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861c20b4 PM |
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" | |
861c20b4 PM |
10 | * - added Z_PACKET_FLUSH (see zlib.h for details) |
11 | * - added inflateIncomp | |
12 | * | |
13 | * $Id$ | |
14 | */ | |
15 | ||
16 | ||
17 | /*+++++*/ | |
18 | /* zutil.h -- internal interface and configuration of the compression library | |
19 | * Copyright (C) 1995 Jean-loup Gailly. | |
20 | * For conditions of distribution and use, see copyright notice in zlib.h | |
21 | */ | |
22 | ||
23 | /* WARNING: this file should *not* be used by applications. It is | |
24 | part of the implementation of the compression library and is | |
25 | subject to change. Applications should only use zlib.h. | |
26 | */ | |
27 | ||
28 | /* From: zutil.h,v 1.9 1995/05/03 17:27:12 jloup Exp */ | |
29 | ||
30 | #define _Z_UTIL_H | |
31 | ||
ef21f8db | 32 | #include "../rsync.h" |
861c20b4 PM |
33 | #include "zlib.h" |
34 | ||
35 | #ifndef local | |
36 | # define local static | |
37 | #endif | |
38 | /* compile with -Dlocal if your debugger can't find static symbols */ | |
39 | ||
40 | #define FAR | |
41 | ||
42 | typedef unsigned char uch; | |
43 | typedef uch FAR uchf; | |
44 | typedef unsigned short ush; | |
45 | typedef ush FAR ushf; | |
46 | typedef unsigned int ulg; | |
47 | ||
48 | extern char *z_errmsg[]; /* indexed by 1-zlib_error */ | |
49 | ||
50 | #define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err) | |
51 | /* To be used only when the state is known to be valid */ | |
52 | ||
53 | #ifndef NULL | |
54 | #define NULL ((void *) 0) | |
55 | #endif | |
56 | ||
57 | /* common constants */ | |
58 | ||
59 | #define DEFLATED 8 | |
60 | ||
61 | #ifndef DEF_WBITS | |
62 | # define DEF_WBITS MAX_WBITS | |
63 | #endif | |
64 | /* default windowBits for decompression. MAX_WBITS is for compression only */ | |
65 | ||
66 | #if MAX_MEM_LEVEL >= 8 | |
67 | # define DEF_MEM_LEVEL 8 | |
68 | #else | |
69 | # define DEF_MEM_LEVEL MAX_MEM_LEVEL | |
70 | #endif | |
71 | /* default memLevel */ | |
72 | ||
73 | #define STORED_BLOCK 0 | |
74 | #define STATIC_TREES 1 | |
75 | #define DYN_TREES 2 | |
76 | /* The three kinds of block type */ | |
77 | ||
78 | #define MIN_MATCH 3 | |
79 | #define MAX_MATCH 258 | |
80 | /* The minimum and maximum match lengths */ | |
81 | ||
82 | /* functions */ | |
ef21f8db AT |
83 | #define zmemcpy(d, s, n) bcopy((s), (d), (n)) |
84 | #define zmemzero bzero | |
861c20b4 PM |
85 | |
86 | /* Diagnostic functions */ | |
87 | #ifdef DEBUG_ZLIB | |
88 | # include <stdio.h> | |
89 | # ifndef verbose | |
90 | # define verbose 0 | |
91 | # endif | |
92 | # define Assert(cond,msg) {if(!(cond)) z_error(msg);} | |
93 | # define Trace(x) fprintf x | |
94 | # define Tracev(x) {if (verbose) fprintf x ;} | |
95 | # define Tracevv(x) {if (verbose>1) fprintf x ;} | |
96 | # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} | |
97 | # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} | |
98 | #else | |
99 | # define Assert(cond,msg) | |
100 | # define Trace(x) | |
101 | # define Tracev(x) | |
102 | # define Tracevv(x) | |
103 | # define Tracec(c,x) | |
104 | # define Tracecv(c,x) | |
105 | #endif | |
106 | ||
107 | ||
108 | typedef uLong (*check_func) OF((uLong check, Bytef *buf, uInt len)); | |
109 | ||
110 | /* voidpf zcalloc OF((voidpf opaque, unsigned items, unsigned size)); */ | |
111 | /* void zcfree OF((voidpf opaque, voidpf ptr)); */ | |
112 | ||
113 | #define ZALLOC(strm, items, size) \ | |
114 | (*((strm)->zalloc))((strm)->opaque, (items), (size)) | |
115 | #define ZFREE(strm, addr, size) \ | |
116 | (*((strm)->zfree))((strm)->opaque, (voidpf)(addr), (size)) | |
117 | #define TRY_FREE(s, p, n) {if (p) ZFREE(s, p, n);} | |
118 | ||
119 | /* deflate.h -- internal compression state | |
120 | * Copyright (C) 1995 Jean-loup Gailly | |
121 | * For conditions of distribution and use, see copyright notice in zlib.h | |
122 | */ | |
123 | ||
124 | /* WARNING: this file should *not* be used by applications. It is | |
125 | part of the implementation of the compression library and is | |
126 | subject to change. Applications should only use zlib.h. | |
127 | */ | |
128 | ||
129 | ||
130 | /*+++++*/ | |
131 | /* From: deflate.h,v 1.5 1995/05/03 17:27:09 jloup Exp */ | |
132 | ||
133 | /* =========================================================================== | |
134 | * Internal compression state. | |
135 | */ | |
136 | ||
137 | /* Data type */ | |
138 | #define BINARY 0 | |
139 | #define ASCII 1 | |
140 | #define UNKNOWN 2 | |
141 | ||
142 | #define LENGTH_CODES 29 | |
143 | /* number of length codes, not counting the special END_BLOCK code */ | |
144 | ||
145 | #define LITERALS 256 | |
146 | /* number of literal bytes 0..255 */ | |
147 | ||
148 | #define L_CODES (LITERALS+1+LENGTH_CODES) | |
149 | /* number of Literal or Length codes, including the END_BLOCK code */ | |
150 | ||
151 | #define D_CODES 30 | |
152 | /* number of distance codes */ | |
153 | ||
154 | #define BL_CODES 19 | |
155 | /* number of codes used to transfer the bit lengths */ | |
156 | ||
157 | #define HEAP_SIZE (2*L_CODES+1) | |
158 | /* maximum heap size */ | |
159 | ||
160 | #define MAX_BITS 15 | |
161 | /* All codes must not exceed MAX_BITS bits */ | |
162 | ||
163 | #define INIT_STATE 42 | |
164 | #define BUSY_STATE 113 | |
165 | #define FLUSH_STATE 124 | |
166 | #define FINISH_STATE 666 | |
167 | /* Stream status */ | |
168 | ||
169 | ||
170 | /* Data structure describing a single value and its code string. */ | |
171 | typedef struct ct_data_s { | |
172 | union { | |
173 | ush freq; /* frequency count */ | |
174 | ush code; /* bit string */ | |
175 | } fc; | |
176 | union { | |
177 | ush dad; /* father node in Huffman tree */ | |
178 | ush len; /* length of bit string */ | |
179 | } dl; | |
180 | } FAR ct_data; | |
181 | ||
182 | #define Freq fc.freq | |
183 | #define Code fc.code | |
184 | #define Dad dl.dad | |
185 | #define Len dl.len | |
186 | ||
187 | typedef struct static_tree_desc_s static_tree_desc; | |
188 | ||
189 | typedef struct tree_desc_s { | |
190 | ct_data *dyn_tree; /* the dynamic tree */ | |
191 | int max_code; /* largest code with non zero frequency */ | |
192 | static_tree_desc *stat_desc; /* the corresponding static tree */ | |
193 | } FAR tree_desc; | |
194 | ||
195 | typedef ush Pos; | |
196 | typedef Pos FAR Posf; | |
197 | typedef unsigned IPos; | |
198 | ||
199 | /* A Pos is an index in the character window. We use short instead of int to | |
200 | * save space in the various tables. IPos is used only for parameter passing. | |
201 | */ | |
202 | ||
203 | typedef struct deflate_state { | |
204 | z_stream *strm; /* pointer back to this zlib stream */ | |
205 | int status; /* as the name implies */ | |
206 | Bytef *pending_buf; /* output still pending */ | |
207 | Bytef *pending_out; /* next pending byte to output to the stream */ | |
208 | int pending; /* nb of bytes in the pending buffer */ | |
209 | uLong adler; /* adler32 of uncompressed data */ | |
210 | int noheader; /* suppress zlib header and adler32 */ | |
211 | Byte data_type; /* UNKNOWN, BINARY or ASCII */ | |
212 | Byte method; /* STORED (for zip only) or DEFLATED */ | |
861c20b4 PM |
213 | |
214 | /* used by deflate.c: */ | |
215 | ||
216 | uInt w_size; /* LZ77 window size (32K by default) */ | |
217 | uInt w_bits; /* log2(w_size) (8..16) */ | |
218 | uInt w_mask; /* w_size - 1 */ | |
219 | ||
220 | Bytef *window; | |
221 | /* Sliding window. Input bytes are read into the second half of the window, | |
222 | * and move to the first half later to keep a dictionary of at least wSize | |
223 | * bytes. With this organization, matches are limited to a distance of | |
224 | * wSize-MAX_MATCH bytes, but this ensures that IO is always | |
225 | * performed with a length multiple of the block size. Also, it limits | |
226 | * the window size to 64K, which is quite useful on MSDOS. | |
227 | * To do: use the user input buffer as sliding window. | |
228 | */ | |
229 | ||
230 | ulg window_size; | |
231 | /* Actual size of window: 2*wSize, except when the user input buffer | |
232 | * is directly used as sliding window. | |
233 | */ | |
234 | ||
235 | Posf *prev; | |
236 | /* Link to older string with same hash index. To limit the size of this | |
237 | * array to 64K, this link is maintained only for the last 32K strings. | |
238 | * An index in this array is thus a window index modulo 32K. | |
239 | */ | |
240 | ||
241 | Posf *head; /* Heads of the hash chains or NIL. */ | |
242 | ||
243 | uInt ins_h; /* hash index of string to be inserted */ | |
244 | uInt hash_size; /* number of elements in hash table */ | |
245 | uInt hash_bits; /* log2(hash_size) */ | |
246 | uInt hash_mask; /* hash_size-1 */ | |
247 | ||
248 | uInt hash_shift; | |
249 | /* Number of bits by which ins_h must be shifted at each input | |
250 | * step. It must be such that after MIN_MATCH steps, the oldest | |
251 | * byte no longer takes part in the hash key, that is: | |
252 | * hash_shift * MIN_MATCH >= hash_bits | |
253 | */ | |
254 | ||
255 | long block_start; | |
256 | /* Window position at the beginning of the current output block. Gets | |
257 | * negative when the window is moved backwards. | |
258 | */ | |
259 | ||
260 | uInt match_length; /* length of best match */ | |
261 | IPos prev_match; /* previous match */ | |
262 | int match_available; /* set if previous match exists */ | |
263 | uInt strstart; /* start of string to insert */ | |
264 | uInt match_start; /* start of matching string */ | |
265 | uInt lookahead; /* number of valid bytes ahead in window */ | |
266 | ||
267 | uInt prev_length; | |
268 | /* Length of the best match at previous step. Matches not greater than this | |
269 | * are discarded. This is used in the lazy match evaluation. | |
270 | */ | |
271 | ||
272 | uInt max_chain_length; | |
273 | /* To speed up deflation, hash chains are never searched beyond this | |
274 | * length. A higher limit improves compression ratio but degrades the | |
275 | * speed. | |
276 | */ | |
277 | ||
278 | uInt max_lazy_match; | |
279 | /* Attempt to find a better match only when the current match is strictly | |
280 | * smaller than this value. This mechanism is used only for compression | |
281 | * levels >= 4. | |
282 | */ | |
283 | # define max_insert_length max_lazy_match | |
284 | /* Insert new strings in the hash table only if the match length is not | |
285 | * greater than this length. This saves time but degrades compression. | |
286 | * max_insert_length is used only for compression levels <= 3. | |
287 | */ | |
288 | ||
289 | int level; /* compression level (1..9) */ | |
290 | int strategy; /* favor or force Huffman coding*/ | |
291 | ||
292 | uInt good_match; | |
293 | /* Use a faster search when the previous match is longer than this */ | |
294 | ||
295 | int nice_match; /* Stop searching when current match exceeds this */ | |
296 | ||
297 | /* used by trees.c: */ | |
298 | /* Didn't use ct_data typedef below to supress compiler warning */ | |
299 | struct ct_data_s dyn_ltree[HEAP_SIZE]; /* literal and length tree */ | |
300 | struct ct_data_s dyn_dtree[2*D_CODES+1]; /* distance tree */ | |
301 | struct ct_data_s bl_tree[2*BL_CODES+1]; /* Huffman tree for bit lengths */ | |
302 | ||
303 | struct tree_desc_s l_desc; /* desc. for literal tree */ | |
304 | struct tree_desc_s d_desc; /* desc. for distance tree */ | |
305 | struct tree_desc_s bl_desc; /* desc. for bit length tree */ | |
306 | ||
307 | ush bl_count[MAX_BITS+1]; | |
308 | /* number of codes at each bit length for an optimal tree */ | |
309 | ||
310 | int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ | |
311 | int heap_len; /* number of elements in the heap */ | |
312 | int heap_max; /* element of largest frequency */ | |
313 | /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. | |
314 | * The same heap array is used to build all trees. | |
315 | */ | |
316 | ||
317 | uch depth[2*L_CODES+1]; | |
318 | /* Depth of each subtree used as tie breaker for trees of equal frequency | |
319 | */ | |
320 | ||
321 | uchf *l_buf; /* buffer for literals or lengths */ | |
322 | ||
323 | uInt lit_bufsize; | |
324 | /* Size of match buffer for literals/lengths. There are 4 reasons for | |
325 | * limiting lit_bufsize to 64K: | |
326 | * - frequencies can be kept in 16 bit counters | |
327 | * - if compression is not successful for the first block, all input | |
328 | * data is still in the window so we can still emit a stored block even | |
329 | * when input comes from standard input. (This can also be done for | |
330 | * all blocks if lit_bufsize is not greater than 32K.) | |
331 | * - if compression is not successful for a file smaller than 64K, we can | |
332 | * even emit a stored file instead of a stored block (saving 5 bytes). | |
333 | * This is applicable only for zip (not gzip or zlib). | |
334 | * - creating new Huffman trees less frequently may not provide fast | |
335 | * adaptation to changes in the input data statistics. (Take for | |
336 | * example a binary file with poorly compressible code followed by | |
337 | * a highly compressible string table.) Smaller buffer sizes give | |
338 | * fast adaptation but have of course the overhead of transmitting | |
339 | * trees more frequently. | |
340 | * - I can't count above 4 | |
341 | */ | |
342 | ||
343 | uInt last_lit; /* running index in l_buf */ | |
344 | ||
345 | ushf *d_buf; | |
346 | /* Buffer for distances. To simplify the code, d_buf and l_buf have | |
347 | * the same number of elements. To use different lengths, an extra flag | |
348 | * array would be necessary. | |
349 | */ | |
350 | ||
351 | ulg opt_len; /* bit length of current block with optimal trees */ | |
352 | ulg static_len; /* bit length of current block with static trees */ | |
353 | ulg compressed_len; /* total bit length of compressed file */ | |
354 | uInt matches; /* number of string matches in current block */ | |
355 | int last_eob_len; /* bit length of EOB code for last block */ | |
356 | ||
357 | #ifdef DEBUG_ZLIB | |
358 | ulg bits_sent; /* bit length of the compressed data */ | |
359 | #endif | |
360 | ||
361 | ush bi_buf; | |
362 | /* Output buffer. bits are inserted starting at the bottom (least | |
363 | * significant bits). | |
364 | */ | |
365 | int bi_valid; | |
366 | /* Number of valid bits in bi_buf. All bits above the last valid bit | |
367 | * are always zero. | |
368 | */ | |
369 | ||
370 | uInt blocks_in_packet; | |
371 | /* Number of blocks produced since the last time Z_PACKET_FLUSH | |
372 | * was used. | |
373 | */ | |
374 | ||
375 | } FAR deflate_state; | |
376 | ||
377 | /* Output a byte on the stream. | |
378 | * IN assertion: there is enough room in pending_buf. | |
379 | */ | |
380 | #define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} | |
381 | ||
382 | ||
383 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) | |
384 | /* Minimum amount of lookahead, except at the end of the input file. | |
385 | * See deflate.c for comments about the MIN_MATCH+1. | |
386 | */ | |
387 | ||
388 | #define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) | |
389 | /* In order to simplify the code, particularly on 16 bit machines, match | |
390 | * distances are limited to MAX_DIST instead of WSIZE. | |
391 | */ | |
392 | ||
393 | /* in trees.c */ | |
394 | local void ct_init OF((deflate_state *s)); | |
395 | local int ct_tally OF((deflate_state *s, int dist, int lc)); | |
396 | local ulg ct_flush_block OF((deflate_state *s, charf *buf, ulg stored_len, | |
397 | int flush)); | |
398 | local void ct_align OF((deflate_state *s)); | |
399 | local void ct_stored_block OF((deflate_state *s, charf *buf, ulg stored_len, | |
400 | int eof)); | |
401 | local void ct_stored_type_only OF((deflate_state *s)); | |
402 | ||
403 | ||
404 | /*+++++*/ | |
405 | /* deflate.c -- compress data using the deflation algorithm | |
406 | * Copyright (C) 1995 Jean-loup Gailly. | |
407 | * For conditions of distribution and use, see copyright notice in zlib.h | |
408 | */ | |
409 | ||
410 | /* | |
411 | * ALGORITHM | |
412 | * | |
413 | * The "deflation" process depends on being able to identify portions | |
414 | * of the input text which are identical to earlier input (within a | |
415 | * sliding window trailing behind the input currently being processed). | |
416 | * | |
417 | * The most straightforward technique turns out to be the fastest for | |
418 | * most input files: try all possible matches and select the longest. | |
419 | * The key feature of this algorithm is that insertions into the string | |
420 | * dictionary are very simple and thus fast, and deletions are avoided | |
421 | * completely. Insertions are performed at each input character, whereas | |
422 | * string matches are performed only when the previous match ends. So it | |
423 | * is preferable to spend more time in matches to allow very fast string | |
424 | * insertions and avoid deletions. The matching algorithm for small | |
425 | * strings is inspired from that of Rabin & Karp. A brute force approach | |
426 | * is used to find longer strings when a small match has been found. | |
427 | * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze | |
428 | * (by Leonid Broukhis). | |
429 | * A previous version of this file used a more sophisticated algorithm | |
430 | * (by Fiala and Greene) which is guaranteed to run in linear amortized | |
431 | * time, but has a larger average cost, uses more memory and is patented. | |
432 | * However the F&G algorithm may be faster for some highly redundant | |
433 | * files if the parameter max_chain_length (described below) is too large. | |
434 | * | |
435 | * ACKNOWLEDGEMENTS | |
436 | * | |
437 | * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and | |
438 | * I found it in 'freeze' written by Leonid Broukhis. | |
439 | * Thanks to many people for bug reports and testing. | |
440 | * | |
441 | * REFERENCES | |
442 | * | |
443 | * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". | |
444 | * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc | |
445 | * | |
446 | * A description of the Rabin and Karp algorithm is given in the book | |
447 | * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. | |
448 | * | |
449 | * Fiala,E.R., and Greene,D.H. | |
450 | * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 | |
451 | * | |
452 | */ | |
453 | ||
454 | /* From: deflate.c,v 1.8 1995/05/03 17:27:08 jloup Exp */ | |
455 | ||
ef21f8db | 456 | char zlib_copyright[] = " deflate Copyright 1995 Jean-loup Gailly "; |
861c20b4 PM |
457 | /* |
458 | If you use the zlib library in a product, an acknowledgment is welcome | |
459 | in the documentation of your product. If for some reason you cannot | |
460 | include such an acknowledgment, I would appreciate that you keep this | |
461 | copyright string in the executable of your product. | |
462 | */ | |
463 | ||
464 | #define NIL 0 | |
465 | /* Tail of hash chains */ | |
466 | ||
467 | #ifndef TOO_FAR | |
468 | # define TOO_FAR 4096 | |
469 | #endif | |
470 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ | |
471 | ||
472 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) | |
473 | /* Minimum amount of lookahead, except at the end of the input file. | |
474 | * See deflate.c for comments about the MIN_MATCH+1. | |
475 | */ | |
476 | ||
477 | /* Values for max_lazy_match, good_match and max_chain_length, depending on | |
478 | * the desired pack level (0..9). The values given below have been tuned to | |
479 | * exclude worst case performance for pathological files. Better values may be | |
480 | * found for specific files. | |
481 | */ | |
482 | ||
483 | typedef struct config_s { | |
484 | ush good_length; /* reduce lazy search above this match length */ | |
485 | ush max_lazy; /* do not perform lazy search above this match length */ | |
486 | ush nice_length; /* quit search above this match length */ | |
487 | ush max_chain; | |
488 | } config; | |
489 | ||
490 | local config configuration_table[10] = { | |
491 | /* good lazy nice chain */ | |
492 | /* 0 */ {0, 0, 0, 0}, /* store only */ | |
493 | /* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */ | |
494 | /* 2 */ {4, 5, 16, 8}, | |
495 | /* 3 */ {4, 6, 32, 32}, | |
496 | ||
497 | /* 4 */ {4, 4, 16, 16}, /* lazy matches */ | |
498 | /* 5 */ {8, 16, 32, 32}, | |
499 | /* 6 */ {8, 16, 128, 128}, | |
500 | /* 7 */ {8, 32, 128, 256}, | |
501 | /* 8 */ {32, 128, 258, 1024}, | |
502 | /* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ | |
503 | ||
504 | /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 | |
505 | * For deflate_fast() (levels <= 3) good is ignored and lazy has a different | |
506 | * meaning. | |
507 | */ | |
508 | ||
509 | #define EQUAL 0 | |
510 | /* result of memcmp for equal strings */ | |
511 | ||
512 | /* =========================================================================== | |
513 | * Prototypes for local functions. | |
514 | */ | |
515 | ||
516 | local void fill_window OF((deflate_state *s)); | |
517 | local int deflate_fast OF((deflate_state *s, int flush)); | |
518 | local int deflate_slow OF((deflate_state *s, int flush)); | |
519 | local void lm_init OF((deflate_state *s)); | |
520 | local int longest_match OF((deflate_state *s, IPos cur_match)); | |
521 | local void putShortMSB OF((deflate_state *s, uInt b)); | |
522 | local void flush_pending OF((z_stream *strm)); | |
ef21f8db | 523 | local int zread_buf OF((z_stream *strm, charf *buf, unsigned size)); |
861c20b4 PM |
524 | #ifdef ASMV |
525 | void match_init OF((void)); /* asm code initialization */ | |
526 | #endif | |
527 | ||
528 | #ifdef DEBUG_ZLIB | |
529 | local void check_match OF((deflate_state *s, IPos start, IPos match, | |
530 | int length)); | |
531 | #endif | |
532 | ||
533 | ||
534 | /* =========================================================================== | |
535 | * Update a hash value with the given input byte | |
536 | * IN assertion: all calls to to UPDATE_HASH are made with consecutive | |
537 | * input characters, so that a running hash key can be computed from the | |
538 | * previous key instead of complete recalculation each time. | |
539 | */ | |
540 | #define UPDATE_HASH(s,h,c) (h = (((h)<<s->hash_shift) ^ (c)) & s->hash_mask) | |
541 | ||
542 | ||
543 | /* =========================================================================== | |
544 | * Insert string str in the dictionary and set match_head to the previous head | |
545 | * of the hash chain (the most recent string with same hash key). Return | |
546 | * the previous length of the hash chain. | |
547 | * IN assertion: all calls to to INSERT_STRING are made with consecutive | |
548 | * input characters and the first MIN_MATCH bytes of str are valid | |
549 | * (except for the last MIN_MATCH-1 bytes of the input file). | |
550 | */ | |
551 | #define INSERT_STRING(s, str, match_head) \ | |
552 | (UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH-1)]), \ | |
553 | s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ | |
554 | s->head[s->ins_h] = (str)) | |
555 | ||
556 | /* =========================================================================== | |
557 | * Initialize the hash table (avoiding 64K overflow for 16 bit systems). | |
558 | * prev[] will be initialized on the fly. | |
559 | */ | |
560 | #define CLEAR_HASH(s) \ | |
561 | s->head[s->hash_size-1] = NIL; \ | |
562 | zmemzero((charf *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); | |
563 | ||
564 | /* ========================================================================= */ | |
565 | int deflateInit (strm, level) | |
566 | z_stream *strm; | |
567 | int level; | |
568 | { | |
f8062104 | 569 | return deflateInit2 (strm, level, DEFLATED, MAX_WBITS, DEF_MEM_LEVEL, 0); |
861c20b4 PM |
570 | /* To do: ignore strm->next_in if we use it as window */ |
571 | } | |
572 | ||
573 | /* ========================================================================= */ | |
f8062104 | 574 | int deflateInit2 (strm, level, method, windowBits, memLevel, strategy) |
861c20b4 PM |
575 | z_stream *strm; |
576 | int level; | |
577 | int method; | |
578 | int windowBits; | |
579 | int memLevel; | |
580 | int strategy; | |
861c20b4 PM |
581 | { |
582 | deflate_state *s; | |
583 | int noheader = 0; | |
584 | ||
585 | if (strm == Z_NULL) return Z_STREAM_ERROR; | |
586 | ||
587 | strm->msg = Z_NULL; | |
588 | /* if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; */ | |
589 | /* if (strm->zfree == Z_NULL) strm->zfree = zcfree; */ | |
590 | ||
591 | if (level == Z_DEFAULT_COMPRESSION) level = 6; | |
592 | ||
593 | if (windowBits < 0) { /* undocumented feature: suppress zlib header */ | |
594 | noheader = 1; | |
595 | windowBits = -windowBits; | |
596 | } | |
597 | if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED || | |
598 | windowBits < 8 || windowBits > 15 || level < 1 || level > 9) { | |
599 | return Z_STREAM_ERROR; | |
600 | } | |
601 | s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); | |
602 | if (s == Z_NULL) return Z_MEM_ERROR; | |
603 | strm->state = (struct internal_state FAR *)s; | |
604 | s->strm = strm; | |
605 | ||
606 | s->noheader = noheader; | |
607 | s->w_bits = windowBits; | |
608 | s->w_size = 1 << s->w_bits; | |
609 | s->w_mask = s->w_size - 1; | |
610 | ||
611 | s->hash_bits = memLevel + 7; | |
612 | s->hash_size = 1 << s->hash_bits; | |
613 | s->hash_mask = s->hash_size - 1; | |
614 | s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); | |
615 | ||
616 | s->window = (Bytef *) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); | |
617 | s->prev = (Posf *) ZALLOC(strm, s->w_size, sizeof(Pos)); | |
618 | s->head = (Posf *) ZALLOC(strm, s->hash_size, sizeof(Pos)); | |
619 | ||
620 | s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ | |
621 | ||
622 | s->pending_buf = (uchf *) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush)); | |
623 | ||
624 | if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || | |
625 | s->pending_buf == Z_NULL) { | |
626 | strm->msg = z_errmsg[1-Z_MEM_ERROR]; | |
627 | deflateEnd (strm); | |
628 | return Z_MEM_ERROR; | |
629 | } | |
630 | s->d_buf = (ushf *) &(s->pending_buf[s->lit_bufsize]); | |
631 | s->l_buf = (uchf *) &(s->pending_buf[3*s->lit_bufsize]); | |
632 | /* We overlay pending_buf and d_buf+l_buf. This works since the average | |
633 | * output size for (length,distance) codes is <= 32 bits (worst case | |
634 | * is 15+15+13=33). | |
635 | */ | |
636 | ||
637 | s->level = level; | |
638 | s->strategy = strategy; | |
639 | s->method = (Byte)method; | |
861c20b4 PM |
640 | s->blocks_in_packet = 0; |
641 | ||
642 | return deflateReset(strm); | |
643 | } | |
644 | ||
645 | /* ========================================================================= */ | |
646 | int deflateReset (strm) | |
647 | z_stream *strm; | |
648 | { | |
649 | deflate_state *s; | |
650 | ||
651 | if (strm == Z_NULL || strm->state == Z_NULL || | |
652 | strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; | |
653 | ||
654 | strm->total_in = strm->total_out = 0; | |
655 | strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ | |
656 | strm->data_type = Z_UNKNOWN; | |
657 | ||
658 | s = (deflate_state *)strm->state; | |
659 | s->pending = 0; | |
660 | s->pending_out = s->pending_buf; | |
661 | ||
662 | if (s->noheader < 0) { | |
663 | s->noheader = 0; /* was set to -1 by deflate(..., Z_FINISH); */ | |
664 | } | |
665 | s->status = s->noheader ? BUSY_STATE : INIT_STATE; | |
666 | s->adler = 1; | |
667 | ||
668 | ct_init(s); | |
669 | lm_init(s); | |
670 | ||
671 | return Z_OK; | |
672 | } | |
673 | ||
674 | /* ========================================================================= | |
675 | * Put a short in the pending buffer. The 16-bit value is put in MSB order. | |
676 | * IN assertion: the stream state is correct and there is enough room in | |
677 | * pending_buf. | |
678 | */ | |
679 | local void putShortMSB (s, b) | |
680 | deflate_state *s; | |
681 | uInt b; | |
682 | { | |
683 | put_byte(s, (Byte)(b >> 8)); | |
684 | put_byte(s, (Byte)(b & 0xff)); | |
685 | } | |
686 | ||
687 | /* ========================================================================= | |
688 | * Flush as much pending output as possible. | |
689 | */ | |
690 | local void flush_pending(strm) | |
691 | z_stream *strm; | |
692 | { | |
693 | deflate_state *state = (deflate_state *) strm->state; | |
694 | unsigned len = state->pending; | |
695 | ||
696 | if (len > strm->avail_out) len = strm->avail_out; | |
697 | if (len == 0) return; | |
698 | ||
699 | if (strm->next_out != NULL) { | |
700 | zmemcpy(strm->next_out, state->pending_out, len); | |
701 | strm->next_out += len; | |
702 | } | |
703 | state->pending_out += len; | |
704 | strm->total_out += len; | |
705 | strm->avail_out -= len; | |
706 | state->pending -= len; | |
707 | if (state->pending == 0) { | |
708 | state->pending_out = state->pending_buf; | |
709 | } | |
710 | } | |
711 | ||
712 | /* ========================================================================= */ | |
713 | int deflate (strm, flush) | |
714 | z_stream *strm; | |
715 | int flush; | |
716 | { | |
717 | deflate_state *state = (deflate_state *) strm->state; | |
718 | ||
719 | if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; | |
720 | ||
721 | if (strm->next_in == Z_NULL && strm->avail_in != 0) { | |
722 | ERR_RETURN(strm, Z_STREAM_ERROR); | |
723 | } | |
724 | if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); | |
725 | ||
726 | state->strm = strm; /* just in case */ | |
727 | ||
728 | /* Write the zlib header */ | |
729 | if (state->status == INIT_STATE) { | |
730 | ||
731 | uInt header = (DEFLATED + ((state->w_bits-8)<<4)) << 8; | |
732 | uInt level_flags = (state->level-1) >> 1; | |
733 | ||
734 | if (level_flags > 3) level_flags = 3; | |
735 | header |= (level_flags << 6); | |
736 | header += 31 - (header % 31); | |
737 | ||
738 | state->status = BUSY_STATE; | |
739 | putShortMSB(state, header); | |
740 | } | |
741 | ||
742 | /* Flush as much pending output as possible */ | |
743 | if (state->pending != 0) { | |
744 | flush_pending(strm); | |
745 | if (strm->avail_out == 0) return Z_OK; | |
746 | } | |
747 | ||
748 | /* If we came back in here to get the last output from | |
749 | * a previous flush, we're done for now. | |
750 | */ | |
751 | if (state->status == FLUSH_STATE) { | |
752 | state->status = BUSY_STATE; | |
753 | if (flush != Z_NO_FLUSH && flush != Z_FINISH) | |
754 | return Z_OK; | |
755 | } | |
756 | ||
757 | /* User must not provide more input after the first FINISH: */ | |
758 | if (state->status == FINISH_STATE && strm->avail_in != 0) { | |
759 | ERR_RETURN(strm, Z_BUF_ERROR); | |
760 | } | |
761 | ||
762 | /* Start a new block or continue the current one. | |
763 | */ | |
764 | if (strm->avail_in != 0 || state->lookahead != 0 || | |
765 | (flush == Z_FINISH && state->status != FINISH_STATE)) { | |
766 | int quit; | |
767 | ||
768 | if (flush == Z_FINISH) { | |
769 | state->status = FINISH_STATE; | |
770 | } | |
771 | if (state->level <= 3) { | |
772 | quit = deflate_fast(state, flush); | |
773 | } else { | |
774 | quit = deflate_slow(state, flush); | |
775 | } | |
776 | if (quit || strm->avail_out == 0) | |
777 | return Z_OK; | |
778 | /* If flush != Z_NO_FLUSH && avail_out == 0, the next call | |
779 | * of deflate should use the same flush parameter to make sure | |
780 | * that the flush is complete. So we don't have to output an | |
781 | * empty block here, this will be done at next call. This also | |
782 | * ensures that for a very small output buffer, we emit at most | |
783 | * one empty block. | |
784 | */ | |
785 | } | |
786 | ||
787 | /* If a flush was requested, we have a little more to output now. */ | |
788 | if (flush != Z_NO_FLUSH && flush != Z_FINISH | |
789 | && state->status != FINISH_STATE) { | |
790 | switch (flush) { | |
791 | case Z_PARTIAL_FLUSH: | |
792 | ct_align(state); | |
793 | break; | |
794 | case Z_PACKET_FLUSH: | |
795 | /* Output just the 3-bit `stored' block type value, | |
796 | but not a zero length. */ | |
797 | ct_stored_type_only(state); | |
798 | break; | |
799 | default: | |
800 | ct_stored_block(state, (char*)0, 0L, 0); | |
801 | /* For a full flush, this empty block will be recognized | |
802 | * as a special marker by inflate_sync(). | |
803 | */ | |
804 | if (flush == Z_FULL_FLUSH) { | |
805 | CLEAR_HASH(state); /* forget history */ | |
806 | } | |
807 | } | |
808 | flush_pending(strm); | |
809 | if (strm->avail_out == 0) { | |
810 | /* We'll have to come back to get the rest of the output; | |
811 | * this ensures we don't output a second zero-length stored | |
812 | * block (or whatever). | |
813 | */ | |
814 | state->status = FLUSH_STATE; | |
815 | return Z_OK; | |
816 | } | |
817 | } | |
818 | ||
819 | Assert(strm->avail_out > 0, "bug2"); | |
820 | ||
821 | if (flush != Z_FINISH) return Z_OK; | |
822 | if (state->noheader) return Z_STREAM_END; | |
823 | ||
824 | /* Write the zlib trailer (adler32) */ | |
825 | putShortMSB(state, (uInt)(state->adler >> 16)); | |
826 | putShortMSB(state, (uInt)(state->adler & 0xffff)); | |
827 | flush_pending(strm); | |
828 | /* If avail_out is zero, the application will call deflate again | |
829 | * to flush the rest. | |
830 | */ | |
831 | state->noheader = -1; /* write the trailer only once! */ | |
832 | return state->pending != 0 ? Z_OK : Z_STREAM_END; | |
833 | } | |
834 | ||
835 | /* ========================================================================= */ | |
836 | int deflateEnd (strm) | |
837 | z_stream *strm; | |
838 | { | |
839 | deflate_state *state = (deflate_state *) strm->state; | |
840 | ||
841 | if (strm == Z_NULL || state == Z_NULL) return Z_STREAM_ERROR; | |
842 | ||
843 | TRY_FREE(strm, state->window, state->w_size * 2 * sizeof(Byte)); | |
844 | TRY_FREE(strm, state->prev, state->w_size * sizeof(Pos)); | |
845 | TRY_FREE(strm, state->head, state->hash_size * sizeof(Pos)); | |
846 | TRY_FREE(strm, state->pending_buf, state->lit_bufsize * 2 * sizeof(ush)); | |
847 | ||
848 | ZFREE(strm, state, sizeof(deflate_state)); | |
849 | strm->state = Z_NULL; | |
850 | ||
851 | return Z_OK; | |
852 | } | |
853 | ||
854 | /* =========================================================================== | |
855 | * Read a new buffer from the current input stream, update the adler32 | |
856 | * and total number of bytes read. | |
857 | */ | |
ef21f8db | 858 | local int zread_buf(strm, buf, size) |
861c20b4 PM |
859 | z_stream *strm; |
860 | charf *buf; | |
861 | unsigned size; | |
862 | { | |
863 | unsigned len = strm->avail_in; | |
864 | deflate_state *state = (deflate_state *) strm->state; | |
865 | ||
866 | if (len > size) len = size; | |
867 | if (len == 0) return 0; | |
868 | ||
869 | strm->avail_in -= len; | |
870 | ||
871 | if (!state->noheader) { | |
872 | state->adler = adler32(state->adler, strm->next_in, len); | |
873 | } | |
874 | zmemcpy(buf, strm->next_in, len); | |
875 | strm->next_in += len; | |
876 | strm->total_in += len; | |
877 | ||
878 | return (int)len; | |
879 | } | |
880 | ||
881 | /* =========================================================================== | |
882 | * Initialize the "longest match" routines for a new zlib stream | |
883 | */ | |
884 | local void lm_init (s) | |
885 | deflate_state *s; | |
886 | { | |
887 | s->window_size = (ulg)2L*s->w_size; | |
888 | ||
889 | CLEAR_HASH(s); | |
890 | ||
891 | /* Set the default configuration parameters: | |
892 | */ | |
893 | s->max_lazy_match = configuration_table[s->level].max_lazy; | |
894 | s->good_match = configuration_table[s->level].good_length; | |
895 | s->nice_match = configuration_table[s->level].nice_length; | |
896 | s->max_chain_length = configuration_table[s->level].max_chain; | |
897 | ||
898 | s->strstart = 0; | |
899 | s->block_start = 0L; | |
900 | s->lookahead = 0; | |
901 | s->match_length = MIN_MATCH-1; | |
902 | s->match_available = 0; | |
903 | s->ins_h = 0; | |
904 | #ifdef ASMV | |
905 | match_init(); /* initialize the asm code */ | |
906 | #endif | |
907 | } | |
908 | ||
909 | /* =========================================================================== | |
910 | * Set match_start to the longest match starting at the given string and | |
911 | * return its length. Matches shorter or equal to prev_length are discarded, | |
912 | * in which case the result is equal to prev_length and match_start is | |
913 | * garbage. | |
914 | * IN assertions: cur_match is the head of the hash chain for the current | |
915 | * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 | |
916 | */ | |
917 | #ifndef ASMV | |
918 | /* For 80x86 and 680x0, an optimized version will be provided in match.asm or | |
919 | * match.S. The code will be functionally equivalent. | |
920 | */ | |
921 | local int longest_match(s, cur_match) | |
922 | deflate_state *s; | |
923 | IPos cur_match; /* current match */ | |
924 | { | |
925 | unsigned chain_length = s->max_chain_length;/* max hash chain length */ | |
926 | register Bytef *scan = s->window + s->strstart; /* current string */ | |
927 | register Bytef *match; /* matched string */ | |
928 | register int len; /* length of current match */ | |
929 | int best_len = s->prev_length; /* best match length so far */ | |
930 | IPos limit = s->strstart > (IPos)MAX_DIST(s) ? | |
931 | s->strstart - (IPos)MAX_DIST(s) : NIL; | |
932 | /* Stop when cur_match becomes <= limit. To simplify the code, | |
933 | * we prevent matches with the string of window index 0. | |
934 | */ | |
935 | Posf *prev = s->prev; | |
936 | uInt wmask = s->w_mask; | |
937 | ||
938 | #ifdef UNALIGNED_OK | |
939 | /* Compare two bytes at a time. Note: this is not always beneficial. | |
940 | * Try with and without -DUNALIGNED_OK to check. | |
941 | */ | |
942 | register Bytef *strend = s->window + s->strstart + MAX_MATCH - 1; | |
943 | register ush scan_start = *(ushf*)scan; | |
944 | register ush scan_end = *(ushf*)(scan+best_len-1); | |
945 | #else | |
946 | register Bytef *strend = s->window + s->strstart + MAX_MATCH; | |
947 | register Byte scan_end1 = scan[best_len-1]; | |
948 | register Byte scan_end = scan[best_len]; | |
949 | #endif | |
950 | ||
951 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. | |
952 | * It is easy to get rid of this optimization if necessary. | |
953 | */ | |
954 | Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); | |
955 | ||
956 | /* Do not waste too much time if we already have a good match: */ | |
957 | if (s->prev_length >= s->good_match) { | |
958 | chain_length >>= 2; | |
959 | } | |
960 | Assert((ulg)s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); | |
961 | ||
962 | do { | |
963 | Assert(cur_match < s->strstart, "no future"); | |
964 | match = s->window + cur_match; | |
965 | ||
966 | /* Skip to next match if the match length cannot increase | |
967 | * or if the match length is less than 2: | |
968 | */ | |
969 | #if (defined(UNALIGNED_OK) && MAX_MATCH == 258) | |
970 | /* This code assumes sizeof(unsigned short) == 2. Do not use | |
971 | * UNALIGNED_OK if your compiler uses a different size. | |
972 | */ | |
973 | if (*(ushf*)(match+best_len-1) != scan_end || | |
974 | *(ushf*)match != scan_start) continue; | |
975 | ||
976 | /* It is not necessary to compare scan[2] and match[2] since they are | |
977 | * always equal when the other bytes match, given that the hash keys | |
978 | * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at | |
979 | * strstart+3, +5, ... up to strstart+257. We check for insufficient | |
980 | * lookahead only every 4th comparison; the 128th check will be made | |
981 | * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is | |
982 | * necessary to put more guard bytes at the end of the window, or | |
983 | * to check more often for insufficient lookahead. | |
984 | */ | |
985 | Assert(scan[2] == match[2], "scan[2]?"); | |
986 | scan++, match++; | |
987 | do { | |
988 | } while (*(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
989 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
990 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
991 | *(ushf*)(scan+=2) == *(ushf*)(match+=2) && | |
992 | scan < strend); | |
993 | /* The funny "do {}" generates better code on most compilers */ | |
994 | ||
995 | /* Here, scan <= window+strstart+257 */ | |
996 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); | |
997 | if (*scan == *match) scan++; | |
998 | ||
999 | len = (MAX_MATCH - 1) - (int)(strend-scan); | |
1000 | scan = strend - (MAX_MATCH-1); | |
1001 | ||
1002 | #else /* UNALIGNED_OK */ | |
1003 | ||
1004 | if (match[best_len] != scan_end || | |
1005 | match[best_len-1] != scan_end1 || | |
1006 | *match != *scan || | |
1007 | *++match != scan[1]) continue; | |
1008 | ||
1009 | /* The check at best_len-1 can be removed because it will be made | |
1010 | * again later. (This heuristic is not always a win.) | |
1011 | * It is not necessary to compare scan[2] and match[2] since they | |
1012 | * are always equal when the other bytes match, given that | |
1013 | * the hash keys are equal and that HASH_BITS >= 8. | |
1014 | */ | |
1015 | scan += 2, match++; | |
1016 | Assert(*scan == *match, "match[2]?"); | |
1017 | ||
1018 | /* We check for insufficient lookahead only every 8th comparison; | |
1019 | * the 256th check will be made at strstart+258. | |
1020 | */ | |
1021 | do { | |
1022 | } while (*++scan == *++match && *++scan == *++match && | |
1023 | *++scan == *++match && *++scan == *++match && | |
1024 | *++scan == *++match && *++scan == *++match && | |
1025 | *++scan == *++match && *++scan == *++match && | |
1026 | scan < strend); | |
1027 | ||
1028 | Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); | |
1029 | ||
1030 | len = MAX_MATCH - (int)(strend - scan); | |
1031 | scan = strend - MAX_MATCH; | |
1032 | ||
1033 | #endif /* UNALIGNED_OK */ | |
1034 | ||
1035 | if (len > best_len) { | |
1036 | s->match_start = cur_match; | |
1037 | best_len = len; | |
1038 | if (len >= s->nice_match) break; | |
1039 | #ifdef UNALIGNED_OK | |
1040 | scan_end = *(ushf*)(scan+best_len-1); | |
1041 | #else | |
1042 | scan_end1 = scan[best_len-1]; | |
1043 | scan_end = scan[best_len]; | |
1044 | #endif | |
1045 | } | |
1046 | } while ((cur_match = prev[cur_match & wmask]) > limit | |
1047 | && --chain_length != 0); | |
1048 | ||
1049 | return best_len; | |
1050 | } | |
1051 | #endif /* ASMV */ | |
1052 | ||
1053 | #ifdef DEBUG_ZLIB | |
1054 | /* =========================================================================== | |
1055 | * Check that the match at match_start is indeed a match. | |
1056 | */ | |
1057 | local void check_match(s, start, match, length) | |
1058 | deflate_state *s; | |
1059 | IPos start, match; | |
1060 | int length; | |
1061 | { | |
1062 | /* check that the match is indeed a match */ | |
1063 | if (memcmp((charf *)s->window + match, | |
1064 | (charf *)s->window + start, length) != EQUAL) { | |
1065 | fprintf(stderr, | |
1066 | " start %u, match %u, length %d\n", | |
1067 | start, match, length); | |
1068 | do { fprintf(stderr, "%c%c", s->window[match++], | |
1069 | s->window[start++]); } while (--length != 0); | |
1070 | z_error("invalid match"); | |
1071 | } | |
1072 | if (verbose > 1) { | |
1073 | fprintf(stderr,"\\[%d,%d]", start-match, length); | |
1074 | do { putc(s->window[start++], stderr); } while (--length != 0); | |
1075 | } | |
1076 | } | |
1077 | #else | |
1078 | # define check_match(s, start, match, length) | |
1079 | #endif | |
1080 | ||
1081 | /* =========================================================================== | |
1082 | * Fill the window when the lookahead becomes insufficient. | |
1083 | * Updates strstart and lookahead. | |
1084 | * | |
1085 | * IN assertion: lookahead < MIN_LOOKAHEAD | |
1086 | * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD | |
1087 | * At least one byte has been read, or avail_in == 0; reads are | |
1088 | * performed for at least two bytes (required for the zip translate_eol | |
1089 | * option -- not supported here). | |
1090 | */ | |
1091 | local void fill_window(s) | |
1092 | deflate_state *s; | |
1093 | { | |
1094 | register unsigned n, m; | |
1095 | register Posf *p; | |
1096 | unsigned more; /* Amount of free space at the end of the window. */ | |
1097 | uInt wsize = s->w_size; | |
1098 | ||
1099 | do { | |
1100 | more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); | |
1101 | ||
1102 | /* Deal with !@#$% 64K limit: */ | |
1103 | if (more == 0 && s->strstart == 0 && s->lookahead == 0) { | |
1104 | more = wsize; | |
1105 | } else if (more == (unsigned)(-1)) { | |
1106 | /* Very unlikely, but possible on 16 bit machine if strstart == 0 | |
1107 | * and lookahead == 1 (input done one byte at time) | |
1108 | */ | |
1109 | more--; | |
1110 | ||
1111 | /* If the window is almost full and there is insufficient lookahead, | |
1112 | * move the upper half to the lower one to make room in the upper half. | |
1113 | */ | |
1114 | } else if (s->strstart >= wsize+MAX_DIST(s)) { | |
1115 | ||
1116 | /* By the IN assertion, the window is not empty so we can't confuse | |
1117 | * more == 0 with more == 64K on a 16 bit machine. | |
1118 | */ | |
1119 | zmemcpy((charf *)s->window, (charf *)s->window+wsize, | |
1120 | (unsigned)wsize); | |
1121 | s->match_start -= wsize; | |
1122 | s->strstart -= wsize; /* we now have strstart >= MAX_DIST */ | |
1123 | ||
1124 | s->block_start -= (long) wsize; | |
1125 | ||
1126 | /* Slide the hash table (could be avoided with 32 bit values | |
1127 | at the expense of memory usage): | |
1128 | */ | |
1129 | n = s->hash_size; | |
1130 | p = &s->head[n]; | |
1131 | do { | |
1132 | m = *--p; | |
1133 | *p = (Pos)(m >= wsize ? m-wsize : NIL); | |
1134 | } while (--n); | |
1135 | ||
1136 | n = wsize; | |
1137 | p = &s->prev[n]; | |
1138 | do { | |
1139 | m = *--p; | |
1140 | *p = (Pos)(m >= wsize ? m-wsize : NIL); | |
1141 | /* If n is not on any hash chain, prev[n] is garbage but | |
1142 | * its value will never be used. | |
1143 | */ | |
1144 | } while (--n); | |
1145 | ||
1146 | more += wsize; | |
1147 | } | |
1148 | if (s->strm->avail_in == 0) return; | |
1149 | ||
1150 | /* If there was no sliding: | |
1151 | * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && | |
1152 | * more == window_size - lookahead - strstart | |
1153 | * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) | |
1154 | * => more >= window_size - 2*WSIZE + 2 | |
1155 | * In the BIG_MEM or MMAP case (not yet supported), | |
1156 | * window_size == input_size + MIN_LOOKAHEAD && | |
1157 | * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. | |
1158 | * Otherwise, window_size == 2*WSIZE so more >= 2. | |
1159 | * If there was sliding, more >= WSIZE. So in all cases, more >= 2. | |
1160 | */ | |
1161 | Assert(more >= 2, "more < 2"); | |
1162 | ||
ef21f8db | 1163 | n = zread_buf(s->strm, (charf *)s->window + s->strstart + s->lookahead, |
861c20b4 PM |
1164 | more); |
1165 | s->lookahead += n; | |
1166 | ||
1167 | /* Initialize the hash value now that we have some input: */ | |
1168 | if (s->lookahead >= MIN_MATCH) { | |
1169 | s->ins_h = s->window[s->strstart]; | |
1170 | UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); | |
1171 | #if MIN_MATCH != 3 | |
1172 | Call UPDATE_HASH() MIN_MATCH-3 more times | |
1173 | #endif | |
1174 | } | |
1175 | /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage, | |
1176 | * but this is not important since only literal bytes will be emitted. | |
1177 | */ | |
1178 | ||
1179 | } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); | |
1180 | } | |
1181 | ||
1182 | /* =========================================================================== | |
1183 | * Flush the current block, with given end-of-file flag. | |
1184 | * IN assertion: strstart is set to the end of the current match. | |
1185 | */ | |
1186 | #define FLUSH_BLOCK_ONLY(s, flush) { \ | |
1187 | ct_flush_block(s, (s->block_start >= 0L ? \ | |
1188 | (charf *)&s->window[(unsigned)s->block_start] : \ | |
1189 | (charf *)Z_NULL), (long)s->strstart - s->block_start, (flush)); \ | |
1190 | s->block_start = s->strstart; \ | |
1191 | flush_pending(s->strm); \ | |
1192 | Tracev((stderr,"[FLUSH]")); \ | |
1193 | } | |
1194 | ||
1195 | /* Same but force premature exit if necessary. */ | |
1196 | #define FLUSH_BLOCK(s, flush) { \ | |
1197 | FLUSH_BLOCK_ONLY(s, flush); \ | |
1198 | if (s->strm->avail_out == 0) return 1; \ | |
1199 | } | |
1200 | ||
1201 | /* =========================================================================== | |
1202 | * Compress as much as possible from the input stream, return true if | |
1203 | * processing was terminated prematurely (no more input or output space). | |
1204 | * This function does not perform lazy evaluationof matches and inserts | |
1205 | * new strings in the dictionary only for unmatched strings or for short | |
1206 | * matches. It is used only for the fast compression options. | |
1207 | */ | |
1208 | local int deflate_fast(s, flush) | |
1209 | deflate_state *s; | |
1210 | int flush; | |
1211 | { | |
1212 | IPos hash_head = NIL; /* head of the hash chain */ | |
1213 | int bflush; /* set if current block must be flushed */ | |
1214 | ||
1215 | s->prev_length = MIN_MATCH-1; | |
1216 | ||
1217 | for (;;) { | |
1218 | /* Make sure that we always have enough lookahead, except | |
1219 | * at the end of the input file. We need MAX_MATCH bytes | |
1220 | * for the next match, plus MIN_MATCH bytes to insert the | |
1221 | * string following the next match. | |
1222 | */ | |
1223 | if (s->lookahead < MIN_LOOKAHEAD) { | |
1224 | fill_window(s); | |
1225 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; | |
1226 | ||
1227 | if (s->lookahead == 0) break; /* flush the current block */ | |
1228 | } | |
1229 | ||
1230 | /* Insert the string window[strstart .. strstart+2] in the | |
1231 | * dictionary, and set hash_head to the head of the hash chain: | |
1232 | */ | |
1233 | if (s->lookahead >= MIN_MATCH) { | |
1234 | INSERT_STRING(s, s->strstart, hash_head); | |
1235 | } | |
1236 | ||
1237 | /* Find the longest match, discarding those <= prev_length. | |
1238 | * At this point we have always match_length < MIN_MATCH | |
1239 | */ | |
1240 | if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { | |
1241 | /* To simplify the code, we prevent matches with the string | |
1242 | * of window index 0 (in particular we have to avoid a match | |
1243 | * of the string with itself at the start of the input file). | |
1244 | */ | |
1245 | if (s->strategy != Z_HUFFMAN_ONLY) { | |
1246 | s->match_length = longest_match (s, hash_head); | |
1247 | } | |
1248 | /* longest_match() sets match_start */ | |
1249 | ||
1250 | if (s->match_length > s->lookahead) s->match_length = s->lookahead; | |
1251 | } | |
1252 | if (s->match_length >= MIN_MATCH) { | |
1253 | check_match(s, s->strstart, s->match_start, s->match_length); | |
1254 | ||
1255 | bflush = ct_tally(s, s->strstart - s->match_start, | |
1256 | s->match_length - MIN_MATCH); | |
1257 | ||
1258 | s->lookahead -= s->match_length; | |
1259 | ||
1260 | /* Insert new strings in the hash table only if the match length | |
1261 | * is not too large. This saves time but degrades compression. | |
1262 | */ | |
1263 | if (s->match_length <= s->max_insert_length && | |
1264 | s->lookahead >= MIN_MATCH) { | |
1265 | s->match_length--; /* string at strstart already in hash table */ | |
1266 | do { | |
1267 | s->strstart++; | |
1268 | INSERT_STRING(s, s->strstart, hash_head); | |
1269 | /* strstart never exceeds WSIZE-MAX_MATCH, so there are | |
1270 | * always MIN_MATCH bytes ahead. | |
1271 | */ | |
1272 | } while (--s->match_length != 0); | |
1273 | s->strstart++; | |
1274 | } else { | |
1275 | s->strstart += s->match_length; | |
1276 | s->match_length = 0; | |
1277 | s->ins_h = s->window[s->strstart]; | |
1278 | UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); | |
1279 | #if MIN_MATCH != 3 | |
1280 | Call UPDATE_HASH() MIN_MATCH-3 more times | |
1281 | #endif | |
1282 | /* If lookahead < MIN_MATCH, ins_h is garbage, but it does not | |
1283 | * matter since it will be recomputed at next deflate call. | |
1284 | */ | |
1285 | } | |
1286 | } else { | |
1287 | /* No match, output a literal byte */ | |
1288 | Tracevv((stderr,"%c", s->window[s->strstart])); | |
1289 | bflush = ct_tally (s, 0, s->window[s->strstart]); | |
1290 | s->lookahead--; | |
1291 | s->strstart++; | |
1292 | } | |
1293 | if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); | |
1294 | } | |
1295 | FLUSH_BLOCK(s, flush); | |
1296 | return 0; /* normal exit */ | |
1297 | } | |
1298 | ||
1299 | /* =========================================================================== | |
1300 | * Same as above, but achieves better compression. We use a lazy | |
1301 | * evaluation for matches: a match is finally adopted only if there is | |
1302 | * no better match at the next window position. | |
1303 | */ | |
1304 | local int deflate_slow(s, flush) | |
1305 | deflate_state *s; | |
1306 | int flush; | |
1307 | { | |
1308 | IPos hash_head = NIL; /* head of hash chain */ | |
1309 | int bflush; /* set if current block must be flushed */ | |
1310 | ||
1311 | /* Process the input block. */ | |
1312 | for (;;) { | |
1313 | /* Make sure that we always have enough lookahead, except | |
1314 | * at the end of the input file. We need MAX_MATCH bytes | |
1315 | * for the next match, plus MIN_MATCH bytes to insert the | |
1316 | * string following the next match. | |
1317 | */ | |
1318 | if (s->lookahead < MIN_LOOKAHEAD) { | |
1319 | fill_window(s); | |
1320 | if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; | |
1321 | ||
1322 | if (s->lookahead == 0) break; /* flush the current block */ | |
1323 | } | |
1324 | ||
1325 | /* Insert the string window[strstart .. strstart+2] in the | |
1326 | * dictionary, and set hash_head to the head of the hash chain: | |
1327 | */ | |
1328 | if (s->lookahead >= MIN_MATCH) { | |
1329 | INSERT_STRING(s, s->strstart, hash_head); | |
1330 | } | |
1331 | ||
1332 | if (flush == Z_INSERT_ONLY) { | |
1333 | s->strstart++; | |
1334 | s->lookahead--; | |
1335 | continue; | |
1336 | } | |
1337 | ||
1338 | /* Find the longest match, discarding those <= prev_length. | |
1339 | */ | |
1340 | s->prev_length = s->match_length, s->prev_match = s->match_start; | |
1341 | s->match_length = MIN_MATCH-1; | |
1342 | ||
1343 | if (hash_head != NIL && s->prev_length < s->max_lazy_match && | |
1344 | s->strstart - hash_head <= MAX_DIST(s)) { | |
1345 | /* To simplify the code, we prevent matches with the string | |
1346 | * of window index 0 (in particular we have to avoid a match | |
1347 | * of the string with itself at the start of the input file). | |
1348 | */ | |
1349 | if (s->strategy != Z_HUFFMAN_ONLY) { | |
1350 | s->match_length = longest_match (s, hash_head); | |
1351 | } | |
1352 | /* longest_match() sets match_start */ | |
1353 | if (s->match_length > s->lookahead) s->match_length = s->lookahead; | |
1354 | ||
1355 | if (s->match_length <= 5 && (s->strategy == Z_FILTERED || | |
1356 | (s->match_length == MIN_MATCH && | |
1357 | s->strstart - s->match_start > TOO_FAR))) { | |
1358 | ||
1359 | /* If prev_match is also MIN_MATCH, match_start is garbage | |
1360 | * but we will ignore the current match anyway. | |
1361 | */ | |
1362 | s->match_length = MIN_MATCH-1; | |
1363 | } | |
1364 | } | |
1365 | /* If there was a match at the previous step and the current | |
1366 | * match is not better, output the previous match: | |
1367 | */ | |
1368 | if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { | |
1369 | uInt max_insert = s->strstart + s->lookahead - MIN_MATCH; | |
1370 | /* Do not insert strings in hash table beyond this. */ | |
1371 | ||
1372 | check_match(s, s->strstart-1, s->prev_match, s->prev_length); | |
1373 | ||
1374 | bflush = ct_tally(s, s->strstart -1 - s->prev_match, | |
1375 | s->prev_length - MIN_MATCH); | |
1376 | ||
1377 | /* Insert in hash table all strings up to the end of the match. | |
1378 | * strstart-1 and strstart are already inserted. If there is not | |
1379 | * enough lookahead, the last two strings are not inserted in | |
1380 | * the hash table. | |
1381 | */ | |
1382 | s->lookahead -= s->prev_length-1; | |
1383 | s->prev_length -= 2; | |
1384 | do { | |
1385 | if (++s->strstart <= max_insert) { | |
1386 | INSERT_STRING(s, s->strstart, hash_head); | |
1387 | } | |
1388 | } while (--s->prev_length != 0); | |
1389 | s->match_available = 0; | |
1390 | s->match_length = MIN_MATCH-1; | |
1391 | s->strstart++; | |
1392 | ||
1393 | if (bflush) FLUSH_BLOCK(s, Z_NO_FLUSH); | |
1394 | ||
1395 | } else if (s->match_available) { | |
1396 | /* If there was no match at the previous position, output a | |
1397 | * single literal. If there was a match but the current match | |
1398 | * is longer, truncate the previous match to a single literal. | |
1399 | */ | |
1400 | Tracevv((stderr,"%c", s->window[s->strstart-1])); | |
1401 | if (ct_tally (s, 0, s->window[s->strstart-1])) { | |
1402 | FLUSH_BLOCK_ONLY(s, Z_NO_FLUSH); | |
1403 | } | |
1404 | s->strstart++; | |
1405 | s->lookahead--; | |
1406 | if (s->strm->avail_out == 0) return 1; | |
1407 | } else { | |
1408 | /* There is no previous match to compare with, wait for | |
1409 | * the next step to decide. | |
1410 | */ | |
1411 | s->match_available = 1; | |
1412 | s->strstart++; | |
1413 | s->lookahead--; | |
1414 | } | |
1415 | } | |
1416 | if (flush == Z_INSERT_ONLY) { | |
1417 | s->block_start = s->strstart; | |
1418 | return 1; | |
1419 | } | |
1420 | Assert (flush != Z_NO_FLUSH, "no flush?"); | |
1421 | if (s->match_available) { | |
1422 | Tracevv((stderr,"%c", s->window[s->strstart-1])); | |
1423 | ct_tally (s, 0, s->window[s->strstart-1]); | |
1424 | s->match_available = 0; | |
1425 | } | |
1426 | FLUSH_BLOCK(s, flush); | |
1427 | return 0; | |
1428 | } | |
1429 | ||
1430 | ||
1431 | /*+++++*/ | |
1432 | /* trees.c -- output deflated data using Huffman coding | |
1433 | * Copyright (C) 1995 Jean-loup Gailly | |
1434 | * For conditions of distribution and use, see copyright notice in zlib.h | |
1435 | */ | |
1436 | ||
1437 | /* | |
1438 | * ALGORITHM | |
1439 | * | |
1440 | * The "deflation" process uses several Huffman trees. The more | |
1441 | * common source values are represented by shorter bit sequences. | |
1442 | * | |
1443 | * Each code tree is stored in a compressed form which is itself | |
1444 | * a Huffman encoding of the lengths of all the code strings (in | |
1445 | * ascending order by source values). The actual code strings are | |
1446 | * reconstructed from the lengths in the inflate process, as described | |
1447 | * in the deflate specification. | |
1448 | * | |
1449 | * REFERENCES | |
1450 | * | |
1451 | * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". | |
1452 | * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc | |
1453 | * | |
1454 | * Storer, James A. | |
1455 | * Data Compression: Methods and Theory, pp. 49-50. | |
1456 | * Computer Science Press, 1988. ISBN 0-7167-8156-5. | |
1457 | * | |
1458 | * Sedgewick, R. | |
1459 | * Algorithms, p290. | |
1460 | * Addison-Wesley, 1983. ISBN 0-201-06672-6. | |
1461 | */ | |
1462 | ||
1463 | /* From: trees.c,v 1.5 1995/05/03 17:27:12 jloup Exp */ | |
1464 | ||
1465 | #ifdef DEBUG_ZLIB | |
1466 | # include <ctype.h> | |
1467 | #endif | |
1468 | ||
1469 | /* =========================================================================== | |
1470 | * Constants | |
1471 | */ | |
1472 | ||
1473 | #define MAX_BL_BITS 7 | |
1474 | /* Bit length codes must not exceed MAX_BL_BITS bits */ | |
1475 | ||
1476 | #define END_BLOCK 256 | |
1477 | /* end of block literal code */ | |
1478 | ||
1479 | #define REP_3_6 16 | |
1480 | /* repeat previous bit length 3-6 times (2 bits of repeat count) */ | |
1481 | ||
1482 | #define REPZ_3_10 17 | |
1483 | /* repeat a zero length 3-10 times (3 bits of repeat count) */ | |
1484 | ||
1485 | #define REPZ_11_138 18 | |
1486 | /* repeat a zero length 11-138 times (7 bits of repeat count) */ | |
1487 | ||
1488 | local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ | |
1489 | = {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}; | |
1490 | ||
1491 | local int extra_dbits[D_CODES] /* extra bits for each distance code */ | |
1492 | = {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}; | |
1493 | ||
1494 | local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ | |
1495 | = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; | |
1496 | ||
1497 | local uch bl_order[BL_CODES] | |
1498 | = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; | |
1499 | /* The lengths of the bit length codes are sent in order of decreasing | |
1500 | * probability, to avoid transmitting the lengths for unused bit length codes. | |
1501 | */ | |
1502 | ||
1503 | #define Buf_size (8 * 2*sizeof(char)) | |
1504 | /* Number of bits used within bi_buf. (bi_buf might be implemented on | |
1505 | * more than 16 bits on some systems.) | |
1506 | */ | |
1507 | ||
1508 | /* =========================================================================== | |
1509 | * Local data. These are initialized only once. | |
1510 | * To do: initialize at compile time to be completely reentrant. ??? | |
1511 | */ | |
1512 | ||
1513 | local ct_data static_ltree[L_CODES+2]; | |
1514 | /* The static literal tree. Since the bit lengths are imposed, there is no | |
1515 | * need for the L_CODES extra codes used during heap construction. However | |
1516 | * The codes 286 and 287 are needed to build a canonical tree (see ct_init | |
1517 | * below). | |
1518 | */ | |
1519 | ||
1520 | local ct_data static_dtree[D_CODES]; | |
1521 | /* The static distance tree. (Actually a trivial tree since all codes use | |
1522 | * 5 bits.) | |
1523 | */ | |
1524 | ||
1525 | local uch dist_code[512]; | |
1526 | /* distance codes. The first 256 values correspond to the distances | |
1527 | * 3 .. 258, the last 256 values correspond to the top 8 bits of | |
1528 | * the 15 bit distances. | |
1529 | */ | |
1530 | ||
1531 | local uch length_code[MAX_MATCH-MIN_MATCH+1]; | |
1532 | /* length code for each normalized match length (0 == MIN_MATCH) */ | |
1533 | ||
1534 | local int base_length[LENGTH_CODES]; | |
1535 | /* First normalized length for each code (0 = MIN_MATCH) */ | |
1536 | ||
1537 | local int base_dist[D_CODES]; | |
1538 | /* First normalized distance for each code (0 = distance of 1) */ | |
1539 | ||
1540 | struct static_tree_desc_s { | |
1541 | ct_data *static_tree; /* static tree or NULL */ | |
1542 | intf *extra_bits; /* extra bits for each code or NULL */ | |
1543 | int extra_base; /* base index for extra_bits */ | |
1544 | int elems; /* max number of elements in the tree */ | |
1545 | int max_length; /* max bit length for the codes */ | |
1546 | }; | |
1547 | ||
1548 | local static_tree_desc static_l_desc = | |
1549 | {static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; | |
1550 | ||
1551 | local static_tree_desc static_d_desc = | |
1552 | {static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; | |
1553 | ||
1554 | local static_tree_desc static_bl_desc = | |
1555 | {(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; | |
1556 | ||
1557 | /* =========================================================================== | |
1558 | * Local (static) routines in this file. | |
1559 | */ | |
1560 | ||
1561 | local void ct_static_init OF((void)); | |
1562 | local void init_block OF((deflate_state *s)); | |
1563 | local void pqdownheap OF((deflate_state *s, ct_data *tree, int k)); | |
1564 | local void gen_bitlen OF((deflate_state *s, tree_desc *desc)); | |
1565 | local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count)); | |
1566 | local void build_tree OF((deflate_state *s, tree_desc *desc)); | |
1567 | local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code)); | |
1568 | local void send_tree OF((deflate_state *s, ct_data *tree, int max_code)); | |
1569 | local int build_bl_tree OF((deflate_state *s)); | |
1570 | local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes, | |
1571 | int blcodes)); | |
1572 | local void compress_block OF((deflate_state *s, ct_data *ltree, | |
1573 | ct_data *dtree)); | |
1574 | local void set_data_type OF((deflate_state *s)); | |
1575 | local unsigned bi_reverse OF((unsigned value, int length)); | |
1576 | local void bi_windup OF((deflate_state *s)); | |
1577 | local void bi_flush OF((deflate_state *s)); | |
1578 | local void copy_block OF((deflate_state *s, charf *buf, unsigned len, | |
1579 | int header)); | |
1580 | ||
1581 | #ifndef DEBUG_ZLIB | |
1582 | # define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) | |
1583 | /* Send a code of the given tree. c and tree must not have side effects */ | |
1584 | ||
1585 | #else /* DEBUG_ZLIB */ | |
1586 | # define send_code(s, c, tree) \ | |
1587 | { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ | |
1588 | send_bits(s, tree[c].Code, tree[c].Len); } | |
1589 | #endif | |
1590 | ||
1591 | #define d_code(dist) \ | |
1592 | ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) | |
1593 | /* Mapping from a distance to a distance code. dist is the distance - 1 and | |
1594 | * must not have side effects. dist_code[256] and dist_code[257] are never | |
1595 | * used. | |
1596 | */ | |
1597 | ||
1598 | /* =========================================================================== | |
1599 | * Output a short LSB first on the stream. | |
1600 | * IN assertion: there is enough room in pendingBuf. | |
1601 | */ | |
1602 | #define put_short(s, w) { \ | |
1603 | put_byte(s, (uch)((w) & 0xff)); \ | |
1604 | put_byte(s, (uch)((ush)(w) >> 8)); \ | |
1605 | } | |
1606 | ||
1607 | /* =========================================================================== | |
1608 | * Send a value on a given number of bits. | |
1609 | * IN assertion: length <= 16 and value fits in length bits. | |
1610 | */ | |
1611 | #ifdef DEBUG_ZLIB | |
1612 | local void send_bits OF((deflate_state *s, int value, int length)); | |
1613 | ||
1614 | local void send_bits(s, value, length) | |
1615 | deflate_state *s; | |
1616 | int value; /* value to send */ | |
1617 | int length; /* number of bits */ | |
1618 | { | |
1619 | Tracev((stderr," l %2d v %4x ", length, value)); | |
1620 | Assert(length > 0 && length <= 15, "invalid length"); | |
1621 | s->bits_sent += (ulg)length; | |
1622 | ||
1623 | /* If not enough room in bi_buf, use (valid) bits from bi_buf and | |
1624 | * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) | |
1625 | * unused bits in value. | |
1626 | */ | |
1627 | if (s->bi_valid > (int)Buf_size - length) { | |
1628 | s->bi_buf |= (value << s->bi_valid); | |
1629 | put_short(s, s->bi_buf); | |
1630 | s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); | |
1631 | s->bi_valid += length - Buf_size; | |
1632 | } else { | |
1633 | s->bi_buf |= value << s->bi_valid; | |
1634 | s->bi_valid += length; | |
1635 | } | |
1636 | } | |
1637 | #else /* !DEBUG_ZLIB */ | |
1638 | ||
1639 | #define send_bits(s, value, length) \ | |
1640 | { int len = length;\ | |
1641 | if (s->bi_valid > (int)Buf_size - len) {\ | |
1642 | int val = value;\ | |
1643 | s->bi_buf |= (val << s->bi_valid);\ | |
1644 | put_short(s, s->bi_buf);\ | |
1645 | s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\ | |
1646 | s->bi_valid += len - Buf_size;\ | |
1647 | } else {\ | |
1648 | s->bi_buf |= (value) << s->bi_valid;\ | |
1649 | s->bi_valid += len;\ | |
1650 | }\ | |
1651 | } | |
1652 | #endif /* DEBUG_ZLIB */ | |
1653 | ||
1654 | ||
861c20b4 PM |
1655 | /* the arguments must not have side effects */ |
1656 | ||
1657 | /* =========================================================================== | |
1658 | * Initialize the various 'constant' tables. | |
1659 | * To do: do this at compile time. | |
1660 | */ | |
1661 | local void ct_static_init() | |
1662 | { | |
1663 | int n; /* iterates over tree elements */ | |
1664 | int bits; /* bit counter */ | |
1665 | int length; /* length value */ | |
1666 | int code; /* code value */ | |
1667 | int dist; /* distance index */ | |
1668 | ush bl_count[MAX_BITS+1]; | |
1669 | /* number of codes at each bit length for an optimal tree */ | |
1670 | ||
1671 | /* Initialize the mapping length (0..255) -> length code (0..28) */ | |
1672 | length = 0; | |
1673 | for (code = 0; code < LENGTH_CODES-1; code++) { | |
1674 | base_length[code] = length; | |
1675 | for (n = 0; n < (1<<extra_lbits[code]); n++) { | |
1676 | length_code[length++] = (uch)code; | |
1677 | } | |
1678 | } | |
1679 | Assert (length == 256, "ct_static_init: length != 256"); | |
1680 | /* Note that the length 255 (match length 258) can be represented | |
1681 | * in two different ways: code 284 + 5 bits or code 285, so we | |
1682 | * overwrite length_code[255] to use the best encoding: | |
1683 | */ | |
1684 | length_code[length-1] = (uch)code; | |
1685 | ||
1686 | /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ | |
1687 | dist = 0; | |
1688 | for (code = 0 ; code < 16; code++) { | |
1689 | base_dist[code] = dist; | |
1690 | for (n = 0; n < (1<<extra_dbits[code]); n++) { | |
1691 | dist_code[dist++] = (uch)code; | |
1692 | } | |
1693 | } | |
1694 | Assert (dist == 256, "ct_static_init: dist != 256"); | |
1695 | dist >>= 7; /* from now on, all distances are divided by 128 */ | |
1696 | for ( ; code < D_CODES; code++) { | |
1697 | base_dist[code] = dist << 7; | |
1698 | for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { | |
1699 | dist_code[256 + dist++] = (uch)code; | |
1700 | } | |
1701 | } | |
1702 | Assert (dist == 256, "ct_static_init: 256+dist != 512"); | |
1703 | ||
1704 | /* Construct the codes of the static literal tree */ | |
1705 | for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; | |
1706 | n = 0; | |
1707 | while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; | |
1708 | while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; | |
1709 | while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; | |
1710 | while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; | |
1711 | /* Codes 286 and 287 do not exist, but we must include them in the | |
1712 | * tree construction to get a canonical Huffman tree (longest code | |
1713 | * all ones) | |
1714 | */ | |
1715 | gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); | |
1716 | ||
1717 | /* The static distance tree is trivial: */ | |
1718 | for (n = 0; n < D_CODES; n++) { | |
1719 | static_dtree[n].Len = 5; | |
1720 | static_dtree[n].Code = bi_reverse(n, 5); | |
1721 | } | |
1722 | } | |
1723 | ||
1724 | /* =========================================================================== | |
1725 | * Initialize the tree data structures for a new zlib stream. | |
1726 | */ | |
1727 | local void ct_init(s) | |
1728 | deflate_state *s; | |
1729 | { | |
1730 | if (static_dtree[0].Len == 0) { | |
1731 | ct_static_init(); /* To do: at compile time */ | |
1732 | } | |
1733 | ||
1734 | s->compressed_len = 0L; | |
1735 | ||
1736 | s->l_desc.dyn_tree = s->dyn_ltree; | |
1737 | s->l_desc.stat_desc = &static_l_desc; | |
1738 | ||
1739 | s->d_desc.dyn_tree = s->dyn_dtree; | |
1740 | s->d_desc.stat_desc = &static_d_desc; | |
1741 | ||
1742 | s->bl_desc.dyn_tree = s->bl_tree; | |
1743 | s->bl_desc.stat_desc = &static_bl_desc; | |
1744 | ||
1745 | s->bi_buf = 0; | |
1746 | s->bi_valid = 0; | |
1747 | s->last_eob_len = 8; /* enough lookahead for inflate */ | |
1748 | #ifdef DEBUG_ZLIB | |
1749 | s->bits_sent = 0L; | |
1750 | #endif | |
1751 | s->blocks_in_packet = 0; | |
1752 | ||
1753 | /* Initialize the first block of the first file: */ | |
1754 | init_block(s); | |
1755 | } | |
1756 | ||
1757 | /* =========================================================================== | |
1758 | * Initialize a new block. | |
1759 | */ | |
1760 | local void init_block(s) | |
1761 | deflate_state *s; | |
1762 | { | |
1763 | int n; /* iterates over tree elements */ | |
1764 | ||
1765 | /* Initialize the trees. */ | |
1766 | for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; | |
1767 | for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; | |
1768 | for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; | |
1769 | ||
1770 | s->dyn_ltree[END_BLOCK].Freq = 1; | |
1771 | s->opt_len = s->static_len = 0L; | |
1772 | s->last_lit = s->matches = 0; | |
1773 | } | |
1774 | ||
1775 | #define SMALLEST 1 | |
1776 | /* Index within the heap array of least frequent node in the Huffman tree */ | |
1777 | ||
1778 | ||
1779 | /* =========================================================================== | |
1780 | * Remove the smallest element from the heap and recreate the heap with | |
1781 | * one less element. Updates heap and heap_len. | |
1782 | */ | |
1783 | #define pqremove(s, tree, top) \ | |
1784 | {\ | |
1785 | top = s->heap[SMALLEST]; \ | |
1786 | s->heap[SMALLEST] = s->heap[s->heap_len--]; \ | |
1787 | pqdownheap(s, tree, SMALLEST); \ | |
1788 | } | |
1789 | ||
1790 | /* =========================================================================== | |
1791 | * Compares to subtrees, using the tree depth as tie breaker when | |
1792 | * the subtrees have equal frequency. This minimizes the worst case length. | |
1793 | */ | |
1794 | #define smaller(tree, n, m, depth) \ | |
1795 | (tree[n].Freq < tree[m].Freq || \ | |
1796 | (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) | |
1797 | ||
1798 | /* =========================================================================== | |
1799 | * Restore the heap property by moving down the tree starting at node k, | |
1800 | * exchanging a node with the smallest of its two sons if necessary, stopping | |
1801 | * when the heap property is re-established (each father smaller than its | |
1802 | * two sons). | |
1803 | */ | |
1804 | local void pqdownheap(s, tree, k) | |
1805 | deflate_state *s; | |
1806 | ct_data *tree; /* the tree to restore */ | |
1807 | int k; /* node to move down */ | |
1808 | { | |
1809 | int v = s->heap[k]; | |
1810 | int j = k << 1; /* left son of k */ | |
1811 | while (j <= s->heap_len) { | |
1812 | /* Set j to the smallest of the two sons: */ | |
1813 | if (j < s->heap_len && | |
1814 | smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { | |
1815 | j++; | |
1816 | } | |
1817 | /* Exit if v is smaller than both sons */ | |
1818 | if (smaller(tree, v, s->heap[j], s->depth)) break; | |
1819 | ||
1820 | /* Exchange v with the smallest son */ | |
1821 | s->heap[k] = s->heap[j]; k = j; | |
1822 | ||
1823 | /* And continue down the tree, setting j to the left son of k */ | |
1824 | j <<= 1; | |
1825 | } | |
1826 | s->heap[k] = v; | |
1827 | } | |
1828 | ||
1829 | /* =========================================================================== | |
1830 | * Compute the optimal bit lengths for a tree and update the total bit length | |
1831 | * for the current block. | |
1832 | * IN assertion: the fields freq and dad are set, heap[heap_max] and | |
1833 | * above are the tree nodes sorted by increasing frequency. | |
1834 | * OUT assertions: the field len is set to the optimal bit length, the | |
1835 | * array bl_count contains the frequencies for each bit length. | |
1836 | * The length opt_len is updated; static_len is also updated if stree is | |
1837 | * not null. | |
1838 | */ | |
1839 | local void gen_bitlen(s, desc) | |
1840 | deflate_state *s; | |
1841 | tree_desc *desc; /* the tree descriptor */ | |
1842 | { | |
1843 | ct_data *tree = desc->dyn_tree; | |
1844 | int max_code = desc->max_code; | |
1845 | ct_data *stree = desc->stat_desc->static_tree; | |
1846 | intf *extra = desc->stat_desc->extra_bits; | |
1847 | int base = desc->stat_desc->extra_base; | |
1848 | int max_length = desc->stat_desc->max_length; | |
1849 | int h; /* heap index */ | |
1850 | int n, m; /* iterate over the tree elements */ | |
1851 | int bits; /* bit length */ | |
1852 | int xbits; /* extra bits */ | |
1853 | ush f; /* frequency */ | |
1854 | int overflow = 0; /* number of elements with bit length too large */ | |
1855 | ||
1856 | for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; | |
1857 | ||
1858 | /* In a first pass, compute the optimal bit lengths (which may | |
1859 | * overflow in the case of the bit length tree). | |
1860 | */ | |
1861 | tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ | |
1862 | ||
1863 | for (h = s->heap_max+1; h < HEAP_SIZE; h++) { | |
1864 | n = s->heap[h]; | |
1865 | bits = tree[tree[n].Dad].Len + 1; | |
1866 | if (bits > max_length) bits = max_length, overflow++; | |
1867 | tree[n].Len = (ush)bits; | |
1868 | /* We overwrite tree[n].Dad which is no longer needed */ | |
1869 | ||
1870 | if (n > max_code) continue; /* not a leaf node */ | |
1871 | ||
1872 | s->bl_count[bits]++; | |
1873 | xbits = 0; | |
1874 | if (n >= base) xbits = extra[n-base]; | |
1875 | f = tree[n].Freq; | |
1876 | s->opt_len += (ulg)f * (bits + xbits); | |
1877 | if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); | |
1878 | } | |
1879 | if (overflow == 0) return; | |
1880 | ||
1881 | Trace((stderr,"\nbit length overflow\n")); | |
1882 | /* This happens for example on obj2 and pic of the Calgary corpus */ | |
1883 | ||
1884 | /* Find the first bit length which could increase: */ | |
1885 | do { | |
1886 | bits = max_length-1; | |
1887 | while (s->bl_count[bits] == 0) bits--; | |
1888 | s->bl_count[bits]--; /* move one leaf down the tree */ | |
1889 | s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ | |
1890 | s->bl_count[max_length]--; | |
1891 | /* The brother of the overflow item also moves one step up, | |
1892 | * but this does not affect bl_count[max_length] | |
1893 | */ | |
1894 | overflow -= 2; | |
1895 | } while (overflow > 0); | |
1896 | ||
1897 | /* Now recompute all bit lengths, scanning in increasing frequency. | |
1898 | * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all | |
1899 | * lengths instead of fixing only the wrong ones. This idea is taken | |
1900 | * from 'ar' written by Haruhiko Okumura.) | |
1901 | */ | |
1902 | for (bits = max_length; bits != 0; bits--) { | |
1903 | n = s->bl_count[bits]; | |
1904 | while (n != 0) { | |
1905 | m = s->heap[--h]; | |
1906 | if (m > max_code) continue; | |
1907 | if (tree[m].Len != (unsigned) bits) { | |
1908 | Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); | |
1909 | s->opt_len += ((long)bits - (long)tree[m].Len) | |
1910 | *(long)tree[m].Freq; | |
1911 | tree[m].Len = (ush)bits; | |
1912 | } | |
1913 | n--; | |
1914 | } | |
1915 | } | |
1916 | } | |
1917 | ||
1918 | /* =========================================================================== | |
1919 | * Generate the codes for a given tree and bit counts (which need not be | |
1920 | * optimal). | |
1921 | * IN assertion: the array bl_count contains the bit length statistics for | |
1922 | * the given tree and the field len is set for all tree elements. | |
1923 | * OUT assertion: the field code is set for all tree elements of non | |
1924 | * zero code length. | |
1925 | */ | |
1926 | local void gen_codes (tree, max_code, bl_count) | |
1927 | ct_data *tree; /* the tree to decorate */ | |
1928 | int max_code; /* largest code with non zero frequency */ | |
1929 | ushf *bl_count; /* number of codes at each bit length */ | |
1930 | { | |
1931 | ush next_code[MAX_BITS+1]; /* next code value for each bit length */ | |
1932 | ush code = 0; /* running code value */ | |
1933 | int bits; /* bit index */ | |
1934 | int n; /* code index */ | |
1935 | ||
1936 | /* The distribution counts are first used to generate the code values | |
1937 | * without bit reversal. | |
1938 | */ | |
1939 | for (bits = 1; bits <= MAX_BITS; bits++) { | |
1940 | next_code[bits] = code = (code + bl_count[bits-1]) << 1; | |
1941 | } | |
1942 | /* Check that the bit counts in bl_count are consistent. The last code | |
1943 | * must be all ones. | |
1944 | */ | |
1945 | Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1, | |
1946 | "inconsistent bit counts"); | |
1947 | Tracev((stderr,"\ngen_codes: max_code %d ", max_code)); | |
1948 | ||
1949 | for (n = 0; n <= max_code; n++) { | |
1950 | int len = tree[n].Len; | |
1951 | if (len == 0) continue; | |
1952 | /* Now reverse the bits */ | |
1953 | tree[n].Code = bi_reverse(next_code[len]++, len); | |
1954 | ||
1955 | Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ", | |
1956 | n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1)); | |
1957 | } | |
1958 | } | |
1959 | ||
1960 | /* =========================================================================== | |
1961 | * Construct one Huffman tree and assigns the code bit strings and lengths. | |
1962 | * Update the total bit length for the current block. | |
1963 | * IN assertion: the field freq is set for all tree elements. | |
1964 | * OUT assertions: the fields len and code are set to the optimal bit length | |
1965 | * and corresponding code. The length opt_len is updated; static_len is | |
1966 | * also updated if stree is not null. The field max_code is set. | |
1967 | */ | |
1968 | local void build_tree(s, desc) | |
1969 | deflate_state *s; | |
1970 | tree_desc *desc; /* the tree descriptor */ | |
1971 | { | |
1972 | ct_data *tree = desc->dyn_tree; | |
1973 | ct_data *stree = desc->stat_desc->static_tree; | |
1974 | int elems = desc->stat_desc->elems; | |
1975 | int n, m; /* iterate over heap elements */ | |
1976 | int max_code = -1; /* largest code with non zero frequency */ | |
1977 | int node; /* new node being created */ | |
1978 | ||
1979 | /* Construct the initial heap, with least frequent element in | |
1980 | * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. | |
1981 | * heap[0] is not used. | |
1982 | */ | |
1983 | s->heap_len = 0, s->heap_max = HEAP_SIZE; | |
1984 | ||
1985 | for (n = 0; n < elems; n++) { | |
1986 | if (tree[n].Freq != 0) { | |
1987 | s->heap[++(s->heap_len)] = max_code = n; | |
1988 | s->depth[n] = 0; | |
1989 | } else { | |
1990 | tree[n].Len = 0; | |
1991 | } | |
1992 | } | |
1993 | ||
1994 | /* The pkzip format requires that at least one distance code exists, | |
1995 | * and that at least one bit should be sent even if there is only one | |
1996 | * possible code. So to avoid special checks later on we force at least | |
1997 | * two codes of non zero frequency. | |
1998 | */ | |
1999 | while (s->heap_len < 2) { | |
2000 | node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); | |
2001 | tree[node].Freq = 1; | |
2002 | s->depth[node] = 0; | |
2003 | s->opt_len--; if (stree) s->static_len -= stree[node].Len; | |
2004 | /* node is 0 or 1 so it does not have extra bits */ | |
2005 | } | |
2006 | desc->max_code = max_code; | |
2007 | ||
2008 | /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, | |
2009 | * establish sub-heaps of increasing lengths: | |
2010 | */ | |
2011 | for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); | |
2012 | ||
2013 | /* Construct the Huffman tree by repeatedly combining the least two | |
2014 | * frequent nodes. | |
2015 | */ | |
2016 | node = elems; /* next internal node of the tree */ | |
2017 | do { | |
2018 | pqremove(s, tree, n); /* n = node of least frequency */ | |
2019 | m = s->heap[SMALLEST]; /* m = node of next least frequency */ | |
2020 | ||
2021 | s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ | |
2022 | s->heap[--(s->heap_max)] = m; | |
2023 | ||
2024 | /* Create a new node father of n and m */ | |
2025 | tree[node].Freq = tree[n].Freq + tree[m].Freq; | |
2026 | s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); | |
2027 | tree[n].Dad = tree[m].Dad = (ush)node; | |
2028 | #ifdef DUMP_BL_TREE | |
2029 | if (tree == s->bl_tree) { | |
2030 | fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", | |
2031 | node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); | |
2032 | } | |
2033 | #endif | |
2034 | /* and insert the new node in the heap */ | |
2035 | s->heap[SMALLEST] = node++; | |
2036 | pqdownheap(s, tree, SMALLEST); | |
2037 | ||
2038 | } while (s->heap_len >= 2); | |
2039 | ||
2040 | s->heap[--(s->heap_max)] = s->heap[SMALLEST]; | |
2041 | ||
2042 | /* At this point, the fields freq and dad are set. We can now | |
2043 | * generate the bit lengths. | |
2044 | */ | |
2045 | gen_bitlen(s, (tree_desc *)desc); | |
2046 | ||
2047 | /* The field len is now set, we can generate the bit codes */ | |
2048 | gen_codes ((ct_data *)tree, max_code, s->bl_count); | |
2049 | } | |
2050 | ||
2051 | /* =========================================================================== | |
2052 | * Scan a literal or distance tree to determine the frequencies of the codes | |
2053 | * in the bit length tree. | |
2054 | */ | |
2055 | local void scan_tree (s, tree, max_code) | |
2056 | deflate_state *s; | |
2057 | ct_data *tree; /* the tree to be scanned */ | |
2058 | int max_code; /* and its largest code of non zero frequency */ | |
2059 | { | |
2060 | int n; /* iterates over all tree elements */ | |
2061 | int prevlen = -1; /* last emitted length */ | |
2062 | int curlen; /* length of current code */ | |
2063 | int nextlen = tree[0].Len; /* length of next code */ | |
2064 | int count = 0; /* repeat count of the current code */ | |
2065 | int max_count = 7; /* max repeat count */ | |
2066 | int min_count = 4; /* min repeat count */ | |
2067 | ||
2068 | if (nextlen == 0) max_count = 138, min_count = 3; | |
2069 | tree[max_code+1].Len = (ush)0xffff; /* guard */ | |
2070 | ||
2071 | for (n = 0; n <= max_code; n++) { | |
2072 | curlen = nextlen; nextlen = tree[n+1].Len; | |
2073 | if (++count < max_count && curlen == nextlen) { | |
2074 | continue; | |
2075 | } else if (count < min_count) { | |
2076 | s->bl_tree[curlen].Freq += count; | |
2077 | } else if (curlen != 0) { | |
2078 | if (curlen != prevlen) s->bl_tree[curlen].Freq++; | |
2079 | s->bl_tree[REP_3_6].Freq++; | |
2080 | } else if (count <= 10) { | |
2081 | s->bl_tree[REPZ_3_10].Freq++; | |
2082 | } else { | |
2083 | s->bl_tree[REPZ_11_138].Freq++; | |
2084 | } | |
2085 | count = 0; prevlen = curlen; | |
2086 | if (nextlen == 0) { | |
2087 | max_count = 138, min_count = 3; | |
2088 | } else if (curlen == nextlen) { | |
2089 | max_count = 6, min_count = 3; | |
2090 | } else { | |
2091 | max_count = 7, min_count = 4; | |
2092 | } | |
2093 | } | |
2094 | } | |
2095 | ||
2096 | /* =========================================================================== | |
2097 | * Send a literal or distance tree in compressed form, using the codes in | |
2098 | * bl_tree. | |
2099 | */ | |
2100 | local void send_tree (s, tree, max_code) | |
2101 | deflate_state *s; | |
2102 | ct_data *tree; /* the tree to be scanned */ | |
2103 | int max_code; /* and its largest code of non zero frequency */ | |
2104 | { | |
2105 | int n; /* iterates over all tree elements */ | |
2106 | int prevlen = -1; /* last emitted length */ | |
2107 | int curlen; /* length of current code */ | |
2108 | int nextlen = tree[0].Len; /* length of next code */ | |
2109 | int count = 0; /* repeat count of the current code */ | |
2110 | int max_count = 7; /* max repeat count */ | |
2111 | int min_count = 4; /* min repeat count */ | |
2112 | ||
2113 | /* tree[max_code+1].Len = -1; */ /* guard already set */ | |
2114 | if (nextlen == 0) max_count = 138, min_count = 3; | |
2115 | ||
2116 | for (n = 0; n <= max_code; n++) { | |
2117 | curlen = nextlen; nextlen = tree[n+1].Len; | |
2118 | if (++count < max_count && curlen == nextlen) { | |
2119 | continue; | |
2120 | } else if (count < min_count) { | |
2121 | do { send_code(s, curlen, s->bl_tree); } while (--count != 0); | |
2122 | ||
2123 | } else if (curlen != 0) { | |
2124 | if (curlen != prevlen) { | |
2125 | send_code(s, curlen, s->bl_tree); count--; | |
2126 | } | |
2127 | Assert(count >= 3 && count <= 6, " 3_6?"); | |
2128 | send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); | |
2129 | ||
2130 | } else if (count <= 10) { | |
2131 | send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); | |
2132 | ||
2133 | } else { | |
2134 | send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); | |
2135 | } | |
2136 | count = 0; prevlen = curlen; | |
2137 | if (nextlen == 0) { | |
2138 | max_count = 138, min_count = 3; | |
2139 | } else if (curlen == nextlen) { | |
2140 | max_count = 6, min_count = 3; | |
2141 | } else { | |
2142 | max_count = 7, min_count = 4; | |
2143 | } | |
2144 | } | |
2145 | } | |
2146 | ||
2147 | /* =========================================================================== | |
2148 | * Construct the Huffman tree for the bit lengths and return the index in | |
2149 | * bl_order of the last bit length code to send. | |
2150 | */ | |
2151 | local int build_bl_tree(s) | |
2152 | deflate_state *s; | |
2153 | { | |
2154 | int max_blindex; /* index of last bit length code of non zero freq */ | |
2155 | ||
2156 | /* Determine the bit length frequencies for literal and distance trees */ | |
2157 | scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); | |
2158 | scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); | |
2159 | ||
2160 | /* Build the bit length tree: */ | |
2161 | build_tree(s, (tree_desc *)(&(s->bl_desc))); | |
2162 | /* opt_len now includes the length of the tree representations, except | |
2163 | * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. | |
2164 | */ | |
2165 | ||
2166 | /* Determine the number of bit length codes to send. The pkzip format | |
2167 | * requires that at least 4 bit length codes be sent. (appnote.txt says | |
2168 | * 3 but the actual value used is 4.) | |
2169 | */ | |
2170 | for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { | |
2171 | if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; | |
2172 | } | |
2173 | /* Update opt_len to include the bit length tree and counts */ | |
2174 | s->opt_len += 3*(max_blindex+1) + 5+5+4; | |
2175 | Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", | |
2176 | s->opt_len, s->static_len)); | |
2177 | ||
2178 | return max_blindex; | |
2179 | } | |
2180 | ||
2181 | /* =========================================================================== | |
2182 | * Send the header for a block using dynamic Huffman trees: the counts, the | |
2183 | * lengths of the bit length codes, the literal tree and the distance tree. | |
2184 | * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. | |
2185 | */ | |
2186 | local void send_all_trees(s, lcodes, dcodes, blcodes) | |
2187 | deflate_state *s; | |
2188 | int lcodes, dcodes, blcodes; /* number of codes for each tree */ | |
2189 | { | |
2190 | int rank; /* index in bl_order */ | |
2191 | ||
2192 | Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); | |
2193 | Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, | |
2194 | "too many codes"); | |
2195 | Tracev((stderr, "\nbl counts: ")); | |
2196 | send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ | |
2197 | send_bits(s, dcodes-1, 5); | |
2198 | send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ | |
2199 | for (rank = 0; rank < blcodes; rank++) { | |
2200 | Tracev((stderr, "\nbl code %2d ", bl_order[rank])); | |
2201 | send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); | |
2202 | } | |
2203 | Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); | |
2204 | ||
2205 | send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ | |
2206 | Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); | |
2207 | ||
2208 | send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ | |
2209 | Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); | |
2210 | } | |
2211 | ||
2212 | /* =========================================================================== | |
2213 | * Send a stored block | |
2214 | */ | |
2215 | local void ct_stored_block(s, buf, stored_len, eof) | |
2216 | deflate_state *s; | |
2217 | charf *buf; /* input block */ | |
2218 | ulg stored_len; /* length of input block */ | |
2219 | int eof; /* true if this is the last block for a file */ | |
2220 | { | |
2221 | send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ | |
2222 | s->compressed_len = (s->compressed_len + 3 + 7) & ~7L; | |
2223 | s->compressed_len += (stored_len + 4) << 3; | |
2224 | ||
2225 | copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ | |
2226 | } | |
2227 | ||
2228 | /* Send just the `stored block' type code without any length bytes or data. | |
2229 | */ | |
2230 | local void ct_stored_type_only(s) | |
2231 | deflate_state *s; | |
2232 | { | |
2233 | send_bits(s, (STORED_BLOCK << 1), 3); | |
2234 | bi_windup(s); | |
2235 | s->compressed_len = (s->compressed_len + 3) & ~7L; | |
2236 | } | |
2237 | ||
2238 | ||
2239 | /* =========================================================================== | |
2240 | * Send one empty static block to give enough lookahead for inflate. | |
2241 | * This takes 10 bits, of which 7 may remain in the bit buffer. | |
2242 | * The current inflate code requires 9 bits of lookahead. If the EOB | |
2243 | * code for the previous block was coded on 5 bits or less, inflate | |
2244 | * may have only 5+3 bits of lookahead to decode this EOB. | |
2245 | * (There are no problems if the previous block is stored or fixed.) | |
2246 | */ | |
2247 | local void ct_align(s) | |
2248 | deflate_state *s; | |
2249 | { | |
2250 | send_bits(s, STATIC_TREES<<1, 3); | |
2251 | send_code(s, END_BLOCK, static_ltree); | |
2252 | s->compressed_len += 10L; /* 3 for block type, 7 for EOB */ | |
2253 | bi_flush(s); | |
2254 | /* Of the 10 bits for the empty block, we have already sent | |
2255 | * (10 - bi_valid) bits. The lookahead for the EOB of the previous | |
2256 | * block was thus its length plus what we have just sent. | |
2257 | */ | |
2258 | if (s->last_eob_len + 10 - s->bi_valid < 9) { | |
2259 | send_bits(s, STATIC_TREES<<1, 3); | |
2260 | send_code(s, END_BLOCK, static_ltree); | |
2261 | s->compressed_len += 10L; | |
2262 | bi_flush(s); | |
2263 | } | |
2264 | s->last_eob_len = 7; | |
2265 | } | |
2266 | ||
2267 | /* =========================================================================== | |
2268 | * Determine the best encoding for the current block: dynamic trees, static | |
2269 | * trees or store, and output the encoded block to the zip file. This function | |
2270 | * returns the total compressed length for the file so far. | |
2271 | */ | |
2272 | local ulg ct_flush_block(s, buf, stored_len, flush) | |
2273 | deflate_state *s; | |
2274 | charf *buf; /* input block, or NULL if too old */ | |
2275 | ulg stored_len; /* length of input block */ | |
2276 | int flush; /* Z_FINISH if this is the last block for a file */ | |
2277 | { | |
2278 | ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ | |
2279 | int max_blindex; /* index of last bit length code of non zero freq */ | |
2280 | int eof = flush == Z_FINISH; | |
2281 | ||
2282 | ++s->blocks_in_packet; | |
2283 | ||
2284 | /* Check if the file is ascii or binary */ | |
2285 | if (s->data_type == UNKNOWN) set_data_type(s); | |
2286 | ||
2287 | /* Construct the literal and distance trees */ | |
2288 | build_tree(s, (tree_desc *)(&(s->l_desc))); | |
2289 | Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, | |
2290 | s->static_len)); | |
2291 | ||
2292 | build_tree(s, (tree_desc *)(&(s->d_desc))); | |
2293 | Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, | |
2294 | s->static_len)); | |
2295 | /* At this point, opt_len and static_len are the total bit lengths of | |
2296 | * the compressed block data, excluding the tree representations. | |
2297 | */ | |
2298 | ||
2299 | /* Build the bit length tree for the above two trees, and get the index | |
2300 | * in bl_order of the last bit length code to send. | |
2301 | */ | |
2302 | max_blindex = build_bl_tree(s); | |
2303 | ||
2304 | /* Determine the best encoding. Compute first the block length in bytes */ | |
2305 | opt_lenb = (s->opt_len+3+7)>>3; | |
2306 | static_lenb = (s->static_len+3+7)>>3; | |
2307 | ||
2308 | Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", | |
2309 | opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, | |
2310 | s->last_lit)); | |
2311 | ||
2312 | if (static_lenb <= opt_lenb) opt_lenb = static_lenb; | |
2313 | ||
2314 | /* If compression failed and this is the first and last block, | |
2315 | * and if the .zip file can be seeked (to rewrite the local header), | |
2316 | * the whole file is transformed into a stored file: | |
2317 | */ | |
2318 | #ifdef STORED_FILE_OK | |
2319 | # ifdef FORCE_STORED_FILE | |
2320 | if (eof && compressed_len == 0L) /* force stored file */ | |
2321 | # else | |
2322 | if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) | |
2323 | # endif | |
2324 | { | |
2325 | /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ | |
2326 | if (buf == (charf*)0) error ("block vanished"); | |
2327 | ||
2328 | copy_block(buf, (unsigned)stored_len, 0); /* without header */ | |
2329 | s->compressed_len = stored_len << 3; | |
2330 | s->method = STORED; | |
2331 | } else | |
2332 | #endif /* STORED_FILE_OK */ | |
2333 | ||
861c20b4 PM |
2334 | #ifdef FORCE_STORED |
2335 | if (buf != (char*)0) /* force stored block */ | |
2336 | #else | |
2337 | if (stored_len+4 <= opt_lenb && buf != (char*)0) | |
2338 | /* 4: two words for the lengths */ | |
2339 | #endif | |
2340 | { | |
2341 | /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. | |
2342 | * Otherwise we can't have processed more than WSIZE input bytes since | |
2343 | * the last block flush, because compression would have been | |
2344 | * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to | |
2345 | * transform a block into a stored block. | |
2346 | */ | |
2347 | ct_stored_block(s, buf, stored_len, eof); | |
2348 | } else | |
2349 | ||
2350 | #ifdef FORCE_STATIC | |
2351 | if (static_lenb >= 0) /* force static trees */ | |
2352 | #else | |
2353 | if (static_lenb == opt_lenb) | |
2354 | #endif | |
2355 | { | |
2356 | send_bits(s, (STATIC_TREES<<1)+eof, 3); | |
2357 | compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); | |
2358 | s->compressed_len += 3 + s->static_len; | |
2359 | } else { | |
2360 | send_bits(s, (DYN_TREES<<1)+eof, 3); | |
2361 | send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, | |
2362 | max_blindex+1); | |
2363 | compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); | |
2364 | s->compressed_len += 3 + s->opt_len; | |
2365 | } | |
2366 | Assert (s->compressed_len == s->bits_sent, "bad compressed size"); | |
2367 | init_block(s); | |
2368 | ||
2369 | if (eof) { | |
2370 | bi_windup(s); | |
2371 | s->compressed_len += 7; /* align on byte boundary */ | |
2372 | } | |
2373 | Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, | |
2374 | s->compressed_len-7*eof)); | |
2375 | ||
2376 | return s->compressed_len >> 3; | |
2377 | } | |
2378 | ||
2379 | /* =========================================================================== | |
2380 | * Save the match info and tally the frequency counts. Return true if | |
2381 | * the current block must be flushed. | |
2382 | */ | |
2383 | local int ct_tally (s, dist, lc) | |
2384 | deflate_state *s; | |
2385 | int dist; /* distance of matched string */ | |
2386 | int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ | |
2387 | { | |
2388 | s->d_buf[s->last_lit] = (ush)dist; | |
2389 | s->l_buf[s->last_lit++] = (uch)lc; | |
2390 | if (dist == 0) { | |
2391 | /* lc is the unmatched char */ | |
2392 | s->dyn_ltree[lc].Freq++; | |
2393 | } else { | |
2394 | s->matches++; | |
2395 | /* Here, lc is the match length - MIN_MATCH */ | |
2396 | dist--; /* dist = match distance - 1 */ | |
2397 | Assert((ush)dist < (ush)MAX_DIST(s) && | |
2398 | (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && | |
2399 | (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match"); | |
2400 | ||
2401 | s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; | |
2402 | s->dyn_dtree[d_code(dist)].Freq++; | |
2403 | } | |
2404 | ||
2405 | /* Try to guess if it is profitable to stop the current block here */ | |
2406 | if (s->level > 2 && (s->last_lit & 0xfff) == 0) { | |
2407 | /* Compute an upper bound for the compressed length */ | |
2408 | ulg out_length = (ulg)s->last_lit*8L; | |
2409 | ulg in_length = (ulg)s->strstart - s->block_start; | |
2410 | int dcode; | |
2411 | for (dcode = 0; dcode < D_CODES; dcode++) { | |
2412 | out_length += (ulg)s->dyn_dtree[dcode].Freq * | |
2413 | (5L+extra_dbits[dcode]); | |
2414 | } | |
2415 | out_length >>= 3; | |
2416 | Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", | |
2417 | s->last_lit, in_length, out_length, | |
2418 | 100L - out_length*100L/in_length)); | |
2419 | if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; | |
2420 | } | |
2421 | return (s->last_lit == s->lit_bufsize-1); | |
2422 | /* We avoid equality with lit_bufsize because of wraparound at 64K | |
2423 | * on 16 bit machines and because stored blocks are restricted to | |
2424 | * 64K-1 bytes. | |
2425 | */ | |
2426 | } | |
2427 | ||
2428 | /* =========================================================================== | |
2429 | * Send the block data compressed using the given Huffman trees | |
2430 | */ | |
2431 | local void compress_block(s, ltree, dtree) | |
2432 | deflate_state *s; | |
2433 | ct_data *ltree; /* literal tree */ | |
2434 | ct_data *dtree; /* distance tree */ | |
2435 | { | |
2436 | unsigned dist; /* distance of matched string */ | |
2437 | int lc; /* match length or unmatched char (if dist == 0) */ | |
2438 | unsigned lx = 0; /* running index in l_buf */ | |
2439 | unsigned code; /* the code to send */ | |
2440 | int extra; /* number of extra bits to send */ | |
2441 | ||
2442 | if (s->last_lit != 0) do { | |
2443 | dist = s->d_buf[lx]; | |
2444 | lc = s->l_buf[lx++]; | |
2445 | if (dist == 0) { | |
2446 | send_code(s, lc, ltree); /* send a literal byte */ | |
2447 | Tracecv(isgraph(lc), (stderr," '%c' ", lc)); | |
2448 | } else { | |
2449 | /* Here, lc is the match length - MIN_MATCH */ | |
2450 | code = length_code[lc]; | |
2451 | send_code(s, code+LITERALS+1, ltree); /* send the length code */ | |
2452 | extra = extra_lbits[code]; | |
2453 | if (extra != 0) { | |
2454 | lc -= base_length[code]; | |
2455 | send_bits(s, lc, extra); /* send the extra length bits */ | |
2456 | } | |
2457 | dist--; /* dist is now the match distance - 1 */ | |
2458 | code = d_code(dist); | |
2459 | Assert (code < D_CODES, "bad d_code"); | |
2460 | ||
2461 | send_code(s, code, dtree); /* send the distance code */ | |
2462 | extra = extra_dbits[code]; | |
2463 | if (extra != 0) { | |
2464 | dist -= base_dist[code]; | |
2465 | send_bits(s, dist, extra); /* send the extra distance bits */ | |
2466 | } | |
2467 | } /* literal or match pair ? */ | |
2468 | ||
2469 | /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ | |
2470 | Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); | |
2471 | ||
2472 | } while (lx < s->last_lit); | |
2473 | ||
2474 | send_code(s, END_BLOCK, ltree); | |
2475 | s->last_eob_len = ltree[END_BLOCK].Len; | |
2476 | } | |
2477 | ||
2478 | /* =========================================================================== | |
2479 | * Set the data type to ASCII or BINARY, using a crude approximation: | |
2480 | * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. | |
2481 | * IN assertion: the fields freq of dyn_ltree are set and the total of all | |
2482 | * frequencies does not exceed 64K (to fit in an int on 16 bit machines). | |
2483 | */ | |
2484 | local void set_data_type(s) | |
2485 | deflate_state *s; | |
2486 | { | |
2487 | int n = 0; | |
2488 | unsigned ascii_freq = 0; | |
2489 | unsigned bin_freq = 0; | |
2490 | while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; | |
2491 | while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; | |
2492 | while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; | |
2493 | s->data_type = (Byte)(bin_freq > (ascii_freq >> 2) ? BINARY : ASCII); | |
2494 | } | |
2495 | ||
2496 | /* =========================================================================== | |
2497 | * Reverse the first len bits of a code, using straightforward code (a faster | |
2498 | * method would use a table) | |
2499 | * IN assertion: 1 <= len <= 15 | |
2500 | */ | |
2501 | local unsigned bi_reverse(code, len) | |
2502 | unsigned code; /* the value to invert */ | |
2503 | int len; /* its bit length */ | |
2504 | { | |
2505 | register unsigned res = 0; | |
2506 | do { | |
2507 | res |= code & 1; | |
2508 | code >>= 1, res <<= 1; | |
2509 | } while (--len > 0); | |
2510 | return res >> 1; | |
2511 | } | |
2512 | ||
2513 | /* =========================================================================== | |
2514 | * Flush the bit buffer, keeping at most 7 bits in it. | |
2515 | */ | |
2516 | local void bi_flush(s) | |
2517 | deflate_state *s; | |
2518 | { | |
2519 | if (s->bi_valid == 16) { | |
2520 | put_short(s, s->bi_buf); | |
2521 | s->bi_buf = 0; | |
2522 | s->bi_valid = 0; | |
2523 | } else if (s->bi_valid >= 8) { | |
2524 | put_byte(s, (Byte)s->bi_buf); | |
2525 | s->bi_buf >>= 8; | |
2526 | s->bi_valid -= 8; | |
2527 | } | |
2528 | } | |
2529 | ||
2530 | /* =========================================================================== | |
2531 | * Flush the bit buffer and align the output on a byte boundary | |
2532 | */ | |
2533 | local void bi_windup(s) | |
2534 | deflate_state *s; | |
2535 | { | |
2536 | if (s->bi_valid > 8) { | |
2537 | put_short(s, s->bi_buf); | |
2538 | } else if (s->bi_valid > 0) { | |
2539 | put_byte(s, (Byte)s->bi_buf); | |
2540 | } | |
2541 | s->bi_buf = 0; | |
2542 | s->bi_valid = 0; | |
2543 | #ifdef DEBUG_ZLIB | |
2544 | s->bits_sent = (s->bits_sent+7) & ~7; | |
2545 | #endif | |
2546 | } | |
2547 | ||
2548 | /* =========================================================================== | |
2549 | * Copy a stored block, storing first the length and its | |
2550 | * one's complement if requested. | |
2551 | */ | |
2552 | local void copy_block(s, buf, len, header) | |
2553 | deflate_state *s; | |
2554 | charf *buf; /* the input data */ | |
2555 | unsigned len; /* its length */ | |
2556 | int header; /* true if block header must be written */ | |
2557 | { | |
2558 | bi_windup(s); /* align on byte boundary */ | |
2559 | s->last_eob_len = 8; /* enough lookahead for inflate */ | |
2560 | ||
2561 | if (header) { | |
2562 | put_short(s, (ush)len); | |
2563 | put_short(s, (ush)~len); | |
2564 | #ifdef DEBUG_ZLIB | |
2565 | s->bits_sent += 2*16; | |
2566 | #endif | |
2567 | } | |
2568 | #ifdef DEBUG_ZLIB | |
2569 | s->bits_sent += (ulg)len<<3; | |
2570 | #endif | |
2571 | while (len--) { | |
2572 | put_byte(s, *buf++); | |
2573 | } | |
2574 | } | |
2575 | ||
2576 | ||
2577 | /*+++++*/ | |
2578 | /* infblock.h -- header to use infblock.c | |
2579 | * Copyright (C) 1995 Mark Adler | |
2580 | * For conditions of distribution and use, see copyright notice in zlib.h | |
2581 | */ | |
2582 | ||
2583 | /* WARNING: this file should *not* be used by applications. It is | |
2584 | part of the implementation of the compression library and is | |
2585 | subject to change. Applications should only use zlib.h. | |
2586 | */ | |
2587 | ||
2588 | struct inflate_blocks_state; | |
2589 | typedef struct inflate_blocks_state FAR inflate_blocks_statef; | |
2590 | ||
2591 | local inflate_blocks_statef * inflate_blocks_new OF(( | |
2592 | z_stream *z, | |
2593 | check_func c, /* check function */ | |
2594 | uInt w)); /* window size */ | |
2595 | ||
2596 | local int inflate_blocks OF(( | |
2597 | inflate_blocks_statef *, | |
2598 | z_stream *, | |
2599 | int)); /* initial return code */ | |
2600 | ||
2601 | local void inflate_blocks_reset OF(( | |
2602 | inflate_blocks_statef *, | |
2603 | z_stream *, | |
2604 | uLongf *)); /* check value on output */ | |
2605 | ||
2606 | local int inflate_blocks_free OF(( | |
2607 | inflate_blocks_statef *, | |
2608 | z_stream *, | |
2609 | uLongf *)); /* check value on output */ | |
2610 | ||
2611 | local int inflate_addhistory OF(( | |
2612 | inflate_blocks_statef *, | |
2613 | z_stream *)); | |
2614 | ||
2615 | local int inflate_packet_flush OF(( | |
2616 | inflate_blocks_statef *)); | |
2617 | ||
2618 | /*+++++*/ | |
2619 | /* inftrees.h -- header to use inftrees.c | |
2620 | * Copyright (C) 1995 Mark Adler | |
2621 | * For conditions of distribution and use, see copyright notice in zlib.h | |
2622 | */ | |
2623 | ||
2624 | /* WARNING: this file should *not* be used by applications. It is | |
2625 | part of the implementation of the compression library and is | |
2626 | subject to change. Applications should only use zlib.h. | |
2627 | */ | |
2628 | ||
2629 | /* Huffman code lookup table entry--this entry is four bytes for machines | |
2630 | that have 16-bit pointers (e.g. PC's in the small or medium model). */ | |
2631 | ||
2632 | typedef struct inflate_huft_s FAR inflate_huft; | |
2633 | ||
2634 | struct inflate_huft_s { | |
2635 | union { | |
2636 | struct { | |
2637 | Byte Exop; /* number of extra bits or operation */ | |
2638 | Byte Bits; /* number of bits in this code or subcode */ | |
2639 | } what; | |
2640 | uInt Nalloc; /* number of these allocated here */ | |
2641 | Bytef *pad; /* pad structure to a power of 2 (4 bytes for */ | |
2642 | } word; /* 16-bit, 8 bytes for 32-bit machines) */ | |
2643 | union { | |
2644 | uInt Base; /* literal, length base, or distance base */ | |
2645 | inflate_huft *Next; /* pointer to next level of table */ | |
2646 | } more; | |
2647 | }; | |
2648 | ||
2649 | #ifdef DEBUG_ZLIB | |
2650 | local uInt inflate_hufts; | |
2651 | #endif | |
2652 | ||
2653 | local int inflate_trees_bits OF(( | |
2654 | uIntf *, /* 19 code lengths */ | |
2655 | uIntf *, /* bits tree desired/actual depth */ | |
2656 | inflate_huft * FAR *, /* bits tree result */ | |
2657 | z_stream *)); /* for zalloc, zfree functions */ | |
2658 | ||
2659 | local int inflate_trees_dynamic OF(( | |
2660 | uInt, /* number of literal/length codes */ | |
2661 | uInt, /* number of distance codes */ | |
2662 | uIntf *, /* that many (total) code lengths */ | |
2663 | uIntf *, /* literal desired/actual bit depth */ | |
2664 | uIntf *, /* distance desired/actual bit depth */ | |
2665 | inflate_huft * FAR *, /* literal/length tree result */ | |
2666 | inflate_huft * FAR *, /* distance tree result */ | |
2667 | z_stream *)); /* for zalloc, zfree functions */ | |
2668 | ||
2669 | local int inflate_trees_fixed OF(( | |
2670 | uIntf *, /* literal desired/actual bit depth */ | |
2671 | uIntf *, /* distance desired/actual bit depth */ | |
2672 | inflate_huft * FAR *, /* literal/length tree result */ | |
2673 | inflate_huft * FAR *)); /* distance tree result */ | |
2674 | ||
2675 | local int inflate_trees_free OF(( | |
2676 | inflate_huft *, /* tables to free */ | |
2677 | z_stream *)); /* for zfree function */ | |
2678 | ||
2679 | ||
2680 | /*+++++*/ | |
2681 | /* infcodes.h -- header to use infcodes.c | |
2682 | * Copyright (C) 1995 Mark Adler | |
2683 | * For conditions of distribution and use, see copyright notice in zlib.h | |
2684 | */ | |
2685 | ||
2686 | /* WARNING: this file should *not* be used by applications. It is | |
2687 | part of the implementation of the compression library and is | |
2688 | subject to change. Applications should only use zlib.h. | |
2689 | */ | |
2690 | ||
2691 | struct inflate_codes_state; | |
2692 | typedef struct inflate_codes_state FAR inflate_codes_statef; | |
2693 | ||
2694 | local inflate_codes_statef *inflate_codes_new OF(( | |
2695 | uInt, uInt, | |
2696 | inflate_huft *, inflate_huft *, | |
2697 | z_stream *)); | |
2698 | ||
2699 | local int inflate_codes OF(( | |
2700 | inflate_blocks_statef *, | |
2701 | z_stream *, | |
2702 | int)); | |
2703 | ||
2704 | local void inflate_codes_free OF(( | |
2705 | inflate_codes_statef *, | |
2706 | z_stream *)); | |
2707 | ||
2708 | ||
2709 | /*+++++*/ | |
2710 | /* inflate.c -- zlib interface to inflate modules | |
2711 | * Copyright (C) 1995 Mark Adler | |
2712 | * For conditions of distribution and use, see copyright notice in zlib.h | |
2713 | */ | |
2714 | ||
2715 | /* inflate private state */ | |
2716 | struct internal_state { | |
2717 | ||
2718 | /* mode */ | |
2719 | enum { | |
2720 | METHOD, /* waiting for method byte */ | |
2721 | FLAG, /* waiting for flag byte */ | |
2722 | BLOCKS, /* decompressing blocks */ | |
2723 | CHECK4, /* four check bytes to go */ | |
2724 | CHECK3, /* three check bytes to go */ | |
2725 | CHECK2, /* two check bytes to go */ | |
2726 | CHECK1, /* one check byte to go */ | |
2727 | DONE, /* finished check, done */ | |
a3418f2e | 2728 | ZBAD} /* got an error--stay here */ |
861c20b4 PM |
2729 | mode; /* current inflate mode */ |
2730 | ||
2731 | /* mode dependent information */ | |
2732 | union { | |
2733 | uInt method; /* if FLAGS, method byte */ | |
2734 | struct { | |
2735 | uLong was; /* computed check value */ | |
2736 | uLong need; /* stream check value */ | |
2737 | } check; /* if CHECK, check values to compare */ | |
a3418f2e | 2738 | uInt marker; /* if ZBAD, inflateSync's marker bytes count */ |
861c20b4 PM |
2739 | } sub; /* submode */ |
2740 | ||
2741 | /* mode independent information */ | |
2742 | int nowrap; /* flag for no wrapper */ | |
2743 | uInt wbits; /* log2(window size) (8..15, defaults to 15) */ | |
2744 | inflate_blocks_statef | |
2745 | *blocks; /* current inflate_blocks state */ | |
2746 | ||
2747 | }; | |
2748 | ||
2749 | ||
2750 | int inflateReset(z) | |
2751 | z_stream *z; | |
2752 | { | |
2753 | uLong c; | |
2754 | ||
2755 | if (z == Z_NULL || z->state == Z_NULL) | |
2756 | return Z_STREAM_ERROR; | |
2757 | z->total_in = z->total_out = 0; | |
2758 | z->msg = Z_NULL; | |
2759 | z->state->mode = z->state->nowrap ? BLOCKS : METHOD; | |
2760 | inflate_blocks_reset(z->state->blocks, z, &c); | |
2761 | Trace((stderr, "inflate: reset\n")); | |
2762 | return Z_OK; | |
2763 | } | |
2764 | ||
2765 | ||
2766 | int inflateEnd(z) | |
2767 | z_stream *z; | |
2768 | { | |
2769 | uLong c; | |
2770 | ||
2771 | if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) | |
2772 | return Z_STREAM_ERROR; | |
2773 | if (z->state->blocks != Z_NULL) | |
2774 | inflate_blocks_free(z->state->blocks, z, &c); | |
2775 | ZFREE(z, z->state, sizeof(struct internal_state)); | |
2776 | z->state = Z_NULL; | |
2777 | Trace((stderr, "inflate: end\n")); | |
2778 | return Z_OK; | |
2779 | } | |
2780 | ||
2781 | ||
2782 | int inflateInit2(z, w) | |
2783 | z_stream *z; | |
2784 | int w; | |
2785 | { | |
2786 | /* initialize state */ | |
2787 | if (z == Z_NULL) | |
2788 | return Z_STREAM_ERROR; | |
2789 | /* if (z->zalloc == Z_NULL) z->zalloc = zcalloc; */ | |
2790 | /* if (z->zfree == Z_NULL) z->zfree = zcfree; */ | |
2791 | if ((z->state = (struct internal_state FAR *) | |
2792 | ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) | |
2793 | return Z_MEM_ERROR; | |
2794 | z->state->blocks = Z_NULL; | |
2795 | ||
2796 | /* handle undocumented nowrap option (no zlib header or check) */ | |
2797 | z->state->nowrap = 0; | |
2798 | if (w < 0) | |
2799 | { | |
2800 | w = - w; | |
2801 | z->state->nowrap = 1; | |
2802 | } | |
2803 | ||
2804 | /* set window size */ | |
2805 | if (w < 8 || w > 15) | |
2806 | { | |
2807 | inflateEnd(z); | |
2808 | return Z_STREAM_ERROR; | |
2809 | } | |
2810 | z->state->wbits = (uInt)w; | |
2811 | ||
2812 | /* create inflate_blocks state */ | |
2813 | if ((z->state->blocks = | |
2814 | inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, 1 << w)) | |
2815 | == Z_NULL) | |
2816 | { | |
2817 | inflateEnd(z); | |
2818 | return Z_MEM_ERROR; | |
2819 | } | |
2820 | Trace((stderr, "inflate: allocated\n")); | |
2821 | ||
2822 | /* reset state */ | |
2823 | inflateReset(z); | |
2824 | return Z_OK; | |
2825 | } | |
2826 | ||
2827 | ||
2828 | int inflateInit(z) | |
2829 | z_stream *z; | |
2830 | { | |
2831 | return inflateInit2(z, DEF_WBITS); | |
2832 | } | |
2833 | ||
2834 | ||
2835 | #define NEEDBYTE {if(z->avail_in==0)goto empty;r=Z_OK;} | |
2836 | #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++) | |
2837 | ||
2838 | int inflate(z, f) | |
2839 | z_stream *z; | |
2840 | int f; | |
2841 | { | |
2842 | int r; | |
2843 | uInt b; | |
2844 | ||
2845 | if (z == Z_NULL || z->next_in == Z_NULL) | |
2846 | return Z_STREAM_ERROR; | |
2847 | r = Z_BUF_ERROR; | |
2848 | while (1) switch (z->state->mode) | |
2849 | { | |
2850 | case METHOD: | |
2851 | NEEDBYTE | |
2852 | if (((z->state->sub.method = NEXTBYTE) & 0xf) != DEFLATED) | |
2853 | { | |
a3418f2e | 2854 | z->state->mode = ZBAD; |
861c20b4 PM |
2855 | z->msg = "unknown compression method"; |
2856 | z->state->sub.marker = 5; /* can't try inflateSync */ | |
2857 | break; | |
2858 | } | |
2859 | if ((z->state->sub.method >> 4) + 8 > z->state->wbits) | |
2860 | { | |
a3418f2e | 2861 | z->state->mode = ZBAD; |
861c20b4 PM |
2862 | z->msg = "invalid window size"; |
2863 | z->state->sub.marker = 5; /* can't try inflateSync */ | |
2864 | break; | |
2865 | } | |
2866 | z->state->mode = FLAG; | |
2867 | case FLAG: | |
2868 | NEEDBYTE | |
2869 | if ((b = NEXTBYTE) & 0x20) | |
2870 | { | |
a3418f2e | 2871 | z->state->mode = ZBAD; |
861c20b4 PM |
2872 | z->msg = "invalid reserved bit"; |
2873 | z->state->sub.marker = 5; /* can't try inflateSync */ | |
2874 | break; | |
2875 | } | |
2876 | if (((z->state->sub.method << 8) + b) % 31) | |
2877 | { | |
a3418f2e | 2878 | z->state->mode = ZBAD; |
861c20b4 PM |
2879 | z->msg = "incorrect header check"; |
2880 | z->state->sub.marker = 5; /* can't try inflateSync */ | |
2881 | break; | |
2882 | } | |
2883 | Trace((stderr, "inflate: zlib header ok\n")); | |
2884 | z->state->mode = BLOCKS; | |
2885 | case BLOCKS: | |
2886 | r = inflate_blocks(z->state->blocks, z, r); | |
2887 | if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0) | |
2888 | r = inflate_packet_flush(z->state->blocks); | |
2889 | if (r == Z_DATA_ERROR) | |
2890 | { | |
a3418f2e | 2891 | z->state->mode = ZBAD; |
861c20b4 PM |
2892 | z->state->sub.marker = 0; /* can try inflateSync */ |
2893 | break; | |
2894 | } | |
2895 | if (r != Z_STREAM_END) | |
2896 | return r; | |
2897 | r = Z_OK; | |
2898 | inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was); | |
2899 | if (z->state->nowrap) | |
2900 | { | |
2901 | z->state->mode = DONE; | |
2902 | break; | |
2903 | } | |
2904 | z->state->mode = CHECK4; | |
2905 | case CHECK4: | |
2906 | NEEDBYTE | |
2907 | z->state->sub.check.need = (uLong)NEXTBYTE << 24; | |
2908 | z->state->mode = CHECK3; | |
2909 | case CHECK3: | |
2910 | NEEDBYTE | |
2911 | z->state->sub.check.need += (uLong)NEXTBYTE << 16; | |
2912 | z->state->mode = CHECK2; | |
2913 | case CHECK2: | |
2914 | NEEDBYTE | |
2915 | z->state->sub.check.need += (uLong)NEXTBYTE << 8; | |
2916 | z->state->mode = CHECK1; | |
2917 | case CHECK1: | |
2918 | NEEDBYTE | |
2919 | z->state->sub.check.need += (uLong)NEXTBYTE; | |
2920 | ||
2921 | if (z->state->sub.check.was != z->state->sub.check.need) | |
2922 | { | |
a3418f2e | 2923 | z->state->mode = ZBAD; |
861c20b4 PM |
2924 | z->msg = "incorrect data check"; |
2925 | z->state->sub.marker = 5; /* can't try inflateSync */ | |
2926 | break; | |
2927 | } | |
2928 | Trace((stderr, "inflate: zlib check ok\n")); | |
2929 | z->state->mode = DONE; | |
2930 | case DONE: | |
2931 | return Z_STREAM_END; | |
a3418f2e | 2932 | case ZBAD: |
861c20b4 PM |
2933 | return Z_DATA_ERROR; |
2934 | default: | |
2935 | return Z_STREAM_ERROR; | |
2936 | } | |
2937 | ||
2938 | empty: | |
2939 | if (f != Z_PACKET_FLUSH) | |
2940 | return r; | |
a3418f2e | 2941 | z->state->mode = ZBAD; |
861c20b4 PM |
2942 | z->state->sub.marker = 0; /* can try inflateSync */ |
2943 | return Z_DATA_ERROR; | |
2944 | } | |
2945 | ||
2946 | /* | |
2947 | * This subroutine adds the data at next_in/avail_in to the output history | |
2948 | * without performing any output. The output buffer must be "caught up"; | |
2949 | * i.e. no pending output (hence s->read equals s->write), and the state must | |
2950 | * be BLOCKS (i.e. we should be willing to see the start of a series of | |
2951 | * BLOCKS). On exit, the output will also be caught up, and the checksum | |
2952 | * will have been updated if need be. | |
2953 | */ | |
2954 | ||
2955 | int inflateIncomp(z) | |
2956 | z_stream *z; | |
2957 | { | |
2958 | if (z->state->mode != BLOCKS) | |
2959 | return Z_DATA_ERROR; | |
2960 | return inflate_addhistory(z->state->blocks, z); | |
2961 | } | |
2962 | ||
2963 | ||
2964 | int inflateSync(z) | |
2965 | z_stream *z; | |
2966 | { | |
2967 | uInt n; /* number of bytes to look at */ | |
2968 | Bytef *p; /* pointer to bytes */ | |
2969 | uInt m; /* number of marker bytes found in a row */ | |
2970 | uLong r, w; /* temporaries to save total_in and total_out */ | |
2971 | ||
2972 | /* set up */ | |
2973 | if (z == Z_NULL || z->state == Z_NULL) | |
2974 | return Z_STREAM_ERROR; | |
a3418f2e | 2975 | if (z->state->mode != ZBAD) |
861c20b4 | 2976 | { |
a3418f2e | 2977 | z->state->mode = ZBAD; |
861c20b4 PM |
2978 | z->state->sub.marker = 0; |
2979 | } | |
2980 | if ((n = z->avail_in) == 0) | |
2981 | return Z_BUF_ERROR; | |
2982 | p = z->next_in; | |
2983 | m = z->state->sub.marker; | |
2984 | ||
2985 | /* search */ | |
2986 | while (n && m < 4) | |
2987 | { | |
2988 | if (*p == (Byte)(m < 2 ? 0 : 0xff)) | |
2989 | m++; | |
2990 | else if (*p) | |
2991 | m = 0; | |
2992 | else | |
2993 | m = 4 - m; | |
2994 | p++, n--; | |
2995 | } | |
2996 | ||
2997 | /* restore */ | |
2998 | z->total_in += p - z->next_in; | |
2999 | z->next_in = p; | |
3000 | z->avail_in = n; | |
3001 | z->state->sub.marker = m; | |
3002 | ||
3003 | /* return no joy or set up to restart on a new block */ | |
3004 | if (m != 4) | |
3005 | return Z_DATA_ERROR; | |
3006 | r = z->total_in; w = z->total_out; | |
3007 | inflateReset(z); | |
3008 | z->total_in = r; z->total_out = w; | |
3009 | z->state->mode = BLOCKS; | |
3010 | return Z_OK; | |
3011 | } | |
3012 | ||
3013 | #undef NEEDBYTE | |
3014 | #undef NEXTBYTE | |
3015 | ||
3016 | /*+++++*/ | |
3017 | /* infutil.h -- types and macros common to blocks and codes | |
3018 | * Copyright (C) 1995 Mark Adler | |
3019 | * For conditions of distribution and use, see copyright notice in zlib.h | |
3020 | */ | |
3021 | ||
3022 | /* WARNING: this file should *not* be used by applications. It is | |
3023 | part of the implementation of the compression library and is | |
3024 | subject to change. Applications should only use zlib.h. | |
3025 | */ | |
3026 | ||
3027 | /* inflate blocks semi-private state */ | |
3028 | struct inflate_blocks_state { | |
3029 | ||
3030 | /* mode */ | |
3031 | enum { | |
3032 | TYPE, /* get type bits (3, including end bit) */ | |
3033 | LENS, /* get lengths for stored */ | |
3034 | STORED, /* processing stored block */ | |
3035 | TABLE, /* get table lengths */ | |
3036 | BTREE, /* get bit lengths tree for a dynamic block */ | |
3037 | DTREE, /* get length, distance trees for a dynamic block */ | |
3038 | CODES, /* processing fixed or dynamic block */ | |
3039 | DRY, /* output remaining window bytes */ | |
3040 | DONEB, /* finished last block, done */ | |
3041 | BADB} /* got a data error--stuck here */ | |
3042 | mode; /* current inflate_block mode */ | |
3043 | ||
3044 | /* mode dependent information */ | |
3045 | union { | |
3046 | uInt left; /* if STORED, bytes left to copy */ | |
3047 | struct { | |
3048 | uInt table; /* table lengths (14 bits) */ | |
3049 | uInt index; /* index into blens (or border) */ | |
3050 | uIntf *blens; /* bit lengths of codes */ | |
3051 | uInt bb; /* bit length tree depth */ | |
3052 | inflate_huft *tb; /* bit length decoding tree */ | |
3053 | int nblens; /* # elements allocated at blens */ | |
3054 | } trees; /* if DTREE, decoding info for trees */ | |
3055 | struct { | |
3056 | inflate_huft *tl, *td; /* trees to free */ | |
3057 | inflate_codes_statef | |
3058 | *codes; | |
3059 | } decode; /* if CODES, current state */ | |
3060 | } sub; /* submode */ | |
3061 | uInt last; /* true if this block is the last block */ | |
3062 | ||
3063 | /* mode independent information */ | |
3064 | uInt bitk; /* bits in bit buffer */ | |
3065 | uLong bitb; /* bit buffer */ | |
3066 | Bytef *window; /* sliding window */ | |
3067 | Bytef *end; /* one byte after sliding window */ | |
3068 | Bytef *read; /* window read pointer */ | |
3069 | Bytef *write; /* window write pointer */ | |
3070 | check_func checkfn; /* check function */ | |
3071 | uLong check; /* check on output */ | |
3072 | ||
3073 | }; | |
3074 | ||
3075 | ||
3076 | /* defines for inflate input/output */ | |
3077 | /* update pointers and return */ | |
3078 | #define UPDBITS {s->bitb=b;s->bitk=k;} | |
3079 | #define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} | |
3080 | #define UPDOUT {s->write=q;} | |
3081 | #define UPDATE {UPDBITS UPDIN UPDOUT} | |
3082 | #define LEAVE {UPDATE return inflate_flush(s,z,r);} | |
3083 | /* get bytes and bits */ | |
3084 | #define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} | |
3085 | #define NEEDBYTE {if(n)r=Z_OK;else LEAVE} | |
3086 | #define NEXTBYTE (n--,*p++) | |
3087 | #define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} | |
3088 | #define DUMPBITS(j) {b>>=(j);k-=(j);} | |
3089 | /* output bytes */ | |
3090 | #define WAVAIL (q<s->read?s->read-q-1:s->end-q) | |
3091 | #define LOADOUT {q=s->write;m=WAVAIL;} | |
3092 | #define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}} | |
3093 | #define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} | |
3094 | #define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} | |
3095 | #define OUTBYTE(a) {*q++=(Byte)(a);m--;} | |
3096 | /* load local pointers */ | |
3097 | #define LOAD {LOADIN LOADOUT} | |
3098 | ||
3099 | /* And'ing with mask[n] masks the lower n bits */ | |
3100 | local uInt inflate_mask[] = { | |
3101 | 0x0000, | |
3102 | 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, | |
3103 | 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff | |
3104 | }; | |
3105 | ||
3106 | /* copy as much as possible from the sliding window to the output area */ | |
3107 | local int inflate_flush OF(( | |
3108 | inflate_blocks_statef *, | |
3109 | z_stream *, | |
3110 | int)); | |
3111 | ||
3112 | /*+++++*/ | |
3113 | /* inffast.h -- header to use inffast.c | |
3114 | * Copyright (C) 1995 Mark Adler | |
3115 | * For conditions of distribution and use, see copyright notice in zlib.h | |
3116 | */ | |
3117 | ||
3118 | /* WARNING: this file should *not* be used by applications. It is | |
3119 | part of the implementation of the compression library and is | |
3120 | subject to change. Applications should only use zlib.h. | |
3121 | */ | |
3122 | ||
3123 | local int inflate_fast OF(( | |
3124 | uInt, | |
3125 | uInt, | |
3126 | inflate_huft *, | |
3127 | inflate_huft *, | |
3128 | inflate_blocks_statef *, | |
3129 | z_stream *)); | |
3130 | ||
3131 | ||
3132 | /*+++++*/ | |
3133 | /* infblock.c -- interpret and process block types to last block | |
3134 | * Copyright (C) 1995 Mark Adler | |
3135 | * For conditions of distribution and use, see copyright notice in zlib.h | |
3136 | */ | |
3137 | ||
3138 | /* Table for deflate from PKZIP's appnote.txt. */ | |
3139 | local uInt border[] = { /* Order of the bit length code lengths */ | |
3140 | 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; | |
3141 | ||
3142 | /* | |
3143 | Notes beyond the 1.93a appnote.txt: | |
3144 | ||
3145 | 1. Distance pointers never point before the beginning of the output | |
3146 | stream. | |
3147 | 2. Distance pointers can point back across blocks, up to 32k away. | |
3148 | 3. There is an implied maximum of 7 bits for the bit length table and | |
3149 | 15 bits for the actual data. | |
3150 | 4. If only one code exists, then it is encoded using one bit. (Zero | |
3151 | would be more efficient, but perhaps a little confusing.) If two | |
3152 | codes exist, they are coded using one bit each (0 and 1). | |
3153 | 5. There is no way of sending zero distance codes--a dummy must be | |
3154 | sent if there are none. (History: a pre 2.0 version of PKZIP would | |
3155 | store blocks with no distance codes, but this was discovered to be | |
3156 | too harsh a criterion.) Valid only for 1.93a. 2.04c does allow | |
3157 | zero distance codes, which is sent as one code of zero bits in | |
3158 | length. | |
3159 | 6. There are up to 286 literal/length codes. Code 256 represents the | |
3160 | end-of-block. Note however that the static length tree defines | |
3161 | 288 codes just to fill out the Huffman codes. Codes 286 and 287 | |
3162 | cannot be used though, since there is no length base or extra bits | |
3163 | defined for them. Similarily, there are up to 30 distance codes. | |
3164 | However, static trees define 32 codes (all 5 bits) to fill out the | |
3165 | Huffman codes, but the last two had better not show up in the data. | |
3166 | 7. Unzip can check dynamic Huffman blocks for complete code sets. | |
3167 | The exception is that a single code would not be complete (see #4). | |
3168 | 8. The five bits following the block type is really the number of | |
3169 | literal codes sent minus 257. | |
3170 | 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits | |
3171 | (1+6+6). Therefore, to output three times the length, you output | |
3172 | three codes (1+1+1), whereas to output four times the same length, | |
3173 | you only need two codes (1+3). Hmm. | |
3174 | 10. In the tree reconstruction algorithm, Code = Code + Increment | |
3175 | only if BitLength(i) is not zero. (Pretty obvious.) | |
3176 | 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) | |
3177 | 12. Note: length code 284 can represent 227-258, but length code 285 | |
3178 | really is 258. The last length deserves its own, short code | |
3179 | since it gets used a lot in very redundant files. The length | |
3180 | 258 is special since 258 - 3 (the min match length) is 255. | |
3181 | 13. The literal/length and distance code bit lengths are read as a | |
3182 | single stream of lengths. It is possible (and advantageous) for | |
3183 | a repeat code (16, 17, or 18) to go across the boundary between | |
3184 | the two sets of lengths. | |
3185 | */ | |
3186 | ||
3187 | ||
3188 | local void inflate_blocks_reset(s, z, c) | |
3189 | inflate_blocks_statef *s; | |
3190 | z_stream *z; | |
3191 | uLongf *c; | |
3192 | { | |
3193 | if (s->checkfn != Z_NULL) | |
3194 | *c = s->check; | |
3195 | if (s->mode == BTREE || s->mode == DTREE) | |
3196 | ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt)); | |
3197 | if (s->mode == CODES) | |
3198 | { | |
3199 | inflate_codes_free(s->sub.decode.codes, z); | |
3200 | inflate_trees_free(s->sub.decode.td, z); | |
3201 | inflate_trees_free(s->sub.decode.tl, z); | |
3202 | } | |
3203 | s->mode = TYPE; | |
3204 | s->bitk = 0; | |
3205 | s->bitb = 0; | |
3206 | s->read = s->write = s->window; | |
3207 | if (s->checkfn != Z_NULL) | |
3208 | s->check = (*s->checkfn)(0L, Z_NULL, 0); | |
3209 | Trace((stderr, "inflate: blocks reset\n")); | |
3210 | } | |
3211 | ||
3212 | ||
3213 | local inflate_blocks_statef *inflate_blocks_new(z, c, w) | |
3214 | z_stream *z; | |
3215 | check_func c; | |
3216 | uInt w; | |
3217 | { | |
3218 | inflate_blocks_statef *s; | |
3219 | ||
3220 | if ((s = (inflate_blocks_statef *)ZALLOC | |
3221 | (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) | |
3222 | return s; | |
3223 | if ((s->window = (Bytef *)ZALLOC(z, 1, w)) == Z_NULL) | |
3224 | { | |
3225 | ZFREE(z, s, sizeof(struct inflate_blocks_state)); | |
3226 | return Z_NULL; | |
3227 | } | |
3228 | s->end = s->window + w; | |
3229 | s->checkfn = c; | |
3230 | s->mode = TYPE; | |
3231 | Trace((stderr, "inflate: blocks allocated\n")); | |
3232 | inflate_blocks_reset(s, z, &s->check); | |
3233 | return s; | |
3234 | } | |
3235 | ||
3236 | ||
3237 | local int inflate_blocks(s, z, r) | |
3238 | inflate_blocks_statef *s; | |
3239 | z_stream *z; | |
3240 | int r; | |
3241 | { | |
3242 | uInt t; /* temporary storage */ | |
3243 | uLong b; /* bit buffer */ | |
3244 | uInt k; /* bits in bit buffer */ | |
3245 | Bytef *p; /* input data pointer */ | |
3246 | uInt n; /* bytes available there */ | |
3247 | Bytef *q; /* output window write pointer */ | |
3248 | uInt m; /* bytes to end of window or read pointer */ | |
3249 | ||
3250 | /* copy input/output information to locals (UPDATE macro restores) */ | |
3251 | LOAD | |
3252 | ||
3253 | /* process input based on current state */ | |
3254 | while (1) switch (s->mode) | |
3255 | { | |
3256 | case TYPE: | |
3257 | NEEDBITS(3) | |
3258 | t = (uInt)b & 7; | |
3259 | s->last = t & 1; | |
3260 | switch (t >> 1) | |
3261 | { | |
3262 | case 0: /* stored */ | |
3263 | Trace((stderr, "inflate: stored block%s\n", | |
3264 | s->last ? " (last)" : "")); | |
3265 | DUMPBITS(3) | |
3266 | t = k & 7; /* go to byte boundary */ | |
3267 | DUMPBITS(t) | |
3268 | s->mode = LENS; /* get length of stored block */ | |
3269 | break; | |
3270 | case 1: /* fixed */ | |
3271 | Trace((stderr, "inflate: fixed codes block%s\n", | |
3272 | s->last ? " (last)" : "")); | |
3273 | { | |
3274 | uInt bl, bd; | |
3275 | inflate_huft *tl, *td; | |
3276 | ||
3277 | inflate_trees_fixed(&bl, &bd, &tl, &td); | |
3278 | s->sub.decode.codes = inflate_codes_new(bl, bd, tl, td, z); | |
3279 | if (s->sub.decode.codes == Z_NULL) | |
3280 | { | |
3281 | r = Z_MEM_ERROR; | |
3282 | LEAVE | |
3283 | } | |
3284 | s->sub.decode.tl = Z_NULL; /* don't try to free these */ | |
3285 | s->sub.decode.td = Z_NULL; | |
3286 | } | |
3287 | DUMPBITS(3) | |
3288 | s->mode = CODES; | |
3289 | break; | |
3290 | case 2: /* dynamic */ | |
3291 | Trace((stderr, "inflate: dynamic codes block%s\n", | |
3292 | s->last ? " (last)" : "")); | |
3293 | DUMPBITS(3) | |
3294 | s->mode = TABLE; | |
3295 | break; | |
3296 | case 3: /* illegal */ | |
3297 | DUMPBITS(3) | |
3298 | s->mode = BADB; | |
3299 | z->msg = "invalid block type"; | |
3300 | r = Z_DATA_ERROR; | |
3301 | LEAVE | |
3302 | } | |
3303 | break; | |
3304 | case LENS: | |
3305 | NEEDBITS(32) | |
3306 | if (((~b) >> 16) != (b & 0xffff)) | |
3307 | { | |
3308 | s->mode = BADB; | |
3309 | z->msg = "invalid stored block lengths"; | |
3310 | r = Z_DATA_ERROR; | |
3311 | LEAVE | |
3312 | } | |
3313 | s->sub.left = (uInt)b & 0xffff; | |
3314 | b = k = 0; /* dump bits */ | |
3315 | Tracev((stderr, "inflate: stored length %u\n", s->sub.left)); | |
3316 | s->mode = s->sub.left ? STORED : TYPE; | |
3317 | break; | |
3318 | case STORED: | |
3319 | if (n == 0) | |
3320 | LEAVE | |
3321 | NEEDOUT | |
3322 | t = s->sub.left; | |
3323 | if (t > n) t = n; | |
3324 | if (t > m) t = m; | |
3325 | zmemcpy(q, p, t); | |
3326 | p += t; n -= t; | |
3327 | q += t; m -= t; | |
3328 | if ((s->sub.left -= t) != 0) | |
3329 | break; | |
3330 | Tracev((stderr, "inflate: stored end, %lu total out\n", | |
3331 | z->total_out + (q >= s->read ? q - s->read : | |
3332 | (s->end - s->read) + (q - s->window)))); | |
3333 | s->mode = s->last ? DRY : TYPE; | |
3334 | break; | |
3335 | case TABLE: | |
3336 | NEEDBITS(14) | |
3337 | s->sub.trees.table = t = (uInt)b & 0x3fff; | |
3338 | #ifndef PKZIP_BUG_WORKAROUND | |
3339 | if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) | |
3340 | { | |
3341 | s->mode = BADB; | |
3342 | z->msg = "too many length or distance symbols"; | |
3343 | r = Z_DATA_ERROR; | |
3344 | LEAVE | |
3345 | } | |
3346 | #endif | |
3347 | t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); | |
3348 | if (t < 19) | |
3349 | t = 19; | |
3350 | if ((s->sub.trees.blens = (uIntf*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) | |
3351 | { | |
3352 | r = Z_MEM_ERROR; | |
3353 | LEAVE | |
3354 | } | |
3355 | s->sub.trees.nblens = t; | |
3356 | DUMPBITS(14) | |
3357 | s->sub.trees.index = 0; | |
3358 | Tracev((stderr, "inflate: table sizes ok\n")); | |
3359 | s->mode = BTREE; | |
3360 | case BTREE: | |
3361 | while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) | |
3362 | { | |
3363 | NEEDBITS(3) | |
3364 | s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; | |
3365 | DUMPBITS(3) | |
3366 | } | |
3367 | while (s->sub.trees.index < 19) | |
3368 | s->sub.trees.blens[border[s->sub.trees.index++]] = 0; | |
3369 | s->sub.trees.bb = 7; | |
3370 | t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, | |
3371 | &s->sub.trees.tb, z); | |
3372 | if (t != Z_OK) | |
3373 | { | |
3374 | r = t; | |
3375 | if (r == Z_DATA_ERROR) | |
3376 | s->mode = BADB; | |
3377 | LEAVE | |
3378 | } | |
3379 | s->sub.trees.index = 0; | |
3380 | Tracev((stderr, "inflate: bits tree ok\n")); | |
3381 | s->mode = DTREE; | |
3382 | case DTREE: | |
3383 | while (t = s->sub.trees.table, | |
3384 | s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) | |
3385 | { | |
3386 | inflate_huft *h; | |
3387 | uInt i, j, c; | |
3388 | ||
3389 | t = s->sub.trees.bb; | |
3390 | NEEDBITS(t) | |
3391 | h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); | |
3392 | t = h->word.what.Bits; | |
3393 | c = h->more.Base; | |
3394 | if (c < 16) | |
3395 | { | |
3396 | DUMPBITS(t) | |
3397 | s->sub.trees.blens[s->sub.trees.index++] = c; | |
3398 | } | |
3399 | else /* c == 16..18 */ | |
3400 | { | |
3401 | i = c == 18 ? 7 : c - 14; | |
3402 | j = c == 18 ? 11 : 3; | |
3403 | NEEDBITS(t + i) | |
3404 | DUMPBITS(t) | |
3405 | j += (uInt)b & inflate_mask[i]; | |
3406 | DUMPBITS(i) | |
3407 | i = s->sub.trees.index; | |
3408 | t = s->sub.trees.table; | |
3409 | if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || | |
3410 | (c == 16 && i < 1)) | |
3411 | { | |
3412 | s->mode = BADB; | |
3413 | z->msg = "invalid bit length repeat"; | |
3414 | r = Z_DATA_ERROR; | |
3415 | LEAVE | |
3416 | } | |
3417 | c = c == 16 ? s->sub.trees.blens[i - 1] : 0; | |
3418 | do { | |
3419 | s->sub.trees.blens[i++] = c; | |
3420 | } while (--j); | |
3421 | s->sub.trees.index = i; | |
3422 | } | |
3423 | } | |
3424 | inflate_trees_free(s->sub.trees.tb, z); | |
3425 | s->sub.trees.tb = Z_NULL; | |
3426 | { | |
3427 | uInt bl, bd; | |
3428 | inflate_huft *tl, *td; | |
3429 | inflate_codes_statef *c; | |
3430 | ||
3431 | bl = 9; /* must be <= 9 for lookahead assumptions */ | |
3432 | bd = 6; /* must be <= 9 for lookahead assumptions */ | |
3433 | t = s->sub.trees.table; | |
3434 | t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), | |
3435 | s->sub.trees.blens, &bl, &bd, &tl, &td, z); | |
3436 | if (t != Z_OK) | |
3437 | { | |
3438 | if (t == (uInt)Z_DATA_ERROR) | |
3439 | s->mode = BADB; | |
3440 | r = t; | |
3441 | LEAVE | |
3442 | } | |
3443 | Tracev((stderr, "inflate: trees ok\n")); | |
3444 | if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) | |
3445 | { | |
3446 | inflate_trees_free(td, z); | |
3447 | inflate_trees_free(tl, z); | |
3448 | r = Z_MEM_ERROR; | |
3449 | LEAVE | |
3450 | } | |
3451 | ZFREE(z, s->sub.trees.blens, s->sub.trees.nblens * sizeof(uInt)); | |
3452 | s->sub.decode.codes = c; | |
3453 | s->sub.decode.tl = tl; | |
3454 | s->sub.decode.td = td; | |
3455 | } | |
3456 | s->mode = CODES; | |
3457 | case CODES: | |
3458 | UPDATE | |
3459 | if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) | |
3460 | return inflate_flush(s, z, r); | |
3461 | r = Z_OK; | |
3462 | inflate_codes_free(s->sub.decode.codes, z); | |
3463 | inflate_trees_free(s->sub.decode.td, z); | |
3464 | inflate_trees_free(s->sub.decode.tl, z); | |
3465 | LOAD | |
3466 | Tracev((stderr, "inflate: codes end, %lu total out\n", | |
3467 | z->total_out + (q >= s->read ? q - s->read : | |
3468 | (s->end - s->read) + (q - s->window)))); | |
3469 | if (!s->last) | |
3470 | { | |
3471 | s->mode = TYPE; | |
3472 | break; | |
3473 | } | |
3474 | if (k > 7) /* return unused byte, if any */ | |
3475 | { | |
3476 | Assert(k < 16, "inflate_codes grabbed too many bytes") | |
3477 | k -= 8; | |
3478 | n++; | |
3479 | p--; /* can always return one */ | |
3480 | } | |
3481 | s->mode = DRY; | |
3482 | case DRY: | |
3483 | FLUSH | |
3484 | if (s->read != s->write) | |
3485 | LEAVE | |
3486 | s->mode = DONEB; | |
3487 | case DONEB: | |
3488 | r = Z_STREAM_END; | |
3489 | LEAVE | |
3490 | case BADB: | |
3491 | r = Z_DATA_ERROR; | |
3492 | LEAVE | |
3493 | default: | |
3494 | r = Z_STREAM_ERROR; | |
3495 | LEAVE | |
3496 | } | |
3497 | } | |
3498 | ||
3499 | ||
3500 | local int inflate_blocks_free(s, z, c) | |
3501 | inflate_blocks_statef *s; | |
3502 | z_stream *z; | |
3503 | uLongf *c; | |
3504 | { | |
3505 | inflate_blocks_reset(s, z, c); | |
3506 | ZFREE(z, s->window, s->end - s->window); | |
3507 | ZFREE(z, s, sizeof(struct inflate_blocks_state)); | |
3508 | Trace((stderr, "inflate: blocks freed\n")); | |
3509 | return Z_OK; | |
3510 | } | |
3511 | ||
3512 | /* | |
3513 | * This subroutine adds the data at next_in/avail_in to the output history | |
3514 | * without performing any output. The output buffer must be "caught up"; | |
3515 | * i.e. no pending output (hence s->read equals s->write), and the state must | |
3516 | * be BLOCKS (i.e. we should be willing to see the start of a series of | |
3517 | * BLOCKS). On exit, the output will also be caught up, and the checksum | |
3518 | * will have been updated if need be. | |
3519 | */ | |
3520 | local int inflate_addhistory(s, z) | |
3521 | inflate_blocks_statef *s; | |
3522 | z_stream *z; | |
3523 | { | |
3524 | uLong b; /* bit buffer */ /* NOT USED HERE */ | |
3525 | uInt k; /* bits in bit buffer */ /* NOT USED HERE */ | |
3526 | uInt t; /* temporary storage */ | |
3527 | Bytef *p; /* input data pointer */ | |
3528 | uInt n; /* bytes available there */ | |
3529 | Bytef *q; /* output window write pointer */ | |
3530 | uInt m; /* bytes to end of window or read pointer */ | |
3531 | ||
3532 | if (s->read != s->write) | |
3533 | return Z_STREAM_ERROR; | |
3534 | if (s->mode != TYPE) | |
3535 | return Z_DATA_ERROR; | |
3536 | ||
3537 | /* we're ready to rock */ | |
3538 | LOAD | |
3539 | /* while there is input ready, copy to output buffer, moving | |
3540 | * pointers as needed. | |
3541 | */ | |
3542 | while (n) { | |
3543 | t = n; /* how many to do */ | |
3544 | /* is there room until end of buffer? */ | |
3545 | if (t > m) t = m; | |
3546 | /* update check information */ | |
3547 | if (s->checkfn != Z_NULL) | |
3548 | s->check = (*s->checkfn)(s->check, q, t); | |
3549 | zmemcpy(q, p, t); | |
3550 | q += t; | |
3551 | p += t; | |
3552 | n -= t; | |
3553 | z->total_out += t; | |
3554 | s->read = q; /* drag read pointer forward */ | |
3555 | /* WRAP */ /* expand WRAP macro by hand to handle s->read */ | |
3556 | if (q == s->end) { | |
3557 | s->read = q = s->window; | |
3558 | m = WAVAIL; | |
3559 | } | |
3560 | } | |
3561 | UPDATE | |
3562 | return Z_OK; | |
3563 | } | |
3564 | ||
3565 | ||
3566 | /* | |
3567 | * At the end of a Deflate-compressed PPP packet, we expect to have seen | |
3568 | * a `stored' block type value but not the (zero) length bytes. | |
3569 | */ | |
3570 | local int inflate_packet_flush(s) | |
3571 | inflate_blocks_statef *s; | |
3572 | { | |
3573 | if (s->mode != LENS) | |
3574 | return Z_DATA_ERROR; | |
3575 | s->mode = TYPE; | |
3576 | return Z_OK; | |
3577 | } | |
3578 | ||
3579 | ||
3580 | /*+++++*/ | |
3581 | /* inftrees.c -- generate Huffman trees for efficient decoding | |
3582 | * Copyright (C) 1995 Mark Adler | |
3583 | * For conditions of distribution and use, see copyright notice in zlib.h | |
3584 | */ | |
3585 | ||
3586 | /* simplify the use of the inflate_huft type with some defines */ | |
3587 | #define base more.Base | |
3588 | #define next more.Next | |
3589 | #define exop word.what.Exop | |
3590 | #define bits word.what.Bits | |
3591 | ||
3592 | ||
3593 | local int huft_build OF(( | |
3594 | uIntf *, /* code lengths in bits */ | |
3595 | uInt, /* number of codes */ | |
3596 | uInt, /* number of "simple" codes */ | |
3597 | uIntf *, /* list of base values for non-simple codes */ | |
3598 | uIntf *, /* list of extra bits for non-simple codes */ | |
3599 | inflate_huft * FAR*,/* result: starting table */ | |
3600 | uIntf *, /* maximum lookup bits (returns actual) */ | |
3601 | z_stream *)); /* for zalloc function */ | |
3602 | ||
3603 | local voidpf falloc OF(( | |
3604 | voidpf, /* opaque pointer (not used) */ | |
3605 | uInt, /* number of items */ | |
3606 | uInt)); /* size of item */ | |
3607 | ||
3608 | local void ffree OF(( | |
3609 | voidpf q, /* opaque pointer (not used) */ | |
3610 | voidpf p, /* what to free (not used) */ | |
3611 | uInt n)); /* number of bytes (not used) */ | |
3612 | ||
3613 | /* Tables for deflate from PKZIP's appnote.txt. */ | |
3614 | local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */ | |
3615 | 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, | |
3616 | 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; | |
3617 | /* actually lengths - 2; also see note #13 above about 258 */ | |
3618 | local uInt cplext[] = { /* Extra bits for literal codes 257..285 */ | |
3619 | 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, | |
3620 | 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 192, 192}; /* 192==invalid */ | |
3621 | local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */ | |
3622 | 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, | |
3623 | 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, | |
3624 | 8193, 12289, 16385, 24577}; | |
3625 | local uInt cpdext[] = { /* Extra bits for distance codes */ | |
3626 | 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, | |
3627 | 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, | |
3628 | 12, 12, 13, 13}; | |
3629 | ||
3630 | /* | |
3631 | Huffman code decoding is performed using a multi-level table lookup. | |
3632 | The fastest way to decode is to simply build a lookup table whose | |
3633 | size is determined by the longest code. However, the time it takes | |
3634 | to build this table can also be a factor if the data being decoded | |
3635 | is not very long. The most common codes are necessarily the | |
3636 | shortest codes, so those codes dominate the decoding time, and hence | |
3637 | the speed. The idea is you can have a shorter table that decodes the | |
3638 | shorter, more probable codes, and then point to subsidiary tables for | |
3639 | the longer codes. The time it costs to decode the longer codes is | |
3640 | then traded against the time it takes to make longer tables. | |
3641 | ||
3642 | This results of this trade are in the variables lbits and dbits | |
3643 | below. lbits is the number of bits the first level table for literal/ | |
3644 | length codes can decode in one step, and dbits is the same thing for | |
3645 | the distance codes. Subsequent tables are also less than or equal to | |
3646 | those sizes. These values may be adjusted either when all of the | |
3647 | codes are shorter than that, in which case the longest code length in | |
3648 | bits is used, or when the shortest code is *longer* than the requested | |
3649 | table size, in which case the length of the shortest code in bits is | |
3650 | used. | |
3651 | ||
3652 | There are two different values for the two tables, since they code a | |
3653 | different number of possibilities each. The literal/length table | |
3654 | codes 286 possible values, or in a flat code, a little over eight | |
3655 | bits. The distance table codes 30 possible values, or a little less | |
3656 | than five bits, flat. The optimum values for speed end up being | |
3657 | about one bit more than those, so lbits is 8+1 and dbits is 5+1. | |
3658 | The optimum values may differ though from machine to machine, and | |
3659 | possibly even between compilers. Your mileage may vary. | |
3660 | */ | |
3661 | ||
3662 | ||
3663 | /* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ | |
3664 | #define BMAX 15 /* maximum bit length of any code */ | |
3665 | #define N_MAX 288 /* maximum number of codes in any set */ | |
3666 | ||
3667 | #ifdef DEBUG_ZLIB | |
3668 | uInt inflate_hufts; | |
3669 | #endif | |
3670 | ||
3671 | local int huft_build(b, n, s, d, e, t, m, zs) | |
3672 | uIntf *b; /* code lengths in bits (all assumed <= BMAX) */ | |
3673 | uInt n; /* number of codes (assumed <= N_MAX) */ | |
3674 | uInt s; /* number of simple-valued codes (0..s-1) */ | |
3675 | uIntf *d; /* list of base values for non-simple codes */ | |
3676 | uIntf *e; /* list of extra bits for non-simple codes */ | |
3677 | inflate_huft * FAR *t; /* result: starting table */ | |
3678 | uIntf *m; /* maximum lookup bits, returns actual */ | |
3679 | z_stream *zs; /* for zalloc function */ | |
3680 | /* Given a list of code lengths and a maximum table size, make a set of | |
3681 | tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR | |
3682 | if the given code set is incomplete (the tables are still built in this | |
3683 | case), Z_DATA_ERROR if the input is invalid (all zero length codes or an | |
3684 | over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */ | |
3685 | { | |
3686 | ||
3687 | uInt a; /* counter for codes of length k */ | |
3688 | uInt c[BMAX+1]; /* bit length count table */ | |
3689 | uInt f; /* i repeats in table every f entries */ | |
3690 | int g; /* maximum code length */ | |
3691 | int h; /* table level */ | |
3692 | register uInt i; /* counter, current code */ | |
3693 | register uInt j; /* counter */ | |
3694 | register int k; /* number of bits in current code */ | |
3695 | int l; /* bits per table (returned in m) */ | |
3696 | register uIntf *p; /* pointer into c[], b[], or v[] */ | |
3697 | inflate_huft *q; /* points to current table */ | |
3698 | struct inflate_huft_s r; /* table entry for structure assignment */ | |
3699 | inflate_huft *u[BMAX]; /* table stack */ | |
3700 | uInt v[N_MAX]; /* values in order of bit length */ | |
3701 | register int w; /* bits before this table == (l * h) */ | |
3702 | uInt x[BMAX+1]; /* bit offsets, then code stack */ | |
3703 | uIntf *xp; /* pointer into x */ | |
3704 | int y; /* number of dummy codes added */ | |
3705 | uInt z; /* number of entries in current table */ | |
3706 | ||
3707 | ||
3708 | /* Generate counts for each bit length */ | |
3709 | p = c; | |
3710 | #define C0 *p++ = 0; | |
3711 | #define C2 C0 C0 C0 C0 | |
3712 | #define C4 C2 C2 C2 C2 | |
3713 | C4 /* clear c[]--assume BMAX+1 is 16 */ | |
3714 | p = b; i = n; | |
3715 | do { | |
3716 | c[*p++]++; /* assume all entries <= BMAX */ | |
3717 | } while (--i); | |
3718 | if (c[0] == n) /* null input--all zero length codes */ | |
3719 | { | |
3720 | *t = (inflate_huft *)Z_NULL; | |
3721 | *m = 0; | |
3722 | return Z_OK; | |
3723 | } | |
3724 | ||
3725 | ||
3726 | /* Find minimum and maximum length, bound *m by those */ | |
3727 | l = *m; | |
3728 | for (j = 1; j <= BMAX; j++) | |
3729 | if (c[j]) | |
3730 | break; | |
3731 | k = j; /* minimum code length */ | |
3732 | if ((uInt)l < j) | |
3733 | l = j; | |
3734 | for (i = BMAX; i; i--) | |
3735 | if (c[i]) | |
3736 | break; | |
3737 | g = i; /* maximum code length */ | |
3738 | if ((uInt)l > i) | |
3739 | l = i; | |
3740 | *m = l; | |
3741 | ||
3742 | ||
3743 | /* Adjust last length count to fill out codes, if needed */ | |
3744 | for (y = 1 << j; j < i; j++, y <<= 1) | |
3745 | if ((y -= c[j]) < 0) | |
3746 | return Z_DATA_ERROR; | |
3747 | if ((y -= c[i]) < 0) | |
3748 | return Z_DATA_ERROR; | |
3749 | c[i] += y; | |
3750 | ||
3751 | ||
3752 | /* Generate starting offsets into the value table for each length */ | |
3753 | x[1] = j = 0; | |
3754 | p = c + 1; xp = x + 2; | |
3755 | while (--i) { /* note that i == g from above */ | |
3756 | *xp++ = (j += *p++); | |
3757 | } | |
3758 | ||
3759 | ||
3760 | /* Make a table of values in order of bit lengths */ | |
3761 | p = b; i = 0; | |
3762 | do { | |
3763 | if ((j = *p++) != 0) | |
3764 | v[x[j]++] = i; | |
3765 | } while (++i < n); | |
3766 | ||
3767 | ||
3768 | /* Generate the Huffman codes and for each, make the table entries */ | |
3769 | x[0] = i = 0; /* first Huffman code is zero */ | |
3770 | p = v; /* grab values in bit order */ | |
3771 | h = -1; /* no tables yet--level -1 */ | |
3772 | w = -l; /* bits decoded == (l * h) */ | |
3773 | u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ | |
3774 | q = (inflate_huft *)Z_NULL; /* ditto */ | |
3775 | z = 0; /* ditto */ | |
3776 | ||
3777 | /* go through the bit lengths (k already is bits in shortest code) */ | |
3778 | for (; k <= g; k++) | |
3779 | { | |
3780 | a = c[k]; | |
3781 | while (a--) | |
3782 | { | |
3783 | /* here i is the Huffman code of length k bits for value *p */ | |
3784 | /* make tables up to required level */ | |
3785 | while (k > w + l) | |
3786 | { | |
3787 | h++; | |
3788 | w += l; /* previous table always l bits */ | |
3789 | ||
3790 | /* compute minimum size table less than or equal to l bits */ | |
3791 | z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */ | |
3792 | if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ | |
3793 | { /* too few codes for k-w bit table */ | |
3794 | f -= a + 1; /* deduct codes from patterns left */ | |
3795 | xp = c + k; | |
3796 | if (j < z) | |
3797 | while (++j < z) /* try smaller tables up to z bits */ | |
3798 | { | |
3799 | if ((f <<= 1) <= *++xp) | |
3800 | break; /* enough codes to use up j bits */ | |
3801 | f -= *xp; /* else deduct codes from patterns */ | |
3802 | } | |
3803 | } | |
3804 | z = 1 << j; /* table entries for j-bit table */ | |
3805 | ||
3806 | /* allocate and link in new table */ | |
3807 | if ((q = (inflate_huft *)ZALLOC | |
3808 | (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) | |
3809 | { | |
3810 | if (h) | |
3811 | inflate_trees_free(u[0], zs); | |
3812 | return Z_MEM_ERROR; /* not enough memory */ | |
3813 | } | |
3814 | q->word.Nalloc = z + 1; | |
3815 | #ifdef DEBUG_ZLIB | |
3816 | inflate_hufts += z + 1; | |
3817 | #endif | |
3818 | *t = q + 1; /* link to list for huft_free() */ | |
3819 | *(t = &(q->next)) = Z_NULL; | |
3820 | u[h] = ++q; /* table starts after link */ | |
3821 | ||
3822 | /* connect to last table, if there is one */ | |
3823 | if (h) | |
3824 | { | |
3825 | x[h] = i; /* save pattern for backing up */ | |
3826 | r.bits = (Byte)l; /* bits to dump before this table */ | |
3827 | r.exop = (Byte)j; /* bits in this table */ | |
3828 | r.next = q; /* pointer to this table */ | |
3829 | j = i >> (w - l); /* (get around Turbo C bug) */ | |
3830 | u[h-1][j] = r; /* connect to last table */ | |
3831 | } | |
3832 | } | |
3833 | ||
3834 | /* set up table entry in r */ | |
3835 | r.bits = (Byte)(k - w); | |
3836 | if (p >= v + n) | |
3837 | r.exop = 128 + 64; /* out of values--invalid code */ | |
3838 | else if (*p < s) | |
3839 | { | |
3840 | r.exop = (Byte)(*p < 256 ? 0 : 32 + 64); /* 256 is end-of-block */ | |
3841 | r.base = *p++; /* simple code is just the value */ | |
3842 | } | |
3843 | else | |
3844 | { | |
3845 | r.exop = (Byte)e[*p - s] + 16 + 64; /* non-simple--look up in lists */ | |
3846 | r.base = d[*p++ - s]; | |
3847 | } | |
3848 | ||
3849 | /* fill code-like entries with r */ | |
3850 | f = 1 << (k - w); | |
3851 | for (j = i >> w; j < z; j += f) | |
3852 | q[j] = r; | |
3853 | ||
3854 | /* backwards increment the k-bit code i */ | |
3855 | for (j = 1 << (k - 1); i & j; j >>= 1) | |
3856 | i ^= j; | |
3857 | i ^= j; | |
3858 | ||
3859 | /* backup over finished tables */ | |
3860 | while ((i & ((1 << w) - 1)) != x[h]) | |
3861 | { | |
3862 | h--; /* don't need to update q */ | |
3863 | w -= l; | |
3864 | } | |
3865 | } | |
3866 | } | |
3867 | ||
3868 | ||
3869 | /* Return Z_BUF_ERROR if we were given an incomplete table */ | |
3870 | return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; | |
3871 | } | |
3872 | ||
3873 | ||
3874 | local int inflate_trees_bits(c, bb, tb, z) | |
3875 | uIntf *c; /* 19 code lengths */ | |
3876 | uIntf *bb; /* bits tree desired/actual depth */ | |
3877 | inflate_huft * FAR *tb; /* bits tree result */ | |
3878 | z_stream *z; /* for zfree function */ | |
3879 | { | |
3880 | int r; | |
3881 | ||
3882 | r = huft_build(c, 19, 19, (uIntf*)Z_NULL, (uIntf*)Z_NULL, tb, bb, z); | |
3883 | if (r == Z_DATA_ERROR) | |
3884 | z->msg = "oversubscribed dynamic bit lengths tree"; | |
3885 | else if (r == Z_BUF_ERROR) | |
3886 | { | |
3887 | inflate_trees_free(*tb, z); | |
3888 | z->msg = "incomplete dynamic bit lengths tree"; | |
3889 | r = Z_DATA_ERROR; | |
3890 | } | |
3891 | return r; | |
3892 | } | |
3893 | ||
3894 | ||
3895 | local int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) | |
3896 | uInt nl; /* number of literal/length codes */ | |
3897 | uInt nd; /* number of distance codes */ | |
3898 | uIntf *c; /* that many (total) code lengths */ | |
3899 | uIntf *bl; /* literal desired/actual bit depth */ | |
3900 | uIntf *bd; /* distance desired/actual bit depth */ | |
3901 | inflate_huft * FAR *tl; /* literal/length tree result */ | |
3902 | inflate_huft * FAR *td; /* distance tree result */ | |
3903 | z_stream *z; /* for zfree function */ | |
3904 | { | |
3905 | int r; | |
3906 | ||
3907 | /* build literal/length tree */ | |
3908 | if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK) | |
3909 | { | |
3910 | if (r == Z_DATA_ERROR) | |
3911 | z->msg = "oversubscribed literal/length tree"; | |
3912 | else if (r == Z_BUF_ERROR) | |
3913 | { | |
3914 | inflate_trees_free(*tl, z); | |
3915 | z->msg = "incomplete literal/length tree"; | |
3916 | r = Z_DATA_ERROR; | |
3917 | } | |
3918 | return r; | |
3919 | } | |
3920 | ||
3921 | /* build distance tree */ | |
3922 | if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK) | |
3923 | { | |
3924 | if (r == Z_DATA_ERROR) | |
3925 | z->msg = "oversubscribed literal/length tree"; | |
3926 | else if (r == Z_BUF_ERROR) { | |
3927 | #ifdef PKZIP_BUG_WORKAROUND | |
3928 | r = Z_OK; | |
3929 | } | |
3930 | #else | |
3931 | inflate_trees_free(*td, z); | |
3932 | z->msg = "incomplete literal/length tree"; | |
3933 | r = Z_DATA_ERROR; | |
3934 | } | |
3935 | inflate_trees_free(*tl, z); | |
3936 | return r; | |
3937 | #endif | |
3938 | } | |
3939 | ||
3940 | /* done */ | |
3941 | return Z_OK; | |
3942 | } | |
3943 | ||
3944 | ||
3945 | /* build fixed tables only once--keep them here */ | |
774ef68f PM |
3946 | #ifdef MULTI_THREADED |
3947 | local volatile int fixed_lock = 0; | |
3948 | #endif | |
861c20b4 PM |
3949 | local int fixed_built = 0; |
3950 | #define FIXEDH 530 /* number of hufts used by fixed tables */ | |
3951 | local uInt fixed_left = FIXEDH; | |
3952 | local inflate_huft fixed_mem[FIXEDH]; | |
3953 | local uInt fixed_bl; | |
3954 | local uInt fixed_bd; | |
3955 | local inflate_huft *fixed_tl; | |
3956 | local inflate_huft *fixed_td; | |
3957 | ||
3958 | ||
3959 | local voidpf falloc(q, n, s) | |
3960 | voidpf q; /* opaque pointer (not used) */ | |
3961 | uInt n; /* number of items */ | |
3962 | uInt s; /* size of item */ | |
3963 | { | |
3964 | Assert(s == sizeof(inflate_huft) && n <= fixed_left, | |
3965 | "inflate_trees falloc overflow"); | |
3966 | if (q) s++; /* to make some compilers happy */ | |
3967 | fixed_left -= n; | |
3968 | return (voidpf)(fixed_mem + fixed_left); | |
3969 | } | |
3970 | ||
3971 | ||
3972 | local void ffree(q, p, n) | |
3973 | voidpf q; | |
3974 | voidpf p; | |
3975 | uInt n; | |
3976 | { | |
3977 | Assert(0, "inflate_trees ffree called!"); | |
3978 | if (q) q = p; /* to make some compilers happy */ | |
3979 | } | |
3980 | ||
3981 | ||
3982 | local int inflate_trees_fixed(bl, bd, tl, td) | |
3983 | uIntf *bl; /* literal desired/actual bit depth */ | |
3984 | uIntf *bd; /* distance desired/actual bit depth */ | |
3985 | inflate_huft * FAR *tl; /* literal/length tree result */ | |
3986 | inflate_huft * FAR *td; /* distance tree result */ | |
3987 | { | |
3988 | /* build fixed tables if not built already--lock out other instances */ | |
774ef68f | 3989 | #ifdef MULTI_THREADED |
861c20b4 PM |
3990 | while (++fixed_lock > 1) |
3991 | fixed_lock--; | |
774ef68f | 3992 | #endif |
861c20b4 PM |
3993 | if (!fixed_built) |
3994 | { | |
3995 | int k; /* temporary variable */ | |
3996 | unsigned c[288]; /* length list for huft_build */ | |
3997 | z_stream z; /* for falloc function */ | |
3998 | ||
3999 | /* set up fake z_stream for memory routines */ | |
4000 | z.zalloc = falloc; | |
4001 | z.zfree = ffree; | |
4002 | z.opaque = Z_NULL; | |
4003 | ||
4004 | /* literal table */ | |
4005 | for (k = 0; k < 144; k++) | |
4006 | c[k] = 8; | |
4007 | for (; k < 256; k++) | |
4008 | c[k] = 9; | |
4009 | for (; k < 280; k++) | |
4010 | c[k] = 7; | |
4011 | for (; k < 288; k++) | |
4012 | c[k] = 8; | |
4013 | fixed_bl = 7; | |
4014 | huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); | |
4015 | ||
4016 | /* distance table */ | |
4017 | for (k = 0; k < 30; k++) | |
4018 | c[k] = 5; | |
4019 | fixed_bd = 5; | |
4020 | huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); | |
4021 | ||
4022 | /* done */ | |
4023 | fixed_built = 1; | |
4024 | } | |
774ef68f | 4025 | #ifdef MULTI_THREADED |
861c20b4 | 4026 | fixed_lock--; |
774ef68f | 4027 | #endif |
861c20b4 PM |
4028 | *bl = fixed_bl; |
4029 | *bd = fixed_bd; | |
4030 | *tl = fixed_tl; | |
4031 | *td = fixed_td; | |
4032 | return Z_OK; | |
4033 | } | |
4034 | ||
4035 | ||
4036 | local int inflate_trees_free(t, z) | |
4037 | inflate_huft *t; /* table to free */ | |
4038 | z_stream *z; /* for zfree function */ | |
4039 | /* Free the malloc'ed tables built by huft_build(), which makes a linked | |
4040 | list of the tables it made, with the links in a dummy first entry of | |
4041 | each table. */ | |
4042 | { | |
4043 | register inflate_huft *p, *q; | |
4044 | ||
4045 | /* Go through linked list, freeing from the malloced (t[-1]) address. */ | |
4046 | p = t; | |
4047 | while (p != Z_NULL) | |
4048 | { | |
4049 | q = (--p)->next; | |
4050 | ZFREE(z, p, p->word.Nalloc * sizeof(inflate_huft)); | |
4051 | p = q; | |
4052 | } | |
4053 | return Z_OK; | |
4054 | } | |
4055 | ||
4056 | /*+++++*/ | |
4057 | /* infcodes.c -- process literals and length/distance pairs | |
4058 | * Copyright (C) 1995 Mark Adler | |
4059 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4060 | */ | |
4061 | ||
4062 | /* simplify the use of the inflate_huft type with some defines */ | |
4063 | #define base more.Base | |
4064 | #define next more.Next | |
4065 | #define exop word.what.Exop | |
4066 | #define bits word.what.Bits | |
4067 | ||
4068 | /* inflate codes private state */ | |
4069 | struct inflate_codes_state { | |
4070 | ||
4071 | /* mode */ | |
4072 | enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ | |
4073 | START, /* x: set up for LEN */ | |
4074 | LEN, /* i: get length/literal/eob next */ | |
4075 | LENEXT, /* i: getting length extra (have base) */ | |
4076 | DIST, /* i: get distance next */ | |
4077 | DISTEXT, /* i: getting distance extra */ | |
4078 | COPY, /* o: copying bytes in window, waiting for space */ | |
4079 | LIT, /* o: got literal, waiting for output space */ | |
4080 | WASH, /* o: got eob, possibly still output waiting */ | |
4081 | END, /* x: got eob and all data flushed */ | |
4082 | BADCODE} /* x: got error */ | |
4083 | mode; /* current inflate_codes mode */ | |
4084 | ||
4085 | /* mode dependent information */ | |
4086 | uInt len; | |
4087 | union { | |
4088 | struct { | |
4089 | inflate_huft *tree; /* pointer into tree */ | |
4090 | uInt need; /* bits needed */ | |
4091 | } code; /* if LEN or DIST, where in tree */ | |
4092 | uInt lit; /* if LIT, literal */ | |
4093 | struct { | |
4094 | uInt get; /* bits to get for extra */ | |
4095 | uInt dist; /* distance back to copy from */ | |
4096 | } copy; /* if EXT or COPY, where and how much */ | |
4097 | } sub; /* submode */ | |
4098 | ||
4099 | /* mode independent information */ | |
4100 | Byte lbits; /* ltree bits decoded per branch */ | |
4101 | Byte dbits; /* dtree bits decoder per branch */ | |
4102 | inflate_huft *ltree; /* literal/length/eob tree */ | |
4103 | inflate_huft *dtree; /* distance tree */ | |
4104 | ||
4105 | }; | |
4106 | ||
4107 | ||
4108 | local inflate_codes_statef *inflate_codes_new(bl, bd, tl, td, z) | |
4109 | uInt bl, bd; | |
4110 | inflate_huft *tl, *td; | |
4111 | z_stream *z; | |
4112 | { | |
4113 | inflate_codes_statef *c; | |
4114 | ||
4115 | if ((c = (inflate_codes_statef *) | |
4116 | ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) | |
4117 | { | |
4118 | c->mode = START; | |
4119 | c->lbits = (Byte)bl; | |
4120 | c->dbits = (Byte)bd; | |
4121 | c->ltree = tl; | |
4122 | c->dtree = td; | |
4123 | Tracev((stderr, "inflate: codes new\n")); | |
4124 | } | |
4125 | return c; | |
4126 | } | |
4127 | ||
4128 | ||
4129 | local int inflate_codes(s, z, r) | |
4130 | inflate_blocks_statef *s; | |
4131 | z_stream *z; | |
4132 | int r; | |
4133 | { | |
4134 | uInt j; /* temporary storage */ | |
4135 | inflate_huft *t; /* temporary pointer */ | |
4136 | uInt e; /* extra bits or operation */ | |
4137 | uLong b; /* bit buffer */ | |
4138 | uInt k; /* bits in bit buffer */ | |
4139 | Bytef *p; /* input data pointer */ | |
4140 | uInt n; /* bytes available there */ | |
4141 | Bytef *q; /* output window write pointer */ | |
4142 | uInt m; /* bytes to end of window or read pointer */ | |
4143 | Bytef *f; /* pointer to copy strings from */ | |
4144 | inflate_codes_statef *c = s->sub.decode.codes; /* codes state */ | |
4145 | ||
4146 | /* copy input/output information to locals (UPDATE macro restores) */ | |
4147 | LOAD | |
4148 | ||
4149 | /* process input and output based on current state */ | |
4150 | while (1) switch (c->mode) | |
4151 | { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ | |
4152 | case START: /* x: set up for LEN */ | |
4153 | #ifndef SLOW | |
4154 | if (m >= 258 && n >= 10) | |
4155 | { | |
4156 | UPDATE | |
4157 | r = inflate_fast(c->lbits, c->dbits, c->ltree, c->dtree, s, z); | |
4158 | LOAD | |
4159 | if (r != Z_OK) | |
4160 | { | |
4161 | c->mode = r == Z_STREAM_END ? WASH : BADCODE; | |
4162 | break; | |
4163 | } | |
4164 | } | |
4165 | #endif /* !SLOW */ | |
4166 | c->sub.code.need = c->lbits; | |
4167 | c->sub.code.tree = c->ltree; | |
4168 | c->mode = LEN; | |
4169 | case LEN: /* i: get length/literal/eob next */ | |
4170 | j = c->sub.code.need; | |
4171 | NEEDBITS(j) | |
4172 | t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); | |
4173 | DUMPBITS(t->bits) | |
4174 | e = (uInt)(t->exop); | |
4175 | if (e == 0) /* literal */ | |
4176 | { | |
4177 | c->sub.lit = t->base; | |
4178 | Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? | |
4179 | "inflate: literal '%c'\n" : | |
4180 | "inflate: literal 0x%02x\n", t->base)); | |
4181 | c->mode = LIT; | |
4182 | break; | |
4183 | } | |
4184 | if (e & 16) /* length */ | |
4185 | { | |
4186 | c->sub.copy.get = e & 15; | |
4187 | c->len = t->base; | |
4188 | c->mode = LENEXT; | |
4189 | break; | |
4190 | } | |
4191 | if ((e & 64) == 0) /* next table */ | |
4192 | { | |
4193 | c->sub.code.need = e; | |
4194 | c->sub.code.tree = t->next; | |
4195 | break; | |
4196 | } | |
4197 | if (e & 32) /* end of block */ | |
4198 | { | |
4199 | Tracevv((stderr, "inflate: end of block\n")); | |
4200 | c->mode = WASH; | |
4201 | break; | |
4202 | } | |
4203 | c->mode = BADCODE; /* invalid code */ | |
4204 | z->msg = "invalid literal/length code"; | |
4205 | r = Z_DATA_ERROR; | |
4206 | LEAVE | |
4207 | case LENEXT: /* i: getting length extra (have base) */ | |
4208 | j = c->sub.copy.get; | |
4209 | NEEDBITS(j) | |
4210 | c->len += (uInt)b & inflate_mask[j]; | |
4211 | DUMPBITS(j) | |
4212 | c->sub.code.need = c->dbits; | |
4213 | c->sub.code.tree = c->dtree; | |
4214 | Tracevv((stderr, "inflate: length %u\n", c->len)); | |
4215 | c->mode = DIST; | |
4216 | case DIST: /* i: get distance next */ | |
4217 | j = c->sub.code.need; | |
4218 | NEEDBITS(j) | |
4219 | t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); | |
4220 | DUMPBITS(t->bits) | |
4221 | e = (uInt)(t->exop); | |
4222 | if (e & 16) /* distance */ | |
4223 | { | |
4224 | c->sub.copy.get = e & 15; | |
4225 | c->sub.copy.dist = t->base; | |
4226 | c->mode = DISTEXT; | |
4227 | break; | |
4228 | } | |
4229 | if ((e & 64) == 0) /* next table */ | |
4230 | { | |
4231 | c->sub.code.need = e; | |
4232 | c->sub.code.tree = t->next; | |
4233 | break; | |
4234 | } | |
4235 | c->mode = BADCODE; /* invalid code */ | |
4236 | z->msg = "invalid distance code"; | |
4237 | r = Z_DATA_ERROR; | |
4238 | LEAVE | |
4239 | case DISTEXT: /* i: getting distance extra */ | |
4240 | j = c->sub.copy.get; | |
4241 | NEEDBITS(j) | |
4242 | c->sub.copy.dist += (uInt)b & inflate_mask[j]; | |
4243 | DUMPBITS(j) | |
4244 | Tracevv((stderr, "inflate: distance %u\n", c->sub.copy.dist)); | |
4245 | c->mode = COPY; | |
4246 | case COPY: /* o: copying bytes in window, waiting for space */ | |
4247 | #ifndef __TURBOC__ /* Turbo C bug for following expression */ | |
4248 | f = (uInt)(q - s->window) < c->sub.copy.dist ? | |
4249 | s->end - (c->sub.copy.dist - (q - s->window)) : | |
4250 | q - c->sub.copy.dist; | |
4251 | #else | |
4252 | f = q - c->sub.copy.dist; | |
4253 | if ((uInt)(q - s->window) < c->sub.copy.dist) | |
4254 | f = s->end - (c->sub.copy.dist - (q - s->window)); | |
4255 | #endif | |
4256 | while (c->len) | |
4257 | { | |
4258 | NEEDOUT | |
4259 | OUTBYTE(*f++) | |
4260 | if (f == s->end) | |
4261 | f = s->window; | |
4262 | c->len--; | |
4263 | } | |
4264 | c->mode = START; | |
4265 | break; | |
4266 | case LIT: /* o: got literal, waiting for output space */ | |
4267 | NEEDOUT | |
4268 | OUTBYTE(c->sub.lit) | |
4269 | c->mode = START; | |
4270 | break; | |
4271 | case WASH: /* o: got eob, possibly more output */ | |
4272 | FLUSH | |
4273 | if (s->read != s->write) | |
4274 | LEAVE | |
4275 | c->mode = END; | |
4276 | case END: | |
4277 | r = Z_STREAM_END; | |
4278 | LEAVE | |
4279 | case BADCODE: /* x: got error */ | |
4280 | r = Z_DATA_ERROR; | |
4281 | LEAVE | |
4282 | default: | |
4283 | r = Z_STREAM_ERROR; | |
4284 | LEAVE | |
4285 | } | |
4286 | } | |
4287 | ||
4288 | ||
4289 | local void inflate_codes_free(c, z) | |
4290 | inflate_codes_statef *c; | |
4291 | z_stream *z; | |
4292 | { | |
4293 | ZFREE(z, c, sizeof(struct inflate_codes_state)); | |
4294 | Tracev((stderr, "inflate: codes free\n")); | |
4295 | } | |
4296 | ||
4297 | /*+++++*/ | |
4298 | /* inflate_util.c -- data and routines common to blocks and codes | |
4299 | * Copyright (C) 1995 Mark Adler | |
4300 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4301 | */ | |
4302 | ||
4303 | /* copy as much as possible from the sliding window to the output area */ | |
4304 | local int inflate_flush(s, z, r) | |
4305 | inflate_blocks_statef *s; | |
4306 | z_stream *z; | |
4307 | int r; | |
4308 | { | |
4309 | uInt n; | |
4310 | Bytef *p, *q; | |
4311 | ||
4312 | /* local copies of source and destination pointers */ | |
4313 | p = z->next_out; | |
4314 | q = s->read; | |
4315 | ||
4316 | /* compute number of bytes to copy as far as end of window */ | |
4317 | n = (uInt)((q <= s->write ? s->write : s->end) - q); | |
4318 | if (n > z->avail_out) n = z->avail_out; | |
4319 | if (n && r == Z_BUF_ERROR) r = Z_OK; | |
4320 | ||
4321 | /* update counters */ | |
4322 | z->avail_out -= n; | |
4323 | z->total_out += n; | |
4324 | ||
4325 | /* update check information */ | |
4326 | if (s->checkfn != Z_NULL) | |
4327 | s->check = (*s->checkfn)(s->check, q, n); | |
4328 | ||
4329 | /* copy as far as end of window */ | |
4330 | if (p != NULL) { | |
4331 | zmemcpy(p, q, n); | |
4332 | p += n; | |
4333 | } | |
4334 | q += n; | |
4335 | ||
4336 | /* see if more to copy at beginning of window */ | |
4337 | if (q == s->end) | |
4338 | { | |
4339 | /* wrap pointers */ | |
4340 | q = s->window; | |
4341 | if (s->write == s->end) | |
4342 | s->write = s->window; | |
4343 | ||
4344 | /* compute bytes to copy */ | |
4345 | n = (uInt)(s->write - q); | |
4346 | if (n > z->avail_out) n = z->avail_out; | |
4347 | if (n && r == Z_BUF_ERROR) r = Z_OK; | |
4348 | ||
4349 | /* update counters */ | |
4350 | z->avail_out -= n; | |
4351 | z->total_out += n; | |
4352 | ||
4353 | /* update check information */ | |
4354 | if (s->checkfn != Z_NULL) | |
4355 | s->check = (*s->checkfn)(s->check, q, n); | |
4356 | ||
4357 | /* copy */ | |
4358 | if (p != NULL) { | |
4359 | zmemcpy(p, q, n); | |
4360 | p += n; | |
4361 | } | |
4362 | q += n; | |
4363 | } | |
4364 | ||
4365 | /* update pointers */ | |
4366 | z->next_out = p; | |
4367 | s->read = q; | |
4368 | ||
4369 | /* done */ | |
4370 | return r; | |
4371 | } | |
4372 | ||
4373 | ||
4374 | /*+++++*/ | |
4375 | /* inffast.c -- process literals and length/distance pairs fast | |
4376 | * Copyright (C) 1995 Mark Adler | |
4377 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4378 | */ | |
4379 | ||
4380 | /* simplify the use of the inflate_huft type with some defines */ | |
4381 | #define base more.Base | |
4382 | #define next more.Next | |
4383 | #define exop word.what.Exop | |
4384 | #define bits word.what.Bits | |
4385 | ||
4386 | /* macros for bit input with no checking and for returning unused bytes */ | |
4387 | #define GRABBITS(j) {while(k<(j)){b|=((uLong)NEXTBYTE)<<k;k+=8;}} | |
4388 | #define UNGRAB {n+=(c=k>>3);p-=c;k&=7;} | |
4389 | ||
4390 | /* Called with number of bytes left to write in window at least 258 | |
4391 | (the maximum string length) and number of input bytes available | |
4392 | at least ten. The ten bytes are six bytes for the longest length/ | |
4393 | distance pair plus four bytes for overloading the bit buffer. */ | |
4394 | ||
4395 | local int inflate_fast(bl, bd, tl, td, s, z) | |
4396 | uInt bl, bd; | |
4397 | inflate_huft *tl, *td; | |
4398 | inflate_blocks_statef *s; | |
4399 | z_stream *z; | |
4400 | { | |
4401 | inflate_huft *t; /* temporary pointer */ | |
4402 | uInt e; /* extra bits or operation */ | |
4403 | uLong b; /* bit buffer */ | |
4404 | uInt k; /* bits in bit buffer */ | |
4405 | Bytef *p; /* input data pointer */ | |
4406 | uInt n; /* bytes available there */ | |
4407 | Bytef *q; /* output window write pointer */ | |
4408 | uInt m; /* bytes to end of window or read pointer */ | |
4409 | uInt ml; /* mask for literal/length tree */ | |
4410 | uInt md; /* mask for distance tree */ | |
4411 | uInt c; /* bytes to copy */ | |
4412 | uInt d; /* distance back to copy from */ | |
4413 | Bytef *r; /* copy source pointer */ | |
4414 | ||
4415 | /* load input, output, bit values */ | |
4416 | LOAD | |
4417 | ||
4418 | /* initialize masks */ | |
4419 | ml = inflate_mask[bl]; | |
4420 | md = inflate_mask[bd]; | |
4421 | ||
4422 | /* do until not enough input or output space for fast loop */ | |
4423 | do { /* assume called with m >= 258 && n >= 10 */ | |
4424 | /* get literal/length code */ | |
4425 | GRABBITS(20) /* max bits for literal/length code */ | |
4426 | if ((e = (t = tl + ((uInt)b & ml))->exop) == 0) | |
4427 | { | |
4428 | DUMPBITS(t->bits) | |
4429 | Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? | |
4430 | "inflate: * literal '%c'\n" : | |
4431 | "inflate: * literal 0x%02x\n", t->base)); | |
4432 | *q++ = (Byte)t->base; | |
4433 | m--; | |
4434 | continue; | |
4435 | } | |
4436 | do { | |
4437 | DUMPBITS(t->bits) | |
4438 | if (e & 16) | |
4439 | { | |
4440 | /* get extra bits for length */ | |
4441 | e &= 15; | |
4442 | c = t->base + ((uInt)b & inflate_mask[e]); | |
4443 | DUMPBITS(e) | |
4444 | Tracevv((stderr, "inflate: * length %u\n", c)); | |
4445 | ||
4446 | /* decode distance base of block to copy */ | |
4447 | GRABBITS(15); /* max bits for distance code */ | |
4448 | e = (t = td + ((uInt)b & md))->exop; | |
4449 | do { | |
4450 | DUMPBITS(t->bits) | |
4451 | if (e & 16) | |
4452 | { | |
4453 | /* get extra bits to add to distance base */ | |
4454 | e &= 15; | |
4455 | GRABBITS(e) /* get extra bits (up to 13) */ | |
4456 | d = t->base + ((uInt)b & inflate_mask[e]); | |
4457 | DUMPBITS(e) | |
4458 | Tracevv((stderr, "inflate: * distance %u\n", d)); | |
4459 | ||
4460 | /* do the copy */ | |
4461 | m -= c; | |
4462 | if ((uInt)(q - s->window) >= d) /* offset before dest */ | |
4463 | { /* just copy */ | |
4464 | r = q - d; | |
4465 | *q++ = *r++; c--; /* minimum count is three, */ | |
4466 | *q++ = *r++; c--; /* so unroll loop a little */ | |
4467 | } | |
4468 | else /* else offset after destination */ | |
4469 | { | |
4470 | e = d - (q - s->window); /* bytes from offset to end */ | |
4471 | r = s->end - e; /* pointer to offset */ | |
4472 | if (c > e) /* if source crosses, */ | |
4473 | { | |
4474 | c -= e; /* copy to end of window */ | |
4475 | do { | |
4476 | *q++ = *r++; | |
4477 | } while (--e); | |
4478 | r = s->window; /* copy rest from start of window */ | |
4479 | } | |
4480 | } | |
4481 | do { /* copy all or what's left */ | |
4482 | *q++ = *r++; | |
4483 | } while (--c); | |
4484 | break; | |
4485 | } | |
4486 | else if ((e & 64) == 0) | |
4487 | e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop; | |
4488 | else | |
4489 | { | |
4490 | z->msg = "invalid distance code"; | |
4491 | UNGRAB | |
4492 | UPDATE | |
4493 | return Z_DATA_ERROR; | |
4494 | } | |
4495 | } while (1); | |
4496 | break; | |
4497 | } | |
4498 | if ((e & 64) == 0) | |
4499 | { | |
4500 | if ((e = (t = t->next + ((uInt)b & inflate_mask[e]))->exop) == 0) | |
4501 | { | |
4502 | DUMPBITS(t->bits) | |
4503 | Tracevv((stderr, t->base >= 0x20 && t->base < 0x7f ? | |
4504 | "inflate: * literal '%c'\n" : | |
4505 | "inflate: * literal 0x%02x\n", t->base)); | |
4506 | *q++ = (Byte)t->base; | |
4507 | m--; | |
4508 | break; | |
4509 | } | |
4510 | } | |
4511 | else if (e & 32) | |
4512 | { | |
4513 | Tracevv((stderr, "inflate: * end of block\n")); | |
4514 | UNGRAB | |
4515 | UPDATE | |
4516 | return Z_STREAM_END; | |
4517 | } | |
4518 | else | |
4519 | { | |
4520 | z->msg = "invalid literal/length code"; | |
4521 | UNGRAB | |
4522 | UPDATE | |
4523 | return Z_DATA_ERROR; | |
4524 | } | |
4525 | } while (1); | |
4526 | } while (m >= 258 && n >= 10); | |
4527 | ||
4528 | /* not enough input or output--restore pointers and return */ | |
4529 | UNGRAB | |
4530 | UPDATE | |
4531 | return Z_OK; | |
4532 | } | |
4533 | ||
4534 | ||
4535 | /*+++++*/ | |
4536 | /* zutil.c -- target dependent utility functions for the compression library | |
4537 | * Copyright (C) 1995 Jean-loup Gailly. | |
4538 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4539 | */ | |
4540 | ||
4541 | /* From: zutil.c,v 1.8 1995/05/03 17:27:12 jloup Exp */ | |
4542 | ||
4543 | char *zlib_version = ZLIB_VERSION; | |
4544 | ||
4545 | char *z_errmsg[] = { | |
4546 | "stream end", /* Z_STREAM_END 1 */ | |
4547 | "", /* Z_OK 0 */ | |
4548 | "file error", /* Z_ERRNO (-1) */ | |
4549 | "stream error", /* Z_STREAM_ERROR (-2) */ | |
4550 | "data error", /* Z_DATA_ERROR (-3) */ | |
4551 | "insufficient memory", /* Z_MEM_ERROR (-4) */ | |
4552 | "buffer error", /* Z_BUF_ERROR (-5) */ | |
4553 | ""}; | |
4554 | ||
4555 | ||
4556 | /*+++++*/ | |
4557 | /* adler32.c -- compute the Adler-32 checksum of a data stream | |
4558 | * Copyright (C) 1995 Mark Adler | |
4559 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4560 | */ | |
4561 | ||
4562 | /* From: adler32.c,v 1.6 1995/05/03 17:27:08 jloup Exp */ | |
4563 | ||
4564 | #define BASE 65521L /* largest prime smaller than 65536 */ | |
4565 | #define NMAX 5552 | |
4566 | /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ | |
4567 | ||
4568 | #define DO1(buf) {s1 += *buf++; s2 += s1;} | |
4569 | #define DO2(buf) DO1(buf); DO1(buf); | |
4570 | #define DO4(buf) DO2(buf); DO2(buf); | |
4571 | #define DO8(buf) DO4(buf); DO4(buf); | |
4572 | #define DO16(buf) DO8(buf); DO8(buf); | |
4573 | ||
4574 | /* ========================================================================= */ | |
4575 | uLong adler32(adler, buf, len) | |
4576 | uLong adler; | |
4577 | Bytef *buf; | |
4578 | uInt len; | |
4579 | { | |
4580 | unsigned long s1 = adler & 0xffff; | |
4581 | unsigned long s2 = (adler >> 16) & 0xffff; | |
4582 | int k; | |
4583 | ||
4584 | if (buf == Z_NULL) return 1L; | |
4585 | ||
4586 | while (len > 0) { | |
4587 | k = len < NMAX ? len : NMAX; | |
4588 | len -= k; | |
4589 | while (k >= 16) { | |
4590 | DO16(buf); | |
4591 | k -= 16; | |
4592 | } | |
4593 | if (k != 0) do { | |
4594 | DO1(buf); | |
4595 | } while (--k); | |
4596 | s1 %= BASE; | |
4597 | s2 %= BASE; | |
4598 | } | |
4599 | return (s2 << 16) | s1; | |
4600 | } |