diff options
Diffstat (limited to 'zlib/gzio.c')
| -rw-r--r-- | zlib/gzio.c | 1026 |
1 files changed, 0 insertions, 1026 deletions
diff --git a/zlib/gzio.c b/zlib/gzio.c deleted file mode 100644 index 7e90f4928..000000000 --- a/zlib/gzio.c +++ /dev/null @@ -1,1026 +0,0 @@ -/* gzio.c -- IO on .gz files - * Copyright (C) 1995-2005 Jean-loup Gailly. - * For conditions of distribution and use, see copyright notice in zlib.h - * - * Compile this file with -DNO_GZCOMPRESS to avoid the compression code. - */ - -/* @(#) $Id$ */ - -#include <stdio.h> - -#include "zutil.h" - -#ifdef NO_DEFLATE /* for compatibility with old definition */ -# define NO_GZCOMPRESS -#endif - -#ifndef NO_DUMMY_DECL -struct internal_state {int dummy;}; /* for buggy compilers */ -#endif - -#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 - -#ifdef __MVS__ -# pragma map (fdopen , "\174\174FDOPEN") - FILE *fdopen(int, const char *); -#endif - -#ifndef STDC -extern voidp malloc OF((uInt size)); -extern void free OF((voidpf ptr)); -#endif - -#define ALLOC(size) malloc(size) -#define TRYFREE(p) {if (p) free(p);} - -static int const 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' */ - z_off_t start; /* start of compressed data in file (header skipped) */ - z_off_t in; /* bytes into deflate or inflate */ - z_off_t out; /* bytes out of deflate or inflate */ - int back; /* one character push-back */ - int last; /* true if push-back is last character */ -} 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 returns 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->in = 0; - s->out = 0; - s->back = EOF; - 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 if (*p == 'R') { - strategy = Z_RLE; - } 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_GZCOMPRESS - 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->start = 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 - * start anyway in write mode, so this initialization is not - * necessary. - */ - } else { - check_header(s); /* skip the .gz header */ - s->start = 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[46]; /* allow for up to 128-bit integers */ - - 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 = (uInt)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; - - /* Assure two bytes in the buffer so we can peek ahead -- handle case - where first byte of header is at the end of the buffer after the last - gzip segment */ - len = s->stream.avail_in; - if (len < 2) { - if (len) s->inbuf[0] = s->stream.next_in[0]; - errno = 0; - len = (uInt)fread(s->inbuf + len, 1, Z_BUFSIZE >> len, s->file); - if (len == 0 && ferror(s->file)) s->z_err = Z_ERRNO; - s->stream.avail_in += len; - s->stream.next_in = s->inbuf; - if (s->stream.avail_in < 2) { - s->transparent = s->stream.avail_in; - return; - } - } - - /* Peek ahead to check the gzip magic header */ - if (s->stream.next_in[0] != gz_magic[0] || - s->stream.next_in[1] != gz_magic[1]) { - s->transparent = 1; - return; - } - s->stream.avail_in -= 2; - s->stream.next_in += 2; - - /* Check the rest of the gzip header */ - 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_GZCOMPRESS - 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; - - if (s->stream.avail_out && s->back != EOF) { - *next_out++ = s->back; - s->stream.next_out++; - s->stream.avail_out--; - s->back = EOF; - s->out++; - start++; - if (s->last) { - s->z_err = Z_STREAM_END; - return 1; - } - } - - 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 -= - (uInt)fread(next_out, 1, s->stream.avail_out, s->file); - } - len -= s->stream.avail_out; - s->in += len; - s->out += 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 = (uInt)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->in += s->stream.avail_in; - s->out += s->stream.avail_out; - s->z_err = inflate(&(s->stream), Z_NO_FLUSH); - s->in -= s->stream.avail_in; - s->out -= s->stream.avail_out; - - 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->out in case of concatenated .gz files. - * Check for such files: - */ - check_header(s); - if (s->z_err == Z_OK) { - inflateReset(&(s->stream)); - 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)); - - if (len == s->stream.avail_out && - (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO)) - return -1; - 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; -} - - -/* =========================================================================== - Push one byte back onto the stream. -*/ -int ZEXPORT gzungetc(c, file) - int c; - gzFile file; -{ - gz_stream *s = (gz_stream*)file; - - if (s == NULL || s->mode != 'r' || c == EOF || s->back != EOF) return EOF; - s->back = c; - s->out--; - s->last = (s->z_err == Z_STREAM_END); - if (s->last) s->z_err = Z_OK; - s->z_eof = 0; - return c; -} - - -/* =========================================================================== - 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_GZCOMPRESS -/* =========================================================================== - 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; - voidpc 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->in += s->stream.avail_in; - s->out += s->stream.avail_out; - s->z_err = deflate(&(s->stream), Z_NO_FLUSH); - s->in -= s->stream.avail_in; - s->out -= s->stream.avail_out; - 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; - - buf[sizeof(buf) - 1] = 0; - va_start(va, format); -#ifdef NO_vsnprintf -# ifdef HAS_vsprintf_void - (void)vsprintf(buf, format, va); - va_end(va); - for (len = 0; len < sizeof(buf); len++) - if (buf[len] == 0) break; -# else - len = vsprintf(buf, format, va); - va_end(va); -# endif -#else -# ifdef HAS_vsnprintf_void - (void)vsnprintf(buf, sizeof(buf), format, va); - va_end(va); - len = strlen(buf); -# else - len = vsnprintf(buf, sizeof(buf), format, va); - va_end(va); -# endif -#endif - if (len <= 0 || len >= (int)sizeof(buf) || buf[sizeof(buf) - 1] != 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; - - buf[sizeof(buf) - 1] = 0; -#ifdef NO_snprintf -# ifdef HAS_sprintf_void - sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8, - a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20); - for (len = 0; len < sizeof(buf); len++) - if (buf[len] == 0) break; -# else - len = sprintf(buf, format, a1, a2, a3, a4, a5, a6, a7, a8, - a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20); -# endif -#else -# ifdef HAS_snprintf_void - 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); - len = strlen(buf); -# else - len = 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); -# endif -#endif - if (len <= 0 || len >= sizeof(buf) || buf[sizeof(buf) - 1] != 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->out += s->stream.avail_out; - s->z_err = deflate(&(s->stream), flush); - s->out -= s->stream.avail_out; - - /* 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_GZCOMPRESS */ - -/* =========================================================================== - 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_GZCOMPRESS - return -1L; -#else - if (whence == SEEK_SET) { - offset -= s->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 */ - if (s->inbuf == Z_NULL) return -1L; - 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 s->in; -#endif - } - /* Rest of function is for reading only */ - - /* compute absolute position */ - if (whence == SEEK_CUR) { - offset += s->out; - } - if (offset < 0) return -1L; - - if (s->transparent) { - /* map to fseek */ - s->back = EOF; - s->stream.avail_in = 0; - s->stream.next_in = s->inbuf; - if (fseek(s->file, offset, SEEK_SET) < 0) return -1L; - - s->in = s->out = offset; - return offset; - } - - /* For a negative seek, rewind and use positive seek */ - if (offset >= s->out) { - offset -= s->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); - if (s->outbuf == Z_NULL) return -1L; - } - if (offset && s->back != EOF) { - s->back = EOF; - s->out++; - offset--; - if (s->last) s->z_err = Z_STREAM_END; - } - 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 s->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->back = EOF; - s->stream.avail_in = 0; - s->stream.next_in = s->inbuf; - s->crc = crc32(0L, Z_NULL, 0); - if (!s->transparent) (void)inflateReset(&s->stream); - s->in = 0; - s->out = 0; - return fseek(s->file, s->start, 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; - - /* With concatenated compressed files that can have embedded - * crc trailers, z_eof is no longer the only/best indicator of EOF - * on a gz_stream. Handle end-of-stream error explicitly here. - */ - if (s == NULL || s->mode != 'r') return 0; - if (s->z_eof) return 1; - return s->z_err == Z_STREAM_END; -} - -/* =========================================================================== - Returns 1 if reading and doing so transparently, otherwise zero. -*/ -int ZEXPORT gzdirect (file) - gzFile file; -{ - gz_stream *s = (gz_stream*)file; - - if (s == NULL || s->mode != 'r') return 0; - return s->transparent; -} - -/* =========================================================================== - 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; -{ - gz_stream *s = (gz_stream*)file; - - if (s == NULL) return Z_STREAM_ERROR; - - if (s->mode == 'w') { -#ifdef NO_GZCOMPRESS - return Z_STREAM_ERROR; -#else - if (do_flush (file, Z_FINISH) != Z_OK) - return destroy((gz_stream*)file); - - putLong (s->file, s->crc); - putLong (s->file, (uLong)(s->in & 0xffffffff)); -#endif - } - return destroy((gz_stream*)file); -} - -#ifdef STDC -# define zstrerror(errnum) strerror(errnum) -#else -# define zstrerror(errnum) "" -#endif - -/* =========================================================================== - Returns the error message for the last error which occurred on the - given compressed file. errnum is set to zlib error number. If an - error occurred 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); - if (s->msg == Z_NULL) return (const char*)ERR_MSG(Z_MEM_ERROR); - strcpy(s->msg, s->path); - strcat(s->msg, ": "); - strcat(s->msg, m); - return (const char*)s->msg; -} - -/* =========================================================================== - Clear the error and end-of-file flags, and do the same for the real file. -*/ -void ZEXPORT gzclearerr (file) - gzFile file; -{ - gz_stream *s = (gz_stream*)file; - - if (s == NULL) return; - if (s->z_err != Z_STREAM_END) s->z_err = Z_OK; - s->z_eof = 0; - clearerr(s->file); -} |