Annotation of /trunk/mkinitrd-magellan/busybox/archival/gzip.c
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Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
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Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
File MIME type: text/plain
File size: 67240 byte(s)
-import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
1 | niro | 532 | /* vi: set sw=4 ts=4: */ |
2 | /* | ||
3 | * Gzip implementation for busybox | ||
4 | * | ||
5 | * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly. | ||
6 | * | ||
7 | * Originally adjusted for busybox by Charles P. Wright <cpw@unix.asb.com> | ||
8 | * "this is a stripped down version of gzip I put into busybox, it does | ||
9 | * only standard in to standard out with -9 compression. It also requires | ||
10 | * the zcat module for some important functions." | ||
11 | * | ||
12 | * Adjusted further by Erik Andersen <andersen@codepoet.org> to support | ||
13 | * files as well as stdin/stdout, and to generally behave itself wrt | ||
14 | * command line handling. | ||
15 | * | ||
16 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. | ||
17 | */ | ||
18 | |||
19 | /* big objects in bss: | ||
20 | * 00000020 b bl_count | ||
21 | * 00000074 b base_length | ||
22 | * 00000078 b base_dist | ||
23 | * 00000078 b static_dtree | ||
24 | * 0000009c b bl_tree | ||
25 | * 000000f4 b dyn_dtree | ||
26 | * 00000100 b length_code | ||
27 | * 00000200 b dist_code | ||
28 | * 0000023d b depth | ||
29 | * 00000400 b flag_buf | ||
30 | * 0000047a b heap | ||
31 | * 00000480 b static_ltree | ||
32 | * 000008f4 b dyn_ltree | ||
33 | */ | ||
34 | |||
35 | /* TODO: full support for -v for DESKTOP | ||
36 | * "/usr/bin/gzip -v a bogus aa" should say: | ||
37 | a: 85.1% -- replaced with a.gz | ||
38 | gzip: bogus: No such file or directory | ||
39 | aa: 85.1% -- replaced with aa.gz | ||
40 | */ | ||
41 | |||
42 | #include "busybox.h" | ||
43 | |||
44 | |||
45 | /* =========================================================================== | ||
46 | */ | ||
47 | //#define DEBUG 1 | ||
48 | /* Diagnostic functions */ | ||
49 | #ifdef DEBUG | ||
50 | # define Assert(cond,msg) {if(!(cond)) bb_error_msg(msg);} | ||
51 | # define Trace(x) fprintf x | ||
52 | # define Tracev(x) {if (verbose) fprintf x ;} | ||
53 | # define Tracevv(x) {if (verbose > 1) fprintf x ;} | ||
54 | # define Tracec(c,x) {if (verbose && (c)) fprintf x ;} | ||
55 | # define Tracecv(c,x) {if (verbose > 1 && (c)) fprintf x ;} | ||
56 | #else | ||
57 | # define Assert(cond,msg) | ||
58 | # define Trace(x) | ||
59 | # define Tracev(x) | ||
60 | # define Tracevv(x) | ||
61 | # define Tracec(c,x) | ||
62 | # define Tracecv(c,x) | ||
63 | #endif | ||
64 | |||
65 | |||
66 | /* =========================================================================== | ||
67 | */ | ||
68 | #define SMALL_MEM | ||
69 | |||
70 | /* Compression methods (see algorithm.doc) */ | ||
71 | /* Only STORED and DEFLATED are supported by this BusyBox module */ | ||
72 | #define STORED 0 | ||
73 | /* methods 4 to 7 reserved */ | ||
74 | #define DEFLATED 8 | ||
75 | |||
76 | #ifndef INBUFSIZ | ||
77 | # ifdef SMALL_MEM | ||
78 | # define INBUFSIZ 0x2000 /* input buffer size */ | ||
79 | # else | ||
80 | # define INBUFSIZ 0x8000 /* input buffer size */ | ||
81 | # endif | ||
82 | #endif | ||
83 | |||
84 | #ifndef OUTBUFSIZ | ||
85 | # ifdef SMALL_MEM | ||
86 | # define OUTBUFSIZ 8192 /* output buffer size */ | ||
87 | # else | ||
88 | # define OUTBUFSIZ 16384 /* output buffer size */ | ||
89 | # endif | ||
90 | #endif | ||
91 | |||
92 | #ifndef DIST_BUFSIZE | ||
93 | # ifdef SMALL_MEM | ||
94 | # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */ | ||
95 | # else | ||
96 | # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */ | ||
97 | # endif | ||
98 | #endif | ||
99 | |||
100 | /* gzip flag byte */ | ||
101 | #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ | ||
102 | #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ | ||
103 | #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ | ||
104 | #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ | ||
105 | #define COMMENT 0x10 /* bit 4 set: file comment present */ | ||
106 | #define RESERVED 0xC0 /* bit 6,7: reserved */ | ||
107 | |||
108 | /* internal file attribute */ | ||
109 | #define UNKNOWN 0xffff | ||
110 | #define BINARY 0 | ||
111 | #define ASCII 1 | ||
112 | |||
113 | #ifndef WSIZE | ||
114 | # define WSIZE 0x8000 /* window size--must be a power of two, and */ | ||
115 | #endif /* at least 32K for zip's deflate method */ | ||
116 | |||
117 | #define MIN_MATCH 3 | ||
118 | #define MAX_MATCH 258 | ||
119 | /* The minimum and maximum match lengths */ | ||
120 | |||
121 | #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) | ||
122 | /* Minimum amount of lookahead, except at the end of the input file. | ||
123 | * See deflate.c for comments about the MIN_MATCH+1. | ||
124 | */ | ||
125 | |||
126 | #define MAX_DIST (WSIZE-MIN_LOOKAHEAD) | ||
127 | /* In order to simplify the code, particularly on 16 bit machines, match | ||
128 | * distances are limited to MAX_DIST instead of WSIZE. | ||
129 | */ | ||
130 | |||
131 | #ifndef MAX_PATH_LEN | ||
132 | # define MAX_PATH_LEN 1024 /* max pathname length */ | ||
133 | #endif | ||
134 | |||
135 | #define seekable() 0 /* force sequential output */ | ||
136 | #define translate_eol 0 /* no option -a yet */ | ||
137 | |||
138 | #ifndef BITS | ||
139 | # define BITS 16 | ||
140 | #endif | ||
141 | #define INIT_BITS 9 /* Initial number of bits per code */ | ||
142 | |||
143 | #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */ | ||
144 | /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free. | ||
145 | * It's a pity that old uncompress does not check bit 0x20. That makes | ||
146 | * extension of the format actually undesirable because old compress | ||
147 | * would just crash on the new format instead of giving a meaningful | ||
148 | * error message. It does check the number of bits, but it's more | ||
149 | * helpful to say "unsupported format, get a new version" than | ||
150 | * "can only handle 16 bits". | ||
151 | */ | ||
152 | |||
153 | #ifdef MAX_EXT_CHARS | ||
154 | # define MAX_SUFFIX MAX_EXT_CHARS | ||
155 | #else | ||
156 | # define MAX_SUFFIX 30 | ||
157 | #endif | ||
158 | |||
159 | |||
160 | /* =========================================================================== | ||
161 | * Compile with MEDIUM_MEM to reduce the memory requirements or | ||
162 | * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the | ||
163 | * entire input file can be held in memory (not possible on 16 bit systems). | ||
164 | * Warning: defining these symbols affects HASH_BITS (see below) and thus | ||
165 | * affects the compression ratio. The compressed output | ||
166 | * is still correct, and might even be smaller in some cases. | ||
167 | */ | ||
168 | |||
169 | #ifdef SMALL_MEM | ||
170 | # define HASH_BITS 13 /* Number of bits used to hash strings */ | ||
171 | #endif | ||
172 | #ifdef MEDIUM_MEM | ||
173 | # define HASH_BITS 14 | ||
174 | #endif | ||
175 | #ifndef HASH_BITS | ||
176 | # define HASH_BITS 15 | ||
177 | /* For portability to 16 bit machines, do not use values above 15. */ | ||
178 | #endif | ||
179 | |||
180 | #define HASH_SIZE (unsigned)(1<<HASH_BITS) | ||
181 | #define HASH_MASK (HASH_SIZE-1) | ||
182 | #define WMASK (WSIZE-1) | ||
183 | /* HASH_SIZE and WSIZE must be powers of two */ | ||
184 | #ifndef TOO_FAR | ||
185 | # define TOO_FAR 4096 | ||
186 | #endif | ||
187 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ | ||
188 | |||
189 | |||
190 | /* =========================================================================== | ||
191 | * These types are not really 'char', 'short' and 'long' | ||
192 | */ | ||
193 | typedef uint8_t uch; | ||
194 | typedef uint16_t ush; | ||
195 | typedef uint32_t ulg; | ||
196 | typedef int32_t lng; | ||
197 | |||
198 | |||
199 | /* =========================================================================== | ||
200 | */ | ||
201 | typedef ush Pos; | ||
202 | typedef unsigned IPos; | ||
203 | |||
204 | /* A Pos is an index in the character window. We use short instead of int to | ||
205 | * save space in the various tables. IPos is used only for parameter passing. | ||
206 | */ | ||
207 | |||
208 | static lng block_start; | ||
209 | |||
210 | /* window position at the beginning of the current output block. Gets | ||
211 | * negative when the window is moved backwards. | ||
212 | */ | ||
213 | |||
214 | static unsigned ins_h; /* hash index of string to be inserted */ | ||
215 | |||
216 | #define H_SHIFT ((HASH_BITS+MIN_MATCH-1) / MIN_MATCH) | ||
217 | /* Number of bits by which ins_h and del_h must be shifted at each | ||
218 | * input step. It must be such that after MIN_MATCH steps, the oldest | ||
219 | * byte no longer takes part in the hash key, that is: | ||
220 | * H_SHIFT * MIN_MATCH >= HASH_BITS | ||
221 | */ | ||
222 | |||
223 | static unsigned int prev_length; | ||
224 | |||
225 | /* Length of the best match at previous step. Matches not greater than this | ||
226 | * are discarded. This is used in the lazy match evaluation. | ||
227 | */ | ||
228 | |||
229 | static unsigned strstart; /* start of string to insert */ | ||
230 | static unsigned match_start; /* start of matching string */ | ||
231 | static int eofile; /* flag set at end of input file */ | ||
232 | static unsigned lookahead; /* number of valid bytes ahead in window */ | ||
233 | |||
234 | enum { | ||
235 | WINDOW_SIZE = 2 * WSIZE, | ||
236 | /* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the | ||
237 | * input file length plus MIN_LOOKAHEAD. | ||
238 | */ | ||
239 | |||
240 | max_chain_length = 4096, | ||
241 | /* To speed up deflation, hash chains are never searched beyond this length. | ||
242 | * A higher limit improves compression ratio but degrades the speed. | ||
243 | */ | ||
244 | |||
245 | max_lazy_match = 258, | ||
246 | /* Attempt to find a better match only when the current match is strictly | ||
247 | * smaller than this value. This mechanism is used only for compression | ||
248 | * levels >= 4. | ||
249 | */ | ||
250 | |||
251 | max_insert_length = max_lazy_match, | ||
252 | /* Insert new strings in the hash table only if the match length | ||
253 | * is not greater than this length. This saves time but degrades compression. | ||
254 | * max_insert_length is used only for compression levels <= 3. | ||
255 | */ | ||
256 | |||
257 | good_match = 32, | ||
258 | /* Use a faster search when the previous match is longer than this */ | ||
259 | |||
260 | /* Values for max_lazy_match, good_match and max_chain_length, depending on | ||
261 | * the desired pack level (0..9). The values given below have been tuned to | ||
262 | * exclude worst case performance for pathological files. Better values may be | ||
263 | * found for specific files. | ||
264 | */ | ||
265 | |||
266 | nice_match = 258, /* Stop searching when current match exceeds this */ | ||
267 | /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 | ||
268 | * For deflate_fast() (levels <= 3) good is ignored and lazy has a different | ||
269 | * meaning. | ||
270 | */ | ||
271 | }; | ||
272 | |||
273 | |||
274 | /* =========================================================================== | ||
275 | */ | ||
276 | #define DECLARE(type, array, size) \ | ||
277 | static type * array | ||
278 | |||
279 | #define ALLOC(type, array, size) \ | ||
280 | { \ | ||
281 | array = xzalloc((size_t)(((size)+1L)/2) * 2*sizeof(type)); \ | ||
282 | } | ||
283 | |||
284 | #define FREE(array) \ | ||
285 | { \ | ||
286 | free(array); \ | ||
287 | array = NULL; \ | ||
288 | } | ||
289 | |||
290 | /* global buffers */ | ||
291 | |||
292 | /* buffer for literals or lengths */ | ||
293 | /* DECLARE(uch, l_buf, LIT_BUFSIZE); */ | ||
294 | DECLARE(uch, l_buf, INBUFSIZ); | ||
295 | |||
296 | DECLARE(ush, d_buf, DIST_BUFSIZE); | ||
297 | DECLARE(uch, outbuf, OUTBUFSIZ); | ||
298 | |||
299 | /* Sliding window. Input bytes are read into the second half of the window, | ||
300 | * and move to the first half later to keep a dictionary of at least WSIZE | ||
301 | * bytes. With this organization, matches are limited to a distance of | ||
302 | * WSIZE-MAX_MATCH bytes, but this ensures that IO is always | ||
303 | * performed with a length multiple of the block size. Also, it limits | ||
304 | * the window size to 64K, which is quite useful on MSDOS. | ||
305 | * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would | ||
306 | * be less efficient). | ||
307 | */ | ||
308 | DECLARE(uch, window, 2L * WSIZE); | ||
309 | |||
310 | /* Link to older string with same hash index. To limit the size of this | ||
311 | * array to 64K, this link is maintained only for the last 32K strings. | ||
312 | * An index in this array is thus a window index modulo 32K. | ||
313 | */ | ||
314 | /* DECLARE(Pos, prev, WSIZE); */ | ||
315 | DECLARE(ush, prev, 1L << BITS); | ||
316 | |||
317 | /* Heads of the hash chains or 0. */ | ||
318 | /* DECLARE(Pos, head, 1<<HASH_BITS); */ | ||
319 | #define head (prev+WSIZE) /* hash head (see deflate.c) */ | ||
320 | |||
321 | |||
322 | /* number of input bytes */ | ||
323 | static ulg isize; /* only 32 bits stored in .gz file */ | ||
324 | |||
325 | static int foreground; /* set if program run in foreground */ | ||
326 | static int method = DEFLATED; /* compression method */ | ||
327 | static int exit_code; /* program exit code */ | ||
328 | |||
329 | /* original time stamp (modification time) */ | ||
330 | static ulg time_stamp; /* only 32 bits stored in .gz file */ | ||
331 | |||
332 | static int ifd; /* input file descriptor */ | ||
333 | static int ofd; /* output file descriptor */ | ||
334 | #ifdef DEBUG | ||
335 | static unsigned insize; /* valid bytes in l_buf */ | ||
336 | #endif | ||
337 | static unsigned outcnt; /* bytes in output buffer */ | ||
338 | |||
339 | static uint32_t *crc_32_tab; | ||
340 | |||
341 | |||
342 | /* =========================================================================== | ||
343 | * Local data used by the "bit string" routines. | ||
344 | */ | ||
345 | |||
346 | //// static int zfile; /* output gzip file */ | ||
347 | |||
348 | static unsigned short bi_buf; | ||
349 | |||
350 | /* Output buffer. bits are inserted starting at the bottom (least significant | ||
351 | * bits). | ||
352 | */ | ||
353 | |||
354 | #undef BUF_SIZE | ||
355 | #define BUF_SIZE (8 * sizeof(bi_buf)) | ||
356 | /* Number of bits used within bi_buf. (bi_buf might be implemented on | ||
357 | * more than 16 bits on some systems.) | ||
358 | */ | ||
359 | |||
360 | static int bi_valid; | ||
361 | |||
362 | /* Current input function. Set to mem_read for in-memory compression */ | ||
363 | |||
364 | #ifdef DEBUG | ||
365 | static ulg bits_sent; /* bit length of the compressed data */ | ||
366 | #endif | ||
367 | |||
368 | |||
369 | /* =========================================================================== | ||
370 | * Write the output buffer outbuf[0..outcnt-1] and update bytes_out. | ||
371 | * (used for the compressed data only) | ||
372 | */ | ||
373 | static void flush_outbuf(void) | ||
374 | { | ||
375 | if (outcnt == 0) | ||
376 | return; | ||
377 | |||
378 | xwrite(ofd, (char *) outbuf, outcnt); | ||
379 | outcnt = 0; | ||
380 | } | ||
381 | |||
382 | |||
383 | /* =========================================================================== | ||
384 | */ | ||
385 | /* put_8bit is used for the compressed output */ | ||
386 | #define put_8bit(c) \ | ||
387 | { \ | ||
388 | outbuf[outcnt++] = (c); \ | ||
389 | if (outcnt == OUTBUFSIZ) flush_outbuf(); \ | ||
390 | } | ||
391 | |||
392 | /* Output a 16 bit value, lsb first */ | ||
393 | static void put_16bit(ush w) | ||
394 | { | ||
395 | if (outcnt < OUTBUFSIZ - 2) { | ||
396 | outbuf[outcnt++] = w; | ||
397 | outbuf[outcnt++] = w >> 8; | ||
398 | } else { | ||
399 | put_8bit(w); | ||
400 | put_8bit(w >> 8); | ||
401 | } | ||
402 | } | ||
403 | |||
404 | static void put_32bit(ulg n) | ||
405 | { | ||
406 | put_16bit(n); | ||
407 | put_16bit(n >> 16); | ||
408 | } | ||
409 | |||
410 | /* =========================================================================== | ||
411 | * Clear input and output buffers | ||
412 | */ | ||
413 | static void clear_bufs(void) | ||
414 | { | ||
415 | outcnt = 0; | ||
416 | #ifdef DEBUG | ||
417 | insize = 0; | ||
418 | #endif | ||
419 | isize = 0; | ||
420 | } | ||
421 | |||
422 | |||
423 | /* =========================================================================== | ||
424 | * Run a set of bytes through the crc shift register. If s is a NULL | ||
425 | * pointer, then initialize the crc shift register contents instead. | ||
426 | * Return the current crc in either case. | ||
427 | */ | ||
428 | static uint32_t crc; /* shift register contents */ | ||
429 | static uint32_t updcrc(uch * s, unsigned n) | ||
430 | { | ||
431 | uint32_t c = crc; | ||
432 | while (n) { | ||
433 | c = crc_32_tab[(uch)(c ^ *s++)] ^ (c >> 8); | ||
434 | n--; | ||
435 | } | ||
436 | crc = c; | ||
437 | return c; | ||
438 | } | ||
439 | |||
440 | |||
441 | /* =========================================================================== | ||
442 | * Read a new buffer from the current input file, perform end-of-line | ||
443 | * translation, and update the crc and input file size. | ||
444 | * IN assertion: size >= 2 (for end-of-line translation) | ||
445 | */ | ||
446 | static unsigned file_read(void *buf, unsigned size) | ||
447 | { | ||
448 | unsigned len; | ||
449 | |||
450 | Assert(insize == 0, "l_buf not empty"); | ||
451 | |||
452 | len = safe_read(ifd, buf, size); | ||
453 | if (len == (unsigned)(-1) || len == 0) | ||
454 | return len; | ||
455 | |||
456 | updcrc(buf, len); | ||
457 | isize += len; | ||
458 | return len; | ||
459 | } | ||
460 | |||
461 | |||
462 | /* =========================================================================== | ||
463 | * Send a value on a given number of bits. | ||
464 | * IN assertion: length <= 16 and value fits in length bits. | ||
465 | */ | ||
466 | static void send_bits(int value, int length) | ||
467 | { | ||
468 | #ifdef DEBUG | ||
469 | Tracev((stderr, " l %2d v %4x ", length, value)); | ||
470 | Assert(length > 0 && length <= 15, "invalid length"); | ||
471 | bits_sent += length; | ||
472 | #endif | ||
473 | /* If not enough room in bi_buf, use (valid) bits from bi_buf and | ||
474 | * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) | ||
475 | * unused bits in value. | ||
476 | */ | ||
477 | if (bi_valid > (int) BUF_SIZE - length) { | ||
478 | bi_buf |= (value << bi_valid); | ||
479 | put_16bit(bi_buf); | ||
480 | bi_buf = (ush) value >> (BUF_SIZE - bi_valid); | ||
481 | bi_valid += length - BUF_SIZE; | ||
482 | } else { | ||
483 | bi_buf |= value << bi_valid; | ||
484 | bi_valid += length; | ||
485 | } | ||
486 | } | ||
487 | |||
488 | |||
489 | /* =========================================================================== | ||
490 | * Reverse the first len bits of a code, using straightforward code (a faster | ||
491 | * method would use a table) | ||
492 | * IN assertion: 1 <= len <= 15 | ||
493 | */ | ||
494 | static unsigned bi_reverse(unsigned code, int len) | ||
495 | { | ||
496 | unsigned res = 0; | ||
497 | |||
498 | while (1) { | ||
499 | res |= code & 1; | ||
500 | if (--len <= 0) return res; | ||
501 | code >>= 1; | ||
502 | res <<= 1; | ||
503 | } | ||
504 | } | ||
505 | |||
506 | |||
507 | /* =========================================================================== | ||
508 | * Write out any remaining bits in an incomplete byte. | ||
509 | */ | ||
510 | static void bi_windup(void) | ||
511 | { | ||
512 | if (bi_valid > 8) { | ||
513 | put_16bit(bi_buf); | ||
514 | } else if (bi_valid > 0) { | ||
515 | put_8bit(bi_buf); | ||
516 | } | ||
517 | bi_buf = 0; | ||
518 | bi_valid = 0; | ||
519 | #ifdef DEBUG | ||
520 | bits_sent = (bits_sent + 7) & ~7; | ||
521 | #endif | ||
522 | } | ||
523 | |||
524 | |||
525 | /* =========================================================================== | ||
526 | * Copy a stored block to the zip file, storing first the length and its | ||
527 | * one's complement if requested. | ||
528 | */ | ||
529 | static void copy_block(char *buf, unsigned len, int header) | ||
530 | { | ||
531 | bi_windup(); /* align on byte boundary */ | ||
532 | |||
533 | if (header) { | ||
534 | put_16bit(len); | ||
535 | put_16bit(~len); | ||
536 | #ifdef DEBUG | ||
537 | bits_sent += 2 * 16; | ||
538 | #endif | ||
539 | } | ||
540 | #ifdef DEBUG | ||
541 | bits_sent += (ulg) len << 3; | ||
542 | #endif | ||
543 | while (len--) { | ||
544 | put_8bit(*buf++); | ||
545 | } | ||
546 | } | ||
547 | |||
548 | |||
549 | /* =========================================================================== | ||
550 | * Fill the window when the lookahead becomes insufficient. | ||
551 | * Updates strstart and lookahead, and sets eofile if end of input file. | ||
552 | * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0 | ||
553 | * OUT assertions: at least one byte has been read, or eofile is set; | ||
554 | * file reads are performed for at least two bytes (required for the | ||
555 | * translate_eol option). | ||
556 | */ | ||
557 | static void fill_window(void) | ||
558 | { | ||
559 | unsigned n, m; | ||
560 | unsigned more = WINDOW_SIZE - lookahead - strstart; | ||
561 | /* Amount of free space at the end of the window. */ | ||
562 | |||
563 | /* If the window is almost full and there is insufficient lookahead, | ||
564 | * move the upper half to the lower one to make room in the upper half. | ||
565 | */ | ||
566 | if (more == (unsigned) -1) { | ||
567 | /* Very unlikely, but possible on 16 bit machine if strstart == 0 | ||
568 | * and lookahead == 1 (input done one byte at time) | ||
569 | */ | ||
570 | more--; | ||
571 | } else if (strstart >= WSIZE + MAX_DIST) { | ||
572 | /* By the IN assertion, the window is not empty so we can't confuse | ||
573 | * more == 0 with more == 64K on a 16 bit machine. | ||
574 | */ | ||
575 | Assert(WINDOW_SIZE == 2 * WSIZE, "no sliding with BIG_MEM"); | ||
576 | |||
577 | memcpy(window, window + WSIZE, WSIZE); | ||
578 | match_start -= WSIZE; | ||
579 | strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */ | ||
580 | |||
581 | block_start -= WSIZE; | ||
582 | |||
583 | for (n = 0; n < HASH_SIZE; n++) { | ||
584 | m = head[n]; | ||
585 | head[n] = (Pos) (m >= WSIZE ? m - WSIZE : 0); | ||
586 | } | ||
587 | for (n = 0; n < WSIZE; n++) { | ||
588 | m = prev[n]; | ||
589 | prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : 0); | ||
590 | /* If n is not on any hash chain, prev[n] is garbage but | ||
591 | * its value will never be used. | ||
592 | */ | ||
593 | } | ||
594 | more += WSIZE; | ||
595 | } | ||
596 | /* At this point, more >= 2 */ | ||
597 | if (!eofile) { | ||
598 | n = file_read(window + strstart + lookahead, more); | ||
599 | if (n == 0 || n == (unsigned) -1) { | ||
600 | eofile = 1; | ||
601 | } else { | ||
602 | lookahead += n; | ||
603 | } | ||
604 | } | ||
605 | } | ||
606 | |||
607 | |||
608 | /* =========================================================================== | ||
609 | * Set match_start to the longest match starting at the given string and | ||
610 | * return its length. Matches shorter or equal to prev_length are discarded, | ||
611 | * in which case the result is equal to prev_length and match_start is | ||
612 | * garbage. | ||
613 | * IN assertions: cur_match is the head of the hash chain for the current | ||
614 | * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 | ||
615 | */ | ||
616 | |||
617 | /* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or | ||
618 | * match.s. The code is functionally equivalent, so you can use the C version | ||
619 | * if desired. | ||
620 | */ | ||
621 | static int longest_match(IPos cur_match) | ||
622 | { | ||
623 | unsigned chain_length = max_chain_length; /* max hash chain length */ | ||
624 | uch *scan = window + strstart; /* current string */ | ||
625 | uch *match; /* matched string */ | ||
626 | int len; /* length of current match */ | ||
627 | int best_len = prev_length; /* best match length so far */ | ||
628 | IPos limit = strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : 0; | ||
629 | /* Stop when cur_match becomes <= limit. To simplify the code, | ||
630 | * we prevent matches with the string of window index 0. | ||
631 | */ | ||
632 | |||
633 | /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. | ||
634 | * It is easy to get rid of this optimization if necessary. | ||
635 | */ | ||
636 | #if HASH_BITS < 8 || MAX_MATCH != 258 | ||
637 | # error Code too clever | ||
638 | #endif | ||
639 | uch *strend = window + strstart + MAX_MATCH; | ||
640 | uch scan_end1 = scan[best_len - 1]; | ||
641 | uch scan_end = scan[best_len]; | ||
642 | |||
643 | /* Do not waste too much time if we already have a good match: */ | ||
644 | if (prev_length >= good_match) { | ||
645 | chain_length >>= 2; | ||
646 | } | ||
647 | Assert(strstart <= WINDOW_SIZE - MIN_LOOKAHEAD, "insufficient lookahead"); | ||
648 | |||
649 | do { | ||
650 | Assert(cur_match < strstart, "no future"); | ||
651 | match = window + cur_match; | ||
652 | |||
653 | /* Skip to next match if the match length cannot increase | ||
654 | * or if the match length is less than 2: | ||
655 | */ | ||
656 | if (match[best_len] != scan_end || | ||
657 | match[best_len - 1] != scan_end1 || | ||
658 | *match != *scan || *++match != scan[1]) | ||
659 | continue; | ||
660 | |||
661 | /* The check at best_len-1 can be removed because it will be made | ||
662 | * again later. (This heuristic is not always a win.) | ||
663 | * It is not necessary to compare scan[2] and match[2] since they | ||
664 | * are always equal when the other bytes match, given that | ||
665 | * the hash keys are equal and that HASH_BITS >= 8. | ||
666 | */ | ||
667 | scan += 2, match++; | ||
668 | |||
669 | /* We check for insufficient lookahead only every 8th comparison; | ||
670 | * the 256th check will be made at strstart+258. | ||
671 | */ | ||
672 | do { | ||
673 | } while (*++scan == *++match && *++scan == *++match && | ||
674 | *++scan == *++match && *++scan == *++match && | ||
675 | *++scan == *++match && *++scan == *++match && | ||
676 | *++scan == *++match && *++scan == *++match && scan < strend); | ||
677 | |||
678 | len = MAX_MATCH - (int) (strend - scan); | ||
679 | scan = strend - MAX_MATCH; | ||
680 | |||
681 | if (len > best_len) { | ||
682 | match_start = cur_match; | ||
683 | best_len = len; | ||
684 | if (len >= nice_match) | ||
685 | break; | ||
686 | scan_end1 = scan[best_len - 1]; | ||
687 | scan_end = scan[best_len]; | ||
688 | } | ||
689 | } while ((cur_match = prev[cur_match & WMASK]) > limit | ||
690 | && --chain_length != 0); | ||
691 | |||
692 | return best_len; | ||
693 | } | ||
694 | |||
695 | |||
696 | #ifdef DEBUG | ||
697 | /* =========================================================================== | ||
698 | * Check that the match at match_start is indeed a match. | ||
699 | */ | ||
700 | static void check_match(IPos start, IPos match, int length) | ||
701 | { | ||
702 | /* check that the match is indeed a match */ | ||
703 | if (memcmp(window + match, window + start, length) != 0) { | ||
704 | bb_error_msg(" start %d, match %d, length %d", start, match, length); | ||
705 | bb_error_msg("invalid match"); | ||
706 | } | ||
707 | if (verbose > 1) { | ||
708 | bb_error_msg("\\[%d,%d]", start - match, length); | ||
709 | do { | ||
710 | putc(window[start++], stderr); | ||
711 | } while (--length != 0); | ||
712 | } | ||
713 | } | ||
714 | #else | ||
715 | # define check_match(start, match, length) ((void)0) | ||
716 | #endif | ||
717 | |||
718 | |||
719 | /* trees.c -- output deflated data using Huffman coding | ||
720 | * Copyright (C) 1992-1993 Jean-loup Gailly | ||
721 | * This is free software; you can redistribute it and/or modify it under the | ||
722 | * terms of the GNU General Public License, see the file COPYING. | ||
723 | */ | ||
724 | |||
725 | /* PURPOSE | ||
726 | * Encode various sets of source values using variable-length | ||
727 | * binary code trees. | ||
728 | * | ||
729 | * DISCUSSION | ||
730 | * The PKZIP "deflation" process uses several Huffman trees. The more | ||
731 | * common source values are represented by shorter bit sequences. | ||
732 | * | ||
733 | * Each code tree is stored in the ZIP file in a compressed form | ||
734 | * which is itself a Huffman encoding of the lengths of | ||
735 | * all the code strings (in ascending order by source values). | ||
736 | * The actual code strings are reconstructed from the lengths in | ||
737 | * the UNZIP process, as described in the "application note" | ||
738 | * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program. | ||
739 | * | ||
740 | * REFERENCES | ||
741 | * Lynch, Thomas J. | ||
742 | * Data Compression: Techniques and Applications, pp. 53-55. | ||
743 | * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7. | ||
744 | * | ||
745 | * Storer, James A. | ||
746 | * Data Compression: Methods and Theory, pp. 49-50. | ||
747 | * Computer Science Press, 1988. ISBN 0-7167-8156-5. | ||
748 | * | ||
749 | * Sedgewick, R. | ||
750 | * Algorithms, p290. | ||
751 | * Addison-Wesley, 1983. ISBN 0-201-06672-6. | ||
752 | * | ||
753 | * INTERFACE | ||
754 | * void ct_init(ush *attr, int *methodp) | ||
755 | * Allocate the match buffer, initialize the various tables and save | ||
756 | * the location of the internal file attribute (ascii/binary) and | ||
757 | * method (DEFLATE/STORE) | ||
758 | * | ||
759 | * void ct_tally(int dist, int lc); | ||
760 | * Save the match info and tally the frequency counts. | ||
761 | * | ||
762 | * ulg flush_block(char *buf, ulg stored_len, int eof) | ||
763 | * Determine the best encoding for the current block: dynamic trees, | ||
764 | * static trees or store, and output the encoded block to the zip | ||
765 | * file. Returns the total compressed length for the file so far. | ||
766 | */ | ||
767 | |||
768 | #define MAX_BITS 15 | ||
769 | /* All codes must not exceed MAX_BITS bits */ | ||
770 | |||
771 | #define MAX_BL_BITS 7 | ||
772 | /* Bit length codes must not exceed MAX_BL_BITS bits */ | ||
773 | |||
774 | #define LENGTH_CODES 29 | ||
775 | /* number of length codes, not counting the special END_BLOCK code */ | ||
776 | |||
777 | #define LITERALS 256 | ||
778 | /* number of literal bytes 0..255 */ | ||
779 | |||
780 | #define END_BLOCK 256 | ||
781 | /* end of block literal code */ | ||
782 | |||
783 | #define L_CODES (LITERALS+1+LENGTH_CODES) | ||
784 | /* number of Literal or Length codes, including the END_BLOCK code */ | ||
785 | |||
786 | #define D_CODES 30 | ||
787 | /* number of distance codes */ | ||
788 | |||
789 | #define BL_CODES 19 | ||
790 | /* number of codes used to transfer the bit lengths */ | ||
791 | |||
792 | typedef uch extra_bits_t; | ||
793 | |||
794 | /* extra bits for each length code */ | ||
795 | static const extra_bits_t extra_lbits[LENGTH_CODES]= { | ||
796 | 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, | ||
797 | 4, 4, 5, 5, 5, 5, 0 | ||
798 | }; | ||
799 | |||
800 | /* extra bits for each distance code */ | ||
801 | static const extra_bits_t extra_dbits[D_CODES] = { | ||
802 | 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, | ||
803 | 10, 10, 11, 11, 12, 12, 13, 13 | ||
804 | }; | ||
805 | |||
806 | /* extra bits for each bit length code */ | ||
807 | static const extra_bits_t extra_blbits[BL_CODES] = { | ||
808 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 }; | ||
809 | |||
810 | #define STORED_BLOCK 0 | ||
811 | #define STATIC_TREES 1 | ||
812 | #define DYN_TREES 2 | ||
813 | /* The three kinds of block type */ | ||
814 | |||
815 | #ifndef LIT_BUFSIZE | ||
816 | # ifdef SMALL_MEM | ||
817 | # define LIT_BUFSIZE 0x2000 | ||
818 | # else | ||
819 | # ifdef MEDIUM_MEM | ||
820 | # define LIT_BUFSIZE 0x4000 | ||
821 | # else | ||
822 | # define LIT_BUFSIZE 0x8000 | ||
823 | # endif | ||
824 | # endif | ||
825 | #endif | ||
826 | #ifndef DIST_BUFSIZE | ||
827 | # define DIST_BUFSIZE LIT_BUFSIZE | ||
828 | #endif | ||
829 | /* Sizes of match buffers for literals/lengths and distances. There are | ||
830 | * 4 reasons for limiting LIT_BUFSIZE to 64K: | ||
831 | * - frequencies can be kept in 16 bit counters | ||
832 | * - if compression is not successful for the first block, all input data is | ||
833 | * still in the window so we can still emit a stored block even when input | ||
834 | * comes from standard input. (This can also be done for all blocks if | ||
835 | * LIT_BUFSIZE is not greater than 32K.) | ||
836 | * - if compression is not successful for a file smaller than 64K, we can | ||
837 | * even emit a stored file instead of a stored block (saving 5 bytes). | ||
838 | * - creating new Huffman trees less frequently may not provide fast | ||
839 | * adaptation to changes in the input data statistics. (Take for | ||
840 | * example a binary file with poorly compressible code followed by | ||
841 | * a highly compressible string table.) Smaller buffer sizes give | ||
842 | * fast adaptation but have of course the overhead of transmitting trees | ||
843 | * more frequently. | ||
844 | * - I can't count above 4 | ||
845 | * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save | ||
846 | * memory at the expense of compression). Some optimizations would be possible | ||
847 | * if we rely on DIST_BUFSIZE == LIT_BUFSIZE. | ||
848 | */ | ||
849 | #define REP_3_6 16 | ||
850 | /* repeat previous bit length 3-6 times (2 bits of repeat count) */ | ||
851 | #define REPZ_3_10 17 | ||
852 | /* repeat a zero length 3-10 times (3 bits of repeat count) */ | ||
853 | #define REPZ_11_138 18 | ||
854 | /* repeat a zero length 11-138 times (7 bits of repeat count) */ | ||
855 | |||
856 | /* =========================================================================== | ||
857 | */ | ||
858 | /* Data structure describing a single value and its code string. */ | ||
859 | typedef struct ct_data { | ||
860 | union { | ||
861 | ush freq; /* frequency count */ | ||
862 | ush code; /* bit string */ | ||
863 | } fc; | ||
864 | union { | ||
865 | ush dad; /* father node in Huffman tree */ | ||
866 | ush len; /* length of bit string */ | ||
867 | } dl; | ||
868 | } ct_data; | ||
869 | |||
870 | #define Freq fc.freq | ||
871 | #define Code fc.code | ||
872 | #define Dad dl.dad | ||
873 | #define Len dl.len | ||
874 | |||
875 | #define HEAP_SIZE (2*L_CODES + 1) | ||
876 | /* maximum heap size */ | ||
877 | |||
878 | ////static int heap[HEAP_SIZE]; /* heap used to build the Huffman trees */ | ||
879 | ////let's try this | ||
880 | static ush heap[HEAP_SIZE]; /* heap used to build the Huffman trees */ | ||
881 | static int heap_len; /* number of elements in the heap */ | ||
882 | static int heap_max; /* element of largest frequency */ | ||
883 | |||
884 | /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. | ||
885 | * The same heap array is used to build all trees. | ||
886 | */ | ||
887 | |||
888 | static ct_data dyn_ltree[HEAP_SIZE]; /* literal and length tree */ | ||
889 | static ct_data dyn_dtree[2 * D_CODES + 1]; /* distance tree */ | ||
890 | |||
891 | static ct_data static_ltree[L_CODES + 2]; | ||
892 | |||
893 | /* The static literal tree. Since the bit lengths are imposed, there is no | ||
894 | * need for the L_CODES extra codes used during heap construction. However | ||
895 | * The codes 286 and 287 are needed to build a canonical tree (see ct_init | ||
896 | * below). | ||
897 | */ | ||
898 | |||
899 | static ct_data static_dtree[D_CODES]; | ||
900 | |||
901 | /* The static distance tree. (Actually a trivial tree since all codes use | ||
902 | * 5 bits.) | ||
903 | */ | ||
904 | |||
905 | static ct_data bl_tree[2 * BL_CODES + 1]; | ||
906 | |||
907 | /* Huffman tree for the bit lengths */ | ||
908 | |||
909 | typedef struct tree_desc { | ||
910 | ct_data *dyn_tree; /* the dynamic tree */ | ||
911 | ct_data *static_tree; /* corresponding static tree or NULL */ | ||
912 | const extra_bits_t *extra_bits; /* extra bits for each code or NULL */ | ||
913 | int extra_base; /* base index for extra_bits */ | ||
914 | int elems; /* max number of elements in the tree */ | ||
915 | int max_length; /* max bit length for the codes */ | ||
916 | int max_code; /* largest code with non zero frequency */ | ||
917 | } tree_desc; | ||
918 | |||
919 | static tree_desc l_desc = { | ||
920 | dyn_ltree, static_ltree, extra_lbits, | ||
921 | LITERALS + 1, L_CODES, MAX_BITS, 0 | ||
922 | }; | ||
923 | |||
924 | static tree_desc d_desc = { | ||
925 | dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 | ||
926 | }; | ||
927 | |||
928 | static tree_desc bl_desc = { | ||
929 | bl_tree, NULL, extra_blbits, 0, BL_CODES, MAX_BL_BITS, 0 | ||
930 | }; | ||
931 | |||
932 | |||
933 | static ush bl_count[MAX_BITS + 1]; | ||
934 | |||
935 | /* number of codes at each bit length for an optimal tree */ | ||
936 | |||
937 | static const uch bl_order[BL_CODES] = { | ||
938 | 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 | ||
939 | }; | ||
940 | |||
941 | /* The lengths of the bit length codes are sent in order of decreasing | ||
942 | * probability, to avoid transmitting the lengths for unused bit length codes. | ||
943 | */ | ||
944 | |||
945 | static uch depth[2 * L_CODES + 1]; | ||
946 | |||
947 | /* Depth of each subtree used as tie breaker for trees of equal frequency */ | ||
948 | |||
949 | static uch length_code[MAX_MATCH - MIN_MATCH + 1]; | ||
950 | |||
951 | /* length code for each normalized match length (0 == MIN_MATCH) */ | ||
952 | |||
953 | static uch dist_code[512]; | ||
954 | |||
955 | /* distance codes. The first 256 values correspond to the distances | ||
956 | * 3 .. 258, the last 256 values correspond to the top 8 bits of | ||
957 | * the 15 bit distances. | ||
958 | */ | ||
959 | |||
960 | static int base_length[LENGTH_CODES]; | ||
961 | |||
962 | /* First normalized length for each code (0 = MIN_MATCH) */ | ||
963 | |||
964 | static int base_dist[D_CODES]; | ||
965 | |||
966 | /* First normalized distance for each code (0 = distance of 1) */ | ||
967 | |||
968 | static uch flag_buf[LIT_BUFSIZE / 8]; | ||
969 | |||
970 | /* flag_buf is a bit array distinguishing literals from lengths in | ||
971 | * l_buf, thus indicating the presence or absence of a distance. | ||
972 | */ | ||
973 | |||
974 | static unsigned last_lit; /* running index in l_buf */ | ||
975 | static unsigned last_dist; /* running index in d_buf */ | ||
976 | static unsigned last_flags; /* running index in flag_buf */ | ||
977 | static uch flags; /* current flags not yet saved in flag_buf */ | ||
978 | static uch flag_bit; /* current bit used in flags */ | ||
979 | |||
980 | /* bits are filled in flags starting at bit 0 (least significant). | ||
981 | * Note: these flags are overkill in the current code since we don't | ||
982 | * take advantage of DIST_BUFSIZE == LIT_BUFSIZE. | ||
983 | */ | ||
984 | |||
985 | static ulg opt_len; /* bit length of current block with optimal trees */ | ||
986 | static ulg static_len; /* bit length of current block with static trees */ | ||
987 | |||
988 | static ulg compressed_len; /* total bit length of compressed file */ | ||
989 | |||
990 | static ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */ | ||
991 | static int *file_method; /* pointer to DEFLATE or STORE */ | ||
992 | |||
993 | /* =========================================================================== | ||
994 | */ | ||
995 | static void gen_codes(ct_data * tree, int max_code); | ||
996 | static void build_tree(tree_desc * desc); | ||
997 | static void scan_tree(ct_data * tree, int max_code); | ||
998 | static void send_tree(ct_data * tree, int max_code); | ||
999 | static int build_bl_tree(void); | ||
1000 | static void send_all_trees(int lcodes, int dcodes, int blcodes); | ||
1001 | static void compress_block(ct_data * ltree, ct_data * dtree); | ||
1002 | |||
1003 | |||
1004 | #ifndef DEBUG | ||
1005 | /* Send a code of the given tree. c and tree must not have side effects */ | ||
1006 | # define SEND_CODE(c, tree) send_bits(tree[c].Code, tree[c].Len) | ||
1007 | #else | ||
1008 | # define SEND_CODE(c, tree) \ | ||
1009 | { \ | ||
1010 | if (verbose > 1) bb_error_msg("\ncd %3d ",(c)); \ | ||
1011 | send_bits(tree[c].Code, tree[c].Len); \ | ||
1012 | } | ||
1013 | #endif | ||
1014 | |||
1015 | #define D_CODE(dist) \ | ||
1016 | ((dist) < 256 ? dist_code[dist] : dist_code[256 + ((dist)>>7)]) | ||
1017 | /* Mapping from a distance to a distance code. dist is the distance - 1 and | ||
1018 | * must not have side effects. dist_code[256] and dist_code[257] are never | ||
1019 | * used. | ||
1020 | * The arguments must not have side effects. | ||
1021 | */ | ||
1022 | |||
1023 | |||
1024 | /* =========================================================================== | ||
1025 | * Initialize a new block. | ||
1026 | */ | ||
1027 | static void init_block(void) | ||
1028 | { | ||
1029 | int n; /* iterates over tree elements */ | ||
1030 | |||
1031 | /* Initialize the trees. */ | ||
1032 | for (n = 0; n < L_CODES; n++) | ||
1033 | dyn_ltree[n].Freq = 0; | ||
1034 | for (n = 0; n < D_CODES; n++) | ||
1035 | dyn_dtree[n].Freq = 0; | ||
1036 | for (n = 0; n < BL_CODES; n++) | ||
1037 | bl_tree[n].Freq = 0; | ||
1038 | |||
1039 | dyn_ltree[END_BLOCK].Freq = 1; | ||
1040 | opt_len = static_len = 0; | ||
1041 | last_lit = last_dist = last_flags = 0; | ||
1042 | flags = 0; | ||
1043 | flag_bit = 1; | ||
1044 | } | ||
1045 | |||
1046 | |||
1047 | /* =========================================================================== | ||
1048 | * Restore the heap property by moving down the tree starting at node k, | ||
1049 | * exchanging a node with the smallest of its two sons if necessary, stopping | ||
1050 | * when the heap property is re-established (each father smaller than its | ||
1051 | * two sons). | ||
1052 | */ | ||
1053 | |||
1054 | /* Compares to subtrees, using the tree depth as tie breaker when | ||
1055 | * the subtrees have equal frequency. This minimizes the worst case length. */ | ||
1056 | #define SMALLER(tree, n, m) \ | ||
1057 | (tree[n].Freq < tree[m].Freq \ | ||
1058 | || (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) | ||
1059 | |||
1060 | static void pqdownheap(ct_data * tree, int k) | ||
1061 | { | ||
1062 | int v = heap[k]; | ||
1063 | int j = k << 1; /* left son of k */ | ||
1064 | |||
1065 | while (j <= heap_len) { | ||
1066 | /* Set j to the smallest of the two sons: */ | ||
1067 | if (j < heap_len && SMALLER(tree, heap[j + 1], heap[j])) | ||
1068 | j++; | ||
1069 | |||
1070 | /* Exit if v is smaller than both sons */ | ||
1071 | if (SMALLER(tree, v, heap[j])) | ||
1072 | break; | ||
1073 | |||
1074 | /* Exchange v with the smallest son */ | ||
1075 | heap[k] = heap[j]; | ||
1076 | k = j; | ||
1077 | |||
1078 | /* And continue down the tree, setting j to the left son of k */ | ||
1079 | j <<= 1; | ||
1080 | } | ||
1081 | heap[k] = v; | ||
1082 | } | ||
1083 | |||
1084 | |||
1085 | /* =========================================================================== | ||
1086 | * Compute the optimal bit lengths for a tree and update the total bit length | ||
1087 | * for the current block. | ||
1088 | * IN assertion: the fields freq and dad are set, heap[heap_max] and | ||
1089 | * above are the tree nodes sorted by increasing frequency. | ||
1090 | * OUT assertions: the field len is set to the optimal bit length, the | ||
1091 | * array bl_count contains the frequencies for each bit length. | ||
1092 | * The length opt_len is updated; static_len is also updated if stree is | ||
1093 | * not null. | ||
1094 | */ | ||
1095 | static void gen_bitlen(tree_desc * desc) | ||
1096 | { | ||
1097 | ct_data *tree = desc->dyn_tree; | ||
1098 | const extra_bits_t *extra = desc->extra_bits; | ||
1099 | int base = desc->extra_base; | ||
1100 | int max_code = desc->max_code; | ||
1101 | int max_length = desc->max_length; | ||
1102 | ct_data *stree = desc->static_tree; | ||
1103 | int h; /* heap index */ | ||
1104 | int n, m; /* iterate over the tree elements */ | ||
1105 | int bits; /* bit length */ | ||
1106 | int xbits; /* extra bits */ | ||
1107 | ush f; /* frequency */ | ||
1108 | int overflow = 0; /* number of elements with bit length too large */ | ||
1109 | |||
1110 | for (bits = 0; bits <= MAX_BITS; bits++) | ||
1111 | bl_count[bits] = 0; | ||
1112 | |||
1113 | /* In a first pass, compute the optimal bit lengths (which may | ||
1114 | * overflow in the case of the bit length tree). | ||
1115 | */ | ||
1116 | tree[heap[heap_max]].Len = 0; /* root of the heap */ | ||
1117 | |||
1118 | for (h = heap_max + 1; h < HEAP_SIZE; h++) { | ||
1119 | n = heap[h]; | ||
1120 | bits = tree[tree[n].Dad].Len + 1; | ||
1121 | if (bits > max_length) { | ||
1122 | bits = max_length; | ||
1123 | overflow++; | ||
1124 | } | ||
1125 | tree[n].Len = (ush) bits; | ||
1126 | /* We overwrite tree[n].Dad which is no longer needed */ | ||
1127 | |||
1128 | if (n > max_code) | ||
1129 | continue; /* not a leaf node */ | ||
1130 | |||
1131 | bl_count[bits]++; | ||
1132 | xbits = 0; | ||
1133 | if (n >= base) | ||
1134 | xbits = extra[n - base]; | ||
1135 | f = tree[n].Freq; | ||
1136 | opt_len += (ulg) f *(bits + xbits); | ||
1137 | |||
1138 | if (stree) | ||
1139 | static_len += (ulg) f * (stree[n].Len + xbits); | ||
1140 | } | ||
1141 | if (overflow == 0) | ||
1142 | return; | ||
1143 | |||
1144 | Trace((stderr, "\nbit length overflow\n")); | ||
1145 | /* This happens for example on obj2 and pic of the Calgary corpus */ | ||
1146 | |||
1147 | /* Find the first bit length which could increase: */ | ||
1148 | do { | ||
1149 | bits = max_length - 1; | ||
1150 | while (bl_count[bits] == 0) | ||
1151 | bits--; | ||
1152 | bl_count[bits]--; /* move one leaf down the tree */ | ||
1153 | bl_count[bits + 1] += 2; /* move one overflow item as its brother */ | ||
1154 | bl_count[max_length]--; | ||
1155 | /* The brother of the overflow item also moves one step up, | ||
1156 | * but this does not affect bl_count[max_length] | ||
1157 | */ | ||
1158 | overflow -= 2; | ||
1159 | } while (overflow > 0); | ||
1160 | |||
1161 | /* Now recompute all bit lengths, scanning in increasing frequency. | ||
1162 | * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all | ||
1163 | * lengths instead of fixing only the wrong ones. This idea is taken | ||
1164 | * from 'ar' written by Haruhiko Okumura.) | ||
1165 | */ | ||
1166 | for (bits = max_length; bits != 0; bits--) { | ||
1167 | n = bl_count[bits]; | ||
1168 | while (n != 0) { | ||
1169 | m = heap[--h]; | ||
1170 | if (m > max_code) | ||
1171 | continue; | ||
1172 | if (tree[m].Len != (unsigned) bits) { | ||
1173 | Trace((stderr, "code %d bits %d->%d\n", m, tree[m].Len, bits)); | ||
1174 | opt_len += ((int32_t) bits - tree[m].Len) * tree[m].Freq; | ||
1175 | tree[m].Len = bits; | ||
1176 | } | ||
1177 | n--; | ||
1178 | } | ||
1179 | } | ||
1180 | } | ||
1181 | |||
1182 | |||
1183 | /* =========================================================================== | ||
1184 | * Generate the codes for a given tree and bit counts (which need not be | ||
1185 | * optimal). | ||
1186 | * IN assertion: the array bl_count contains the bit length statistics for | ||
1187 | * the given tree and the field len is set for all tree elements. | ||
1188 | * OUT assertion: the field code is set for all tree elements of non | ||
1189 | * zero code length. | ||
1190 | */ | ||
1191 | static void gen_codes(ct_data * tree, int max_code) | ||
1192 | { | ||
1193 | ush next_code[MAX_BITS + 1]; /* next code value for each bit length */ | ||
1194 | ush code = 0; /* running code value */ | ||
1195 | int bits; /* bit index */ | ||
1196 | int n; /* code index */ | ||
1197 | |||
1198 | /* The distribution counts are first used to generate the code values | ||
1199 | * without bit reversal. | ||
1200 | */ | ||
1201 | for (bits = 1; bits <= MAX_BITS; bits++) { | ||
1202 | next_code[bits] = code = (code + bl_count[bits - 1]) << 1; | ||
1203 | } | ||
1204 | /* Check that the bit counts in bl_count are consistent. The last code | ||
1205 | * must be all ones. | ||
1206 | */ | ||
1207 | Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1, | ||
1208 | "inconsistent bit counts"); | ||
1209 | Tracev((stderr, "\ngen_codes: max_code %d ", max_code)); | ||
1210 | |||
1211 | for (n = 0; n <= max_code; n++) { | ||
1212 | int len = tree[n].Len; | ||
1213 | |||
1214 | if (len == 0) | ||
1215 | continue; | ||
1216 | /* Now reverse the bits */ | ||
1217 | tree[n].Code = bi_reverse(next_code[len]++, len); | ||
1218 | |||
1219 | Tracec(tree != static_ltree, | ||
1220 | (stderr, "\nn %3d %c l %2d c %4x (%x) ", n, | ||
1221 | (isgraph(n) ? n : ' '), len, tree[n].Code, | ||
1222 | next_code[len] - 1)); | ||
1223 | } | ||
1224 | } | ||
1225 | |||
1226 | |||
1227 | /* =========================================================================== | ||
1228 | * Construct one Huffman tree and assigns the code bit strings and lengths. | ||
1229 | * Update the total bit length for the current block. | ||
1230 | * IN assertion: the field freq is set for all tree elements. | ||
1231 | * OUT assertions: the fields len and code are set to the optimal bit length | ||
1232 | * and corresponding code. The length opt_len is updated; static_len is | ||
1233 | * also updated if stree is not null. The field max_code is set. | ||
1234 | */ | ||
1235 | |||
1236 | /* Remove the smallest element from the heap and recreate the heap with | ||
1237 | * one less element. Updates heap and heap_len. */ | ||
1238 | |||
1239 | #define SMALLEST 1 | ||
1240 | /* Index within the heap array of least frequent node in the Huffman tree */ | ||
1241 | |||
1242 | #define PQREMOVE(tree, top) \ | ||
1243 | { \ | ||
1244 | top = heap[SMALLEST]; \ | ||
1245 | heap[SMALLEST] = heap[heap_len--]; \ | ||
1246 | pqdownheap(tree, SMALLEST); \ | ||
1247 | } | ||
1248 | |||
1249 | static void build_tree(tree_desc * desc) | ||
1250 | { | ||
1251 | ct_data *tree = desc->dyn_tree; | ||
1252 | ct_data *stree = desc->static_tree; | ||
1253 | int elems = desc->elems; | ||
1254 | int n, m; /* iterate over heap elements */ | ||
1255 | int max_code = -1; /* largest code with non zero frequency */ | ||
1256 | int node = elems; /* next internal node of the tree */ | ||
1257 | |||
1258 | /* Construct the initial heap, with least frequent element in | ||
1259 | * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. | ||
1260 | * heap[0] is not used. | ||
1261 | */ | ||
1262 | heap_len = 0, heap_max = HEAP_SIZE; | ||
1263 | |||
1264 | for (n = 0; n < elems; n++) { | ||
1265 | if (tree[n].Freq != 0) { | ||
1266 | heap[++heap_len] = max_code = n; | ||
1267 | depth[n] = 0; | ||
1268 | } else { | ||
1269 | tree[n].Len = 0; | ||
1270 | } | ||
1271 | } | ||
1272 | |||
1273 | /* The pkzip format requires that at least one distance code exists, | ||
1274 | * and that at least one bit should be sent even if there is only one | ||
1275 | * possible code. So to avoid special checks later on we force at least | ||
1276 | * two codes of non zero frequency. | ||
1277 | */ | ||
1278 | while (heap_len < 2) { | ||
1279 | int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0); | ||
1280 | |||
1281 | tree[new].Freq = 1; | ||
1282 | depth[new] = 0; | ||
1283 | opt_len--; | ||
1284 | if (stree) | ||
1285 | static_len -= stree[new].Len; | ||
1286 | /* new is 0 or 1 so it does not have extra bits */ | ||
1287 | } | ||
1288 | desc->max_code = max_code; | ||
1289 | |||
1290 | /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, | ||
1291 | * establish sub-heaps of increasing lengths: | ||
1292 | */ | ||
1293 | for (n = heap_len / 2; n >= 1; n--) | ||
1294 | pqdownheap(tree, n); | ||
1295 | |||
1296 | /* Construct the Huffman tree by repeatedly combining the least two | ||
1297 | * frequent nodes. | ||
1298 | */ | ||
1299 | do { | ||
1300 | PQREMOVE(tree, n); /* n = node of least frequency */ | ||
1301 | m = heap[SMALLEST]; /* m = node of next least frequency */ | ||
1302 | |||
1303 | heap[--heap_max] = n; /* keep the nodes sorted by frequency */ | ||
1304 | heap[--heap_max] = m; | ||
1305 | |||
1306 | /* Create a new node father of n and m */ | ||
1307 | tree[node].Freq = tree[n].Freq + tree[m].Freq; | ||
1308 | depth[node] = MAX(depth[n], depth[m]) + 1; | ||
1309 | tree[n].Dad = tree[m].Dad = (ush) node; | ||
1310 | #ifdef DUMP_BL_TREE | ||
1311 | if (tree == bl_tree) { | ||
1312 | bb_error_msg("\nnode %d(%d), sons %d(%d) %d(%d)", | ||
1313 | node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); | ||
1314 | } | ||
1315 | #endif | ||
1316 | /* and insert the new node in the heap */ | ||
1317 | heap[SMALLEST] = node++; | ||
1318 | pqdownheap(tree, SMALLEST); | ||
1319 | |||
1320 | } while (heap_len >= 2); | ||
1321 | |||
1322 | heap[--heap_max] = heap[SMALLEST]; | ||
1323 | |||
1324 | /* At this point, the fields freq and dad are set. We can now | ||
1325 | * generate the bit lengths. | ||
1326 | */ | ||
1327 | gen_bitlen((tree_desc *) desc); | ||
1328 | |||
1329 | /* The field len is now set, we can generate the bit codes */ | ||
1330 | gen_codes((ct_data *) tree, max_code); | ||
1331 | } | ||
1332 | |||
1333 | |||
1334 | /* =========================================================================== | ||
1335 | * Scan a literal or distance tree to determine the frequencies of the codes | ||
1336 | * in the bit length tree. Updates opt_len to take into account the repeat | ||
1337 | * counts. (The contribution of the bit length codes will be added later | ||
1338 | * during the construction of bl_tree.) | ||
1339 | */ | ||
1340 | static void scan_tree(ct_data * tree, int max_code) | ||
1341 | { | ||
1342 | int n; /* iterates over all tree elements */ | ||
1343 | int prevlen = -1; /* last emitted length */ | ||
1344 | int curlen; /* length of current code */ | ||
1345 | int nextlen = tree[0].Len; /* length of next code */ | ||
1346 | int count = 0; /* repeat count of the current code */ | ||
1347 | int max_count = 7; /* max repeat count */ | ||
1348 | int min_count = 4; /* min repeat count */ | ||
1349 | |||
1350 | if (nextlen == 0) { | ||
1351 | max_count = 138; | ||
1352 | min_count = 3; | ||
1353 | } | ||
1354 | tree[max_code + 1].Len = 0xffff; /* guard */ | ||
1355 | |||
1356 | for (n = 0; n <= max_code; n++) { | ||
1357 | curlen = nextlen; | ||
1358 | nextlen = tree[n + 1].Len; | ||
1359 | if (++count < max_count && curlen == nextlen) | ||
1360 | continue; | ||
1361 | |||
1362 | if (count < min_count) { | ||
1363 | bl_tree[curlen].Freq += count; | ||
1364 | } else if (curlen != 0) { | ||
1365 | if (curlen != prevlen) | ||
1366 | bl_tree[curlen].Freq++; | ||
1367 | bl_tree[REP_3_6].Freq++; | ||
1368 | } else if (count <= 10) { | ||
1369 | bl_tree[REPZ_3_10].Freq++; | ||
1370 | } else { | ||
1371 | bl_tree[REPZ_11_138].Freq++; | ||
1372 | } | ||
1373 | count = 0; | ||
1374 | prevlen = curlen; | ||
1375 | |||
1376 | max_count = 7; | ||
1377 | min_count = 4; | ||
1378 | if (nextlen == 0) { | ||
1379 | max_count = 138; | ||
1380 | min_count = 3; | ||
1381 | } else if (curlen == nextlen) { | ||
1382 | max_count = 6; | ||
1383 | min_count = 3; | ||
1384 | } | ||
1385 | } | ||
1386 | } | ||
1387 | |||
1388 | |||
1389 | /* =========================================================================== | ||
1390 | * Send a literal or distance tree in compressed form, using the codes in | ||
1391 | * bl_tree. | ||
1392 | */ | ||
1393 | static void send_tree(ct_data * tree, int max_code) | ||
1394 | { | ||
1395 | int n; /* iterates over all tree elements */ | ||
1396 | int prevlen = -1; /* last emitted length */ | ||
1397 | int curlen; /* length of current code */ | ||
1398 | int nextlen = tree[0].Len; /* length of next code */ | ||
1399 | int count = 0; /* repeat count of the current code */ | ||
1400 | int max_count = 7; /* max repeat count */ | ||
1401 | int min_count = 4; /* min repeat count */ | ||
1402 | |||
1403 | /* tree[max_code+1].Len = -1; *//* guard already set */ | ||
1404 | if (nextlen == 0) | ||
1405 | max_count = 138, min_count = 3; | ||
1406 | |||
1407 | for (n = 0; n <= max_code; n++) { | ||
1408 | curlen = nextlen; | ||
1409 | nextlen = tree[n + 1].Len; | ||
1410 | if (++count < max_count && curlen == nextlen) { | ||
1411 | continue; | ||
1412 | } else if (count < min_count) { | ||
1413 | do { | ||
1414 | SEND_CODE(curlen, bl_tree); | ||
1415 | } while (--count); | ||
1416 | } else if (curlen != 0) { | ||
1417 | if (curlen != prevlen) { | ||
1418 | SEND_CODE(curlen, bl_tree); | ||
1419 | count--; | ||
1420 | } | ||
1421 | Assert(count >= 3 && count <= 6, " 3_6?"); | ||
1422 | SEND_CODE(REP_3_6, bl_tree); | ||
1423 | send_bits(count - 3, 2); | ||
1424 | } else if (count <= 10) { | ||
1425 | SEND_CODE(REPZ_3_10, bl_tree); | ||
1426 | send_bits(count - 3, 3); | ||
1427 | } else { | ||
1428 | SEND_CODE(REPZ_11_138, bl_tree); | ||
1429 | send_bits(count - 11, 7); | ||
1430 | } | ||
1431 | count = 0; | ||
1432 | prevlen = curlen; | ||
1433 | if (nextlen == 0) { | ||
1434 | max_count = 138; | ||
1435 | min_count = 3; | ||
1436 | } else if (curlen == nextlen) { | ||
1437 | max_count = 6; | ||
1438 | min_count = 3; | ||
1439 | } else { | ||
1440 | max_count = 7; | ||
1441 | min_count = 4; | ||
1442 | } | ||
1443 | } | ||
1444 | } | ||
1445 | |||
1446 | |||
1447 | /* =========================================================================== | ||
1448 | * Construct the Huffman tree for the bit lengths and return the index in | ||
1449 | * bl_order of the last bit length code to send. | ||
1450 | */ | ||
1451 | static int build_bl_tree(void) | ||
1452 | { | ||
1453 | int max_blindex; /* index of last bit length code of non zero freq */ | ||
1454 | |||
1455 | /* Determine the bit length frequencies for literal and distance trees */ | ||
1456 | scan_tree((ct_data *) dyn_ltree, l_desc.max_code); | ||
1457 | scan_tree((ct_data *) dyn_dtree, d_desc.max_code); | ||
1458 | |||
1459 | /* Build the bit length tree: */ | ||
1460 | build_tree((tree_desc *) &bl_desc); | ||
1461 | /* opt_len now includes the length of the tree representations, except | ||
1462 | * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. | ||
1463 | */ | ||
1464 | |||
1465 | /* Determine the number of bit length codes to send. The pkzip format | ||
1466 | * requires that at least 4 bit length codes be sent. (appnote.txt says | ||
1467 | * 3 but the actual value used is 4.) | ||
1468 | */ | ||
1469 | for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) { | ||
1470 | if (bl_tree[bl_order[max_blindex]].Len != 0) | ||
1471 | break; | ||
1472 | } | ||
1473 | /* Update opt_len to include the bit length tree and counts */ | ||
1474 | opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4; | ||
1475 | Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len)); | ||
1476 | |||
1477 | return max_blindex; | ||
1478 | } | ||
1479 | |||
1480 | |||
1481 | /* =========================================================================== | ||
1482 | * Send the header for a block using dynamic Huffman trees: the counts, the | ||
1483 | * lengths of the bit length codes, the literal tree and the distance tree. | ||
1484 | * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. | ||
1485 | */ | ||
1486 | static void send_all_trees(int lcodes, int dcodes, int blcodes) | ||
1487 | { | ||
1488 | int rank; /* index in bl_order */ | ||
1489 | |||
1490 | Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); | ||
1491 | Assert(lcodes <= L_CODES && dcodes <= D_CODES | ||
1492 | && blcodes <= BL_CODES, "too many codes"); | ||
1493 | Tracev((stderr, "\nbl counts: ")); | ||
1494 | send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */ | ||
1495 | send_bits(dcodes - 1, 5); | ||
1496 | send_bits(blcodes - 4, 4); /* not -3 as stated in appnote.txt */ | ||
1497 | for (rank = 0; rank < blcodes; rank++) { | ||
1498 | Tracev((stderr, "\nbl code %2d ", bl_order[rank])); | ||
1499 | send_bits(bl_tree[bl_order[rank]].Len, 3); | ||
1500 | } | ||
1501 | Tracev((stderr, "\nbl tree: sent %ld", bits_sent)); | ||
1502 | |||
1503 | send_tree((ct_data *) dyn_ltree, lcodes - 1); /* send the literal tree */ | ||
1504 | Tracev((stderr, "\nlit tree: sent %ld", bits_sent)); | ||
1505 | |||
1506 | send_tree((ct_data *) dyn_dtree, dcodes - 1); /* send the distance tree */ | ||
1507 | Tracev((stderr, "\ndist tree: sent %ld", bits_sent)); | ||
1508 | } | ||
1509 | |||
1510 | |||
1511 | /* =========================================================================== | ||
1512 | * Set the file type to ASCII or BINARY, using a crude approximation: | ||
1513 | * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. | ||
1514 | * IN assertion: the fields freq of dyn_ltree are set and the total of all | ||
1515 | * frequencies does not exceed 64K (to fit in an int on 16 bit machines). | ||
1516 | */ | ||
1517 | static void set_file_type(void) | ||
1518 | { | ||
1519 | int n = 0; | ||
1520 | unsigned ascii_freq = 0; | ||
1521 | unsigned bin_freq = 0; | ||
1522 | |||
1523 | while (n < 7) | ||
1524 | bin_freq += dyn_ltree[n++].Freq; | ||
1525 | while (n < 128) | ||
1526 | ascii_freq += dyn_ltree[n++].Freq; | ||
1527 | while (n < LITERALS) | ||
1528 | bin_freq += dyn_ltree[n++].Freq; | ||
1529 | *file_type = (bin_freq > (ascii_freq >> 2)) ? BINARY : ASCII; | ||
1530 | if (*file_type == BINARY && translate_eol) { | ||
1531 | bb_error_msg("-l used on binary file"); | ||
1532 | } | ||
1533 | } | ||
1534 | |||
1535 | |||
1536 | /* =========================================================================== | ||
1537 | * Save the match info and tally the frequency counts. Return true if | ||
1538 | * the current block must be flushed. | ||
1539 | */ | ||
1540 | static int ct_tally(int dist, int lc) | ||
1541 | { | ||
1542 | l_buf[last_lit++] = lc; | ||
1543 | if (dist == 0) { | ||
1544 | /* lc is the unmatched char */ | ||
1545 | dyn_ltree[lc].Freq++; | ||
1546 | } else { | ||
1547 | /* Here, lc is the match length - MIN_MATCH */ | ||
1548 | dist--; /* dist = match distance - 1 */ | ||
1549 | Assert((ush) dist < (ush) MAX_DIST | ||
1550 | && (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) | ||
1551 | && (ush) D_CODE(dist) < (ush) D_CODES, "ct_tally: bad match" | ||
1552 | ); | ||
1553 | |||
1554 | dyn_ltree[length_code[lc] + LITERALS + 1].Freq++; | ||
1555 | dyn_dtree[D_CODE(dist)].Freq++; | ||
1556 | |||
1557 | d_buf[last_dist++] = dist; | ||
1558 | flags |= flag_bit; | ||
1559 | } | ||
1560 | flag_bit <<= 1; | ||
1561 | |||
1562 | /* Output the flags if they fill a byte: */ | ||
1563 | if ((last_lit & 7) == 0) { | ||
1564 | flag_buf[last_flags++] = flags; | ||
1565 | flags = 0, flag_bit = 1; | ||
1566 | } | ||
1567 | /* Try to guess if it is profitable to stop the current block here */ | ||
1568 | if ((last_lit & 0xfff) == 0) { | ||
1569 | /* Compute an upper bound for the compressed length */ | ||
1570 | ulg out_length = last_lit * 8L; | ||
1571 | ulg in_length = (ulg) strstart - block_start; | ||
1572 | int dcode; | ||
1573 | |||
1574 | for (dcode = 0; dcode < D_CODES; dcode++) { | ||
1575 | out_length += dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]); | ||
1576 | } | ||
1577 | out_length >>= 3; | ||
1578 | Trace((stderr, | ||
1579 | "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ", | ||
1580 | last_lit, last_dist, in_length, out_length, | ||
1581 | 100L - out_length * 100L / in_length)); | ||
1582 | if (last_dist < last_lit / 2 && out_length < in_length / 2) | ||
1583 | return 1; | ||
1584 | } | ||
1585 | return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE); | ||
1586 | /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K | ||
1587 | * on 16 bit machines and because stored blocks are restricted to | ||
1588 | * 64K-1 bytes. | ||
1589 | */ | ||
1590 | } | ||
1591 | |||
1592 | /* =========================================================================== | ||
1593 | * Send the block data compressed using the given Huffman trees | ||
1594 | */ | ||
1595 | static void compress_block(ct_data * ltree, ct_data * dtree) | ||
1596 | { | ||
1597 | unsigned dist; /* distance of matched string */ | ||
1598 | int lc; /* match length or unmatched char (if dist == 0) */ | ||
1599 | unsigned lx = 0; /* running index in l_buf */ | ||
1600 | unsigned dx = 0; /* running index in d_buf */ | ||
1601 | unsigned fx = 0; /* running index in flag_buf */ | ||
1602 | uch flag = 0; /* current flags */ | ||
1603 | unsigned code; /* the code to send */ | ||
1604 | int extra; /* number of extra bits to send */ | ||
1605 | |||
1606 | if (last_lit != 0) do { | ||
1607 | if ((lx & 7) == 0) | ||
1608 | flag = flag_buf[fx++]; | ||
1609 | lc = l_buf[lx++]; | ||
1610 | if ((flag & 1) == 0) { | ||
1611 | SEND_CODE(lc, ltree); /* send a literal byte */ | ||
1612 | Tracecv(isgraph(lc), (stderr, " '%c' ", lc)); | ||
1613 | } else { | ||
1614 | /* Here, lc is the match length - MIN_MATCH */ | ||
1615 | code = length_code[lc]; | ||
1616 | SEND_CODE(code + LITERALS + 1, ltree); /* send the length code */ | ||
1617 | extra = extra_lbits[code]; | ||
1618 | if (extra != 0) { | ||
1619 | lc -= base_length[code]; | ||
1620 | send_bits(lc, extra); /* send the extra length bits */ | ||
1621 | } | ||
1622 | dist = d_buf[dx++]; | ||
1623 | /* Here, dist is the match distance - 1 */ | ||
1624 | code = D_CODE(dist); | ||
1625 | Assert(code < D_CODES, "bad d_code"); | ||
1626 | |||
1627 | SEND_CODE(code, dtree); /* send the distance code */ | ||
1628 | extra = extra_dbits[code]; | ||
1629 | if (extra != 0) { | ||
1630 | dist -= base_dist[code]; | ||
1631 | send_bits(dist, extra); /* send the extra distance bits */ | ||
1632 | } | ||
1633 | } /* literal or match pair ? */ | ||
1634 | flag >>= 1; | ||
1635 | } while (lx < last_lit); | ||
1636 | |||
1637 | SEND_CODE(END_BLOCK, ltree); | ||
1638 | } | ||
1639 | |||
1640 | |||
1641 | /* =========================================================================== | ||
1642 | * Determine the best encoding for the current block: dynamic trees, static | ||
1643 | * trees or store, and output the encoded block to the zip file. This function | ||
1644 | * returns the total compressed length for the file so far. | ||
1645 | */ | ||
1646 | static ulg flush_block(char *buf, ulg stored_len, int eof) | ||
1647 | { | ||
1648 | ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ | ||
1649 | int max_blindex; /* index of last bit length code of non zero freq */ | ||
1650 | |||
1651 | flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */ | ||
1652 | |||
1653 | /* Check if the file is ascii or binary */ | ||
1654 | if (*file_type == (ush) UNKNOWN) | ||
1655 | set_file_type(); | ||
1656 | |||
1657 | /* Construct the literal and distance trees */ | ||
1658 | build_tree((tree_desc *) &l_desc); | ||
1659 | Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len)); | ||
1660 | |||
1661 | build_tree((tree_desc *) &d_desc); | ||
1662 | Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len)); | ||
1663 | /* At this point, opt_len and static_len are the total bit lengths of | ||
1664 | * the compressed block data, excluding the tree representations. | ||
1665 | */ | ||
1666 | |||
1667 | /* Build the bit length tree for the above two trees, and get the index | ||
1668 | * in bl_order of the last bit length code to send. | ||
1669 | */ | ||
1670 | max_blindex = build_bl_tree(); | ||
1671 | |||
1672 | /* Determine the best encoding. Compute first the block length in bytes */ | ||
1673 | opt_lenb = (opt_len + 3 + 7) >> 3; | ||
1674 | static_lenb = (static_len + 3 + 7) >> 3; | ||
1675 | |||
1676 | Trace((stderr, | ||
1677 | "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ", | ||
1678 | opt_lenb, opt_len, static_lenb, static_len, stored_len, | ||
1679 | last_lit, last_dist)); | ||
1680 | |||
1681 | if (static_lenb <= opt_lenb) | ||
1682 | opt_lenb = static_lenb; | ||
1683 | |||
1684 | /* If compression failed and this is the first and last block, | ||
1685 | * and if the zip file can be seeked (to rewrite the local header), | ||
1686 | * the whole file is transformed into a stored file: | ||
1687 | */ | ||
1688 | if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) { | ||
1689 | /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ | ||
1690 | if (buf == NULL) | ||
1691 | bb_error_msg("block vanished"); | ||
1692 | |||
1693 | copy_block(buf, (unsigned) stored_len, 0); /* without header */ | ||
1694 | compressed_len = stored_len << 3; | ||
1695 | *file_method = STORED; | ||
1696 | |||
1697 | } else if (stored_len + 4 <= opt_lenb && buf != NULL) { | ||
1698 | /* 4: two words for the lengths */ | ||
1699 | /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. | ||
1700 | * Otherwise we can't have processed more than WSIZE input bytes since | ||
1701 | * the last block flush, because compression would have been | ||
1702 | * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to | ||
1703 | * transform a block into a stored block. | ||
1704 | */ | ||
1705 | send_bits((STORED_BLOCK << 1) + eof, 3); /* send block type */ | ||
1706 | compressed_len = (compressed_len + 3 + 7) & ~7L; | ||
1707 | compressed_len += (stored_len + 4) << 3; | ||
1708 | |||
1709 | copy_block(buf, (unsigned) stored_len, 1); /* with header */ | ||
1710 | |||
1711 | } else if (static_lenb == opt_lenb) { | ||
1712 | send_bits((STATIC_TREES << 1) + eof, 3); | ||
1713 | compress_block((ct_data *) static_ltree, (ct_data *) static_dtree); | ||
1714 | compressed_len += 3 + static_len; | ||
1715 | } else { | ||
1716 | send_bits((DYN_TREES << 1) + eof, 3); | ||
1717 | send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, | ||
1718 | max_blindex + 1); | ||
1719 | compress_block((ct_data *) dyn_ltree, (ct_data *) dyn_dtree); | ||
1720 | compressed_len += 3 + opt_len; | ||
1721 | } | ||
1722 | Assert(compressed_len == bits_sent, "bad compressed size"); | ||
1723 | init_block(); | ||
1724 | |||
1725 | if (eof) { | ||
1726 | bi_windup(); | ||
1727 | compressed_len += 7; /* align on byte boundary */ | ||
1728 | } | ||
1729 | Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3, | ||
1730 | compressed_len - 7 * eof)); | ||
1731 | |||
1732 | return compressed_len >> 3; | ||
1733 | } | ||
1734 | |||
1735 | |||
1736 | /* =========================================================================== | ||
1737 | * Update a hash value with the given input byte | ||
1738 | * IN assertion: all calls to to UPDATE_HASH are made with consecutive | ||
1739 | * input characters, so that a running hash key can be computed from the | ||
1740 | * previous key instead of complete recalculation each time. | ||
1741 | */ | ||
1742 | #define UPDATE_HASH(h, c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK) | ||
1743 | |||
1744 | |||
1745 | /* =========================================================================== | ||
1746 | * Same as above, but achieves better compression. We use a lazy | ||
1747 | * evaluation for matches: a match is finally adopted only if there is | ||
1748 | * no better match at the next window position. | ||
1749 | * | ||
1750 | * Processes a new input file and return its compressed length. Sets | ||
1751 | * the compressed length, crc, deflate flags and internal file | ||
1752 | * attributes. | ||
1753 | */ | ||
1754 | |||
1755 | /* Flush the current block, with given end-of-file flag. | ||
1756 | * IN assertion: strstart is set to the end of the current match. */ | ||
1757 | #define FLUSH_BLOCK(eof) \ | ||
1758 | flush_block( \ | ||
1759 | block_start >= 0L \ | ||
1760 | ? (char*)&window[(unsigned)block_start] \ | ||
1761 | : (char*)NULL, \ | ||
1762 | (ulg)strstart - block_start, \ | ||
1763 | (eof) \ | ||
1764 | ) | ||
1765 | |||
1766 | /* Insert string s in the dictionary and set match_head to the previous head | ||
1767 | * of the hash chain (the most recent string with same hash key). Return | ||
1768 | * the previous length of the hash chain. | ||
1769 | * IN assertion: all calls to to INSERT_STRING are made with consecutive | ||
1770 | * input characters and the first MIN_MATCH bytes of s are valid | ||
1771 | * (except for the last MIN_MATCH-1 bytes of the input file). */ | ||
1772 | #define INSERT_STRING(s, match_head) \ | ||
1773 | { \ | ||
1774 | UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]); \ | ||
1775 | prev[(s) & WMASK] = match_head = head[ins_h]; \ | ||
1776 | head[ins_h] = (s); \ | ||
1777 | } | ||
1778 | |||
1779 | static ulg deflate(void) | ||
1780 | { | ||
1781 | IPos hash_head; /* head of hash chain */ | ||
1782 | IPos prev_match; /* previous match */ | ||
1783 | int flush; /* set if current block must be flushed */ | ||
1784 | int match_available = 0; /* set if previous match exists */ | ||
1785 | unsigned match_length = MIN_MATCH - 1; /* length of best match */ | ||
1786 | |||
1787 | /* Process the input block. */ | ||
1788 | while (lookahead != 0) { | ||
1789 | /* Insert the string window[strstart .. strstart+2] in the | ||
1790 | * dictionary, and set hash_head to the head of the hash chain: | ||
1791 | */ | ||
1792 | INSERT_STRING(strstart, hash_head); | ||
1793 | |||
1794 | /* Find the longest match, discarding those <= prev_length. | ||
1795 | */ | ||
1796 | prev_length = match_length, prev_match = match_start; | ||
1797 | match_length = MIN_MATCH - 1; | ||
1798 | |||
1799 | if (hash_head != 0 && prev_length < max_lazy_match | ||
1800 | && strstart - hash_head <= MAX_DIST | ||
1801 | ) { | ||
1802 | /* To simplify the code, we prevent matches with the string | ||
1803 | * of window index 0 (in particular we have to avoid a match | ||
1804 | * of the string with itself at the start of the input file). | ||
1805 | */ | ||
1806 | match_length = longest_match(hash_head); | ||
1807 | /* longest_match() sets match_start */ | ||
1808 | if (match_length > lookahead) | ||
1809 | match_length = lookahead; | ||
1810 | |||
1811 | /* Ignore a length 3 match if it is too distant: */ | ||
1812 | if (match_length == MIN_MATCH && strstart - match_start > TOO_FAR) { | ||
1813 | /* If prev_match is also MIN_MATCH, match_start is garbage | ||
1814 | * but we will ignore the current match anyway. | ||
1815 | */ | ||
1816 | match_length--; | ||
1817 | } | ||
1818 | } | ||
1819 | /* If there was a match at the previous step and the current | ||
1820 | * match is not better, output the previous match: | ||
1821 | */ | ||
1822 | if (prev_length >= MIN_MATCH && match_length <= prev_length) { | ||
1823 | check_match(strstart - 1, prev_match, prev_length); | ||
1824 | flush = ct_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH); | ||
1825 | |||
1826 | /* Insert in hash table all strings up to the end of the match. | ||
1827 | * strstart-1 and strstart are already inserted. | ||
1828 | */ | ||
1829 | lookahead -= prev_length - 1; | ||
1830 | prev_length -= 2; | ||
1831 | do { | ||
1832 | strstart++; | ||
1833 | INSERT_STRING(strstart, hash_head); | ||
1834 | /* strstart never exceeds WSIZE-MAX_MATCH, so there are | ||
1835 | * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH | ||
1836 | * these bytes are garbage, but it does not matter since the | ||
1837 | * next lookahead bytes will always be emitted as literals. | ||
1838 | */ | ||
1839 | } while (--prev_length != 0); | ||
1840 | match_available = 0; | ||
1841 | match_length = MIN_MATCH - 1; | ||
1842 | strstart++; | ||
1843 | if (flush) { | ||
1844 | FLUSH_BLOCK(0); | ||
1845 | block_start = strstart; | ||
1846 | } | ||
1847 | } else if (match_available) { | ||
1848 | /* If there was no match at the previous position, output a | ||
1849 | * single literal. If there was a match but the current match | ||
1850 | * is longer, truncate the previous match to a single literal. | ||
1851 | */ | ||
1852 | Tracevv((stderr, "%c", window[strstart - 1])); | ||
1853 | if (ct_tally(0, window[strstart - 1])) { | ||
1854 | FLUSH_BLOCK(0); | ||
1855 | block_start = strstart; | ||
1856 | } | ||
1857 | strstart++; | ||
1858 | lookahead--; | ||
1859 | } else { | ||
1860 | /* There is no previous match to compare with, wait for | ||
1861 | * the next step to decide. | ||
1862 | */ | ||
1863 | match_available = 1; | ||
1864 | strstart++; | ||
1865 | lookahead--; | ||
1866 | } | ||
1867 | Assert(strstart <= isize && lookahead <= isize, "a bit too far"); | ||
1868 | |||
1869 | /* Make sure that we always have enough lookahead, except | ||
1870 | * at the end of the input file. We need MAX_MATCH bytes | ||
1871 | * for the next match, plus MIN_MATCH bytes to insert the | ||
1872 | * string following the next match. | ||
1873 | */ | ||
1874 | while (lookahead < MIN_LOOKAHEAD && !eofile) | ||
1875 | fill_window(); | ||
1876 | } | ||
1877 | if (match_available) | ||
1878 | ct_tally(0, window[strstart - 1]); | ||
1879 | |||
1880 | return FLUSH_BLOCK(1); /* eof */ | ||
1881 | } | ||
1882 | |||
1883 | |||
1884 | /* =========================================================================== | ||
1885 | * Initialize the bit string routines. | ||
1886 | */ | ||
1887 | static void bi_init(void) //// int zipfile) | ||
1888 | { | ||
1889 | //// zfile = zipfile; | ||
1890 | bi_buf = 0; | ||
1891 | bi_valid = 0; | ||
1892 | #ifdef DEBUG | ||
1893 | bits_sent = 0L; | ||
1894 | #endif | ||
1895 | } | ||
1896 | |||
1897 | |||
1898 | /* =========================================================================== | ||
1899 | * Initialize the "longest match" routines for a new file | ||
1900 | */ | ||
1901 | static void lm_init(ush * flagsp) | ||
1902 | { | ||
1903 | unsigned j; | ||
1904 | |||
1905 | /* Initialize the hash table. */ | ||
1906 | memset(head, 0, HASH_SIZE * sizeof(*head)); | ||
1907 | /* prev will be initialized on the fly */ | ||
1908 | |||
1909 | /* speed options for the general purpose bit flag */ | ||
1910 | *flagsp |= 2; /* FAST 4, SLOW 2 */ | ||
1911 | /* ??? reduce max_chain_length for binary files */ | ||
1912 | |||
1913 | strstart = 0; | ||
1914 | block_start = 0L; | ||
1915 | |||
1916 | lookahead = file_read(window, | ||
1917 | sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE); | ||
1918 | |||
1919 | if (lookahead == 0 || lookahead == (unsigned) -1) { | ||
1920 | eofile = 1; | ||
1921 | lookahead = 0; | ||
1922 | return; | ||
1923 | } | ||
1924 | eofile = 0; | ||
1925 | /* Make sure that we always have enough lookahead. This is important | ||
1926 | * if input comes from a device such as a tty. | ||
1927 | */ | ||
1928 | while (lookahead < MIN_LOOKAHEAD && !eofile) | ||
1929 | fill_window(); | ||
1930 | |||
1931 | ins_h = 0; | ||
1932 | for (j = 0; j < MIN_MATCH - 1; j++) | ||
1933 | UPDATE_HASH(ins_h, window[j]); | ||
1934 | /* If lookahead < MIN_MATCH, ins_h is garbage, but this is | ||
1935 | * not important since only literal bytes will be emitted. | ||
1936 | */ | ||
1937 | } | ||
1938 | |||
1939 | |||
1940 | /* =========================================================================== | ||
1941 | * Allocate the match buffer, initialize the various tables and save the | ||
1942 | * location of the internal file attribute (ascii/binary) and method | ||
1943 | * (DEFLATE/STORE). | ||
1944 | * One callsite in zip() | ||
1945 | */ | ||
1946 | static void ct_init(ush * attr, int *methodp) | ||
1947 | { | ||
1948 | int n; /* iterates over tree elements */ | ||
1949 | int length; /* length value */ | ||
1950 | int code; /* code value */ | ||
1951 | int dist; /* distance index */ | ||
1952 | |||
1953 | file_type = attr; | ||
1954 | file_method = methodp; | ||
1955 | compressed_len = 0L; | ||
1956 | |||
1957 | #ifdef NOT_NEEDED | ||
1958 | if (static_dtree[0].Len != 0) | ||
1959 | return; /* ct_init already called */ | ||
1960 | #endif | ||
1961 | |||
1962 | /* Initialize the mapping length (0..255) -> length code (0..28) */ | ||
1963 | length = 0; | ||
1964 | for (code = 0; code < LENGTH_CODES - 1; code++) { | ||
1965 | base_length[code] = length; | ||
1966 | for (n = 0; n < (1 << extra_lbits[code]); n++) { | ||
1967 | length_code[length++] = code; | ||
1968 | } | ||
1969 | } | ||
1970 | Assert(length == 256, "ct_init: length != 256"); | ||
1971 | /* Note that the length 255 (match length 258) can be represented | ||
1972 | * in two different ways: code 284 + 5 bits or code 285, so we | ||
1973 | * overwrite length_code[255] to use the best encoding: | ||
1974 | */ | ||
1975 | length_code[length - 1] = code; | ||
1976 | |||
1977 | /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ | ||
1978 | dist = 0; | ||
1979 | for (code = 0; code < 16; code++) { | ||
1980 | base_dist[code] = dist; | ||
1981 | for (n = 0; n < (1 << extra_dbits[code]); n++) { | ||
1982 | dist_code[dist++] = code; | ||
1983 | } | ||
1984 | } | ||
1985 | Assert(dist == 256, "ct_init: dist != 256"); | ||
1986 | dist >>= 7; /* from now on, all distances are divided by 128 */ | ||
1987 | for (; code < D_CODES; code++) { | ||
1988 | base_dist[code] = dist << 7; | ||
1989 | for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) { | ||
1990 | dist_code[256 + dist++] = code; | ||
1991 | } | ||
1992 | } | ||
1993 | Assert(dist == 256, "ct_init: 256+dist != 512"); | ||
1994 | |||
1995 | /* Construct the codes of the static literal tree */ | ||
1996 | /* already zeroed - it's in bss | ||
1997 | for (n = 0; n <= MAX_BITS; n++) | ||
1998 | bl_count[n] = 0; */ | ||
1999 | |||
2000 | n = 0; | ||
2001 | while (n <= 143) { | ||
2002 | static_ltree[n++].Len = 8; | ||
2003 | bl_count[8]++; | ||
2004 | } | ||
2005 | while (n <= 255) { | ||
2006 | static_ltree[n++].Len = 9; | ||
2007 | bl_count[9]++; | ||
2008 | } | ||
2009 | while (n <= 279) { | ||
2010 | static_ltree[n++].Len = 7; | ||
2011 | bl_count[7]++; | ||
2012 | } | ||
2013 | while (n <= 287) { | ||
2014 | static_ltree[n++].Len = 8; | ||
2015 | bl_count[8]++; | ||
2016 | } | ||
2017 | /* Codes 286 and 287 do not exist, but we must include them in the | ||
2018 | * tree construction to get a canonical Huffman tree (longest code | ||
2019 | * all ones) | ||
2020 | */ | ||
2021 | gen_codes((ct_data *) static_ltree, L_CODES + 1); | ||
2022 | |||
2023 | /* The static distance tree is trivial: */ | ||
2024 | for (n = 0; n < D_CODES; n++) { | ||
2025 | static_dtree[n].Len = 5; | ||
2026 | static_dtree[n].Code = bi_reverse(n, 5); | ||
2027 | } | ||
2028 | |||
2029 | /* Initialize the first block of the first file: */ | ||
2030 | init_block(); | ||
2031 | } | ||
2032 | |||
2033 | |||
2034 | /* =========================================================================== | ||
2035 | * Deflate in to out. | ||
2036 | * IN assertions: the input and output buffers are cleared. | ||
2037 | * The variables time_stamp and save_orig_name are initialized. | ||
2038 | */ | ||
2039 | |||
2040 | /* put_header_byte is used for the compressed output | ||
2041 | * - for the initial 4 bytes that can't overflow the buffer. */ | ||
2042 | #define put_header_byte(c) outbuf[outcnt++] = (c) | ||
2043 | |||
2044 | static void zip(int in, int out) | ||
2045 | { | ||
2046 | uch my_flags = 0; /* general purpose bit flags */ | ||
2047 | ush attr = 0; /* ascii/binary flag */ | ||
2048 | ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */ | ||
2049 | |||
2050 | ifd = in; | ||
2051 | ofd = out; | ||
2052 | outcnt = 0; | ||
2053 | |||
2054 | /* Write the header to the gzip file. See algorithm.doc for the format */ | ||
2055 | |||
2056 | method = DEFLATED; | ||
2057 | put_header_byte(0x1f); /* magic header for gzip files, 1F 8B */ | ||
2058 | put_header_byte(0x8b); | ||
2059 | put_header_byte(DEFLATED); /* compression method */ | ||
2060 | put_header_byte(my_flags); /* general flags */ | ||
2061 | put_32bit(time_stamp); | ||
2062 | |||
2063 | /* Write deflated file to zip file */ | ||
2064 | crc = ~0; | ||
2065 | |||
2066 | bi_init(); //// (out); | ||
2067 | ct_init(&attr, &method); | ||
2068 | lm_init(&deflate_flags); | ||
2069 | |||
2070 | put_8bit(deflate_flags); /* extra flags */ | ||
2071 | put_8bit(3); /* OS identifier = 3 (Unix) */ | ||
2072 | |||
2073 | deflate(); | ||
2074 | |||
2075 | /* Write the crc and uncompressed size */ | ||
2076 | put_32bit(~crc); | ||
2077 | put_32bit(isize); | ||
2078 | |||
2079 | flush_outbuf(); | ||
2080 | } | ||
2081 | |||
2082 | |||
2083 | /* ======================================================================== */ | ||
2084 | static void abort_gzip(int ATTRIBUTE_UNUSED ignored) | ||
2085 | { | ||
2086 | exit(1); | ||
2087 | } | ||
2088 | |||
2089 | int gzip_main(int argc, char **argv) | ||
2090 | { | ||
2091 | enum { | ||
2092 | OPT_tostdout = 0x1, | ||
2093 | OPT_force = 0x2, | ||
2094 | }; | ||
2095 | |||
2096 | unsigned opt; | ||
2097 | int inFileNum; | ||
2098 | int outFileNum; | ||
2099 | int i; | ||
2100 | struct stat statBuf; | ||
2101 | |||
2102 | opt = getopt32(argc, argv, "cf123456789qv" USE_GUNZIP("d")); | ||
2103 | //if (opt & 0x1) // -c | ||
2104 | //if (opt & 0x2) // -f | ||
2105 | /* Ignore 1-9 (compression level) options */ | ||
2106 | //if (opt & 0x4) // -1 | ||
2107 | //if (opt & 0x8) // -2 | ||
2108 | //if (opt & 0x10) // -3 | ||
2109 | //if (opt & 0x20) // -4 | ||
2110 | //if (opt & 0x40) // -5 | ||
2111 | //if (opt & 0x80) // -6 | ||
2112 | //if (opt & 0x100) // -7 | ||
2113 | //if (opt & 0x200) // -8 | ||
2114 | //if (opt & 0x400) // -9 | ||
2115 | //if (opt & 0x800) // -q | ||
2116 | //if (opt & 0x1000) // -v | ||
2117 | #if ENABLE_GUNZIP /* gunzip_main may not be visible... */ | ||
2118 | if (opt & 0x2000) { // -d | ||
2119 | /* FIXME: getopt32 should not depend on optind */ | ||
2120 | optind = 1; | ||
2121 | return gunzip_main(argc, argv); | ||
2122 | } | ||
2123 | #endif | ||
2124 | |||
2125 | foreground = signal(SIGINT, SIG_IGN) != SIG_IGN; | ||
2126 | if (foreground) { | ||
2127 | signal(SIGINT, abort_gzip); | ||
2128 | } | ||
2129 | #ifdef SIGTERM | ||
2130 | if (signal(SIGTERM, SIG_IGN) != SIG_IGN) { | ||
2131 | signal(SIGTERM, abort_gzip); | ||
2132 | } | ||
2133 | #endif | ||
2134 | #ifdef SIGHUP | ||
2135 | if (signal(SIGHUP, SIG_IGN) != SIG_IGN) { | ||
2136 | signal(SIGHUP, abort_gzip); | ||
2137 | } | ||
2138 | #endif | ||
2139 | |||
2140 | /* Allocate all global buffers (for DYN_ALLOC option) */ | ||
2141 | ALLOC(uch, l_buf, INBUFSIZ); | ||
2142 | ALLOC(uch, outbuf, OUTBUFSIZ); | ||
2143 | ALLOC(ush, d_buf, DIST_BUFSIZE); | ||
2144 | ALLOC(uch, window, 2L * WSIZE); | ||
2145 | ALLOC(ush, prev, 1L << BITS); | ||
2146 | |||
2147 | /* Initialise the CRC32 table */ | ||
2148 | crc_32_tab = crc32_filltable(0); | ||
2149 | |||
2150 | clear_bufs(); | ||
2151 | |||
2152 | if (optind == argc) { | ||
2153 | time_stamp = 0; | ||
2154 | zip(STDIN_FILENO, STDOUT_FILENO); | ||
2155 | return exit_code; | ||
2156 | } | ||
2157 | |||
2158 | for (i = optind; i < argc; i++) { | ||
2159 | char *path = NULL; | ||
2160 | |||
2161 | clear_bufs(); | ||
2162 | if (LONE_DASH(argv[i])) { | ||
2163 | time_stamp = 0; | ||
2164 | inFileNum = STDIN_FILENO; | ||
2165 | outFileNum = STDOUT_FILENO; | ||
2166 | } else { | ||
2167 | inFileNum = xopen(argv[i], O_RDONLY); | ||
2168 | if (fstat(inFileNum, &statBuf) < 0) | ||
2169 | bb_perror_msg_and_die("%s", argv[i]); | ||
2170 | time_stamp = statBuf.st_ctime; | ||
2171 | |||
2172 | if (!(opt & OPT_tostdout)) { | ||
2173 | path = xasprintf("%s.gz", argv[i]); | ||
2174 | |||
2175 | /* Open output file */ | ||
2176 | #if defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1 && defined(O_NOFOLLOW) | ||
2177 | outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW); | ||
2178 | #else | ||
2179 | outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL); | ||
2180 | #endif | ||
2181 | if (outFileNum < 0) { | ||
2182 | bb_perror_msg("%s", path); | ||
2183 | free(path); | ||
2184 | continue; | ||
2185 | } | ||
2186 | |||
2187 | /* Set permissions on the file */ | ||
2188 | fchmod(outFileNum, statBuf.st_mode); | ||
2189 | } else | ||
2190 | outFileNum = STDOUT_FILENO; | ||
2191 | } | ||
2192 | |||
2193 | if (path == NULL && isatty(outFileNum) && !(opt & OPT_force)) { | ||
2194 | bb_error_msg("compressed data not written " | ||
2195 | "to a terminal. Use -f to force compression."); | ||
2196 | free(path); | ||
2197 | continue; | ||
2198 | } | ||
2199 | |||
2200 | zip(inFileNum, outFileNum); | ||
2201 | |||
2202 | if (path != NULL) { | ||
2203 | char *delFileName; | ||
2204 | |||
2205 | close(inFileNum); | ||
2206 | close(outFileNum); | ||
2207 | |||
2208 | /* Delete the original file */ | ||
2209 | // Pity we don't propagate zip failures to this place... | ||
2210 | //if (zip_is_ok) | ||
2211 | delFileName = argv[i]; | ||
2212 | //else | ||
2213 | // delFileName = path; | ||
2214 | if (unlink(delFileName) < 0) | ||
2215 | bb_perror_msg("%s", delFileName); | ||
2216 | } | ||
2217 | |||
2218 | free(path); | ||
2219 | } | ||
2220 | |||
2221 | return exit_code; | ||
2222 | } |