1/* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "apr_general.h" 18 19#include "mod_cache.h" 20#include "cache_hash.h" 21#include "cache_pqueue.h" 22#include "cache_cache.h" 23 24#if APR_HAVE_STDLIB_H 25#include <stdlib.h> 26#endif 27#if APR_HAVE_STRING_H 28#include <string.h> 29#endif 30 31struct cache_cache_t { 32 int max_entries; 33 apr_size_t max_size; 34 apr_size_t current_size; 35 int total_purges; 36 long queue_clock; 37 cache_hash_t *ht; 38 cache_pqueue_t *pq; 39 cache_pqueue_set_priority set_pri; 40 cache_pqueue_get_priority get_pri; 41 cache_cache_inc_frequency *inc_entry; 42 cache_cache_get_size *size_entry; 43 cache_cache_get_key *key_entry; 44 cache_cache_free *free_entry; 45}; 46 47cache_cache_t* cache_init(int max_entries, 48 apr_size_t max_size, 49 cache_pqueue_get_priority get_pri, 50 cache_pqueue_set_priority set_pri, 51 cache_pqueue_getpos get_pos, 52 cache_pqueue_setpos set_pos, 53 cache_cache_inc_frequency *inc_entry, 54 cache_cache_get_size *size_entry, 55 cache_cache_get_key* key_entry, 56 cache_cache_free *free_entry) 57{ 58 cache_cache_t *tmp; 59 tmp = malloc(sizeof(cache_cache_t)); 60 tmp->max_entries = max_entries; 61 tmp->max_size = max_size; 62 tmp->current_size = 0; 63 tmp->total_purges = 0; 64 tmp->queue_clock = 0; 65 tmp->get_pri = get_pri; 66 tmp->set_pri = set_pri; 67 tmp->inc_entry = inc_entry; 68 tmp->size_entry = size_entry; 69 tmp->key_entry = key_entry; 70 tmp->free_entry = free_entry; 71 72 tmp->ht = cache_hash_make(max_entries); 73 tmp->pq = cache_pq_init(max_entries, get_pri, get_pos, set_pos); 74 75 return tmp; 76} 77 78void cache_free(cache_cache_t *c) 79{ 80 cache_pq_free(c->pq); 81 cache_hash_free(c->ht); 82 free(c); 83} 84 85 86void* cache_find(cache_cache_t* c, const char *key) 87{ 88 return cache_hash_get(c->ht, key, CACHE_HASH_KEY_STRING); 89} 90 91void cache_update(cache_cache_t* c, void *entry) 92{ 93 long old_priority; 94 long new_priority; 95 96 old_priority = c->set_pri(c->queue_clock, entry); 97 c->inc_entry(entry); 98 new_priority = c->set_pri(c->queue_clock, entry); 99 cache_pq_change_priority(c->pq, old_priority, new_priority, entry); 100} 101 102void cache_insert(cache_cache_t* c, void *entry) 103{ 104 void *ejected = NULL; 105 long priority; 106 107 c->set_pri(c->queue_clock, entry); 108 /* FIX: check if priority of bottom item is greater than inserted one */ 109 while ((cache_pq_size(c->pq) >= c->max_entries) || 110 ((c->current_size + c->size_entry(entry)) > c->max_size)) { 111 112 ejected = cache_pq_pop(c->pq); 113 /* FIX: If ejected is NULL, we'll segfault here */ 114 priority = c->get_pri(ejected); 115 116 if (c->queue_clock > priority) 117 c->queue_clock = priority; 118 119 cache_hash_set(c->ht, 120 c->key_entry(ejected), 121 CACHE_HASH_KEY_STRING, 122 NULL); 123 124 ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL, "Cache Purge of %s",c->key_entry(ejected)); 125 c->current_size -= c->size_entry(ejected); 126 c->free_entry(ejected); 127 c->total_purges++; 128 } 129 c->current_size += c->size_entry(entry); 130 131 cache_pq_insert(c->pq, entry); 132 cache_hash_set(c->ht, c->key_entry(entry), CACHE_HASH_KEY_STRING, entry); 133} 134 135void* cache_pop(cache_cache_t *c) 136{ 137 void *entry; 138 139 if (!c) 140 return NULL; 141 142 entry = cache_pq_pop(c->pq); 143 144 if (!entry) 145 return NULL; 146 147 c->current_size -= c->size_entry(entry); 148 cache_hash_set(c->ht, c->key_entry(entry), CACHE_HASH_KEY_STRING, NULL); 149 150 return entry; 151} 152 153apr_status_t cache_remove(cache_cache_t *c, void *entry) 154{ 155 apr_size_t entry_size = c->size_entry(entry); 156 apr_status_t rc; 157 rc = cache_pq_remove(c->pq, entry); 158 if (rc != APR_SUCCESS) 159 return rc; 160 161 cache_hash_set(c->ht, c->key_entry(entry), CACHE_HASH_KEY_STRING, NULL); 162 c->current_size -= entry_size; 163 164 return APR_SUCCESS; 165} 166