vendor/opensolaris/20100818vendor/opensolaris

1 files changed, 132 insertions, 0 deletions

diff --git a/uts/common/fs/zfs/zio_compress.c b/uts/common/fs/zfs/zio_compress.c
new file mode 100644
index 000000000000..f148977c4468
--- /dev/null
+++ b/uts/common/fs/zfs/zio_compress.c
@@ -0,0 +1,132 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/compress.h>
+#include <sys/spa.h>
+#include <sys/zio.h>
+#include <sys/zio_compress.h>
+
+/*
+ * Compression vectors.
+ */
+
+zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
+	{NULL,			NULL,			0,	"inherit"},
+	{NULL,			NULL,			0,	"on"},
+	{NULL,			NULL,			0,	"uncompressed"},
+	{lzjb_compress,		lzjb_decompress,	0,	"lzjb"},
+	{NULL,			NULL,			0,	"empty"},
+	{gzip_compress,		gzip_decompress,	1,	"gzip-1"},
+	{gzip_compress,		gzip_decompress,	2,	"gzip-2"},
+	{gzip_compress,		gzip_decompress,	3,	"gzip-3"},
+	{gzip_compress,		gzip_decompress,	4,	"gzip-4"},
+	{gzip_compress,		gzip_decompress,	5,	"gzip-5"},
+	{gzip_compress,		gzip_decompress,	6,	"gzip-6"},
+	{gzip_compress,		gzip_decompress,	7,	"gzip-7"},
+	{gzip_compress,		gzip_decompress,	8,	"gzip-8"},
+	{gzip_compress,		gzip_decompress,	9,	"gzip-9"},
+	{zle_compress,		zle_decompress,		64,	"zle"},
+};
+
+enum zio_compress
+zio_compress_select(enum zio_compress child, enum zio_compress parent)
+{
+	ASSERT(child < ZIO_COMPRESS_FUNCTIONS);
+	ASSERT(parent < ZIO_COMPRESS_FUNCTIONS);
+	ASSERT(parent != ZIO_COMPRESS_INHERIT && parent != ZIO_COMPRESS_ON);
+
+	if (child == ZIO_COMPRESS_INHERIT)
+		return (parent);
+
+	if (child == ZIO_COMPRESS_ON)
+		return (ZIO_COMPRESS_ON_VALUE);
+
+	return (child);
+}
+
+size_t
+zio_compress_data(enum zio_compress c, void *src, void *dst, size_t s_len)
+{
+	uint64_t *word, *word_end;
+	size_t c_len, d_len, r_len;
+	zio_compress_info_t *ci = &zio_compress_table[c];
+
+	ASSERT((uint_t)c < ZIO_COMPRESS_FUNCTIONS);
+	ASSERT((uint_t)c == ZIO_COMPRESS_EMPTY || ci->ci_compress != NULL);
+
+	/*
+	 * If the data is all zeroes, we don't even need to allocate
+	 * a block for it.  We indicate this by returning zero size.
+	 */
+	word_end = (uint64_t *)((char *)src + s_len);
+	for (word = src; word < word_end; word++)
+		if (*word != 0)
+			break;
+
+	if (word == word_end)
+		return (0);
+
+	if (c == ZIO_COMPRESS_EMPTY)
+		return (s_len);
+
+	/* Compress at least 12.5% */
+	d_len = P2ALIGN(s_len - (s_len >> 3), (size_t)SPA_MINBLOCKSIZE);
+	if (d_len == 0)
+		return (s_len);
+
+	c_len = ci->ci_compress(src, dst, s_len, d_len, ci->ci_level);
+
+	if (c_len > d_len)
+		return (s_len);
+
+	/*
+	 * Cool.  We compressed at least as much as we were hoping to.
+	 * For both security and repeatability, pad out the last sector.
+	 */
+	r_len = P2ROUNDUP(c_len, (size_t)SPA_MINBLOCKSIZE);
+	if (r_len > c_len) {
+		bzero((char *)dst + c_len, r_len - c_len);
+		c_len = r_len;
+	}
+
+	ASSERT3U(c_len, <=, d_len);
+	ASSERT(P2PHASE(c_len, (size_t)SPA_MINBLOCKSIZE) == 0);
+
+	return (c_len);
+}
+
+int
+zio_decompress_data(enum zio_compress c, void *src, void *dst,
+    size_t s_len, size_t d_len)
+{
+	zio_compress_info_t *ci = &zio_compress_table[c];
+
+	if ((uint_t)c >= ZIO_COMPRESS_FUNCTIONS || ci->ci_decompress == NULL)
+		return (EINVAL);
+
+	return (ci->ci_decompress(src, dst, s_len, d_len, ci->ci_level));
+}