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1 /* gzio.c -- IO on .gz files | |
2 * Copyright (C) 1995-2005 Jean-loup Gailly. | |
3 * For conditions of distribution and use, see copyright notice in zlib.h | |
4 * | |
5 * Compile this file with -DNO_GZCOMPRESS to avoid the compression code. | |
6 */ | |
7 | |
8 /* @(#) $Id: gzio.c,v 3.7 2005/08/04 19:14:14 tor%cs.brown.edu Exp $ */ | |
9 | |
10 #include <stdio.h> | |
11 | |
12 #include "zutil.h" | |
13 | |
14 #ifdef NO_DEFLATE /* for compatibility with old definition */ | |
15 # define NO_GZCOMPRESS | |
16 #endif | |
17 | |
18 #ifndef NO_DUMMY_DECL | |
19 struct internal_state {int dummy;}; /* for buggy compilers */ | |
20 #endif | |
21 | |
22 #ifndef Z_BUFSIZE | |
23 # ifdef MAXSEG_64K | |
24 # define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */ | |
25 # else | |
26 # define Z_BUFSIZE 16384 | |
27 # endif | |
28 #endif | |
29 #ifndef Z_PRINTF_BUFSIZE | |
30 # define Z_PRINTF_BUFSIZE 4096 | |
31 #endif | |
32 | |
33 #ifdef __MVS__ | |
34 # pragma map (fdopen , "\174\174FDOPEN") | |
35 FILE *fdopen(int, const char *); | |
36 #endif | |
37 | |
38 #ifndef STDC | |
39 extern voidp malloc OF((uInt size)); | |
40 extern void free OF((voidpf ptr)); | |
41 #endif | |
42 | |
43 #define ALLOC(size) malloc(size) | |
44 #define TRYFREE(p) {if (p) free(p);} | |
45 | |
46 static int const gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */ | |
47 | |
48 /* gzip flag byte */ | |
49 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ | |
50 #define HEAD_CRC 0x02 /* bit 1 set: header CRC present */ | |
51 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ | |
52 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ | |
53 #define COMMENT 0x10 /* bit 4 set: file comment present */ | |
54 #define RESERVED 0xE0 /* bits 5..7: reserved */ | |
55 | |
56 typedef struct gz_stream { | |
57 z_stream stream; | |
58 int z_err; /* error code for last stream operation */ | |
59 int z_eof; /* set if end of input file */ | |
60 FILE *file; /* .gz file */ | |
61 Byte *inbuf; /* input buffer */ | |
62 Byte *outbuf; /* output buffer */ | |
63 uLong crc; /* crc32 of uncompressed data */ | |
64 char *msg; /* error message */ | |
65 char *path; /* path name for debugging only */ | |
66 int transparent; /* 1 if input file is not a .gz file */ | |
67 char mode; /* 'w' or 'r' */ | |
68 z_off_t start; /* start of compressed data in file (header skipped) */ | |
69 z_off_t in; /* bytes into deflate or inflate */ | |
70 z_off_t out; /* bytes out of deflate or inflate */ | |
71 int back; /* one character push-back */ | |
72 int last; /* true if push-back is last character */ | |
73 } gz_stream; | |
74 | |
75 | |
76 local gzFile gz_open OF((const char *path, const char *mode, int fd)); | |
77 #ifndef NO_GZCOMPRESS // Google Gears addition, to avoid compile warning | |
78 local int do_flush OF((gzFile file, int flush)); | |
79 #endif | |
80 local int get_byte OF((gz_stream *s)); | |
81 local void check_header OF((gz_stream *s)); | |
82 local int destroy OF((gz_stream *s)); | |
83 #ifndef NO_GZCOMPRESS // Google Gears addition, to avoid compile warning | |
84 local void putLong OF((FILE *file, uLong x)); | |
85 #endif | |
86 local uLong getLong OF((gz_stream *s)); | |
87 | |
88 /* =========================================================================== | |
89 Opens a gzip (.gz) file for reading or writing. The mode parameter | |
90 is as in fopen ("rb" or "wb"). The file is given either by file descriptor | |
91 or path name (if fd == -1). | |
92 gz_open returns NULL if the file could not be opened or if there was | |
93 insufficient memory to allocate the (de)compression state; errno | |
94 can be checked to distinguish the two cases (if errno is zero, the | |
95 zlib error is Z_MEM_ERROR). | |
96 */ | |
97 local gzFile gz_open (path, mode, fd) | |
98 const char *path; | |
99 const char *mode; | |
100 int fd; | |
101 { | |
102 int err; | |
103 int level = Z_DEFAULT_COMPRESSION; /* compression level */ | |
104 int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */ | |
105 char *p = (char*)mode; | |
106 gz_stream *s; | |
107 char fmode[80]; /* copy of mode, without the compression level */ | |
108 char *m = fmode; | |
109 | |
110 if (!path || !mode) return Z_NULL; | |
111 | |
112 s = (gz_stream *)ALLOC(sizeof(gz_stream)); | |
113 if (!s) return Z_NULL; | |
114 | |
115 s->stream.zalloc = (alloc_func)0; | |
116 s->stream.zfree = (free_func)0; | |
117 s->stream.opaque = (voidpf)0; | |
118 s->stream.next_in = s->inbuf = Z_NULL; | |
119 s->stream.next_out = s->outbuf = Z_NULL; | |
120 s->stream.avail_in = s->stream.avail_out = 0; | |
121 s->file = NULL; | |
122 s->z_err = Z_OK; | |
123 s->z_eof = 0; | |
124 s->in = 0; | |
125 s->out = 0; | |
126 s->back = EOF; | |
127 s->crc = crc32(0L, Z_NULL, 0); | |
128 s->msg = NULL; | |
129 s->transparent = 0; | |
130 | |
131 s->path = (char*)ALLOC(strlen(path)+1); | |
132 if (s->path == NULL) { | |
133 return destroy(s), (gzFile)Z_NULL; | |
134 } | |
135 strcpy(s->path, path); /* do this early for debugging */ | |
136 | |
137 s->mode = '\0'; | |
138 do { | |
139 if (*p == 'r') s->mode = 'r'; | |
140 if (*p == 'w' || *p == 'a') s->mode = 'w'; | |
141 if (*p >= '0' && *p <= '9') { | |
142 level = *p - '0'; | |
143 } else if (*p == 'f') { | |
144 strategy = Z_FILTERED; | |
145 } else if (*p == 'h') { | |
146 strategy = Z_HUFFMAN_ONLY; | |
147 } else if (*p == 'R') { | |
148 strategy = Z_RLE; | |
149 } else { | |
150 *m++ = *p; /* copy the mode */ | |
151 } | |
152 } while (*p++ && m != fmode + sizeof(fmode)); | |
153 if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL; | |
154 | |
155 if (s->mode == 'w') { | |
156 #ifdef NO_GZCOMPRESS | |
157 err = Z_STREAM_ERROR; | |
158 #else | |
159 err = deflateInit2(&(s->stream), level, | |
160 Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy); | |
161 /* windowBits is passed < 0 to suppress zlib header */ | |
162 | |
163 s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE); | |
164 #endif | |
165 if (err != Z_OK || s->outbuf == Z_NULL) { | |
166 return destroy(s), (gzFile)Z_NULL; | |
167 } | |
168 } else { | |
169 s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); | |
170 | |
171 err = inflateInit2(&(s->stream), -MAX_WBITS); | |
172 /* windowBits is passed < 0 to tell that there is no zlib header. | |
173 * Note that in this case inflate *requires* an extra "dummy" byte | |
174 * after the compressed stream in order to complete decompression and | |
175 * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are | |
176 * present after the compressed stream. | |
177 */ | |
178 if (err != Z_OK || s->inbuf == Z_NULL) { | |
179 return destroy(s), (gzFile)Z_NULL; | |
180 } | |
181 } | |
182 s->stream.avail_out = Z_BUFSIZE; | |
183 | |
184 errno = 0; | |
185 s->file = fd < 0 ? F_OPEN(path, fmode) : (FILE*)fdopen(fd, fmode); | |
186 | |
187 if (s->file == NULL) { | |
188 return destroy(s), (gzFile)Z_NULL; | |
189 } | |
190 if (s->mode == 'w') { | |
191 /* Write a very simple .gz header: | |
192 */ | |
193 fprintf(s->file, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], gz_magic[1], | |
194 Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE); | |
195 s->start = 10L; | |
196 /* We use 10L instead of ftell(s->file) to because ftell causes an | |
197 * fflush on some systems. This version of the library doesn't use | |
198 * start anyway in write mode, so this initialization is not | |
199 * necessary. | |
200 */ | |
201 } else { | |
202 check_header(s); /* skip the .gz header */ | |
203 s->start = ftell(s->file) - s->stream.avail_in; | |
204 } | |
205 | |
206 return (gzFile)s; | |
207 } | |
208 | |
209 /* =========================================================================== | |
210 Opens a gzip (.gz) file for reading or writing. | |
211 */ | |
212 gzFile ZEXPORT gzopen (path, mode) | |
213 const char *path; | |
214 const char *mode; | |
215 { | |
216 return gz_open (path, mode, -1); | |
217 } | |
218 | |
219 /* =========================================================================== | |
220 Associate a gzFile with the file descriptor fd. fd is not dup'ed here | |
221 to mimic the behavio(u)r of fdopen. | |
222 */ | |
223 gzFile ZEXPORT gzdopen (fd, mode) | |
224 int fd; | |
225 const char *mode; | |
226 { | |
227 char name[46]; /* allow for up to 128-bit integers */ | |
228 | |
229 if (fd < 0) return (gzFile)Z_NULL; | |
230 sprintf(name, "<fd:%d>", fd); /* for debugging */ | |
231 | |
232 return gz_open (name, mode, fd); | |
233 } | |
234 | |
235 /* =========================================================================== | |
236 * Update the compression level and strategy | |
237 */ | |
238 int ZEXPORT gzsetparams (file, level, strategy) | |
239 gzFile file; | |
240 int level; | |
241 int strategy; | |
242 { | |
243 gz_stream *s = (gz_stream*)file; | |
244 | |
245 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; | |
246 | |
247 /* Make room to allow flushing */ | |
248 if (s->stream.avail_out == 0) { | |
249 | |
250 s->stream.next_out = s->outbuf; | |
251 if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) { | |
252 s->z_err = Z_ERRNO; | |
253 } | |
254 s->stream.avail_out = Z_BUFSIZE; | |
255 } | |
256 | |
257 return deflateParams (&(s->stream), level, strategy); | |
258 } | |
259 | |
260 /* =========================================================================== | |
261 Read a byte from a gz_stream; update next_in and avail_in. Return EOF | |
262 for end of file. | |
263 IN assertion: the stream s has been sucessfully opened for reading. | |
264 */ | |
265 local int get_byte(s) | |
266 gz_stream *s; | |
267 { | |
268 if (s->z_eof) return EOF; | |
269 if (s->stream.avail_in == 0) { | |
270 errno = 0; | |
271 s->stream.avail_in = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file); | |
272 if (s->stream.avail_in == 0) { | |
273 s->z_eof = 1; | |
274 if (ferror(s->file)) s->z_err = Z_ERRNO; | |
275 return EOF; | |
276 } | |
277 s->stream.next_in = s->inbuf; | |
278 } | |
279 s->stream.avail_in--; | |
280 return *(s->stream.next_in)++; | |
281 } | |
282 | |
283 /* =========================================================================== | |
284 Check the gzip header of a gz_stream opened for reading. Set the stream | |
285 mode to transparent if the gzip magic header is not present; set s->err | |
286 to Z_DATA_ERROR if the magic header is present but the rest of the header | |
287 is incorrect. | |
288 IN assertion: the stream s has already been created sucessfully; | |
289 s->stream.avail_in is zero for the first time, but may be non-zero | |
290 for concatenated .gz files. | |
291 */ | |
292 local void check_header(s) | |
293 gz_stream *s; | |
294 { | |
295 int method; /* method byte */ | |
296 int flags; /* flags byte */ | |
297 uInt len; | |
298 int c; | |
299 | |
300 /* Assure two bytes in the buffer so we can peek ahead -- handle case | |
301 where first byte of header is at the end of the buffer after the last | |
302 gzip segment */ | |
303 len = s->stream.avail_in; | |
304 if (len < 2) { | |
305 if (len) s->inbuf[0] = s->stream.next_in[0]; | |
306 errno = 0; | |
307 len = (uInt)fread(s->inbuf + len, 1, Z_BUFSIZE >> len, s->file); | |
308 if (len == 0 && ferror(s->file)) s->z_err = Z_ERRNO; | |
309 s->stream.avail_in += len; | |
310 s->stream.next_in = s->inbuf; | |
311 if (s->stream.avail_in < 2) { | |
312 s->transparent = s->stream.avail_in; | |
313 return; | |
314 } | |
315 } | |
316 | |
317 /* Peek ahead to check the gzip magic header */ | |
318 if (s->stream.next_in[0] != gz_magic[0] || | |
319 s->stream.next_in[1] != gz_magic[1]) { | |
320 s->transparent = 1; | |
321 return; | |
322 } | |
323 s->stream.avail_in -= 2; | |
324 s->stream.next_in += 2; | |
325 | |
326 /* Check the rest of the gzip header */ | |
327 method = get_byte(s); | |
328 flags = get_byte(s); | |
329 if (method != Z_DEFLATED || (flags & RESERVED) != 0) { | |
330 s->z_err = Z_DATA_ERROR; | |
331 return; | |
332 } | |
333 | |
334 /* Discard time, xflags and OS code: */ | |
335 for (len = 0; len < 6; len++) (void)get_byte(s); | |
336 | |
337 if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */ | |
338 len = (uInt)get_byte(s); | |
339 len += ((uInt)get_byte(s))<<8; | |
340 /* len is garbage if EOF but the loop below will quit anyway */ | |
341 while (len-- != 0 && get_byte(s) != EOF) ; | |
342 } | |
343 if ((flags & ORIG_NAME) != 0) { /* skip the original file name */ | |
344 while ((c = get_byte(s)) != 0 && c != EOF) ; | |
345 } | |
346 if ((flags & COMMENT) != 0) { /* skip the .gz file comment */ | |
347 while ((c = get_byte(s)) != 0 && c != EOF) ; | |
348 } | |
349 if ((flags & HEAD_CRC) != 0) { /* skip the header crc */ | |
350 for (len = 0; len < 2; len++) (void)get_byte(s); | |
351 } | |
352 s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK; | |
353 } | |
354 | |
355 /* =========================================================================== | |
356 * Cleanup then free the given gz_stream. Return a zlib error code. | |
357 Try freeing in the reverse order of allocations. | |
358 */ | |
359 local int destroy (s) | |
360 gz_stream *s; | |
361 { | |
362 int err = Z_OK; | |
363 | |
364 if (!s) return Z_STREAM_ERROR; | |
365 | |
366 TRYFREE(s->msg); | |
367 | |
368 if (s->stream.state != NULL) { | |
369 if (s->mode == 'w') { | |
370 #ifdef NO_GZCOMPRESS | |
371 err = Z_STREAM_ERROR; | |
372 #else | |
373 err = deflateEnd(&(s->stream)); | |
374 #endif | |
375 } else if (s->mode == 'r') { | |
376 err = inflateEnd(&(s->stream)); | |
377 } | |
378 } | |
379 if (s->file != NULL && fclose(s->file)) { | |
380 #ifdef ESPIPE | |
381 if (errno != ESPIPE) /* fclose is broken for pipes in HP/UX */ | |
382 #endif | |
383 err = Z_ERRNO; | |
384 } | |
385 if (s->z_err < 0) err = s->z_err; | |
386 | |
387 TRYFREE(s->inbuf); | |
388 TRYFREE(s->outbuf); | |
389 TRYFREE(s->path); | |
390 TRYFREE(s); | |
391 return err; | |
392 } | |
393 | |
394 /* =========================================================================== | |
395 Reads the given number of uncompressed bytes from the compressed file. | |
396 gzread returns the number of bytes actually read (0 for end of file). | |
397 */ | |
398 int ZEXPORT gzread (file, buf, len) | |
399 gzFile file; | |
400 voidp buf; | |
401 unsigned len; | |
402 { | |
403 gz_stream *s = (gz_stream*)file; | |
404 Bytef *start = (Bytef*)buf; /* starting point for crc computation */ | |
405 Byte *next_out; /* == stream.next_out but not forced far (for MSDOS) */ | |
406 | |
407 if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR; | |
408 | |
409 if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1; | |
410 if (s->z_err == Z_STREAM_END) return 0; /* EOF */ | |
411 | |
412 next_out = (Byte*)buf; | |
413 s->stream.next_out = (Bytef*)buf; | |
414 s->stream.avail_out = len; | |
415 | |
416 if (s->stream.avail_out && s->back != EOF) { | |
417 *next_out++ = s->back; | |
418 s->stream.next_out++; | |
419 s->stream.avail_out--; | |
420 s->back = EOF; | |
421 s->out++; | |
422 start++; | |
423 if (s->last) { | |
424 s->z_err = Z_STREAM_END; | |
425 return 1; | |
426 } | |
427 } | |
428 | |
429 while (s->stream.avail_out != 0) { | |
430 | |
431 if (s->transparent) { | |
432 /* Copy first the lookahead bytes: */ | |
433 uInt n = s->stream.avail_in; | |
434 if (n > s->stream.avail_out) n = s->stream.avail_out; | |
435 if (n > 0) { | |
436 zmemcpy(s->stream.next_out, s->stream.next_in, n); | |
437 next_out += n; | |
438 s->stream.next_out = next_out; | |
439 s->stream.next_in += n; | |
440 s->stream.avail_out -= n; | |
441 s->stream.avail_in -= n; | |
442 } | |
443 if (s->stream.avail_out > 0) { | |
444 s->stream.avail_out -= | |
445 (uInt)fread(next_out, 1, s->stream.avail_out, s->file); | |
446 } | |
447 len -= s->stream.avail_out; | |
448 s->in += len; | |
449 s->out += len; | |
450 if (len == 0) s->z_eof = 1; | |
451 return (int)len; | |
452 } | |
453 if (s->stream.avail_in == 0 && !s->z_eof) { | |
454 | |
455 errno = 0; | |
456 s->stream.avail_in = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file); | |
457 if (s->stream.avail_in == 0) { | |
458 s->z_eof = 1; | |
459 if (ferror(s->file)) { | |
460 s->z_err = Z_ERRNO; | |
461 break; | |
462 } | |
463 } | |
464 s->stream.next_in = s->inbuf; | |
465 } | |
466 s->in += s->stream.avail_in; | |
467 s->out += s->stream.avail_out; | |
468 s->z_err = inflate(&(s->stream), Z_NO_FLUSH); | |
469 s->in -= s->stream.avail_in; | |
470 s->out -= s->stream.avail_out; | |
471 | |
472 if (s->z_err == Z_STREAM_END) { | |
473 /* Check CRC and original size */ | |
474 s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start)); | |
475 start = s->stream.next_out; | |
476 | |
477 if (getLong(s) != s->crc) { | |
478 s->z_err = Z_DATA_ERROR; | |
479 } else { | |
480 (void)getLong(s); | |
481 /* The uncompressed length returned by above getlong() may be | |
482 * different from s->out in case of concatenated .gz files. | |
483 * Check for such files: | |
484 */ | |
485 check_header(s); | |
486 if (s->z_err == Z_OK) { | |
487 inflateReset(&(s->stream)); | |
488 s->crc = crc32(0L, Z_NULL, 0); | |
489 } | |
490 } | |
491 } | |
492 if (s->z_err != Z_OK || s->z_eof) break; | |
493 } | |
494 s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start)); | |
495 | |
496 if (len == s->stream.avail_out && | |
497 (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO)) | |
498 return -1; | |
499 return (int)(len - s->stream.avail_out); | |
500 } | |
501 | |
502 | |
503 /* =========================================================================== | |
504 Reads one byte from the compressed file. gzgetc returns this byte | |
505 or -1 in case of end of file or error. | |
506 */ | |
507 int ZEXPORT gzgetc(file) | |
508 gzFile file; | |
509 { | |
510 unsigned char c; | |
511 | |
512 return gzread(file, &c, 1) == 1 ? c : -1; | |
513 } | |
514 | |
515 | |
516 /* =========================================================================== | |
517 Push one byte back onto the stream. | |
518 */ | |
519 int ZEXPORT gzungetc(c, file) | |
520 int c; | |
521 gzFile file; | |
522 { | |
523 gz_stream *s = (gz_stream*)file; | |
524 | |
525 if (s == NULL || s->mode != 'r' || c == EOF || s->back != EOF) return EOF; | |
526 s->back = c; | |
527 s->out--; | |
528 s->last = (s->z_err == Z_STREAM_END); | |
529 if (s->last) s->z_err = Z_OK; | |
530 s->z_eof = 0; | |
531 return c; | |
532 } | |
533 | |
534 | |
535 /* =========================================================================== | |
536 Reads bytes from the compressed file until len-1 characters are | |
537 read, or a newline character is read and transferred to buf, or an | |
538 end-of-file condition is encountered. The string is then terminated | |
539 with a null character. | |
540 gzgets returns buf, or Z_NULL in case of error. | |
541 | |
542 The current implementation is not optimized at all. | |
543 */ | |
544 char * ZEXPORT gzgets(file, buf, len) | |
545 gzFile file; | |
546 char *buf; | |
547 int len; | |
548 { | |
549 char *b = buf; | |
550 if (buf == Z_NULL || len <= 0) return Z_NULL; | |
551 | |
552 while (--len > 0 && gzread(file, buf, 1) == 1 && *buf++ != '\n') ; | |
553 *buf = '\0'; | |
554 return b == buf && len > 0 ? Z_NULL : b; | |
555 } | |
556 | |
557 | |
558 #ifndef NO_GZCOMPRESS | |
559 /* =========================================================================== | |
560 Writes the given number of uncompressed bytes into the compressed file. | |
561 gzwrite returns the number of bytes actually written (0 in case of error). | |
562 */ | |
563 int ZEXPORT gzwrite (file, buf, len) | |
564 gzFile file; | |
565 voidpc buf; | |
566 unsigned len; | |
567 { | |
568 gz_stream *s = (gz_stream*)file; | |
569 | |
570 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; | |
571 | |
572 s->stream.next_in = (Bytef*)buf; | |
573 s->stream.avail_in = len; | |
574 | |
575 while (s->stream.avail_in != 0) { | |
576 | |
577 if (s->stream.avail_out == 0) { | |
578 | |
579 s->stream.next_out = s->outbuf; | |
580 if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) { | |
581 s->z_err = Z_ERRNO; | |
582 break; | |
583 } | |
584 s->stream.avail_out = Z_BUFSIZE; | |
585 } | |
586 s->in += s->stream.avail_in; | |
587 s->out += s->stream.avail_out; | |
588 s->z_err = deflate(&(s->stream), Z_NO_FLUSH); | |
589 s->in -= s->stream.avail_in; | |
590 s->out -= s->stream.avail_out; | |
591 if (s->z_err != Z_OK) break; | |
592 } | |
593 s->crc = crc32(s->crc, (const Bytef *)buf, len); | |
594 | |
595 return (int)(len - s->stream.avail_in); | |
596 } | |
597 | |
598 | |
599 /* =========================================================================== | |
600 Converts, formats, and writes the args to the compressed file under | |
601 control of the format string, as in fprintf. gzprintf returns the number of | |
602 uncompressed bytes actually written (0 in case of error). | |
603 */ | |
604 #ifdef STDC | |
605 #include <stdarg.h> | |
606 | |
607 int ZEXPORTVA gzprintf (gzFile file, const char *format, /* args */ ...) | |
608 { | |
609 char buf[Z_PRINTF_BUFSIZE]; | |
610 va_list va; | |
611 int len; | |
612 | |
613 buf[sizeof(buf) - 1] = 0; | |
614 va_start(va, format); | |
615 #ifdef NO_vsnprintf | |
616 # ifdef HAS_vsprintf_void | |
617 (void)vsprintf(buf, format, va); | |
618 va_end(va); | |
619 for (len = 0; len < sizeof(buf); len++) | |
620 if (buf[len] == 0) break; | |
621 # else | |
622 len = vsprintf(buf, format, va); | |
623 va_end(va); | |
624 # endif | |
625 #else | |
626 # ifdef HAS_vsnprintf_void | |
627 (void)vsnprintf(buf, sizeof(buf), format, va); | |
628 va_end(va); | |
629 len = strlen(buf); | |
630 # else | |
631 len = vsnprintf(buf, sizeof(buf), format, va); | |
632 va_end(va); | |
633 # endif | |
634 #endif | |
635 if (len <= 0 || len >= (int)sizeof(buf) || buf[sizeof(buf) - 1] != 0) | |
636 return 0; | |
637 return gzwrite(file, buf, (unsigned)len); | |
638 } | |
639 #else /* not ANSI C */ | |
640 | |
641 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, | |
642 a11, a12, a13, a14, a15, a16, a17, a18, a19, a20) | |
643 gzFile file; | |
644 const char *format; | |
645 int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, | |
646 a11, a12, a13, a14, a15, a16, a17, a18, a19, a20; | |
647 { | |
648 char buf[Z_PRINTF_BUFSIZE]; | |
649 int len; | |
650 | |
651 buf[sizeof(buf) - 1] = 0; | |
652 #ifdef NO_snprintf | |
653 # ifdef HAS_sprintf_void | |
654 sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8, | |
655 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20); | |
656 for (len = 0; len < sizeof(buf); len++) | |
657 if (buf[len] == 0) break; | |
658 # else | |
659 len = sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8, | |
660 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20); | |
661 # endif | |
662 #else | |
663 # ifdef HAS_snprintf_void | |
664 snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8, | |
665 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20); | |
666 len = strlen(buf); | |
667 # else | |
668 len = snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8, | |
669 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20); | |
670 # endif | |
671 #endif | |
672 if (len <= 0 || len >= sizeof(buf) || buf[sizeof(buf) - 1] != 0) | |
673 return 0; | |
674 return gzwrite(file, buf, len); | |
675 } | |
676 #endif | |
677 | |
678 /* =========================================================================== | |
679 Writes c, converted to an unsigned char, into the compressed file. | |
680 gzputc returns the value that was written, or -1 in case of error. | |
681 */ | |
682 int ZEXPORT gzputc(file, c) | |
683 gzFile file; | |
684 int c; | |
685 { | |
686 unsigned char cc = (unsigned char) c; /* required for big endian systems */ | |
687 | |
688 return gzwrite(file, &cc, 1) == 1 ? (int)cc : -1; | |
689 } | |
690 | |
691 | |
692 /* =========================================================================== | |
693 Writes the given null-terminated string to the compressed file, excluding | |
694 the terminating null character. | |
695 gzputs returns the number of characters written, or -1 in case of error. | |
696 */ | |
697 int ZEXPORT gzputs(file, s) | |
698 gzFile file; | |
699 const char *s; | |
700 { | |
701 return gzwrite(file, (char*)s, (unsigned)strlen(s)); | |
702 } | |
703 | |
704 | |
705 /* =========================================================================== | |
706 Flushes all pending output into the compressed file. The parameter | |
707 flush is as in the deflate() function. | |
708 */ | |
709 local int do_flush (file, flush) | |
710 gzFile file; | |
711 int flush; | |
712 { | |
713 uInt len; | |
714 int done = 0; | |
715 gz_stream *s = (gz_stream*)file; | |
716 | |
717 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; | |
718 | |
719 s->stream.avail_in = 0; /* should be zero already anyway */ | |
720 | |
721 for (;;) { | |
722 len = Z_BUFSIZE - s->stream.avail_out; | |
723 | |
724 if (len != 0) { | |
725 if ((uInt)fwrite(s->outbuf, 1, len, s->file) != len) { | |
726 s->z_err = Z_ERRNO; | |
727 return Z_ERRNO; | |
728 } | |
729 s->stream.next_out = s->outbuf; | |
730 s->stream.avail_out = Z_BUFSIZE; | |
731 } | |
732 if (done) break; | |
733 s->out += s->stream.avail_out; | |
734 s->z_err = deflate(&(s->stream), flush); | |
735 s->out -= s->stream.avail_out; | |
736 | |
737 /* Ignore the second of two consecutive flushes: */ | |
738 if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK; | |
739 | |
740 /* deflate has finished flushing only when it hasn't used up | |
741 * all the available space in the output buffer: | |
742 */ | |
743 done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END); | |
744 | |
745 if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break; | |
746 } | |
747 return s->z_err == Z_STREAM_END ? Z_OK : s->z_err; | |
748 } | |
749 | |
750 int ZEXPORT gzflush (file, flush) | |
751 gzFile file; | |
752 int flush; | |
753 { | |
754 gz_stream *s = (gz_stream*)file; | |
755 int err = do_flush (file, flush); | |
756 | |
757 if (err) return err; | |
758 fflush(s->file); | |
759 return s->z_err == Z_STREAM_END ? Z_OK : s->z_err; | |
760 } | |
761 #endif /* NO_GZCOMPRESS */ | |
762 | |
763 /* =========================================================================== | |
764 Sets the starting position for the next gzread or gzwrite on the given | |
765 compressed file. The offset represents a number of bytes in the | |
766 gzseek returns the resulting offset location as measured in bytes from | |
767 the beginning of the uncompressed stream, or -1 in case of error. | |
768 SEEK_END is not implemented, returns error. | |
769 In this version of the library, gzseek can be extremely slow. | |
770 */ | |
771 z_off_t ZEXPORT gzseek (file, offset, whence) | |
772 gzFile file; | |
773 z_off_t offset; | |
774 int whence; | |
775 { | |
776 gz_stream *s = (gz_stream*)file; | |
777 | |
778 if (s == NULL || whence == SEEK_END || | |
779 s->z_err == Z_ERRNO || s->z_err == Z_DATA_ERROR) { | |
780 return -1L; | |
781 } | |
782 | |
783 if (s->mode == 'w') { | |
784 #ifdef NO_GZCOMPRESS | |
785 return -1L; | |
786 #else | |
787 if (whence == SEEK_SET) { | |
788 offset -= s->in; | |
789 } | |
790 if (offset < 0) return -1L; | |
791 | |
792 /* At this point, offset is the number of zero bytes to write. */ | |
793 if (s->inbuf == Z_NULL) { | |
794 s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); /* for seeking */ | |
795 if (s->inbuf == Z_NULL) return -1L; | |
796 zmemzero(s->inbuf, Z_BUFSIZE); | |
797 } | |
798 while (offset > 0) { | |
799 uInt size = Z_BUFSIZE; | |
800 if (offset < Z_BUFSIZE) size = (uInt)offset; | |
801 | |
802 size = gzwrite(file, s->inbuf, size); | |
803 if (size == 0) return -1L; | |
804 | |
805 offset -= size; | |
806 } | |
807 return s->in; | |
808 #endif | |
809 } | |
810 /* Rest of function is for reading only */ | |
811 | |
812 /* compute absolute position */ | |
813 if (whence == SEEK_CUR) { | |
814 offset += s->out; | |
815 } | |
816 if (offset < 0) return -1L; | |
817 | |
818 if (s->transparent) { | |
819 /* map to fseek */ | |
820 s->back = EOF; | |
821 s->stream.avail_in = 0; | |
822 s->stream.next_in = s->inbuf; | |
823 if (fseek(s->file, offset, SEEK_SET) < 0) return -1L; | |
824 | |
825 s->in = s->out = offset; | |
826 return offset; | |
827 } | |
828 | |
829 /* For a negative seek, rewind and use positive seek */ | |
830 if (offset >= s->out) { | |
831 offset -= s->out; | |
832 } else if (gzrewind(file) < 0) { | |
833 return -1L; | |
834 } | |
835 /* offset is now the number of bytes to skip. */ | |
836 | |
837 if (offset != 0 && s->outbuf == Z_NULL) { | |
838 s->outbuf = (Byte*)ALLOC(Z_BUFSIZE); | |
839 if (s->outbuf == Z_NULL) return -1L; | |
840 } | |
841 if (offset && s->back != EOF) { | |
842 s->back = EOF; | |
843 s->out++; | |
844 offset--; | |
845 if (s->last) s->z_err = Z_STREAM_END; | |
846 } | |
847 while (offset > 0) { | |
848 int size = Z_BUFSIZE; | |
849 if (offset < Z_BUFSIZE) size = (int)offset; | |
850 | |
851 size = gzread(file, s->outbuf, (uInt)size); | |
852 if (size <= 0) return -1L; | |
853 offset -= size; | |
854 } | |
855 return s->out; | |
856 } | |
857 | |
858 /* =========================================================================== | |
859 Rewinds input file. | |
860 */ | |
861 int ZEXPORT gzrewind (file) | |
862 gzFile file; | |
863 { | |
864 gz_stream *s = (gz_stream*)file; | |
865 | |
866 if (s == NULL || s->mode != 'r') return -1; | |
867 | |
868 s->z_err = Z_OK; | |
869 s->z_eof = 0; | |
870 s->back = EOF; | |
871 s->stream.avail_in = 0; | |
872 s->stream.next_in = s->inbuf; | |
873 s->crc = crc32(0L, Z_NULL, 0); | |
874 if (!s->transparent) (void)inflateReset(&s->stream); | |
875 s->in = 0; | |
876 s->out = 0; | |
877 return fseek(s->file, s->start, SEEK_SET); | |
878 } | |
879 | |
880 /* =========================================================================== | |
881 Returns the starting position for the next gzread or gzwrite on the | |
882 given compressed file. This position represents a number of bytes in the | |
883 uncompressed data stream. | |
884 */ | |
885 z_off_t ZEXPORT gztell (file) | |
886 gzFile file; | |
887 { | |
888 return gzseek(file, 0L, SEEK_CUR); | |
889 } | |
890 | |
891 /* =========================================================================== | |
892 Returns 1 when EOF has previously been detected reading the given | |
893 input stream, otherwise zero. | |
894 */ | |
895 int ZEXPORT gzeof (file) | |
896 gzFile file; | |
897 { | |
898 gz_stream *s = (gz_stream*)file; | |
899 | |
900 /* With concatenated compressed files that can have embedded | |
901 * crc trailers, z_eof is no longer the only/best indicator of EOF | |
902 * on a gz_stream. Handle end-of-stream error explicitly here. | |
903 */ | |
904 if (s == NULL || s->mode != 'r') return 0; | |
905 if (s->z_eof) return 1; | |
906 return s->z_err == Z_STREAM_END; | |
907 } | |
908 | |
909 /* =========================================================================== | |
910 Returns 1 if reading and doing so transparently, otherwise zero. | |
911 */ | |
912 int ZEXPORT gzdirect (file) | |
913 gzFile file; | |
914 { | |
915 gz_stream *s = (gz_stream*)file; | |
916 | |
917 if (s == NULL || s->mode != 'r') return 0; | |
918 return s->transparent; | |
919 } | |
920 | |
921 #ifndef NO_GZCOMPRESS // Google Gears addition, to avoid compile warning | |
922 /* =========================================================================== | |
923 Outputs a long in LSB order to the given file | |
924 */ | |
925 local void putLong (file, x) | |
926 FILE *file; | |
927 uLong x; | |
928 { | |
929 int n; | |
930 for (n = 0; n < 4; n++) { | |
931 fputc((int)(x & 0xff), file); | |
932 x >>= 8; | |
933 } | |
934 } | |
935 #endif | |
936 | |
937 /* =========================================================================== | |
938 Reads a long in LSB order from the given gz_stream. Sets z_err in case | |
939 of error. | |
940 */ | |
941 local uLong getLong (s) | |
942 gz_stream *s; | |
943 { | |
944 uLong x = (uLong)get_byte(s); | |
945 int c; | |
946 | |
947 x += ((uLong)get_byte(s))<<8; | |
948 x += ((uLong)get_byte(s))<<16; | |
949 c = get_byte(s); | |
950 if (c == EOF) s->z_err = Z_DATA_ERROR; | |
951 x += ((uLong)c)<<24; | |
952 return x; | |
953 } | |
954 | |
955 /* =========================================================================== | |
956 Flushes all pending output if necessary, closes the compressed file | |
957 and deallocates all the (de)compression state. | |
958 */ | |
959 int ZEXPORT gzclose (file) | |
960 gzFile file; | |
961 { | |
962 gz_stream *s = (gz_stream*)file; | |
963 | |
964 if (s == NULL) return Z_STREAM_ERROR; | |
965 | |
966 if (s->mode == 'w') { | |
967 #ifdef NO_GZCOMPRESS | |
968 return Z_STREAM_ERROR; | |
969 #else | |
970 if (do_flush (file, Z_FINISH) != Z_OK) | |
971 return destroy((gz_stream*)file); | |
972 | |
973 putLong (s->file, s->crc); | |
974 putLong (s->file, (uLong)(s->in & 0xffffffff)); | |
975 #endif | |
976 } | |
977 return destroy((gz_stream*)file); | |
978 } | |
979 | |
980 // Google Gears modification: strerror is not present on WinCE. | |
981 #if defined(STDC) && !defined(_WIN32_WCE) | |
982 # define zstrerror(errnum) strerror(errnum) | |
983 #else | |
984 # define zstrerror(errnum) "" | |
985 #endif | |
986 | |
987 /* =========================================================================== | |
988 Returns the error message for the last error which occurred on the | |
989 given compressed file. errnum is set to zlib error number. If an | |
990 error occurred in the file system and not in the compression library, | |
991 errnum is set to Z_ERRNO and the application may consult errno | |
992 to get the exact error code. | |
993 */ | |
994 const char * ZEXPORT gzerror (file, errnum) | |
995 gzFile file; | |
996 int *errnum; | |
997 { | |
998 char *m; | |
999 gz_stream *s = (gz_stream*)file; | |
1000 | |
1001 if (s == NULL) { | |
1002 *errnum = Z_STREAM_ERROR; | |
1003 return (const char*)ERR_MSG(Z_STREAM_ERROR); | |
1004 } | |
1005 *errnum = s->z_err; | |
1006 if (*errnum == Z_OK) return (const char*)""; | |
1007 | |
1008 m = (char*)(*errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg); | |
1009 | |
1010 if (m == NULL || *m == '\0') m = (char*)ERR_MSG(s->z_err); | |
1011 | |
1012 TRYFREE(s->msg); | |
1013 s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3); | |
1014 if (s->msg == Z_NULL) return (const char*)ERR_MSG(Z_MEM_ERROR); | |
1015 strcpy(s->msg, s->path); | |
1016 strcat(s->msg, ": "); | |
1017 strcat(s->msg, m); | |
1018 return (const char*)s->msg; | |
1019 } | |
1020 | |
1021 /* =========================================================================== | |
1022 Clear the error and end-of-file flags, and do the same for the real file. | |
1023 */ | |
1024 void ZEXPORT gzclearerr (file) | |
1025 gzFile file; | |
1026 { | |
1027 gz_stream *s = (gz_stream*)file; | |
1028 | |
1029 if (s == NULL) return; | |
1030 if (s->z_err != Z_STREAM_END) s->z_err = Z_OK; | |
1031 s->z_eof = 0; | |
1032 clearerr(s->file); | |
1033 } | |
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