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- /* 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 <stdlib.h>
- #include <string.h>
- #include <errno.h>
- //#include "zutil.h"
- #include <EZlib.h>
- #include "gzio_symb.h"
- #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 local
- # define local static
- #endif
- #ifndef OS_CODE
- # define OS_CODE 0x03 /* assume Unix */
- #endif
- #ifndef F_OPEN
- # define F_OPEN(name, mode) fopen((name), (mode))
- #endif
- #if MAX_MEM_LEVEL >= 8
- # define DEF_MEM_LEVEL 8
- #else
- # define DEF_MEM_LEVEL MAX_MEM_LEVEL
- #endif
- #define ALLOC(size) malloc(size)
- #define TRYFREE(p) {if (p) free(p);}
- #define zmemcpy memcpy
- 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);
- }
- /* ===========================================================================
- * 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);
- }
- #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);
- }
- /* ===========================================================================
- 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;
- }
- #endif /* NO_GZCOMPRESS */
- /* ===========================================================================
- 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);
- }
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