1/*
2 * Copyright (C) 2014 Sergey Senozhatsky.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10#ifndef _ZCOMP_H_
11#define _ZCOMP_H_
12
13#include <linux/mutex.h>
14
15struct zcomp_strm {
16	/* compression/decompression buffer */
17	void *buffer;
18	/*
19	 * The private data of the compression stream, only compression
20	 * stream backend can touch this (e.g. compression algorithm
21	 * working memory)
22	 */
23	void *private;
24	/* used in multi stream backend, protected by backend strm_lock */
25	struct list_head list;
26};
27
28/* static compression backend */
29struct zcomp_backend {
30	int (*compress)(const unsigned char *src, unsigned char *dst,
31			size_t *dst_len, void *private);
32
33	int (*decompress)(const unsigned char *src, size_t src_len,
34			unsigned char *dst);
35
36	void *(*create)(void);
37	void (*destroy)(void *private);
38
39	const char *name;
40};
41
42/* dynamic per-device compression frontend */
43struct zcomp {
44	void *stream;
45	struct zcomp_backend *backend;
46
47	struct zcomp_strm *(*strm_find)(struct zcomp *comp);
48	void (*strm_release)(struct zcomp *comp, struct zcomp_strm *zstrm);
49	bool (*set_max_streams)(struct zcomp *comp, int num_strm);
50	void (*destroy)(struct zcomp *comp);
51};
52
53ssize_t zcomp_available_show(const char *comp, char *buf);
54
55struct zcomp *zcomp_create(const char *comp, int max_strm);
56void zcomp_destroy(struct zcomp *comp);
57
58struct zcomp_strm *zcomp_strm_find(struct zcomp *comp);
59void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm);
60
61int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
62		const unsigned char *src, size_t *dst_len);
63
64int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
65		size_t src_len, unsigned char *dst);
66
67bool zcomp_set_max_streams(struct zcomp *comp, int num_strm);
68#endif /* _ZCOMP_H_ */
69