zio_compress.c revision c9431fa1e59a88c2f0abf611f25b97af964449e5
/*
* 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
* 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 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/zfs_context.h>
#include <sys/compress.h>
#include <sys/zio_compress.h>
/*
* Compression vectors.
*/
};
{
if (child == ZIO_COMPRESS_INHERIT)
return (parent);
if (child == ZIO_COMPRESS_ON)
return (ZIO_COMPRESS_ON_VALUE);
return (child);
}
int
{
char *dest;
/*
* If the data is all zeroes, we don't even need to allocate
* a block for it. We indicate this by setting *destsizep = 0.
*/
allzero = 1;
if (*word++ != 0) {
allzero = 0;
break;
}
}
if (allzero) {
*destsizep = 0;
*destbufsizep = 0;
return (1);
}
if (cpfunc == ZIO_COMPRESS_EMPTY)
return (0);
/* Compress at least 12.5% */
if (destbufsize == 0)
return (0);
if (ciosize > destbufsize) {
return (0);
}
/* Cool. We compressed at least as much as we were hoping to. */
/* For security, make sure we don't write random heap crap to disk */
if (gapsize != 0) {
}
return (1);
}
int
{
}