FCL/interim/QEMU: comparison symbian-qemu-0.9.1-12/python-2.6.1/Modules/zlib/gzio.c

equal deleted inserted replaced

-:ffa851df0825
+:2fb8b9db1c86
+/* 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);
+}