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