zmod.c revision 168404 
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#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29#include <sys/types.h>
30#include <sys/zmod.h>
31
32#include "zlib.h"
33
34/*
35 * Uncompress the buffer 'src' into the buffer 'dst'.  The caller must store
36 * the expected decompressed data size externally so it can be passed in.
37 * The resulting decompressed size is then returned through dstlen.  This
38 * function return Z_OK on success, or another error code on failure.
39 */
40int
41z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
42{
43	z_stream zs;
44	int err;
45
46	bzero(&zs, sizeof (zs));
47	zs.next_in = (uchar_t *)src;
48	zs.avail_in = srclen;
49	zs.next_out = dst;
50	zs.avail_out = *dstlen;
51
52	if ((err = inflateInit(&zs)) != Z_OK)
53		return (err);
54
55	if ((err = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
56		(void) inflateEnd(&zs);
57		return (err == Z_OK ? Z_BUF_ERROR : err);
58	}
59
60	*dstlen = zs.total_out;
61	return (inflateEnd(&zs));
62}
63
64int
65z_compress_level(void *dst, size_t *dstlen, const void *src, size_t srclen,
66    int level)
67{
68
69	z_stream zs;
70	int err;
71
72	bzero(&zs, sizeof (zs));
73	zs.next_in = (uchar_t *)src;
74	zs.avail_in = srclen;
75	zs.next_out = dst;
76	zs.avail_out = *dstlen;
77
78	if ((err = deflateInit(&zs, level)) != Z_OK)
79		return (err);
80
81	if ((err = deflate(&zs, Z_FINISH)) != Z_STREAM_END) {
82		(void) deflateEnd(&zs);
83		return (err == Z_OK ? Z_BUF_ERROR : err);
84	}
85
86	*dstlen = zs.total_out;
87	return (deflateEnd(&zs));
88}
89
90int
91z_compress(void *dst, size_t *dstlen, const void *src, size_t srclen)
92{
93	return (z_compress_level(dst, dstlen, src, srclen,
94	    Z_DEFAULT_COMPRESSION));
95}
96
97/*
98 * Convert a zlib error code into a string error message.
99 */
100const char *
101z_strerror(int err)
102{
103	int i = Z_NEED_DICT - err;
104
105	if (i < 0 || i > Z_NEED_DICT - Z_VERSION_ERROR)
106		return ("unknown error");
107
108	return (zError(err));
109}
110