2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #ifndef __NSCD_CACHEPLCS_H__
30 #define __NSCD_CACHEPLCS_H__
32 #include <sys/queue.h>
34 /* common policy definitions */
35 #define CACHELIB_MAX_FREQUENCY 100
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.
42 struct cache_policy_item_ {
47 struct timeval last_request_time;
48 struct timeval creation_time;
50 struct cache_policy_item_ *connected_item;
54 * cache_policy_ represents an abstract policy queue. It can be customized by
55 * setting appropriate function pointers
57 struct cache_policy_ {
58 struct cache_policy_item_* (*create_item_func)(void);
59 void (*destroy_item_func)(struct cache_policy_item_ *);
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_ *);
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_ *);
79 * LFU cache policy item "inherited" from cache_policy_item_ structure
81 struct cache_lfu_policy_item_ {
82 struct cache_policy_item_ parent_data;
85 TAILQ_ENTRY(cache_lfu_policy_item_) entries;
88 TAILQ_HEAD(cache_lfu_policy_group_, cache_lfu_policy_item_);
91 * LFU policy queue "inherited" from cache_policy_.
93 struct cache_lfu_policy_ {
94 struct cache_policy_ parent_data;
95 struct cache_lfu_policy_group_ groups[CACHELIB_MAX_FREQUENCY];
99 * LRU and FIFO policies item "inherited" from cache_policy_item_
101 struct cache_queue_policy_item_ {
102 struct cache_policy_item_ parent_data;
103 TAILQ_ENTRY(cache_queue_policy_item_) entries;
107 * LRU and FIFO policies "inherited" from cache_policy_
109 struct cache_queue_policy_ {
110 struct cache_policy_ parent_data;
111 TAILQ_HEAD(cache_queue_policy_head_, cache_queue_policy_item_) head;
114 typedef struct cache_queue_policy_ cache_fifo_policy_;
115 typedef struct cache_queue_policy_ cache_lru_policy_;
117 /* fifo policy routines */
118 struct cache_policy_ *init_cache_fifo_policy(void);
119 void destroy_cache_fifo_policy(struct cache_policy_ *);
121 /* lru policy routines */
122 struct cache_policy_ *init_cache_lru_policy(void);
123 void destroy_cache_lru_policy(struct cache_policy_ *);
125 /* lfu policy routines */
126 struct cache_policy_ *init_cache_lfu_policy(void);
127 void destroy_cache_lfu_policy(struct cache_policy_ *);