some skin adjustments
[picodrive.git] / zlib / gzio.c
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cc68a136 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/* @(#) $Id$ */
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
19struct 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
39extern voidp malloc OF((uInt size));
40extern void free OF((voidpf ptr));
41#endif
42
43#define ALLOC(size) malloc(size)
44#define TRYFREE(p) {if (p) free(p);}
45
46static 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
56typedef 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
76local gzFile gz_open OF((const char *path, const char *mode, int fd));
77local int do_flush OF((gzFile file, int flush));
78local int get_byte OF((gz_stream *s));
79local void check_header OF((gz_stream *s));
83bd0b76 80//local
81 int destroy OF((gz_stream *s));
cc68a136 82local void putLong OF((FILE *file, uLong x));
83local uLong getLong OF((gz_stream *s));
84
85/* ===========================================================================
86 Opens a gzip (.gz) file for reading or writing. The mode parameter
87 is as in fopen ("rb" or "wb"). The file is given either by file descriptor
88 or path name (if fd == -1).
89 gz_open returns NULL if the file could not be opened or if there was
90 insufficient memory to allocate the (de)compression state; errno
91 can be checked to distinguish the two cases (if errno is zero, the
92 zlib error is Z_MEM_ERROR).
93*/
94local gzFile gz_open (path, mode, fd)
95 const char *path;
96 const char *mode;
97 int fd;
98{
99 int err;
100 int level = Z_DEFAULT_COMPRESSION; /* compression level */
101 int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */
102 char *p = (char*)mode;
103 gz_stream *s;
104 char fmode[80]; /* copy of mode, without the compression level */
105 char *m = fmode;
106
107 if (!path || !mode) return Z_NULL;
108
109 s = (gz_stream *)ALLOC(sizeof(gz_stream));
110 if (!s) return Z_NULL;
111
112 s->stream.zalloc = (alloc_func)0;
113 s->stream.zfree = (free_func)0;
114 s->stream.opaque = (voidpf)0;
115 s->stream.next_in = s->inbuf = Z_NULL;
116 s->stream.next_out = s->outbuf = Z_NULL;
117 s->stream.avail_in = s->stream.avail_out = 0;
118 s->file = NULL;
119 s->z_err = Z_OK;
120 s->z_eof = 0;
121 s->in = 0;
122 s->out = 0;
123 s->back = EOF;
124 s->crc = crc32(0L, Z_NULL, 0);
125 s->msg = NULL;
126 s->transparent = 0;
127
128 s->path = (char*)ALLOC(strlen(path)+1);
129 if (s->path == NULL) {
130 return destroy(s), (gzFile)Z_NULL;
131 }
132 strcpy(s->path, path); /* do this early for debugging */
133
134 s->mode = '\0';
135 do {
136 if (*p == 'r') s->mode = 'r';
137 if (*p == 'w' || *p == 'a') s->mode = 'w';
138 if (*p >= '0' && *p <= '9') {
139 level = *p - '0';
140 } else if (*p == 'f') {
141 strategy = Z_FILTERED;
142 } else if (*p == 'h') {
143 strategy = Z_HUFFMAN_ONLY;
144 } else if (*p == 'R') {
145 strategy = Z_RLE;
146 } else {
147 *m++ = *p; /* copy the mode */
148 }
149 } while (*p++ && m != fmode + sizeof(fmode));
150 if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL;
151
152 if (s->mode == 'w') {
153#ifdef NO_GZCOMPRESS
154 err = Z_STREAM_ERROR;
155#else
156 err = deflateInit2(&(s->stream), level,
157 Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy);
158 /* windowBits is passed < 0 to suppress zlib header */
159
160 s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
161#endif
162 if (err != Z_OK || s->outbuf == Z_NULL) {
163 return destroy(s), (gzFile)Z_NULL;
164 }
165 } else {
166 s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
167
168 err = inflateInit2(&(s->stream), -MAX_WBITS);
169 /* windowBits is passed < 0 to tell that there is no zlib header.
170 * Note that in this case inflate *requires* an extra "dummy" byte
171 * after the compressed stream in order to complete decompression and
172 * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are
173 * present after the compressed stream.
174 */
175 if (err != Z_OK || s->inbuf == Z_NULL) {
176 return destroy(s), (gzFile)Z_NULL;
177 }
178 }
179 s->stream.avail_out = Z_BUFSIZE;
180
181 errno = 0;
182 s->file = fd < 0 ? F_OPEN(path, fmode) : (FILE*)fdopen(fd, fmode);
183
184 if (s->file == NULL) {
185 return destroy(s), (gzFile)Z_NULL;
186 }
187 if (s->mode == 'w') {
188 /* Write a very simple .gz header:
189 */
190 fprintf(s->file, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], gz_magic[1],
191 Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE);
192 s->start = 10L;
193 /* We use 10L instead of ftell(s->file) to because ftell causes an
194 * fflush on some systems. This version of the library doesn't use
195 * start anyway in write mode, so this initialization is not
196 * necessary.
197 */
198 } else {
199 check_header(s); /* skip the .gz header */
200 s->start = ftell(s->file) - s->stream.avail_in;
201 }
202
203 return (gzFile)s;
204}
205
206/* ===========================================================================
207 Opens a gzip (.gz) file for reading or writing.
208*/
209gzFile ZEXPORT gzopen (path, mode)
210 const char *path;
211 const char *mode;
212{
213 return gz_open (path, mode, -1);
214}
215
216/* ===========================================================================
217 Associate a gzFile with the file descriptor fd. fd is not dup'ed here
218 to mimic the behavio(u)r of fdopen.
219*/
220gzFile ZEXPORT gzdopen (fd, mode)
221 int fd;
222 const char *mode;
223{
224 char name[46]; /* allow for up to 128-bit integers */
225
226 if (fd < 0) return (gzFile)Z_NULL;
227 sprintf(name, "<fd:%d>", fd); /* for debugging */
228
229 return gz_open (name, mode, fd);
230}
231
232/* ===========================================================================
233 * Update the compression level and strategy
234 */
235int ZEXPORT gzsetparams (file, level, strategy)
236 gzFile file;
237 int level;
238 int strategy;
239{
240 gz_stream *s = (gz_stream*)file;
241
242 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
243
244 /* Make room to allow flushing */
245 if (s->stream.avail_out == 0) {
246
247 s->stream.next_out = s->outbuf;
248 if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
249 s->z_err = Z_ERRNO;
250 }
251 s->stream.avail_out = Z_BUFSIZE;
252 }
253
254 return deflateParams (&(s->stream), level, strategy);
255}
256
257/* ===========================================================================
258 Read a byte from a gz_stream; update next_in and avail_in. Return EOF
259 for end of file.
260 IN assertion: the stream s has been sucessfully opened for reading.
261*/
262local int get_byte(s)
263 gz_stream *s;
264{
265 if (s->z_eof) return EOF;
266 if (s->stream.avail_in == 0) {
267 errno = 0;
268 s->stream.avail_in = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file);
269 if (s->stream.avail_in == 0) {
270 s->z_eof = 1;
271 if (ferror(s->file)) s->z_err = Z_ERRNO;
272 return EOF;
273 }
274 s->stream.next_in = s->inbuf;
275 }
276 s->stream.avail_in--;
277 return *(s->stream.next_in)++;
278}
279
280/* ===========================================================================
281 Check the gzip header of a gz_stream opened for reading. Set the stream
282 mode to transparent if the gzip magic header is not present; set s->err
283 to Z_DATA_ERROR if the magic header is present but the rest of the header
284 is incorrect.
285 IN assertion: the stream s has already been created sucessfully;
286 s->stream.avail_in is zero for the first time, but may be non-zero
287 for concatenated .gz files.
288*/
289local void check_header(s)
290 gz_stream *s;
291{
292 int method; /* method byte */
293 int flags; /* flags byte */
294 uInt len;
295 int c;
296
297 /* Assure two bytes in the buffer so we can peek ahead -- handle case
298 where first byte of header is at the end of the buffer after the last
299 gzip segment */
300 len = s->stream.avail_in;
301 if (len < 2) {
302 if (len) s->inbuf[0] = s->stream.next_in[0];
303 errno = 0;
304 len = (uInt)fread(s->inbuf + len, 1, Z_BUFSIZE >> len, s->file);
305 if (len == 0 && ferror(s->file)) s->z_err = Z_ERRNO;
306 s->stream.avail_in += len;
307 s->stream.next_in = s->inbuf;
308 if (s->stream.avail_in < 2) {
309 s->transparent = s->stream.avail_in;
310 return;
311 }
312 }
313
314 /* Peek ahead to check the gzip magic header */
315 if (s->stream.next_in[0] != gz_magic[0] ||
316 s->stream.next_in[1] != gz_magic[1]) {
317 s->transparent = 1;
318 return;
319 }
320 s->stream.avail_in -= 2;
321 s->stream.next_in += 2;
322
323 /* Check the rest of the gzip header */
324 method = get_byte(s);
325 flags = get_byte(s);
326 if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
327 s->z_err = Z_DATA_ERROR;
328 return;
329 }
330
331 /* Discard time, xflags and OS code: */
332 for (len = 0; len < 6; len++) (void)get_byte(s);
333
334 if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
335 len = (uInt)get_byte(s);
336 len += ((uInt)get_byte(s))<<8;
337 /* len is garbage if EOF but the loop below will quit anyway */
338 while (len-- != 0 && get_byte(s) != EOF) ;
339 }
340 if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
341 while ((c = get_byte(s)) != 0 && c != EOF) ;
342 }
343 if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
344 while ((c = get_byte(s)) != 0 && c != EOF) ;
345 }
346 if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
347 for (len = 0; len < 2; len++) (void)get_byte(s);
348 }
349 s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
350}
351
352 /* ===========================================================================
353 * Cleanup then free the given gz_stream. Return a zlib error code.
354 Try freeing in the reverse order of allocations.
355 */
83bd0b76 356//local
357int destroy (s)
cc68a136 358 gz_stream *s;
359{
360 int err = Z_OK;
361
362 if (!s) return Z_STREAM_ERROR;
363
364 TRYFREE(s->msg);
365
366 if (s->stream.state != NULL) {
367 if (s->mode == 'w') {
368#ifdef NO_GZCOMPRESS
369 err = Z_STREAM_ERROR;
370#else
371 err = deflateEnd(&(s->stream));
372#endif
373 } else if (s->mode == 'r') {
374 err = inflateEnd(&(s->stream));
375 }
376 }
377 if (s->file != NULL && fclose(s->file)) {
378#ifdef ESPIPE
379 if (errno != ESPIPE) /* fclose is broken for pipes in HP/UX */
380#endif
381 err = Z_ERRNO;
382 }
383 if (s->z_err < 0) err = s->z_err;
384
385 TRYFREE(s->inbuf);
386 TRYFREE(s->outbuf);
387 TRYFREE(s->path);
388 TRYFREE(s);
389 return err;
390}
391
392/* ===========================================================================
393 Reads the given number of uncompressed bytes from the compressed file.
394 gzread returns the number of bytes actually read (0 for end of file).
395*/
396int ZEXPORT gzread (file, buf, len)
397 gzFile file;
398 voidp buf;
399 unsigned len;
400{
401 gz_stream *s = (gz_stream*)file;
402 Bytef *start = (Bytef*)buf; /* starting point for crc computation */
403 Byte *next_out; /* == stream.next_out but not forced far (for MSDOS) */
404
405 if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;
406
407 if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
408 if (s->z_err == Z_STREAM_END) return 0; /* EOF */
409
410 next_out = (Byte*)buf;
411 s->stream.next_out = (Bytef*)buf;
412 s->stream.avail_out = len;
413
414 if (s->stream.avail_out && s->back != EOF) {
415 *next_out++ = s->back;
416 s->stream.next_out++;
417 s->stream.avail_out--;
418 s->back = EOF;
419 s->out++;
420 start++;
421 if (s->last) {
422 s->z_err = Z_STREAM_END;
423 return 1;
424 }
425 }
426
427 while (s->stream.avail_out != 0) {
428
429 if (s->transparent) {
430 /* Copy first the lookahead bytes: */
431 uInt n = s->stream.avail_in;
432 if (n > s->stream.avail_out) n = s->stream.avail_out;
433 if (n > 0) {
434 zmemcpy(s->stream.next_out, s->stream.next_in, n);
435 next_out += n;
436 s->stream.next_out = next_out;
437 s->stream.next_in += n;
438 s->stream.avail_out -= n;
439 s->stream.avail_in -= n;
440 }
441 if (s->stream.avail_out > 0) {
442 s->stream.avail_out -=
443 (uInt)fread(next_out, 1, s->stream.avail_out, s->file);
444 }
445 len -= s->stream.avail_out;
446 s->in += len;
447 s->out += len;
448 if (len == 0) s->z_eof = 1;
449 return (int)len;
450 }
451 if (s->stream.avail_in == 0 && !s->z_eof) {
452
453 errno = 0;
454 s->stream.avail_in = (uInt)fread(s->inbuf, 1, Z_BUFSIZE, s->file);
455 if (s->stream.avail_in == 0) {
456 s->z_eof = 1;
457 if (ferror(s->file)) {
458 s->z_err = Z_ERRNO;
459 break;
460 }
461 }
462 s->stream.next_in = s->inbuf;
463 }
464 s->in += s->stream.avail_in;
465 s->out += s->stream.avail_out;
466 s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
467 s->in -= s->stream.avail_in;
468 s->out -= s->stream.avail_out;
469
470 if (s->z_err == Z_STREAM_END) {
471 /* Check CRC and original size */
472 s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
473 start = s->stream.next_out;
474
475 if (getLong(s) != s->crc) {
476 s->z_err = Z_DATA_ERROR;
477 } else {
478 (void)getLong(s);
479 /* The uncompressed length returned by above getlong() may be
480 * different from s->out in case of concatenated .gz files.
481 * Check for such files:
482 */
483 check_header(s);
484 if (s->z_err == Z_OK) {
485 inflateReset(&(s->stream));
486 s->crc = crc32(0L, Z_NULL, 0);
487 }
488 }
489 }
490 if (s->z_err != Z_OK || s->z_eof) break;
491 }
492 s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
493
494 if (len == s->stream.avail_out &&
495 (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO))
496 return -1;
497 return (int)(len - s->stream.avail_out);
498}
499
500
501/* ===========================================================================
502 Reads one byte from the compressed file. gzgetc returns this byte
503 or -1 in case of end of file or error.
504*/
505int ZEXPORT gzgetc(file)
506 gzFile file;
507{
508 unsigned char c;
509
510 return gzread(file, &c, 1) == 1 ? c : -1;
511}
512
513
514/* ===========================================================================
515 Push one byte back onto the stream.
516*/
517int ZEXPORT gzungetc(c, file)
518 int c;
519 gzFile file;
520{
521 gz_stream *s = (gz_stream*)file;
522
523 if (s == NULL || s->mode != 'r' || c == EOF || s->back != EOF) return EOF;
524 s->back = c;
525 s->out--;
526 s->last = (s->z_err == Z_STREAM_END);
527 if (s->last) s->z_err = Z_OK;
528 s->z_eof = 0;
529 return c;
530}
531
532
533/* ===========================================================================
534 Reads bytes from the compressed file until len-1 characters are
535 read, or a newline character is read and transferred to buf, or an
536 end-of-file condition is encountered. The string is then terminated
537 with a null character.
538 gzgets returns buf, or Z_NULL in case of error.
539
540 The current implementation is not optimized at all.
541*/
542char * ZEXPORT gzgets(file, buf, len)
543 gzFile file;
544 char *buf;
545 int len;
546{
547 char *b = buf;
548 if (buf == Z_NULL || len <= 0) return Z_NULL;
549
550 while (--len > 0 && gzread(file, buf, 1) == 1 && *buf++ != '\n') ;
551 *buf = '\0';
552 return b == buf && len > 0 ? Z_NULL : b;
553}
554
555
556#ifndef NO_GZCOMPRESS
557/* ===========================================================================
558 Writes the given number of uncompressed bytes into the compressed file.
559 gzwrite returns the number of bytes actually written (0 in case of error).
560*/
561int ZEXPORT gzwrite (file, buf, len)
562 gzFile file;
563 voidpc buf;
564 unsigned len;
565{
566 gz_stream *s = (gz_stream*)file;
567
568 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
569
570 s->stream.next_in = (Bytef*)buf;
571 s->stream.avail_in = len;
572
573 while (s->stream.avail_in != 0) {
574
575 if (s->stream.avail_out == 0) {
576
577 s->stream.next_out = s->outbuf;
578 if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
579 s->z_err = Z_ERRNO;
580 break;
581 }
582 s->stream.avail_out = Z_BUFSIZE;
583 }
584 s->in += s->stream.avail_in;
585 s->out += s->stream.avail_out;
586 s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
587 s->in -= s->stream.avail_in;
588 s->out -= s->stream.avail_out;
589 if (s->z_err != Z_OK) break;
590 }
591 s->crc = crc32(s->crc, (const Bytef *)buf, len);
592
593 return (int)(len - s->stream.avail_in);
594}
595
596
597/* ===========================================================================
598 Converts, formats, and writes the args to the compressed file under
599 control of the format string, as in fprintf. gzprintf returns the number of
600 uncompressed bytes actually written (0 in case of error).
601*/
602#ifdef STDC
603#include <stdarg.h>
604
605int ZEXPORTVA gzprintf (gzFile file, const char *format, /* args */ ...)
606{
607 char buf[Z_PRINTF_BUFSIZE];
608 va_list va;
609 int len;
610
611 buf[sizeof(buf) - 1] = 0;
612 va_start(va, format);
613#ifdef NO_vsnprintf
614# ifdef HAS_vsprintf_void
615 (void)vsprintf(buf, format, va);
616 va_end(va);
617 for (len = 0; len < sizeof(buf); len++)
618 if (buf[len] == 0) break;
619# else
620 len = vsprintf(buf, format, va);
621 va_end(va);
622# endif
623#else
624# ifdef HAS_vsnprintf_void
625 (void)vsnprintf(buf, sizeof(buf), format, va);
626 va_end(va);
627 len = strlen(buf);
628# else
629 len = vsnprintf(buf, sizeof(buf), format, va);
630 va_end(va);
631# endif
632#endif
633 if (len <= 0 || len >= (int)sizeof(buf) || buf[sizeof(buf) - 1] != 0)
634 return 0;
635 return gzwrite(file, buf, (unsigned)len);
636}
637#else /* not ANSI C */
638
639int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
640 a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
641 gzFile file;
642 const char *format;
643 int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
644 a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
645{
646 char buf[Z_PRINTF_BUFSIZE];
647 int len;
648
649 buf[sizeof(buf) - 1] = 0;
650#ifdef NO_snprintf
651# ifdef HAS_sprintf_void
652 sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8,
653 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
654 for (len = 0; len < sizeof(buf); len++)
655 if (buf[len] == 0) break;
656# else
657 len = sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8,
658 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
659# endif
660#else
661# ifdef HAS_snprintf_void
662 snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8,
663 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
664 len = strlen(buf);
665# else
666 len = snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8,
667 a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
668# endif
669#endif
670 if (len <= 0 || len >= sizeof(buf) || buf[sizeof(buf) - 1] != 0)
671 return 0;
672 return gzwrite(file, buf, len);
673}
674#endif
675
676/* ===========================================================================
677 Writes c, converted to an unsigned char, into the compressed file.
678 gzputc returns the value that was written, or -1 in case of error.
679*/
680int ZEXPORT gzputc(file, c)
681 gzFile file;
682 int c;
683{
684 unsigned char cc = (unsigned char) c; /* required for big endian systems */
685
686 return gzwrite(file, &cc, 1) == 1 ? (int)cc : -1;
687}
688
689
690/* ===========================================================================
691 Writes the given null-terminated string to the compressed file, excluding
692 the terminating null character.
693 gzputs returns the number of characters written, or -1 in case of error.
694*/
695int ZEXPORT gzputs(file, s)
696 gzFile file;
697 const char *s;
698{
699 return gzwrite(file, (char*)s, (unsigned)strlen(s));
700}
701
702
703/* ===========================================================================
704 Flushes all pending output into the compressed file. The parameter
705 flush is as in the deflate() function.
706*/
707local int do_flush (file, flush)
708 gzFile file;
709 int flush;
710{
711 uInt len;
712 int done = 0;
713 gz_stream *s = (gz_stream*)file;
714
715 if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
716
717 s->stream.avail_in = 0; /* should be zero already anyway */
718
719 for (;;) {
720 len = Z_BUFSIZE - s->stream.avail_out;
721
722 if (len != 0) {
723 if ((uInt)fwrite(s->outbuf, 1, len, s->file) != len) {
724 s->z_err = Z_ERRNO;
725 return Z_ERRNO;
726 }
727 s->stream.next_out = s->outbuf;
728 s->stream.avail_out = Z_BUFSIZE;
729 }
730 if (done) break;
731 s->out += s->stream.avail_out;
732 s->z_err = deflate(&(s->stream), flush);
733 s->out -= s->stream.avail_out;
734
735 /* Ignore the second of two consecutive flushes: */
736 if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK;
737
738 /* deflate has finished flushing only when it hasn't used up
739 * all the available space in the output buffer:
740 */
741 done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
742
743 if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
744 }
745 return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
746}
747
748int ZEXPORT gzflush (file, flush)
749 gzFile file;
750 int flush;
751{
752 gz_stream *s = (gz_stream*)file;
753 int err = do_flush (file, flush);
754
755 if (err) return err;
756 fflush(s->file);
757 return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
758}
759#endif /* NO_GZCOMPRESS */
760
761/* ===========================================================================
762 Sets the starting position for the next gzread or gzwrite on the given
763 compressed file. The offset represents a number of bytes in the
764 gzseek returns the resulting offset location as measured in bytes from
765 the beginning of the uncompressed stream, or -1 in case of error.
766 SEEK_END is not implemented, returns error.
767 In this version of the library, gzseek can be extremely slow.
768*/
769z_off_t ZEXPORT gzseek (file, offset, whence)
770 gzFile file;
771 z_off_t offset;
772 int whence;
773{
774 gz_stream *s = (gz_stream*)file;
775
776 if (s == NULL || whence == SEEK_END ||
777 s->z_err == Z_ERRNO || s->z_err == Z_DATA_ERROR) {
778 return -1L;
779 }
780
781 if (s->mode == 'w') {
782#ifdef NO_GZCOMPRESS
783 return -1L;
784#else
785 if (whence == SEEK_SET) {
786 offset -= s->in;
787 }
788 if (offset < 0) return -1L;
789
790 /* At this point, offset is the number of zero bytes to write. */
791 if (s->inbuf == Z_NULL) {
792 s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); /* for seeking */
793 if (s->inbuf == Z_NULL) return -1L;
794 zmemzero(s->inbuf, Z_BUFSIZE);
795 }
796 while (offset > 0) {
797 uInt size = Z_BUFSIZE;
798 if (offset < Z_BUFSIZE) size = (uInt)offset;
799
800 size = gzwrite(file, s->inbuf, size);
801 if (size == 0) return -1L;
802
803 offset -= size;
804 }
805 return s->in;
806#endif
807 }
808 /* Rest of function is for reading only */
809
810 /* compute absolute position */
811 if (whence == SEEK_CUR) {
812 offset += s->out;
813 }
814 if (offset < 0) return -1L;
815
816 if (s->transparent) {
817 /* map to fseek */
818 s->back = EOF;
819 s->stream.avail_in = 0;
820 s->stream.next_in = s->inbuf;
821 if (fseek(s->file, offset, SEEK_SET) < 0) return -1L;
822
823 s->in = s->out = offset;
824 return offset;
825 }
826
827 /* For a negative seek, rewind and use positive seek */
828 if (offset >= s->out) {
829 offset -= s->out;
830 } else if (gzrewind(file) < 0) {
831 return -1L;
832 }
833 /* offset is now the number of bytes to skip. */
834
835 if (offset != 0 && s->outbuf == Z_NULL) {
836 s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
837 if (s->outbuf == Z_NULL) return -1L;
838 }
839 if (offset && s->back != EOF) {
840 s->back = EOF;
841 s->out++;
842 offset--;
843 if (s->last) s->z_err = Z_STREAM_END;
844 }
845 while (offset > 0) {
846 int size = Z_BUFSIZE;
847 if (offset < Z_BUFSIZE) size = (int)offset;
848
849 size = gzread(file, s->outbuf, (uInt)size);
850 if (size <= 0) return -1L;
851 offset -= size;
852 }
853 return s->out;
854}
855
856/* ===========================================================================
857 Rewinds input file.
858*/
859int ZEXPORT gzrewind (file)
860 gzFile file;
861{
862 gz_stream *s = (gz_stream*)file;
863
864 if (s == NULL || s->mode != 'r') return -1;
865
866 s->z_err = Z_OK;
867 s->z_eof = 0;
868 s->back = EOF;
869 s->stream.avail_in = 0;
870 s->stream.next_in = s->inbuf;
871 s->crc = crc32(0L, Z_NULL, 0);
872 if (!s->transparent) (void)inflateReset(&s->stream);
873 s->in = 0;
874 s->out = 0;
875 return fseek(s->file, s->start, SEEK_SET);
876}
877
878/* ===========================================================================
879 Returns the starting position for the next gzread or gzwrite on the
880 given compressed file. This position represents a number of bytes in the
881 uncompressed data stream.
882*/
883z_off_t ZEXPORT gztell (file)
884 gzFile file;
885{
886 return gzseek(file, 0L, SEEK_CUR);
887}
888
889/* ===========================================================================
890 Returns 1 when EOF has previously been detected reading the given
891 input stream, otherwise zero.
892*/
893int ZEXPORT gzeof (file)
894 gzFile file;
895{
896 gz_stream *s = (gz_stream*)file;
897
898 /* With concatenated compressed files that can have embedded
899 * crc trailers, z_eof is no longer the only/best indicator of EOF
900 * on a gz_stream. Handle end-of-stream error explicitly here.
901 */
902 if (s == NULL || s->mode != 'r') return 0;
903 if (s->z_eof) return 1;
904 return s->z_err == Z_STREAM_END;
905}
906
907/* ===========================================================================
908 Returns 1 if reading and doing so transparently, otherwise zero.
909*/
910int ZEXPORT gzdirect (file)
911 gzFile file;
912{
913 gz_stream *s = (gz_stream*)file;
914
915 if (s == NULL || s->mode != 'r') return 0;
916 return s->transparent;
917}
918
919/* ===========================================================================
920 Outputs a long in LSB order to the given file
921*/
922local void putLong (file, x)
923 FILE *file;
924 uLong x;
925{
926 int n;
927 for (n = 0; n < 4; n++) {
928 fputc((int)(x & 0xff), file);
929 x >>= 8;
930 }
931}
932
933/* ===========================================================================
934 Reads a long in LSB order from the given gz_stream. Sets z_err in case
935 of error.
936*/
937local uLong getLong (s)
938 gz_stream *s;
939{
940 uLong x = (uLong)get_byte(s);
941 int c;
942
943 x += ((uLong)get_byte(s))<<8;
944 x += ((uLong)get_byte(s))<<16;
945 c = get_byte(s);
946 if (c == EOF) s->z_err = Z_DATA_ERROR;
947 x += ((uLong)c)<<24;
948 return x;
949}
950
951/* ===========================================================================
952 Flushes all pending output if necessary, closes the compressed file
953 and deallocates all the (de)compression state.
954*/
955int ZEXPORT gzclose (file)
956 gzFile file;
957{
958 gz_stream *s = (gz_stream*)file;
959
960 if (s == NULL) return Z_STREAM_ERROR;
961
962 if (s->mode == 'w') {
963#ifdef NO_GZCOMPRESS
964 return Z_STREAM_ERROR;
965#else
966 if (do_flush (file, Z_FINISH) != Z_OK)
967 return destroy((gz_stream*)file);
968
969 putLong (s->file, s->crc);
970 putLong (s->file, (uLong)(s->in & 0xffffffff));
971#endif
972 }
973 return destroy((gz_stream*)file);
974}
975
976#ifdef STDC
977# define zstrerror(errnum) strerror(errnum)
978#else
979# define zstrerror(errnum) ""
980#endif
981
982/* ===========================================================================
983 Returns the error message for the last error which occurred on the
984 given compressed file. errnum is set to zlib error number. If an
985 error occurred in the file system and not in the compression library,
986 errnum is set to Z_ERRNO and the application may consult errno
987 to get the exact error code.
988*/
989const char * ZEXPORT gzerror (file, errnum)
990 gzFile file;
991 int *errnum;
992{
993 char *m;
994 gz_stream *s = (gz_stream*)file;
995
996 if (s == NULL) {
997 *errnum = Z_STREAM_ERROR;
998 return (const char*)ERR_MSG(Z_STREAM_ERROR);
999 }
1000 *errnum = s->z_err;
1001 if (*errnum == Z_OK) return (const char*)"";
1002
1003 m = (char*)(*errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg);
1004
1005 if (m == NULL || *m == '\0') m = (char*)ERR_MSG(s->z_err);
1006
1007 TRYFREE(s->msg);
1008 s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3);
1009 if (s->msg == Z_NULL) return (const char*)ERR_MSG(Z_MEM_ERROR);
1010 strcpy(s->msg, s->path);
1011 strcat(s->msg, ": ");
1012 strcat(s->msg, m);
1013 return (const char*)s->msg;
1014}
1015
1016/* ===========================================================================
1017 Clear the error and end-of-file flags, and do the same for the real file.
1018*/
1019void ZEXPORT gzclearerr (file)
1020 gzFile file;
1021{
1022 gz_stream *s = (gz_stream*)file;
1023
1024 if (s == NULL) return;
1025 if (s->z_err != Z_STREAM_END) s->z_err = Z_OK;
1026 s->z_eof = 0;
1027 clearerr(s->file);
1028}