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 2009 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#include <sys/zfs_context.h>
28#include <sys/compress.h>
29#include <sys/spa.h>
30#include <sys/zio.h>
31#include <sys/zio_compress.h>
32
33/*
34 * Compression vectors.
35 */
36
37zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
38	{NULL,			NULL,			0,	"inherit"},
39	{NULL,			NULL,			0,	"on"},
40	{NULL,			NULL,			0,	"uncompressed"},
41	{lzjb_compress,		lzjb_decompress,	0,	"lzjb"},
42	{NULL,			NULL,			0,	"empty"},
43	{gzip_compress,		gzip_decompress,	1,	"gzip-1"},
44	{gzip_compress,		gzip_decompress,	2,	"gzip-2"},
45	{gzip_compress,		gzip_decompress,	3,	"gzip-3"},
46	{gzip_compress,		gzip_decompress,	4,	"gzip-4"},
47	{gzip_compress,		gzip_decompress,	5,	"gzip-5"},
48	{gzip_compress,		gzip_decompress,	6,	"gzip-6"},
49	{gzip_compress,		gzip_decompress,	7,	"gzip-7"},
50	{gzip_compress,		gzip_decompress,	8,	"gzip-8"},
51	{gzip_compress,		gzip_decompress,	9,	"gzip-9"},
52	{zle_compress,		zle_decompress,		64,	"zle"},
53};
54
55enum zio_compress
56zio_compress_select(enum zio_compress child, enum zio_compress parent)
57{
58	ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
59	ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
60	ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON);
61
62	if (child == ZIO_COMPRESS_INHERIT)
63		return (parent);
64
65	if (child == ZIO_COMPRESS_ON)
66		return (ZIO_COMPRESS_ON_VALUE);
67
68	return (child);
69}
70
71size_t
72zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len)
73{
74	uint64_t *word, *word_end;
75	size_t c_len, d_len, r_len;
76	zio_compress_info_t *ci = &zio_compress_table[c];
77
78	ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
79	ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
80
81	/*
82	 * If the data is all zeroes, we don't even need to allocate
83	 * a block for it.  We indicate this by returning zero size.
84	 */
85	word_end = (uint64_t *)((char *)src + s_len);
86	for (word = src; word < word_end; word++)
87		if (*word != 0)
88			break;
89
90	if (word == word_end)
91		return (0);
92
93	if (c == ZIO_COMPRESS_EMPTY)
94		return (s_len);
95
96	/* Compress at least 12.5% */
97	d_len = P2ALIGN(s_len - (s_len >> 3), (size_t)SPA_MINBLOCKSIZE);
98	if (d_len == 0)
99		return (s_len);
100
101	c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level);
102
103	if (c_len > d_len)
104		return (s_len);
105
106	/*
107	 * Cool.  We compressed at least as much as we were hoping to.
108	 * For both security and repeatability, pad out the last sector.
109	 */
110	r_len = P2ROUNDUP(c_len, (size_t)SPA_MINBLOCKSIZE);
111	if (r_len > c_len) {
112		bzero((char *)dst + c_len, r_len - c_len);
113		c_len = r_len;
114	}
115
116	ASSERT3U(c_len, <=, d_len);
117	ASSERT(P2PHASE(c_len, (size_t)SPA_MINBLOCKSIZE) == 0);
118
119	return (c_len);
120}
121
122int
123zio_decompress_data(enum zio_compress c, void *src, void *dst,
124    size_t s_len, size_t d_len)
125{
126	zio_compress_info_t *ci = &zio_compress_table[c];
127
128	if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
129		return (EINVAL);
130
131	return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
132}
133