box-o-sand/php-practice/web-cake/html/cake/libs/cache/memcache.php

218 lines
6.1 KiB
PHP

<?php
/**
* Memcache storage engine for cache
*
*
* PHP versions 4 and 5
*
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
*
* Licensed under The MIT License
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @package cake
* @subpackage cake.cake.libs.cache
* @since CakePHP(tm) v 1.2.0.4933
* @license MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
/**
* Memcache storage engine for cache. Memcache has some limitations in the amount of
* control you have over expire times far in the future. See MemcacheEngine::write() for
* more information.
*
* @package cake
* @subpackage cake.cake.libs.cache
*/
class MemcacheEngine extends CacheEngine {
/**
* Memcache wrapper.
*
* @var Memcache
* @access private
*/
var $__Memcache = null;
/**
* Settings
*
* - servers = string or array of memcache servers, default => 127.0.0.1. If an
* array MemcacheEngine will use them as a pool.
* - compress = boolean, default => false
*
* @var array
* @access public
*/
var $settings = array();
/**
* Initialize the Cache Engine
*
* Called automatically by the cache frontend
* To reinitialize the settings call Cache::engine('EngineName', [optional] settings = array());
*
* @param array $setting array of setting for the engine
* @return boolean True if the engine has been successfully initialized, false if not
* @access public
*/
function init($settings = array()) {
if (!class_exists('Memcache')) {
return false;
}
parent::init(array_merge(array(
'engine'=> 'Memcache',
'prefix' => Inflector::slug(APP_DIR) . '_',
'servers' => array('127.0.0.1'),
'compress'=> false
), $settings)
);
if ($this->settings['compress']) {
$this->settings['compress'] = MEMCACHE_COMPRESSED;
}
if (!is_array($this->settings['servers'])) {
$this->settings['servers'] = array($this->settings['servers']);
}
if (!isset($this->__Memcache)) {
$return = false;
$this->__Memcache =& new Memcache();
foreach ($this->settings['servers'] as $server) {
list($host, $port) = $this->_parseServerString($server);
if ($this->__Memcache->addServer($host, $port)) {
$return = true;
}
}
return $return;
}
return true;
}
/**
* Parses the server address into the host/port. Handles both IPv6 and IPv4
* addresses
*
* @param string $server The server address string.
* @return array Array containing host, port
*/
function _parseServerString($server) {
if (substr($server, 0, 1) == '[') {
$position = strpos($server, ']:');
if ($position !== false) {
$position++;
}
} else {
$position = strpos($server, ':');
}
$port = 11211;
$host = $server;
if ($position !== false) {
$host = substr($server, 0, $position);
$port = substr($server, $position + 1);
}
return array($host, $port);
}
/**
* Write data for key into cache. When using memcache as your cache engine
* remember that the Memcache pecl extension does not support cache expiry times greater
* than 30 days in the future. If you wish to create cache entries that do not expire, set the duration
* to `0` in your cache configuration.
*
* @param string $key Identifier for the data
* @param mixed $value Data to be cached
* @param integer $duration How long to cache the data, in seconds
* @return boolean True if the data was succesfully cached, false on failure
* @see http://php.net/manual/en/memcache.set.php
* @access public
*/
function write($key, &$value, $duration) {
return $this->__Memcache->set($key, $value, $this->settings['compress'], $duration);
}
/**
* Read a key from the cache
*
* @param string $key Identifier for the data
* @return mixed The cached data, or false if the data doesn't exist, has expired, or if there was an error fetching it
* @access public
*/
function read($key) {
return $this->__Memcache->get($key);
}
/**
* Increments the value of an integer cached key
*
* @param string $key Identifier for the data
* @param integer $offset How much to increment
* @param integer $duration How long to cache the data, in seconds
* @return New incremented value, false otherwise
* @access public
*/
function increment($key, $offset = 1) {
if ($this->settings['compress']) {
trigger_error(sprintf(__('Method increment() not implemented for compressed cache in %s', true), get_class($this)), E_USER_ERROR);
}
return $this->__Memcache->increment($key, $offset);
}
/**
* Decrements the value of an integer cached key
*
* @param string $key Identifier for the data
* @param integer $offset How much to substract
* @param integer $duration How long to cache the data, in seconds
* @return New decremented value, false otherwise
* @access public
*/
function decrement($key, $offset = 1) {
if ($this->settings['compress']) {
trigger_error(sprintf(__('Method decrement() not implemented for compressed cache in %s', true), get_class($this)), E_USER_ERROR);
}
return $this->__Memcache->decrement($key, $offset);
}
/**
* Delete a key from the cache
*
* @param string $key Identifier for the data
* @return boolean True if the value was succesfully deleted, false if it didn't exist or couldn't be removed
* @access public
*/
function delete($key) {
return $this->__Memcache->delete($key);
}
/**
* Delete all keys from the cache
*
* @return boolean True if the cache was succesfully cleared, false otherwise
* @access public
*/
function clear() {
return $this->__Memcache->flush();
}
/**
* Connects to a server in connection pool
*
* @param string $host host ip address or name
* @param integer $port Server port
* @return boolean True if memcache server was connected
* @access public
*/
function connect($host, $port = 11211) {
if ($this->__Memcache->getServerStatus($host, $port) === 0) {
if ($this->__Memcache->connect($host, $port)) {
return true;
}
return false;
}
return true;
}
}