c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-05-22 10:37:35 +03:00
Code Issues Packages Projects Releases Wiki Activity

Fix zlib compression

Browse Source 
While portions of the code needed to support z_compress_level() and
z_uncompress() where in place.  In reality the current implementation
was non-functional, it just was compilable.

The critical missing component was to setup a workspace for the
compress/uncompress stream structures to use.  A kmem_cache was
added for the workspace area because we require a large chunk
of memory.  This avoids to need to continually alloc/free this
memory and vmap() the pages which is very slow.  Several objects
will reside in the per-cpu kmem_cache making them quick to acquire
and release.  A further optimization would be to adjust the
implementation to additional ensure the memory is local to the cpu.
Currently that may not be the case.
This commit is contained in:
Brian Behlendorf
2011-02-25 13:26:19 -08:00
parent 5a52a782a0
commit 5c1967ebe2
6 changed files with 238 additions and 100 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/sys/zmod.h
+7 -97
View File
@@ -55,105 +55,15 @@
#ifndef _SPL_ZMOD_H
#define _SPL_ZMOD_H
#include <sys/types.h>
#include <linux/zlib.h>
/*
* Compresses the source buffer into the destination buffer. The level
* parameter has the same meaning as in deflateInit. sourceLen is the byte
* length of the source buffer. Upon entry, destLen is the total size of the
* destination buffer, which must be at least 0.1% larger than sourceLen plus
* 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
*
* compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
* memory, Z_BUF_ERROR if there was not enough room in the output buffer,
* Z_STREAM_ERROR if the level parameter is invalid.
*/
static __inline__ int
z_compress_level(void *dest, size_t *destLen, const void *source,
size_t sourceLen, int level)
{
z_stream stream;
int err;
extern int z_compress_level(void *dest, size_t *destLen, const void *source,
size_t sourceLen, int level);
extern int z_uncompress(void *dest, size_t *destLen, const void *source,
size_t sourceLen);
stream.next_in = (Byte *)source;
stream.avail_in = (uInt)sourceLen;
#ifdef MAXSEG_64K
/* Check for source > 64K on 16-bit machine: */
if ((size_t)stream.avail_in != sourceLen)
return Z_BUF_ERROR;
#endif
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((size_t)stream.avail_out != *destLen)
return Z_BUF_ERROR;
err = zlib_deflateInit(&stream, level);
if (err != Z_OK)
return err;
err = zlib_deflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
zlib_deflateEnd(&stream);
return err == Z_OK ? Z_BUF_ERROR : err;
}
*destLen = stream.total_out;
err = zlib_deflateEnd(&stream);
return err;
} /* z_compress_level() */
/*
* Decompresses the source buffer into the destination buffer. sourceLen is
* the byte length of the source buffer. Upon entry, destLen is the total
* size of the destination buffer, which must be large enough to hold the
* entire uncompressed data. (The size of the uncompressed data must have
* been saved previously by the compressor and transmitted to the decompressor
* by some mechanism outside the scope of this compression library.)
* Upon exit, destLen is the actual size of the compressed buffer.
* This function can be used to decompress a whole file at once if the
* input file is mmap'ed.
*
* uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
* enough memory, Z_BUF_ERROR if there was not enough room in the output
* buffer, or Z_DATA_ERROR if the input data was corrupted.
*/
static __inline__ int
z_uncompress(void *dest, size_t *destLen, const void *source, size_t sourceLen)
{
z_stream stream;
int err;
stream.next_in = (Byte *)source;
stream.avail_in = (uInt)sourceLen;
/* Check for source > 64K on 16-bit machine: */
if ((size_t)stream.avail_in != sourceLen)
return Z_BUF_ERROR;
stream.next_out = dest;
stream.avail_out = (uInt)*destLen;
if ((size_t)stream.avail_out != *destLen)
return Z_BUF_ERROR;
err = zlib_inflateInit(&stream);
if (err != Z_OK)
return err;
err = zlib_inflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
zlib_inflateEnd(&stream);
if (err == Z_NEED_DICT ||
(err == Z_BUF_ERROR && stream.avail_in == 0))
return Z_DATA_ERROR;
return err;
}
*destLen = stream.total_out;
err = zlib_inflateEnd(&stream);
return err;
} /* z_uncompress() */
int zlib_init(void);
void zlib_fini(void);
#endif /* SPL_ZMOD_H */