1 /* 2 * cache.h : deal with indexed LRU caches 3 * 4 * Copyright (c) 2008-2009 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 { 33 /* force alignment for pointers and u64 */ 34 u64 u64align; 35 void *ptralign; 36 } fixed[0]; 37 } ; 38 39 struct CACHED_INODE { 40 struct CACHED_INODE *next; 41 struct CACHED_INODE *previous; 42 const char *pathname; 43 size_t varsize; 44 /* above fields must match "struct CACHED_GENERIC" */ 45 u64 inum; 46 } ; 47 48 struct CACHED_NIDATA { 49 struct CACHED_NIDATA *next; 50 struct CACHED_NIDATA *previous; 51 const char *pathname; /* not used */ 52 size_t varsize; /* not used */ 53 /* above fields must match "struct CACHED_GENERIC" */ 54 u64 inum; 55 ntfs_inode *ni; 56 } ; 57 58 struct CACHED_LOOKUP { 59 struct CACHED_LOOKUP *next; 60 struct CACHED_LOOKUP *previous; 61 const char *name; 62 size_t namesize; 63 /* above fields must match "struct CACHED_GENERIC" */ 64 u64 parent; 65 u64 inum; 66 } ; 67 68 enum { 69 CACHE_FREE = 1, 70 CACHE_NOHASH = 2 71 } ; 72 73 typedef int (*cache_compare)(const struct CACHED_GENERIC *cached, 74 const struct CACHED_GENERIC *item); 75 typedef void (*cache_free)(const struct CACHED_GENERIC *cached); 76 typedef int (*cache_hash)(const struct CACHED_GENERIC *cached); 77 78 struct HASH_ENTRY { 79 struct HASH_ENTRY *next; 80 struct CACHED_GENERIC *entry; 81 } ; 82 83 struct CACHE_HEADER { 84 const char *name; 85 struct CACHED_GENERIC *most_recent_entry; 86 struct CACHED_GENERIC *oldest_entry; 87 struct CACHED_GENERIC *free_entry; 88 struct HASH_ENTRY *free_hash; 89 struct HASH_ENTRY **first_hash; 90 cache_free dofree; 91 cache_hash dohash; 92 unsigned long reads; 93 unsigned long writes; 94 unsigned long hits; 95 int fixed_size; 96 int max_hash; 97 struct CACHED_GENERIC entry[0]; 98 } ; 99 100 /* cast to generic, avoiding gcc warnings */ 101 #define GENERIC(pstr) ((const struct CACHED_GENERIC*)(const void*)(pstr)) 102 103 struct CACHED_GENERIC *ntfs_fetch_cache(struct CACHE_HEADER *cache, 104 const struct CACHED_GENERIC *wanted, 105 cache_compare compare); 106 struct CACHED_GENERIC *ntfs_enter_cache(struct CACHE_HEADER *cache, 107 const struct CACHED_GENERIC *item, 108 cache_compare compare); 109 int ntfs_invalidate_cache(struct CACHE_HEADER *cache, 110 const struct CACHED_GENERIC *item, 111 cache_compare compare, int flags); 112 int ntfs_remove_cache(struct CACHE_HEADER *cache, 113 struct CACHED_GENERIC *item, int flags); 114 115 void ntfs_create_lru_caches(ntfs_volume *vol); 116 void ntfs_free_lru_caches(ntfs_volume *vol); 117 118 #endif /* _NTFS_CACHE_H_ */ 119 120