Search moodle.org's
Developer Documentation

See Release Notes

  • Bug fixes for general core bugs in 4.3.x will end 7 October 2024 (12 months).
  • Bug fixes for security issues in 4.3.x will end 21 April 2025 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.2.x is supported too.
<?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.
 */

if (!class_exists('Google_Client')) {
  require_once dirname(__FILE__) . '/../autoload.php';
}

/**
 * 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>
 */
> #[AllowDynamicProperties]
class Google_Cache_Memcache extends Google_Cache_Abstract { private $connection = false; private $mc = false; private $host; private $port; /** * @var Google_Client the current client */ private $client; public function __construct(Google_Client $client) { if (!function_exists('memcache_connect') && !class_exists("Memcached")) { $error = "Memcache functions not available"; $client->getLogger()->error($error); throw new Google_Cache_Exception($error); } $this->client = $client; if ($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")) { $error = "You need to supply a valid memcache host and port"; $client->getLogger()->error($error); throw new Google_Cache_Exception($error); } } } /** * @inheritDoc */ public function get($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) { $this->client->getLogger()->debug( 'Memcache cache miss', array('key' => $key) ); return false; } if (is_numeric($expiration) && (time() - $ret['time'] > $expiration)) { $this->client->getLogger()->debug( 'Memcache cache miss (expired)', array('key' => $key, 'var' => $ret) ); $this->delete($key); return false; } $this->client->getLogger()->debug( 'Memcache cache hit', array('key' => $key, 'var' => $ret) ); return $ret['data']; } /** * @inheritDoc * @param string $key * @param string $value * @throws Google_Cache_Exception */ public function set($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) { $this->client->getLogger()->error( 'Memcache cache set failed', array('key' => $key, 'var' => $data) ); throw new Google_Cache_Exception("Couldn't store data in cache"); } $this->client->getLogger()->debug( 'Memcache cache set', array('key' => $key, 'var' => $data) ); } /** * @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); } $this->client->getLogger()->debug( 'Memcache cache delete', array('key' => $key) ); } /** * Lazy initialiser for memcache connection. Uses pconnect for to take * advantage of the persistence pool where possible. */ private function connect() { if ($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) { $error = "Couldn't connect to memcache server"; $this->client->getLogger()->error($error); throw new Google_Cache_Exception($error); } } }