1 files changed, 316 insertions, 31 deletions

diff --git a/gzio.c b/gzio.c
index 6c82677..0b9915c 100644
--- a/gzio.c
+++ b/gzio.c
@@ -1,9 +1,11 @@
 /* gzio.c -- IO on .gz files
- * Copyright (C) 1995-1996 Jean-loup Gailly.
+ * 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: gzio.c,v 1.14 1996/07/24 13:41:01 me Exp $ */
+/* @(#) $Id$ */
 
 #include <stdio.h>
 
@@ -38,10 +40,12 @@ typedef struct gz_stream {
     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));
@@ -64,6 +68,7 @@ local gzFile gz_open (path, mode, 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 */
@@ -99,6 +104,10 @@ local gzFile gz_open (path, mode, fd)
         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 */
         }
@@ -106,19 +115,24 @@ local gzFile gz_open (path, mode, fd)
     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, 0);
+                           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 {
-        err = inflateInit2(&(s->stream), -MAX_WBITS);
         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 */
+
         if (err != Z_OK || s->inbuf == Z_NULL) {
             return destroy(s), (gzFile)Z_NULL;
         }
@@ -126,7 +140,7 @@ local gzFile gz_open (path, mode, fd)
     s->stream.avail_out = Z_BUFSIZE;
 
     errno = 0;
-    s->file = fd < 0 ? FOPEN(path, fmode) : (FILE*)fdopen(fd, fmode);
+    s->file = fd < 0 ? F_OPEN(path, fmode) : (FILE*)fdopen(fd, fmode);
 
     if (s->file == NULL) {
         return destroy(s), (gzFile)Z_NULL;
@@ -136,16 +150,19 @@ local gzFile gz_open (path, mode, fd)
          */
         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 = ftell(s->file);
     } 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 gzopen (path, mode)
+gzFile EXPORT gzopen (path, mode)
     const char *path;
     const char *mode;
 {
@@ -156,7 +173,7 @@ gzFile gzopen (path, mode)
      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)
+gzFile EXPORT gzdopen (fd, mode)
     int fd;
     const char *mode;
 {
@@ -169,6 +186,31 @@ gzFile gzdopen (fd, mode)
 }
 
 /* ===========================================================================
+ * Update the compression level and strategy
+ */
+int EXPORT 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.
@@ -212,8 +254,11 @@ local void check_header(s)
     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--;
+            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;
         }
@@ -260,14 +305,21 @@ local int destroy (s)
     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->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)) {
-        err = Z_ERRNO;
+#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;
 
@@ -282,13 +334,13 @@ local int destroy (s)
      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)
+int EXPORT gzread (file, buf, len)
     gzFile file;
     voidp buf;
     unsigned len;
 {
     gz_stream *s = (gz_stream*)file;
-    Bytef *start = buf; /* starting point for crc computation */
+    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;
@@ -296,7 +348,8 @@ int gzread (file, buf, len)
     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;
+    next_out = (Byte*)buf;
+    s->stream.next_out = (Bytef*)buf;
     s->stream.avail_out = len;
 
     while (s->stream.avail_out != 0) {
@@ -345,7 +398,12 @@ int gzread (file, buf, len)
                 /* Check for concatenated .gz 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);
                 }
             }
@@ -357,11 +415,26 @@ int gzread (file, buf, len)
     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 EXPORT gzgetc(file)
+    gzFile file;
+{
+    int c;
+
+    return gzread(file, &c, 1) == 1 ? c : -1;
+}
+
+
+#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 gzwrite (file, buf, len)
+int EXPORT gzwrite (file, buf, len)
     gzFile file;
     const voidp buf;
     unsigned len;
@@ -370,7 +443,7 @@ int gzwrite (file, buf, len)
 
     if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
 
-    s->stream.next_in = buf;
+    s->stream.next_in = (Bytef*)buf;
     s->stream.avail_in = len;
 
     while (s->stream.avail_in != 0) {
@@ -387,18 +460,79 @@ int gzwrite (file, buf, len)
         s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
         if (s->z_err != Z_OK) break;
     }
-    s->crc = crc32(s->crc, buf, len);
+    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 EXPORTVA gzprintf (gzFile file, const char *format, /* args */ ...)
+{
+    char buf[Z_BUFSIZE];
+    va_list va;
+    int len;
+
+    va_start(va, format);
+#ifdef HAS_vsnprintf
+    len = vsnprintf(buf, sizeof(buf), format, va);
+#else
+    len = vsprintf(buf, format, va);
+#endif
+    va_end(va);
+    if (len <= 0) return 0;
+
+    return gzwrite(file, buf, (unsigned)len);
+}
+#else /* not ANSI C */
+
+int EXPORTVA 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_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 EXPORT gzputc(file, c)
+    gzFile file;
+    int c;
+{
+    return gzwrite(file, &c, 1) == 1 ? c : -1;
+}
+
+
+/* ===========================================================================
      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)
+local int do_flush (file, flush)
     gzFile file;
     int flush;
 {
@@ -424,6 +558,9 @@ int gzflush (file, flush)
         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: 
          */
@@ -431,9 +568,154 @@ int gzflush (file, flush)
  
         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 EXPORT 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 EXPORT 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) return -1L;
+
+    s->z_err = Z_OK;
+    s->z_eof = 0;
+    
+    if (s->mode == 'w') {
+#ifdef NO_DEFLATE
+        return -1L;
+#else
+        if (whence == SEEK_SET) {
+            offset -= s->stream.total_out;
+        }
+        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 s->stream.total_in;
+#endif
+    }
+    /* Rest of function is for reading only */
+
+    if (s->z_err == Z_DATA_ERROR) return -1L;
+
+    /* 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;
+        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 s->stream.total_out;
+}
+
+/* ===========================================================================
+     Rewinds input file. 
+*/
+int EXPORT 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;
+        
+    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 EXPORT 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 EXPORT 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
@@ -470,7 +752,7 @@ local uLong getLong (s)
      Flushes all pending output if necessary, closes the compressed file
    and deallocates all the (de)compression state.
 */
-int gzclose (file)
+int EXPORT gzclose (file)
     gzFile file;
 {
     int err;
@@ -479,14 +761,17 @@ int gzclose (file)
     if (s == NULL) return Z_STREAM_ERROR;
 
     if (s->mode == 'w') {
-        err = gzflush (file, Z_FINISH);
-        if (err != Z_OK) return destroy(file);
+#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(file);
+    return destroy((gz_stream*)file);
 }
 
 /* ===========================================================================
@@ -496,7 +781,7 @@ int gzclose (file)
    errnum is set to Z_ERRNO and the application may consult errno
    to get the exact error code.
 */
-const char*  gzerror (file, errnum)
+const char*  EXPORT gzerror (file, errnum)
     gzFile file;
     int *errnum;
 {