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/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_general.h"
#include "mod_cache.h"
#include "cache_hash.h"
#include "cache_pqueue.h"
#include "cache_cache.h"
#if APR_HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if APR_HAVE_STRING_H
#include <string.h>
#endif
struct cache_cache_t {
int max_entries;
apr_size_t max_size;
apr_size_t current_size;
int total_purges;
long queue_clock;
cache_hash_t *ht;
cache_pqueue_t *pq;
cache_pqueue_set_priority set_pri;
cache_pqueue_get_priority get_pri;
cache_cache_inc_frequency *inc_entry;
cache_cache_get_size *size_entry;
cache_cache_get_key *key_entry;
cache_cache_free *free_entry;
};
CACHE_DECLARE(cache_cache_t *)cache_init(int max_entries,
apr_size_t max_size,
cache_pqueue_get_priority get_pri,
cache_pqueue_set_priority set_pri,
cache_pqueue_getpos get_pos,
cache_pqueue_setpos set_pos,
cache_cache_inc_frequency *inc_entry,
cache_cache_get_size *size_entry,
cache_cache_get_key* key_entry,
cache_cache_free *free_entry)
{
cache_cache_t *tmp;
tmp = malloc(sizeof(cache_cache_t));
tmp->max_entries = max_entries;
tmp->max_size = max_size;
tmp->current_size = 0;
tmp->total_purges = 0;
tmp->queue_clock = 0;
tmp->get_pri = get_pri;
tmp->set_pri = set_pri;
tmp->inc_entry = inc_entry;
tmp->size_entry = size_entry;
tmp->key_entry = key_entry;
tmp->free_entry = free_entry;
tmp->ht = cache_hash_make(max_entries);
tmp->pq = cache_pq_init(max_entries, get_pri, get_pos, set_pos);
return tmp;
}
CACHE_DECLARE(void) cache_free(cache_cache_t *c)
{
cache_pq_free(c->pq);
cache_hash_free(c->ht);
free(c);
}
CACHE_DECLARE(void*) cache_find(cache_cache_t* c, const char *key)
{
void *e;
e = cache_hash_get(c->ht, key, CACHE_HASH_KEY_STRING);
if (!e)
return NULL;
return e;
}
CACHE_DECLARE(void) cache_update(cache_cache_t* c, void *entry)
{
long old_priority;
long new_priority;
old_priority = c->set_pri(c->queue_clock, entry);
c->inc_entry(entry);
new_priority = c->set_pri(c->queue_clock, entry);
cache_pq_change_priority(c->pq, old_priority, new_priority, entry);
}
CACHE_DECLARE(void) cache_insert(cache_cache_t* c, void *entry)
{
void *ejected = NULL;
long priority;
c->set_pri(c->queue_clock, entry);
/* FIX: check if priority of bottom item is greater than inserted one */
while ((cache_pq_size(c->pq) >= c->max_entries) ||
((c->current_size + c->size_entry(entry)) > c->max_size)) {
ejected = cache_pq_pop(c->pq);
/* FIX: If ejected is NULL, we'll segfault here */
priority = c->get_pri(ejected);
if (c->queue_clock > priority)
c->queue_clock = priority;
cache_hash_set(c->ht,
c->key_entry(ejected),
CACHE_HASH_KEY_STRING,
NULL);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL, "Cache Purge of %s",c->key_entry(ejected));
c->current_size -= c->size_entry(ejected);
c->free_entry(ejected);
c->total_purges++;
}
c->current_size += c->size_entry(entry);
cache_pq_insert(c->pq, entry);
cache_hash_set(c->ht, c->key_entry(entry), CACHE_HASH_KEY_STRING, entry);
}
CACHE_DECLARE(void *) cache_pop(cache_cache_t *c)
{
void *entry;
if (!c)
return NULL;
entry = cache_pq_pop(c->pq);
if (!entry)
return NULL;
c->current_size -= c->size_entry(entry);
cache_hash_set(c->ht, c->key_entry(entry), CACHE_HASH_KEY_STRING, NULL);
return entry;
}
CACHE_DECLARE(apr_status_t) cache_remove(cache_cache_t *c, void *entry)
{
apr_size_t entry_size = c->size_entry(entry);
apr_status_t rc;
rc = cache_pq_remove(c->pq, entry);
if (rc != APR_SUCCESS)
return rc;
cache_hash_set(c->ht, c->key_entry(entry), CACHE_HASH_KEY_STRING, NULL);
c->current_size -= entry_size;
return APR_SUCCESS;
}
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