cacheplcs.h revision 194089
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: head/usr.sbin/nscd/cacheplcs.h 194089 2009-06-13 00:06:52Z des $ 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 */ 42struct cache_policy_item_ 43{ 44 char *key; 45 size_t key_size; 46 47 size_t request_count; 48 struct timeval last_request_time; 49 struct timeval creation_time; 50 51 struct cache_policy_item_ *connected_item; 52}; 53 54/* 55 * cache_policy_ represents an abstract policy queue. It can be customized by 56 * setting appropriate function pointers 57 */ 58struct cache_policy_ 59{ 60 struct cache_policy_item_* (*create_item_func)(void); 61 void (*destroy_item_func)(struct cache_policy_item_ *); 62 63 void (*add_item_func)(struct cache_policy_ *, 64 struct cache_policy_item_ *); 65 void (*remove_item_func)(struct cache_policy_ *, 66 struct cache_policy_item_ *); 67 void (*update_item_func)(struct cache_policy_ *, 68 struct cache_policy_item_ *); 69 70 struct cache_policy_item_ *(*get_first_item_func)( 71 struct cache_policy_ *); 72 struct cache_policy_item_ *(*get_last_item_func)( 73 struct cache_policy_ *); 74 struct cache_policy_item_ *(*get_next_item_func)( 75 struct cache_policy_ *, struct cache_policy_item_ *); 76 struct cache_policy_item_ *(*get_prev_item_func)( 77 struct cache_policy_ *, struct cache_policy_item_ *); 78}; 79 80/* 81 * LFU cache policy item "inherited" from cache_policy_item_ structure 82 */ 83struct cache_lfu_policy_item_ 84{ 85 struct cache_policy_item_ parent_data; 86 int frequency; 87 88 TAILQ_ENTRY(cache_lfu_policy_item_) entries; 89}; 90 91TAILQ_HEAD(cache_lfu_policy_group_, cache_lfu_policy_item_); 92 93/* 94 * LFU policy queue "inherited" from cache_policy_. 95 */ 96struct cache_lfu_policy_ 97{ 98 struct cache_policy_ parent_data; 99 struct cache_lfu_policy_group_ groups[CACHELIB_MAX_FREQUENCY]; 100}; 101 102/* 103 * LRU and FIFO policies item "inherited" from cache_policy_item_ 104 */ 105struct cache_queue_policy_item_ 106{ 107 struct cache_policy_item_ parent_data; 108 TAILQ_ENTRY(cache_queue_policy_item_) entries; 109}; 110 111/* 112 * LRU and FIFO policies "inherited" from cache_policy_ 113 */ 114struct cache_queue_policy_ 115{ 116 struct cache_policy_ parent_data; 117 TAILQ_HEAD(cache_queue_policy_head_, cache_queue_policy_item_) head; 118}; 119 120typedef struct cache_queue_policy_ cache_fifo_policy_; 121typedef struct cache_queue_policy_ cache_lru_policy_; 122 123/* fifo policy routines */ 124extern struct cache_policy_ *init_cache_fifo_policy(void); 125extern void destroy_cache_fifo_policy(struct cache_policy_ *); 126 127/* lru policy routines */ 128extern struct cache_policy_ *init_cache_lru_policy(void); 129extern void destroy_cache_lru_policy(struct cache_policy_ *); 130 131/* lfu policy routines */ 132extern struct cache_policy_ *init_cache_lfu_policy(void); 133extern void destroy_cache_lfu_policy(struct cache_policy_ *); 134 135#endif 136