diff options
Diffstat (limited to 'compr_zlib.c')
-rw-r--r-- | compr_zlib.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/compr_zlib.c b/compr_zlib.c new file mode 100644 index 0000000..167946e --- /dev/null +++ b/compr_zlib.c @@ -0,0 +1,148 @@ +/* + * 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. + * + * $Id: compr_zlib.c,v 1.4 2005/11/07 11:15:09 gleixner Exp $ + * + */ + +#include <stdint.h> +#include <zlib.h> +#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 + +int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out, + uint32_t *sourcelen, uint32_t *dstlen, void *model) +{ + 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; +} + +int jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out, + uint32_t srclen, uint32_t destlen, void *model) +{ + 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); +} |