module/zfs/gzip.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27
  28
  29 #include <sys/debug.h>
  30 #include <sys/types.h>
  31
  32 #ifdef _KERNEL
  33
  34 #include <sys/systm.h>
  35 #include <sys/zmod.h>
  36
  37 typedef size_t zlen_t;
  38 #define compress_func   z_compress_level
  39 #define uncompress_func z_uncompress
  40
  41 #else /* _KERNEL */
  42
  43 #include <strings.h>
  44 #include <zlib.h>
  45
  46 typedef uLongf zlen_t;
  47 #define compress_func   compress2
  48 #define uncompress_func uncompress
  49
  50 #endif
  51
  52 size_t
  53 gzip_compress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
  54 {
  55         zlen_t dstlen = d_len;
  56
  57         ASSERT(d_len <= s_len);
  58
  59         if (compress_func(d_start, &dstlen, s_start, s_len, n) != Z_OK) {
  60                 if (d_len != s_len)
  61                         return (s_len);
  62
  63                 bcopy(s_start, d_start, s_len);
  64                 return (s_len);
  65         }
  66
  67         return ((size_t) dstlen);
  68 }
  69
  70 /*ARGSUSED*/
  71 int
  72 gzip_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
  73 {
  74         zlen_t dstlen = d_len;
  75
  76         ASSERT(d_len >= s_len);
  77
  78         if (uncompress_func(d_start, &dstlen, s_start, s_len) != Z_OK)
  79                 return (-1);
  80
  81         return (0);
  82 }