[net-next-2.6.git] / fs / logfs / compr.c

/*
 * fs/logfs/compr.c	- compression routines
 *
 * As should be obvious for Linux kernel code, license is GPLv2
 *
 * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
 */
#include "logfs.h"
#include <linux/vmalloc.h>
#include <linux/zlib.h>

#define COMPR_LEVEL 3

static DEFINE_MUTEX(compr_mutex);
static struct z_stream_s stream;

int logfs_compress(void *in, void *out, size_t inlen, size_t outlen)
{
	int err, ret;

	ret = -EIO;
	mutex_lock(&compr_mutex);
	err = zlib_deflateInit(&stream, COMPR_LEVEL);
	if (err != Z_OK)
		goto error;

	stream.next_in = in;
	stream.avail_in = inlen;
	stream.total_in = 0;
	stream.next_out = out;
	stream.avail_out = outlen;
	stream.total_out = 0;

	err = zlib_deflate(&stream, Z_FINISH);
	if (err != Z_STREAM_END)
		goto error;

	err = zlib_deflateEnd(&stream);
	if (err != Z_OK)
		goto error;

	if (stream.total_out >= stream.total_in)
		goto error;

	ret = stream.total_out;
error:
	mutex_unlock(&compr_mutex);
	return ret;
}

int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen)
{
	int err, ret;

	ret = -EIO;
	mutex_lock(&compr_mutex);
	err = zlib_inflateInit(&stream);
	if (err != Z_OK)
		goto error;

	stream.next_in = in;
	stream.avail_in = inlen;
	stream.total_in = 0;
	stream.next_out = out;
	stream.avail_out = outlen;
	stream.total_out = 0;

	err = zlib_inflate(&stream, Z_FINISH);
	if (err != Z_STREAM_END)
		goto error;

	err = zlib_inflateEnd(&stream);
	if (err != Z_OK)
		goto error;

	ret = 0;
error:
	mutex_unlock(&compr_mutex);
	return ret;
}

int __init logfs_compr_init(void)
{
	size_t size = max(zlib_deflate_workspacesize(),
			zlib_inflate_workspacesize());
	stream.workspace = vmalloc(size);
	if (!stream.workspace)
		return -ENOMEM;
	return 0;
}

void logfs_compr_exit(void)
{
	vfree(stream.workspace);
}
Commit	Line	Data
5db53f3e JE	1	/*
	2	* fs/logfs/compr.c - compression routines
	3	*
	4	* As should be obvious for Linux kernel code, license is GPLv2
	5	*
	6	* Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
	7	*/
	8	#include "logfs.h"
	9	#include <linux/vmalloc.h>
	10	#include <linux/zlib.h>
	11
	12	#define COMPR_LEVEL 3
	13
	14	static DEFINE_MUTEX(compr_mutex);
	15	static struct z_stream_s stream;
	16
	17	int logfs_compress(void in, void out, size_t inlen, size_t outlen)
	18	{
	19	int err, ret;
	20
	21	ret = -EIO;
	22	mutex_lock(&compr_mutex);
	23	err = zlib_deflateInit(&stream, COMPR_LEVEL);
	24	if (err != Z_OK)
	25	goto error;
	26
	27	stream.next_in = in;
	28	stream.avail_in = inlen;
	29	stream.total_in = 0;
	30	stream.next_out = out;
	31	stream.avail_out = outlen;
	32	stream.total_out = 0;
	33
	34	err = zlib_deflate(&stream, Z_FINISH);
	35	if (err != Z_STREAM_END)
	36	goto error;
	37
	38	err = zlib_deflateEnd(&stream);
	39	if (err != Z_OK)
	40	goto error;
	41
	42	if (stream.total_out >= stream.total_in)
	43	goto error;
	44
	45	ret = stream.total_out;
	46	error:
	47	mutex_unlock(&compr_mutex);
	48	return ret;
	49	}
	50
	51	int logfs_uncompress(void in, void out, size_t inlen, size_t outlen)
	52	{
	53	int err, ret;
	54
	55	ret = -EIO;
	56	mutex_lock(&compr_mutex);
	57	err = zlib_inflateInit(&stream);
	58	if (err != Z_OK)
	59	goto error;
	60
	61	stream.next_in = in;
	62	stream.avail_in = inlen;
	63	stream.total_in = 0;
	64	stream.next_out = out;
65	stream.avail_out = outlen;
66	stream.total_out = 0;
67
68	err = zlib_inflate(&stream, Z_FINISH);
69	if (err != Z_STREAM_END)
70	goto error;
71
72	err = zlib_inflateEnd(&stream);
73	if (err != Z_OK)
74	goto error;
75
76	ret = 0;
77	error:
78	mutex_unlock(&compr_mutex);
79	return ret;
80	}
81
82	int __init logfs_compr_init(void)
83	{
84	size_t size = max(zlib_deflate_workspacesize(),
85	zlib_inflate_workspacesize());
86	stream.workspace = vmalloc(size);
87	if (!stream.workspace)
88	return -ENOMEM;
89	return 0;
90	}
91
92	void logfs_compr_exit(void)
93	{
94	vfree(stream.workspace);
95	}