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 15 struct 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 */ 29 struct 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 */ 43 struct 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 53 ssize_t zcomp_available_show(const char *comp, char *buf); 54 bool zcomp_available_algorithm(const char *comp); 55 56 struct zcomp *zcomp_create(const char *comp, int max_strm); 57 void zcomp_destroy(struct zcomp *comp); 58 59 struct zcomp_strm *zcomp_strm_find(struct zcomp *comp); 60 void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm); 61 62 int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm, 63 const unsigned char *src, size_t *dst_len); 64 65 int zcomp_decompress(struct zcomp *comp, const unsigned char *src, 66 size_t src_len, unsigned char *dst); 67 68 bool zcomp_set_max_streams(struct zcomp *comp, int num_strm); 69 #endif /* _ZCOMP_H_ */ 70