<?php
/**
* @package Joomla.Platform
* @subpackage Cache
*
* @copyright Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE
*/
defined('JPATH_PLATFORM') or die;
/**
* Memcache cache storage handler
*
* @package Joomla.Platform
* @subpackage Cache
* @since 11.1
*/
class JCacheStorageMemcache extends JCacheStorage
{
/**
* @since 11.1
*/
private static $_db = null;
/**
* @since 11.1
*/
private $_persistent = false;
/**
* @since 11.1
*/
private $_compress = 0;
/**
* Constructor
*
* @param array $options optional parameters
* @since 11.1
*/
public function __construct($options = array())
{
parent::__construct($options);
if (self::$_db === null) {
$this->getConnection();
}
}
/**
* return memcache connection object
*
* @return object memcache connection object
* @since 11.1
*/
private function getConnection()
{
if ((extension_loaded('memcache') && class_exists('Memcache')) != true ) {
return false;
}
$config = JFactory::getConfig();
$this->_persistent = $config->get('memcache_persist', true);
$this->_compress = $config->get('memcache_compress', false) == false ? 0 : MEMCACHE_COMPRESSED;
// This will be an array of loveliness
// @todo: multiple servers
//$servers = (isset($params['servers'])) ? $params['servers'] : array();
$server=array();
$server['host'] = $config->get('memcache_server_host', 'localhost');
$server['port'] = $config->get('memcache_server_port', 11211);
// Create the memcache connection
self::$_db = new Memcache;
self::$_db->addServer($server['host'], $server['port'], $this->_persistent);
$memcachetest = @self::$_db->connect($server['host'], $server['port']);
if ($memcachetest == false) {
return JError::raiseError(404, "Could not connect to memcache server");
}
// memcahed has no list keys, we do our own accounting, initalise key index
if (self::$_db->get($this->_hash.'-index') === false) {
$empty = array();
self::$_db->set($this->_hash.'-index', $empty , $this->_compress, 0);
}
return;
}
/**
* Get cached data from memcache by id and group
*
* @param string $id The cache data id
* @param string $group The cache data group
* @param boolean $checkTime True to verify cache time expiration threshold
* @return mixed Boolean false on failure or a cached data string
* @since 11.1
*/
public function get($id, $group, $checkTime = true)
{
$cache_id = $this->_getCacheId($id, $group);
$back = self::$_db->get($cache_id);
return $back;
}
/**
* Get all cached data
*
* @return array data
* @since 11.1
*/
public function getAll()
{
parent::getAll();
$keys = self::$_db->get($this->_hash.'-index');
$secret = $this->_hash;
$data = array();
if (!empty($keys)){
foreach ($keys as $key) {
if (empty($key)) {
continue;
}
$namearr=explode('-',$key->name);
if ($namearr !== false && $namearr[0]==$secret && $namearr[1]=='cache') {
$group = $namearr[2];
if (!isset($data[$group])) {
$item = new JCacheStorageHelper($group);
} else {
$item = $data[$group];
}
$item->updateSize($key->size/1024);
$data[$group] = $item;
}
}
}
return $data;
}
/**
* Store the data to memcache by id and group
*
* @param string $id The cache data id
* @param string $group The cache data group
* @param string $data The data to store in cache
* @return boolean True on success, false otherwise
* @since 11.1
*/
public function store($id, $group, $data)
{
$cache_id = $this->_getCacheId($id, $group);
if (!$this->lockindex()) {
return false;
}
$index = self::$_db->get($this->_hash.'-index');
if ($index === false) {
$index = array();
}
$tmparr = new stdClass;
$tmparr->name = $cache_id;
$tmparr->size = strlen($data);
$index[] = $tmparr;
self::$_db->replace($this->_hash.'-index', $index , 0, 0);
$this->unlockindex();
// prevent double writes, write only if it doesn't exist else replace
if (!self::$_db->replace($cache_id, $data, $this->_compress, $this->_lifetime)) {
self::$_db->set($cache_id, $data, $this->_compress, $this->_lifetime);
}
return true;
}
/**
* Remove a cached data entry by id and group
*
* @param string $id The cache data id
* @param string $group The cache data group
* @return boolean True on success, false otherwise
* @since 11.1
*/
public function remove($id, $group)
{
$cache_id = $this->_getCacheId($id, $group);
if (!$this->lockindex()) {
return false;
}
$index = self::$_db->get($this->_hash.'-index');
if ($index === false) {
$index = array();
}
foreach ($index as $key => $value) {
if ($value->name == $cache_id) unset ($index[$key]);
break;
}
self::$_db->replace($this->_hash.'-index', $index, 0, 0);
$this->unlockindex();
return self::$_db->delete($cache_id);
}
/**
* Clean cache for a group given a mode.
*
* group mode : cleans all cache in the group
* notgroup mode : cleans all cache not in the group
*
* @param string $group The cache data group
* @param string $mode The mode for cleaning cache [group|notgroup]
* @return boolean True on success, false otherwise
* @since 11.1
*/
public function clean($group, $mode = null)
{
if (!$this->lockindex()) {
return false;
}
$index = self::$_db->get($this->_hash.'-index');
if ($index === false) {
$index = array();
}
$secret = $this->_hash;
foreach ($index as $key=>$value) {
if (strpos($value->name, $secret.'-cache-'.$group.'-')===0 xor $mode != 'group') {
self::$_db->delete($value->name,0);
unset ($index[$key]);
}
}
self::$_db->replace($this->_hash.'-index', $index , 0, 0);
$this->unlockindex();
return true;
}
/**
* Test to see if the cache storage is available.
*
* @return boolean True on success, false otherwise.
*/
public static function test()
{
if ((extension_loaded('memcache') && class_exists('Memcache')) != true ) {
return false;
}
$config = JFactory::getConfig();
$host = $config->get('memcache_server_host', 'localhost');
$port = $config->get('memcache_server_port', 11211);
$memcache = new Memcache;
$memcachetest = @$memcache->connect($host, $port);
if (!$memcachetest) {
return false;
} else {
return true;
}
}
/**
* Lock cached item - override parent as this is more efficient
*
* @param string $id The cache data id
* @param string $group The cache data group
* @param integer $locktime Cached item max lock time
* @return boolean True on success, false otherwise.
* @since 11.1
*/
public function lock($id,$group,$locktime)
{
$returning = new stdClass();
$returning->locklooped = false;
$looptime = $locktime * 10;
$cache_id = $this->_getCacheId($id, $group);
if (!$this->lockindex()) {
return false;
}
$index = self::$_db->get($this->_hash.'-index');
if ($index === false) {
$index = array();
}
$tmparr = new stdClass;
$tmparr->name = $cache_id;
$tmparr->size = 1;
$index[] = $tmparr;
self::$_db->replace($this->_hash.'-index', $index , 0, 0);
$this->unlockindex();
$data_lock = self::$_db->add($cache_id.'_lock', 1, false, $locktime);
if ($data_lock === FALSE) {
$lock_counter = 0;
// loop until you find that the lock has been released. that implies that data get from other thread has finished
while ($data_lock === FALSE) {
if ($lock_counter > $looptime) {
$returning->locked = false;
$returning->locklooped = true;
break;
}
usleep(100);
$data_lock = self::$_db->add($cache_id.'_lock', 1, false, $locktime);
$lock_counter++;
}
}
$returning->locked = $data_lock;
return $returning;
}
/**
* Unlock cached item - override parent for cacheid compatibility with lock
*
* @param string $id The cache data id
* @param string $group The cache data group
* @param integer $locktime Cached item max lock time
* @since 11.1
* @return boolean True on success, false otherwise.
*/
public function unlock($id,$group=null)
{
$unlock = false;
$cache_id = $this->_getCacheId($id, $group).'_lock';
if (!$this->lockindex()) return false;
$index = self::$_db->get($this->_hash.'-index');
if ($index === false) {$index = array();}
foreach ($index as $key=>$value){
if ($value->name == $cache_id) unset ($index[$key]);
break;
}
self::$_db->replace($this->_hash.'-index', $index, 0, 0);
$this->unlockindex();
return self::$_db->delete($cache_id);
}
/**
* Lock cache index
*
* @since 11.1
* @return boolean True on success, false otherwise.
*/
private function lockindex()
{
$looptime = 300;
$data_lock = self::$_db->add($this->_hash.'-index_lock', 1, false, 30);
if ($data_lock === FALSE) {
$lock_counter = 0;
// loop until you find that the lock has been released. that implies that data get from other thread has finished
while ( $data_lock === FALSE ) {
if ( $lock_counter > $looptime ) {
return false;
break;
}
usleep(100);
$data_lock = self::$_db->add($this->_hash.'-index_lock', 1, false, 30);
$lock_counter++;
}
}
return true;
}
/**
* Unlock cache index
*
* @return boolean True on success, false otherwise.
* @since 11.1
*/
private function unlockindex()
{
return self::$_db->delete($this->_hash.'-index_lock');
}
}
