laipower/wp-content/plugins/w3-total-cache/lib/Google/Cache/Memcache.php

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<?php
/*
* Copyright 2008 Google Inc.
*
* Licensed 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.
*/
/**
* A persistent storage class based on the memcache, which is not
* really very persistent, as soon as you restart your memcache daemon
* the storage will be wiped.
*
* Will use either the memcache or memcached extensions, preferring
* memcached.
*
* @author Chris Chabot <chabotc@google.com>
*/
class W3TCG_Google_Cache_Memcache extends W3TCG_Google_Cache_Abstract
{
private $connection = false;
private $mc = false;
private $host;
private $port;
public function __construct(W3TCG_Google_Client $client)
{
if (!function_exists('memcache_connect') && !class_exists("Memcached")) {
throw new W3TCG_Google_Cache_Exception("Memcache functions not available");
}
if ($client->isAppEngine()) {
// No credentials needed for GAE.
$this->mc = new Memcached();
$this->connection = true;
} else {
$this->host = $client->getClassConfig($this, 'host');
$this->port = $client->getClassConfig($this, 'port');
if (empty($this->host) || (empty($this->port) && (string) $this->port != "0")) {
throw new W3TCG_Google_Cache_Exception("You need to supply a valid memcache host and port");
}
}
}
/**
* @inheritDoc
*/
public function get($key, $expiration = false)
{
$this->connect();
$ret = false;
if ($this->mc) {
$ret = $this->mc->get($key);
} else {
$ret = memcache_get($this->connection, $key);
}
if ($ret === false) {
return false;
}
if (is_numeric($expiration) && (time() - $ret['time'] > $expiration)) {
$this->delete($key);
return false;
}
return $ret['data'];
}
/**
* @inheritDoc
* @param string $key
* @param string $value
* @throws W3TCG_Google_Cache_Exception
*/
public function set($key, $value)
{
$this->connect();
// we store it with the cache_time default expiration so objects will at
// least get cleaned eventually.
$data = array('time' => time(), 'data' => $value);
$rc = false;
if ($this->mc) {
$rc = $this->mc->set($key, $data);
} else {
$rc = memcache_set($this->connection, $key, $data, false);
}
if ($rc == false) {
throw new W3TCG_Google_Cache_Exception("Couldn't store data in cache");
}
}
/**
* @inheritDoc
* @param String $key
*/
public function delete($key)
{
$this->connect();
if ($this->mc) {
$this->mc->delete($key, 0);
} else {
memcache_delete($this->connection, $key, 0);
}
}
/**
* Lazy initialiser for memcache connection. Uses pconnect for to take
* advantage of the persistence pool where possible.
*/
private function connect()
{
if ($this->connection) {
return;
}
if (class_exists("Memcached")) {
$this->mc = new Memcached();
$this->mc->addServer($this->host, $this->port);
$this->connection = true;
} else {
$this->connection = memcache_pconnect($this->host, $this->port);
}
if (! $this->connection) {
throw new W3TCG_Google_Cache_Exception("Couldn't connect to memcache server");
}
}
}