support/zlib_macros.c

   1 /*
   2  * Helper routines to use Zlib
   3  *
   4  * Author:
   5  *   Christopher Lahey (clahey@ximian.co)
   6  *
   7  * (C) 2004 Novell, Inc.
   8  */
   9 #include <zlib.h>
  10 #include <stdlib.h>
  11
  12 z_stream *
  13 create_z_stream(int compress, unsigned char gzip)
  14 {
  15         z_stream *z;
  16         int retval;
  17
  18 #if !defined(ZLIB_VERNUM) || (ZLIB_VERNUM < 0x1204)
  19         /* Older versions of zlib do not support raw deflate or gzip */
  20         return NULL;
  21 #endif
  22
  23         z = malloc (sizeof (z_stream));
  24         z->next_in = Z_NULL;
  25         z->avail_in = 0;
  26         z->next_out = Z_NULL;
  27         z->avail_out = 0;
  28         z->zalloc = Z_NULL;
  29         z->zfree = Z_NULL;
  30         z->opaque = NULL;
  31         if (compress) {
  32                 retval = deflateInit2 (z, Z_DEFAULT_COMPRESSION, Z_DEFLATED, gzip ? 31 : -15, 8, Z_DEFAULT_STRATEGY);
  33         } else {
  34                 retval = inflateInit2 (z, gzip ? 31 : -15);
  35         }
  36
  37         if (retval == Z_OK)
  38                 return z;
  39
  40         free (z);
  41         return NULL;
  42 }
  43
  44 void
  45 free_z_stream(z_stream *z, int compress)
  46 {
  47         if (compress) {
  48                 deflateEnd (z);
  49         } else {
  50                 inflateEnd (z);
  51         }
  52         free (z);
  53 }
  54
  55 void
  56 z_stream_set_next_in(z_stream *z, unsigned char *next_in)
  57 {
  58         z->next_in = next_in;
  59 }
  60
  61 void
  62 z_stream_set_avail_in(z_stream *z, int avail_in)
  63 {
  64         z->avail_in = avail_in;
  65 }
  66
  67 int
  68 z_stream_get_avail_in(z_stream *z)
  69 {
  70         return z->avail_in;
  71 }
  72
  73 void
  74 z_stream_set_next_out(z_stream *z, unsigned char *next_out)
  75 {
  76         z->next_out = next_out;
  77 }
  78
  79 void
  80 z_stream_set_avail_out(z_stream *z, int avail_out)
  81 {
  82         z->avail_out = avail_out;
  83 }
  84
  85 int
  86 z_stream_deflate (z_stream *z, int flush, unsigned char *next_out, int *avail_out)
  87 {
  88         int ret_val;
  89
  90         z->next_out = next_out;
  91         z->avail_out = *avail_out;
  92
  93         ret_val = deflate (z, flush);
  94
  95         *avail_out = z->avail_out;
  96
  97         return ret_val;
  98 }
  99
 100 int
 101 z_stream_inflate (z_stream *z, int *avail_out)
 102 {
 103         int ret_val;
 104
 105         z->avail_out = *avail_out;
 106
 107         ret_val = inflate (z, Z_NO_FLUSH);
 108
 109         *avail_out = z->avail_out;
 110
 111         return ret_val;
 112 }