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-rw-r--r--libpng/gzio.c875
1 files changed, 875 insertions, 0 deletions
diff --git a/libpng/gzio.c b/libpng/gzio.c
new file mode 100644
index 0000000..f7c336a
--- /dev/null
+++ b/libpng/gzio.c
@@ -0,0 +1,875 @@
+/* gzio.c -- IO on .gz files
+ * Copyright (C) 1995-1998 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ *
+ * Compile this file with -DNO_DEFLATE to avoid the compression code.
+ */
+
+/* @(#) $Id$ */
+
+#include <stdio.h>
+
+#include "zutil.h"
+
+struct internal_state {int dummy;}; /* for buggy compilers */
+
+#ifndef Z_BUFSIZE
+# ifdef MAXSEG_64K
+# define Z_BUFSIZE 4096 /* minimize memory usage for 16-bit DOS */
+# else
+# define Z_BUFSIZE 16384
+# endif
+#endif
+#ifndef Z_PRINTF_BUFSIZE
+# define Z_PRINTF_BUFSIZE 4096
+#endif
+
+#define ALLOC(size) malloc(size)
+#define TRYFREE(p) {if (p) free(p);}
+
+static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
+
+/* gzip flag byte */
+#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
+#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
+#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
+#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
+#define COMMENT 0x10 /* bit 4 set: file comment present */
+#define RESERVED 0xE0 /* bits 5..7: reserved */
+
+typedef struct gz_stream {
+ z_stream stream;
+ int z_err; /* error code for last stream operation */
+ int z_eof; /* set if end of input file */
+ FILE *file; /* .gz file */
+ Byte *inbuf; /* input buffer */
+ Byte *outbuf; /* output buffer */
+ uLong crc; /* crc32 of uncompressed data */
+ char *msg; /* error message */
+ char *path; /* path name for debugging only */
+ int transparent; /* 1 if input file is not a .gz file */
+ char mode; /* 'w' or 'r' */
+ long startpos; /* start of compressed data in file (header skipped) */
+} gz_stream;
+
+
+local gzFile gz_open OF((const char *path, const char *mode, int fd));
+local int do_flush OF((gzFile file, int flush));
+local int get_byte OF((gz_stream *s));
+local void check_header OF((gz_stream *s));
+local int destroy OF((gz_stream *s));
+local void putLong OF((FILE *file, uLong x));
+local uLong getLong OF((gz_stream *s));
+
+/* ===========================================================================
+ Opens a gzip (.gz) file for reading or writing. The mode parameter
+ is as in fopen ("rb" or "wb"). The file is given either by file descriptor
+ or path name (if fd == -1).
+ gz_open return NULL if the file could not be opened or if there was
+ insufficient memory to allocate the (de)compression state; errno
+ can be checked to distinguish the two cases (if errno is zero, the
+ zlib error is Z_MEM_ERROR).
+*/
+local gzFile gz_open (path, mode, fd)
+ const char *path;
+ const char *mode;
+ int fd;
+{
+ int err;
+ int level = Z_DEFAULT_COMPRESSION; /* compression level */
+ int strategy = Z_DEFAULT_STRATEGY; /* compression strategy */
+ char *p = (char*)mode;
+ gz_stream *s;
+ char fmode[80]; /* copy of mode, without the compression level */
+ char *m = fmode;
+
+ if (!path || !mode) return Z_NULL;
+
+ s = (gz_stream *)ALLOC(sizeof(gz_stream));
+ if (!s) return Z_NULL;
+
+ s->stream.zalloc = (alloc_func)0;
+ s->stream.zfree = (free_func)0;
+ s->stream.opaque = (voidpf)0;
+ s->stream.next_in = s->inbuf = Z_NULL;
+ s->stream.next_out = s->outbuf = Z_NULL;
+ s->stream.avail_in = s->stream.avail_out = 0;
+ s->file = NULL;
+ s->z_err = Z_OK;
+ s->z_eof = 0;
+ s->crc = crc32(0L, Z_NULL, 0);
+ s->msg = NULL;
+ s->transparent = 0;
+
+ s->path = (char*)ALLOC(strlen(path)+1);
+ if (s->path == NULL) {
+ return destroy(s), (gzFile)Z_NULL;
+ }
+ strcpy(s->path, path); /* do this early for debugging */
+
+ s->mode = '\0';
+ do {
+ if (*p == 'r') s->mode = 'r';
+ if (*p == 'w' || *p == 'a') s->mode = 'w';
+ if (*p >= '0' && *p <= '9') {
+ level = *p - '0';
+ } else if (*p == 'f') {
+ strategy = Z_FILTERED;
+ } else if (*p == 'h') {
+ strategy = Z_HUFFMAN_ONLY;
+ } else {
+ *m++ = *p; /* copy the mode */
+ }
+ } while (*p++ && m != fmode + sizeof(fmode));
+ if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL;
+
+ if (s->mode == 'w') {
+#ifdef NO_DEFLATE
+ err = Z_STREAM_ERROR;
+#else
+ err = deflateInit2(&(s->stream), level,
+ Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, strategy);
+ /* windowBits is passed < 0 to suppress zlib header */
+
+ s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
+#endif
+ if (err != Z_OK || s->outbuf == Z_NULL) {
+ return destroy(s), (gzFile)Z_NULL;
+ }
+ } else {
+ s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
+
+ err = inflateInit2(&(s->stream), -MAX_WBITS);
+ /* windowBits is passed < 0 to tell that there is no zlib header.
+ * Note that in this case inflate *requires* an extra "dummy" byte
+ * after the compressed stream in order to complete decompression and
+ * return Z_STREAM_END. Here the gzip CRC32 ensures that 4 bytes are
+ * present after the compressed stream.
+ */
+ if (err != Z_OK || s->inbuf == Z_NULL) {
+ return destroy(s), (gzFile)Z_NULL;
+ }
+ }
+ s->stream.avail_out = Z_BUFSIZE;
+
+ errno = 0;
+ s->file = fd < 0 ? F_OPEN(path, fmode) : (FILE*)fdopen(fd, fmode);
+
+ if (s->file == NULL) {
+ return destroy(s), (gzFile)Z_NULL;
+ }
+ if (s->mode == 'w') {
+ /* Write a very simple .gz header:
+ */
+ fprintf(s->file, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0], gz_magic[1],
+ Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE);
+ s->startpos = 10L;
+ /* We use 10L instead of ftell(s->file) to because ftell causes an
+ * fflush on some systems. This version of the library doesn't use
+ * startpos anyway in write mode, so this initialization is not
+ * necessary.
+ */
+ } else {
+ check_header(s); /* skip the .gz header */
+ s->startpos = (ftell(s->file) - s->stream.avail_in);
+ }
+
+ return (gzFile)s;
+}
+
+/* ===========================================================================
+ Opens a gzip (.gz) file for reading or writing.
+*/
+gzFile ZEXPORT gzopen (path, mode)
+ const char *path;
+ const char *mode;
+{
+ return gz_open (path, mode, -1);
+}
+
+/* ===========================================================================
+ Associate a gzFile with the file descriptor fd. fd is not dup'ed here
+ to mimic the behavio(u)r of fdopen.
+*/
+gzFile ZEXPORT gzdopen (fd, mode)
+ int fd;
+ const char *mode;
+{
+ char name[20];
+
+ if (fd < 0) return (gzFile)Z_NULL;
+ sprintf(name, "<fd:%d>", fd); /* for debugging */
+
+ return gz_open (name, mode, fd);
+}
+
+/* ===========================================================================
+ * Update the compression level and strategy
+ */
+int ZEXPORT gzsetparams (file, level, strategy)
+ gzFile file;
+ int level;
+ int strategy;
+{
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+ /* Make room to allow flushing */
+ if (s->stream.avail_out == 0) {
+
+ s->stream.next_out = s->outbuf;
+ if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
+ s->z_err = Z_ERRNO;
+ }
+ s->stream.avail_out = Z_BUFSIZE;
+ }
+
+ return deflateParams (&(s->stream), level, strategy);
+}
+
+/* ===========================================================================
+ Read a byte from a gz_stream; update next_in and avail_in. Return EOF
+ for end of file.
+ IN assertion: the stream s has been sucessfully opened for reading.
+*/
+local int get_byte(s)
+ gz_stream *s;
+{
+ if (s->z_eof) return EOF;
+ if (s->stream.avail_in == 0) {
+ errno = 0;
+ s->stream.avail_in = fread(s->inbuf, 1, Z_BUFSIZE, s->file);
+ if (s->stream.avail_in == 0) {
+ s->z_eof = 1;
+ if (ferror(s->file)) s->z_err = Z_ERRNO;
+ return EOF;
+ }
+ s->stream.next_in = s->inbuf;
+ }
+ s->stream.avail_in--;
+ return *(s->stream.next_in)++;
+}
+
+/* ===========================================================================
+ Check the gzip header of a gz_stream opened for reading. Set the stream
+ mode to transparent if the gzip magic header is not present; set s->err
+ to Z_DATA_ERROR if the magic header is present but the rest of the header
+ is incorrect.
+ IN assertion: the stream s has already been created sucessfully;
+ s->stream.avail_in is zero for the first time, but may be non-zero
+ for concatenated .gz files.
+*/
+local void check_header(s)
+ gz_stream *s;
+{
+ int method; /* method byte */
+ int flags; /* flags byte */
+ uInt len;
+ int c;
+
+ /* Check the gzip magic header */
+ for (len = 0; len < 2; len++) {
+ c = get_byte(s);
+ if (c != gz_magic[len]) {
+ if (len != 0) s->stream.avail_in++, s->stream.next_in--;
+ if (c != EOF) {
+ s->stream.avail_in++, s->stream.next_in--;
+ s->transparent = 1;
+ }
+ s->z_err = s->stream.avail_in != 0 ? Z_OK : Z_STREAM_END;
+ return;
+ }
+ }
+ method = get_byte(s);
+ flags = get_byte(s);
+ if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
+ s->z_err = Z_DATA_ERROR;
+ return;
+ }
+
+ /* Discard time, xflags and OS code: */
+ for (len = 0; len < 6; len++) (void)get_byte(s);
+
+ if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
+ len = (uInt)get_byte(s);
+ len += ((uInt)get_byte(s))<<8;
+ /* len is garbage if EOF but the loop below will quit anyway */
+ while (len-- != 0 && get_byte(s) != EOF) ;
+ }
+ if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
+ while ((c = get_byte(s)) != 0 && c != EOF) ;
+ }
+ if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
+ while ((c = get_byte(s)) != 0 && c != EOF) ;
+ }
+ if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
+ for (len = 0; len < 2; len++) (void)get_byte(s);
+ }
+ s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
+}
+
+ /* ===========================================================================
+ * Cleanup then free the given gz_stream. Return a zlib error code.
+ Try freeing in the reverse order of allocations.
+ */
+local int destroy (s)
+ gz_stream *s;
+{
+ int err = Z_OK;
+
+ if (!s) return Z_STREAM_ERROR;
+
+ TRYFREE(s->msg);
+
+ if (s->stream.state != NULL) {
+ if (s->mode == 'w') {
+#ifdef NO_DEFLATE
+ err = Z_STREAM_ERROR;
+#else
+ err = deflateEnd(&(s->stream));
+#endif
+ } else if (s->mode == 'r') {
+ err = inflateEnd(&(s->stream));
+ }
+ }
+ if (s->file != NULL && fclose(s->file)) {
+#ifdef ESPIPE
+ if (errno != ESPIPE) /* fclose is broken for pipes in HP/UX */
+#endif
+ err = Z_ERRNO;
+ }
+ if (s->z_err < 0) err = s->z_err;
+
+ TRYFREE(s->inbuf);
+ TRYFREE(s->outbuf);
+ TRYFREE(s->path);
+ TRYFREE(s);
+ return err;
+}
+
+/* ===========================================================================
+ Reads the given number of uncompressed bytes from the compressed file.
+ gzread returns the number of bytes actually read (0 for end of file).
+*/
+int ZEXPORT gzread (file, buf, len)
+ gzFile file;
+ voidp buf;
+ unsigned len;
+{
+ gz_stream *s = (gz_stream*)file;
+ Bytef *start = (Bytef*)buf; /* starting point for crc computation */
+ Byte *next_out; /* == stream.next_out but not forced far (for MSDOS) */
+
+ if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;
+
+ if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
+ if (s->z_err == Z_STREAM_END) return 0; /* EOF */
+
+ next_out = (Byte*)buf;
+ s->stream.next_out = (Bytef*)buf;
+ s->stream.avail_out = len;
+
+ while (s->stream.avail_out != 0) {
+
+ if (s->transparent) {
+ /* Copy first the lookahead bytes: */
+ uInt n = s->stream.avail_in;
+ if (n > s->stream.avail_out) n = s->stream.avail_out;
+ if (n > 0) {
+ zmemcpy(s->stream.next_out, s->stream.next_in, n);
+ next_out += n;
+ s->stream.next_out = next_out;
+ s->stream.next_in += n;
+ s->stream.avail_out -= n;
+ s->stream.avail_in -= n;
+ }
+ if (s->stream.avail_out > 0) {
+ s->stream.avail_out -= fread(next_out, 1, s->stream.avail_out,
+ s->file);
+ }
+ len -= s->stream.avail_out;
+ s->stream.total_in += (uLong)len;
+ s->stream.total_out += (uLong)len;
+ if (len == 0) s->z_eof = 1;
+ return (int)len;
+ }
+ if (s->stream.avail_in == 0 && !s->z_eof) {
+
+ errno = 0;
+ s->stream.avail_in = fread(s->inbuf, 1, Z_BUFSIZE, s->file);
+ if (s->stream.avail_in == 0) {
+ s->z_eof = 1;
+ if (ferror(s->file)) {
+ s->z_err = Z_ERRNO;
+ break;
+ }
+ }
+ s->stream.next_in = s->inbuf;
+ }
+ s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
+
+ if (s->z_err == Z_STREAM_END) {
+ /* Check CRC and original size */
+ s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
+ start = s->stream.next_out;
+
+ if (getLong(s) != s->crc) {
+ s->z_err = Z_DATA_ERROR;
+ } else {
+ (void)getLong(s);
+ /* The uncompressed length returned by above getlong() may
+ * be different from s->stream.total_out) in case of
+ * concatenated .gz files. Check for such files:
+ */
+ check_header(s);
+ if (s->z_err == Z_OK) {
+ uLong total_in = s->stream.total_in;
+ uLong total_out = s->stream.total_out;
+
+ inflateReset(&(s->stream));
+ s->stream.total_in = total_in;
+ s->stream.total_out = total_out;
+ s->crc = crc32(0L, Z_NULL, 0);
+ }
+ }
+ }
+ if (s->z_err != Z_OK || s->z_eof) break;
+ }
+ s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
+
+ return (int)(len - s->stream.avail_out);
+}
+
+
+/* ===========================================================================
+ Reads one byte from the compressed file. gzgetc returns this byte
+ or -1 in case of end of file or error.
+*/
+int ZEXPORT gzgetc(file)
+ gzFile file;
+{
+ unsigned char c;
+
+ return gzread(file, &c, 1) == 1 ? c : -1;
+}
+
+
+/* ===========================================================================
+ Reads bytes from the compressed file until len-1 characters are
+ read, or a newline character is read and transferred to buf, or an
+ end-of-file condition is encountered. The string is then terminated
+ with a null character.
+ gzgets returns buf, or Z_NULL in case of error.
+
+ The current implementation is not optimized at all.
+*/
+char * ZEXPORT gzgets(file, buf, len)
+ gzFile file;
+ char *buf;
+ int len;
+{
+ char *b = buf;
+ if (buf == Z_NULL || len <= 0) return Z_NULL;
+
+ while (--len > 0 && gzread(file, buf, 1) == 1 && *buf++ != '\n') ;
+ *buf = '\0';
+ return b == buf && len > 0 ? Z_NULL : b;
+}
+
+
+#ifndef NO_DEFLATE
+/* ===========================================================================
+ Writes the given number of uncompressed bytes into the compressed file.
+ gzwrite returns the number of bytes actually written (0 in case of error).
+*/
+int ZEXPORT gzwrite (file, buf, len)
+ gzFile file;
+ const voidp buf;
+ unsigned len;
+{
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+ s->stream.next_in = (Bytef*)buf;
+ s->stream.avail_in = len;
+
+ while (s->stream.avail_in != 0) {
+
+ if (s->stream.avail_out == 0) {
+
+ s->stream.next_out = s->outbuf;
+ if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) {
+ s->z_err = Z_ERRNO;
+ break;
+ }
+ s->stream.avail_out = Z_BUFSIZE;
+ }
+ s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
+ if (s->z_err != Z_OK) break;
+ }
+ s->crc = crc32(s->crc, (const Bytef *)buf, len);
+
+ return (int)(len - s->stream.avail_in);
+}
+
+/* ===========================================================================
+ Converts, formats, and writes the args to the compressed file under
+ control of the format string, as in fprintf. gzprintf returns the number of
+ uncompressed bytes actually written (0 in case of error).
+*/
+#ifdef STDC
+#include <stdarg.h>
+
+int ZEXPORTVA gzprintf (gzFile file, const char *format, /* args */ ...)
+{
+ char buf[Z_PRINTF_BUFSIZE];
+ va_list va;
+ int len;
+
+ va_start(va, format);
+#ifdef HAS_vsnprintf
+ (void)vsnprintf(buf, sizeof(buf), format, va);
+#else
+ (void)vsprintf(buf, format, va);
+#endif
+ va_end(va);
+ len = strlen(buf); /* some *sprintf don't return the nb of bytes written */
+ if (len <= 0) return 0;
+
+ return gzwrite(file, buf, (unsigned)len);
+}
+#else /* not ANSI C */
+
+int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+ a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
+ gzFile file;
+ const char *format;
+ int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
+ a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
+{
+ char buf[Z_PRINTF_BUFSIZE];
+ int len;
+
+#ifdef HAS_snprintf
+ snprintf(buf, sizeof(buf), format, a1, a2, a3, a4, a5, a6, a7, a8,
+ a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#else
+ sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8,
+ a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
+#endif
+ len = strlen(buf); /* old sprintf doesn't return the nb of bytes written */
+ if (len <= 0) return 0;
+
+ return gzwrite(file, buf, len);
+}
+#endif
+
+/* ===========================================================================
+ Writes c, converted to an unsigned char, into the compressed file.
+ gzputc returns the value that was written, or -1 in case of error.
+*/
+int ZEXPORT gzputc(file, c)
+ gzFile file;
+ int c;
+{
+ unsigned char cc = (unsigned char) c; /* required for big endian systems */
+
+ return gzwrite(file, &cc, 1) == 1 ? (int)cc : -1;
+}
+
+
+/* ===========================================================================
+ Writes the given null-terminated string to the compressed file, excluding
+ the terminating null character.
+ gzputs returns the number of characters written, or -1 in case of error.
+*/
+int ZEXPORT gzputs(file, s)
+ gzFile file;
+ const char *s;
+{
+ return gzwrite(file, (char*)s, (unsigned)strlen(s));
+}
+
+
+/* ===========================================================================
+ Flushes all pending output into the compressed file. The parameter
+ flush is as in the deflate() function.
+*/
+local int do_flush (file, flush)
+ gzFile file;
+ int flush;
+{
+ uInt len;
+ int done = 0;
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
+
+ s->stream.avail_in = 0; /* should be zero already anyway */
+
+ for (;;) {
+ len = Z_BUFSIZE - s->stream.avail_out;
+
+ if (len != 0) {
+ if ((uInt)fwrite(s->outbuf, 1, len, s->file) != len) {
+ s->z_err = Z_ERRNO;
+ return Z_ERRNO;
+ }
+ s->stream.next_out = s->outbuf;
+ s->stream.avail_out = Z_BUFSIZE;
+ }
+ if (done) break;
+ s->z_err = deflate(&(s->stream), flush);
+
+ /* Ignore the second of two consecutive flushes: */
+ if (len == 0 && s->z_err == Z_BUF_ERROR) s->z_err = Z_OK;
+
+ /* deflate has finished flushing only when it hasn't used up
+ * all the available space in the output buffer:
+ */
+ done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
+
+ if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
+ }
+ return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
+}
+
+int ZEXPORT gzflush (file, flush)
+ gzFile file;
+ int flush;
+{
+ gz_stream *s = (gz_stream*)file;
+ int err = do_flush (file, flush);
+
+ if (err) return err;
+ fflush(s->file);
+ return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
+}
+#endif /* NO_DEFLATE */
+
+/* ===========================================================================
+ Sets the starting position for the next gzread or gzwrite on the given
+ compressed file. The offset represents a number of bytes in the
+ gzseek returns the resulting offset location as measured in bytes from
+ the beginning of the uncompressed stream, or -1 in case of error.
+ SEEK_END is not implemented, returns error.
+ In this version of the library, gzseek can be extremely slow.
+*/
+z_off_t ZEXPORT gzseek (file, offset, whence)
+ gzFile file;
+ z_off_t offset;
+ int whence;
+{
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || whence == SEEK_END ||
+ s->z_err == Z_ERRNO || s->z_err == Z_DATA_ERROR) {
+ return -1L;
+ }
+
+ if (s->mode == 'w') {
+#ifdef NO_DEFLATE
+ return -1L;
+#else
+ if (whence == SEEK_SET) {
+ offset -= s->stream.total_in;
+ }
+ if (offset < 0) return -1L;
+
+ /* At this point, offset is the number of zero bytes to write. */
+ if (s->inbuf == Z_NULL) {
+ s->inbuf = (Byte*)ALLOC(Z_BUFSIZE); /* for seeking */
+ zmemzero(s->inbuf, Z_BUFSIZE);
+ }
+ while (offset > 0) {
+ uInt size = Z_BUFSIZE;
+ if (offset < Z_BUFSIZE) size = (uInt)offset;
+
+ size = gzwrite(file, s->inbuf, size);
+ if (size == 0) return -1L;
+
+ offset -= size;
+ }
+ return (z_off_t)s->stream.total_in;
+#endif
+ }
+ /* Rest of function is for reading only */
+
+ /* compute absolute position */
+ if (whence == SEEK_CUR) {
+ offset += s->stream.total_out;
+ }
+ if (offset < 0) return -1L;
+
+ if (s->transparent) {
+ /* map to fseek */
+ s->stream.avail_in = 0;
+ s->stream.next_in = s->inbuf;
+ if (fseek(s->file, offset, SEEK_SET) < 0) return -1L;
+
+ s->stream.total_in = s->stream.total_out = (uLong)offset;
+ return offset;
+ }
+
+ /* For a negative seek, rewind and use positive seek */
+ if ((uLong)offset >= s->stream.total_out) {
+ offset -= s->stream.total_out;
+ } else if (gzrewind(file) < 0) {
+ return -1L;
+ }
+ /* offset is now the number of bytes to skip. */
+
+ if (offset != 0 && s->outbuf == Z_NULL) {
+ s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
+ }
+ while (offset > 0) {
+ int size = Z_BUFSIZE;
+ if (offset < Z_BUFSIZE) size = (int)offset;
+
+ size = gzread(file, s->outbuf, (uInt)size);
+ if (size <= 0) return -1L;
+ offset -= size;
+ }
+ return (z_off_t)s->stream.total_out;
+}
+
+/* ===========================================================================
+ Rewinds input file.
+*/
+int ZEXPORT gzrewind (file)
+ gzFile file;
+{
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL || s->mode != 'r') return -1;
+
+ s->z_err = Z_OK;
+ s->z_eof = 0;
+ s->stream.avail_in = 0;
+ s->stream.next_in = s->inbuf;
+ s->crc = crc32(0L, Z_NULL, 0);
+
+ if (s->startpos == 0) { /* not a compressed file */
+ rewind(s->file);
+ return 0;
+ }
+
+ (void) inflateReset(&s->stream);
+ return fseek(s->file, s->startpos, SEEK_SET);
+}
+
+/* ===========================================================================
+ Returns the starting position for the next gzread or gzwrite on the
+ given compressed file. This position represents a number of bytes in the
+ uncompressed data stream.
+*/
+z_off_t ZEXPORT gztell (file)
+ gzFile file;
+{
+ return gzseek(file, 0L, SEEK_CUR);
+}
+
+/* ===========================================================================
+ Returns 1 when EOF has previously been detected reading the given
+ input stream, otherwise zero.
+*/
+int ZEXPORT gzeof (file)
+ gzFile file;
+{
+ gz_stream *s = (gz_stream*)file;
+
+ return (s == NULL || s->mode != 'r') ? 0 : s->z_eof;
+}
+
+/* ===========================================================================
+ Outputs a long in LSB order to the given file
+*/
+local void putLong (file, x)
+ FILE *file;
+ uLong x;
+{
+ int n;
+ for (n = 0; n < 4; n++) {
+ fputc((int)(x & 0xff), file);
+ x >>= 8;
+ }
+}
+
+/* ===========================================================================
+ Reads a long in LSB order from the given gz_stream. Sets z_err in case
+ of error.
+*/
+local uLong getLong (s)
+ gz_stream *s;
+{
+ uLong x = (uLong)get_byte(s);
+ int c;
+
+ x += ((uLong)get_byte(s))<<8;
+ x += ((uLong)get_byte(s))<<16;
+ c = get_byte(s);
+ if (c == EOF) s->z_err = Z_DATA_ERROR;
+ x += ((uLong)c)<<24;
+ return x;
+}
+
+/* ===========================================================================
+ Flushes all pending output if necessary, closes the compressed file
+ and deallocates all the (de)compression state.
+*/
+int ZEXPORT gzclose (file)
+ gzFile file;
+{
+ int err;
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL) return Z_STREAM_ERROR;
+
+ if (s->mode == 'w') {
+#ifdef NO_DEFLATE
+ return Z_STREAM_ERROR;
+#else
+ err = do_flush (file, Z_FINISH);
+ if (err != Z_OK) return destroy((gz_stream*)file);
+
+ putLong (s->file, s->crc);
+ putLong (s->file, s->stream.total_in);
+#endif
+ }
+ return destroy((gz_stream*)file);
+}
+
+/* ===========================================================================
+ Returns the error message for the last error which occured on the
+ given compressed file. errnum is set to zlib error number. If an
+ error occured in the file system and not in the compression library,
+ errnum is set to Z_ERRNO and the application may consult errno
+ to get the exact error code.
+*/
+const char* ZEXPORT gzerror (file, errnum)
+ gzFile file;
+ int *errnum;
+{
+ char *m;
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL) {
+ *errnum = Z_STREAM_ERROR;
+ return (const char*)ERR_MSG(Z_STREAM_ERROR);
+ }
+ *errnum = s->z_err;
+ if (*errnum == Z_OK) return (const char*)"";
+
+ m = (char*)(*errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg);
+
+ if (m == NULL || *m == '\0') m = (char*)ERR_MSG(s->z_err);
+
+ TRYFREE(s->msg);
+ s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3);
+ strcpy(s->msg, s->path);
+ strcat(s->msg, ": ");
+ strcat(s->msg, m);
+ return (const char*)s->msg;
+}
generated by cgit v0.12 at 2024-11-18 06:12:45 (GMT)