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/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2001 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@cambridge.redhat.com>
*
* The original JFFS, from which the design for JFFS2 was derived,
* was designed and implemented by Axis Communications AB.
*
* The contents of this file are subject to the Red Hat eCos Public
* License Version 1.1 (the "Licence"); you may not use this file
* except in compliance with the Licence. You may obtain a copy of
* the Licence at http://www.redhat.com/
*
* Software distributed under the Licence is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
* See the Licence for the specific language governing rights and
* limitations under the Licence.
*
* The Original Code is JFFS2 - Journalling Flash File System, version 2
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License version 2 (the "GPL"), in
* which case the provisions of the GPL are applicable instead of the
* above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use your
* version of this file under the RHEPL, indicate your decision by
* deleting the provisions above and replace them with the notice and
* other provisions required by the GPL. If you do not delete the
* provisions above, a recipient may use your version of this file
* under either the RHEPL or the GPL.
*/
#include <stdint.h>
#define crc32 __zlib_crc32
#include <zlib.h>
#undef crc32
#include <stdio.h>
#include <asm/types.h>
#include <linux/jffs2.h>
#include "compr.h"
#define min(x,y) ((x)<(y)?(x):(y))
/* Plan: call deflate() with avail_in == *sourcelen,
avail_out = *dstlen - 12 and flush == Z_FINISH.
If it doesn't manage to finish, call it again with
avail_in == 0 and avail_out set to the remaining 12
bytes for it to clean up.
Q: Is 12 bytes sufficient?
*/
#define STREAM_END_SPACE 12
static int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out,
uint32_t *sourcelen, uint32_t *dstlen)
{
z_stream strm;
int ret;
if (*dstlen <= STREAM_END_SPACE)
return -1;
strm.zalloc = (void *)0;
strm.zfree = (void *)0;
if (Z_OK != deflateInit(&strm, 3)) {
return -1;
}
strm.next_in = data_in;
strm.total_in = 0;
strm.next_out = cpage_out;
strm.total_out = 0;
while (strm.total_out < *dstlen - STREAM_END_SPACE && strm.total_in < *sourcelen) {
strm.avail_out = *dstlen - (strm.total_out + STREAM_END_SPACE);
strm.avail_in = min((unsigned)(*sourcelen-strm.total_in), strm.avail_out);
ret = deflate(&strm, Z_PARTIAL_FLUSH);
if (ret != Z_OK) {
deflateEnd(&strm);
return -1;
}
}
strm.avail_out += STREAM_END_SPACE;
strm.avail_in = 0;
ret = deflate(&strm, Z_FINISH);
if (ret != Z_STREAM_END) {
deflateEnd(&strm);
return -1;
}
deflateEnd(&strm);
if (strm.total_out >= strm.total_in)
return -1;
*dstlen = strm.total_out;
*sourcelen = strm.total_in;
return 0;
}
static int jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out,
uint32_t srclen, uint32_t destlen)
{
z_stream strm;
int ret;
strm.zalloc = (void *)0;
strm.zfree = (void *)0;
if (Z_OK != inflateInit(&strm)) {
return 1;
}
strm.next_in = data_in;
strm.avail_in = srclen;
strm.total_in = 0;
strm.next_out = cpage_out;
strm.avail_out = destlen;
strm.total_out = 0;
while((ret = inflate(&strm, Z_FINISH)) == Z_OK)
;
inflateEnd(&strm);
return 0;
}
static struct jffs2_compressor jffs2_zlib_comp = {
.priority = JFFS2_ZLIB_PRIORITY,
.name = "zlib",
.disabled = 0,
.compr = JFFS2_COMPR_ZLIB,
.compress = &jffs2_zlib_compress,
.decompress = &jffs2_zlib_decompress,
};
int jffs2_zlib_init(void)
{
return jffs2_register_compressor(&jffs2_zlib_comp);
}
void jffs2_zlib_exit(void)
{
jffs2_unregister_compressor(&jffs2_zlib_comp);
}
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