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OpenCloudOS-Kernel/fs/squashfs/decompressor.h

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Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
#ifndef DECOMPRESSOR_H
#define DECOMPRESSOR_H
/*
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Squashfs: update email address My existing email address may stop working in a month or two, so update email to one that will continue working. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-05-26 17:39:56 +08:00
* Phillip Lougher <phillip@squashfs.org.uk>
Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* decompressor.h
*/
struct squashfs_decompressor {
Squashfs: Refactor decompressor interface and code The decompressor interface and code was written from the point of view of single-threaded operation. In doing so it mixed a lot of single-threaded implementation specific aspects into the decompressor code and elsewhere which makes it difficult to seamlessly support multiple different decompressor implementations. This patch does the following: 1. It removes compressor_options parsing from the decompressor init() function. This allows the decompressor init() function to be dynamically called to instantiate multiple decompressors, without the compressor options needing to be read and parsed each time. 2. It moves threading and all sleeping operations out of the decompressors. In doing so, it makes the decompressors non-blocking wrappers which only deal with interfacing with the decompressor implementation. 3. It splits decompressor.[ch] into decompressor generic functions in decompressor.[ch], and moves the single threaded decompressor implementation into decompressor_single.c. The result of this patch is Squashfs should now be able to support multiple decompressors by adding new decompressor_xxx.c files with specialised implementations of the functions in decompressor_single.c Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reviewed-by: Minchan Kim <minchan@kernel.org>
2013-11-13 10:56:26 +08:00
void *(*init)(struct squashfs_sb_info *, void *);
void *(*comp_opts)(struct squashfs_sb_info *, void *, int);
Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
void (*free)(void *);
Squashfs: Generalise paging handling in the decompressors Further generalise the decompressors by adding a page handler abstraction. This adds helpers to allow the decompressors to access and process the output buffers in an implementation independant manner. This allows different types of output buffer to be passed to the decompressors, with the implementation specific aspects handled at decompression time, but without the knowledge being held in the decompressor wrapper code. This will allow the decompressors to handle Squashfs cache buffers, and page cache pages. This patch adds the abstraction and an implementation for the caches. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reviewed-by: Minchan Kim <minchan@kernel.org>
2013-11-18 10:59:12 +08:00
int (*decompress)(struct squashfs_sb_info *, void *,
struct buffer_head **, int, int, int,
struct squashfs_page_actor *);
Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
int id;
char *name;
int supported;
};
Squashfs: Refactor decompressor interface and code The decompressor interface and code was written from the point of view of single-threaded operation. In doing so it mixed a lot of single-threaded implementation specific aspects into the decompressor code and elsewhere which makes it difficult to seamlessly support multiple different decompressor implementations. This patch does the following: 1. It removes compressor_options parsing from the decompressor init() function. This allows the decompressor init() function to be dynamically called to instantiate multiple decompressors, without the compressor options needing to be read and parsed each time. 2. It moves threading and all sleeping operations out of the decompressors. In doing so, it makes the decompressors non-blocking wrappers which only deal with interfacing with the decompressor implementation. 3. It splits decompressor.[ch] into decompressor generic functions in decompressor.[ch], and moves the single threaded decompressor implementation into decompressor_single.c. The result of this patch is Squashfs should now be able to support multiple decompressors by adding new decompressor_xxx.c files with specialised implementations of the functions in decompressor_single.c Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reviewed-by: Minchan Kim <minchan@kernel.org>
2013-11-13 10:56:26 +08:00
static inline void *squashfs_comp_opts(struct squashfs_sb_info *msblk,
void *buff, int length)
Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
{
Squashfs: Refactor decompressor interface and code The decompressor interface and code was written from the point of view of single-threaded operation. In doing so it mixed a lot of single-threaded implementation specific aspects into the decompressor code and elsewhere which makes it difficult to seamlessly support multiple different decompressor implementations. This patch does the following: 1. It removes compressor_options parsing from the decompressor init() function. This allows the decompressor init() function to be dynamically called to instantiate multiple decompressors, without the compressor options needing to be read and parsed each time. 2. It moves threading and all sleeping operations out of the decompressors. In doing so, it makes the decompressors non-blocking wrappers which only deal with interfacing with the decompressor implementation. 3. It splits decompressor.[ch] into decompressor generic functions in decompressor.[ch], and moves the single threaded decompressor implementation into decompressor_single.c. The result of this patch is Squashfs should now be able to support multiple decompressors by adding new decompressor_xxx.c files with specialised implementations of the functions in decompressor_single.c Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk> Reviewed-by: Minchan Kim <minchan@kernel.org>
2013-11-13 10:56:26 +08:00
return msblk->decompressor->comp_opts ?
msblk->decompressor->comp_opts(msblk, buff, length) : NULL;
Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
}
Squashfs: Add XZ compression configuration option Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2010-12-09 10:08:31 +08:00
#ifdef CONFIG_SQUASHFS_XZ
extern const struct squashfs_decompressor squashfs_xz_comp_ops;
#endif
Squashfs: Add LZ4 compression configuration option Add the glue code, and also update the documentation. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2014-11-28 02:48:44 +08:00
#ifdef CONFIG_SQUASHFS_LZ4
extern const struct squashfs_decompressor squashfs_lz4_comp_ops;
#endif
Squashfs: simplify CONFIG_SQUASHFS_LZO handling Get rid of messy repeated #if(n)def CONFIG_SQUASHFS_LZO code in decompressor.c Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-06 02:23:53 +08:00
#ifdef CONFIG_SQUASHFS_LZO
extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
#endif
Squashfs: Make ZLIB compression support optional Squashfs now supports XZ and LZO compression in addition to ZLIB. As such it no longer makes sense to always include ZLIB support. In particular embedded systems may only use LZO or XZ compression, and the ability to exclude ZLIB support will reduce kernel size. Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2011-07-22 10:01:28 +08:00
#ifdef CONFIG_SQUASHFS_ZLIB
extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
#endif
squashfs: Add zstd support Add zstd compression and decompression support to SquashFS. zstd is a great fit for SquashFS because it can compress at ratios approaching xz, while decompressing twice as fast as zlib. For SquashFS in particular, it can decompress as fast as lzo and lz4. It also has the flexibility to turn down the compression ratio for faster compression times. The compression benchmark is run on the file tree from the SquashFS archive found in ubuntu-16.10-desktop-amd64.iso [1]. It uses `mksquashfs` with the default block size (128 KB) and and various compression algorithms/levels. xz and zstd are also benchmarked with 256 KB blocks. The decompression benchmark times how long it takes to `tar` the file tree into `/dev/null`. See the benchmark file in the upstream zstd source repository located under `contrib/linux-kernel/squashfs-benchmark.sh` [2] for details. I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. | Method | Ratio | Compression MB/s | Decompression MB/s | |----------------|-------|------------------|--------------------| | gzip | 2.92 | 15 | 128 | | lzo | 2.64 | 9.5 | 217 | | lz4 | 2.12 | 94 | 218 | | xz | 3.43 | 5.5 | 35 | | xz 256 KB | 3.53 | 5.4 | 40 | | zstd 1 | 2.71 | 96 | 210 | | zstd 5 | 2.93 | 69 | 198 | | zstd 10 | 3.01 | 41 | 225 | | zstd 15 | 3.13 | 11.4 | 224 | | zstd 16 256 KB | 3.24 | 8.1 | 210 | This patch was written by Sean Purcell <me@seanp.xyz>, but I will be taking over the submission process. [1] http://releases.ubuntu.com/16.10/ [2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/squashfs-benchmark.sh zstd source repository: https://github.com/facebook/zstd Signed-off-by: Sean Purcell <me@seanp.xyz> Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: Phillip Lougher <phillip@squashfs.org.uk>
2017-08-10 10:42:36 +08:00
#ifdef CONFIG_SQUASHFS_ZSTD
extern const struct squashfs_decompressor squashfs_zstd_comp_ops;
#endif
Squashfs: add a decompressor framework This adds a decompressor framework which allows multiple compression algorithms to be cleanly supported. Also update zlib wrapper and other code to use the new framework. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2009-10-06 11:04:15 +08:00
#endif