gnu-social/lib/cache.php
2010-01-02 20:26:33 -10:00

114 lines
3.1 KiB
PHP

<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* Cache interface plus default in-memory cache implementation
*
* PHP version 5
*
* LICENCE: This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category Cache
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
/**
* Interface for caching
*
* An abstract interface for caching.
*
*/
class Cache
{
var $_items = array();
static $_inst = null;
static function instance()
{
if (is_null(self::$_inst)) {
self::$_inst = new Cache();
}
return self::$_inst;
}
static function key($extra)
{
$base_key = common_config('memcached', 'base');
if (empty($base_key)) {
$base_key = common_keyize(common_config('site', 'name'));
}
return 'statusnet:' . $base_key . ':' . $extra;
}
static function keyize($str)
{
$str = strtolower($str);
$str = preg_replace('/\s/', '_', $str);
return $str;
}
function get($key)
{
$value = null;
if (!Event::handle('StartCacheGet', array(&$key, &$value))) {
if (array_key_exists($_items, $key)) {
common_log(LOG_INFO, 'Cache HIT for key ' . $key);
$value = $_items[$key];
} else {
common_log(LOG_INFO, 'Cache MISS for key ' . $key);
}
Event::handle('EndCacheGet', array($key, &$value));
}
return $value;
}
function set($key, $value, $flag=null, $expiry=null)
{
$success = false;
if (!Event::handle('StartCacheSet', array(&$key, &$value, &$flag, &$expiry, &$success))) {
common_log(LOG_INFO, 'Setting cache value for key ' . $key);
$_items[$key] = $value;
$success = true;
Event::handle('EndCacheSet', array($key, $value, $flag, $expiry));
}
return $success;
}
function delete($key)
{
$success = false;
if (!Event::handle('StartCacheDelete', array(&$key, &$success))) {
common_log(LOG_INFO, 'Deleting cache value for key ' . $key);
unset($_items[$key]);
$success = true;
Event::handle('EndCacheDelete', array($key));
}
return $success;
}
}