diff options
Diffstat (limited to 'linux-2.4.x/fs/jffs2/compr_rtime.c')
| -rw-r--r-- | linux-2.4.x/fs/jffs2/compr_rtime.c | 104 |
1 files changed, 54 insertions, 50 deletions
diff --git a/linux-2.4.x/fs/jffs2/compr_rtime.c b/linux-2.4.x/fs/jffs2/compr_rtime.c index 1a71020..42ee158 100644 --- a/linux-2.4.x/fs/jffs2/compr_rtime.c +++ b/linux-2.4.x/fs/jffs2/compr_rtime.c @@ -1,43 +1,19 @@ /* * JFFS2 -- Journalling Flash File System, Version 2. * - * Copyright (C) 2001 Red Hat, Inc. + * Copyright (C) 2001-2003 Red Hat, Inc. * * Created by Arjan van de Ven <arjanv@redhat.com> * - * The original JFFS, from which the design for JFFS2 was derived, - * was designed and implemented by Axis Communications AB. + * For licensing information, see the file 'LICENCE' in this directory. * - * 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_rtime.c,v 1.5 2001/03/15 15:38:23 dwmw2 Exp $ + * $Id: compr_rtime.c,v 1.16 2005/11/07 11:14:38 gleixner Exp $ * * * Very simple lz77-ish encoder. * * Theory of operation: Both encoder and decoder have a list of "last - * occurances" for every possible source-value; after sending the + * occurrences" for every possible source-value; after sending the * first source-byte, the second byte indicated the "run" length of * matches * @@ -48,29 +24,33 @@ #include <linux/kernel.h> #include <linux/types.h> #include <linux/errno.h> -#include <linux/string.h> +#include <linux/string.h> +#include <linux/jffs2.h> +#include "compr.h" /* _compress returns the compressed size, -1 if bigger */ -int rtime_compress(unsigned char *data_in, unsigned char *cpage_out, - __u32 *sourcelen, __u32 *dstlen) +static int jffs2_rtime_compress(unsigned char *data_in, + unsigned char *cpage_out, + uint32_t *sourcelen, uint32_t *dstlen, + void *model) { - int positions[256]; + short positions[256]; int outpos = 0; int pos=0; - memset(positions,0,sizeof(positions)); - + memset(positions,0,sizeof(positions)); + while (pos < (*sourcelen) && outpos <= (*dstlen)-2) { int backpos, runlen=0; unsigned char value; - + value = data_in[pos]; cpage_out[outpos++] = data_in[pos++]; - + backpos = positions[value]; positions[value]=pos; - + while ((backpos < pos) && (pos < (*sourcelen)) && (data_in[pos]==data_in[backpos++]) && (runlen<255)) { pos++; @@ -83,33 +63,35 @@ int rtime_compress(unsigned char *data_in, unsigned char *cpage_out, /* We failed */ return -1; } - + /* Tell the caller how much we managed to compress, and how much space it took */ *sourcelen = pos; *dstlen = outpos; return 0; -} +} -void rtime_decompress(unsigned char *data_in, unsigned char *cpage_out, - __u32 srclen, __u32 destlen) +static int jffs2_rtime_decompress(unsigned char *data_in, + unsigned char *cpage_out, + uint32_t srclen, uint32_t destlen, + void *model) { - int positions[256]; + short positions[256]; int outpos = 0; int pos=0; - - memset(positions,0,sizeof(positions)); - + + memset(positions,0,sizeof(positions)); + while (outpos<destlen) { unsigned char value; int backoffs; int repeat; - + value = data_in[pos++]; cpage_out[outpos++] = value; /* first the verbatim copied byte */ repeat = data_in[pos++]; backoffs = positions[value]; - + positions[value]=outpos; if (repeat) { if (backoffs + repeat >= outpos) { @@ -119,10 +101,32 @@ void rtime_decompress(unsigned char *data_in, unsigned char *cpage_out, } } else { memcpy(&cpage_out[outpos],&cpage_out[backoffs],repeat); - outpos+=repeat; + outpos+=repeat; } } - } -} + } + return 0; +} + +static struct jffs2_compressor jffs2_rtime_comp = { + .priority = JFFS2_RTIME_PRIORITY, + .name = "rtime", + .compr = JFFS2_COMPR_RTIME, + .compress = &jffs2_rtime_compress, + .decompress = &jffs2_rtime_decompress, +#ifdef JFFS2_RTIME_DISABLED + .disabled = 1, +#else + .disabled = 0, +#endif +}; +int jffs2_rtime_init(void) +{ + return jffs2_register_compressor(&jffs2_rtime_comp); +} +void jffs2_rtime_exit(void) +{ + jffs2_unregister_compressor(&jffs2_rtime_comp); +} |