1 /* 2 * Copyright (c) 2006-2007 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 #ifndef __XFS_MRU_CACHE_H__ 19 #define __XFS_MRU_CACHE_H__ 20 21 22 /* Function pointer type for callback to free a client's data pointer. */ 23 typedef void (*xfs_mru_cache_free_func_t)(unsigned long, void*); 24 25 typedef struct xfs_mru_cache 26 { 27 struct radix_tree_root store; /* Core storage data structure. */ 28 struct list_head *lists; /* Array of lists, one per grp. */ 29 struct list_head reap_list; /* Elements overdue for reaping. */ 30 spinlock_t lock; /* Lock to protect this struct. */ 31 unsigned int grp_count; /* Number of discrete groups. */ 32 unsigned int grp_time; /* Time period spanned by grps. */ 33 unsigned int lru_grp; /* Group containing time zero. */ 34 unsigned long time_zero; /* Time first element was added. */ 35 unsigned long next_reap; /* Time that the reaper should 36 next do something. */ 37 unsigned int reap_all; /* if set, reap all lists */ 38 xfs_mru_cache_free_func_t free_func; /* Function pointer for freeing. */ 39 struct delayed_work work; /* Workqueue data for reaping. */ 40 } xfs_mru_cache_t; 41 42 int xfs_mru_cache_init(void); 43 void xfs_mru_cache_uninit(void); 44 int xfs_mru_cache_create(struct xfs_mru_cache **mrup, unsigned int lifetime_ms, 45 unsigned int grp_count, 46 xfs_mru_cache_free_func_t free_func); 47 void xfs_mru_cache_flush(xfs_mru_cache_t *mru, int restart); 48 void xfs_mru_cache_destroy(struct xfs_mru_cache *mru); 49 int xfs_mru_cache_insert(struct xfs_mru_cache *mru, unsigned long key, 50 void *value); 51 void * xfs_mru_cache_remove(struct xfs_mru_cache *mru, unsigned long key); 52 void xfs_mru_cache_delete(struct xfs_mru_cache *mru, unsigned long key); 53 void *xfs_mru_cache_lookup(struct xfs_mru_cache *mru, unsigned long key); 54 void *xfs_mru_cache_peek(struct xfs_mru_cache *mru, unsigned long key); 55 void xfs_mru_cache_done(struct xfs_mru_cache *mru); 56 57 #endif /* __XFS_MRU_CACHE_H__ */ 58