gzlib.c@ 105770

最後變更在這個檔案從105770是 97832,由 vboxsync 提交於 2 年前
zlib-1.2.13: adding svn:sync-process property to all zlib files (except LICESNSE and zlib.3.pdf). bugref:10335
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1	/* gzlib.c -- zlib functions common to reading and writing gzip files
2	* Copyright (C) 2004-2019 Mark Adler
3	* For conditions of distribution and use, see copyright notice in zlib.h
4	*/
5
6	#include "gzguts.h"
7
8	#if defined(_WIN32) && !defined(__BORLANDC__)
9	# define LSEEK _lseeki64
10	#else
11	#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
12	# define LSEEK lseek64
13	#else
14	# define LSEEK lseek
15	#endif
16	#endif
17
18	/* Local functions */
19	local void gz_reset OF((gz_statep));
20	local gzFile gz_open OF((const void , int, const char ));
21
22	#if defined UNDER_CE
23
24	/* Map the Windows error number in ERROR to a locale-dependent error message
25	string and return a pointer to it. Typically, the values for ERROR come
26	from GetLastError.
27
28	The string pointed to shall not be modified by the application, but may be
29	overwritten by a subsequent call to gz_strwinerror
30
31	The gz_strwinerror function does not change the current setting of
32	GetLastError. */
33	char ZLIB_INTERNAL *gz_strwinerror(error)
34	DWORD error;
35	{
36	static char buf[1024];
37
38	wchar_t *msgbuf;
39	DWORD lasterr = GetLastError();
40	DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
41	\| FORMAT_MESSAGE_ALLOCATE_BUFFER,
42	NULL,
43	error,
44	0, /* Default language */
45	(LPVOID)&msgbuf,
46	0,
47	NULL);
48	if (chars != 0) {
49	/* If there is an \r\n appended, zap it. */
50	if (chars >= 2
51	&& msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
52	chars -= 2;
53	msgbuf[chars] = 0;
54	}
55
56	if (chars > sizeof (buf) - 1) {
57	chars = sizeof (buf) - 1;
58	msgbuf[chars] = 0;
59	}
60
61	wcstombs(buf, msgbuf, chars + 1);
62	LocalFree(msgbuf);
63	}
64	else {
65	sprintf(buf, "unknown win32 error (%ld)", error);
66	}
67
68	SetLastError(lasterr);
69	return buf;
70	}
71
72	#endif /* UNDER_CE */
73
74	/* Reset gzip file state */
75	local void gz_reset(state)
76	gz_statep state;
77	{
78	state->x.have = 0; /* no output data available */
79	if (state->mode == GZ_READ) { /* for reading ... */
80	state->eof = 0; /* not at end of file */
81	state->past = 0; /* have not read past end yet */
82	state->how = LOOK; /* look for gzip header */
83	}
84	else /* for writing ... */
85	state->reset = 0; /* no deflateReset pending */
86	state->seek = 0; /* no seek request pending */
87	gz_error(state, Z_OK, NULL); /* clear error */
88	state->x.pos = 0; /* no uncompressed data yet */
89	state->strm.avail_in = 0; /* no input data yet */
90	}
91
92	/* Open a gzip file either by name or file descriptor. */
93	local gzFile gz_open(path, fd, mode)
94	const void *path;
95	int fd;
96	const char *mode;
97	{
98	gz_statep state;
99	z_size_t len;
100	#ifndef IPRT_NO_CRT /* VBox */
101	int oflag;
102	#else /* VBox */
103	uint64_t fOpen; /* VBox */
104	int rc; /* VBox */
105	# define O_CLOEXEC /* VBox */
106	# define O_EXCL /* VBox */
107	#endif /* VBox */
108	#ifdef O_CLOEXEC
109	int cloexec = 0;
110	#endif
111	#ifdef O_EXCL
112	int exclusive = 0;
113	#endif
114
115	/* check input */
116	if (path == NULL)
117	return NULL;
118
119	/* allocate gzFile structure to return */
120	state = (gz_statep)malloc(sizeof(gz_state));
121	if (state == NULL)
122	return NULL;
123	state->size = 0; /* no buffers allocated yet */
124	state->want = GZBUFSIZE; /* requested buffer size */
125	state->msg = NULL; /* no error message yet */
126
127	/* interpret mode */
128	state->mode = GZ_NONE;
129	state->level = Z_DEFAULT_COMPRESSION;
130	state->strategy = Z_DEFAULT_STRATEGY;
131	state->direct = 0;
132	while (*mode) {
133	if (mode >= '0' && mode <= '9')
134	state->level = *mode - '0';
135	else
136	switch (*mode) {
137	case 'r':
138	state->mode = GZ_READ;
139	break;
140	#ifndef NO_GZCOMPRESS
141	case 'w':
142	state->mode = GZ_WRITE;
143	break;
144	case 'a':
145	state->mode = GZ_APPEND;
146	break;
147	#endif
148	case '+': /* can't read and write at the same time */
149	free(state);
150	return NULL;
151	case 'b': /* ignore -- will request binary anyway */
152	break;
153	#ifdef O_CLOEXEC
154	case 'e':
155	cloexec = 1;
156	break;
157	#endif
158	#ifdef O_EXCL
159	case 'x':
160	exclusive = 1;
161	break;
162	#endif
163	case 'f':
164	state->strategy = Z_FILTERED;
165	break;
166	case 'h':
167	state->strategy = Z_HUFFMAN_ONLY;
168	break;
169	case 'R':
170	state->strategy = Z_RLE;
171	break;
172	case 'F':
173	state->strategy = Z_FIXED;
174	break;
175	case 'T':
176	state->direct = 1;
177	break;
178	default: /* could consider as an error, but just ignore */
179	;
180	}
181	mode++;
182	}
183
184	/* must provide an "r", "w", or "a" */
185	if (state->mode == GZ_NONE) {
186	free(state);
187	return NULL;
188	}
189
190	/* can't force transparent read */
191	if (state->mode == GZ_READ) {
192	if (state->direct) {
193	free(state);
194	return NULL;
195	}
196	state->direct = 1; /* for empty file */
197	}
198
199	/* save the path name for error messages */
200	#ifdef WIDECHAR
201	if (fd == -2) {
202	len = wcstombs(NULL, path, 0);
203	if (len == (z_size_t)-1)
204	len = 0;
205	}
206	else
207	#endif
208	len = strlen((const char *)path);
209	state->path = (char *)malloc(len + 1);
210	if (state->path == NULL) {
211	free(state);
212	return NULL;
213	}
214	#ifdef WIDECHAR
215	if (fd == -2)
216	if (len)
217	wcstombs(state->path, path, len + 1);
218	else
219	*(state->path) = 0;
220	else
221	#endif
222	#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
223	(void)snprintf(state->path, len + 1, "%s", (const char *)path);
224	#else
225	strcpy(state->path, path);
226	#endif
227
228	/* compute the flags for open() */
229	#ifndef IPRT_NO_CRT /* VBox */
230	oflag =
231	#ifdef O_LARGEFILE
232	O_LARGEFILE \|
233	#endif
234	#ifdef O_BINARY
235	O_BINARY \|
236	#endif
237	#ifdef O_CLOEXEC
238	(cloexec ? O_CLOEXEC : 0) \|
239	#endif
240	(state->mode == GZ_READ ?
241	O_RDONLY :
242	(O_WRONLY \| O_CREAT \|
243	#ifdef O_EXCL
244	(exclusive ? O_EXCL : 0) \|
245	#endif
246	(state->mode == GZ_WRITE ?
247	O_TRUNC :
248	O_APPEND)));
249	#else /* IPRT_NO_CRT / / VBox */
250	fOpen = RTFILE_O_DENY_NONE /* VBox */
251	\| (0666 << RTFILE_O_CREATE_MODE_SHIFT) /* VBox */
252	\| (cloexec ? 0 : RTFILE_O_INHERIT) /* VBox */
253	\| (state->mode == GZ_READ /* VBox */
254	? RTFILE_O_READ \| RTFILE_O_OPEN /* VBox */
255	: RTFILE_O_WRITE /* VBox */
256	\| (exclusive /* VBox */
257	? RTFILE_O_CREATE /* VBox */
258	: state->mode == GZ_WRITE /* VBox */
259	? RTFILE_O_CREATE_REPLACE /* VBox */
260	: RTFILE_O_OPEN_CREATE \| RTFILE_O_APPEND) /* VBox */
261	); /* VBox */
262	#endif /* IPRT_NO_CRT / / VBox */
263
264	/* open the file with the appropriate flags (or just use fd) */
265	#ifndef IPRT_NO_CRT /* VBox */
266	state->fd = fd > -1 ? fd : (
267	#ifdef WIDECHAR
268	fd == -2 ? _wopen(path, oflag, 0666) :
269	#endif
270	open((const char *)path, oflag, 0666));
271	if (state->fd == -1) {
272	#else /* IPRT_NO_CRT / / VBox */
273	rc = RTFileOpen(&state->fd, path, fOpen); /* VBox */
274	if (RT_FAILURE(rc)) { /* VBox */
275	#endif /* IPRT_NO_CRT / / VBox */
276
277	free(state->path);
278	free(state);
279	return NULL;
280	}
281	if (state->mode == GZ_APPEND) {
282	#ifndef IPRT_NO_CRT /* VBox */
283	LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */
284	#else /* VBox */
285	RTFileSeek(state->fd, 0, RTFILE_SEEK_END, NULL); /* VBox */
286	#endif /* VBox */
287	state->mode = GZ_WRITE; /* simplify later checks */
288	}
289
290	/* save the current position for rewinding (only if reading) */
291	if (state->mode == GZ_READ) {
292	#ifndef IPRT_NO_CRT /* VBox */
293	state->start = LSEEK(state->fd, 0, SEEK_CUR);
294	#else /* VBox */
295	state->start = RTFileTell(state->fd); /* VBox */
296	#endif /* VBox */
297	if (state->start == -1) state->start = 0;
298	}
299
300	/* initialize stream */
301	gz_reset(state);
302
303	/* return stream */
304	return (gzFile)state;
305	}
306
307	/* -- see zlib.h -- */
308	gzFile ZEXPORT gzopen(path, mode)
309	const char *path;
310	const char *mode;
311	{
312	return gz_open(path, -1, mode);
313	}
314
315	/* -- see zlib.h -- */
316	gzFile ZEXPORT gzopen64(path, mode)
317	const char *path;
318	const char *mode;
319	{
320	return gz_open(path, -1, mode);
321	}
322
323	/* -- see zlib.h -- */
324	gzFile ZEXPORT gzdopen(fd, mode)
325	int fd;
326	const char *mode;
327	{
328	char path; / identifier for error messages */
329	gzFile gz;
330
331	if (fd == -1 \|\| (path = (char )malloc(7 + 3 sizeof(int))) == NULL)
332	return NULL;
333	#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
334	(void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
335	#else
336	sprintf(path, "<fd:%d>", fd); /* for debugging */
337	#endif
338	gz = gz_open(path, fd, mode);
339	free(path);
340	return gz;
341	}
342
343	/* -- see zlib.h -- */
344	#ifdef WIDECHAR
345	gzFile ZEXPORT gzopen_w(path, mode)
346	const wchar_t *path;
347	const char *mode;
348	{
349	return gz_open(path, -2, mode);
350	}
351	#endif
352
353	/* -- see zlib.h -- */
354	int ZEXPORT gzbuffer(file, size)
355	gzFile file;
356	unsigned size;
357	{
358	gz_statep state;
359
360	/* get internal structure and check integrity */
361	if (file == NULL)
362	return -1;
363	state = (gz_statep)file;
364	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
365	return -1;
366
367	/* make sure we haven't already allocated memory */
368	if (state->size != 0)
369	return -1;
370
371	/* check and set requested size */
372	if ((size << 1) < size)
373	return -1; /* need to be able to double it */
374	if (size < 2)
375	size = 2; /* need two bytes to check magic header */
376	state->want = size;
377	return 0;
378	}
379
380	/* -- see zlib.h -- */
381	int ZEXPORT gzrewind(file)
382	gzFile file;
383	{
384	gz_statep state;
385
386	/* get internal structure */
387	if (file == NULL)
388	return -1;
389	state = (gz_statep)file;
390
391	/* check that we're reading and that there's no error */
392	if (state->mode != GZ_READ \|\|
393	(state->err != Z_OK && state->err != Z_BUF_ERROR))
394	return -1;
395
396	/* back up and start over */
397	#ifndef IPRT_NO_CRT /* VBox */
398	if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
399	#else /* VBox */
400	if (RT_FAILURE(RTFileSeek(state->fd, state->start, RTFILE_SEEK_CURRENT, NULL))) /* VBox */
401	#endif /* VBox */
402	return -1;
403	gz_reset(state);
404	return 0;
405	}
406
407	/* -- see zlib.h -- */
408	z_off64_t ZEXPORT gzseek64(file, offset, whence)
409	gzFile file;
410	z_off64_t offset;
411	int whence;
412	{
413	unsigned n;
414	z_off64_t ret;
415	gz_statep state;
416
417	/* get internal structure and check integrity */
418	if (file == NULL)
419	return -1;
420	state = (gz_statep)file;
421	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
422	return -1;
423
424	/* check that there's no error */
425	if (state->err != Z_OK && state->err != Z_BUF_ERROR)
426	return -1;
427
428	/* can only seek from start or relative to current position */
429	if (whence != SEEK_SET && whence != SEEK_CUR)
430	return -1;
431
432	/* normalize offset to a SEEK_CUR specification */
433	if (whence == SEEK_SET)
434	offset -= state->x.pos;
435	else if (state->seek)
436	offset += state->skip;
437	state->seek = 0;
438
439	/* if within raw area while reading, just go there */
440	if (state->mode == GZ_READ && state->how == COPY &&
441	state->x.pos + offset >= 0) {
442	#ifndef IPRT_NO_CRT /* VBox */
443	ret = LSEEK(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR);
444	if (ret == -1)
445	#else /* VBox */
446	ret = RTFileSeek(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR, NULL); /* VBox */
447	if (RT_FAILURE(ret)) /* VBox */
448	#endif /* VBox */
449	return -1;
450	state->x.have = 0;
451	state->eof = 0;
452	state->past = 0;
453	state->seek = 0;
454	gz_error(state, Z_OK, NULL);
455	state->strm.avail_in = 0;
456	state->x.pos += offset;
457	return state->x.pos;
458	}
459
460	/* calculate skip amount, rewinding if needed for back seek when reading */
461	if (offset < 0) {
462	if (state->mode != GZ_READ) /* writing -- can't go backwards */
463	return -1;
464	offset += state->x.pos;
465	if (offset < 0) /* before start of file! */
466	return -1;
467	if (gzrewind(file) == -1) /* rewind, then skip to offset */
468	return -1;
469	}
470
471	/* if reading, skip what's in output buffer (one less gzgetc() check) */
472	if (state->mode == GZ_READ) {
473	n = GT_OFF(state->x.have) \|\| (z_off64_t)state->x.have > offset ?
474	(unsigned)offset : state->x.have;
475	state->x.have -= n;
476	state->x.next += n;
477	state->x.pos += n;
478	offset -= n;
479	}
480
481	/* request skip (if not zero) */
482	if (offset) {
483	state->seek = 1;
484	state->skip = offset;
485	}
486	return state->x.pos + offset;
487	}
488
489	/* -- see zlib.h -- */
490	z_off_t ZEXPORT gzseek(file, offset, whence)
491	gzFile file;
492	z_off_t offset;
493	int whence;
494	{
495	z_off64_t ret;
496
497	ret = gzseek64(file, (z_off64_t)offset, whence);
498	return ret == (z_off_t)ret ? (z_off_t)ret : -1;
499	}
500
501	/* -- see zlib.h -- */
502	z_off64_t ZEXPORT gztell64(file)
503	gzFile file;
504	{
505	gz_statep state;
506
507	/* get internal structure and check integrity */
508	if (file == NULL)
509	return -1;
510	state = (gz_statep)file;
511	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
512	return -1;
513
514	/* return position */
515	return state->x.pos + (state->seek ? state->skip : 0);
516	}
517
518	/* -- see zlib.h -- */
519	z_off_t ZEXPORT gztell(file)
520	gzFile file;
521	{
522	z_off64_t ret;
523
524	ret = gztell64(file);
525	return ret == (z_off_t)ret ? (z_off_t)ret : -1;
526	}
527
528	/* -- see zlib.h -- */
529	z_off64_t ZEXPORT gzoffset64(file)
530	gzFile file;
531	{
532	z_off64_t offset;
533	gz_statep state;
534
535	/* get internal structure and check integrity */
536	if (file == NULL)
537	return -1;
538	state = (gz_statep)file;
539	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
540	return -1;
541
542	/* compute and return effective offset in file */
543	#ifndef IPRT_NO_CRT /* VBox */
544	offset = LSEEK(state->fd, 0, SEEK_CUR);
545	if (offset == -1)
546	#else /* VBox */
547	offset = RTFileTell(state->fd); /* VBox */
548	if ((uint64_t)offset == UINT64_MAX) /* VBox */
549	#endif /* VBox */
550	return -1;
551	if (state->mode == GZ_READ) /* reading */
552	offset -= state->strm.avail_in; /* don't count buffered input */
553	return offset;
554	}
555
556	/* -- see zlib.h -- */
557	z_off_t ZEXPORT gzoffset(file)
558	gzFile file;
559	{
560	z_off64_t ret;
561
562	ret = gzoffset64(file);
563	return ret == (z_off_t)ret ? (z_off_t)ret : -1;
564	}
565
566	/* -- see zlib.h -- */
567	int ZEXPORT gzeof(file)
568	gzFile file;
569	{
570	gz_statep state;
571
572	/* get internal structure and check integrity */
573	if (file == NULL)
574	return 0;
575	state = (gz_statep)file;
576	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
577	return 0;
578
579	/* return end-of-file state */
580	return state->mode == GZ_READ ? state->past : 0;
581	}
582
583	/* -- see zlib.h -- */
584	const char * ZEXPORT gzerror(file, errnum)
585	gzFile file;
586	int *errnum;
587	{
588	gz_statep state;
589
590	/* get internal structure and check integrity */
591	if (file == NULL)
592	return NULL;
593	state = (gz_statep)file;
594	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
595	return NULL;
596
597	/* return error information */
598	if (errnum != NULL)
599	*errnum = state->err;
600	return state->err == Z_MEM_ERROR ? "out of memory" :
601	(state->msg == NULL ? "" : state->msg);
602	}
603
604	/* -- see zlib.h -- */
605	void ZEXPORT gzclearerr(file)
606	gzFile file;
607	{
608	gz_statep state;
609
610	/* get internal structure and check integrity */
611	if (file == NULL)
612	return;
613	state = (gz_statep)file;
614	if (state->mode != GZ_READ && state->mode != GZ_WRITE)
615	return;
616
617	/* clear error and end-of-file */
618	if (state->mode == GZ_READ) {
619	state->eof = 0;
620	state->past = 0;
621	}
622	gz_error(state, Z_OK, NULL);
623	}
624
625	/* Create an error message in allocated memory and set state->err and
626	state->msg accordingly. Free any previous error message already there. Do
627	not try to free or allocate space if the error is Z_MEM_ERROR (out of
628	memory). Simply save the error message as a static string. If there is an
629	allocation failure constructing the error message, then convert the error to
630	out of memory. */
631	void ZLIB_INTERNAL gz_error(state, err, msg)
632	gz_statep state;
633	int err;
634	const char *msg;
635	{
636	/* free previously allocated message and clear */
637	if (state->msg != NULL) {
638	if (state->err != Z_MEM_ERROR)
639	free(state->msg);
640	state->msg = NULL;
641	}
642
643	/* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
644	if (err != Z_OK && err != Z_BUF_ERROR)
645	state->x.have = 0;
646
647	/* set error code, and if no message, then done */
648	state->err = err;
649	if (msg == NULL)
650	return;
651
652	/* for an out of memory error, return literal string when requested */
653	if (err == Z_MEM_ERROR)
654	return;
655
656	/* construct error message with path */
657	if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
658	NULL) {
659	state->err = Z_MEM_ERROR;
660	return;
661	}
662	#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
663	(void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
664	"%s%s%s", state->path, ": ", msg);
665	#else
666	strcpy(state->msg, state->path);
667	strcat(state->msg, ": ");
668	strcat(state->msg, msg);
669	#endif
670	}
671
672	#ifndef INT_MAX
673	/* portably return maximum value for an int (when limits.h presumed not
674	available) -- we need to do this to cover cases where 2's complement not
675	used, since C standard permits 1's complement and sign-bit representations,
676	otherwise we could just use ((unsigned)-1) >> 1 */
677	unsigned ZLIB_INTERNAL gz_intmax()
678	{
679	unsigned p, q;
680
681	p = 1;
682	do {
683	q = p;
684	p <<= 1;
685	p++;
686	} while (p > q);
687	return q >> 1;
688	}
689	#endif

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