15+15+13=33).
652 */
653
654 s->level = level;
655 s->strategy = strategy;
656 s->method = (Byte)method;
657 s->minCompr = minCompression;
658 s->blocks_in_packet = 0;
659
660 return deflateReset(strm);
661 }
662
663 /* ========================================================================= */
deflateReset(strm)664 int deflateReset (strm)
665 z_stream *strm;
666 {
667 deflate_state *s;
668
669 if (strm == Z_NULL || strm->state == Z_NULL ||
670 strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR;
671
672 strm->total_in = strm->total_out = 0;
673 strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */
674 strm->data_type = Z_UNKNOWN;
675
676 s = (deflate_state *)strm->state;
677 s->pending = 0;
678 s->pending_out = s->pending_buf;
679
680 if (s->noheader < 0) {
681 s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */
682 }
683 s->status = s->noheader ? BUSY_STATE : INIT_STATE;
684 s->adler = 1;
685
686 ct_init(s);
687 lm_init(s);
688
689 return Z_OK;
690 }
691
692 /* =========================================================================
693 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
694 * IN assertion: the stream state is correct and there is enough room in
695 * pending_buf.
696 */
putShortMSB(s,b)697 local void putShortMSB (s, b)
698 deflate_state *s;
699 uInt b;
700 {
701 put_byte(s, (Byte)(b >> 8));
702 put_byte(s, (Byte)(b & 0xff));
703 }
704
705 /* =========================================================================
706 * Flush as much pending output as possible.
707 */
flush_pending(strm)708 local void flush_pending(strm)
709 z_stream *strm;
710 {
711 deflate_state *state = (deflate_state *) strm->state;
712 unsigned len = state->pending;
713
714 if (len > strm->avail_out) len = strm->avail_out;
715 if (len == 0) return;
716
717 if (strm->next_out != NULL) {
718 zmemcpy(strm->next_out, state->pending_out, len);
719 strm->next_out += len;
720 }
721 state->pending_out += len;
722 strm->total_out += len;
723 strm->avail_out -= len;
724 state->pending -= len;
725 if (state->pending == 0) {
726 state->pending_out = state->pending_buf;
727 }
728 }
729
730 /* ========================================================================= */
deflate(strm,flush)731 int deflate (strm, flush)
732 z_stream *strm;
733 int flush;
734 {
735 deflate_state *state = (deflate_state *) strm->state;
736
737 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
738
739 if (strm->next_in == Z_NULL && strm->avail_in != 0) {
740 ERR_RETURN(strm, Z_STREAM_ERROR);
741 }
742 if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR);
743
744 state->strm = strm; /* just in case */
745
746 /* Write the zlib header */
747 if (state->status == INIT_STATE) {
748
749 uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8;
750 uInt level_flags = (state->level-1) >> 1;
751
752 if (level_flags > 3) level_flags = 3;
753 header |= (level_flags << 6);
754 header += 31 - (header % 31);
755
756 state->status = BUSY_STATE;
757 putShortMSB(state, header);
758 }
759
760 /* Flush as much pending output as possible */
761 if (state->pending != 0) {
762 flush_pending(strm);
763 if (strm->avail_out == 0) return Z_OK;
764 }
765
766 /* If we came back in here to get the last output from
767 * a previous flush, we're done for now.
768 */
769 if (state->status == FLUSH_STATE) {
770 state->status = BUSY_STATE;
771 if (flush != Z_NO_FLUSH && flush != Z_FINISH)
772 return Z_OK;
773 }
774
775 /* User must not provide more input after the first FINISH: */
776 if (state->status == FINISH_STATE && strm->avail_in != 0) {
777 ERR_RETURN(strm, Z_BUF_ERROR);
778 }
779
780 /* Start a new block or continue the current one.
781 */
782 if (strm->avail_in != 0 || state->lookahead != 0 ||
783 (flush == Z_FINISH && state->status != FINISH_STATE)) {
784 int quit;
785
786 if (flush == Z_FINISH) {
787 state->status = FINISH_STATE;
788 }
789 if (state->level <= 3) {
790 quit = deflate_fast(state, flush);
791 } else {
792 quit = deflate_slow(state, flush);
793 }
794 if (quit || strm->avail_out == 0)
795 return Z_OK;
796 /* If flush != Z_NO_FLUSH && avail_out == 0, the next call
797 * of deflate should use the same flush parameter to make sure
798 * that the flush is complete. So we don't have to output an
799 * empty block here, this will be done at next call. This also
800 * ensures that for a very small output buffer, we emit at most
801 * one empty block.
802 */
803 }
804
805 /* If a flush was requested, we have a little more to output now. */
806 if (flush != Z_NO_FLUSH && flush != Z_FINISH
807 && state->status != FINISH_STATE) {
808 switch (flush) {
809 case Z_PARTIAL_FLUSH:
810 ct_align(state);
811 break;
812 case Z_PACKET_FLUSH:
813 /* Output just the 3-bit `stored' block type value,
814 but not a zero length. */
815 ct_stored_type_only(state);
816 break;
817 default:
818 ct_stored_block(state, (char*)0, 0L, 0);
819 /* For a full flush, this empty block will be recognized
820 * as a special marker by inflate_sync().
821 */
822 if (flush == Z_FULL_FLUSH) {
823 CLEAR_HASH(state); /* forget history */
824 }
825 }
826 flush_pending(strm);
827 if (strm->avail_out == 0) {
828 /* We'll have to come back to get the rest of the output;
829 * this ensures we don't output a second zero-length stored
830 * block (or whatever).
831 */
832 state->status = FLUSH_STATE;
833 return Z_OK;
834 }
835 }
836
837 Assert(strm->avail_out > 0, "bug2");
838
839 if (flush != Z_FINISH) return Z_OK;
840 if (state->noheader) return Z_STREAM_END;
841
842 /* Write the zlib trailer (adler32) */
843 putShortMSB(state, (uInt)(state->adler >> 16));
844 putShortMSB(state, (uInt)(state->adler & 0xffff));
845 flush_pending(strm);
846 /* If avail_out is zero, the application will call deflate again
847 * to flush the rest.
848 */
849 state->noheader = -1; /* write the trailer only once! */
850 return state->pending != 0 ? Z_OK : Z_STREAM_END;
851 }
852
853 /* ========================================================================= */
deflateEnd(strm)854 int deflateEnd (strm)
855 z_stream *strm;
856 {
857 deflate_state *state = (deflate_state *) strm->state;
858
859 if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR;
860
861 TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte));
862 TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos));
863 TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos));
864 TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush));
865
866 ZFREE(strm, state, sizeof(deflate_state));
867 strm->state = Z_NULL;
868
869 return Z_OK;
870 }
871
872 /* ===========================================================================
873 * Read a new buffer from the current input stream, update the adler32
874 * and total number of bytes read.
875 */
read_buf(strm,buf,size)876 local int read_buf(strm, buf, size)
877 z_stream *strm;
878 charf *buf;
879 unsigned size;
880 {
881 unsigned len = strm->avail_in;
882 deflate_state *state = (deflate_state *) strm->state;
883
884 if (len > size) len = size;
885 if (len == 0) return 0;
886
887 strm->avail_in -= len;
888
889 if (!state->noheader) {
890 state->adler = adler32(state->adler, strm->next_in, len);
891 }
892 zmemcpy(buf, strm->next_in, len);
893 strm->next_in += len;
894 strm->total_in += len;
895
896 return (int)len;
897 }
898
899 /* ===========================================================================
900 * Initialize the "longest match" routines for a new zlib stream
901 */
lm_init(s)902 local void lm_init (s)
903 deflate_state *s;
904 {
905 s->window_size = (ulg)2L*s->w_size;
906
907 CLEAR_HASH(s);
908
909 /* Set the default configuration parameters:
910 */
911 s->max_lazy_match = configuration_table[s->level].max_lazy;
912 s->good_match = configuration_table[s->level].good_length;
913 s->nice_match = configuration_table[s->level].nice_length;
914 s->max_chain_length = configuration_table[s->level].max_chain;
915
916 s->strstart = 0;
917 s->block_start = 0L;
918 s->lookahead = 0;
919 s->match_length = MIN_MATCH-1;
920 s->match_available = 0;
921 s->ins_h = 0;
922 #ifdef ASMV
923 match_init(); /* initialize the asm code */
924 #endif
925 }
926
927 /* ===========================================================================
928 * Set match_start to the longest match starting at the given string and
929 * return its length. Matches shorter or equal to prev_length are discarded,
930 * in which case the result is equal to prev_length and match_start is
931 * garbage.
932 * IN assertions: cur_match is the head of the hash chain for the current
933 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
934 */
935 #ifndef ASMV
936 /* For 80x86 and 680x0, an optimized version will be provided in match.asm or
937 * match.S. The code will be functionally equivalent.
938 */
longest_match(s,cur_match)939 local int longest_match(s, cur_match)
940 deflate_state *s;
941 IPos cur_match; /* current match */
942 {
943 unsigned chain_length = s->max_chain_length;/* max hash chain length */
944 register Bytef *scan = s->window + s->strstart; /* current string */
945 register Bytef *match; /* matched string */
946 register int len; /* length of current match */
947 int best_len = s->prev_length; /* best match length so far */
948 IPos limit = s->strstart > (IPos)MAX_DIST(s) ?
949 s->strstart - (IPos)MAX_DIST(s) : NIL;
950 /* Stop when cur_match becomes <= limit. To simplify the code,
951 * we prevent matches with the string of window index 0.
952 */
953 Posf *prev = s->prev;
954 uInt wmask = s->w_mask;
955
956 #ifdef UNALIGNED_OK
957 /* Compare two bytes at a time. Note: this is not always beneficial.
958 * Try with and without -DUNALIGNED_OK to check.
959 */
960 register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1;
961 register ush scan_start = *(ushf*)scan;
962 register ush scan_end = *(ushf*)(scan+best_len-1);
963 #else
964 register Bytef *strend = s->window + s->strstart + MAX_MATCH;
965 register Byte scan_end1 = scan[best_len-1];
966 register Byte scan_end = scan[best_len];
967 #endif
968
969 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
970 * It is easy to get rid of this optimization if necessary.
971 */
972 Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever");
973
974 /* Do not waste too much time if we already have a good match: */
975 if (s->prev_length >= s->good_match) {
976 chain_length >>= 2;
977 }
978 Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead");
979
980 do {
981 Assert(cur_match < s->strstart, "no future");
982 match = s->window + cur_match;
983
984 /* Skip to next match if the match length cannot increase
985 * or if the match length is less than 2:
986 */
987 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
988 /* This code assumes sizeof(unsigned short) == 2. Do not use
989 * UNALIGNED_OK if your compiler uses a different size.
990 */
991 if (*(ushf*)(match+best_len-1) != scan_end ||
992 *(ushf*)match != scan_start) continue;
993
994 /* It is not necessary to compare scan[2] and match[2] since they are
995 * always equal when the other bytes match, given that the hash keys
996 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
997 * strstart+3, +5, ... up to strstart+257. We check for insufficient
998 * lookahead only every 4th comparison; the 128th check will be made
999 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1000 * necessary to put more guard bytes at the end of the window, or
1001 * to check more often for insufficient lookahead.
1002 */
1003 Assert(scan[2] == match[2], "scan[2]?");
1004 scan++, match++;
1005 do {
1006 } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1007 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1008 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1009 *(ushf*)(scan+=2) == *(ushf*)(match+=2) &&
1010 scan < strend);
1011 /* The funny "do {}" generates better code on most compilers */
1012
1013 /* Here, scan <= window+strstart+257 */
1014 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1015 if (*scan == *match) scan++;
1016
1017 len = (MAX_MATCH - 1) - (int)(strend-scan);
1018 scan = strend - (MAX_MATCH-1);
1019
1020 #else /* UNALIGNED_OK */
1021
1022 if (match[best_len] != scan_end ||
1023 match[best_len-1] != scan_end1 ||
1024 *match != *scan ||
1025 *++match != scan[1]) continue;
1026
1027 /* The check at best_len-1 can be removed because it will be made
1028 * again later. (This heuristic is not always a win.)
1029 * It is not necessary to compare scan[2] and match[2] since they
1030 * are always equal when the other bytes match, given that
1031 * the hash keys are equal and that HASH_BITS >= 8.
1032 */
1033 scan += 2, match++;
1034 Assert(*scan == *match, "match[2]?");
1035
1036 /* We check for insufficient lookahead only every 8th comparison;
1037 * the 256th check will be made at strstart+258.
1038 */
1039 do {
1040 } while (*++scan == *++match && *++scan == *++match &&
1041 *++scan == *++match && *++scan == *++match &&
1042 *++scan == *++match && *++scan == *++match &&
1043 *++scan == *++match && *++scan == *++match &&
1044 scan < strend);
1045
1046 Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan");
1047
1048 len = MAX_MATCH - (int)(strend - scan);
1049 scan = strend - MAX_MATCH;
1050
1051 #endif /* UNALIGNED_OK */
1052
1053 if (len > best_len) {
1054 s->match_start = cur_match;
1055 best_len = len;
1056 if (len >= s->nice_match) break;
1057 #ifdef UNALIGNED_OK
1058 scan_end = *(ushf*)(scan+best_len-1);
1059 #else
1060 scan_end1 = scan[best_len-1];
1061 scan_end = scan[best_len];
1062 #endif
1063 }
1064 } while ((cur_match = prev[cur_match & wmask]) > limit
1065 && --chain_length != 0);
1066
1067 return best_len;
1068 }
1069 #endif /* ASMV */
1070
1071 #ifdef DEBUG_ZLIB
1072 /* ===========================================================================
1073 * Check that the match at match_start is indeed a match.
1074 */
check_match(s,start,match,length)1075 local void check_match(s, start, match, length)
1076 deflate_state *s;
1077 IPos start, match;
1078 int length;
1079 {
1080 /* check that the match is indeed a match */
1081 if (memcmp((charf *)s->window + match,
1082 (charf *)s->window + start, length) != EQUAL) {
1083 fprintf(stderr,
1084 " start %u, match %u, length %d\n",
1085 start, match, length);
1086 do { fprintf(stderr, "%c%c", s->window[match++],
1087 s->window[start++]); } while (--length != 0);
1088 z_error("invalid match");
1089 }
1090 if (verbose > 1) {
1091 fprintf(stderr,"\\[%d,%d]", start-match, length);
1092 do { putc(s->window[start++], stderr); } while (--length != 0);
1093 }
1094 }
1095 #else
1096 # define check_match(s, start, match, length)
1097 #endif
1098
1099 /* ===========================================================================
1100 * Fill the window when the lookahead becomes insufficient.
1101 * Updates strstart and lookahead.
1102 *
1103 * IN assertion: lookahead < MIN_LOOKAHEAD
1104 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
1105 * At least one byte has been read, or avail_in == 0; reads are
1106 * performed for at least two bytes (required for the zip translate_eol
1107 * option -- not supported here).
1108 */
fill_window(s)1109 local void fill_window(s)
1110 deflate_state *s;
1111 {
1112 register unsigned n, m;
1113 register Posf *p;
1114 unsigned more; /* Amount of free space at the end of the window. */
1115 uInt wsize = s->w_size;
1116
1117 do {
1118 more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);
1119
1120 /* Deal with !@#$% 64K limit: */
1121 if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
1122 more = wsize;
1123 } else if (more == (unsigned)(-1)) {
1124 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1125 * and lookahead == 1 (input done one byte at time)
1126 */
1127 more--;
1128
1129 /* If the window is almost full and there is insufficient lookahead,
1130 * move the upper half to the lower one to make room in the upper half.
1131 */
1132 } else if (s->strstart >= wsize+MAX_DIST(s)) {
1133
1134 /* By the IN assertion, the window is not empty so we can't confuse
1135 * more == 0 with more == 64K on a 16 bit machine.
1136 */
1137 zmemcpy((charf *)s->window, (charf *)s->window+wsize,
1138 (unsigned)wsize);
1139 s->match_start -= wsize;
1140 s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
1141
1142 s->block_start -= (long) wsize;
1143
1144 /* Slide the hash table (could be avoided with 32 bit values
1145 at the expense of memory usage):
1146 */
1147 n = s->hash_size;
1148 p = &s->head[n];
1149 do {
1150 m = *--p;
1151 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1152 } while (--n);
1153
1154 n = wsize;
1155 p = &s->prev[n];
1156 do {
1157 m = *--p;
1158 *p = (Pos)(m >= wsize ? m-wsize : NIL);
1159 /* If n is not on any hash chain, prev[n] is garbage but
1160 * its value will never be used.
1161 */
1162 } while (--n);
1163
1164 more += wsize;
1165 }
1166 if (s->strm->avail_in == 0) return;
1167
1168 /* If there was no sliding:
1169 * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
1170 * more == window_size - lookahead - strstart
1171 * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
1172 * => more >= window_size - 2*WSIZE + 2
1173 * In the BIG_MEM or MMAP case (not yet supported),
1174 * window_size == input_size + MIN_LOOKAHEAD &&
1175 * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
1176 * Otherwise, window_size == 2*WSIZE so more >= 2.
1177 * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
1178 */
1179 Assert(more >= 2, "more < 2");
1180
1181 n = read_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead,
1182 more);
1183 s->lookahead += n;
1184
1185 /* Initialize the hash value now that we have some input: */
1186 if (s->lookahead >= MIN_MATCH) {
1187 s->ins_h = s->window[s->strstart];
1188 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1189 #if MIN_MATCH != 3
1190 Call UPDATE_HASH() MIN_MATCH-3 more times
1191 #endif
1192 }
1193 /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
1194 * but this is not important since only literal bytes will be emitted.
1195 */
1196
1197 } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
1198 }
1199
1200 /* ===========================================================================
1201 * Flush the current block, with given end-of-file flag.
1202 * IN assertion: strstart is set to the end of the current match.
1203 */
1204 #define FLUSH_BLOCK_ONLY(s, flush) { \
1205 ct_flush_block(s, (s->block_start >= 0L ? \
1206 (charf *)&s->window[(unsigned)s->block_start] : \
1207 (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \
1208 s->block_start = s->strstart; \
1209 flush_pending(s->strm); \
1210 Tracev((stderr,"[FLUSH]")); \
1211 }
1212
1213 /* Same but force premature exit if necessary. */
1214 #define FLUSH_BLOCK(s, flush) { \
1215 FLUSH_BLOCK_ONLY(s, flush); \
1216 if (s->strm->avail_out == 0) return 1; \
1217 }
1218
1219 /* ===========================================================================
1220 * Compress as much as possible from the input stream, return true if
1221 * processing was terminated prematurely (no more input or output space).
1222 * This function does not perform lazy evaluationof matches and inserts
1223 * new strings in the dictionary only for unmatched strings or for short
1224 * matches. It is used only for the fast compression options.
1225 */
deflate_fast(s,flush)1226 local int deflate_fast(s, flush)
1227 deflate_state *s;
1228 int flush;
1229 {
1230 IPos hash_head = NIL; /* head of the hash chain */
1231 int bflush; /* set if current block must be flushed */
1232
1233 s->prev_length = MIN_MATCH-1;
1234
1235 for (;;) {
1236 /* Make sure that we always have enough lookahead, except
1237 * at the end of the input file. We need MAX_MATCH bytes
1238 * for the next match, plus MIN_MATCH bytes to insert the
1239 * string following the next match.
1240 */
1241 if (s->lookahead < MIN_LOOKAHEAD) {
1242 fill_window(s);
1243 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1244
1245 if (s->lookahead == 0) break; /* flush the current block */
1246 }
1247
1248 /* Insert the string window[strstart .. strstart+2] in the
1249 * dictionary, and set hash_head to the head of the hash chain:
1250 */
1251 if (s->lookahead >= MIN_MATCH) {
1252 INSERT_STRING(s, s->strstart, hash_head);
1253 }
1254
1255 /* Find the longest match, discarding those <= prev_length.
1256 * At this point we have always match_length < MIN_MATCH
1257 */
1258 if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) {
1259 /* To simplify the code, we prevent matches with the string
1260 * of window index 0 (in particular we have to avoid a match
1261 * of the string with itself at the start of the input file).
1262 */
1263 if (s->strategy != Z_HUFFMAN_ONLY) {
1264 s->match_length = longest_match (s, hash_head);
1265 }
1266 /* longest_match() sets match_start */
1267
1268 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1269 }
1270 if (s->match_length >= MIN_MATCH) {
1271 check_match(s, s->strstart, s->match_start, s->match_length);
1272
1273 bflush = ct_tally(s, s->strstart - s->match_start,
1274 s->match_length - MIN_MATCH);
1275
1276 s->lookahead -= s->match_length;
1277
1278 /* Insert new strings in the hash table only if the match length
1279 * is not too large. This saves time but degrades compression.
1280 */
1281 if (s->match_length <= s->max_insert_length &&
1282 s->lookahead >= MIN_MATCH) {
1283 s->match_length--; /* string at strstart already in hash table */
1284 do {
1285 s->strstart++;
1286 INSERT_STRING(s, s->strstart, hash_head);
1287 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1288 * always MIN_MATCH bytes ahead.
1289 */
1290 } while (--s->match_length != 0);
1291 s->strstart++;
1292 } else {
1293 s->strstart += s->match_length;
1294 s->match_length = 0;
1295 s->ins_h = s->window[s->strstart];
1296 UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]);
1297 #if MIN_MATCH != 3
1298 Call UPDATE_HASH() MIN_MATCH-3 more times
1299 #endif
1300 /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not
1301 * matter since it will be recomputed at next deflate call.
1302 */
1303 }
1304 } else {
1305 /* No match, output a literal byte */
1306 Tracevv((stderr,"%c", s->window[s->strstart]));
1307 bflush = ct_tally (s, 0, s->window[s->strstart]);
1308 s->lookahead--;
1309 s->strstart++;
1310 }
1311 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1312 }
1313 FLUSH_BLOCK(s, flush);
1314 return 0; /* normal exit */
1315 }
1316
1317 /* ===========================================================================
1318 * Same as above, but achieves better compression. We use a lazy
1319 * evaluation for matches: a match is finally adopted only if there is
1320 * no better match at the next window position.
1321 */
deflate_slow(s,flush)1322 local int deflate_slow(s, flush)
1323 deflate_state *s;
1324 int flush;
1325 {
1326 IPos hash_head = NIL; /* head of hash chain */
1327 int bflush; /* set if current block must be flushed */
1328
1329 /* Process the input block. */
1330 for (;;) {
1331 /* Make sure that we always have enough lookahead, except
1332 * at the end of the input file. We need MAX_MATCH bytes
1333 * for the next match, plus MIN_MATCH bytes to insert the
1334 * string following the next match.
1335 */
1336 if (s->lookahead < MIN_LOOKAHEAD) {
1337 fill_window(s);
1338 if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1;
1339
1340 if (s->lookahead == 0) break; /* flush the current block */
1341 }
1342
1343 /* Insert the string window[strstart .. strstart+2] in the
1344 * dictionary, and set hash_head to the head of the hash chain:
1345 */
1346 if (s->lookahead >= MIN_MATCH) {
1347 INSERT_STRING(s, s->strstart, hash_head);
1348 }
1349
1350 /* Find the longest match, discarding those <= prev_length.
1351 */
1352 s->prev_length = s->match_length, s->prev_match = s->match_start;
1353 s->match_length = MIN_MATCH-1;
1354
1355 if (hash_head != NIL && s->prev_length < s->max_lazy_match &&
1356 s->strstart - hash_head <= MAX_DIST(s)) {
1357 /* To simplify the code, we prevent matches with the string
1358 * of window index 0 (in particular we have to avoid a match
1359 * of the string with itself at the start of the input file).
1360 */
1361 if (s->strategy != Z_HUFFMAN_ONLY) {
1362 s->match_length = longest_match (s, hash_head);
1363 }
1364 /* longest_match() sets match_start */
1365 if (s->match_length > s->lookahead) s->match_length = s->lookahead;
1366
1367 if (s->match_length <= 5 && (s->strategy == Z_FILTERED ||
1368 (s->match_length == MIN_MATCH &&
1369 s->strstart - s->match_start > TOO_FAR))) {
1370
1371 /* If prev_match is also MIN_MATCH, match_start is garbage
1372 * but we will ignore the current match anyway.
1373 */
1374 s->match_length = MIN_MATCH-1;
1375 }
1376 }
1377 /* If there was a match at the previous step and the current
1378 * match is not better, output the previous match:
1379 */
1380 if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) {
1381 uInt max_insert = s->strstart + s->lookahead - MIN_MATCH;
1382 /* Do not insert strings in hash table beyond this. */
1383
1384 check_match(s, s->strstart-1, s->prev_match, s->prev_length);
1385
1386 bflush = ct_tally(s, s->strstart -1 - s->prev_match,
1387 s->prev_length - MIN_MATCH);
1388
1389 /* Insert in hash table all strings up to the end of the match.
1390 * strstart-1 and strstart are already inserted. If there is not
1391 * enough lookahead, the last two strings are not inserted in
1392 * the hash table.
1393 */
1394 s->lookahead -= s->prev_length-1;
1395 s->prev_length -= 2;
1396 do {
1397 if (++s->strstart <= max_insert) {
1398 INSERT_STRING(s, s->strstart, hash_head);
1399 }
1400 } while (--s->prev_length != 0);
1401 s->match_available = 0;
1402 s->match_length = MIN_MATCH-1;
1403 s->strstart++;
1404
1405 if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH);
1406
1407 } else if (s->match_available) {
1408 /* If there was no match at the previous position, output a
1409 * single literal. If there was a match but the current match
1410 * is longer, truncate the previous match to a single literal.
1411 */
1412 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1413 if (ct_tally (s, 0, s->window[s->strstart-1])) {
1414 FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH);
1415 }
1416 s->strstart++;
1417 s->lookahead--;
1418 if (s->strm->avail_out == 0) return 1;
1419 } else {
1420 /* There is no previous match to compare with, wait for
1421 * the next step to decide.
1422 */
1423 s->match_available = 1;
1424 s->strstart++;
1425 s->lookahead--;
1426 }
1427 }
1428 Assert (flush != Z_NO_FLUSH, "no flush?");
1429 if (s->match_available) {
1430 Tracevv((stderr,"%c", s->window[s->strstart-1]));
1431 ct_tally (s, 0, s->window[s->strstart-1]);
1432 s->match_available = 0;
1433 }
1434 FLUSH_BLOCK(s, flush);
1435 return 0;
1436 }
1437
1438
1439 /*+++++*/
1440 /* trees.c -- output deflated data using Huffman coding
1441 * Copyright (C) 1995 Jean-loup Gailly
1442 * For conditions of distribution and use, see copyright notice in zlib.h
1443 */
1444
1445 /*
1446 * ALGORITHM
1447 *
1448 * The "deflation" process uses several Huffman trees. The more
1449 * common source values are represented by shorter bit sequences.
1450 *
1451 * Each code tree is stored in a compressed form which is itself
1452 * a Huffman encoding of the lengths of all the code strings (in
1453 * ascending order by source values). The actual code strings are
1454 * reconstructed from the lengths in the inflate process, as described
1455 * in the deflate specification.
1456 *
1457 * REFERENCES
1458 *
1459 * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
1460 * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
1461 *
1462 * Storer, James A.
1463 * Data Compression: Methods and Theory, pp. 49-50.
1464 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1465 *
1466 * Sedgewick, R.
1467 * Algorithms, p290.
1468 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1469 */
1470
1471 /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */
1472
1473 #ifdef DEBUG_ZLIB
1474 # include <ctype.h>
1475 #endif
1476
1477 /* ===========================================================================
1478 * Constants
1479 */
1480
1481 #define MAX_BL_BITS 7
1482 /* Bit length codes must not exceed MAX_BL_BITS bits */
1483
1484 #define END_BLOCK 256
1485 /* end of block literal code */
1486
1487 #define REP_3_6 16
1488 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
1489
1490 #define REPZ_3_10 17
1491 /* repeat a zero length 3-10 times (3 bits of repeat count) */
1492
1493 #define REPZ_11_138 18
1494 /* repeat a zero length 11-138 times (7 bits of repeat count) */
1495
1496 local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */
1497 = {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};
1498
1499 local int extra_dbits[D_CODES] /* extra bits for each distance code */
1500 = {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};
1501
1502 local int extra_blbits[BL_CODES]/* extra bits for each bit length code */
1503 = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
1504
1505 local uch bl_order[BL_CODES]
1506 = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
1507 /* The lengths of the bit length codes are sent in order of decreasing
1508 * probability, to avoid transmitting the lengths for unused bit length codes.
1509 */
1510
1511 #define Buf_size (8 * 2*sizeof(char))
1512 /* Number of bits used within bi_buf. (bi_buf might be implemented on
1513 * more than 16 bits on some systems.)
1514 */
1515
1516 /* ===========================================================================
1517 * Local data. These are initialized only once.
1518 * To do: initialize at compile time to be completely reentrant. ???
1519 */
1520
1521 local ct_data static_ltree[L_CODES+2];
1522 /* The static literal tree. Since the bit lengths are imposed, there is no
1523 * need for the L_CODES extra codes used during heap construction. However
1524 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1525 * below).
1526 */
1527
1528 local ct_data static_dtree[D_CODES];
1529 /* The static distance tree. (Actually a trivial tree since all codes use
1530 * 5 bits.)
1531 */
1532
1533 local uch dist_code[512];
1534 /* distance codes. The first 256 values correspond to the distances
1535 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1536 * the 15 bit distances.
1537 */
1538
1539 local uch length_code[MAX_MATCH-MIN_MATCH+1];
1540 /* length code for each normalized match length (0 == MIN_MATCH) */
1541
1542 local int base_length[LENGTH_CODES];
1543 /* First normalized length for each code (0 = MIN_MATCH) */
1544
1545 local int base_dist[D_CODES];
1546 /* First normalized distance for each code (0 = distance of 1) */
1547
1548 struct static_tree_desc_s {
1549 ct_data *static_tree; /* static tree or NULL */
1550 intf *extra_bits; /* extra bits for each code or NULL */
1551 int extra_base; /* base index for extra_bits */
1552 int elems; /* max number of elements in the tree */
1553 int max_length; /* max bit length for the codes */
1554 };
1555
1556 local static_tree_desc static_l_desc =
1557 {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};
1558
1559 local static_tree_desc static_d_desc =
1560 {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};
1561
1562 local static_tree_desc static_bl_desc =
1563 {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};
1564
1565 /* ===========================================================================
1566 * Local (static) routines in this file.
1567 */
1568
1569 local void ct_static_init OF((void));
1570 local void init_block OF((deflate_state *s));
1571 local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
1572 local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
1573 local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));
1574 local void build_tree OF((deflate_state *s, tree_desc *desc));
1575 local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));
1576 local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));
1577 local int build_bl_tree OF((deflate_state *s));
1578 local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,
1579 int blcodes));
1580 local void compress_block OF((deflate_state *s, ct_data *ltree,
1581 ct_data *dtree));
1582 local void set_data_type OF((deflate_state *s));
1583 local unsigned bi_reverse OF((unsigned value, int length));
1584 local void bi_windup OF((deflate_state *s));
1585 local void bi_flush OF((deflate_state *s));
1586 local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
1587 int header));
1588
1589 #ifndef DEBUG_ZLIB
1590 # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
1591 /* Send a code of the given tree. c and tree must not have side effects */
1592
1593 #else /* DEBUG_ZLIB */
1594 # define send_code(s, c, tree) \
1595 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
1596 send_bits(s, tree[c].Code, tree[c].Len); }
1597 #endif
1598
1599 #define d_code(dist) \
1600 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1601 /* Mapping from a distance to a distance code. dist is the distance - 1 and
1602 * must not have side effects. dist_code[256] and dist_code[257] are never
1603 * used.
1604 */
1605
1606 /* ===========================================================================
1607 * Output a short LSB first on the stream.
1608 * IN assertion: there is enough room in pendingBuf.
1609 */
1610 #define put_short(s, w) { \
1611 put_byte(s, (uch)((w) & 0xff)); \
1612 put_byte(s, (uch)((ush)(w) >> 8)); \
1613 }
1614
1615 /* ===========================================================================
1616 * Send a value on a given number of bits.
1617 * IN assertion: length <= 16 and value fits in length bits.
1618 */
1619 #ifdef DEBUG_ZLIB
1620 local void send_bits OF((deflate_state *s, int value, int length));
1621
send_bits(s,value,length)1622 local void send_bits(s, value, length)
1623 deflate_state *s;
1624 int value; /* value to send */
1625 int length; /* number of bits */
1626 {
1627 Tracev((stderr," l %2d v %4x ", length, value));
1628 Assert(length > 0 && length <= 15, "invalid length");
1629 s->bits_sent += (ulg)length;
1630
1631 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
1632 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
1633 * unused bits in value.
1634 */
1635 if (s->bi_valid > (int)Buf_size - length) {
1636 s->bi_buf |= (value << s->bi_valid);
1637 put_short(s, s->bi_buf);
1638 s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);
1639 s->bi_valid += length - Buf_size;
1640 } else {
1641 s->bi_buf |= value << s->bi_valid;
1642 s->bi_valid += length;
1643 }
1644 }
1645 #else /* !DEBUG_ZLIB */
1646
1647 #define send_bits(s, value, length) \
1648 { int len = length;\
1649 if (s->bi_valid > (int)Buf_size - len) {\
1650 int val = value;\
1651 s->bi_buf |= (val << s->bi_valid);\
1652 put_short(s, s->bi_buf);\
1653 s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\
1654 s->bi_valid += len - Buf_size;\
1655 } else {\
1656 s->bi_buf |= (value) << s->bi_valid;\
1657 s->bi_valid += len;\
1658 }\
1659 }
1660 #endif /* DEBUG_ZLIB */
1661
1662
1663 #define MAX(a,b) (a >= b ? a : b)
1664 /* the arguments must not have side effects */
1665
1666 /* ===========================================================================
1667 * Initialize the various 'constant' tables.
1668 * To do: do this at compile time.
1669 */
ct_static_init()1670 local void ct_static_init()
1671 {
1672 int n; /* iterates over tree elements */
1673 int bits; /* bit counter */
1674 int length; /* length value */
1675 int code; /* code value */
1676 int dist; /* distance index */
1677 ush bl_count[MAX_BITS+1];
1678 /* number of codes at each bit length for an optimal tree */
1679
1680 /* Initialize the mapping length (0..255) -> length code (0..28) */
1681 length = 0;
1682 for (code = 0; code < LENGTH_CODES-1; code++) {
1683 base_length[code] = length;
1684 for (n = 0; n < (1<<extra_lbits[code]); n++) {
1685 length_code[length++] = (uch)code;
1686 }
1687 }
1688 Assert (length == 256, "ct_static_init: length != 256");
1689 /* Note that the length 255 (match length 258) can be represented
1690 * in two different ways: code 284 + 5 bits or code 285, so we
1691 * overwrite length_code[255] to use the best encoding:
1692 */
1693 length_code[length-1] = (uch)code;
1694
1695 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1696 dist = 0;
1697 for (code = 0 ; code < 16; code++) {
1698 base_dist[code] = dist;
1699 for (n = 0; n < (1<<extra_dbits[code]); n++) {
1700 dist_code[dist++] = (uch)code;
1701 }
1702 }
1703 Assert (dist == 256, "ct_static_init: dist != 256");
1704 dist >>= 7; /* from now on, all distances are divided by 128 */
1705 for ( ; code < D_CODES; code++) {
1706 base_dist[code] = dist << 7;
1707 for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
1708 dist_code[256 + dist++] = (uch)code;
1709 }
1710 }
1711 Assert (dist == 256, "ct_static_init: 256+dist != 512");
1712
1713 /* Construct the codes of the static literal tree */
1714 for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
1715 n = 0;
1716 while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
1717 while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
1718 while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
1719 while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
1720 /* Codes 286 and 287 do not exist, but we must include them in the
1721 * tree construction to get a canonical Huffman tree (longest code
1722 * all ones)
1723 */
1724 gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
1725
1726 /* The static distance tree is trivial: */
1727 for (n = 0; n < D_CODES; n++) {
1728 static_dtree[n].Len = 5;
1729 static_dtree[n].Code = bi_reverse(n, 5);
1730 }
1731 }
1732
1733 /* ===========================================================================
1734 * Initialize the tree data structures for a new zlib stream.
1735 */
ct_init(s)1736 local void ct_init(s)
1737 deflate_state *s;
1738 {
1739 if (static_dtree[0].Len == 0) {
1740 ct_static_init(); /* To do: at compile time */
1741 }
1742
1743 s->compressed_len = 0L;
1744
1745 s->l_desc.dyn_tree = s->dyn_ltree;
1746 s->l_desc.stat_desc = &static_l_desc;
1747
1748 s->d_desc.dyn_tree = s->dyn_dtree;
1749 s->d_desc.stat_desc = &static_d_desc;
1750
1751 s->bl_desc.dyn_tree = s->bl_tree;
1752 s->bl_desc.stat_desc = &static_bl_desc;
1753
1754 s->bi_buf = 0;
1755 s->bi_valid = 0;
1756 s->last_eob_len = 8; /* enough lookahead for inflate */
1757 #ifdef DEBUG_ZLIB
1758 s->bits_sent = 0L;
1759 #endif
1760 s->blocks_in_packet = 0;
1761
1762 /* Initialize the first block of the first file: */
1763 init_block(s);
1764 }
1765
1766 /* ===========================================================================
1767 * Initialize a new block.
1768 */
init_block(s)1769 local void init_block(s)
1770 deflate_state *s;
1771 {
1772 int n; /* iterates over tree elements */
1773
1774 /* Initialize the trees. */
1775 for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;
1776 for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;
1777 for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;
1778
1779 s->dyn_ltree[END_BLOCK].Freq = 1;
1780 s->opt_len = s->static_len = 0L;
1781 s->last_lit = s->matches = 0;
1782 }
1783
1784 #define SMALLEST 1
1785 /* Index within the heap array of least frequent node in the Huffman tree */
1786
1787
1788 /* ===========================================================================
1789 * Remove the smallest element from the heap and recreate the heap with
1790 * one less element. Updates heap and heap_len.
1791 */
1792 #define pqremove(s, tree, top) \
1793 {\
1794 top = s->heap[SMALLEST]; \
1795 s->heap[SMALLEST] = s->heap[s->heap_len--]; \
1796 pqdownheap(s, tree, SMALLEST); \
1797 }
1798
1799 /* ===========================================================================
1800 * Compares to subtrees, using the tree depth as tie breaker when
1801 * the subtrees have equal frequency. This minimizes the worst case length.
1802 */
1803 #define smaller(tree, n, m, depth) \
1804 (tree[n].Freq < tree[m].Freq || \
1805 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1806
1807 /* ===========================================================================
1808 * Restore the heap property by moving down the tree starting at node k,
1809 * exchanging a node with the smallest of its two sons if necessary, stopping
1810 * when the heap property is re-established (each father smaller than its
1811 * two sons).
1812 */
pqdownheap(s,tree,k)1813 local void pqdownheap(s, tree, k)
1814 deflate_state *s;
1815 ct_data *tree; /* the tree to restore */
1816 int k; /* node to move down */
1817 {
1818 int v = s->heap[k];
1819 int j = k << 1; /* left son of k */
1820 while (j <= s->heap_len) {
1821 /* Set j to the smallest of the two sons: */
1822 if (j < s->heap_len &&
1823 smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
1824 j++;
1825 }
1826 /* Exit if v is smaller than both sons */
1827 if (smaller(tree, v, s->heap[j], s->depth)) break;
1828
1829 /* Exchange v with the smallest son */
1830 s->heap[k] = s->heap[j]; k = j;
1831
1832 /* And continue down the tree, setting j to the left son of k */
1833 j <<= 1;
1834 }
1835 s->heap[k] = v;
1836 }
1837
1838 /* ===========================================================================
1839 * Compute the optimal bit lengths for a tree and update the total bit length
1840 * for the current block.
1841 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1842 * above are the tree nodes sorted by increasing frequency.
1843 * OUT assertions: the field len is set to the optimal bit length, the
1844 * array bl_count contains the frequencies for each bit length.
1845 * The length opt_len is updated; static_len is also updated if stree is
1846 * not null.
1847 */
gen_bitlen(s,desc)1848 local void gen_bitlen(s, desc)
1849 deflate_state *s;
1850 tree_desc *desc; /* the tree descriptor */
1851 {
1852 ct_data *tree = desc->dyn_tree;
1853 int max_code = desc->max_code;
1854 ct_data *stree = desc->stat_desc->static_tree;
1855 intf *extra = desc->stat_desc->extra_bits;
1856 int base = desc->stat_desc->extra_base;
1857 int max_length = desc->stat_desc->max_length;
1858 int h; /* heap index */
1859 int n, m; /* iterate over the tree elements */
1860 int bits; /* bit length */
1861 int xbits; /* extra bits */
1862 ush f; /* frequency */
1863 int overflow = 0; /* number of elements with bit length too large */
1864
1865 for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
1866
1867 /* In a first pass, compute the optimal bit lengths (which may
1868 * overflow in the case of the bit length tree).
1869 */
1870 tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */
1871
1872 for (h = s->heap_max+1; h < HEAP_SIZE; h++) {
1873 n = s->heap[h];
1874 bits = tree[tree[n].Dad].Len + 1;
1875 if (bits > max_length) bits = max_length, overflow++;
1876 tree[n].Len = (ush)bits;
1877 /* We overwrite tree[n].Dad which is no longer needed */
1878
1879 if (n > max_code) continue; /* not a leaf node */
1880
1881 s->bl_count[bits]++;
1882 xbits = 0;
1883 if (n >= base) xbits = extra[n-base];
1884 f = tree[n].Freq;
1885 s->opt_len += (ulg)f * (bits + xbits);
1886 if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);
1887 }
1888 if (overflow == 0) return;
1889
1890 Trace((stderr,"\nbit length overflow\n"));
1891 /* This happens for example on obj2 and pic of the Calgary corpus */
1892
1893 /* Find the first bit length which could increase: */
1894 do {
1895 bits = max_length-1;
1896 while (s->bl_count[bits] == 0) bits--;
1897 s->bl_count[bits]--; /* move one leaf down the tree */
1898 s->bl_count[bits+1] += 2; /* move one overflow item as its brother */
1899 s->bl_count[max_length]--;
1900 /* The brother of the overflow item also moves one step up,
1901 * but this does not affect bl_count[max_length]
1902 */
1903 overflow -= 2;
1904 } while (overflow > 0);
1905
1906 /* Now recompute all bit lengths, scanning in increasing frequency.
1907 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1908 * lengths instead of fixing only the wrong ones. This idea is taken
1909 * from 'ar' written by Haruhiko Okumura.)
1910 */
1911 for (bits = max_length; bits != 0; bits--) {
1912 n = s->bl_count[bits];
1913 while (n != 0) {
1914 m = s->heap[--h];
1915 if (m > max_code) continue;
1916 if (tree[m].Len != (unsigned) bits) {
1917 Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
1918 s->opt_len += ((long)bits - (long)tree[m].Len)
1919 *(long)tree[m].Freq;
1920 tree[m].Len = (ush)bits;
1921 }
1922 n--;
1923 }
1924 }
1925 }
1926
1927 /* ===========================================================================
1928 * Generate the codes for a given tree and bit counts (which need not be
1929 * optimal).
1930 * IN assertion: the array bl_count contains the bit length statistics for
1931 * the given tree and the field len is set for all tree elements.
1932 * OUT assertion: the field code is set for all tree elements of non
1933 * zero code length.
1934 */
gen_codes(tree,max_code,bl_count)1935 local void gen_codes (tree, max_code, bl_count)
1936 ct_data *tree; /* the tree to decorate */
1937 int max_code; /* largest code with non zero frequency */
1938 ushf *bl_count; /* number of codes at each bit length */
1939 {
1940 ush next_code[MAX_BITS+1]; /* next code value for each bit length */
1941 ush code = 0; /* running code value */
1942 int bits; /* bit index */
1943 int n; /* code index */
1944
1945 /* The distribution counts are first used to generate the code values
1946 * without bit reversal.
1947 */
1948 for (bits = 1; bits <= MAX_BITS; bits++) {
1949 next_code[bits] = code = (code + bl_count[bits-1]) << 1;
1950 }
1951 /* Check that the bit counts in bl_count are consistent. The last code
1952 * must be all ones.
1953 */
1954 Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
1955 "inconsistent bit counts");
1956 Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
1957
1958 for (n = 0; n <= max_code; n++) {
1959 int len = tree[n].Len;
1960 if (len == 0) continue;
1961 /* Now reverse the bits */
1962 tree[n].Code = bi_reverse(next_code[len]++, len);
1963
1964 Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
1965 n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
1966 }
1967 }
1968
1969 /* ===========================================================================
1970 * Construct one Huffman tree and assigns the code bit strings and lengths.
1971 * Update the total bit length for the current block.
1972 * IN assertion: the field freq is set for all tree elements.
1973 * OUT assertions: the fields len and code are set to the optimal bit length
1974 * and corresponding code. The length opt_len is updated; static_len is
1975 * also updated if stree is not null. The field max_code is set.
1976 */
build_tree(s,desc)1977 local void build_tree(s, desc)
1978 deflate_state *s;
1979 tree_desc *desc; /* the tree descriptor */
1980 {
1981 ct_data *tree = desc->dyn_tree;
1982 ct_data *stree = desc->stat_desc->static_tree;
1983 int elems = desc->stat_desc->elems;
1984 int n, m; /* iterate over heap elements */
1985 int max_code = -1; /* largest code with non zero frequency */
1986 int node; /* new node being created */
1987
1988 /* Construct the initial heap, with least frequent element in
1989 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1990 * heap[0] is not used.
1991 */
1992 s->heap_len = 0, s->heap_max = HEAP_SIZE;
1993
1994 for (n = 0; n < elems; n++) {
1995 if (tree[n].Freq != 0) {
1996 s->heap[++(s->heap_len)] = max_code = n;
1997 s->depth[n] = 0;
1998 } else {
1999 tree[n].Len = 0;
2000 }
2001 }
2002
2003 /* The pkzip format requires that at least one distance code exists,
2004 * and that at least one bit should be sent even if there is only one
2005 * possible code. So to avoid special checks later on we force at least
2006 * two codes of non zero frequency.
2007 */
2008 while (s->heap_len < 2) {
2009 node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);
2010 tree[node].Freq = 1;
2011 s->depth[node] = 0;
2012 s->opt_len--; if (stree) s->static_len -= stree[node].Len;
2013 /* node is 0 or 1 so it does not have extra bits */
2014 }
2015 desc->max_code = max_code;
2016
2017 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2018 * establish sub-heaps of increasing lengths:
2019 */
2020 for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
2021
2022 /* Construct the Huffman tree by repeatedly combining the least two
2023 * frequent nodes.
2024 */
2025 node = elems; /* next internal node of the tree */
2026 do {
2027 pqremove(s, tree, n); /* n = node of least frequency */
2028 m = s->heap[SMALLEST]; /* m = node of next least frequency */
2029
2030 s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */
2031 s->heap[--(s->heap_max)] = m;
2032
2033 /* Create a new node father of n and m */
2034 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2035 s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1);
2036 tree[n].Dad = tree[m].Dad = (ush)node;
2037 #ifdef DUMP_BL_TREE
2038 if (tree == s->bl_tree) {
2039 fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
2040 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
2041 }
2042 #endif
2043 /* and insert the new node in the heap */
2044 s->heap[SMALLEST] = node++;
2045 pqdownheap(s, tree, SMALLEST);
2046
2047 } while (s->heap_len >= 2);
2048
2049 s->heap[--(s->heap_max)] = s->heap[SMALLEST];
2050
2051 /* At this point, the fields freq and dad are set. We can now
2052 * generate the bit lengths.
2053 */
2054 gen_bitlen(s, (tree_desc *)desc);
2055
2056 /* The field len is now set, we can generate the bit codes */
2057 gen_codes ((ct_data *)tree, max_code, s->bl_count);
2058 }
2059
2060 /* ===========================================================================
2061 * Scan a literal or distance tree to determine the frequencies of the codes
2062 * in the bit length tree.
2063 */
scan_tree(s,tree,max_code)2064 local void scan_tree (s, tree, max_code)
2065 deflate_state *s;
2066 ct_data *tree; /* the tree to be scanned */
2067 int max_code; /* and its largest code of non zero frequency */
2068 {
2069 int n; /* iterates over all tree elements */
2070 int prevlen = -1; /* last emitted length */
2071 int curlen; /* length of current code */
2072 int nextlen = tree[0].Len; /* length of next code */
2073 int count = 0; /* repeat count of the current code */
2074 int max_count = 7; /* max repeat count */
2075 int min_count = 4; /* min repeat count */
2076
2077 if (nextlen == 0) max_count = 138, min_count = 3;
2078 tree[max_code+1].Len = (ush)0xffff; /* guard */
2079
2080 for (n = 0; n <= max_code; n++) {
2081 curlen = nextlen; nextlen = tree[n+1].Len;
2082 if (++count < max_count && curlen == nextlen) {
2083 continue;
2084 } else if (count < min_count) {
2085 s->bl_tree[curlen].Freq += count;
2086 } else if (curlen != 0) {
2087 if (curlen != prevlen) s->bl_tree[curlen].Freq++;
2088 s->bl_tree[REP_3_6].Freq++;
2089 } else if (count <= 10) {
2090 s->bl_tree[REPZ_3_10].Freq++;
2091 } else {
2092 s->bl_tree[REPZ_11_138].Freq++;
2093 }
2094 count = 0; prevlen = curlen;
2095 if (nextlen == 0) {
2096 max_count = 138, min_count = 3;
2097 } else if (curlen == nextlen) {
2098 max_count = 6, min_count = 3;
2099 } else {
2100 max_count = 7, min_count = 4;
2101 }
2102 }
2103 }
2104
2105 /* ===========================================================================
2106 * Send a literal or distance tree in compressed form, using the codes in
2107 * bl_tree.
2108 */
send_tree(s,tree,max_code)2109 local void send_tree (s, tree, max_code)
2110 deflate_state *s;
2111 ct_data *tree; /* the tree to be scanned */
2112 int max_code; /* and its largest code of non zero frequency */
2113 {
2114 int n; /* iterates over all tree elements */
2115 int prevlen = -1; /* last emitted length */
2116 int curlen; /* length of current code */
2117 int nextlen = tree[0].Len; /* length of next code */
2118 int count = 0; /* repeat count of the current code */
2119 int max_count = 7; /* max repeat count */
2120 int min_count = 4; /* min repeat count */
2121
2122 /* tree[max_code+1].Len = -1; */ /* guard already set */
2123 if (nextlen == 0) max_count = 138, min_count = 3;
2124
2125 for (n = 0; n <= max_code; n++) {
2126 curlen = nextlen; nextlen = tree[n+1].Len;
2127 if (++count < max_count && curlen == nextlen) {
2128 continue;
2129 } else if (count < min_count) {
2130 do { send_code(s, curlen, s->bl_tree); } while (--count != 0);
2131
2132 } else if (curlen != 0) {
2133 if (curlen != prevlen) {
2134 send_code(s, curlen, s->bl_tree); count--;
2135 }
2136 Assert(count >= 3 && count <= 6, " 3_6?");
2137 send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);
2138
2139 } else if (count <= 10) {
2140 send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);
2141
2142 } else {
2143 send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);
2144 }
2145 count = 0; prevlen = curlen;
2146 if (nextlen == 0) {
2147 max_count = 138, min_count = 3;
2148 } else if (curlen == nextlen) {
2149 max_count = 6, min_count = 3;
2150 } else {
2151 max_count = 7, min_count = 4;
2152 }
2153 }
2154 }
2155
2156 /* ===========================================================================
2157 * Construct the Huffman tree for the bit lengths and return the index in
2158 * bl_order of the last bit length code to send.
2159 */
build_bl_tree(s)2160 local int build_bl_tree(s)
2161 deflate_state *s;
2162 {
2163 int max_blindex; /* index of last bit length code of non zero freq */
2164
2165 /* Determine the bit length frequencies for literal and distance trees */
2166 scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);
2167 scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);
2168
2169 /* Build the bit length tree: */
2170 build_tree(s, (tree_desc *)(&(s->bl_desc)));
2171 /* opt_len now includes the length of the tree representations, except
2172 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2173 */
2174
2175 /* Determine the number of bit length codes to send. The pkzip format
2176 * requires that at least 4 bit length codes be sent. (appnote.txt says
2177 * 3 but the actual value used is 4.)
2178 */
2179 for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
2180 if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
2181 }
2182 /* Update opt_len to include the bit length tree and counts */
2183 s->opt_len += 3*(max_blindex+1) + 5+5+4;
2184 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
2185 s->opt_len, s->static_len));
2186
2187 return max_blindex;
2188 }
2189
2190 /* ===========================================================================
2191 * Send the header for a block using dynamic Huffman trees: the counts, the
2192 * lengths of the bit length codes, the literal tree and the distance tree.
2193 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2194 */
send_all_trees(s,lcodes,dcodes,blcodes)2195 local void send_all_trees(s, lcodes, dcodes, blcodes)
2196 deflate_state *s;
2197 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2198 {
2199 int rank; /* index in bl_order */
2200
2201 Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2202 Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
2203 "too many codes");
2204 Tracev((stderr, "\nbl counts: "));
2205 send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */
2206 send_bits(s, dcodes-1, 5);
2207 send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */
2208 for (rank = 0; rank < blcodes; rank++) {
2209 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2210 send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);
2211 }
2212 Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
2213
2214 send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */
2215 Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
2216
2217 send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */
2218 Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
2219 }
2220
2221 /* ===========================================================================
2222 * Send a stored block
2223 */
ct_stored_block(s,buf,stored_len,eof)2224 local void ct_stored_block(s, buf, stored_len, eof)
2225 deflate_state *s;
2226 charf *buf; /* input block */
2227 ulg stored_len; /* length of input block */
2228 int eof; /* true if this is the last block for a file */
2229 {
2230 send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */
2231 s->compressed_len = (s->compressed_len + 3 + 7) & ~7L;
2232 s->compressed_len += (stored_len + 4) << 3;
2233
2234 copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
2235 }
2236
2237 /* Send just the `stored block' type code without any length bytes or data.
2238 */
ct_stored_type_only(s)2239 local void ct_stored_type_only(s)
2240 deflate_state *s;
2241 {
2242 send_bits(s, (STORED_BLOCK << 1), 3);
2243 bi_windup(s);
2244 s->compressed_len = (s->compressed_len + 3) & ~7L;
2245 }
2246
2247
2248 /* ===========================================================================
2249 * Send one empty static block to give enough lookahead for inflate.
2250 * This takes 10 bits, of which 7 may remain in the bit buffer.
2251 * The current inflate code requires 9 bits of lookahead. If the EOB
2252 * code for the previous block was coded on 5 bits or less, inflate
2253 * may have only 5+3 bits of lookahead to decode this EOB.
2254 * (There are no problems if the previous block is stored or fixed.)
2255 */
ct_align(s)2256 local void ct_align(s)
2257 deflate_state *s;
2258 {
2259 send_bits(s, STATIC_TREES<<1, 3);
2260 send_code(s, END_BLOCK, static_ltree);
2261 s->compressed_len += 10L; /* 3 for block type, 7 for EOB */
2262 bi_flush(s);
2263 /* Of the 10 bits for the empty block, we have already sent
2264 * (10 - bi_valid) bits. The lookahead for the EOB of the previous
2265 * block was thus its length plus what we have just sent.
2266 */
2267 if (s->last_eob_len + 10 - s->bi_valid < 9) {
2268 send_bits(s, STATIC_TREES<<1, 3);
2269 send_code(s, END_BLOCK, static_ltree);
2270 s->compressed_len += 10L;
2271 bi_flush(s);
2272 }
2273 s->last_eob_len = 7;
2274 }
2275
2276 /* ===========================================================================
2277 * Determine the best encoding for the current block: dynamic trees, static
2278 * trees or store, and output the encoded block to the zip file. This function
2279 * returns the total compressed length for the file so far.
2280 */
ct_flush_block(s,buf,stored_len,flush)2281 local ulg ct_flush_block(s, buf, stored_len, flush)
2282 deflate_state *s;
2283 charf *buf; /* input block, or NULL if too old */
2284 ulg stored_len; /* length of input block */
2285 int flush; /* Z_FINISH if this is the last block for a file */
2286 {
2287 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2288 int max_blindex; /* index of last bit length code of non zero freq */
2289 int eof = flush == Z_FINISH;
2290
2291 ++s->blocks_in_packet;
2292
2293 /* Check if the file is ascii or binary */
2294 if (s->data_type == UNKNOWN) set_data_type(s);
2295
2296 /* Construct the literal and distance trees */
2297 build_tree(s, (tree_desc *)(&(s->l_desc)));
2298 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,
2299 s->static_len));
2300
2301 build_tree(s, (tree_desc *)(&(s->d_desc)));
2302 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,
2303 s->static_len));
2304 /* At this point, opt_len and static_len are the total bit lengths of
2305 * the compressed block data, excluding the tree representations.
2306 */
2307
2308 /* Build the bit length tree for the above two trees, and get the index
2309 * in bl_order of the last bit length code to send.
2310 */
2311 max_blindex = build_bl_tree(s);
2312
2313 /* Determine the best encoding. Compute first the block length in bytes */
2314 opt_lenb = (s->opt_len+3+7)>>3;
2315 static_lenb = (s->static_len+3+7)>>3;
2316
2317 Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",
2318 opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,
2319 s->last_lit));
2320
2321 if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
2322
2323 /* If compression failed and this is the first and last block,
2324 * and if the .zip file can be seeked (to rewrite the local header),
2325 * the whole file is transformed into a stored file:
2326 */
2327 #ifdef STORED_FILE_OK
2328 # ifdef FORCE_STORED_FILE
2329 if (eof && compressed_len == 0L) /* force stored file */
2330 # else
2331 if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable())
2332 # endif
2333 {
2334 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2335 if (buf == (charf*)0) error ("block vanished");
2336
2337 copy_block(buf, (unsigned)stored_len, 0); /* without header */
2338 s->compressed_len = stored_len << 3;
2339 s->method = STORED;
2340 } else
2341 #endif /* STORED_FILE_OK */
2342
2343 /* For Z_PACKET_FLUSH, if we don't achieve the required minimum
2344 * compression, and this block contains all the data since the last
2345 * time we used Z_PACKET_FLUSH, then just omit this block completely
2346 * from the output.
2347 */
2348 if (flush == Z_PACKET_FLUSH && s->blocks_in_packet == 1
2349 && opt_lenb > stored_len - s->minCompr) {
2350 s->blocks_in_packet = 0;
2351 /* output nothing */
2352 } else
2353
2354 #ifdef FORCE_STORED
2355 if (buf != (char*)0) /* force stored block */
2356 #else
2357 if (stored_len+4 <= opt_lenb && buf != (char*)0)
2358 /* 4: two words for the lengths */
2359 #endif
2360 {
2361 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2362 * Otherwise we can't have processed more than WSIZE input bytes since
2363 * the last block flush, because compression would have been
2364 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2365 * transform a block into a stored block.
2366 */
2367 ct_stored_block(s, buf, stored_len, eof);
2368 } else
2369
2370 #ifdef FORCE_STATIC
2371 if (static_lenb >= 0) /* force static trees */
2372 #else
2373 if (static_lenb == opt_lenb)
2374 #endif
2375 {
2376 send_bits(s, (STATIC_TREES<<1)+eof, 3);
2377 compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
2378 s->compressed_len += 3 + s->static_len;
2379 } else {
2380 send_bits(s, (DYN_TREES<<1)+eof, 3);
2381 send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,
2382 max_blindex+1);
2383 compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree);
2384 s->compressed_len += 3 + s->opt_len;
2385 }
2386 Assert (s->compressed_len == s->bits_sent, "bad compressed size");
2387 init_block(s);
2388
2389 if (eof) {
2390 bi_windup(s);
2391 s->compressed_len += 7; /* align on byte boundary */
2392 }
2393 Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
2394 s->compressed_len-7*eof));
2395
2396 return s->compressed_len >> 3;
2397 }
2398
2399 /* ===========================================================================
2400 * Save the match info and tally the frequency counts. Return true if
2401 * the current block must be flushed.
2402 */
ct_tally(s,dist,lc)2403 local int ct_tally (s, dist, lc)
2404 deflate_state *s;
2405 int dist; /* distance of matched string */
2406 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2407 {
2408 s->d_buf[s->last_lit] = (ush)dist;
2409 s->l_buf[s->last_lit++] = (uch)lc;
2410 if (dist == 0) {
2411 /* lc is the unmatched char */
2412 s->dyn_ltree[lc].Freq++;
2413 } else {
2414 s->matches++;
2415 /* Here, lc is the match length - MIN_MATCH */
2416 dist--; /* dist = match distance - 1 */
2417 Assert((ush)dist < (ush)MAX_DIST(s) &&
2418 (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
2419 (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
2420
2421 s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
2422 s->dyn_dtree[d_code(dist)].Freq++;
2423 }
2424
2425 /* Try to guess if it is profitable to stop the current block here */
2426 if (s->level > 2 && (s->last_lit & 0xfff) == 0) {
2427 /* Compute an upper bound for the compressed length */
2428 ulg out_length = (ulg)s->last_lit*8L;
2429 ulg in_length = (ulg)s->strstart - s->block_start;
2430 int dcode;
2431 for (dcode = 0; dcode < D_CODES; dcode++) {
2432 out_length += (ulg)s->dyn_dtree[dcode].Freq *
2433 (5L+extra_dbits[dcode]);
2434 }
2435 out_length >>= 3;
2436 Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",
2437 s->last_lit, in_length, out_length,
2438 100L - out_length*100L/in_length));
2439 if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;
2440 }
2441 return (s->last_lit == s->lit_bufsize-1);
2442 /* We avoid equality with lit_bufsize because of wraparound at 64K
2443 * on 16 bit machines and because stored blocks are restricted to
2444 * 64K-1 bytes.
2445 */
2446 }
2447
2448 /* ===========================================================================
2449 * Send the block data compressed using the given Huffman trees
2450 */
compress_block(s,ltree,dtree)2451 local void compress_block(s, ltree, dtree)
2452 deflate_state *s;
2453 ct_data *ltree; /* literal tree */
2454 ct_data *dtree; /* distance tree */
2455 {
2456 unsigned dist; /* distance of matched string */
2457 int lc; /* match length or unmatched char (if dist == 0) */
2458 unsigned lx = 0; /* running index in l_buf */
2459 unsigned code; /* the code to send */
2460 int extra; /* number of extra bits to send */
2461
2462 if (s->last_lit != 0) do {
2463 dist = s->d_buf[lx];
2464 lc = s->l_buf[lx++];
2465 if (dist == 0) {
2466 send_code(s, lc, ltree); /* send a literal byte */
2467 Tracecv(isgraph(lc), (stderr," '%c' ", lc));
2468 } else {
2469 /* Here, lc is the match length - MIN_MATCH */
2470 code = length_code[lc];
2471 send_code(s, code+LITERALS+1, ltree); /* send the length code */
2472 extra = extra_lbits[code];
2473 if (extra != 0) {
2474 lc -= base_length[code];
2475 send_bits(s, lc, extra); /* send the extra length bits */
2476 }
2477 dist--; /* dist is now the match distance - 1 */
2478 code = d_code(dist);
2479 Assert (code < D_CODES, "bad d_code");
2480
2481 send_code(s, code, dtree); /* send the distance code */
2482 extra = extra_dbits[code];
2483 if (extra != 0) {
2484 dist -= base_dist[code];
2485 send_bits(s, dist, extra); /* send the extra distance bits */
2486 }
2487 } /* literal or match pair ? */
2488
2489 /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */
2490 Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow");
2491
2492 } while (lx < s->last_lit);
2493
2494 send_code(s, END_BLOCK, ltree);
2495 s->last_eob_len = ltree[END_BLOCK].Len;
2496 }
2497
2498 /* ===========================================================================
2499 * Set the data type to ASCII or BINARY, using a crude approximation:
2500 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2501 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2502 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2503 */
set_data_type(s)2504 local void set_data_type(s)
2505 deflate_state *s;
2506 {
2507 int n = 0;
2508 unsigned ascii_freq = 0;
2509 unsigned bin_freq = 0;
2510 while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
2511 while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
2512 while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
2513 s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII);
2514 }
2515
2516 /* ===========================================================================
2517 * Reverse the first len bits of a code, using straightforward code (a faster
2518 * method would use a table)
2519 * IN assertion: 1 <= len <= 15
2520 */
bi_reverse(code,len)2521 local unsigned bi_reverse(code, len)
2522 unsigned code; /* the value to invert */
2523 int len; /* its bit length */
2524 {
2525 register unsigned res = 0;
2526 do {
2527 res |= code & 1;
2528 code >>= 1, res <<= 1;
2529 } while (--len > 0);
2530 return res >> 1;
2531 }
2532
2533 /* ===========================================================================
2534 * Flush the bit buffer, keeping at most 7 bits in it.
2535 */
bi_flush(s)2536 local void bi_flush(s)
2537 deflate_state *s;
2538 {
2539 if (s->bi_valid == 16) {
2540 put_short(s, s->bi_buf);
2541 s->bi_buf = 0;
2542 s->bi_valid = 0;
2543 } else if (s->bi_valid >= 8) {
2544 put_byte(s, (Byte)s->bi_buf);
2545 s->bi_buf >>= 8;
2546 s->bi_valid -= 8;
2547 }
2548 }
2549
2550 /* ===========================================================================
2551 * Flush the bit buffer and align the output on a byte boundary
2552 */
bi_windup(s)2553 local void bi_windup(s)
2554 deflate_state *s;
2555 {
2556 if (s->bi_valid > 8) {
2557 put_short(s, s->bi_buf);
2558 } else if (s->bi_valid > 0) {
2559 put_byte(s, (Byte)s->bi_buf);
2560 }
2561 s->bi_buf = 0;
2562 s->bi_valid = 0;
2563 #ifdef DEBUG_ZLIB
2564 s->bits_sent = (s->bits_sent+7) & ~7;
2565 #endif
2566 }
2567
2568 /* ===========================================================================
2569 * Copy a stored block, storing first the length and its
2570 * one's complement if requested.
2571 */
copy_block(s,buf,len,header)2572 local void copy_block(s, buf, len, header)
2573 deflate_state *s;
2574 charf *buf; /* the input data */
2575 unsigned len; /* its length */
2576 int header; /* true if block header must be written */
2577 {
2578 bi_windup(s); /* align on byte boundary */
2579 s->last_eob_len = 8; /* enough lookahead for inflate */
2580
2581 if (header) {
2582 put_short(s, (ush)len);
2583 put_short(s, (ush)~len);
2584 #ifdef DEBUG_ZLIB
2585 s->bits_sent += 2*16;
2586 #endif
2587 }
2588 #ifdef DEBUG_ZLIB
2589 s->bits_sent += (ulg)len<<3;
2590 #endif
2591 while (len--) {
2592 put_byte(s, *buf++);
2593 }
2594 }
2595
2596
2597 /*+++++*/
2598 /* infblock.h -- header to use infblock.c
2599 * Copyright (C) 1995 Mark Adler
2600 * For conditions of distribution and use, see copyright notice in zlib.h
2601 */
2602
2603 /* WARNING: this file should *not* be used by applications. It is
2604 part of the implementation of the compression library and is
2605 subject to change. Applications should only use zlib.h.
2606 */
2607
2608 struct inflate_blocks_state;
2609 typedef struct inflate_blocks_state FAR inflate_blocks_statef;
2610
2611 local inflate_blocks_statef * inflate_blocks_new OF((
2612 z_stream *z,
2613 check_func c, /* check function */
2614 uInt w)); /* window size */
2615
2616 local int inflate_blocks OF((
2617 inflate_blocks_statef *,
2618 z_stream *,
2619 int)); /* initial return code */
2620
2621 local void inflate_blocks_reset OF((
2622 inflate_blocks_statef *,
2623 z_stream *,
2624 uLongf *)); /* check value on output */
2625
2626 local int inflate_blocks_free OF((
2627 inflate_blocks_statef *,
2628 z_stream *,
2629 uLongf *)); /* check value on output */
2630
2631 local int inflate_addhistory OF((
2632 inflate_blocks_statef *,
2633 z_stream *));
2634
2635 local int inflate_packet_flush OF((
2636 inflate_blocks_statef *));
2637
2638 /*+++++*/
2639 /* inftrees.h -- header to use inftrees.c
2640 * Copyright (C) 1995 Mark Adler
2641 * For conditions of distribution and use, see copyright notice in zlib.h
2642 */
2643
2644 /* WARNING: this file should *not* be used by applications. It is
2645 part of the implementation of the compression library and is
2646 subject to change. Applications should only use zlib.h.
2647 */
2648
2649 /* Huffman code lookup table entry--this entry is four bytes for machines
2650 that have 16-bit pointers (e.g. PC's in the small or medium model). */
2651
2652 typedef struct inflate_huft_s FAR inflate_huft;
2653
2654 struct inflate_huft_s {
2655 union {
2656 struct {
2657 Byte Exop; /* number of extra bits or operation */
2658 Byte Bits; /* number of bits in this code or subcode */
2659 } what;
2660 uInt Nalloc; /* number of these allocated here */
2661 Bytef *pad; /* pad structure to a power of 2 (4 bytes for */
2662 } word; /* 16-bit, 8 bytes for 32-bit machines) */
2663 union {
2664 uInt Base; /* literal, length base, or distance base */
2665 inflate_huft *Next; /* pointer to next level of table */
2666 } more;
2667 };
2668
2669 #ifdef DEBUG_ZLIB
2670 local uInt inflate_hufts;
2671 #endif
2672
2673 local int inflate_trees_bits OF((
2674 uIntf *, /* 19 code lengths */
2675 uIntf *, /* bits tree desired/actual depth */
2676 inflate_huft * FAR *, /* bits tree result */
2677 z_stream *)); /* for zalloc, zfree functions */
2678
2679 local int inflate_trees_dynamic OF((
2680 uInt, /* number of literal/length codes */
2681 uInt, /* number of distance codes */
2682 uIntf *, /* that many (total) code lengths */
2683 uIntf *, /* literal desired/actual bit depth */
2684 uIntf *, /* distance desired/actual bit depth */
2685 inflate_huft * FAR *, /* literal/length tree result */
2686 inflate_huft * FAR *, /* distance tree result */
2687 z_stream *)); /* for zalloc, zfree functions */
2688
2689 local int inflate_trees_fixed OF((
2690 uIntf *, /* literal desired/actual bit depth */
2691 uIntf *, /* distance desired/actual bit depth */
2692 inflate_huft * FAR *, /* literal/length tree result */
2693 inflate_huft * FAR *)); /* distance tree result */
2694
2695 local int inflate_trees_free OF((
2696 inflate_huft *, /* tables to free */
2697 z_stream *)); /* for zfree function */
2698
2699
2700 /*+++++*/
2701 /* infcodes.h -- header to use infcodes.c
2702 * Copyright (C) 1995 Mark Adler
2703 * For conditions of distribution and use, see copyright notice in zlib.h
2704 */
2705
2706 /* WARNING: this file should *not* be used by applications. It is
2707 part of the implementation of the compression library and is
2708 subject to change. Applications should only use zlib.h.
2709 */
2710
2711 struct inflate_codes_state;
2712 typedef struct inflate_codes_state FAR inflate_codes_statef;
2713
2714 local inflate_codes_statef *inflate_codes_new OF((
2715 uInt, uInt,
2716 inflate_huft *, inflate_huft *,
2717 z_stream *));
2718
2719 local int inflate_codes OF((
2720 inflate_blocks_statef *,
2721 z_stream *,
2722 int));
2723
2724 local void inflate_codes_free OF((
2725 inflate_codes_statef *,
2726 z_stream *));
2727
2728
2729 /*+++++*/
2730 /* inflate.c -- zlib interface to inflate modules
2731 * Copyright (C) 1995 Mark Adler
2732 * For conditions of distribution and use, see copyright notice in zlib.h
2733 */
2734
2735 /* inflate private state */
2736 struct internal_state {
2737
2738 /* mode */
2739 enum {
2740 METHOD, /* waiting for method byte */
2741 FLAG, /* waiting for flag byte */
2742 BLOCKS, /* decompressing blocks */
2743 CHECK4, /* four check bytes to go */
2744 CHECK3, /* three check bytes to go */
2745 CHECK2, /* two check bytes to go */
2746 CHECK1, /* one check byte to go */
2747 DONE, /* finished check, done */
2748 BAD} /* got an error--stay here */
2749 mode; /* current inflate mode */
2750
2751 /* mode dependent information */
2752 union {
2753 uInt method; /* if FLAGS, method byte */
2754 struct {
2755 uLong was; /* computed check value */
2756 uLong need; /* stream check value */
2757 } check; /* if CHECK, check values to compare */
2758 uInt marker; /* if BAD, inflateSync's marker bytes count */
2759 } sub; /* submode */
2760
2761 /* mode independent information */
2762 int nowrap; /* flag for no wrapper */
2763 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
2764 inflate_blocks_statef
2765 *blocks; /* current inflate_blocks state */
2766
2767 };
2768
2769
inflateReset(z)2770 int inflateReset(z)
2771 z_stream *z;
2772 {
2773 uLong c;
2774
2775 if (z == Z_NULL || z->state == Z_NULL)
2776 return Z_STREAM_ERROR;
2777 z->total_in = z->total_out = 0;
2778 z->msg = Z_NULL;
2779 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
2780 inflate_blocks_reset(z->state->blocks, z, &c);
2781 Trace((stderr, "inflate: reset\n"));
2782 return Z_OK;
2783 }
2784
2785
inflateEnd(z)2786 int inflateEnd(z)
2787 z_stream *z;
2788 {
2789 uLong c;
2790
2791 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
2792 return Z_STREAM_ERROR;
2793 if (z->state->blocks != Z_NULL)
2794 inflate_blocks_free(z->state->blocks, z, &c);
2795 ZFREE(z, z->state, sizeof(struct internal_state));
2796 z->state = Z_NULL;
2797 Trace((stderr, "inflate: end\n"));
2798 return Z_OK;
2799 }
2800
2801
inflateInit2(z,w)2802 int inflateInit2(z, w)
2803 z_stream *z;
2804 int w;
2805 {
2806 /* initialize state */
2807 if (z == Z_NULL)
2808 return Z_STREAM_ERROR;
2809 /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */
2810 /* if (z->zfree == Z_NULL) z->zfree = zcfree; */
2811 if ((z->state = (struct internal_state FAR *)
2812 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
2813 return Z_MEM_ERROR;
2814 z->state->blocks = Z_NULL;
2815
2816 /* handle undocumented nowrap option (no zlib header or check) */
2817 z->state->nowrap = 0;
2818 if (w < 0)
2819 {
2820 w = - w;
2821 z->state->nowrap = 1;
2822 }
2823
2824 /* set window size */
2825 if (w < 8 || w > 15)
2826 {
2827 inflateEnd(z);
2828 return Z_STREAM_ERROR;
2829 }
2830 z->state->wbits = (uInt)w;
2831
2832 /* create inflate_blocks state */
2833 if ((z->state->blocks =
2834 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w))
2835 == Z_NULL)
2836 {
2837 inflateEnd(z);
2838 return Z_MEM_ERROR;
2839 }
2840 Trace((stderr, "inflate: allocated\n"));
2841
2842 /* reset state */
2843 inflateReset(z);
2844 return Z_OK;
2845 }
2846
2847
inflateInit(z)2848 int inflateInit(z)
2849 z_stream *z;
2850 {
2851 return inflateInit2(z, DEF_WBITS);
2852 }
2853
2854
2855 #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;}
2856 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
2857
inflate(z,f)2858 int inflate(z, f)
2859 z_stream *z;
2860 int f;
2861 {
2862 int r;
2863 uInt b;
2864
2865 if (z == Z_NULL || z->next_in == Z_NULL)
2866 return Z_STREAM_ERROR;
2867 r = Z_BUF_ERROR;
2868 while (1) switch (z->state->mode)
2869 {
2870 case METHOD:
2871 NEEDBYTE
2872 if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED)
2873 {
2874 z->state->mode = BAD;
2875 z->msg = "unknown compression method";
2876 z->state->sub.marker = 5; /* can't try inflateSync */
2877 break;
2878 }
2879 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
2880 {
2881 z->state->mode = BAD;
2882 z->msg = "invalid window size";
2883 z->state->sub.marker = 5; /* can't try inflateSync */
2884 break;
2885 }
2886 z->state->mode = FLAG;
2887 case FLAG:
2888 NEEDBYTE
2889 if ((b = NEXTBYTE) & 0x20)
2890 {
2891 z->state->mode = BAD;
2892 z->msg = "invalid reserved bit";
2893 z->state->sub.marker = 5; /* can't try inflateSync */
2894 break;
2895 }
2896 if (((z->state->sub.method << 8) + b) % 31)
2897 {
2898 z->state->mode = BAD;
2899 z->msg = "incorrect header check";
2900 z->state->sub.marker = 5; /* can't try inflateSync */
2901 break;
2902 }
2903 Trace((stderr, "inflate: zlib header ok\n"));
2904 z->state->mode = BLOCKS;
2905 case BLOCKS:
2906 r = inflate_blocks(z->state->blocks, z, r);
2907 if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
2908 r = inflate_packet_flush(z->state->blocks);
2909 if (r == Z_DATA_ERROR)
2910 {
2911 z->state->mode = BAD;
2912 z->state->sub.marker = 0; /* can try inflateSync */
2913 break;
2914 }
2915 if (r != Z_STREAM_END)
2916 return r;
2917 r = Z_OK;
2918 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
2919 if (z->state->nowrap)
2920 {
2921 z->state->mode = DONE;
2922 break;
2923 }
2924 z->state->mode = CHECK4;
2925 case CHECK4:
2926 NEEDBYTE
2927 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
2928 z->state->mode = CHECK3;
2929 case CHECK3:
2930 NEEDBYTE
2931 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
2932 z->state->mode = CHECK2;
2933 case CHECK2:
2934 NEEDBYTE
2935 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
2936 z->state->mode = CHECK1;
2937 case CHECK1:
2938 NEEDBYTE
2939 z->state->sub.check.need += (uLong)NEXTBYTE;
2940
2941 if (z->state->sub.check.was != z->state->sub.check.need)
2942 {
2943 z->state->mode = BAD;
2944 z->msg = "incorrect data check";
2945 z->state->sub.marker = 5; /* can't try inflateSync */
2946 break;
2947 }
2948 Trace((stderr, "inflate: zlib check ok\n"));
2949 z->state->mode = DONE;
2950 case DONE:
2951 return Z_STREAM_END;
2952 case BAD:
2953 return Z_DATA_ERROR;
2954 default:
2955 return Z_STREAM_ERROR;
2956 }
2957
2958 empty:
2959 if (f != Z_PACKET_FLUSH)
2960 return r;
2961 z->state->mode = BAD;
2962 z->state->sub.marker = 0; /* can try inflateSync */
2963 return Z_DATA_ERROR;
2964 }
2965
2966 /*
2967 * This subroutine adds the data at next_in/avail_in to the output history
2968 * without performing any output. The output buffer must be "caught up";
2969 * i.e. no pending output (hence s->read equals s->write), and the state must
2970 * be BLOCKS (i.e. we should be willing to see the start of a series of
2971 * BLOCKS). On exit, the output will also be caught up, and the checksum
2972 * will have been updated if need be.
2973 */
2974
inflateIncomp(z)2975 int inflateIncomp(z)
2976 z_stream *z;
2977 {
2978 if (z->state->mode != BLOCKS)
2979 return Z_DATA_ERROR;
2980 return inflate_addhistory(z->state->blocks, z);
2981 }
2982
2983
inflateSync(z)2984 int inflateSync(z)
2985 z_stream *z;
2986 {
2987 uInt n; /* number of bytes to look at */
2988 Bytef *p; /* pointer to bytes */
2989 uInt m; /* number of marker bytes found in a row */
2990 uLong r, w; /* temporaries to save total_in and total_out */
2991
2992 /* set up */
2993 if (z == Z_NULL || z->state == Z_NULL)
2994 return Z_STREAM_ERROR;
2995 if (z->state->mode != BAD)
2996 {
2997 z->state->mode = BAD;
2998 z->state->sub.marker = 0;
2999 }
3000 if ((n = z->avail_in) == 0)
3001 return Z_BUF_ERROR;
3002 p = z->next_in;
3003 m = z->state->sub.marker;
3004
3005 /* search */
3006 while (n && m < 4)
3007 {
3008 if (*p == (Byte)(m < 2 ? 0 : 0xff))
3009 m++;
3010 else if (*p)
3011 m = 0;
3012 else
3013 m = 4 - m;
3014 p++, n--;
3015 }
3016
3017 /* restore */
3018 z->total_in += p - z->next_in;
3019 z->next_in = p;
3020 z->avail_in = n;
3021 z->state->sub.marker = m;
3022
3023 /* return no joy or set up to restart on a new block */
3024 if (m != 4)
3025 return Z_DATA_ERROR;
3026 r = z->total_in; w = z->total_out;
3027 inflateReset(z);
3028 z->total_in = r; z->total_out = w;
3029 z->state->mode = BLOCKS;
3030 return Z_OK;
3031 }
3032
3033 #undef NEEDBYTE
3034 #undef NEXTBYTE
3035
3036 /*+++++*/
3037 /* infutil.h -- types and macros common to blocks and codes
3038 * Copyright (C) 1995 Mark Adler
3039 * For conditions of distribution and use, see copyright notice in zlib.h
3040 */
3041
3042 /* WARNING: this file should *not* be used by applications. It is
3043 part of the implementation of the compression library and is
3044 subject to change. Applications should only use zlib.h.
3045 */
3046
3047 /* inflate blocks semi-private state */
3048 struct inflate_blocks_state {
3049
3050 /* mode */
3051 enum {
3052 TYPE, /* get type bits (3, including end bit) */
3053 LENS, /* get lengths for stored */
3054 STORED, /* processing stored block */
3055 TABLE, /* get table lengths */
3056 BTREE, /* get bit lengths tree for a dynamic block */
3057 DTREE, /* get length, distance trees for a dynamic block */
3058 CODES, /* processing fixed or dynamic block */
3059 DRY, /* output remaining window bytes */
3060 DONEB, /* finished last block, done */
3061 BADB} /* got a data error--stuck here */
3062 mode; /* current inflate_block mode */
3063
3064 /* mode dependent information */
3065 union {
3066 uInt left; /* if STORED, bytes left to copy */
3067 struct {
3068 uInt table; /* table lengths (14 bits) */
3069 uInt index; /* index into blens (or border) */
3070 uIntf *blens; /* bit lengths of codes */
3071 uInt bb; /* bit length tree depth */
3072 inflate_huft *tb; /* bit length decoding tree */
3073 int nblens; /* # elements allocated at blens */
3074 } trees; /* if DTREE, decoding info for trees */
3075 struct {
3076 inflate_huft *tl, *td; /* trees to free */
3077 inflate_codes_statef
3078 *codes;
3079 } decode; /* if CODES, current state */
3080 } sub; /* submode */
3081 uInt last; /* true if this block is the last block */
3082
3083 /* mode independent information */
3084 uInt bitk; /* bits in bit buffer */
3085 uLong bitb; /* bit buffer */
3086 Bytef *window; /* sliding window */
3087 Bytef *end; /* one byte after sliding window */
3088 Bytef *read; /* window read pointer */
3089 Bytef *write; /* window write pointer */
3090 check_func checkfn; /* check function */
3091 uLong check; /* check on output */
3092
3093 };
3094
3095
3096 /* defines for inflate input/output */
3097 /* update pointers and return */
3098 #define UPDBITS {s->bitb=b;s->bitk=k;}
3099 #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;}
3100 #define UPDOUT {s->write=q;}
3101 #define UPDATE {UPDBITS UPDIN UPDOUT}
3102 #define LEAVE {UPDATE return inflate_flush(s,z,r);}
3103 /* get bytes and bits */
3104 #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;}
3105 #define NEEDBYTE {if(n)r=Z_OK;else LEAVE}
3106 #define NEXTBYTE (n--,*p++)
3107 #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}}
3108 #define DUMPBITS(j) {b>>=(j);k-=(j);}
3109 /* output bytes */
3110 #define WAVAIL (q<s->read?s->read-q-1:s->end-q)
3111 #define LOADOUT {q=s->write;m=WAVAIL;}
3112 #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}}
3113 #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT}
3114 #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;}
3115 #define OUTBYTE(a) {*q++=(Byte)(a);m--;}
3116 /* load local pointers */
3117 #define LOAD {LOADIN LOADOUT}
3118
3119 /* And'ing with mask[n] masks the lower n bits */
3120 local uInt inflate_mask[] = {
3121 0x0000,
3122 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
3123 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
3124 };
3125
3126 /* copy as much as possible from the sliding window to the output area */
3127 local int inflate_flush OF((
3128 inflate_blocks_statef *,
3129 z_stream *,
3130 int));
3131
3132 /*+++++*/
3133 /* inffast.h -- header to use inffast.c
3134 * Copyright (C) 1995 Mark Adler
3135 * For conditions of distribution and use, see copyright notice in zlib.h
3136 */
3137
3138 /* WARNING: this file should *not* be used by applications. It is
3139 part of the implementation of the compression library and is
3140 subject to change. Applications should only use zlib.h.
3141 */
3142
3143 local int inflate_fast OF((
3144 uInt,
3145 uInt,
3146 inflate_huft *,
3147 inflate_huft *,
3148 inflate_blocks_statef *,
3149 z_stream *));
3150
3151
3152 /*+++++*/
3153 /* infblock.c -- interpret and process block types to last block
3154 * Copyright (C) 1995 Mark Adler
3155 * For conditions of distribution and use, see copyright notice in zlib.h
3156 */
3157
3158 /* Table for deflate from PKZIP's appnote.txt. */
3159 local uInt border[] = { /* Order of the bit length code lengths */
3160 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
3161
3162 /*
3163 Notes beyond the 1.93a appnote.txt:
3164
3165 1. Distance pointers never point before the beginning of the output
3166 stream.
3167 2. Distance pointers can point back across blocks, up to 32k away.
3168 3. There is an implied maximum of 7 bits for the bit length table and
3169 15 bits for the actual data.
3170 4. If only one code exists, then it is encoded using one bit. (Zero
3171 would be more efficient, but perhaps a little confusing.) If two
3172 codes exist, they are coded using one bit each (0 and 1).
3173 5. There is no way of sending zero distance codes--a dummy must be
3174 sent if there are none. (History: a pre 2.0 version of PKZIP would
3175 store blocks with no distance codes, but this was discovered to be
3176 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
3177 zero distance codes, which is sent as one code of zero bits in
3178 length.
3179 6. There are up to 286 literal/length codes. Code 256 represents the
3180 end-of-block. Note however that the static length tree defines
3181 288 codes just to fill out the Huffman codes. Codes 286 and 287
3182 cannot be used though, since there is no length base or extra bits
3183 defined for them. Similarily, there are up to 30 distance codes.
3184 However, static trees define 32 codes (all 5 bits) to fill out the
3185 Huffman codes, but the last two had better not show up in the data.
3186 7. Unzip can check dynamic Huffman blocks for complete code sets.
3187 The exception is that a single code would not be complete (see #4).
3188 8. The five bits following the block type is really the number of
3189 literal codes sent minus 257.
3190 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
3191 (1+6+6). Therefore, to output three times the length, you output
3192 three codes (1+1+1), whereas to output four times the same length,
3193 you only need two codes (1+3). Hmm.
3194 10. In the tree reconstruction algorithm, Code = Code + Increment
3195 only if BitLength(i) is not zero. (Pretty obvious.)
3196 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
3197 12. Note: length code 284 can represent 227-258, but length code 285
3198 really is 258. The last length deserves its own, short code
3199 since it gets used a lot in very redundant files. The length
3200 258 is special since 258 - 3 (the min match length) is 255.
3201 13. The literal/length and distance code bit lengths are read as a
3202 single stream of lengths. It is possible (and advantageous) for
3203 a repeat code (16, 17, or 18) to go across the boundary between
3204 the two sets of lengths.
3205 */
3206
3207
inflate_blocks_reset(s,z,c)3208 local void inflate_blocks_reset(s, z, c)
3209 inflate_blocks_statef *s;
3210 z_stream *z;
3211 uLongf *c;
3212 {
3213 if (s->checkfn != Z_NULL)
3214 *c = s->check;
3215 if (s->mode == BTREE || s->mode == DTREE)
3216 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3217 if (s->mode == CODES)
3218 {
3219 inflate_codes_free(s->sub.decode.codes, z);
3220 inflate_trees_free(s->sub.decode.td, z);
3221 inflate_trees_free(s->sub.decode.tl, z);
3222 }
3223 s->mode = TYPE;
3224 s->bitk = 0;
3225 s->bitb = 0;
3226 s->read = s->write = s->window;
3227 if (s->checkfn != Z_NULL)
3228 s->check = (*s->checkfn)(0L, Z_NULL, 0);
3229 Trace((stderr, "inflate: blocks reset\n"));
3230 }
3231
3232
inflate_blocks_new(z,c,w)3233 local inflate_blocks_statef *inflate_blocks_new(z, c, w)
3234 z_stream *z;
3235 check_func c;
3236 uInt w;
3237 {
3238 inflate_blocks_statef *s;
3239
3240 if ((s = (inflate_blocks_statef *)ZALLOC
3241 (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL)
3242 return s;
3243 if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL)
3244 {
3245 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3246 return Z_NULL;
3247 }
3248 s->end = s->window + w;
3249 s->checkfn = c;
3250 s->mode = TYPE;
3251 Trace((stderr, "inflate: blocks allocated\n"));
3252 inflate_blocks_reset(s, z, &s->check);
3253 return s;
3254 }
3255
3256
inflate_blocks(s,z,r)3257 local int inflate_blocks(s, z, r)
3258 inflate_blocks_statef *s;
3259 z_stream *z;
3260 int r;
3261 {
3262 uInt t; /* temporary storage */
3263 uLong b; /* bit buffer */
3264 uInt k; /* bits in bit buffer */
3265 Bytef *p; /* input data pointer */
3266 uInt n; /* bytes available there */
3267 Bytef *q; /* output window write pointer */
3268 uInt m; /* bytes to end of window or read pointer */
3269
3270 /* copy input/output information to locals (UPDATE macro restores) */
3271 LOAD
3272
3273 /* process input based on current state */
3274 while (1) switch (s->mode)
3275 {
3276 case TYPE:
3277 NEEDBITS(3)
3278 t = (uInt)b & 7;
3279 s->last = t & 1;
3280 switch (t >> 1)
3281 {
3282 case 0: /* stored */
3283 Trace((stderr, "inflate: stored block%s\n",
3284 s->last ? " (last)" : ""));
3285 DUMPBITS(3)
3286 t = k & 7; /* go to byte boundary */
3287 DUMPBITS(t)
3288 s->mode = LENS; /* get length of stored block */
3289 break;
3290 case 1: /* fixed */
3291 Trace((stderr, "inflate: fixed codes block%s\n",
3292 s->last ? " (last)" : ""));
3293 {
3294 uInt bl, bd;
3295 inflate_huft *tl, *td;
3296
3297 inflate_trees_fixed(&bl, &bd, &tl, &td);
3298 s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z);
3299 if (s->sub.decode.codes == Z_NULL)
3300 {
3301 r = Z_MEM_ERROR;
3302 LEAVE
3303 }
3304 s->sub.decode.tl = Z_NULL; /* don't try to free these */
3305 s->sub.decode.td = Z_NULL;
3306 }
3307 DUMPBITS(3)
3308 s->mode = CODES;
3309 break;
3310 case 2: /* dynamic */
3311 Trace((stderr, "inflate: dynamic codes block%s\n",
3312 s->last ? " (last)" : ""));
3313 DUMPBITS(3)
3314 s->mode = TABLE;
3315 break;
3316 case 3: /* illegal */
3317 DUMPBITS(3)
3318 s->mode = BADB;
3319 z->msg = "invalid block type";
3320 r = Z_DATA_ERROR;
3321 LEAVE
3322 }
3323 break;
3324 case LENS:
3325 NEEDBITS(32)
3326 if (((~b) >> 16) != (b & 0xffff))
3327 {
3328 s->mode = BADB;
3329 z->msg = "invalid stored block lengths";
3330 r = Z_DATA_ERROR;
3331 LEAVE
3332 }
3333 s->sub.left = (uInt)b & 0xffff;
3334 b = k = 0; /* dump bits */
3335 Tracev((stderr, "inflate: stored length %u\n", s->sub.left));
3336 s->mode = s->sub.left ? STORED : TYPE;
3337 break;
3338 case STORED:
3339 if (n == 0)
3340 LEAVE
3341 NEEDOUT
3342 t = s->sub.left;
3343 if (t > n) t = n;
3344 if (t > m) t = m;
3345 zmemcpy(q, p, t);
3346 p += t; n -= t;
3347 q += t; m -= t;
3348 if ((s->sub.left -= t) != 0)
3349 break;
3350 Tracev((stderr, "inflate: stored end, %lu total out\n",
3351 z->total_out + (q >= s->read ? q - s->read :
3352 (s->end - s->read) + (q - s->window))));
3353 s->mode = s->last ? DRY : TYPE;
3354 break;
3355 case TABLE:
3356 NEEDBITS(14)
3357 s->sub.trees.table = t = (uInt)b & 0x3fff;
3358 #ifndef PKZIP_BUG_WORKAROUND
3359 if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
3360 {
3361 s->mode = BADB;
3362 z->msg = "too many length or distance symbols";
3363 r = Z_DATA_ERROR;
3364 LEAVE
3365 }
3366 #endif
3367 t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
3368 if (t < 19)
3369 t = 19;
3370 if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL)
3371 {
3372 r = Z_MEM_ERROR;
3373 LEAVE
3374 }
3375 s->sub.trees.nblens = t;
3376 DUMPBITS(14)
3377 s->sub.trees.index = 0;
3378 Tracev((stderr, "inflate: table sizes ok\n"));
3379 s->mode = BTREE;
3380 case BTREE:
3381 while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10))
3382 {
3383 NEEDBITS(3)
3384 s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7;
3385 DUMPBITS(3)
3386 }
3387 while (s->sub.trees.index < 19)
3388 s->sub.trees.blens[border[s->sub.trees.index++]] = 0;
3389 s->sub.trees.bb = 7;
3390 t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb,
3391 &s->sub.trees.tb, z);
3392 if (t != Z_OK)
3393 {
3394 r = t;
3395 if (r == Z_DATA_ERROR)
3396 s->mode = BADB;
3397 LEAVE
3398 }
3399 s->sub.trees.index = 0;
3400 Tracev((stderr, "inflate: bits tree ok\n"));
3401 s->mode = DTREE;
3402 case DTREE:
3403 while (t = s->sub.trees.table,
3404 s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f))
3405 {
3406 inflate_huft *h;
3407 uInt i, j, c;
3408
3409 t = s->sub.trees.bb;
3410 NEEDBITS(t)
3411 h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]);
3412 t = h->word.what.Bits;
3413 c = h->more.Base;
3414 if (c < 16)
3415 {
3416 DUMPBITS(t)
3417 s->sub.trees.blens[s->sub.trees.index++] = c;
3418 }
3419 else /* c == 16..18 */
3420 {
3421 i = c == 18 ? 7 : c - 14;
3422 j = c == 18 ? 11 : 3;
3423 NEEDBITS(t + i)
3424 DUMPBITS(t)
3425 j += (uInt)b & inflate_mask[i];
3426 DUMPBITS(i)
3427 i = s->sub.trees.index;
3428 t = s->sub.trees.table;
3429 if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) ||
3430 (c == 16 && i < 1))
3431 {
3432 s->mode = BADB;
3433 z->msg = "invalid bit length repeat";
3434 r = Z_DATA_ERROR;
3435 LEAVE
3436 }
3437 c = c == 16 ? s->sub.trees.blens[i - 1] : 0;
3438 do {
3439 s->sub.trees.blens[i++] = c;
3440 } while (--j);
3441 s->sub.trees.index = i;
3442 }
3443 }
3444 inflate_trees_free(s->sub.trees.tb, z);
3445 s->sub.trees.tb = Z_NULL;
3446 {
3447 uInt bl, bd;
3448 inflate_huft *tl, *td;
3449 inflate_codes_statef *c;
3450
3451 bl = 9; /* must be <= 9 for lookahead assumptions */
3452 bd = 6; /* must be <= 9 for lookahead assumptions */
3453 t = s->sub.trees.table;
3454 t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f),
3455 s->sub.trees.blens, &bl, &bd, &tl, &td, z);
3456 if (t != Z_OK)
3457 {
3458 if (t == (uInt)Z_DATA_ERROR)
3459 s->mode = BADB;
3460 r = t;
3461 LEAVE
3462 }
3463 Tracev((stderr, "inflate: trees ok\n"));
3464 if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL)
3465 {
3466 inflate_trees_free(td, z);
3467 inflate_trees_free(tl, z);
3468 r = Z_MEM_ERROR;
3469 LEAVE
3470 }
3471 ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt));
3472 s->sub.decode.codes = c;
3473 s->sub.decode.tl = tl;
3474 s->sub.decode.td = td;
3475 }
3476 s->mode = CODES;
3477 case CODES:
3478 UPDATE
3479 if ((r = inflate_codes(s, z, r)) != Z_STREAM_END)
3480 return inflate_flush(s, z, r);
3481 r = Z_OK;
3482 inflate_codes_free(s->sub.decode.codes, z);
3483 inflate_trees_free(s->sub.decode.td, z);
3484 inflate_trees_free(s->sub.decode.tl, z);
3485 LOAD
3486 Tracev((stderr, "inflate: codes end, %lu total out\n",
3487 z->total_out + (q >= s->read ? q - s->read :
3488 (s->end - s->read) + (q - s->window))));
3489 if (!s->last)
3490 {
3491 s->mode = TYPE;
3492 break;
3493 }
3494 if (k > 7) /* return unused byte, if any */
3495 {
3496 Assert(k < 16, "inflate_codes grabbed too many bytes")
3497 k -= 8;
3498 n++;
3499 p--; /* can always return one */
3500 }
3501 s->mode = DRY;
3502 case DRY:
3503 FLUSH
3504 if (s->read != s->write)
3505 LEAVE
3506 s->mode = DONEB;
3507 case DONEB:
3508 r = Z_STREAM_END;
3509 LEAVE
3510 case BADB:
3511 r = Z_DATA_ERROR;
3512 LEAVE
3513 default:
3514 r = Z_STREAM_ERROR;
3515 LEAVE
3516 }
3517 }
3518
3519
inflate_blocks_free(s,z,c)3520 local int inflate_blocks_free(s, z, c)
3521 inflate_blocks_statef *s;
3522 z_stream *z;
3523 uLongf *c;
3524 {
3525 inflate_blocks_reset(s, z, c);
3526 ZFREE(z, s->window, s->end - s->window);
3527 ZFREE(z, s, sizeof(struct inflate_blocks_state));
3528 Trace((stderr, "inflate: blocks freed\n"));
3529 return Z_OK;
3530 }
3531
3532 /*
3533 * This subroutine adds the data at next_in/avail_in to the output history
3534 * without performing any output. The output buffer must be "caught up";
3535 * i.e. no pending output (hence s->read equals s->write), and the state must
3536 * be BLOCKS (i.e. we should be willing to see the start of a series of
3537 * BLOCKS). On exit, the output will also be caught up, and the checksum
3538 * will have been updated if need be.
3539 */
inflate_addhistory(s,z)3540 local int inflate_addhistory(s, z)
3541 inflate_blocks_statef *s;
3542 z_stream *z;
3543 {
3544 uLong b; /* bit buffer */ /* NOT USED HERE */
3545 uInt k; /* bits in bit buffer */ /* NOT USED HERE */
3546 uInt t; /* temporary storage */
3547 Bytef *p; /* input data pointer */
3548 uInt n; /* bytes available there */
3549 Bytef *q; /* output window write pointer */
3550 uInt m; /* bytes to end of window or read pointer */
3551
3552 if (s->read != s->write)
3553 return Z_STREAM_ERROR;
3554 if (s->mode != TYPE)
3555 return Z_DATA_ERROR;
3556
3557 /* we're ready to rock */
3558 LOAD
3559 /* while there is input ready, copy to output buffer, moving
3560 * pointers as needed.
3561 */
3562 while (n) {
3563 t = n; /* how many to do */
3564 /* is there room until end of buffer? */
3565 if (t > m) t = m;
3566 /* update check information */
3567 if (s->checkfn != Z_NULL)
3568 s->check = (*s->checkfn)(s->check, q, t);
3569 zmemcpy(q, p, t);
3570 q += t;
3571 p += t;
3572 n -= t;
3573 z->total_out += t;
3574 s->read = q; /* drag read pointer forward */
3575 /* WRAP */ /* expand WRAP macro by hand to handle s->read */
3576 if (q == s->end) {
3577 s->read = q = s->window;
3578 m = WAVAIL;
3579 }
3580 }
3581 UPDATE
3582 return Z_OK;
3583 }
3584
3585
3586 /*
3587 * At the end of a Deflate-compressed PPP packet, we expect to have seen
3588 * a `stored' block type value but not the (zero) length bytes.
3589 */
inflate_packet_flush(s)3590 local int inflate_packet_flush(s)
3591 inflate_blocks_statef *s;
3592 {
3593 if (s->mode != LENS)
3594 return Z_DATA_ERROR;
3595 s->mode = TYPE;
3596 return Z_OK;
3597 }
3598
3599
3600 /*+++++*/
3601 /* inftrees.c -- generate Huffman trees for efficient decoding
3602 * Copyright (C) 1995 Mark Adler
3603 * For conditions of distribution and use, see copyright notice in zlib.h
3604 */
3605
3606 /* simplify the use of the inflate_huft type with some defines */
3607 #define base more.Base
3608 #define next more.Next
3609 #define exop word.what.Exop
3610 #define bits word.what.Bits
3611
3612
3613 local int huft_build OF((
3614 uIntf *, /* code lengths in bits */
3615 uInt, /* number of codes */
3616 uInt, /* number of "simple" codes */
3617 uIntf *, /* list of base values for non-simple codes */
3618 uIntf *, /* list of extra bits for non-simple codes */
3619 inflate_huft * FAR*,/* result: starting table */
3620 uIntf *, /* maximum lookup bits (returns actual) */
3621 z_stream *)); /* for zalloc function */
3622
3623 local voidpf falloc OF((
3624 voidpf, /* opaque pointer (not used) */
3625 uInt, /* number of items */
3626 uInt)); /* size of item */
3627
3628 local void ffree OF((
3629 voidpf q, /* opaque pointer (not used) */
3630 voidpf p, /* what to free (not used) */
3631 uInt n)); /* number of bytes (not used) */
3632
3633 /* Tables for deflate from PKZIP's appnote.txt. */
3634 local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */
3635 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
3636 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
3637 /* actually lengths - 2; also see note #13 above about 258 */
3638 local uInt cplext[] = { /* Extra bits for literal codes 257..285 */
3639 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
3640 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */
3641 local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */
3642 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
3643 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
3644 8193, 12289, 16385, 24577};
3645 local uInt cpdext[] = { /* Extra bits for distance codes */
3646 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
3647 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
3648 12, 12, 13, 13};
3649
3650 /*
3651 Huffman code decoding is performed using a multi-level table lookup.
3652 The fastest way to decode is to simply build a lookup table whose
3653 size is determined by the longest code. However, the time it takes
3654 to build this table can also be a factor if the data being decoded
3655 is not very long. The most common codes are necessarily the
3656 shortest codes, so those codes dominate the decoding time, and hence
3657 the speed. The idea is you can have a shorter table that decodes the
3658 shorter, more probable codes, and then point to subsidiary tables for
3659 the longer codes. The time it costs to decode the longer codes is
3660 then traded against the time it takes to make longer tables.
3661
3662 This results of this trade are in the variables lbits and dbits
3663 below. lbits is the number of bits the first level table for literal/
3664 length codes can decode in one step, and dbits is the same thing for
3665 the distance codes. Subsequent tables are also less than or equal to
3666 those sizes. These values may be adjusted either when all of the
3667 codes are shorter than that, in which case the longest code length in
3668 bits is used, or when the shortest code is *longer* than the requested
3669 table size, in which case the length of the shortest code in bits is
3670 used.
3671
3672 There are two different values for the two tables, since they code a
3673 different number of possibilities each. The literal/length table
3674 codes 286 possible values, or in a flat code, a little over eight
3675 bits. The distance table codes 30 possible values, or a little less
3676 than five bits, flat. The optimum values for speed end up being
3677 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
3678 The optimum values may differ though from machine to machine, and
3679 possibly even between compilers. Your mileage may vary.
3680 */
3681
3682
3683 /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */
3684 #define BMAX 15 /* maximum bit length of any code */
3685 #define N_MAX 288 /* maximum number of codes in any set */
3686
3687 #ifdef DEBUG_ZLIB
3688 uInt inflate_hufts;
3689 #endif
3690
huft_build(b,n,s,d,e,t,m,zs)3691 local int huft_build(b, n, s, d, e, t, m, zs)
3692 uIntf *b; /* code lengths in bits (all assumed <= BMAX) */
3693 uInt n; /* number of codes (assumed <= N_MAX) */
3694 uInt s; /* number of simple-valued codes (0..s-1) */
3695 uIntf *d; /* list of base values for non-simple codes */
3696 uIntf *e; /* list of extra bits for non-simple codes */
3697 inflate_huft * FAR *t; /* result: starting table */
3698 uIntf *m; /* maximum lookup bits, returns actual */
3699 z_stream *zs; /* for zalloc function */
3700 /* Given a list of code lengths and a maximum table size, make a set of
3701 tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR
3702 if the given code set is incomplete (the tables are still built in this
3703 case), Z_DATA_ERROR if the input is invalid (all zero length codes or an
3704 over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */
3705 {
3706
3707 uInt a; /* counter for codes of length k */
3708 uInt c[BMAX+1]; /* bit length count table */
3709 uInt f; /* i repeats in table every f entries */
3710 int g; /* maximum code length */
3711 int h; /* table level */
3712 register uInt i; /* counter, current code */
3713 register uInt j; /* counter */
3714 register int k; /* number of bits in current code */
3715 int l; /* bits per table (returned in m) */
3716 register uIntf *p; /* pointer into c[], b[], or v[] */
3717 inflate_huft *q; /* points to current table */
3718 struct inflate_huft_s r; /* table entry for structure assignment */
3719 inflate_huft *u[BMAX]; /* table stack */
3720 uInt v[N_MAX]; /* values in order of bit length */
3721 register int w; /* bits before this table == (l * h) */
3722 uInt x[BMAX+1]; /* bit offsets, then code stack */
3723 uIntf *xp; /* pointer into x */
3724 int y; /* number of dummy codes added */
3725 uInt z; /* number of entries in current table */
3726
3727
3728 /* Generate counts for each bit length */
3729 p = c;
3730 #define C0 *p++ = 0;
3731 #define C2 C0 C0 C0 C0
3732 #define C4 C2 C2 C2 C2
3733 C4 /* clear c[]--assume BMAX+1 is 16 */
3734 p = b; i = n;
3735 do {
3736 c[*p++]++; /* assume all entries <= BMAX */
3737 } while (--i);
3738 if (c[0] == n) /* null input--all zero length codes */
3739 {
3740 *t = (inflate_huft *)Z_NULL;
3741 *m = 0;
3742 return Z_OK;
3743 }
3744
3745
3746 /* Find minimum and maximum length, bound *m by those */
3747 l = *m;
3748 for (j = 1; j <= BMAX; j++)
3749 if (c[j])
3750 break;
3751 k = j; /* minimum code length */
3752 if ((uInt)l < j)
3753 l = j;
3754 for (i = BMAX; i; i--)
3755 if (c[i])
3756 break;
3757 g = i; /* maximum code length */
3758 if ((uInt)l > i)
3759 l = i;
3760 *m = l;
3761
3762
3763 /* Adjust last length count to fill out codes, if needed */
3764 for (y = 1 << j; j < i; j++, y <<= 1)
3765 if ((y -= c[j]) < 0)
3766 return Z_DATA_ERROR;
3767 if ((y -= c[i]) < 0)
3768 return Z_DATA_ERROR;
3769 c[i] += y;
3770
3771
3772 /* Generate starting offsets into the value table for each length */
3773 x[1] = j = 0;
3774 p = c + 1; xp = x + 2;
3775 while (--i) { /* note that i == g from above */
3776 *xp++ = (j += *p++);
3777 }
3778
3779
3780 /* Make a table of values in order of bit lengths */
3781 p = b; i = 0;
3782 do {
3783 if ((j = *p++) != 0)
3784 v[x[j]++] = i;
3785 } while (++i < n);
3786
3787
3788 /* Generate the Huffman codes and for each, make the table entries */
3789 x[0] = i = 0; /* first Huffman code is zero */
3790 p = v; /* grab values in bit order */
3791 h = -1; /* no tables yet--level -1 */
3792 w = -l; /* bits decoded == (l * h) */
3793 u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */
3794 q = (inflate_huft *)Z_NULL; /* ditto */
3795 z = 0; /* ditto */
3796
3797 /* go through the bit lengths (k already is bits in shortest code) */
3798 for (; k <= g; k++)
3799 {
3800 a = c[k];
3801 while (a--)
3802 {
3803 /* here i is the Huffman code of length k bits for value *p */
3804 /* make tables up to required level */
3805 while (k > w + l)
3806 {
3807 h++;
3808 w += l; /* previous table always l bits */
3809
3810 /* compute minimum size table less than or equal to l bits */
3811 z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */
3812 if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
3813 { /* too few codes for k-w bit table */
3814 f -= a + 1; /* deduct codes from patterns left */
3815 xp = c + k;
3816 if (j < z)
3817 while (++j < z) /* try smaller tables up to z bits */
3818 {
3819 if ((f <<= 1) <= *++xp)
3820 break; /* enough codes to use up j bits */
3821 f -= *xp; /* else deduct codes from patterns */
3822 }
3823 }
3824 z = 1 << j; /* table entries for j-bit table */
3825
3826 /* allocate and link in new table */
3827 if ((q = (inflate_huft *)ZALLOC
3828 (zs,z + 1,sizeof(inflate_huft))) == Z_NULL)
3829 {
3830 if (h)
3831 inflate_trees_free(u[0], zs);
3832 return Z_MEM_ERROR; /* not enough memory */
3833 }
3834 q->word.Nalloc = z + 1;
3835 #ifdef DEBUG_ZLIB
3836 inflate_hufts += z + 1;
3837 #endif
3838 *t = q + 1; /* link to list for huft_free() */
3839 *(t = &(q->next)) = Z_NULL;
3840 u[h] = ++q; /* table starts after link */
3841
3842 /* connect to last table, if there is one */
3843 if (h)
3844 {
3845 x[h] = i; /* save pattern for backing up */
3846 r.bits = (Byte)l; /* bits to dump before this table */
3847 r.exop = (Byte)j; /* bits in this table */
3848 r.next = q; /* pointer to this table */
3849 j = i >> (w - l); /* (get around Turbo C bug) */
3850 u[h-1][j] = r; /* connect to last table */
3851 }
3852 }
3853
3854 /* set up table entry in r */
3855 r.bits = (Byte)(k - w);
3856 if (p >= v + n)
3857 r.exop = 128 + 64; /* out of values--invalid code */
3858 else if (*p < s)
3859 {
3860 r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */
3861 r.base = *p++; /* simple code is just the value */
3862 }
3863 else
3864 {
3865 r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */
3866 r.base = d[*p++ - s];
3867 }
3868
3869 /* fill code-like entries with r */
3870 f = 1 << (k - w);
3871 for (j = i >> w; j < z; j += f)
3872 q[j] = r;
3873
3874 /* backwards increment the k-bit code i */
3875 for (j = 1 << (k - 1); i & j; j >>= 1)
3876 i ^= j;
3877 i ^= j;
3878
3879 /* backup over finished tables */
3880 while ((i & ((1 << w) - 1)) != x[h])
3881 {
3882 h--; /* don't need to update q */
3883 w -= l;
3884 }
3885 }
3886 }
3887
3888
3889 /* Return Z_BUF_ERROR if we were given an incomplete table */
3890 return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK;
3891 }
3892
3893
inflate_trees_bits(c,bb,tb,z)3894 local int inflate_trees_bits(c, bb, tb, z)
3895 uIntf *c; /* 19 code lengths */
3896 uIntf *bb; /* bits tree desired/actual depth */
3897 inflate_huft * FAR *tb; /* bits tree result */
3898 z_stream *z; /* for zfree function */
3899 {
3900 int r;
3901
3902 r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z);
3903 if (r == Z_DATA_ERROR)
3904 z->msg = "oversubscribed dynamic bit lengths tree";
3905 else if (r == Z_BUF_ERROR)
3906 {
3907 inflate_trees_free(*tb, z);
3908 z->msg = "incomplete dynamic bit lengths tree";
3909 r = Z_DATA_ERROR;
3910 }
3911 return r;
3912 }
3913
3914
inflate_trees_dynamic(nl,nd,c,bl,bd,tl,td,z)3915 local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z)
3916 uInt nl; /* number of literal/length codes */
3917 uInt nd; /* number of distance codes */
3918 uIntf *c; /* that many (total) code lengths */
3919 uIntf *bl; /* literal desired/actual bit depth */
3920 uIntf *bd; /* distance desired/actual bit depth */
3921 inflate_huft * FAR *tl; /* literal/length tree result */
3922 inflate_huft * FAR *td; /* distance tree result */
3923 z_stream *z; /* for zfree function */
3924 {
3925 int r;
3926
3927 /* build literal/length tree */
3928 if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK)
3929 {
3930 if (r == Z_DATA_ERROR)
3931 z->msg = "oversubscribed literal/length tree";
3932 else if (r == Z_BUF_ERROR)
3933 {
3934 inflate_trees_free(*tl, z);
3935 z->msg = "incomplete literal/length tree";
3936 r = Z_DATA_ERROR;
3937 }
3938 return r;
3939 }
3940
3941 /* build distance tree */
3942 if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK)
3943 {
3944 if (r == Z_DATA_ERROR)
3945 z->msg = "oversubscribed literal/length tree";
3946 else if (r == Z_BUF_ERROR) {
3947 #ifdef PKZIP_BUG_WORKAROUND
3948 r = Z_OK;
3949 }
3950 #else
3951 inflate_trees_free(*td, z);
3952 z->msg = "incomplete literal/length tree";
3953 r = Z_DATA_ERROR;
3954 }
3955 inflate_trees_free(*tl, z);
3956 return r;
3957 #endif
3958 }
3959
3960 /* done */
3961 return Z_OK;
3962 }
3963
3964
3965 /* build fixed tables only once--keep them here */
3966 local int fixed_lock = 0;
3967 local int fixed_built = 0;
3968 #define FIXEDH 530 /* number of hufts used by fixed tables */
3969 local uInt fixed_left = FIXEDH;
3970 local inflate_huft fixed_mem[FIXEDH];
3971 local uInt fixed_bl;
3972 local uInt fixed_bd;
3973 local inflate_huft *fixed_tl;
3974 local inflate_huft *fixed_td;
3975
3976
falloc(q,n,s)3977 local voidpf falloc(q, n, s)
3978 voidpf q; /* opaque pointer (not used) */
3979 uInt n; /* number of items */
3980 uInt s; /* size of item */
3981 {
3982 Assert(s == sizeof(inflate_huft) && n <= fixed_left,
3983 "inflate_trees falloc overflow");
3984 if (q) s++; /* to make some compilers happy */
3985 fixed_left -= n;
3986 return (voidpf)(fixed_mem + fixed_left);
3987 }
3988
3989
ffree(q,p,n)3990 local void ffree(q, p, n)
3991 voidpf q;
3992 voidpf p;
3993 uInt n;
3994 {
3995 Assert(0, "inflate_trees ffree called!");
3996 if (q) q = p; /* to make some compilers happy */
3997 }
3998
3999
inflate_trees_fixed(bl,bd,tl,td)4000 local int inflate_trees_fixed(bl, bd, tl, td)
4001 uIntf *bl; /* literal desired/actual bit depth */
4002 uIntf *bd; /* distance desired/actual bit depth */
4003 inflate_huft * FAR *tl; /* literal/length tree result */
4004 inflate_huft * FAR *td; /* distance tree result */
4005 {
4006 /* build fixed tables if not built already--lock out other instances */
4007 while (++fixed_lock > 1)
4008 fixed_lock--;
4009 if (!fixed_built)
4010 {
4011 int k; /* temporary variable */
4012 unsigned c[288]; /* length list for huft_build */
4013 z_stream z; /* for falloc function */
4014
4015 /* set up fake z_stream for memory routines */
4016 z.zalloc = falloc;
4017 z.zfree = ffree;
4018 z.opaque = Z_NULL;
4019
4020 /* literal table */
4021 for (k = 0; k < 144; k++)
4022 c[k] = 8;
4023 for (; k < 256; k++)
4024 c[k] = 9;
4025 for (; k < 280; k++)
4026 c[k] = 7;
4027 for (; k < 288; k++)
4028 c[k] = 8;
4029 fixed_bl = 7;
4030 huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z);
4031
4032 /* distance table */
4033 for (k = 0; k < 30; k++)
4034 c[k] = 5;
4035 fixed_bd = 5;
4036 huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z);
4037
4038 /* done */
4039 fixed_built = 1;
4040 }
4041 fixed_lock--;
4042 *bl = fixed_bl;
4043 *bd = fixed_bd;
4044 *tl = fixed_tl;
4045 *td = fixed_td;
4046 return Z_OK;
4047 }
4048
4049
inflate_trees_free(t,z)4050 local int inflate_trees_free(t, z)
4051 inflate_huft *t; /* table to free */
4052 z_stream *z; /* for zfree function */
4053 /* Free the malloc'ed tables built by huft_build(), which makes a linked
4054 list of the tables it made, with the links in a dummy first entry of
4055 each table. */
4056 {
4057 register inflate_huft *p, *q;
4058
4059 /* Go through linked list, freeing from the malloced (t[-1]) address. */
4060 p = t;
4061 while (p != Z_NULL)
4062 {
4063 q = (--p)->next;
4064 ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft));
4065 p = q;
4066 }
4067 return Z_OK;
4068 }
4069
4070 /*+++++*/
4071 /* infcodes.c -- process literals and length/distance pairs
4072 * Copyright (C) 1995 Mark Adler
4073 * For conditions of distribution and use, see copyright notice in zlib.h
4074 */
4075
4076 /* simplify the use of the inflate_huft type with some defines */
4077 #define base more.Base
4078 #define next more.Next
4079 #define exop word.what.Exop
4080 #define bits word.what.Bits
4081
4082 /* inflate codes private state */
4083 struct inflate_codes_state {
4084
4085 /* mode */
4086 enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4087 START, /* x: set up for LEN */
4088 LEN, /* i: get length/literal/eob next */
4089 LENEXT, /* i: getting length extra (have base) */
4090 DIST, /* i: get distance next */
4091 DISTEXT, /* i: getting distance extra */
4092 COPY, /* o: copying bytes in window, waiting for space */
4093 LIT, /* o: got literal, waiting for output space */
4094 WASH, /* o: got eob, possibly still output waiting */
4095 END, /* x: got eob and all data flushed */
4096 BADCODE} /* x: got error */
4097 mode; /* current inflate_codes mode */
4098
4099 /* mode dependent information */
4100 uInt len;
4101 union {
4102 struct {
4103 inflate_huft *tree; /* pointer into tree */
4104 uInt need; /* bits needed */
4105 } code; /* if LEN or DIST, where in tree */
4106 uInt lit; /* if LIT, literal */
4107 struct {
4108 uInt get; /* bits to get for extra */
4109 uInt dist; /* distance back to copy from */
4110 } copy; /* if EXT or COPY, where and how much */
4111 } sub; /* submode */
4112
4113 /* mode independent information */
4114 Byte lbits; /* ltree bits decoded per branch */
4115 Byte dbits; /* dtree bits decoder per branch */
4116 inflate_huft *ltree; /* literal/length/eob tree */
4117 inflate_huft *dtree; /* distance tree */
4118
4119 };
4120
4121
inflate_codes_new(bl,bd,tl,td,z)4122 local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z)
4123 uInt bl, bd;
4124 inflate_huft *tl, *td;
4125 z_stream *z;
4126 {
4127 inflate_codes_statef *c;
4128
4129 if ((c = (inflate_codes_statef *)
4130 ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL)
4131 {
4132 c->mode = START;
4133 c->lbits = (Byte)bl;
4134 c->dbits = (Byte)bd;
4135 c->ltree = tl;
4136 c->dtree = td;
4137 Tracev((stderr, "inflate: codes new\n"));
4138 }
4139 return c;
4140 }
4141
4142
inflate_codes(s,z,r)4143 local int inflate_codes(s, z, r)
4144 inflate_blocks_statef *s;
4145 z_stream *z;
4146 int r;
4147 {
4148 uInt j; /* temporary storage */
4149 inflate_huft *t; /* temporary pointer */
4150 uInt e; /* extra bits or operation */
4151 uLong b; /* bit buffer */
4152 uInt k; /* bits in bit buffer */
4153 Bytef *p; /* input data pointer */
4154 uInt n; /* bytes available there */
4155 Bytef *q; /* output window write pointer */
4156 uInt m; /* bytes to end of window or read pointer */
4157 Bytef *f; /* pointer to copy strings from */
4158 inflate_codes_statef *c = s->sub.decode.codes; /* codes state */
4159
4160 /* copy input/output information to locals (UPDATE macro restores) */
4161 LOAD
4162
4163 /* process input and output based on current state */
4164 while (1) switch (c->mode)
4165 { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */
4166 case START: /* x: set up for LEN */
4167 #ifndef SLOW
4168 if (m >= 258 && n >= 10)
4169 {
4170 UPDATE
4171 r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z);
4172 LOAD
4173 if (r != Z_OK)
4174 {
4175 c->mode = r == Z_STREAM_END ? WASH : BADCODE;
4176 break;
4177 }
4178 }
4179 #endif /* !SLOW */
4180 c->sub.code.need = c->lbits;
4181 c->sub.code.tree = c->ltree;
4182 c->mode = LEN;
4183 case LEN: /* i: get length/literal/eob next */
4184 j = c->sub.code.need;
4185 NEEDBITS(j)
4186 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4187 DUMPBITS(t->bits)
4188 e = (uInt)(t->exop);
4189 if (e == 0) /* literal */
4190 {
4191 c->sub.lit = t->base;
4192 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4193 "inflate: literal '%c'\n" :
4194 "inflate: literal 0x%02x\n", t->base));
4195 c->mode = LIT;
4196 break;
4197 }
4198 if (e & 16) /* length */
4199 {
4200 c->sub.copy.get = e & 15;
4201 c->len = t->base;
4202 c->mode = LENEXT;
4203 break;
4204 }
4205 if ((e & 64) == 0) /* next table */
4206 {
4207 c->sub.code.need = e;
4208 c->sub.code.tree = t->next;
4209 break;
4210 }
4211 if (e & 32) /* end of block */
4212 {
4213 Tracevv((stderr, "inflate: end of block\n"));
4214 c->mode = WASH;
4215 break;
4216 }
4217 c->mode = BADCODE; /* invalid code */
4218 z->msg = "invalid literal/length code";
4219 r = Z_DATA_ERROR;
4220 LEAVE
4221 case LENEXT: /* i: getting length extra (have base) */
4222 j = c->sub.copy.get;
4223 NEEDBITS(j)
4224 c->len += (uInt)b & inflate_mask[j];
4225 DUMPBITS(j)
4226 c->sub.code.need = c->dbits;
4227 c->sub.code.tree = c->dtree;
4228 Tracevv((stderr, "inflate: length %u\n", c->len));
4229 c->mode = DIST;
4230 case DIST: /* i: get distance next */
4231 j = c->sub.code.need;
4232 NEEDBITS(j)
4233 t = c->sub.code.tree + ((uInt)b & inflate_mask[j]);
4234 DUMPBITS(t->bits)
4235 e = (uInt)(t->exop);
4236 if (e & 16) /* distance */
4237 {
4238 c->sub.copy.get = e & 15;
4239 c->sub.copy.dist = t->base;
4240 c->mode = DISTEXT;
4241 break;
4242 }
4243 if ((e & 64) == 0) /* next table */
4244 {
4245 c->sub.code.need = e;
4246 c->sub.code.tree = t->next;
4247 break;
4248 }
4249 c->mode = BADCODE; /* invalid code */
4250 z->msg = "invalid distance code";
4251 r = Z_DATA_ERROR;
4252 LEAVE
4253 case DISTEXT: /* i: getting distance extra */
4254 j = c->sub.copy.get;
4255 NEEDBITS(j)
4256 c->sub.copy.dist += (uInt)b & inflate_mask[j];
4257 DUMPBITS(j)
4258 Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist));
4259 c->mode = COPY;
4260 case COPY: /* o: copying bytes in window, waiting for space */
4261 #ifndef __TURBOC__ /* Turbo C bug for following expression */
4262 f = (uInt)(q - s->window) < c->sub.copy.dist ?
4263 s->end - (c->sub.copy.dist - (q - s->window)) :
4264 q - c->sub.copy.dist;
4265 #else
4266 f = q - c->sub.copy.dist;
4267 if ((uInt)(q - s->window) < c->sub.copy.dist)
4268 f = s->end - (c->sub.copy.dist - (q - s->window));
4269 #endif
4270 while (c->len)
4271 {
4272 NEEDOUT
4273 OUTBYTE(*f++)
4274 if (f == s->end)
4275 f = s->window;
4276 c->len--;
4277 }
4278 c->mode = START;
4279 break;
4280 case LIT: /* o: got literal, waiting for output space */
4281 NEEDOUT
4282 OUTBYTE(c->sub.lit)
4283 c->mode = START;
4284 break;
4285 case WASH: /* o: got eob, possibly more output */
4286 FLUSH
4287 if (s->read != s->write)
4288 LEAVE
4289 c->mode = END;
4290 case END:
4291 r = Z_STREAM_END;
4292 LEAVE
4293 case BADCODE: /* x: got error */
4294 r = Z_DATA_ERROR;
4295 LEAVE
4296 default:
4297 r = Z_STREAM_ERROR;
4298 LEAVE
4299 }
4300 }
4301
4302
inflate_codes_free(c,z)4303 local void inflate_codes_free(c, z)
4304 inflate_codes_statef *c;
4305 z_stream *z;
4306 {
4307 ZFREE(z, c, sizeof(struct inflate_codes_state));
4308 Tracev((stderr, "inflate: codes free\n"));
4309 }
4310
4311 /*+++++*/
4312 /* inflate_util.c -- data and routines common to blocks and codes
4313 * Copyright (C) 1995 Mark Adler
4314 * For conditions of distribution and use, see copyright notice in zlib.h
4315 */
4316
4317 /* copy as much as possible from the sliding window to the output area */
inflate_flush(s,z,r)4318 local int inflate_flush(s, z, r)
4319 inflate_blocks_statef *s;
4320 z_stream *z;
4321 int r;
4322 {
4323 uInt n;
4324 Bytef *p, *q;
4325
4326 /* local copies of source and destination pointers */
4327 p = z->next_out;
4328 q = s->read;
4329
4330 /* compute number of bytes to copy as far as end of window */
4331 n = (uInt)((q <= s->write ? s->write : s->end) - q);
4332 if (n > z->avail_out) n = z->avail_out;
4333 if (n && r == Z_BUF_ERROR) r = Z_OK;
4334
4335 /* update counters */
4336 z->avail_out -= n;
4337 z->total_out += n;
4338
4339 /* update check information */
4340 if (s->checkfn != Z_NULL)
4341 s->check = (*s->checkfn)(s->check, q, n);
4342
4343 /* copy as far as end of window */
4344 if (p != NULL) {
4345 zmemcpy(p, q, n);
4346 p += n;
4347 }
4348 q += n;
4349
4350 /* see if more to copy at beginning of window */
4351 if (q == s->end)
4352 {
4353 /* wrap pointers */
4354 q = s->window;
4355 if (s->write == s->end)
4356 s->write = s->window;
4357
4358 /* compute bytes to copy */
4359 n = (uInt)(s->write - q);
4360 if (n > z->avail_out) n = z->avail_out;
4361 if (n && r == Z_BUF_ERROR) r = Z_OK;
4362
4363 /* update counters */
4364 z->avail_out -= n;
4365 z->total_out += n;
4366
4367 /* update check information */
4368 if (s->checkfn != Z_NULL)
4369 s->check = (*s->checkfn)(s->check, q, n);
4370
4371 /* copy */
4372 if (p != NULL) {
4373 zmemcpy(p, q, n);
4374 p += n;
4375 }
4376 q += n;
4377 }
4378
4379 /* update pointers */
4380 z->next_out = p;
4381 s->read = q;
4382
4383 /* done */
4384 return r;
4385 }
4386
4387
4388 /*+++++*/
4389 /* inffast.c -- process literals and length/distance pairs fast
4390 * Copyright (C) 1995 Mark Adler
4391 * For conditions of distribution and use, see copyright notice in zlib.h
4392 */
4393
4394 /* simplify the use of the inflate_huft type with some defines */
4395 #define base more.Base
4396 #define next more.Next
4397 #define exop word.what.Exop
4398 #define bits word.what.Bits
4399
4400 /* macros for bit input with no checking and for returning unused bytes */
4401 #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}}
4402 #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;}
4403
4404 /* Called with number of bytes left to write in window at least 258
4405 (the maximum string length) and number of input bytes available
4406 at least ten. The ten bytes are six bytes for the longest length/
4407 distance pair plus four bytes for overloading the bit buffer. */
4408
inflate_fast(bl,bd,tl,td,s,z)4409 local int inflate_fast(bl, bd, tl, td, s, z)
4410 uInt bl, bd;
4411 inflate_huft *tl, *td;
4412 inflate_blocks_statef *s;
4413 z_stream *z;
4414 {
4415 inflate_huft *t; /* temporary pointer */
4416 uInt e; /* extra bits or operation */
4417 uLong b; /* bit buffer */
4418 uInt k; /* bits in bit buffer */
4419 Bytef *p; /* input data pointer */
4420 uInt n; /* bytes available there */
4421 Bytef *q; /* output window write pointer */
4422 uInt m; /* bytes to end of window or read pointer */
4423 uInt ml; /* mask for literal/length tree */
4424 uInt md; /* mask for distance tree */
4425 uInt c; /* bytes to copy */
4426 uInt d; /* distance back to copy from */
4427 Bytef *r; /* copy source pointer */
4428
4429 /* load input, output, bit values */
4430 LOAD
4431
4432 /* initialize masks */
4433 ml = inflate_mask[bl];
4434 md = inflate_mask[bd];
4435
4436 /* do until not enough input or output space for fast loop */
4437 do { /* assume called with m >= 258 && n >= 10 */
4438 /* get literal/length code */
4439 GRABBITS(20) /* max bits for literal/length code */
4440 if ((e = (t = tl + ((uInt)b & ml))->exop) == 0)
4441 {
4442 DUMPBITS(t->bits)
4443 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4444 "inflate: * literal '%c'\n" :
4445 "inflate: * literal 0x%02x\n", t->base));
4446 *q++ = (Byte)t->base;
4447 m--;
4448 continue;
4449 }
4450 do {
4451 DUMPBITS(t->bits)
4452 if (e & 16)
4453 {
4454 /* get extra bits for length */
4455 e &= 15;
4456 c = t->base + ((uInt)b & inflate_mask[e]);
4457 DUMPBITS(e)
4458 Tracevv((stderr, "inflate: * length %u\n", c));
4459
4460 /* decode distance base of block to copy */
4461 GRABBITS(15); /* max bits for distance code */
4462 e = (t = td + ((uInt)b & md))->exop;
4463 do {
4464 DUMPBITS(t->bits)
4465 if (e & 16)
4466 {
4467 /* get extra bits to add to distance base */
4468 e &= 15;
4469 GRABBITS(e) /* get extra bits (up to 13) */
4470 d = t->base + ((uInt)b & inflate_mask[e]);
4471 DUMPBITS(e)
4472 Tracevv((stderr, "inflate: * distance %u\n", d));
4473
4474 /* do the copy */
4475 m -= c;
4476 if ((uInt)(q - s->window) >= d) /* offset before dest */
4477 { /* just copy */
4478 r = q - d;
4479 *q++ = *r++; c--; /* minimum count is three, */
4480 *q++ = *r++; c--; /* so unroll loop a little */
4481 }
4482 else /* else offset after destination */
4483 {
4484 e = d - (q - s->window); /* bytes from offset to end */
4485 r = s->end - e; /* pointer to offset */
4486 if (c > e) /* if source crosses, */
4487 {
4488 c -= e; /* copy to end of window */
4489 do {
4490 *q++ = *r++;
4491 } while (--e);
4492 r = s->window; /* copy rest from start of window */
4493 }
4494 }
4495 do { /* copy all or what's left */
4496 *q++ = *r++;
4497 } while (--c);
4498 break;
4499 }
4500 else if ((e & 64) == 0)
4501 e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop;
4502 else
4503 {
4504 z->msg = "invalid distance code";
4505 UNGRAB
4506 UPDATE
4507 return Z_DATA_ERROR;
4508 }
4509 } while (1);
4510 break;
4511 }
4512 if ((e & 64) == 0)
4513 {
4514 if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0)
4515 {
4516 DUMPBITS(t->bits)
4517 Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ?
4518 "inflate: * literal '%c'\n" :
4519 "inflate: * literal 0x%02x\n", t->base));
4520 *q++ = (Byte)t->base;
4521 m--;
4522 break;
4523 }
4524 }
4525 else if (e & 32)
4526 {
4527 Tracevv((stderr, "inflate: * end of block\n"));
4528 UNGRAB
4529 UPDATE
4530 return Z_STREAM_END;
4531 }
4532 else
4533 {
4534 z->msg = "invalid literal/length code";
4535 UNGRAB
4536 UPDATE
4537 return Z_DATA_ERROR;
4538 }
4539 } while (1);
4540 } while (m >= 258 && n >= 10);
4541
4542 /* not enough input or output--restore pointers and return */
4543 UNGRAB
4544 UPDATE
4545 return Z_OK;
4546 }
4547
4548
4549 /*+++++*/
4550 /* zutil.c -- target dependent utility functions for the compression library
4551 * Copyright (C) 1995 Jean-loup Gailly.
4552 * For conditions of distribution and use, see copyright notice in zlib.h
4553 */
4554
4555 /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */
4556
4557 char *zlib_version = ZLIB_VERSION;
4558
4559 char *z_errmsg[] = {
4560 "stream end", /* Z_STREAM_END 1 */
4561 "", /* Z_OK 0 */
4562 "file error", /* Z_ERRNO (-1) */
4563 "stream error", /* Z_STREAM_ERROR (-2) */
4564 "data error", /* Z_DATA_ERROR (-3) */
4565 "insufficient memory", /* Z_MEM_ERROR (-4) */
4566 "buffer error", /* Z_BUF_ERROR (-5) */
4567 ""};
4568
4569
4570 /*+++++*/
4571 /* adler32.c -- compute the Adler-32 checksum of a data stream
4572 * Copyright (C) 1995 Mark Adler
4573 * For conditions of distribution and use, see copyright notice in zlib.h
4574 */
4575
4576 /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */
4577
4578 #define BASE 65521L /* largest prime smaller than 65536 */
4579 #define NMAX 5552
4580 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
4581
4582 #define DO1(buf) {s1 += *buf++; s2 += s1;}
4583 #define DO2(buf) DO1(buf); DO1(buf);
4584 #define DO4(buf) DO2(buf); DO2(buf);
4585 #define DO8(buf) DO4(buf); DO4(buf);
4586 #define DO16(buf) DO8(buf); DO8(buf);
4587
4588 /* ========================================================================= */
adler32(adler,buf,len)4589 uLong adler32(adler, buf, len)
4590 uLong adler;
4591 Bytef *buf;
4592 uInt len;
4593 {
4594 unsigned long s1 = adler & 0xffff;
4595 unsigned long s2 = (adler >> 16) & 0xffff;
4596 int k;
4597
4598 if (buf == Z_NULL) return 1L;
4599
4600 while (len > 0) {
4601 k = len < NMAX ? len : NMAX;
4602 len -= k;
4603 while (k >= 16) {
4604 DO16(buf);
4605 k -= 16;
4606 }
4607 if (k != 0) do {
4608 DO1(buf);
4609 } while (--k);
4610 s1 %= BASE;
4611 s2 %= BASE;
4612 }
4613 return (s2 << 16) | s1;
4614 }
4615