path: root/include/ntfs-3g/cache.h (plain)
blob: be63b1a4bd7f37907e5f83745fd8500763aa26a5

1	/*
2	* cache.h : deal with indexed LRU caches
3	*
4	* Copyright (c) 2008-2010 Jean-Pierre Andre
5	*
6	* This program/include file is free software; you can redistribute it and/or
7	* modify it under the terms of the GNU General Public License as published
8	* by the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program/include file is distributed in the hope that it will be
12	* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
13	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program (in the main directory of the NTFS-3G
18	* distribution in the file COPYING); if not, write to the Free Software
19	* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20	*/
21
22	#ifndef _NTFS_CACHE_H_
23	#define _NTFS_CACHE_H_
24
25	#include "volume.h"
26
27	struct CACHED_GENERIC {
28	struct CACHED_GENERIC *next;
29	struct CACHED_GENERIC *previous;
30	void *variable;
31	size_t varsize;
32	union ALIGNMENT payload[0];
33	} ;
34
35	struct CACHED_INODE {
36	struct CACHED_INODE *next;
37	struct CACHED_INODE *previous;
38	const char *pathname;
39	size_t varsize;
40	union ALIGNMENT payload[0];
41	/* above fields must match "struct CACHED_GENERIC" */
42	u64 inum;
43	} ;
44
45	struct CACHED_NIDATA {
46	struct CACHED_NIDATA *next;
47	struct CACHED_NIDATA *previous;
48	const char *pathname; /* not used */
49	size_t varsize; /* not used */
50	union ALIGNMENT payload[0];
51	/* above fields must match "struct CACHED_GENERIC" */
52	u64 inum;
53	ntfs_inode *ni;
54	} ;
55
56	struct CACHED_LOOKUP {
57	struct CACHED_LOOKUP *next;
58	struct CACHED_LOOKUP *previous;
59	const char *name;
60	size_t namesize;
61	union ALIGNMENT payload[0];
62	/* above fields must match "struct CACHED_GENERIC" */
63	u64 parent;
64	u64 inum;
65	} ;
66
67	enum {
68	CACHE_FREE = 1,
69	CACHE_NOHASH = 2
70	} ;
71
72	typedef int (*cache_compare)(const struct CACHED_GENERIC *cached,
73	const struct CACHED_GENERIC *item);
74	typedef void (*cache_free)(const struct CACHED_GENERIC *cached);
75	typedef int (*cache_hash)(const struct CACHED_GENERIC *cached);
76
77	struct HASH_ENTRY {
78	struct HASH_ENTRY *next;
79	struct CACHED_GENERIC *entry;
80	} ;
81
82	struct CACHE_HEADER {
83	const char *name;
84	struct CACHED_GENERIC *most_recent_entry;
85	struct CACHED_GENERIC *oldest_entry;
86	struct CACHED_GENERIC *free_entry;
87	struct HASH_ENTRY *free_hash;
88	struct HASH_ENTRY **first_hash;
89	cache_free dofree;
90	cache_hash dohash;
91	unsigned long reads;
92	unsigned long writes;
93	unsigned long hits;
94	int fixed_size;
95	int max_hash;
96	struct CACHED_GENERIC entry[0];
97	} ;
98
99	/* cast to generic, avoiding gcc warnings */
100	#define GENERIC(pstr) ((const struct CACHED_GENERIC*)(const void*)(pstr))
101
102	struct CACHED_GENERIC *ntfs_fetch_cache(struct CACHE_HEADER *cache,
103	const struct CACHED_GENERIC *wanted,
104	cache_compare compare);
105	struct CACHED_GENERIC *ntfs_enter_cache(struct CACHE_HEADER *cache,
106	const struct CACHED_GENERIC *item,
107	cache_compare compare);
108	int ntfs_invalidate_cache(struct CACHE_HEADER *cache,
109	const struct CACHED_GENERIC *item,
110	cache_compare compare, int flags);
111	int ntfs_remove_cache(struct CACHE_HEADER *cache,
112	struct CACHED_GENERIC *item, int flags);
113
114	void ntfs_create_lru_caches(ntfs_volume *vol);
115	void ntfs_free_lru_caches(ntfs_volume *vol);
116
117	#endif /* _NTFS_CACHE_H_ */
118
119