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SMB3, combo, fskip fixes
[fceu.git] / zlib / gzio.c
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c62d2810 1/* gzio.c -- IO on .gz files
2 * Copyright (C) 1995-2002 Jean-loup Gailly.
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 *
5 * Compile this file with -DNO_DEFLATE to avoid the compression code.
6 */
7
8/* @(#) $Id: gzio.c,v 1.2 2002/03/13 17:45:56 xodnizel Exp $ */
9
10#include <stdio.h>
11
12#include "zutil.h"
13
14struct internal_state {int dummy;}; /* for buggy compilers */
15
16#ifndef Z_BUFSIZE
17# ifdef MAXSEG_64K
18# define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */
19# else
20# define Z_BUFSIZE 16384
21# endif
22#endif
23#ifndef Z_PRINTF_BUFSIZE
24# define Z_PRINTF_BUFSIZE 4096
25#endif
26
27#define ALLOC(size) malloc(size)
28#define TRYFREE(p) {if (p) free(p);}
29
30static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
31
32/* gzip flag byte */
33#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
34#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
35#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
36#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
37#define COMMENT 0x10 /* bit 4 set: file comment present */
38#define RESERVED 0xE0 /* bits 5..7: reserved */
39
40typedef struct gz_stream {
41 z_stream stream;
42 int z_err; /* error code for last stream operation */
43 int z_eof; /* set if end of input file */
44 FILE *file; /* .gz file */
45 Byte *inbuf; /* input buffer */
46 Byte *outbuf; /* output buffer */
47 uLong crc; /* crc32 of uncompressed data */
48 char *msg; /* error message */
49 char *path; /* path name for debugging only */
50 int transparent; /* 1 if input file is not a .gz file */
51 char mode; /* 'w' or 'r' */
52 long startpos; /* start of compressed data in file (header skipped) */
53} gz_stream;
54
55
56local gzFile gz_open OF((const char *path, const char *mode, int fd));
57local int do_flush OF((gzFile file, int flush));
58local int get_byte OF((gz_stream *s));
59local void check_header OF((gz_stream *s));
60local int destroy OF((gz_stream *s));
61local void putLong OF((FILE *file, uLong x));
62local uLong getLong OF((gz_stream *s));
63
64/* ===========================================================================
65 Opens a gzip (.gz) file for reading or writing. The mode parameter
66 is as in fopen ("rb" or "wb"). The file is given either by file descriptor
67 or path name (if fd == -1).
68 gz_open return NULL if the file could not be opened or if there was
69 insufficient memory to allocate the (de)compression state; errno
70 can be checked to distinguish the two cases (if errno is zero, the
71 zlib error is Z_MEM_ERROR).
72*/
73local gzFile gz_open (path, mode, fd)
74 const char *path;
75 const char *mode;
76 int fd;
77{
78 int err;
79 int level = Z_DEFAULT_COMPRESSION; /* compression level */
80 int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */
81 char *p = (char*)mode;
82 gz_stream *s;
83 char fmode[80]; /* copy of mode, without the compression level */
84 char *m = fmode;
85
86 if (!path || !mode) return Z_NULL;
87
88 s = (gz_stream *)ALLOC(sizeof(gz_stream));
89 if (!s) return Z_NULL;
90
91 s->stream.zalloc = (alloc_func)0;
92 s->stream.zfree = (free_func)0;
93 s->stream.opaque = (voidpf)0;
94 s->stream.next_in = s->inbuf = Z_NULL;
95 s->stream.next_out = s->outbuf = Z_NULL;
96 s->stream.avail_in = s->stream.avail_out = 0;
97 s->file = NULL;
98 s->z_err = Z_OK;
99 s->z_eof = 0;
100 s->crc = crc32(0L, Z_NULL, 0);
101 s->msg = NULL;
102 s->transparent = 0;
103
104 s->path = (char*)ALLOC(strlen(path)+1);
105 if (s->path == NULL) {
106 return destroy(s), (gzFile)Z_NULL;
107 }
108 strcpy(s->path, path); /* do this early for debugging */
109
110 s->mode = '\0';
111 do {
112 if (*p == 'r') s->mode = 'r';
113 if (*p == 'w' || *p == 'a') s->mode = 'w';
114 if (*p >= '0' && *p <= '9') {
115 level = *p - '0';
116 } else if (*p == 'f') {
117 strategy = Z_FILTERED;
118 } else if (*p == 'h') {
119 strategy = Z_HUFFMAN_ONLY;
120 } else {
121 *m++ = *p; /* copy the mode */
122 }
123 } while (*p++ && m != fmode + sizeof(fmode));
124 if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL;
125
126 if (s->mode == 'w') {
127#ifdef NO_DEFLATE
128 err = Z_STREAM_ERROR;
129#else
130 err = deflateInit2(&(s->stream), level,
131 Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy);
132 /* windowBits is passed < 0 to suppress zlib header */
133
134 s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
135#endif
136 if (err != Z_OK || s->outbuf == Z_NULL) {
137 return destroy(s), (gzFile)Z_NULL;
138 }
139 } else {
140 s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
141
142 err = inflateInit2(&(s->stream), -MAX_WBITS);
143 /* windowBits is passed < 0 to tell that there is no zlib header.
144 * Note that in this case inflate *requires* an extra "dummy" byte
145 * after the compressed stream in order to complete decompression and
146 * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are
147 * present after the compressed stream.
148 */
149 if (err != Z_OK || s->inbuf == Z_NULL) {
150 return destroy(s), (gzFile)Z_NULL;
151 }
152 }
153 s->stream.avail_out = Z_BUFSIZE;
154
155 errno = 0;
156 s->file = fd < 0 ? F_OPEN(path, fmode) : (FILE*)fdopen(fd, fmode);
157
158 if (s->file == NULL) {
159 return destroy(s), (gzFile)Z_NULL;
160 }
161 if (s->mode == 'w') {
162 /* Write a very simple .gz header:
163 */
164 fprintf(s->file, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], gz_magic[1],
165 Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE);
166 s->startpos = 10L;
167 /* We use 10L instead of ftell(s->file) to because ftell causes an
168 * fflush on some systems. This version of the library doesn't use
169 * startpos anyway in write mode, so this initialization is not
170 * necessary.
171 */
172 } else {
173 check_header(s); /* skip the .gz header */
174 s->startpos = (ftell(s->file) - s->stream.avail_in);
175 }
176
177 return (gzFile)s;
178}
179
180/* ===========================================================================
181 Opens a gzip (.gz) file for reading or writing.
182*/
183gzFile ZEXPORT gzopen (path, mode)
184 const char *path;
185 const char *mode;
186{
187 return gz_open (path, mode, -1);
188}
189
190/* ===========================================================================
191 Associate a gzFile with the file descriptor fd. fd is not dup'ed here
192 to mimic the behavio(u)r of fdopen.
193*/
194gzFile ZEXPORT gzdopen (fd, mode)
195 int fd;
196 const char *mode;
197{
198 char name[20];
199
200 if (fd < 0) return (gzFile)Z_NULL;
201 sprintf(name, "<fd:%d>", fd); /* for debugging */
202
203 return gz_open (name, mode, fd);
204}
205
206/* ===========================================================================
207 * Update the compression level and strategy
208 */
209int ZEXPORT gzsetparams (file, level, strategy)
210 gzFile file;
211 int level;
212 int strategy;
213{
214 gz_stream *s = (gz_stream*)file;
215
216 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
217
218 /* Make room to allow flushing */
219 if (s->stream.avail_out == 0) {
220
221 s->stream.next_out = s->outbuf;
222 if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
223 s->z_err = Z_ERRNO;
224 }
225 s->stream.avail_out = Z_BUFSIZE;
226 }
227
228 return deflateParams (&(s->stream), level, strategy);
229}
230
231/* ===========================================================================
232 Read a byte from a gz_stream; update next_in and avail_in. Return EOF
233 for end of file.
234 IN assertion: the stream s has been sucessfully opened for reading.
235*/
236local int get_byte(s)
237 gz_stream *s;
238{
239 if (s->z_eof) return EOF;
240 if (s->stream.avail_in == 0) {
241 errno = 0;
242 s->stream.avail_in = fread(s->inbuf, 1, Z_BUFSIZE, s->file);
243 if (s->stream.avail_in == 0) {
244 s->z_eof = 1;
245 if (ferror(s->file)) s->z_err = Z_ERRNO;
246 return EOF;
247 }
248 s->stream.next_in = s->inbuf;
249 }
250 s->stream.avail_in--;
251 return *(s->stream.next_in)++;
252}
253
254/* ===========================================================================
255 Check the gzip header of a gz_stream opened for reading. Set the stream
256 mode to transparent if the gzip magic header is not present; set s->err
257 to Z_DATA_ERROR if the magic header is present but the rest of the header
258 is incorrect.
259 IN assertion: the stream s has already been created sucessfully;
260 s->stream.avail_in is zero for the first time, but may be non-zero
261 for concatenated .gz files.
262*/
263local void check_header(s)
264 gz_stream *s;
265{
266 int method; /* method byte */
267 int flags; /* flags byte */
268 uInt len;
269 int c;
270
271 /* Check the gzip magic header */
272 for (len = 0; len < 2; len++) {
273 c = get_byte(s);
274 if (c != gz_magic[len]) {
275 if (len != 0) s->stream.avail_in++, s->stream.next_in--;
276 if (c != EOF) {
277 s->stream.avail_in++, s->stream.next_in--;
278 s->transparent = 1;
279 }
280 s->z_err = s->stream.avail_in != 0 ? Z_OK : Z_STREAM_END;
281 return;
282 }
283 }
284 method = get_byte(s);
285 flags = get_byte(s);
286 if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
287 s->z_err = Z_DATA_ERROR;
288 return;
289 }
290
291 /* Discard time, xflags and OS code: */
292 for (len = 0; len < 6; len++) (void)get_byte(s);
293
294 if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
295 len = (uInt)get_byte(s);
296 len += ((uInt)get_byte(s))<<8;
297 /* len is garbage if EOF but the loop below will quit anyway */
298 while (len-- != 0 && get_byte(s) != EOF) ;
299 }
300 if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
301 while ((c = get_byte(s)) != 0 && c != EOF) ;
302 }
303 if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
304 while ((c = get_byte(s)) != 0 && c != EOF) ;
305 }
306 if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
307 for (len = 0; len < 2; len++) (void)get_byte(s);
308 }
309 s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
310}
311
312 /* ===========================================================================
313 * Cleanup then free the given gz_stream. Return a zlib error code.
314 Try freeing in the reverse order of allocations.
315 */
316local int destroy (s)
317 gz_stream *s;
318{
319 int err = Z_OK;
320
321 if (!s) return Z_STREAM_ERROR;
322
323 TRYFREE(s->msg);
324
325 if (s->stream.state != NULL) {
326 if (s->mode == 'w') {
327#ifdef NO_DEFLATE
328 err = Z_STREAM_ERROR;
329#else
330 err = deflateEnd(&(s->stream));
331#endif
332 } else if (s->mode == 'r') {
333 err = inflateEnd(&(s->stream));
334 }
335 }
336 if (s->file != NULL && fclose(s->file)) {
337#ifdef ESPIPE
338 if (errno != ESPIPE) /* fclose is broken for pipes in HP/UX */
339#endif
340 err = Z_ERRNO;
341 }
342 if (s->z_err < 0) err = s->z_err;
343
344 TRYFREE(s->inbuf);
345 TRYFREE(s->outbuf);
346 TRYFREE(s->path);
347 TRYFREE(s);
348 return err;
349}
350
351/* ===========================================================================
352 Reads the given number of uncompressed bytes from the compressed file.
353 gzread returns the number of bytes actually read (0 for end of file).
354*/
355int ZEXPORT gzread (file, buf, len)
356 gzFile file;
357 voidp buf;
358 unsigned len;
359{
360 gz_stream *s = (gz_stream*)file;
361 Bytef *start = (Bytef*)buf; /* starting point for crc computation */
362 Byte *next_out; /* == stream.next_out but not forced far (for MSDOS) */
363
364 if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;
365
366 if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
367 if (s->z_err == Z_STREAM_END) return 0; /* EOF */
368
369 next_out = (Byte*)buf;
370 s->stream.next_out = (Bytef*)buf;
371 s->stream.avail_out = len;
372
373 while (s->stream.avail_out != 0) {
374
375 if (s->transparent) {
376 /* Copy first the lookahead bytes: */
377 uInt n = s->stream.avail_in;
378 if (n > s->stream.avail_out) n = s->stream.avail_out;
379 if (n > 0) {
380 zmemcpy(s->stream.next_out, s->stream.next_in, n);
381 next_out += n;
382 s->stream.next_out = next_out;
383 s->stream.next_in += n;
384 s->stream.avail_out -= n;
385 s->stream.avail_in -= n;
386 }
387 if (s->stream.avail_out > 0) {
388 s->stream.avail_out -= fread(next_out, 1, s->stream.avail_out,
389 s->file);
390 }
391 len -= s->stream.avail_out;
392 s->stream.total_in += (uLong)len;
393 s->stream.total_out += (uLong)len;
394 if (len == 0) s->z_eof = 1;
395 return (int)len;
396 }
397 if (s->stream.avail_in == 0 && !s->z_eof) {
398
399 errno = 0;
400 s->stream.avail_in = fread(s->inbuf, 1, Z_BUFSIZE, s->file);
401 if (s->stream.avail_in == 0) {
402 s->z_eof = 1;
403 if (ferror(s->file)) {
404 s->z_err = Z_ERRNO;
405 break;
406 }
407 }
408 s->stream.next_in = s->inbuf;
409 }
410 s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
411
412 if (s->z_err == Z_STREAM_END) {
413 /* Check CRC and original size */
414 s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
415 start = s->stream.next_out;
416
417 if (getLong(s) != s->crc) {
418 s->z_err = Z_DATA_ERROR;
419 } else {
420 (void)getLong(s);
421 /* The uncompressed length returned by above getlong() may
422 * be different from s->stream.total_out) in case of
423 * concatenated .gz files. Check for such files:
424 */
425 check_header(s);
426 if (s->z_err == Z_OK) {
427 uLong total_in = s->stream.total_in;
428 uLong total_out = s->stream.total_out;
429
430 inflateReset(&(s->stream));
431 s->stream.total_in = total_in;
432 s->stream.total_out = total_out;
433 s->crc = crc32(0L, Z_NULL, 0);
434 }
435 }
436 }
437 if (s->z_err != Z_OK || s->z_eof) break;
438 }
439 s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
440
441 return (int)(len - s->stream.avail_out);
442}
443
444
445/* ===========================================================================
446 Reads one byte from the compressed file. gzgetc returns this byte
447 or -1 in case of end of file or error.
448*/
449int ZEXPORT gzgetc(file)
450 gzFile file;
451{
452 unsigned char c;
453
454 return gzread(file, &c, 1) == 1 ? c : -1;
455}
456
457
458/* ===========================================================================
459 Reads bytes from the compressed file until len-1 characters are
460 read, or a newline character is read and transferred to buf, or an
461 end-of-file condition is encountered. The string is then terminated
462 with a null character.
463 gzgets returns buf, or Z_NULL in case of error.
464
465 The current implementation is not optimized at all.
466*/
467char * ZEXPORT gzgets(file, buf, len)
468 gzFile file;
469 char *buf;
470 int len;
471{
472 char *b = buf;
473 if (buf == Z_NULL || len <= 0) return Z_NULL;
474
475 while (--len > 0 && gzread(file, buf, 1) == 1 && *buf++ != '\n') ;
476 *buf = '\0';
477 return b == buf && len > 0 ? Z_NULL : b;
478}
479
480
481#ifndef NO_DEFLATE
482/* ===========================================================================
483 Writes the given number of uncompressed bytes into the compressed file.
484 gzwrite returns the number of bytes actually written (0 in case of error).
485*/
486int ZEXPORT gzwrite (file, buf, len)
487 gzFile file;
488 const voidp buf;
489 unsigned len;
490{
491 gz_stream *s = (gz_stream*)file;
492
493 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
494
495 s->stream.next_in = (Bytef*)buf;
496 s->stream.avail_in = len;
497
498 while (s->stream.avail_in != 0) {
499
500 if (s->stream.avail_out == 0) {
501
502 s->stream.next_out = s->outbuf;
503 if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
504 s->z_err = Z_ERRNO;
505 break;
506 }
507 s->stream.avail_out = Z_BUFSIZE;
508 }
509 s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
510 if (s->z_err != Z_OK) break;
511 }
512 s->crc = crc32(s->crc, (const Bytef *)buf, len);
513
514 return (int)(len - s->stream.avail_in);
515}
516
517/* ===========================================================================
518 Converts, formats, and writes the args to the compressed file under
519 control of the format string, as in fprintf. gzprintf returns the number of
520 uncompressed bytes actually written (0 in case of error).
521*/
522#ifdef STDC
523#include <stdarg.h>
524
525int ZEXPORTVA gzprintf (gzFile file, const char *format, /* args */ ...)
526{
527 char buf[Z_PRINTF_BUFSIZE];
528 va_list va;
529 int len;
530
531 va_start(va, format);
532#ifdef HAS_vsnprintf
533 (void)vsnprintf(buf, sizeof(buf), format, va);
534#else
535 (void)vsprintf(buf, format, va);
536#endif
537 va_end(va);
538 len = strlen(buf); /* some *sprintf don't return the nb of bytes written */
539 if (len <= 0) return 0;
540
541 return gzwrite(file, buf, (unsigned)len);
542}
543#else /* not ANSI C */
544
545int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
546 a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
547 gzFile file;
548 const char *format;
549 int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
550 a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
551{
552 char buf[Z_PRINTF_BUFSIZE];
553 int len;
554
555#ifdef HAS_snprintf
556 snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8,
557 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
558#else
559 sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8,
560 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
561#endif
562 len = strlen(buf); /* old sprintf doesn't return the nb of bytes written */
563 if (len <= 0) return 0;
564
565 return gzwrite(file, buf, len);
566}
567#endif
568
569/* ===========================================================================
570 Writes c, converted to an unsigned char, into the compressed file.
571 gzputc returns the value that was written, or -1 in case of error.
572*/
573int ZEXPORT gzputc(file, c)
574 gzFile file;
575 int c;
576{
577 unsigned char cc = (unsigned char) c; /* required for big endian systems */
578
579 return gzwrite(file, &cc, 1) == 1 ? (int)cc : -1;
580}
581
582
583/* ===========================================================================
584 Writes the given null-terminated string to the compressed file, excluding
585 the terminating null character.
586 gzputs returns the number of characters written, or -1 in case of error.
587*/
588int ZEXPORT gzputs(file, s)
589 gzFile file;
590 const char *s;
591{
592 return gzwrite(file, (char*)s, (unsigned)strlen(s));
593}
594
595
596/* ===========================================================================
597 Flushes all pending output into the compressed file. The parameter
598 flush is as in the deflate() function.
599*/
600local int do_flush (file, flush)
601 gzFile file;
602 int flush;
603{
604 uInt len;
605 int done = 0;
606 gz_stream *s = (gz_stream*)file;
607
608 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
609
610 s->stream.avail_in = 0; /* should be zero already anyway */
611
612 for (;;) {
613 len = Z_BUFSIZE - s->stream.avail_out;
614
615 if (len != 0) {
616 if ((uInt)fwrite(s->outbuf, 1, len, s->file) != len) {
617 s->z_err = Z_ERRNO;
618 return Z_ERRNO;
619 }
620 s->stream.next_out = s->outbuf;
621 s->stream.avail_out = Z_BUFSIZE;
622 }
623 if (done) break;
624 s->z_err = deflate(&(s->stream), flush);
625
626 /* Ignore the second of two consecutive flushes: */
627 if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK;
628
629 /* deflate has finished flushing only when it hasn't used up
630 * all the available space in the output buffer:
631 */
632 done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
633
634 if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
635 }
636 return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
637}
638
639int ZEXPORT gzflush (file, flush)
640 gzFile file;
641 int flush;
642{
643 gz_stream *s = (gz_stream*)file;
644 int err = do_flush (file, flush);
645
646 if (err) return err;
647 fflush(s->file);
648 return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
649}
650#endif /* NO_DEFLATE */
651
652/* ===========================================================================
653 Sets the starting position for the next gzread or gzwrite on the given
654 compressed file. The offset represents a number of bytes in the
655 gzseek returns the resulting offset location as measured in bytes from
656 the beginning of the uncompressed stream, or -1 in case of error.
657 SEEK_END is not implemented, returns error.
658 In this version of the library, gzseek can be extremely slow.
659*/
660z_off_t ZEXPORT gzseek (file, offset, whence)
661 gzFile file;
662 z_off_t offset;
663 int whence;
664{
665 gz_stream *s = (gz_stream*)file;
666
667 if (s == NULL || whence == SEEK_END ||
668 s->z_err == Z_ERRNO || s->z_err == Z_DATA_ERROR) {
669 return -1L;
670 }
671
672 if (s->mode == 'w') {
673#ifdef NO_DEFLATE
674 return -1L;
675#else
676 if (whence == SEEK_SET) {
677 offset -= s->stream.total_in;
678 }
679 if (offset < 0) return -1L;
680
681 /* At this point, offset is the number of zero bytes to write. */
682 if (s->inbuf == Z_NULL) {
683 s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); /* for seeking */
684 zmemzero(s->inbuf, Z_BUFSIZE);
685 }
686 while (offset > 0) {
687 uInt size = Z_BUFSIZE;
688 if (offset < Z_BUFSIZE) size = (uInt)offset;
689
690 size = gzwrite(file, s->inbuf, size);
691 if (size == 0) return -1L;
692
693 offset -= size;
694 }
695 return (z_off_t)s->stream.total_in;
696#endif
697 }
698 /* Rest of function is for reading only */
699
700 /* compute absolute position */
701 if (whence == SEEK_CUR) {
702 offset += s->stream.total_out;
703 }
704 if (offset < 0) return -1L;
705
706 if (s->transparent) {
707 /* map to fseek */
708 s->stream.avail_in = 0;
709 s->stream.next_in = s->inbuf;
710 if (fseek(s->file, offset, SEEK_SET) < 0) return -1L;
711
712 s->stream.total_in = s->stream.total_out = (uLong)offset;
713 return offset;
714 }
715
716 /* For a negative seek, rewind and use positive seek */
717 if ((uLong)offset >= s->stream.total_out) {
718 offset -= s->stream.total_out;
719 } else if (gzrewind(file) < 0) {
720 return -1L;
721 }
722 /* offset is now the number of bytes to skip. */
723
724 if (offset != 0 && s->outbuf == Z_NULL) {
725 s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
726 }
727 while (offset > 0) {
728 int size = Z_BUFSIZE;
729 if (offset < Z_BUFSIZE) size = (int)offset;
730
731 size = gzread(file, s->outbuf, (uInt)size);
732 if (size <= 0) return -1L;
733 offset -= size;
734 }
735 return (z_off_t)s->stream.total_out;
736}
737
738/* ===========================================================================
739 Rewinds input file.
740*/
741int ZEXPORT gzrewind (file)
742 gzFile file;
743{
744 gz_stream *s = (gz_stream*)file;
745
746 if (s == NULL || s->mode != 'r') return -1;
747
748 s->z_err = Z_OK;
749 s->z_eof = 0;
750 s->stream.avail_in = 0;
751 s->stream.next_in = s->inbuf;
752 s->crc = crc32(0L, Z_NULL, 0);
753
754 if (s->startpos == 0) { /* not a compressed file */
755 rewind(s->file);
756 return 0;
757 }
758
759 (void) inflateReset(&s->stream);
760 return fseek(s->file, s->startpos, SEEK_SET);
761}
762
763/* ===========================================================================
764 Returns the starting position for the next gzread or gzwrite on the
765 given compressed file. This position represents a number of bytes in the
766 uncompressed data stream.
767*/
768z_off_t ZEXPORT gztell (file)
769 gzFile file;
770{
771 return gzseek(file, 0L, SEEK_CUR);
772}
773
774/* ===========================================================================
775 Returns 1 when EOF has previously been detected reading the given
776 input stream, otherwise zero.
777*/
778int ZEXPORT gzeof (file)
779 gzFile file;
780{
781 gz_stream *s = (gz_stream*)file;
782
783 return (s == NULL || s->mode != 'r') ? 0 : s->z_eof;
784}
785
786/* ===========================================================================
787 Outputs a long in LSB order to the given file
788*/
789local void putLong (file, x)
790 FILE *file;
791 uLong x;
792{
793 int n;
794 for (n = 0; n < 4; n++) {
795 fputc((int)(x & 0xff), file);
796 x >>= 8;
797 }
798}
799
800/* ===========================================================================
801 Reads a long in LSB order from the given gz_stream. Sets z_err in case
802 of error.
803*/
804local uLong getLong (s)
805 gz_stream *s;
806{
807 uLong x = (uLong)get_byte(s);
808 int c;
809
810 x += ((uLong)get_byte(s))<<8;
811 x += ((uLong)get_byte(s))<<16;
812 c = get_byte(s);
813 if (c == EOF) s->z_err = Z_DATA_ERROR;
814 x += ((uLong)c)<<24;
815 return x;
816}
817
818/* ===========================================================================
819 Flushes all pending output if necessary, closes the compressed file
820 and deallocates all the (de)compression state.
821*/
822int ZEXPORT gzclose (file)
823 gzFile file;
824{
825 int err;
826 gz_stream *s = (gz_stream*)file;
827
828 if (s == NULL) return Z_STREAM_ERROR;
829
830 if (s->mode == 'w') {
831#ifdef NO_DEFLATE
832 return Z_STREAM_ERROR;
833#else
834 err = do_flush (file, Z_FINISH);
835 if (err != Z_OK) return destroy((gz_stream*)file);
836
837 putLong (s->file, s->crc);
838 putLong (s->file, s->stream.total_in);
839#endif
840 }
841 return destroy((gz_stream*)file);
842}
843
844/* ===========================================================================
845 Returns the error message for the last error which occured on the
846 given compressed file. errnum is set to zlib error number. If an
847 error occured in the file system and not in the compression library,
848 errnum is set to Z_ERRNO and the application may consult errno
849 to get the exact error code.
850*/
851const char* ZEXPORT gzerror (file, errnum)
852 gzFile file;
853 int *errnum;
854{
855 char *m;
856 gz_stream *s = (gz_stream*)file;
857
858 if (s == NULL) {
859 *errnum = Z_STREAM_ERROR;
860 return (const char*)ERR_MSG(Z_STREAM_ERROR);
861 }
862 *errnum = s->z_err;
863 if (*errnum == Z_OK) return (const char*)"";
864
865 m = (char*)(*errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg);
866
867 if (m == NULL || *m == '\0') m = (char*)ERR_MSG(s->z_err);
868
869 TRYFREE(s->msg);
870 s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3);
871 strcpy(s->msg, s->path);
872 strcat(s->msg, ": ");
873 strcat(s->msg, m);
874 return (const char*)s->msg;
875}
ARM optimized FCE Ultra port