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-rw-r--r--zlib/gzio.c523
1 files changed, 523 insertions, 0 deletions
diff --git a/zlib/gzio.c b/zlib/gzio.c
new file mode 100644
index 000000000..1715539f7
--- /dev/null
+++ b/zlib/gzio.c
@@ -0,0 +1,523 @@
+/* gzio.c -- IO on .gz files
+ * Copyright (C) 1995-1996 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* $Id$ */
+
+#include <stdio.h>
+
+#include "zutil.h"
+
+struct internal_state {int dummy;}; /* for buggy compilers */
+
+#define Z_BUFSIZE 4096
+
+#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' */
+} gz_stream;
+
+
+local gzFile gz_open OF((const char *path, const char *mode, int fd));
+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 */
+ 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 {
+ *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') {
+ err = deflateInit2(&(s->stream), level,
+ Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL, 0);
+ /* windowBits is passed < 0 to suppress zlib header */
+
+ s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
+
+ if (err != Z_OK || s->outbuf == Z_NULL) {
+ return destroy(s), (gzFile)Z_NULL;
+ }
+ } else {
+ err = inflateInit2(&(s->stream), -MAX_WBITS);
+ s->stream.next_in = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
+
+ 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 ? FOPEN(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);
+ } else {
+ check_header(s); /* skip the .gz header */
+ }
+ return (gzFile)s;
+}
+
+/* ===========================================================================
+ Opens a gzip (.gz) file for reading or writing.
+*/
+gzFile 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 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);
+}
+
+/* ===========================================================================
+ 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]) {
+ s->transparent = 1;
+ if (c != EOF) s->stream.avail_in++, s->stream.next_in--;
+ 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') {
+ err = deflateEnd(&(s->stream));
+ } else if (s->mode == 'r') {
+ err = inflateEnd(&(s->stream));
+ }
+ }
+ if (s->file != NULL && fclose(s->file)) {
+ 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 gzread (file, buf, len)
+ gzFile file;
+ voidp buf;
+ unsigned len;
+{
+ gz_stream *s = (gz_stream*)file;
+ Bytef *start = 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 */
+
+ s->stream.next_out = next_out = 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);
+ }
+ return (int)(len - s->stream.avail_out);
+ }
+ 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 || getLong(s) != s->stream.total_out) {
+ s->z_err = Z_DATA_ERROR;
+ } else {
+ /* Check for concatenated .gz 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));
+
+ return (int)(len - s->stream.avail_out);
+}
+
+/* ===========================================================================
+ 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 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 = 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, 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.
+ gzflush should be called only when strictly necessary because it can
+ degrade compression.
+*/
+int gzflush (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);
+
+ /* 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;
+ }
+ fflush(s->file);
+ return s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
+}
+
+/* ===========================================================================
+ 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
+*/
+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 gzclose (file)
+ gzFile file;
+{
+ int err;
+ gz_stream *s = (gz_stream*)file;
+
+ if (s == NULL) return Z_STREAM_ERROR;
+
+ if (s->mode == 'w') {
+ err = gzflush (file, Z_FINISH);
+ if (err != Z_OK) return destroy(file);
+
+ putLong (s->file, s->crc);
+ putLong (s->file, s->stream.total_in);
+
+ }
+ return destroy(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* 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;
+}
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