<?php
/**
* Joomla! Content Management System
*
* @copyright (C) 2012 Open Source Matters, Inc. <https://www.joomla.org>
* @license GNU General Public License version 2 or later; see LICENSE.txt
*/
namespace Joomla\CMS\Cache\Storage;
use Joomla\CMS\Cache\Cache;
use Joomla\CMS\Cache\CacheStorage;
use Joomla\CMS\Cache\Exception\CacheConnectingException;
use Joomla\CMS\Factory;
// phpcs:disable PSR1.Files.SideEffects
\defined('_JEXEC') or die;
// phpcs:enable PSR1.Files.SideEffects
/**
* Memcached cache storage handler
*
* @link https://www.php.net/manual/en/book.memcached.php
* @since 3.0.0
*/
class MemcachedStorage extends CacheStorage
{
/**
* Memcached connection object
*
* @var \Memcached
* @since 3.0.0
*/
protected static $_db = null;
/**
* Payload compression level
*
* @var integer
* @since 3.0.0
*/
protected $_compress = 0;
/**
* Constructor
*
* @param array $options Optional parameters.
*
* @since 3.0.0
*/
public function __construct($options = [])
{
parent::__construct($options);
$this->_compress = Factory::getApplication()->get('memcached_compress', false) ? \Memcached::OPT_COMPRESSION : 0;
if (static::$_db === null) {
$this->getConnection();
}
}
/**
* Create the Memcached connection
*
* @return void
*
* @since 3.0.0
* @throws \RuntimeException
*/
protected function getConnection()
{
if (!static::isSupported()) {
throw new \RuntimeException('Memcached Extension is not available');
}
$app = Factory::getApplication();
$host = $app->get('memcached_server_host', 'localhost');
$port = $app->get('memcached_server_port', 11211);
// Create the memcached connection
if ($app->get('memcached_persist', true)) {
static::$_db = new \Memcached($this->_hash);
$servers = static::$_db->getServerList();
if ($servers && ($servers[0]['host'] != $host || $servers[0]['port'] != $port)) {
static::$_db->resetServerList();
$servers = [];
}
if (!$servers) {
static::$_db->addServer($host, $port);
}
} else {
static::$_db = new \Memcached();
static::$_db->addServer($host, $port);
}
static::$_db->setOption(\Memcached::OPT_COMPRESSION, $this->_compress);
$stats = static::$_db->getStats();
$result = !empty($stats["$host:$port"]) && $stats["$host:$port"]['pid'] > 0;
if (!$result) {
// Null out the connection to inform the constructor it will need to attempt to connect if this class is instantiated again
static::$_db = null;
throw new CacheConnectingException('Could not connect to memcached server');
}
}
/**
* Get a cache_id string from an id/group pair
*
* @param string $id The cache data id
* @param string $group The cache data group
*
* @return string The cache_id string
*
* @since 1.7.0
*/
protected function _getCacheId($id, $group)
{
$prefix = Cache::getPlatformPrefix();
$length = \strlen($prefix);
$cache_id = parent::_getCacheId($id, $group);
if ($length) {
// Memcached use suffix instead of prefix
$cache_id = substr($cache_id, $length) . strrev($prefix);
}
return $cache_id;
}
/**
* Check if the cache contains data stored by ID and group
*
* @param string $id The cache data ID
* @param string $group The cache data group
*
* @return boolean
*
* @since 3.7.0
*/
public function contains($id, $group)
{
static::$_db->get($this->_getCacheId($id, $group));
return static::$_db->getResultCode() !== \Memcached::RES_NOTFOUND;
}
/**
* Get cached data by ID and group
*
* @param string $id The cache data ID
* @param string $group The cache data group
* @param boolean $checkTime True to verify cache time expiration threshold
*
* @return mixed Boolean false on failure or a cached data object
*
* @since 3.0.0
*/
public function get($id, $group, $checkTime = true)
{
return static::$_db->get($this->_getCacheId($id, $group));
}
/**
* Get all cached data
*
* @return mixed Boolean false on failure or a cached data object
*
* @since 3.0.0
*/
public function getAll()
{
$keys = static::$_db->get($this->_hash . '-index');
$secret = $this->_hash;
$data = [];
if (\is_array($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])) {
$item = new CacheStorageHelper($group);
} else {
$item = $data[$group];
}
$item->updateSize($key->size);
$data[$group] = $item;
}
}
}
return $data;
}
/**
* Store the data to cache by ID and group
*
* @param string $id The cache data ID
* @param string $group The cache data group
* @param string $data The data to store in cache
*
* @return boolean
*
* @since 3.0.0
*/
public function store($id, $group, $data)
{
$cache_id = $this->_getCacheId($id, $group);
if (!$this->lockindex()) {
return false;
}
$index = static::$_db->get($this->_hash . '-index');
if (!\is_array($index)) {
$index = [];
}
$tmparr = new \stdClass();
$tmparr->name = $cache_id;
$tmparr->size = \strlen($data);
$index[] = $tmparr;
static::$_db->set($this->_hash . '-index', $index, 0);
$this->unlockindex();
static::$_db->set($cache_id, $data, $this->_lifetime);
return true;
}
/**
* Remove a cached data entry by ID and group
*
* @param string $id The cache data ID
* @param string $group The cache data group
*
* @return boolean
*
* @since 3.0.0
*/
public function remove($id, $group)
{
$cache_id = $this->_getCacheId($id, $group);
if (!$this->lockindex()) {
return false;
}
$index = static::$_db->get($this->_hash . '-index');
if (\is_array($index)) {
foreach ($index as $key => $value) {
if ($value->name == $cache_id) {
unset($index[$key]);
static::$_db->set($this->_hash . '-index', $index, 0);
break;
}
}
}
$this->unlockindex();
return static::$_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 $mode The mode for cleaning cache [group|notgroup]
*
* @return boolean
*
* @since 3.0.0
*/
public function clean($group, $mode = null)
{
if (!$this->lockindex()) {
return false;
}
$index = static::$_db->get($this->_hash . '-index');
if (\is_array($index)) {
$prefix = $this->_hash . '-cache-' . $group . '-';
foreach ($index as $key => $value) {
if (strpos($value->name, $prefix) === 0 xor $mode !== 'group') {
static::$_db->delete($value->name);
unset($index[$key]);
}
}
static::$_db->set($this->_hash . '-index', $index, 0);
}
$this->unlockindex();
return true;
}
/**
* Flush all existing items in storage.
*
* @return boolean
*
* @since 3.6.3
*/
public function flush()
{
if (!$this->lockindex()) {
return false;
}
return static::$_db->flush();
}
/**
* Test to see if the storage handler is available.
*
* @return boolean
*
* @since 3.0.0
*/
public static function isSupported()
{
/*
* GAE and HHVM have both had instances where Memcached the class was defined but no extension was loaded.
* If the class is there, we can assume support.
*/
return class_exists('Memcached');
}
/**
* Lock cached item
*
* @param string $id The cache data ID
* @param string $group The cache data group
* @param integer $locktime Cached item max lock time
*
* @return mixed Boolean false if locking failed or an object containing properties lock and locklooped
*
* @since 3.0.0
*/
public function lock($id, $group, $locktime)
{
$returning = new \stdClass();
$returning->locklooped = false;
$looptime = $locktime * 10;
$cache_id = $this->_getCacheId($id, $group);
$data_lock = static::$_db->add($cache_id . '_lock', 1, $locktime);
if ($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) {
break;
}
usleep(100);
$data_lock = static::$_db->add($cache_id . '_lock', 1, $locktime);
$lock_counter++;
}
$returning->locklooped = true;
}
$returning->locked = $data_lock;
return $returning;
}
/**
* Unlock cached item
*
* @param string $id The cache data ID
* @param string $group The cache data group
*
* @return boolean
*
* @since 3.0.0
*/
public function unlock($id, $group = null)
{
$cache_id = $this->_getCacheId($id, $group) . '_lock';
return static::$_db->delete($cache_id);
}
/**
* Lock cache index
*
* @return boolean
*
* @since 3.0.0
*/
protected function lockindex()
{
$looptime = 300;
$data_lock = static::$_db->add($this->_hash . '-index_lock', 1, 30);
if ($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;
}
usleep(100);
$data_lock = static::$_db->add($this->_hash . '-index_lock', 1, 30);
$lock_counter++;
}
}
return true;
}
/**
* Unlock cache index
*
* @return boolean
*
* @since 3.0.0
*/
protected function unlockindex()
{
return static::$_db->delete($this->_hash . '-index_lock');
}
}