1 /*- 2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #ifndef __NSCD_CACHEPLCS_H__ 30 #define __NSCD_CACHEPLCS_H__ 31 32 #include <sys/queue.h> 33 34 /* common policy definitions */ 35 #define CACHELIB_MAX_FREQUENCY 100 36 37 /* 38 * cache_policy_item_ represents some abstract cache element in the policy 39 * queue. connected_item pointers to the corresponding cache_policy_item_ in 40 * another policy queue. 41 */ 42 struct cache_policy_item_ { 43 char *key; 44 size_t key_size; 45 46 size_t request_count; 47 struct timeval last_request_time; 48 struct timeval creation_time; 49 50 struct cache_policy_item_ *connected_item; 51 }; 52 53 /* 54 * cache_policy_ represents an abstract policy queue. It can be customized by 55 * setting appropriate function pointers 56 */ 57 struct cache_policy_ { 58 struct cache_policy_item_* (*create_item_func)(void); 59 void (*destroy_item_func)(struct cache_policy_item_ *); 60 61 void (*add_item_func)(struct cache_policy_ *, 62 struct cache_policy_item_ *); 63 void (*remove_item_func)(struct cache_policy_ *, 64 struct cache_policy_item_ *); 65 void (*update_item_func)(struct cache_policy_ *, 66 struct cache_policy_item_ *); 67 68 struct cache_policy_item_ *(*get_first_item_func)( 69 struct cache_policy_ *); 70 struct cache_policy_item_ *(*get_last_item_func)( 71 struct cache_policy_ *); 72 struct cache_policy_item_ *(*get_next_item_func)( 73 struct cache_policy_ *, struct cache_policy_item_ *); 74 struct cache_policy_item_ *(*get_prev_item_func)( 75 struct cache_policy_ *, struct cache_policy_item_ *); 76 }; 77 78 /* 79 * LFU cache policy item "inherited" from cache_policy_item_ structure 80 */ 81 struct cache_lfu_policy_item_ { 82 struct cache_policy_item_ parent_data; 83 int frequency; 84 85 TAILQ_ENTRY(cache_lfu_policy_item_) entries; 86 }; 87 88 TAILQ_HEAD(cache_lfu_policy_group_, cache_lfu_policy_item_); 89 90 /* 91 * LFU policy queue "inherited" from cache_policy_. 92 */ 93 struct cache_lfu_policy_ { 94 struct cache_policy_ parent_data; 95 struct cache_lfu_policy_group_ groups[CACHELIB_MAX_FREQUENCY]; 96 }; 97 98 /* 99 * LRU and FIFO policies item "inherited" from cache_policy_item_ 100 */ 101 struct cache_queue_policy_item_ { 102 struct cache_policy_item_ parent_data; 103 TAILQ_ENTRY(cache_queue_policy_item_) entries; 104 }; 105 106 /* 107 * LRU and FIFO policies "inherited" from cache_policy_ 108 */ 109 struct cache_queue_policy_ { 110 struct cache_policy_ parent_data; 111 TAILQ_HEAD(cache_queue_policy_head_, cache_queue_policy_item_) head; 112 }; 113 114 typedef struct cache_queue_policy_ cache_fifo_policy_; 115 typedef struct cache_queue_policy_ cache_lru_policy_; 116 117 /* fifo policy routines */ 118 struct cache_policy_ *init_cache_fifo_policy(void); 119 void destroy_cache_fifo_policy(struct cache_policy_ *); 120 121 /* lru policy routines */ 122 struct cache_policy_ *init_cache_lru_policy(void); 123 void destroy_cache_lru_policy(struct cache_policy_ *); 124 125 /* lfu policy routines */ 126 struct cache_policy_ *init_cache_lfu_policy(void); 127 void destroy_cache_lfu_policy(struct cache_policy_ *); 128 129 #endif 130